Browsing by Author "Lin, SS"

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A low-complexity adaptive echo canceller for xDSL applications
(2004-05-01)
Lin, SS
;
Wu, WR
;
電信工程研究所
;
Institute of Communications Engineering
A finite impulse response (FIR)-based adaptive filter structure is proposed for echo cancellation in xDSL applications. The proposed algorithm consists of an FIR filter, a cascaded interpolated FIR filter, and a tap-weight overlapping and nulling scheme. This filter requires low computational complexity and inherits the stable characteristics of the conventional FIR filter. Simulations show that the proposed echo canceller can effectively cancel the echo, up to 73:4 dB [for a single-pair high-speed digital subscriber line (SHDSL) system]. About 55% complexity reduction can be achieved compared with a conventional FIR filter.
A more general dual projected pseudo quasi-Newton method for large network optimization problems
(1999)
Lin, SY
;
Lin, SS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
One of the major computational steps in the dual projectd pseudo quasi-Newton method for neweork type optimization problems is the projection onto a convex set formed by the linear inequlity constraints of the problem. When the inequlity constraints are coupled, the large-dimension projection problem is a difficult one. In this paper, we propose a graphic-method based decomposition technique to determine a smallest subset of inequality contraints to be converted to equality constraints so that the rest of the inequality constraints become disjoint subsets. Consequently, the large-dimension projection problem can be decomposed into several independent small-dimension projection subproblems, and the computation complexity for the projection step will be largely reduced. Copyright (C) 1998 IFAC.
A parallel block scaled gradient method with decentralized step-size for block additive unconstrained optimization problems of large distributed systems
(2003-03-01)
Lin, SY
;
Lin, SS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, we propose a modified parallel block scaled gradient method for solving block additive unconstrained optimization problems of large distributed systems. Our method makes two major modifications to the typical parallel block scaled gradient method: First, we include a pre-processing step which reduces the computational time; second, we propose a decentralized Armijo-type step-size rule. This rule circumvents the difficulty of determining a step-size in a distributed computing environment and enables the proposed parallel algorithm to execute in a distributed computer network with a limited amount of data transfer. We have applied our method to the weighted-least-square problems of power system state estimation and demonstrated the convergence of our method by testing numerous examples on a PC network. The speedup ratio of the distributed version of our method tends to increase proportionally with the number of subsystems (or computers).
An optimal interpolated FIR echo canceller for digital subscriber lines
(2004-12-01)
Lin, SS
;
Wu, WR
;
電信工程研究所
;
Institute of Communications Engineering
An adaptive interpolated FIR (IFIR) echo canceller was recently proposed for xDSL applications. This canceller consists of an FIR filter, an IFIR filter, and a tap-weight overlapping and nulling scheme. The FIR filter is used to cancel the short and rapidly changing head echo while the IFIR filter is used to cancel the long and slowly decaying tail echo. This echo canceller, which inherits the stable characteristics of the conventional FIR filter, requires low computational complexity. It is well known that the interpolation filter for an IFIR filter has great influence on the interpolated result. In this paper, a least-squares method is proposed to obtain optimal interpolation filters such that the performance of the IFIR echo canceller can be further improved. Simulations with a wide variety of loop topologies show that the optimal IFIR echo canceller can effectively cancel the echo up to 73.0 dB (for an SHDSL system). About 57% complexity reduction can be achieved compared to a conventional FIR filter.
Approach to room temperature process - A novel thin liquid-phase deposited oxide
(1996)
Yeh, CF
;
Lin, SS
;
交大名義發表
;
電子工程學系及電子研究所
;
National Chiao Tung University
To continuously reduce dimensions, and increase reliability of devices, low-temperature process (LTP) is an important issue. Pursuing a novel LTP, room-temperature process can be as a norm. In this paper, as an approach to room-temperature process, the feasible technologies of versatile liquid-phase deposited oxide will be introduced.
Bifurcations and chaos in two-cell cellular neural networks with periodic inputs
(2004-09-01)
Lin, SS
;
Lin, WW
;
Yang, TH
;
應用數學系
;
Department of Applied Mathematics
This study investigates bifurcations and chaos in two-cell Cellular Neural Networks (CNN) with periodic inputs. Without the inputs, the time periodic solutions are obtained for template A = [r, p, s] with p > 1, r > p - 1 and -s > p - 1. The number of periodic solutions can be proven to be no more than two in exterior regions. The input is b sin 2pit/T with period T > 0 and amplitude b > 0. The typical trajectories Gamma(b, T, A) and their omega-limit set omega(b, T, A) vary with b, T and A are also considered. The asymptotic limit cycles A,,(T, A) with period T of Gamma(b, T, A) are obtained as b --> infinity. When T-0 less than or equal to T-0* (given in (67)), Lambda(infinity) and -Lambda(infinity) can be separated. The onset of chaos can be induced by crises of omega(b, T, A) and -omega(b, T, A) for suitable T and b. The ratio A(b) = aT(b)/a(1)(b), of largest amplitude a(1)(b) except for T-mode and amplitude of the T-mode of the Fast Fourier Transform (FFT) of r(b, T, A), can be used to compare the strength of sustained periodic cycle Lambdao(A) and the inputs. When A(b) much less than 1, Lambda(o)(A) dominates and the attractor omega(b, T, A) is either a quasi-periodic or a periodic. Moreover, the range b of the window of periodic cycles constitutes a devil's staircase. When A(b) similar to 1, finitely many chaotic regions and window regions exist and interweave with each other. In each window, the basic periodic cycle can be identified. A sequence of period-doubling is observed to the left of the basic periodic cycle and a quasi-periodic region is observed to the right of it. For large b, the input dominates, omega(b, T, A) becomes simpler, from quasi-periodic to periodic as b increases.
Cellular neural networks: Local patterns for general templates
(2000-07-01)
Hsu, CH
;
Juang, J
;
Lin, SS
;
Lin, WW
;
應用數學系
This work investigates the mosaic local patterns for cellular neural networks with general templates. Our results demonstrate that the set of templates can be divided into many finite regions. In each region, the same family of local patterns can be generated. Conversely, our results further demonstrate that some templates can realize a family of local patterns which can be linearly separated by a hyperplane in the configuration space. This study also proposes algorithms for verifying the linear separability for a given family of local patterns and, when it is separable, for obtaining the associated template.
Cellular neural networks: Mosaic pattern and spatial chaos
(2000-03-21)
Juang, J
;
Lin, SS
;
應用數學系
;
Department of Applied Mathematics
We consider a cellular neural network (CNN) with a bias term z in the integer lattice Z(2) on the plane R-2. We impose a symmetric coupling between nearest neighbors, and also between next-nearest neighbors. Two parameters, a and epsilon, are used to describe the weights between such interacting cells. We study patterns that can exist as stable equilibria. In particular, the relationship between mosaic patterns and the parameter space (z, a; epsilon) can be completely characterized. This, in turn, addresses the so-called learning problem in CNNs. The complexities of mosaic patterns are also addressed.
Complete stability for standard cellular neural networks
(1999-05-01)
Lin, SS
;
Shih, CW
;
應用數學系
;
Department of Applied Mathematics
We consider cellular neural networks with symmetric space-variant feedback template. The complete stability is proved via detailed analysis on the energy function. The proof is presented for the two-dimensional case with Dirichlet boundary condition. It can be extended to other dimensions with minor adjustments. Modifications to the cases of Neumann and periodic boundary conditions are also mentioned.
Devil's staircase of gap maps
(2003-01-01)
Ban, JC
;
Hsu, CH
;
Lin, SS
;
應用數學系
;
Department of Applied Mathematics
This study demonstrates the devil's staircase structure of topological entropy functions for one-dimensional symmetric unimodal maps with a gap inside. The results are obtained by using kneading theory and are helpful in investigating the communication of chaos.
Electromigration in eutectic SnPb solder bumps with Ni/Cu UBM
(2005)
Chiu, SH
;
Liang, SW
;
Chen, C
;
Lin, SS
;
Chou, CM
This study investigates the electromigration behavior of eutectic SnPb solder bumps with Ni/Cu UBM, in which the thickness of the Ni and Cu layer is 3 pm and 5 pm, respectively. It was found that the SnPb solderjoints have better electromigration resistance than that of SnAg bumps with thin film UBM. The thermal characteristic of SnPb solder joints under current stressing was measured by infrared technique. The Joule heating effect was less serious due to the wide Al trace of 100 mu m. Besides, a three-dimensional simulation on current density distribution was performed to examine the current crowding behavior in the joint. The results show that the current crowding occurs at the entrance point of the Al trace, which caused higher formation rate of intermetallic compounds there, and thus open failure occurred.
Exact number of mosaic patterns in cellular neural networks
(2001-06-01)
Ban, JC
;
Lin, SS
;
Shih, CW
;
應用數學系
;
Department of Applied Mathematics
This work investigates mosaic patterns for the one-dimensional cellular neural networks with various boundary conditions. These patterns can be formed by combining the basic patterns. The parameter space is partitioned so that the existence of basic patterns can be determined for each parameter region. The mosaic patterns can then be completely characterized through formulating suitable transition matrices and boundary-pattern matrices. These matrices generate the patterns for the interior cells from the basic patterns and indicate the feasible patterns for the boundary cells. As an illustration, we elaborate on the cellular neural networks with a general 1 x 3 template. The exact number of mosaic patterns will be computed for the system with the Dirichlet, Neumann and periodic boundary conditions respectively. The idea in this study can be extended to other one-dimensional lattice systems with finite-range interaction.
Existence and multiplicity of traveling waves in a lattice dynamical system
(2000-07-01)
Hsu, CH
;
Lin, SS
;
應用數學系
;
Department of Applied Mathematics
This work proves the existence and multiplicity results of monotonic traveling wave solutions for some lattice differential equations by using the monotone iteration method. Our results include the model of cellular neural networks (CNN). In addition to the monotonic traveling wave solutions, non-monotonic and oscillating traveling wave solutions in the delay type of CNN are also obtained. (C) 2000 Academic Press.
Improvements on the duality based method used in solving optimal power flow problems
(2002-05-01)
Lin, CH
;
Lin, SY
;
Lin, SS
;
電控工程研究所
;
Institute of Electrical and Control Engineering
To improve the previously developed dual-type (DT) method used in solving optimal power flow (OPF) problems with large number of thermal-limit constraints, we propose two new techniques in this paper. The first one is a graph-method based decomposition technique which can decompose the large-dimension projection problem, caused by the large number of thermal-limit constraints, into several independent medium-dimension projection subproblems at the expense of slight increment of the dual problem's dimension. The second technique is an active-set strategy based DT method which can solve the medium-dimension projection subproblems efficiently. We have used the DT method embedded with these two new techniques in solving numerous OPF's with large number of thermal-limit constraints. The test results show that the proposed techniques are very efficient and effectively improve the DT method for handling large number of thermal-limit constraints.
Lagrangian stability of a nonlinear quasi-periodic system
(2004-05-01)
Lin, SS
;
Wang, YQ
;
應用數學系
;
Department of Applied Mathematics
In this paper, we prove the Lagrangian stability of the quasi-periodic system d(2)x/dt(2) + G(x)(x, t) 0, where G is quasi-periodic in both x and t, respectively. (C) 2004 Elsevier Inc. All rights reserved.
Metallurgical reactions of Sn-3.5Ag solder with various thicknesses of electroplated Ni/Cu under bump metallization
(2005-10-01)
Huang, CP
;
Chen, C
;
Liu, CY
;
Lin, SS
;
Chen, KH
Nickel has been widely used as an under-bump metallization (UBM) material in the microelectronics industry. The solid-state reaction between the eutectic SnAg solder bumps and three thicknesses of Ni/Cu UBM was investigated, with 5 mu m-Cu/3 mu m-Ni, 3 mu m-Cu/2 mu m-Ni, and 0 mu m-Cu/1 mu m-Ni. It was found that the shear strength of the solder bumps decreased after the solid-state aging at 150 degrees C for 200 h, and it did not change much after it was prolonged for 500 and 1000 h. Aging of the Ag3Sn intermetallic compound (IMC) and grain growth of the solder are responsible for the decrease in the shear strength. Furthermore, the shear test results indicated that the fracture mode switched from ductile to brittle for the solder bumps with 1 mu m Ni after aging longer than 200 h, causing the strength of the solder to decrease abruptly. This is attributed to the consumption of the peripheral Ni layer after the solid-state aging for 1000 It. The Ni consumption rate was measured to be 0.02 mu m/h(1/2) at 150 degrees C.
Novel low-stress SiO2-F-x(x) film deposited by room-temperature liquid-phase deposition method
(1995)
Yeh, CF
;
Lin, SS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
On spherically symmetric solutions of the relativistic Euler equation
(2004-06-20)
Hsu, CH
;
Lin, SS
;
Makino, T
;
應用數學系
;
Department of Applied Mathematics
This work investigates the spherical symmetric solutions of more realistic equation of states. We generalize the method of Hsu et al. (Methods Appl. Anal. 8 (2001) 159) to show the existence of spherical symmetric weak Solution of the relativistic Euler equation with initial data containing the vacuum state. (C) 2004 Elsevier Inc. All rights reserved.
On the spatial entropy and patterns of two-dimensional cellular neural networks
(2002-01-01)
Lin, SS
;
Yang, TS
;
應用數學系
;
Department of Applied Mathematics
This work investigates binary pattern formations of two-dimensional standard cellular neural networks (CNN) as well as the complexity of the binary patterns. The complexity is measured by the exponential growth rate in which the patterns grow as the size of the lattice increases, i.e. spatial entropy. We propose an algorithm to generate the patterns in the finite lattice for general two-dimensional CNN. For the simplest two-dimensional template, the parameter space is split up into finitely many regions which give rise to different binary patterns. Qualitatively, the global patterns are classified for each region. Quantitatively, the upper bound of the spatial entropy is estimated by computing the number of patterns in the finite lattice, and the lower bound is given by observing a maximal set of patterns of a suitable size which can be adjacent to each other.
Patterns generation and transition matrices in multi-dimensional lattice models
(2005-08-01)
Ban, JC
;
Lin, SS
;
應用數學系
;
Department of Applied Mathematics
In this paper we develop a general approach for investigating pattern generation problems in multi-dimensional lattice models. Let S be a set of p symbols or colors, Z(N) a fixed finite rectangular sublattice of Z(d), d >= 1 and N a d-tuple of positive integers. Functions U : Z(d) --> S and U-N : Z(N) --> S are called a global pattern and a local pattern on ZN, respectively. We introduce an ordering matrix X-N for Sigma(N), the set of all local patterns on Z(N). For a larger finite lattice Z((N) over tilde) (N) over tilde >= N, we derive a recursion formula to obtain the ordering matrix X-(N) over tilde of Sigma((N) over tilde) from XN. For a given basic admissible local patterns set 13 C Ely, the transition matrix T-N(B) is defined. For each (N) over tilde >= N denoted by Sigma((N) over tilde)(B) the set of all local patterns which can be generated from B, the cardinal number of Sigma((N) over tilde)(B) is the sum of entries of the transition matrix T-(N) over tilde(B) which can be obtained from T-N(B) recursively. The spatial entropy h(B) can be obtained by computing the maximum eigenvalues of a sequence of transition matrices T-n(B). The results can be applied to study the set of global stationary solutions in various Lattice Dynamical Systems and Cellular Neural Networks.