• Title/Summary/Keyword: Negative-resistance

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A Study on the Forward I-V Characteristics of the Separated Shorted-Anode Lateral Insulated Gate Bipolar Transistor (분리된 단락 애노드를 이용한 수평형 SA-LIGBT 의 순방향 전류-전압 특성 연구)

  • Byeon, Dae-Seok;Chun, Jeong-Hun;Lee, Byeong-Hun;Kim, Du-Yeong;Han, Min-Ku;Choi, Yeon-Ik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.3
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    • pp.161-166
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    • 1999
  • We investigate the device characteristics of the separated shorted-anode LIGBT (SSA-LIGBT), which suppresses effectively the negative differential resistance regime, by 2-dimensional numerical simulation. The SSA-LIGBT increases the pinch resistance by employing the highly resistive n-drift region as an electron conduction path instead of the lowly resistive n buffer region of the conventional SA-LIGBT. The negative differential resistance regime of the SSA-LIGBT is significantly suppressed as compared with that of the conventional SA-LIGBT. The SSA-LIGBT shows the lower forward voltage drop than that of the conventional SA-LIGBT.

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A Study on Composition of Current Stable Negative Resistance Circuitwith LED and CdS. (광전소자를 이용한 전류안정부저항 특성회로의 구성)

  • Park, Ui-Yeol;Do, Si-Hong;Mun, Jae-Deok
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.12 no.5
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    • pp.1-5
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    • 1975
  • 접합형 트린지스터와 발광다이오드(LED) 및 광도전소자(CdS)로서 구성된 광결합 전류안정부저항회로를 진안하였다. 이는 일반적으로 광트랜지스터보다도 더 예민한 것을 이용하여, CdS와 LED를 밀착 시켜서 LED에 흐르는 전류와 CdS의 실효저항변화로써 결합된 광결합방식을 택하였다. 트랜지스터의 콜랙터-에미터간에 인위적인 누변저항을 삽입하는 방법을 도입함으로써 부저항치 및 최대입력단자전압치를 임의로 변화할 수 있게 하였으며, 제안한 회로를 분석하고 또 이를 실험적으로 확인하였다. 누변저항을 1KΩ에서 30KΩ까지 변화시켰을 때 최대입력단자전압은 1.65V에서 4.22V로 변하였고, 부저항치는 -1.0KΩ에서 -10.0KΩ까지 변하였다. 또 실험치에 대한 계산치에의 상대백분최대오차가 11%이었다. A current stable negative resistance circuit has been constucted with combination of coulplementary symmetrical transistors, a light emitting diode and a photoconductive cell. The negative resistance(Rn) and break-over voltage(VBo) can be set at a designed value according to adjustment of the artificial leakage resistance of p-n-p transistor. The RN and VBo calculated in this designed circuit are checked though the experiments, the errors are found less than 11%.

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Distribution of Coagulase-Negative Staphylococci and Antibiotic Resistance

  • Park, Heechul;Park, Sung-Bae;Kim, Junseong;Kim, Sunghyun
    • Biomedical Science Letters
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    • v.27 no.2
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    • pp.45-50
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    • 2021
  • Coagulase-negative staphylococci (CoNS) are a typical group of microorganisms, and the recent advances in laboratory technology and medicine has dramatically modified their significance in medical practice. CoNS, which were previously classified as normal bacterial flora, have recently been reported to be associated with serious infectious diseases, such as surgical wound infection or periprosthetic joint infection. Representative CoNS include Staphylococcus epidermidis, S. haemolyticus, and S. saprophyticus, which are known to cause serious problems in biomaterial-based and prosthetic device infections, as well as to cause simple urinary tract infections in sexually active women. Over the last decade, the clinical isolation rate of CoNS has been increasing, and antibiotic resistance has also been occurring. This review aimed to investigate the incidence of CoNS infection and to use the results as basic data for the management of CoNS, with a focus on the isolation rate and antibiotic resistance in clinical surgery.

Determination of Insulin Signaling Pathways in Hepatocytes

  • Kim, Sang-Kyum
    • Toxicological Research
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    • v.21 no.3
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    • pp.195-208
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    • 2005
  • Diabetes is a major cause of morbidity and mortality, and associated with a high risk of atherosclerosis, and liver, kidney, nerve and tissue damage. Defective insulin secretion in pancreas and/or insulin resistance in peripheral tissues is a central component of diabetes. It is well established that, regardless of the degree of muscle insulin resistance, glucose levels in diabetic and non-diabetic individuals are determined by the rate of hepatic glucose production. Moreover recently studies using liver-specific insulin receptor knockout mice show the paramount role of the liver in insulin resistance and diabetes. Insulin exerts a multifaceted and highly integrated series of actions via its intracellular signaling systems. The first major section of this review defines the major insulin-mediated signaling pathways including phosphatidylinositol 3-kinase and mitogen activated protein kinases. The second major section of the review presents a summary and evaluation of methods for determination of the role and function of signaling pathways, including methods for determination of kinase phosphorylation, the use of pharmacological inhibitors of kinase and dominant-negative kinase constructs, and the application of new RNA interference methods.

The Impact of the Antibiotic Burden on the Selection of its Resistance among Gram Negative Bacteria Isolated from Children (항생제 사용량 변화에 따른 그람음성균주의 항생제 내성률의 변화 양상)

  • Kim, Seohee;Yoo, Reenar;Lee, Jina
    • Pediatric Infection and Vaccine
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    • v.22 no.3
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    • pp.178-185
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    • 2015
  • Purpose: We investigated trends in antibiotic pressure and the antibiotic susceptibility of gram negative bacteria isolated from Korean children over 10 consecutive years. Methods: From January 2004 to December 2013, the antibiotic susceptibility of Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii blood isolates obtained from children <18 years of age was determined according to the 2009 Clinical and Laboratory Standards Institute guidelines. Antibiotic consumption data were also analyzed. Results: The prevalence of K. pneumoniae, E. coli, P. aeruginosa, and A. baumannii bacteremia was 4.6, 3.5, 3.4, and 2.2 cases/1,000 blood cultures/year, respectively. In K. pneumoniae, resistance to the third and fourth cephalosporin did not increase significantly. However, carbapenem-resistant K. pneumoniae first appeared in 2010, and the resistance rate increased to 9% between 2012 and 2013. Resistance to 3rd and 4th cephalosporin increased from 10% to 50% in E. coli, and resistance to carbapenem rose abruptly from 11% to 71% in A. baumannii (P for trend <0.01). However, such an increase of resistance was not observed in P. aeruginosa. There is a positive correlation between the resistance rate of cefepime in E. coli and the consumption of cefepime (r=0.900, P=0.037). Conclusion: The significant burden of antibiotic consumption and the high prevalence of antibiotic resistance to gram negative pathogen isolated from bacteremic children were observed. Empirical antibiotics should be wisely selected, and continued efforts to decrease the overall antibiotic pressure are mandatory, especially in highly resistant situations.

Microwave-Induced Negative-Differential Resistance Observed in Josephson Junction (마이크로파가 조셉슨 접합에서 유발하는 부의 미분저항)

  • Kim, Kyu-Tae;Koutovoi, Viatcheslav D.;Hong, Hyun-Kwon
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.237-237
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    • 1999
  • We have observed that a stable and reproducible Negative Differential Resistance(NDR) is induced by external microwave at low power in Nb/AlO$_x$/Al/Alo$_x$/Nb junctions. To study the erratic and pozzling NDR observations we have simulated Stewart-McCumber model in the region. Experimental results and simulation results will be presented with a discussion to draw a dynamic interpreration of the NDR.

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Abtibiotic Resistance in Gram Negative Enteric Bacteria Isolated from Feces of Domestic Animals (가축 분뇨 중의 항생제 내성 균주)

  • 문경호;이종철
    • YAKHAK HOEJI
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    • v.30 no.1
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    • pp.51-54
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    • 1986
  • Fecal samples from Kim-Hae farm animals were examined for the frequency of gram-negative enteric organisms resistant to tetracycline, streptomycin, or penicillin. The propertions of antibiotic resistant to total organisms in fecal specimens of poultry, swine and cow were as follows: 95%, 92%, 70% for tetracycline, 100%, 27%, 9% for streptomycin, 18%, 1%, 1% for penicillin, respectively. The bacteria had multiresistance to antibiotics. These strains had more than one plasmid. From the transformation study, it was concluded that the resistance to streptomycin was attributed to one of these plasmids.

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Study on the negative resistance of the FET with series reactive feedback (직렬궤환을 이용한 FET의 부성저항에 관한 연구)

  • Eom, Gyeong-Hwan;Na, Jeong-Ung
    • Proceedings of the KIEE Conference
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    • 1985.07a
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    • pp.341-343
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    • 1985
  • In designing the high frequency oscillator with FET, it may be necessary to make the FFT unstable using feedback. For convenient realization, sir feedback type is usually employed. It is convenient to determine the load which makes oscillation possible, with the contour plot of the negative resistance of the FET positively feedback for each type. Analytic formulas are given for this contour plot in this paper, and the results are discussed.

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The Study of User Resistance to Fintech Payment Service: In the Perspective of Innovation Diffusion And Status Quo Bias Theory (핀테크 지급결제 서비스 수용 저항요인 연구 : 혁신저항이론과 현상유지편향이론을 중심으로)

  • Hwang, Sin-Hae;Kim, Jeoung-Kun
    • The Journal of Information Systems
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    • v.27 no.1
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    • pp.133-151
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    • 2018
  • Purpose Global fintech industry is proliferating. Although domestic investment in fintech service is also increasing fast, user acceptance of fintech payment service seems slower than expected. Previous fintech literature mainly focuses on overall characteristics and technical aspects of fintech including security issues and explores factors affecting the service adoption. This study aims to examine crucial factors affecting user's resistance intention to fintech payment service adoption. The research model was formulated based on innovation diffusion theory and status quo bias theory and validated empirically. Design/methodology/approach The proposed research model was empirically validated with 149 responses from college students who have used fintech payment service. The component-based SEM was employed for data analysis. Findings The significant findings are as follow. First, compatibility has significant negative effect and complexity, and perceived risk has a positive effect on user resistance. Second, institutional trust does not show a significant effect on user resistance but has an indirect effect through the mediation of trust in service provider. Finally, trust in service provider shows the significant negative effect on user resistance.

A Study on the Relationship between Psychophysiological Experience and Negative Attitude in Smoking Serious Games (흡연 기능성 게임에서 심리생리학적 경험과 흡연의 부정적 태도와의 관계에 대한 연구)

  • Jang, Han-Jin;Noh, Ghee-Young
    • Journal of Korea Game Society
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    • v.17 no.6
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    • pp.189-198
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    • 2017
  • The purpose of this study is to investigate the relationship between smoking attitudes and psychophysiological variables and to find out whether smoking cessation activities can be helpful for smoking cessation. We set up Negative Attitudes experience as a dependent variable. Several factors including Psychological Resistance, Psychological Distress and brainwave(Left brain ${\theta}$, Right Brain ${\theta}$) as a physiological indicator, which was expected to affect flow, were set up as independent variables to perform regression analysis. As a result, psychological resistance had negative influences on negative attitudes toward smoking in smoking simulation game and psychological distress had positive effect. And left brain ${\theta}$ had negative influences on negative attitudes toward smoking in smoking simulation game and right brain ${\theta}$ had positive effect.