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1.
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
Vangelis GazisEmail:
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2.
  Although the Simple Network Management Protocol (SNMP) has proven to be a powerful tool for network administrators, it is widely accepted that SNMP does not offer the scalability or the functionality needed to manage large systems of routers and end systems. Active/programmable networks and mobile agent systems have been proposed as alternative network management solutions, offering new functionality and better scalability. Unfortunately, the flexibility and programmability of these (heavyweight) systems comes with its own set of problems, which has prevented them from becoming widely adopted.This paper presents an ultra-lightweight programmable network service called ephemeral state processing (ESP) that can be used to efficiently monitor and collect information from large-scale networks. Although the service offers a limited set of features, the building blocks it does offer can be combined in novel ways to solve a wide range of network management problems while avoiding the problems that plague (heavyweight) active network approaches. The simplicity of ESP allows us to make it available as a general-purpose service that can be used by all packets in the network. We demonstrate the utility of the service by showing how it can be used to efficiently solve common network management problems.
Kenneth L. CalvertEmail:
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3.
4.
XML technologies have been recently introduced in network management towards alleviating limitations of SNMP. The XML W3C standard, along with XML technologies has the potential to boost open, interoperable, cost-effective and standards-based management solutions. This paper highlights recent efforts towards XML network management and introduces an architecture supporting XML-based network management applications. This architecture specifies a runtime environment that parses XML documents containing composite operations for individual devices, as well as for heterogeneous mutli-vendor networks. Management operations in the scope of XML documents are defined in a programmable fashion based on an XML-based composition language supporting aggregations of elementary operations, looping commands, conditional statements, as well as simple rules signifying the occurrence of specific events. The introduced environment allows network managers to define management operations featuring high-level semantics and accordingly produce sophisticated applications through XML authoring. Following the illustration of the architecture, its composition language and issues relating to security and error handling, the paper ends up presenting a prototype implementation, along with associated performance evaluation results.
Dimitris AlexopoulosEmail:
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5.
Consideration was given to the queuing system with Poisson flows of incoming positive and negative customers. For the positive customers, there is an infinite-capacity buffer. The arriving negative customer knocks out a positive customer queued in the buffer and moves it to an infinite-capacity buffer of ousted customers (bunker). If the buffer is empty, then the negative customer discharges the system without affecting it. After servicing the current customer, the server receives a customer from the buffer or, if the buffer is empty, the bunker. The customers arriving from both the buffer and bunker are distributed exponentially with the same parameter. Relations for calculation of the stationary distributions of the queues in the buffer and bunker were obtained.  相似文献   

6.
Consideration was given to the linear-quadratic problem of optimal control for the discrete linear system with fast and slow variables under incomplete information about system state. Decomposition of the discrete matrix Riccati equations was carried out. The proposed decomposition algorithm relies on a geometrical approach using the properties of the invariant manifolds of slow and fast motions of the nonlinear multirate discrete systems as basis. The splitting transformation was constructed in the form of asymptotic decomposition in the degrees of a small parameter.  相似文献   

7.
For the parallel computer systems, a new formulation of the problem of constructing parallel asynchronous abstract programs of the desired length was proposed. The conditions for the problem of planning were represented as a system of Boolean equations (constraints) whose solutions define the feasible plans for activation of the program modules specified in the planner’s knowledge base. The constraints on the number of processors and time delays arising at execution of the program modules were taken into consideration.  相似文献   

8.
Multimedia applications often have performance requirements that make these applications computing resource intense; e.g., the number of video frames displayed to the user must be about 25 frames per second. A user hint is an indication of the interest that a user has in an application. Examples of user hints include a screen saver being invoked or covering a window with another window. In the case that the user is running video, the occurrence of these hints imply that the user is no longer viewing the video. However, the resource usage of the application has not changed. This paper describes an architecture that make use of user hints to reduce the resource consumption of an application. The emphasis is on network traffic and CPU usage. Experimental results are presented.
Hanan LutfiyyaEmail:
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9.
Reductions that aggregate fine-grained transitions into coarser transitions can significantly reduce the cost of automated verification, by reducing the size of the state space. We propose a reduction that can exploit common synchronization disciplines, such as the use of mutual exclusion for accesses to shared data structures. Exploiting them using traditional reduction theorems requires checking that the discipline is followed in the original (i.e., unreduced) system. That check can be prohibitively expensive. This paper presents a reduction that instead requires checking whether the discipline is followed in the reduced system. This check may be much cheaper, because the reachable state space is smaller.
Ernie CohenEmail:
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10.
Various types of optimality criteria and conditions, which define the set of admissible solution, are brought to the canonical form. For the problem set in this form, the optimality conditions of sliding modes are stated. It is shown that the optimality conditions emerge from these conditions in the form of the maximum principle for problems with a scalar argument and an arbitrary combination of the optimality criterion and constraints.  相似文献   

11.
In practice of design of control systems, the cases occur when some of the roots of the transfer function of a controllable object are disposed on the imaginary axis of the complex plane. The optimal controller constructed for such objects, despite its realizability, will not afford the robustness properties in the system. The methods of removal of this phenomenon are given. The comparative estimate of the solution of this problem is provided both in the space of states and in the input-output relations (in the space of operators).  相似文献   

12.
The conventional concepts of invariance are extended in this article to include impulsive control systems represented by measure driven differential inclusions. Invariance conditions and some of their main features are derived. The solution concept plays a critical role in the extension of the conditions for conventional problems to the impulsive control context.  相似文献   

13.
随着星座模式技术的出现及其应用 ,未来的卫星网络将会是一个异构和繁杂的网络 ,传统的网络管理体系结构已不再适用 .在对卫星网进行分层的基础上 ,将移动 Agent技术应用到卫星网络管理 ,提出了一种基于移动 Agent与 SNMP相结合的卫星网络管理 ,充分发挥了移动 Agent及 SNMP各自的优势 ,有效的降低了网络负载 ,并解决了卫星节点高度动态性给网络管理所带来的困难  相似文献   

14.
Traditional explanation strategies in machine learning have been dominated by rule and decision tree based approaches. Case-based explanations represent an alternative approach which has inherent advantages in terms of transparency and user acceptability. Case-based explanations are based on a strategy of presenting similar past examples in support of and as justification for recommendations made. The traditional approach to such explanations, of simply supplying the nearest neighbour as an explanation, has been found to have shortcomings. Cases should be selected based on their utility in forming useful explanations. However, the relevance of the explanation case may not be clear to the end user as it is retrieved using domain knowledge which they themselves may not have. In this paper the focus is on a knowledge-light approach to case-based explanations that works by selecting cases based on explanation utility and offering insights into the effects of feature-value differences. In this paper we examine to two such a knowledge-light frameworks for case-based explanation. We look at explanation oriented retrieval (EOR) a strategy which explicitly models explanation utility and also at the knowledge-light explanation framework (KLEF) that uses local logistic regression to support case-based explanation.
Pádraig CunninghamEmail:
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15.
Major principles of the method of the linear codes multithreshhold decoding as search for the global functional extremum for a great number of variables are considered. It was demonstrated that the multithreshold decoding efficiency is close to the results ensured by the optimum exhaustive search methods. Decoding complexity under software and hardware realizations is evaluated.  相似文献   

16.
Sylvie Duvernoy reports on the seventh international, interdisciplinary Nexus conference for architecture and mathematics. Point Loma Nazarene University, San Diego, USA 23-25 June 2008  相似文献   

17.
A new form of a partial frequency criterion of absolute stability for nonlinear automatic control systems is obtained basing on a quadratic transformation of the state vector. As is shown, the obtained criterion is stronger than V.M. Popov’s one. An alternative formulation of the criterion is given in terms excluding the notions of quadratic transformation.  相似文献   

18.
Singularly perturbed systems of ordinary differential equations are studied. A method for analysis of canard-type trajectories in such systems based on the topological degree theory is suggested. The method does not require smoothness of the right-hand side of the system. A result on the existence of periodic canards in systems with non-smooth perturbations is obtained. The trajectories located in this way are not necessarily Lyapunov stable, and appropriate control algorithms are required to stabilize them, e.g., feedback control.  相似文献   

19.
We consider a problem of discrete control for a class of nonlinear time-varying objects. Only set estimations for object parameters are available. The aim is to design controls that ensure robust stability of closed-loop systems in a given domain of state space. Since the considered class of objects is large enough not to have a stabilizing control, the proposed design method has to verify at the last step if the obtained conditions of robust stability are satisfied for a nonlinear system “in a given domain.”  相似文献   

20.
The problem of maximizing the profit of an economic organization with simultaneous selection of its composition and structure was formulated. Consideration was given to a class of the power cost functions whose parameters reflect the organization environmental characteristics. The optimal organization was analytically established for this case, and the regularities of its variation vs. the environmental conditions were investigated.  相似文献   

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