예측전류제어기를 이용한 3상 PWM 컨버터

한홍일,함년근,성낙규,이승환,이훈구,오봉환,한경희 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

PWM converter has better power factor and low harmonic components than conventional diode rectifiers and phase controlled rectifier. Also the DC link voltage can be regulated fast and stable against the variation in the load. In order to regulate for DC link voltage, rapid current control is need for source current control. This paper focuses on the improvement of quickness of current controller to know the transient state characteristics of regulated DC link voltage against the variation in the load. To do this, it is adopted to three phase voltage type PWM converter with space vector pulse width modulation(SVPWM) method and synchronously rotating d, q axis current. Each d, q axis current is controlled independently. To control d, q axis current, Current control methods to be applied in system are PI current control and Predictive current control respectively. As a result, Transient response characteristic of Predictive current controller is superior to PI current controller.

단선사고보상기능을 갖는 능동전력필터에 관한 연구

한경희,박인석,이정준,오봉환 명지대학교 대학원 1999 대학원논문집 Vol.3 No.-

Recently, for increasing consumed power and informational society, confidence of power supply is demanded. Beside, owing to most of these loads are nonlinear, utility line is polluted by these components. therefore, it is demanded compensation of harmonic current. In times past, special order of harmonic current is only compensated by passive filter, but active power filter compensate whole harmonic current. Therefore, this paper propose uninterruptable power supply(UPS) with performance of active power filter.

전기자동차 운전을 위한 직류타여자 전동기의 쵸퍼제어

한경희,강승욱,김용주,정연택,이승환 明知大學校 産業技術硏究所 1994 産業技術硏究所論文集 Vol.13 No.-

Recently, the speed control of electric motorcar usually adapts the chopper control method by the development of power electronics and semiconductor manufacturing techniques. When the chooper control is adapted to the speed control of electric motorcar. D.C.series motor is mostly used because of the large starting torques and good control characteristics. But with respect to the economy, D.C. separately excited motor with shunt characteristics is profitable because of high adhesivesness and consumption. So, we compare the characteristics of the bilateral variable-ratio chopper controlled D.C. separately exited motor with that of the D.C. series motor theoretically and experimentally, and present the method which is able to simplify the main chopper circuit by selecting among the forward powering, forward regenerative braking, backward powering, and backward regenerative braking only by using the main chopper control signal. Also, control method is studied which has similar driving characteristics to that of the gasoline motorcar.

하부팽창형 임프란트의 유한요소 분석 및 골형성에 대한 연구

한석환,김영규,민경기,조완석,권종진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.3

The aim of this study was to evaluate by finite element analysis influence of investigated expanding implant on stress distribution and to observe biocompatibility, bone formation feature and change in the bone contact area around the explanding implant through experimental animal study. FEA models of the mandible were constructed based on three-dimensional graphic data of the bone structure around an osseointegrated implant, analysis of stress distribution followed by 100N vertical, 50N horizontal was done. And in the animal study, expanding implant were placed in the mandibles of eight Korean mongrel dogs and analyzed the results with histomorphometric measurements. In finite element analysis, compressive stresses are produced at the bone tissue surrounding the implant, and the contact area between the implant and the bone tissue is increased, which result in increased resistance to horizontal and vertical pressure loads. In the histomorphometric analysis, the measured ratio of the contact surface and bon density between implant and bone was similar to those of the controlled group from 6 weeks. It is thought that increased horizontal and vertical resistance is a great help to the immediate loading on expanding implant and that there needs standardizing quantitative measurement of implant stability and osseointegration to determine whether or not to use the functional loading and to reduce the total treatment period reliably by placing functional loading on each implant based on both bone quality and implant stability.

Fluoroacetate(Platol)중독 증상 연구 : 자살기도자를 중심으로

한창환,황주연,김경식,안석철 大韓神經精神醫學會 1984 신경정신의학 Vol.23 No.1

This study was designed to evaluate the clinical problems of fluoroacetate intoxication. The total number of the fluoroacetate intoxication patients who came to the emergency room of Han Gang Sacred Heart Hospital from Jan. 1, 1983 to Aug. 31, 1983 were 96 cases. Among them, 41 attempters who were consulted to the psychiatrist were evaluated and observed in detail. The following results were obtained. 1. The rodenticide poisoning accounts for 37.2% of all toxic substance intoxication(total 266 cases) at Han Gang Sacred Heart Hospital from Jan. 1983 to Aug. 1983. Among them, 96 cases(36.1%) of fluorcacetate intoxication were observed. 2. Female was affected 2.4 times more frequently than male. 35.5% of total cases belonged to age group 21∼30years, when incidence was most prevalent 3. As the route of drug obtainment, supplement were commonest(63.3%), purchase in 29.4%. 4. CNS disturbances such as drowsiness, stupor, semicoma and irritability were observed in 75.6% of the cases. Speech disturbances such as dysarthria, childish speech was observed in 9.8%of the cases. Convulsion(29.3%), tremor(12.2%) spasm and twitching(4.9%) were also frequently observed. Tachycardia was found in 43.8% of the cases and other frequent symptoms were nausea and vomiting(53.7%), abdominal pain(34.2%), mild or high fever(26.8%). Lower calcium(below 9mg) was found in 29.3% of the cases and lower potassium(below 3.5mEq) was found in 22.0% of the cases. EKG findings revealed QT prolongation(22.0%), ST-T change(22.0%) and u-wave, RBBB, and PVC(14.6%). 5. 92 cases(95.8%) recovered without sequelae and 4 cases(4.2%) expired.

세 갈래로 가른 전두근판을 이용한 안검하수증의 교정

한기환,이경호 大韓成形外科學會 1988 Archives of Plastic Surgery Vol.15 No.1

The aim of blepharoptosis surgery is normal restoration of eyelid cosmetically and functionally. Methods of the correction of ptosis are many. While most of the operations can produce improved or even satisfactory results in mild ptosis, none is entirely satisfactory for the severe case. In 1982 Song reported a procedure using frontalis muscle which sutured to the anterior surface of the tarsus. Using his method, the authors have experienced arching of the upper eyelid margin. The authors divided distal portion of the frontalis muscle flap to 3 parts like a tripartite. The authors have used this tripartite frontalis muscle flap technique to severe and moderate cases with satisfactory results. The results were as follows: 1. In order to prevent an ectropion, the tunnel underneath the orbicularis oculi muscle is made so small that only the frontalis muscle flap can be passed through. 2. The height and curvature of the corrected lid margin is good and lasting. 3. Excision of excessive lid skin must be adequate in order to construct a complete and natural supratarsal fold. 4. Little or no ptosis was developed when looking forward and upward gazes. 5. The lagophthalmos during sleeping spontaneously disappeared about six month. 6. Recorrection is easy in the cases of over or undercorrection. 7. The wrinkles on the forehead disappeared by themselves.

반측안면소체증의 측두골 전산화 단층촬영소견

한종규,한경렬,백병준,김형환,배원경,김일영 순천향의학연구소 2005 Journal of Soonchunhyang Medical Science Vol.11 No.1

Hemifacial microsomia(HFM) is a craniofacial disorder and complex malformation syndrome with a variable and asymmetric malformation involving first and second pharyngeal arch derivatives. Multiple etiological mechanisms for HFM have been considered. Mechanisms proposed include genetic factors, early embryogenesis insults involving abnormal neural crest development and migration, and stapedial artery hematoma. HFM is the second most common craniofacial malformation but has been rarely reported in korea, and we report five cases of HFM in temporal bone CT findings. The temporal bone CT findings of five patients aged 6 days and 19 years(mean, 9 years) with hemifacial microsomia were reviewed and evaluated. Particular attention was focused on auricular malformation, external auditory canal, volume of middle ear cavity, ossicular anomaly, facial nerve anomaly and inner ear anomaly. In all patients, temporal bone CT scans revealed the stenosis or atresia of external auditory canals, decreased middle ear cavities, matoid underdevelopment and ossicular anomalies including ossicular ankylosis, but only one patient showed facial nerve or inner ear anomaly. In conclusion, temporal bone CT scan is a useful diagnosis modality of hemifacial microsomia, which is especially more useful in preoperative evaulation and estimation of postoperative prognosis that demonstate middle and inner ear anomalies.

직렬형 PWM 인버터를 이용한 동적전압보상기에 관한 연구

배정환,한병문,한경희,김희중 명지대학교 대학원 1997 대학원논문집 Vol.1 No.-

This paper presents a novel compensation method for the voltage sag problem for a critical load. This method is able to restore the supply voltage to the original magnitude and shape by injecting the vector diffence between the desired voltage and the actual voltage. The proposed system consists of a dc energy storage device, dc-ac converter, and a coupling transformer to inject the output of the inverter in series with the line. It can make up for the weakness of UPS and SPS. The operation of this system is verified by the computer simulation with EMTP code and experimental work with a scaled model. The advantages of this new system over the existing system are the fast reaction time and the low compensation energy in operation.

면역학적 특성에 따른 yeast cytochrome c의 구조에 관한 연구

조경환,우기민,조만희,이상한,박현경,김창세 순천향의학연구소 2000 Journal of Soonchunhyang Medical Science Vol.6 No.2

The antiserum against yeast cytochrome c and horse heart cytochrome c was reacted immunologically with those from various species. The results were as followings; 1. The antiserum against horse heart cytochrome c was reacted immunologically with heart cytochrome c of horse, cow, rabbit, mouse, chicken, pigeon, frog, tuna, and guanaco, and were not with yeast and neurospora cytochrome c. 2. However, antiserum against yeast cytochrome c was only reacted immunologically with yeast cytochrome c, and was not mammals and vertebrates horse, cow, rabbit, mouse, chicken, pigeon, frog, tuna, guanaco, even neurospora 3. CNBr-digested peptides of horse heart cytochrome c were obtained 5 peaks, Ⅰ(1-80), Ⅱ(1-65), Ⅲ(66-104), Ⅳ(81-104), Ⅴ(66-80), and other peptide (1-50). Among them peptides Ⅰ and Ⅱ were weakly reacted immunologically with antiserum against horse heart cytochrome c. CNBr-digested peptides of horse heart cytochrome c were not reacted with antiserum against yeast cytochrome c. 4. From the above, the immunologically positive cross reaction was thought to be related with Ω loop D.

혈관성 두개골판 사용의 경험 : 편측하악 재건 2례

이경호,이동훈,한기환,강진성 大韓成形外科學會 1988 Archives of Plastic Surgery Vol.15 No.4

Although various materials have been used for the rrconstruction of mandible, autogenous bone graft is still preferred. However, it has limitation in its use where the bony defect is large because of partial bone absorption. To solve this problem, a free vascularized bone graft using microsurgical technique has been tried, but the disadvantage of microvascular surgery led to the development of a vascularized bone flap technique. Many authors reported the method of vascularized calvarial bone flap, all of which include the temporalis muscle. Recent anatomic studies and clinical success with a technique which employs only the superficial temporal vessels, galea, temporal fascia, and periosteum have convinced us of the superiority of vascularized bone flaps without temporalis muscle. The authors effected reconstruction of the heminandible with a vascularized parietal bone flap as a full-thickness,immediately after resection of a giant cavernous hemangioma, and after resection of a fibrous dysplasia of the hemimandible, as the puter table. The results were as follows: Advantages: 1. Curvature of calvarial bone is similar with the mandibular arch and adequate amount of bone may be obtained. 2. Donor site is in the same operative field. 3. Complication of donor site is less than with other sites. 4. Scar can be hidden in hair. 5. Rich vascular supply is noted even in full thickness calvarial bone flap. 6. Relatively simple surgical procedure compared with micrevascular surgical precedures. 7.Arc of rotation is long enough. 8. Vascular pedicle is thin. 9. Total reconstruction of the mandible is possible when calvarial bone flaps are elevated from both sides of the skull. Disadvantages: 1. Subfollicular dissection is tedious. 2. Temporal and buccal branches of the facial nerve may be damaed. 3. About 1 cm side postoperative alopecia is inevitable. 4. Dura may be damaged by inadvertent approach. 5. Partial necrosis of the distal flap is possible, due to stripping of the overlying periosteum from the flap.