Algorithm (Total 1494263 Papers Found)

In this paper we propose a distributed and scalable algorithm that eliminates congestion within a sensor network, and that ensures the fair delivery of packets to a central node, or base station. We say that fairness is achieved when equal number of packets are received from each node. Since in general we have many sensors transmitting data to the base station, we consider the scenario where we have many-to-one multihop routing, noting that it can easily be extended to unicast or many-to-many ro ...
In a Bayesian analysis of finite mixture models, parameter estimation and clustering are sometimes less straightforward that might be expected. In particular, the common practice of estimating parameters by their posterior mean, and summarising joint posterior distributions by marginal distributions, often leads to nonsensical answers. This is due to the so-called “labelswitching” problem, which is caused by symmetry in the likelihood of the model parameters. A frequent response to this prob ...
We present a novel message passing algorithm for approximating the MAP problem in graphical models. The algorithm is similar in structure to max-product but unlike max-product it always converges, and can be proven to find the exact MAP solution in various settings. The algorithm is derived via block coordinate descent in a dual of the LP relaxation of MAP, but does not require any tunable parameters such as step size or tree weights. We also describe a generalization of the method to cluster ba ...
We consider the problem of learning sparsely used dictionaries with an arbitrary square dictionary and a random, sparse coefficient matrix. We prove that O(n log n) samples are sufficient to uniquely determine the coefficient matrix. Based on this proof, we design a polynomial-time algorithm, called Exact Recovery of Sparsely-Used Dictionaries (ER-SpUD), and prove that it probably recovers the dictionary and coefficient matrix when the coefficient matrix is sufficiently sparse. Simulation result ...
Current watermarking technology focuses on media types like still images,lm4 and video5 and audio streams? Obviously, more and more CAD-based 3D data is entering the World Wide Web, mostly as Virtual Reality Modeling Language (VRML) scenes. Accordingly, companies or copyright owners who present or sell their products in virtual space will face copyright-related problems. The straightforward demand is to preThis article addresses the vent their SD-based (catalogue) material from unauthorized (unl ...
Dynamic consolidation of virtual machines (VMs) is an effective way to improve the utilization of resources and energy efficiency in cloud data centers. Determining when it is best to reallocate VMs from an overloaded host is an aspect of dynamic VM consolidation that directly influences the resource utilization and quality of service (QoS) delivered by the system. The influence on the QoS is explained by the fact that server overloads cause resource shortages and performance degradation of appl ...
Graphical models, such as Bayesian networks and Markov random elds, represent statistical dependencies of variables by a graph. The max-product \belief propagation" algorithm is a local-message passing algorithm on this graph that is known to converge to a unique xed point when the graph is a tree. Furthermore, when the graph is a tree, the assignment based on the xed-point yields the most probable a posteriori (MAP) values of the unobserved variables given the observed ones. Recently, good empi ...
Compression of information is an important concept in the theory of learning. We argue for the hypothesis that there is an inherent compression pressure towards short, elegant and general solutions in a genetic programming system and other variable length evolutionary algorithms. This pressure becomes visible if the size or complexity of solutions are measured without non-eeective code segments called introns. The built in parsi-mony pressure eeects complex tness functions , crossover probabilit ...
In order to reduce the power dissipation of CMOS products, semiconductor manufacturers are reducing the power supply voltage. This requires that the transistor threshold voltages be reduced as well to maintain adequate performance and noise margins. However, this increases the subthreshold leakage current of p and n MOSFETs, which starts to offset the power savings obtained from power supply reduction. This problem will worsen in future generations of technology, as threshold voltages are reduce ...
DKAL is a new declarative authorization language for distributed systems. It is based on existential fixed-point logic and is considerably more expressive than existing authorization languages in the literature. Yet its query algorithm is within the same bounds of computational complexity as e.g. that of SecPAL. DKAL's communication is targeted which is beneficial for security and for liability protection. DKAL enables flexible use of functions; in particular principals can quote (to other princ ...
If a piece of information is released from a media site, can we predict whether it may spread to one million web pages, in a month ? This influence estimation problem is very challenging since both the time-sensitive nature of the task and the requirement of scalability need to be addressed simultaneously. In this paper, we propose a randomized algorithm for influence estimation in continuous-time diffusion networks. Our algorithm can estimate the influence of every node in a network with |V| no ...
An adaptive statistical language model is described, which successfully integrates long distance linguistic information with other knowledge sources. Most existing statistical language models exploit only the immediate history of a text. To extract information from further back in the document’s history, we propose and use trigger pairs as the basic information bearing elements. This allows the model to adapt its expectations to the topic of discourse. Next, statistical evidence from multiple ...
In this paper, we investigate reducing the power consumption of a synchronous digital system by minimizing the total power consumed by the clock signals. We construct activity-driven clock trees wherein sections of the clock tree are turned off by gating the clock signals. Since gating the clock signal implies that additional control signals and gates are needed, there exists a tradeoff between the amount of clock tree gating and the total power consumption of the clock tree. We exploit similari ...
In this paper we present Mastro, a Java tool for ontology-based data access (OBDA) developed at the Sapienza Università di Roma and at the Free University of Bozen-Bolzano. Mastro manages OBDA systems in which the ontology is specified in DL-LiteA,id , a logic of the DL-Lite family of tractable Description Logics specifically tailored to ontology-based data access, and is connected to external JDBC enabled data management systems through semantic mappings that associate SQL queries over the ext ...
BACKGROUND The continual reassessment method (CRM) is an adaptive model-based design used to estimate the maximum tolerated dose in dose finding clinical trials. A way to evaluate the sensitivity of a given CRM model including the functional form of the dose-toxicity curve, the prior distribution on the model parameter, and the initial guesses of toxicity probability at each dose is using indifference intervals. While the indifference interval technique provides a succinct summary of model sensi ...
We develop opportunistic scheduling policies for cognitive radio networks that maximize the throughput utility of the secondary (unlicensed) users subject to maximum collision constraints with the primary (licensed) users. We consider a cognitive network with static primary users and potentially mobile secondary users. We use the technique of Lyapunov optimization to design an online flow control, scheduling, and resource allocation algorithm that meets the desired objectives and provides explic ...
In the past few years, there has been growing interest in wide area \All Optical Networks" with wavelength division multiplexing (WDM), using wavelength routing. Due to the huge band-width inherent in optical ber, and the use of WDM to match user and network bandwidths, the wavelength routing architecture is an attractive candidate for future backbone transport networks. A virtual topology over a WDM WAN consists of clear channels between nodes called light-paths, with traac carried from source ...
Campylobacter jejuni is the leading bacterial cause of human gastroenteritis in the developed world. To improve our understanding of this important human pathogen, the C. jejuni NCTC11168 genome was sequenced and published in 2000. The original annotation was a milestone in Campylobacter research, but is outdated. We now describe the complete re-annotation and re-analysis of the C. jejuni NCTC11168 genome using current database information, novel tools and annotation techniques not used during t ...
Average consensus is a widely used algorithm for distributed computing and control, where all the agents in the network constantly communicate and update their states in order to achieve an agreement. This approach could result in an undesirable disclosure of information on the initial state of an agent to the other agents. In this paper, we propose a privacy preserving average consensus algorithm to guarantee the privacy of the initial state and asymptotic consensus on the exact average of the ...
As technology for microarray analysis becomes widespread, it is becoming increasingly important to be able to compare and combine the results of experiments that explore the same scientific question. In this article, we present a rank-aggregation approach for combining results from several microarray studies. The motivation for this approach is twofold; first, the final results of microarray studies are typically expressed as lists of genes, rank-ordered by a measure of the strength of evidence ...
Datacenter WAN traffic consists of high priority transfers that have to be carried as soon as they arrive alongside large transfers with pre-assigned deadlines on their completion (ranging from minutes to hours). The ability to offer guarantees to large transfers is crucial for business needs and impacts overall cost-of-business. State-of-the-art traffic engineering solutions only consider the current time epoch and hence cannot provide pre-facto promises for long-lived transfers. We present Tem ...
PURPOSE Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-worn accelerometer-based activity monitors that collect raw data. The goal is to increase wear time by asking subjects to wear the monitors on the wrist instead of the hip, and then to use information in the raw signal to improve activity type and intensity estimation. The purposes of this work was to obtain an algorithm to process wrist and ankle raw data and to classify behavior into four br ...
BACKGROUND & AIMS Cholangiocarcinoma, the second most common liver cancer, can be classified as intrahepatic cholangiocarcinoma (ICC) or extrahepatic cholangiocarcinoma. We performed an integrative genomic analysis of ICC samples from a large series of patients. METHODS We performed a gene expression profile, high-density single-nucleotide polymorphism array, and mutation analyses using formalin-fixed ICC samples from 149 patients. Associations with clinicopathologic traits and patient outcome ...
This paper deals with typical problems that arise when using wavelets in numerical analysis applications. The rst part involves the construction of quadrature formulae for the calculation of inner products of smooth functions and scaling functions. Several types of quadratures are discussed and compared for diierent classes of wavelets. Since their construction using mono-mials is ill-conditioned, also a modiied, well-conditioned construction using Chebyshev polynomials is presented. The second ...
Multivariate pattern analysis approaches toward detection of brain regions from fMRI data have been gaining attention recently. In this study, we introduce an iterative sparse-representation-based algorithm for detection of voxels in functional MRI (fMRI) data with task relevant information. In each iteration of the algorithm, a linear programming problem is solved and a sparse weight vector is subsequently obtained. The final weight vector is the mean of those obtained in all iterations. The ch ...
This manual describes the inla program, a new instrument which allows the user to easily perform approximate Bayesian inference using integrated nested Laplace approximation (INLA). We describe the set of models which can be solved by the inla program and provide a series of worked out examples illustrating its usage in details. Appendix A contains a reference manual for the inla program. This manual is for version snapshot of the inla program. ...
We study the problem of detecting general global predicates in distributed systems where all application processes and at most t < m monitor processes may be subject to crash faults, where m is the total number of monitor processes in the system. We introduce two new observation modalities called negotiably and discernibly (which correspond to possibly and definitely in fault-free systems) and present detection algorithms for them which work under increasingly weak fault assumptions. ...
Methods exhibiting linear scaling with respect to the size of the system, so called O(N) methods, are an essential tool for the calculation of the electronic structure of large systems containing many atoms. They are based on algorithms which take advantage of the decay properties of the density matrix. In this article the physical decay properties of the density matrix will first be studied for both metals and insulators. Several strategies to construct O(N) algorithms will then be presented an ...