• Title/Summary/Keyword: Strain test

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Working Mothers' Work-Child Rearing Strain and Their Demand on Back-up Care Services (취업모의 일-자녀양육 양립 부담감과 영유아기 자녀를 위한 시간연장 보육서비스 요구)

  • Lee, Wan-Jeong
    • Journal of Families and Better Life
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    • v.27 no.4
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    • pp.117-126
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    • 2009
  • The purpose of this study was to analyze the difference of working mothers' work-child rearing strain and their demand on special care services according to each mother's work conditions and childcare situation. 477 working mothers who have only one child each were gathered by the use of the purposive quota sampling method and analyzed with t-test, F-test, correlation, and multiple regression. The main results showed that working mothers had high work-child rearing strain and demand on special care services when their working conditions were inflexible and they were not satisfied with the care services for their child. The major variable which explained working mothers' demand on special care services was e their work-child rearing strain.

The Development of On-Line Model for the Prediction of Strain Distribution in Finishing Mill by FEM (유한요소법을 이용한 열간 사상 압연에서의 판 변형률 분포 예측 온라인 모델 개발)

  • 김성훈;이중형;황상무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.180-183
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    • 2003
  • In this research, on-line model for prediction of effective strain distribution hi strip on finishing mill process is prescribed. It has been developed using several selected non-dimensional parameters and previously made average effective strain model via series of finite element process simulations, $\Delta$$\varepsilon$ was introduced to describe the effective strain distribution in strip. To confirm adequate non-dimensional variables uniqueness test was done. And to decide the order of polynomial in on-line model equation tendency test for each variables was done. The prediction accuracy of the proposed model is examined through comparison with finite element calculation results.

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Studies on E-coli Isolated from Bile Juice of Slaughtered Cattle (도축우 담낭에서 분리한 대장균에 관한 연구)

  • 심항섭;우종래;정준용;강순근;고영생;박찬숙;조중현
    • Korean Journal of Veterinary Service
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    • v.14 no.2
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    • pp.127-133
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    • 1991
  • The present study was conducted to investigate the biochemical properties, pathogenicity, antimicrobial test, and serotype of E-coli isolated from slaughtered cattle during the period from March 1991 to May 1991. 1. A total of 12 E-coli isolates were isolated from 132 bile juice of slaughtered cattle. 2. All isolates were resistant to Erythromycin, Cephalothin, Neomycin and Lincomycin while the majority of them were susceptible to Trimethoprimsulfamethoxazol (67%), Chloramphenicol(58%), Gentamicin(58%), Ampicillin(17%), Kanamycin(9%) and Tetracycline (9%). 3. In the test of colicinogenecity and congo-red binding capability, 4(33%) isolates produced colicin, all isolates were congo-red negative. 4. The serotypes of isolated E-coli were identified as 008: K- (2 strain), 015: K- (1 strain), 08: K87: K88ab(1 strain), 0139: Kl2(1 strain), 0147: K89(1 strain), others(6 strains ) were autoagglutination.

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A Study of Consolidation Characteristics of Constant Rate of Strain Consolidation tests with Rates of Strain (변형률속도에 따른 일정변형률시험의 압밀특성 비교연구)

  • 장병욱;차경섭;원정윤
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.455-460
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    • 1998
  • This study performed to establish tile characteristics of constant rate of strain consolidation(CRSC) tests. The values obtained by the CRCS tests were compared with oedometer tests. From the comparision of the results of oedometer and CRSC tests for soft soil from Haenam, Korea, it was concluded that. 1. When rate of strain is 0.9mm/hr, compression curve of CRSC test was not coincided with those of tile oedometer test, then preconsolidation stress was larger than those of other rates of strain. 2. Permeabilities from CRSC tests and direct measurements were about same each other, but permeabilities from Oedometer tests were large than those from others.

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토양길항세균 Bacillus sp. KL-3의 대사산물을 이용한 벼도열병균 Pyricularia oryzae의 생물학적방제

  • 김규영;김상달
    • Microbiology and Biotechnology Letters
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    • v.25 no.4
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    • pp.396-402
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    • 1997
  • Biocontrol of plant pathogens provides an alternative means of reducing the incidence of plant diseases without the negative aspects of chemical pesticides. Nowdays, as the resistant fungi about the chemical fungicides have revealed and the concern of environment has increased, the biological control of phytopathogenic fungi by the antagonistic microorganisms is very much indispensable. For the selection of strong antagonistic bacterium for biological control agent of rice leafblast and cucumber gray mold rot, the antifungal strain KL-3 strain was selected among 120 strains isolated from the rhizosphere soils. And the strain was identified to be a species of Bacillus subtilis or closely related strain. In several biochemical and in vitro antibiosis tests, antifungal substances of Bacillus sp. KL-3 were presumed heat stable, micromolecular antibiotic substances. In vivo test and vinyl house field test, the antifungal substances of Bacillus sp. KL-3 represented excellent biocontrol ability aganist Alternaria mali, Phyricularia oryzae, and Alternaria kikuchiana as well as broad spectrum of other fungi. In particular, Bacillus sp. KL-3 strain showed more predominant activity than some chemical fungicides against fungi shown to resist chemcal fungicides.

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An Experimental Study on the Stress-Strain Relationship of Concrete Columns Confined with Composite Materials (복합재료에 의하여 구속된 콘크리트 기둥의 응력-변형률 관계에 대한 실험적 연구)

  • 오영준;황현복;이정윤
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.194-197
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    • 2003
  • The stress-strain curve of concrete confined with both lateral ties and carbon fiber sheet(CFS) is different to that of concrete confined with only lateral ties or CFS. The objective of this study is to investigate the stress-strain relation of reinforced concrete columns confined by composite material. The main variable of the specimens was the content rate of lateral ties to CFS. In the test a total 24 rectangular specimens, which are all 148$\times$148$\times$300mm size. The test results indicated that while the compressive strength of specimens confined with both lateral ties and CFS increased proportionally to the aided amount of two materials, the maximum strain of specimens depended on the larger strain of lateral ties or CFS.

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Evaluation of Displacement Measurement Technique Using Laser Speckle and Digital Image Correlation Method (레이저 스페클과 디지털 화상관련법을 이용한 변위 측정방법의 평가)

  • 강기주;이정현;전문창
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.6
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    • pp.47-54
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    • 2003
  • As a tool for strain measurement to work with screw driven or hydraulic material test systems, in which mechanical vibration is inherent, SSDG (Speckle Strain/Displacement Gage), ESP (Electronic Speckle Photography) and its 3-dimension version SDSP are evaluated for the theory and practical appliance. Through tension test of steel strips, their validity and shortcomings are examined. As the results, it has been shown that, although SSDG and ESP provide direct measurement of in-plane strain in one direction, they are so sensitive to the out-plane displacement. On the other hand, SDSP which is aided with DIC (Digital Image Correlation) technique to trace the movement of the speckles provides not only in-plane 2-dimensional displacement field, but also out-of-plane displacement simultaneously. However, because the DIC is time-consuming, not automated yet and it needs post-processing to evaluate strain from the displacement field, SDSP appears to be not adequate as a real time sensor.

High strain rate tensile test of sheet metals with a new tension split Hopkinson bar (박판의 고변형률에서의 기계적특성을 얻기위한 Tension Split Hopkinson bar의 제작 및 실험)

  • Jung, Dong-Taek;Huh, Hoon;Kang, Woo-Jong;Cho, Sang-Soon
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.03a
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    • pp.106-110
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    • 1997
  • A split Hopkinson bar has been used for obtaining material properties in high strain rate state, In this paper, the apparatus was modified to obtain the high strain rate properties of sheet metal for an autobody. From the experiments with the new apparatus, the material properties of SPCEN in the high strain rate state have been acquired and compared with quasi-static experimental results.

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Strain Properties on Rear Side of Fiber Reinforced Concrete and Cement Composite by Impact Load (충격하중을 받는 섬유보강 콘크리트 및 시멘트 복합체의 배면변형특성)

  • Lee, Sang-Kyu;Kim, Gyu-Yong;Lee, Bo-Kyeong;Yoon, Min-Ho;Son, Min-Jae;Kim, Gyeong-Tae
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.158-159
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    • 2017
  • In this study, it evaluate the strain properties of fiber reinforced concrete and fiber reinforced cement composite. The types of fiber are Hooked steel fiber and it was mixed 0.5, 1.0 vol.% in concrete and 1.0, 2.0 vol.% in cement composites. The impact test was conducted by using a projectile (diameter: 25mm, velocity: 170m/s) and strain properties on the rear side of each specimen was evaluated by strain gage. After the impact test, fracture grade, fracture depth was evaluated.

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A Study on dynamic Fracturing Behavior of Anisotropic Granite by SHPB Test (스플릿 흡킨슨 바(SHPB)를 이용한 이방성 화강암의 동적파괴거동 연구)

  • Choi, Mi-Jin;Cho, Sang-Ho;Yang, Hyung-Sik
    • Tunnel and Underground Space
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    • v.18 no.3
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    • pp.214-218
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    • 2008
  • Dynamic fracturing of anisotropic granite was investigated by SHPB (Split Hopkinson Pressure Bar). Energy absorption during the test and maximum stress were increased as strain rate increased. Maximum stresses in every direction were dependent on the strain rate but not so sensitive to anisotropy. Elastic wave velocity was decreased as strain rate increased and dependent on strain rate in every direction. Especially, elastic wave velocity decreased more rapidly in a strong rock.