this paper proposes a novel framework called distributed compressed video sensing (DISCOS) - a solution for distributed video coding (DVC) based on the recently emerging compressed sensing theory. the DISCOS framework...
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this paper proposes a novel framework called distributed compressed video sensing (DISCOS) - a solution for distributed video coding (DVC) based on the recently emerging compressed sensing theory. the DISCOS framework compressively samples each video frame independently at the encoder. However, it recovers video frames jointly at the decoder by exploiting an interframe sparsity model and by performing sparse recovery with side information. In particular, along with global frame-based measurements, the DISCOS encoder also acquires local block-based measurements for block prediction at the decoder. Our interframe sparsity model mimics state-of-the-art video codecs: the sparsest representation of a block is a linear combination of a few temporal neighboring blocks that are in previously reconstructed frames or in nearby key frames. this model enables a block to be optimally predicted from its local measurements by l 1 -minimization. the DISCOS decoder also employs a sparse recovery with side information to jointly reconstruct a frame from its global measurements and its local block-based prediction. simulation results show that the proposed framework outperforms the baseline compressed sensing-based scheme of intraframe-coding and intraframe-decoding by 8 - 10dB. Finally, unlike conventional DVC schemes, our DISCOS framework can perform most encoding operations in the analog domain with very low-complexity, making it be a promising candidate for real-time, practical applications where the analog to digital conversion is expensive, e.g., in Terahertz imaging.
thanks to the recent advancements in the Software-Defined Networking (SDN) and Network Function Virtualization research domains, telecom operators are encouraged to upgrade their optical transport networks towards pro...
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thanks to the recent advancements in the Software-Defined Networking (SDN) and Network Function Virtualization research domains, telecom operators are encouraged to upgrade their optical transport networks towards programmable, energy-efficient, service-oriented, and interoperable architectures. the availability of a large set of open-source building blocks, supported by different standardization bodies makes the selection and the integration of such technologies a very complex task. In this context, the INTENTO project has the objective to create an innovative simulation framework by selecting the best technologies and use it to test applications, services, and advanced optimization algorithms in a real environment. In the initial phase, the project designed a large-scale, distributed, and hierarchical Transport SDN architecture, where optical switches and networking functionalities are monitored and dynamically configured through a two-level structure of SDN controllers. On top of that, Virtual Network Functions are optimally deployed and managed by a centralized orchestrator, based on network condition, user requests, and application requirements. Based on this architecture, the project team started to develop a complex simulation environment that harmoniously integrates within the OpenStack cloud: optical node simulators composed by simulation agent and a suitable hardware emulation layer; proprietary SDN network controller designed to enable the innovative optical nodes characteristics; Open Network Operating System as the second level controller, enabling the integration of third-party or standardized models (multivendor environment), based on standardized interfaces and communication protocols. After having described the main components and functionalities already implemented into the simulation framework, the paper concludes by highlighting future research and development activities.
An essential part of the energy systems design procedure is simulation, since it serves as a tool for verification of the respective design. It serves the verifying of a stable operation of developed energy systems in...
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An essential part of the energy systems design procedure is simulation, since it serves as a tool for verification of the respective design. It serves the verifying of a stable operation of developed energy systems infrastructure, before it comes to the realization. As energy systems integration becomes an important part in a low carbon energy scenario in the future, the cooperation of experts specialized in various domains crucial to single aspects of the energy system is indispensable. Cosimulation, yet, enables the modelling in the familiar environment of the experts, but requires a detailed coordination of the simulation interfaces between the specific expert models. Hence, standardized interfaces are crucial to the efficient use of expert knowledge in distributed co-simulations. therefore, in the presented paper a workflow for the co-simulation development of energy systems simulations, which simplifies the coordination procedure significantly by standardizing the interfaces between the models and their simulations, is introduced. the approach is exemplarily applied to the energy system design of a district comprising electricity and heat in order to show its successful performance.
Dealing with a growing amount of data is a crucial challenge for the future of information and communication technologies. More and more devices are expected to transfer data through the Internet, therefore new soluti...
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ISBN:
(纸本)9781665433266
Dealing with a growing amount of data is a crucial challenge for the future of information and communication technologies. More and more devices are expected to transfer data through the Internet, therefore new solutions have to be designed in order to guarantee low latency and efficient traffic management. In this paper, we propose a solution that combines the edge computing paradigm with a decentralized communication approach based on Peer-to-Peer (P2P). According to the proposed scheme, participants to the system are employed to relay messages of other devices, so as to reach a destination (usually a server at the edge of the network) even in absence of an Internet connection. this approach can be useful in dynamic and crowded environments, allowing the system to outsource part of the traffic management from the Cloud servers to end-devices. To evaluate our proposal, we carry out some experiments withthe help of LUNES, an open source discrete events simulator specifically designed for distributed environments. In our simulations, we tested several system configurations in order to understand the impact of the algorithms involved in the data dissemination and some possible network arrangements.
Since the beginning of the 2010 decade, many improvements have been made in terms of Virtual reality (VR) hardware technologies and software platforms. Such trend is expected to continue, pushing the penetration rate ...
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ISBN:
(纸本)9781665433266
Since the beginning of the 2010 decade, many improvements have been made in terms of Virtual reality (VR) hardware technologies and software platforms. Such trend is expected to continue, pushing the penetration rate of VR headsets. In the meantime, two research questions emerge: (a) how 3D-based immersive environments may get to be used, and with which benefits, in place of 2D ones, and, (b) how to support such integration. We focus on the latter, taking as a case study SUMO, a well-known PC-based vehicular traffic simulation tool. To this aim, we adopt an approach based on the OpenGL intercept technique, withthe implementation of the OGL2VR middleware, which has been extended to remove graphical artifacts and to include the on/off toggling of dynamic elements in a 3D scene. We here describe the solutions that have been embraced, as well as the challenges that still remain along this path, to render dynamic traffic animations in an immersive setting to support the use of a blended 2D/3D environment.
Agent-based simulations relying on synchronous state updates using a fixed time step size are considered attractive candidates for parallel execution in order to reduce simulation running times for large and complex s...
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ISBN:
(纸本)9781665433266
Agent-based simulations relying on synchronous state updates using a fixed time step size are considered attractive candidates for parallel execution in order to reduce simulation running times for large and complex scenarios. However, if the underlying models are formulated with respect to continuous time, a time-stepped execution may only approximate the strict model semantics. To simulate continuous-time agent-based models, parallel discrete event algorithms can be applied. Traditionally those are based on logical processes exchanging time-stamped events, which clashes withthe properties of models in which tightly coupled agents frequently access each other's states. To illustrate the challenges of such models and to derive a solution, we consider the domain-specific modeling language ML3, which allows modelers to succinctly express transitions and interactions of linked agents based on a continuous-time Markov chain (CTMC) semantics. We propose an optimistic synchronization scheme tailored towards simulations of finegrained interactions among tightly coupled agents in highly dynamic topologies. By restricting the progress per round to at most one state change per agent, the synchronization scheme enables efficient direct read and write accesses among agents. To maintain concurrency given actions that depend on dynamically updated macro-level properties, we introduce a simple relaxation scheme with guaranteed error bounds. Using an extended variant of the classical susceptible-infected-recovered network model, we demonstrate that the proposed synchronization scheme accelerates simulations even under challenging model configurations.
this work aims at the development of tools for supporting modelling and analysis of timed systems by Stochastic Reward Nets (SRN). In a first approach it was proposed and experimented a formal reduction of SRN over Ti...
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ISBN:
(纸本)9781665433266
this work aims at the development of tools for supporting modelling and analysis of timed systems by Stochastic Reward Nets (SRN). In a first approach it was proposed and experimented a formal reduction of SRN over timed Automata (TA) in the context of the Uppaal popular toolbox. the reduction has the merit to allow both exhaustive model checking of an SRN model, useful for the assessment of qualitative properties (e.g., absence of deadlocks, occurrence of particular event sequences etc.), and quantitative analysis through the statistical model checker, which is based on simulations. However, although Uppaal enabled formal reasoning on the semantics of SRN, its practical usage suffers of scalability problems, that is it can introduce severe limitations in time and space when studying complex models. To cope withthis problem, this paper describes a Java implementation of the SRN operational core engine, using the lock-free and efficient theatre actor system which permits the parallel simulation of large models. the realization can be used for functional property checking on an untimed version of a source SRN model, and quantitative estimation of measurables through simulations. the paper discusses the design and implementation of the core engine of SRN on top of theatre, together with supported intuitive configuration process of an SRN model, and reports some experimental results using a scalable grid computing model. the experiments confirm theatre/SRN are capable of exploiting the potential of modern multi-core machines and can deliver good execution performances on large models.
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