• Title/Summary/Keyword: intrinsic region

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A Semi-analytical Model for Depletion-mode N-type Nanowire Field-effect Transistor (NWFET) with Top-gate Structure

  • Yu, Yun-Seop
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.2
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    • pp.152-159
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    • 2010
  • We propose a semi-analytical current conduction model for depletion-mode n-type nanowire field-effect transistors (NWFETs) with top-gate structure. The NWFET model is based on an equivalent circuit consisting of two back-to-back Schottky diodes for the metal-semiconductor (MS) contacts and the intrinsic top-gate NWFET. The intrinsic top-gate NWFET model is derived from the current conduction mechanisms due to bulk charges through the center neutral region as well as of accumulation charges through the surface accumulation region, based on the electrostatic method, and thus it includes all current conduction mechanisms of the NWFET operating at various top-gate bias conditions. Our previously developed Schottky diode model is used for the MS contacts. The newly developed model is integrated into ADS, in which the intrinsic part of the NWFET is developed by utilizing the Symbolically Defined Device (SDD) for an equation-based nonlinear model. The results simulated from the newly developed NWFET model reproduce considerably well the reported experimental results.

Chain Dimensions and Intrinsic Viscosities of Polypeptides in the Helix-Coil Transition Region

  • Jong-Ryul Kim;Tai-Kyue Ree
    • Bulletin of the Korean Chemical Society
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    • v.4 no.1
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    • pp.36-41
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    • 1983
  • An equation is derived which correlates the unperturbed dimensions $_0$ of polypeptides with the helical contents in the helix-coil transition region by using a simple model of a polypeptide chain. The model is a chain of connected balls which represent the repeating units, -CO-NH-CHR-, based on the fact that the repeating unit has a plane structure. The changing trend of the expansion factor ${\alpha}_{\eta}$ in the transition region is connected with the helical content $f_H$. The intrinsic viscosities [${\eta}$] of polypeptides are calculated from the unperturbed dimensions and the ${\alpha}_{\eta}$ factors. The above calculated results concerning $_0$ and [${\eta}$] are compared with other authors' theoretical and experimental results. From the comparison, we concluded that our theory explains better the chain dimensional behavior of polypeptides in the helix-coil transition region than others.

Properties of NiO-doped WO$_3$ (NiO 첨가에 따른 WO$_3$의 물성)

  • No, Hyo-Seop;Bae, In-Su;Jeong, Hun-Taek;Lee, Su-Seon;Hong, Gwang-Jun;Lee, Hyeon-Gyu;Park, Jin-Seong
    • Korean Journal of Materials Research
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    • v.11 no.4
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    • pp.272-277
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    • 2001
  • NiO-doped $WO_3$ thick films were prepared by a screen printing technique. The electrical Property and microstructure of the films were investigated with the partial pressure of oxygen and the amount of NiO. The grain size of NiO-doped $WO_3$ was smaller than that of undoped $WO_3$ but the grain sixte of 0.1, 1, 10 mol% NiO-doped$ WO_3$ were nearly the same. The electrical conductance of the $WO_3$ thick films decreased with the oxygen partial pressure, and increased with the amount of NiO to the limit of solid solution. The variation of the electrical conductance with temperature is not so large in the extrinsic region, but it changed rapidly in the intrinsic region. The conductance decreased with adsorption of oxygen in the intermediate range between the extrinsic and intrinsic region.

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Effects of NiO Addition in $WO_3$-based Gas Sensors Prepared by Thick film Process (후막법으로 제조된 $WO_3$ 기체센서의 NiO 첨가효과)

  • Noh, Whyo-Sub;Bae, In-Soo;Chung, Hoon-Taek;Lee, Woo-Sun;Hong, Kwang-Joon;Lee, Hyun-Kyu;Park, Jin-Seong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05b
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    • pp.61-66
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    • 2001
  • NiO-doped $WO_3$ thick films were prepared by a screen printing technique. The electrical property and microstructure of the films were investigated with the partial pressure of oxygen and the amount of NiO. The grain size of NiO-doped $WO_3$ was smaller than that of undoped $WO_3$, but the grain size of 0.1, 1, 10 mol% NiO-doped $WO_3$ were nearly the same. The electrical conductance of the $WO_3$ thick films decreased with the oxygen partial pressure, and increased with the amount of NiO to the limit of solid solution. The variation of the electrical conductance with temperature is not so large in the extrinsic region, but it changed rapidly in the intrinsic region. The conductance decreased with adsorption of oxygen in the intermediate range between the extrinsic and intrinsic region.

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Statistical implications of extrapolating the overall result to the target region in multi-regional clinical trials

  • Kang, Seung-Ho;Kim, Saemina
    • Communications for Statistical Applications and Methods
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    • v.25 no.4
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    • pp.341-354
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    • 2018
  • The one of the principles described in ICH E9 is that only results obtained from pre-specified statistical methods in a protocol are regarded as confirmatory evidence. However, in multi-regional clinical trials, even when results obtained from pre-specified statistical methods in protocol are significant, it does not guarantee that the test treatment is approved by regional regulatory agencies. In other words, there is no so-called global approval, and each regional regulatory agency makes its own decision in the face of the same set of data from a multi-regional clinical trial. Under this situation, there are two natural methods a regional regulatory agency can use to estimate the treatment effect in a particular region. The first method is to use the overall treatment estimate, which is to extrapolate the overall result to the region of interest. The second method is to use regional treatment estimate. If the treatment effect is completely identical across all regions, it is obvious that the overall treatment estimator is more efficient than the regional treatment estimator. However, it is not possible to confirm statistically that the treatment effect is completely identical in all regions. Furthermore, some magnitude of regional differences within the range of clinical relevance may naturally exist for various reasons due to, for instance, intrinsic and extrinsic factors. Nevertheless, if the magnitude of regional differences is relatively small, a conventional method to estimate the treatment effect in the region of interest is to extrapolate the overall result to that region. The purpose of this paper is to investigate the effects produced by this type of extrapolation via estimations, followed by hypothesis testing of the treatment effect in the region of interest. This paper is written from the viewpoint of regional regulatory agencies.

Conduction Band Model of the System ${\alpha}-Fe_2O_3$-CdO at Extrinsic Region (외성영역에서 ${\alpha}-Fe_2O_3$-CdO 계의 전도띠 모델)

  • Keu Hong Kim;Seok Ho Yun;Young Sik Kwon;Jae Shi Choi
    • Journal of the Korean Chemical Society
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    • v.31 no.5
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    • pp.406-412
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    • 1987
  • The electrical conductivities of ${\alpha}-Fe_2O_3$ containing 2.5 and 5.0mol% of cadmium were measured from 300 to $900^{\circ}C$ under oxygen pressures of 10$^{-7}$ to 10$^{-1}$ atmosphere. Plots of log ${\sigma}$ vs. 10$^3$/T show the extrinsic conductivity at oxygen pressure higher than $5{\times}10$^{-2}$atm. The transition points appear at about 550$^{\circ}$C and the activation energies are 1.34 eV for the intrinsic region and 0.50 eV for the extrinsic region on 5mol% Cd-doped ${\alpha}-Fe_2O_3$. The extrinsic conductivity disappears at oxygen partial pressures lower than $5{\times}10$^{-2}$ atm, and the intrinsic conductivity predominates. The electrical conductivities decrease with increasing mol% of cadmium doped. The predominant defect of ${\alpha}-Fe_2O_3$ doped with Cd is believed to be Fe${2+}$ interstitial for the intrinsic, however, oxygen vacancy predominates for the extrinsic region. The electrical conduction mechanisms are proposed and the conduction band model is suggested for the extrinsic region.

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The Analysis of the Nano-Scale MOSFET Resistance

  • Lee Jun Ha;Lee Hoong Joo;Song Young Jin
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.801-803
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    • 2004
  • The current drive in an MOSFET is limited by the intrinsic channel resistance. All the other parasitic elements in a device structure playa significant role and degrade the device performance. These other resistances need to be less than $10{\%}-20{\%}$ of the channel resistance. To achieve the requirements, we should investigate the methodology of separation and quantification of those resistances. In this paper, we developed the extraction method of resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that forms under the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

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Separation and Quantification of Parasitic Resistance in Nano-scale Silicon MOSFET

  • Lee Jun-Ha;Lee Hoong-Joo;Song Young-Jin;Yoon Young-Sik
    • KIEE International Transactions on Electrophysics and Applications
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    • v.5C no.2
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    • pp.49-53
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    • 2005
  • The current drive in a MOSFET is limited by the intrinsic channel resistance. All other parasitic elements in a device structure perform significant functions leading to degradation in the device performance. These other resistances must be less than 10$\%$-20$\%$ of the channel resistance. To meet the necessary requirements, the methodology of separation and quantification of those resistances should be investigated. In this paper, we developed an extraction method for the resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that gathers below the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

Intrinsic bent DNA colocalizes with the sequence involved in the Nd-sD mutation in the Bombyx mori fibroin light chain gene

  • Barbosa, Joice Felipes;Bravo, Juliana Pereira;Takeda, Karen Izumi;Zanatta, Daniela Bertolini;Silva, Jose Luis Da Conceicao;Balani, Valerio Americo;Fiorini, Adriana;Fernandez, Maria Aparecida
    • BMB Reports
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    • v.41 no.5
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    • pp.394-399
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    • 2008
  • Multiple sequence alignments of the Bombyx mori fibroin light chain gene (fib-L) from hybrids and from Chinese and Japanese strains demonstrated that 51.6% of the fib-L third intron is conserved. One of these conserved segments, 41 bp long, contains the sequence CGTTATTATACATATT, which is duplicated in the B. mori Nd-$s^D$ mutant. In the present work, electrophoretic mobility assays and computational analyses revealed a major peak of intrinsic bent DNA within the segment that undergoes breakage in the previously-described Nd-$s^D$ mutation. This result suggested that this intrinsically-curved region might mediate DNA cleavage and enhance recombination events in the third intron of the Bombyx mori fib-L gene.

Effect of Molecular Weight and NaCI Concentration on Dilute Solution Properties of Chitosan

  • Hwang, Jae-Kwan;Hong, Sang-Pill;Kim, Chong-Tai
    • Preventive Nutrition and Food Science
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    • v.2 no.1
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    • pp.1-5
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    • 1997
  • Solution Properties of polyelectrolytic biopolymers such as chitosen, pectin, alginate and etc. are significantly influenced by molecular weight and salt concentrations. The effect of NaCI concentration on the hydrodynamic properties of chitosan in dilute region was investigated for chitosans of varying molecular weight. Intrinsic vicosity([η]) of citosans with 5 different molecular weight was determined by glass capillary viscometer, and the viscosity average molecular weight was calculated using Mark-Houwink equation. Intrinsic viscosity decreased with increasing NaCI concentration for all chitosan samples, and it was proportional to the logarithmic NaCI concentration, i.e.,[η]∝log{TEX}$(C_{NaCl})^{$\alpha$}${/TEX}. Decreasing trend of[η] with NaCI concentration became more pronounced with increasing molecular weight. It was also found that the a values, indicating {TEX}$C_{NaCl}${/TEX} dependence of[η], were linearly correlated with the logarithmic molecular weight({TEX}$R^{2}${/TEX}=0.980). The chain stiffness parameters(B) were calculated by B=S./{TEX}$([η]_{0.1})^{1.32}${/TEX}, in which S was obtained from slope of [η] va {TEX}$I^{-1/2}${/TEX}. The B values of chitosan samples were determined to be 0.113~0071 with a average of 0.09.

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