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1.
The quality of software systems are determined in part by their optimal configurations. Optimal configurations are desired
when the software is being deployed and during its lifetime. However, initial deployment and subsequent dynamic reconfiguration
of a software system is difficult because of the interplay of many interdependent factors, including cost, time, application
state, and system resources. As the size and complexity of software systems increases, procedures (manual or automated) that
assume a static software architecture and environment are becoming untenable. We have developed a novel technique for carrying
out the deployment and reconfiguration planning processes that leverages recent advances in the field of temporal planning.
We describe a tool called Planit, which manages the deployment and reconfiguration of a software system utilizing a temporal
planner. Given a model of the structure of a software system, the network upon which the system should be hosted, and a goal
configuration, Planit will use the temporal planner to devise possible deployments of the system. Given information about
changes in the state of the system, network and a revised goal, Planit will use the temporal planner to devise possible reconfigurations
of the system. We present the results of a case study in which Planit is applied to a system consisting of various components
that communicate across an application-level overlay network.
An earlier version of this paper was presented at ICTAI’03.
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2.
A design pattern is realized in various forms depending on the context of the applications. There has been intensive research
on detecting pattern instances in models and in implementations. However, little work addresses variations of pattern realization.
This paper describes an approach for evaluating conformance of pattern variations. This approach uses a divide-and-conquer
strategy to evaluate the structural conformance of a UML class diagram to the solution of a design pattern. A design pattern
is specified in an extension of the UML that defines the pattern in terms of roles. To demonstrate the approach, we use the
Visitor pattern and two case studies of a price calculator and a word processor. We also present a prototype tool that supports
the approach.
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3.
The unified modelling language (UML), besides its traditional use in describing software artifacts, is increasingly being
used for conceptual modelling, the activity of describing an application domain. For models to be clear and unambiguous, every
construct of the modelling language must have well-defined semantics, which is its mapping to elements of the semantic domain.
When used for conceptual modelling, the semantic domain of UML is the application domain, as perceived by the modeller. Modellers
perceive and structure their perceptions using cognitive concepts. This paper proposes a mapping of the UML association construct
to those concepts. Implications for the use of the association construct for conceptual modelling are derived, a UML profile
for conceptual modelling is presented, along with the results of a case study using the semantics and profile.
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4.
3D computer graphics have been an important feature in games development since it was first introduced in the early 80s and
there is no doubt that 3D based content is often viewed as more attractive in games than the more abstract 2D graphics. Many
games publishers are keen to leverage their success in the console market into the mobile phone platform. However, the resource
constraints of mobile phones and the fragmented nature of the environment present considerable challenges for games developers.
In this paper we consider some of the current constraints together with current and, probable, future developments both in
the software and hardware of mobile phones. As part of this process we benchmark some of the latest and most prevalent software
and hardware devices to ascertain both the quality of the graphics produced and the effects upon battery life. Whilst our
test results highlight that the current market does indeed present challenges, our research into the future developments highlights
the fact we are approaching greater standardization, which will be an important factor for the successful development of 3D
mobile games.
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5.
Technology evolution makes possible the integration of heterogeneous components as programmable elements (processors), hardware
dedicated blocks, hierarchical memories and buses. Furthermore, an optimized reconfigurable logic core embedded within a System-on-Chip
will associate the performances of dedicated architecture and the flexibility of programmable ones. In order to increase performances,
some of the applications are carried out in hardware, using dynamically reconfigurable logic, rather than software, using
programmable elements. This approach offers a suitable hardware support to design malleable systems able to adapt themselves
to a specific application. This article makes a synthesis of the Ardoise project. The first objective of Ardoise project was
to design and to produce a dynamically reconfigurable platform based on commercial FPGAs. The concept of dynamically reconfigurable
architecture depends partially on new design methodologies elaboration as well as on the programming environment. The platform
architecture was designed to be suitable for real-time image processing. The article outlines mainly the Ardoise tools aspect:
development environment and real-time management of the hardware tasks. The proposed methodology is based on a dynamic management
of tasks according to an application scenario written using C++ language.
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6.
This paper describes the recently published Technical Specification ISO 16071 from the International Organisation for Standardisation (ISO), along with the process through which the document has been developed. ISO TS 16071 contains guidelines on designing accessible software. This paper also relates the activities within ISO to other ongoing standardisation activities, within, for example, W3C and ETSI. Scope, contents, guidelines and the definition of accessibility in ISO 16071 are discussed in relation to other definitions. Finally, the process of turning the technical specification (TS) into an international standard (IS) is discussed. 相似文献
7.
The Stanford Event Heap has been shown to provide appropriate support for constructing interactive workspace applications.
Given this success it is natural to consider the Event Heap as a platform to support other classes of Ubiquitous Computing
applications. In this paper we argue that the distributed, spontaneous nature of these applications places additional demands
on the Event Heap that require extensions to both the engineering and API. Suitable extensions are described and their use
to support a typical Ubicomp application is discussed.
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8.
This research involves a methodology and associated proof of concept tool to partially automate software validation by comparing
UML use cases with particular execution scenarios in source code. These execution scenarios are represented as the internal
documentation (identifier names and comments) associated with sequences of execution in static call graphs. This methodology
has the potential to reduce validation time and associated costs in many organizations, by enabling quick and easy validation
of software relative to the use cases that describe the requirements. The proof of concept tool as it currently stands is
intended as an aid to an IV&V software engineer, to assist in directing the software validation process. The approach is lightweight
and easily implemented.
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9.
The paper reflects on the unique experience of social and technological development in Lithuania since the regaining of independence
as a newly reshaped society constructing a distinctive competitive IST-based model at global level. This has presented Lithuanian
pattern of how to integrate different experiences and relations between generations in implementing complex information society
approaches. The resulting programme in general is linked to the Lisbon objectives of the European Union. The experience of
transitional countries in Europe, each different but facing some common problems, may be useful to developing countries in
Africa.
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10.
Image registration is a computationally intensive application in the medical imaging domain that places stringent requirements
on performance and memory management efficiency. This paper develops techniques for mapping rigid image registration applications
onto configurable hardware under real-time performance constraints. Building on the framework of homogeneous parameterized
dataflow, which provides an effective formal model of design and analysis of hardware and software for signal processing applications,
we develop novel methods for representing and exploring the hardware design space when mapping image registration algorithms
onto configurable hardware. Our techniques result in an efficient framework for trading off performance and configurable hardware
resource usage based on the constraints of a given application. Based on trends that we have observed when applying these
techniques, we also present a novel architecture that enables dynamically-reconfigurable image registration. This proposed
architecture has the ability to tune its parallel processing structure adaptively based on relevant characteristics of the
input images.
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11.
This paper describes the simulated car racing competition that was arranged as part of the 2007 IEEE Congress on Evolutionary
Computation. Both the game that was used as the domain for the competition, the controllers submitted as entries to the competition
and its results are presented. With this paper, we hope to provide some insight into the efficacy of various computational
intelligence methods on a well-defined game task, as well as an example of one way of running a competition. In the process,
we provide a set of reference results for those who wish to use the simplerace game to benchmark their own algorithms. The paper is co-authored by the organizers and participants of the competition.
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12.
Scenarios have been shown to be very helpful in identifying and communicating requirements for computer-based systems (CBSs). However, they appear not to be applicable to the rest of the CBS development process. Making scenarios more useful for the entire software development lifecycle requires integrating scenarios to other representations used during CBS development. This integration is achieved with tracing technology. Having integrated scenarios into the entire software development lifecycle creates the necessity to maintain scenarios through the inevitable changes that they and other documents undergo and to subject them to configuration management. We have prototyped automated support for full-lifecycle scenario management and have applied it to some non-trivial systems.This paper is an amalgamation and extension of the conference papers numbered 8, 9, 10, and 11 in the bibliography of this paper. 相似文献
14.
A number of mobile applications have emerged that allow users to locate one another. However, people have expressed concerns
about the privacy implications associated with this class of software, suggesting that broad adoption may only happen to the
extent that these concerns are adequately addressed. In this article, we report on our work on P eopleF inder, an application that enables cell phone and laptop users to selectively share their locations with others (e.g. friends,
family, and colleagues). The objective of our work has been to better understand people’s attitudes and behaviors towards
privacy as they interact with such an application, and to explore technologies that empower users to more effectively and
efficiently specify their privacy preferences (or “policies”). These technologies include user interfaces for specifying rules
and auditing disclosures, as well as machine learning techniques to refine user policies based on their feedback. We present
evaluations of these technologies in the context of one laboratory study and three field studies.
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15.
Assumptions are frequently made during requirements analysis of a system about the trustworthiness of its various components
(including human components). These trust assumptions, whether implicit or explicit, affect the scope of the analysis, derivation
of security requirements, and in some cases how functionality is realized. This paper presents trust assumptions in the context
of analysis of security requirements. A running example shows how trust assumptions can be used by a requirements engineer
to help define and limit the scope of analysis and to document the decisions made during the process. The paper concludes
with a case study examining the impact of trust assumptions on software that uses the secure electronic transaction specification.
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16.
Global communication is essential to industry, research and education. The Access Grid (AG) is a suite of hardware, software,
and tools to facilitate communication and collaboration over the Internet. These resources are used at over 500 institutions
worldwide to support group-to-group interactions across the Grid including collaborative research work sessions, tutorials,
lectures, large-scale distributed meetings and training. This paper will provide an overview of the technology to encourage
professionals to integrate benefits and tools of the Grid into their instruction and research. Furthermore, this paper will
compare this new technology to more traditional videoconferencing and distributed collaborative working environments. Lastly,
it will present issues and challenges that must be addressed to incorporate this momentous technology within the classroom
and for collaboration throughout the world.
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17.
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed. 相似文献
18.
This paper presents a quantitative framework for early prediction of resource usage and load in distributed real-time systems
(DRTS). The prediction is based on an analysis of UML 2.0 sequence diagrams, augmented with timing information, to extract
timed-control flow information. It is aimed at improving the early predictability of a DRTS by offering a systematic approach
to predict, at the design phase, system behavior in each time instant during its execution. Since behavioral models such as
sequence diagrams are available in early design phases of the software life cycle, the framework enables resource analysis
at a stage when design decisions are still easy to change. Though we provide a general framework, we use network traffic as
an example resource type to illustrate how the approach is applied. We also indicate how usage and load analysis of other
types of resources (e.g., CPU and memory) can be performed in a similar fashion. A case study illustrates the feasibility
of the approach.
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19.
Package merge allows the content of one package to be combined with that of another package. Package merge is used extensively
in the UML 2 specification to modularize the definition of the UML 2 meta model and to define the four compliance levels of
UML 2. Package merge is a novel construct in UML and currently not well understood. This paper summarizes our work to understand
and improve package merge. First, we identify ambiguous and missing rules in the package merge definition and suggest corrections.
Then, we formalize package merge and analyze it with respect to some desirable properties. Our analyses employs Alloy, a first-order
modelling language with tool support, and concepts from mathematical logic which allow us to develop a general taxonomy of
package extension mechanisms. The analyses reveal the unexpected failure of important properties.
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20.
Listening to music on personal, digital devices whilst mobile is an enjoyable, everyday activity. We explore a scheme for
exploiting this practice to immerse listeners in navigation cues. Our prototype, ONTRACK, continuously adapts audio, modifying
the spatial balance and volume to lead listeners to their target destination. First we report on an initial lab-based evaluation
that demonstrated the approach’s efficacy: users were able to complete tasks within a reasonable time and their subjective
feedback was positive. Encouraged by these results we constructed a handheld prototype. Here, we discuss this implementation
and the results of field-trials. These indicate that even with a low-fidelity realisation of the concept, users can quite
effectively navigate complicated routes.
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