• Title/Summary/Keyword: V-t Characteristic

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A Study on the Strength Characteristics of the FRP Bonding Method (FRP 이음방식에 따른 구조강도 특성에 관한 연구)

  • Kim, Kung-Woo;Kang, Dae-Kon;Baek, Myoung-Kee;Park, Jai-Hak
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.6
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    • pp.778-783
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    • 2015
  • We studied about the strength characteristics of the FRP bonding method due to reduce accident on the oceans and protect life for my people. We test tension and bending strength of butt joint, lap joint, V-scarf joint, X-scarf joint. The result of test, it's pattern is similar both tension and bending strength. Tension strength and bending strength was excellent in order to X-scarf-butt joint-V-scarf-lap joint. The tension strength is the best properties X-scarf showed a 57% strength rate of the basic material, and bending strength showed a 77% strength rate of the basic material. Overall, the X-scarf 12t joint has most excellent properties of tension and bending strength. The lap joint has worst properties of tension and bending strength. We have to test having different over-lay of V-scarf and X-scarf joint each 12t, 16t, 20t. V-scarf of 20t over-lay has excellent character of tension and bending strength. But X-scarf of 12t over-lay has excellent character of tension and bending strength. The results are shown to the contrary. The ship is received a lot of stress. it's hard to compare a direction both actual and test. But we can acknowledge material basic characteristic of strength through tension and bending test. We give the four repair method; butt joint, lap joint, V-scarf joint, X-scarf joint and the reduced ratio in comparison with basic material; In addition give the separated data for V-scarf and X-scarf characteristic of 12t, 16t, 20t overlay length. For our study repair man can select good repair method in his work station.

Analysis of the Differences in Re-employment Need on the Individual Characteristic of Career Interrupted Woman (경력단절여성의 개인특성에 따른 재취업욕구 차이 분석)

  • Shin, Yean-Ha;Lee, Dong-Myung
    • The Journal of the Korea Contents Association
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    • v.17 no.9
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    • pp.310-323
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    • 2017
  • The purpose of this study is to provide necessary data and information in order to support economic activity of career interrupted woman by analysis the differences between seeking work need on individual characteristic and re-employment need of job-seeking activities. This study includes the result of reviewing a prospective study and an enpinical analysis based on the theoretical background of career interrupted woman, vocational education, individual characteristic and re-employment need to achieve its goal. The collected data from 150 career interrupted women who had a vocational education was analyzed by one-way analysis of variance, T-verification and SPSS 12.0v program. In summary of this study, re-employment need would be different by individual characteristic, seeking work need and job-seeking activities. It shows that the method of re-employment should be provided as considering the individual characteristic of career interrupted woman. Therefore, this study suggests the necessity of suited education and improved system for individual characteristic of career interrupted woman.

An Experimental Study on the Vibrational Characteristics of the Rotor Blade with Fiber Reinforced Plastics (복합재료 FRP로 제작된 Rotor Blade 진동특성 분석에 관한 실험적 연구)

  • Paik, J.S.;Lee, K.S.;Park, J.V.;Lee, J.T.;Son, C.Y.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.11 s.104
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    • pp.1232-1240
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    • 2005
  • The purpose of this paper is that investigates the dynamic behavior characteristic of W.T.S (wind turbine system) and carries out the evaluation analysis during operating W.T.S. To investigate the dynamic behavior characteristic of W.T.S, the experiments to measure vibration of the blade from the attached accelerometer on the flap and edge section of the blade that is one of the most important elements of dynamic characteristic of W.T.S are performed. Natural frequency and mode shape are calculated with commercial program ( ANSYS) using the measured vibration acceleration that receives the signal with F.F.T Analyzer from the accelerometer For validation of these experiments, the finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape. The results indicate that experimental values have good agreements with the finite element analysis.

Esterase Isozyme Variation in the Tissues of Glycine soja S. and Z. , Vigna vexillata var. tsusimensis Matsmura , and Trifolium repens L. in Korea (돌콩 , 돌동부 , 화이트 클로버의 조직별 Esterase Isozyme 변이에 관한 연구)

  • 이성규
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.12 no.4
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    • pp.253-259
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    • 1992
  • The esterase isozyme in tissue of wild legume plants were separated by horizontal starch gel electrophoresis. Extracts used in this study were prepared from fully expanded young leaf, cotyledon and radicle of seedling and root-nodule of Glycine sola, Vigna vexillata var. tsuscmensis and Trifoliwn repens. The results are as follows; 1. Each tissue examined had a characteristic banding pattcrn. Number of bands in each species, G. soja, V. vexillata, and T . repens, were 14, 8 and 1 1 bands, respectively. And difference in esterase isozyme bands were greater from tissue to tissue than difference between habitat. 2. Est-I, Est-2. Est-3 and Est-4 in G. soja, Est-I in V. vexillata and Est-l and Est-2 in T. repens showed strong cnzyme activity than other enzyme. 3. Esterase isozyme variation in G. soja and T . repens showed more variety than V. vexillata. This is resulted from many genotypic differences within species. 4. The main enLyme among thc esterase isozyme were Est-I. Est-2, Est-3 and Est-4.

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Surface flashover discharge and partial discharge of polymer film in liquid helium (액체 He중 고분자 film의 연면 및 부분방전 연구)

  • 김상현;김현희;정순용;최효상
    • Electrical & Electronic Materials
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    • v.9 no.9
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    • pp.942-948
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    • 1996
  • Electrical properties such as surface flashover discharge and discharge degradations of insulating materials for superconducting cable have been investigated. It is found that the surface voltage is proportional to $l^{0.7}$ (l: discharge length) in liquid helium (LHe). V-t characteristic in LHe was a n=5.5 that was less than liquid nitrogen (L $N_{2}$). After applied AC voltage, the surface condition of polymer films was observed non-eroded areas and eroded areas. The eroded area is depending on the applied voltage. In case of LHe, the crack was observed.d.

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Prediction of Life-Time on the Macroscopic Interface between Solid Materials with Analysis of V-t Characteristics (V-t 특성 분석에 의한 고체 거시계면의 수명 평가)

  • 오재한;이경섭;배덕권;김충혁;이준웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.7
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    • pp.607-611
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    • 2000
  • The characteristics on the interface between Epoxy and EPDM which are materials of the underground insulation systems of power delivery have studied. The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law and the long breakdown life time can be evaluated. AC breakdown strength and life time is improved by oiling to the interface. When the low viscosity oil is spread interface has the highest life time.

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T.O.V.A. PROFILES OF CLINICALLY REFERRED CHILDREN WITH SYMPTOMS OF INATTENTION (주의산만을 주소로 소아정신과를 내원한 아동의 인지적 특성 - T.O.V.A. 양상을 중심으로 -)

  • Lee, Soo-Jin;Lee, Hye-Ran;Ko, Ryo-Won;Shin, Yee-Jin
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.11 no.2
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    • pp.290-296
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    • 2000
  • Objective:This study aims to investigate the cognitive characteristics of clinically referred children with symptoms of inattention, cach as having ADHD, tic disorder, and emotional disorder. Methods:65 boys(38 with ADHD, 17 with Tic disorder, and 10 with Emotional disorder) were individually assessed using the KEDI-WISC(FIQ, VIQ, PIQ) and T.O.V.A.(errors of omission, errors of commission, reaction time, variability, anticipatory response, multiple response), and the results of those tests were analyzed. Results:There was significant difference among three diagnostic groups of the VIQ of KEDIWISC and the reaction time of T.O.V.A. after the correction of the effect of age difference. Conclusion:The findings suggest that the reaction time of T.O.V.A. might be the useful variable to differentiate the ADHD from other psychiatric disorders and the effect of age and IQ difference should be considered carefully to diagnose in clinical setting.

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Neutronic design of pulsed neutron facility (PNF) for PGNAA studies of biological samples

  • Oh, Kyuhak
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.262-268
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    • 2022
  • This paper introduces a novel concept of the pulsed neutron facility (PNF) for maximizing the production of the thermal neutrons and its application to medical use based on prompt gamma neutron activation analysis (PGNAA) using Monte Carlo simulations. The PNF consists of a compact D-T neutron generator, a graphite pile, and a detection system using Cadmium telluride (CdTe) detector arrays. The configuration of fuel pins in the graphite monolith and the design and materials for the moderating layer were studied to optimize the thermal neutron yields. Biological samples - normal and cancerous breast tissues - including chlorine, a trace element, were used to investigate the sensitivity of the characteristic γ-rays by neutron-trace material interactions and the detector responses of multiple particles. Around 90 % of neutrons emitted from a deuterium-tritium (D-T) neutron generator thermalized as they passed through the graphite stockpile. The thermal neutrons captured the chlorines in the samples, then the characteristic γ-rays with specific energy levels of 6.12, 7.80 and 8.58 MeV were emitted. Since the concentration of chlorine in the cancerous tissue is twice that in the normal tissue, the count ratio of the characteristic g-rays of the cancerous tissue over the normal tissue is approximately 2.

Parametric Analysis of the Electric and Magnetic Field Waveforms Produced by Intracloud Lightning Discharges (운방전에 의해 발생한 전계와 자계 파형의 파라미터 분석)

  • Lee, Bok-Hee;Lee, Woo-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.81-88
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    • 2006
  • In this study, the electric and magnetic fields measuring system were designed and fabricated to investigate the electric characteristics of lightning discharges. Frequency bandwidth of electric field measuring system ranges from 40[Hz] to 2.6[MHz] and its response characteristic is 2.1[(V/m)/mV]. Frequency bandwidth of magnetic field measuring system ranges from 300[Hz] to 1[MHz] and its response characteristic is 2.8[nT/mV]. Electric and magnetic fields due to intracloud lightning discharges were observed and their waveform parameters were statistically analyzed. As a result, waveform parameters of electric and magnetic fields are nearly independent of polarity. The mean rise times and the zero-crossing times of electric and magnetic fields are approximately $5.5[{\mu}s]\;and\;21[{\mu}s]$, respectively.

Stress Fields for the V-notched Crack and Fracture Parameters by Boundary Collocation Method (V-노치균열의 응력장과 경계배치법에 의한 파괴변수)

  • Pae, Jung-Pae;Choi, Sung-Ryul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.1
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    • pp.66-76
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    • 2003
  • The arbitrary V-notched crack problem is considered. The general expressions for the stress components on this problem are obtained as explicit series forms composed of independent unknown coefficients which are denoted by coefficients of eigenvector. For this results eigenvalue equation is performed first through introducing complex stress functions and applying the traction free boundary conditions. Next solving this equation, eigenvalues and corresponding eigenvectors are obtained respectively, and finally inserting these results into stress components, the general equations are obtained. These results are also shown to be applicable to the symmetric V-notched crack or straight crack. It can be shown that this solutions are composed of the linear combination of Mode I and Mode II solutions which are obtained from different characteristic equations, respectively. Through performing asymptotic analysis for stresses, the stress intensity factor is given as a closed form equipped with the unknown coefficients of eigenvector. In order to calculate the unknown coefficients. based on these general explicit equations, numerical programming using the overdetermined boundary collocation method which is algorithmed originally by Carpenter is also worked out. As this programming requires the input data, the commercial FE analysis for stresses is performed. From this study, for some V-notched problems, unknown coefficients can be calculated numerically and also fracture parameters are determined.