Browsing by Author "Lin, JY"

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A 1 logN parallel algorithm for detecting convex Hulls on image boards
(1998-06-01)
Lin, JC
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Lin, JY
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資訊工程學系
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Department of Computer Science
By finding the maximum and minimum of {y(i) - mx(i) 1 less than or equal to i less than or equal to N} for certain slopes m, we propose here a simple and fast parallel algorithm to obtain the convex hull of N arbitrarily given points on an image hoard. The mathematical theory needed is included, and computation time is 1 log N.
A classification tree based on discriminant functions
(2006-05-01)
Chien, BC
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Lin, JY
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Yang, WP
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資訊工程學系
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Department of Computer Science
The classification problem is an important topic in knowledge discovery and machine learning. Traditional classification tree methods and their improvements have been discussed widely. This work proposes a new approach to construct decision trees based on discriminant functions which are learned using genetic programming. A discriminant function is a mathematical function for classifying data into a specific class. To learn discriminant functions effectively and efficiently, a distance-based fitness function for genetic programming is designed. After the set of discriminant functions for all classes is generated. a classifier is created as a binary decision tree with the Z-value measure to resolve the problem of ambiguity among discriminant functions. Several popular datasets from the UCI Repository were selected to illustrate the effectiveness of the proposed classifiers by comparing with previous methods. The results show that the proposed classification tree demonstrates high accuracy on the selected datasets.
A comparison between the Fehrenbacher-Rice and the Liechtenstein-Mazin models
(2000-11-01)
Liu, SJ
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Lin, JY
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Chen, JM
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Nachimuthu, P
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Luo, CW
Unoccupied electronic states of Y1-xPrxCu3O7-y (x = 0 - 1) thin films have been investigated using high-resolution polarization-dependent O K-edge x-ray absorption spectroscopy (XANES). After determining the hole distribution among different oxygen sites of the Pr-doped thin films, we compare the experimental data with the Fehrenbacher and Rice (FR) model and the Liechtenstein and Mazin (LM) model, both of which are based on the hybridization of Pr 4f(z(x2-y2)) and O 2p(pi) orbitals in PrBa2Cu3O7-y. Our experimental results are more consistent with the FR model.
A consistent co-rotational finite element formulation for geometrically nonlinear dynamic analysis of 3-D beams
(1999-01-29)
Hsiao, KM
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Lin, JY
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Lin, WY
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機械工程學系
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Department of Mechanical Engineering
A co-rotational total Lagrangian finite element formulation for the geometrically nonlinear dynamic analysis of spatial Euler beam with large rotations but small strain, is presented. The nodal coordinates, displacements, rotations, velocities, accelerations, and the equations of motion of the structure are defined in a fixed global set of coordinates. The beam element has two nodes with six degrees of freedom per node. The element nodal forces are conventional forces and moments. The kinematics of beam element are defined in terms of element coordinates, which are constructed at the current configuration of the beam element. Both the element deformation nodal forces and inertia nodal forces are systematically derived by consistent linearization of the fully geometrically nonlinear beam theory using the d'Alembert principle and the virtual work principle in the current element coordinates. An incremental-iterative method based on the Newmark direct integration method and the Newton-Raphson method is employed here for the solution of the nonlinear equations of motion. Numerical examples are presented to demonstrate the accuracy and efficiency of the proposed method. (C) 1999 Elsevier Science S.A. All rights reserved.
A fast dual symbol context-based arithmetic coding for MPEG-4 shape coding
(2004)
Lee, KB
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Lin, JY
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Jen, CW
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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
MPEG-4 shape coding comprises context-based arithmetic encoding (CAE) as its centerpiece. Since the CAE algorithm has complicated coding procedure and strong data dependency, it is hard to exploit its pipeline and parallel facilities. This paper presents a fast dual symbol CAE that runs at a higher clock rate whereas requires less clock cycle count for encoding. The proposed design is based on the unique characteristics of shape information as well as the numerical properties of the probabilities indexed by the contexts, and it is capable of encoding either a singe symbol or two symbols within each clock cycle. Together with the adaptive predication for the order of coding process, redundant operations can be skipped and therefore the average clock cycles for each coding process is improved by a factor of 1.72. Furthermore, the probability table is rearranged to reduce critical path delay. When synthesized from Verilog RTL design by using TSMC 0.35mum 1P4M CMOS technology, the design with I/O pads occupies an area of 2528 x 2520 mum(2) and is capable of running at 100 MHz.
A method for measuring the complex refractive index of a turbid medium
(2005)
Jian, ZC
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Lin, JY
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Hsieh, PJ
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Chen, HW
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Su, DC
Based on the heterodyne interferometry and Fresnel equations, an alternative method for measuring the complex refractive index of a turbid medium. A light beam is incident on the boundary between a right-angle prism and a turbid medium. The phase difference between s- and p- polarizations of the reflected light occurs. The phase difference depends on then incident angle and the complex refractive index of a turbid medium-, their relation can be derived from Fresnel equations. The phase difference can be measured accurately with the heterodyne interferometry. Because there are two unknown parameters to be estimated, at least the phase differences under two different conditions should be measured. Then, these measured data are substituted into the derived relation, and a set simultaneous equation is obtained. If the simultaneous equation is solved. the complex refractive index can be estimated. Because the reflected light from the boundary is measured, the scattering noises coming from the turbidity of the tested medium can be greatly reduced. In addition, this method has some merits such as simple optical setup, high sensitivity, high stability, and suitability for a little amount of the tested medium in its native state (without dilution).
A method for measuring the rotatory power of a chiral medium
(2001)
Su, DC
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Hsu, CC
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Lin, JY
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Lee, JY
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光電工程學系
A light beam coming from a circularly polarized heterodyne light source passes through a chiral medium, its rotation angle is just half of the phase difference between p- and s- polarization components. And this phase difference can be measured accurately with heterodyne interferometric technique. The rotatory power is obtained by dividing the estimated rotation angle with its path length. This method has many advantages, such as, high stability, high resolution, easy operation, and real-time measurement.
A multisymbol context-based arithmetic coding architecture for MPEG-4 shape coding
(2005-02-01)
Lee, KB
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Lin, JY
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Jen, CW
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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
MPEG-4 shape coding comprises context-based arithmetic encoding (CAE) as its centerpiece. Since the CAE algorithm has a complicated coding procedure and strong data dependency, it is hard to exploit its pipeline and parallel facilities. Furthermore, to encode multiple symbols within one, clock cycle, it needs to overcome the issues of extracting multiple contexts of these symbols, deriving multiple probabilities from these contexts, and performing multiple multiplicative range update operations. This paper presents an efficient pipelined multisymbol CAE architecture for real-time MPEG-4 shape encoding. The proposed design is based on the inherent characteristics of binary alpha blocks as well as the numerical properties of the probabilities indexed;by the contexts, and it is capable of encoding either a singe symbol, or multiple symbols within each clock cycle. To overcome the aforementioned issues under the consideration of the hardware cost and the critical path delay, only symbols with a particular set of contexts are chosen to be processed simultaneously within the same clock cycle. Theoretical analysis shows that the majority of symbols have contexts belonging to this particular set, and therefore CAE processing can be significantly accelerated. An example VLSI implementation of proposed architecture that encodes two symbols within each clock cycle without sacrificing the clock rate can achieve a speedup of 1.47 in comparison with traditional CAE architectures. This particular two-symbol design can support MPEG-4 Main Profile at levels 3 and 4 under extreme and typical conditions, respectively. When synthesized from Verilog RTL design by using TSMC 0.35-mum 1P4M CMOS technology, the design can run at 90 MHz.
A new method for constructing IP level power model based on power sensitivity
(2000-12-01)
Huang, HL
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Lin, JY
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Shen, WZ
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Jou, JY
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電子工程學系及電子研究所
As the function uf a system getting more complex. IP (Intellectual Property) reusing is the trend of system design style. Designers need to evaluate the performance and features of every candidate IP block that can be used in their design, while IP providers hope to keep the structure of tilt ir IP blocks a secret. An IP level power model is a model that takes only the primary) input statistics its parameters and does not reveal any information about the sizes of the transistors or the structure of the circuit. This paper proposes a new method for constructing power model that is suitable for IP level circuit blocks. It is a nominal point selection method, fur power models based oil power sensitivities. BS analyzing the relationship between the dynamic power consumption uf CMOS circuits and their input signal statistics, a guideline of selecting the nominal point is proposed. From our analysis. the first nominal point is selected to minimize the average Estimation error and two other nominal points are selected to minimize the maximum estimation error. Our experimental results on a number of benchmark circuits show the effectiveness of the proposed method. Average estimation accuracy within 5.78% of transistor level simulations is achieved. The proposed method can he applied to build a system level power estimation environment without revealing the contents of the IP blocks inside. Thereby. it is a promising method for IP level power model construction.
A new method for measuring the chiral parameter and the average refractive index of a chiral liquid
(2003-04-01)
Lin, JY
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Su, DC
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光電工程學系
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Department of Photonics
We designed a method for measuring chiral parameter and average refractive index of an isotropic chiral medium using critical angle phenomena. Linearly polarized light is guided to project onto the interface of a semi-spherical glass and a chiral liquid. The reflected light passes through an analyzer to extract the interference signal of s- and p-polarization lights. Their phase difference is first optimized by a suitable optical arrangement and subsequently measured by a heterodyne interferometer. The result, then, is fed into equations to estimate the chiral parameter. We determine the average index of refraction from the critical angle occurred at the discontinuity of the phase difference of two polarized lights. Our method of measurement has the implicational merits of both common-path interferometry and heterodyne interferometry. (C) 2003 Elsevier Science B.V. All rights reserved.
A new postprocessing method for the block-based DCT coding based on the convex-projection theory
(1998-08-01)
Liu, CM
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Wang, CN
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Lin, JY
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資訊科學與工程研究所
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Institute of Computer Science and Engineering
The block-based DCT coding has been adopted in image compression standards such as JPEG and MPEGs. This type of coding causes some noticeable artifacts known as the blocking effect. Various post processing methods have been devoted to removing the blocking effect; however, these methods also unavoidably blur the decoded image. Removing the blocking effect while avoiding blurring is the main issue of the postprocessing. This paper presents a new postprocessing method based on convex-projection theory. This method is shown to have keep good tradeoff for the blocking effects and the blurring effects.
A new type of optical heterodyne polarimeter
(2003-01-01)
Lin, JY
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Su, DC
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光電工程學系
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Department of Photonics
Phase variations occur when a circularly polarized light beam either passes through a chiral solution or is reflected from a non-absorbing material. They can be measured accurately with a circular heterodyne interferometry. These data are substituted into the special equations derived from Jones calculus. The chiral parameter and the average refractive index of a chiral solution can be estimated simultaneously in just one optical configuration. This polarimeter has the merits of both the common-path interferometer and the heterodyne interferometer. The proposed device was validated in this work.
A power modeling and characterization method for macrocells using structure information
(1997)
Lin, JY
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Shen, WZ
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Jou, JY
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交大名義發表
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電子工程學系及電子研究所
To characterize a macrocell, a general method is to stare the power consumption of all possible transition events at primary inputs in the lookup tables, Though this approach is very accurate, the lookup tables could be huge for tile macrocells with many inputs, In this paper, we present a new power modeling method which rakes advantage of the structure information of macrocells and selects minimum number of primary inputs or internal nodes in a macrocell as state variables to build a state transition graph (STG). Those state variables can completely model the transitions of ail internal nodes and the primary outputs. By carefully deleting some state variables, we further introduce an incomplete power modeling technique which can simplify the STG without losing much accuracy. In addition, we exploit the properly of the compatible patterns of a macrocell to further reduce the number of edges in the corresponding STG. Experimental results show that our modeling techniques can provide SPICE-like accuracy and can reduce the size of the lookup table significantly comparing to the general approach.
A power modeling and characterization method for the CMOS standard cell library
(1996)
Lin, JY
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Shen, WZ
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Jou, JY
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交大名義發表
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電子工程學系及電子研究所
In this paper, we propose power consumption models for complex gates and transmission gates, which are extended from the model of basic gates proposed in [1]. We also describe an accurate power characterization method for CMOS standard cell libraries which accounts for the effects of input slew rare, output loading, and logic state dependencies. The characterization methodology separates the power consumption of a cell into three components, e.g., capacitive feedthrough power, short-circuit power, and dynamic power. For each component, power equation is derived from SPICE simulation results where the netlist is extracted from cell's layout. Experimental results on a set of ISCAS'85 benchmark circuits show that the power estimation based on our power modeling and characterization provides within 7% error of SPICE simulation on average while the CPU time consumed is more than two orders of magnitude less.
A robust word boundary detection algorithm for variable noise-level environment in cars
(2002-03-01)
Lin, CT
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Lin, JY
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Wu, GD
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper discusses the problem of automatic word boundary detection in the presence of variable-level background noise in cars. Commonly used robust word boundary detection algorithms always assume that the background noise level is fixed and sets fixed thresholds to rind the boundary of word signal. In fact, the background noise level in cars varies in the procedure of recording due to speed change and moving environment, and some thresholds should be tuned according to the variation of background noise level. This is the major reason that most robust word boundary detection algorithms cannot work well in the condition of variable background noise level. To solve this problem, we propose a minimum mel-scale frequency band (MiMSB) parameter which can estimate the varying background noise level in cars by adaptively choosing one band with minimum energy from the mel-scale frequency bank. With the MiMSB parameter, some preset thresholds used to find the boundary of word signal are no longer fixed in all the recording intervals. These thresholds will be tuned according to the MiMSB parameter. We also propose an enhanced time-frequency (ETF) parameter by extending the time-frequency (TF) parameter proposed by Junqua et al from single band to multiband spectrum analysis, where the frequency bands help to make the distinction between speech signal and noise. The ETF parameter can extract useful frequency information by choosing some bands of the mel-scale frequency bank. Based on the MiMSB and ETF parameters, we finally propose a new robust algorithm for word boundary detection in variable noise-level environment. The new algorithm has been tested over a variety of noise conditions in cars and has been found to perform well not only under variable background noise level condition, but also under fixed background noise level condition. The new robust algorithm using the MiMSB and ETF parameters achieved higher recognition rate than the TF-based robust algorithm, which has been shown to outperform several commonly used algorithms, by about 5% in variable background noise level condition. It also reduced the recognition error rate due to endpoint detection to 25%, compared to an average of 34% obtained with the TF-based robust algorithm.
A structure-oriented power modeling technique for macrocells
(1999-09-01)
Lin, JY
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Shen, WZ
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Jou, JY
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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
To characterize the power consumption of a macrocell, a general method involves recording the power consumption of all possible input transition events in the look-up tables. However, though this approach is accurate, the size of the table becomes very large. In this paper, we propose a new power modeling technique that takes advantage of the structural information of a macrocell, In this approach, a subset of primary inputs and internal nodes in the macrocell are selected as the state variables to build a state transition graph (STG), These state variables can model the steady-state transitions completely. Moreover, by selecting the characterization patterns properly, the STG can also model the glitch power in the macrocell accurately. To further simplify the complexity of the STG, an incomplete power modeling technique is presented. Without losing much accuracy, the property of compatible patterns is exploited for a macrocell to further reduce the number of edges in the corresponding STG, Experimental results show that our modeling techniques can provide SPICE-like accuracy, while the size of the look-up table is significantly reduced.
A study on the dual vanishing point property
(1999-12-01)
Huang, JB
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Chen, Z
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Lin, JY
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資訊科學與工程研究所
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Institute of Computer Science and Engineering
Vanishing points and vanishing lines are useful information in computer vision. In this study, an interesting dual property of vanishing point is first introduced. Next, we point out that there also exists a dual property of vanishing line. With the dual vanishing point and vanishing line properties, some 3D intersection inference can be made based on their image lines. Two applications are given to illustrate the usage of the new results. The first one is to derive the 3D pose determination of a circle using two parallel image lines. The second one uses six specially designed 3D lines to adjust the cameras with respect to a fixture in a binocular vision system such that the resultant camera coordinate axes become parallel. (C) 1999 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.
Absence of the paramagnetic contribution in the low-temperature specific heat of La1.9Sr0.1Cu0.98Zn0.02O4
(2000-11-01)
Lin, JY
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Chang, CF
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Yang, HD
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物理研究所
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Institute of Physics
The absence of the paramagnetic contribution in the low-temperature specific heat (C) of Zn-doped cuprates has attracted much attention recently. The phenomenon was usually explained as possible screening in the superconducting state. We have measured C of La1.9Sr0.1Cu0.98Zn0.02O4 which is not superconducting. Intriguingly, The upper limit of the magnetic contribution is found to be two orders of magnitude smaller than the expected value with no screening effect. This result puts the above explanation in a serious jeopardy.
Alternative method for measuring both the refractive indices and the thickness of silver-halide holographic plates
(2005-05-01)
Hsu, CC
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Lin, JY
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Chen, KH
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Su, DC
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光電工程學系
First, the phase differences between s- and p-polarizations of a circularly polarized heterodyne light beam reflected from the emulsion layer, and that from its substrate, are measured, respectively. The measured data are substituted into specially derived equations, so the refractive indices of the emulsion layer and its substrate can be calculated. Second, the variations of phase differences between s- and p-polarizations due to the wavelength shifts and the extraction of the holographic plate in a modified Michelson interferometer are measured. Then, the thickness of the emulsion layer and its substrate can be estimated based on the measured values of refractive indices, the wavelength shifts, and the phase difference variations. This method has some advantages, such as high resolution and easy operation in only one optical configuration. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
Anisotropic characteristics of in-plane aligned a-axis YBa2Cu3O7-delta thin films
(2003-05-01)
Luo, CW
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Chen, MH
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Chin, CC
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Wu, KH
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Juang, JY
Highly in-plane aligned a-axis oriented YBa2Cu3O7-delta (YBCO) thin films with unprecedented transition temperature (T-c similar to 91.3 K) have been deposited on (100) LaSrGaO4 substrates using a continuously grown PrBa2Cu3O7-delta (PBCO) template layer by pulsed laser. The anisotropies between b- and c-axis were investigated by transport measurements and atomic force microscopy (AFM). Although, the onset T-c's along b- and c-axis appeared approximately the same, a significant filing was observed in the resistive transition along c-axis. The temperature-dependent of the tailing effect, however, cannot be explained by thermally activated phase-slippage (TAPS) commonly encountered in grain-boundary weak links.