OpenRaiser/Intern-Atlas huggingface dataset:
On Multiplicative Matrix Channels over Finite Chain Rings
Venue: arXiv cs.IT 2013
Year: 2013

Motivated by physical-layer network coding, this paper considers communication in multiplicative matrix channels over finite chain rings. Such channels are defined by the law $Y =A X$, where $X$ and $Y$ are the input and output matrices, respectively, and $A$ is called the transfer matrix. It is assumed a coherent scenario in which the instances of the transfer matrix are unknown to the transmitter, but available to the receiver. It is also assumed that $A$ and $X$ are independent. Besides that, no restrictions on the statistics of $A$ are imposed. As contributions, a closed-form expression for the channel capacity is obtained, and a coding scheme for the channel is proposed. It is then shown that the scheme can achieve the capacity with polynomial time complexity and can provide correcting guarantees under a worst-case channel model. The results in the paper extend the corresponding ones for finite fields.
Multitask Diffusion Adaptation over Networks
Venue: arXiv cs.MA 2013
Year: 2013

Adaptive networks are suitable for decentralized inference tasks, e.g., to monitor complex natural phenomena. Recent research works have intensively studied distributed optimization problems in the case where the nodes have to estimate a single optimum parameter vector collaboratively. However, there are many important applications that are multitask-oriented in the sense that there are multiple optimum parameter vectors to be inferred simultaneously, in a collaborative manner, over the area covered by the network. In this paper, we employ diffusion strategies to develop distributed algorithms that address multitask problems by minimizing an appropriate mean-square error criterion with $\ell_2$-regularization. The stability and convergence of the algorithm in the mean and in the mean-square sense is analyzed. Simulations are conducted to verify the theoretical findings, and to illustrate how the distributed strategy can be used in several useful applications related to spectral sensing, target localization, and hyperspectral data unmixing.
TDCS-based Cognitive Radio Networks with Multiuser Interference Avoidance
Venue: arXiv cs.IT 2013
Year: 2013

For overlay cognitive radio networks (CRNs), transform domain communication system (TDCS) has been proposed to support multiuser communications through spectrum bin nulling and frequency domain spreading. In TDCS-based CRNs, each user is assigned a specific pseudorandom spreading sequence. However, the existence of multiuser interference (MUI) is one of main concerns, due to the non-zero cross-correlations between any pair of TDCS signals. In this paper, a novel framework of TDCS-based CRNs with the joint design of sequences and modulation schemes is presented to realize MUI avoidance. With the uncertainty of spectrum sensing results in CRNs, we first introduce a unique sequence design through two-dimensional time-frequency synthesis and obtain a class of almost perfect sequences. That is, periodic auto-correlation and cross-correlations are identically zero for most circular shifts. These correlation properties are further exploited in conjunction with a specially-designed cyclic code shift keying in order to achieve the advantage of MUI avoidance. Numerical results demonstrate that the proposed TDCS-based CRNs are considered as preferable candidates for decentralized networks against the near-far problem.
A Methodology to Engineer and Validate Dynamic Multi-level Multi-agent Based Simulations
Venue: arXiv cs.MA 2013
Year: 2013

This article proposes a methodology to model and simulate complex systems, based on IRM4MLS, a generic agent-based meta-model able to deal with multi-level systems. This methodology permits the engineering of dynamic multi-level agent-based models, to represent complex systems over several scales and domains of interest. Its goal is to simulate a phenomenon using dynamically the lightest representation to save computer resources without loss of information. This methodology is based on two mechanisms: (1) the activation or deactivation of agents representing different domain parts of the same phenomenon and (2) the aggregation or disaggregation of agents representing the same phenomenon at different scales.
Human Mobility and Predictability enriched by Social Phenomena Information (extended abstract)
Venue: arXiv cs.SI 2013
Year: 2013

The information collected by mobile phone operators can be considered as the most detailed information on human mobility across a large part of the population. The study of the dynamics of human mobility using the collected geolocations of users, and applying it to predict future users' locations, has been an active field of research in recent years. In this work, we study the extent to which social phenomena are reflected in mobile phone data, focusing in particular in the cases of urban commute and major sports events. We illustrate how these events are reflected in the data, and show how information about the events can be used to improve predictability in a simple model for a mobile phone user's location.
An Improved Variable Step-size Affine Projection Sign Algorithm for Echo Cancellation
Venue: arXiv cs.OH 2013
Year: 2013

This paper proposes an improved variable step-size (VSS) algorithm for the recently introduced affine projection sign algorithm (APSA) based on the recovery of the near-end signal energy in the error signal. Simulation results demonstrate that, compared to the previous VSS for APSA, the proposed approach provides both more robustness to impulse interference and better tracking ability of echo path change.
Achievable Rate Regions for Two-Way Relay Channel using Nested Lattice Coding
Venue: arXiv cs.IT 2013
Year: 2013

This paper studies Gaussian Two-Way Relay Channel where two communication nodes exchange messages with each other via a relay. It is assumed that all nodes operate in half duplex mode without any direct link between the communication nodes. A compress-and-forward relaying strategy using nested lattice codes is first proposed. Then, the proposed scheme is improved by performing a layered coding : a common layer is decoded by both receivers and a refinement layer is recovered only by the receiver which has the best channel conditions. The achievable rates of the new scheme are characterized and are shown to be higher than those provided by the decode-and-forward strategy in some regions.
Sonification Abstraite/Sonification Concrète: An 'Aesthetic Perspective Space' for Classifying Auditory Displays in the Ars Musica Domain
Venue: arXiv cs.HC 2013
Year: 2013

This paper discusses æsthetic issues of sonifications and the relationships between sonification (ars informatica) and music & sound art (ars musica). It is posited that many sonifications have suffered from poor internal ecological validity which makes listening more difficult, thereby resulting in poorer data extraction and inference on the part of the listener. Lessons are drawn from the electroacoustic music and musique concrète communities as it is argued that it is not instructive to distinguish between sonifications and music/sound art.
Complexity measurement of natural and artificial languages
Venue: arXiv cs.CL 2013
Year: 2013

We compared entropy for texts written in natural languages (English, Spanish) and artificial languages (computer software) based on a simple expression for the entropy as a function of message length and specific word diversity. Code text written in artificial languages showed higher entropy than text of similar length expressed in natural languages. Spanish texts exhibit more symbolic diversity than English ones. Results showed that algorithms based on complexity measures differentiate artificial from natural languages, and that text analysis based on complexity measures allows the unveiling of important aspects of their nature. We propose specific expressions to examine entropy related aspects of tests and estimate the values of entropy, emergence, self-organization and complexity based on specific diversity and message length.
The Well-tempered Compiler? The Aesthetics of Program Auralization
Venue: arXiv cs.HC 2013
Year: 2013

In this chapter we are concerned with external auditory representations of programs, also known as program auralization. As program auralization systems tend to use musical representations they are necessarily affected by artistic and aesthetic considerations. Therefore, it is instructive to explore program auralization in the light of aesthetic computing principles.
Dynamic Integration of ALM Tools for Agile Software Development
Venue: arXiv cs.SE 2013
Year: 2013

The paper describes the need for and goals of tool-integration within software development processes. In particular we focus on agile software development but are not limited to. The integration of tools and data between the different domains of the process is essential for an efficient, effective and customized software development. We describe what the next steps in the pursuit of integration are and how major goals can be achieved. Beyond theoretical and architectural considerations we describe the prototypical implementation of an open platform approach. The paper introduces platform apps and a functionality store as general concepts to make apps and their functionalities available to the community. We describe the implementation of the approach and how it can be practically utilized. The description is based on one major use case and further steps are motivated by various other examples.
Submodular Welfare Maximization
Venue: arXiv cs.GT 2013
Year: 2013

An overview of different variants of the submodular welfare maximization problem in combinatorial auctions. In particular, I studied the existing algorithmic and game theoretic results for submodular welfare maximization problem and its applications in other areas such as social networks.
Tracking and Characterizing Botnets Using Automatically Generated Domains
Venue: arXiv cs.CR 2013
Year: 2013

Modern botnets rely on domain-generation algorithms (DGAs) to build resilient command-and-control infrastructures. Recent works focus on recognizing automatically generated domains (AGDs) from DNS traffic, which potentially allows to identify previously unknown AGDs to hinder or disrupt botnets' communication capabilities. The state-of-the-art approaches require to deploy low-level DNS sensors to access data whose collection poses practical and privacy issues, making their adoption problematic. We propose a mechanism that overcomes the above limitations by analyzing DNS traffic data through a combination of linguistic and IP-based features of suspicious domains. In this way, we are able to identify AGD names, characterize their DGAs and isolate logical groups of domains that represent the respective botnets. Moreover, our system enriches these groups with new, previously unknown AGD names, and produce novel knowledge about the evolving behavior of each tracked botnet. We used our system in real-world settings, to help researchers that requested intelligence on suspicious domains and were able to label them as belonging to the correct botnet automatically. Additionally, we ran an evaluation on 1,153,516 domains, including AGDs from both modern (e.g., Bamital) and traditional (e.g., Conficker, Torpig) botnets. Our approach correctly isolated families of AGDs that belonged to distinct DGAs, and set automatically generated from non-automatically generated domains apart in 94.8 percent of the cases.
Lemma 4: Haptic Input + Auditory Display = Musical Instrument?
Venue: arXiv cs.HC 2013
Year: 2013

In this paper we look at some of the design issues that affect the success of multimodal displays that combine acoustic and haptic modalities. First, issues affecting successful sonification design are explored and suggestions are made about how the language of electroacoustic music can assist. Next, haptic interaction is introduced in the light of this discussion, particularly focusing on the roles of gesture and mimesis. Finally, some observations are made regarding some of the issues that arise when the haptic and acoustic modalities are combined in the interface. This paper looks at examples of where auditory and haptic interaction have been successfully combined beyond the strict confines of the human-computer application interface (musical instruments in particular) and discusses lessons that may be drawn from these domains and applied to the world of multimodal human-computer interaction. The argument is made that combined haptic-auditory interaction schemes can be thought of as musical instruments and some of the possible ramifications of this are raised.
Sinkless: A Preliminary Study of Stress Propagation in Group Project Social Networks using a Variant of the Abelian Sandpile Model
Venue: arXiv cs.SI 2013
Year: 2013

We perform social network analysis on 53 students split over three semesters and 13 groups, using conventional measures like eigenvector centrality, betweeness centrality, and degree centrality, as well as defining a variant of the Abelian Sandpile Model (ASM) with the intention of modeling stress propagation in the college classroom. We correlate the results of these analyses with group project grades received; due to a small or poorly collected dataset, we are unable to conclude that any of these network measures relates to those grades. However, we are successful in using this dataset to define a discrete, recursive, and more generalized variant of the ASM. Abelian Sandpile Model, College Grades, Self-organized Criticality, Sinkless Sandpile Model, Social Network Analysis, Stress Propagation
A traffic model based on fuzzy cellular automata
Venue: arXiv cs.ET 2013
Year: 2013

Cellular automata (CA) play an important role in the development of computationally efficient microscopic traffic models and recently have gained considerable importance as a mean of optimising traffic control strategies. However, real-time application of the available CA models in traffic control systems is a difficult task due to their discrete and stochastic nature. This paper introduces a novel method for simulation of signalised traffic streams, which combines CA and fuzzy numbers. The introduced traffic simulation algorithm eliminates main drawbacks of the CA approach, i.e. necessity of multiple Monte Carlo simulations and calibration issues. Computational cost of traffic simulation for the proposed algorithm is considerably lower than the cost of simulation based on stochastic CA. Thus, the simulation results can be obtained in a much shorter time. Experiments confirmed that the simulation results for the introduced algorithm are consistent with that observed for stochastic CA. The proposed simulation algorithm is suitable for real-time applications in traffic control systems.
Delay-Constrained Video Transmission: Quality-driven Resource Allocation and Scheduling
Venue: arXiv cs.IT 2013
Year: 2013

Real-time video demands quality-of-service (QoS) guarantees such as delay bounds for end-user satisfaction. Furthermore, the tolerable delay varies depending on the use case such as live streaming or two-way video conferencing. Due to the inherently stochastic nature of wireless fading channels, deterministic delay bounds are difficult to guarantee. Instead, we propose providing statistical delay guarantees using the concept of effective capacity. We consider a multiuser setup whereby different users have (possibly different) delay QoS constraints. We derive the resource allocation policy that maximizes the sum video quality and applies to any quality metric with concave rate-quality mapping. We show that the optimal operating point per user is such that the rate-distortion slope is the inverse of the supported video source rate per unit bandwidth, a key metric we refer to as the source spectral efficiency. We also solve the alternative problem of fairness-based resource allocation whereby the objective is to maximize the minimum video quality across users. Finally, we derive user admission and scheduling policies that enable selecting a maximal user subset such that all selected users can meet their statistical delay requirement. Results show that video users with differentiated QoS requirements can achieve similar video quality with vastly different resource requirements. Thus, QoS-aware scheduling and resource allocation enable supporting significantly more users under the same resource constraints.
Research and innovative design of a zeroemissions vehicle by multidisciplinary student teams in multi-years
Venue: arXiv cs.SY 2013
Year: 2013

This paper presents a unique learning and research experience for students from mechanical and electrical engineering majors in a course on senior design projects involving research and development, design and production of a proof-of-concept electric vehicle, the ZEM (Zero EMissions) vehicle. The ZEM vehicle combined positive aspects and latest technologies in electric vehicle design,solar-electric power conversions, and ergonomic human power into one affordable and environmentally sustainable vehicle for urban transportation. The 43 mechanical and 10 electrical engineering majors plus 7 students from business participated in this multidisciplinary project spanned over two academic years. The students involved in this multiyear endeavor gained valuable experiences in real-world working environment with multifunctional and multi-year sub-groups. The success of this new attempt in conducting senior design projects classes have set a model for faculty members in the authors' university in conducting similar courses.
Build Electronic Arabic Lexicon
Venue: arXiv cs.CL 2013
Year: 2013

There are many known Arabic lexicons organized on different ways, each of them has a different number of Arabic words according to its organization way. This paper has used mathematical relations to count a number of Arabic words, which proofs the number of Arabic words presented by Al Farahidy. The paper also presents new way to build an electronic Arabic lexicon by using a hash function that converts each word (as input) to correspond a unique integer number (as output), these integer numbers will be used as an index to a lexicon entry.
Analytical Studies of Quasi Steady-State Model in Power System Long-Term Stability Analysis
Venue: arXiv cs.SY 2013
Year: 2013

In this paper, a theoretical foundation for the Quasi Steady-State (QSS) model in power system long-term stability analysis is developed. Sufficient conditions under which the QSS model gives accurate approximations of the long-term stability model in terms of trajectory and !-limit set are derived. These sufficient conditions provide some physical insights regarding the reason for the failure of the QSS model. Additionally, several numerical examples are presented to illustrate the analytical results derived.
Ordered Biclique Partitions and Communication Complexity Problems
Venue: arXiv cs.CC 2013
Year: 2013

An ordered biclique partition of the complete graph $K_n$ on $n$ vertices is a collection of bicliques (i.e., complete bipartite graphs) such that (i) every edge of $K_n$ is covered by at least one and at most two bicliques in the collection, and (ii) if an edge $e$ is covered by two bicliques then each endpoint of $e$ is in the first class in one of these bicliques and in the second class in other one. In this note, we give an explicit construction of such a collection of size $n^{1/2+o(1)}$, which improves the $O(n^{2/3})$ bound shown in the previous work [Disc. Appl. Math., 2014]. As the immediate consequences of this result, we show (i) a construction of $n \times n$ 0/1 matrices of rank $n^{1/2+o(1)}$ which have a fooling set of size $n$, i.e., the gap between rank and fooling set size can be at least almost quadratic, and (ii) an improved lower bound $(2-o(1)) \log N$ on the nondeterministic communication complexity of the clique vs. independent set problem, which matches the best known lower bound on the deterministic version of the problem shown by Kushilevitz, Linial and Ostrovsky [Combinatorica, 1999].
A Decision Tree Approach to Classify Web Services using Quality Parameters
Venue: arXiv cs.IR 2013
Year: 2013

With the increase in the number of web services, many web services are available on internet providing the same functionality, making it difficult to choose the best one, fulfilling users all requirements. This problem can be solved by considering the quality of web services to distinguish functionally similar web services. Nine different quality parameters are considered. Web services can be classified and ranked using decision tree approach since they do not require long training period and can be easily interpreted. Various decision tree and rules approaches available are applied and tested to find the optimal decision method to correctly classify functionally similar web services considering their quality parameters.
Full-Duplex Relaying with Half-Duplex Relays
Venue: arXiv cs.IT 2013
Year: 2013

We consider "virtual" full-duplex relaying by means of half-duplex relays. In this configuration, each relay stage in a multi-hop relaying network is formed by at least two relays, used alternatively in transmit and receive modes, such that while one relay transmits its signal to the next stage, the other relay receives a signal from the previous stage. With such a pipelined scheme, the source is active and sends a new information message in each time slot. We consider the achievable rates for different coding schemes and compare them with a cut-set upper bound, which is tight in certain conditions. In particular, we show that both lattice-based Compute and Forward (CoF) and Quantize reMap and Forward (QMF) yield attractive performance and can be easily implemented. In particular, QMF in this context does not require "long" messages and joint (non-unique) decoding, if the quantization mean-square distortion at the relays is chosen appropriately. Also, in the multi-hop case the gap of QMF from the cut-set upper bound grows logarithmically with the number of stages, and not linearly as in the case of "noise level" quantization. Furthermore, we show that CoF is particularly attractive in the case of multi-hop relaying, when the channel gains have fluctuations not larger than 3dB, yielding a rate that does not depend on the number of relaying stages. In particular, we argue that such architecture may be useful for a wireless backhaul with line-of-sight propagation between the relays.
Channel Service Based High Speed Railway Base Station Arrangement
Venue: arXiv cs.IT 2013
Year: 2013

With the rapid development of high-speed railways, demands on high mobility wireless communication increase greatly. To provide stable and high data rate wireless access for users in the train, it is necessary to properly deploy base stations along the railway. In this paper, we consider this issue from the perspective of channel service which is defined as the integral of the time-varying instantaneous channel capacity. It will show that the total service quantity of each base station is a constant. In order to keep high service efficiency of the railway communication system with multiple base stations along the railway, we need to use the time division to schedule the multiple stations and allow one base station to work when the train is running close to it. In this way, we find a fact that if the ratio of the service quantity provided by each station to its total service quantity is given, the base station interval(i.e. the distance between two adjacent base stations) is a constant, regardless of the speed of the train. On the other hand, interval between two neighboring base stations will increase with the speed of the train. Furthermore, using the concept of channel service, we also analyze the transmission strategy of base stations.