OpenRaiser/Intern-Atlas huggingface dataset:
Constraint Handling Rules with Multiset Comprehension Patterns
Venue: arXiv cs.PL 2014
Year: 2014

CHR is a declarative, concurrent and committed choice rule-based constraint programming language. We extend CHR with multiset comprehension patterns, providing the programmer with the ability to write multiset rewriting rules that can match a variable number of constraints in the store. This enables writing more readable, concise and declarative code for algorithms that coordinate large amounts of data or require aggregate operations. We call this extension $\mathit{CHR}^\mathit{cp}$. We give a high-level abstract semantics of $\mathit{CHR}^\mathit{cp}$, followed by a lower-level operational semantics. We then show the soundness of this operational semantics with respect to the abstract semantics.
Digital Watermarking Techniques in Spatial and Frequency Domain
Venue: arXiv cs.CR 2014
Year: 2014

Digital watermarking is the act of hiding information in multimedia data, for the purposes of content protection or authentication. In ordinary digital watermarking, the secret information is embedded into the multimedia data (cover data) with minimum distortion of the cover data. Due to these watermarking techniques the watermark image is almost negligible visible. In this paper we will discuss about various techniques of Digital Watermarking techniques in spatial and frequency domains
Survey on Variants of Distributed Energy efficient Clustering Protocols in heterogeneous Wireless Sensor Network
Venue: arXiv cs.NI 2014
Year: 2014

Wireless sensor networks are composed of low cost and extremely power constrained sensor nodes which are scattered over a region forming self organized networks, making energy consumption a crucial design issue. Thus, finite network lifetime is widely regarded as a fundamental performance bottleneck. These networks are used for various applications such as field monitoring, home automation, medical data collection or surveillance. Research has shown that clustering sensor nodes is an efficient method to manage energy consumption for prolonging the network lifetime. Presence of heterogeneity enhances the lifetime and reliability in network. In this paper, we present the distributed and energy efficient clustering protocols which follow the thoughts of Distributed Energy Efficient Clustering protocol. Objective of our work is to analyze that how these extended routing protocols work in order to optimize network lifetime and how routing protocols are improved. We emphasizes on issues experienced by various protocols and how these issues are tackled by other enhanced protocols. This provides a survey of work done on distributed energy efficient protocols
Distributed MIN-MAX Optimization Application to Time-optimal Consensus: An Alternating Projection Approach
Venue: arXiv cs.SY 2014
Year: 2014

In this paper, we proposed an alternating projection based algorithm to solve a class of distributed MIN-MAX convex optimization problems. We firstly transform this MINMAX problem into the problem of searching for the minimum distance between some hyper-plane and the intersection of the epigraphs of convex functions. The Bregman's alternating method is employed in our algorithm to achieve the distance by iteratively projecting onto the hyper-plane and the intersection. The projection onto the intersection is obtained by cyclic Dykstra's projection method. We further apply our algorithm to the minimum time multi-agent consensus problem. The attainable states set for the agent can be transformed into the epigraph of some convex functions, and the search for time-optimal state for consensus satisfies the MIN-MAX problem formulation. Finally, the numerous simulation proves the validity of our algorithm.
Decentralized Adaptive Helper Selection in Multi-channel P2P Streaming Systems
Venue: arXiv cs.NI 2014
Year: 2014

In Peer-to-Peer (P2P) multichannel live streaming, helper peers with surplus bandwidth resources act as micro-servers to compensate the server deficiencies in balancing the resources between different channel overlays. With deployment of helper level between server and peers, optimizing the user/helper topology becomes a challenging task since applying well-known reciprocity-based choking algorithms is impossible due to the one-directional nature of video streaming from helpers to users. Because of selfish behavior of peers and lack of central authority among them, selection of helpers requires coordination. In this paper, we design a distributed online helper selection mechanism which is adaptable to supply and demand pattern of various video channels. Our solution for strategic peers' exploitation from the shared resources of helpers is to guarantee the convergence to correlated equilibria (CE) among the helper selection strategies. Online convergence to the set of CE is achieved through the regret-tracking algorithm which tracks the equilibrium in the presence of stochastic dynamics of helpers' bandwidth. The resulting CE can help us select proper cooperation policies. Simulation results demonstrate that our algorithm achieves good convergence, load distribution on helpers and sustainable streaming rates for peers.
ProvGen: generating synthetic PROV graphs with predictable structure
Venue: arXiv cs.DB 2014
Year: 2014

This paper introduces provGen, a generator aimed at producing large synthetic provenance graphs with predictable properties and of arbitrary size. Synthetic provenance graphs serve two main purposes. Firstly, they provide a variety of controlled workloads that can be used to test storage and query capabilities of provenance management systems at scale. Secondly, they provide challenging testbeds for experimenting with graph algorithms for provenance analytics, an area of increasing research interest. provGen produces PROV graphs and stores them in a graph DBMS (Neo4J). A key feature is to let users control the relationship makeup and topological features of the graph, by providing a seed provenance pattern along with a set of constraints, expressed using a custom Domain Specific Language. We also propose a simple method for evaluating the quality of the generated graphs, by measuring how realistically they simulate the structure of real-world patterns.
Maximizing Diversity for Multimodal Optimization
Venue: arXiv cs.NE 2014
Year: 2014

Most multimodal optimization algorithms use the so called \textit{niching methods}~\cite{mahfoud1995niching} in order to promote diversity during optimization, while others, like \textit{Artificial Immune Systems}~\cite{de2010conceptual} try to find multiple solutions as its main objective. One of such algorithms, called \textit{dopt-aiNet}~\cite{de2005artificial}, introduced the Line Distance that measures the distance between two solutions regarding their basis of attraction. In this short abstract I propose the use of the Line Distance measure as the main objective-function in order to locate multiple optima at once in a population.
Some Aspects concerning the Cyber-Physical Systems Approach in Power Systems
Venue: arXiv cs.SY 2014
Year: 2014

The paper carries out a review of the main functional aspects of an electro-energetic system, principles which lead to an evolution or even to a paradigm change the the control of such complex systems. The repositioning of the physical and information systems, mainly through the development of the computing and communication distributed entities, lead to a new structuring of the control approach in power systems, in accordance to the modern Cyber-Physical Systems (CPS) paradigm.
Wireless Backhaul Networks: Capacity Bound, Scalability Analysis and Design Guidelines
Venue: arXiv cs.IT 2014
Year: 2014

This paper studies the scalability of a wireless backhaul network modeled as a random extended network with multi-antenna base stations (BSs), where the number of antennas per BS is allowed to scale as a function of the network size. The antenna scaling is justified by the current trend towards the use of higher carrier frequencies, which allows to pack large number of antennas in small form factors. The main goal is to study the per-BS antenna requirement that ensures scalability of this network, i.e., its ability to deliver non-vanishing rate to each source-destination pair. We first derive an information theoretic upper bound on the capacity of this network under a general propagation model, which provides a lower bound on the per-BS antenna requirement. Then, we characterize the scalability requirements for two competing strategies of interest: (i) long hop: each source-destination pair minimizes the number of hops by sacrificing multiplexing gain while achieving full beamforming (power) gain over each hop, and (ii) short hop: each source-destination pair communicates through a series of short hops, each achieving full multiplexing gain. While long hop may seem more intuitive in the context of massive multiple-input multiple-output (MIMO) transmission, we show that the short hop strategy is significantly more efficient in terms of per-BS antenna requirement for throughput scalability. As a part of the proof, we construct a scalable short hop strategy and show that it does not violate any fundamental limits on the spatial degrees of freedom (DoFs).
Green Computing In Developed And Developing Countries
Venue: arXiv cs.CY 2014
Year: 2014

Today e-waste are becoming a major problem for the developing countries. E-waste is defined something as a discarded parts of electronic devices which contains most of the times, hazardous chemicals which is deadly for our environment, example is computer components. Green Computing is the study and practice of designing, using, disposing and manufacturing electronic components in an eco-friendly manner and Green Computing is one of the solution to tackle with this hazardous e-waste problem which is an emerging concern towards the environment. The objective of this paper is to draw the attention towards the lack of awareness about green computing or we can say how green computing policies is being ignored by developing countries and how developed countries are adopting green IT policies seriously. This paper also discusses the analysis which has been done on how the amount of e-waste has been increased in developing countries in past years
real-time audio translation module between iax and rsw
Venue: arXiv cs.MM 2014
Year: 2014

At the last few years, multimedia communication has been developed and improved rapidly in order to enable users to communicate between each other over the internet. Generally, multimedia communication consists of audio and video communication. However, this research concentrates on audio conferencing only. The audio translation between protocols is a very critical issue, because it solves the communication problems between any two protocols. So, it enables people around the world to talk with each other even they use different protocols. In this research, a real time audio translation module between two protocols has been done. These two protocols are: InterAsterisk eXchange Protocol (IAX) and Real-Time Switching Control Protocol (RSW), which they are widely used to provide two ways audio transfer feature. The solution here is to provide inter-working between the two protocols which they have different media transports, audio codecs, header formats and different transport protocols for the audio transmission. This translation will help bridging the gap between the two protocols by providing inter-working capability between the two audio streams of IAX and RSW. Some related works have been done to provide translation between IAX and RSW control signalling messages. But, this research paper concentrates on the translation that depends on the media transfer. The proposed translation module was tested and evaluated in different scenarios in order to examine its performance. The obtained results showed that the Real-Time Audio Translation Module produces lower rates of packet delay and jitter than the acceptance values for each of the mentioned performance metrics.
A New Class of Multiple-rate Codes Based on Block Markov Superposition Transmission
Venue: arXiv cs.IT 2014
Year: 2014

Hadamard transform~(HT) as over the binary field provides a natural way to implement multiple-rate codes~(referred to as {\em HT-coset codes}), where the code length $N=2^p$ is fixed but the code dimension $K$ can be varied from $1$ to $N-1$ by adjusting the set of frozen bits. The HT-coset codes, including Reed-Muller~(RM) codes and polar codes as typical examples, can share a pair of encoder and decoder with implementation complexity of order $O(N \log N)$. However, to guarantee that all codes with designated rates perform well, HT-coset coding usually requires a sufficiently large code length, which in turn causes difficulties in the determination of which bits are better for being frozen. In this paper, we propose to transmit short HT-coset codes in the so-called block Markov superposition transmission~(BMST) manner. At the transmitter, signals are spatially coupled via superposition, resulting in long codes. At the receiver, these coupled signals are recovered by a sliding-window iterative soft successive cancellation decoding algorithm. Most importantly, the performance around or below the bit-error-rate~(BER) of $10^{-5}$ can be predicted by a simple genie-aided lower bound. Both these bounds and simulation results show that the BMST of short HT-coset codes performs well~(within one dB away from the corresponding Shannon limits) in a wide range of code rates.
A Framework for the Evaluation of SaaS Impact
Venue: arXiv cs.SE 2014
Year: 2014

Nowadays the technological progress allows us to have highly flexible solutions, easily accessible with lower levels of investment, which leads to many companies adopting SaaS (Software-as-a-Service) to support their business processes. Associated with this movement and considering the advantages of SaaS, it is important to understand whether work is being developed that is underutilized because companies are not taking advantage of it, and in this case it is necessary to understand the reasons thereof. This knowledge is important even for people who do not use or do not develop/provide SaaS, since sooner or later it will be unavoidable due to current trends. In the near future, nearly all decision-makers of IT strategies will be forced to consider adopting SaaS as an IT solution for the convenience benefits associated with technology or market competition. At that time they will have to know how to evaluate impacts and decide. Often, decision-makers of business strategies consider only the attractive incentives of using SaaS ignoring the impacts associated with new technologies. The need for tools and processes to assess these impacts before adopting a SaaS solution is crucial to ensure the sustainability of the information system, reduce uncertainty and facilitate decision making. This article presents a framework for evaluating impacts of SaaS called SIE (SaaS Impact Evaluation) which in addition to guidance for the present research, aims to provide guidelines for the collection, data analysis, impact assessment and decision making about including SaaS on the organizations strategic plans.
Partitionnement Déterministe pour Résoudre les Problèmes de Programmation Par Contraintes en utilisant le Framework Parallèle Bobpp
Venue: arXiv cs.DC 2014
Year: 2014

This paper presents a deterministic parallelization to explore a Constraint Programming search space. This work is an answer to an industrial project named PAJERO, which is in need of a parallel constraint solver which always responds with the same solution whether using sequential or parallel machines. It is well known that parallel tree search changes the order in which the exploration of solution space is done. In the context where the first solution found is returned, using a different number of cores may change the returned solution. In the literature, several non deterministic strategies have been proposed to parallelize the exploration of Constraint Programming search space. Most of them are based on the Work Stealing technique used to partition the Constraint Programming search space on demand and during the execution of the search algorithm. Our study focuses on the determinism of the parallel search versus the sequential one. We consider that the sequential search algorithm is deterministic, then propose an elegant solution introducing a total order on the nodes in which the parallel algorithm always gives the same solution as the sequential one regardless of the number of cores used. To evaluate this deterministic strategy, we ran tests using the Google OR-Tools Constraint Programming solver on top of our parallel Bobpp framework. The performances are illustrated by solving Constraint Programming problems modeled in FlatZinc format.
Quantum POMDPs
Venue: arXiv cs.AI 2014
Year: 2014

We present quantum observable Markov decision processes (QOMDPs), the quantum analogues of partially observable Markov decision processes (POMDPs). In a QOMDP, an agent's state is represented as a quantum state and the agent can choose a superoperator to apply. This is similar to the POMDP belief state, which is a probability distribution over world states and evolves via a stochastic matrix. We show that the existence of a policy of at least a certain value has the same complexity for QOMDPs and POMDPs in the polynomial and infinite horizon cases. However, we also prove that the existence of a policy that can reach a goal state is decidable for goal POMDPs and undecidable for goal QOMDPs.
A Modified Design of ACF Operation for Reducing PAPR of OFDM Signal
Venue: arXiv cs.NI 2014
Year: 2014

Next generation wireless communication technology long term evolution (LTE) has implemented orthogonal frequency division multiplexing (OFDM) technique as a strong candidate for radio access systems. It has several attributes such as providing robustness to multipath fading & impulse noise, eliminating intersymbol interference (ISI), inter carrier interference (ICI) & the need for equalizers. The major challenging issue of OFDM technique is the high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. A trade-off is necessary for reducing PAPR with increasing bit error rate (BER), computational complexity or data rate loss etc. In this paper, a moderately modified design of amplitude clipping & filtering operation (ACF) is proposed and implemented which shows the significant improvement in case of PAPR reduction for both quadrature phase shift keying (QPSK) & quadrature amplitude modulation (QAM) while increasing slight BER match up to to an existing method.
Lower Bounds for Tropical Circuits and Dynamic Programs
Venue: arXiv cs.CC 2014
Year: 2014

Tropical circuits are circuits with Min and Plus, or Max and Plus operations as gates. Their importance stems from their intimate relation to dynamic programming algorithms. The power of tropical circuits lies somewhere between that of monotone boolean circuits and monotone arithmetic circuits. In this paper we present some lower bounds arguments for tropical circuits, and hence, for dynamic programs.
Optimized Adaptive Streaming Representations based on System Dynamics
Venue: arXiv cs.MM 2014
Year: 2014

Adaptive streaming addresses the increasing and heterogenous demand of multimedia content over the Internet by offering several encoded versions for each video sequence. Each version (or representation) has a different resolution and bit rate, aimed at a specific set of users, like TV or mobile phone clients. While most existing works on adaptive streaming deal with effective playout-control strategies at the client side, we take in this paper a providers' perspective and propose solutions to improve user satisfaction by optimizing the encoding rates of the video sequences. We formulate an integer linear program that maximizes users' average satisfaction, taking into account the network dynamics, the video content information, and the user population characteristics. The solution of the optimization is a set of encoding parameters that permit to create different streams to robustly satisfy users' requests over time. We simulate multiple adaptive streaming sessions characterized by realistic network connections models, where the proposed solution outperforms commonly used vendor recommendations, in terms of user satisfaction but also in terms of fairness and outage probability. The simulation results further show that video content information as well as network constraints and users' statistics play a crucial role in selecting proper encoding parameters to provide fairness a mong users and to reduce network resource usage. We finally propose a few practical guidelines that can be used to choose the encoding parameters based on the user base characteristics, the network capacity and the type of video content.
Multicasting in Cognitive Radio Networks: Algorithms, Techniques and Protocols
Venue: arXiv cs.NI 2014
Year: 2014

Multicasting is a fundamental networking primitive utilized by numerous applications. This also holds true for cognitive radio networks (CRNs) which have been proposed as a solution to the problems that emanate from the static non-adaptive features of classical wireless networks. A prime application of CRNs is dynamic spectrum access (DSA), which improves the efficiency of spectrum allocation by allowing a secondary network, comprising of secondary users (SUs), to share spectrum licensed to a primary licensed networks comprising of primary users (PUs). Multicasting in CRNs is a challenging problem due to the dynamic nature of spectrum opportunities available to the SUs. Various approaches, including those based in optimization theory, network coding, algorithms, have been proposed for performing efficient multicast in CRNs. In this paper, we provide a self-contained tutorial on algorithms and techniques useful for solving the multicast problem, and then provide a comprehensive survey of protocols that have been proposed for multicasting in CRNs. We conclude this paper by identifying open research questions and future research directions.
SocialSpy: Browsing (Supposedly) Hidden Information in Online Social Networks
Venue: arXiv cs.SI 2014
Year: 2014

Online Social Networks are becoming the most important "places" where people share information about their lives. With the increasing concern that users have about privacy, most social networks offer ways to control the privacy of the user. Unfortunately, we believe that current privacy settings are not as effective as users might think. In this paper, we highlight this problem focusing on one of the most popular social networks, Facebook. In particular, we show how easy it is to retrieve information that a user might have set as (and hence thought as) "private". As a case study, we focus on retrieving the list of friends for users that did set this information as "hidden" (to non-friends). We propose four different strategies to achieve this goal, and we evaluate them. The results of our thorough experiments show the feasibility of our strategies as well as their effectiveness: our approach is able to retrieve a significant percentage of the names of the "hidden" friends: i.e., some 25% on average, and more than 70% for some users.