OpenRaiser/Intern-Atlas huggingface dataset:
Simple Cellular Automata-Based Linear Models for the Shrinking Generator
Venue: arXiv cs.CR 2010
Year: 2010

Structural properties of two well-known families of keystream generators, Shrinking Generators and Cellular Automata, have been analyzed. Emphasis is on the equivalence of the binary sequences obtained from both kinds of generators. In fact, Shrinking Generators (SG) can be identified with a subset of linear Cellular Automata (mainly rule 90, rule 150 or a hybrid combination of both rules). The linearity of these cellular models can be advantageously used in the cryptanalysis of those keystream generators.
Mix and Match
Venue: arXiv cs.GT 2010
Year: 2010

Consider a matching problem on a graph where disjoint sets of vertices are privately owned by self-interested agents. An edge between a pair of vertices indicates compatibility and allows the vertices to match. We seek a mechanism to maximize the number of matches despite self-interest, with agents that each want to maximize the number of their own vertices that match. Each agent can choose to hide some of its vertices, and then privately match the hidden vertices with any of its own vertices that go unmatched by the mechanism. A prominent application of this model is to kidney exchange, where agents correspond to hospitals and vertices to donor-patient pairs. Here hospitals may game an exchange by holding back pairs and harm social welfare. In this paper we seek to design mechanisms that are strategyproof, in the sense that agents cannot benefit from hiding vertices, and approximately maximize efficiency, i.e., produce a matching that is close in cardinality to the maximum cardinality matching. Our main result is the design and analysis of the eponymous Mix-and-Match mechanism; we show that this randomized mechanism is strategyproof and provides a 2-approximation. Lower bounds establish that the mechanism is near optimal.
Cloning Voronoi Diagrams via Retroactive Data Structures
Venue: arXiv cs.CG 2010
Year: 2010

We address the problem of replicating a Voronoi diagram $V(S)$ of a planar point set $S$ by making proximity queries, which are of three possible (in decreasing order of information content): 1. the exact location of the nearest site(s) in $S$; 2. the distance to and label(s) of the nearest site(s) in $S$; 3. a unique label for every nearest site in $S$. We provide algorithms showing how queries of Type 1 and Type 2 allow an exact cloning of $V(S)$ with $O(n)$ queries and $O(n \log^2 n)$ processing time. We also prove that queries of Type 3 can never exactly clone $V(S)$, but we show that with $O(n \log\frac{1}ε)$ queries we can construct an $ε$-approximate cloning of $V(S)$. In addition to showing the limits of nearest-neighbor database security, our methods also provide one of the first natural algorithmic applications of retroactive data structures.
Throughput, Bit-Cost, Network State Information: Tradeoffs in Cooperative CSMA Protocols
Venue: arXiv cs.IT 2010
Year: 2010

In wireless local area networks, spatially varying channel conditions result in a severe performance discrepancy between different nodes in the uplink, depending on their position. Both throughput and energy expense are affected. Cooperative protocols were proposed to mitigate these discrepancies. However, additional network state information (NSI) from other nodes is needed to enable cooperation. The aim of this work is to assess how NSI and the degree of cooperation affect throughput and energy expenses. To this end, a CSMA protocol called fairMAC is defined, which allows to adjust the amount of NSI at the nodes and the degree of cooperation among the nodes in a distributed manner. By analyzing the data obtained by Monte Carlo simulations with varying protocol parameters for fairMAC, two fundamental tradeoffs are identified: First, more cooperation leads to higher throughput, but also increases energy expenses. Second, using more than one helper increases throughput and decreases energy expenses, however, more NSI has to be acquired by the nodes in the network. The obtained insights are used to increase the lifetime of a network. While full cooperation shortens the lifetime compared to no cooperation at all, lifetime can be increased by over 25% with partial cooperation.
Parameterized Two-Player Nash Equilibrium
Venue: arXiv cs.CC 2010
Year: 2010

We study the computation of Nash equilibria in a two-player normal form game from the perspective of parameterized complexity. Recent results proved hardness for a number of variants, when parameterized by the support size. We complement those results, by identifying three cases in which the problem becomes fixed-parameter tractable. These cases occur in the previously studied settings of sparse games and unbalanced games as well as in the newly considered case of locally bounded treewidth games that generalizes both these two cases.
Classification rule with simple select SQL statement
Venue: arXiv cs.DB 2010
Year: 2010

A simple sql statement can be used to search learning or rule in relational database for data mining purposes particularly for classification rule. With just only one simple sql statement, characteristic and classification rule can be created simultaneously. Collaboration sql statement with any other application software will increase the ability for creating t-weight as measurement the typicality of each record in the characteristic rule and d-weight as measurement the discriminating behavior of the learned classification/discriminant rule, specifically for further generalization in characteristic rule. Handling concept hierarchy into tables based on concept tree will influence for the successful simple sql statement and by knowing the right standard knowledge to transform each of concept tree in concept hierarchy into one table as to transform concept hierarchy into table, the simple sql statement can be run properly.
The duality of computation under focus
Venue: arXiv cs.LO 2010
Year: 2010

We review the close relationship between abstract machines for (call-by-name or call-by-value) lambda-calculi (extended with Felleisen's C) and sequent calculus, reintroducing on the way Curien-Herbelin's syntactic kit expressing the duality of computation. We use this kit to provide a term language for a presentation of LK (with conjunction, disjunction, and negation), and to transcribe cut elimination as (non confluent) rewriting. A key slogan here, which may appear here in print for the first time, is that commutative cut elimination rules are explicit substitution propagation rules. We then describe the focalised proof search discipline (in the classical setting), and narrow down the language and the rewriting rules to a confluent calculus (a variant of the second author's focalising system L). We then define a game of patterns and counterpatterns, leading us to a fully focalised finitary syntax for a synthetic presentation of classical logic, that provides a quotient on (focalised) proofs, abstracting out the order of decomposition of negative connectives.
Unification in the Description Logic EL
Venue: arXiv cs.AI 2010
Year: 2010

The Description Logic EL has recently drawn considerable attention since, on the one hand, important inference problems such as the subsumption problem are polynomial. On the other hand, EL is used to define large biomedical ontologies. Unification in Description Logics has been proposed as a novel inference service that can, for example, be used to detect redundancies in ontologies. The main result of this paper is that unification in EL is decidable. More precisely, EL-unification is NP-complete, and thus has the same complexity as EL-matching. We also show that, w.r.t. the unification type, EL is less well-behaved: it is of type zero, which in particular implies that there are unification problems that have no finite complete set of unifiers.
L2-optimal image interpolation and its applications to medical imaging
Venue: arXiv cs.CV 2010
Year: 2010

Digital medical images are always displayed scaled to fit particular view. Interpolation is responsible for this scaling, and if not done properly, can significantly degrade diagnostic image quality. However, theoretically-optimal interpolation algorithms may also be the most time-consuming and impractical. We propose a new approach, adapted to the needs of digital medical imaging, to combine high interpolation speed and superior L2-optimal image quality.
An attack on MySQL's login protocol
Venue: arXiv cs.CR 2010
Year: 2010

The MySQL challenge-and-response authentication protocol is proved insecure. We show how can an eavesdropper impersonate a valid user after witnessing only a few executions of this protocol. The algorithm of the underlying attack is presented. Finally we comment about implementations and statistical results.
Anonymous Gossiping
Venue: arXiv cs.DC 2010
Year: 2010

In this paper we introduce a novel gossiping primitive to support privacy preserving data analytics (PPDA). In contrast to existing computational PPDA primitives such as secure multiparty computation and data randomization based approaches, the proposed primitive `anonymous gossiping' is a communication primitive for privacy preserving personalized information aggregation complementing such traditional computational analytics. We realize this novel primitive by composing existing gossiping mechanisms for peer sampling & information aggregation and onion routing technique for establishing anonymous communication. This is more an `ideas' paper, rather than providing concrete and quantified results.
A Study on Performance Analysis Tools for Applications Running on Large Distributed Systems
Venue: arXiv cs.DC 2010
Year: 2010

The evolution of distributed architectures and programming paradigms for performance-oriented program development, challenge the state-of-the-art technology for performance tools. The area of high performance computing is rapidly expanding from single parallel systems to clusters and grids of heterogeneous sequential and parallel systems. Performance analysis and tuning applications is becoming crucial because it is hardly possible to otherwise achieve the optimum performance of any application. The objective of this paper is to study the state-of-the-art technology of the existing performance tools for distributed systems. The paper surveys some representative tools from different aspects in order to highlight the approaches and technologies used by them.
Experimentation for Packet Loss on MSP430 and nRF24L01 Based Wireless Sensor Network
Venue: arXiv cs.NI 2010
Year: 2010

In this paper,a new design of wireless sensor network (WSN)node is discussed which is based on components with ultra low power.We ha e de eloped a Low cost and low power WSN Node using MSP430 and nRF24L01.The architectural circuit details are presented.This architecture fulfils the requirements like low cost,low power,compact size and self organization.Various tests are carried out to test the performance of the nRF24L01 module.The packet loss,free Space loss (FSL)and battery lifetime calculations are described.These test results will help the researchers to build new applications using abo e node and to work efficiently with nRF24L01.
High Speed Reconfigurable FFT Design by Vedic Mathematics
Venue: arXiv cs.OH 2010
Year: 2010

The Fast Fourier Transform (FFT) is a computationally intensive digital signal processing (DSP) function widely used in applications such as imaging, software-defined radio, wireless communication, instrumentation. In this paper, a reconfigurable FFT design using Vedic multiplier with high speed and small area is presented. Urdhava Triyakbhyam algorithm of ancient Indian Vedic Mathematics is utilized to improve its efficiency. In the proposed architecture, the 4x4 bit multiplication operation is fragmented reconfigurable FFT modules. The 4x4 multiplication modules are implemented using small 2x2bit multipliers. Reconfigurability at run time is provided for attaining power saving. The reconfigurable FFT has been designed, optimized and implemented on an FPGA based system. This reconfigurable FFT is having the high speed and small area as compared to the conventional FFT.
Component Interaction Graph: A new approach to test component composition
Venue: arXiv cs.SE 2010
Year: 2010

The key factor of component based software development is component composition technology. A Component interaction graph is used to describe the interrelation of components. Drawing a complete component interaction graph (CIG) provides an objective basis and technical means for making the testing outline. Although many researches have focused on this subject, the quality of system that is composed of components has not been guaranteed. In this paper, a CIG is constructed from a state chart diagram and new test cases are generated to test the component composition.
Two-Timescale Learning Using Idiotypic Behaviour Mediation For A Navigating Mobile Robot
Venue: arXiv cs.AI 2010
Year: 2010

A combined Short-Term Learning (STL) and Long-Term Learning (LTL) approach to solving mobile-robot navigation problems is presented and tested in both the real and virtual domains. The LTL phase consists of rapid simulations that use a Genetic Algorithm to derive diverse sets of behaviours, encoded as variable sets of attributes, and the STL phase is an idiotypic Artificial Immune System. Results from the LTL phase show that sets of behaviours develop very rapidly, and significantly greater diversity is obtained when multiple autonomous populations are used, rather than a single one. The architecture is assessed under various scenarios, including removal of the LTL phase and switching off the idiotypic mechanism in the STL phase. The comparisons provide substantial evidence that the best option is the inclusion of both the LTL phase and the idiotypic system. In addition, this paper shows that structurally different environments can be used for the two phases without compromising transferability.
Approximation Algorithm for Line Segment Coverage for Wireless Sensor Network
Venue: arXiv cs.CG 2010
Year: 2010

The coverage problem in wireless sensor networks deals with the problem of covering a region or parts of it with sensors. In this paper, we address the problem of covering a set of line segments in sensor networks. A line segment ` is said to be covered if it intersects the sensing regions of at least one sensor distributed in that region. We show that the problem of finding the minimum number of sensors needed to cover each member in a given set of line segments in a rectangular area is NP-hard. Next, we propose a constant factor approximation algorithm for the problem of covering a set of axis-parallel line segments. We also show that a PTAS exists for this problem.
Two-Domain DNA Strand Displacement
Venue: arXiv cs.LO 2010
Year: 2010

We investigate the computing power of a restricted class of DNA strand displacement structures: those that are made of double strands with nicks (interruptions) in the top strand. To preserve this structural invariant, we impose restrictions on the single strands they interact with: we consider only two-domain single strands consisting of one toehold domain and one recognition domain. We study fork and join signal-processing gates based on these structures, and we show that these systems are amenable to formalization and to mechanical verification.
Bounding the Rate Region of Vector Gaussian Multiple Descriptions with Individual and Central Receivers
Venue: arXiv cs.IT 2010
Year: 2010

In this work, the rate region of the vector Gaussian multiple description problem with individual and central quadratic distortion constraints is studied. In particular, an outer bound to the rate region of the L-description problem is derived. The bound is obtained by lower bounding a weighted sum rate for each supporting hyperplane of the rate region. The key idea is to introduce at most L-1 auxiliary random variables and further impose upon the variables a Markov structure according to the ordering of the description weights. This makes it possible to greatly simplify the derivation of the outer bound. In the scalar Gaussian case, the complete rate region is fully characterized by showing that the outer bound is tight. In this case, the optimal weighted sum rate for each supporting hyperplane is obtained by solving a single maximization problem. This contrasts with existing results, which require solving a min-max optimization problem.
A General Framework for Equivalences in Answer-Set Programming by Countermodels in the Logic of Here-and-There
Venue: arXiv cs.AI 2010
Year: 2010

Different notions of equivalence, such as the prominent notions of strong and uniform equivalence, have been studied in Answer-Set Programming, mainly for the purpose of identifying programs that can serve as substitutes without altering the semantics, for instance in program optimization. Such semantic comparisons are usually characterized by various selections of models in the logic of Here-and-There (HT). For uniform equivalence however, correct characterizations in terms of HT-models can only be obtained for finite theories, respectively programs. In this article, we show that a selection of countermodels in HT captures uniform equivalence also for infinite theories. This result is turned into coherent characterizations of the different notions of equivalence by countermodels, as well as by a mixture of HT-models and countermodels (so-called equivalence interpretations). Moreover, we generalize the so-called notion of relativized hyperequivalence for programs to propositional theories, and apply the same methodology in order to obtain a semantic characterization which is amenable to infinite settings. This allows for a lifting of the results to first-order theories under a very general semantics given in terms of a quantified version of HT. We thus obtain a general framework for the study of various notions of equivalence for theories under answer-set semantics. Moreover, we prove an expedient property that allows for a simplified treatment of extended signatures, and provide further results for non-ground logic programs. In particular, uniform equivalence coincides under open and ordinary answer-set semantics, and for finite non-ground programs under these semantics, also the usual characterization of uniform equivalence in terms of maximal and total HT-models of the grounding is correct, even for infinite domains, when corresponding ground programs are infinite.
Algebraic Theories over Nominal Sets
Venue: arXiv cs.LO 2010
Year: 2010

We investigate the foundations of a theory of algebraic data types with variable binding inside classical universal algebra. In the first part, a category-theoretic study of monads over the nominal sets of Gabbay and Pitts leads us to introduce new notions of finitary based monads and uniform monads. In a second part we spell out these notions in the language of universal algebra, show how to recover the logics of Gabbay-Mathijssen and Clouston-Pitts, and apply classical results from universal algebra.
Concurrent Goal-Based Execution of Constraint Handling Rules
Venue: arXiv cs.PL 2010
Year: 2010

(To appear in Theory and Practice of Logic Programming (TPLP)) We introduce a systematic, concurrent execution scheme for Constraint Handling Rules (CHR) based on a previously proposed sequential goal-based CHR semantics. We establish strong correspondence results to the abstract CHR semantics, thus guaranteeing that any answer in the concurrent, goal-based CHR semantics is reproducible in the abstract CHR semantics. Our work provides the foundation to obtain efficient, parallel CHR execution schemes.
Solving Functional Constraints by Variable Substitution
Venue: arXiv cs.AI 2010
Year: 2010

Functional constraints and bi-functional constraints are an important constraint class in Constraint Programming (CP) systems, in particular for Constraint Logic Programming (CLP) systems. CP systems with finite domain constraints usually employ CSP-based solvers which use local consistency, for example, arc consistency. We introduce a new approach which is based instead on variable substitution. We obtain efficient algorithms for reducing systems involving functional and bi-functional constraints together with other non-functional constraints. It also solves globally any CSP where there exists a variable such that any other variable is reachable from it through a sequence of functional constraints. Our experiments on random problems show that variable elimination can significantly improve the efficiency of solving problems with functional constraints.
Optimal Constant-Time Approximation Algorithms and (Unconditional) Inapproximability Results for Every Bounded-Degree CSP
Venue: arXiv cs.DS 2010
Year: 2010

Raghavendra (STOC 2008) gave an elegant and surprising result: if Khot's Unique Games Conjecture (STOC 2002) is true, then for every constraint satisfaction problem (CSP), the best approximation ratio is attained by a certain simple semidefinite programming and a rounding scheme for it. In this paper, we show that similar results hold for constant-time approximation algorithms in the bounded-degree model. Specifically, we present the followings: (i) For every CSP, we construct an oracle that serves an access, in constant time, to a nearly optimal solution to a basic LP relaxation of the CSP. (ii) Using the oracle, we give a constant-time rounding scheme that achieves an approximation ratio coincident with the integrality gap of the basic LP. (iii) Finally, we give a generic conversion from integrality gaps of basic LPs to hardness results. All of those results are \textit{unconditional}. Therefore, for every bounded-degree CSP, we give the best constant-time approximation algorithm among all. A CSP instance is called $ε$-far from satisfiability if we must remove at least an $ε$-fraction of constraints to make it satisfiable. A CSP is called testable if there is a constant-time algorithm that distinguishes satisfiable instances from $ε$-far instances with probability at least $2/3$. Using the results above, we also derive, under a technical assumption, an equivalent condition under which a CSP is testable in the bounded-degree model.
A Fixed Precoding Approach to Achieve the Degrees of Freedom in X channel
Venue: arXiv cs.IT 2010
Year: 2010

This paper aims to provide a fixed precoding scheme to achieve the Degrees of Freedom DoF of the generalized ergodic X channel. This is achieved through using the notion of ergodic interference alignment technique. Accordingly, in the proposed method the transmitters do not require to know the full channel state information, while this assumption is the integral part of existing methods. Instead, a finite-rate feed-back channel is adequate to achieve the DoF. In other words, it is demonstrated that quantized versions of channel gains are adequate to achieve theDOF. To get an insight regarding the functionality of the proposed method, first we rely on finite field channel models, and then extend the terminology to more realistic cases, including dispersive fading channels in the presence of quantizer. Accordingly, in a Rayliegh fading environment, it is shown a feedback rate of 2log(p)+Theta(log(log(p))) can provide the DoF, where $p$ is the total transmit power.