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0908.0175
BGP Route Analysis and Management Systems
cs.NI cs.IT math.IT
The Border Gateway Protocol (BGP) is an important component in today's IP network infrastructure. As the main routing protocol of the Internet, clear understanding of its dynamics is crucial for configuring, diagnosing and debugging Internet routing problems. Despite the increase in the services that BGP provide such...
0908.0221
FPGA-based Controller for a Mobile Robot
cs.RO cs.AR
With application in the robotics and automation, more and more it becomes necessary the development of applications based on methodologies that facilitate future modifications, updates and enhancements in the original projected system. This project presents a conception of mobile robots using rapid prototyping, distr...
0908.0302
Polarization for arbitrary discrete memoryless channels
cs.IT math.IT
Channel polarization, originally proposed for binary-input channels, is generalized to arbitrary discrete memoryless channels. Specifically, it is shown that when the input alphabet size is a prime number, a similar construction to that for the binary case leads to polarization. This method can be extended to channel...
0908.0319
Regret Bounds for Opportunistic Channel Access
stat.ML cs.AI cs.LG cs.NI
We consider the task of opportunistic channel access in a primary system composed of independent Gilbert-Elliot channels where the secondary (or opportunistic) user does not dispose of a priori information regarding the statistical characteristics of the system. It is shown that this problem may be cast into the fram...
0908.0358
Outage analysis of Block-Fading Gaussian Interference Channels
cs.IT math.IT
This paper considers the asymptotic behavior of two-source block-fading single-antenna Gaussian interference channels in the high-SNR regime by means of the diversity-multiplexing tradeoff. We consider a general setting where the users and the average channel gains are not restricted to be symmetric. Our results are ...
0908.0373
A Reflection on the Structure and Process of the Web of Data
cs.AI cs.DL cs.GL
The Web community has introduced a set of standards and technologies for representing, querying, and manipulating a globally distributed data structure known as the Web of Data. The proponents of the Web of Data envision much of the world's data being interrelated and openly accessible to the general public. This vis...
0908.0390
Byzantine Convergence in Robots Networks: The Price of Asynchrony
cs.DC cs.RO
We study the convergence problem in fully asynchronous, uni-dimensional robot networks that are prone to Byzantine (i.e. malicious) failures. In these settings, oblivious anonymous robots with arbitrary initial positions are required to eventually converge to an a apriori unknown position despite a subset of them exh...
0908.0411
Data management in systems biology I - Overview and bibliography
cs.DB cs.DS q-bio.OT
Large systems biology projects can encompass several workgroups often located in different countries. An overview about existing data standards in systems biology and the management, storage, exchange and integration of the generated data in large distributed research projects is given, the pros and cons of the diffe...
0908.0464
Prioritized Repairing and Consistent Query Answering in Relational Databases
cs.DB
A consistent query answer in an inconsistent database is an answer obtained in every (minimal) repair. The repairs are obtained by resolving all conflicts in all possible ways. Often, however, the user is able to provide a preference on how conflicts should be resolved. We investigate here the framework of preferred ...
0908.0497
Network Coding for Multi-Resolution Multicast
cs.NI cs.IT math.IT
Multi-resolution codes enable multicast at different rates to different receivers, a setup that is often desirable for graphics or video streaming. We propose a simple, distributed, two-stage message passing algorithm to generate network codes for single-source multicast of multi-resolution codes. The goal of this "p...
0908.0515
Mobile Anchor Assisted Node Localization for Wireless Sensor Networks
cs.IT math.IT
In this paper, a cooperative localization algorithm is proposed that considers the existence of obstacles in mobilityassisted wireless sensor networks (WSNs). In this scheme, a mobile anchor (MA) node cooperates with static sensor nodes and moves actively to refine location performance. The localization accuracy of t...
0908.0516
Still doing evolutionary algorithms with Perl
cs.NE
Algorithm::Evolutionary (A::E from now on) was introduced in 2002, after a talk in YAPC::EU in Munich. 7 years later, A::E is in its 0.67 version (past its "number of the beast" 0.666), and has been used extensively, to the point of being the foundation of much of the (computer) science being done by our research gro...
0908.0567
LinkedCT: A Linked Data Space for Clinical Trials
cs.DB cs.CE cs.IR
The Linked Clinical Trials (LinkedCT) project aims at publishing the first open semantic web data source for clinical trials data. The database exposed by LinkedCT is generated by (1) transforming existing data sources of clinical trials into RDF, and (2) discovering semantic links between the records in the trials d...
0908.0570
The Infinite Hierarchical Factor Regression Model
cs.LG stat.ML
We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with a hierarchical model over factors, based on Kingman's coalescent. ...
0908.0572
Streamed Learning: One-Pass SVMs
cs.LG stat.ML
We present a streaming model for large-scale classification (in the context of $\ell_2$-SVM) by leveraging connections between learning and computational geometry. The streaming model imposes the constraint that only a single pass over the data is allowed. The $\ell_2$-SVM is known to have an equivalent formulation i...
0908.0583
Proceedings of 1st International Workshop on Collaborative Information Seeking
cs.IR cs.HC
The goal of the workshop is to bring together researchers interested in various aspects of small-team collaborative search to share ideas, to stimulate research in the area, and to increase the visibility of this emerging area. We expect to identify promising directions for further exploration and to establish collab...
0908.0586
Understanding Groups' Properties as a Means of Improving Collaborative Search Systems
cs.IR cs.HC
Understanding the similar properties of people involved in group search sessions has the potential to significantly improve collaborative search systems; such systems could be enhanced by information retrieval algorithms and user interface modifications that take advantage of important properties, for example by re-o...
0908.0595
Towards a Model of Understanding Social Search
cs.IR cs.HC
Search engine researchers typically depict search as the solitary activity of an individual searcher. In contrast, results from our critical-incident survey of 150 users on Amazon's Mechanical Turk service suggest that social interactions play an important role throughout the search process. Our main contribution is ...
0908.0619
Deterministic Construction of Compressed Sensing Matrices using BCH Codes
cs.IT math.IT
In this paper we introduce deterministic $m\times n$ RIP fulfilling $\pm 1$ matrices of order $k$ such that $\frac{\log m}{\log k}\approx \frac{\log(\log_2 n)}{\log(\log_2 k)}$. The columns of these matrices are binary BCH code vectors that their zeros are replaced with -1 (excluding the normalization factor). The sa...
0908.0660
A Short Note on Compressed Sensing with Partially Known Signal Support
cs.IT math.IT
This short note studies a variation of the Compressed Sensing paradigm introduced recently by Vaswani et al., i.e. the recovery of sparse signals from a certain number of linear measurements when the signal support is partially known. The reconstruction method is based on a convex minimization program coined "innovat...
0908.0703
Evaluating Collaborative Search Interfaces with Information Seeking Theory
cs.IR cs.HC
Despite the many implicit references to the social aspects of search within Information Seeking and Retrieval research, there has been relatively little work that has specifically investigated the additional requirements for collaborative search software. In this paper we re-assess a recent evaluation framework, desi...
0908.0704
A Taxonomy of Collaboration in Online Information Seeking
cs.IR cs.HC
People can help other people find information in networked information seeking environments. Recently, many such systems and algorithms have proliferated in industry and in academia. Unfortunately, it is difficult to compare the systems in meaningful ways because they often define collaboration in different ways. In ...
0908.0709
Toward Collaborative Information Seeking (CIS)
cs.IR cs.HC
It is natural for humans to collaborate while dealing with complex problems. In this article I consider this process of collaboration in the context of information seeking. The study and discussion presented here are driven by two dissatisfactions: (1) the majority of IR systems today do not facilitate collaboration ...
0908.0744
Performance analysis for sparse support recovery
cs.IT math.IT
The performance of estimating the common support for jointly sparse signals based on their projections onto lower-dimensional space is analyzed. Support recovery is formulated as a multiple-hypothesis testing problem. Both upper and lower bounds on the probability of error are derived for general measurement matrices...
0908.0753
Algebraic Decoding for Doubly Cyclic Convolutional Codes
cs.IT math.IT math.OC
An iterative decoding algorithm for convolutional codes is presented. It successively processes $N$ consecutive blocks of the received word in order to decode the first block. A bound is presented showing which error configurations can be corrected. The algorithm can be efficiently used on a particular class of convo...
0908.0764
Learning about Potential Users of Collaborative Information Retrieval Systems
cs.IR cs.HC
One of the key components of designing usable and useful collaborative information retrieval systems is to understand the needs of the users of these systems. Our research team has been exploring collaborative information behavior in a variety of organizational settings. Our research goals have been two-fold: First, ...
0908.0772
Online Learning of Assignments that Maximize Submodular Functions
cs.LG cs.DS
Which ads should we display in sponsored search in order to maximize our revenue? How should we dynamically rank information sources to maximize value of information? These applications exhibit strong diminishing returns: Selection of redundant ads and information sources decreases their marginal utility. We show tha...
0908.0775
Modeling the emergence of universality in color naming patterns
physics.soc-ph cond-mat.stat-mech cs.GT cs.MA q-bio.PE
The empirical evidence that human color categorization exhibits some universal patterns beyond superficial discrepancies across different cultures is a major breakthrough in cognitive science. As observed in the World Color Survey (WCS), indeed, any two groups of individuals develop quite different categorization pat...
0908.0794
Quantization Errors of Modulo Sigma-Delta Modulated ARMA Processes
cs.IT cs.NI math.IT
In this paper, we study the quantization errors of modulo sigma-delta modulated finite, asymptotically-infinite, infinite causal stable ARMA processes. We prove that the normalized quantization error can be taken as a uniformly distributed white noise for all the cases. Moreover, we find that this nice property is gu...
0908.0833
Top-down Paradigm in Engineering Software Integration
cs.CE cs.SE
The top-down approach of engineering software integration is considered in this parer. A set of advantages of this approach are presented, by examples. All examples are supplied by open source code.
0908.0856
Outage Capacity of Incremental Relaying at Low Signal-to-Noise Ratios
cs.IT math.IT
We present the \epsilon-outage capacity of incremental relaying at low signal-to-noise ratios (SNR) in a wireless cooperative network with slow Rayleigh fading channels. The relay performs decode-and-forward and repetition coding is employed in the network, which is optimal in the low SNR regime. We derive an express...
0908.0898
On Secrecy Capacity Scaling in Wireless Networks
cs.IT cs.CR math.IT
This work studies the achievable secure rate per source-destination pair in wireless networks. First, a path loss model is considered, where the legitimate and eavesdropper nodes are assumed to be placed according to Poisson point processes with intensities $\lambda$ and $\lambda_e$, respectively. It is shown that, a...
0908.0912
Evaluation of Coordination Techniques in Synchronous Collaborative Information Retrieval
cs.IR
Traditional Information Retrieval (IR) research has focussed on a single user interaction modality, where a user searches to satisfy an information need. Recent advances in web technologies and computer hardware have enabled multiple users to collaborate on many computer-supported tasks, therefore there is an increas...
0908.0919
Collaborative Search Trails for Video Search
cs.IR
In this paper we present an approach for supporting users in the difficult task of searching for video. We use collaborative feedback mined from the interactions of earlier users of a video search system to help users in their current search tasks. Our objective is to improve the quality of the results that users fin...
0908.0932
The Medical Algorithms Project
cs.HC cs.IR
The Medical Algorithms Project, a web-based resource located at www.medal.org, is the world's largest collection of medical-related spreadsheets, consisting of over 13,500 Excel spreadsheets each encoding a medical algorithm from 45 different areas of medical practice. This free resource is in use worldwide with over...
0908.0939
Clustering for Improved Learning in Maze Traversal Problem
cs.LG
The maze traversal problem (finding the shortest distance to the goal from any position in a maze) has been an interesting challenge in computational intelligence. Recent work has shown that the cellular simultaneous recurrent neural network (CSRN) can solve this problem for simple mazes. This thesis focuses on explo...
0908.0982
A multidimensional approach for context-aware recommendation in mobile commerce
cs.CY cs.MA
Context as the dynamic information describing the situation of items and users and affecting the users decision process is essential to be used by recommender systems in mobile commerce to guarantee the quality of recommendation. This paper proposes a novel multidimensional approach for context aware recommendation i...
0908.0984
An Application of Bayesian classification to Interval Encoded Temporal mining with prioritized items
cs.DB cs.LG
In real life, media information has time attributes either implicitly or explicitly known as temporal data. This paper investigates the usefulness of applying Bayesian classification to an interval encoded temporal database with prioritized items. The proposed method performs temporal mining by encoding the database ...
0908.0993
Outage Regions and Optimal Power Allocation for Wireless Relay Networks
cs.IT math.IT
We study outage regions for energy-constrained multi-hop and adaptive multi-route networks with an arbitrary number of relay nodes. Optimal power allocation strategies in the sense that outage probability is minimized are derived depending on the distances between the transmit nodes. We further investigate the rate g...
0908.0994
A Secure Multi-Party Computation Protocol for Malicious Computation Prevention for preserving privacy during Data Mining
cs.CR cs.DB
Secure Multi-Party Computation (SMC) allows parties with similar background to compute results upon their private data, minimizing the threat of disclosure. The exponential increase in sensitive data that needs to be passed upon networked computers and the stupendous growth of internet has precipitated vast opportuni...
0908.1004
A New Scaling Law on Throughput and Delay Performance of Wireless Mobile Relay Networks over Parallel Fading Channels
cs.IT math.IT
In this paper, utilizing the relay buffers, we propose an opportunistic decode-wait-and-forward relay scheme for a point-to-point communication system with a half-duplexing relay network to better exploit the time diversity and relay mobility. For instance, we analyze the asymptotic throughput-delay tradeoffs in a de...
0908.1071
Optimal Joint Target Detection and Parameter Estimation By MIMO Radar
cs.IT math.IT
We consider multiple-input multiple-output (MIMO) radar systems with widely-spaced antennas. Such antenna configuration facilitates capturing the inherent diversity gain due to independent signal dispersion by the target scatterers. We consider a new MIMO radar framework for detecting a target that lies in an unknown...
0908.1076
Multi-Agent Model Predictive Control: A Survey
cs.MA
In this report we define characteristic control design elements and show how conventional single-agent MPC implements these. We survey recent literature on multi-agent MPC and discuss how this literature deals with decomposition, problem assignment, and cooperation.
0908.1077
Beamforming and Rate Allocation in MISO Cognitive Radio Networks
cs.IT math.IT
We consider decentralized multi-antenna cognitive radio networks where secondary (cognitive) users are granted simultaneous spectrum access along with license-holding (primary) users. We treat the problem of distributed beamforming and rate allocation for the secondary users such that the minimum weighted secondary r...
0908.1116
Enhanced Algorithm for Link to System level Interface Mapping
cs.IT cs.PF math.IT
The current SINR mechanism does not provide the base station (BS) with any knowledge on the frequency selectivity of channel from mobile service station(MSS). This knowledge is important since, contrary to the AWGN channel, in a frequency selective channel there is no longer a 1 to 1 relation between amount of increa...
0908.1162
STBCs with Reduced Sphere Decoding Complexity for Two-User MIMO-MAC
cs.IT math.IT
In this paper, Space-Time Block Codes (STBCs) with reduced Sphere Decoding Complexity (SDC) are constructed for two-user Multiple-Input Multiple-Output (MIMO) fading multiple access channels. In this set-up, both the users employ identical STBCs and the destination performs sphere decoding for the symbols of the two ...
0908.1163
Trellis Coded Modulation for Two-User Unequal-Rate Gaussian MAC
cs.IT math.IT
In this paper, code pairs based on trellis coded modulation are proposed over PSK signal sets for a two-user Gaussian multiple access channel. In order to provide unique decodability property to the receiver and to maximally enlarge the constellation constrained (CC) capacity region, a relative angle of rotation is i...
0908.1185
Side-channel attack on labeling CAPTCHAs
cs.CR cs.CV cs.CY cs.HC
We propose a new scheme of attack on the Microsoft's ASIRRA CAPTCHA which represents a significant shortcut to the intended attacking path, as it is not based in any advance in the state of the art on the field of image recognition. After studying the ASIRRA Public Corpus, we conclude that the security margin as stat...
0908.1193
NLP-SIR: A Natural Language Approach for Spreadsheet Information Retrieval
cs.SE cs.HC cs.IR
Spreadsheets are a ubiquitous software tool, used for a wide variety of tasks such as financial modelling, statistical analysis and inventory management. Extracting meaningful information from such data can be a difficult task, especially for novice users unfamiliar with the advanced data processing features of many ...
0908.1208
Real Interference Alignment with Real Numbers
cs.IT math.IT
A novel coding scheme applicable in networks with single antenna nodes is proposed. This scheme converts a single antenna system to an equivalent Multiple Input Multiple Output (MIMO) system with fractional dimensions. Interference can be aligned along these dimensions and higher Multiplexing gains can be achieved. T...
0908.1222
Distributed Joint Source-Channel Coding for Functions over a Multiple Access Channel
cs.IT math.IT
In this paper we provide sufficient conditions for lossy transmission of functions of correlated data over a multiple access channel (MAC). The conditions obtained can be shown as generalized version of Yamamoto's result. We also obtain efficient joint source-channel coding schemes for transmission of discrete and co...
0908.1223
Joint Source-Channel Coding over a Fading Multiple Access Channel with Partial Channel State Information
cs.IT math.IT
In this paper we address the problem of transmission of correlated sources over a fast fading multiple access channel (MAC) with partial channel state information available at both the encoders and the decoder. We provide sufficient conditions for transmission with given distortions. Next these conditions are special...
0908.1264
Adaptive Training for Correlated Fading Channels with Feedback
cs.IT math.IT
We consider data transmission through a time-selective, correlated (first-order Markov) Rayleigh fading channel subject to an average power constraint. The channel is estimated at the receiver with a pilot signal, and the estimate is fed back to the transmitter. The estimate is used for coherent demodulation, and to ...
0908.1273
A General Class of Throughput Optimal Routing Policies in Multi-hop Wireless Networks
math.OC cs.NI cs.SY
This paper considers the problem of throughput optimal routing/scheduling in a multi-hop constrained queueing network with random connectivity whose special case includes opportunistic multi-hop wireless networks and input-queued switch fabrics. The main challenge in the design of throughput optimal routing policies ...
0908.1298
Exposing Pseudoweight Layers in Regular LDPC Code Ensembles
cs.IT math.IT
A solution is presented for the asymptotic growth rate of the AWGN-pseudoweight distribution of regular low-density parity-check (LDPC) code ensembles for a selected graph cover degree M >= 1. The evaluation of the growth rate requires solution of a system of 2M+1 nonlinear equations in 2M+1 unknowns. Simulation resu...
0908.1348
The non-existence of a [[13,5,4]] quantum stabilizer code
cs.IT math.IT quant-ph
We solve one of the oldest problems in the theory of quantum stabilizer codes by proving the non-existence of quantum [[13,5,4]]-codes.
0908.1369
Segmentation for radar images based on active contour
cs.CV
We exam various geometric active contour methods for radar image segmentation. Due to special properties of radar images, we propose our new model based on modified Chan-Vese functional. Our method is efficient in separating non-meteorological noises from meteorological images.
0908.1407
Generalized Analysis of a Distributed Energy Efficient Algorithm for Change Detection
cs.IT cs.PF math.IT stat.AP
An energy efficient distributed Change Detection scheme based on Page's CUSUM algorithm was presented in \cite{icassp}. In this paper we consider a nonparametric version of this algorithm. In the algorithm in \cite{icassp}, each sensor runs CUSUM and transmits only when the CUSUM is above some threshold. The transmis...
0908.1453
Training Process Reduction Based On Potential Weights Linear Analysis To Accelarate Back Propagation Network
cs.NE
Learning is the important property of Back Propagation Network (BPN) and finding the suitable weights and thresholds during training in order to improve training time as well as achieve high accuracy. Currently, data pre-processing such as dimension reduction input values and pre-training are the contributing factors...
0908.1457
General Scheme for Perfect Quantum Network Coding with Free Classical Communication
quant-ph cs.IT math.IT
This paper considers the problem of efficiently transmitting quantum states through a network. It has been known for some time that without additional assumptions it is impossible to achieve this task perfectly in general -- indeed, it is impossible even for the simple butterfly network. As additional resource we all...
0908.1490
Asymmetric Transmitter Cooperation in Multiuser Wireless Networks: Achievable Rate Regions
cs.IT math.IT
In this work, we derive achievable rate regions for the three-user interference channels with asymmetric transmitter cooperation and various decoding capabilities at the receivers. The three-user channel facilitates different ways of message sharing between the transmitters. We introduce two natural ways of extending...
0908.1510
Efficient On-line Schemes for Encoding Individual Sequences with Side Information at the Decoder
cs.IT math.IT
We present adaptive on-line schemes for lossy encoding of individual sequences under the conditions of the Wyner-Ziv (WZ) problem. In the first part of this article, a set of fixed-rate scalar source codes with zero delay is presented. We propose a randomized on-line coding scheme, which achieves asymptotically (and ...
0908.1564
Interfacing network coding with TCP: an implementation
cs.NI cs.IT math.IT
In previous work (`Network coding meets TCP') we proposed a new protocol that interfaces network coding with TCP by means of a coding layer between TCP and IP. Unlike the usual batch-based coding schemes, the protocol uses a TCP-compatible sliding window code in combination with new rules for acknowledging bytes to T...
0908.1597
A quantum diffusion network
cs.NE
Wong's diffusion network is a stochastic, zero-input Hopfield network with a Gibbs stationary distribution over a bounded, connected continuum. Previously, logarithmic thermal annealing was demonstrated for the diffusion network and digital versions of it were studied and applied to imaging. Recently, "quantum" annea...
0908.1669
The Weights in MDS Codes
cs.IT math.IT
The weights in MDS codes of length n and dimension k over the finite field GF(q) are studied. Up to some explicit exceptional cases, the MDS codes with parameters given by the MDS conjecture are shown to contain all k weights in the range n-k+1 to n. The proof uses the covering radius of the dual code
0908.1676
Improved Sparsity Thresholds Through Dictionary Splitting
cs.IT math.IT
Known sparsity thresholds for basis pursuit to deliver the maximally sparse solution of the compressed sensing recovery problem typically depend on the dictionary's coherence. While the coherence is easy to compute, it can lead to rather pessimistic thresholds as it captures only limited information about the diction...
0908.1769
Approximating the Permanent with Belief Propagation
cs.LG cs.IT math.IT
This work describes a method of approximating matrix permanents efficiently using belief propagation. We formulate a probability distribution whose partition function is exactly the permanent, then use Bethe free energy to approximate this partition function. After deriving some speedups to standard belief propagatio...
0908.1774
Energy-Efficient Transmission Scheduling with Strict Underflow Constraints
math.OC cs.IT math.IT
We consider a single source transmitting data to one or more receivers/users over a shared wireless channel. Due to random fading, the wireless channel conditions vary with time and from user to user. Each user has a buffer to store received packets before they are drained. At each time step, the source determines ho...
0908.1789
Maximum-Likelihood Sequence Detector for Dynamic Mode High Density Probe Storage
cs.IT math.IT
There is an increasing need for high density data storage devices driven by the increased demand of consumer electronics. In this work, we consider a data storage system that operates by encoding information as topographic profiles on a polymer medium. A cantilever probe with a sharp tip (few nm radius) is used to cr...
0908.1826
An Efficient Greedy Algorithm for Sparse Recovery in Noisy Environment
cs.IT math.IT
Greedy algorithm are in widespread use for sparse recovery because of its efficiency. But some evident flaws exists in most popular greedy algorithms, such as CoSaMP, which includes unreasonable demands on prior knowledge of target signal and excessive sensitivity to random noise. A new greedy algorithm called AMOP i...
0908.1916
Caching in Wireless Networks
cs.IT math.IT
We consider the problem of delivering content cached in a wireless network of n nodes randomly located on a square of area n. The network performance is described by the n2^n-dimensional caching capacity region of the wireless network. We provide an inner bound on this caching capacity region, and, in the high path-l...
0908.1919
A dyadic solution of relative pose problems
cs.CV
A hierarchical interval subdivision is shown to lead to a $p$-adic encoding of image data. This allows in the case of the relative pose problem in computer vision and photogrammetry to derive equations having 2-adic numbers as coefficients, and to use Hensel's lifting method to their solution. This method is applied ...
0908.1948
Interference Mitigation Through Limited Receiver Cooperation: Symmetric Case
cs.IT math.IT
Interference is a major issue that limits the performance in wireless networks, and cooperation among receivers can help mitigate interference by forming distributed MIMO systems. The rate at which receivers cooperate, however, is limited in most scenarios. How much interference can one bit of receiver cooperation mi...
0908.1966
Spectral Graph Analysis of Quasi-Cyclic Codes
cs.IT math.IT
In this paper we analyze the bound on the additive white Gaussian noise channel (AWGNC) pseudo-weight of a (c,d)-regular linear block code based on the two largest eigenvalues of H^T H. In particular, we analyze (c,d)-regular quasi-cyclic (QC) codes of length rL described by J x L block parity-check matrices with cir...
0908.2005
Fault Identification via Non-parametric Belief Propagation
cs.IT math.IT
We consider the problem of identifying a pattern of faults from a set of noisy linear measurements. Unfortunately, maximum a posteriori probability estimation of the fault pattern is computationally intractable. To solve the fault identification problem, we propose a non-parametric belief propagation approach. We sho...
0908.2024
On the accessibility of adaptive phenotypes of a bacterial metabolic network
q-bio.PE cs.IT math.IT q-bio.MN q-bio.QM
The mechanisms by which adaptive phenotypes spread within an evolving population after their emergence are understood fairly well. Much less is known about the factors that influence the evolutionary accessibility of such phenotypes, a pre-requisite for their emergence in a population. Here, we investigate the influe...
0908.2042
Problems in application of LDPC codes to information reconciliation in quantum key distribution protocols
cs.IT cs.CR math.IT quant-ph
The information reconciliation in a quantum key distribution protocol can be studied separately from other steps in the protocol. The problem of information reconciliation can be reduced to that of distributed source coding. Its solution by LDPC codes is reviewed. We list some obstacles preventing the LDPC-based dist...
0908.2050
View-based Propagator Derivation
cs.AI
When implementing a propagator for a constraint, one must decide about variants: When implementing min, should one also implement max? Should one implement linear constraints both with unit and non-unit coefficients? Constraint variants are ubiquitous: implementing them requires considerable (if not prohibitive) effo...
0908.2061
Sequence-Length Requirement of Distance-Based Phylogeny Reconstruction: Breaking the Polynomial Barrier
math.PR cs.CE cs.DS math.ST q-bio.PE q-bio.QM stat.TH
We introduce a new distance-based phylogeny reconstruction technique which provably achieves, at sufficiently short branch lengths, a polylogarithmic sequence-length requirement -- improving significantly over previous polynomial bounds for distance-based methods. The technique is based on an averaging procedure that...
0908.2117
Multiuser Modulation Classification Based on Cumulants in AWGN Channel
cs.IT math.IT
In this paper the negative impacts of interference transmitters on automatic modulation classification (AMC) have been discussed. We proposed two approaches for AMC in the presence of interference: single user modulation classification (SUMC) and multiuser modulation classification (MUMC). When the received power of ...
0908.2119
Compute-and-Forward: Harnessing Interference through Structured Codes
cs.IT math.IT
Interference is usually viewed as an obstacle to communication in wireless networks. This paper proposes a new strategy, compute-and-forward, that exploits interference to obtain significantly higher rates between users in a network. The key idea is that relays should decode linear functions of transmitted messages a...
0908.2141
Source and Channel Simulation Using Arbitrary Randomness
cs.IT math.IT
Necessary and sufficient conditions for approximation of a general channel by a general source are proved. For the special case in which the channel input is deterministic, which corresponds to source simulation, we prove a stronger necessary condition. As the approximation criteria, vanishing variational distance be...
0908.2153
Phased-MIMO Radar: A Tradeoff Between Phased-Array and MIMO Radars
cs.IT math.IT
We propose a new technique for multiple-input multiple-output (MIMO) radar with colocated antennas which we call phased-MIMO radar. The new technique enjoys the advantages of MIMO radar without sacrificing the main advantage of phased-array radar which is the coherent processing gain at the transmitting side. The ess...
0908.2174
Distributed Source Coding with One Distortion Criterion and Correlated Messages
cs.IT math.IT
In this paper, distributed (or multiterminal) source coding with one distortion criterion and correlated messages is considered. This problem can be also called ``Berger-Yeung problem with correlated messages''. It corresponds to the source coding part of the graph-based framework for transmission of a pair of correl...
0908.2198
The Berlekamp-Massey Algorithm and the Euclidean Algorithm: a Closer Link
cs.IT cs.DM math.IT
The two primary decoding algorithms for Reed-Solomon codes are the Berlekamp-Massey algorithm and the Sugiyama et al. adaptation of the Euclidean algorithm, both designed to solve a key equation. In this article an alternative version of the key equation and a new way to use the Euclidean algorithm to solve it are pr...
0908.2203
Transmitting an analog Gaussian source over a Gaussian wiretap channel under SNR mismatch
cs.IT math.IT
In this work we study encoding/decoding schemes for the transmission of a discrete time analog Gaussian source over a Gaussian wiretap channel. The intended receiver is assumed to have a certain minimum signal to noise ratio (SNR) and the eavesdropper is assumed to have a strictly lower SNR compared to the intended r...
0908.2277
Optimization of Training and Feedback Overhead for Beamforming over Block Fading Channels
cs.IT math.IT
We examine the capacity of beamforming over a single-user, multi-antenna link taking into account the overhead due to channel estimation and limited feedback of channel state information. Multi-input single-output (MISO) and multi-input multi-output (MIMO) channels are considered subject to block Rayleigh fading. Eac...
0908.2282
Real Interference Alignment: Exploiting the Potential of Single Antenna Systems
cs.IT math.IT
In this paper, the available spatial Degrees-Of-Freedoms (DOF) in single antenna systems is exploited. A new coding scheme is proposed in which several data streams having fractional multiplexing gains are sent by transmitters and interfering streams are aligned at receivers. Viewed as a field over rational numbers, ...
0908.2328
ARQ Secrecy: From Theory to Practice
cs.IT cs.CR math.IT
Inspired by our earlier work on Automatic Repeat reQuest (ARQ) secrecy, we propose a simple, yet efficient, security overlay protocol to existing 802.11 networks. Our work targets networks secured by the Wired Equivalent Privacy (WEP) protocol because of its widespread use and vulnerability to a multitude of security...
0908.2397
Interference Assisted Secret Communication
cs.IT cs.CR math.IT
Wireless communication is susceptible to eavesdropping attacks because of its broadcast nature. This paper illustrates how interference can be used to counter eavesdropping and assist secrecy. In particular, a wire-tap channel with a helping interferer (WT-HI) is considered. Here, a transmitter sends a confidential m...
0908.2408
Power Allocation Strategies and Lattice Based Coding schemes for Bi-directional relaying
cs.IT math.IT
We consider a communication system where two transmitters wish to exchange information through a half-duplex relay in the middle. The channels between the transmitters and the relay have asymmetric channel gains. More specifically, the channels are assumed to be synchronized with complex inputs and complex fading coe...
0908.2440
Reconfiguration of 3D Crystalline Robots Using O(log n) Parallel Moves
cs.CG cs.RO
We consider the theoretical model of Crystalline robots, which have been introduced and prototyped by the robotics community. These robots consist of independently manipulable unit-square atoms that can extend/contract arms on each side and attach/detach from neighbors. These operations suffice to reconfigure between...
0908.2467
Low-complexity non-uniform demand multicast network coding problems
cs.IT math.IT
The non-uniform demand network coding problem is posed as a single-source and multiple-sink network transmission problem where the sinks may have heterogeneous demands. In contrast with multicast problems, non-uniform demand problems are concerned with the amounts of data received by each sink, rather than the specif...
0908.2494
A Channel Coding Perspective of Collaborative Filtering
cs.IT math.IT
We consider the problem of collaborative filtering from a channel coding perspective. We model the underlying rating matrix as a finite alphabet matrix with block constant structure. The observations are obtained from this underlying matrix through a discrete memoryless channel with a noisy part representing noisy us...
0908.2505
On the Decay of the Determinants of Multiuser MIMO Lattice Codes
cs.IT cs.DM math.IT math.RA
In a recent work, Coronel et al. initiated the study of the relation between the diversity-multiplexing tradeoff (DMT) performance of a multiuser multiple-input multiple-output (MU-MIMO) lattice code and the rate of the decay of the determinants of the code matrix as a function of the size of the signal constellation...
0908.2529
A Low-Overhead Energy Detection Based Cooperative Sensing Protocol for Cognitive Radio Systems
cs.IT math.IT
Cognitive radio and dynamic spectrum access represent a new paradigm shift in more effective use of limited radio spectrum. One core component behind dynamic spectrum access is the sensing of primary user activity in the shared spectrum. Conventional distributed sensing and centralized decision framework involving mu...
0908.2578
New method to characterize a machining system: application in turning
cs.CE
Many studies simulates the machining process by using a single degree of freedom spring-mass sytem to model the tool stiffness, or the workpiece stiffness, or the unit tool-workpiece stiffness in modelings 2D. Others impose the tool action, or use more or less complex modelings of the efforts applied by the tool taki...
0908.2588
Wild Card Queries for Searching Resources on the Web
cs.DB cs.IR
We propose a domain-independent framework for searching and retrieving facts and relationships within natural language text sources. In this framework, an extraction task over a text collection is expressed as a query that combines text fragments with wild cards, and the query result is a set of facts in the form of ...
0908.2656
Semantic Robot Vision Challenge: Current State and Future Directions
cs.CV cs.RO
The Semantic Robot Vision Competition provided an excellent opportunity for our research lab to integrate our many ideas under one umbrella, inspiring both collaboration and new research. The task, visual search for an unknown object, is relevant to both the vision and robotics communities. Moreover, since the interp...
0908.2661
Human-Robot Teams in Entertainment and Other Everyday Scenarios
cs.MA cs.CY cs.HC
A new and relatively unexplored research direction in robotics systems is the coordination of humans and robots working as a team. In this paper, we focus upon problem domains and tasks in which multiple robots, humans and other agents are cooperating through coordination to satisfy a set of goals or to maximize util...