Advances in massively parallel platforms are increasing the prospects for high performance discrete event simulation. Still the difficulty in parallel programming persists and there is increasing demand for high level...
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ISBN:
(纸本)9780818675393
Advances in massively parallel platforms are increasing the prospects for high performance discrete event simulation. Still the difficulty in parallel programming persists and there is increasing demand for high level support for building discrete event models to execute on such platforms. We present a parallel DEVS-based (Discrete Event System Specification) simulation environment that can execute on distributed memory multicomputer systems with benchmarking results of a class of high resolution, large scale ecosystem models. Underlying the environment is a parallel container class library for hiding the details of message passing technology while providing high level abstractions for hierarchical, modular DEVS models. The C++ implementation working on the Thinking Machines CM-5 demonstrates that the desire for high level modeling support need not be irreconcilable with sustained high performance.
The growing popularity of wired and wireless Internet requires distributed systems to be more flexible, adaptive and easily extensible. Dynamic reconfiguration of component-based distributed systems is one possible so...
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ISBN:
(纸本)0769517366
The growing popularity of wired and wireless Internet requires distributed systems to be more flexible, adaptive and easily extensible. Dynamic reconfiguration of component-based distributed systems is one possible solution to meet these demands. However, there are some challenges for building dynamically reconfigurable distributed systems. Managing dependencies among components is one of the most crucial problems we have to solve before a system can be dynamically reconfigured at runtime. This paper describes a dependence management for dynamic reconfiguration of distributed systems. The dependence management analyzes not only the static dependencies among components, but also the dynamic dependencies that take place at runtime, in order to support an efficient consistent reconfiguration of distributed systems. In addition, the dependence management can deal with nested dependencies during a dynamic reconfiguration.
The paper describes an implementation of a module for calculating fair values and balance values of financial instruments, according to International Accounting Standard 39. Position balance values are estimated by Am...
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ISBN:
(纸本)9789549641387
The paper describes an implementation of a module for calculating fair values and balance values of financial instruments, according to International Accounting Standard 39. Position balance values are estimated by Amortization Cost Method (method of effectiveness rate of interest). This module is part of Portfolio Management System (PMS) of Much-Net AG. The module is developed in Microsoft Visual C++. The application is a Windows PC based system that operates on many database/data sources.
The increased complexity and short life cycle of toady'sembedded systems increase the need ofmore aggressivemethodology capable of designing systems quicker andmore *** this paper with the hetp of Dynamic DataFloW...
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ISBN:
(纸本)0780379411
The increased complexity and short life cycle of toady'sembedded systems increase the need ofmore aggressivemethodology capable of designing systems quicker andmore *** this paper with the hetp of Dynamic DataFloW modeling technique and a component-orientedimplementation architecture we presents a concurrentdesign approach for data flow dominated *** approach can decompose the design processof an embedded system into a lot of separate design itemswith the consistency being *** generation ofimplementation code framework for hardwarelsoftwarecomponents and implementation code for，different types ofdata paths not onty accelerates the design process，butalso provides a guarantee for the integrity of the target system．
The design of software applications largely amounts to capturing constraints, representing the domain under study. Current case-tools do not provide an unambiguous way to represent constraints and ignore most of the c...
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ISBN:
(纸本)9780909925888
The design of software applications largely amounts to capturing constraints, representing the domain under study. Current case-tools do not provide an unambiguous way to represent constraints and ignore most of the constraints when moving to code. In this article constraints are expressed in the object Constraint Language (OCL) on class diagrams of the Unified Modelling Language (UML). We present a framework assisting the developer in making the transition from constraints on detailed design level to implementation. This framework defines a structure representing the issues related to turning declarative constraints into operational code. Our approach exploits the object-oriented paradigm by representing constraints as explicit classes in the implementation. The points in the code where the constraints must be checked are automatically deduced using the model and by performing path analysis on declarative constraint expressions. An improved code generator is built and integrated in the Argo/UML case-tool. This framework enables developers to exploit the high levels of information that are available in UML/OCL models.
The high variability of students' backgrounds typically found in introductory programming courses creates additional difficulties to foster motivation and ensure the desired competency and retention rates. This pa...
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ISBN:
(纸本)9781581136722
The high variability of students' backgrounds typically found in introductory programming courses creates additional difficulties to foster motivation and ensure the desired competency and retention rates. This paper presents and discusses the results of applying an assessment methodology strongly based upon lab exams (or on-computer exams) with the objective of ensuring programming pratice competency while maintaining students' motivation. It discusses the difficult balances of several assessment methods, details the used assessment methodology and finally presents students results and views. These show that lab exams, although more demanding then group assignments, can be made popular among students if they perceived them as fairer.
The nascent and rapidly evolving state of parallel systems often leaves parallel application developers at the mercy of inefficient, inflexible operating system software. To assess the feasibility of performance tunin...
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The nascent and rapidly evolving state of parallel systems often leaves parallel application developers at the mercy of inefficient, inflexible operating system software. To assess the feasibility of performance tuning via malleable system software and to understand the performance penalties for detailed operating system performance data capture, we describe a set of performance experiments with Choices, an experimental, object-oriented operating system designed for use with parallel systems.< >
Search in repeated contexts can lead to increased search efficiency due to contextual cueing. Contextual cueing has mainly been investigated in two-dimensional displays. However, contextual cueing is affected by depth...
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Search in repeated contexts can lead to increased search efficiency due to contextual cueing. Contextual cueing has mainly been investigated in two-dimensional displays. However, contextual cueing is affected by depth information as well as by the “realism” of the search environment. To investigate these aspects further, we present a guide to design contextual cueing experiments in virtual three-dimensional environments. Specifically, we provide a general introduction to the Unity gaming engine and scripting in C#. We will focus on experimental workflows, but also cover topics like timing precision, how to process and handle participants’ input, or how to create visual assets and manipulate aspects like color. Ultimately, we will turn the entire project into a virtual reality experiment. less
The deterministic simulation library SALMO-OO represents an object-oriented implementation of mass balance equations for pelagic food webs （diatoms,green algae,blue-green algae,cladocerans） and nutrient cycles （PO-...
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The deterministic simulation library SALMO-OO represents an object-oriented implementation of mass balance equations for pelagic food webs （diatoms,green algae,blue-green algae,cladocerans） and nutrient cycles （PO-P,NO-N,DO,detritus） in *** gains its structural flexibility from optional access to alternative process representations for algal growth and grazing,and zooplankton growth and *** validation of distinctive model structures determined by SALMO-OO is shown for three lake categories defined by:a)circulation types that reflect climate and morphometry,and b)
Plasma simulation is an important example of a high-performance computing application where computer science issues are of great relevance. In a plasma, each particle, electron or ion, interacts with the external fiel...
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Plasma simulation is an important example of a high-performance computing application where computer science issues are of great relevance. In a plasma, each particle, electron or ion, interacts with the external fields and with other particles in ways that can be readily and effectively emulated using object-oriented programming. However, the great cost of plasma simulations has traditionally discouraged object-oriented implementations due to their perceived inferior performance compared with classic procedural FORTRAN or C. In the present paper, we revisit this issue. We have developed a Java particle-in-cell code for plasma simulation, called Parsek. The paper considers different choices for the object orientation and tests their performance. We find that coarse-grained object orientation is faster and practically immune from any degradation compared with a standard procedural implementation (with static classes). The loss in performance for a fine-grained object orientation is a factor of about 50%, which can be almost completely eliminated using advanced Java compilation techniques. The Java code Parsek also provides an interesting realistic application of high-performance computing to compare the performance of Java with FORTRAN. We have conducted a series of tests considering various Java implementations and various FORTRAN implementations. We have also considered different computer architectures and different Java Virtual Machines and FORTRAN compilers. The conclusion is that with Parsek, object-oriented Java can reach CPU speed performances more or less comparable with procedural FORTRAN. This conclusion is remarkable and it is in agreement with the most recent benchmarks, but is at variance with widely held misconceptions about the alleged slowness of Java. Copyright (c) 2005 John Wiley & Sons, Ltd.
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