This paper assesses the performance of a network management scheme where network engineering (NE) is used to complement traffic engineering (TE) in a multi-layer setting where a data network is layered above an optica...
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This paper assesses the performance of a network management scheme where network engineering (NE) is used to complement traffic engineering (TE) in a multi-layer setting where a data network is layered above an optical network. We present a TE strategy which is based on a multi-constraint optimization model consisting of finding bandwidth-guaranteed IP tunnels subject to contention avoidance minimization and bandwidth usage maximization constraints. The TE model is complemented by a NE model which uses a bandwidth trading mechanism to rapidly re-size and re-optimize the established tunnels (LSPs/lambdaSPs) under quality of service (QoS) mismatches between the traffic carried by the tunnels and the resources available for carrying the traffic. The resulting TE+NE strategy can be used to achieve bandwidth on demand (BoD) in emerging generation IP networks using a (G)MPLS- like integrated architecture in a cost effective way. We evaluate the performance of this hybrid strategy when routing, re-routing and re-sizing the tunnels carrying the traffic offered to a 23-node test network.
Nature has optimized the processing of visual information, especially in primates. The estimation of optical flow is a complex task that gives information about ego-motion, and permits tracking objects from a given sc...
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Nature has optimized the processing of visual information, especially in primates. The estimation of optical flow is a complex task that gives information about ego-motion, and permits tracking objects from a given scene. The multi-channel spatio-temporal filtering required to detect motion is suitable for a parallel implementation on reconfigurable circuitry. We detail here the design of a neuromorphic FPGA implementation of the pre-processing stages for optical flow estimation that permits highly parallel real-time filtering
Performance uncertainty is a barrier to implementation of innovative technologies. This research investigates the potential of flexible design - one that enables future change - to improve the economic performance of ...
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ISBN:
(纸本)089553178X
Performance uncertainty is a barrier to implementation of innovative technologies. This research investigates the potential of flexible design - one that enables future change - to improve the economic performance of a naturally ventilated building. The flexible design of the naturally ventilated building enables future installation of a mechanical cooling system by including features such as space for pipes and chillers. The benefits of the flexible design are energy savings, delay of capital costs and capability of mitigating the risk of a failed building (by installing the mechanical cooling system). To evaluate the flexible design, building energy simulation is conducted over a multi-year time period with stochastic outdoor temperature variables. One result is a probability distribution of the time when the maximum allowable indoor temperature under natural ventilation is exceeded, which may be "never." Probability distributions are also obtained for energy savings and cost savings as compared to a mechanically cooled building. Together, these results allow decision-makers to evaluate the long-term performance risks and opportunities afforded by a flexible implementation strategy for natural ventilation. It is shown that the likelihood of future installation of mechanical cooling is most sensitive to design parameters. The impact of increased climate variability depends on the local climate. The probability of installing the mechanical system also depends on the comfort criteria. The results show that capital costs for cooling equipment are much greater than the present value of 10 years of cooling energy costs. This result motivates consideration of flexible design as opposed to hybrid cooling designs (which have immediate installation of mechanical cooling). Future work will study the impact of uncertain energy prices on investment attractiveness of naturally ventilated buildings. Other applications of the framework presented herein include replacing the build
Estimation of Distribution Algorithms (EDAs) are a set of optimization techniques that have been successfully applied to different kinds of problems. In this paper, we deal with the creation of multivariate calibratio...
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ISBN:
(纸本)9781424430116
Estimation of Distribution Algorithms (EDAs) are a set of optimization techniques that have been successfully applied to different kinds of problems. In this paper, we deal with the creation of multivariate calibration models in quantitative chemistry. For this purpose, we use parallel implementations of two EDAs (EBNABIC and UMDA), using different approaches to create a calibration model using data obtained from controlled reactions. Once the calibration model has been trained, it can be used to predict initial concentrations for some species taking part in new reactions. The results show that these new approaches are able to obtain good-quality calibration models. Moreover, the use of parallel algorithms allows researchers to complete experiments faster and to study a wider set of alternative solutions.
It is well known that space and time complexity is one of the main bottlenecks of supervisor synthesis. The model of a large system is usually too big to be explicitly expressed, owing to composition of local componen...
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It is well known that space and time complexity is one of the main bottlenecks of supervisor synthesis. The model of a large system is usually too big to be explicitly expressed, owing to composition of local components' models, making supervisor synthesis difficult, if still possible. In this paper, we propose a distributed supervisor synthesis approach, where instead of computing a model of the entire system, a local abstraction of the system with respect to each local component is computed based on weak bisimulation. Then a local supervisor for each component is computed based on the component model and the abstract system model, by using well developed centralized supervisor synthesis approaches. The collection of all resulting local supervisors forms a distributed supervisor
This paper explores the characteristics (i.e. stability and performance) of transfers to, and captures at Europa. We focus on optimal low-thrust transfers from Ganymede to potential science orbits at Europa and compar...
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ISBN:
(纸本)0877035288
This paper explores the characteristics (i.e. stability and performance) of transfers to, and captures at Europa. We focus on optimal low-thrust transfers from Ganymede to potential science orbits at Europa and compare different capture types, transfer resonances, and thrust accelerations. The two types of capture methods we consider are capture in a distant retrograde orbit (DRO) and capture by targeting a state on a stable invariant manifold of a halo orbit. We show that each type has its advantages and disadvantages. The first part of DRO-type capture may be easier than a halo-type capture in some design schemes because DROs are generally extremely stable. However, halo-type captures using stable invariant manifolds typically result in fewer escapes even when full ephemeris is used. Moreover, changing the inclination to achieve a high inclination science orbit at Europa is much easier in a halo-type capture. We study these trade-offs in this paper.
This paper introduces a system model of CDMA stress testing service platform based on state machine technology. This system provides an efficient service oriented solution on protocol and stress testing of CDMA system...
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This paper introduces a system model of CDMA stress testing service platform based on state machine technology. This system provides an efficient service oriented solution on protocol and stress testing of CDMA system, with high performance and automatic capability. The concurrent multitask mechanism and the state machine framework enable the high performance and automatic capability of this system. And the scalable distributed architecture offers the maximum flexibility of deployment
As the rapid increase of network security events, network security monitoring and management on network behavior become more and more focused in the fields of computerscience. This paper develops a kind of network se...
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As the rapid increase of network security events, network security monitoring and management on network behavior become more and more focused in the fields of computerscience. This paper develops a kind of network security management framework using collection, analysis and integration, event-correlation and scenario-analysis technique to process the raw data gathered from hybrid network. Data-mining and wavelet technology are introduced into this framework, which can rapidly identify the types of security events from integrated information by using frequent episodes, wavelet and case-based reasoning. By these means, it can help to analyze the status of network security and then adjust the strategy to secure the network. We have implemented a prototype system following this framework, which can rapidly react to typical security events with visual output of result
In this paper, we propose a bidirectional buffer repeater insertion to reduce the RLC tree delay in multi-source multi-sink systems which involve four significant factors in our works. First, inductance effect is take...
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In this paper, we propose a bidirectional buffer repeater insertion to reduce the RLC tree delay in multi-source multi-sink systems which involve four significant factors in our works. First, inductance effect is taken into account due to the reason that chip sizes with the exponential reduction and high work frequency. Second, bidirectional buffer repeater could improve interconnect delay more than unidirectional buffer insertion. Third, the location of insertion buffer is also considered in our work. Fourth, more than one buffer could be inserted in critical path while buffers have already existed. Finally, we develop a graphical user interface for designers to estimate the delay with bidirectional buffer repeater insertion target multi-source multi-sink systems. Experiment results shown that the reduced delay rate is 50.73% and 64.47% in 0.18 and 0.35 micron fabrication process, respectively
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