비선형상태피드백을 이용한 송전용 무효전력보상기의 제어시스템 설계

최대길,한병문 명지대학교 대학원 1997 대학원논문집 Vol.1 No.-

This paper describes a control system design for the transmission STATCOM by applying a no-linear state feedback, and the performance analysis of the control system by simulations and scaled-model experiments. A mathematical model for the STATCOM was derived using a 3-phase equivalent circuit and a perturbation state equation with respect to a typical operating point. A transfer function to describe the dynamics of STATCOM was derived by considering non-linear state feedback. A controller design was completed by anaylzing the feedback system stability with bode plot and root locus methods. The performance analysis of the conceived control system was verified by simulations with the EMTP and experiments with scaled model, assuming that the STATCOM is connected to an 154kV transmission system. The results show that the conceived control system has excellant performance to control the reactive power of the transmission system.

하악골 충격시 안면 두개골의 응력분산양상에 미치는 구강보호장치의 역할에 관한 유한요소법적 연구

김일한,노관태,노현식,김지연,우이형,Kung-Rock Kwon,최대균 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

연구 목적: 이 연구의 목적은 하악골 충격 시 안면 두개골의 응력 분산양상에 미치는 구강보호장치의 효과에 대해 조사하는 것이다. 연구 재료 및 방법:: 구강보호장치를 제작하고 사람의 머리부위와 치열의 3차원적 유한요소 모델을 컴퓨터 토모그래피를 사용하여 제작하였다. 머리부위의 finite element model은 356,092요소와, 87,099절점으로 이루어져 있다. 그리고 skull과 maxillae, mandible, articular disc, teeth, 그리고 구강보호장치로 구성되었다. 경부의 움직임을 묘사하기 위하여 스프링이 사용되었다. 하악골의 충격점은 gnathion, center of inferior border 와 anterior edge of gonial angle이었다. 충격방향은 수직, 경사방향(45 도), 그리고 수평이다. 충격량은 0.1초당 800 N이었다. 결과: 수직충격을 가한 경우에는 구강보호장치의 장착여부와 무관하게 비슷한 응력과 분산양상이 나타났다(P>.05). 경사충격(45 도)을 가한 경우 구강보호장치를 장착한 모델에서는 응력이 치아와 안면골 및 두개골로 넓게 분산되었으나 이에 비하여 장착하지 않은 모델에서는 치아에 응력이 집중되었다(P<.05). 수평충격을 가한 경우 구강보호 장치를 장착한 모델에서는 응력이 치아와 안면골 및 두개골로 넓게 분산되었으나 이에 비하여 장착하지 않은 모델에서는 치아에 응력이 집중되었다(P<.05). 구강보호장치를 장착하지 않은 모델에서는 상악 치아에 응력이 집중되는 반면, 장착한 모델에서는 모든 충격실험에서 계측된 응력이 매우 낮았으며, 전달된 응력이 상악 치아와 안면골 및 두개골로 넓게 분산되었다. 결론: 구강보호장치는 외부충격 시에 하악에 수직으로 가해지는 충격에는 완충효과가 적었고, 45 도 경사 충격과 수평 충격에는 발생하는 응력을 안면골과 두개골의 넓은 범위로 분산시키고 응력을 감소시켜 응력의 완충 효과가 있었다. PURPOSE. The purpose of this study was to investigate the effects of a mouthguard on stress distribution under mandibular impact. MATERIALS AND METHODS. The FEM model of head consisted of skull, maxilla, mandible, articular disc, teeth, and mouthguard. The impact locations on mandible were gnathion, the center of inferior border, and the anterior edge of gonial angle. And the impact directions were vertical, oblique (45 degrees), and horizontal. The impact load was 800 N for 0.1 sec. RESULTS. When vertical impact was applied, the similar stress and the distribution pattern was occurred without the relation of the mouthguard use (P>.05). The model with mouthguard was dispersed the stress to the teeth, the facial bone and the skull when the oblique (45 degrees) impacts were happened. However, the stress was centralized on the teeth in the model without mouthguard (P<.05). The model with mouthguard was dispersed the stress to the teeth, the facial bone and the skull when the horizontal impacts was occurred. However, the stress was centralized on the teeth without mouthguard (P<.05). For all impact loads, stress concentrated on maxillary anterior teeth in model without mouthguard, on the contrary, the stress was low in the model with mouthguard and distributed broadly on maxillary anterior teeth, facial bone, and skull. CONCLUSION. The mouthguard was less effective at shock absorbing when vertical impact was added. However, it was approved that mouthguard absorbed the shock regarded to the oblique (45 degrees) and horizontal impact by dispersing the shock to the broader areas and decreasing the stress.

조명광원의 색온도와 조도 및 스펙트럼 측정

최대욱,박성진,임춘우,석성수,오철한 慶北大學校 師範大學 科學敎育硏究所 1999 科學敎育硏究誌 Vol.23 No.-

The peak wavelength and temperatures of W-Halogen standard light source were measured by using the modified Wien's Law. In the case of graybody, the emissivity ε should be taken into account in using the Wien's Law. In the experiment, PDA spectroscope was used for the measurement of peak wavelength of intensity distribution of spectrum. As the current of light source increases from 5A to 7.4A, the peak wavelength of intensity distribution of the spectrum decreased from 717nm to 690nm, and temperature increased from 3127K to 3330K. Illuminations of three-wavelength lamps and light source were also measured. It was found that irradiation spectrum of those three-wavelength lamps are not coincident to blue(450nm), green(550nm) and red(610nm).

스위치드 릴럭턴스 전동기를 위한 구동시스템의 역률개선과 고효율에 관한 연구

한대희,최준혁,윤용호,정동효,김도군,원충연 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

Switched Reluctance Motor (SRM) offers the advantages of simple and robust motor construction, high speeds and high efficiencies over a wide operating range of torque and speed, excellent controllability. However, SRM has the disadvantages of high current harmonics, and low power factor because of a capacitor filter is inserted in the power converter and inductance of SRM is high, it has pulse waveform of current. This paper deals with an energy efficient converter fed SRM system with the reduced harmonics and improved power factor and with higher efficiency. The validity of the proposed scheme is verified via experiment. We are implemented the proposed control system using 8OC196KC micro-controller.

다량의 하부위장관출혈이 병발된 Vibrio vulnificus 패혈증 1예

최주연,유진홍,한석원,이대훈,최민호,박순민,김연식,김선우,신완식,강문원,강성구 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.2

최근 저자들은 Vibrio vulnificus 감염에 의해 패혈증 및 이차성 피부 병변을 보인 42세의 남자 환자의 치료중 하부 위장관 출혈이 병발된 1예를 경험하였기에 보고하는 바이다. We experienced a case of Vibrop vulnificus septicemia which showed an unusual manifestation such as hematochezia. The patient was a 42-year-old man with chronic liver disease. The blood and wound culture revealed the organism. During intensive care, he suffered from massive hematochezi for several days. Colonoscopy and abdominal CT showed findings suspicious of ischemic colitis. To our knowledge, this is the first unusual case of V.vulnificus infection which showed massive lower gastrointestinal bleeding.

양산시 하수관거의 불명수 산정을 위한 유량 및 수질특성

최호은,김한석,정연화,김대용,성낙창 東亞大學校 建設技術硏究所 2008 硏究論文集 Vol.31 No.2

The objective of this study were to investigated the water quantity and quality characteristics of sewer infiltration/inflow(I/I) computation in Yangsan City. infiltration/inflow(I/I) were evaluated the water-use evaluation, average daily minimum flow-water quality evaluation and minimum daily flow evaluation. Flow meter for infiltration/inflow(I/I) evaluation was used the FLO-TOTE II. Contaminant came into very low concentration at all sampling points as BOD5 standard. Also, I/I evaluation during dry weather on maximum daily infiltration flow-water quality evaluation, maximum-minimum daily flow evaluation, average daily-minimum flow-water quality evaluation is desirable than water-use evaluation. Because that infiltration/inflow(I/I) amount is much different than other evaluation methods.

Nucleophilic Substitution Reaction of Dabsyl Chloride with p-Substituted Anilines

嚴泰燮,崔舜圭,成大東,韓性彬 東亞大學校 大學院 1985 大學院論文集 Vol.10 No.-

염화답실과 치환아닐린과의 친핵성 치환반응을 여러 용매계에서 진행시키고 이때의 반응속도 상수를 결정하였다. Br?nsted β값과 Hammett ρ?값들의 결과로부터 전이상태에서 결합파괴보다 결합형성이 우선함을 알 수 있었다. 분광용매화 상관관계식으로부터 용매의 수소결합주게(HBD) 산도 값(α)의 기여도 보다 용매의 편극-극성값(π?)의 기여도가 더 크게 작용함으로서 전이상태에서 결합 형성에 용매의 작용이 큼을 알았다. 또한 Dansyl과 Bansyl의 산 염화물보다 속도상수값이 크게 관측되어지는데 이것은 친핵체가 반응기질의 평면에 수직되게 공격함으로써 전이상태가 더욱 안정화되기 때문이며 이느 Marcus의 전이상태이론에서 concerted mechanism이 작용함을 의미한다 하겠다.

횡문근융해증과 급성 신부전 및 범발성 혈관내 응고장애를 동반한 열사병 1예

최대은,박수진,권오경,이한규,이영모,이상주,나기량,이강욱,신영태 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Heat stroke is a life-threatening illness characterized by an elevated core body temperature that rises above 40% and central nervous system dysfunctions that results in delirium, convulsions, or coma. Heat stroke is subdivided into two forms, classic and exertional. Since strenuous exercise is one of the major exacerbating and precipitating factors, the incidence of exertional heat stroke is high among young adult, especially military personnel undergoing military training. Exertional heat stroke commonly causes rhabdomyolysis, lactic acidosis, acute renal failure, shock and pulmonary edema. We report a case of heat stroke with rhabdomyolysis, acute renal failure, disseminated intravascular coagulopathy(DIC) after strenuous exercise. A 18 year old man was admitted to the hospital because of loss of consciousness. He was a wrestler and he had tried to lose 6kg in weight by jogging and strenuous exercise on that summer day with hot temperature. The development of this illness was favoured by much clothes inappropriate for that environmental condition with a purpose to enhance sweating, and by restricted intake of water and food. On admission, the blood pressure was 80/50mmHg, and body temperature was 39.4℃ with stuporous mentality. Laboratory finding were as follows : in complete blood cell count, hemoglobin was 16.7g/dL and platelet count was 158,000/ mm³. In blood chemistry, AST 1061U/L, ALT 201U/L, BUN 30mg/dL, Cr 2.2mg/dL, LDH 941IU/L, CK 696IU/L were resulted. In arterial blood gas analysis, pH 7.39, pCO₂ 30mmHg pO₂ 86mmHg, HCO₃ 18.4mEq/L, O₂ saturation 96.7% were resulted. In urinalysis, specific gravity 1.025, protein 3+, erythrocyte 2+ were resulted. In brain imaging study, brain CT finding was normal. After appropriate treatments with rapid cooling, hydration and supportive care, he improved with alert mental status. On 2nd hospital day, in laboratory result, thrombocytopenia and coagulopathy were appeared and renal insufficiency was aggravated. So he was treated with platelet concentrate and fresh frosen plasma for DIC, and enough hydration for appropriate urine volume preservation. After all, On 22nd hospital day, he fully recovered and discharged. Nowadays, with followed for some duration, he is wellbeing with no complications.

한국성인 정상교합자의 치아크기와 비율에 관한 연구

김대식,김영준,최재훈,한종훈 대한치과교정학회 2001 대한치과교정학회지 Vol.31 No.5

대한치과교정학회 부정교합백서 발간위원회에서 보관중인 한국성인 정상교합자의 표본(남 : 22명, 여 : 55)과 연세대학교 치과대학 교정과에서 부정교합 백서발간을 위하여 수집한 표본(남자 : 21명)을 이용한 한국성인 정상교합자의 치아크기의 계측과 비율에 관한 연구를 통해, 한국성인 정상교합자의 치아크기의 평균치를 구하고, 조화로운 교합관계와 심미성의 획득에 기여하는 치아크기의 비율을 구하여 다음과 같은 결론을 얻었다. 1.한국성인 정상교합자의 남녀 치아크기의 평균치를 구하였다. 2.남녀간 치아크기의 평균치 비교에서 상하악 제1대구치를 제외한 치아에서 총계적으로 유의하게 남자의 치아크기가 여자의 치아크기에 비하여 크게 계측되었다(p<0.05) 3.계측된 한국성인 정상교합자의 치아크기 평균치를 바탕으로 교정치료시 전치부에서의 적절한 수직피개도와 수평피개도, 구치부에서의 적절한 교합관계를 예측할 수 있게 해주는 치아비율을 산출하였다. 1) Sum of incisors = 4 : 2.97 2) Neff의 anterior coefficient = 1.28 3) Bolton의 anterior ratio = 78.29%, overall ratio = 91.14% 4.혼합치열기에서 맹출된 4전치 폭경의 합과 강하악 편측 미맹출 견치와 소구치 폭겸의 합과의 상관관계를 조사한 결과 양의 상관관계를 나타내었으며, 이 상관관계에 의해 상하악 편측 미맹출 소구치 폭경의 합을 예측할 수 있는 회귀방정식을 구하였다. 1) 미맹출 편측 상악 견치와 소구치 폭경의 합 예측 회귀방정식 =10.435018+0.513346×(하악 4전치의 합) 2) 미맹출 편측 하악 견치와 소구치 폭경의 합 예측 회귀방정식 = 9.654002+0.502565×(하악 4전치의 합) The purpose of this study was to measure the average tooth size of Korean with normal occlusion. According to the study, the average tooth ratios between the upper and lower teeth which could assure the proper ovebite, overjet and good interdigitation ware calculated. The normal occluson sample of this study consisted of 43 Korean male adults and 51 Korean female adults. Among them, 22 Korean male adults and 51 Korean female adults were from KAO(Korean Association of Orthodontists), 21 Korean male adults were from Department of Orthodontics, College of Dentistry, Yonsei University. The results from this study were as follows : 1.The average tooth size of Korean Norm classified by male and female was measured. 2.The average tooth size of Korean male adults with normal occlusion was significantly larger than that of Korean female adults except upper and lower first molars.(p<0.05) 3.The tooth ratio which could predict the proper overbite and overjet in anterior teeth and proper occlusion in posterior teeth was calculated. 1) Sum of inciosrs = 4 : 2.97 2) Neff's anterior coefficient = 1.22 3) Bolton's anterior ratio = 78.29%, overall ratio = 91.14% 4.A positive correlation was observed between the sum of lower anterior incisors and the sum of unilateral canine and premolars in each jaw. Based this correlation, the regression equation was made which could predict the sum of unerupted unilateral canine and premolars in mixed dentition, 1) Sum of unilateral unerupted upper canine and premolars' width = 10.435018+0.513346×(sum of lower 4 incisors' width) 2) Sum of unilateral unerupted lower canine and premolars' width = 9.654002+0.502565×(sum of lower 4 incisors' width)

한국 성인 유치악자의 하악 치열궁에 관한 조사

김일한,박남수,최대균 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.2

The purposes of this study are to evaluate the Korean mandibular dental arch and classify the mandibular dental arch shape and size based on the incisal angle, canine angle, inter second molar width and height. In this study the mandibular study models were fabricated using irreversible hydrocolloid impression material from 225 volunteers with a mean age 23.62 (range 19-29). And the study models were measured with 3-dimensional measuring device and the mandibular dental arch was classified by means of K-means clustering method and visual inspection, then obtained data were analyzed with t-test for the statistical analysis. The results `were as follows ; 1. The average canine height was 5.19mm(s.d. 1.17) in both sex, 5.34mm in male, and 35.83mm in female. And the sexual difference was significant(0<p <―0.05). 2. The average second molar height was 39.81mm(sd. 2.44) in both sex, 40.19mm in male, and 39.21mm in female. And the sexual difference was significant(0<p50.01). 3. The average inter-canine width was 27.16mm(s.d. 1.78) in both sex, 27.41mm in male, and 26.77mm in female. And the sexual difference was significant(0<p<0.01). 4. The average inter-first molar width was 46.93mm(s.d. 2.67) in both sex, 47.72mm in male, and 45.7mm in female And the sexual difference was significant(0<p―<0.01). 5. 'the inter-second molar width was average 56.09mm(s.d. 3.01) in both sex, 57.24mm in male, and 54.32mm in woma. And the sexual difference was significant(0<p<―0.01). 6. The arch form was classified into three shapes based on the incisal and canine angle. V-shape showed 124.88 of incisal angle and 141.64 of canine angle, U-shape showed 152.76° and 125.35° , and 0-shape showed 138:03° and 133.66° respectively. Each arch shape distribution was that the V-shape was 142%, the Ushape was 14.7%, and the 0-shape was 71.1% of the 225 study models. 7. It was thought that the use of second molar width is more reasonable than height for classifying the dental arch size. The arch size was classified into four sizes based on the 2nd molar width. Size 1 showed range of 42.24-48.'23 mm, size 2 showed 48.24-54.23mm, and size 3 showed 54.24-60.23mm size 4 showed 60.24-66.23mm respectively Each arch size distribution was that the size I was 1.3%, the size 2 was 27.1%, the size 3 was 63.6%, and the size 4 was 8:0% of the 225 study models.