OpenRaiser/Intern-Atlas huggingface dataset:
DAG-Based Attack and Defense Modeling: Don't Miss the Forest for the Attack Trees
Venue: arXiv cs.CR 2013
Year: 2013

This paper presents the current state of the art on attack and defense modeling approaches that are based on directed acyclic graphs (DAGs). DAGs allow for a hierarchical decomposition of complex scenarios into simple, easily understandable and quantifiable actions. Methods based on threat trees and Bayesian networks are two well-known approaches to security modeling. However there exist more than 30 DAG-based methodologies, each having different features and goals. The objective of this survey is to present a complete overview of graphical attack and defense modeling techniques based on DAGs. This consists of summarizing the existing methodologies, comparing their features and proposing a taxonomy of the described formalisms. This article also supports the selection of an adequate modeling technique depending on user requirements.
Measuring Similarity Between Curves on 2-Manifolds via Homotopy Area
Venue: arXiv cs.CG 2013
Year: 2013

Measuring the similarity of curves is a fundamental problem arising in many application fields. There has been considerable interest in several such measures, both in Euclidean space and in more general setting such as curves on Riemannian surfaces or curves in the plane minus a set of obstacles. However, so far, efficiently computable similarity measures for curves on general surfaces remain elusive. This paper aims at developing a natural curve similarity measure that can be easily extended and computed for curves on general orientable 2-manifolds. Specifically, we measure similarity between homotopic curves based on how hard it is to deform one curve into the other one continuously, and define this "hardness" as the minimum possible surface area swept by a homotopy between the curves. We consider cases where curves are embedded in the plane or on a triangulated orientable surface with genus $g$, and we present efficient algorithms (which are either quadratic or near linear time, depending on the setting) for both cases.
Optimizing Throughput on Guaranteed-Bandwidth WAN Networks for the Large Synoptic Survey Telescope (LSST)
Venue: arXiv cs.NI 2013
Year: 2013

The Large Synoptic Survey Telescope (LSST) is a proposed 8.4-meter telescope that will be located in the Andes mountains in Chile. Every 17 seconds, a 6.4 GB image is transferred to Illinois for immediate processing. That transfer needs to complete within approximately five seconds. LSST is provisioning an international WAN with a 10Gbps bandwidth guarantee for this and other project-related data transfers. The stringent latency requirement drives a re-examination of TCP congestion control for this use case. Specifically, prior work on dedicated Long Fat Networks (LFNs) does not go far enough in fully leveraging the opportunity provided by the bandwidth guarantee. This paper presents an approach for how optimal network throughput can be obtained for the LSST use case, and the conditions under which any project can achieve data throughput rates on long-distance networks approaching wire speed.
Translation-Invariant Shrinkage/Thresholding of Group Sparse Signals
Venue: arXiv cs.CV 2013
Year: 2013

This paper addresses signal denoising when large-amplitude coefficients form clusters (groups). The L1-norm and other separable sparsity models do not capture the tendency of coefficients to cluster (group sparsity). This work develops an algorithm, called 'overlapping group shrinkage' (OGS), based on the minimization of a convex cost function involving a group-sparsity promoting penalty function. The groups are fully overlapping so the denoising method is translation-invariant and blocking artifacts are avoided. Based on the principle of majorization-minimization (MM), we derive a simple iterative minimization algorithm that reduces the cost function monotonically. A procedure for setting the regularization parameter, based on attenuating the noise to a specified level, is also described. The proposed approach is illustrated on speech enhancement, wherein the OGS approach is applied in the short-time Fourier transform (STFT) domain. The denoised speech produced by OGS does not suffer from musical noise.
Entanglement Zoo II: Examples in Physics and Cognition
Venue: arXiv cs.AI 2013
Year: 2013

We have recently presented a general scheme enabling quantum modeling of different types of situations that violate Bell's inequalities. In this paper, we specify this scheme for a combination of two concepts. We work out a quantum Hilbert space model where 'entangled measurements' occur in addition to the expected 'entanglement between the component concepts', or 'state entanglement'. We extend this result to a macroscopic physical entity, the 'connected vessels of water', which maximally violates Bell's inequalities. We enlighten the structural and conceptual analogies between the cognitive and physical situations which are both examples of a nonlocal non-marginal box modeling in our classification.
Meaning-focused and Quantum-inspired Information Retrieval
Venue: arXiv cs.IR 2013
Year: 2013

In recent years, quantum-based methods have promisingly integrated the traditional procedures in information retrieval (IR) and natural language processing (NLP). Inspired by our research on the identification and application of quantum structures in cognition, more specifically our work on the representation of concepts and their combinations, we put forward a 'quantum meaning based' framework for structured query retrieval in text corpora and standardized testing corpora. This scheme for IR rests on considering as basic notions, (i) 'entities of meaning', e.g., concepts and their combinations and (ii) traces of such entities of meaning, which is how documents are considered in this approach. The meaning content of these 'entities of meaning' is reconstructed by solving an 'inverse problem' in the quantum formalism, consisting of reconstructing the full states of the entities of meaning from their collapsed states identified as traces in relevant documents. The advantages with respect to traditional approaches, such as Latent Semantic Analysis (LSA), are discussed by means of concrete examples.
Finding a largest empty convex subset in space is W[1]-hard
Venue: arXiv cs.CG 2013
Year: 2013

We consider the following problem: Given a point set in space find a largest subset that is in convex position and whose convex hull is empty. We show that the (decision version of the) problem is W[1]-hard.
An optimal problem for relative entropy
Venue: arXiv cs.IT 2013
Year: 2013

Relative entropy is an essential tool in quantum information theory. There are so many problems which are related to relative entropy. In this article, the optimal values which are defined by $\displaystyle\max_{U\in{U(\cX_{d})}} S(Uρ{U^{\ast}}\parallelσ)$ and $\displaystyle\min_{U\in{U(\cX_{d})}} S(Uρ{U^{\ast}}\parallelσ)$ for two positive definite operators $ρ,σ\in{\textmd{Pd}(\cX)}$ are obtained. And the set of $S(Uρ{U^{\ast}}\parallelσ)$ for every unitary operator $U$ is full of the interval $[\displaystyle\min_{U\in{U(\cX_{d})}} S(Uρ{U^{\ast}}\parallelσ),\displaystyle\max_{U\in{U(\cX_{d})}} S(Uρ{U^{\ast}}\parallelσ)]$
First and High Order Sliding Mode-Multimodel Stabilizing Control Synthesis using Single and Several Sliding Surfaces for Nonlinear Systems: Simulation on an Autonomous Underwater Vehicles (AUV)
Venue: arXiv cs.SY 2013
Year: 2013

This paper provides new analytic tools for a rigorous control formulation and stability analysis of sliding mode-multimodel controller (SM-MMC). In this way to minimise the chattering effect we will adopt as a starting point the multimodel approach to change the commutation of the sliding mode control (SMC) into fusion using a first order then a high order sliding mode control with single sliding surface and, then, with several sliding surfaces. For that the stability conditions invoke the existence of two Lyapunov-type functions, the first associated to the passage to the sliding set in finite time, and the second with convergence to the desired state. The approaches presented in this work are simulated on the immersion control of a submarine mobile which presents a problem for the actuators because of the high level of system non linearity and because of the external disturbances. Simulation results show that this control strategy can attain excellent performances with no chattering problem and low control level.
The Smartphone Brain Scanner: A Mobile Real-time Neuroimaging System
Venue: arXiv cs.HC 2013
Year: 2013

Combining low cost wireless EEG sensors with smartphones offers novel opportunities for mobile brain imaging in an everyday context. We present a framework for building multi-platform, portable EEG applications with real-time 3D source reconstruction. The system - Smartphone Brain Scanner - combines an off-the-shelf neuroheadset or EEG cap with a smartphone or tablet, and as such represents the first fully mobile system for real-time 3D EEG imaging. We discuss the benefits and challenges of a fully portable system, including technical limitations as well as real-time reconstruction of 3D images of brain activity. We present examples of the brain activity captured in a simple experiment involving imagined finger tapping, showing that the acquired signal in a relevant brain region is similar to that obtained with standard EEG lab equipment. Although the quality of the signal in a mobile solution using a off-the-shelf consumer neuroheadset is lower compared to that obtained using high density standard EEG equipment, we propose that mobile application development may offset the disadvantages and provide completely new opportunities for neuroimaging in natural settings.
Stroke-Based Cursive Character Recognition
Venue: arXiv cs.CV 2013
Year: 2013

Human eye can see and read what is written or displayed either in natural handwriting or in printed format. The same work in case the machine does is called handwriting recognition. Handwriting recognition can be broken down into two categories: off-line and on-line. ...
Algorithms for Routing an Unmanned Aerial Vehicle in the presence of Refueling Depots
Venue: arXiv cs.DS 2013
Year: 2013

We consider a single Unmanned Aerial Vehicle (UAV) routing problem where there are multiple depots and the vehicle is allowed to refuel at any depot. The objective of the problem is to find a path for the UAV such that each target is visited at least once by the vehicle, the fuel constraint is never violated along the path for the UAV, and the total fuel required by the UAV is a minimum. We develop an approximation algorithm for the problem, and propose fast construction and improvement heuristics to solve the same. Computational results show that solutions whose costs are on an average within 1.4% of the optimum can be obtained relatively fast for the problem involving 5 depots and 25 targets.
A Fast Algorithm for Well-Spaced Points and Approximate Delaunay Graphs
Venue: arXiv cs.CG 2013
Year: 2013

We present a new algorithm that produces a well-spaced superset of points conforming to a given input set in any dimension with guaranteed optimal output size. We also provide an approximate Delaunay graph on the output points. Our algorithm runs in expected time $O(2^{O(d)}(n\log n + m))$, where $n$ is the input size, $m$ is the output point set size, and $d$ is the ambient dimension. The constants only depend on the desired element quality bounds. To gain this new efficiency, the algorithm approximately maintains the Voronoi diagram of the current set of points by storing a superset of the Delaunay neighbors of each point. By retaining quality of the Voronoi diagram and avoiding the storage of the full Voronoi diagram, a simple exponential dependence on $d$ is obtained in the running time. Thus, if one only wants the approximate neighbors structure of a refined Delaunay mesh conforming to a set of input points, the algorithm will return a size $2^{O(d)}m$ graph in $2^{O(d)}(n\log n + m)$ expected time. If $m$ is superlinear in $n$, then we can produce a hierarchically well-spaced superset of size $2^{O(d)}n$ in $2^{O(d)}n\log n$ expected time.
Massive MIMO and Small Cells: Improving Energy Efficiency by Optimal Soft-Cell Coordination
Venue: arXiv cs.IT 2013
Year: 2013

To improve the cellular energy efficiency, without sacrificing quality-of-service (QoS) at the users, the network topology must be densified to enable higher spatial reuse. We analyze a combination of two densification approaches, namely "massive" multiple-input multiple-output (MIMO) base stations and small-cell access points. If the latter are operator-deployed, a spatial soft-cell approach can be taken where the multiple transmitters serve the users by joint non-coherent multiflow beamforming. We minimize the total power consumption (both dynamic emitted power and static hardware power) while satisfying QoS constraints. This problem is proved to have a hidden convexity that enables efficient solution algorithms. Interestingly, the optimal solution promotes exclusive assignment of users to transmitters. Furthermore, we provide promising simulation results showing how the total power consumption can be greatly improved by combining massive MIMO and small cells; this is possible with both optimal and low-complexity beamforming.
A Novel Network Coded Parallel Transmission Framework for High-Speed Ethernet
Venue: arXiv cs.NI 2013
Year: 2013

Parallel transmission, as defined in high-speed Ethernet standards, enables to use less expensive optoelectronics and offers backwards compatibility with legacy Optical Transport Network (OTN) infrastructure. However, optimal parallel transmission does not scale to large networks, as it requires computationally expensive multipath routing algorithms to minimize differential delay, and thus the required buffer size, optimize traffic splitting ratio, and ensure frame synchronization. In this paper, we propose a novel framework for high-speed Ethernet, which we refer to as network coded parallel transmission, capable of effective buffer management and frame synchronization without the need for complex multipath algorithms in the OTN layer. We show that using network coding can reduce the delay caused by packet reordering at the receiver, thus requiring a smaller overall buffer size, while improving the network throughput. We design the framework in full compliance with high-speed Ethernet standards specified in IEEE802.3ba and present solutions for network encoding, data structure of coded parallel transmission, buffer management and decoding at the receiver side. The proposed network coded parallel transmission framework is simple to implement and represents a potential major breakthrough in the system design of future high-speed Ethernet.
Decentralized Synchronization for Wireless Sensor Networks
Venue: arXiv cs.NI 2013
Year: 2013

Due to their heavy restrictions on the hardware side, Wireless Sensor Networks (WSN) require specially adapted synchronization protocols to maximize measurement precision and minimize computation efforts and energy costs. A promising approach is given by the 'Firefly Protocol'. Inspired by the behavior of fireflies it is intrinsically robust, specific to the wireless broadcast nature of WSNs and promises high precision. So far only theoretically evaluated, this thesis implements the 'Firefly Protocol' on a system of MICAz Berkeley motes using TinyOS 2.x. In order to implement the theoretical framework on actual hardware, several adaptations were made to compensate hardware delays. Although Berkeley motes have the advantage of being readily available and highly flexible, they bear many delay sources which have to be addressed. In small networks, the protocol was found to deliver precisions up to three microseconds over one hop.
On the Performance of Adaptive Modulation in Cognitive Radio Networks
Venue: arXiv cs.NI 2013
Year: 2013

We study the performance of cognitive radio networks (CRNs) when incorporating adaptive modulation at the physical layer. Three types of CRNs are considered, namely opportunistic spectrum access (OSA), spectrum sharing (SS) and sensing-based SS. We obtain closed-form expressions for the average spectral efficiency achieved at the secondary network and the optimal power allocation for both continuous and discrete rate types of adaptive modulation assuming perfect channel state information. The obtained numerical results show the achievable performance gain in terms of average spectral efficiency and the impact on power allocation when adaptive modulation is implemented at the physical layer that is due to the effect of the cut-off level that is determined from the received signal-to-noise ratio for each CRN type. The performance assessment is taking place for different target bit error rate values and fading regions, thereby providing useful performance insights for various possible implementations.
Multiscale Hybrid Non-local Means Filtering Using Modified Similarity Measure
Venue: arXiv cs.CV 2013
Year: 2013

A new multiscale implementation of non-local means filtering for image denoising is proposed. The proposed algorithm also introduces a modification of similarity measure for patch comparison. The standard Euclidean norm is replaced by weighted Euclidean norm for patch based comparison. Assuming the patch as an oriented surface, notion of normal vector patch is being associated with each patch. The inner product of these normal vector patches is then used in weighted Euclidean distance of photometric patches as the weight factor. The algorithm involves two steps: The first step is multiscale implementation of an accelerated non-local means filtering in the stationary wavelet domain to obtain a refined version of the noisy patches for later comparison. This step is inspired by a preselection phase of finding similar patches in various non-local means approaches. The next step is to apply the modified non-local means filtering to the noisy image using the reference patches obtained in the first step. These refined patches contain less noise, and consequently the computation of normal vectors and partial derivatives is more accurate. Experimental results indicate equivalent or better performance of proposed algorithm as compared to various state of the art algorithms.
Coalitional Manipulation for Schulze's Rule
Venue: arXiv cs.AI 2013
Year: 2013

Schulze's rule is used in the elections of a large number of organizations including Wikimedia and Debian. Part of the reason for its popularity is the large number of axiomatic properties, like monotonicity and Condorcet consistency, which it satisfies. We identify a potential shortcoming of Schulze's rule: it is computationally vulnerable to manipulation. In particular, we prove that computing an unweighted coalitional manipulation (UCM) is polynomial for any number of manipulators. This result holds for both the unique winner and the co-winner versions of UCM. This resolves an open question stated by Parkes and Xia (2012). We also prove that computing a weighted coalitional manipulation (WCM) is polynomial for a bounded number of candidates. Finally, we discuss the relation between the unique winner UCM problem and the co-winner UCM problem and argue that they have substantially different necessary and sufficient conditions for the existence of a successful manipulation.
C Language Extensions for Hybrid CPU/GPU Programming with StarPU
Venue: arXiv cs.MS 2013
Year: 2013

Modern platforms used for high-performance computing (HPC) include machines with both general-purpose CPUs, and "accelerators", often in the form of graphical processing units (GPUs). StarPU is a C library to exploit such platforms. It provides users with ways to define "tasks" to be executed on CPUs or GPUs, along with the dependencies among them, and by automatically scheduling them over all the available processing units. In doing so, it also relieves programmers from the need to know the underlying architecture details: it adapts to the available CPUs and GPUs, and automatically transfers data between main memory and GPUs as needed. While StarPU's approach is successful at addressing run-time scheduling issues, being a C library makes for a poor and error-prone programming interface. This paper presents an effort started in 2011 to promote some of the concepts exported by the library as C language constructs, by means of an extension of the GCC compiler suite. Our main contribution is the design and implementation of language extensions that map to StarPU's task programming paradigm. We argue that the proposed extensions make it easier to get started with StarPU,eliminate errors that can occur when using the C library, and help diagnose possible mistakes. We conclude on future work.
Structures Without Scattered-Automatic Presentation
Venue: arXiv cs.FL 2013
Year: 2013

Bruyere and Carton lifted the notion of finite automata reading infinite words to finite automata reading words with shape an arbitrary linear order L. Automata on finite words can be used to represent infinite structures, the so-called word-automatic structures. Analogously, for a linear order L there is the class of L-automatic structures. In this paper we prove the following limitations on the class of L-automatic structures for a fixed L of finite condensation rank 1+α. Firstly, no scattered linear order with finite condensation rank above ω^(α+1) is L-α-automatic. In particular, every L-automatic ordinal is below ω^ω^(α+1). Secondly, we provide bounds on the (ordinal) height of well-founded order trees that are L-automatic. If αis finite or L is an ordinal, the height of such a tree is bounded by ω^{α+1}. Finally, we separate the class of tree-automatic structures from that of L-automatic structures for any ordinal L: the countable atomless boolean algebra is known to be tree-automatic, but we show that it is not L-automatic.
Conditional Tables in practice
Venue: arXiv cs.DB 2013
Year: 2013

Due to the ever increasing importance of the internet, interoperability of heterogeneous data sources is as well of ever increasing importance. Interoperability can be achieved e.g. through data integration and data exchange. Common to both approaches is the need for the DBMS to be able to store and query incomplete databases. In this report we present PossDB, a DBMS capable of storing and querying incomplete databases. The system is wrapper over PostgreSQL, and the query language is an extension of a subset of standard SQL. Our experimental results show that our system scales well, actually better than comparable systems.
Quantum Cryptography Using Various Reversible Quantum Logic Gates in WSNs
Venue: arXiv cs.CR 2013
Year: 2013

As sensor nodes are deployed anywhere in a wireless sensor network, hence their communication can be easily monitored. In these networks, message protection and node identification are very issues. Hence, security of large scale such networks requires efficient key distribution and management mechanisms. Quantum cryptography and particularly quantum key distribution is such a technique that allocates secure keys only for short distances. While not completely secure, it offers huge advantages over traditional methods by the use of entanglement swapping and quantum teleportation. Reversible logic gates like CNOT, Toffoli, Fredkin etc. are of basic importance in Quantum Computing. In our research, we adopted a EPR-pair allocation scheme in terms of these quantum gates to overcome the susceptibility caused by malicious nodes. As the qubits stored in a sensor node can be used only once and cannot be duplicated, hence risk of information leakage reduced even if the node are compromised.