OpenRaiser/Intern-Atlas huggingface dataset:
Bounds on the ML Decoding Error Probability of RS-Coded Modulation over AWGN Channels
Venue: arXiv cs.IT 2014
Year: 2014

This paper is concerned with bounds on the maximum-likelihood (ML) decoding error probability of Reed-Solomon (RS) codes over additive white Gaussian noise (AWGN) channels. To resolve the difficulty caused by the dependence of the Euclidean distance spectrum on the way of signal mapping, we propose to use random mapping, resulting in an ensemble of RS-coded modulation (RS-CM) systems. For this ensemble of RS-CM systems, analytic bounds are derived, which can be evaluated from the known (symbol-level) Hamming distance spectrum. Also presented in this paper are simulation-based bounds, which are applicable to any specific RS-CM system and can be evaluated by the aid of a list decoding (in the Euclidean space) algorithm. The simulation-based bounds do not need distance spectrum and are numerically tight for short RS codes in the regime where the word error rate (WER) is not too low. Numerical comparison results are relevant in at least three aspects. First, in the short code length regime, RS-CM using BPSK modulation with random mapping has a better performance than binary random linear codes. Second, RS-CM with random mapping (time varying) can have a better performance than with specific mapping. Third, numerical results show that the recently proposed Chase-type decoding algorithm is essentially the ML decoding algorithm for short RS codes.
Linear MIMO Precoding in Jointly-Correlated Fading Multiple Access Channels with Finite Alphabet Signaling
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, we investigate the design of linear precoders for multiple-input multiple-output (MIMO) multiple access channels (MAC). We assume that statistical channel state information (CSI) is available at the transmitters and consider the problem under the practical finite alphabet input assumption. First, we derive an asymptotic (in the large-system limit) weighted sum rate (WSR) expression for the MIMO MAC with finite alphabet inputs and general jointly-correlated fading. Subsequently, we obtain necessary conditions for linear precoders maximizing the asymptotic WSR and propose an iterative algorithm for determining the precoders of all users. In the proposed algorithm, the search space of each user for designing the precoding matrices is its own modulation set. This significantly reduces the dimension of the search space for finding the precoding matrices of all users compared to the conventional precoding design for the MIMO MAC with finite alphabet inputs, where the search space is the combination of the modulation sets of all users. As a result, the proposed algorithm decreases the computational complexity for MIMO MAC precoding design with finite alphabet inputs by several orders of magnitude. Simulation results for finite alphabet signalling indicate that the proposed iterative algorithm achieves significant performance gains over existing precoder designs, including the precoder design based on the Gaussian input assumption, in terms of both the sum rate and the coded bit error rate.
Beyond One-Way Communication: Degrees of Freedom of Multi-Way Relay MIMO Interference Networks
Venue: arXiv cs.IT 2014
Year: 2014

We characterize the degrees of freedom (DoF) of multi-way relay MIMO interference networks. In particular, we consider a wireless network consisting of 4 user nodes, each with M antennas, and one N-antenna relay node. In this network, each user node sends one independent message to each of the other user nodes, and there are no direct links between any two user nodes, i.e., all communication must pass through the relay node. For this network, we show that the symmetric DoF value per message is given by max(min(M/3,N/7),min(2M/7,N/6)) normalized by space dimensions, i.e., piecewise linear depending on M and N alternatively. While the information theoretic DoF upper bound is established for every M and N, the achievability relying on linear signal subspace alignment is established in the spatially-normalized sense in general. In addition, by deactivating 4 messages to form a two-way relay MIMO X channel, we also present the DoF result in the similar piecewise linear type. The central new insight to emerge from this work is the notion of inter-user signal subspace alignment incorporating the idea of network coding, which is the key to achieve the optimal DoF for multi-way relay interference networks. Moreover, this work also settles the feasibility of linear interference alignment that extends the feasibility framework from one-way to multi-way relay interference networks.
Specification of the State Lifetime in the DEVS Formalism by Fuzzy Controller
Venue: arXiv cs.OH 2014
Year: 2014

This paper aims to develop a new approach to assess the duration of state in the DEVS formalism by fuzzy controller. The idea is to define a set of fuzzy rules obtained from observers or expert knowledge and to specify a fuzzy model which computes this duration, this latter is fed into the simulator to specify the new value in the model. In conventional model, each state is defined by a mean lifetime value whereas our method, calculates for each state the new lifetime according to inputs values. A wildfire case study is presented at the end of the paper. It is a challenging task due to its complex behavior, dynamical weather condition, and various variables involved. A global specification of the fuzzy controller and the forest fire model are presented in the DEVS formalism and comparison between conventional and fuzzy method is illustrated.
Generalized Biwords for Bitext Compression and Translation Spotting
Venue: arXiv cs.CL 2014
Year: 2014

Large bilingual parallel texts (also known as bitexts) are usually stored in a compressed form, and previous work has shown that they can be more efficiently compressed if the fact that the two texts are mutual translations is exploited. For example, a bitext can be seen as a sequence of biwords ---pairs of parallel words with a high probability of co-occurrence--- that can be used as an intermediate representation in the compression process. However, the simple biword approach described in the literature can only exploit one-to-one word alignments and cannot tackle the reordering of words. We therefore introduce a generalization of biwords which can describe multi-word expressions and reorderings. We also describe some methods for the binary compression of generalized biword sequences, and compare their performance when different schemes are applied to the extraction of the biword sequence. In addition, we show that this generalization of biwords allows for the implementation of an efficient algorithm to look on the compressed bitext for words or text segments in one of the texts and retrieve their counterpart translations in the other text ---an application usually referred to as translation spotting--- with only some minor modifications in the compression algorithm.
Increasing Server Availability for Overall System Security: A Preventive Maintenance Approach Based on Failure Prediction
Venue: arXiv cs.DC 2014
Year: 2014

Server Availability (SA) is an important measure of overall systems security. Important security systems rely on the availability of their hosting servers to deliver critical security services. Many of these servers offer management interface through web mainly using an Apache server. This paper investigates the increase of Server Availability by the use of Artificial Neural Networks (ANN) to predict software aging phenomenon. Several resource usage data is collected and analyzed on a typical long-running software system (a web server). A Multi-Layer Perceptron feed forward Artificial Neural Network was trained on an Apache web server data-set to predict future server resource exhaustion through uni-variate time series forecasting. The results were benchmarked against those obtained from non-parametric statistical techniques, parametric time series models and empirical modeling techniques reported in the literature.
Multilingual Part-of-Speech Tagging: Two Unsupervised Approaches
Venue: arXiv cs.CL 2014
Year: 2014

We demonstrate the effectiveness of multilingual learning for unsupervised part-of-speech tagging. The central assumption of our work is that by combining cues from multiple languages, the structure of each becomes more apparent. We consider two ways of applying this intuition to the problem of unsupervised part-of-speech tagging: a model that directly merges tag structures for a pair of languages into a single sequence and a second model which instead incorporates multilingual context using latent variables. Both approaches are formulated as hierarchical Bayesian models, using Markov Chain Monte Carlo sampling techniques for inference. Our results demonstrate that by incorporating multilingual evidence we can achieve impressive performance gains across a range of scenarios. We also found that performance improves steadily as the number of available languages increases.
Wikipedia-based Semantic Interpretation for Natural Language Processing
Venue: arXiv cs.CL 2014
Year: 2014

Adequate representation of natural language semantics requires access to vast amounts of common sense and domain-specific world knowledge. Prior work in the field was based on purely statistical techniques that did not make use of background knowledge, on limited lexicographic knowledge bases such as WordNet, or on huge manual efforts such as the CYC project. Here we propose a novel method, called Explicit Semantic Analysis (ESA), for fine-grained semantic interpretation of unrestricted natural language texts. Our method represents meaning in a high-dimensional space of concepts derived from Wikipedia, the largest encyclopedia in existence. We explicitly represent the meaning of any text in terms of Wikipedia-based concepts. We evaluate the effectiveness of our method on text categorization and on computing the degree of semantic relatedness between fragments of natural language text. Using ESA results in significant improvements over the previous state of the art in both tasks. Importantly, due to the use of natural concepts, the ESA model is easy to explain to human users.
Who is Dating Whom: Characterizing User Behaviors of a Large Online Dating Site
Venue: arXiv cs.SI 2014
Year: 2014

Online dating sites have become popular platforms for people to look for potential romantic partners. It is important to understand users' dating preferences in order to make better recommendations on potential dates. The message sending and replying actions of a user are strong indicators for what he/she is looking for in a potential date and reflect the user's actual dating preferences. We study how users' online dating behaviors correlate with various user attributes using a large real-world dateset from a major online dating site in China. Many of our results on user messaging behavior align with notions in social and evolutionary psychology: males tend to look for younger females while females put more emphasis on the socioeconomic status (e.g., income, education level) of a potential date. In addition, we observe that the geographic distance between two users and the photo count of users play an important role in their dating behaviors. Our results show that it is important to differentiate between users' true preferences and random selection. Some user behaviors in choosing attributes in a potential date may largely be a result of random selection. We also find that both males and females are more likely to reply to users whose attributes come closest to the stated preferences of the receivers, and there is significant discrepancy between a user's stated dating preference and his/her actual online dating behavior. These results can provide valuable guidelines to the design of a recommendation engine for potential dates.
Smart Deferral of Messages for Privacy Protection in Online Social Networks
Venue: arXiv cs.SI 2014
Year: 2014

Despite the several advantages commonly attributed to social networks such as easiness and immediacy to communicate with acquaintances and friends, significant privacy threats provoked by unexperienced or even irresponsible users recklessly publishing sensitive material are also noticeable. Yet, a different, but equally hazardous privacy risk might arise from social networks profiling the online activity of their users based on the timestamp of the interactions between the former and the latter. In order to thwart this last type of commonly neglected attacks, this paper presents a novel, smart deferral mechanism for messages in online social networks. Such solution suggests intelligently delaying certain messages posted by end users in social networks in a way that the observed online-activity profile generated by the attacker does not reveal any time-based sensitive information. Conducted experiments as well as a proposed architecture implementing this approach demonstrate the suitability and feasibility of our mechanism.
Partition Expanders
Venue: arXiv cs.CC 2014
Year: 2014

We introduce a new concept, which we call partition expanders. The basic idea is to study quantitative properties of graphs in a slightly different way than it is in the standard definition of expanders. While in the definition of expanders it is required that the number of edges between any pair of sufficiently large sets is close to the expected number, we consider partitions and require this condition only for most of the pairs of blocks. As a result, the blocks can be substantially smaller. We show that for some range of parameters, to be a partition expander a random graph needs exponentially smaller degree than any expander would require in order to achieve similar expanding properties. We apply the concept of partition expanders in communication complexity. First, we give a PRG for the SMP model of the optimal seed length, n+O(log k). Second, we compare the model of SMP to that of Simultaneous Two-Way Communication, and give a new separation that is stronger both qualitatively and quantitatively than the previously known ones.
Orthogonal Matrix in Cryptography
Venue: arXiv cs.CR 2014
Year: 2014

In this work is proposed a method using orthogonal matrix transform properties to encrypt and decrypt a message. It will be showed how to use matrix functions to create complex encryptions. Because orthogonal matrix are always diagonalizable on R, and the exponential of a diagonal matrix is easy to compute, the exponential of orthogonal matrix will be used to encrypt text messages.
Advanced Signal Processing Techniqes to Study Normal and Epileptic EEG
Venue: arXiv cs.CE 2014
Year: 2014

EEG monitoring has an important milestone provide valuable information of those candidates who suffer from epilepsy.In this paper human normal and epileptic Electroencephalogram signals are analyzed with popular and efficient signal processing techniques like Fourier and Wavelet transform. The delta, theta, alpha, beta and gamma sub bands of EEG are obtained and studied for detection of seizure and epilepsy. The extracted feature is then applied to ANN for classification of the EEG signals.
A Prediction Model for System Testing Defects using Regression Analysis
Venue: arXiv cs.SE 2014
Year: 2014

This research describes the initial effort of building a prediction model for defects in system testing carried out by an independent testing team. The motivation to have such defect prediction model is to serve as early quality indicator of the software entering system testing and assist the testing team to manage and control test execution activities. Metrics collected from prior phases to system testing are identified and analyzed to determine the potential predictors for building the model. The selected metrics are then put into regression analysis to generate several mathematical equations. Mathematical equation that has p-value of less than 0.05 with R-squared and R-squared (adjusted) more than 90% is selected as the desired prediction model for system testing defects. This model is verified using new projects to confirm that it is fit for actual implementation.
Narrative Planning: Compilations to Classical Planning
Venue: arXiv cs.AI 2014
Year: 2014

A model of story generation recently proposed by Riedl and Young casts it as planning, with the additional condition that story characters behave intentionally. This means that characters have perceivable motivation for the actions they take. I show that this condition can be compiled away (in more ways than one) to produce a classical planning problem that can be solved by an off-the-shelf classical planner, more efficiently than by Riedl and Youngs specialised planner.
Online Speedup Learning for Optimal Planning
Venue: arXiv cs.AI 2014
Year: 2014

Domain-independent planning is one of the foundational areas in the field of Artificial Intelligence. A description of a planning task consists of an initial world state, a goal, and a set of actions for modifying the world state. The objective is to find a sequence of actions, that is, a plan, that transforms the initial world state into a goal state. In optimal planning, we are interested in finding not just a plan, but one of the cheapest plans. A prominent approach to optimal planning these days is heuristic state-space search, guided by admissible heuristic functions. Numerous admissible heuristics have been developed, each with its own strengths and weaknesses, and it is well known that there is no single "best heuristic for optimal planning in general. Thus, which heuristic to choose for a given planning task is a difficult question. This difficulty can be avoided by combining several heuristics, but that requires computing numerous heuristic estimates at each state, and the tradeoff between the time spent doing so and the time saved by the combined advantages of the different heuristics might be high. We present a novel method that reduces the cost of combining admissible heuristics for optimal planning, while maintaining its benefits. Using an idealized search space model, we formulate a decision rule for choosing the best heuristic to compute at each state. We then present an active online learning approach for learning a classifier with that decision rule as the target concept, and employ the learned classifier to decide which heuristic to compute at each state. We evaluate this technique empirically, and show that it substantially outperforms the standard method for combining several heuristics via their pointwise maximum.
Distribution properties of compressing sequences derived from primitive sequences modulo odd prime powers
Venue: arXiv cs.IT 2014
Year: 2014

Let $\underline{a}$ and $\underline{b}$ be primitive sequences over $\mathbb{Z}/(p^e)$ with odd prime $p$ and $e\ge 2$. For certain compressing maps, we consider the distribution properties of compressing sequences of $\underline{a}$ and $\underline{b}$, and prove that $\underline{a}=\underline{b}$ if the compressing sequences are equal at the times $t$ such that $α(t)=k$, where $\underlineα$ is a sequence related to $\underline{a}$. We also discuss the $s$-uniform distribution property of compressing sequences. For some compressing maps, we have that there exist different primitive sequences such that the compressing sequences are $s$-uniform. We also discuss that compressing sequences can be $s$-uniform for how many elements $s$.
Timed-Release Secret Sharing Scheme with Information Theoretic Security
Venue: arXiv cs.CR 2014
Year: 2014

In modern cryptography, the secret sharing scheme is an important cryptographic primitive and it is used in various situations. In this paper, a timed-release secret sharing scheme (TR-SS) with information-theoretic security is first studied. TR-SS is a secret sharing scheme with the property that participants more than a threshold number can reconstruct a secret by using their shares only when the time specified by a dealer has come. Specifically, in this paper we first introduce a model and formalization of security for TR-SS based on the traditional secret sharing scheme and information-theoretic timed-release security. We also derive tight lower bounds on the sizes of shares, time-signals, and entities' secret-keys required for TR-SS. In addition, we propose a direct construction for TR-SS. Our direct construction is optimal in the sense that the construction meets equality in each of our bounds. As a result, it is shown that the timed-release security can be realized without any additional redundancy on the share-size.
A Generalization of Threshold Saturation: Application to Spatially Coupled BICM-ID
Venue: arXiv cs.IT 2014
Year: 2014

Spatial coupling was proved to improve the belief-propagation (BP) performance up to the maximum-a-posteriori (MAP) performance. This paper addresses an extended class of spatially coupled (SC) systems. A potential function is derived for characterizing a lower bound on the BP performance of the extended SC systems, and shown to be different from the potential for the conventional SC systems. This may imply that the BP performance for the extended SC systems does not coincide with the MAP performance for the corresponding uncoupled system. SC bit-interleaved coded modulation with iterative decoding (BICM-ID) is also investigated as an application of the extended SC systems.
Applications of the Gauss-Jordan algorithm, done right
Venue: arXiv cs.LO 2014
Year: 2014

Computer Algebra systems are widely spread because of some of their remarkable features such as their ease of use and performance. Nonetheless, this focus on performance sometimes leads to unwanted consequences: algorithms and computations are implemented and carried out in a way which is sometimes not transparent to the users, and that can lead to unexpected failures. In this paper we present a formalisation in a proof assistant system of a \emph{naive} version of the Gauss-Jordan algorithm, with explicit proofs of some of its applications, and additionally a process to obtain versions of this algorithm in two different functional languages (SML and Haskell) by means of code generation techniques from the verified algorithm. The obtained programs are then applied to test cases, which, despite the simplicity of the original algorithm, have shown remarkable features in comparison to some Computer Algebra systems, such as Mathematica\textsuperscript{\textregistered} (where some of these computations are even incorrect), or Sage (in comparison to which the generated programs show a compelling performance). The aim of the paper is to show that, with the current technology in Theorem Proving, formalising Linear Algebra procedures is a challenging but rewarding task, which provides programs that can be compared in some aspects to \emph{state of the art} procedures in Computer Algebra systems, and whose correctness is formally proved.
Accelerated Assistant to SubOptimum Receiver for Multi Carrier Code Division Multiple Access System
Venue: arXiv cs.IT 2014
Year: 2014

The Multiple Input Multiple output system are considered to be the strongest candidate for the maximum utilization of available bandwidth. In this paper, the MIMO system with the combination of Multi-Carrier Code Division Multiple Access and Space Time Coding using the Alamoutis scheme is considered. A Genetic Algorithm based receiver with an exceptional relationship between filter weights while detecting symbols is proposed. This scheme has better Convergence Rate and Bit Error Rate than the Fast-LMS Adaptive receiver.