OpenRaiser/Intern-Atlas huggingface dataset:
A General Method for the Design of Tree Networks Under Communication Constraints
Venue: arXiv cs.IT 2015
Year: 2015

We consider a distributed detection system with communication constraints, where several nodes are arranged in an arbitrary tree topology, under the assumption of conditionally independent observations. We propose a cyclic design procedure using the minimum expected error probability as a design criterion while adopting a person-by-person methodology. We design each node jointly together with the fusion center, while other nodes are kept fixed, and show that the design of each node using the person-by-person methodology is analogous to the design of a network with two nodes, a network which we refer to as the restricted model. We further show how the parameters in the restricted model for the design of a node in the tree network can be found in a computationally efficient manner. The proposed numerical methodology can be applied for the design of nodes arranged in arbitrary tree topologies with arbitrary channel rates for the links between nodes and for a general M-ary hypothesis testing problem.
Chasing the Ghosts of Ibsen: A computational stylistic analysis of drama in translation
Venue: arXiv cs.CL 2015
Year: 2015

Research into the stylistic properties of translations is an issue which has received some attention in computational stylistics. Previous work by Rybicki (2006) on the distinguishing of character idiolects in the work of Polish author Henryk Sienkiewicz and two corresponding English translations using Burrow's Delta method concluded that idiolectal differences could be observed in the source texts and this variation was preserved to a large degree in both translations. This study also found that the two translations were also highly distinguishable from one another. Burrows (2002) examined English translations of Juvenal also using the Delta method, results of this work suggest that some translators are more adept at concealing their own style when translating the works of another author whereas other authors tend to imprint their own style to a greater extent on the work they translate. Our work examines the writing of a single author, Norwegian playwright Henrik Ibsen, and these writings translated into both German and English from Norwegian, in an attempt to investigate the preservation of characterization, defined here as the distinctiveness of textual contributions of characters.
Analysis of Performance Parameters in Wireless Networks by using Game Theory for the non Cooperative Slotted Aloha Enhanced by ZigZag Decoding Mechanism
Venue: arXiv cs.GT 2015
Year: 2015

In wireless communication networks, when the workload increases, sources become more aggressive at the equilibrium in the game setting in comparison with the team problem by using slotted Aloha mechanism. Consequently, more packets are in collision and are lost. To reduce these phenomena and to enhance the performance of the networks, we propose to combine ZigZag decoding approach with non cooperative slotted Aloha mechanism. This approach was introduced in our previous work based on the cooperative slotted Aloha mechanism. The obtained results showed that this approach has significantly improved the cooperative slotted Aloha mechanism and gave best results for the throughput and delay. In this paper, we analyze the impact of combining non cooperative slotted Aloha and ZigZag Decoding. We model the system by a two dimensional Markov chain that integrates the effect of ZigZag decoding. The states of the Markov chain describe the number of backlogged packets among the users. We use a stochastic game to achieve our objective; we evaluate and compare the performances parameters of the proposed approach with those of a simple slotted Aloha mechanism. All found results show that our approach improves the performance parameters of the system.
Sharing Channel In IEEE 802.16 Using The Cooperative Model Of Slotted ALOHA
Venue: arXiv cs.IT 2015
Year: 2015

One of the main problems in WIMAX is to share the medium by multiple users who compete for access. Various random access mechanisms, such as ALOHA and its corresponding variations have been widely studied as efficient methods to coordinate the medium access among competing users. In this paper the slotted ALOHA protocol is implemented as a two-state system. Using Markov Models, we evaluate the channel utilization and we analyze the throughput under different fairness conditions. The cooperative team problem is considered.
Note on Perfect Forests
Venue: arXiv cs.DM 2015
Year: 2015

A spanning subgraph $F$ of a graph $G$ is called perfect if $F$ is a forest, the degree $d_F(x)$ of each vertex $x$ in $F$ is odd, and each tree of $F$ is an induced subgraph of $G$. We provide a short proof of the following theorem of A.D. Scott (Graphs & Combin., 2001): a connected graph $G$ contains a perfect forest if and only if $G$ has an even number of vertices.
Stem-Calyx Recognition of an Apple using Shape Descriptors
Venue: arXiv cs.CV 2015
Year: 2015

This paper presents a novel method to recognize stem - calyx of an apple using shape descriptors. The main drawback of existing apple grading techniques is that stem - calyx part of an apple is treated as defects, this leads to poor grading of apples. In order to overcome this drawback, we proposed an approach to recognize stem-calyx and differentiated from true defects based on shape features. Our method comprises of steps such as segmentation of apple using grow-cut method, candidate objects such as stem-calyx and small defects are detected using multi-threshold segmentation. The shape features are extracted from detected objects using Multifractal, Fourier and Radon descriptor and finally stem-calyx regions are recognized and differentiated from true defects using SVM classifier. The proposed algorithm is evaluated using experiments conducted on apple image dataset and results exhibit considerable improvement in recognition of stem-calyx region compared to other techniques.
A Novel Design of a Parallel Machine Learnt Generational Garbage Collector
Venue: arXiv cs.PL 2015
Year: 2015

The Generational Garbage collection involves organizing the heap into different divisions of memory space in-order to filter long-lived objects from short-lived objects through moving the surviving object of each generation Garbage Collection cycle to another memory space updating its age and reclaiming space from the dead ones. The problem in this method is that the longer an object is alive during its initial generations the longer the garbage collector will have to deal with it by checking for its reachability from the root and promoting it to other space divisions where as the ultimate goal of the Garbage Collector is to reclaim memory from unreachable objects at a minimal time possible. This paper is a proposal of a method where the lifetime of every object getting into the heap will be predicted and will be placed in heap accordingly for the garbage collector to deal more with reclaiming space from dead objects and less in promoting the live ones to the higher level.
On the minimum distance of elliptic curve codes
Venue: arXiv cs.IT 2015
Year: 2015

Computing the minimum distance of a linear code is one of the fundamental problems in algorithmic coding theory. Vardy [14] showed that it is an \np-hard problem for general linear codes. In practice, one often uses codes with additional mathematical structure, such as AG codes. For AG codes of genus $0$ (generalized Reed-Solomon codes), the minimum distance has a simple explicit formula. An interesting result of Cheng [3] says that the minimum distance problem is already \np-hard (under \rp-reduction) for general elliptic curve codes (ECAG codes, or AG codes of genus $1$). In this paper, we show that the minimum distance of ECAG codes also has a simple explicit formula if the evaluation set is suitably large (at least $2/3$ of the group order). Our method is purely combinatorial and based on a new sieving technique from the first two authors [8]. This method also proves a significantly stronger version of the MDS (maximum distance separable) conjecture for ECAG codes.
Linear decomposition attack on public key exchange protocols using semidirect products of (semi)groups
Venue: arXiv cs.CR 2015
Year: 2015

We show that a linear decomposition attack based on the decomposition method introduced by the author works by finding the exchanged secret keys in all main protocols using semidirect products of (semi)grops proposed by Kahrobaei, Shpilrain, Habeeb, Koupparis and Lam.
Un résumeur à base de graphes, indépéndant de la langue
Venue: arXiv cs.CL 2015
Year: 2015

In this paper we present REG, a graph-based approach for study a fundamental problem of Natural Language Processing (NLP): the automatic text summarization. The algorithm maps a document as a graph, then it computes the weight of their sentences. We have applied this approach to summarize documents in three languages.
Optimisation using Natural Language Processing: Personalized Tour Recommendation for Museums
Venue: arXiv cs.AI 2015
Year: 2015

This paper proposes a new method to provide personalized tour recommendation for museum visits. It combines an optimization of preference criteria of visitors with an automatic extraction of artwork importance from museum information based on Natural Language Processing using textual energy. This project includes researchers from computer and social sciences. Some results are obtained with numerical experiments. They show that our model clearly improves the satisfaction of the visitor who follows the proposed tour. This work foreshadows some interesting outcomes and applications about on-demand personalized visit of museums in a very near future.
Using Linear Dynamical Topic Model for Inferring Temporal Social Correlation in Latent Space
Venue: arXiv cs.SI 2015
Year: 2015

The abundance of online user data has led to a surge of interests in understanding the dynamics of social relationships using computational methods. Utilizing users' items adoption data, we develop a new method to compute the Granger-causal (GC) relationships among users. In order to handle the high dimensional and sparse nature of the adoption data, we propose to model the relationships among users in latent space instead of the original data space. We devise a Linear Dynamical Topic Model (LDTM) that can capture the dynamics of the users' items adoption behaviors in latent (topic) space. Using the time series of temporal topic distributions learned by LDTM, we conduct Granger causality tests to measure the social correlation relationships between pairs of users. We call the combination of our LDTM and Granger causality tests as Temporal Social Correlation. By conducting extensive experiments on bibliographic data, where authors are analogous to users, we show that the ordering of authors' name on their publications plays a statistically significant role in the interaction of research topics among the authors. We also present a case study to illustrate the correlational relationships between pairs of authors.
Recent Developments in Cloud Based Systems: State of Art
Venue: arXiv cs.DC 2015
Year: 2015

Cloud computing is the new buzzword in the head of the techies round the clock these days. The importance and the different applications of cloud computing are overwhelming and thus, it is a topic of huge significance. It provides several astounding features like Multitenancy, on demand service, pay per use etc. This manuscript presents an exhaustive survey on cloud computing technology and potential research issues in cloud computing that needs to be addressed.
Program Synthesis from Axiomatic Proof of Correctness
Venue: arXiv cs.LO 2015
Year: 2015

Program Synthesis is the mapping of a specification of what a computer program is supposed to do, into a computer program that does what the specification says to do. This is equivalent to constructing any computer program and a sound proof that it meets the given specification. We axiomatically prove statements of the form: program PROG meets specification SPEC. We derive 7 axioms from the definition of the PHP programming language in which the programs are to be written. For each primitive function or process described, we write a program that uses only that feature (function or process), and we have an axiom that this program meets the specification described. Generic ways to alter or combine programs, that meet known specifications, into new programs that meet known specifications, are our 7 rules of inference. To efficiently prove statements that some program meets a given specification, we work backwards from the specification. We apply the inverses of the rules to the specifications that we must meet, until we reach axioms that are combined by these rules to prove that a particular program meets the given specification. Due to their distinct nature, typically few inverse rules apply. To avoid complex wff and program manipulation algorithms, we advocate the use of simple table maintenance and look-up functions to simulate these complexities as a prototype. Examples Include: "$B=FALSE ; for ($a=1;!($j<$a);++$a){ $A=FALSE ; if (($a*$i)==$j) $A=TRUE ; if ($A) $B=TRUE ; } ; echo $B ;" and "echo ($j % $i) == 0" : Is one number a factor of another? "for ($a=1 ; !($i<$a) ;++$a) {if (($i%$a) == 0) echo $a ; }" : List the factors of I. "$A=FALSE ; for ($a=1;$a<$i;++$a){ if (1<$a) { if (($i % $a) == 0) $A=TRUE ; } ; } ; echo (!($A)) && (!($i<2)) ;" : Is I a prime number?
Alamouti OFDM/OQAM systems with time reversal technique
Venue: arXiv cs.IT 2015
Year: 2015

Orthogonal Frequency Division Multiplexing with Offset Quadrature Amplitude Modulation (OFDM/OQAM) is a multicarrier modulation scheme that can be considered as an alternative to the conventional Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) for transmission over multipath fading channels. In this paper, we investigate the combination of the OFDM/OQAM with Alamouti system with Time Reversal (TR) technique. TR can be viewed as a precoding scheme which can be combined with OFDM/OQAM and easily carried out in a Multiple Input Single Output (MISO) context such as Alamouti system. We present the simulation results of the performance of OFDM/OQAM system in SISO case compared with the conventional CP-OFDM system and the performance of the combination Alamouti OFDM/OQAM with TR compared to Alamouti CP-OFDM. The performance is derived by computing the Bit Error Rate (BER) as a function of the transmit signal-to-noise ratio (SNR).
Comparison of Selection Methods in On-line Distributed Evolutionary Robotics
Venue: arXiv cs.AI 2015
Year: 2015

In this paper, we study the impact of selection methods in the context of on-line on-board distributed evolutionary algorithms. We propose a variant of the mEDEA algorithm in which we add a selection operator, and we apply it in a taskdriven scenario. We evaluate four selection methods that induce different intensity of selection pressure in a multi-robot navigation with obstacle avoidance task and a collective foraging task. Experiments show that a small intensity of selection pressure is sufficient to rapidly obtain good performances on the tasks at hand. We introduce different measures to compare the selection methods, and show that the higher the selection pressure, the better the performances obtained, especially for the more challenging food foraging task.
Enhanced HARQ for Delay Tolerant Services in Mobile Satellite Communications
Venue: arXiv cs.IT 2015
Year: 2015

The objective of our paper is to improve efficiency (in terms of throughput or system capacity) for mobile satellite communications. In this context, we propose an enhanced Hybrid Automatic Repeat reQuest (HARQ) for delay tolerant services. Our proposal uses the estimation of the mutual information. We evaluate the performance of the proposed method for a land mobile satellite channel by means of simulations. Results are compared with those obtained with a classical incremental redundancy (IR) HARQ scheme. The technique we propose, shows a better performance in terms of efficiency while maintaining an acceptable delay for services.
On decoding of digital data sent over a noisy MIMO channel
Venue: arXiv cs.IT 2015
Year: 2015

The transmission of digital data is one of the principal tasks in modern wireless communication. Classically, the communication channel consists of one transmitter and one receiver; however, due to the constantly increasing demand in higher transmission rates, the popularity of using several receivers and transmitters has been rapidly growing. In this paper, we combine a number of fairly standard techniques from numerical linear algebra and probability to develop several (apparently novel) randomized schemes for the decoding of digital messages sent over a noisy multivariate Gaussian channel. We use a popular mathematical model for such channels to illustrate the performance of our schemes via numerical experiments.
Provably Delay Efficient Data Retrieving in Storage Clouds
Venue: arXiv cs.DC 2015
Year: 2015

One key requirement for storage clouds is to be able to retrieve data quickly. Recent system measurements have shown that the data retrieving delay in storage clouds is highly variable, which may result in a long latency tail. One crucial idea to improve the delay performance is to retrieve multiple data copies by using parallel downloading threads. However, how to optimally schedule these downloading threads to minimize the data retrieving delay remains to be an important open problem. In this paper, we develop low-complexity thread scheduling policies for several important classes of data downloading time distributions, and prove that these policies are either delay-optimal or within a constant gap from the optimum delay performance. These theoretical results hold for an arbitrary arrival process of read requests that may contain finite or infinite read requests, and for heterogeneous MDS storage codes that can support diverse storage redundancy and reliability requirements for different data files. Our numerical results show that the delay performance of the proposed policies is significantly better than that of First-Come- First-Served (FCFS) policies considered in prior work.
Robustness Properties of Dimensionality Reduction with Gaussian Random Matrices
Venue: arXiv cs.IT 2015
Year: 2015

In this paper we study the robustness properties of dimensionality reduction with Gaussian random matrices having arbitrarily erased rows. We first study the robustness property against erasure for the almost norm preservation property of Gaussian random matrices by obtaining the optimal estimate of the erasure ratio for a small given norm distortion rate. As a consequence, we establish the robustness property of Johnson-Lindenstrauss lemma and the robustness property of restricted isometry property with corruption for Gaussian random matrices. Secondly, we obtain a sharp estimate for the optimal lower and upper bounds of norm distortion rates of Gaussian random matrices under a given erasure ratio. This allows us to establish the strong restricted isometry property with the almost optimal RIP constants, which plays a central role in the study of phaseless compressed sensing.
Super-resolution MRI Using Finite Rate of Innovation Curves
Venue: arXiv cs.CV 2015
Year: 2015

We propose a two-stage algorithm for the super-resolution of MR images from their low-frequency k-space samples. In the first stage we estimate a resolution-independent mask whose zeros represent the edges of the image. This builds off recent work extending the theory of sampling signals of finite rate of innovation (FRI) to two-dimensional curves. We enable its application to MRI by proposing extensions of the signal models allowed by FRI theory, and by developing a more robust and efficient means to determine the edge mask. In the second stage of the scheme, we recover the super-resolved MR image using the discretized edge mask as an image prior. We evaluate our scheme on simulated single-coil MR data obtained from analytical phantoms, and compare against total variation reconstructions. Our experiments show improved performance in both noiseless and noisy settings.
Distributed Resource Allocation for Epidemic control
Venue: arXiv cs.SY 2015
Year: 2015

We present a distributed resource allocation strategy to control an epidemic outbreak in a networked population based on a Distributed Alternating Direction Method of Multipliers (D-ADMM) algorithm. We consider a linearized Susceptible- Infected-Susceptible (SIS) epidemic spreading model in which agents in the network are able to allocate vaccination resources (for prevention) and antidotes (for treatment) in the presence of a contagion. We express our epidemic control condition as a spectral constraint involving the Perron-Frobenius eigenvalue, and formulate the resource allocation problem as a Geometric Program (GP). Next, we separate the network-wide optimization problem into subproblems optimally solved by each agent in a fully distributed way. We conclude the paper by illustrating performance of our solution framework with numerical simulations.
LDPC Coded Modulation with Probabilistic Shaping for Optical Fiber Systems
Venue: arXiv cs.IT 2015
Year: 2015

An LDPC coded modulation scheme with probabilistic shaping, optimized interleavers and noniterative demapping is proposed. Full-field simulations show an increase in transmission distance by 8% compared to uniformly distributed input.
Minimization of image watermarking side effects through subjective optimization
Venue: arXiv cs.MM 2015
Year: 2015

This paper investigates the use of Structural Similaritys (SSIM) index on the minimized side effect to image watermarking. For fast implementation and more compatibility with the standard DCT based codecs, watermark insertion is carried out on the DCT coefficients and hence a SSIM model for DCT based watermarking is developed. For faster implementation, the SSIM index is maximized over independent 4x4 non-overlapped blocks but the disparity between the adjacent blocks reduces the overall image quality. This problem is resolved through optimization of overlapped blocks, but, the higher image quality is achieved at a cost of high computational complexity. To reduce the computational complexity while preserving the good quality, optimization of semi-overlapped blocks is introduced. We show that while SSIM-based optimization over overlapped blocks has as high as 64 times the complexity of the 4x4 non-overlapped method, with semi-overlapped optimization the high quality of overlapped method is preserved only at a cost of less than 8 times the non-overlapped method.
Central Trajectories
Venue: arXiv cs.CG 2015
Year: 2015

An important task in trajectory analysis is clustering. The results of a clustering are often summarized by a single representative trajectory and an associated size of each cluster. We study the problem of computing a suitable representative of a set of similar trajectories. To this end we define a central trajectory $\mathcal{C}$, which consists of pieces of the input trajectories, switches from one entity to another only if they are within a small distance of each other, and such that at any time $t$, the point $\mathcal{C}(t)$ is as central as possible. We measure centrality in terms of the radius of the smallest disk centered at $\mathcal{C}(t)$ enclosing all entities at time $t$, and discuss how the techniques can be adapted to other measures of centrality. We first study the problem in $\mathbb{R}^1$, where we show that an optimal central trajectory $\mathcal{C}$ representing $n$ trajectories, each consisting of $τ$ edges, has complexity $Θ(τn^2)$ and can be computed in $O(τn^2 \log n)$ time. We then consider trajectories in $\mathbb{R}^d$ with $d\geq 2$, and show that the complexity of $\mathcal{C}$ is at most $O(τn^{5/2})$ and can be computed in $O(τn^3)$ time.