OpenRaiser/Intern-Atlas huggingface dataset:
Searching and Establishment of S-P-O Relationships for Linked RDF Graphs : An Adaptive Approach
Venue: arXiv cs.IR 2013
Year: 2013

In the coming era of semantic web linked data analysis is a very burning issue for efficient searching and retrieval of information. One way of establishing this link is to implement subject predicate object relationship through Set Theory approach which is already done in our previous work. For analyzing inter relationship between two RDF Graphs, RDF- Schema (RDFS) should also be taken care of. In the present paper, an adaptive combination rule based framework has been proposed for establishment of S P O relationship and RDF Graph searching is reported. Hence the identification of criteria for inter-relationship of RDF Graphs opens up new road in semantic search.
Solving Minimum Vertex Cover Problem Using Learning Automata
Venue: arXiv cs.AI 2013
Year: 2013

Minimum vertex cover problem is an NP-Hard problem with the aim of finding minimum number of vertices to cover graph. In this paper, a learning automaton based algorithm is proposed to find minimum vertex cover in graph. In the proposed algorithm, each vertex of graph is equipped with a learning automaton that has two actions in the candidate or non-candidate of the corresponding vertex cover set. Due to characteristics of learning automata, this algorithm significantly reduces the number of covering vertices of graph. The proposed algorithm based on learning automata iteratively minimize the candidate vertex cover through the update its action probability. As the proposed algorithm proceeds, a candidate solution nears to optimal solution of the minimum vertex cover problem. In order to evaluate the proposed algorithm, several experiments conducted on DIMACS dataset which compared to conventional methods. Experimental results show the major superiority of the proposed algorithm over the other methods.
A Fraud Detection Visualization System Utilizing Radial Drawings and Heat-maps
Venue: arXiv cs.OH 2013
Year: 2013

We present a prototype system developed in cooperation with a business organization that combines information visualization and pattern-matching techniques to detect fraudulent activity by employees. The system is built upon common fraud patterns searched while trying to detect occupational fraud suggested by internal auditors of a business company. The main visualization of the system consists of a multi-layer radial drawing that represents the activity of the employees and clients. Each layer represents a different examined pattern whereas heat-maps indicating suspicious activity are incorporated in the visualization. The data are first preprocessed based on a decision tree generated by the examined patterns and each employee is assigned a value indicating whether or not there exist indications of fraud. The visualization is presented as an animation and the employees are visualized one by one according to their severity values together with their related clients.
Glasgow's Stereo Image Database of Garments
Venue: arXiv cs.RO 2013
Year: 2013

To provide insight into cloth perception and manipulation with an active binocular robotic vision system, we compiled a database of 80 stereo-pair colour images with corresponding horizontal and vertical disparity maps and mask annotations, for 3D garment point cloud rendering has been created and released. The stereo-image garment database is part of research conducted under the EU-FP7 Clothes Perception and Manipulation (CloPeMa) project and belongs to a wider database collection released through CloPeMa (www.clopema.eu). This database is based on 16 different off-the-shelve garments. Each garment has been imaged in five different pose configurations on the project's binocular robot head. A full copy of the database is made available for scientific research only at https://sites.google.com/site/ugstereodatabase/.
Worst-Case Analysis of Weber's Algorithm
Venue: arXiv cs.DS 2013
Year: 2013

Recently, Ken Weber introduced an algorithm for finding the $(a,b)$-pairs satisfying $au+bv\equiv 0\pmod{k}$, with $0<|a|,|b|<\sqrt{k}$, where $(u,k)$ and $(v,k)$ are coprime. It is based on Sorenson's and Jebelean's "$k$-ary reduction" algorithms. We provide a formula for $N(k)$, the maximal number of iterations in the loop of Weber's GCD algorithm.
Remarks on Privileged Words
Venue: arXiv cs.FL 2013
Year: 2013

We discuss the notion of privileged word, recently introduced by Peltomaki. A word w is privileged if it is of length <=1, or has a privileged border that occurs exactly twice in w. We prove the following results: (1) if w^k is privileged for some k >=1, then w^j is privileged for all j >= 0; (2) the language of privileged words is neither regular nor context-free; (3) there is a linear-time algorithm to check if a given word is privileged; and (4) there are at least 2^{n-5}/n^2 privileged binary words of length n.
Linear Network Error Correction Multicast/Broadcast/Dispersion/Generic Codes
Venue: arXiv cs.IT 2013
Year: 2013

In the practical network communications, many internal nodes in the network are required to not only transmit messages but decode source messages. For different applications, four important classes of linear network codes in network coding theory, i.e., linear multicast, linear broadcast, linear dispersion, and generic network codes, have been studied extensively. More generally, when channels of communication networks are noisy, information transmission and error correction have to be under consideration simultaneously, and thus these four classes of linear network codes are generalized to linear network error correction (LNEC) coding, and we say them LNEC multicast, broadcast, dispersion, and generic codes, respectively. Furthermore, in order to characterize their efficiency of information transmission and error correction, we propose the (weakly, strongly) extended Singleton bounds for them, and define the corresponding optimal codes, i.e., LNEC multicast/broadcast/dispersion/generic MDS codes, which satisfy the corresponding Singleton bounds with equality. The existences of such MDS codes are discussed in detail by algebraic methods and the constructive algorithms are also proposed.
Dynamic coupling design for nonlinear output agreement and time-varying flow control
Venue: arXiv cs.SY 2013
Year: 2013

This paper studies the problem of output agreement in networks of nonlinear dynamical systems under time-varying disturbances, using dynamic diffusive couplings. Necessary conditions are derived for general networks of nonlinear systems, and these conditions are explicitly interpreted as conditions relating the node dynamics and the network topology. For the class of incrementally passive systems, necessary and sufficient conditions for output agreement are derived. The approach proposed in the paper lends itself to solve flow control problems in distribution networks. As a first case study, the internal model approach is used for designing a controller that achieves an optimal routing and inventory balancing in a dynamic transportation network with storage and time-varying supply and demand. It is in particular shown that the time-varying optimal routing problem can be solved by applying an internal model controller to the dual variables of a certain convex network optimization problem. As a second case study, we show that droop-controllers in microgrids have also an interpretation as internal model controllers.
Universal Polar Decoding with Channel Knowledge at the Encoder
Venue: arXiv cs.IT 2013
Year: 2013

Polar coding over a class of binary discrete memoryless channels with channel knowledge at the encoder is studied. It is shown that polar codes achieve the capacity of convex and one-sided classes of symmetric channels.
Combination of Diverse Ranking Models for Personalized Expedia Hotel Searches
Venue: arXiv cs.LG 2013
Year: 2013

The ICDM Challenge 2013 is to apply machine learning to the problem of hotel ranking, aiming to maximize purchases according to given hotel characteristics, location attractiveness of hotels, user's aggregated purchase history and competitive online travel agency information for each potential hotel choice. This paper describes the solution of team "binghsu & MLRush & BrickMover". We conduct simple feature engineering work and train different models by each individual team member. Afterwards, we use listwise ensemble method to combine each model's output. Besides describing effective model and features, we will discuss about the lessons we learned while using deep learning in this competition.
On the Secrecy Capacity of Block Fading Channels with a Hybrid Adversary
Venue: arXiv cs.IT 2013
Year: 2013

We consider a block fading wiretap channel, where a transmitter attempts to send messages securely to a receiver in the presence of a hybrid half-duplex adversary, which arbitrarily decides to either jam or eavesdrop the transmitter-to- receiver channel. We provide bounds to the secrecy capacity for various possibilities on receiver feedback and show special cases where the bounds are tight. We show that, without any feedback from the receiver, the secrecy capacity is zero if the transmitter-to-adversary channel stochastically dominates the effective transmitter-to-receiver channel. However, the secrecy capacity is non-zero even when the receiver is allowed to feed back only one bit at the end of each block. Our novel achievable strategy improves the rates proposed in the literature for the non-hybrid adversarial model. We also analyze the effect of multiple adversaries and delay constraints on the secrecy capacity. We show that our novel time sharing approach leads to positive secrecy rates even under strict delay constraints.
Extended Role Based Access Control with Blob Service on Cloud
Venue: arXiv cs.DC 2013
Year: 2013

Role-based access control (RBAC) models have generated a great interest in the security community as a powerful and generalized approach to security management and ability to model organizational structure and their capability to reduce administrative expenses. In this paper, we highlight the drawbacks of latest developed RBAC models in terms of access control and authorization and later provide a more viable extended-RBAC model, which enhances and extends its powers to make any system more secure by adding valuable constraints. Later the Blobs are stored on cloud server which is then accessed by the end users via this Extended RBAC model.
Integration of a city GIS data with Google Map API and Google Earth API for a web based 3D Geospatial Application
Venue: arXiv cs.CY 2013
Year: 2013

Geospatial applications are becoming indispensible part of information systems, they provides detailed informations regarding the attribute data of spatial objects in real world. Due to the rapid technological developments in web based geographical information systems, the uses of web based geospatial application varies from Geotagging to Geolocation capabilities. Therefore, effective utilization of web based information system can only be realized by representing the world in its original view, where attributes data of spatial objects are integrated with spatial object and available for the user on the web, using integrated Google API and Google Earth API. In this study a city in the south-western part of Nigeria called EDE is examined and used as a case study. Using Google Map API and Google Earth API, the attribute data of the study area stored in XML databases will be integrated with the corresponding existing spatial data of the study area; to create a web based 3D geospatial application. We envisage that this system will enhance the effectiveness of web-based Geographical Information System (GIS) and the overall user experience.
Impact of Co-Channel Interference on Performance of Multi-Hop Relaying over Nakagami-$m$ Fading Channels
Venue: arXiv cs.IT 2013
Year: 2013

This paper studies the impact of co-channel interferences (CCIs) on the system performance of multi-hop amplify-and-forward (AF) relaying, in a simple and explicit way. For generality, the desired channels along consecutive relaying hops and the CCIs at all nodes are subject to Nakagami-$m$ fading with different shape factors. This study reveals that the diversity gain is determined only by the fading shape factor of the desired channels, regardless of the interference and the number of relaying hops. On the other hand, although the coding gain is in general a complex function of various system parameters, if the desired channels are subject to Rayleigh fading, the coding gain is inversely proportional to the accumulated interference at the destination, i.e. the product of the number of relaying hops and the average interference-to-noise ratio, irrespective of the fading distribution of the CCIs.
Inclusion of regular and linear languages in group languages
Venue: arXiv cs.FL 2013
Year: 2013

Let $Σ= X\cup X^{-1} = \{ x_1 ,x_2 ,..., x_m ,x_1^{-1} ,x_2^{-1} ,..., x_m^{-1} \}$ and let $G$ be a group with set of generators $Σ$. Let $\mathfrak{L} (G) =\left\{ \left. ω\in Σ^* \; \right\vert \;ω\equiv e \; (\textrm{mod} \; G) \right\} \subseteq Σ^*$ be the group language representing $G$, where $Σ^*$ is a free monoid over $Σ$ and $e$ is the identity in $G$. The problem of determining whether a context-free language is subset of a group language is discussed. Polynomial algorithms are presented for testing whether a regular language, or a linear language is included in a group language. A few finite sets are built, such that each of them is included in the group language $\mathfrak{L} (G)$ if and only if the respective context-free language is included in $\mathfrak{L} (G)$.
Some Combinatorial Problems on Binary Matrices in Programming Courses
Venue: arXiv cs.DS 2013
Year: 2013

The study proves the existence of an algorithm to receive all elements of a class of binary matrices without obtaining redundant elements, e. g. without obtaining binary matrices that do not belong to the class. This makes it possible to avoid checking whether each of the objects received possesses the necessary properties. This significantly improves the efficiency of the algorithm in terms of the criterion of time. Certain useful educational effects related to the analysis of such problems in programming classes are also pointed out.
A Combined Approach for Constraints over Finite Domains and Arrays
Venue: arXiv cs.LO 2013
Year: 2013

Arrays are ubiquitous in the context of software verification. However, effective reasoning over arrays is still rare in CP, as local reasoning is dramatically ill-conditioned for constraints over arrays. In this paper, we propose an approach combining both global symbolic reasoning and local consistency filtering in order to solve constraint systems involving arrays (with accesses, updates and size constraints) and finite-domain constraints over their elements and indexes. Our approach, named FDCC, is based on a combination of a congruence closure algorithm for the standard theory of arrays and a CP solver over finite domains. The tricky part of the work lies in the bi-directional communication mechanism between both solvers. We identify the significant information to share, and design ways to master the communication overhead. Experiments on random instances show that FDCC solves more formulas than any portfolio combination of the two solvers taken in isolation, while overhead is kept reasonable.
Sparse Time Frequency Representations and Dynamical Systems
Venue: arXiv cs.IT 2013
Year: 2013

In this paper, we establish a connection between the recently developed data-driven time-frequency analysis \cite{HS11,HS13-1} and the classical second order differential equations. The main idea of the data-driven time-frequency analysis is to decompose a multiscale signal into a sparsest collection of Intrinsic Mode Functions (IMFs) over the largest possible dictionary via nonlinear optimization. These IMFs are of the form $a(t) \cos(θ(t))$ where the amplitude $a(t)$ is positive and slowly varying. The non-decreasing phase function $θ(t)$ is determined by the data and in general depends on the signal in a nonlinear fashion. One of the main results of this paper is that we show that each IMF can be associated with a solution of a second order ordinary differential equation of the form $\ddot{x}+p(x,t)\dot{x}+q(x,t)=0$. Further, we propose a localized variational formulation for this problem and develop an effective $l^1$-based optimization method to recover $p(x,t)$ and $q(x,t)$ by looking for a sparse representation of $p$ and $q$ in terms of the polynomial basis. Depending on the form of nonlinearity in $p(x,t)$ and $q(x,t)$, we can define the degree of nonlinearity for the associated IMF. %and the corresponding coefficients for the associated highest order nonlinear terms. This generalizes a concept recently introduced by Prof. N. E. Huang et al. \cite{Huang11}. Numerical examples will be provided to illustrate the robustness and stability of the proposed method for data with or without noise. This manuscript should be considered as a proof of concept.
Distributed Data Placement via Graph Partitioning
Venue: arXiv cs.DB 2013
Year: 2013

With the widespread use of shared-nothing clusters of servers, there has been a proliferation of distributed object stores that offer high availability, reliability and enhanced performance for MapReduce-style workloads. However, relational workloads cannot always be evaluated efficiently using MapReduce without extensive data migrations, which cause network congestion and reduced query throughput. We study the problem of computing data placement strategies that minimize the data communication costs incurred by typical relational query workloads in a distributed setting. Our main contribution is a reduction of the data placement problem to the well-studied problem of {\sc Graph Partitioning}, which is NP-Hard but for which efficient approximation algorithms exist. The novelty and significance of this result lie in representing the communication cost exactly and using standard graphs instead of hypergraphs, which were used in prior work on data placement that optimized for different objectives (not communication cost). We study several practical extensions of the problem: with load balancing, with replication, with materialized views, and with complex query plans consisting of sequences of intermediate operations that may be computed on different servers. We provide integer linear programs (IPs) that may be used with any IP solver to find an optimal data placement. For the no-replication case, we use publicly available graph partitioning libraries (e.g., METIS) to efficiently compute nearly-optimal solutions. For the versions with replication, we introduce two heuristics that utilize the {\sc Graph Partitioning} solution of the no-replication case. Using the TPC-DS workload, it may take an IP solver weeks to compute an optimal data placement, whereas our reduction produces nearly-optimal solutions in seconds.
Times in noise-based logic: increased dimensions of logic hyperspace
Venue: arXiv cs.ET 2013
Year: 2013

Time shifts beyond the correlation time of the logic and reference signals create new elements that are orthogonal to the original components. This fact can be utilized to increase the number of dimensions of the logic space while keeping the number of reference noises fixed. Using just a single noise and time shifts can realize exponentially large hyperspaces with large numbers of dimensions. Other, independent applications of time shifts include holographic noise-based logic systems and changing commutative operations into non-commuting ones. For the sake of simplicity, these ideas are illustrated by deterministic time shifts, even though random timing and random time shifts would yield the most robust systems.
State Transition Analysis of Time-Frequency Resource Conversion-based Call Admission Control for LTE-Type Cellular Network
Venue: arXiv cs.NI 2013
Year: 2013

To address network congestion stemmed from traffic generated by advanced user equipments, in [1] we propose a novel network resource allocation strategy, time-frequency resource conversion (TFRC), via exploiting user behavior, a specific kind of context information. Considering an LTE-type cellular network, a call admission control policy called double-threshold guard channel policy is proposed there to facilitate the implementation of TFRC. In this report, we present state transition analysis of this TFRC-based call admission control policy for an LTE-type cellular network. Overall, there are five categories of events that can trigger a transition of the system state: 1) a new call arrival; 2) a handoff user arrival; 3) a handoff user departure; 4) a call termination; and 5) a periodic time-frequency resource conversion. We analyze them case by case in this report and the validation of the analysis has been provided in [1].
Asymptotic Rate Analysis of Downlink Multi-user Systems with Co-located and Distributed Antennas
Venue: arXiv cs.IT 2013
Year: 2013

A great deal of efforts have been made on the performance evaluation of distributed antenna systems (DASs). Most of them assume a regular base-station (BS) antenna layout where the number of BS antennas is usually small. With the growing interest in cellular systems with large antenna arrays at BSs, it becomes increasingly important for us to study how the BS antenna layout affects the rate performance when a massive number of BS antennas are employed. This paper presents a comparative study of the asymptotic rate performance of downlink multi-user systems with multiple BS antennas either co-located or uniformly distributed within a circular cell. Two representative linear precoding schemes, maximum ratio transmission (MRT) and zero-forcing beamforming (ZFBF), are considered, with which the effect of BS antenna layout on the rate performance is characterized. The analysis shows that as the number of BS antennas $L$ and the number of users $K$ grow infinitely while $L/K{\rightarrow}\upsilon$, the asymptotic average user rates with the co-located antenna (CA) layout for both MRT and ZFBF are logarithmic functions of the ratio $\upsilon$. With the distributed antenna (DA) layout, in contrast, the scaling behavior of the average user rate closely depends on the precoding schemes. With ZFBF, for instance, the average user rate grows unboundedly as $L, K{\rightarrow} \infty$ and $L/K{\rightarrow}\upsilon{>}1$, which indicates that substantial rate gains over the CA layout can be achieved when the number of BS antennas $L$ is large. The gain, nevertheless, becomes marginal when MRT is adopted.
Practical Collapsed Stochastic Variational Inference for the HDP
Venue: arXiv cs.LG 2013
Year: 2013

Recent advances have made it feasible to apply the stochastic variational paradigm to a collapsed representation of latent Dirichlet allocation (LDA). While the stochastic variational paradigm has successfully been applied to an uncollapsed representation of the hierarchical Dirichlet process (HDP), no attempts to apply this type of inference in a collapsed setting of non-parametric topic modeling have been put forward so far. In this paper we explore such a collapsed stochastic variational Bayes inference for the HDP. The proposed online algorithm is easy to implement and accounts for the inference of hyper-parameters. First experiments show a promising improvement in predictive performance.