이방성 적층복합재 구조에서 AE 발생원 위치표정을 위한 실용적인 방법

김정곤,권오양,강용규 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.3

이방성 복합재료 적층판에서는 섬유의 배열방향에 따라 탄성계수가 변하므로 속도가 섬유의 방향성에 의존하게 된다. 등방성 속도를 기준으로 도달 시간차를 측정하는 전통적인 2차원 음향방출 위치표정 방법을 그대로 적용할 경우 위치표정의 오차가 매우 커지며, 그 과정이 복잡해지는 것을 피할 수 없다. 본 연구에서는 위치표정의 대상이 되는 관심영역(ROI)를 마치 유한요소법에서 사용하는 메쉬(mesh)처럼 적절한 크기의 정사각형 요소로 나눈 뒤, 각각을 가상의 AE 발생원으로 간주하였으며, 모든 요소에 대해 이방성을 고려한 속도를 기준으로 각 센서와의 도달시간차를 구하였다. 실험적인 검증을 위하여 알루미늄 박판 및 복합재료 적층판에 대해 0부터 90까지의 속도를 측정하고 위치표정을 실시함으로써 이방성 적층복합재로 이루어진 실제 구조물에서의 실시간 활용 가능성을 확인하였다. Since the velocity is dependent on the fiber orientation in anisotropic composites, the application of traditional acoustic emission(AE) source location techniques based on the constant velocity to composite structures has been practically impossible. The anisotropy makes the source location procedure complicated and deteriorate the accuracy of the location. In this study, we have divided the region of interest(ROI) into a set of finite elements, taken each element as a virtual source, and calculated the arrival time differences between sensors by using the velocities at every degree from 0 to 90. The calculated the experimentally measured values of the arrival time difference are then compared to minimize the location error. The results from two different materials, namely AA6061-T6 and CFRP(uni-directional; UD, [0]_32) laminate confirmed the practical usefulness of the proposed method.

文敎行政의 改革에 따른 大學行政의 連繫方案

金容郁,朴鍾珠,金貴坤,辛京勳 圓光大學校 1981 論文集 Vol.15 No.1

The government of the Republic of Korea has been actively engaged in the process of national developm ent over the past two decades and has accomplished great development in many fields, especially in industry, and national defence. As the result, the industrial and occupational structures have been changed into highly sophisticated ones, and the national standard of living also has been upgraded. In the process of that change, higher education has been the most influential agent. Higher education itself also has developed, particularly in terms of quantitative aspect. But there is no denying the fact that wide-spread private tutoring has virtually paralyzed high school education, while putting heavy financial burdens on the household economy. And also there were fears that a sense of frustration was developing among poor families which were unable to gain access to costly private tutors. To slove these educational, economic, and social problems the「Special Committee for National Security Measures」announced a package of drastic measures, that is,「7.30 educational reform in 1981」designed to discourage overheated private tutoring and put the school education back to normal, including the abolition of individually-held college entrance examinations and the introduction of a「graduation system」. In this context the purpose of the present study aims to investigate linkage between educational policy reform and university administration. To identify the variables of school system the conceptual frame-work was tentatively built as input-transformation-output model. The principal methods used in this study are analy sing the related references and interivew. Prospecting the future of higher education in Wonkwang university, following educational administration directions were identified as follows: ① Effective and flexible management of a "graduation system". ② Operating rigid evaluation systems for academic achievement. ③ Improving the quality of faculties. ④ Improving the management of personnel and finance. ⑤ Developing public relation media.

플랜트輸出 促進方案

金舜坤,金炳台,金容福,申甲 건국대학교 1979 學術誌 Vol.23 No.1

The plant export is as not the export of machinery but machine system bearing technique and know-how. The plant export means export of equipments and techniques in need of materialization of the importers project and maintaining and enlarging the importer's business. Therefore, the plant export is the comprehensive export industry to be composed of the compound factor's, that proves very significant to both sides of importer and exporter from a view point of production method having productive function which is not the raw materials and the ultimate consumer's goods. Therefore, while the plant export has a big value added and an high productive effect, the plant export neccessitate not only the skill of a high order and accumulated experiences but also a large sun of funds. In view of the fact that the plant export have the distinquishing feature above mentioned, the six developed countries which are the united state of America, west Germany, France, Italy, Japan have occupied 70-80% of the world's plant export. Compared with it, Korea's actual records of the plant export are still in significant, in particular, the plant export's ability in fields of engineering and machinary is still in a really early stage. But the Korea's plant export contract amount had been rapidly increased to $877 millions at the end of June,1978 since exporting the textile plant of 1 million to Parkistan in 1973. Though the Korea's plant export is still under insignificant stage, the plant export might be a business with a blight future. This article, firstly, is to inquire into the meanings of plant export, a technical subject, a world's trend and plant expert strategy and supporting policy in the main Developed Countries. Secondly this article has searched the device for improvement of expert through the study of problems which Korean policies of plant export have confronted. A conclusion, writer intended to present the followings for the perspectives of export policy. Firstly, In order to enlarge the productive foundation of plants and to establish the harmonious supply system it needs to aceelate the heavy chemical industrization of domestic industries, and to promote and to specialize the main items of plant industries. Secondly, in order to improve the technology, which is lower than that of the advanced countries, it is necessary to be active in the introctuction of technology and the promotion of manufacturing level of technicians. Thirdly, plant industries being large scope in unit dealings and it's period being lengthy, it needs to enlarge the plant industries, and to specialize and to enlarge the engineering and other soft ware part. Fourthly, it needs the positive export activities through the consolidation and enlargement of supporting system as monetary, tax system and insurance. Finally, it needy the active support of the governmental level as embassies and legations for the strenghening of acceptance competition and the acceptance of large scale projects from foreign states.

흑연-메소페이스핏치 복합재료의 열이방성

유승곤,김영일,이보성,주혁종 忠南大學校 産業技術硏究所 1986 산업기술연구논문집 Vol.1 No.1

In the development of thermal anisotropic materials with natural graphite powder and pitches as raw materials, extruding and hot-press method were investigated. Pitches should be reformed to mesophase pitch precursor by thermal pretreatment for using as a binder, and the heating rate was recommended within 0.2℃/min in the carbonization process. The tensile strength of axial direction of all specimens was about three times larger than that of radial direction and it could be increased about 25-60% by adding 1% chopped carbon fiber. The thermal expansion coefficient of axial direction was about 1/3-1/5 than that of radial direction and the thermal expansion was repressed by adding carbon fiber. The thermal conductivity of carbon fiber added specimens was increased with increasing the temperature, while that of without carbon fiber was decreased. The thermal conductivity of axial direction was about 8.0-4.58 times larger than that of radial direction by adding carbon fiber in the range of 0-400℃. As a general, properties of hot-pressed specimens were better than those of extruded specimens.

搜査權 體制에 관한 小考 : 警察搜査權 獨立 論議를 중심으로

박용현,오태곤 朝鮮大學校 社會科學硏究所 2003 社會科學硏究 Vol.24 No.2

노인의 운동유형에 따른 혈관탄성과 혈압의 반응

전용수,김일곤,이종호,차진 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

The purpose of this study was to analyze the response of Vascular Compliance and blood pressure on aerobic, muscular endurance, stretching exercise and to ascertain the best effects of exercise for improve vascular health in the Elderly men, The subjects were 20 old men, I measured blood pressure and vascular compliance pre and post exercise. For the data, all the measurement were represented by mean(M) and standard deviation(SD) using SPSS package(version 10.0). Statistical techniques for data analysis were paired t-test to determine the difference in pre-post data into group and were one-way ANOVA to determine the rank between group, The Conclusions of this study were as follows; 1. The vascular compliance(p<.01) and blood pressure(p<.05) showed significant differences between pre and post exercise in aerobic exercise groups, 2, The vascular compliance(p<.000) and blood pressure(p<.01) showed significant differences between pre and post exercise in muscular endurance exercise. 3. The vascular compliance(p<.000) and the systolic blood(p<.01) showed significant differences between pre and post exercise in stretching exercise, But diastolic blood pressure showed no significant(p<.437) differences between pre and post exercise. 4. The vascular compliance showed significant(p<.05) only left ankle which differences in order of muscular endurance, stretching, aerobic post-exercise between group. The systolic blood pressure showed significant(p<.001) which differences in order of aerobic, muscular endurance, stretching and the diastolic blood pressure showed significant(p<.01) which differences in order of muscular endurance, aerobic, stretching past-exercise between group.

運動種目別 最適運動遂行 年齡分析

金一坤,김정박,李勇仁 忠南大學校體育科學硏究所 1990 體育科學硏究誌 Vol.8 No.1

The purpose of this paper is searching for the proper age for the most suitable performances in all kinds of sports. We compared the Korean representatives with the other 9 country representatives (U. S. A., U. S. S. R., East Germany, China, Japan, France, Yugoslavia, Hungary, England) who particapated in the Seoul Olympic Games. Finally we got those conclusions. 1. The ages of the Korean representatives in all kinds of sports are generally lower than those of the other 9 country ones. 2. Female representatives a. The average ages of the Korean representatives in all kinds of sports are lower than those of the 9 country one except for basketball. b. The high est average age of the Korean representatives is basketball's 25 and the lowest is gymnastics's 17. c. Equestrian's 36 is the highest in all kinds of sports in each group. 2. Male representatives. a. The average ages of the Korean representatives in all kinds of sports are lower than those of the 9 country ones except for soccer and basketball. b. The high est average age the Korean representatives is shooting's 29 and the lowest is swimming's 23. c. Equestrian's 35 is the highest in all kinds of sports in each group.

류마티스 질환의 약물요법

朴容範,李守坤 대한의사협회 2000 대한의사협회지 Vol.43 No.4

소형 가시화 시험 엔진 개발(Ⅰ)

전인곤,김용덕,전흥신 경희대학교 산학협력기술연구원 1998 산학협력기술연구논문집 Vol.4 No.-

University, college and Technical high school those have a department of mechanical engineering need a experimental practice engine form educational machinery and using this practice student in structure of engine, operation and efficiency characteristics. But, because the engine that they have purchased is for vehicles, agriculture and industry, it is not available to experimental practice, can't alter fuel and the ration of compression and also the combustion process is not visible so efficiency of education for practical machinery is very low. In this study, a fuel, ignition time, the ration of compression is alterable and we design a single cylinder 4-cycle engine of 60~100cc rate of stroke volume with a heat-proof glass that is visible.

공공부조의 실태와 방향 : 대구시를 중심으로 A Case of Taegu City

황감용,송건섭,이곤수 大邱大學校 社會科學硏究所 2000 社會科學硏究 Vol.7 No.3

이 연구는 공공부조의 실태를 대구시를 중심으로 분석하고, 운영상의 문제점, 제도와 현실의 괴리 등을 밝혀 시사점을 제공하여 하였다. 분석결과 문제점으로 대상자 선정 및 선정기준이 모호하고 비현실적이라는 점, 보호내용이 미비하고, 보호행정 체계가 부실하다는 점 등이 나타났다. 방향으로는 대상자선정과 보호수준의 개선, 보호내용강화, 보호행정체계의 정비 등은 물론이고, 의료보호 급여수준을 확대하고 사회복지전담요원을 많이 양성하여 확대 배치하는 노력이 필요하다. 특히 시대적 요청에 의해 생활보호법은 폐지되고 새로운 법(국민기초생활보장법)이 제정되어 그 시행을 눈앞에 두고 있다 이 법의 시행으로 그 동안 우려하던 보호대상자 선정기준, 수급권자의 범위, 최저생계비 문제 등은 다소 해결될 것으로 보인다.