• 제목/요약/키워드: Evalution

검색결과 202건 처리시간 0.027초

두께변화에 따른 엔지니어링 플라스틱의 파괴인성과 AE특성 (Fracture toughness and AE Characteristics of Engineering plastic according to thickness)

  • 남기우;김선진;안병현
    • 한국해양공학회지
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    • 제10권4호
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    • pp.51-57
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    • 1996
  • A standard method for the evalution of the fracture toughness of the high polymer materials has not been fully developed in comparison with that for metallic materials, and has not yet established. In this paper, fracture toughness tests using polycarbonate specimens were carried out. The fracture thughness tests using polycabonate specimens were carried out. The fracture toughness of commercial polycarbonate were dependent on the specimen thickness. The specimen thickness is necessary above 8mm to obtain the valid $K_{IC}$. A cumulative counts were slightly dependent on specimen thickness.

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DIFFUSION APPROXIMATION OF TIME DEPENDENT QUEUE SIZE DISTRIBUTION FOR $M^X$/$G^Y$/$_c$ SYSTEM$^1$

  • Choi, Bong-Dae;Shin, Yang-Woo
    • 대한수학회논문집
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    • 제10권2호
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    • pp.419-438
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    • 1995
  • We investigate a tansient diffusion approximation of queue size distribution in $M^{X}/G^{Y}/c$ system using the diffusion process with elementary return boundary. We choose an appropriate diffusion process which approxiamtes the queue size in the system and derive the transient solution of Kolmogorov forward equation of the diffusion process. We derive an approximation formula for the transient queue size distribution and mean queue size, and then obtain the stationary solution from the transient solution. Accuracy evalution is presented by comparing approximation results for the mean queue size with the exact results or simulation results numerically.

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전산수치해석을 통한 가스차단기의 차단성능 평가 (Evalution of Current interrupting capability in GCB by computational approach)

  • 최영길;이광식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1677-1681
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    • 2002
  • A computational approach of the arc quenching process in GCB was developed. it is capable to calculates the thermodynamic quantities of the gas as a function of time taking into account of all spaces concerned with the arc quenching. Basically using so-called FLIC method, this program adoptes 'Simplified Enthalpy Arc Model', which is somewhat modified. And, to examine whether our works were done properly, it was simulated the whole process of the arc quenching that is based on self-flow generation phenomena/current interruption in a thermal expansion type circuit breaker. This program was verified by experiments, both showed fairly good agreement.

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Box단면 접합부의 Panel Zone 거동특성 (Panel Zone Behavior of Steel Box Connections)

  • 황원섭
    • 한국강구조학회 논문집
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    • 제9권4호통권33호
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    • pp.683-695
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    • 1997
  • 본 연구는 강제 라멘교각 접합부 panel zone의 전단거동특성에 대하여 검토한 것이다. 여기에서는 접합부 시험체 20개에 대한 재하실험 결과와 3가지의 FEM해석 모델에 대한 결과를 제시 하였다. 이와같은 실험및 해석결과를 비교 검토한 결과, panel zone의 강도와 변형 성능은 단면적비와 전단좌굴등에 의하여 감소하는 경향을 보이고 있음을 알 수 있었다. 따라서 본 연구에서는 이상의 결과를 기초로 panel zone의 강도와 변형성능에 대한 새로운 평가식을 제안하였으며, 또한 기존의 라멘교각 접합부에 대한 변형성능에 관해서 검토하였다.

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최근 5년간 전간(癲癎)에 관한 중의학의 연구 경향 (A Study on the Research Tendency in Traditional Chinese Medicine in Recent 5 Years)

  • 이승기
    • 동의신경정신과학회지
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    • 제21권4호
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    • pp.113-122
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    • 2010
  • Objectives : This study was performed to review the research tendency in traditional medical journals of epilepsy in China. Methods: 26 studies were selected by searching CNKI(China National Knowledge Infrastructure) from 2006 to 2010. Results : Those were analyzed and classified into cause, symptoms, herbal therapy, acupuncture therapy, diagnosis, clinical trials, case studies and evalution of treatment in epilepsy. Conclusions : The results show that traditional medical researches of epilepsy are performed variously and actively in China and there are some differences comparing with Korea. I hope these results activate the studies on eilepsy in Korean traditional medicine.

심장관류SPECT 검사 프로토콜 (Protocols of Myocardial Perfusion SPECT)

  • 김성민
    • 대한핵의학회지
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    • 제39권2호
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    • pp.82-86
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    • 2005
  • In myocardial perfusion scintigraphy, the results of this evalution now confront the practitioner of nuclear medicing with methodologic options. Most nuclear cardiologic studies are performed using thallium-201, Tc-99m sestamibi and Tc-99m tetrofosmin. Some part of these studies use some form of pharmacologic stress test. While tailoring each test to the individual is ideal, this may be impractical for a busy department. Accordingly, established protocols to be used for patients with similar clinical presentations will be helpful. The following review presents methodology of various imaging protocols mainly according to the guidelines of nuclear cardiology procedures in American Society of Nuclear Cardiology.

초음파 현미경 및 AE에 의한 결함 측정

  • 최만용;박익근;한응교
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1991년도 춘계학술대회 논문집
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    • pp.127-133
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    • 1991
  • Acoustic microscopy has attracted much intrest recently as potential mondestructive evalution technique for detecting and sizing defects of surface and sub-surface. Also acoustic emission testing method has been developed for detecting microcracks which is more than 30 umm in length quintitatively on ceramics material. In the present paper, acoustic emission during the four point bending test in hot-pressed sintered Si$\_$3/N$\_$4/ specimen which was stressed bythermal shock has been measured by high sensitive sensing system. The surface and sub-surface cracks were detected by scanning acoustic microscope of 800 MHz and conventional ultrasonic testing in C-scope image. The purpose was to investigate the location and size of cracks by SAM and AE technique, whose experimental datas demontrates good agreement for detecting microcracks.

나사연삭기 회전전달 및 테이블 이송오차 평가에 관한 연구 (A Study on the Evalution of Rotational and Linear Movement Error in Thread Grinder)

  • 박철우;윤영식;이상조
    • 한국정밀공학회지
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    • 제13권1호
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    • pp.45-52
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    • 1996
  • It is one of the important causes that the precision of the thread grinder decide the machining errors of the ball screw. The approach described in this study demonstrates how the dominant causes of the inaccuracies in thread grinding system can be determined. To evaluate the machining error of thread grinder, rotary encoder is allocated to spindle shaft and master screw for measuring the rotational transfer error between spindle shaft and master screw and the laser measuring system is used for checking the movement error.

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셀룰라아제 처리된 데님직물의 태에 관한 연구(제1보);주관적인 태 평가를 위한 척도개발 (The Assessment of Hand for Enzyme Hydrolyzed Denim fabrics(Part I))

  • 김경애;이미식;김정희
    • 한국의류학회지
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    • 제23권8호
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    • pp.1139-1148
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    • 1999
  • This paper discussed the assessment of hand of denim fabrics finished by enzymatic hydrolysis. The semantic differential scale established using the database collected from university students. Analyzing the subjective rating by common factor analysis with oblimin rotation five factors expressing the hand were induced. Factor one was the surface property related to the surface roughness or softness Factor two was the durability which was related to the compactness and bearing strength Factor three was the sense of weight which was related to the thickness and weight. The moisture related properties and the sense of shape recovery were the forth and fifth factors respectively. the evaluations on the surface property weight and moisture related properties were similar by men and women However the shape recovery and the durability were evaluated differently. Surface and weight related properties were important factors judging the hand of fabrics by both group.

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엔진 흡입포트 시스템 유동특성 규명을 위한 스월-텀블 합성효과에 관한 연구 (A Study on Combined Effects between Swirl and Tumble Flow of Intake Port System in Cylinder Head)

  • 윤정의
    • 한국자동차공학회논문집
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    • 제7권8호
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    • pp.76-82
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    • 1999
  • The object of this study is to find new evalution index for in-cylinder flow characteristics insteady of current swirl, tumble coefficient using steady flow test rig on intake port system. To this end, port flow rig test was conducted on DOHC head varying intake valve lift respectively. Finally combination angular coefficient and inclination angle were introduced as new evaluation index for in-cylinder angular flow characteristics.

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