세가지 형상의 부유식 방파제 특성에 대한 비교연구

조원철,한덕만,양우석,이진원 중앙대학교 기술과학연구소 2000 기술과학연구소 논문집 Vol.30 No.-

본 연구는 2차원 유한요소모델을 이용한 부유식 방파제의 파랑감쇠특성에 대한 이론적 연구이다. 유체의 운동은 선형적이고, 2차원적인 포텐셜 흐름으로 가정하고 수치해석을 수행하였으며, 2차원 유한요소해석과 무한요소해석을 채택하여 부유식 방파제 영역에 적용하였다. 따라서 2개의 영역에 있어 방파제 근처 영역에서는 유한요소해석을 적용하였으며, 그 외의 영역에서는 무한요소해석을 사용하였다. 방파제의 형식은 직사각형, 원형, 사다리꼴의 세가지 형상으로 하였으며, 그 결과를 기존의 실험결과와 비교하였다. A theoretical investigation on the wave-attenuation characteristics of floating breakwaters are presented. The fluid motion is idealized as linearized, two dimensional potential flow. A two-dimensional finite element model is adopted to study the performance of floating breakwaters. The near field region surrounding the solid body is modeld using conventional finite elements, however, the far field region is represented appling the infinite elements. Numerical analysis is carried out for floating breakwaters with three different cross-sectional shapes, rectangular, circular and trapezoidal shapes, respectively. Comparison with hydraulic experimental results measured in the past is carried out to prove the validity of the numerical results.

NC 선반의 직선 사이클 평면 위치결정 정도 측정 및 분석

김영석,정정표,한지희,윤원주 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.2

It is very important t o measure linear cycle plane positioning accuracy of NC lathes because the plane positioning accuracy affects accuracy, performance, interchange-ability and quality of machine parts machined by the NC lathes in industries. Until now, linear cycle plane positioning accuracy test of NC lathes has not been carried out because the two axes of NC lathe are moving simultaneously crossing a t right angle each other. while positioning accuracy test of one axis of NC lathe is briskly carried out using a laser interferometer system in industries. So, in this study, a measuring units system to measure simultaneously two axes' plane. positioning accuracy of NC lathe was composed of two optical linear scales installed on the. z and x-axis of work coordinate system on NC lathe and a computer inserted with PC counter card enables to obtain measuring data. Here, ATC(Automatic Tool Changer) and moving part of linear scale are fixed with magnet bases in order to measure displacement of the ATC of NC lathe. And next, computer software was developed in order to measure the lathe under resolution of 0.1㎛ by the linear scales, and also computer soft measuring data could be modeled on plots and be analyzed to numerically.

NC 선반의 직선 사이클 평면 위치결정 정도 측정에 관한 연구

김영석,송인석,정정표,한지희,윤원주 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.2

It is very important to measure linear cycle plane positioning accuracy of NC lathe as it affects all other parts of machines machined by them in industries. If the plane positioning accuracy of NC lathe is bad, the dimension accuracy and the change-ability of works will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear cycle plane positioning displacements of ATC(Automatic tool changer) on zx plane of NC lathe using two linear scales and the time pulses comming out from computer in order to get data at constant time intervals from the linear scales. And each sets of error data obtained from the test is discripted to plots and the results of linear cycle plane positioning errors are expressed as numerics by computer treatment.

超高壓送電에 따른 長幹碍子의 開發에 關한 硏究

金元燮,金斗燮 全北大學校 1980 論文集 Vol.22 No.-

This paper explains well in developing new long Rod insulator and it's design at the base of new method of insulation development, and will serve the safety of power supply system and the improvement of reliability. I analyze theoretically flashover discharge characteristics of Long Rod insulators and develop the new type Long Rod insulator experimentally in this paper. Generally, flashover phenomena of suspension insulator or Bushing etc. are called flashover discharge in space and surface series air gaps. Their characteristics, according to creeping surface distance and space air gap, show various phenomena. The destructive voltage and progress of creeping surface corona and creeping flashover discharge varies according to the shape and arrangement of the electrode, the surface condition of the solid dielectrics and the amount of moisture in the air. Whole gap flashover discharge characteristics change according to arrangement and relative size of the electrode can be classified according to the following three forms; continuously increasing, decreasing, decreasing after increasing and increasing after decresing. Whole gap maximum flashover voltage will be obtained by adjusting the gap ratio and the size electrode. The characteristics may be obtained by theoretical analysis and it will be an important factor on development of new long Rod insulators in super high voltage Transmission. All the advanced countries has adopted the Transmission system by super High voltage Transmission. Lately, many European countries are prepared to 1000kv High Voltage transmission system, therefore it is necessary for us to develop new type insulators and other many transmission devices.

국가 대표급과 제주도 고교 대표급 수영선수들의 그랩 스타트의 운동학적 분석

김철원,김승곤,오만원,임상용,김성찬,이창준,남사웅,이세형,류재청,신석종,김세민 濟州大學敎 體育科學硏究所 1998 체육과학연구 Vol.4 No.-

The purpose of the study was to undertaken to analysis the Grab starting technique between national representive team(3) and Cheju's representive team(3) with 3D cinematography. The conclusions obtained were as follows: Cheju's showed more elapsed time than national representive team on starting block. and more vertical than horizontal direction of COG position, more concentrated vertical velocity & acceleration than forward direction. Therefore It is necessory for cheju's to train balanced trust force in horizontal and vertical direction in grab starting technique.

정신분열병 환자 자녀에서의 위스콘신 카드분류 검사

김철권,변원탄,장우석,장정희,조진석,김명정 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.5

연구목적 : 위스콘신 카드분류 검사가 정신분열병의 취약지표를 측정하는 도구로 이용될 수 있는지를 알아보기 위한 것이다. 방 법 : 중고등학교 재학생인 정신분열병 환자의 자녀 28명과 부모중 한 명이 알코올 의존증으로 정신과적 치료를 받고 있는 환자의 자녀 18명, 그리고 정신과학적으로 건강한 부모의 자녀 41명을 대상으로 위스콘신 카드분류 검사를 시행하여 세 군간에 그 결과를 서로 비교하였다. 결 과 : 위스콘신 카드분류 검사에서 세 군간에 총 시행 횟수, 총 정답반응 퍼센트, 총 오답반응 퍼센트, 보속반응 퍼센트, 보속 오답반응 퍼센트, 비보속 오답반응 퍼센트, 개념수준 반응 퍼센트, 완성한 범주 수, 첫 범주를 완성하기까지의 시행 횟수, 한 분류범주를 지속하지 못한 횟수, 그리고 학습 효율성 등과 같은 모든 변인에서 유의한 차이가 없었다. 정상 대조군의 하위 10%에 해당되는 총 정답반응 퍼센트 점수를 절단점으로 삼아 세 군에서 그보다 낮은 점수를 얻은 피검자들의 숫자를 확인한 결과 세 군간에 유의한 차이를 발견할 수 없었다. 결 론 : 본 연구 결과는 위스콘신 카드분류 검사에 의해 정신분열병의 유전적 취약지표를 찾아낼 수 없다는 가능성을 강하게 시사한다. In order to evaluate whether Wisconsin Card Sorting Test(WCST) could be used to detect the vulnerability markers of schizophrenia, three groups such as offsprings of schizophrenic patients(n=28), offsprings of alcoholic patients(n=18), and offsprings of psychiatrically normal persons(n=41) were examined for their concept formation and abstract thinking by means of WCST. The results were as follows ; 1) No significant differences were noted in all variables of the WCST such as number of total administered trials, total correct response %, total error response %, perseverative response %, perseverative error response %, nonperseverative error response %, conceptual level response %, number of completed category, number of trials to complete lst category, number of failure to maintain a set, and learning to learn among three groups. 2) There was no difference in the number of cases with extreme low WCST total correct % of lower 10% of the normal controls among three groups. These results suggest that WCST could be an ineffective instrument for using to detect the vulnerability markers of schizophrenia.

경과 관찰 중에 폐감염이 동반된 선천성 낭성 선종양 기형 1예

김정아,이석현,오동훈,김종연,허진원,이성순 인제대학교 2006 仁濟醫學 Vol.27 No.-

We reported a case of congenital cystic adenomatoid malformation (CCAM), diagnosed two years ago, has been infected during medical observation. She underwent VATS guided right lower lobectomy because of little response to the medical treatment. The prognosis turned out to be excellent and now she is under regular medical observation. Management of asymptomatic CCAM still has a likelihood of controversy but the early surgical resection is recommended on a basis of a variety of reference and literature to verify the diagnosis and lessen the risk of infection or malignant degeneration. Moreover the early surgical intervention has a good prognosis settling complications. Recently VATS lobectomy is considered as an alternative strategy for CCAM, and the early surgical resection may be an ideal approach for asymptomatic CCAM.

1가 알코올 용매계를 이용한 α-셀룰로오즈와 AN의 Grafting에 관한 연구

이동호,정원석,설수덕 동아대학교 환경문제연구소 1998 硏究報告 Vol.21 No.1

To study of influence of medium on grafting of Acrylonitrile onto partially a-cellulose, the experiment was cattied out in water/solvent mixtures. the solvent used included methanol, ethanol, propanol. the Acrylonitde concentration was held at 6%. and grafting was carried out in a monomer/liquor ratio of 1 : 100 using a temperature of 40℃ and the reaction time of six hours. in the many figure and table, it is clear that regardless of water/solvent system employed, a substantial amount of grafting is obtained. a regular decrease also occurse with increase in the solvent ratio in the water/solvent mixture. decrease in the graft yield, which results from an increase in the ratio of solvent in the water/solvent mixture, could be interpretied in terms of the adverse effect of the solvent on the swelling properties of a-cellulose in water, the data suggest that the relative sorptive and swelling properties follow the order : methanol>ethanol>propanol.

흉통의 양상에 따라 분류한 불안정형 협심증 환자의 임상적 소견의 비교

김명수,김성구,정호석,온영근,신원용,김철현,최태명,현민수,권영주 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Background and aims : The clinical syndrome unstable angina pectoris that encompasses a variety of symptoms and clincal presentations of transient episode of myocardial ischemia, was devided to several subgroups. Also, it has variable pathophysiologic factors to cause myocardial ischemia. According to clincal presentation, coronary angiographic finding and prognostic factor, the result of unstable angina pectoris is variable. In fact, there were a few data reported on the prognosis of wide spectrum of patients with unstable angina. However, the precise risk of subgroups according to classitication has not been established because it was difficult to compare between studies. We classified unstable angina pectoris by clinical nature of chest pain, and performed to establish and compare the clinical presentations, coronary angiographic findings, treatement and prognosis of patients with unstable angina within subgroups of classification. Methods : Retrospenctive data for 164 unstable angina pectoris patients admitted to the Internal Cardiology Division of Soon Chun Hyang University Hospital from May 1996 to July 1999 was analyzed. The patients were classified into one of the following categories: Class I, new onset of severe angina; Class II, acceleration of previous chronic stable angina; Class III, angina at rest. Clinical presentations, echocardiographic findings, coronary angiographic findings, treatment and prognosis were compared. Results : From the total 164 patients, the subjects of classes were as follows : Class I, 46 cases (28.1%); Class II, 74 cases (45.1%); Class III, 44 cases (26.8%). In view of age distribution, the 7th decade had the highest incidence, and then, 6th, 8th decades were followed. There was no baseline differences among the 3 classes with respect to gender, number of risk factors. Significantly, class II showed more severe findings in abnormal Q wave 15 cases (20.8%), total occclusive lesion 10 cases (20.8%) and three vessel coronary disease 11 cases (22.9%) than other classes. The change of ST segment was significantly apparent (p<0.02) among class I 28 cases (60.8%), class III 26 cases (59.0%), comparing with class II 30 cases (40.5%). Class III had the higher incidence of one vessel coronary artery disease than class I and III. The heparin treatment was performed in 99 cases (60.1%). The incidence of nonfatal myocardial infarction was much more in class I and III, each 4 cases (8.7%, 9.8%) than in class II 1 cases (1.4%). In-Hospital death was occurred in class I and II, each 1 case. Conclusion : The patients with the acclerated angina from chronic stable angina had more severe coronary artery disease than other classes, but they had better in-hospital prognosis.

Periodic occurrence of pine caterpillar, Dendrolimus spectabilis (Lepidoptera: Lasiocampidae) over 900 years based on the ancient literature

Won Il Choi,Yu Jin Shin,Young-Seuk Park 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

The periodic occurrence of biological population is affected by several biological and environmental factors and ancient literature survey offers insight into ecological process related to the cyclicity. The periodic occurrence of a Lepidopteran species, the pine caterpillar (Dendrolimus spectabilis), was estimated based on ancient literature survey. The pine caterpillar was one of the most injurious defoliators of pine trees in northeast Asia, especially Korea during 1960s and 1970s. Outbreaks of this species have long history in Korea. Since about 900 years ago, damages of pine forest by this species and its control were recorded both in History of Corea dynasty which cover 475 years (918-1392) of the history of the Corea Dynasty and in the Annals of Joseon Dynasty (Joseon Wangjo Shillok) which cover 472 years (1392-1863) of the history of the Joseon Dynasty, respectively. At least over 20 and 30 occurrences of pine caterpillar were recorded during Corea dynasty and Joseon Dynasty, respectively. These results showed that the pine caterpillar had been one of the most severe forest pests during Corea and Joseon Dynasty. Our result showed that the ancient literature survey is useful to understand the long-term periodic occurrence of the pine caterpillar.