Fast QR Algorithms Based on Backward Prediction Errors: A New Implementation and Its Finite Precision Performance

QR decomposition techniques are well known for their good numerical behavior and low complexity. Fast QRD recursive least squares adaptive algorithms benefit from these characteristics to offer robust and fast adaptive filters. This paper examines two different versions of the fast QR algorithm based on a priori backward prediction errors as well as two other corresponding versions of the fast QR algorithm based on a posteriori backward prediction errors. The main matrix equations are presented with different versions derived from two distinct deployments of a particular matrix equation. From this study, a new algorithm is derived. The discussed algorithms are compared, and differences in computational complexity and in finite-precision behavior are shown.     

基于FireWire总线的动态内存获取

Although FireWire-based memory acquisition method has been introduced for several years, the methodologies are not discussed in detail and still lack of practical tools. Besides, the existing method is not working stably when dealing with different versions of Windows. In this paper, we try to compare different memory acquisition methods and discuss their virtues and disadvantages. Then, the methodologies of FireWire-based memory acquisition are discussed. Finally, we give a practical implementation of FireWire-based acquisition tool that can work well with different versions of Windows without causing BSoD problems.     

Reversible integer-to-integer wavelet transforms for imagecompression: performance evaluation and analysis

In the context of image coding, a number of reversible integer-to-integer wavelet transforms are compared on the basis of their lossy compression performance, lossless compression performance, and computational complexity. Of the transforms considered, several were found to perform particularly well, with the best choice for a given application depending on the relative importance of the preceding criteria. Reversible integer-to-integer versions of numerous transforms are also compared to their conventional (i.e., nonreversible real-to-real) counterparts for lossy compression. At low bit rates, reversible integer-to-integer and conventional versions of transforms were found to often yield results of comparable quality. Factors affecting the compression performance of reversible integer-to-integer wavelet transforms are also presented, supported by both experimental data and theoretical arguments.     

Integrable accurate linear negative impedance conversion circuits

Easily integrable versions of accurate and linear negative-impedance converters have been experimentally demonstrated. The converted impedance can be directly coupled with very small external bias currents, and their terminals are truly floating.     

Design and characterization of NULL convention arithmetic logic units

In this paper, a number of 4-bit, 8-operation arithmetic logic units (ALUs) are designed using the delay-insensitive NULL convention logic paradigm, and are characterized in terms of speed and area. Both dual-rail and quad-rail, pipelined and non-pipelined versions are developed, and the tradeoffs and design considerations for each are discussed. Comparing the various architectures shows that the fastest dual-rail and quad-rail ALUs achieve average speedups of 1.72 and 1.59, respectively, over their non-pipelined counterparts, while requiring 133% and 119% more area, respectively. Overall, the dual-rail designs are both faster and require less area than their respective quad-rail counterparts; however, the quad-rail versions are expected to consume less power.     

CDMA系统中2D-RAKE接收机性能比较

该文探讨了CDMA系统中2D-RAKE接收机的各种可能形式,并对其性能进行了分析比较,最后给出了数值模拟结果。     

Global stability of generalized additive fuzzy systems

The paper explores the stability of a class of feedback fuzzy systems. The class consists of generalized additive fuzzy systems that compute a system output as a convex sum of linear operators, continuous versions of these systems are globally asymptotically stable if all rule matrices are stable (negative definite). So local rule stability leads to global system stability. This relationship between local and global system stability does not hold for the better known discrete versions of feedback fuzzy systems. A corollary shows that it does hold for the discrete versions in the special but practical case of diagonal rule matrices. The paper first reviews additive fuzzy systems and then extends them to the class of generalized additive fuzzy systems. It also derives the basic ratio structure of additive fuzzy systems and shows how supervised learning can tune their parameters     

Comment on: dynamic reliability analysis of coherent multistatesystems

The authors comment on the paper by J. Xue and K. Yang (see ibid., vol.44, p.683-8, 1995) Some typographical errors and their correct versions are given. Two of the errors were pointed out by the original authors in their correspondence with the responsible editor. Some comments on the original paper are also given     

A built-in self-test method for diagnosis of synchronous sequentialcircuits

We propose an approach for built-in fault diagnosis of synchronous sequential circuits. The proposed approach distinguishes faults based on their detection by modified versions of a fault detection test sequence generated on-chip. The modified versions are defined by one-bit-wide auxiliary sequences, also generated on-chip. The auxiliary sequences indicate which test vectors of the fault detection test sequence need to be applied to the circuit. Experimental results presented indicate that the proposed on-chip test generation method is effective in achieving high levels of diagnostic-resolution     

通信,计算机与消费电子的结合—C＆C＆C（上）

九十年代开始了通信，计算机和消费电子的三结合。文章介绍这三者相结合的意义，对信息化社会的作用及其最新的进展。     

A comparison of range-Doppler and wavenumber domain SAR focusingalgorithms

Focusing of SAR data requires a space-variant two-dimensional correlation. Different algorithms are compared with each other in terms of their focusing quality and their ability to handle the space-variance of the correlation kernel: the range-Doppler approach with and without secondary range compression, modified range-Doppler algorithms, and four versions of the wavenumber domain processor. The phase aberrations of the different algorithms are given in analytic form. Numerical examples are presented for Seasat and ERS-1. A novel systems theoretical derivation of the wavenumber domain algorithm is presented     

On lapped orthogonal transforms [signal coding applications]

The energy compaction performance of several lapped orthogonal transforms (LOTs) are presented. It is shown that the LOT outperforms the conventional block transforms for all the cases considered. The performance of the poorly performing block transforms for high correlation sources increased dramatically in their LOT versions. It is found that the energy compaction performance of the LOT versions of the different block transforms considered is about the same. Therefore, the choice of LOT is based on the efficiency of the transform algorithm. The LOT is an alternative to the block transforms for signal coding applications. Also, the blocking effect is reduced with the increase in the computational complexity of the transform algorithm     

The use of Burr type XII distribution on software reliability growth modelling

In this paper a new reliability growth model in which the operating time between successive failures is a continuous random variable is proposed. This model is based on Burr type XII distribution with one Parameter which is discussed in three versions: the other statistics, Bayesian and non-homogeneous Poisson process. Several software reliability measures are obtained. The performance of all three versions of the suggested model is tested on two data sets. The versions perform with variable accuracy, which suggests that no universal “best” among the three versions of the model could be attained.     

Information projections revisited

The goal of this paper is to complete results available about I-projections, reverse I-projections, and their generalized versions, with focus on linear and exponential families. Pythagorean-like identities and inequalities are revisited and generalized, and generalized maximum-likelihood (ML) estimates for exponential families are introduced. The main tool is a new concept of extension of exponential families, based on our earlier results on convex cores of measures.     

Sine squared shaping of sync and drive pulses

Networks for generating or shaping sine-squared synchronizing pulses utilized in television systems are discussed and the reasons for their use are explained. Some tests of a simple shaping network which demonstrate the usefulness of sine-squared shaping are described. The network considered utilizes a delay line, or clocked shift register to allow generation of multiple delay versions of the sync pulse, with weighted summing of the delayed signals to produce the desired shaping     

Following standards-the importance of keeping up

Most manufacturers are familiar with the official list of harmonised European standards for use under the self-certification route of the EMC Directive. This list is published from time to time in the Official Journal of the EC. It contains standards for the emissions and immunity performance of specific product types and, by means of generic standards, the emissions and immunity performance of most other product types also. But it is important to realise that the published list is subject to change. and there have in fact been three issues of the list since the Directive came into force in 1992. As new versions of standards have their titles published in the Official Journal, the manufacturer has to reexamine certification. Dates are specified in the revised standard showing withdrawal of previous versions and the period for which existing certification is valid. Specific standards are discussed, standards to be avoided are briefly mentioned, and the impact on design of the changing standards are discussed     

March of the sandbots

Goldman at Georgia Tech, Koditschek and Komsuoglu at the University of Pennsylvania, in Philadelphia, and other collaborators - are hoping that by studying the zebra-tailed lizard and a menagerie of other desert-dwelling creatures, we can create more agile versions of their six-legged robot, SandBot.     

Efficient reconstruction of sequences

We introduce and solve some new problems of efficient reconstruction of an unknown sequence from its versions distorted by errors of a certain type. These erroneous versions are considered as outputs of repeated transmissions over a channel, either a combinatorial channel defined by the maximum number of permissible errors of a given type, or a discrete memoryless channel. We are interested in the smallest N such that N erroneous versions always suffice to reconstruct a sequence of length n, either exactly or with a preset accuracy and/or with a given probability. We are also interested in simple reconstruction algorithms. Complete solutions for combinatorial channels with some types of errors of interest in coding theory, namely, substitutions, transpositions, deletions, and insertions of symbols are given. For these cases, simple reconstruction algorithms based on majority and threshold principles and their nontrivial combination are found. In general, for combinatorial channels the considered problem is reduced to a new problem of reconstructing a vertex of an arbitrary graph with the help of the minimum number of vertices in its metrical ball of a given radius. A certain sufficient condition for solution of this problem is presented. For a discrete memoryless channel, the asymptotic behavior of the minimum number of repeated transmissions which are sufficient to reconstruct any sequence of length n within Hamming distance d with error probability ϵ is found when d/n and ϵ tend to 0 as n→∞. A similar result for the continuous channel with discrete time and additive Gaussian noise is also obtained     

Study of energy and performance of space-time decoding systems in concatenation with turbo decoding

Recent studies have shown that using space-time code is an effective approach to increase the data rate over wireless channels. Space-time turbo (ST-Turbo) codes formed by concatenating space-time codes with turbo codes, take advantage of both the high diversity order of space-time systems and the randomness of the turbo codes. In this paper, we compare two ST-Turbo codes, i.e., simple space-time turbo codes (SiSTT) and turbo trellis-coded modulation space-time block codes (TTCM-STBCs), and their approximate versions with respect to performance and energy consumption for both general-purpose processor and synthesized implementations. The approximations are aimed at reducing the computational complexity and include reduction in the number of paths, number of iterations, and datapath computations. Analysis of the simulation results show that SiSTT-based versions should be used for higher SNR applications where low energy consumption is the primary design objective, and TTCM-STBC-based versions should be used where performance is the primary design objective. Finally, four ST-Turbo algorithms (i.e., baseline SiSTT and its energy-efficient approximate version and the baseline TTCM-STBC and its energy-efficient approximate version) have been synthesized in 0.18-/spl mu/m CMOS technology and the implementations compared with respect to area, power, and latency.     

Analysis and design-optimization of LCC resonant inverter forhigh-frequency AC distributed power system

The analysis and design of an LCC resonant inverter for a 20 kHz AC distributed power system are presented. Several resonant converter topologies are assessed to determine their suitability for high efficiency power conversion, under resistive and reactive loads. Two LCC-resonant inverter designs were implemented. One with all switches operating with zero voltage switching (ZVS), and another with two switches operating with ZVS and two switches with zero current switching (ZCS). The experimental results are presented along with a performance comparison of the two versions