Semi-boost PFC에 의한 형광등용 전자식 안정기 해석

한재현,조계현,박종연 강원대학교 산업기술연구소 2003 産業技術硏究 Vol.23 No.A

There are many kinds of electronic ballast for various kinks of fluorescent lamps The PFC(Power Factor Correction) circuit in electronic ballast is classified in two types One is the active PFC and the other is the passive PFC circuit. The active type PFC is higher than the passive type. but the cost of the passive type is cheaper than the active type. In this study, we introduced the modified passive PFC method which is called semi-boost PFC. and then we analyzed and experimented the electronic ballast which is composed of the semi-boost PFC, half-bridge. and LCC resonant tank Experimental results showed that the PF 0.98, CF 1.4 and input current THD??15%

8등 형광 램프용 전자식 안정기 설계

한재현,박종연,박재일 강원대학교 정보통신연구소 2003 정보통신논문지 Vol.7 No.-

Nowadays, a new modern building needs much more fluorescent lamps than before. It means that the cost would be increased by the installation of more ballasts. This paper presented a ballast for 8 fluorescent lamps. Recently, the 32W fluorescent lamp is more popular than other fluorescent lamps. The proposed ballast consisted of a valley-fill passive power factor correction circuit, two half-bridge inverters, and LCC resonant circuits. The driver IC is a uc3525 for full-bridge inverter, because the inverter has two half-bridges like as a full-bridge. The Valley-fill circuit has a low cost advantage but the maximum power factor is generally lower than 0.95.

三天池의 環境과 微生物의 多樣性

한상국,이종운,배소현,장무웅,김시균 嶺南大學校 環境問題硏究所 1993 環境硏究 Vol.13 No.1

경상북도 경산시에 위치하고 있는 삼천지에 대한 환경요인 및 미생물상에 관하여 조사하였다. 삼천지 수계의 환경요인 분석결과, 그 평균값은 기온이 25.8℃, pH6.77, 경도 117.94mg/ℓ, 부유물질 4.5mg/ℓ, 용존산소량 3.3mg/ℓ, 생물학적 산소요구량 6.6mg/ℓ, 화학적 산쇼요구량 7.2㎎/ℓ, 염소이온 17.56㎎/ℓ, 황산이온 7.14㎎/ℓ로 나타났고, 중금속류는 Mn과 Zn만이 소량 검출되었으나 전반적인 오염도가 높아 수질환경 기준 IV급수에 해당하였다. 총 세균수는 3.32-8.85×?? No. inds/㎖의 분포를 나타냈고, 식물플랑크톤의 종구성은 규조류 33종, 녹조류 26종, 남조류 8종, 유글레나 13종, 와편모조류 6종 등 86종이 확인되었다. 규조류중 띠돌말과에 속하는 Fragilaria capucina, Synedra acus, S. familiaris 가 우점종이였다. Environmental factors and microflora of Samchun-impoundment in Kyongsan, Kyongpook were studied. Average data of environmental factors analysis are as followings : air temperature 25.8℃, pH 6.77, total hardness 117.94mg/ℓ, SS 4.5mg/ℓ, DO 3.3mg/ℓ, BOD 6.6mg/ℓ, COD 7.2mg/ℓ, ?? 17.56mg/ℓ, ?? 7.14mg/ℓ, Mn 0.05mg/ℓ, Zn 0.04mg/ℓ. Total bacteria in 4 site were 3.32×?? No. inds/㎖. Distribution and species of phytoplankton and zooplankton were 86 species including 33 species of bacillariophyceae, 26 of chlorophyta, 8 of cyanophyceae, 13 of euglenaceae, 6 of dinophyceae. Fragilaria capucina, Synedra acus, S. familiaris were dominant species.

형광등의 수명 연장을 위한 예열 방식의 비교 연구

한재현,조계현,박종연 강원대학교 산업기술연구소 2003 産業技術硏究 Vol.23 No.A

This paper proposed methods of filament preheating to extend a fluorescent lamp life The ballast for the fluorescent lamp can be classified into two main groups magnetics and electronics. The electronic ballast is lighter and smaller than the magnetic ballast and it can dim up and down. There are two ways to start the fluorescent lamp in the electronic ballast: rapid start and instant start Also there are two methods of the driving inverter self excited oscillation and force excited oscillation. The rapid starting is different from the instant starting in that the rapid start is preheating the filament before the steady state If there is a preheating process before the lamp ignition. the life of the fluorescent lamp can be increased This paper presented the preheating methods for self excited oscillating system and force excited oscillating system.

급성 심근 경색에서 시행한 관상 동맥 우회술의 조기 결과

지현근,이원용,김응중,두영철,한규록,오동진,임종윤 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

수직적 안모형태와 치아성숙도의 상관관계에 대한 연구

구용한,현홍근,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.1

본 연구는 수직적 안모형태와 치아성숙도의 관계를 평가하고 이러한 연관성에 대한 사춘기 성장의 영향을 평가하기 위한 것이다. 이번 연구를 위해 7세에서 9세, 13세에서 15세 환자 1306명을 Ricketts의 VERT index를 이용하여 수직적 안모 형태를 분류하였고 환자들의 치령을 Demirjian법으로 평가하여 다음과 같은 결과를 얻었다. 1. 모든 군에서 치령이 역령과 비교 시 통계적으로 유의한 수준에서 크게 측정되었다. 2. 사춘기 연령군에서 brachyfacial type의 경우가 dolichofacial type 보다 치아성숙도가 크게 나타나는 경향을 보였다. 여성의 경우는 통계적으로 유의성있게 차이가 나타났으며, 남성의 경우는 통계적 유의성은 보이지 않았다. 3. Brachyfacial type의 경우 사춘기전 군들과 비교 시 사춘기 군들에서 치아성숙도가 유의성있게 높게 나타났으며, dolichofacial type의 경우는 연령층간 치아성숙도의 차이를 보이지 않았다. The purpose of this investigation was to study the relationship between vertical facial pattern and dental maturation in children in pubertal and pre-pubertal periods. The material consisted of lateral head films and panoramic radiographs of 1306 patients. The subjects were selected according to Ricketts's VERT index and other including criteria. These subjects were divided by VERT index to brachyfacial group and dolichofacial group. In each selected subject, dental age was determined according to Demirjian's dental maturity score. All subjects were distributed according to age, vertical facial type and sex, mean and standard deviation of chronological age, dental age and age difference were determined in each group. And the data were analysed to find the difference of tooth maturation by facial pattern. Findings of this study include: 1. In all groups, dental age was determined higher than chronological age in statistically significant level. 2. Compared by vertical facial pattern, in pubertal age groups, it seems that subjects with brachyfacial type presented the tendency to have an advanced dental maturation, only in female group. 3. Compared by pubertal period, brachyfacial groups presented more advanced dental maturation in pubertal groups than pre-pubertal groups.

서울대학교치과병원 소아치과를 내원한 교정환자의 분포양상에 대한 연구

구용한,현홍근,김정욱,장기택,이상훈,한세현,김종철 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.4

과거에 비해 소아 및 청소년기에 교정치료를 시작하는 경우가 증가하고 있으며 따라서 소아치과에서 교정치료가 차지하는 비율 역시 증가하는 추세이다. 이러한 변화에 맞추어 소아치과에 내원하는 교정환자의 분포 양상을 파악하기 위하여 본 연구를 시행하였다. 2006년 1월부터 2008년 12월까지 서울대학교 치과병원 소아치과를 내원한 환자 중 교정 진단 받은 792명을 대상으로 조사를 진행하였으며 다음과 같은 결과를 얻었다. 1. 교정 진단을 받은 환자의 연령 분포는 8세가 22%로 가장 많았고 7세(19%), 9세(16%) 순서로 나타났다. 2. 골격 분포는 골격성 1급 부정교합이 52%로 가장 많았고 3급(29%), 2급(19%)순서로 나타났으며 연령이 낮은 경우 3급 부정교합 환자의 비율이 높은 경향을 보였다. 3. 총 792명의 환자 중 28%인 218명에서 전치부 반대교합을 보였으며 연령이 낮은 경우 그 비율이 높은 경향을 보였다. Distribution of orthodontic patients in pediatric dental clinics has increased recently. So it is worth to study about the present status of orthodontic patients in pediatric dental clinics. The purpose of this study was to recognize the characteristics and orthodontic patterns of orthodontic patients in pediatric dental clinics. The material consisted of distribution and orthodontic analysis records of 792 new patients in the department of pediatric dentistry, Seoul National University Dental Hospital, from 2006 to 2008. Results were as follows 1. In age distribution, 8-year-olds group comprised 22%, 7-year-olds 19%, 9-year-olds 16%, 10-year olds 15%, 11-year-olds 11%, and other age groups comprised 18%. 2. In skeletal patterns, skeletal class Ⅰ patients comprised 52%, class Ⅱ 29%, and class Ⅲ 19%. 3. In vertical facial types mesofacial comprised 41%, brachyfacial 35%, and dolichofacial 24%. 4. Out of 792 patients 218 patients(28%) showed anterior cross-bite, and the occurrence ratio of anterior cross-bite increased as the age decreased.

腸內棲息菌에 對한 硏究 : 變形菌(Proteus)에 關한 硏究

石鐘聲,金漢壽,張友鉉,李承薰 現代醫學社 1969 現代醫學 Vol.10 No.2

The proteus group are known to be widely distributed in nature and also constitute one of the important micro-flora, of human intestines. The identification of the Proteus and further differentiation into 5 species are made chiefly by their biochemical activities, which are conventionally studied with the cultures grown at 37℃. Since it is known that the metabolic activities of bacteria are influenced by the physicochemical natures of environment, it is conceivable that results of bacterial identification and differentiation based on their biochemical reactions might be different when the culture conditions differ. Thus, 100 strains of the proteus isolated from various clinical specimens were grown aerobically at 37℃ and 22℃ and the patterns of their 1, biochemical activities under the different cultural conditions were studied. The results might be summarized as follows: 1) By the biochemical activities with the cultures grown at 37℃, 100 proteus strains were differentiated into 4 species; P. rettgeri 4, P. vulgaris 14, P. mirabilis 36, and P. morganii 46. 2) If the differentiation into the species was made by the biochemical activities with the cultures grown at 22℃, the 100 strains might be classified into, P. rettgeri 41, P. vulgaris 20, P. mirabilis 34, and P. morganii 5. 3) Regardless the difference of the culture temperatures, 47 strains among the 100 strains were identified into the same species of proteus; P. rettgeri 2, P. vulgaris 7, P. mirabilis 33, and P. morganii 5. 4) Biochemically the proteus strains appeared to be more active at 37℃ than at 22℃. 5) The distribution of the 100 strains among the clinical specimens were stool or recta swat 68, pus or discharge 14, urine 10 and miscelleneous specimen 8.

자기구성 퍼지 제어기법에 의한 수직다관절(AMI)로봇의 위치 및 속도 제어

김종수,배길호,한성현 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

본 연구에서는 산업용 로봇 시스템의 정밀도 및 견실성을 향상시키기 위하여 자기구성 퍼지제어 알고리즘을 개발하여 디지털 신호 처리기에 기초한 관절제어기를 설계하고 이의 실시간 제어실현에 대한 연구가 수행되었다. 제안된 자기구성 퍼지 제어기는 적절한 제어입력을 출력하면서 환경을 관측하고 이 제어입력으로 인한 결과를 이용하여 다음에 나올 결과를 향상시킨다. 그러므로 자기구성 퍼지 제어기를 이용하면 환경에 대한 최소의 정보만을 가지고도 견실 제어기를 설계할 수 있다. 본 논문에서는 조정인자와 규칙을 동시에 수정하여 제어규칙이 점근적으로 수렴하면서 수렴속도를 향상시킬 수 있는 자기구성 퍼지 제어기를 제안하였다. 제안된 자기구성 퍼지 제어기는 위에서 언급한 바와 같이 퍼지 제어기의 단점을 보완하는 측면이 있기 때문에 성능향상을 기대할 수 있다. 따라서, 본 논문에서는 퍼지추론기능과 퍼지규칙 조정능력을 갖는 퍼지 알고리즘을 개발하고 외부환경의 변화 즉, 제어대상인 플랜트의 파라미터변화 및 부하의 변동에 대해서도 능동적이고 우수한 제어성능이 유지될 수 있는 고정도 산업용 로봇 제어기 설계기법을 제안하고, 수직다관절(AM1)로봇에 대한 시뮬레이션 및 실험을 통해 그 성능을 검증하였다. In this paper, it is presented a new technique to the design and real-time implementation of fuzzy control system based-on digital signal processors in order to improve the precision and robustness for system of industrial robot. Fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the real of industrial processes. In this thesis, a self-organizing fuzzy controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variable of the controller, In the synthesis of a FLC, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult, SOFC is proposed for a hierarchical control structure consisting of basic level and high level that modify control rules.

광양만의 저질 중금속 농도 분포 특성

김도희,유한홍,정종성,조현서,신현출 木浦海洋大學校 2002 論文集 Vol.10 No.1

The main goals of the study were to investigate the sediment quality and trace metal distribution in sediment of Kwangyang Bay, south coastal of Korea. Surface sediment sampling were performed in November, 2000 and February and March, 2001. The concentration of H₂S, IL and COD in sediment were measured by a manual of the Department of Marine Environment of Korea. The extracted trace metals Fe, Cu, Cd, Pb, and Zn in sediments mean analyzed by the flame atomic absorption spectrophotometer with an instrument of model Shimadzu AA-6701F. H₂S, IL and COD in the surface sediment were 1.3 mg/g, 5.9 % and 15.0 mg/g, respectively. The mean content of Fe, Cu, Cd, Pb and Zn were 1523 mg/kg, 4.799 mg/kg, 1.321 mg/kg 9.285 mg/kg and 9.353 mg/kg, respectively. All of these measured trace metals level were over the other reported trace metal level in sediment of coastal area. According to histograms, the content of H₂S, IL and COD and trace metals in sediment of this study were affected by artificial activities rather than natural process.