Browsing by Author "Lin, HH"

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A study of oxide patterning on titanium thin films using scanning probe microscopy
(2001)
Tsai, HR
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Hsieh, TE
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Lo, SC
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Lin, HH
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材料科學與工程學系
This work studies the fabrication of oxide patterns on titanium (Ti) thin films using scanning probe microscopy (SPM). We employed three different SPM techniques, namely, AFM in contact mode, lift mode incorporated with contact mode AFM, and STM. It was found that bias voltages.. scanning speed, scanning height of the probe (for lift mode), and setpoint current (for STM) play important roles in forming the attainable oxide features. Among these three methods, contact mode AFM exhibited the best patterning efficiency and stability and this method was adopted to oxidize the I-shaped Ti films. The resistance of I-shaped specimen after anoxidization raised from 10(4)Omega to 10(8)_10(9)Omega which evidenced the occurrence of oxidation in Ti.
Analyzing accelerated degradation data by nonparametric regression
(1999-06-01)
Shiau, JJH
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Lin, HH
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統計學研究所
;
Institute of Statistics
This paper presents a nonparametric regression accelerated life-stress (NPRALS) model for accelerated degradation data wherein the data consist of groups of degrading curve data. In contrast to the usual parametric modeling, a nonparametric regression model relaxes assumptions on the form of the regression functions and lets data speak for themselves in searching for a suitable model for data. NPRALS assumes that various stress levels affect only the degradation rate, but not the shape of the degradation curve. An algorithm is presented for estimating the components of NPRALS. By investigating the relationship between the acceleration factors and the stress levels, the mean time to failure estimate of the product under the usual use condition is obtained. The procedure is applied to a set of data obtained from an accelerated degradation test for a light emitting diode product. The results look very promising. The performance of NPRALS is further checked by a simulated example and found satisfactory. We anticipate that NPRALS can be applied to other applications as well.
Cloning and expression of human haptoglobin subunits in Escherichia coli: The potential use of mini-haptoglobin as an antioxidant
(2006-03-07)
Lai, IH
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Tsai, TI
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Lai, WY
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Lin, HH
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Mao, SJT
Comparison of active noise control structures in the presence of acoustical feedback by using the H-infinity synthesis technique
(1997-10-02)
Bai, MR
;
Lin, HH
;
交大名義發表
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機械工程學系
;
National Chiao Tung University
This study compares three control structures of active noise cancellation for ducts: feedback control, feedforward control, and hybrid control. These structures are compared in terms of performance, stability, and robustness by using a general framework of the H-infinity robust control theory. In addition, the H-infinity synthesis procedure automatically incorporates the acoustic feedback path that is usually a plaguing problem to feedforward control design. The controllers are implemented by using a digital signal processor and tested on a finite-length duct. In an experimental verification, the proposed controllers are also compared with the well-known filtered-u least mean square (FULMS) controller. The advantages and disadvantages of each ANC structure as well as the adverse effects due to acoustic feedback are addressed. (C) 1997 Academic Press Limited.
Enhanced dopant activation and elimination of end-of-range defects in BF2+-implanted silicon-on-insulator by high-density current
(2001-12-10)
Lin, HH
;
Cheng, SL
;
Chen, LJ
;
Chen, C
;
Tu, KN
Enhanced dopant activation and elimination of end-of-range (EOR) defects in BF2+-implanted silicon-on-insulator (SOI) have been achieved by high-density current stressing. With the high-density current stressing, the implantation amorphous silicon underwent recrystallization, enhanced dopant activation and elimination of the (EOR) defects. The current stressing method allows the complete removal of EOR defects that has not been possible with conventional thermal annealing in the processing of high-performance SOI devices. (C) 2001 American Institute of Physics.
Fabrication and nonlinear optical properties of nanoparticle silver oxide films
(2003-08-01)
Chiu, Y
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Rambabu, U
;
Hsu, MH
;
Shieh, HPD
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Chen, CY
We report the fabrication of nanoparticle silver oxide thin films by rf magnetron sputtering and characterization of their nonlinear optical properties. The chemical decomposition and reversibility of AgOx compounds were studied by thermogravimetric analysis, differential scanning calorimetry, and x-ray diffraction. Electron spectroscopy for chemical analysis measurements revealed a 0.5 eV negative binding energy shift from AgO to Ag2O phase. The effect of particle plasmon resonance was confirmed by the absorption band shift with increased Ag2O Particle size. The measured third-order nonlinear susceptibility (chi(3) = 3.4 x 10(-7) esu) and response time (27 ps) of the Ag2O nanoparticles makes it promising for applications in all-optical switching devices and optical data storage systems. (C) 2003 American Institute of Physics.
Formation of D(-) centers in GaAs/AlGaAs quantum wells
(1998-06-01)
Lee, CH
;
Chang, YH
;
Lin, HH
;
Lee, CP
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電子工程學系及電子研究所
Three different experiments were employed to study the behaviors of neutral (D(0)) and negatively charged donors (D(-)) in doped GaAs/AlGaAs multiple quantum wells. The existence of the D(-) centers in such structures were demonstrated, and its optical properties were investigated. The spectral responses of such systems under different experimental conditions, such as different barrier doping concentration, different temperature, and different exposure to light illumination were studied. A potential fluctuation model was proposed to explain the experimental results.
Formation of D- centers in GaAs/AlGaAs quantum wells
(1998-06-01)
Lee, CH
;
Chang, YH
;
Lin, HH
;
Lee, CP
;
電子工程學系及電子研究所
Three different experiments were employed to study the behaviors of neutral (D-0) and negatively charged donors (D-) in doped GaAs/AlGaAs multiple quantum wells. The existence of the D- centers in such structures were demonstrated, and its optical properties were investigated. The spectral responses of such systems under different experimental conditions, such as different barrier doping concentration, different temperature, and different exposure to light illumination were studied. A potential fluctuation model was proposed to explain the experimental results.
On the performance improvement of H.264 through foreground and background analyses
(2005)
Lin, ZK
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Lin, HH
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Chen, YH
;
Chuang, JH
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資訊工程學系
A more efficient coding scheme for H.264 by heuristically assign macroblock partition types for video foreground and background coding is proposed. High visual quality of foreground regions are retained while low bit-rate background coding is achieved. More importantly, the encoding time is reduced significantly owing to the elimination of the exhausted searches over all partition types during the RD optimization.
Oxygen- and growth rate-dependent regulation of Escherichia coli fumarase (FumA, FumB, and FumC) activity
(2001-01-01)
Tseng, CP
;
Yu, CC
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Lin, HH
;
Chang, CY
;
Kuo, JT
Escherichia coli contains three biochemically distinct fumarases which catalyze the interconversion of fumarate to L-malate in the tricarboxylic acid cycle, Batch culture studies indicated that fumarase activities varied according to carbon substrate and cell doubling time. Growth rate control of fumarase activities in the wild type and mutants was demonstrated in continuous culture; FumA and FumC activities were induced four- to fivefold when the cell growth rate (k) was lowered from 1.2/h to 0.24/h at 1 and 21% O-2, respectively. There was a twofold induction of FumA and FumC activities when acetate was utilized instead of glucose as the sole carbon source. However, these fumarase activities were still shown to be under growth rate control. Thus, the activity of the fumarases is regulated by the cell growth rate and carbon source utilization independently, Further examination of FumA and FumC activities in a cya mutant suggested that growth rate control of FumA acid FumC activities is cyclic AMP dependent, Although the total fumarase activity increased under aerobic conditions, the individual fumarase activities varied under different oxygen levels. While FumB activity was maximal during anaerobic growth (k = 0.6/h), FumA was the major enzyme under anaerobic cell growth, and the maximum activity was achieved when oxygen was elevated to 1 to 2%. Further increase in the oxygen level caused inactivation of FumA and FumB activities by the high oxidized state, but FumC activity increased simultaneously when the oxygen level aas higher than 4%. The same regulation of the activities of fumarases in response to different oxygen levels was also found in mutants. Therefore, synthesis of the three fumarase enzymes is controlled in a hierarchical fashion depending on the environmental oxygen that the cell encounters.
Plant uncertainty analysis in a duct active noise control problem by using the H-infinity theory
(1998-07-01)
Bai, MR
;
Lin, HH
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機械工程學系
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Department of Mechanical Engineering
Plant uncertainty is one of the major contributing factors that could affect the performance as well as stability of active noise control (ANC) systems. Plant uncertainty may be caused by either the errors in modeling, computation, and measurement, or the perturbations in physical conditions. These factors lead to deviations of the plant from the nominal model, which will in turn affect the robustness of the control system. In this paper, the effects due to changes in physical conditions on the ANC system are investigated. The analysis is carried out in terms of performance and robustness by using a general framework of the H-infinity robust control theory. The size of plant uncertainty is estimated according to the infinity norm of the perturbations to physical conditions, which provides useful information for subsequent controller design that accommodates both performance and stability in an optimal and robust manner. The guidelines for designing the ANC systems with reference to plant uncertainties are also addressed. (C) 1998 Acoustical Society of America. [S0001-4966(98)02007-4].
Thermal stability of Cu/NiSi-contacted p(+)n shallow junction
(2004-09-01)
Wang, CC
;
Lin, HH
;
Chen, MC
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The thermal stability of Cu/NiSi-contacted p(+)n shallow junction diodes was investigated with respect to their electrical characteristics and metallurgical reactions. The TaN/Cu/NiSi/p(+)n junction diode remained intact after 30min thermal annealing at temperatures of up to 350degreesC. Upon annealing at 375degreesC, a marked increase in reverse bias leakage current occurred, and secondary ion mass spectrometry (SIMS) analysis indicated that Cu started to penetrate into the NiSi-contacted shallow junction region. After a higher temperature annealing at 425degreesC, a Cu3Si phase was formed. The failure of the TaN/ Cu/NiSi/p(+)n junction diodes is attributed to the penetration of Cu through the NiSi layer into the junction region, leading to junction degradation by introducing deep-level trap states and the eventual formation Of Cu3Si.
Transport and optical studies of the D--conduction band in doped GaAs/AlGaAs quantum wells
(2001-08-01)
Lee, CH
;
Chang, YH
;
Huang, CF
;
Huang, MY
;
Lin, HH
The properties of D- ions in quantum wells were studied. It is found that, with an intermediate concentration of D- ions, electrons in the quantum wells possess both band-like and impurity-like properties. The appearance of the Quantum Hall effect makes it possible to rule out the existence of an impurity band that is separated from the conduction band. The results are interpreted in terms of the formation of a D- conduction band, with the D- band becoming a tail of the conduction band. The implications of our experimental results on the metal-insulator transitions in doped semiconductors are discussed.