Abstract: A system for collecting and displaying performance improvement information for a computer is implemented in a method for providing performance improvement information to a client device. The method includes the steps of receiving a request from the client device for network content, retrieving the requested network content, and transmitting the network content to the client computer with information relating to a performance improvement associated with the retrieval and/or transmission of the network content.

Abstract: This short paper presents a more general formulation to evaluate the global performance improvement in decentralized multiple-sensor distributed detection systems with data fusion. Furthermore, a comparative study of the global performance improvement in centralized and decentralized approaches is discussed in case of Gaussian distributed observations. The performance loss due to the decentralized approach is also discussed. The needed number of sensors, in the decentralized approach to achieve a performance non inferior to the centralized approach, is also obtained. We consider more complicated examples by considering a large number of sensors to characterize the performance trade-off between the centralized and decentralized approaches. Then the communications requirements can be compared to choose a preferred architecture.

Abstract: Massive uniform nested loops are broadly used in multidimensional digital signal processing (DSP) applications. Due to the large amount of data handled by such applications, the optimization of data accesses by fully utilizing the local memory and minimizing communication overhead is important in order to improve the overall system performance. Most of the traditional partition strategies do not consider the effect of data access on the computational performance. In this paper, a multilevel partitioning method, based on a static data scheduling technique known as carrot-hole data scheduling, is proposed to control the data traffic between different levels of memory. Based on this data schedule, optimal partition vector, scheduling vector and the partition size are chosen in such a way to minimize communication overhead. Nonhomogeneous size partitions are the final result of the partition scheme which produces a significant performance improvement. Experiments show that by using this technique, local memory misses are significantly reduced as compared to results obtained from traditional methods. This method can be used in application specific DSP system design and compiler for DSP processors.

Abstract: Why Perfomance Improvement? Who Are Our Customers? Identifying Customer Requirements Charting a Course for the Organization The Vital Role of Leadership Leading Change in the Organizational Culture Measuring Organizational Performance Constructing the Infrastructure for Organizational Improvement Intergrating the Tools and Techniques of Performance Improvement Case Study References and Resources

Abstract: A method is presented for incremental development of high performance parallel programs, using an application from molecular dynamics as a case study. The method uses the technique of overhead analysis, which aims to explain experimental observations using models of execution behaviour, as a means of determining successive steps in program development. The case study illustrates how this technique can be applied to the complexities of real-world parallel computations.

Abstract: We present a novel tool, called S-Check, for identifying performance bottlenecks in parallel and networked programs. S-Check is a highly-automated sensitivity analysis tool for programs that extends benchmarking and conventional profiling. It predicts how refinements in parts of a program are going to affect performance by making focal changes in code efficiencies and correlating these against overall program performance. This analysis is a sophisticated comparison that catches interactions arising from shared resources or communication links. S-Check's performance assessment ranks code segments "bottleneck" according to their sensitivity to the code efficiency changes. This rank-ordered list serves as a guide for tuning applications. In practice, S-Check code analysis yields faster parallel programs. A case study compares and contrasts sensitivity analyses of the same program on different architectures and offers solutions for performance improvement. An initial implementation of S-Check runs on Silicon Graphics multiprocessors and IBM SP machines. Particulars of the underlying methodology are only sketched with main emphasis given to details of the tool S-Check and its use.

Abstract: In this article, an approach for improving the performance of industrial robots using multilayer feedforward neural networks is presented. The controller based on this approach consists of two main components: a PID control and a neural network. The function of the neural network is to complement the PID control for the specific purpose of improving the performance of the system over time. Analytical and experimental results concerning this synthesis of neural networks and PID control are presented. The analytical results assert that the performance of PID-controlled industrial robots can be improved through proper utilization of the learning and generalization ability of neural networks. The experimental results, obtained through actual implementation using a commercial industrial robot, demonstrate the effectiveness of such control synthesis for practical applications. The results of this work suggest that neural networks could be added to existing PID-controlled industrial robots for performance improvement.

Abstract: An automated modeling approach was developed for the improvement of construction operations by integrating computer simulation and belief networks. Computer simulation is used to model the construction operations while the belief network provides diagnostics to evaluate the simulated construction project performance. Belief networks, also called Bayesian networks, are a form of artificial intelligence (AI) that incorporate uncertainty through probability theory and conditional dependence. While the objective of most construction operations is either reduced cost or shortened duration, a surrogate objective, namely improved performance as measured by performance indices, has been identified to focus the recommendations of the belief network. Five domain-generic performance measurement indices were developed to facilitate the analysis of simulated construction operations: the Queue Length Index (QL), the Queue Wait Index (QW), the Server Quantity Index (SQ), the Server Utilization Index (SU), and the Customer Delay Index (CD). Where a performance index falls outside the acceptable limits or bounds, remedial actions are evaluated by the belief network. Remedial actions include modifying the number of servers or customers, and/or modifying the capacity of either the customer or server. The model has many advantages including: (1) the ability to compare various construction methods or operation strategies; (2) the ability to present solutions even if all user-defined constraints are not met; and, (3) the ability to present more than one solution. The contributions of this research are (1) the development of an automated approach for improving simulated operations, (2) the identification of a surrogate objective, performance improvement, that directs the improvement search toward changes in resource capacities, and, (3) the introduction of belief networks to construction research.

Abstract: This paper proposes an improved power control method, changing the target bit energy per noise spectral density (Eb/No) threshold with adaptive up and down step sizes in variable fading environments. We carry out computer simulations and hardware experiments for verification of the method. The new method results in better frame error rate (FER) and Eb/No performance than the existing ones.

Abstract: The proliferating demand for cellular mobile radio services, and the relatively scarce resource of frequency spectrum provide the need for a fundamental improvement in spectrum efficiency of the new generation cellular mobile radio systems. The switched-beam smart antenna is more attractive when compared to the adaptive null steering, phased array smart antennas. In this paper, a theoretical approach is adopted to ascertain the performance improvement of multi-beam antennas, in which the fading and shadowing models are included. Numerical results of the outage probability under different values of protection ratios and co-channel reuse factors are provided. It is shown that a marked improvement in spectrum efficiency is achieved by reducing the co-channel interference level with adaptive multi-beam antennas employed at the base-stations.

Abstract: A simulation study of dynamic load balancing for parallel processing on network of workstations (NOW) is presented in this paper. A simulation model is constructed. It includes a representative CPU scheduling policy, and also considers the message exchange, task transfer and migration costs explicitly. A global dynamic load balancing algorithm is simulated. Both task transfer and task migration are considered. The performance of the algorithm under both homogeneous and heterogeneous environments is analyzed. In addition, the interaction of parallel and sequential workloads on an NOW is also examined. Our results show that dynamic load balancing can achieve better performance improvement for heterogeneous systems than for homogeneous systems; it is especially effective in a system where both parallel and sequential tasks concurrently exist; and the use of task migration generally does not further improve performance.

Abstract: For decades, top and middle managers have been conditioned to evaluate performance mainly with financial indicators. However, for a business to survive and succeed in today's complex and uncertain environment, it is imperative to monitor performance on the basis of measures that relate to quality, response time to market changes and productivity. Such indicators are the 'vital signs' that determine competitiveness, because they reflect the effectiveness of efforts to improve the performance of business processes through total quality management or other approaches. Today, we have no methods to relate improvements in business processes to economic results. This paper proposes such an approach, to assist management in evaluating more reliably the impact of process improvements that lead to greater customer satisfaction on economic results.

Abstract: This paper proposes a control system for the flexible material handling robot. In the past, there has been reported much research work on flexible material handling robot systems. In most of the previous work, control system parameters were treated as fixed. However, they often change due to variation of the flexible payloads. In some cases, control performance is degraded and the production process is terminated in some situations. To deal with these cases, we propose an error detection method and a replanning system. If system parameters change and control performance is degraded, this system detects error by itself and changes control parameters to recover from the error automatically. Some experimental examples are shown to confirm effectiveness of this proposed system.

Abstract: The selection literature has long debated the theoretical and practical significance of dynamic criteria. Recent research has begun to explore the nature of individual performance over time. This study contributes to this body of research through a hierarchical linear modeling analysis of dynamic criteria. The purpose of this study was to investigate the role of ability in explaining initial job performance, as well as the rate of improvement-or performance trend-among a sample of 408 sewing machine operators over a 24 week period. The results of a hierarchical linear modeling analysis suggest that ability measures are differentially related to initial performance and performance improvement trend.

Abstract: Most real-time systems keep the whole databases in main memory for high performance. In this paper we presuppose that the system has client-server architecture with the restrictions on the memory and the time. In the light of these presupposition, we suggest an effective recovery technique for the index structures, a part of the database, and describe how it provides further performance improvement in the real-time client-server system. The basic paradigm of the proposed recovery technique is that the recovery technique of the indices should be designed differently from that of the other data part to tackle the constraints of the systems. The more client systems are appended to the system, the better performance can be guaranteed in the proposed recovery technique compared with the previous techniques.

Abstract: In this paper a new technique for improving quality of signal transmission over mobile radio channels with flat fading of Rayleigh statistics, is suggested. It is the technique based on implementation of 16QAM trellis modulation. After an original analytical model for such signal processing scheme is defined, the mobile radio system performance are determined through calculation of bit error rate at the system output. It is shown that the technique proposed in this paper enables better received signal quality in comparison with other known techniques such as diversity reception with various combination methods or trellis coding with phase- shift keying modulations.

Abstract: The performance and the architecture of the network that interconnects the diverse functions of computer integrated manufacturing (CIM) are of much importance. Indeed, the majority of these functions have critical-time constraints that must be considered when designing this network. In this paper, an architecture based on the OSI reference model is presented with elements of services and protocols which match the requirements for these constraints. The authors discuss the implementation of their architecture and evaluate the performance of this implementation. Finally, they compare the performance improvement with the existing implementation.

Abstract: Multicomputers are cost-effective alternatives to the conventional supercomputers. Contemporary processor management schemes tend to underutilize the processors and leave many of the processors in the system idle while jobs are waiting for execution. Instead of designing faster processors or interconnection networks, a substantial performance improvement can be obtained by implementing better processor management strategies. This dissertation studies the performance issues related to the processor management schemes and proposes several ways to enhance the multicomputer systems by means of processor management. The proposed schemes incorporate the concepts of size-reduction, non-contiguous allocation, as well as job migration. Job scheduling using a bypass-queue is also studied. All the proposed schemes are proven effective in improving the system performance via extensive simulations. Each proposed scheme has different implementation cost and constraints. In order to take advantage of these schemes, judicious selection of system parameters is important and is discussed.

Abstract: Current interest in self-timed systems is motivated by the area, power and design effort required for the global clock of VLSI synchronous designs. A self-timed data-path, based on the ARM (Advanced RISC Machine) processor, using 'micropipeline' control techniques has been developed for a newly updated high-performance differential bipolar technology. This paper describes the architectural model produced to verify the correctness of the prototype design, and the use of the model in evaluating and enhancing the processor performance. Self-timed design comprises independent blocks whose operation depends solely on input data and unit availability. The modelling of the dynamic behaviour of blocks and the control structures required are presented. These illustrate how easily and well the self-timed operation is mapped onto the Verilog modelling language. Benchmark results on the processor indicate a factor-of-two performance improvement over a CMOS version. The system state at a particular instant is difficult to determine and the effects of interactions between modules are difficult to quantify. The use of the model to explore design changes, particularly to the buffering structures, is presented. This allows the design to be 'tuned' to the technology. It also enables a better understanding of total system behaviour.

Abstract: Most maintenance studies deal with the problem of maintenance-costs optimization, given the cost of the available maintenance actions and a cost objective function. The focus in this paper is on yet another relevant aspect namely the improvement in performance that results from a maintenance action in terms of performance criteria of interest. The evaluation of performance improvement requires comparisons of random quantities which is done by means of suitable probabilistic ordering notions. Different modelling situations are considered, and for each of them conditions are obtained on the life distributions of the present item, and the new one if of different type, that ensure performance improvement. Apart from providing a decision tool for maintenance application, the paper also contributes to clarifying relationships between (probabilistic) ordering notions and aging properties within the maintenance context.

Abstract: Pre-processing images prior to encoding can remove noise, or unimportant detail, and thus improve the overall performance of the coder. Typical objective image quality metrics are obtained by computing a single or several numbers as a function of the difference image between the original and coded images. Such metrics may ont reflect the improvement in performance. In a recent paper we have presented a methodology that allows the quantitative determination of image quality when the image has been processed prior to encoding. We now present an extension of the work showing global objective quality measures that quantify the value of pre-processing for image coding using a wavelet coder. Because many options are available in wavelet coder design, we limit our study to a 'best' coder obtained in previous work, and determine what further performance improvement can be achieved by image processing.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Abstract: High performance dynamic structures have strict requirements on structural motion that are emphasized by the flexibility inherent in lightweight space systems. Vibration isolation is used to prevent disturbances from affecting critical payload components where motion is to be minimized. Isolation, however, is often an engineering solution that is not properly considered in the early conceptual design of the spacecraft. It is at this key stage of a program that mission driving performance targets and resource allocations are made yet little analysis has been performed. A conceptual design methodology for isolation is developed and applied to the conceptual design of a proposed space shuttle based telescope system. In the developed methodology, frequency domain computation of the closed loop performance without isolation pinpoints frequency regimes and disturbance to performance channels targeted for improvement. A coarse fidelity structural model, with well defined disturbance and performance characterization, is more useful than a costly high fidelity analysis when evaluating the many isolation options available early in a project. Isolation design choices are made by trading their performance improvement against their complexity/cost. Simple, idealized mechanical descriptions of the passive or active isolation system provide the needed frequency domain effect on performance without the costly analysis that a detailed isolator design entails. Similarly, the effects of other integrating subsystems, such as structural or optical control are approximated by frequency domain descriptions.

Abstract: The proliferating demand for cellular mobile radio services, and the relatively scarce resource of frequency spectrum provide the need for a fundamental improvement in spectrum efficiency of the new generation cellular mobile radio systems. The switched-beam smart antenna is more attractive when compared to the adaptive null steering, phased array smart antennas. In this paper, a theoretical approach is adopted to ascertain the performance improvement of multi-beam antennas, in which the fading and shadowing models are included. Numerical results of the outage probability under different values of protection ratios and co-channel reuse factors are provided. It is shown that a marked improvement in spectrum efficiency is achieved by reducing the co-channel interference level with adaptive multi-beam antennas eqployed at the base-stations.

Abstract: The nature and use of management models to analyze a systems integration firm are described and the resultant setup of a Virtual Project Office (VPO) is outlined. Business and organizational benefits that arose are reported together with lessons about the models' role in facilitating rapid organizational change and performance improvement.

Abstract: In this paper a framework for an iterative procedure of identification and robust control design is introduced wherein the robust performance is monitored during the subsequent steps of the iterative scheme. By monitoring the performance via a model-based approach, the possibility to guarantee performance improvement in the iterative scheme is being employed. In order to monitor achieved performance (for a present controller) and to guarantee robust performance (for a future controller), an uncertainty set is used where the uncertainty structure is chosen in terms of model perturbations in the dual Youla parametrization. This uncertainty structure is shown to be particularly suitable for the control performance measure that is considered. The model uncertainty set can be identified by an uncertainty estimation procedure on the basis of closed-loop experimental data. To obtain performance robustness, robust control design tools are used to synthesise controllers on the basis of the identified uncertainty set.