OpenRaiser/Intern-Atlas huggingface dataset:
DiFS: Distributed Flow Scheduling for Data Center Networks
Venue: arXiv cs.NI 2013
Year: 2013

Data center networks leverage multiple parallel paths connecting end host pairs to offer high bisection bandwidth for cluster computing applications. However, state of the art distributed multi-pathing protocols such as Equal Cost Multipath (ECMP) use static flow-to-link assignment, which is load-oblivious. They may cause bandwidth loss due to \emph{flow collisions} on a same link. Recently proposed centralized scheduling algorithm or host-based multi-pathing may suffer from scalability problems. In this paper, we present Distributed Flow Scheduling (DiFS) for data center networks, which is a switch-only distributed solution. DiFS allows switches cooperate to avoid over-utilized links and find available paths without centralized control. DiFS is scalable and can react quickly to dynamic traffic, because it is independently executed on switches and requires no synchronization. Extensive experiments show that the aggregate bisection bandwidth of DiFS using various traffic patterns is much better than that of ECMP, and is similar to or higher than that of a recent proposed centralized scheduling algorithm.
Compositionality of Approximate Bisimulation for Probabilistic Systems
Venue: arXiv cs.LO 2013
Year: 2013

Probabilistic transition system specifications using the rule format ntmuft-ntmuxt provide structural operational semantics for Segala-type systems and guarantee that probabilistic bisimilarity is a congruence. Probabilistic bisimilarity is for many applications too sensitive to the exact probabilities of transitions. Approximate bisimulation provides a robust semantics that is stable with respect to implementation and measurement errors of probabilistic behavior. We provide a general method to quantify how much a process combinator expands the approximate bisimulation distance. As a direct application we derive an appropriate rule format that guarantees compositionality with respect to approximate bisimilarity. Moreover, we describe how specification formats for non-standard compositionality requirements may be derived.
ReAct! An Interactive Tool for Hybrid Planning in Robotics
Venue: arXiv cs.AI 2013
Year: 2013

We present ReAct!, an interactive tool for high-level reasoning for cognitive robotic applications. ReAct! enables robotic researchers to describe robots' actions and change in dynamic domains, without having to know about the syntactic and semantic details of the underlying formalism in advance, and solve planning problems using state-of-the-art automated reasoners, without having to learn about their input/output language or usage. In particular, ReAct! can be used to represent sophisticated dynamic domains that feature concurrency, indirect effects of actions, and state/transition constraints. It allows for embedding externally defined calculations (e.g., checking for collision-free continuous trajectories) into representations of hybrid domains that require a tight integration of (discrete) high-level reasoning with (continuous) geometric reasoning. ReAct! also enables users to solve planning problems that involve complex goals. Such variety of utilities are useful for robotic researchers to work on interesting and challenging domains, ranging from service robotics to cognitive factories. ReAct! provides sample formalizations of some action domains (e.g., multi-agent path planning, Tower of Hanoi), as well as dynamic simulations of plans computed by a state-of-the-art automated reasoner (e.g., a SAT solver or an ASP solver).
Universal Polarization
Venue: arXiv cs.IT 2013
Year: 2013

A method to polarize channels universally is introduced. The method is based on combining two distinct channels in each polarization step, as opposed to Arikan's original method of combining identical channels. This creates an equal number of only two types of channels, one of which becomes progressively better as the other becomes worse. The locations of the good polarized channels are independent of the underlying channel, guaranteeing universality. Polarizing the good channels further with Arikan's method results in universal polar codes of rate 1/2. The method is generalized to construct codes of arbitrary rates. It is also shown that the less noisy ordering of channels is preserved under polarization, and thus a good polar code for a given channel will perform well over a less noisy one.
Wi-Fi Offload: Tragedy of the Commons or Land of Milk and Honey?
Venue: arXiv cs.NI 2013
Year: 2013

Fueled by its recent success in provisioning on-site wireless Internet access, Wi-Fi is currently perceived as the best positioned technology for pervasive mobile macro network offloading. However, the broad transitions of multiple collocated operators towards this new paradigm may result in fierce competition for the common unlicensed spectrum at hand. In this light, our paper game-theoretically dissects market convergence scenarios by assessing the competition between providers in terms of network performance, capacity constraints, cost reductions, and revenue prospects. We will closely compare the prospects and strategic positioning of fixed line operators offering Wi-Fi services with respect to competing mobile network operators utilizing unlicensed spectrum. Our results highlight important dependencies upon inter-operator collaboration models, and more importantly, upon the ratio between backhaul and Wi-Fi access bit-rates. Furthermore, our investigation of medium- to long-term convergence scenarios indicates that a rethinking of control measures targeting the large-scale monetization of unlicensed spectrum may be required, as otherwise the used free bands may become subject to tragedy-of-commons type of problems.
Automated Attack Planning
Venue: arXiv cs.AI 2013
Year: 2013

Penetration Testing is a methodology for assessing network security, by generating and executing possible attacks. Doing so automatically allows for regular and systematic testing. A key question then is how to automatically generate the attacks. A natural way to address this issue is as an attack planning problem. In this thesis, we are concerned with the specific context of regular automated pentesting, and use the term "attack planning" in that sense. The following three research directions are investigated. First, we introduce a conceptual model of computer network attacks, based on an analysis of the penetration testing practices. We study how this attack model can be represented in the PDDL language. Then we describe an implementation that integrates a classical planner with a penetration testing tool. This allows us to automatically generate attack paths for real world pentesting scenarios, and to validate these attacks by executing them. Secondly, we present efficient probabilistic planning algorithms, specifically designed for this problem, that achieve industrial-scale runtime performance (able to solve scenarios with several hundred hosts and exploits). These algorithms take into account the probability of success of the actions and their expected cost (for example in terms of execution time, or network traffic generated). Finally, we take a different direction: instead of trying to improve the efficiency of the solutions developed, we focus on improving the model of the attacker. We model the attack planning problem in terms of partially observable Markov decision processes (POMDP). This grounds penetration testing in a well-researched formalism. POMDPs allow the modelling of information gathering as an integral part of the problem, thus providing for the first time a means to intelligently mix scanning actions with actual exploits.
Truthful Mechanisms for Secure Communication in Wireless Cooperative System
Venue: arXiv cs.CR 2013
Year: 2013

To ensure security in data transmission is one of the most important issues for wireless relay networks, and physical layer security is an attractive alternative solution to address this issue. In this paper, we consider a cooperative network, consisting of one source node, one destination node, one eavesdropper node, and a number of relay nodes. Specifically, the source may select several relays to help forward the signal to the corresponding destination to achieve the best security performance. However, the relays may have the incentive not to report their true private channel information in order to get more chances to be selected and gain more payoff from the source. We propose a Vickey-Clark-Grove (VCG) based mechanism and an Arrow-d'Aspremont-Gerard-Varet (AGV) based mechanism into the investigated relay network to solve this cheating problem. In these two different mechanisms, we design different "transfer payment" functions to the payoff of each selected relay and prove that each relay gets its maximum (expected) payoff when it truthfully reveals its private channel information to the source. And then, an optimal secrecy rate of the network can be achieved. After discussing and comparing the VCG and AGV mechanisms, we prove that the AGV mechanism can achieve all of the basic qualifications (incentive compatibility, individual rationality and budget balance) for our system. Moreover, we discuss the optimal quantity of relays that the source node should select. Simulation results verify efficiency and fairness of the VCG and AGV mechanisms, and consolidate these conclusions.
A Fixed-Parameter Algorithm for Minimum Common String Partition with Few Duplications
Venue: arXiv cs.DS 2013
Year: 2013

Motivated by the study of genome rearrangements, the NP-hard Minimum Common String Partition problems asks, given two strings, to split both strings into an identical set of blocks. We consider an extension of this problem to unbalanced strings, so that some elements may not be covered by any block. We present an efficient fixed-parameter algorithm for the parameters number k of blocks and maximum occurrence d of a letter in either string. We then evaluate this algorithm on bacteria genomes and synthetic data.
Image Tag Refinement by Regularized Latent Dirichlet Allocation
Venue: arXiv cs.IR 2013
Year: 2013

Tagging is nowadays the most prevalent and practical way to make images searchable. However, in reality many manually-assigned tags are irrelevant to image content and hence are not reliable for applications. A lot of recent efforts have been conducted to refine image tags. In this paper, we propose to do tag refinement from the angle of topic modeling and present a novel graphical model, regularized Latent Dirichlet Allocation (rLDA). In the proposed approach, tag similarity and tag relevance are jointly estimated in an iterative manner, so that they can benefit from each other, and the multi-wise relationships among tags are explored. Moreover, both the statistics of tags and visual affinities of images in the corpus are explored to help topic modeling. We also analyze the superiority of our approach from the deep structure perspective. The experiments on tag ranking and image retrieval demonstrate the advantages of the proposed method.
A Rational Convex Program for Linear Arrow-Debreu Markets
Venue: arXiv cs.DS 2013
Year: 2013

We give a new, flow-type convex program describing equilibrium solutions to linear Arrow-Debreu markets. Whereas convex formulations were previously known [Nenakov, Primak 83; Jain 07; Cornet '89], our program exhibits several new features. It gives a simple necessary and sufficient condition and a concise proof of the existence and rationality of equilibria, settling an open question raised by Vazirani. As a consequence we also obtain a simple new proof of Mertens's result that the equilibrium prices form a convex polyhedral set.
A Review on Secured Money Transaction with Fingerprint Technique in ATM System
Venue: arXiv cs.CY 2013
Year: 2013

In the present day, the requirement of securing electronic cash flow system are increasing significantly. Todays life is so busy that spending a valuable second cost so much. In, such situation if money flow is possible swiftly by just one swipe it would be a great relief. Biometric based authentication can be a new approach to satisfy user needs by replacing password-based authentication. Among all biometric techniques fingerprinting is the oldest and secured methodology practised till date. In the proposed system user can transact money by placing his/her thumb imprint on new proposed ATM card. This new system will smoothen the transaction with security.
An Oblivious Password Cracking Server
Venue: arXiv cs.CR 2013
Year: 2013

Building a password cracking server that preserves the privacy of the queries made to the server is a problem that has not yet been solved. Such a server could acquire practical relevance in the future: for instance, the tables used to crack the passwords could be calculated, stored and hosted in cloud-computing services, and could be queried from devices with limited computing power. In this paper we present a method to preserve the confidentiality of a password cracker---wherein the tables used to crack the passwords are stored by a third party---by combining Hellman tables and Private Information Retrieval (PIR) protocols. We provide the technical details of this method, analyze its complexity, and show the experimental results obtained with our implementation.
Bounding normalization time through intersection types
Venue: arXiv cs.LO 2013
Year: 2013

Non-idempotent intersection types are used in order to give a bound of the length of the normalization beta-reduction sequence of a lambda term: namely, the bound is expressed as a function of the size of the term.
Enhancing Java Call Control with Media Server Control functions
Venue: arXiv cs.NI 2013
Year: 2013

In this paper, we propose a novel abstraction layer for application service implementation compliant with the Java Call Control (JCC) specifications. It simplifies creation of multimedia services using the Session Initiation Protocol (SIP) and the Media Gateway Control Protocol (MGCP). In order to show its effectiveness, we have implemented a JCC Resource Adaptor for a JAIN Service Logic Execution Environment (JSLEE), using the Mobicents application server, which is the only existing open source JSLEE implementation. Experimental results, obtained by implementing a complex VoIP service, show both a significant simplification of service implementation and improved performance over legacy solutions.
AIDSS-HR: An Automated Intelligent Decision Support System for Enhancing the Performance of Employees
Venue: arXiv cs.CY 2013
Year: 2013

The performance of employees in an organization is a very important issue for effective delivery and output. Various performance management systems with the aid of Information and Communication Technology (ICT) are currently being used by companies. Such systems are most of the time connected and accessible through to the internet / www. Through review of relevant literature and a system development methodology, this paper proposes an Automated Intelligent Decision Support Human Resource (AIDSS-HR) system that seeks to control and manage employee activities by tracking the number of years a staff has been at post, keeping inventory on logistics, analyzing appraisal reports of an individual staff and invoking real time prompts devoid of false alarm. The implementation of AIDSS-HR will improve the performance management of employees and benefit the organization, employees and developing nations as a whole.
A simple technique for steganography
Venue: arXiv cs.MM 2013
Year: 2013

A new technique for data hiding in digital image is proposed in this paper. Steganography is a well known technique for hiding data in an image, but generally the format of image plays a pivotal role in it, and the scheme is format dependent. In this paper we will discuss a new technique where irrespective of the format of image, we can easily hide a large amount of data without deteriorating the quality of the image. The data to be hidden is enciphered with the help of a secret key. This enciphered data is then embedded at the end of the image. The enciphered data bits are extracted and then deciphered with the help of same key used for encryption. Simulation results show that Image Quality Measures of this proposed scheme are better than the conventional LSB replacing technique. The proposed method is simple and is easy to implement.
Analysis of a Proportionally Fair and Locally Adaptive spatial Aloha in Poisson Networks
Venue: arXiv cs.NI 2013
Year: 2013

The proportionally fair sharing of the capacity of a Poisson network using Spatial-Aloha leads to closed-form performance expressions in two extreme cases: (1) the case without topology information, where the analysis boils down to a parametric optimization problem leveraging stochastic geometry; (2) the case with full network topology information, which was recently solved using shot-noise techniques. We show that there exists a continuum of adaptive controls between these two extremes, based on local stopping sets, which can also be analyzed in closed form. We also show that these control schemes are implementable, in contrast to the full information case which is not. As local information increases, the performance levels of these schemes are shown to get arbitrarily close to those of the full information scheme. The analytical results are combined with discrete event simulation to provide a detailed evaluation of the performance of this class of medium access controls.
On Lattices and the Dualities of Information Measures
Venue: arXiv cs.IT 2013
Year: 2013

Measures of dependence among variables, and measures of information content and shared information have become valuable tools of multi-variable data analysis. Information measures, like marginal entropies, mutual and multi-information, have a number of significant advantages over more standard statistical methods, like their reduced sensitivity to sampling limitations than statistical estimates of probability densities. There are also interesting applications of these measures to the theory of complexity and to statistical mechanics. Their mathematical properties and relationships are therefore of interest at several levels. Of the interesting relationships between common information measures, perhaps none are more intriguing and as elegant as the duality relationships based on Mobius inversions. These inversions are directly related to the lattices (posets) that describe these sets of variables and their multi-variable measures. In this paper we describe extensions of the duality previously noted by Bell to a range of measures, and show how the structure of the lattice determines fundamental relationships of these functions. Our major result is a set of interlinked duality relations among marginal entropies, interaction information, and conditional interaction information. The implications of these results include a flexible range of alternative formulations of information-based measures, and a new set of sum rules that arise from path-independent sums on the lattice. Our motivation is to advance the fundamental integration of this set of ideas and relations, and to show explicitly the ways in which all these measures are interrelated through lattice properties. These ideas can be useful in constructing theories of complexity, descriptions of large scale stochastic processes and systems, and in devising algorithms and approximations for computations in multi-variable data analysis.
Drawing Arrangement Graphs In Small Grids, Or How To Play Planarity
Venue: arXiv cs.CG 2013
Year: 2013

We describe a linear-time algorithm that finds a planar drawing of every graph of a simple line or pseudoline arrangement within a grid of area O(n^{7/6}). No known input causes our algorithm to use area Ω(n^{1+ε}) for any ε>0; finding such an input would represent significant progress on the famous k-set problem from discrete geometry. Drawing line arrangement graphs is the main task in the Planarity puzzle.
Resistive Threshold Logic
Venue: arXiv cs.ET 2013
Year: 2013

We report a resistance based threshold logic family useful for mimicking brain like large variable logic functions in VLSI. A universal Boolean logic cell based on an analog resistive divider and threshold logic circuit is presented. The resistive divider is implemented using memristors and provides output voltage as a summation of weighted product of input voltages. The output of resistive divider is converted into a binary value by a threshold operation implemented by CMOS inverter and/or Opamp. An universal cell structure is presented to decrease the overall implementation complexity and number of components. When the number of input variables become very high, the proposed cell offers advantages of smaller area and design simplicity in comparison with CMOS based logic circuits.
Space complexity of list H-colouring: a dichotomy
Venue: arXiv cs.CC 2013
Year: 2013

The Dichotomy Conjecture for constraint satisfaction problems (CSPs) states that every CSP is in P or is NP-complete (Feder-Vardi, 1993). It has been verified for conservative problems (also known as list homomorphism problems) by A. Bulatov (2003). We augment this result by showing that for digraph templates H, every conservative CSP, denoted LHOM(H), is solvable in logspace or is hard for NL. More precisely, we introduce a digraph structure we call a circular N, and prove the following dichotomy: if H contains no circular N then LHOM(H) admits a logspace algorithm, and otherwise LHOM(H) is hard for NL. Our algorithm operates by reducing the lists in a complex manner based on a novel decomposition of an auxiliary digraph, combined with repeated applications of Reingold's algorithm for undirected reachability (2005). We also prove an algebraic version of this dichotomy: the digraphs without a circular N are precisely those that admit a finite chain of polymorphisms satisfying the Hagemann-Mitschke identities. This confirms a conjecture of Larose and Tesson (2007) for LHOM(H). Moreover, we show that the presence of a circular N can be decided in time polynomial in the size of H.
An n-ary Constraint for the Stable Marriage Problem
Venue: arXiv cs.DS 2013
Year: 2013

We present an n-ary constraint for the stable marriage problem. This constraint acts between two sets of integer variables where the domains of those variables represent preferences. Our constraint enforces stability and disallows bigamy. For a stable marriage instance with $n$ men and $n$ women we require only one of these constraints, and the complexity of enforcing arc-consistency is $O(n^2)$ which is optimal in the size of input. Our computational studies show that our n-ary constraint is significantly faster and more space efficient than the encodings presented in \cite{cp01}. We also introduce a new problem to the constraint community, the sex-equal stable marriage problem.
Design and Development of an Expert System to Help Head of University Departments
Venue: arXiv cs.AI 2013
Year: 2013

One of the basic tasks which is responded for head of each university department, is employing lecturers based on some default factors such as experience, evidences, qualifies and etc. In this respect, to help the heads, some automatic systems have been proposed until now using machine learning methods, decision support systems (DSS) and etc. According to advantages and disadvantages of the previous methods, a full automatic system is designed in this paper using expert systems. The proposed system is included two main steps. In the first one, the human expert's knowledge is designed as decision trees. The second step is included an expert system which is evaluated using extracted rules of these decision trees. Also, to improve the quality of the proposed system, a majority voting algorithm is proposed as post processing step to choose the best lecturer which satisfied more expert's decision trees for each course. The results are shown that the designed system average accuracy is 78.88. Low computational complexity, simplicity to program and are some of other advantages of the proposed system.