The main characteristic of Reconfigurable Computing is the presence of hardware that can be reconfigured to implement specific functionality more suitable for specially tailored hardware than on a simple uniprocessor. Reconfigurable computing systems join microprocessors and programmable hardware in order to take advantage of the combined strengths of hardware and software and have been used in applications ranging from embedded systems to high performance computing. Many of the fundamental theories have been identified and used by the Hardware/Software Co-Design research field. Although the same background ideas are shared in both areas, they have different goals and use different approaches.This book is intended as an introduction to the entire range of issues important to reconfigurable computing, using FPGAs as the context, or "computing vehicles" to implement this powerful technology. It will take a reader with a background in the basics of digital design and software programming and provide them with the knowledge needed to be an effective designer or researcher in this rapidly evolving field.

· Treatment of FPGAs as computing vehicles rather than glue-logic or ASIC substitutes
· Views of FPGA programming beyond Verilog/VHDL
· Broad set of case studies demonstrating how to use FPGAs in novel and efficient ways

Reconfigurable Computing: The Theory and Practice of FPGA-Based Computation

As the dominating CMOS technology is fast approaching a "brick wall," new opportunities arise for competing solutions. Nanoelectronics has achieved several breakthroughs lately and promises to overcome many of the limitations intrinsic to current semiconductor approaches. Most of the results in this area reported until now focus on devices and interconnect; this work goes several steps further and presents issues related to circuits and architecture. Based on proposed nanoscale interconnect and device structures, we explore the design space available to the nanoelectronic circuit designer and system architect.

/pdf/molecular-electronics-from-devices-and-interconnect-to-2jv7ya1vbw.pdf

Molecular electronics: from devices and interconnect to circuits and architecture

Immersive virtual reality (IVR) has the potential to be a powerful tool for the visualization of burgeoning scientific data sets and models. We sketch a research agenda for the hardware and software technology underlying IVR for scientific visualization. In contrast to Brooks' (1999) excellent survey which reported on the state of IVR and provided concrete examples of its production use, this article is somewhat speculative. It does not present solutions but rather a progress report, a hope, and a call to action, to help scientists cope with a major crisis that threatens to impede their progress.

Immersive VR for scientific visualization: a progress report

In spite of the significant recent progress, the incorporation of haptics into virtual environments is still in its infancy due to limitations in the hardware, the cost of development, as well as the level of reality they provide. Nonetheless, we believe that the field will one day be one of the groundbreaking media of the future. It has its current holdups but the promise of the future is worth the wait. The technology is becoming cheaper and applications are becoming more forthcoming and apparent. If we can survive this infancy, it will promise to be an amazing revolution in the way we interact with computers and the virtual world. The researchers organize the rapidly increasing multidisciplinary research of haptics into four subareas: human haptics, machine haptics, computer haptics, and multimedia haptics

The Potential of Haptics Technologies

We present a new visualization method for 2d flows which allows us to combine multiple data values in an image for simultaneous viewing. We utilize concepts from oil painting, art, and design as introduced in [1] to examine problems within fluid mechanics. We use a combination of discrete and continuous visual elements arranged in multiple layers to visually represent the data. The representations are inspired by the brush strokes artists apply in layers to create an oil painting. We display commonly visualized quantities such as velocity and vorticity together with three additional mathematically derived quantities: the rate of strain tensor (defined in section 4), and the turbulent charge and turbulent current (defined in section 5). We describe the motivation for simultaneously examining these quantities and use the motivation to guide our choice of visual representation for each particular quantity. We present visualizations of three flow examples and observations concerning some of the physical relationships made apparent by the simultaneous display technique that we employed.

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Visualizing multivalued data from 2D incompressible flows using concepts from painting

Much effort has been put into the development of atomic-scale switches and the construction of computers from atomic-scale components. We propose the construction of physically homogeneous, undifferentiated hardware that is later, after manufacture, differentiated into various digital circuits. This achieves both the immediate goal of achieving specific CPU and memory architectures using atomic-scale switches as well as the larger goal of being able to construct any digital circuit, using the same fixed manufacturing process. Moreover, this opens the way to implementing fundamentally new types of circuit, including dynamic, massively parallel, self-modifying ones. Additionally, the specific architecture in question is not particularly complex, making it easier to construct than most other architectures. We have developed a computing architecture, the Cell MatrixTM, that fits this more attainable manufacturing goal, as well as a process for taking undifferentiated hardware and differentiating it efficiently and cheaply into desirable circuitry. The Cell Matrix is based on a single atomic unit called a cell, which is repeated over and over to form a multidimensional matrix of cells. In addition to being general purpose, the architecture is highly scalable, so much so that it appears to provide access to the differentiation and use of trillion trillion switch hardware. This is not possible with a field programmable gate array architecture, because its gate array is configured serially, and serial configuration of trillion trillion switch hardware would take years. This paper describes the cell in detail and describes how networks of cells in a matrix are used to create small circuits. It also describes a sample application of the architecture that makes beneficial use of high switch counts.

http://iopscience.iop.org/article/10.1088/0957-4484/12/3/305/pdf

The Cell Matrix: an architecture for nanocomputing

Sociological models of human behavior can explain population-level phenomena within social systems; computer modeling can simulate a wide variety of scenarios and allow one to pose and test hypotheses about the social system. In this paper, we model and examine the spread of information through personal conversations in a simulated socio-technical network that provides a high degree of realism and a great deal of captured detail. To our knowledge thisis the first time information spread via conversation has been modeled against a statistically accurate simulation of people's daily interactions within a specific urban or rural environment, capturing the points in time and space at which two people could converse, and providing a realistic basis formodeling human behavior during face-to-face interaction.We use a probabilistic model to decide whether two people will converse about a particular topic based on their similarity and familiarity. Similarity is modeled by matching selected demographic characteristics, while familiarity is modeled by the amount of contact required to convey information. We report our findings on the effects of familiarity and similarity on the spread of information over the social network. We resolve the results by age group, daily activities, time, household income, household size and examine the relative effect of these factors.For informal topics where little familiarity is required, shopping and recreational activities predominate; otherwise, home, work, and school predominate. We find that youths play a significant role in spreading information through a community rapidly, mainly through interactions in schools and recreational activities.

A Study of Information Diffusion over a Realistic Social Network Model

People who use scientific visualizations are generally trying to analyze or solve a scientific problem. The visualizations are usually animations or interactive graphics that scientists create for themselves. The visualizations are intermediate representations intended to represent the problem or its solution graphically (1, 2). Ideally these visualizations are accurate, information-rich, interactive, and illustrative of key features of the phenomenon or data set. They should make the problem (or its solution) easier to understand. Toward this goal we augmented existing graphical visualizations with force feedback (3), as well as true 3-D interaction, in ways that highlight key features such as flow lines. The haptic interface we have developed allows the user to form a high-level view of his data more quickly and accurately.

/pdf/scirun-haptic-display-for-scientific-visualization-3i44i788p5.pdf

SCIRun Haptic Display for Scientific Visualization

A fault testing methodology for a cell-based self configurable hardware platform (the Cell Matrix) is described. Background on the Cell Matrix is given, including its amenability to use despite the presence of manufacturing defects. The ability of cells within the Cell Matrix to isolate faulty regions is also described. A method for testing individual cells, based on an external test driver, is discussed. The benefits of locating this test driver inside the device under test are explained. A method is described for efficient, autonomous, robust creation of a network of self-testing structures (called Supercells) for parallel implementation and execution of this test driver. Sample tests are described, and their results are given, demonstrating the effectiveness and robustness of the testing methodology. A discussion of the research, including conclusions, is presented. Plans for future work are discussed.

Defect-tolerant, fine-grained parallel testing of a Cell Matrix

Open architectures like the one recently unveiled by Facebook allow a detailed assessment of the energy efficiency of commercial data centers. This paper explores the fit of Zipf-like distributions typical of network traffic, to updates of user pages and the entity graph, for the new Facebook data center network architecture. We find that network resource consumption could be reduced by as much as 40–50% through several changes, either to the software, or to the data center design. Of these, employing a connected hub-and-spoke subgraph representation for each popular node, with each pod operating locally on its node of the subgraph, appears to hold the most energy savings potential. This work is part of a larger effort to more completely characterize the efficiency of data center computer-and network architectures beyond the normal reporting of facility power utilization efficiency (PUE), which is blind to energy proportionality and other aspects of the efficiency within the computer- and network architecture, or IT portion, of the data center.

Lisa J. K. Durbeck

Papers

The Cell Matrix: an architecture for nanocomputing

A Study of Information Diffusion over a Realistic Social Network Model

SCIRun Haptic Display for Scientific Visualization

Defect-tolerant, fine-grained parallel testing of a Cell Matrix

Energy efficiency of Zipf traffic distributions within Facebook's data center fabric architecture