Browsing by Issue Date, starting with "2008-09-01"

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反哲學的讀書論：三木清〈讀書論〉
(國立陽明交通大學出版社, 2008-09-01)
子安宣邦
;
馮啓斌
High field emission efficiency surface conduction electron emitters
(2008-09-01)
Li, Yiming
;
Chao, Hsueh-Yung
;
Lo, Hsiang-Yu
;
電信工程研究所
;
Institute of Communications Engineering
Two different surface conduction electron-emitter (SCE) structures with the nanogap of 90 nm wide fabricated by hydrogen embrittlement (HE) and focused ion beam techniques are simulated for the first time. We employ a three-dimensional particle-in-cell method coupling with finite-difference time-domain scheme to simulate the property of electron emission in these SCEs. Our calibrated simulation predicts high emission efficiency of the SCE structure which is fabricated by HE. Compared with the other SCE structure, it is observed that the proposed structure possesses low power consumption at the fixed emission current when the width of nanogap becomes narrower. The current-voltage characteristics including conducting mechanisms are investigated and explained.
Three-dimensional simulation of field emission triode structure using carbon-nanotube emitters
(2008-09-01)
Li, Yiming
;
Yeh, Ta-Ching
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電信工程研究所
;
Institute of Communications Engineering
Field emission (FE) triode arrays with the anodic aluminum oxide (AAO) template carbon nanotubes (CNTs) as the field emitters are successfully fabricated and analyzed. Both the experimental measurement and numerical calculation are conducted to examine the electron conduction properties of AAO-CNTs. Using a three-dimensional finite-difference time-domain particle-in-cell method, a set of Maxwell equations and Lorentz equation is solved self-consistently, where the FE current is computed with Fowler-Nordheim equation. We explore the FE characteristics of AAO-CNTs in the triode structure. After calibration with the measured data, we study the evolution of current density and the convergence of the electron beams on anode plate with different gate voltages, anode heights, and SiO2 thickness. The current density and focus performance maintain a trade-off relationship, where a larger current density accompanies more divergent electron beam.
Effective Decap Insertion in Area-Array SoC Floorplan Design
(2008-09-01)
Lu, Chao-Hung
;
Chen, Hung-Ming
;
Liu, Chien-Nan Jimmy
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
As VLSI technology enters the nanometer era, supply voltages continue to drop due to the reduction of power dissipation, but it makes power integrity problems even worse. Employing decoupling capacitances (decaps) in floorplan stage is a common approach to alleviating supply noise problems. Previous researches overestimate the decap budget and do not fully utilize the empty space of the floorplan. A floorplan usually has a lot of available space that can be used to insert the decap without increasing the floorplan area. Therefore, the goal of this work is to develop a better model to calculate the required decap to solve the power supply noise problem in area-array based designs, and increase the usage of available space in the floorplan to reduce the area overhead caused by decap insertion. The experimental results of this work are encouraging. Compared with previous approaches, our methodology reduces 38% of the decap budget in average for MCNC benchmarks but can still meet the power supply noise requirements. The final floorplan areas with decap are also smaller than the numbers reported in previous works.
Optical Properties of Ce-Doped ZnO Nanowires Directionally Grown by Hydrothermal Method
(2008-09-01)
Chen, Y. S.
;
Tseng, T. Y.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Well directionally grown Ce-doped ZnO nanowires were successfully synthesized by a simple hydrothermal method. The Ce dopant plays a key role in evolving the morphology, affecting the crystalline size, and forming the uniform nanostructure of the ZnO nanowires. The amount of Ce dopant in the ZnO nanowires also affects the regions of blue-shift in the UV and green emission peaks and the intensities of emission peaks based on the cathodoluminescence spectra of the nanowires. Moreover, the effect of Ce doping amount on the microstructure of the nanowires is also presented.
A WSN-Based Intelligent Light Control System Considering User Activities and Profiles
(2008-09-01)
Pan, Meng-Shiuan
;
Yeh, Lun-Wu
;
Chen, Yen-Ann
;
Lin, Yu-Hsuan
;
Tseng, Yu-Chee
Recently, wireless sensor networks (WSNs) have been widely discussed in many applications. In this paper, we propose a WSN-based intelligent light control system for indoor environments. Wireless sensors are responsible for measuring current illuminations. Two kinds of lighting devices, namely, whole lighting and local lighting devices, are used to provide background and concentrated illuminations, respectively. Users may have various illumination requirements according to their activities and profiles. An illumination requirement is as the combination of background and concentrated illumination demands and users' locations. We consider two requirement models, namely, binary satisfaction and continuous satisfaction models, and propose two decision algorithms to determine the proper illuminations of devices and to achieve the desired optimization goals. Then, a closed-loop device control algorithm is applied to adjust the illumination levels of lighting devices. The prototyping results verify that our ideas are practical and feasible.
A compact RF CMOS modeling for accurate high-frequency noise simulation in sub-100-nm MOSFETs
(2008-09-01)
Guo, Jyh-Chyurn
;
Lin, Yi-Min
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A compact RF CMOS model incorporating an improved thermal noise model is developed. Short-channel effects (SCEs), substrate potential fluctuation effect, and parasitic-resistance-induced excess noises were implemented in analytical formulas to accurately simulate RF noises in sub-100-nm MOSFETs. The intrinsic noise extracted through a previously developed lossy substrate de-embedding method and calculated by the improved noise model can consistently predict gate length scaling effects. For 65- and 80-nm n-channel MOS with f(T) above 160 and 100 GHz, NF(min) at 10 GHz can be suppressed to 0.5 and 0.7 dB, respectively. Drain current noise S(id) reveals an apparently larger value for 65-nm devices than that for 80-nm devices due to SCE. On the other hand, the shorter channel helps reduce the gate current noise S(ig) attributed to smaller gate capacitances. Gate resistance R(g)-induced excess noise dominates in S(ig) near one order higher than the intrinsic gate noise that is free from R(g) for 65-nm devices. The compact RF CMOS modeling can facilitate high-frequency noise simulation accuracy in nanoscale RF CMOS circuits for low-noise design.
Relevance feedback for category search in music retrieval based on semantic concept learning
(2008-09-01)
Shan, Man-Kwan
;
Chiang, Meng-Fen
;
Kuo, Fang-Fei
;
資訊工程學系
;
Department of Computer Science
Traditional content-based music retrieval systems retrieve a specific music object which is similar to what a user has requested. However, the need exists for the development of category search for the retrieval of a specific category of music objects which share a common semantic concept. The concept of category search in content-based music retrieval is subjective and dynamic. Therefore, this paper investigates a relevance feedback mechanism for category search of polyphonic symbolic music based on semantic concept learning. For the consideration of both global and local properties of music objects, a segment-based music object modeling approach is presented. Furthermore, in order to discover the user semantic concept in terms of discriminative features of discriminative segments, a concept learning mechanism based on data mining techniques is proposed to find the discriminative characteristics between relevant and irrelevant objects. Moreover, three strategies, the Most-Positive, the Most-Informative, and the Hybrid, to return music objects concerning user relevance judgments are investigated. Finally, comparative experiments are conducted to evaluate the effectiveness of the proposed relevance feedback mechanism. Experimental results show that, for a database of 215 polyphonic music objects, 60% average precision can be achieved through the use of the proposed relevance feedback mechanism.
眞實世界的消失：布希亞的現身
(國立陽明交通大學出版社, 2008-09-01)
S. Loehr
;
洪菁勵
Membrane translocation of small GTPase Rac1 and activation of STAT1 and STAT3 in pacing-induced sustained atrial fibrillation
(2008-09-01)
Tsai, Chia-Ti
;
Lin, Jiunn-Lee
;
Lai, Ling-Ping
;
Lin, Chih-Sheng
;
Huang, Sheoi K. Stephen
BACKGROUND Angiotensin II and its downstream mitogen-activated protein kinase signaling pathways are involved in the pathogenesis of AF. Pro-inflammatory JAK/STAT is another downstream signaling pathway of Angiotensin II, and its status in AF remains unknown. OBJECTIVE The aim of this study was to characterize the status of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathways in pacing-induced sustained atrial fibrillation (AF). METHODS AF was induced by atrial pacing at 600/min in 10 adult pigs (AF group), while 10 sham-operated pigs served as the control group. RESULTS Significant structural and inflammatory changes were noted in the AF group. Atrial tissue angiotensin II level was elevated and STAT1 and STAT3 were activated in the AF group. Nuclear translocation of activated STAT3 and binding to STAT3 consensus DNA sequence were also increased in the AF group. Rac1, the molecular target of statin, which mediates the activation of STAT3 by angiotensin II, was also activated in the AF group. The tissue levels of interteukin-6, leukemia inhibitory factor (LIF) and cardiotrophin-1 (CT-1), which are known to activate STATs through membrane gp130 and JAKs, were not increased in the AF group. Membrane gp130 and JAKs were also not activated in the AF group. CONCLUSION Activated angiotensin II/Rac1/STAT may be associated with or perhaps contribute to the structural and inflammatory changes in pacing-induced sustained trial fibrillation. It may further imply the therapeutic option of combination of angiotensin receptor blocker and statin.
Optimal design of triple-gate devices for high-performance and low-power applications
(2008-09-01)
Chiang, Meng-Hsueh
;
Lin, Jeng-Nan
;
Kim, Keunwoo
;
Chuang, Ching-Te
;
電子工程學系及電子研究所
Pragmatic design of triple-gate (TG) devices is presented by considering corner effects, short-channel effects, and channel-doping profiles. A novel TG MOSFET structure with a polysilicon gate process is proposed using asymmetrical (n(+)/p(+)) polysilicon gates. CMOS-compatible V(T)'s for high-performance circuit applications can be achieved for both nFET and pFET. The superior subthreshold characteristics and device performance are analyzed and validated by 3-D numerical simulations. Comparisons of device characteristics with a midgap metal gate are presented.
Spin Hall effect in a Josephson contact
(2008-09-01)
Mal'shukov, A. G.
;
Chu, C. S.
;
電子物理學系
;
Department of Electrophysics
The spin Hall effect on the Josephson tunneling through a two-dimensional normal contact with a spin-orbit split conduction band has been studied in the diffusive regime and at the zero electric bias. Linearized Usadel equations for triplet components of the pairing function in the presence of intrinsic spin-orbit interaction have been derived. These equations have been employed for analysis of the spin Hall effect induced by the super-current. We predict that a nondissipative out-of-plane spin Hall polarization accumulates at lateral edges and an in-plane polarization is induced throughout the entire normal region. At the same time, in contrast to the spin Hall effect in normal systems, the spin current is absent in the considered case of the stationary Josephson effect.
A NOVEL FLUOROMETRIC ASSAY OF HUMAN 3'-PHOSPHOADENOSINE 5'-PHOSPHOSULFATE SYNTHETASE
(2008-09-01)
Liu, Tzu-An
;
Yang, Yuh-Shyong
;
生物科技學系
;
Department of Biological Science and Technology
法國思想與游牧烏托邦：與何內•謝黑在席亞克的訪談
(國立陽明交通大學出版社, 2008-09-01)
洪菁勵
;
楊凱麟
Toward incorporating a task-stage identification technique into the long-term document support process
(2008-09-01)
Wu, I-Chin
;
Liu, Duen-Ren
;
Chang, Pei-Cheng
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Effective knowledge management in a knowledge-intensive environment can place heavy demands on the information filtering (IF) strategies used to model workers' long-term task-needs. Because of the growing complexity of knowledge-intensive work tasks, a profiling technique is needed to deliver task-relevant documents to workers. In this study, we propose an IF technique with task-stage identification that provides effective codification-based support throughout the execution of a task. Task-needs pattern similarity analysis based on a correlation value is used to identify a worker's task-stage (the pre-focus, focus formulation, or post-focus task-stage). The identified task-stage is then incorporated into a profile adaptation process to generate the worker's current task profile. The results of a pilot study conducted in a research institute confirm that there is a low or negative correlation between search sessions and transactions in the pre-focus task-stage, whereas there is at least a moderate correlation between search sessions/transactions in the post-focus stage. Compared with the traditional IF technique, the proposed IF technique with task-stage identification achieves, on average, a 19.49%, improvement in task-relevant document support. The results confirm the effectiveness of the proposed method for knowledge-intensive work tasks. (c) 2007 Elsevier Ltd. All rights reserved.
Analysis of terahertz pulses from large-aperture biased semi-insulating and arsenic-ion-implanted GaAs antennas
(2008-09-01)
Chou, Rone-Hwa
;
Liu, Tze-An
;
Pan, Ci-Ling
;
光電工程學系
;
Department of Photonics
We investigate the characteristics of terahertz radiation pulses generated using biased semi-insulating and arsenic-ion-implanted GaAs photoconductive antennas with 1.5 cm aperture size under various pump fluences and bias fields. Compared with semi-insulating GaAs antenna, our arsenic-ion-implanted GaAs antenna exhibits larger bandwidth and better emission efficiency. Our simulation verifies that the superior characteristics for the latter can be partly attributed to larger optical absorption in the ion-implanted layer. For both types of antennas, we observe that the radiated peak terahertz amplitude displays an anomalous dependence on pump fluence, which deviates from the prediction given by the scaling rule. Analyzing the theoretical and simulation results, we infer that this behavior arises from band filling and two-photon absorption effects. At specific pump fluence, we find that the dependence of peak terahertz amplitude on bias field is distinct from the usual linear relationship predicted by the scaling rule. (c) 2008 American Institute of Physics.
A simple method to characterize the afterpulsing effect in single photon avalanche photodiode
(2008-09-01)
Yen, H. T.
;
Lin, S. D.
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Tsai, C. M.
;
電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A simple method is introduced for studying the afterpulsing effect in InGaAs single photon avalanche photodiode. The afterpulsing probability is obtained through measuring the detection efficiencies of various biasing pulses, while the incident photons are kept constant. The effect of excess bias and temperature on the afterpulsing probability is investigated. When the device temperature is higher than 170 K, the afterpulsing probability is lower than 5% for all excess bias voltages because the trapped carrier lifetime is much shorter than the repetition period. (C) 2008 American Institute of Physics.
An on-chip test structure and digital measurement method for statistical characterization of local random variability in a process
(2008-09-01)
Mukhopadhyay, Saibal
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Kim, Keunwoo
;
Jenkins, Keith A.
;
Chuang, Ching-Te
;
Roy, Kaushik
This paper presents an on-chip characterization method for random variation in minimum sized devices in nanometer technologies, using a sense amplifier-based test circuit. Instead of analog current measurements required in conventional techniques, the presented circuit operates using digital voltage measurements. Simulations of the test structure using predictive 70 nm and hardware based 0.13 mu m CMOS technologies show good accuracy (error similar to 5%-10%) in the prediction of random variation even in the presence of systematic variations. A test chip is fabricated in 0.13 mu m bulk CMOS technology and measured to demonstrate the operation of the test structure.
Investigation of Coulomb Mobility in Nanoscale Strained PMOSFETs
(2008-09-01)
Chen, William Po-Nien
;
Su, Pin
;
Goto, Ken-Ichi
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper provides an experimental assessment of Coulomb scattering mobility for advanced strained devices. By accurate short-channel mobility extraction, we examine the impact of process-induced uniaxial strain on Coulomb mobility in short-channel pMOSFETs. Our extracted Coulomb mobility shows very weak stress dependency at room temperature. This finding has also been verified in both long- and short-channel devices by the four-point wafer bending measurement. Therefore, in order to maximize the process-induced strain efficiency on nanoscale pMOSFETs, lower surface impurity concentration is suggested to avoid the Coulomb mobility domination in carrier transport.
駕馭速度(?)的理論：評哈穆特•羅沙《加速：現代時間結構的改變》
(國立陽明交通大學出版社, 2008-09-01)
鄭作彧