고온에서 HAN 계열 추진제 액적의 거동에 대한 연구

황창환(Chang Hwan Hwang),백승욱(Seung Wook Baek),한조영(Cho Young Han),김수겸(Su Kyum Kim),전형열(Hyung Yeol Jeon) 한국연소학회 2012 KOSCOSYMPOSIUM논문집 Vol.- No.45

The droplet behavior of 83.9 wt.% HAN water solution was investigated experimentally with various ambient temperature and nitrogen environment. At the initial stage of evaporation under thermal decomposition temperature of HAN, gradual decreasing of droplet diameter was observed. After that, the droplet started to expand due to the internal pressure build up by water nucleation inside the droplet. The micro explosion was observed at higher temperature than the decomposition temperature of HAN and the remaining droplet showed similar behavior of single composition droplet. The decreasing rate was augmented as the ambient temperature increasing.

用寒遠寒과 用熱遠熱에 대한 考察 : 六元正紀大論에서

채영진,신창환,임현택,여성원,한성규,이재원,정헌영,금경수 한국전통의학연구소 2003 한국전통의학지 Vol.13 No.1

Five elements motion and six kinds of natural factors influence not only human disease but also difference of medicine effect. Because the climate of summer is very hot, that is easy to increase the properties of hot medicines, a doctor must be careful to use it in summer. Also the climate of winter is very cold, that is easy to increase the properties of cold medicines, a doctor must be careful to use it in winter. But in the certain conditions to use diaphoretics or purgatives, in spite of that regulation a doctor can use them.

New method for an evaluation of the esthetical improvements resulting from a mandibular angle reduction

Joo-Hwan Kim,Se-Jin Han,Moon-Young Kim 대한구강악안면외과학회 2017 대한구강악안면외과학회지 Vol.43 No.4

Objectives: This paper proposes Han’s ratio as an objective and quantitative comparative result obtained from pre and postoperative data in patients with a mandibular angle reduction. Materials and Methods: Thirty patients, 12 men and 18 women, who visited the Department of Oral and Maxillofacial Surgery with the chief com-plaints of skeletal mandibular prognathism and prominent mandibular angle were selected. The subjects were classified into 3 groups according to the types of surgical procedures involved. Group A consisted of patients who underwent mandibular angle resection and mandibular setback. Group B was comprised of patients with mandibular angle resection, mandibular setback and genioplasty. Group C consisted of patients with mandibular angle resection, mandibular setback, Le Fort I osteotomy, and genioplasty. The landmarks placed in pre and postoperative frontal photographs were used to obtain the Han’s ratio in each group. The Han’s ratios were compared pre- and postoperation and according to the surgical techniques applied. Results: Of the 3 groups who had undergone a mandibular angle resection, all showed a statistically significant increase in Han’s ratio. On the other hand, there was no statistically significant difference based on the surgical techniques used. Conclusion: The ratio of the lateral lower face proposed in this study is a potential indicator of postoperative esthetic enhancement in mandibular angle reduction surgery.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

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.

망막분지정맥 폐쇄증의 임상적 고찰

한영복,최시환 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.2

Clinical manifestations and results of photocoagulation therapy were reviewed in the thirty patients with branch retinal vein occlusion. The average age was 54.3 years old. Most commonly involved vein was superior temporal branch retinal vein. Systemic hypertension and diabetes mellitus were the commonly associated systemic diseases. Macular edema and neovascularization complicating retinal branch vein occlusion produced a profound visual disability. Nine patients with persistent macular edema, neovascularization and extensive retinal capillary nonperfusion area were treated with argon laser photocoagulation. Of those, visual acuity and fundus picture improved in five patients, aggravated in one patient and were stationary in three patients.

지능형 교육시스템 구축을 위한 지식 도메인의 표현 방법 연구 : 물리학을 중심으로 Case of Physics

한선관,이철환,김영기 仁川敎育大學校 科學敎育硏究所 2003 과학교육논총 Vol.15 No.-

본 연구는 지능적인 학습 시스템을 구축하기 위한 지식 도메인의 효율적인 표현 방법을 제안한다. 지능형 학습 시스템의 효율성은 학습 내용의 지식과 학습자의 학습 상태에 대한 지식을 추론하는 방법에 좌우된다. 따라서 지능형 교육 시스템의 구축을 위한 효율적인 지식 표현 방법은 매우 중요하다고 할 수 있다. 본 연구에서 뉴턴 역학에 대한 절차적 지식과 선언적 지식을 컴퓨터가 추론하기 쉬운 규칙 기반 언어를 예로 제안하였다. 본 연구에서 제안된 지식 표현 방법은 다른 학습 영역의 지능형 교수 시스템의 구축을 위한 기반을 제공할 수 있으며, 시스템의 실제 구현에 매우 효율적으로 적용될 수 있다. This study proposes an efficient knowledge representation method to development the intelligent tutoring systems. The performance of the intelligent tutoring system depends on the inference method to evaluate the differences between the knowledge of the learning contents and the students knowledge. Accordingly, the efficient knowledge representation is very important as well as is preceded to construct the intelligent tutoring system. In this study, we propose the method of the procedural and declarative knowledge representation by using rule and case in problem solving learning. Proposed knowledge representation method can be effectively applied to construct the intelligent tutoring systems.

Biwa 호수중 용존유기물질의 변화에 관한 연구

한성욱,김동일,김용환 경운대학교 산업기술연구소 1999 産業技術硏究論文誌 Vol.1 No.1(B)

Dissolved Organic Materials in Lake Biwa and its four inflowing rivers were fractionated using three resin adsorbents into six classes : divided by hydrophobic and hydrophilic from each acids, bases and neutrals. The variation of dissolved organic materials was investigated with distribution of fractionated and UV_260nm absorbance. Hydrophobic acids and hydrophilic acids were found to dominate both lake and rivers. In the lake water, hydrophilic acids were greater than hydrophobic acids, and in the river waters, the opposite was observed.

지능형 교수 시스템의 학습자 모듈에 관한 연구

한선관,이철환,김영기 仁川敎育大學校 科學敎育硏究所 2003 과학교육논총 Vol.15 No.-

본 연구는 지능형 교수 학습 시스템의 4가지 모듈 즉, 전문가 모듈, 교수전략 모듈, 학습자 모듈, 인터페이스 모듈 중 가장 핵심이 되는 학습자 모듈에 관한 연구이다. 우선 기존 지능형 교수 시스템을 고찰하고 그에 따른 학습자 모듈의 종류를 분석하였다. 그리고 실제적인 학습자 모듈의 구축을 위한 최근의 연구 방법을 고찰하였다. 이러한 연구 결과를 토대로 향후 e-Learning에서 지능적인 학습을 제공하기 위한 학습자 모델링로 활용될 수 있다. The purpose of this study is to stand on the basis of the student model in the intelligent tutoring systems that are composed four modules, namely the tutor module, expert module, student module and interface module. For this purpose, we conducted an inquiry into the intelligent tutoring systems and defined student model cognitively. Moreover we analyzed the types of student models and studied the resent research methods to construct the concrete student model. Hereafter, these results of study can be used the foundation of the student modelling to provide the intelligent learning in e-learning systems.

부상공정에서 금속이온의 기포 표면 전위 특성 및 반응효율

한무영,독고석,김영환 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

Flotation processes involve the use of very small bubbles(micro-bubbles) to separate particles from water. The process has become a good alternative to sedimentation, especially where the particles are small or of low density. Although the flotation process commences with a collision between particles and bubbles, most research has been focused only on the characteristics of the particles. In this paper, recent theoretical and experimental research on the characteristics of bubbles is summarized. The effect on the collision efficiency of the size and charge of bubbles is calculated through trajectory analysis. The size and charge of bubbles are measured under different conditions and the ramifications of the results are discussed. The results may lead to a better understanding and optimization of the existing process. In particular, we discuss an idea that a new advanced flotation process might be possible by the modification of the characteristics of the bubble alone or of both bubble and particle.