• 제목/요약/키워드: resistance

검색결과 31,550건 처리시간 0.048초

포장노면 미끄럼 저항특성 (Skid Resistance Characteristics of Pavement Surface)

  • 김용석;홍재청;유형목
    • 한국도로학회논문집
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    • 제14권4호
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    • pp.1-8
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    • 2012
  • PURPOSES : Skid resistance on pavements plays an important role in reducing the risk of vehicle skidding on wet surface particularly. Almost 9.3 percent of traffic accidents were occurred under rainy condition and these are over-represented in terms of the severity of the crashes. Recently, unusual weather conditions referred widely as the intensified rainfalls justify the need of a systematic management of skid resistance. In this context, the study carried out the observational study on the skid resistance characteristics of different types of pavement with the time passage. METHODS : This study measured the skid resistance with Pavement Friction Tester at three times within five years. The skid resistance measurement has followed the method suggested by ASTM. RESULTS : As the main results under the scope of this study, skid resistance of asphalt concrete has not nearly reduced with time. On the contrary, skid resistance of cement concrete has been rapidly reduced with time though the highest resistance was gained at the early observation. Porous asphalt concrete shows a steady decrease of skid resistance with time, anyway, the reduction rate according to the increase of measurement speeds is relatively lower than the others. CONCLUSIONS : Based on our study, skid resistance of the pavement should be regarded as one of the pavement management system, so periodic measurement should be made to assure road safety as a whole.

Functional Metagenome Mining of Soil for a Novel Gentamicin Resistance Gene

  • Im, Hyunjoo;Kim, Kyung Mo;Lee, Sang-Heon;Ryu, Choong-Min
    • Journal of Microbiology and Biotechnology
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    • 제26권3호
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    • pp.521-529
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    • 2016
  • Extensive use of antibiotics over recent decades has led to bacterial resistance against antibiotics, including gentamicin, one of the most effective aminoglycosides. The emergence of resistance is problematic for hospitals, since gentamicin is an important broad-spectrum antibiotic for the control of bacterial pathogens in the clinic. Previous study to identify gentamicin resistance genes from environmental samples have been conducted using culture-dependent screening methods. To overcome these limitations, we employed a metagenome-based culture-independent protocol to identify gentamicin resistance genes. Through functional screening of metagenome libraries derived from soil samples, a fosmid clone was selected as it conferred strong gentamicin resistance. To identify a specific functioning gene conferring gentamicin resistance from a selected fosmid clone (35-40 kb), a shot-gun library was constructed and four shot-gun clones (2-3 kb) were selected. Further characterization of these clones revealed that they contained sequences similar to that of the RNA ligase, T4 rnlA that is known as a toxin gene. The overexpression of the rnlA-like gene in Escherichia coli increased gentamicin resistance, indicating that this toxin gene modulates this trait. The results of our metagenome library analysis suggest that the rnlA-like gene may represent a new class of gentamicin resistance genes in pathogenic bacteria. In addition, we demonstrate that the soil metagenome can provide an important resource for the identification of antibiotic resistance genes, which are valuable molecular targets in efforts to overcome antibiotic resistance.

도전성 팽창 접지저감재의 접지저항 저감 효과 (The Ground Resistance Reduction Effect of o Conductive Expansion Ground Resistance Reducing Material)

  • 김종욱;김경철;최종기;강민규;백남웅
    • 조명전기설비학회논문지
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    • 제22권2호
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    • pp.155-161
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    • 2008
  • 접지시스템은 고장전류나 상시 전류를 낮은 저항의 대지로 흘러 보낸다. 접지전극 주변에 접지저감재를 매설하면 접촉 면적을 증가시켜 낮은 접지저항을 얻을 수 있다. 접지전극의 접촉면적을 확대시키면 접지저항값이 낮아진다는 특성을 이용하여 접지 시공시 팽창 특성을 가진 도전성 팽창 접지저감재를 개발하였다. 본 논문에서는 실험을 통하여 도전성 팽창 접지저감재가 일반 접지저감재보다 접지저항 저감 효과가 뛰어남을 검증하였다.

Effects of Resistance and Resistance & Stabilization Exercises on the Strength of Lumbar and Lower Limbs of the Elderly

  • Choi, Seok Joo;Kim, Jong Woo;Hwang, Byeong Jun
    • 국제물리치료학회지
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    • 제4권2호
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    • pp.611-617
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    • 2013
  • The purpose of this study is to identify the effective lumbar area exercise program to prevent falls of the elderly by dividing 14 female elders over 65 living in Daegu into two groups such as resistance exercise group and resistance & stabilization exercise group, and applying a 60 minute exercise program three times a week for 12 weeks. The followings are the results. First, both of resistance exercise and resistance & stabilization exercise brought improvement of lumbar strength and there was no significant difference between two groups. Second, there was no significant difference in lower limb strength in resistance exercise group but resistance & stabilization exercise group showed significant increase in lower limb flexor strength. To make a summary of the above results, it can be said that 12 weeks' resistance & stabilization exercise is effective to the lumbar strength and lower limb strength of the elderly. Accordingly, if combining resistance exercise and stabilization exercise appropriately, we can build a successful preventive program which even the elderly who cannot perform resistance exercise easily can follow.

말뚝기초의 연적 방향 극한하중

  • 김명모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 기초기술위원회 워크샵
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    • pp.209-236
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    • 2002
  • Ultimate pile capacity - Point resistance - Frictional resistance - Determination of point and frictional resistances from field tests - Summary of recommendations from design Group effects Settlement analysis.

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마케팅관리자들이 어떻게 혁신에 대한 소비자저항을 극복할 수 있는가? - 혁신에 대한 소비자의 개인적 사회적 저항의 근원 탐색 - (How Can Marketers Overcome Consumer Resistance to Innovations? - The Investigation of Psychological and Social Origins of Consumer Resistance to Innovations -)

  • Bagozzi, Richard P.;Lee, Kyu-Hyun
    • 마케팅과학연구
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    • 제15권3호
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    • pp.211-231
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    • 2005
  • 마케팅관리자들이 글로벌 시장에 혁신을 성공적으로 진출시키기 위해서는 개인적 저항과 집단 저항에 대하여 이해하는 것이 중요하다. 우리가 제한하기로는 소비자들은 개인으로서, 집단의 한 구성원으로서 혁신에 저항하며, 의사결정의 다른 단계에 다른 방법으로 저항한다. 개인적인 저항은 초기저항(initial resistance)의 형태에서 시작하여 급박한 저항(emergent resistance)으로 발전하고 최종적으로는 늦은 저항(belated resistance)으로 발전한다. 또한, 개인의 도덕적 기준이 혁신수용 의사결정에 영향을 미칠 수 있다. 때때로 개인적 저항은 집단저항에 의해서 수반되거나 집단저항으로 진화한다. 우리는 혁신에 대한 소비자저항을 개인에 대하여, 개인이 속한 집단에 대하여, 다른 개인과 집단에 대하여 작용하는 사회정체감의 결과로서 생각하는 체계를 제시한다. 어떤 집단 구성원인 소비자들은 사회비교과정을 통하여 자아존중감을 증가시킨다. 소비자들이 어떤 집단에 대하여 강한 정체감을 가지고 결속하면 할수록, 내부집단 결속력과 외부집단 배타성이 더 많이 나타난다. 외부 집단 배타성은 집단 구성원들에게 외부 집단과 관련된 제품과 서비스에 대하여 강한 저항을 나타낸다. 개인적인 저항과 집단 저항은 마케팅관리자들을 위협하고 성과를 침해한다. 혁신에 대한 저항의 존재를 고려하고, 극복하려는 전략을 추구함으로써 마케팅관리자들은 이러한 위협을 새로운 기회로 전환시킬 수 있다. 소비자저항에 대한 이해는 혁신의 소비자수용에 대한 연구를 보완하고, 소비자행동의 보편적인 모형을 개발하는 데 도움이 될 수 있다.

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병렬로 접속된 저항체에서 저항온도계수의 거동 (Behavior of the Temperature Coefficient of Resistance at Parallelly Connected Resistors)

  • 이선우
    • 한국전기전자재료학회논문지
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    • 제31권2호
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    • pp.98-101
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    • 2018
  • In this paper, we discuss the fabrication of metal alloy resistors. We connected them in parallel to estimate their resistance and temperature coefficient of resistance (TCR). The fabricated resistors have different resistances, 5 and $10{\Omega}$ and different TCRs, 50 and $200ppm/^{\circ}C$. Each resistor was confirmed to have the correct atomic composition through the use of energy dispersive X-ray (EDX). The resistors' electrical properties were confirmed by measuring resistance and TCR. The resistance and TCR of the resistors connected in parallel were estimated through the increase in resistance due to the increase in temperature, and were compared with the measured values. We are confident that this TCR estimation technique, which uses the increase in resistance due to temperature, will be very useful in designing and fabricating resistors with low and stable TCR.

Study on Inheritance of Potato virus X Resistance in Capsicum annuum

  • Shi, Jinxia;Choi, Do-Il;Kim, Byung-Dong;Kang, Byoung-Cheorl
    • The Plant Pathology Journal
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    • 제24권4호
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    • pp.433-438
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    • 2008
  • Potato virus X (PVX) resistance in potato is one of the best-characterized resistance models, however little is known in pepper. To evaluate the resistance to PVX in Capsicum annuum, a total of eleven pepper accessions were used for resistance screening against two PVX strains, USA and UK3. None of them were resistant against strain UK3, whereas four resistant genotypes were found against strain USA, three of which were further characterized. Two unlinked dominant genes were identified for both genotypes Bukang and Perennial; resistance in the genotype CV3 seemed to be conferred by two complementary dominant genes. These results demonstrated that the resistance to PVX in C. annuum is different from that in potato. This is the first report on genetic analysis of PVX resistance in C. annuum.

Estimation of load and resistance factors based on the fourth moment method

  • Lu, Zhao-Hui;Zhao, Yan-Gang;Ang, Alfredo H.S.
    • Structural Engineering and Mechanics
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    • 제36권1호
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    • pp.19-36
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    • 2010
  • The load and resistance factors are generally obtained using the First Order Reliability Method (FORM), in which the design point should be determined and derivative-based iterations have to be used. In this paper, a simple method for estimating the load and resistance factors using the first four moments of the basic random variables is proposed and a simple formula for the target mean resistance is also proposed to avoid iteration computation. Unlike the currently used method, the load and resistance factors can be determined using the proposed method even when the probability density functions (PDFs) of the basic random variables are not available. Moreover, the proposed method does not need either the iterative computation of derivatives or any design points. Thus, the present method provides a more convenient and effective way to estimate the load and resistance factors in practical engineering. Numerical examples are presented to demonstrate the advantages of the proposed fourth moment method for determining the load and resistance factors.

가스보일러용 STS 304의 부식특성에 미치는 용수의 비저항의 영향 (Effect of the Specific Resistance of Water on Corrosion Characteristics of STS 304 for Gas Boiler)

  • 임우조;김환식;윤병두
    • 수산해양교육연구
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    • 제19권3호
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    • pp.323-328
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    • 2007
  • This paper was studied on the effect of the specific resistance of water on corrosion characteristics of STS 304 for gas boiler. The electrochemical polarization test of STS 304 for gas boiler was carried out. And the polarization resistance, uniform corrosion, corrosion behavior by impressed potential and corrosion sensitivity of STS 304 with specific resistance were considered. The main results are as following: 1) With being low the specific resistance of water, the polarization resistance and corrosion potential of STS 304 decreases, while corrosion current density increases. 2) Under constant impressed potential, the corrosion sensitivity of STS 304 is large with being low the specific resistance due to synergy effect of Cl ion.