共查询到20条相似文献,搜索用时 156 毫秒
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根据处理器芯片的特点,提出了一种基于RTOS的软硬件协同验证方法,该方法在RTOS的基础上建立了一个可移植的协同验证环境,在处理器芯片设计阶段,通过建立一个与芯片相近的硬件平台,在其上利用协同验证环境先验证软件设计的正确性,然后把这些正确的软件放入由处理器芯片构成的协同验证环境中验证设计的芯片。采用这种方法,不仅可以验证处理器芯片设计的正确性,减少错误存在的可能性,而且缩短了芯片验证的时间。 相似文献
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提出了一个具有消息恢复的共享验证代理签名方案。在该方案中,把签名的验证权让[n]个验证人分享,使得指定验证组中的[t]个或更多验证人合作能从签名中恢复消息并能验证签名的有效性。该方案满足代理签名方案的安全要求,传送签名时无需传送消息,和其他代理签名方案相比,降低了通信开销;同时也降低了验证人欺骗的风险,万一遇到验证人欺骗,该方案能准确地检查出哪一个验证人在欺骗。 相似文献
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随着集成电路的快速发展,一个SCC的规模已经在几百万门至几千万门左右,面对这样高的复杂度,功能验证成为芯片设计中的一个挑战。传统的验证方法已经成为SoC设计的“瓶颈”。基于事务的验证方法成为SoC设计中功能验证最有效的途径之一。文中重点阐述了基于事务验证的相关概念,给出了完成SoC事务验证的一般流程和设计方法,并详细分析了事务验证平台的设计调试和功能覆盖率分析,最后对传统的验证方法和基于事务的验证方法进行了比较,给出了基于事务验证方法的优点。 相似文献
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Holarchy formation and optimization in holonic manufacturing systems with contract net 总被引:1,自引:0,他引:1
Fu-Shiung Hsieh Author Vitae 《Automatica》2008,44(4):959-970
Holonic manufacturing systems (HMS) is based on the notion of holon, an autonomous, cooperative and intelligent entity to provide a econfigurable, flexible and decentralized manufacturing environment to respond to changing needs and opportunities. A set of holons that cooperate to achieve a goal forms a holarchy. How to design a mechanism to form a holarchy to achieve a goal while minimizing the overall cost is a challenge. The objectives of this paper are to propose models and develop collaborative algorithms to guide the holons to form a holarchy to coherently move toward the desired goal state ultimately. We adopt contract net protocol (CNP) to model mutual selection of holons in forming a holarchy. We formulate a holarchy optimization problem to minimize the cost subject to the feasibility constraints. To analyze the feasibility of a holarchy, a Petri net (PN) model is proposed. As classical PN models do not take into account the cost involved in firing transitions, we augment the PN model with cost functions in the problem formulation. Due to the distributed architecture of HMS, the internal structure of each potential holarchy that acts as bidder in CNP is not available to the manager. A key issue is to determine the feasibility of a holarchy without constructing the whole PN model of the given hierarchy. We study the feasible conditions for a holarchy and propose a collaborative algorithm to analyze the feasibility and award contracts to holons without constructing the whole model of a holarchy. 相似文献
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Bing Wang 《International Journal on Digital Libraries》1999,2(2-3):91-110
A digital library (DL) consists of a database which contains library information and a user interface which provides a visual
window for users to search relevant information stored in the database. Thus, an abstract structure of a digital library can
be defined as a combination of a special purpose database and a user-friendly interface. This paper addresses one of the fundamental aspects of such
a combination. This is the formal data structure for linking an object oriented database with hypermedia to support digital
libraries. It is important to establish a formal structure for a digital library in order to efficiently maintain different
types of library information. This article discusses how to build an object oriented hybrid system to support digital libraries.
In particular, we focus on the discussion of a general purpose data model for digital libraries and the design of the corresponding
hypermedia interface. The significant features of this research are, first, a formalized data model to define a digital library
system structure; second, a practical approach to manage the global schema of a library system; and finally, a design strategy
to integrate hypermedia with databases to support a wide range of application areas.
Received: 15 December 1997 / Revised: June 1999 相似文献
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Cory J. Rupp Anton Evgrafov Kurt Maute Martin L. Dunn 《Structural and Multidisciplinary Optimization》2007,34(2):111-121
We develop a topology optimization approach to design two- and three-dimensional phononic (elastic) materials, focusing primarily
on surface wave filters and waveguides. These utilize propagation modes that transmit elastic waves where the energy is contained
near a free surface of a material. The design of surface wave devices is particularly attractive given recent advances in
nano- and micromanufacturing processes, such as thin-film deposition, etching, and lithography, which make it possible to
precisely place thin film materials on a substrate with submicron feature resolution. We apply our topology optimization approach
to a series of three problems where the layout of two materials (silicon and aluminum) is sought to achieve a prescribed objective:
(1) a grating to filter bulk waves of a prescribed frequency in two and three dimensions, (2) a surface wave device that uses
a patterned thin film to filter waves of a single or range of frequencies, and (3) a fully three-dimensional structure to
guide a wave generated by a harmonic input on a free surface to a specified output port on the surface. From the first to
the third example, the resulting topologies increase in sophistication. The results demonstrate the power and promise of our
computational framework to design sophisticated surface wave devices. 相似文献
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Abstract This paper describes a case study where a distributed learning model was used to enhance the traditional teaching of a freshwater ecology practical class by providing students with a student-centred constructivist environment. Prior to the practical session, a website was created and students were encouraged to think about the morphological adaptations of stream organisms. They were then divided into groups and taken to a real stream to collect specimens and bring them back to the laboratory for further examination and discussion. After the practical, each student group was required to produce a web page concerning the adaptations of the stream organisms to answer a set of online tutorial questions, and to participate in web-based discussion. Feedback by questionnaire showed that the great majority of students enjoyed working with the website and found the content very useful. More than half of the students preferred this type of web-assisted, student-centred practical to conventional practicals, while about a third showed no special preference between the two approaches. 相似文献
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The per service cost has been a serious impediment to wide spread usage of on-line digital continuous media service, especially in the entertainment arena. Although handling continuous media may be achievable due to technology advances in the past few years, its competitiveness in the market with existing service type such as video rental is still in question. In this paper, we propose a model for continuous media service in a distributed infrastructure which has a video warehouse and intermediate storages connected via a high speed communication network, in an effort to reduce the resource requirement to support a set of service requests. The storage resource and network resource to support a set of requests should be properly quantified to a uniform metric to measure the efficiency of the service schedule. We developed a cost model which maps the given service schedule to a quantity. The proposed cost model is used to capture the amortized resource requirement of the schedule and thus to measure the efficiency of the schedule. The distributed environment consists of a massive scale continuous media server called a video warehouse, and intermediate storages connected via a high speed communication network. An intermediate storage is located in each neighborhood, and its main purpose is to avoid the repeated delivery of the same file to a neighborhood. We consider a situation where a request for a video file is made sometime in advance. We develop a scheduling algorithm which strategically replicates the requested continuous media files at the various intermediate storages. 相似文献
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Ebenezer R. H. P. Isaac Susan Elias Srinivasan Rajagopalan K.S. Easwarakumar 《IEEE/CAA Journal of Automatica Sinica》2019,6(1):209-219
While gait recognition is the mapping of a gait sequence to an identity known to the system, gait authentication refers to the problem of identifying whether a given gait sequence belongs to the claimed identity. A typical gait authentication system starts with a feature representation such as a gait template, then proceeds to extract its features, and a transformation is ultimately applied to obtain a discriminant feature set. Almost every authentication approach in literature favours the use of Euclidean distance as a threshold to mark the boundary between a legitimate subject and an impostor. This article proposes a method that uses the posterior probability of a Bayes' classifier in place of the Euclidean distance. The proposed framework is applied to template-based gait feature representations and is evaluated using the standard CASIA-B gait database. Our study experimentally demonstrates that the Bayesian posterior probability performs significantly better than the de facto Euclidean distance approach and the cosine distance which is established in research to be the current state of the art. 相似文献
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Inductive behaviours may be classified according to their aim. We intend to show that there are at least two kinds of inductive behaviours. Most of the publications seem to take into consideration only one of these: to copy as exactly as possible the behaviour of a probability process. After a brief discussion to explain the necessity of a learning criterion and a recall about one criterion, representative of most of them, we shall define a new criterion, and show why it is better fitted to learn the laws of a deterministic process from a set of observations.This criterion has been used to implement a program which builds an acceptor of natural language sentences in a CAI environment using a tutorial strategy, and then for a question answering device. As attractive as the results are, their improvement requires a semantic model. We give the basic principles of a model which we currently develop, and whose main feature is approximation. 相似文献
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This paper proposes a three-phase approach to forecast a competitive price for a notebook computer as a function of constituent features. Phase I uses regression analysis to relate computer price to constituent features in each of a series of time periods. Phase II involves a time series analysis of each regression coefficient to quantify how trends in market conditions (e.g., the evolution of component technology) affect the market value of each feature. Phase III uses the time series analysis to forecast future market values of each feature and combines these results to forecast a competitive selling price for a notebook model that is composed of a selected set of features. The approach can be used in support of management decisions related to prescribing when to upgrade a notebook model and what features to include in each upgrade. The approach can be used, for example, to forecast notebook model price at introduction, and the rate at which price will erode over the model’s life cycle. Computational results indicate that the approach can forecast the price of a notebook computer model up to four months in advance of its introduction to within 10%. It can also forecast the rate of price erosion to within 10% for up to seven months after introduction — the length of the life cycle of a typical notebook model. Since this approach uses only publicly available data, it can be used easily in industry. 相似文献
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Requirements Engineering-Based Conceptual Modelling 总被引:1,自引:1,他引:1
The software production process involves a set of phases where a clear relationship and smooth transitions between them should
be introduced. In this paper, a requirements engineering-based conceptual modelling approach is introduced as a way to improve
the quality of the software production process. The aim of this approach is to provide a set of techniques and methods to
capture software requirements and to provide a way to move from requirements to a conceptual schema in a traceable way. The
approach combines a framework for requirements engineering (TRADE) and a graphical object-oriented method for conceptual modelling
and code generation (OO-Method). The intended improvement of the software production process is accomplished by providing
a precise methodological guidance to go from the user requirements (represented through the use of the appropriate TRADE techniques)
to the conceptual schema that properly represents them (according to the conceptual constructs provided by the OO-Method).
Additionally, as the OO-Method provides full model-based code generation features, this combination minimises the time dedicated
to obtaining the final software product. 相似文献
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Universal Serial Bus (USB) is a popular choice of interfacing computer systems with peripherals. With the increasing support of modern operating systems, it is now truly plug-and-play for most USB devices. However, this great convenience comes with a risk that can allow a device to perform arbitrary actions at any time while it is connected. Researchers have confirmed that a simple USB device such as a mass storage device can be disguised to have an additional functionality such as a keyboard. An unauthorized keyboard attachment can compromise the security of the host by allowing arbitrary keystrokes to enter the host. This undetectable threat differs from traditional virus that spreads via USB devices due to the location where it is stored and the way it behaves. We propose a novel way to protect the host via a software/hardware solution we named a USBWall. USBWall uses BeagleBone Black (BBB), a low-cost open-source computer, to act as a middleware to enumerate the devices on behalf of the host. We developed a program to assist the user to identify the risk of a device. We present a simulated USB device with malicious firmware to the USBWall. Based on the results, we confirm that using the USBWall to enumerate USB devices on behalf of the host eliminates risks to the hosts. 相似文献