• 제목/요약/키워드: Well resistance

검색결과 3,096건 처리시간 0.033초

New Aspects of Gene-for-Gene Interactions for Disease Resistance in Plant

  • Nam, Jaesung
    • The Plant Pathology Journal
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    • 제17권2호
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    • pp.83-87
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    • 2001
  • Disease resistance in plants is often controlled by gene-for-gene mechanism in which avirulence (avr) gene products encoding by pathogens are specifically recognized, either directly or indirectly by plant disease resistance (R) gene products. Recent studies arising from molecular cloning of a number of R genes from various plant species that confer resistance to different pathogens and corresponding avr genes from various pathogens resulted in the accumulation of a wealth of knowledge on mode of action of gene-for-gene interaction. Specially, members of the NBS-LRR class of R genes encoding proteins containing a nucleotide binding site (NBS) and carboxyl-terminal leucine-rich repeats (LRRs) confer resistance to very different types of phytopathogens, such as bacteria, fungi, oomycetes, viruses, nematodes and aphids. This article reviewed the molecular events that occur up-stream of defense response pathway, specially, bacterial avr gene protein recognition mediated by NBS-LRR type R gene product in plant based on current research results of well studied model plants.

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매입말뚝의 인발저항특성에 관한 연구 (Analytical Study on the Pullout Resistance Characteristics of Bored Pile)

  • 박종배;천영수
    • 토지주택연구
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    • 제7권4호
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    • pp.281-289
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    • 2016
  • 압축 부재인 PHC 말뚝(직경 600mm)도 강선의 부착력을 높이면 83.6~91.6tonf의 극한 인장력에 대해 구조적으로 저항할 수 있는 것으로 실험결과 나타났다. 이러한 시험결과에 안전율을 고려하여 적절한 허용값을 제시하면 부상방지 앵커를 대체하거나 절감시킬 수 있는 것으로 기대되었다. 이를 위해서는 구조적 인장성능과 함께 실제 지반에 시공된 매입말뚝의 인발저항 거동이 규명되어야 한다. 본 연구에서는 현장에 시공된 실제 매입말뚝의 인발거동 특성을 파악하기 위하여 정적 인발재하시험을 실시하여 주면마찰력 산정식과 비교하였다. 또한, 간편하게 인발저항력을 평가하기 위하여 PDA를 이용한 동재하시험을 실시하여 정적 인발재하시험 결과와 비교하였다. 그 결과, 매입말뚝의 시멘트풀이 충분히 경화한 후인 15일 후에는 LH 주면마찰력 산정식의 마찰력과 정적인발재하시험결과가 잘 일치하였고 동재하시험에서 구한 마찰력과도 비교적 잘 일치하는 것으로 나타났다.

Effects of d-${\alpha}$-tocopherol supplements on lipid metabolism in a high-fat diet-fed animal model

  • Kim, Do Yeon;Kim, Jinkyung;Ham, Hye Jin;Choue, Ryowon
    • Nutrition Research and Practice
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    • 제7권6호
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    • pp.481-487
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    • 2013
  • High-fat diet up-regulates either insulin resistance or triglycerides, which is assumed to be related to the expression of peroxisome proliferator-activated receptor (PPAR)-${\alpha}$ and PPAR-${\gamma}$. The beneficial effects of vitamin E on insulin resistance are well known; however, it is not clear if vitamin E with a high-fat diet alters the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$. We investigated the effects of d-${\alpha}$-tocopherol supplementation on insulin sensitivity, blood lipid profiles, lipid peroxidation, and the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat (HF) diet-fed male C57BL/6J model of insulin resistance. The animals were given a regular diet (CON; 10% fat), a HF diet containing 45% fat, or a HF diet plus d-${\alpha}$-tocopherol (HF-E) for a period of 20 weeks. The results showed that the HF diet induced insulin resistance and altered the lipid profile, specifically the triglyceride (TG) and total cholesterol (TC) levels (P < 0.05). In this animal model, supplementation with d-${\alpha}$-tocopherol improved insulin resistance as well as the serum levels of TG and very-low-density lipoprotein-cholesterol (VLDL-C) (P < 0.05). Moreover, the treatment decreased the levels of malondialdehyde (MDA) in the serum and liver while increasing hepatic PPAR-${\alpha}$ expression and decreasing PPAR-${\gamma}$ expression. In conclusion, the oral administration of d-${\alpha}$-tocopherol with a high-fat diet had positive effects on insulin resistance, lipid profiles, and oxidative stress through the expression of PPAR-${\alpha}$ and PPAR-${\gamma}$ in a high-fat diet-fed male mice.

고속카메라를 이용한 저항 점 용접의 너겟 형성 메커니즘 관찰 (Observation of Nugget Formation Mechanism by using High Speed Camera)

  • 조용준;이세헌
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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    • pp.43-45
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    • 2000
  • Resistance Spot Welding has been one of the important process in the sheet metal fabrication of auto-body industry It is well known that the nugget formation of RSW is the major factor for the strength of the body. A high speed camera was used to consider initial melting and growth of the weld nugget in order to find out the nugget formation mechanism. It was observed that such mechanism had an effect on the dynamic resistance, which was a process parameter of resistance spot welding. Also, the relationship between the mechanism and process parameter was considered for the industrial application.

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자동차용 강판(TRIP강)에 대한 저항 점 용접 품질 평가 알고리즘 개발 (Intelligent quality estimation of automobile steel sheet during Resistance spot welding)

  • 김태형;이세헌
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2001년도 추계학술발표대회 개요집
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    • pp.184-186
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    • 2001
  • Quality estimation of the weld has been one of the important issues in RSW which is a main process of the sheet metal fabrication in auto-body industry. It was well known that among the various welding process variables, dynamic resistance has a close relation with nugget formation. In this study, a new quality estimation algorithm is developed with the primary dynamic resistance measured at welding machine timer. For this, Back propagation algorithm of neural network is used.

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스탠딩컬럼웰형(SCW) 지중열교환기의 열성능 측정에 관한 실험적 연구 (An Experimental Study on the Thermal Performance Measurement of Standing Column Well type Borehole Heat Exchanger)

  • 이상훈;최용석;안근묵
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.122.2-122.2
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    • 2010
  • Knowledge of ground thermal properties is most important for the proper design of BHE(borehole heat exchanger) systems. The configure type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for in-situ determination of design data for Standing Column Well apply. The main purpose has been to determine in-situ values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a sub-circulation pump, a boiler, temperature sensors, flow meter and a data logger for recording the temperature and circulation fluid flow data. A constant heating power is injected into the SCW through the test rig and the resulting temperature change in the SCW is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective in-situ values of rock thermal conductivity and thermal resistance of SCW.

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GaAs/AlGaAs 이종접합된 양자흘 소자의 전기적 특성 (The Electrical Characterization of the Quantized Hall Device with GaAs/AlGaAs heterojunction structure)

  • 유광민;류제천;한권수;서경철;임국형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.334-337
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    • 2002
  • The Quantum Hall Resistance(QHR) device which consists of GaAs/AlGaAs heterojunction structure is used for the realization of QHR Standard based on QHE. In order to characterize electrical contact resistances and dissipations of the device, it is slowly cooled down for eliminating thermal shock and unwanted noise. Then, the two properties are measured under 1.5 K and 5.15 T. Contact resistances are all within 1.2 Ω and longitudinal resistivities are all within 1 mΩ up to DC 90${\mu}$A. The results mean the device is operated well to realize the QHR Standard. To confirm it, the QHR Standard having the device is compared using a direct current comparator bridge with a 1 Ω resistance standard which the calibrated value is known from QHR standards maintained by other countries. The difference between them is agreed well within measurement uncertainty. It is thus considered that the properties of the device is estimated well and has good performance.

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A Study on the Propulsion Performance of KCS in Still Water and Regular Wave

  • Lee, Sang-Min;Jeong, Uh-Cheul;Kim, Dae-Hae
    • 한국항해항만학회지
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    • 제37권1호
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    • pp.63-69
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    • 2013
  • Since most merchant vessels are mainly influenced by the added resistance in an actual sea, they could be navigated more efficiently if this added resistance could be precisely predicted and then effectively reduced. In this paper, we have computed the effective horsepower based on the resistance performance in still water and then calculated the added resistance in regular wave in order to estimate a ship's propulsion performance on a voyage. Firstly, we have performed experiments using a model of KCS in a circulating water channel to estimate the flow characteristics around a container ship and the ship's resistance in still water. Then we have calculated the motion response function in regular wave as well as the values for the increase in resistance, and evaluated the ship's motion performance in waves according to the calculated response function. It was found that the resistance in waves increased because the ship's motion response value became larger as the ship's speed increased in the case of head sea. The effect of the added resistance could be reduced by maneuvering the ship to the encounter angle of $120^{\circ}$ in areas of long wavelengths and to head sea in areas of short wavelengths.

스마트폰 채택 및 지속사용에 있어 사용자 저항과 사회적 영향력의 역할에 대한 탐색연구 (Exploring the Roles of User Resistance and Social Influences on Smartphone Acceptance and Continuous Usage)

  • 최새솔;유재흥
    • Journal of Information Technology Applications and Management
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    • 제19권4호
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    • pp.41-59
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    • 2012
  • This study examines the roles of user resistance and social influences on the acceptance and continuous usage of smartphones at different stages of adoption. The respondents were classified into three groups according to their innovation adoption stage : non-user group, the potential user group and the trial user group. Theories relevant to user resistance, social influences including normative social influences and informational social influences, as well as user adoption and continuance behavior were reviewed and integrated into our research model. In order to verify the proposed structured equation model, we conducted an online survey by targeting mobile phone users and collected data to be analyzed through a partial least squares (PLS) test. This study tested whether there exists differences in the effects of user resistance and different types of social influence on user's adoption or continuance intetion among these three groups. The results showed that user resistance exists in all adopter groups and that it has significant negative influences on intention to use a smartphone. The findings also revealed that user resistance can be enhanced or resolved by two types of social influence; informational social influence resolves user resistance regardless of the adopter category, while normative social influence enhances the user resistance of potential users. Furthermore, the findings show that social influence regardless of the type positively affects user intention. Several theoretic and practical implications pertaining to the results are discussed.

조직 내 빅데이터 시스템 확산에 영향을 주는 요인에 대한 연구 (Factors for the Intra-organizational Diffusion of Big Data Systems)

  • 박성관;김청
    • 한국IT서비스학회지
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    • 제18권2호
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    • pp.97-121
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    • 2019
  • In this paper, factors affecting intra-organizational diffusion of Big Data systems from the perspective of the Big Data system vendors have been analyzed. In particular, the theory of resistance against innovation that exists in some form before the adoption or rejection of innovation has been focused on. In order to do that, the resistance has been divided into three categories : postponement, rejection and opposition. The variables affecting each type are also divided into four independent variables : perceived risk, innovation characteristics, user attributes, and organizational attributes. As a result of the survey, it was confirmed that the influences of each variable are different according to the type of resistance. As the strength of the resistance was increased, the influence of the trialability was increased as well. As the strength of the resistance was decreased, the satisfaction with the existing system became more influential on the resistance. The time risk and the satisfaction with the existing system were found to affect all types of resistance. From the vendor's point of view, strategic implications are presented in terms of marketing or system development for diffusion, depending on the degree of resistance of the adopter.