• Title/Summary/Keyword: Relative resistance

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A Simple Method for Testing Freezing Resistance Based on Chlorophyll Fluorescence in Tea (Camellia sinensis L.)

  • Chun, Jong-Un;Jeong, In-Ho;Choi, Hyoung-Kog
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.5
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    • pp.322-327
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    • 2000
  • For the stable production of high quality tea, the freezing resistance is a very important character. Most of the farmers have planted out-pollinated seeds that are not genetically pure. So, with small sample, a quick and simple method is required to test freezing resistance of lots of germ-plasm and early generation of hybrids. The absorbances(A530 nm) of TTC reduction solution at -5$^{\circ}C$ were positively correlated with resistance to photoinhibition of PSII in 6 hour photoinhibitory treatments, being significantly fitted by simple linear regression ($R^2$=${0.64}^{**}$). Chlorophyll fluorescence measured by Fv/Fm was found to be very useful in evaluating the relative levels of freezing resistance in tea.

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Effects of Position of Auxiliary Probe on Ground Resistance Measurement Using Fall-of-Potential Method

  • Gil, Hyoung-Jun;Kim, Dong-Woo;Kim, Dong-Ook;Lee, Ki-Yeon;Kim, Hyang-Kon
    • International Journal of Safety
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    • v.7 no.2
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    • pp.1-6
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    • 2008
  • In this paper, the effects of the position and the angle of the potential probes on the measurements of the ground resistance using the fall-of-potential method are described and the testing techniques for minimizing the measuring errors are proposed. The fall-of-potential method is theoretically based on the potential and current measuring principle and the measuring error is primarily caused by the position and angle of auxiliary probes. In order to analyze the relative error in the measured value of the ground resistance due to the position of the potential probe, the ground resistance was measured for the case in which the distance of the current probe was fixed at 50[m] and the distance of the potential probe was located from 10[m] to 50[m]. Also, the potential probe was located in turn at $30[^{\circ}]$, $45[^{\circ}]$, $60[^{\circ}]$, $90[^{\circ}]$, and $180[^{\circ}]$. As a consequence, relative error decreased with increasing distance of the potential probe and decreasing angle between the current probe and potential probe. The results could help to determine the position of the potential probe during the ground resistance measurement.

Effect of Stress History on CPT-DMT Correlations in Granular Soil (응력이력이 사질토의 CPT-DMT 상관관계에 미치는 영향)

  • Lee, Moon-Joo;Choi, Sung-Kun;Kim, Min-Tae;Lee, Ju-Hyeong;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.730-739
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    • 2010
  • Stress history increases in penetration resistance due to the increase in residual horizontal stress of granular soil. This study analyzes the effect of stress history on the results of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance with regard to vertical effective stress is a little affected by stress history. The horizontal stress index($K_D$) in DMT more reflects the influence of stress history on granular soil than the dilatometer modulus($E_D$) and cone resistance($q_c$). The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress($E_D/{\sigma_m}'$) is unique correlated with the state parameter, regardless of stress history.

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An Analytical Study on the Influence of Resistance Factors in Adoption and Diffusion of Innovation as for Introducing ERP Systems into Universities (전사적자원관리(ERP) 시스템의 조직 내 확산에 대한 저항요인 분석)

  • Kim, Hyeon-Jeong;Kim, Young-Hee;Kim, Moon-Sun
    • The Journal of Society for e-Business Studies
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    • v.18 no.1
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    • pp.129-146
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    • 2013
  • This paper focuses on the systematic approach to handle possible resistance by the members of an organization which adopts ERP system. We also analyze various factors that affect the members' receptivity to the new system. The analytic result from the data of 169 universities shows that emotional factors such as fear and doubt play a significant role, while other factors such as relative advantages of efficiency, relative advantages of system and technology support does not. This research demonstrates both the psychological and behavioral aspects of resistance to technology, and then provides a new perspective on the adoption and diffusion of technological innovation in an organization by systematically analyzing the possible negative consequences while the majority of existing research emphasizes on the rosy prospects of the innovation.

Liquefaction Characteristic of Pohang Sand Based on Cyclic Triaxial Test (진동삼축시험을 통한 포항 지역 사질토의 액상화 저항 특성 연구)

  • Hwang, Byongyoun;Han, Jin-Tae;Kim, Jongkwan;Kwak, Tae-Young
    • Journal of the Korean Geotechnical Society
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    • v.36 no.9
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    • pp.21-32
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    • 2020
  • In this study, series of cyclic triaxial tests and shear velocity measurement were conducted using Pohang sand, which was taken from liquefaction observed area, to verify the liquefaction characteristics of Pohang. The cyclic resistance ratio(CRR) was derived based on the test results. A specimen was reconstituted into 40% and 80% relative density conditions and then a series of cyclic triaxial tests and shear-wave velocity measurement were conducted. As a result, the effect of particle distribution and relative density to liquefaction resistance was verified. The liquefaction resistance of Pohang sand was evaluated by comparing with other liquefaction resistance of sands from previous research. In addition, the liquefaction resistance curve from field observation data was used to verify the reliability of results from this study by measured shear-wave velocity.

Relation between Cone Tip Resistance and Deformation Modulus of Cemented Sand (고결모래의 콘선단저항과 변형계수의 관계)

  • Lee, Moon-Joo;Choi, Sung-Kun;Choo, Hyun-Wook;Lee, Woo-Jin
    • Journal of the Korean Geotechnical Society
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    • v.24 no.12
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    • pp.53-63
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    • 2008
  • In this study, the cone tip resistances of cemented sand are measured by performing a series of miniature cone penetration tests in large calibration chamber, and the relations with constrained modulus, unconfined compressive strength, and shear strength of cemented sand are suggested. Experimental results show that both the cone tip resistance and constrained modulus of sand increase with increasing cementation effect as well as relative density and confining stress. However, it is observed that the relative density and confining stress have more significant influence on cone tip resistance than constrained modulus of cemented sand. Since the cone penetration into the ground induces the damage of cementation, the cone tip resistance can't properly reflect the cementation effect of sand. An analysis based on the constrained modulus shows that the measured cone tip resistance underestimates the deformation modulus of cemented sand by about $70{\sim}85%$. In addition, this study establishes various relationships among the above soil properties from the regression analysis.

Drought Resistance Assessment of Four Shrub Species Including Nandina Domestica for Extensive Green Roof (옥상녹화를 위한 남천 외 3수종의 내건성 평가)

  • Shin, Chang-Seob;Li, Hexi
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.267-273
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    • 2014
  • This study is to compare drought-resistance and to find the permanent wilting coefficient of Syringa Dilatata, Euonymus Japonica, Ligustrum Obtusifolium, Nandina Domestica, which are commonly used for rooftop garden due to their relatively strong drought resistance To compare the drought resistance precipitation was blocked from June 4, 2013 to July 20, 2013. During this time, the relative water content, specific electrical conductance, and water potential were measured every seven days and permanent wilting coefficients were investigated. Two days after precipitation was blocked, the relative water content in leaves were measured as follows: Ligustrum Obtusifolium 91.3%, Syringa Dilatata 92.9%, Nandina Domestica 91.2%, and Euonymus Japonica 90.1% respectively. After 28 days, relative water contents of leaves were reduced greatly 60.2% for Ligustrum Obtusifolium and 67.8% for Syringa Dilatata, but Nandina Domestica and Euonymus Japonica's reduced to 80.1% and 81.7% respectively. Permanent wilting coefficient was Ligustrum Obtusifolium 3.1%, Syringa Dilatata 2.1%, Nandina Domestica 1.6% and Euonymus Japonica 0.7%. In other words, the above four tree species are strong in drought resistance and Euonymus Japonica's drought resistance is the strongest while Nandina Domestica, Syringa Dilatata, Ligustrum Obtusifolium follow in that order.

Effects of the Electrical Characteristics of Capacitive Relative Humidity Sensor by Polyimide Film and Upper Electrode Grain by Sputtering Method (폴리이미드 박막과 스퍼터링 방법으로 증착한 상부금속 그레인이 용량형 습도센서의 전기적 특성에 미치는 영향)

  • Lee, Jin-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.3
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    • pp.224-228
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    • 2011
  • This research, integratable capacitive relative humidity sensor was produced using polyimide on glass substrate. Also, at the time of upper electrode formation, upper electrode grain size was affected by giving changes to sputtering condition. Through this analyzing electrical characteristics affect from capacitive relative humidity sensor was possible. Capacitance of capacitive relative humidity sensor was 330 pF, linearity of 0.6%FS and it showed less than 3% of low hysterisis. Specially, hysterisis was affected more from interface than interstitial. Also was affected by the grain size which is one of the formation condition of upper electrode.

A Study on Field Applicability Evaluation of the Hydrophobic - Low Viscosity Surface Treatment Material for Pavement Preventive Maintenance (소수성 특성을 이용한 저점도 AP 표면처리재의 현장 적용성 연구)

  • Choi, Jun Seong
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.31-39
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    • 2014
  • PURPOSES : Surface treatment material for pavement preventive maintenance should be inspected field applicability. This study(Part II) aimed to checkup coating characteristics and performance analysis using lab and field tests. The hydrophobic - low viscosity filling material for pavement preventive maintenance is presented in Part I, which is a series of companion study. METHODS : Relative comparison between general asphalt mixtures and surface treatment asphalt mixtures are analyzed and measured for the field application such as indirect tensile strength ratio(TSR), abrasion resistance, crack propagation resistance, temperature resistance, coating thickness, permeability resistance and skid resistance in terms of british pendulum number(BPN). RESULTS : It is found that TSR, crack propagation resistance and permeability resistance is increased as against uncoated asphalt specimen. Abrasion resistance and temperature resistance is secured from the initial coating thickness point of view, which is about 0.2~0.3mm. Skid resistance on the surface treatment pavement is satisfied with the BPN criteria of national highway because of exposed aggregate and crack sill induced pavement deterioration and damage cracks. CONCLUSIONS : The hydrophobic - low viscosity surface treatment material for pavement preventive maintenance is validated on field applicability evaluation based on quantitative analysis of coating thickness and performance analysis using lab and field tests.

A Study on the Community Characteristics and Changes of Benthic Macroinvertebrates in the Conservation Area of the Shinbulsan Wetland (신불산 고산습지 보호지역 저서성 대형무척추동물의 군집특성 및 변화상 연구)

  • Hong, Sung-Jin;Cheong, Seon-Woo
    • Journal of Environmental Science International
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    • v.29 no.11
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    • pp.1079-1088
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    • 2020
  • The Shinbulsan wetland, located in Yangsan-si, Gyeongsangnam-do, South Korea, was designated as a conservation area in 2004. The area was monitored from 2015 to 2019 to investigate the community characteristics and changes of benthic macroinvertebrates. Between 2015 and 2016, several insects of the orders Ephemeroptera, Odonata, and Hemiptera were identified, but their numbers decreased significantly in 2017 and 2018 following the loss and recovery of the moor owing to drought. During this period, there were relatively more insects of the order Diptera. Within this order, three functional feeding groups, gathering-collectors, plant-piercers, and predators were investigated. Predator species were the most abundant (83.3%), whereas gathering-collectors accounted for the largest proportion of individual insects (50.5%). Between 2015 and 2016, when the moors were stable, groups I and III had the highest community stability. After 2017, when the moors had dried up, group III effectively disappeared because of its lower relative resistance and resilience, and only taxa belonging to group I remained. The results of this study indicate that benthic macroinvertebrates that adapt early during moor formation inhabit the Shinbulsan wetland.