Browsing by Issue Date, starting with "2006-06-12"

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Erbium doped GaSe crystal for mid-IR applications
(2006-06-12)
Hsu, YK
;
Chen, CW
;
Huang, JY
;
Pan, CL
;
光電工程學系
We reported a type-I difference-frequency generator (DFG), based on erbium doped GaSe (Er: GaSe) crystals as a coherent infrared source tunable from 2.4 mu m to 28 mu m. The two mixing beams used for the DFG are a tunable near infrared output (1.1-1.8 mu m) from an optical parametric amplifier (OPA) and the fundamental beam of a picosecond Nd: YAG laser at 1.064 mu m. The system can produce a maximum output pulse energy of 5 mu J at wavelength of 3.5 mu m, corresponding to a photon conversion efficiency of 8% at a pump intensity of 1.7 GW/cm(2). The nonlinear coefficient (d(eff)) of 0.5 atom % erbium doped GaSe crystal was found to be 55.3 pm/V or 24 % higher than that of a pure GaSe crystal. The improvement of deff is attributed to the substitutive and interstitial doping of Er ion in GaSe unit cell. The optical properties of GaSe influenced by the erbium doping are also presented. (c) 2006 Optical Society of America.
Optically heterodyne diagnosis of a high-saturation-power undoped InP sandwiched InGaAs p-i-n photodiode grown on GaAs
(2006-06-12)
Liao, YS
;
Shi, JW
;
Wu, YS
;
Kuo, HC
;
Feng, M
We demonstrate the optical heterodyne diagnostics and high saturation power characteristics of a novel undoped InP sandwiched In0.53Ga0.47As p-i-n photodiode with a partially p-doped photoabsorption layer, which is grown on a linearly graded metamorphic InxGa1-xP buffered GaAs substrate layer and exhibits an excellent low dark current density of 3.6 x 10(-7) A/cm(2). Such a top-illuminated optical receiver exhibits an illuminating window of 60-mu m diameter, which performs ultra-linear power handling capability up to 18 dBm at 1550 nm, providing a maximum photocurrent of 35 mA under a reverse bias of 9 volts. These result in extremely high current bandwidth and bandwidth-responsivity products of 350 mA center dot GHz and 4.8 GHz center dot A/W, respectively, at receiving frequency of up to 10 GHz. (c) 2006 Optical Society of America.
Energy-tunable transmission x-ray microscope for differential contrast imaging with near 60 nm resolution tomography
(2006-06-12)
Yin, GC
;
Tang, MT
;
Song, YF
;
Chen, FR
;
Liang, KS
An energy-tunable transmission hard x-ray microscope with close to 60 nm spatial resolution in three dimensions (3D) has been developed. With a cone beam illumination, a zone plate of 50 nm outmost zone width, a stable mechanical design, and software feedback, we obtained tomographic data sets that are close to 60 nm spatial resolution. Meanwhile, the element specific imaging was also obtained by a differential absorption contrast technique used below and above the absorption of the element. Examples of advanced intergraded circuit devices are used to demonstrate the element selectivity and spatial resolution in 3D of the microscope.
Single-longitudinal-mode, tunable dual-wavelength, CWNd : YVO4 laser
(2006-06-12)
Lin, YY
;
Chen, SY
;
Chiang, AC
;
Tu, RY
;
Huang, YC
We report a single-longitudinal-mode CW diode-pumped Nd:YVO4 laser emitting at both 1064 and 1342 nm with 10% optical efficiency at 20-W pump power. The measured spectral widths at 1064 and 1342 nm were less than 450 MHz and 400 MHz, respectively. The two emission wavelengths can be independently tuned over the lasing bandwidths of the dual-wavelength laser. (c) 2006 Optical Society of America.
Analysis of circular genome rearrangement by fusions, fissions and block-interchanges
(2006-06-12)
Lu, Chin Lung
;
Huang, Yen Lin
;
Wang, Tsui Ching
;
Chiu, Hsien-Tai
;
生物科技學系
Background: Analysis of genomes evolving via block-interchange events leads to a combinatorial problem of sorting by block-interchanges, which has been studied recently to evaluate the evolutionary relationship in distance between two biological species since block-interchange can be considered as a generalization of transposition. However, for genomes consisting of multiple chromosomes, their evolutionary history should also include events of chromosome fusions and fissions, where fusion merges two chromosomes into one and fission splits a chromosome into two. Results: In this paper, we study the problem of genome rearrangement between two genomes of circular and multiple chromosomes by considering fusion, fission and block-interchange events altogether. By use of permutation groups in algebra, we propose an O(n(2)) time algorithm to efficiently compute and obtain a minimum series of fusions, fissions and block-interchanges required to transform one circular multi-chromosomal genome into another, where n is the number of genes shared by the two studied genomes. In addition, we have implemented this algorithm as a web server, called FFBI, and have also applied it to analyzing by gene orders the whole genomes of three human Vibrio pathogens, each with multiple and circular chromosomes, to infer their evolutionary relationships. Consequently, our experimental results coincide well with our previous results obtained using the chromosome-by-chromosome comparisons by landmark orders between any two Vibrio chromosomal sequences as well as using the traditional comparative analysis of 16S rRNA sequences. Conclusion: FFBI is a useful tool for the bioinformatics analysis of circular and multiple genome rearrangement by fusions, fissions and block-interchanges.
Common stabilizers for linear control systems in the presence of actuators outage
(2006-06-15)
Liang, Yew-Wen
;
Liaw, Der-Cherng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Issue concerning the existence of common stabilizers for a linear control system experiences actuators. outage are presented. The possible outage of actuators examined in this study are not restricted to a pre-specified set. By finding Common quadratic-type Lyapunov functions. we obtain sufficient conditions for the existence of common stabilizers. For cases of which all the possible failed actuators belonged to a pre-specified set. the results presented in this paper agree with those obtained by Veillette in 1995. The control gain of common stabilizer for non-nested case is explicitly derived to guarantee system stability. A simplified checking condition for the existence of common stabilizers is also obtained for the extreme case when only single actuator can normally operate. (c) 2005 Elsevier Inc. All rights reserved.
管管作品三首
(2006-06-15)
管管
Epoxy/polyhedral oligomeric silsesquioxane nanocomposites from octakis(glycidyidimethylsiloxy)octasilsesquioxane and small-molecule curing agents
(2006-06-15)
Liu, YL
;
Chang, GP
;
Hsu, KY
;
Chang, FC
;
應用化學系
Epoxy/polyhedral oligomeric silsesquioxane (POSS) nanocomposites were obtained from octakis(glycidyldimethylsiloxy)octasilsesquioxane (OG) and diglycidyl ether of bisphenol A cured with small-molecule curing agents of diethylphosphite (DEP) and dicyandiamide (DICY). An increase in the POSS contents of the nanocomposites and an improvement in the nanocomposite homogeneity were observed with the use of the small-molecule curing agents. Phosphorus in DEP and nitrogen in DICY also performed synergism with POSS for thermal stability enhancement and flammability improvement in the nanocomposites. The nanocomposites possessing high OG contents exhibited good thermal stability, improved flammability, and high storage moduli. (c) 2006 Wiley Periodicals, Inc.
管管作品三首
(2006-06-15)
管管
Tool replacement for production with a low fraction of defectives
(2006-06-15)
Pearn, WL
;
Hsu, YC
;
Wu, CW
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
In manufacturing industry, the tool replacement cost is, in many cases, a significant portion of the production cost. Early tool replacement increases the production cost. Overdue tool replacement, however, results in poor production quality. Accordingly, improving production quality while maintaining a low production cost is essential. The index C-pk is regarded as a yield-based index. For a fixed C-pk value, the production yield and fraction of defectives can be calculated. In this paper, we present an analytical approach using C-pk to determine the optimal tool replacement time. An accurate process capability must be calculated, particularly when the data contain assignable cause variation. Tool wear is a dominant and inseparable component in many machining processes (a systematic assignable cause), and ordinary capability measures become inaccurate because process data are contaminated by the assignable cause variation. Considering process capability changes dynamically, an estimator of C-pk is investigated. The closed form of the exact sampling distribution is derived. An effective tool management procedure for determining the optimal tool replacement time is presented for processes with a low fraction of defectives. For illustrative purposes, an application example involving tool wear is presented.
管管作品三首
(2006-06-15)
管管
管管作品三首
(2006-06-15)
管管
Fast solvers for 3D Poisson equations involving interfaces in a finite or the infinite domain
(2006-06-15)
Lai, MC
;
Li, ZL
;
Lin, XB
;
應用數學系
;
Department of Applied Mathematics
In this paper, numerical methods are proposed for Poisson equations defined in a finite or infinite domain in three dimensions. In the domain, there can exists an interface across which the source term, the flux, and therefore the solution may be discontinuous. The existence and uniqueness of the solution are also discussed. To deal with the discontinuity in the source term and in the flux, the original problem is transformed to a new one with a smooth solution. Such a transformation can be carried out easily through an extension of the jumps along the normal direction if the interface is expressed as the zero level set of a three-dimensional function. An auxiliary sphere is used to separate the infinite region into an interior and exterior domain. The Kelvin's inversion is used to map the exterior domain into an interior domain. The two Poisson equations defined in the interior and the exterior written in spherical coordinates are solved simultaneously. By choosing the mesh size carefully and exploiting the fast Fourier transform, the resulting finite difference equations can be solved efficiently. The approach in dealing with the interface has also been used with the artificial boundary condition technique which truncates the infinite domain. Numerical results demonstrate second order accuracy of our algorithms. (c) 2005 Elsevier B.V. All rights reserved.
A recursively construction scheme for super fault-tolerant hamiltonian graphs
(2006-06-15)
Chen, Y-Chuang
;
Hsu, Lih-Hsing
;
Tan, Jimmy J. M.
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資訊工程學系
;
Department of Computer Science
For the interconnection network topology, it is usually represented by a graph. When a network is used. processors and/or links faults may happen. Thus, it is meaningful to consider faulty networks, We consider k-regular graphs in this paper. We define a k-regular hamiltonian and hamiltonian connected graph G is super fault-tolerant hamiltonian if G remains hamiltonian after removing at most k - 2 vertices and/or edges and remains hamiltonian connected after removing at most k - 3 vertices and/or edges. A Super fault-tolerant hamiltonian graph has a certain optimal flavor with respect to the fault tolerant hamiltonicity and fault-tolerant hamiltonian connectivity. The aim of this paper is to investigate a construction scheme to construct various super fault-tolerant hamiltonian graphs. Along the way. the recursire circulant graph is a special case of our construction scheme. and the super fault-tolerant hamiltonian property of recursive circulant graph is obtained. (c) 2005 Elsevier Inc. All rights reserved.
管管作品三首
(2006-06-15)
管管
Architecture of an embedded internet robot system controlled by brain waves
(2006-06-15)
Wu, Li-Wei
;
Liao, Hsien-Cheng
The present invention discloses an architecture of an embedded internet robot system controlled by brain waves, wherein the brain-computer interface and the internet robot system cooperate with the alertness level detection technology and the instruction translation technology, and thereby, the user can control a distal-end robot purely via consciousness activities and can interact with the environment as if there were an entity representing the user's consciousness appearing in the distal end. The seriously disabled person can regain his expressive ability via the present invention. Further, the present invention can also be applied to a multi-player interactive game system.
Bicriteria scheduling in a two-machine permutation flowshop
(2006-06-15)
Lin, BMT
;
Wu, JM
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
In this paper we consider a production scheduling problem in a two-machine flowshop. The bicriteria objective is a linear combination or weighted sum of the makespan and total completion time. This problem is computationally hard because the special case concerning the minimization of the total completion time is already known to be strongly NP-hard. To find an optimal schedule, we deploy the Johnson algorithm and a lower bound scheme that was previously developed for total completion time scheduling. Computational experiments are presented to study the relative performance of different lower bounds. While the best known bound for the bicriteria problem can successfully solve test cases of 10 jobs within a time limit of 30 min, under the same setting our branch-and-bound algorithm solely equipped with the new scheme can produce optimal schedules for most instances with 30 or less jobs. The results demonstrate the convincing capability of the lower bound scheme in curtailing unnecessary branching during problem-solving sessions. The computational experience also suggests the practical significance and potential implications of this scheme.
Effect of growth rate on the composition fluctuation of InGaAsN/GaAs single quantum wells
(2006-06-15)
Chen, JF
;
Hsiao, RS
;
Hsieh, PC
;
Wang, JS
;
Chi, JY
Effect of growth rate on the composition fluctuation is investigated in In0.34Ga0.66As0.98N0.02/GaAs single quantum wells (QWs) by photoluminescence (PL), transmission electron microscopy, and admittance spectroscopy. In an InGaAsN layer grown at a normal growth rate, the PL spectra show a low-energy bump at the tail of an InGaAsN emission, suggesting the presence of composition fluctuation. Lowering the growth rate degrades the composition fluctuation by segregating into bimodal phases of an InGaAsN and InGaAs-rich phase. Further lowering the growth rate leads to a three-dimensional growth and enhances the InGaAs-rich phase. The carrier distribution for the InGaAsN layer grown at the normal rate shows a carrier bump at the tail of a strong accumulation peak, suggesting the presence of an electron state below the QW ground state. The admittance spectroscopy shows that the activation energy (32 meV) of this electron state is comparable to the energy separation (30 meV) between the InGaAsN emission and the low-energy bump, and thus it is possible that the composition fluctuation actually induces an electron state closely below the QW ground state. (c) 2006 American Institute of Physics.
管管作品三首
(2006-06-15)
管管
Optical and electrical transport properties of facing-target sputtered Al doped ZnO transparent film
(2006-06-15)
Li, ZQ
;
Zhang, DX
;
Lin, JJ
;
電子物理學系
;
物理研究所
Al doped zinc oxide thin film was prepared by dc facing-target sputtering method and its structural, optical, and electrical transport properties have been investigated. The average transmittance of the films is greater than 90% in the wavelength region of 450-700 nm while the resistivity is as high as 3x10(-3) Omega cm. The band gap energy derived from the transmission data is 3.76 eV, which is higher than that of pure ZnO thin film. This band gap growth phenomenon cannot be explained in terms of the Burstein-Moss effect. The resistivity and Hall effect measurements suggest that the interaction between the charge carriers and phonons plays a key role in the electrical transport properties of the film between 60 and 300 K. The film exhibits negative magnetoresistance at low temperatures, which can be well described by a semiempirical expression that takes into account the third order s-d exchange Hamiltonians describing a negative part and a two-band model for positive contribution.