A two-dimensional laser beam profiler has been developed that can measure the intensity distribution on a sample surface of a single-shot of an excimer-laser light beam from not only the macroscopic viewpoint, but also the microscopic viewpoint, which is important to excimer-laser triggered lateral large-grain growth of Si. A resolution as fine as 0.4 µm was obtained with a field of view of as large as 30 µm 30 µm. The effects of homogenizers, phase-shifters, and their combination on beam profiles were quantitatively investigated by using this apparatus. The relationship between the microscopic beam profile and the surface morphology of laterally grown grains was also examined.

To speed up on-line analytical processing (OLAP), data warehouse, which is usually derived from operational databases, is introduced. When the operational databases happen to change, the data warehouse gets stale. To maintain the freshness of data warehouse, operational database changes need to be frequently and concurrently propagated into the data warehouse. However, if several update transactions are allowed to execute concurrently without an appropriate concurrency control, data inconsistency between data warehouse and operational databases could arise due to incorrect propagation of changes on the operational databases into the data warehouse. In this paper, we propose a new concurrency control scheme, which could execute a number of update transactions in a consistent way. Whenever an update transaction tries to update a data that is being used by OLAP transactions, our scheme allows the update transaction to create a new version of the data. To investigate the applicable areas of our scheme, its performance is evaluated by means of simulation approach. Our experimental results show that the proposed scheme enables OLAP transactions to continuously read a very fresh data without wasting a lot of time to find out an appropriate version of the data from the version pool.

Multi-Code CDMA (MC-CDMA) can not only be integrated easily with a conventional CDMA system, but also achieve good spectral efficiency and high processing gain. MC-CDMA requires a linear amplifier due to the increasing value of its peak-to-average power ratio (PAPR) as the number of codes increases. As such, a multi-phased MC-CDMA (MP-CDMA) system is proposed to provide a variable rate service that is not susceptible to the nonlinear characteristics of an amplifier. A clipping technique is used between the output of a multi-code modulator and the input of an MPSK modulator to improve the performance of the MPSK chip demodulator and reduce the system's complexity. System performance is analyzed and compared with the number of codes and clipping levels. The optimum clipping level is also evaluated for the number of codes on both AWGN and flat fading channels.

Finding a nonnegative integer solution x for Ax = b (A Zmn, b Zm1) in Petri nets is NP-complete. Being NP-complete, even algorithms with theoretically bad worst case and with average complexity can be useful for a special class of problems, hence deserve investigation. Then a Grobner basis approach to integer programming problems was proposed in 1991 and some symbolic computation systems became to have useful tools for ideals, varieties, and algorithms for algebraic geometry. In this letter, Grobner basis approach is applied to three typical problems with respect to state equation in P/T Petri nets. In other words, after Grobner bases are derived by the tool Maple 7, we consider how to derive the T-invariants and particular solutions of the Petri nets by using them in this letter.

This letter proposes a novel technique for evaluating the longitudinal distribution of the Raman gain characteristics in optical fibers connected to a reference optical fiber with a known Raman gain efficiency. This technique can evaluate the Raman gain efficiency in test fibers using a simplified experimental setup. We performed experiments on various test fibers and confirmed that their Raman gain efficiency can be obtained easily and accurately by employing a reference fiber.

Fault-tolerant execution of a mobile agent is an important design issue to build a reliable mobile agent system. Several fault-tolerant schemes for a single agent system have been proposed, however, there has been little research result on the multi-agent system. For the cooperating mobile agents, fault-tolerant schemes should consider the inter-agent dependency as well as the mobility; and try to localize the effect of a failure. In this paper, we investigate properties of inter-agent dependency and agent mobility; and then characterize rollback propagation caused by the dependency and the mobility. We then suggest some schemes to localize rollback propagation.

Holonic Manufacturing Systems (HMSs), in which decisions are made through cooperation among holons (autonomous and cooperative manufacturing entities), eliminate various bottlenecks that exist in conventional systems to adapt to high-variety low-volume production. This paper describes the architecture of HMSs. Issues regarding incremental development and dynamic reconfiguration of cooperation mechanisms themselves, and mechanisms for ensuring stable and safe behaviors of HMSs are also discussed with reference to several proposals, with a view to applying the HMS architecture to large and complicated applications.

Edge linking is a fundamental computer vision task, yet presents difficulties arising from the lack of information in the image. Viewed as a constrained optimization problem, it is NP hard-being isomorphic to the classical Traveling Salesman Problem. This paper proposes a gradient ascent learning algorithm of the elastic net approach for edge linking of images. The learning algorithm has two phases: an elastic net phase, and a gradient ascent phase. The elastic net phase minimizes the path through the edge points. The procedure is equivalent to gradient descent of an energy function, and leads to a local minimum of energy that represents a good solution to the problem. Once the elastic net gets stuck in local minima, the gradient ascent phase attempts to fill up the valley by modifying parameters in a gradient ascent direction of the energy function. Thus, these two phases are repeated until the elastic net gets out of local minima and produces the shortest or better contour through edge points. We test the algorithm on a set of artificial images devised with the aim of demonstrating the sort of features that may occur in real images. For all problems, the systems are shown to be capable of escaping from the elastic net local minima and producing more meaningful contours than the original elastic net.

Parameter-optimized cubic convolution is used to accurately analyze the pitch center, rate and extent of vibrato tones. We interpolate the time-tracing fundamental frequencies of vibrato tones using parametric cubic convolution, and analytically estimate the positions and values of the extrema, which are used to analyze the characteristics of the vibrato. The optimal values of α, the parameter of the interpolation kernel, are also shown as a function of the normalized vibrato rates.

The paper develops the transformation rules in order to use the Stochastic Petri Net model to evaluate the performance of various task scheduling algorithms. The transformation rules are applied to DFRN scheduling algorithm to investigate its effectiveness. The performance comparison reveals that the proposed approach provides very accurate evaluation for the scheduling algorithm when the Communication to Computation Ratio value is small.

The purpose of this paper is to propose a novel cluster map based blind RBF equalizer for received signal constellation (RSC) independent channel, which belongs to RSC based blind equalization approach. Without channel estimator, firstly, the desired numbers of unlabeled RBF centers are obtained by an unsupervised clustering algorithm. Then a cluster map generated from the known RBF equalizer structure is used to partition the unlabeled centers into appropriate subsets merely by several simple sorting operations, which corresponds to the weight initialization. Finally, the weight is adjusted iteratively by an unsupervised least mean square (LMS) algorithm. Since the process of the weight initialization using the underlying structure of RBF equalizer is very effective, the proposed blind RBF equalizer can achieve almost identical performance with the optimal RBF equalizer. The validity of the proposed equalizer is also demonstrated by computer simulations.

We show examples of accurate computer-aided design of power coupling between two dielectric slab waveguides of finite length by using the boundary-element method (BEM) based on guided-mode extracted integral equations (GMEIE's). The integral equations derived in this paper can be solved by the conventional BEM. Various properties in numerical calculations of GMEIE's are examined. The reflection and coupling coefficients of the guided wave as well as the scattering power are calculated numerically for the case of incidence TM guided-mode. The presented results are checked by the energy conservation law and reciprocity theorem. The results show that it is possible to design an optimum coupling between two dielectric slab waveguides by using the BEM based on GMEIE's.

This investigation proposes a new multiplication algorithm in the finite field GF(2m) over the polynomial basis, in which the irreducible xm +xn + 1 with gcd(m,n) = 1 generates the field GF(2m). The algorithm involves two steps--the intermediate multiplication and the modulo reduction. In the first step, the intermediate multiplication algorithm permutes a polynomial to construct the full-bit-parallel systolic intermediate multiplier. The circuit is identical of m2 cells, each cell is identical of one 2-input AND gate, one 2-input XOR gate, and four 1-bit latches. In the second step, based on the results of the intermediate multiplication in the first step, the modulo reduction circuit is built using regular and simple reduction operations. The latency of the proposed multiplier requires m + k + 1 clock cycles, where k = + 1. Notably, the latency can be very low if n is in the range 1 n . For the computing multiplication in GF(2m), the novel multiplier exhibits much lower latency than the existing systolic multipliers, and is well suited to VLSI systems due to their regular interconnection pattern, modular structure and fully inherent parallelism.

The knowledge of a good enclosure of the range of a function over small interval regions allows us to avoid convergence of optimization algorithms to a non-global point(s). We used interval slopes f[X,x] to check for monotonicity and integrated their derivative forms g[X,x], x X by quadratic and Newton methods to obtain narrow enclosures. In order to include boundary points in the search for the optimum point(s), we expanded the initial box by a small width on each dimension. These procedures resulted in an improvement in the algorithm proposed by Hansen.

This paper presents a distinct approach to the robustness stability analysis and design of linear uncertain systems. Based on the extension version of the projection method, the specific stability issue, which ensures the poles within a specific region, can be efficiently analyzed. Furthermore, we derive a simple design scheme for a class of uncertain systems. By the proposed numerical algorithm, some examples are given to demonstrate the validity and effectiveness.

Genetic algorithm (GA) is a widely used numerical technique to simplify some analytical solutions in electromagnetic theory. Genetic algorithms can be combined with the geometric optics method to tackle electromagnetic scattering problems. This paper presents an extrapolation procedure, which derived, as a first step, a functional representation of the radar cross section (RCS) of three different dielectric objects that was computed via the Mie solution or the method of moments (MOM). An algorithm was employed to fit the scattering characteristics of dielectric objects at high frequencies.

Field-theoretical equivalent circuit models of a variety of coplanar waveguide (CPW) lumped-element discontinuities for two dominant modes are characterized by executing the short-open calibration (SOC) procedure in the fullwave method of moments (MoM). In our developed MoM platform, the impressed current sources with even or odd symmetry are introduced at the selected ports in order to separately excite the even and odd dominant modes, i.e., CPW- and CSL-mode. After the port network parameters are numerically derived using the Galerkin's technique, the two SOC standards are defined and evaluated in the self-consistent MoM to effectively de-embed and extract the core model parameters of a CPW circuit or discontinuity. After the validation is confirmed via comparison with the published data, extensive investigation is carried out to for the first time demonstrate the distinctive model properties of one-port CPW short- and open-end elements as well as two-port inductive and capacitive coupling elements with resorting to its two different dominant modes.

In this paper, a novel technique using proportional current feedback is proposed to improve dynamic response of digital PWM DC-DC converters. Generally, digital controllers are implemented using microprocessors or DSPs. Additional A/D converters are required to sense feedback signals. Proposed simple structure makes it feasible to integrate both A/D converter and digital controller on a single chip. System complexity and hardware cost are therefore greatly reduced. A behavioral time domain circuit model is proposed and analyzed using MATLAB. Both simulation and experimental results showed satisfactory performance to meet power requirements of microprocessors.

In this paper a second order Volterra series model of an operational amplifier (opamp) circuit is presented. Such a model is suitable to the investigation of the rectification and demodulation effects of radio frequency (RF) interference superimposed on the nominal input signals and on the power supply voltage of an opamp. On the basis of the new model, some design criteria to improve the immunity of opamps to RF interference are proposed. Model predictions are verified by comparison with experimental test results.

This paper presents a novel digit-level algorithm for motion estimation (ME) and its hardware implementations. It uses the most-significant-digit-first (MSD-first) processing and on-line arithmetic ME components. A dedicated array architecture is also proposed for applications with high-throughput ME. Various fast search algorithms were presented in literatures to reduce the complexity but sacrifice the motion vector (MV) quality. Our MSD-first ME decomposes the summation of absolute differences (SAD) and comparison operations to digit level with MSD-plane first. These comparisons are interleaved into SADs to distinguish the MV as soon as possible. The algorithm precisely extracts the impossible candidates and removes their rest operations. It saves 47.4 % to 64.3 % of SAD computations in full search block matching (FSBM) ME. In the past, the high implementation cost of redundant number system prevented the practical use of on-line arithmetic. Besides, the redundant SAD removal results in irregular data flow in system-level integration. All these problems are solved by our novel architecture design. In this paper, we propose novel architecture designs to solve these problems. Besides, the architecture requires only one memory access per pixel to lower memory bandwidth by extensive data parallelism and a particular memory addressing while keeping the controller simple. A 4 4 array processor is implemented in 0.35 µm 1P4M CMOS cell library, with 2.84 ns cycle time and 1510 gates. It can support 83 M FSBM operations per second. After normalization, our implementation can support 2.67 times SAD operations per unit area (estimated in gate count) of the conventional two's complement ones. MSD-first ME can realize with other ME algorithms to improve the performance as well.