7,669 research outputs found

    Application of bus emulation techniques to the design of a PCI/MC68000 bridge

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    Bridges easy the interconnection and communication of devices that operate using different buses. In fact, we can see a computer as a hierarchy of buses to which devices are connected. In this paper we design a PCI/MC68000 bridge in order to improve communications between a Personal Computer and a MC68000 based system. The previous interface between both devices was based on the old 16-bit ISA bus, which represented a bottleneck in their communication. However, the methodology described here is generic and can be applied to the design of PCI bridges to other buses. We finish this work with an analysis of the bridge performance improvement which can also be easily adapted to other situations. As an example our interface is used in an interesting situation, i.e., updating the obsolete control unit of a highly valuable system (an industrial robot)

    Mining Dynamic Document Spaces with Massively Parallel Embedded Processors

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    Currently Océ investigates future document management services. One of these services is accessing dynamic document spaces, i.e. improving the access to document spaces which are frequently updated (like newsgroups). This process is rather computational intensive. This paper describes the research conducted on software development for massively parallel processors. A prototype has been built which processes streams of information from specified newsgroups and transforms them into personal information maps. Although this technology does speed up the training part compared to a general purpose processor implementation, however, its real benefits emerges with larger problem dimensions because of the scalable approach. It is recommended to improve on quality of the map as well as on visualisation and to better profile the performance of the other parts of the pipeline, i.e. feature extraction and visualisation

    The Progress of Computing

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    The present study analyzes computer performance over the last century and a half. Three results stand out. First, there has been a phenomenal increase in computer power over the twentieth century. Performance in constant dollars or in terms of labor units has improved since 1900 by a factor in the order of 1 trillion to 5 trillion, which represent compound growth rates of over 30 percent per year for a century. Second, there were relatively small improvements in efficiency (perhaps a factor of ten) in the century before World War II. Around World War II, however, there was a substantial acceleration in productivity, and the growth in computer power from 1940 to 2001 has averaged 55 percent per year. Third, this study develops estimates of the growth in computer power relying on performance rather than on input-based measures typically used by official statistical agencies. The price declines using performance-based measures are markedly higher than those reported in the official statistics.Productivity, hedonic pricing, history of computing

    Secure Cloud Storage with Client-Side Encryption Using a Trusted Execution Environment

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    With the evolution of computer systems, the amount of sensitive data to be stored as well as the number of threats on these data grow up, making the data confidentiality increasingly important to computer users. Currently, with devices always connected to the Internet, the use of cloud data storage services has become practical and common, allowing quick access to such data wherever the user is. Such practicality brings with it a concern, precisely the confidentiality of the data which is delivered to third parties for storage. In the home environment, disk encryption tools have gained special attention from users, being used on personal computers and also having native options in some smartphone operating systems. The present work uses the data sealing, feature provided by the Intel Software Guard Extensions (Intel SGX) technology, for file encryption. A virtual file system is created in which applications can store their data, keeping the security guarantees provided by the Intel SGX technology, before send the data to a storage provider. This way, even if the storage provider is compromised, the data are safe. To validate the proposal, the Cryptomator software, which is a free client-side encryption tool for cloud files, was integrated with an Intel SGX application (enclave) for data sealing. The results demonstrate that the solution is feasible, in terms of performance and security, and can be expanded and refined for practical use and integration with cloud synchronization services

    A Reconfigurable Tile-Based Architecture to Compute FFT and FIR Functions in the Context of Software-Defined Radio

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    Software-defined radio (SDR) is the term used for flexible radio systems that can deal with multiple standards. For an efficient implementation, such systems require appropriate reconfigurable architectures. This paper targets the efficient implementation of the most computationally intensive kernels of two significantly different standards, viz. Bluetooth and HiperLAN/2, on the same reconfigurable hardware. These kernels are FIR filtering and FFT. The designed architecture is based on a two-dimensional arrangement of 17 tiles. Each tile contains a multiplier, an adder, local memory and multiplexers allowing flexible communication with the neighboring tiles. The tile-base data path is complemented with a global controller and various memories. The design has been implemented in SystemC and simulated extensively to prove equivalence with a reference all-software design. It has also been synthesized and turns out to outperform significantly other reconfigurable designs with respect to speed and area

    High performance computing of explicit schemes for electrofusion jointing process based on message-passing paradigm

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    The research focused on heterogeneous cluster workstations comprising of a number of CPUs in single and shared architecture platform. The problem statements under consideration involved one dimensional parabolic equations. The thermal process of electrofusion jointing was also discussed. Numerical schemes of explicit type such as AGE, Brian, and Charlies Methods were employed. The parallelization of these methods were based on the domain decomposition technique. Some parallel performance measurement for these methods were also addressed. Temperature profile of the one dimensional radial model of the electrofusion process were also given
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