A peer-to-peer estimator computes local estimates at each node by combining the information from neighboring nodes without the need of central coordination. Although more flexible and scalable, peer-to-peer minimum va...
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A peer-to-peer estimator computes local estimates at each node by combining the information from neighboring nodes without the need of central coordination. Although more flexible and scalable, peer-to-peer minimum variance estimators are difficult to design because of message losses and lack of network coordination. In this paper, we propose a new peer-to-peer estimator that allows to recover a time-varying scalar signal from measurements corrupted by an unknown non-zero mean independent noise or disturbances. Message losses occurring over the network and absence of central coordination are considered. Novel theoretical solutions are developed by taking advantage of a model of the signal dynamics. The proposed approach simultaneously guarantees a bounded mean value and minimum variance of the estimation error. Simulation results illustrate the performance of the proposed method.
It has often been argued that microgrids that predominantly contain customer-owned generation (co-gen) should have autonomous control, i.e., their operation, even in gridconnected mode, should not be controlled by the...
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ISBN:
(纸本)9781467327275
It has often been argued that microgrids that predominantly contain customer-owned generation (co-gen) should have autonomous control, i.e., their operation, even in gridconnected mode, should not be controlled by the utility providing the point of common coupling (PCC). Some of the control strategies proposed in recent literature rely on distributed control platforms, such as multi-agent systems (MAS). The analytics, i.e., computational and decision-making processes, that occur on these distributed computation platforms are fundamentally different from those that are performed in traditional control centers. This is due partly to the difference in the computation platforms and partly to the fact that microgrids are dynamic in configuration. This paper describes current research in the application of graph-theoretic and distributed computation concepts toward the development of analytics, such as load balancing and optimal operation, that can be implemented on a distributed platform, for the steady state operation of microgrids.
In the search engine of Google, the PageRank algorithm plays a crucial role in ranking the search results. The algorithm quantifies the importance of each web page based on the link structure of the web. We first prov...
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In the search engine of Google, the PageRank algorithm plays a crucial role in ranking the search results. The algorithm quantifies the importance of each web page based on the link structure of the web. We first provide an overview of the original problem setup. Then, we propose several distributed randomized schemes for the computation of the PageRank, where the pages can locally update their values by communicating to those connected by links. The main objective of the paper is to show that these schemes asymptotically converge in the mean-square sense to the true PageRank values. A detailed discussion on the close relations to the multi-agent consensus problems is also given.
Iterative distributed algorithms are studied for computing arithmetic averages over networks of agents connected through memoryless broadcast erasure channels. These algorithms do not require the agents to have any kn...
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Iterative distributed algorithms are studied for computing arithmetic averages over networks of agents connected through memoryless broadcast erasure channels. These algorithms do not require the agents to have any knowledge about the global network structure or size. Almost sure convergence to state agreement is proved, and the communication and computational complexities of the algorithms are analyzed. Both the number of transmissions and the number of computations performed by each agent of the network are shown to grow not faster than poly-logarithmically in the desired precision. The impact of the graph topology on the algorithms performance is analyzed as well. Moreover, it is shown how, in the presence of noiseless communication feedback, one can modify the algorithms, significantly improving their performance versus complexity trade-off. (C) 2010 Elsevier Ltd. All rights reserved.
Wireless sensor networks are powerful, distributed, self-organizing systems used for event and environmental monitoring. In-network query processors like TinyDB offer a user friendly SQL-like application development. ...
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Wireless sensor networks are powerful, distributed, self-organizing systems used for event and environmental monitoring. In-network query processors like TinyDB offer a user friendly SQL-like application development. Due to the sensor nodes' resource limitations, monolithic approaches often support only a restricted number of operators. For this reason, complex processing is typically outsourced to the base station. Nevertheless, previous work has shown that complete or partial in-network processing can be more efficient than the base station approach. In this paper, we introduce AnduIN, a system for developing, deploying, and running complex in-network processing tasks. In particular, we present the query planning and execution strategies used in AnduIN, a system combining sensor-local in-network processing and a data stream engine. Query planning employs a multi-dimensional cost model taking energy consumption into account and decides autonomously which query parts will be processed within the sensor network and which parts will be processed at the central instance.
Inferring gene networks from longitudinal gene expression microarrays is a crucial step towards the study of gene regulatory mechanisms. A decade ago, expensive microarray technology restricted the number of samples u...
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Inferring gene networks from longitudinal gene expression microarrays is a crucial step towards the study of gene regulatory mechanisms. A decade ago, expensive microarray technology restricted the number of samples undergoing gene expression profiling in single studies, leading the inference algorithms that assume stationary gene networks to the best solution. Thanks to decreasing cost of modern microarray technologies, more gene expression profiles can be assessed in single studies. With more samples available, we can relax the stationarity assumption and develop a method to infer dynamic gene networks, which can reflect more realistic biology where genes adaptively orchestrate each other. This paper applied the framework of dynamic Bayesian networks to infer adaptive gene interactions by identifying individual transition networks between pairs of consecutive times. Due to high computational burden of inferring the interconnection patterns among all genes over time, we designed a parallelizable inference algorithm to make feasible the task. We validated our approach by two clinical studies: yellow fever vaccination and mechanical periodontal therapy. The inferred dynamic networks achieved more than 90% predictive accuracy, a significant improvement when compared to stationary models (p<0.05). The adaptive models can help explain the induction of innate immunology in greater details after yellow fever vaccination and interpret the anti-inflammatory effect of mechanical periodontal therapy.
Finding optimal weights for the problem of fastest distributed consensus on sensor networks with different topologies has been an active area of research for a number of years. In this work, we present an analytical s...
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Finding optimal weights for the problem of fastest distributed consensus on sensor networks with different topologies has been an active area of research for a number of years. In this work, we present an analytical solution for the problem of Fastest distributed Consensus for a sensor network formed by fusing two different symmetric star sensor networks. In other words, a sensor network consisting of two different symmetric star sensor networks which are sharing the same central node. The solution procedure consists of stratification of associated connectivity graph of network and Semidefinite Programming ( SDP), particularly solving the slackness conditions. The optimal weights are obtained by inductive comparing of the characteristic polynomials initiated by slackness conditions. Some numerical simulations are carried out to investigate the tradeoff between the parameters of two fused star sensor networks, namely, the length and number of branches. Also, the obtained optimal weights has been compared with different weighting methods by evaluating the Second Largest Eigenvalue Modulus (SLEM) and comparing convergence time improvements numerically. Moreover, several examples of two fused star sensor networks with branches other than path graphs are introduced along with their optimal weights and SLEM.
In classical mechanism design the outcome of the mechanism is computed by a trusted central party. In this paper, we consider the design of distributed mechanisms in which the outcome is computed by the agents themsel...
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In classical mechanism design the outcome of the mechanism is computed by a trusted central party. In this paper, we consider the design of distributed mechanisms in which the outcome is computed by the agents themselves. We propose distributed MinWork (DMW), a mechanism for solving the problem of scheduling on unrelated machines. We show that DMW is a faithful implementation of the MinWork mechanism, which was proposed by Nisan and Ronen in their seminal work (Nisan and Rouen (2001) [30]). We show that in addition to being faithful, DMW protects the anonymity of the losing agents and the privacy of their bids. Furthermore, we show that DMW is efficient as it has polynomial communication and computation costs. (C) 2010 Elsevier Inc. All rights reserved.
Small-world networks have been one of the most influential concepts in complex systems science, partly due to their prevalence in naturally occurring networks. It is often suggested that this prevalence is due to an i...
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Small-world networks have been one of the most influential concepts in complex systems science, partly due to their prevalence in naturally occurring networks. It is often suggested that this prevalence is due to an inherent capability to store and transfer information efficiently. We perform an ensemble investigation of the computational capabilities of small-world networks as compared to ordered and random topologies. To generate dynamic behavior for this experiment, we imbue the nodes in these networks with random Boolean functions. We find that the ordered phase of the dynamics (low activity in dynamics) and topologies with low randomness are dominated by information storage, while the chaotic phase (high activity in dynamics) and topologies with high randomness are dominated by information transfer. Information storage and information transfer are somewhat balanced (crossed over) near the small-world regime, providing quantitative evidence that small-world networks do indeed have a propensity to combine comparably large information storage and transfer capacity.
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