Browsing by Issue Date, starting with "2001-10-01"

Now showing 1 - 20 of 76228

An automatic macro program for radio frequency MOSFET characteristics analysis
(2001-10-01)
Su, CY
;
Chang, SJ
;
Chen, LP
;
Ho, YP
;
Huang, GW
The parameter extraction language (PEL) in Agilent IC-CAP software is used to develop an automatic macro program for the analysis of the characteristics of RF MOSFETs. By using this powerful macro program, the time spent on the measurement of the MOSFET characteristics and the related analysis is effectively reduced. This macro program permits a fast and accurate method to obtain the DC and RF characteristics of MOSFETs with different device geometries and operating conditions. It is also suitable for high volume measurements and analyses of MOSFET, and provides a solid jou 71 dation for RF circuit design.
Sensitivity of the photo-crosslinkable polyimide for liquid crystal alignment
(2001-10-01)
Lee, WC
;
Hsu, CS
;
Wu, ST
;
應用化學系
;
Department of Applied Chemistry
Two methods were developed for enhancing the photosensitivity of the cinnamates-contained polyimide (PICA), One is to increase the content of cinnamate side chain in PICA main chain and another is to blend some photosensitizer into PICA films. Our experimental results show that increasing the rate of photo-dimerization decreases the alignment ability of the PICA films. Using the molecular simulation method, we successfully describe the photoalignment mechanism of the PICA films. It is also found that photo-induced LC alignment ability of the PICA film could be enhanced through choosing a proper coating solvent.
Internet heavy use and addiction among Taiwanese college students: An online interview study
(2001-10-01)
Chou, C
;
教育研究所
;
Institute of Education
This paper presents empirical qualitative results of Internet heavy-use and addiction among some college students in Taiwan. It offers in-depth, online interviews of student-subjects in order to facilitate an interdisciplinary understanding of Internet heavy use, addiction and its potential impacts. A total of 83 subjects were interviewed, both as individuals and in chat-room groups. The analysis of qualitative data presented in six major themes: (1) Internet use and reasons; (2) Internet features; (3) the Internet as replacement for other media; (4) impact of Internet overuse; (5) controlling Internet use; and (6) coping with Internet withdrawal. Discussions, explanations, along with examples and quotes from subjects, are provided in each section. Implications for student affairs administrators and further research directions are also addressed.
Improving the RF performance of 0.18 mu m CMOS with deep n-well implantation
(2001-10-01)
Su, JG
;
Hsu, HM
;
Wong, SC
;
Chang, CY
;
Huang, TY
The radio-frequency (RF) figures of merit of 0.18 mum complementary metal-oxide-semiconductor (CMOS) technology are investigated by evaluating the unity-current-gain cutoff frequency (F-t) and maximum oscillation frequency (F-max). The device fabricated with an added deep n-well structure is shown to greatly enhance both the cutoff frequency and the maximum oscillation frequency, with negligible dc disturbance. Specifically, 18% increase in F-t and 25% increase in F-max are achieved. Since the deep n-well implant can be easily adopted in a standard CMOS process, the approach appears to be very promising for future CMOS RF applications.
The dispersive approach to electroweak processes in the dackground magnetic field
(2001-10-01)
Lin, GL
;
物理研究所
;
Institute of Physics
We propose a new method to compute amplitudes of electroweak processes in the strong background magnetic field, using gamma --> e(+)e(-) as an example. We show that the moments of gamma --> e(+)e(-) width are proportional to the derivatives of photon polarization function at the zero energy. Hence, the pair-production width can be easily calculated from the latter by the inverse Mellin transform. The prospects of our approach are commented.
A performance criterion for the depth estimation with application to robot visual servo control
(2001-10-01)
Fang, CJ
;
Lin, SK
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This article deals with the depth observability problem of a robot visual system with a moving camera. In the visual system, the unknown depth of a feature point is estimated from the input of the camera velocity and the output of the image of the feature point. Although it is well known that the linear velocity of the camera must satisfy some constraints for successful depth estimation, this proposes a criterion to measure the performance of the depth estimation, which is a heuristic extension from an estimation result of a linear system. This performance criterion depends on both the image position and the linear velocity of the camera. Some simulation and experiment examples demonstrate and verify the proposed performance criterion. Furthermore, this criterion is used to develop a new visual servo control scheme that has good performance in both the depth estimation and the visual control. This control scheme is also verified by a simulation example. (C) 2001 John Wiley & Sons, Inc.
Utilization of a dispersion-shifted fiber for simultaneous measurement of distributed strain and temperature through Brillouin frequency shift
(2001-10-01)
Lee, CC
;
Chiang, PW
;
Chi, S
;
光電工程學系
;
Department of Photonics
In this letter, we propose and realize a new method that utilizes a dispersion-shifted fiber having compound compositions with different temperature coefficients in core to simultaneously measure the distributed strain and temperature based on Brillouin frequency shift. In a 3682-m sensing length of large-effective-area nonzero dispersion-shifted fiber, a temperature resolution of 5 degreesC, a strain resolution of 60 mu epsilon, and a spatial resolution of 2 in are achieved simultaneously.
Dynamic analysis of rotating beams with nonuniform cross sections using the dynamic stiffness method
(2001-10-01)
Huang, KJ
;
Liu, TS
;
機械工程學系
;
Department of Mechanical Engineering
This study develops dynamic analysis based on the dynamic stiffness method for a rotating beam of nonuniform cross-section. To deal with nonuniform beams, coefficients related to material and geometric properties in the equation of motion are expressed in a polynomial form. A dynamic stiffness matrix is accordingly formulated in terms of power series. The dynamic response of the rotating beam is calculated by performing modal analysis. It is demonstrated that the present method provides an alternative to the finite element method in dealing with nonuniform rotating beams.
Research into two source-based control algorithms for Internet traffic flows
(2001-10-01)
Yang, CY
;
Fu, CH
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
TCP and UDP are the major applications over the Internet, the characteristics of them lead to different network transmission behaviors. Two source-based mechanisms are proposed in this paper to regulate TCP and UDP flows. One is the-congestion control mechanism, which uses TCP flows' congestion signal to regulate the flows at the source node. The other is the time slot mechanism, which is a time-sharing application to control their flow transmission, Based on the priorities of flows, different bandwidth proportions are allocated and differential services are provided for flows. Several scenarios are simulated to observe the transmission operations of these two mechanisms. Simulation results show some insights into two mechanisms. Moreover, the several simulation parameters that may impact the performance of these two mechanisms are summarized. (C) 2001 Elsevier Science B,V, All rights reserved.
Design and analysis of a merging algorithm for multipoint-to-point ABR service in ATM networks
(2001-10-01)
Lee, CL
;
Chen, YC
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a merging algorithm, which can provide efficient support for multipoint-to-point ABR service in ATM networks. By forwarding the FRM cells belonging to the VC with the largest FRM-cell arrival rate in a merge point, the proposed algorithm can achieve better link utilization than existing merging algorithms. In addition, the proposed algorithm reduces the number of FRM cells forwarded by a C merge point. As a result, it can reduce the control overhead of ABR service. Most importantly, it does not incur extra complexity in switches. We also discuss the impact of different network topologies on our algorithm. Simulation results show that the proposed algorithm is able to achieve better performance while requiring significantly fewer RM cells. (C) 2001 Elsevier Science B.V. All rights reserved.
Electronic stopping powers of solids for slow atoms
(2001-10-01)
Kwei, CM
;
Chou, JJ
;
Yao, J
;
Tung, CJ
;
電子工程學系及電子研究所
Based on the dielectric response theory, electronic stopping powers of solids for slow atoms have been studied. Using a local-field-correction dielectric function, we have calculated these stopping powers by including the correlation and exchange effects. The screening of shellwise electron charge densities of slow atoms by the conduction electrons in solids was estimated using a Thomas-Fermi screening model. In this model, atomic shellwise electron densities were constructed by a superposition of several Yukawa potentials. Stopping powers of Al, Ni, Ag, and Au were calculated for atoms with atomic number between 6 and 18. Calculated results showed that stopping powers oscillated with atomic number consistent with experimental data. Present results also indicated that our approach is much improved over other theoretical calculations. A comparison of presently calculated results with available theoretical and experimental data was made and discussed.
An accurate integral-based scheme for advection-diffusion equation
(2001-10-01)
Tsai, TL
;
Yang, JC
;
Huang, LH
;
土木工程學系
;
Department of Civil Engineering
This paper proposes an accurate integral-based scheme for solving the advection-diffusion equation. In the proposed scheme the advection-diffusion equation is integrated over a computational element using the quadratic polynomial interpolation function. Then elements are connected by the continuity of first derivative at boundary points of adjacent elements. The proposed scheme is unconditionally stable and results in a tridiagonal system of equations which can be solved efficiently by the Thomas algorithm. Using the method of fractional steps, the proposed scheme can be extended straightforwardly from one-dimensional to multi-dimensional problems without much difficulty and complication. To investigate the computational performances of the proposed scheme five numerical examples are considered: (i) dispersion of Gaussian concentration distribution in one-dimensional uniform flow; (ii) one-dimensional viscous Burgers equation; (iii) pure advection of Gaussian concentration distribution in two-dimensional uniform flow; (iv) pure advection of Gaussian concentration distribution in two-dimensional rigid-body rotating flow; and (v) three-dimensional diffusion in a shear flow. In comparison not only with the QUICKEST scheme, the fully time-centred implicit QUICK scheme and the fully time-centred implicit TCSD scheme for one-dimensional problem but also with the ADI-QUICK scheme, the ADI-TCSD scheme and the MOSQUITO scheme for two-dimensional problems, the proposed scheme shows convincing computational performances. Copyright (C) 2001 John Wiley & Sons, Ltd.
Impact of silicide formation on the resistance of common source/drain region
(2001-10-01)
Tsui, BY
;
Wu, MD
;
Gan, TC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Silicide had been used to reduce the sheet resistance of diffusion region for almost 20 years. However, as the silicided region becomes small, the contact resistance of silicide/silicon interface becomes higher than the resistance of the Si diffusion region such that current may not flow into the silicide layer. The effect of Mi silicide thickness and contact resistivity on the total resistance of the silicided diffusion region was studied by two-dimensional simulation. It is observed that below a threshold length, the resistance of silicided diffusion region is higher than the unsilicided diffusion region if the silicon consumption during silicide formation is taken into consideration. Thinner silicide and lower contact resistivity reduce total resistance and threshold length but the threshold length is still much longer than the typical design rule of poly-Si to poly-Si distance. It is thus recommended to inhibit silicide formation at the common source/drain region at the metal-gate generation.
No-hole 2-distant colorings for unit interval graphs
(2001-10-01)
Chang, GJ
;
Juan, ST
;
Liu, DDF
;
應用數學系
;
Department of Applied Mathematics
Given a graph, a no-hole 2-distant coloring (also called N-coloring) is a function f that assigns to each vertex a non-negative integer (color) such that the separation of the colors of any pair of adjacent vertices must be at least 2, and all the colors used by f form a consecutive set (the no-hole assumption). The minimum consecutive N-span of G, csp(1)(G), is the minimum difference of the largest and the smallest colors used in an N-coloring of G, if there exists such a coloring; otherwise, define csp(1)(G) = infinity. Here we investigate the exact values of csp(1)(G) for unit interval graphs (also known as 1-unit sphere graphs). Earlier results by Roberts [18] indicate that if G is a unit interval graph on n vertices, then csp(1) (G) is either 2 chi (G) - 1 or 2 chi (G) - 2, if n > 2 chi (G) - 1; csp(1)(G) = infinity, if n < 2(G) - 1, where chi (G) denotes the chromatic number. We show that in the former case (when n > 2 chi (G) - 1), both values of csp(1)(G) are attained, and give several families of unit interval graphs such that csp(1)(G) = 2 chi (G) - 2. In addition, the exact values of csp(1)(G) are completely determined for unit interval graphs with chi (G) = 3.
Kinetics of decomposition of polyethylene glycol in electroplating solution by ozonation with UV radiation
(2001-10-01)
Chang, CY
;
Chen, YH
;
Li, H
;
Chiu, CY
;
Yu, YH
The kinetics of the ozonation of polyethylene glycol (PEG) with ultraviolet (UV) radiation in the acid-based electroplating solution of the printed wiring board industry is studied. The substrate prescription of a typical electroplating solution is with pH of 0. 18-0.42, [CuSO4 . 5H(2)O] of 200 g/L, [H2SO4] of 60 g/L, and [Cl-] of 0.03 g/L. Certainly, the discarded electroplating solution is hard to treat with the common chemical and biological processes because of its acidic and metallic compositions. In addition, it contains valuable substances suitable for recovery and reutilization. One of the most important processes for reviving it is to remove the aged organic additives such as PEG. A two-step reaction mechanism in terms of ozone A and total organic carbon is proposed to express the reaction kinetics of PEG ozonation with UV radiation with intensity [I-uv]. The initial concentration of PEG is 30 mg/L, according to the recipe of a typical electroplating solution, which is equivalent to total organic carbon of 16.3 mg/L. The reaction rate r expressions of the concentrations of the liquid phase ozone C-ALb, PEG C-BLb, and intermediates C-ILb are r(A) (=dC(ALb)/dt) = -(k(Am) + k(t)[I-uv)C-ALb (k(R1) + k(RI1)[I-uv])CALbCBLb - (k(R2) + k(RI2)[I-uv])CALbCILb, r(B) (=dC(BLb)/dt) = -(k(R1) + k(RI1)[I-uv])CALbCBLb, r(int) (=dC(ILb)/dt) (k(R1) + k(RI1)[I-uv])CALbCBLb - (k(R2) + k(RI2)[I-uv])CALbCILb, with k(Am) = 0.0036 s(-1), k(1) = 4.654 X 10(-5)s(-1)/(Wm(-2)), k(R1) = 13.525 M(-1)s(-1), k(R2) = 0.751 M(-1)s(-1), k(RI1) = 0.683 M(-1)s(-1)/(Wm(-2)), and k(RI2) = 0.042 M(-1)s(-1)/(Wm(-2)). These reaction kinetic expressions are useful and referable for the proper design of an ozonation system with UV radiation for the treatment of PEG in the printed wiring board electroplating solution.
X-ray reflectivity and FTIR measurements of N-2 plasma effects on the density profile of hydrogen silsesquioxane thin films
(2001-10-01)
Lee, HJ
;
Lin, EK
;
Wu, WL
;
Fanconi, BM
;
Lan, JK
The density depth profile and chemical bond structure of hydrogen silsesquioxane (HSQ) thin films treated with an N-2 plasma with varying power and exposure time were measured using specular X-ray reflectivity (SXR) and Fourier transform infrared (FTIR) spectroscopy. The SXR data indicated that the density profile of an untreated HSQ film is not uniform. At least four layers with different electron densities were required to fit the SXR data. For HSQ films treated with either increasing plasma power or plasma exposure time, the film roughness increased and a densified layer was observed at the film/air interface. The thickness of the densified layer increased with both plasma power and plasma exposure time. In the FTIR spectra of the plasma-treated films, the intensities of the Si-O peaks due to the network structure and the Si-OH peak due to water absorption increased and the intensities of the Si-H peaks decreased. The FTIR data show that the plasma converts the HSQ structure into a SiO2-like structure and are consistent with the densification observed in the SXR measurements. In general, the HSQ film is more sensitive to increasing plasma power than to increasing plasma exposure time. (C) 2001 The Electrochemical Society.
Thickness and stress polarity effects on the reliability of the low thermal budget polyoixdes
(2001-10-01)
Chang, KM
;
Chung, YH
;
Chen, HY
;
Lee, TC
;
Sun, YL
In this paper, the thickness and the stress polarity effects on the reliability of the low thermal budget polyoxides are investigated. The polyoxides are prepared by two methods: the low-temperature tetraethylorthosilicate (TEOS) polyoxide deposition and in the rapid thermal chamber in N2O ambient (RTN2O). It is observed that the thinner TEOS polyoxides exhibit higher charge to breakdown (Q(bd)) and larger stress polarity effect than those of the thicker TEOS polyoxides. However, for the RTN2O grown polyoxides from 8.5 nm to 12.9 run, they have the similar values of the Qbd and the stress polarity effects, The nitrogen atoms incorporated in the RTN2O grown polyoxides may be the reason to this less thickness dependence of the Q(bd). Higher barrier height is also observed for the RTN2O grown polyoxides than that of the deposited TEOS polyoxide to obtain a lower tunneling current under a fixed electric field.
Digital camcorder image stabilizer based on gray-coded bit-plane block matching
(2001-10-01)
Yeh, YM
;
Chiang, HC
;
Wang, SJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We propose an efficient algorithm to eliminate the nonpleasing effect caused by involuntary hand movement of camera holders. In our approach, 1-bit gray-coded bit-plane block matching, instead of 8-bit gray-level block matching, is used to greatly simplify the computation of motion estimation. This computation saving makes possible a finer division of image frame and thus facilitates the employment of a much more robust procedure for motion decision. To deal with various interfering factors in motion estimation, the temporal information of each local motion vector is also used to efficiently distinguish random-like movement from temporally correlated movement. To compensate for camera rotation, an affine model is used in the motion compensation unit without adding too much computation load. Having considered both programming flexibility and hardware efficiency, the motion decision unit and the motion compensation unit are coded in a microprocessor that interconnects with the stabilization hardware, which consists of the motion estimation unit and the digital zooming unit. A slightly simplified version of the proposed stabilizer is implemented on a field programmable gate array (FPGA) board. (C) 2001 Society of Photo-Optical Instrumentation Engineers.
Chaotic behaviors of bistable laser diodes and its application in synchronization of optical communication
(2001-10-01)
Wang, WC
;
Hwang, TM
;
Juang, C
;
Juang, J
;
Liu, CY
Period-doubling routes to chaos behavior in bistable laser diodes is examined numerically, An external sinusoidal electronic drive is injected to generate chaotic light output. Phase portrait, Poincare map, bifurcation diagram, and Lyapunov exponent are then calculated to assert the existence of chaos. Furthermore, according to Pecora and Carroll's theory, a drive-response system is constructed by using the bistable laser diodes to mask the sinusoidal electronic signal with chaotic light. Synchronization can be achieved for optical simplex and duplex transmissions using bistable laser diodes. The proposed synchronization scheme between two separate chaotic systems provides a key step toward optical chaotic communication.
Active circuit's under wire bonding I/O, pads in 0.13 mu m eight-level Cu metal, FSG low-K inter-metal dielectric CMOS technology(+)
(2001-10-01)
Chou, KY
;
Chen, MJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Active circuits in terms of ring oscillator are moved to the place under the wire bonding pads in 0.13 mum fall eight-level copper metal complementary metal-oxide-semiconductor process with fluorinated silicate glass low-k inter-metal dielectric. The bond pad with the 12 K Angstrom thick aluminum metal film. as a bonding mechanical stress buffer layer is deposited on the topmost copper metal layer. No noticeable degradations in gate delay or cycle time of ring oscillator are detected in a variety of test structures subjected to bonding mechanical stress and thermal cycling stress. This indicates that the underlying process technology may be reliable and manufacturable in placing active circuits under the bonding pads and thereby the die area utility is recovered fully. More evidence is created from transmission fine pulsing experiments as well as capacitive-coupling experiments.