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Software Defined Networking (SDN) emphasizes the separation of data and control plane while network function virtualization (NFV) decouples network function from underlying hardware. Combining SDN with NFV would have many benefits, but the problem is how to integrate them. There are two possible architectures for such integration: the controller interacts with virtualized network functions (VNFs)...
OpenFlow has been applied to a variety of demands of the transmission quality of the Internet business and it is still growing on its way. To test this protocol with its evolution consideration, we analyzed the working process of OpenFlow protocol and constructed the CPN model through phasing firstly and then role division for version 1.0. In addition, the selection of tokens and their given values...
Virtual switches are a key elements within the new paradigms of Software Defined Networking (SDN) and Network Function Virtualization (NFV). Unlike proprietary networking appliances, virtual switches come with a high level of flexibility in the management of their physical resources such as the number of CPU cores, their allocation to the switching function, and the capacities of the RX queues, which...
Software Defined Networking (SDN) is the latest network architecture that does for networking what virtualisation did for servers in data centres. In SDN, separation of the control plane from the data plane brought about new flexibility in the routing of flows through the network. Closely associated with SDN is OpenFlow, the most widely used protocol governing the information exchange between the...
As software functions can be separated from the device hardware, new techniques as SDN and NFV can be enabled in the management and operation of communication networks. However, the automatic configuration and SDN tools give only moderate information to the control or orchestration systems, and this can affect the performance and reliability of the managed network. The control and orchestration functions...
The use of Remedial Action Scheme(s) (RAS) is an economic means to facilitate the interconnection of renewable generation while supporting the reliable operation of the transmission system. With the increasing prevalence of RAS on the system, automatic modeling is imperative in order to accurately capture the potential impacts and interaction between these schemes. Within the Western United States,...
Fault-injection is a commonly used method for testing safety-relevant embedded systems. Especially after the introduction of the ISO 26262 the importance of this technique has gained attention in the automotive domain to test the proper implementation of safety concepts. To enable meaningful tests, the possible random hardware faults need to be aligned in early stages of the development process between...
According to the mechanical failure of Gas Insulated Switchgear (GIS) in the earthquake will cause a great loss to the power system. This paper, by using the three-dimension design software to build a geometric model of 420 kV GIS, by using the finite element analysis method to make the mode analysis, and then acquired structural frequencies and mode features of the GIS, and by using spectral analysis...
Monitoring, diagnosis and control systems represent a variant of modern informational technologies used for broadcasting, data acquisition and visualization of primary technical data as well as automated long distance control of dynamic processes from amongst very diverse fields, ranging from metallurgical engineering, chemistry and energy engineering to nuclear engineering. This paper deals with...
The paper shows how an agent-based system can be subjected to formal verification using a deductive approach. The particular system for gathering open source intelligence is considered, which is build on a framework for data integration. Techniques allowing for automatic extraction of logical specifications are described with emphasis on pattern-based and rule-based approaches. An example illustrates...
Component-Based Development (CBD) reduces development time and effort by allowing systems to be built from pre-developed reusable components. Partitioning the behavior into a set of major operational modes is a classical approach to reduce complexity of embedded systems design and execution. In supporting system modes in CBD, a key issue is seamless composition of pre-developed multi-mode components...
This paper presents the modeling and simulation of a dynamic voltage restorer as a voltage sag/swell mitigation device in electrical power distribution networks. The dynamic voltage restorer, with its excellent dynamic capabilities, when installed between the supply and a critical load feeder, can compensate for voltage sags/swell, restoring line voltage to its nominal value within few milliseconds...
As the time of system running increases, the performance of the system will decrease. This phenomenon is called software aging. Recently software rejuvenation as an efficient method to counteract software aging emerges. This method recovers the performance of the system through cleaning the internal state of system. Now component-oriented programming concept has been proposed and spreaded. And software...
A brand-new equipment used to cut kinds of pipe had been brought out and took the place of existent cutter machine, which was of low degree in automation and behindhand. So structure analysis and pneumatic control technology of the device had been introduced based on simulation technique. First, three-dimensional software PRO/E was used for avoiding the overlap and penetration phenomenon before the...
The interest in system survivability under a variety of attacks, faults or accidents has been on the rise in recent years and survivability is receiving increasing attention as a key property of the mission critical system. Distributed systems are vital for all and it is a critical task to make such systems secure and survive. Survivability in the presence of attacks or failures depends on three key...
The paper addresses the problem of creating a comprehensive fault injection environment, which integrates and improves various simulation and supplementary functions. This is illustrated with experimental results.
In this paper a BISR architecture for embedded memories is presented. The proposed scheme utilises a multiple bank cache-like memory for repairs. Statistical analysis is used for minimisation of the total resources required to achieve a very high fault coverage. Simulation results show that the proposed BISR scheme is characterised by high efficiency and low area overhead, even for high defect densities...
In this paper we present a low cost fault-tolerant attitude determination system to a scientific satellite using COTS devices. We related our experience in developing the attitude determination system, where we combine proven fault tolerance techniques to protect the whole system composed only by COTS from the effects produced by transient faults. We detailed the failure cases and the detection, reconfiguration...
The conflicting requirements of real-time embedded systems, e.g. minimizing memory usage while still ensuring that all deadlines are met at run-time, require rigorous analysis of the system's resource consumption, starting at early design stages. In this paper, we glance through several representative frameworks that model and estimate resource usage of embedded systems, pointing out advantages and...
This paper describes a methodology for building a reliable internet core router that considers the vulnerability of its electronic components to single event upset (SEU). It begins with a set of meaningful system level metrics that can be related to product reliability requirements. A specification is then defined that can be effectively used during the system architecture, silicon and software design...
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