75 research outputs found

    A survey and taxonomy of layout compaction algorithms

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    This paper presents a survey and a taxonomy of layout compaction algorithms, which are an essential part of modern symbolic layout tools employed in VLSI circuit design. Layout compaction techniques are also used in the low-end stages of silicon compilation tools and module generators. The paper addresses the main algorithms used in compaction, focusing on their implementation characteristics, performance, advantages and drawbacks. Compaction is a highly important operation to optimize the use of silicon area, achieve higher speed through wire length minimization, support technology retargeting and also allow the use of legacy layouts. Optimized cells that were developed for a fabrication process with a set of design rules have to be retargeted for a new and more compact process with a different set of design rules

    Formal modelling and analysis of broadcasting embedded control systems

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    PhD ThesisEmbedded systems are real-time, communicating systems, and the effective modelling and analysis of these aspects of their behaviour is regarded as essential for acquiring confidence in their correct operation. In practice, it is important to minimise the burden of model construction and to automate the analysis, if possible. Among the most promising techniques for real-time systems are reachability analysis and model-checking of networks of timed automata. We identify two obstacles to the application of these techniques to a large class of distributed embedded systems: firstly, the language of timed automata is too low-level for straightforward model construction, and secondly, the synchronous, handshake communication mechanism of the timed automata model does not fit well with the asynchronous, broadcast mechanism employed in many distributed embedded systems. As a result, the task of model construction can be unduly onerous. This dissertation proposes an expressive language for the construction of models of real-time, broadcasting control systems, and demonstrates how effi- cient analysis techniques can be applied to them. The dissertation is concerned in particular with the Controller Area Network (CAN) protocol which is emerging as a de facto standard in the automotive industry. An abstract formal model of CAN is developed. This model is adopted as the communication primitive in a new language, bCANDLE, which includes value passing, broadcast communication, message priorities and explicit time. A high-level language, CANDLE, is introduced and its semantics defined by translation to bCANDLE. We show how realistic CAN systems can be described in CANDLE and how a timed transition model of a system can be extracted for analysis. Finally, it is shown how efficient methods of analysis, such as 'on-the- fly' and symbolic techniques, can be applied to these models. The dissertation contributes to the practical application of formal methods within the domain of broadcasting, embedded control systemsSchool of Computing and Mathematics at the University of Northumbri

    Space Communications: Theory and Applications. Volume 3: Information Processing and Advanced Techniques. A Bibliography, 1958 - 1963

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    Annotated bibliography on information processing and advanced communication techniques - theory and applications of space communication

    Remote Sensing and Geosciences for Archaeology

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    This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications

    Fences: Physical and Socio-Cultural Boundaries

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    Fences, walls, and lines exist around the world, across many cultures, and are generally universally understood symbols of defense, inclusion, and exclusion. Barriers are created intentionally and their purposes vary. Fences can act as a tension or relief between public and private spaces. Physical barriers can been seen as metaphors for social dynamics and relations; boundaries can be reflections of both our internal and external landscapes. Incorporates fences / walls from a number of perspectives; historical, anthropological, archaeological, and cultural. Inspired by a reflexive moment in moving to a new town, buying a house, having a garden, and wanting a fence against deer; Wondering what new neighbors would think about different styles of fences. This resulted in an ethnography of a number of different experiences and memories from New York, mainly the Hudson Valley. The main question was, “What makes a fence culturally appropriate?” The goal was to explore various points of views, including mostly neighbors, a field surveyor, code enforcer, stonemason, gardeners, dog owners, business owners, homeowners, and renters. Themes and surprises arose from interviews. Analysis was done comparing interlocutors social openness compared with how open or private their fences were. Results on the year-long experiment of planting a border garden as a way to hold boundaries are taken into account and also includes season progress photos for context

    A Versatile Tuple-Based Optimization Framework

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    This thesis describes a versatile tuple-based optimization framework. This framework is capable of optimizing traditional imperative codes (such as sparse matrix computations) as well as declarative codes (such as database queries). In the first part of this thesis, the vertical integration of database applications is discussed. Using the described framework it is possible to represent the application codes as well as the declarative database queries within the same intermediate representation, unlocking many optimization opportunities. The second part of this thesis explores the optimization of irregular codes using this framework. It is shown that by expressing irregular codes within the presented framework, many different variants of this code using different data structures can be generated automatically.Computer Systems, Imagery and Medi

    HAL/S-FC and HAL/S-360 compiler system program description

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    The compiler is a large multi-phase design and can be broken into four phases: Phase 1 inputs the source language and does a syntactic and semantic analysis generating the source listing, a file of instructions in an internal format (HALMAT) and a collection of tables to be used in subsequent phases. Phase 1.5 massages the code produced by Phase 1, performing machine independent optimization. Phase 2 inputs the HALMAT produced by Phase 1 and outputs machine language object modules in a form suitable for the OS-360 or FCOS linkage editor. Phase 3 produces the SDF tables. The four phases described are written in XPL, a language specifically designed for compiler implementation. In addition to the compiler, there is a large library containing all the routines that can be explicitly called by the source language programmer plus a large collection of routines for implementing various facilities of the language

    A History of Materials and Technologies Development

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    The purpose of the book is to provide the students with the text that presents an introductory knowledge about the development of materials and technologies and includes the most commonly available information on human development. The idea of the publication has been generated referring to the materials taken from the organic and non-organic evolution of nature. The suggested texts might be found a purposeful tool for the University students proceeding with studying engineering due to the fact that all subjects in this particular field more or less have to cover the history and development of the studied object. It is expected that studying different materials and technologies will help the students with a better understanding of driving forces, positive and negative consequences of technological development, etc
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