888,505 research outputs found
Generating a Performance Stochastic Model from UML Specifications
Since its initiation by Connie Smith, the process of Software Performance
Engineering (SPE) is becoming a growing concern. The idea is to bring
performance evaluation into the software design process. This suitable
methodology allows software designers to determine the performance of software
during design. Several approaches have been proposed to provide such
techniques. Some of them propose to derive from a UML (Unified Modeling
Language) model a performance model such as Stochastic Petri Net (SPN) or
Stochastic process Algebra (SPA) models. Our work belongs to the same category.
We propose to derive from a UML model a Stochastic Automata Network (SAN) in
order to obtain performance predictions. Our approach is more flexible due to
the SAN modularity and its high resemblance to UML' state-chart diagram
Power aware early design stage hardware software co-optimization
Co-optimizing hardware and software can lead to substantial performance and energy benefits, and is becoming an increasingly important design paradigm. In scientific computing, power constraints increasingly necessitate the return to specialized chips such as Intel’s MIC or IBM’s Blue-Gene architectures. To enable hardware/software co-design in early stages of the design cycle, we propose a simulation infrastructure methodology by combining high-abstraction performance simulation using Sniper with power modeling using McPAT and custom DRAM power models. Sniper/McPAT is fast — simulation speed is around 2 MIPS on an 8-core host machine — because it uses analytical modeling to abstract away core performance during multi-core simulation. We demonstrate Sniper/McPAT’s accuracy through validation against real hardware; we report average performance and power prediction errors of 22.1% and 8.3%, respectively, for a set of SPEComp benchmarks
Statistical modelling of software reliability
During the six-month period from 1 April 1991 to 30 September 1991 the following research papers in statistical modeling of software reliability appeared: (1) A Nonparametric Software Reliability Growth Model; (2) On the Use and the Performance of Software Reliability Growth Models; (3) Research and Development Issues in Software Reliability Engineering; (4) Special Issues on Software; and (5) Software Reliability and Safety
An architecture-based dependability modeling framework using AADL
For efficiency reasons, the software system designers' will is to use an
integrated set of methods and tools to describe specifications and designs, and
also to perform analyses such as dependability, schedulability and performance.
AADL (Architecture Analysis and Design Language) has proved to be efficient for
software architecture modeling. In addition, AADL was designed to accommodate
several types of analyses. This paper presents an iterative dependency-driven
approach for dependability modeling using AADL. It is illustrated on a small
example. This approach is part of a complete framework that allows the
generation of dependability analysis and evaluation models from AADL models to
support the analysis of software and system architectures, in critical
application domains
Kerncraft: A Tool for Analytic Performance Modeling of Loop Kernels
Achieving optimal program performance requires deep insight into the
interaction between hardware and software. For software developers without an
in-depth background in computer architecture, understanding and fully utilizing
modern architectures is close to impossible. Analytic loop performance modeling
is a useful way to understand the relevant bottlenecks of code execution based
on simple machine models. The Roofline Model and the Execution-Cache-Memory
(ECM) model are proven approaches to performance modeling of loop nests. In
comparison to the Roofline model, the ECM model can also describes the
single-core performance and saturation behavior on a multicore chip. We give an
introduction to the Roofline and ECM models, and to stencil performance
modeling using layer conditions (LC). We then present Kerncraft, a tool that
can automatically construct Roofline and ECM models for loop nests by
performing the required code, data transfer, and LC analysis. The layer
condition analysis allows to predict optimal spatial blocking factors for loop
nests. Together with the models it enables an ab-initio estimate of the
potential benefits of loop blocking optimizations and of useful block sizes. In
cases where LC analysis is not easily possible, Kerncraft supports a cache
simulator as a fallback option. Using a 25-point long-range stencil we
demonstrate the usefulness and predictive power of the Kerncraft tool.Comment: 22 pages, 5 figure
A methodology for software performance modeling and its application to a border inspection system
It is essential that software systems meet their performance objectives. Many factors affect software performance and it is fundamental to identify those factors and the magnitude of their effects early in the software lifecycle to avoid costly and extensive changes to software design, implementation, or requirements. In the last decade the development of techniques and methodologies to carry out performance analysis in the early stages of the software lifecycle has gained a lot of attention within the research community. Different approaches to evaluate software performance have been developed. Each of them is characterized by a certain software specification and performance modeling notation.;In this thesis we present a methodology for predictive performance modeling and analysis of software systems. We use the Unified Modeling Language (UML) as a software modeling notation and Layered Queuing Networks (LQN) as a performance modeling notation. Our focus is on the definition of a UML to LQN transformation We extend existing approaches by applying the transformation to a different set of UML diagrams, and propose a few extensions to the current UML Profile for Schedulability, Performance, and Time , which we use to annotate UML diagrams with performance-related information. We test the applicability of our methodology to the performance evaluation of a complex software system used at border entry ports to grant or deny access to incoming travelers
Software systems for modeling articulated figures
Research in computer animation and simulation of human task performance requires sophisticated geometric modeling and user interface tools. The software for a research environment should present the programmer with a powerful but flexible substrate of facilities for displaying and manipulating geometric objects, yet insure that future tools have a consistent and friendly user interface. Jack is a system which provides a flexible and extensible programmer and user interface for displaying and manipulating complex geometric figures, particularly human figures in a 3D working environment. It is a basic software framework for high-performance Silicon Graphics IRIS workstations for modeling and manipulating geometric objects in a general but powerful way. It provides a consistent and user-friendly interface across various applications in computer animation and simulation of human task performance. Currently, Jack provides input and control for applications including lighting specification and image rendering, anthropometric modeling, figure positioning, inverse kinematics, dynamic simulation, and keyframe animation
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The uses of process modeling : a framework for understanding modeling formalisms
There is wide-spread recognition of the urgent need to improve software processes in order to improve the performance of software organizations. Process models are essential in achieving understanding and visibility of processes and are important for other uses including the analysis of processes for improvement. It has been increasingly difficult to compare and evaluate the variety of process modeling formalisms that have appeared in recent years without a clear understanding of precisely for what they will be used. The contribution of this paper is to provide an understanding and a fairly comprehensive catalog of the applications of process modeling for which formalisms may be used. The primary mechanism for doing this is a guided tour of the literature on process modeling supplemented by recent industrial experience. In the paper, basic definitions concerning processes, process descriptions and process modeling are reviewed and then uses of process modeling are surveyed under the following headings: communication among process participants, construction of new processes, control of processes, process· analysis, and process support by automation. Comments are offered on paradigms for process modeling formalisms and directions for future work to permit evolution of a discipline of process engineering are given
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