Journal: Computing Research Repository - CORR, 2012]]>

This is a report, where preliminary work regarding the topic of voting intention inference from Social Media - such as Twitter - is presented. Our case study is the UK 2010 General Election and we are focusing on predicting the percentages of voting intention polls (conducted by YouGov) for the three major political parties - Conservatives, Labours and Liberal Democrats - during a 5-...

Journal: Computing Research Repository - CORR, 2012]]>Journal: Computing Research Repository - CORR, vol. abs/1103.3, 2011]]>

The degrees of freedom (DoF) region of the $2$-user MIMO interference channel (IC) is studied under fast fading and the assumption of delayed channel state information (CSI) wherein all terminals know all channel matrices perfectly, but with a delay, and each receiver in addition knows its own incoming channels instantaneously. The general MIMO IC is considered with an arbitrary ...

Journal: Computing Research Repository - CORR, vol. abs/1101.5, 2011]]>In this paper, we describe a framework for similarity based retrieval and clustering from a 3D human database. Our technique is based on both body and head shape representation and the retrieval is based on similarity of both of them. The 3D human database used in our study is the CAESAR anthropometric database which contains approximately 5000 bodies. We have ...

Journal: Computing Research Repository - CORR, vol. abs/1105.2, 2011]]>We give the parameters of any evaluation code on a smooth quadric surface. For hyperbolic quadrics the approach uses elementary results on product codes and the parameters of codes on elliptic quadrics are obtained by detecting a BCH structure of these codes and using the BCH bound. The elliptic quadric is a twist of the surface P^1 x P^...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>Simulation of arterial stenting procedures prior to intervention allows for appropriate device selection as well as highlights potential complications. To this end, we present a framework for facilitating virtual aortic stenting from a contrast computer tomography (CT) scan. More specifically, we present a method for both lumen and outer wall segmentation that may be employed in determining both the appropriateness ...

Journal: Computing Research Repository - CORR, vol. abs/1103.1, 2011]]>In this paper, we investigate the performance of selection cooperation in the presence of imperfect channel estimation. In particular, we consider a cooperative scenario with multiple relays and amplify-and- forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-noise ratio (SNR) at the receiver end is selected. ...

Journal: Computing Research Repository - CORR, vol. abs/1101.0, 2011]]>Under what conditions is an edge present in a social network at time t likely to decay or persist by some future time t + Delta(t)? Previous research addressing this issue suggests that the network range of the people involved in the edge, the extent to which the edge is embedded in a surrounding structure, and the age of ...

Journal: Computing Research Repository - CORR, vol. abs/1102.1, 2011]]>We introduce and discuss the concept of Gaussian probability density function (pdf) for the n-dimensional hyperbolic space which has been proposed as an environment for coding and decoding signals. An upper bound for the error probability of signal transmission associated with the hyperbolic distance is established. The pdf and the upper bound were developed using Poincare models for the ...

Journal: Computing Research Repository - CORR, vol. abs/1101.3, 2011]]>Journal: Computing Research Repository - CORR, vol. abs/1105.4, 2011]]>

In this paper we investigate the word problem of the free Burnside semigroup satisfying x^2=x^3 and having two generators. Elements of this semigroup are classes of equivalent words. A natural way to solve the word problem is to select a unique "canonical" representative for each equivalence class. We prove that overlap-free words and so-called almost ...

Journal: Computing Research Repository - CORR, vol. abs/1102.4, 2011]]>We consider the MIMO (multiple-input multiple-output) Gaussian interference channel with i.i.d. fading across antennas and channel uses and with the delayed local channel state information at the transmitters (CSIT). For the two-user case, achievability results for the degrees of freedom (DoF) region of this channel are provided. We also prove the tightness of our achievable ...

Journal: Computing Research Repository - CORR, vol. abs/1102.5, 2011]]>Kripke Structures and Labelled Transition Systems are the two most prominent semantic models used in concurrency theory. Both models are commonly believed to be equi-expressive. One can find many ad-hoc embeddings of one of these models into the other. We build upon the seminal work of De Nicola and Vaandrager that firmly established the correspondence between stuttering equivalence ...

Journal: Computing Research Repository - CORR, vol. abs/1011.0, pp. 494-505, 2011]]>One of the most common types of functions in mathematics, physics, and engineering is a sum of products, sometimes called a partition function. After "normalization," a sum of products has a natural graphical representation, called a normal factor graph (NFG), in which vertices represent factors, edges represent internal variables, and half-edges represent the external variables of the partition function. ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>In this paper, we propose a new ensemble of rateless forward error correction (FEC) codes. The proposed codes are serially concatenated codes with Reed-Solomon (RS) codes as outer codes and Kite codes as inner codes. The inner Kite codes are a special class of prefix rateless low-density parity-check (PRLDPC) codes, which can generate potentially infinite (or as ...

Journal: Computing Research Repository - CORR, vol. abs/1104.4, 2011]]>It is commonly accepted in the practice of on-line analytical processing of databases that the multidimensional database organization is less scalable than the relational one. It is easy to see that the size of the multidimensional organization may increase very quickly. For example, if we introduce one additional dimension, then the total number of possible cells will be at ...

Journal: Computing Research Repository - CORR, vol. abs/1103.3, 2011]]>To maximize its success, an AGI typically needs to explore its initially unknown world. Is there an optimal way of doing so? Here we derive an affirmative answer for a broad class of environments.

Journal: Computing Research Repository - CORR, vol. abs/1103.5, 2011]]>We show how to extract existential witnesses from classical proofs using Krivine's classical realizability---where classical proofs are interpreted as lambda-terms with the call/cc control operator. We first recall the basic framework of classical realizability (in classical second-order arithmetic) and show how to extend it with primitive numerals for faster computations. Then we show how to ...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>In this paper we consider an interacting two-agent sequential decision-making problem consisting of a Markov source process, a causal encoder with feedback, and a causal decoder. Motivated by a desire to foster links between control and information theory, we augment the standard formulation by considering general alphabets and a cost function operating on current and previous symbols. Using ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>We present controllers that enable mobile robots to persistently monitor or sweep a changing environment. The changing environment is modeled as a field which grows in locations that are not within range of a robot, and decreases in locations that are within range of a robot. We assume that the robots travel on given closed paths. The speed of each ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>Sellar tumors are approximately 10-15% among all intracranial neoplasms. The most common sellar lesion is the pituitary adenoma. Manual segmentation is a time-consuming process that can be shortened by using adequate algorithms. In this contribution, we present a segmentation method for pituitary adenoma. The method is based on an algorithm we developed recently in previous work where the ...

Journal: Computing Research Repository - CORR, vol. abs/1103.1, 2011]]>Randomness extraction is the process of constructing a source of randomness of high quality from one or several sources of randomness of lower quality. The problem can be modeled using probability distributions and min-entropy to measure their quality and also by using individual strings and Kolmogorov complexity to measure their quality. Complexity theorists are more familiar with the rst ...

Journal: Computing Research Repository - CORR, vol. abs/1104.0, 2011]]>Dickson's Lemma is a simple yet powerful tool widely used in termination proofs, especially when dealing with counters or related data structures. However, most computer scientists do not know how to derive complexity upper bounds from such termination proofs, and the existing literature is not very helpful in these matters. We propose a new analysis of the length of ...

Journal: Computing Research Repository - CORR, vol. abs/1007.2, pp. 269-278, 2011]]>With the forecast increase in air traffic demand over the next decades, it is imperative to develop tools to provide traffic flow managers with the information required to support decision making. In particular, decision-support tools for traffic flow management should aid in limiting controller workload and complexity, while supporting increases in air traffic throughput. While many decision-support tools ...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>Displays based on organic light-emitting diode (OLED) technology are appearing on many mobile devices. Unlike liquid crystal displays (LCD), OLED displays consume dramatically different power for showing different colors. In particular, OLED displays are inefficient for showing bright colors. This has made them undesirable for mobile devices because much of the web content is of bright colors. To tackle ...

Journal: Computing Research Repository - CORR, vol. abs/1101.1, pp. 85-98, 2011]]>In this paper, we study linear programming based approaches to the maximum matching problem in the semi-streaming model. The semi-streaming model has gained attention as a model for processing massive graphs as the importance of such graphs has increased. This is a model where edges are streamed-in in an adversarial order and we are allowed a space ...

Journal: Computing Research Repository - CORR, vol. abs/1104.2, 2011]]>This paper considers the cognitive interference channel (CIC) with two transmitters and two receivers, in which the cognitive transmitter non-causally knows the message and codeword of the primary transmitter. We first introduce a discrete memoryless more capable CIC, which is an extension to the more capable broadcast channel (BC). Using superposition coding, we propose an inner bound and an ...

Journal: Computing Research Repository - CORR, vol. abs/1101.1, 2011]]>Information distributed through the Web keeps growing faster day by day, and for this reason, several techniques for extracting Web data have been suggested during last years. Often, extraction tasks are performed through so called wrappers, procedures extracting information from Web pages, e.g. implementing logic-based techniques. Many fields of application today require a strong degree of robustness of ...

Journal: Computing Research Repository - CORR, 2011]]>The Linear-Algebraic λ-Calculus extends the λ-calculus with the possibility of making arbitrary linear combinations of terms α.t+β.u. Since one can express fixed points over sums in this calculus, one has a notion of infinities arising, and hence indefinite forms. As a consequence, in order to guarantee the confluence, t−t does not always reduce to 0 – ...

Journal: Computing Research Repository - CORR, vol. 270, no. 2, pp. 219-229, 2011]]>In this paper we show that gossip algorithms may be effectively used to disseminate game events in Peer-to-Peer (P2P) Multiplayer Online Games (MOGs). Game events are disseminated through an overlay network. The proposed scheme exploits the typical behavior of players to tune the data dissemination. In fact, it is well known that users playing a MOG typically generate ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>Journal: Computing Research Repository - CORR, vol. abs/1105.2, 2011]]>

We present a study on lookahead hierarchies for restarting automata with auxiliary symbols and small lookahead. In particular, we show that there are at just two different classes of languages recognised RRWW automata, through the restriction of lookahead size. We also show that the respective (left-) monotone restarting automaton models characterise the context-free languages and that the respective right-...

Journal: Computing Research Repository - CORR, vol. abs/1101.1, 2011]]>We study properties of binary codes with parameters close to the parameters of 1-perfect codes. An arbitrary binary $(n=2^m-3, 2^{n-m-1}, 4)$ code $C$, i.e., a code with parameters of a triply-shortened extended Hamming code, is a cell of an equitable partition of the $n$-cube into six cells. An arbitrary binary $(...

Journal: Computing Research Repository - CORR, vol. abs/1104.0, 2011]]>We propose reactive Turing machines (RTMs), extending classical Turing machines with a process-theoretical notion of interaction. We show that every effective transition system is simulated modulo branching bisimilarity by an RTM, and that every computable transition system with a bounded branching degree is simulated modulo divergence-preserving branching bisimilarity. We conclude from these results that the parallel composition of (...

Journal: Computing Research Repository - CORR, vol. abs/1104.1, 2011]]>A constant K-user interference channel in which the users are not symbol synchronous is considered. It is shown that asynchronism among the users does not affect the total number of degrees of freedom (DOF) of this channel; however, it facilitates aligning interfering signals at each receiver node. To achieve the total K/2 DOF of the channel when single ...

Journal: Computing Research Repository - CORR, vol. abs/1101.0, 2011]]>Solutions for mobility management in wireless networks have been investigated and proposed in various research projects and standardization bodies. With the continuing deployment of different access networks, the wider range of applications tailored for a mobile environment, and a larger diversity of wireless end systems, it emerged that a single mobility protocol (such as Mobile IP) is not sufficient to ...

Journal: Computing Research Repository - CORR, vol. abs/1105.1, 2011]]>Thinning of character images is a big challenge. Removal of strokes or deformities in thinning is a difficult problem. In this paper, we have proposed a medial axis based thinning strategy used for performing skeletonization of printed and handwritten character images. In this method, we have used shape characteristics of text to get skeleton of nearly same as the true ...

Journal: Computing Research Repository - CORR, vol. abs/1103.0, 2011]]>The neocortex has a remarkably uniform neuronal organization, suggesting that common principles of processing are employed throughout its extent. In particular, the patterns of connectivity observed in the superficial layers of the visual cortex are consistent with the recurrent excitation and inhibitory feedback required for cooperative-competitive circuits such as the soft winner-take-all (WTA). WTA circuits offer interesting ...

Journal: Computing Research Repository - CORR, vol. abs/1105.3, 2011]]>Compressive sensing (CS) is a sampling technique designed for reducing the complexity of sparse data acquisition. One of the major obstacles for practical deployment of CS techniques is the signal reconstruction time and the high storage cost of random sensing matrices. We propose a new structured compressive sensing scheme, based on codes of graphs, that allows for a joint design ...

Journal: Computing Research Repository - CORR, vol. abs/1101.3, 2011]]>Journal: Computing Research Repository - CORR, vol. abs/1101.5, 2011]]>

We study convex relaxations of the image labeling problem on a continuous domain with regularizers based on metric interaction potentials. The generic framework ensures existence of minimizers and covers a wide range of relaxations of the originally combinatorial problem. We focus on two specific relaxations that differ in flexibility and simplicity -- one can be used to tightly relax any metric ...

Journal: Computing Research Repository - CORR, vol. abs/1102.5, 2011]]>The realm of this thesis is cryptographic protocol theory in the quantum world. We study the security of quantum and classical protocols against adversaries that are assumed to exploit quantum effects to their advantage. Security in the quantum world means that quantum computation does not jeopardize the assumption, underlying the protocol construction. But moreover, we encounter additional setbacks in the ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>We consider two-soure two-destination (i.e., two-unicast) multi-hop wireless networks that have a layered structure with arbitrary connectivity. We show that, with probability 1 over the choice of the channel gains, two-unicast layered Gaussian networks can only have 1, 3/2 or 2 sum degrees-of-freedom. We provide sufficient and necessary conditions for each ...

Journal: Computing Research Repository - CORR, vol. abs/1102.2, 2011]]>This user guide outlines the use of TIM, an interactive ray-tracing program. TIM was originally conceived as a tool for METATOYs research; TIM is a acronym for The Interactive METATOY. TIM can be customised and embedded into internet pages, making it suitable not only for research but also for its dissemination.

Journal: Computing Research Repository - CORR, vol. abs/1103.5, 2011]]>The problem of reconstructing source sequences with the presence of decoder side-information that is mis-synchronized to the source due to deletions is studied in a distributed source coding framework. Motivated by practical applications, the deletion process is assumed to be bursty and is modeled by a Markov chain. The minimum rate needed to reconstruct the source sequences with ...

Journal: Computing Research Repository - CORR, vol. abs/1102.3, 2011]]>A Pseudo-Boolean constraint (PB-constraint) is a generalization of a clause. A PB-constraint is an inequality (equality) on a linear combination of Boolean literals (å</font >i=1n aili OP b)\left(\sum_{i=1}^n a_il_i\ OP\ b\right) where a 1, ⋯ a n and b are constant integers, l 1, ⋯ ,l n are...

Journal: Computing Research Repository - CORR, vol. abs/1104.1, 2011]]>We address the problem of a group of n nodes, connected to the same broadcast channel (e.g., a wireless network), wanting to establish a common secret in the presence of a passive eavesdropper. If these nodes have no access to an out-of-band channel, the only practical solution today is to use public-key cryptography,which relies on ...

Journal: Computing Research Repository - CORR, vol. abs/1105.4, 2011]]>Today World Wide Web (WWW) has become a huge ocean of information and it is growing in size everyday. Downloading even a fraction of this mammoth data is like sailing through a huge ocean and it is a challenging task indeed. In order to download a large portion of data from WWW, it has become absolutely essential to make the ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>Hybrid-ARQ protocols have become common in many packet transmission systems due to their incorporation in various standards. Hybrid-ARQ combines the normal automatic repeat request (ARQ) method with error correction codes to increase reliability and throughput. In this paper, we look at improving upon this performance using feedback information from the receiver, in particular, using a powerful forward error ...

Journal: Computing Research Repository - CORR, vol. abs/1104.2, 2011]]>The multi-layer bit-wise unequal error protection problem is considered for variable length block codes with feedback. Inner and outer bounds are derived for achievable performance for finite expected decoding time. These bounds completely characterize the achievable volume for rate vector-error exponent vector pairs. The single message message-wise unequal error protection problem is also solved as a ...

Journal: Computing Research Repository - CORR, vol. abs/1101.1, 2011]]>Compressed sensing (CS) demonstrates that sparse signals can be recovered from underdetermined linear measurements. We focus on the joint sparse recovery problem where multiple signals share the same common sparse support sets, and they are measured through the same sensing matrix. Leveraging a recent information theoretic characterization of single signal CS, we formulate the optimal minimum mean square error (MMSE) ...

Journal: Computing Research Repository - CORR, vol. abs/1102.3, 2011]]>We consider a set of natural operations on languages, and prove that the orbit of any language L under the monoid generated by this set is finite and bounded, independently of L. This generalizes previous results about complement, Kleene closure, and positive closure.

Journal: Computing Research Repository - CORR, vol. abs/1101.1, 2011]]>We establish a new outer bound for the capacity region of product broadcast channels. This outer bound matches Marton's inner bound for a variety of classes of product broadcast channels whose capacity regions were previously unknown. These classes include product of reversely semi-deterministic and product of reversely more-capable channels. A significant consequence of this new outer bound ...

Journal: Computing Research Repository - CORR, vol. abs/1105.5, 2011]]>The Long Term Evolution of UMTS is one of the latest steps in an advancing series of mobile telecommunications systems. Many articles have already been published on the LTE subject but these publications have viewed the subject from particular perspectives. In the present paper, a different approach has been taken. We are interested in the security features and the cryptographic ...

Journal: Computing Research Repository - CORR, vol. abs/1102.5, 2011]]>In this paper, we present the design of a scalable, distributed stream processing system for RFID tracking and monitoring. Since RFID data lacks containment and location information that is key to query processing, we propose to combine location and containment inference with stream query processing in a single architecture, with inference as an enabling mechanism for high-level query processing. ...

Journal: Computing Research Repository - CORR, vol. abs/1103.4, 2011]]>In this paper we study the topological properties of wireless communication maps and their usability in algorithmic design. We consider the SINR model, which compares the received power of a signal at a receiver against the sum of strengths of other interfering signals plus background noise. To describe the behavior of a multi-station network, we use the convenient representation ...

Journal: Computing Research Repository - CORR, vol. abs/1103.4, pp. 383-392, 2011]]>We show that a subclass of infinite-state probabilistic programs that can be modeled by probabilistic one-counter automata (pOC) admits an efficient quantitative analysis. In particular, we show that the expected termination time can be approximated up to an arbitrarily small relative error with polynomially many arithmetic operations, and the same holds for the probability of all runs that ...

Journal: Computing Research Repository - CORR, vol. abs/1102.2, 2011]]>The Saratoga transfer protocol was developed by Surrey Satellite Technology Ltd (SSTL) for its Disaster Monitoring Constellation (DMC) satellites. In over seven years of operation, Saratoga has provided efficient delivery of remote-sensing Earth observation imagery, across private wireless links, from these seven low-orbit satellites to ground stations, using the Internet Protocol (IP). Saratoga is designed to cope with ...

Journal: Computing Research Repository - CORR, vol. abs/1101.2, pp. 1-8, 2011]]>Routing games are used to to understand the impact of individual users' decisions on network efficiency. Most prior work on routing games uses a simplified model of network flow where all flow exists simultaneously, and users care about either their maximum delay or their total delay. Both of these measures are surrogates for measuring how long it takes to get ...

Journal: Computing Research Repository - CORR, vol. abs/1010.3, pp. 192-201, 2011]]>We consider a small extent sensor network for event detection, in which nodes take samples periodically and then contend over a {\em random access network} to transmit their measurement packets to the fusion center. We consider two procedures at the fusion center to process the measurements. The Bayesian setting is assumed; i.e., the fusion center has a prior distribution ...

Journal: Computing Research Repository - CORR, vol. abs/1105.6, 2011]]>The World Wide Web (WWW) allows the people to share the information (data) from the large database repositories globally. The amount of information grows billions of databases. We need to search the information will specialize tools known generically search engine. There are many of search engines available today, retrieving meaningful information is difficult. However to overcome this problem in search ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>In this paper we consider the problem of universal prediction of individual continuous sequences with square-error loss, using a deterministic finite-state machine (FSM). The goal is to attain universally the performance of the best constant predictor tuned to the sequence, which predicts the empirical mean and incurs the empirical variance as the loss. The paper analyzes the tradeoff ...

Journal: Computing Research Repository - CORR, vol. abs/1102.2, 2011]]>We consider the Gaussian wiretap channel, where two legitimate players Alice and Bob communicate over an AWGN channel, while Eve is eavesdropping, also through an AWGN channel. We propose a coding strategy based on lattice coset encoding. We analyze Eve's probability of decoding, from which we define the secrecy gain as a design criterion for lattice codes, expressed in ...

Journal: Computing Research Repository - CORR, vol. abs/1103.4, 2011]]>We prove a Fife-like characterization of the infinite binary (7/3)-power-free words, by giving a finite automaton of 15 states that encodes all such words. As a consequence, we characterize all such words that are 2-automatic.

Journal: Computing Research Repository - CORR, vol. abs/1104.3, 2011]]>Xampling generalizes compressed sensing (CS) to reduced-rate sampling of analog signals. A unified framework is introduced for low rate sampling and processing of signals lying in a union of subspaces. Xampling consists of two main blocks: Analog compression that narrows down the input bandwidth prior to sampling with commercial devices followed by a nonlinear algorithm that detects the input ...

Journal: Computing Research Repository - CORR, vol. abs/1103.2, 2011]]>We study the correspondence between a concurrent lambda-calculus in administrative, continuation passing style and a pi-calculus and we derive a termination result for the latter.

Journal: Computing Research Repository - CORR, vol. abs/1102.2, 2011]]>Outage probability and capacity of a class of block-fading MIMO channels are considered with partial channel distribution information. Specifically, the channel or its distribution are not known but the latter is known to belong to a class of distributions where each member is within a certain distance (uncertainty) from a nominal distribution. Relative entropy is used as a measure ...

Journal: Computing Research Repository - CORR, vol. abs/1102.1, 2011]]>Most of legacy systems use nowadays were modeled and documented using structured approach. Expansion of these systems in terms of functionality and maintainability requires shift towards object-oriented documentation and design, which has been widely accepted by the industry. In this paper, we present a survey of the existing Data Flow Diagram (DFD) to Unified Modeling language (UML) transformation techniques. ...

Journal: Computing Research Repository - CORR, vol. abs/1102.4, 2011]]>We present an item-based approach for collaborative filtering. We determine a list of recommended items for a user by considering their previous purchases. Additionally other features of the users could be considered such as page views, search queries, etc... In particular we address the problem of efficiently comparing items. Our algorithm can efficiently approximate an estimate of the similarity ...

Journal: Computing Research Repository - CORR, vol. abs/1101.2, 2011]]>We develop several analytical lower bounds on the capacity of binary insertion and deletion channels by considering independent uniformly distributed (i.u.d.) inputs and computing lower bounds on the mutual information between the input and output sequences. For the deletion channel, we consider three different models: independent identically distributed (i.i.d.) deletion channel, i.i.d. deletion/substitution ...

Journal: Computing Research Repository - CORR, vol. abs/1101.1, 2011]]>If a modeling task is distributed, it will frequently be necessary to integrate models developed by different team members. Problems occur in the models integration step and particularly, in the comparison phase of the integration. This issue had been discussed in several domains and various models. However, previous approaches have not correctly handled the semantic comparison. In the current paper, ...

Journal: Computing Research Repository - CORR, vol. abs/1105.6, 2011]]>A perfect matching in a 3-uniform hypergraph on $n=3k$ vertices is a subset of $\frac{n}{3}$ disjoint edges. We prove that if $H$ is a 3-uniform hypergraph on $n=3k$ vertices such that every vertex belongs to at least ${n-1\choose 2} - {2n/3\choose 2}+1$ edges then $H$ contains a perfect matching. We ...

Journal: Computing Research Repository - CORR, vol. abs/1101.5, 2011]]>Log files contain information about User Name, IP Address, Time Stamp, Access Request, number of Bytes Transferred, Result Status, URL that Referred and User Agent. The log files are maintained by the web servers. By analysing these log files gives a neat idea about the user. This paper gives a detailed discussion about these log files, their formats, their creation, ...

Journal: Computing Research Repository - CORR, vol. abs/1101.5, 2011]]>Cloud computing is rapidly emerging as a new paradigm for delivering IT services as utlity-oriented services on subscription-basis. The rapid development of applications and their deployment in Cloud computing environments in efficient manner is a complex task. In this article, we give a brief introduction to Cloud computing technology and Platform as a Service, we examine the offerings ...

Journal: Computing Research Repository - CORR, vol. abs/1104.4, 2011]]>This paper presents a detailed proof for the triality theorem in a class of global optimization problems. The method is based on elementary linear algebra but it solves an open problem on the double-min duality left seven years ago. Results show that the triality theory holds strongly in the tri-duality form if the primal problem and its canonical ...

Journal: Computing Research Repository - CORR, vol. abs/1104.2, 2011]]>IEEE 802.11 is a widely used wireless LAN standard which offers a good bandwidth at low cost In an ESS, multiple APs can co-exist with overlapping coverage area. A mobile node connects to the AP from which it receives the best signal. Changes in traffic to and from different MNs occur over time. Load imbalance may develop on ...

Journal: Computing Research Repository - CORR, vol. abs/1105.5, 2011]]>English Character Recognition (CR) has been extensively studied in the last half century and progressed to a level, sufficient to produce technology driven applications. But same is not the case for Indian languages which are complicated in terms of structure and computations. Rapidly growing computational power may enable the implementation of Indic CR methodologies. Digital document processing is gaining popularity ...

Journal: Computing Research Repository - CORR, vol. abs/1101.2, 2011]]>Chaotic neural networks have received a great deal of attention these last years. In this paper we establish a precise correspondence between the so-called chaotic iterations and a particular class of artificial neural networks: global recurrent multi-layer perceptrons. We show formally that it is possible to make these iterations behave chaotically, as defined by Devaney, and thus we ...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>Limited feedback is a paradigm for the feedback of channel state information in wireless systems. In multiple antenna wireless systems, limited feedback usually entails quantizing a source that lives on the Grassmann manifold. Most work on limited feedback beamforming considered single-shot quantization. In wireless systems, however, the channel is temporally correlated, which can be used to reduce feedback requirements. ...

Journal: Computing Research Repository - CORR, vol. abs/1105.5, 2011]]>A restricted two-way communication problem in a small network is investigated. The network consists of three nodes, all having access to a common channel with half-duplex constraint. Two nodes want to establish a dialog while the third node can assist in the bi-directional transmission process. All nodes have agreed on a transmission protocol a priori and the ...

Journal: Computing Research Repository - CORR, vol. abs/1101.3, 2011]]>Label propagation has proven to be a fast method for detecting communities in complex networks. Recent work has also improved the accuracy and stability of the basic algorithm, however, a general approach is still an open issue. We propose different label propagation algorithms that convey two unique strategies of community formation, namely, defensive preservation and offensive expansion of communities. Furthermore, ...

Journal: Computing Research Repository - CORR, vol. abs/1103.2, 2011]]>In this paper, the problem of designing network codes that are both communicationally and computationally efficient over packet line networks with worst-case schedules is considered. In this context, random linear network codes (dense codes) are asymptotically capacity-achieving, but require highly complex coding operations. To reduce the coding complexity, Maymounkov et al. proposed chunked codes (CC). Chunked codes operate ...

Journal: Computing Research Repository - CORR, vol. abs/1105.5, 2011]]>Let G=(V,E) be a graph. A set S is independent if no two vertices from S are adjacent. The independence number alpha(G) is the cardinality of a maximum independent set, and mu(G) is the size of a maximum matching. The number id_{c}(G)=max{|I|-|N(I)|:I is an independent set} is called the ...

Journal: Computing Research Repository - CORR, vol. abs/1102.0, 2011]]>A set S is independent if no two vertices from S are adjacent. In this paper we prove that if F is a collection of maximum independent sets of a graph, then there is a matching from S-{intersection of all members of F} into {union of all members of F}-S, for every independent set S. Based on this ...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>In the past few years, the number of OLAP applications increased quickly. These applications use two significantly different DB structures: multidimensional (MD) and table-based. One can show that the traditional model of relational databases cannot make difference between these two structures. Another model is necessary to make the differences visible. One of these is the speed of the system. ...

Journal: Computing Research Repository - CORR, vol. abs/1103.3, 2011]]>One of the first step in the realization of an automatic system of check recognition is the extraction of the handwritten area. We propose in this paper an hybrid method to extract these areas. This method is based on digit recognition by Fourier descriptors and different steps of colored image processing . It requires the bank recognition of its code which ...

Journal: Computing Research Repository - CORR, vol. abs/1103.3, 2011]]>In this paper, new techniques are presented to either simplify or improve most existing upper bounds on the maximum-likelihood (ML) decoding performance of the binary linear codes over additive white Gaussian noise (AWGN) channels. Firstly, the recently proposed union bound using truncated weight spectrums by Ma {\em et al} is re-derived in a detailed way based on Gallager'...

Journal: Computing Research Repository - CORR, vol. abs/1104.1, 2011]]>Recent years have seen several earnest initiatives from both academic researchers as well as open source communities to implement and deploy decentralized online social networks (DOSNs). The primary motivations for DOSNs are privacy and autonomy from big brotherly service providers. The promise of decentralization is complete freedom for end-users from any service providers both in terms of keeping privacy ...

Journal: Computing Research Repository - CORR, vol. abs/1105.0, 2011]]>In this note we establish two facts concerning the so-called {\em New-Jersey} outer bound. We show that this outer bound is equivalent to a much simpler {\em computable} region; and secondly we show that in the absence of private information this bound is exactly same as the $UV$-outerbound.

Journal: Computing Research Repository - CORR, vol. abs/1101.0, 2011]]>Traditional radio telescopes use large, steel dishes to observe radio sources. The LOFAR radio telescope is different, and uses tens of thousands of fixed, non-movable antennas instead, a novel design that promises ground-breaking research in astronomy. The antennas observe omnidirectionally, and sky sources are observed by signal-processing techniques that combine the data from all antennas. Another new ...

Journal: Computing Research Repository - CORR, vol. abs/1105.0, 2011]]>Journal: Computing Research Repository - CORR, vol. abs/1105.3, 2011]]>

We introduce a new technique for proving kernelization lower bounds, called cross-composition. A classical problem L cross-composes into a parameterized problem Q if an instance of Q with polynomially bounded parameter value can express the logical OR of a sequence of instances of L. Building on work by Bodlaender et al. (ICALP 2008) and using a result by ...

Journal: Computing Research Repository - CORR, vol. abs/1011.4, pp. 165-176, 2011]]>We study the interaction between two interfering Gaussian 2-user multiple access channels. The capacity region is characterized under mixed strong--extremely strong interference and individually very strong interference. Furthermore, the sum capacity is derived under a less restricting definition of very strong interference. Finally, a general upper bound on the sum capacity is provided, which is nearly tight for ...

Journal: Computing Research Repository - CORR, vol. abs/1103.2, 2011]]>In cyber-physical systems where sensors measure the temporal evolution of a given phenomenon of interest and radio communication takes place over short distances, the energy spent for source acquisition and compression may be comparable with that used for transmission. Additionally, in order to avoid limited lifetime issues, sensors may be powered via energy harvesting and thus collect all the ...

Journal: Computing Research Repository - CORR, vol. abs/1103.4, 2011]]>We study the computational complexity of approximately counting the number of independent sets of a graph with maximum degree Δ. More generally, for an input graph G = (V,E) and an activity λ > 0, we are interested in the quantity Z G (λ) defined as the sum over independent sets I weighted as w(I) = λ |I|. ...

Journal: Computing Research Repository - CORR, vol. abs/1105.5, 2011]]>We consider the problem of human-assisted graph search: given a directed acyclic graph with some (unknown) target node(s), we consider the problem of finding the target node(s) by asking an omniscient human questions of the form "Is there a target node that is reachable from the current node?". This general problem has applications in many domains that ...

Journal: Computing Research Repository - CORR, vol. abs/1103.3, 2011]]>Given a C^1 path of systems of homogeneous polynomial equations f_t, t in [a,b] and an approximation x_a to a zero zeta_a of the initial system f_a, we show how to adaptively choose the step size for a Newton based homotopy method so that we approximate the lifted path (f_t,zeta_t) in ...

Journal: Computing Research Repository - CORR, vol. abs/1104.2, 2011]]>Higher-order recursion schemes are recursive equations defining new operations from given ones called "terminals". Every such recursion scheme is proved to have a least interpreted semantics in every Scott's model of \lambda-calculus in which the terminals are interpreted as continuous operations. For the uninterpreted semantics based on infinite \lambda-terms we follow the idea of Fiore, Plotkin ...

Journal: Computing Research Repository - CORR, vol. abs/1101.4, 2011]]>This paper presents prefix codes which minimize various criteria constructed as a convex combination of maximum codeword length and average codeword length or maximum redundancy and average redundancy, including a convex combination of the average of an exponential function of the codeword length and the average redundancy. This framework encompasses as a special case several criteria previously investigated in the ...

Journal: Computing Research Repository - CORR, vol. abs/1102.2, 2011]]>