Research Publications
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| Temporal autocorrelation of the dynamic on-body radio channel is characterized empirically and theoretically based on measurements. The channel coherence time is found to be approximately 20 to 70~ms for a human subject either walking or running. Using a ... 300+ hours of sleeping BAN channel measurements with characterisation of data in terms of outages with respect to receiver sensitivity. Showing that channel outages are greater than 10% with -100 dBm receiver sensitivity. Relation extraction is the task of extracting semantic relations— such as synonymy or hypernymy—between word pairs from corpus data. Past work in relation extraction has concentrated on manually creating templates to use in directly extracting word pairs ... During the last decade, the Ministry of Health of the Republic of Serbia, a developing country, funded several projects aiming to make the public healthcare system more efficient through the use of information technology (IT). This system development ... 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 ... In this paper, we present a study in understanding sensing error’s impact on traffic signal control performance. Adaptive traffic signal control systems depend on information from traffic sensors to interpret the state of traffic. Signal timings are ... Consider the following problem: given sets of unlabeled observations, each set with known label proportions, predict the labels of another set of observations, possibly with known label propor- tions. This problem occurs in areas like e-commerce, ... In this paper, we formulate the feature clustering problem as a general Bayesian model and solve it using MCMC. The proposed approach exhibits two advantages over existing methods: Bayesian model handles arbitrary objective functions and MCMC guarantees ... Many computer vision algorithms such as object tracking and event detection assume that a background model of the scene under analysis is known. However, in many practical circumstances it is unavailable and needs to be estimated from cluttered image ... This study investigates the effects of November superstorms on the daytime-evening northern topside ionosphere. We utilize multi-instrument interplanetary and geomagnetic data to analyze the interplanetary shock/electric (E) field events. To assess their ... Tendency of individuals to develop relationships with similar individuals, to form relationships based on mutual acquaintances and proximity, and to form relationships based on common interests are documented in the social science literature as ... This paper presents the design and implementation of SPINdle - a defeasible logic reasoner that is capable to perform efficient and scalable reasoning on defeasible logic theories (including theories with over 1 million rules). The implementation ... Static program analysers typically come with a set of hard-coded checks, leaving little room for the user to add additional properties. In this work, we present a uniform approach to enable the speci cation of new static analysis checks in a concise ... In this paper we show how a non-monotonic rule based system (defeasible logic) can be integrated with numerical computation engines. To this end we simulate a physical system from which we obtain numerical information. The physical system perceives ... Purpose of review. We outline and discuss recent work on auditory displays, covering both auditory alarms that indicate technical or physiological threshold levels, and informative auditory displays that provide a continuous awareness of a patient’s ... Purpose of review. Head-mounted displays (HMDs) are head-worn display devices that project an information display over the wearer’s field of view. This article reviews a recent program of research that investigates the advantages and disadvantages of ... Topic models are a discrete analogue to principle component analysis and independent component analysis that model {\it topic} at the word level within a document. They have many variants such as NMF, PLSI and LDA, and are used in many fields such as ... CNF simplifiers play a very important role in minimising structured problem hardness. Altough they can be used in an in-search process, most of them serve in a pre-search phase and are developed based on the old resolution procedure. Based on our ... In this survey paper we summarize the requirements for rule interchange languages for applications in the legal domain and use these requirements to evaluate RuleML, SBVR, SWRL and RIF. We also present the Legal Knowledge Interchange Format (LKIF), a new ... We extend the framework of Constraint Satisfaction Problems to make it more suitable for/applicable to modern constraint programming languages where both constraint satisfaction and constraint solving have a role. Some rough principles for local ... Clinical systematic reviews are based on expert, laborious search of well-annotated literature. Boolean search on bibliographic databases, such as MEDLINE, continues to be the preferred discovery method, but the size of these databases, now approaching ... One of the major challenges encountered by current face recognition techniques lies in the difficulties of handling varying poses, i.e., recognition of faces in arbitrary in-depth rotations. The face image differences caused by rotations are often ... In this book, we describe the proposed pedestrian classification and tracking system that is able to track and label multiple people in an outdoor environment such as a railway station. We propose an approach that combines blob matching with particle ... 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.... The Policy-Aware Web is the promise for supporting semantic policy management at the Web infrastructure level. A policy is any set of rules or statements that capture and express the re- quirements of individuals and organisations from a corporate, legal,... This paper presents a high-level access control model of the seL4 microkernel. We extend an earlier formalisation by Elkaduwe et al with non-determinism, explicit sharing of capability storage, and a delete-operation for entities. We formally prove ... This short note explains how to install PHAVer (and the needed libraries) for a single user on Mac OS X running Leopard (10.5.6). It might also work for earlier versions (you can report to me in ... In this paper, we address the problem of synthesizing \emph{opaque} systems. A secret predicate $S$ over the runs of a system $G$ is \emph{opaque} to an external user having partial observability over $G$, if s/he can never infer from the ... In this paper, we focus on the synthesis of secure timed systems which are given by timed automata. The security property that the system must satisfy is a \emph{non-interference} property. Various notions of non-interference have been ... Goanna is an industrial-strength static analysis tool used in academia and industry alike to find bugs in C/C++ programs. Unlike existing approaches, Goanna uses the off-the-shelf model checker NuSMV as its core analysis engine on a syntactic ... We provide an overview of a Maritime Intelligent Transport System (ITS) which consists of a high speed maritime mesh network, satellite communications and middleware components. The work is an outcome of a collaboration project between I$^{\textrm{\... Modern mobile devices are increasingly capable of simultaneously connecting to multiple access networks with different characteristics. Restricted coverage combined with user mobility will vary the availability of networks for a mobile device. Most ... It is well known that WLAN based on the IEEE 802.11 stan- dard suffers from interference and scalability problems due to a limited number of non-overlapping channels. In order to mitigate the interference problem, channel assignment al- gorithms ... The Road and Traffic Authority (RTA) of NSW, partnered with NICTA, are looking into wireless sensor network technologies to monitor the structural health of bridges. The task involves exploring different sensing, networking, and distributed computation ... In this book Chapter we address the problem of controller synthesis for timed systems. By timed systems we refer to systems which are subject to quantitative (hard) real-time constraints. We assume the reader is familiar with the basics of Timed ... In this book Chapter, we review the main results pertaining to the problem of fault diagnosis of timed automata. Timed automata are introduced in Chapter 1 and Chapter 2 in this book, and the reader... We consider cooperative retransmission strategies in wireless networks, where the retransmission of a failed frame is handled not by the original source but rather by common neighbors overhearing the transmission. The majority of existing literature in ... Cooperative communication methods in wireless networks, ranging from relaying by a common neighbor over a single wireless hop to opportunistic routing at the network layer, have been shown in recent years to offer significant performance gains over ... In wireless networks, transmissions can generally be overheard by unintended nodes in the vicinity of the sender and receiver, potentially causing interference to their own communications. Much of the related research has considered this as a nuisance and... We propose a framework to optimize the communication performance and mobility management in vehicular networks. By having a single unified decision algorithm taking into account both stack-related and external contextual information such as GPS ... In Mobile Social Networks (MSN) individuals with similar interests or commonalities, connect to each other using the mobile phones. Validation of protocols for MSN relies al- most exclusively on simulations. Thus a simulation using a mobility model ... This volume contains the proceedings of the 4th International Workshop on Systems Software Verification (SSV) held in Aachen, Germany, June 22--24, 2009. The purpose of SSV is to bring together researchers and developers from both academia and ... In this paper, we address the problem of synthesizing \emph{opaque} systems. A secret predicate $S$ over the runs of a system $G$ is \emph{opaque} to an external user having partial observability over $G$, if s/he can never infer from the ... To build trust between two entities in VANET is particularly difficult due to lack of infra-structure, openness of wireless links and the usually highly dynamic network topology. To address these problems, we propose an effective trusted routing mechanism... Complete formal verification is the only known way to guarantee that a system is free of programming errors. We present our experience in performing the formal, machine-checked verification of the seL4 microkernel from an abstract specification down to ... Networking testbeds are playing an increasingly important role in the development of new communication technologies. Testbeds are traditionally built for a particular project or to study a specific technology. An alternative approach is to federate ... In sports competitions, teams can manipulate the result by, for instance, throwing games. We show that we can decide how to manipulate round robin and cup competitions, two of the most popular types of sporting competitions in polynomial time. In ... The stable marriage problem has many practical applications in two sided markets like those that assign doctors to hospitals, students to schools, or buyers to vendors. Most algorithms to find stable marriages assume that the participants explicitly ... Faulty device drivers cause significant damage through downtime and data loss. The problem can be mitigated by an improved driver development process that guarantees correctness by construction. We achieve this by synthesizing... This paper presents a method for learning Radial Basis Functions (RBF) model with variable dimensions for aligning/ registrating images of deformable surface. Traditional RBF-based approach, which is mainly based on a fixed dimension parametric model,... We address the problem of identifying dry areas in the tear film as part of a diagnostic tool for dry-eye syndrome. The requirement is to identify and measure the growth of the dry regions to provide a time-evolving map of degrees of dryness. We ... Faced with increasing congestion on urban roads, authorities need better real-time traffic information to manage traffic. Kalman Filters are efficient algorithms that can be adapted to track vehicles in urban traffic given noisy sensor data. A Kalman ... The energy consumed by radio transceivers is a significant factor limiting the lifetime of wireless sensor networks (WSNs). Maximizing WSN lifetime is the overall aim of this work, which proposes that optimal routing be defined with a network design... This paper shows how to use an ideal rubber string, which is clamped down at both ends, as a memory device. The information is stored on the string by giving it an initial shape, where the Fourier coefficients of this shape represent the code bits. Once ... Due to the recent progress in computer vision to interpret images and sequence of images, the video camera is a promising sensor for traffic monitoring and traffic surveillance at low cost. This paper focuses on the detection and tracking of multiple ... A new method for optimal robust estimation. The algorithm mBPCR is a tool for estimating the profile of the log2ratio of copy number data. The procedure is a Bayesian piecewise constant regression and can be applied, generally, to estimate any piecewise constant function (like the log2ratio of the ... We give an continuation-based implementation of rewriting for systems in the LCF tradition. These systems must construct explicit proofs of equations when rewriting, and currently do so in a way that can be very space-inefficient. An explicit ... The objective of the 1st International Workshop on Social Interoperable Networks - is to bring together the Social Networks community and to discuss the technical interoperability issues facing service providers and end users. The workshop will attract ... A multiclass classification problem can be reduced to a collection of binary problems using an error-correcting coding matrix that specifies the binary partitions of the classes. The final classifier is an ensemble of base classifiers learned on the ... Roundabouts are widely used traffic control measures that function particularly well under balanced, light-to-medium approach traffic flows. However, even moderate flow imbalance can cause disruption and lengthy delays. One solution is to meter traffic on... The ubiquitous computing vision includes Single Display Groupware (SDG) devices embedded in our normal envi- ronment. This paper explores the nature of interfaces for supporting people in accessing their files on such displays. To do this, we designed ... We describe an energy minimization algorithm for functions defined on 4-connected lattices, of the type usually encountered in problems involving images. Such functions are often minimized using graph-cuts/max-flow, but this method is only applicable... In this paper, we identify the constraints under which the generally ill-posed problem of simultaneous recovery of surface shape and its photometric invariants can be rendered tractable. We examine the cases where a single or more images are acquired ... We describe the research outcomes and resulting implementation and validation of a prototype IP telephony and data acceleration system for satellite communications. The system has been designed as a quickly deployable solution for generic use with fixed ... Gait is one of well recognized biometrics that has been widely used for human identification. However, viewing direction change causes many difficulties to the current gait recognition because the viewing angle under which the gait signature database was ... One of the reasons for introducing software product lines (SPL) is the reduction of costs through reusing common assets for different products. Developing assets to be reused in different products is often not easy. Increasing complexity due to the ... The immense popularity of new-age ``Web 2'' applications such as YouTube, Flickr, and Facebook, and non-Web applications such as Peer-to-Peer (P2P) file sharing, Voice over IP, online games, and media streaming have significantly altered the ... We present a method for calibrating the rotation between two cameras in a camera rig in the case of non-overlapping fields of view and in a globally consistent manner. First, rotation averaging strategies are discussed and an $L_1$-optimal rotation ... 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 present a feature combination approach to object tracking based upon graph embedding techniques. The method presented here abstracts the low complexity features used for purposes of tracking to a relational structure and employs ... The move towards the Policy-Oriented Web is destined to provide support for policy expression and management in the core web layers. One of the most promising areas that can drive this new technology adoption is e-Society communities. With so much ... Heuristic forward search is the dominant approach to satisficing planning to date. Most successful planning systems, however, go beyond plain heuristic search by employing various search-enhancement techniques. One example is the use of helpful ... A distance metric that can accurately reflect the intrinsic characteristics of data is critical for visual recognition tasks. An effective solution to defining such a metric is to learn it from a set of training samples. In this work, we propose a fast... |