OpenRaiser/Intern-Atlas huggingface dataset:
On the Trade-off Between Spectrum Efficiency with Dedicated Access and Short End-to-End Transmission Delays with Random Access in DVB-RCS2
Venue: arXiv cs.NI 2013
Year: 2013

This paper analyses the performance of TCP over random and dedicated access methods in the context of DVB-RCS2. Random access methods introduce a lower connection delay compared to dedicated methods. We investigate the poten- tial to improve the performance of short flows in regards to transmission delay, over random access methods for DVB- RCS2 that is currently under development. Our simulation experiments show that the transmission of the first ten IP datagrams of each TCP flow can be 500 ms faster with ran- dom access than with dedicated access making the former of interest to carry Internet traffic. Such methods, however, are less efficient in regards to bandwidth usage than dedicated access mecanisms and less reliable in overloaded network conditions. Two aspects of channel usage optimization can be distinguished: reducing the duration of ressource utiliza- tion with random access methods, or increasing the spec- trum efficiency with dedicated access methods. This article argues that service providers may let low-cost users exploit the DVB-RCS2 to browse the web by introducing different services, which choice is based on the channel access method.
Identifying Playerś Strategies in No Limit Texas Holdém Poker through the Analysis of Individual Moves
Venue: arXiv cs.AI 2013
Year: 2013

The development of competitive artificial Poker playing agents has proven to be a challenge, because agents must deal with unreliable information and deception which make it essential to model the opponents in order to achieve good results. This paper presents a methodology to develop opponent modeling techniques for Poker agents. The approach is based on applying clustering algorithms to a Poker game database in order to identify player types based on their actions. First, common game moves were identified by clustering all players\' moves. Then, player types were defined by calculating the frequency with which the players perform each type of movement. With the given dataset, 7 different types of players were identified with each one having at least one tactic that characterizes him. The identification of player types may improve the overall performance of Poker agents, because it helps the agents to predict the opponentś moves, by associating each opponent to a distinct cluster.
Linear-Time Algorithms for Scattering Number and Hamilton-Connectivity of Interval Graphs
Venue: arXiv cs.DS 2013
Year: 2013

Hung and Chang showed that for all k>=1 an interval graph has a path cover of size at most k if and only if its scattering number is at most k. They also showed that an interval graph has a Hamilton cycle if and only if its scattering number is at most 0. We complete this characterization by proving that for all k<=-1 an interval graph is -(k+1)-Hamilton-connected if and only if its scattering number is at most k. We also give an O(m+n) time algorithm for computing the scattering number of an interval graph with n vertices an m edges, which improves the O(n^4) time bound of Kratsch, Kloks and Müller. As a consequence of our two results the maximum k for which an interval graph is k-Hamilton-connected can be computed in O(m+n) time.
QoS-Aware Transmission Policies for OFDM Bidirectional Decode-and-Forward Relaying
Venue: arXiv cs.IT 2013
Year: 2013

Two-way relaying can considerably improve spectral efficiency in relay-assisted bidirectional communications. However, the benefits and flexible structure of orthogonal frequency division multiplexing (OFDM)-based two-way decode-and-forward (DF) relay systems is much less exploited. Moreover, most of existing works have not considered quality-of-service (QoS) provisioning for two-way relaying. In this paper, we consider the OFDM-based bidirectional transmission where a pair of users exchange information with or without the assistance of a single DF relay. Each user can communicate with the other via three transmission modes: direct transmission, one-way relaying, and two-way relaying. We jointly optimize the transmission policies, including power allocation, transmission mode selection, and subcarrier assignment for maximizing the weighted sum rates of the two users with diverse quality-of-service (QoS) guarantees. We formulate the joint optimization problem as a mixed integer programming problem. By using the dual method, we efficiently solve the problem in an asymptotically optimal manner. Moreover, we derive the capacity region of two-way DF relaying in parallel channels. Simulation results show that the proposed resource-allocation scheme can substantially improve system performance compared with the conventional schemes. A number of interesting insights are also provided via comprehensive simulations.
Higher genus universally decodable matrices (UDMG)
Venue: arXiv cs.IT 2013
Year: 2013

We introduce the notion of Universally Decodable Matrices of Genus g (UDMG), which for g=0 reduces to the notion of Universally Decodable Matrices (UDM) introduced in [8]. A UDMG is a set of L matrices over a finite field, each with K rows, and a linear independence condition satisfied by collections of K+g columns formed from the initial segments of the matrices. We consider the mathematical structure of UDMGs and their relation to linear vector codes. We then give a construction of UDMG based on curves of genus g over the finite field, which is a natural generalization of the UDM constructed in [8]. We provide upper (and constructable lower) bounds for L in terms of K, q, g, and the number of columns of the matrices. We will show there is a fundamental trade off (Theorem 5.4) between L and g, akin to the Singleton bound for the minimal Hamming distance of linear vector codes.
The Case for Cross-Layer Optimizations in Storage: A Workflow-Optimized Storage System
Venue: arXiv cs.DC 2013
Year: 2013

This paper proposes using file system custom metadata as a bidirectional communication channel between applications and the storage system. This channel can be used to pass hints that enable cross-layer optimizations, an option hindered today by the ossified file-system interface. We study this approach in context of storage system support for large-scale workflow execution systems: Our workflow optimized storage system (WOSS), exploits application hints to provide per-file optimized operations, and exposes data location to enable location-aware scheduling. This paper argues that an incremental adoption path for adopting cross-layer optimizations in storage systems exists, presents the system architecture for a workflow-optimized storage system and its integration with a workflow runtime engine, and evaluates the proposed approach using synthetic as well as real applications workloads.
Problems of Inheritance at Java Inner Class
Venue: arXiv cs.PL 2013
Year: 2013

Single inheritance has been widely accepted in the current programming practice to avoid the complication that incurred by multiple inheritance. Single inheritance enhances the reusability of codes and eliminates the confusion of identical methods that possibly defined in two superclasses. However, the mechanism of inner class in Java potentially reintroduces the problems encountered by multiple inheritance. When the depth of Java inner class is increased, the problem becomes severe. This paper aims at exposing the problems of inheritance at the Java inner class. In addition, a measure is proposed to evaluate the potential problem of inheritance for Java inner class
Deterministic Constructions for Large Girth Protograph LDPC Codes
Venue: arXiv cs.IT 2013
Year: 2013

The bit-error threshold of the standard ensemble of Low Density Parity Check (LDPC) codes is known to be close to capacity, if there is a non-zero fraction of degree-two bit nodes. However, the degree-two bit nodes preclude the possibility of a block-error threshold. Interestingly, LDPC codes constructed using protographs allow the possibility of having both degree-two bit nodes and a block-error threshold. In this paper, we analyze density evolution for protograph LDPC codes over the binary erasure channel and show that their bit-error probability decreases double exponentially with the number of iterations when the erasure probability is below the bit-error threshold and long chain of degree-two variable nodes are avoided in the protograph. We present deterministic constructions of such protograph LDPC codes with girth logarithmic in blocklength, resulting in an exponential fall in bit-error probability below the threshold. We provide optimized protographs, whose block-error thresholds are better than that of the standard ensemble with minimum bit-node degree three. These protograph LDPC codes are theoretically of great interest, and have applications, for instance, in coding with strong secrecy over wiretap channels.
Simultaneous Information and Energy Transfer: A Two-User MISO Interference Channel Case
Venue: arXiv cs.IT 2013
Year: 2013

This paper considers the sum rate maximization problem of a two-user multiple-input single-output interference channel with receivers that can scavenge energy from the radio signals transmitted by the transmitters. We first study the optimal transmission strategy for an ideal scenario where the two receivers can simultaneously decode the information signal and harvest energy. Then, considering the limitations of the current circuit technology, we propose two practical schemes based on TDMA, where, at each time slot, the receiver either operates in the energy harvesting mode or in the information detection mode. Optimal transmission strategies for the two practical schemes are respectively investigated. Simulation results show that the three schemes exhibit interesting tradeoff between achievable sum rate and energy harvesting requirement, and do not dominate each other in terms of maximum achievable sum rate.
Multiple-Antenna Interference Channel with Receive Antenna Joint Processing and Real Interference Alignment
Venue: arXiv cs.IT 2013
Year: 2013

We consider a constant $K$-user Gaussian interference channel with $M$ antennas at each transmitter and $N$ antennas at each receiver, denoted as a $(K,M,N)$ channel. Relying on a result on simultaneous Diophantine approximation, a real interference alignment scheme with joint receive antenna processing is developed. The scheme is used to provide new proofs for two previously known results, namely 1) the total degrees of freedom (DoF) of a $(K, N, N)$ channel is $NK/2$; and 2) the total DoF of a $(K, M, N)$ channel is at least $KMN/(M+N)$. We also derive the DoF region of the $(K,N,N)$ channel, and an inner bound on the DoF region of the $(K,M,N)$ channel.
Aplikasi belajar membaca iqro' berbasis mobile
Venue: arXiv cs.OH 2013
Year: 2013

IPTEK and IMTAQ should be followed by knowledge of the ability in reading the hijaiyah letters as Al Qur-an base. Current people are so busy with their activities thats way authors develop this mobile application using pocket pc. The development of this research using waterfall model. Authors use the programming language of Microsoft Visual BASIC.Net. Authors also use Photoshop to prepare the image of every letter. In Indonesia, there six level in reading Al Qur-an, but for the purpose of thi research authors only use Iqro-1 until Iqro-4. This mobile application also enriched with the voice for every letter image.
An "Umbrella" Bound of the Lovász-Gallager Type
Venue: arXiv cs.IT 2013
Year: 2013

We propose a novel approach for bounding the probability of error of discrete memoryless channels with a zero-error capacity based on a combination of Lovász' and Gallager's ideas. The obtained bounds are expressed in terms of a function $\vartheta(ρ)$, introduced here, that varies from the cut-off rate of the channel to the Lovázs theta function as $ρ$ varies from 1 to $\infty$ and which is intimately related to Gallager's expurgated coefficient. The obtained bound to the reliability function, though loose in its present form, is finite for all rates larger than the Lovász theta function.
Achieving Fully Proportional Representation is Easy in Practice
Venue: arXiv cs.MA 2013
Year: 2013

We provide experimental evaluation of a number of known and new algorithms for approximate computation of Monroe's and Chamberlin-Courant's rules. Our experiments, conducted both on real-life preference-aggregation data and on synthetic data, show that even very simple and fast algorithms can in many cases find near-perfect solutions. Our results confirm and complement very recent theoretical analysis of Skowron et al., who have shown good lower bounds on the quality of (some of) the algorithms that we study.
Linear Programming Decoding of Spatially Coupled Codes
Venue: arXiv cs.IT 2013
Year: 2013

For a given family of spatially coupled codes, we prove that the LP threshold on the BSC of the graph cover ensemble is the same as the LP threshold on the BSC of the derived spatially coupled ensemble. This result is in contrast with the fact that the BP threshold of the derived spatially coupled ensemble is believed to be larger than the BP threshold of the graph cover ensemble as noted by the work of Kudekar et al. (2011, 2012). To prove this, we establish some properties related to the dual witness for LP decoding which was introduced by Feldman et al. (2007) and simplified by Daskalakis et al. (2008). More precisely, we prove that the existence of a dual witness which was previously known to be sufficient for LP decoding success is also necessary and is equivalent to the existence of certain acyclic hyperflows. We also derive a sublinear (in the block length) upper bound on the weight of any edge in such hyperflows, both for regular LPDC codes and for spatially coupled codes and we prove that the bound is asymptotically tight for regular LDPC codes. Moreover, we show how to trade crossover probability for "LP excess" on all the variable nodes, for any binary linear code.
On Connectivity Thresholds in the Intersection of Random Key Graphs on Random Geometric Graphs
Venue: arXiv cs.IT 2013
Year: 2013

In a random key graph (RKG) of $n$ nodes each node is randomly assigned a key ring of $K_n$ cryptographic keys from a pool of $P_n$ keys. Two nodes can communicate directly if they have at least one common key in their key rings. We assume that the $n$ nodes are distributed uniformly in $[0,1]^2.$ In addition to the common key requirement, we require two nodes to also be within $r_n$ of each other to be able to have a direct edge. Thus we have a random graph in which the RKG is superposed on the familiar random geometric graph (RGG). For such a random graph, we obtain tight bounds on the relation between $K_n,$ $P_n$ and $r_n$ for the graph to be asymptotically almost surely connected.
Generalizing the Sampling Property of the Q-function for Error Rate Analysis of Cooperative Communication in Fading Channels
Venue: arXiv cs.IT 2013
Year: 2013

This paper extends some approximation methods that are used to identify closed form Bit Error Rate (BER) expressions which are frequently utilized in investigation and comparison of performance for wireless communication systems in the literature. By using this group of approximation methods, some expectation integrals, which are complicated to analyze and have high computational complexity to evaluate through Monte Carlo simulations, are computed. For these integrals, by using the sampling property of the integrand functions of one or more arguments, reliable BER expressions revealing the diversity and coding gains are derived. Although the methods we present are valid for a larger class of integration problems, in this work we show the step by step derivation of the BER expressions for a canonical cooperative communication scenario in addition to a network coded system starting from basic building blocks. The derived expressions agree with the simulation results for a very wide range of signal-to-noise ratio (SNR) values.
Variational Equalities of Directed Information and Applications
Venue: arXiv cs.IT 2013
Year: 2013

In this paper we introduce two variational equalities of directed information, which are analogous to those of mutual information employed in the Blahut-Arimoto Algorithm (BAA). Subsequently, we introduce nonanticipative Rate Distortion Function (RDF) ${R}^{na}_{0,n}(D)$ defined via directed information introduced in [1], and we establish its equivalence to Gorbunov-Pinsker's nonanticipatory $ε$-entropy $R^{\varepsilon}_{0,n}(D)$. By invoking certain results we first establish existence of the infimizing reproduction distribution for ${R}^{na}_{0,n}(D)$, and then we give its implicit form for the stationary case. Finally, we utilize one of the variational equalities and the closed form expression of the optimal reproduction distribution to provide an algorithm for the computation of ${R}^{na}_{0,n}(D)$.
Generalised Multi-sequence Shift-Register Synthesis using Module Minimisation
Venue: arXiv cs.IT 2013
Year: 2013

We show how to solve a generalised version of the Multi-sequence Linear Feedback Shift-Register (MLFSR) problem using minimisation of free modules over $\mathbb F[x]$. We show how two existing algorithms for minimising such modules run particularly fast on these instances. Furthermore, we show how one of them can be made even faster for our use. With our modeling of the problem, classical algebraic results tremendously simplify arguing about the algorithms. For the non-generalised MLFSR, these algorithms are as fast as what is currently known. We then use our generalised MLFSR to give a new fast decoding algorithm for Reed Solomon codes.
Self-Organizing Map and social networks: Unfolding online social popularity
Venue: arXiv cs.SI 2013
Year: 2013

The present study uses the Kohonen self organizing map (SOM) to represent the popularity patterns of Myspace music artists from their attributes on the platform and their position in the social network. The method is applied to cluster the profiles (the nodes of the social network) and the best friendship links (the edges). It shows that the SOM is an efficient tool to interpret the complex links between the audience and the influence of the musicians. It finally provides a robust classifier of the online social network behaviors.
PDF articles metadata harvester
Venue: arXiv cs.DL 2013
Year: 2013

Scientific journals are very important in recording the finding from researchers around the world. The recent media to disseminate scientific journals is PDF. On scheme to find the scientific journals over the internet is via metadata. Metadata stores information about article summary. Embedding metadata into PDF of scientific article will grant the consistency of metadata readness. Harvesting the metadata from scientific journal is very interesting field at the moment. This paper will discuss about scientific journal metadata harvesters involving XMP.
Discriminative Feature Selection for Uncertain Graph Classification
Venue: arXiv cs.LG 2013
Year: 2013

Mining discriminative features for graph data has attracted much attention in recent years due to its important role in constructing graph classifiers, generating graph indices, etc. Most measurement of interestingness of discriminative subgraph features are defined on certain graphs, where the structure of graph objects are certain, and the binary edges within each graph represent the "presence" of linkages among the nodes. In many real-world applications, however, the linkage structure of the graphs is inherently uncertain. Therefore, existing measurements of interestingness based upon certain graphs are unable to capture the structural uncertainty in these applications effectively. In this paper, we study the problem of discriminative subgraph feature selection from uncertain graphs. This problem is challenging and different from conventional subgraph mining problems because both the structure of the graph objects and the discrimination score of each subgraph feature are uncertain. To address these challenges, we propose a novel discriminative subgraph feature selection method, DUG, which can find discriminative subgraph features in uncertain graphs based upon different statistical measures including expectation, median, mode and phi-probability. We first compute the probability distribution of the discrimination scores for each subgraph feature based on dynamic programming. Then a branch-and-bound algorithm is proposed to search for discriminative subgraphs efficiently. Extensive experiments on various neuroimaging applications (i.e., Alzheimer's Disease, ADHD and HIV) have been performed to analyze the gain in performance by taking into account structural uncertainties in identifying discriminative subgraph features for graph classification.
On the Performance of Low Density Parity Check Codes for Gaussian Interference Channels
Venue: arXiv cs.IT 2013
Year: 2013

In this paper, two-user Gaussian interference channel(GIC) is revisited with the objective of developing implementable (explicit) channel codes. Specifically, low density parity check (LDPC) codes are adopted for use over these channels, and their benefits are studied. Different scenarios on the level of interference are considered. In particular, for strong interference channel examples with binary phase shift keying (BPSK), it is demonstrated that rates better than those offered by single user codes with time sharing are achievable. Promising results are also observed with quadrature-shift-keying (QPSK). Under general interference a Han-Kobayashi coding based scheme is employed splitting the information into public and private parts, and utilizing appropriate iterative decoders at the receivers. Using QPSK modulation at the two transmitters, it is shown that rate points higher than those achievable by time sharing are obtained.
Learning Polytrees
Venue: arXiv cs.AI 2013
Year: 2013

We consider the task of learning the maximum-likelihood polytree from data. Our first result is a performance guarantee establishing that the optimal branching (or Chow-Liu tree), which can be computed very easily, constitutes a good approximation to the best polytree. We then show that it is not possible to do very much better, since the learning problem is NP-hard even to approximately solve within some constant factor.
A Hybrid Anytime Algorithm for the Constructiion of Causal Models From Sparse Data
Venue: arXiv cs.AI 2013
Year: 2013

We present a hybrid constraint-based/Bayesian algorithm for learning causal networks in the presence of sparse data. The algorithm searches the space of equivalence classes of models (essential graphs) using a heuristic based on conventional constraint-based techniques. Each essential graph is then converted into a directed acyclic graph and scored using a Bayesian scoring metric. Two variants of the algorithm are developed and tested using data from randomly generated networks of sizes from 15 to 45 nodes with data sizes ranging from 250 to 2000 records. Both variations are compared to, and found to consistently outperform two variations of greedy search with restarts.
Model-Based Bayesian Exploration
Venue: arXiv cs.AI 2013
Year: 2013

Reinforcement learning systems are often concerned with balancing exploration of untested actions against exploitation of actions that are known to be good. The benefit of exploration can be estimated using the classical notion of Value of Information - the expected improvement in future decision quality arising from the information acquired by exploration. Estimating this quantity requires an assessment of the agent's uncertainty about its current value estimates for states. In this paper we investigate ways of representing and reasoning about this uncertainty in algorithms where the system attempts to learn a model of its environment. We explicitly represent uncertainty about the parameters of the model and build probability distributions over Q-values based on these. These distributions are used to compute a myopic approximation to the value of information for each action and hence to select the action that best balances exploration and exploitation.