• 제목/요약/키워드: Threshold model

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무접합 원통형 게이트 MOSFET에서 문턱전압이동 분석을 위한 문턱전압이하 전류 모델 (Subthreshold Current Model for Threshold Voltage Shift Analysis in Junctionless Cylindrical Surrounding Gate(CSG) MOSFET)

  • 정학기
    • 한국정보통신학회논문지
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    • 제21권4호
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    • pp.789-794
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    • 2017
  • 본 논문에서는 무접합 원통형 MOSFET의 해석학적 전위분포를 이용하여 문턱전압이하 전류모델을 제시하고 이를 이용하여 문턱전압이동을 해석하였다. 무접합 원통형 MOSFET는 채널을 게이트 단자가 감싸고 있기 때문에 캐리어 흐름을 제어하는 게이트 단자의 능력이 매우 우수하다. 본 연구에서는 쌍곡선 전위분포모델을 이용하여 포아송방정식을 풀고 이 때 얻어진 중심 전위분포를 이용하여 문턱전압이하 전류 모델을 제시하였다. 제시된 전류모델을 이용하여 $0.1{\mu}A$의 전류가 흐를 때 게이트 전압을 문턱전압으로 정의하고 2차원 시뮬레이션 값과 비교하였다. 비교결과 잘 일치하였으므로 이 전류모델을 이용하여 채널크기 및 도핑농도에 따라 문턱전압이동을 고찰하였다. 결과적으로 채널 반지름이 증가할수록 문턱전압이동은 매우 크게 나타났으며 산화막 두께가 증가할 경우도 문턱전압이동은 증가하였다. 채널 도핑농도에 따라 문턱전압을 관찰한 결과, 소스/드레인과 채널 간 도핑농도의 차이가 클수록 문턱전압은 크게 증가하는 것을 관찰하였다.

Threshold burnup for recrystallization and model for rim porosity in the high burnup $UO_2$ fuel

  • Lee, Byung-Ho;Koo, Yang-Hyun;Sohn, Dong-Seong
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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    • pp.279-284
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    • 1998
  • Applicability of the threshold burnup for rim formation was investigated as a function of temperature by Rest's model. The threshold burnup was the lowest in the intermediate temperature region, while on the other temperature regions the threshold burnup is higher. The rim porosity was predicted by the van der Waals equation based of the rim pore radius of 0.75${\mu}{\textrm}{m}$ and the overpressurization model on rim pores. The calculated centerline temperature is in good agreement with the measured temperature. However, more efforts seem to be necessary for the mechanistic model of the rim effect including rim growth with the fuel burnup.

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통합 서보 액츄에이터의 고장 감지시스템 연구 (A Study on the Fault Detection of an Integrated Servo Actuator)

  • 신기현;임광호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.306-312
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    • 1996
  • The performance of the failure detection algorithm may be greatly influenced by the model uncertainty. It is very important to design a robust failure detection system to the model uncertainty. In this paper, a design procedure to generate failure detection algorithm is proposed. The design procedure suggested is based on the concept of the‘threshold selector[1]’. The H$\infty$ control algorithm is used to derive a threshold selector which is robust to the model uncertainty, The threshold selector derived can be used to develop a failure detection system together with the weighted cumulative sum algorithm[3]. Computer simulation study showed that the failure detection system designed for an ISA(Integrated Servo Actuator) system by using the proposed method is robust to the model uncertainty.

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Identity-based Threshold Broadcast Encryption in the Standard Model

  • Zhang, Leyou;Hu, Yupu;Wu, Qing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제4권3호
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    • pp.400-410
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    • 2010
  • In an identity-based threshold broadcast encryption (IDTHBE) scheme, a broadcaster chooses a set of n recipients and a threshold value t, and the plaintext can be recovered only if at least t receivers cooperate. IDTHBE scheme is different from the standard threshold public key encryption schemes, where the set of receivers and the threshold value are decided from the beginning. This kind of scheme has wide applications in ad hoc networks. Previously proposed IDTHBE schemes have ciphertexts which contain at least n elements. In addition, the security of theses schemes relies on the random oracles. In this paper, we introduce two new constructions of IDTHBE for ad hoc networks. Our first scheme achieves S-size private keys while the modified scheme achieves constant size private keys. Both schemes achieve approximately (n-t)-size ciphertexts. Furthermore, we also show that they are provablesecurity under the decision bilinear Diffie-Hellman Exponent (BDHE) assumption in the standard model.

미세 구조 MOSFET에서 문턱전압 변화를 최소화하기 위한 최적의 스켈링 이론 (Scaling theory to minimize the roll-off of threshold voltage for ultra fine MOSFET)

  • 정학기;김재홍;고석웅
    • 한국정보통신학회논문지
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    • 제7권4호
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    • pp.719-724
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    • 2003
  • 본 논문은 halo doping profile을 갖는 나노구조 LDD MOSFET의 문턱전압에 대하여 연구하였다. 소자의 크기는 일반화된 스켈링 이론을 사용하여 100nm 에서 40m까지 스켈링하였다. Van Dort Quantum Correction Model(QM) 모델을 정전계 스켈링 이론과 정전압 스켈링 이론에 적용하여 문턱전압을 조사하였으며, gate oxide 두께의 변화 따른 direct tunneling current를 조사하였다. 결과적으로 게이트 길이가 감소됨에 따라 문턱전압이 정전계 스켈링에서는 감소하고 정전압 스켈링에서는 증가함을 알았고 direct tunneling current는 gate oxide 두께가 감소함에 따라 증가됨을 알았다. 또한 채널 길이의 감소에 따른 MOSFET의 문턱전압에 대한 roll-off특성을 최소화하기 위하여 일반화된 스켈링에서 $\alpha$값은 거의 1 이여야 함을 알았다.

집적 (불)경제와 공간경제로서의 지역 경제 성장 (Agglomeration (Dis-) Economies and Regional Economic Growth as a Spatial Economy)

  • 김홍배;박재룡
    • 지역연구
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    • 제13권2호
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    • pp.45-54
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    • 1997
  • A regional economy is characterized as a spatial economy. However the literature shows that it has been treated as a point economy since space is little recognized in regional modeling due to mathematical complication. This leads to the fact that regional model does not sufficiently represent regional characteristic. This paper attempts to construct a regional growth model in a partial equilibrium framework specifically taking into consideration land as a primary factor. The model is formulated largely neoclassical. Labor is assumed to move in response to differences in the wage rate, while capital is perfectly mobile across regions. The paper shows that two growth equilibrium points exist, one stable equilibrium point and the other unstable equilibrium point. The unstable growth equilibrium indicates the existence of minimum threshold that a region must overcome the minimum threshold to grow constantly. Consequently, directions of regional growth are characterized by two growth paths depending on the initial condition of a region. That is to say, a region below the minimum threshold is converging toward the lower stable equilibrium point over time. When a regional economy initially lies above the minimum threshold, it will grow forever. A regional economy is not thus necessarily converging a stationary is not thus necessarily converging a stationary equilibrium point through factor movement. Finally, the impacts of the presence of agglomeration economies and diseconomies are analyzed through the phase diagram. The paper also shows that agglomeration economies result in lowering the minimum threshold and in escalating the level of stable equilibrium However, when agglomeration diseconomies prevail, the results are opposite, i.e., rising the minimum threshold of growth and lowering the growth level of stable equilibrium.

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나노 구조 MOSFET의 문턱전압 변화를 최소화하기 위한 스케일링 이론 (Scaling theory to minimize the roll-off of threshold voltage for nano scale MOSFET)

  • 김영동;김재홍;정학기
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2002년도 추계종합학술대회
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    • pp.494-497
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    • 2002
  • 본 논문에서는 halo doping profile을 갖는 나노구조 LDD MOSFET의 문턱전압에 대한 시뮬레이션 결과를 나타내었다. 소자 크기는 generalized scaling을 사용하여 100nm에서 40nm까지 스케일링하였다. Van Dort Quantum Correction Model(QM)을 사용하여 정전계 스케일링과 정전압 스케일링에 대한 문턱 전압과 각각의 게이트 oxide 두께에 대한 direct tunneling 전류를 조사하였다. 게이트 길이가 감소할 때 정전계 스케일링에서는 문턱전압이 감소하고, 정전압 스케일링에서는 문턱전압이 증가하는 것을 알 수 있었고, 게이트 oxide두께가 감소할 때 direct tunneling 전류는 증가함을 알 수 있었다. 감소하는 채널 길이를 갖는 MOSFET 문턱전압에 대한 roll-off 특성을 최소화하기 위해 generalized scaling에서 $\alpha$값은 1에 가깝게 되는 것을 볼 수 있었다.

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순서범주형자료 분석을 위한 베이지안 분계점 모형 (A Bayesian Threshold Model for Ordered Categorical Traits)

  • 최병수;이승천
    • 응용통계연구
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    • 제18권1호
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    • pp.173-182
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    • 2005
  • 순서를 갖는 범주형자료의 분석을 위한 중요한 통계적 방법인 순위로짓모형의 대안으로 무정보 사전분포에 의한 베이지안 분계점 모형을 정의하고, 실증 자료분석을 통해 베이지안 모형의 유용성을 살펴보았다.

접합 및 무접합 이중게이트 MOSFET에 대한 문턱전압 이동 및 드레인 유도 장벽 감소 분석 (Analysis of Threshold Voltage Roll-Off and Drain Induced Barrier Lowering in Junction-Based and Junctionless Double Gate MOSFET)

  • 정학기
    • 한국전기전자재료학회논문지
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    • 제32권2호
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    • pp.104-109
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    • 2019
  • An analytical threshold voltage model is proposed to analyze the threshold voltage roll-off and drain-induced barrier lowering (DIBL) for a junction-based double-gate (JBDG) MOSFET and a junction-less double-gate (JLDG) MOSFET. We used the series-type potential distribution function derived from the Poisson equation, and observed that it is sufficient to use n=1 due to the drastic decrease in eigenvalues when increasing the n of the series-type potential function. The threshold voltage derived from this threshold voltage model was in good agreement with the result of TCAD simulation. The threshold voltage roll-off of the JBDG MOSFET was about 57% better than that of the JLDG MOSFET for a channel length of 25 nm, channel thickness of 10 nm, and oxide thickness of 2 nm. The DIBL of the JBDG MOSFET was about 12% better than that of the JLDG MOSFET, at a gate metal work-function of 5 eV. It was also found that decreasing the work-function of the gate metal significantly reduces the DIBL.

Infrastructure-Growth Link and the Threshold Effects of Sub-Indices of Institutions

  • OGBARO, Eyitayo Oyewunmi;OLADEJI, Sunday Idowu
    • Asian Journal of Business Environment
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    • 제11권1호
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    • pp.17-25
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    • 2021
  • Purpose: This study extends previous empirical work on the threshold effects of institutions on the relationship between infrastructure and economic growth. It does so by using three sub-indices of institutions as the threshold variable in place of aggregate index. This is with a view to determining the roles of the sub-indices in the nexus between infrastructure and economic growth. Research design, data and methodology: The analysis is based on a dynamic panel threshold regression model using a panel data set comprising 41 countries in Sub-Saharan Africa over the sample period of 1996-2015. Data are obtained from Ogbaro (2019). Results: The study finds that infrastructure exerts significant positive effects on economic growth below and above the threshold values of the three sub-indices, with higher effects above the threshold values. Results also show that on average, the Sub-Saharan African countries are not able to satisfy any of the threshold conditions, which accounts for their poor growth experience. Conclusion: The study concludes that countries with weak institutions do not benefit maximally from infrastructure development policies. The paper, therefore, recommends that countries in Sub-Saharan Africa need to focus on improving their institutional patterns if they are to reap the optimum benefits from their infrastructure development efforts.