PWM AC-DC 컨버터의 입력전류 직접추종제어

우정인,최선영,정영일,서정기,허태원 東亞大學校 大學院 1999 大學院論文集 Vol.24 No.-

본 논문에서는 PWM AC-DC 컨버터의 정상상태 제어오차를 제거하고, 과도 특성을 향상시키기 위한 새로운 전류제어계를 제안한다. 먼저, 일반적인 PWM 컨버터에 대한 상태공간 모델로 표현된 수학적 모델이 제시된다. 컨버터의 상태공간 모델은 제안하는 전류제어계를 포함한 PWM 컨버터의 시뮬레이션에 사용된다. 본문에서 제안하는 정현추종 제어계는 교류성분의 전류를 직접추정 제어 하기때문에 좌표변환 알고리즘을 필요로하지 않는다. 입력전류 제어계의 전달함수롤부터 정상상태 오차가 영이되는 것을 입증한다. 그리고, 시뮬레이션과 실험을 통하열 본 제어방식의 타당성을 입증하고자 한다.

Plasma arc light curing unit을 이용한 광중립형 수복재의 중합양상

우연선,정태성,김신 大韓小兒齒科學會 2002 大韓小兒齒科學會誌 Vol.29 No.2

본 연구는 할로겐광과 비교하여, 고강도의 단축된 중합 시간을 장점으로 하는 플라즈마광의 효율성을 평가할 목적으로, 첫째, 중합 시간과 중합 거리에 따른 중합도의 변화를 검토, 광조사 시간을 증가시킬 경우 특정거리 이상에서도 수복물 하층까지 충분한 중합이 이루어지는지 알아 보고, 둘째, 중합 반경에 따라 균일한 중합이 이루어지는지 보기 위해 광조사 부위의 중심부와 외측 변연부의 중합도 차이를 비교하였다. 2mm 두께의 복합레진 시편의 상·하면 미세경도 측정을 통해 중합도를 비교해 본 결과, 다음과 같은 결론을 얻었다. 1. 거리증가에 따른 상대광도의 감소는 할로겐광에 비해 플라즈마광에서 그 차이가 적었다(p<0.05). 2. 플라즈마광, 할로겐광 모두 상면의 미세경도는 중합거리 2mm 이상부터 유의하게 감소되었으며, 중합시간의 증가에 따라 증가되었다(p<0.05). 3. 플라즈마광 3초를 제외하고, 하면의 미세경도 변화는 4mm 이상에서 급격히 감소하였으며, 상면에 비해 중합시간가 거리의 영향을 많이 받았다(p<0.05). 4. 플라즈마광, 할로겐광 모두 조사시간의 증가에도 불구하고 4mm 와 6mm 사이에서 하면의 미세 경도차는 비교적 크게 나타났다(p<0.05). 5. 플라즈마광을 6∼9초 적용한 때와 할로겐광을 40∼80초 적용한 때의 미세경도치 및 거리에 따른 경도 변화는 유사하였다(p>0.05). 6. 플라즈마광, 할로겐광 모두 레진 시편의 중앙에서 외측으로 갈수록 미세경도는 유의하게 감소하였다(p<0.05). The purpose of this study was to compae the dffect of distance of light tip to resin surfaces and exposure time on the polymerization of surface and 2 mm subsurface of composite resins cured with two light sources; conven-tional halogen light (XL 3000, 3M, U.S.A.) and plasma arc light (Flipo, LOKKI, France) and compare the uni-formity of polymerization from the center to the periphery of resin surfaces according to polymerization diameter cure with two light sources. From the experiment, the following results were obtained. 1. Difference of relative light intensity decrease in plasma arc light smaller than that of conventional haloger light(p<0.05). 2. In all groups, microhardness of top surfaces was decreased when distance of the light tip to resin surfaces is more than 2mm and increased according to increase of exposure time(p<0.05). 3. Difference of microhardness of the 2mm subsurface was rapidly decreased when distance of light tip to resin surfaces is more than 4mm(except, plasma arc light exposure time of 3 seconds). and the distance of light tip to resin surfaces and exposure time more affected 2mm subsurface rather than top surface(p<0.05). 4. Although exposure time was increased, difference of microhardness of the 2mm subsurface with the distance of light tip resin surfaces was relatively high in groups between below 4mm and 6 mm(p<0.05). 5. Plasma arc light exposure time of 6 to 9 seconds produced microhardness values and microhardness change according to various distance similar to those produced with 40 to 80 second exposure to a conventional halogen light(p>0.05). 6. In all groups, microhardness was decreased gradually from the center to the periphery of resin surfaces(p<0.05).

선천 결손으로 오인될 수 있는 하악 제2소구치의 발육지연

우연선,정태성,김신 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.3

하악 제2소구치의 선천결손은 비교적 흔히 나타나는 이상으로, 방사선사진에서 결손으로 확인되는 경우 여러가지 치료방법을 고려할 수 있다. 환자의 연령 , 제2유구치 치근의 흡수상태 , 총생의 정도, 악골의 성장, 측모의 형태 , 절치의 돌출도, 하안 모고경 등을 고려하여 치료방법을 선택하게 된다. 그러나.선천결손의 진단과 치료방법의 결정에 있어서 주의해야 할 점이 있다. 하악 제2소구치는 분화와 석회화과정에 있어서 가장 많은 변이를 보이는 치아이다. 경조직 형성은 2를∼2룰세에 시작되며, 대부분 적어도 3∼3를세에는 시작된다. 그러나, 이 시기는 다른 영구치에 비해 그 범위가 매우 넓어서 5∼6세, 드물게는 그 이후에 발육이 시작되는 경우도 있다 그러므로 하악 제2소구치의 선천결손을 조기에 진단하기에는 어려움이 있으며 선천결손으로 진단한 경우라도 오진할 가능성이 있음을 인식하는 것이 중요하다. 저자는 두 가지 증례를 통한 임상연구와 문헌고찰을 통해 다음과 같은 결론을 얻었다. 1. 두 증례 모두에서 하악 제2소구치의 두드러진 발육지연이 관찰되었다. 2.치배형성 이후의 석회화 속도는 거의 정상적으로 나타난 것을 보아, 발육지연은 석회화 과정보다는 분화과정에 있었던 것으로 판단되었다 . 3. 이와 유사한 증례를 접하였을 경우 치아의 선천결손으로 단정하기 보다는 발육지연의 가능성을 함께 고려할 필요가 있을 것으로 사료되었다. The congenital missing of mandibular second premolars is among the common dental anomaly in children. When a second premolar is diagnosed as congenitally missed, we should consider many factors influencing the treatment plan such as patient's age, states of roots of 2nd primary molar, degree of crowding, skeletal growth pattern, facial profile, procumbency of the incisor and lower facial height, etc. The mineralization of the second premolars begins in the majority of cases at the age of 2∼2½ years, but this period varies more widely than those for other permanent teeth. Also, mandibular second premolars show the greatest variations in differentiation and calcification. For this reason, aplasia of this group of teeth cannot be diagnosed at early age and with the same degree of certainty. From the clinical studies with 2 cases and some literature review on late development of second premolars, it could be summarized as follows : 1. The 2 cases showed marked delay in the development of mandibular second premolars. 2. After the crypt formation, the speed of calcification seemed nearly normal, suggesting that the delay was due to differentiation rather than calcification. 3. When one is encountered with similar conditions, it would be desirable to consider the possiblity of delayed tooth development.

정현추종 제어기를 이용한 전압형 PWM 컨버터의 입력전류제어

우정인,정기화,최선영,허태원 東亞大學校 附設 情報通信硏究所 1999 情報通信硏究所論文誌 Vol.7 No.1

This paper presents the sinusoidal tracking controllr in order to eliminate the steady state control error and to improve the transient characteristics for input current in voltage source PWN congerter. A general mathematical model with switching functions of the PWM converter that is represented as differential equation is established. The proposed model in current control system that does not require coordinate transformations is described. It is proved that the steady state deviation reduces to zero from a transfer function of input current control system. The sinusoidal tracking controller is realized by differential equations for the LC equivalent circuit. From simulations and experimental work, it is verified that the control system can eliminate the steady state error of input current and also improve the transient state characteristic.

미세가공 시스템을 이용한 미세 그루브 가공실험

이선우,이동주,이응숙,제태진 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

The needs for precision machining of micro to milli parts have been increased as the industry require high quality products, especially for the micro-machining of IT products. The ultra-precision machining system is essential for the micro machining of fine structures, which insures machining accuracy, low systematic and random error and repeatability. In this study, we developed micro machining system, which is equipped with air bearing stage for ultra precision machining and also we present the results of V-grooving experiments, conducted by the developed system, to verify the performance of system. The results show that the machined V-grooving had good accuracy with repeatable stability.

卵巢未分化胚細胞腫 1例

柳友國,李起煥,權善鎬,盧興泰 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.1

Ovarian Dysgerminoma is a tumor purely of germ cells without any attempt to form teratomatous elements and is believed to arise from the primordial germ cells of the indifferent stage of gonadogenesis. We have had a Dysgerminoma of right ovary in 28 years old multigravida and report the case with review of literatures briefly.

HDPE 개질 아스팔트 혼합물의 강도 및 변형특성

김광우,이기호,권오선,고태영 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

본 연구는 폐비닐 펠렛을 도로포장재료로 재활용하여 자원절약 및 아스팔트 혼합물의 품질향상을 위한 연구이다. 이를 위하여 폐비닐의 첨가량별 배합설계를 수행하여 적정 폐비닐 첨가량과 최적 아스팔트 함량으로 편마암과 화강암 2가지 골재와 폐비닐인 RHDPE의 함량을 4가지로 혼합물을 제작하여 8종류의 재질 혼합물과 2종류의 무개질 혼합물을 제작하였다. 그리고 이 공시체에 대하여 마샬안정도, 간접인장강도 및 Kim test와 반복주행시험 등 실내시험을 통하여 혼합물의 특성을 분석하였다. 폐비닐 첨가량은 RHDPE가 8%일 때 안정도와 간접인장강도 모두 가장 우수한 것으로 나타났고 취성도 나타나지 않았다. RHDPE를 첨가한 혼합물에 대하여 Kim test를 수행한 결과 DR과 DS 모두 높은 상관성을 보였다. 그리고 반복주행시험에서는 RHDPE를 첨가한 혼합물이 일반 혼합물보다 우수하였다. 향후 많은 실험을 통해 RHDPE의 우수성을 입증한다면 소성변형 저항성에 우수한 재료로 이용될 수 있을 것이다. This study is a fundamental research for recycled high-density polyethylene (RHDPE) in asphalt mixture for improving roadway pavement. Marshall mix design was conducted and optimum asphalt content(OAC) was determined for dense-graded surface course mixture by RHDPE content. Marshall stability test, indirect tensile strength (ITS) test, wheel tracking trest and Kim-test were carried out to measure the characteristics of RHDPE-added asphalt concretes. From the results of this study, RHDPE in asphalt mixture if possible. It could be considered that adding too much RHDPE in asphalt mixture is not proper. The optimum content of RHDPE was appeared to be 8%. In Kim-test, statistical analysis was performed for each loading head and aggregate to find out correlation between S_(D) values and each rut parameter. The analysis result showed that S_(D) had very high coefficient of determination with rut parameters on the average.

이주노동자와 국내 한국인노동자의 산업재해현황 및 특성 비교

이선웅,김규상,김태우 大韓産業醫學會 2008 대한직업환경의학회지 Vol.20 No.4

목적 산업재해 발생 현황 통계자료를 이용하여 대표적인 산업안전보건 취약계층인 이주노동자들의 산업재해 현황과 산업재해 발생과 관련된 특성을 국내 한국인 노동자와 비교 분석하고자 하였다 방법 2004년부터 2006년까지 산업재해 발생 현황 원자료를 통해 파악된 이주노동자의 연 간 산재 발생자수에 대해 매년 12월의 이주노동자 종 노동인구와 외국인노동자의 산재보험 가입률을 적용하여 산재율을 추정하고 산재발생의 특성 분포를 파악하였으며 국내 한국인노동자 산재발생 결과와 비교하였다 또한 2006년 한국산업안전공단 안전지도원 관내 지역 사업장에서 산재 승인된 국내 한국인노동자와 이주노동자 7,210명과 458명에 대해 산업재해 특성 분포를 비교 분석하였다 결과 본 연구방법을 통해 계산된 이주노동자의 총 산재율은 2004년 0.93% 2005년 0.90% 2006년 1.0G% 이었다 사고부상 산재율은 0.90% 0.86% 1.00% 이었고 사고사망 만인율은 2.29 2.22 2.39 이었으며 업무상질병 산재율은 0.011% 0.014% 0.027%이었다 사고부상의 발생 원인에서 감김/끼임과 절단의 비율은 이주노동자에서 유의하게 높았으며 업종 사업장 규모 근무기간이 보정된 후에도 감김/끼임의 비율이 여전히 이주노동자에서 유의하게 높게 나타났다 결론 이주노동자들은 산재보험 누락과 산재보험 비적용 사업장에 대한 배제가 고려되지 않은 공식 통계자료로도 국내 한국인노동자에 비해 높은 산재율을 보이고 있었으며 사고사망의 경우 2006년 기준의 만인율이 2.2배 높은 결과를 보였다 업무상질병의 경우 국내 노동자에 비해 뚜렷이 낮은 산재율을 보여 산재 처리 과정 중에 많은 누락이 실제로 존재할 가능성이 높음을 추측할 수 있었다 5인 미만 제조업의 6개월 이하 근무자에서도 감김/끼임이 유의하게 높게 발생하여 이주노동자들의 내재된 안전 취약성인 기계설비 사용의 안전정보 부족과 위험에 대한 소통부족이 해결되지 않고 있다고 판단된다. Objectives To analyze the status and characteristics of the industrial accidents of migrant workers with comparison to those of native workers. Methods The industrial accident rate of migrant workers was estimated by the annual number of industrial accidents divided by the total number of annual labor population multiplied by the annual admission rate of industrial accident insurance The characteristics of industrial accidents for total migrant workers were assessed and compared with those of total native workers (from 2004 to 2006) In addition, we compared the industrial accidental characteristics of the 7,210 native workers and the 458 migrant workers employed in the Incheon area who received compensation from the industrial accident insurance in 2006. Results In 2004, 2005 and 2006 the total annual industrial accident rates of the migrant workers were 0.93%, 0.90% and 1.06%, the injury accident rates were 0.90% 0.86% and 1.00% the number of injury deaths per 10,000 persons were 2.29, 2.22 and 2.39 and the disease rates were 0.011% 0.014% and 0.027% respectively. As for the cause of injury rolled/jammed and cutting-type injures were more prevalent in the migrant workers. With the standardization of job category industry size and work tenure, the rolled/jammed-type injury was still significantly more prevalent in the migrant workers. Conclusions Even considering the exclusion of the possible missing numbers of the submission of industrial accident cases, and the numbers of workplaces not registered for industrial accident insurance the publicized statistics confirm the higher industrial accident rate of migrant workers compared to native workers Especially the injury death rate was 2.2 times higher for migrant workers than for native workers in 2006. In addition, the remarkably lower occupational disease rate of the migrant workers compared to that of the native workers, suggested that numerous cases of disease were not reported Finally the lack of communication and former education that usually lead to the most prevalent injury type i.e, the rolled/jammed type, supported our conclusion that the migrant workers were in need of more education regarding workplace safety.

Oyster(Crassostrea gigas) shell에 의한 重金屬 吸着除去 特性에 관한 硏究

황선치,우용태,이무강 慶星大學校 環境問題硏究所 1994 環境硏報 Vol.4 No.1

The purpose of this study was to find out the characteristics of oyster shell powder as a absorbent and remover of heavy metal ions such as Cd(Ⅱ), Cu(Ⅱ) and Pb(Ⅱ) and to get an information to reduce water contamination and destruction of underwater ecosystem by the application of oyster shell powder as a remover of the heavy metal ions. (1) When oyster shell powder was utilized as a remover of the heavy metal ions, the removing ability of 1 gram oyster shell powder to the ions of Cd(Ⅱ), Cu(Ⅱ), and Pb(Ⅱ) was 4.945㎎,1.9946㎎ and 14.970㎎, respectively, and the removing rate was above 99%. (2) In the case of varying the concentration of the heavy metal ions, Cd(Ⅱ) and Pb(Ⅱ) were removed above 90% so far as 150㎎/ℓ, whereas the removing rate of Cu(Ⅱ) beagan to decrease at the concentration over 70㎎/ℓ. The removing rates of the heavy metal ions were ordered as Pb(Ⅱ), Cd(Ⅱ), and Cu(Ⅱ), and each adsorption Constant of Cd(Ⅱ) and Cu(Ⅱ) was 3.353 and 1.792. But because of the result of experimentation in dilute solution. the adsorption Constant of Pb(Ⅱ) could not be decided. The size of adsorption zone was 4.8cm. (3) The removing ability of oyster shell powder to the heavy metal ions was ordered as Pb(Ⅱ) Cd(Ⅱ) and Cu(Ⅱ), but that of activated carbon powder was differently ordered as Pb(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ). However, a total of the removing ability of oyster shell powder was highe, than that of activated corbon powder under the same condition of experiment. (4) At the concentration of the heavy metal ions of 50㎎/ℓ, break-through curve was formed and the size of Vz was 128㎖. Because the removing ability of oyster shell powder to the heavy metal ions is made from both adsorptive removal and hydrate precipitation, it will be a good neutralizer and absorven of heavy metal ions in acid water especially, and contribnte to reduce water contamination and to preserve underwater ecosystem.

한의진단명과 진단요건의 표준화 연구 III : 3차년도 연구결과 보고

최선미,양기상,최승훈,박경모,박종현,심범상,김성우,노석선,이인선,정진홍,이진용,김달래,임형호,김윤범,박성식,송태원,김종우,이승기,최윤정,신순식 한국한의학연구원 1997 한국한의학연구원논문집 Vol.3 No.1

The diagnostic requirements were suggested and explained regarding the systems of differentiation of symptoms and signs in the third year study of standardization and unification of the terms and conditions used for diagnosis in oriental medicine. The systems were as follows : - analyzing and differentiating of epidemic febrile disease - analyzing and differentiating in accordance with the Sasang constitution medicine based on four-type recognition - differentiation of disease according to pathological changes of Chong and Ren channels - standards for diagnosis of women's disease - standards for diagnosis of children's disease - standards for diagnosis of motor and sensor disturbance (-muscle. born, joint, etc.) - standards for diagnosis of neuropsychiatric disease - standards for diagnosis of five sense organ disease - standards for diagnosis of external disease The indivisual diagnosis pattern was arranged by the diagnostic requirements in the following order : another name, notion of diagnosis pattern, index of differentiation of symptoms and signs, the main point of diagnosis, analysis of diagnosis pattern, discrimination of diagnosis pattern, prognosis, a way of curing a disease, prescription, herbs in common use, disease appearing the diagnosis pattern, documents. The standards for diagnosis of each disease was arranged by the diagnostic requirements in the following order : another name, notion of disease, the main point of diagnosis, analyzing and differentiating of disease, analysis of disease, discrimination of disease, prognosis, a way of curing and prescription of disease, disease in western medicine appearing the disease in oriental medicine, documents.