674 research outputs found

    Techniques for the Integration of Existing Tools

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    The purpose of this paper is to explain and demonstrate the advantages of tool integration and the reuse of tools. Several techniques for the integration of existing tools are presented and discussed. These techniques include the use of a monitor, simlated incremental operation, syntax padding, view extraction, and output distribution. The advantages of the use of these methods of tool intregation are illustrated by their use in integrating an existing compiler and on-line debugger. The commands that are produced by this synergisln have increased both the user friendliness of the tools and the power of the resultant command

    The Integration of Software Development Tools

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    The effectiveness of software development tools can be dr creased by their integration (i.e. their cooperation). This paper discusses the problems to be overcome in integration of tools, and a categorization of the degree of tool integration. The continuum from loose to tight integration is parameterized. An informal method is described to apply these parameters to tools in order to determine some nxeasure of their ability to be integrated

    A Multiprocessor Distributed Debugger

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    This thesis presents the design and implementation of a distributed debugger. The debugger was designed to support the debugging of a system containing multiple processors from a single debug console. The debugger implementation consists of host software which runs on a VAX minicomputer and target software which runs on Intel SDK-86 single board computers. The host and targets communicate using an RS-232 channel. The debugger supports breakpoints, disassembly of target code, symbolic reference of program procedures and variables, and download of Intel Object Module Format binary files

    Software Projects 2006-2007

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    An integrated programming environment for pseudo-code development, IPE-PC

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    An Integrated Programming Environment, IPE-PC, that supports pseudo-code development has been designed and implemented. This environment is based on a Pascal-like language which is designed according to the requirements of a language-based environment. The nucleus of IPE-PC is a language-based editor which represents programs as graphs internally. The same representation is used in every mode of the environment (i.e., editing, compilation, execution, debugging and translation). The system provides facilities to take advantage of both top-down and bottom-up programming. Stepwise refinement has been supported by providing comment structures that can be transformed into procedures. Bottom-up programming is supported because it is possible to create and save program segments which can be inserted to the programs at the appropriate points --Abstract, page ii

    A tour of the worm

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    technical reportOn the evening of November 2, 1988, a self-replicating program was released upon the Internet 1. This program (a worm) invaded VAX and Sun-3 computers running versions of Berkeley UNIX, and used their sources to attack still more computers2. Within the space of hours this program had spread aacross the U.S., infecting hundreds or thousands of computers and making many of them unusable due to the burden of its activity. This paper provides a chronology for the outbreak and presents a detailed description of the internals of the worm, based on a C version produced by decompiling

    A new approach to reversible computing with applications to speculative parallel simulation

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    In this thesis, we propose an innovative approach to reversible computing that shifts the focus from the operations to the memory outcome of a generic program. This choice allows us to overcome some typical challenges of "plain" reversible computing. Our methodology is to instrument a generic application with the help of an instrumentation tool, namely Hijacker, which we have redesigned and developed for the purpose. Through compile-time instrumentation, we enhance the program's code to keep track of the memory trace it produces until the end. Regardless of the complexity behind the generation of each computational step of the program, we can build inverse machine instructions just by inspecting the instruction that is attempting to write some value to memory. Therefore from this information, we craft an ad-hoc instruction that conveys this old value and the knowledge of where to replace it. This instruction will become part of a more comprehensive structure, namely the reverse window. Through this structure, we have sufficient information to cancel all the updates done by the generic program during its execution. In this writing, we will discuss the structure of the reverse window, as the building block for the whole reversing framework we designed and finally realized. Albeit we settle our solution in the specific context of the parallel discrete event simulation (PDES) adopting the Time Warp synchronization protocol, this framework paves the way for further general-purpose development and employment. We also present two additional innovative contributions coming from our innovative reversibility approach, both of them still embrace traditional state saving-based rollback strategy. The first contribution aims to harness the advantages of both the possible approaches. We implement the rollback operation combining state saving together with our reversible support through a mathematical model. This model enables the system to choose in autonomicity the best rollback strategy, by the mutable runtime dynamics of programs. The second contribution explores an orthogonal direction, still related to reversible computing aspects. In particular, we will address the problem of reversing shared libraries. Indeed, leading from their nature, shared objects are visible to the whole system and so does every possible external modification of their code. As a consequence, it is not possible to instrument them without affecting other unaware applications. We propose a different method to deal with the instrumentation of shared objects. All our innovative proposals have been assessed using the last generation of the open source ROOT-Sim PDES platform, where we integrated our solutions. ROOT-Sim is a C-based package implementing a general purpose simulation environment based on the Time Warp synchronization protocol

    Can global de-carbonization inhibit developing country industrialization ?

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    Most economic analyses of climate change have focused on the aggregate impact on countries of mitigation actions. The authors depart first in disaggregating the impact by sector, focusing particularly on manufacturing output and exports because of the potential growth consequences. Second, they decompose the impact of an agreement on emissions reductions into three components: the change in the price of carbon due to each country’s emission cuts per se; the further change in this price due to emissions tradability; and the changes due to any international transfers (private and public). Manufacturing output and exports in low carbon intensity countries such as Brazil are not adversely affected. In contrast, in high carbon intensity countries, such as China and India, even a modest agreement depresses manufacturing output by 6-7 percent and manufacturing exports by 9-11 percent. The increase in the carbon price induced by emissions tradability hurts manufacturing output most while the Dutch disease effects of transfers hurt exports most. If the growth costs of these structural changes are judged to be substantial, the current policy consensus, which favors emissions tradability (on efficiency grounds) supplemented with financial transfers (on equity grounds), needs re-consideration.Climate Change Mitigation and Green House Gases,Climate Change Economics,Environment and Energy Efficiency,Energy and Environment,Carbon Policy and Trading

    Can Global De-Carbonization Inhibit Developing-Country Industrialization?

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    Most economic analyses of climate change have focused on the aggregate impact on countries of mitigation actions. We depart first in disaggregating the impact by sector, focusing particularly on manufacturing output and exports because of the potential growth consequences. Second, we decompose the impact of an agreement on emissions reductions into three components: the change in the price of carbon due to each country’s emission cuts per se; the further change in this price due to emissions tradability; and the changes due to any international transfers (private and public). Manufacturing output and exports in low carbon intensity countries such as Brazil are not adversely affected. In contrast, in high carbon intensity countries, such as China and India, even a modest agreement depresses manufacturing output by 6-7 percent and manufacturing exports by 9-11 percent. The increase in the carbon price induced by emissions tradability hurts manufacturing output most while the Dutch disease effects of transfers hurt exports most. If the growth costs of these structural changes are judged to be substantial, the current policy consensus, which favors emissions tradability (on efficiency grounds) supplemented with financial transfers (on equity grounds), needs re-consideration.trade; environment; climate change; emissions trading

    A small perturbation based optimization approach for the frequency placement of high aspect ratio wings

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    Design denotes the transformation of an identified need to its physical embodiment in a traditionally iterative approach of trial and error. Conceptual design plays a prominent role but an almost infinite number of possible solutions at the outset of design necessitates fast evaluations. The traditional practice of empirical databases loses adequacy for novel concepts and an ever increasing system complexity and resource scarsity mandate new approaches to adequately capture system characteristics. Contemporary concerns in atmospheric science and homeland security created an operational need for unconventional configurations. Unmanned long endurance flight at high altitudes offers a unique showcase for the exploration of new design spaces and the incidental deficit of conceptual modeling and simulation capabilities. The present research effort evolves around the development of an efficient and accurate optimization algorithm for high aspect ratio wings subject to natural frequency constraints. Foundational corner stones are beam dimensional reduction and modal perturbation redesign. Local and global analyses inherent to the former suggest corresponding levels of local and global optimization. The present approach departs from this suggestion. It introduces local level surrogate models to capacitate a methodology that consists of multi level analyses feeding into a single level optimization. The innovative heart of the new algorithm originates in small perturbation theory. A sequence of small perturbation solutions allows the optimizer to make incremental movements within the design space. It enables a directed search that is free of costly gradients. System matrices are decomposed based on a Timoshenko stiffness effect separation. The formulation of respective linear changes falls back on surrogate models that approximate cross sectional properties. Corresponding functional responses are readily available. Their direct use by the small perturbation based optimizer ensures constitutive laws and eliminates a previously necessary optimization at the local level. The great economy of the developed algorithm makes it suitable for the conceptual phase of aircraft design.Ph.D.Committee Chair: Mavris, Dimitri; Committee Member: Bauchau, Olivier; Committee Member: Schrage, Daniel; Committee Member: Volovoi, Vitali; Committee Member: Yu, Wenbi
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