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1.
The principles of open editing in wiki technology are described as illustrated by the example of Wikipedia, a popular free Web encyclopedia. Information is given about GNU software, Uniform Computer Information Transaction Act, licenses for free software and their corresponding free user manuals, as well as about legal issues arising in connection with the Free Documentation License.  相似文献   

2.
This paper considers the need to provide some form of local area network management. Although Ethernet systems form the main example, the requirements are the same, in general, for other local networks. The authors argue why network management is necessary, examine the difficulties involved, and take a look at the current standards work in the area. Finally, they discuss management of their own particular local area network environment.  相似文献   

3.
We describe our approach to secure authentication and authorization for extended enterprises, which combines distributed role-based access control (RBAC), a public key infrastructure (PKI), and a privilege management infrastructure (PMI). We have implemented a J2EE-based prototype system, DRBAC-EE, which shows the feasibility of our approach.  相似文献   

4.
The National Institute of Standards and Technology is responsible for the development and dissemination of cost-effective solutions for protecting unclassified information processed by US Government agencies. NIST activities include developing standards and guidelines, providing advice and assistance to US Government agencies, and conducting research. Ongoing work addresses application issues such as encryption, risk management, and network security techniques. Future challenges in computer security will include the development of new cost-effective solutions for complex and decentralized systems of the 1990s.  相似文献   

5.
Computer systems increasingly carry out tasks in mixed networks, that is in group settings in which they interact both with other computer systems and with people. Participants in these heterogeneous human-computer groups vary in their capabilities, goals, and strategies; they may cooperate, collaborate, or compete. The presence of people in mixed networks raises challenges for the design and the evaluation of decision-making strategies for computer agents. This paper describes several new decision-making models that represent, learn and adapt to various social attributes that influence people's decision-making and presents a novel approach to evaluating such models. It identifies a range of social attributes in an open-network setting that influence people's decision-making and thus affect the performance of computer-agent strategies, and establishes the importance of learning and adaptation to the success of such strategies. The settings vary in the capabilities, goals, and strategies that people bring into their interactions. The studies deploy a configurable system called Colored Trails (CT) that generates a family of games. CT is an abstract, conceptually simple but highly versatile game in which players negotiate and exchange resources to enable them to achieve their individual or group goals. It provides a realistic analogue to multi-agent task domains, while not requiring extensive domain modeling. It is less abstract than payoff matrices, and people exhibit less strategic and more helpful behavior in CT than in the identical payoff matrix decision-making context. By not requiring extensive domain modeling, CT enables agent researchers to focus their attention on strategy design, and it provides an environment in which the influence of social factors can be better isolated and studied.  相似文献   

6.
The problem of managing large communication networks using statistical tests, alerts, and correlation among alerts is considered. The authors propose a model of these network management functions as data-manipulation operations. They argue that this approach can improve the flexibility of network management systems by providing a language that is declarative and set-oriented. These are properties of existing data-manipulation languages and it is shown that any data-manipulation language, augmented with several new capabilities, can serve as a language for specifying the aforementioned network management functions. The new capabilities required are specification of events, correlation among events, and change-tracking  相似文献   

7.
Software is a major source of reliability degradation in dependable systems. One of the classical remedies is to provide software fault tolerance by using N-Version Programming (NVP). However, due to requirements on non-standard hardware and the need for changes and additions at all levels of the system, NVP solutions are costly, and have only been used in special cases.In a previous work, a low-cost architecture for NVP execution was developed. The key features of this architecture are the use of off-the-shelf components including communication standards and that the fault tolerance functionality, including voting, error detection, fault-masking, consistency management, and recovery, is moved into a separate redundancy management circuitry (one for each redundant computing node).In this article we present an improved design of that architecture, specifically resolving some potential inconsistencies that were not treated in detail in the original design. In particular, we present novel techniques for enforcing replica determinism.Our improved architecture is based on using the Controller Area Network (CAN). This choice goes beyond the obvious interest of using standards in order to reduce the cost, since all the rest of the architecture is designed to take full advantage of the CAN standard features, such as data consistency, in order to significantly reduce the complexity, the efficiency and the cost of the resultant system.Although initially developed for NVP, our redundancy management circuitry also supports other software replication techniques, such as active replication.  相似文献   

8.
In a mobile ad-hoc network (MANET), mobile hosts can move freely and communicate with each other directly through a wireless medium without the existence of a fixed wired infrastructure. MANET is typically used in battlefields and disaster recovery situations where it is not feasible to have a fixed network. Techniques that manage database transactions in MANET need to address additional issues such as host mobility, energy limitation and real-time constraints. This paper proposes a solution for transaction management that reduces the number of transactions missing deadlines while balancing the energy consumption by the mobile hosts in the system. This paper then reports the simulation experiments that were conducted to evaluate the performance of the proposed solution in terms of number of transactions missing deadlines, total energy consumption and the distribution of energy consumption among mobile hosts. Recommended by: Ahmed Elmagarmid This work is partially supported by the National Science Foundation grants No. EIA-9973465 and IIS-0312746.  相似文献   

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10.
This article argues against the promulgation of copyright protection to fashion designs in the USA, largely due to its antitrust laws. Even though copyright protection is granted in European nations, certain markets in the USA are highly susceptible to monopolistic activities; specifically, the eyeglass frame market in the USA. Congress has been increasingly introducing bills such as the Innovative Design Protection Act of 2012 (‘IDPA’) to grant copyright protection to fashion designs. If this bill or a similar bill were promulgated, the current near monopolies in the fashion industry would then be given the opportunity to raise prices for improper purposes. Congress has not thoroughly considered whether the IDPA would have anticompetitive effects in the USA. Thus, granting copyright protection for fashion designs should not be enacted without careful consideration of the anticompetitive effects it will have on the fashion industry.  相似文献   

11.
License compliance in Free and Open Source Software development is a significant issue today and organizations using free and open source software are predominately focusing on this issue. The non-compliance to licenses in free and open source software development leads to the loss of reputation and the high costs of litigation for organizations. Towards an automated compliance management, we use the Open Digital Rights Language to implement the clauses of open source software licenses in a machine interpretable way and propose a novel algorithm that analyzes compatibility between free and open source software licenses. Also, we describe a framework that inductively manages compliance of license clauses in a free and open source software development. We simulate and evaluate the formalized license compliance management by analyzing a real-time open source software project GRASS.  相似文献   

12.
Distributed peer-to-peer computing in which no centralized control server is assumed, and in some cases, client-server architecture is actually rejected, has been the subject of intense investigations in the field of information technologies in the recent years. This new paradigm of designing large-scale distributed intelligent systems attracts attention of both researchers and developers of industrial applications. This paradigm provides qualitatively new capabilities, especially for designing systems consisting of a large number of autonomous instances which can appear and disappear from the system at any time instant. The idea of integration of these systems (hereinafter, P2P systems for brevity) and multi-agent technologies is especially attractive; it realizes the advantages of both paradigms, namely, the maturity of technologies and the relative simplicity of creation of multi-agent systems consisting of autonomous intelligent programs which interact via a high-level language, as well as the openness, the scalability, and the reliability of P2P systems. This integration seems quite natural. Indeed, multi-agent systems is the set of autonomous intelligent programs; therefore, the structuring of these programs into the network whose nodes interact directly without any intermediate server is the natural step if the technology of P2P interactions has been well developed using a high level language. However, for practical realization of this idea, it is necessary to make one very important step, namely, to develop mechanisms for agent interaction on a semantic level, when agents query some functionalities (services) from each other, possibly, not knowing a priori what particular agents can provide the queried functionality (service) and whether these agents exist in the network. The application of the agent variant of the architecture, the service oriented architecture, another new paradigm of construction of information systems, provides practical capability of realization of mechanisms of semantic interaction of agents of the open P2P network. This work represents the P2P agent platform developed by the authors whose instances installed on the network nodes above the standard P2P service form the distributed meta-knowledge knowledge base intended for organization of semantic P2P interaction of agents. Application-oriented agents placed on the network nodes above the instances of the agent platform receive the capability of semantic interaction. The program realization of the platform is supported by the mechanism of P2P interaction of agents using messages with standard formats and pair communications of the network nodes. The role, functions, and the essence of the processes of operation of this platform is explained using two applications as the examples; these applications are sufficiently important from the practical point of view. They are used for verification of basic solutions presented in this work.  相似文献   

13.
Boundary feedback control in networks of open channels   总被引:1,自引:0,他引:1  
This article deals with the regulation of water flow in open-channels modelled by Saint-Venant equations. By means of a Riemann invariants approach, we deduce stabilizing control laws for a single horizontal reach without friction. The stability condition is extended to a general class of hyperbolic systems which can describe canal networks with more general topologies. A control law design based on this condition is illustrated with a simple case study: two reaches in cascade. The proof of the main stability theorem is based on a previous result from Li Ta-tsien concerning the existence and decay of classical solutions of hyperbolic systems.  相似文献   

14.
In this paper, we use the event-based optimization framework to study the admission control problem in an open Jackson network. The external arriving customers are controlled by an admission controller. The controller makes decision only at the epoch when an event of customer arrival happens. Every customer in the network obtains a fixed reward for each service completion and pays a cost with a fixed rate during its sojourn time (including waiting time and service time). The complete information of the system state is not available for the controller. The controller can observe only the number of total customers in the network. Based on the property of closed form solution of Jackson networks, we prove that the system performance is monotonic with respect to the admission probabilities and the optimal control policy has a threshold form. That is, when the number of total customers is smaller than a threshold, all of the arriving customers are admitted; otherwise, all are rejected. The sufficient condition and necessary condition of optimal policy are also derived. Furthermore, we develop an iterative algorithm to find the optimal policy. The algorithm can be executed based on a single sample path, which makes the algorithm online implementable. Simulation experiments are conducted to demonstrate the effectiveness of our approach.  相似文献   

15.
Open set recognition is a classification-like task. It is accomplished not only by the identification of observations which belong to targeted classes (i.e., the classes among those represented in the training sample which should be later recognized) but also by the rejection of inputs from other classes in the problem domain. The need for proper handling of elements of classes beyond those of interest is frequently ignored, even in works found in the literature. This leads to the improper development of learning systems, which may obtain misleading results when evaluated in their test beds, consequently failing to keep the performance level while facing some real challenge. The adaptation of a classifier for open set recognition is not always possible: the probabilistic premises most of them are built upon are not valid in a open-set setting. Still, this paper details how this was realized for WiSARD a weightless artificial neural network model. Such achievement was based on an elaborate distance-like computation this model provides and the definition of rejection thresholds during training. The proposed methodology was tested through a collection of experiments, with distinct backgrounds and goals. The results obtained confirm the usefulness of this tool for open set recognition.  相似文献   

16.
With the increasing prevalence of multi-user environments in distributed systems, it has become an increasingly challenging task to precisely identify who is doing what on an enterprise network. Current management systems that rely on inference for user identity and application are not capable of accurately reporting and managing a large-scale network due to the coarseness of the collected data or scaling of the collection mechanism. We propose a system that focuses data collection in the form of local context, i.e. the precise user and application associated with a network connection. Through the use of dynamic correlation and novel graph modeling, we developed a visualization tool called ENAVis (the work appeared in earlier form in [1] and received USENIX best paper award). (Enterprise Network Activities Visualization). ENAVis aids a real-world administrator in allowing them to more efficiently manage and gain insight about the connectivity between hosts, users, applications and data access offering significant streamlining of the management process.  相似文献   

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Open zero-buffer multi-server general queueing networks occur throughout a number of physical systems in the semi-process and process industries. In this paper, we evaluate the performance of these systems in terms of throughput using the generalized expansion method (GEM) and compare our results with simulation. Secondly, we embed the performance evaluation in a multi-objective optimization setting. This multi-objective optimization approach results in the Pareto efficient curves showing the trade-off between the total number of servers used and the throughput. Experiments for a large number of settings and different network topologies are presented in detail.  相似文献   

20.
This paper presents a market-enabling framework where users, content providers and network operators can interact in the seamless, transparent sale and delivery of a wide range of services. The framework allows for dynamic creation, configuration and delivery of services with quality assurance, via automated management of Service Level Agreements (SLAs). We propose an approach relying on a systemic treatment of business, service and network layer issues, which translates into a layered architecture where components belonging to different levels interact on the basis of a mediation paradigm. We use mediation as a generic term for a combination of negotiation, brokerage and state notification, jointly concurring to the realization of the entire life-cycle of a service.  相似文献   

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