The purpose of this panel is to present a broad range of best practices of SOA strategization and operationalization in the use of Web services in real-world SOA implementations. The focus will be on the common challenges and issues encountered in SOA projects. Topics include, but are not limited to, tenets, methodology, architecture, service management, standards, tools, process, organization, governance, security, and quality of services. Practitioner's guides and anti-patterns as well as trends will be discussed in the context. Real-life pragmatic solutions to business problems will be exemplified and illustrated in case studies.

This panel is devoted to the topic of Services Architectures, which play a significant role in the effective operations and delivery of services businesses today.

Summary form only given. Software as a service (SAS) was introduced with the promise of lowering the costs associated with business software applications. To enable SAS and similar software service deployments to function smoothly, service-oriented architectures (SOAs) were introduced and have been quickly evolving for the past five years. Now, with SOAs well understood and software development environments so efficient, the return to insourcing, especially in the larger enterprises, is cutting into the earlier SAS gains. Providers for the mid-market, on the other hand, are wrestling with the dual problem - how to survive with on-demand requirements in a low margin arena? For many of the early pioneers in SAS and SOA, the past year has been one of tough demands from customers and harsh reactions from financial markets, as they continue to figure out how to survive in challenging, unchartered waters.

Panel Theme: now account for more than half of the U.S. economy. Services Computing has become a cross-discipline that covers the science and technology of Innovation Research, which leverages IT and computing technology to model, create, and manage business solutions, scientific applications, as well as modernized services. The underneath technology suite includes Web services and service-oriented architecture (SOA), business consulting methodology and utilities, business process modeling, transformation and integration. (http://tab.computer.org/tcsc)

The market is demanding seamless application integration. Those who can deliver on this demand will be rewarded. Web services will play a key role in making it possible, affordable, and ease to use.

While overlapped block motion compensation (OBMC) with block matching motion vectors yields better estimation accuracy than standard block matching, these estimates may be significantly improved by optimizing the motion vectors. Optimal motion vectors may be determined by an iterative and computationally intensive process. However, for a low-cost system (e.g., videoconferencing), such an approach is not feasible. An analysis of the compensation errors after motion optimization reveals that most gains in estimation accuracy result from the optimization of a fraction of the total number of blocks in a frame. It is thus conceivable that, by defining suitable ordering algorithms for blocks, coding systems could see improved performance by optimizing some number of blocks based on the ordering depending on available computational resources. With the aid of simulations we first show that most improvements by optimizing motion are limited to a few motion vectors. Then we present simple and intuitive algorithms based on compensation error after OBMC with block matching vectors to order blocks. Simulation results using these algorithms for ordering and optimizing motion are presented for two video sequences. The results reveal improvements obtained by optimizing the motion of the blocks from the ordering are reasonable; however, the improvements are not limited to the first fraction of blocks from the ordering, suggesting that better ordering algorithms be investigated in the future.

We present an encoder rate control algorithm based on a perceptual criterion for very low bit rate video. The emerging H.263 recommendation for transmission of video over narrow bandwidth channels supports variable frame rate video streams. This additional freedom enables the rate control algorithm to explore the tradeoff between temporal sampling and spatial quality, while keeping the generated bit rate within the available channel bandwidth. The proposed criterion takes advantage of this tradeoff by using dynamic models of encoder performance and characteristics of the human visual system to adaptively set the nominal quantizer scale factor and instantaneous frame rate. Experiments with typical video-conference sequences demonstrate the application of this new algorithm to both constant and variable bit rate channels.

A block-based gradient descent search (BBGDS) algorithm is proposed in this paper to perform block motion estimation in video coding. The BBGDS evaluates the values of a given objective function starting from a small centralized checking block. The minimum within the checking block is found, and the gradient descent direction where the minimum is expected to lie is used to determine the search direction and the position of the new checking block. The BBGDS is compared with full search (FS), three-step search (TSS), one-at-a-time search (OTS), and new three-step search (NTSS). Experimental results show that the proposed technique provides competitive performance with reduced computational complexity.

This paper describes a new image compression technique, referred to as spatial prediction. Spatial prediction works in a manner similar to fractal-based image compression techniques, and is in fact a result of several experiments that we conducted to gain a better understanding of why fractal compression works. Spatial prediction compresses an image by storing, for each image block, either the quantized discrete cosine transform (DCT) coefficients or the parameters of an affine transformation that constructs the block using another image block from the already encoded portion of the image. This technique does not require contractivity in the at fine transformations and performs as well as or better than fractal compression. Spatial prediction does not out-perform pure DCT-based techniques (such as JPEG) in terms of PSNR/bit-rate tradeoff. However, at very low bit rates it results in far fewer blocky artifacts and markedly better visual quality.

The multiplicative complexity of discrete cosine transforms (DCTs) of arbitrary dimensions on input sizes, which are powers of two, are obtained. New upper bounds on the multiplicative complexity of scaled DCTs on input sizes, which are powers of two, are also obtained.>

The authors present novel scaled discrete cosine transform (DCT) and inverse scaled DCT algorithms designed for fused multiply/add architecture. Since the most popular case used in image processing involves 8*8 blocks (both emerging JPEG and MPEG standards call for DCT coding on blocks of this size), the authors discuss this case in detail. The scaled DCT and inverse scaled DCT each use 416 operations, so that, combined with scaling or descaling, each uses 480 operations. For the inverse, the descaling can be combined with computation of the IDCT (inverse DCT). If multiplicative constants, which depend on the quantization matrix, can be computed offline, then the descaling and IDCT can be computed simultaneously with 417 operations.>

The authors introduce a model, called the uniform memory hierarchy (UMH) model, which reflects the hierarchical nature of computer memory more accurately than the RAM (random-access-machine) model, which assumes that any item in memory can be accessed with unit cost. In the model memory occurs as a sequence of increasingly large levels. Data are transferred between levels in fixed-size blocks (the size is level dependent). Within a level blocks are random access. The model is easily extended to handle parallelism. The UMH model is really a family of models parameterized by the rate at which the bandwidth decays as one travels up the hierarchy. A program is parsimonious on a UMH if the leading terms of the program's (time) complexity on the UMH and on a RAM are identical. If these terms differ by more than a constant factor, then the program is inefficient. The authors analyze two standard FFT programs with the same RAM complexity. One is efficient; the other is not.>

A practical implementation of digital frequency division multiplexing is presented. The design goals are the use of very few modulation schemes (two or three), uniform reliability across the subchannels, and the avoidance of peak power violation. The FTDM (Fourier transform division multiplexing) method is used to design signals for transmission. Data are encoded in the frequency domain, Fourier transformed to yield a real sequence, and a signal is transmitted whose sampled values, when inverse Fourier transformed, yield the original code. Spectral characteristics for the code are easily obtained because it is designed in the frequency domain.>

An analysis is presented of the output of class-IV partial-response channels corrupted simultaneously by jitter and additive white noise. The authors analyze the behavior of the least-squares (LS) decoder for this channel. They introduce the projection-minimization (P-M) algorithm and demonstrate that, under favorable conditions, its performance, even when not acceptable on its own, could possibly be beneficial when used in conjunction with the LS decoder in enhancing the reliability of the channel. Implementation of the P-M decoder is rather expensive, and it is not at all clear that combining the P-M algorithm with LS decoding and traditional error control schemes is the best way of dealing with channels corrupted by jitter. It may be possible to avoid the P-M algorithm and instead utilize a more aggressive traditional error correction scheme. Alternatively, it may be possible to choose modulation schemes which utilize pulses whose derivatives at the sampled values are small, and perhaps obtain better results than with partial-response class-IV signaling.>

The authors present a coding/modulation scheme with design criteria to deal with the peak power constraint on Fourier transform division multiplexing (FTDM). They clip the transmitted signal at some prescribed limit to preserve linearity and base the design on an estimate of the statistics of the errors due to clipping. They have tested these schemes on simulated data with good results. The authors comment on the performance of these schemes and how it relates to the shape of the channel response.>

Given a polynomial $p(z)$ of degree n with m bit integer coefficients and an integer $\mu $, the problem of determining all its roots with error less than $2^{ - \mu } $ is considered. It is shown that this problem is in the class NC if $p(z)$ has all real roots. Some very interesting properties of a Sturm sequence of a polynomial with distinct real roots are proved and used in the design of a fast parallel algorithm for this problem. Using Newton identities and a novel numerical integration scheme for evaluating a contour integral to high precision, this algorithm determines good approximations to the linear factors of $p(z)$.

Article Free Access Share on A fast parallel algorithm for determining all roots of a polynomial with real roots Authors: M Ben-Or Hebrew University, Jerusalem, Israel Hebrew University, Jerusalem, IsraelView Profile , E Feig IBM Research, Yorktown Heights, NY IBM Research, Yorktown Heights, NYView Profile , D Kozen Dept. of Computer Science, Cornell University, Ithaca, NY Dept. of Computer Science, Cornell University, Ithaca, NYView Profile , P Tiwari Coordinated Science Lab., University of Illinois at Urbana-Champaign, Urbana, IL Coordinated Science Lab., University of Illinois at Urbana-Champaign, Urbana, ILView Profile Authors Info & Claims STOC '86: Proceedings of the eighteenth annual ACM symposium on Theory of computingNovember 1986 Pages 340–349https://doi.org/10.1145/12130.12165Published:01 November 1986Publication History 15citation381DownloadsMetricsTotal Citations15Total Downloads381Last 12 Months35Last 6 weeks16 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Abstract We prove the direct sum conjecture for various sets of systems of bilinear forms. Our results depend on a priori knowledge of the complexity of at least one of the direct summands and its underlying algebraic structure. We also briefly survey some previous results concerning the complexity and structure of minimal algorithms for various direct sum systems.