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By Year By Research Group | This work concerns an automatic information fusion scheme for state estimation where the inputs (or measurements) that are used to reduce the uncertainty in the state of a subject are in the form of natural language propositions. In particular, we ... This work concerns an automatic information fusion scheme for state estimation where the inputs (or measurements) that are used to reduce the uncertainty in the state of a subject are in the form of natural language propositions. In particular, we ... A new algorithm for maximum-likelihood blind image restoration is presented in this paper. It is obtained by modeling the original image and the additive noise as multivariate Gaussian processes with unknown covariance matrices. The blurring process is... A variety of social, biological and communication networks can be modelled using graph theoretical tools. Similar graphical tools can be used to model the topology by which disease, errors, and/or other undesired phenomenon etc is spread and propagated ... The problem of estimating the transmission power levels of an uncooperative radio transmitter is examined in this short paper. The Cayley-Menger matrix is shown to provide an underlying geometrical constraint on the possible solutions and is subsequently ... In this paper we explore the problem of static target localization in 3-dimensions from a single image frame taken from multiple stationary imaging sensors. Specifically we provide a robust numerical algorithm which can be initialized quite naturally when... Differentiation is an epigenetic program that involves the gradual loss of pluripotency and acquisition of cell type–specific features. Understanding these processes requires genome-wide analysis of epigenetic and gene expression profiles, which have been... Collinear or near collinear placement of some sensors in a wireless sensor network causes the location estimates of nearby sensors to be sensitive to erroneous distance measurements which leads to large location estimation errors. These errors and the ... In this paper, we study the information propagation process in a 1D mobile ad hoc network formed by vehicles Poissonly distributed on a highway and travelling in the same direction at randomly distributed speeds, independent between vehicles. ... We consider wireless multi-hop networks with a finite number of (ordinary) nodes randomly deployed in a given 2D area. A finite number of gateways (infrastructure nodes) are deterministically placed in the same area. We study the connectivity between the ... Extracting the directional interaction between activated brain areas from functional magnetic resonance imaging (fMRI) time series measurements of their activity is a significant step in understanding the process of brain functions. In this paper, the... Machine transliteration is the process of automatically transforming the script of a word from a source language to a target language, while preserving pronunciation. The development of algorithms specifically for machine transliteration began over a ... Consider a network where all nodes are distributed on a unit square following a Poisson distribution with known density and a pair of nodes separated by an Euclidean distance x are directly connected with probability g x r , where g : [0;1... Abstract We examine the problem of segmenting foreground objects in live video when background scene textures change over time. In particular, we formulate background subtraction as minimizing a penalized instantaneous risk functional—yielding a ... This paper proposes algorithms to coordinate a formation of mobile agents when the agents are not able to measure the relative positions of their neighbors, but only the distances to their respective neighbors. In this sense, less information is available... Estimation of the expected Kullback-Leibler information is the basis for deriving the Akaike information criterion (AIC) and its corrected version AICc. Both criteria were designed for selecting multivariate regression models with an appropriateness of ... Existing polyp detection methods rely heavily on curvature-based characteristics to differentiate between lesions. These assume that the discrete triangulated surface mesh or volume closely approximates a smooth continuous surface. However, this is often ... In ad hoc querying of document collections, current approaches to ranking primarily rely on identifying the documents that contain the query terms. Methods such as query expansion, based on thesaural information or automatic feedback, are used to add ... Extended Boolean retrieval (EBR) models were proposed nearly three decades ago, but have had little practical impact, despite their significant advantages compared to either ranked keyword or pure Boolean retrieval. In particular, EBR models produce ... Kalman filter, particle filter, IMM, PDA, ITS, random sets The number of useful object-tracking methods is exploding. But how are they related? How do they help track everything from aircraft, missiles and extra-terrestrial objects to people and ... \section{Motivation:} Second generation sequencing technology makes it feasible for many researches to obtain enough sequence reads to attempt the \emph{de~novo} assembly of higher eukaryotes (including mammals). \emph{De~novo} assembly not only ... IEEE 802.11p and 1609 standards are currently under development to support Wireless Access in Vehicular Environment (WAVE) and to deliver both safety and non-safety related applications and services to vehicles on the road. For infrastructure-based ... Computed tomographic (CT) colonography is a promising alternative to traditional invasive colonoscopic methods used in the detection and removal of cancerous growths, or polyps in the colon. Existing computer-aided diagnosis (CAD) algorithms used in CT ... We introduce a discrete-time Markov switching system control model for a control algorithm that is executed on a device with time-varying computing resources. We outline the stability expressions for a number of linear control scenarios and we illustrate ... This paper outlines the problem of multi-static Doppler-based target position and velocity estimation. The Fisher information matrix is derived given a separate target illuminator and then given a target-based isotropic signal emission. Some remarks ... Wireless multi-hop networks with infrastructure support have been actively studied to solve the scalability problem in large scale vehicular and sensor networks that the end-toend throughput and other performance metrics decrease sharply with the ... In this paper, we study the information propagation speed in a 1D mobile ad hoc network formed by vehicles Poissonly distributed on a highway and travelling in the same direction but with random Gaussianly-distributed speeds, independent between vehicles.... Consider a wireless sensor network with i.i.d. sen- sors following a homogeneous Poisson distribution in a given area A in R2. A sensor located at x2 ∈ A is directly connected to a sensor located at x1 ∈ A with probability g (x2 − x1), independent of any ... This paper introduces and surveys a number of determinant constraints on the measurement errors in a variety of positioning scenarios. An algorithm for exploiting the constraints for accurate positioning is introduced and the relationship between the ... The problem of global positioning using a rigorous Bayesian framework based on the theory of random finite sets and their corresponding density functions is covered in this condensed tutorial. The positioning scenario considered involves a number of ... Firstly, an exposition of random-set-based estimation in general networked control systems is examined. This provides a background for the work introduced in this paper. This exposition is also aimed at highlighting the advantages of the random-set-based ... A cornerstone for cognitive mobile agents is to represent the vast body of knowledge about space in which they operate. In order to be robust and efficient, such representation must address requirements imposed on the integrated system as a whole, but ... The problem of multi-object tracking with sen- sor networks is studied using the probability hypothesis density filter. The sensors are assumed to generate signals which are sent to an estimator via parallel channels which incur independent delays. These ... We re-examine the problem of global localization of a robot using a rigorous Bayesian framework based on the idea of random finite sets. Random sets allow us to naturally develop a complete model of the underlying problem accounting for the statistics of ... The problem of multiple-sensor-based multiple-object tracking is studied for adverse environments involving clutter (false positives), missing measurements (false negatives) and random target births and deaths (a priori unknown target numbers). Various (... We consider the problem of distributed bearing-only formation control. Each agent measures the inter-agent bearings in a local coordinate system and is tasked at maintaining a specified angular separation relative to its neighbors. The problem we consider... Erroneous local geometric realizations in some parts of the network due to the sensitivity to certain distance measurement errors is a major problem in wireless sensor network localization, which may in turn affect the reliability of the localization ... Coverage is an important problem in wireless networks. Together with the access probability, which measures how well an arbitrary user can access a wireless network, in particular VANET, they are often used as major indicators of the quality of the ... We analytically characterize the energy consumption per successfully transmitted packet in end-to-end packet transmissions in a identically and independently distributed in a square area following a homogeneous Poisson process. It is assumed that a ... This letter introduces a simple convex, constraint based, optimization protocol for the problem of relative clock synchronization in wireless (sensor) networks. The problem of target localization involves estimating the position of a target from multiple and typically noisy measurements of the target position. It is well known that the relative sensor-target geometry can significantly affect the performance of ... The problem of target localization involves estimating the position of a target from multiple and typically noisy measurements of the target position. It is well known that the relative sensor-target geometry can significantly affect the performance of ... In passive target localization using direction finding (DF), there are particular sensor-target placements that cause large biases in the estimates or the failure of estimates to converge to a unique solution. Identification of such problematic ... Because of the simpleness, robustness and accuracy, sonar sensing has wide applications in navigation, target tracking and distance estimation for both civilian and defence use. This paper presents the applications of sonar sensors in the area of ... Abstract—In this paper, we study the well-known phase transition behavior of connectivity in a wireless multi-hop network, but, in contrast to other studies, in a shadowing environment. We consider that a total of n nodes are randomly, independently ... Location information for sensors in wireless sensor networks (WSNs) is essential to many tasks. In the presence of noise, locations must be estimated and thus the errors are unavoidable. Moreover, the errors can propagate (i.e. increase) as sensors ... In this paper, we study the transmission power to secure connectivity of a network. Instead of requiring all nodes to be connected, we require only that a large fraction (e.g. 95%) be connected, termed the giant component. We show that with this ... Relay technologies have been actively studied and considered in the standardization process of next generation mobile broadband communication systems. This paper first introduces and compares different relay types in 3GPP LTE-Advanced and WiMAX standards.... Relay technologies have been actively studied and considered in the standardization process of next-generation mobile broadband communication systems such as 3GPP LTE-Advanced, IEEE 802.16j, and IEEE 802.16m. This article first introduces and ... In this paper we report some new results obtained in the field of multi-agent systems that are based on convex optimization. First, we provide review of a set of polynomial function optimization tools including sum of squares (SOS) and semidefinite ... In this paper we propose a method for enhancing synchronizability using convex optimization. This method is based on adding new edges to the network, later the performance of the proposed method is tested through providing some numerical examples. ... Consider a stationary agent A at an unknown location and a mobile agent B that must move to the vicinity of and then circumnavigate A at a prescribed distance from A. In doing so, B can only measure its distance from A, and knows its own position in ... This paper is concerned with obstacle avoidance of robots moving on a plane, based on a fluid mechanical principle known as the Circle Theorem. Considering the motion region as a fictitious fluid environment surrounding the obstacles, fluid ... This paper is on obstacle avoidance of swarms of robots moving in certain geometric planar formations. Focus is given to a particular obstacle avoidance approach, which is based on the fluid mechanical principle known as the Circle Theorem. ... In this paper, we study the phase transition behavior of k-connectivity (k = 1; 2; :::) in wireless multi-hop networks where a total of n nodes are randomly and independently distributed following a uniform distribution in the unit cube [0; 1]d (d = 1... This paper proposes a systematic approach to the problem of restoring rigidity after loss of an agent, for two dimensional rigid multi-agent formations based on a particular graph operation, the edge contraction operation. A rigidity maintenance method ... In this paper we introduce a polynomial method for addressing sensor network localization problems when the measurements are noisy. We compare the result obtained applying this method with the result obtained by other methods in the literature. Later ... The sensor network localization problem is one of determining the Euclidean positions of all sensors in a network given knowledge of the Euclidean positions of some, and knowledge of a number of inter-sensor distances. This paper identifies graphical ... Edited book on localization Abstract— Localization is an important aspect in the field of wireless sensor networks that has attracted significant research interest recently. The interest in wireless sensor network localization is expected to grow further with the advances in the ... In this paper we examine the problem of optimal bearing-only localization of a single target using synchronous measurements from multiple sensors. We approach the problem by forming geometric relationships between the measured parameters and their ... This paper considers the problem of reduction of self-localization errors in multi-agent autonomous formations when only distance measurements are available to the agents in a globally rigid formation. It is shown that there is a relationship between ... In this paper, we study the giant component, the largest component containing a non-vanishing fraction of nodes, in a wireless multi-hop network where n nodes are randomly and uniformly distributed in [0; 1]d (d = 1; 2) and any two nodes can ... Wireless multihop networks, in various forms, are being increasingly used in military and civilian applications. Advanced applications of wireless multihop networks demand better understanding on their properties. Existing research on wireless ... Energy saving is an important design consideration in wireless sensor networks. In this paper, we analyze the energy savings that can be achieved in a sensor network where each sensor is capable of reducing its transmission power from a maximum power ... Erroneous local geometric realizations in some parts of the network due to their sensitivity to certain distance measurement errors is a major problem in wireless sensor network localization. This may in turn affect the localization of either the ... In this paper, we study the giant component, the largest component containing a non-vanishing fraction of nodes, in wireless multi-hop networks in The sensor network localization problem with distance information is to determine the positions of all sensors in a network, given the positions of some of the sensors and the distances between some pairs of sensors. A definition is given of what is ... This paper studies the problem of controlling the shape of a formation of point agents in the plane. A model is considered where the distance between certain agent pairs is maintained by one of the agents making up the pair; if enough appropriately ... The problem of source localization has assumed increased importance in recent years. In this paper, we formulate a continuous time adaptive localization algorithm, that permits a mobile agent to estimate the location of a stationary source, using only ... We develop a novel localization theory for planar networks of nodes that measure each other’s relative position, i.e., we assume that nodes do not have the ability to perform measurements expressed in a common reference frame. We begin with some basic... In this paper the problem of close target reconnaissance by a formation of 3 unmanned aerial vehicles (UAVs) is considered. The overall close target reconnaissance (CTR) involves subtasks of avoiding obstacles or no-fly-zones, avoiding inter-agent ... Consider a wireless multi-hop network formed by distributing a total of n nodes randomly and uniformly in the unit cube [0, 1]d (d = 1, 2, 3) and connecting any two distinct nodes directly iff (if and only if) their Euclidean distance is not greater ... A major problem in wireless sensor network localization is erroneous local geometric realizations in some parts of the network due to the sensitivity to certain distance measurement errors, which may in turn affect the reliability of the localization of ... This paper formulates and solves a version of the widely studied Vicsek consensus problem in which each member of a group of n > 1 agents independently updates its heading at times determined by its own clock. It is not assumed that the agents’ clocks... This paper considers localization of a source or a sensor from distance measurements. We argue that linear algorithms proposed for this purpose are susceptible to poor noise performance. Instead given a set of sensors/anchors of known positions and ... In this chapter, we summarize the graphical properties of a wireless sensor network to attain certain properties such as connectivity, k-connectivity, unique localizability and easily localizability with low computational cost. For a sensor network ... In earlier articles we had developed a formation control method based on single view depth estimation. In this paper, we implement that strategy on a robotic swarm composed of non-holonomic agents using the physics based Webots robot simulator. First, we ... Given a multi-hop network in which a total of n nodes are randomly and independently distributed in a unit square following a uniform distribution and each node has a uniform transmission range r(n), and two distinct nodes can directly communicate with ... This paper proposes a new type of algorithm aimed at finding the traditional maximum likelihood estimate of the position of a target given time difference of arrival information, contaminated by noise. The novelty lies in the fact that a performance ... This paper considers the problem of reduction of self-localization errors in multiagent autonomous formations when only distance measurement is available to the agents in a globally rigid formation. It is shown that there is a relationship between the ... In this paper, we consider motion and formation control of a team of three unmanned aerial vehicles (UAVs) for a particular surveillance task. The UAVs are required to fly in an equilateral triangle formation (to optimize target location estimation ... This paper presents a practical formation motion control scheme for robotic swarms based on single view depth estimation. The single view depth estimation for each robot in the swarm is performed using a single non-sophisticated camera on the agent, ... In a companion paper we have presented a practical formation motion control scheme for robotic swarms based on single view depth estimation. In this paper we adapt this control scheme to the cases where there are obstacles to be avoided in the region ... In this article we consider tracking a maneuvering target with a non-holonomic agent. The target and the agent move in 2-dimensional space. The task is to capture/intercept the moving target using a continuous time control scheme based on artificial ... In this paper, we study the construction and transformation of 2-D persistent graphs. Persistence is a generalization to directed graphs of the undirected notion of rigidity. Both notions are currently being used in various studies on coordination and... This paper considers initially the problem of localizing three agents moving in the plane when the inter-agent distances are known, and in addition, the angle subtended at each agent by lines drawn from two landmarks at known positions is also known. ... This paper treats the problem of the merging of formations, where the underlying model of a formation is graphical. We first analyze the rigidity and persistence of metaformations, which are formations obtained by connecting several rigid or ... This paper presents new graph-theoretic results appropriate for the analysis of a variety of consensus problems cast in dynamically changing environments. The concepts of rooted, strongly rooted, and neighbor-shared are defined, and conditions are derived... This paper uses recently established properties of compositions of directed graphs together with results from the theory of nonhomogeneous Markov chains to derive worst case convergence rates for the headings of a group of mobile autonomous agents which ... This paper presents new graph-theoretic results appropriate for the analysis of a variety of consensus problems cast in dynamically changing environments. The concepts of rooted, strongly rooted, and neighbor-shared are defined, and conditions are ... This paper uses recently established properties of compositions of directed graphs together with results from the theory of nonhomogeneous Markov chains to derive worst case convergence rates for the headings of a group of mobile autonomous agents which... This paper presents new graph-theoretic results appropriate for the analysis of a variety of consensus problems cast in dynamically changing environments. The concepts of rooted, strongly rooted, and neighbor-shared are defined, and conditions are ... This paper uses recently established properties of compositions of directed graphs together with results from the theory of nonhomogeneous Markov chains to derive worst case convergence rates for the headings of a group of mobile autonomous agents which... Unmanned airborne vehicles (UAVs) are finding use in military operations and starting to find use in civilian operations. UAVs often fly in formation, meaning that the distances between individual pairs of UAVs stay fixed, and the formation of UAVs ... This paper considers localization of a source or a sensor from distance measurements. We argue that linear algorithms proposed for this purpose are susceptible to poor noise performance. Instead given a set of sensors/anchors of known positions and ... A central goal of medical genetics is to create models that accurately predict complex disease given genotype. To maximize predictive value and identify causal single-nucleotide polymorphisms (SNPs), all SNPs should be modeled simultaneously. Lasso ... In a wireless network, multi-user diversity can be employed to improve system throughput performance by scheduling the channel to the user with the best instantaneous channel state information (CSI). However, the overhead induced by polling CSIs of a ... The conventional adaptive resource allocation schemes for Orthogonal Frequency Division Multiple Access (OFDMA) systems cannot guarantee that the peak power of its time-domain modulated signal shall not exceed the transmitter peak power limit. When ... In this paper a novel analytical approach is proposed to approximate and correct the bias in localization problems in n-dimensional space (n = 2 or 3) with N (N >= n) independently usable measurements (such as distance, bearing, TDOA etc.). Here N is ... This paper proposes a constrained optimization approach to improve the accuracy of a Time-of-Arrival (ToA) based multiple target localization system. Instead of using an overdetermined measurement system, this paper uses local distance measurements ... In this paper, a novel bias reduction method is proposed to analytically express and reduce the bias arising in localization problems, thereby improving the localization accuracy. The proposed bias reduction method mixes Taylor series and a maximum ... This paper investigates the cluster consensus for a group of double-integrator agents under two different frameworks, viz, the framework that all agents share the same position and velocity interaction topology and the framework that the position and ... In this paper we investigate the critical node density required to ensure that an arbitrary node in a large-scale wireless multi-hop network is connected (via multi-hop path) to infinitely many other nodes with a positive probability. Specifically we ... Broadcast in mobile ad-hoc networks is a challenging and resource demanding task, due to the affects of dynamic network topology and channel randomness. In this paper, we consider 2D wireless ad-hoc networks where nodes are randomly distributed and move ... We assess a mutation extraction tool with respect to the task of curation of the literature for the purpose of populating a database of genetic variation information. Our analysis shows that the ability of text mining tools to recover the mutations ... Humans have the subconscious ability to create simple ab- stractions from observations of their physical environment. The ability to consider the colour of an object in terms of “red” or “blue”, rather than spatial distributions of reflected light ... |