OpenRaiser/Intern-Atlas huggingface dataset:
Non-spatial Probabilistic Condorcet Election Methodology
Venue: arXiv cs.GT 2015
Year: 2015

There is a class of models for pol/mil/econ bargaining and conflict that is loosely based on the Median Voter Theorem which has been used with great success for about 30 years. However, there are fundamental mathematical limitations to these models. They apply to issues which can be represented on a single one-dimensional continuum. They represent fundamental group decision process by a deterministic Condorcet Election: deterministic voting by all actors, and deterministic outcomes of each vote. This work provides a methodology for addressing a broader class of problems. The first extension is to continuous issue sets where the consequences of policies are not well-described by a distance measure or utility is not monotonic in distance. The second fundamental extension is to inherently discrete issue sets. Because the options cannot easily be mapped into a multidimensional space so that the utility depends on distance, we refer to it as a non-spatial issue set. The third, but most fundamental, extension is to represent the negotiating process as a probabilistic Condorcet election (PCE). The actors' generalized voting is deterministic, but the outcomes of the votes is probabilistic. The PCE provides the flexibility to make the first two extensions possible; this flexibility comes at the cost of less precise predictions and more complex validation. The methodology has been implemented in two proof-of-concept prototypes which address the subset selection problem of forming a parliament, and strategy optimization for one-dimensional issues.
Relations between MDDs and Tuples and Dynamic Modifications of MDDs based constraints
Venue: arXiv cs.AI 2015
Year: 2015

We study the relations between Multi-valued Decision Diagrams (MDD) and tuples (i.e. elements of the Cartesian Product of variables). First, we improve the existing methods for transforming a set of tuples, Global Cut Seeds, sequences of tuples into MDDs. Then, we present some in-place algorithms for adding and deleting tuples from an MDD. Next, we consider an MDD constraint which is modified during the search by deleting some tuples. We give an algorithm which adapts MDD-4R to these dynamic and persistent modifications. Some experiments show that MDD constraints are competitive with Table constraints.
Notions of bidirectional computation and entangled state monads
Venue: arXiv cs.PL 2015
Year: 2015

Bidirectional transformations (bx) support principled consistency maintenance between data sources. Each data source corresponds to one perspective on a composite system, manifested by operations to 'get' and 'set' a view of the whole from that particular perspective. Bx are important in a wide range of settings, including databases, interactive applications, and model-driven development. We show that bx are naturally modelled in terms of mutable state; in particular, the 'set' operations are stateful functions. This leads naturally to considering bx that exploit other computational effects too, such as I/O, nondeterminism, and failure, all largely ignored in the bx literature to date. We present a semantic foundation for symmetric bidirectional transformations with effects. We build on the mature theory of monadic encapsulation of effects in functional programming, develop the equational theory and important combinators for effectful bx, and provide a prototype implementation in Haskell along with several illustrative examples.
Distributed Lustre activity tracking
Venue: arXiv cs.DC 2015
Year: 2015

Numerous administration tools and techniques require near real time vision of the activity occurring on a distributed filesystem. The changelog facility provided by Lustre to address this need suffers limitations in terms of scalability and flexibility. We have been working on reducing those limitations by enhancing Lustre itself and developing external tools such as Lustre ChangeLog Aggregate and Publish (LCAP) proxy. Beyond the ability to distribute changelog processing, this effort aims at opening new prospectives by making the changelog stream simpler to leverage for various purposes.
How Resilient Are Our Societies? Analyses, Models, and Preliminary Results
Venue: arXiv cs.OH 2015
Year: 2015

Traditional social organizations such as those for the management of healthcare and civil defence are the result of designs and realizations that matched well with an operational context considerably different from the one we are experiencing today: A simpler world, characterized by a greater amount of resources to match less users producing lower peaks of requests. The new context reveals all the fragility of our societies: unmanageability is just around the corner unless we do not complement the "old recipes" with smarter forms of social organization. Here we analyze this problem and propose a refinement to our fractal social organizations as a model for resilient cyber-physical societies. Evidence to our claims is provided by simulating our model in terms of multi-agent systems.
Benefit of Multipath TCP on the Stability of Network
Venue: arXiv cs.NI 2015
Year: 2015

Multipath-TCP receives a lot of attention recently and can potentially improve quality of service for both private and commercial users. It leverages the multiple available paths and send packets through all the available paths. The growing of Mutipath TCP has received a growing interest from both researchers who publish a growing number of articles on the topic and the vendors since Apple has decided to use Multipath TCP on its smartphones and tablets to support the Siri voice recognition application. In this paper, we study the performance of Multipath TCP from its impact on the stability of the network. In particular, we study three scenarios, Internet, which is the largest networks and involves heterogeneous traffic, data center, which is smaller but has different traffic patterns compared with Internet scale network and wireless network, whose energy consumption also needs to be considered. Our study shows that stability is affected but not seriouly for Internet and wireless network, but datacenter network stability is seriously affected due to its bursty traffic pattern.
On the Capacity of Narrowband PLC Channels
Venue: arXiv cs.IT 2015
Year: 2015

Power line communications (PLC) is the central communications technology for the realization of smart power grids. As the designated band for smart grid communications is the narrowband (NB) power line channel, NB-PLC has been receiving substantial attention in recent years. Narrowband power line channels are characterized by cyclic short-term variations of the channel transfer function (CTF) and strong noise with periodic statistics. In this work, modeling the CTF as a linear periodically time-varying filter and the noise as an additive cyclostationary Gaussian process, we derive the capacity of discrete-time NB-PLC channels. As part of the capacity derivation, we characterize the capacity achieving transmission scheme, which leads to a practical code construction that approaches capacity. The capacity derived in this work is numerically evaluated for several NB-PLC channel configurations taken from previous works, and the results show that the optimal scheme achieves a substantial rate gain over a previously proposed ad-hoc scheme. This gain is due to optimally accounting for the periodic properties of the channel and the noise.
Sum-Rate Maximizing Cell Association via Dual-Connectivity
Venue: arXiv cs.NI 2015
Year: 2015

This paper proposes a dual-connectivity (DC) profile allocation algorithm, in which a central macro base station (MBS) is underlaid with randomly scattered small base stations (SBSs), operating on different carrier frequencies. We introduce two dual-connectivity profiles and the differences among them. We utilize the characteristics of dual-connectivity profiles and their applying scenarios to reduce feasible combination set to consider. Algorithm analysis and numerical results verify that our proposed algorithm achieve the optimal algorithm's performance within 5 \% gap with quite low complexity up to $10^6$ times.
A Holant Dichotomy: Is the FKT Algorithm Universal?
Venue: arXiv cs.CC 2015
Year: 2015

We prove a complexity dichotomy for complex-weighted Holant problems with an arbitrary set of symmetric constraint functions on Boolean variables. This dichotomy is specifically to answer the question: Is the FKT algorithm under a holographic transformation a \emph{universal} strategy to obtain polynomial-time algorithms for problems over planar graphs that are intractable in general? This dichotomy is a culmination of previous ones, including those for Spin Systems, Holant, and #CSP. A recurring theme has been that a holographic reduction to FKT is a universal strategy. Surprisingly, for planar Holant, we discover new planar tractable problems that are not expressible by a holographic reduction to FKT. In previous work, an important tool was a dichotomy for #CSP^d, which denotes #CSP where every variable appears a multiple of d times. However its proof violates planarity. We prove a dichotomy for planar #CSP^2. We apply this planar #CSP^2 dichotomy in the proof of the planar Holant dichotomy. As a special case of our new planar tractable problems, counting perfect matchings (#PM) over k-uniform hypergraphs is polynomial-time computable when the incidence graph is planar and k >= 5. The same problem is #P-hard when k=3 or k=4, which is also a consequence of our dichotomy. When k=2, it becomes #PM over planar graphs and is tractable again. More generally, over hypergraphs with specified hyperedge sizes and the same planarity assumption, #PM is polynomial-time computable if the greatest common divisor of all hyperedge sizes is at least 5.
Knowledge Acquisition from Social Platforms Based on Network Distributions Fitting
Venue: arXiv cs.SI 2015
Year: 2015

The uniqueness of online social networks makes it possible to implement new methods that increase the quality and effectiveness of research processes. While surveys are one of the most important tools for research, the representativeness of selected online samples is often a challenge and the results are hardly generalizable. An approach based on surveys with representativeness targeted at network measure distributions is proposed and analysed in this paper. Its main goal is to focus not only on sample representativeness in terms of demographic attributes, but also to follow the measures distributions within main network. The approach presented has many application areas related to online research, sampling a network for the evaluation of collaborative learning processes, and candidate selection for training purposes with the ability to distribute information within a social network.
SFAMSS: a secure framework for atm machines via secret sharing
Venue: arXiv cs.CR 2015
Year: 2015

As ATM applications deploy for a banking system, the need to secure communications will become critical. However, multicast protocols do not fit the point-to-point model of most network security protocols which were designed with unicast communications in mind. In recent years, we have seen the emergence and the growing of ATMs (Automatic Teller Machines) in banking systems. Many banks are extending their activity and increasing transactions by using ATMs. ATM will allow them to reach more customers in a cost effective way and to make their transactions fast and efficient. However, communicating in the network must satisfy integrity, privacy, confidentiality, authentication and non-repudiation. Many frameworks have been implemented to provide security in communication and transactions. In this paper, we analyze ATM communication protocol and propose a novel framework for ATM systems that allows entities communicate in a secure way without using a lot of storage. We describe the architecture and operation of SFAMSS in detail. Our framework is implemented with Java and the software architecture, and its components are studied in detailed.
Self-Organization in Disaster Resilient Heterogeneous Small Cell Networks
Venue: arXiv cs.NI 2015
Year: 2015

Heterogeneous small cell networks with overlay femtocells and macrocell is a promising solution for future heterogeneous wireless cellular communications. However, great resilience is needed in heterogeneous small cells in case of accidents, attacks and natural disasters. In this article, we first describe the network architecture of disaster resilient heterogeneous small cell networks (DRHSCNs), where several self-organization inspired approaches are applied. Based on the proposed resilient heterogeneous small cell network architecture, self-configuring (power, physical cell ID and neighbor cell list self-configuration) and self-optimizing (coverage and capacity optimization and mobility robustness optimization) techniques are investigated in the DRHSCN. Simulation results show that self-configuration and self-optimization can effectively improve the performance of the deployment and operation of the small cell networks in disaster scenarios.
Time Localization and Capacity of Faster-Than-Nyquist Signaling
Venue: arXiv cs.IT 2015
Year: 2015

In this paper, we consider communication over the bandwidth limited analog white Gaussian noise channel using non-orthogonal pulses. In particular, we consider non-orthogonal transmission by signaling samples at a rate higher than the Nyquist rate. Using the faster-than-Nyquist (FTN) framework, Mazo showed that one may transmit symbols carried by sinc pulses at a higher rate than that dictated by Nyquist without loosing bit error rate. However, as we will show in this paper, such pulses are not necessarily well localized in time. In fact, assuming that signals in the FTN framework are well localized in time, one can construct a signaling scheme that violates the Shannon capacity bound. We also show directly that FTN signals are in general not well localized in time. Therefore, the results of Mazo do not imply that one can transmit more data per time unit without degrading performance in terms of error probability. We also consider FTN signaling in the case of pulses that are different from the sinc pulses. We show that one can use a precoding scheme of low complexity to remove the inter-symbol interference. This leads to the possibility of increasing the number of transmitted samples per time unit and compensate for spectral inefficiency due to signaling at the Nyquist rate of the non sinc pulses. We demonstrate the power of the precoding scheme by simulations.
New economy: from crisis of dot-coms to virtual business
Venue: arXiv cs.CY 2015
Year: 2015

Article about objective regularity and mechanisms of formation of network economy in the conditions of crisis of «new economy». The network economy is considered as a basis of a following business cycle. The author analyzes features of institutional transformation of economic relations under the influence of development of cloudy technologies and the virtual organizations.
A parallel edge orientation algorithm for quadrilateral meshes
Venue: arXiv cs.MS 2015
Year: 2015

One approach to achieving correct finite element assembly is to ensure that the local orientation of facets relative to each cell in the mesh is consistent with the global orientation of that facet. Rognes et al. have shown how to achieve this for any mesh composed of simplex elements, and deal.II contains a serial algorithm to construct a consistent orientation of any quadrilateral mesh of an orientable manifold. The core contribution of this paper is the extension of this algorithm for distributed memory parallel computers, which facilitates its seamless application as part of a parallel simulation system. Furthermore, our analysis establishes a link between the well-known Union-Find algorithm and the construction of a consistent orientation of a quadrilateral mesh. As a result, existing work on the parallelisation of the Union-Find algorithm can be easily adapted to construct further parallel algorithms for mesh orientations.
Identifiability in Blind Deconvolution with Subspace or Sparsity Constraints
Venue: arXiv cs.IT 2015
Year: 2015

Blind deconvolution (BD), the resolution of a signal and a filter given their convolution, arises in many applications. Without further constraints, BD is ill-posed. In practice, subspace or sparsity constraints have been imposed to reduce the search space, and have shown some empirical success. However, existing theoretical analysis on uniqueness in BD is rather limited. As an effort to address the still mysterious question, we derive sufficient conditions under which two vectors can be uniquely identified from their circular convolution, subject to subspace or sparsity constraints. These sufficient conditions provide the first algebraic sample complexities for BD. We first derive a sufficient condition that applies to almost all bases or frames. For blind deconvolution of vectors in $\mathbb{C}^n$, with two subspace constraints of dimensions $m_1$ and $m_2$, the required sample complexity is $n\geq m_1m_2$. Then we impose a sub-band structure on one basis, and derive a sufficient condition that involves a relaxed sample complexity $n\geq m_1+m_2-1$, which we show to be optimal. We present the extensions of these results to BD with sparsity constraints or mixed constraints, with the sparsity level replacing the subspace dimension. The cost for the unknown support in this case is an extra factor of 2 in the sample complexity.
Symbolic-numeric methods for improving structural analysis of differential-algebraic equation systems
Venue: arXiv cs.SC 2015
Year: 2015

Systems of differential-algebraic equations (DAEs) are generated routinely by simulation and modeling environments such as Modelica and MapleSim. Before a simulation starts and a numerical solution method is applied, some kind of structural analysis is performed to determine the structure and the index of a DAE. Structural analysis methods serve as a necessary preprocessing stage, and among them, Pantelides's algorithm is widely used. Recently Pryce's $Σ$-method is becoming increasingly popular, owing to its straightforward approach and capability of analyzing high-order systems. Both methods are equivalent in the sense that when one succeeds, producing a nonsingular system Jacobian, the other also succeeds, and the two give the same structural index. Although provably successful on fairly many problems of interest, the structural analysis methods can fail on some simple, solvable DAEs and give incorrect structural information including the index. In this report, we focus on the $Σ$-method. We investigate its failures, and develop two symbolic-numeric conversion methods for converting a DAE, on which the $Σ$-method fails, to an equivalent problem on which this method succeeds. Aimed at making structural analysis methods more reliable, our conversion methods exploit structural information of a DAE, and require a symbolic tool for their implementation.
CAT2000: A Large Scale Fixation Dataset for Boosting Saliency Research
Venue: arXiv cs.CV 2015
Year: 2015

Saliency modeling has been an active research area in computer vision for about two decades. Existing state of the art models perform very well in predicting where people look in natural scenes. There is, however, the risk that these models may have been overfitting themselves to available small scale biased datasets, thus trapping the progress in a local minimum. To gain a deeper insight regarding current issues in saliency modeling and to better gauge progress, we recorded eye movements of 120 observers while they freely viewed a large number of naturalistic and artificial images. Our stimuli includes 4000 images; 200 from each of 20 categories covering different types of scenes such as Cartoons, Art, Objects, Low resolution images, Indoor, Outdoor, Jumbled, Random, and Line drawings. We analyze some basic properties of this dataset and compare some successful models. We believe that our dataset opens new challenges for the next generation of saliency models and helps conduct behavioral studies on bottom-up visual attention.
A Subset Selection Algorithm for Wireless Sensor Networks
Venue: arXiv cs.IT 2015
Year: 2015

One of the main challenges facing wireless sensor networks (WSNs) is the limited power resources available at small sensor nodes. It is therefore desired to reduce the power consumption of sensors while keeping the distortion between the source information and its estimate at the fusion centre (FC) below a specific threshold. In this paper, given the channel state information at the FC, we propose a subset selection algorithm of sensor nodes to reduce the average transmission power of the WSN. We assume the channels between the source and the sensors to be correlated fading channels, modeled by the Gilbert-Elliott model. We show that when these channels are known at the FC, a subset of sensors can be selected by the FC such that the received observations from this subset is sufficient to estimate the source information at the FC while maintaining the distortion between source information and its estimate below a specific threshold. Through analyses, we find the probability distribution of the size of this subset and provide results to evaluate the power efficiency of our proposed algorithm.
Massive MIMO with Multi-cell MMSE Processing: Exploiting All Pilots for Interference Suppression
Venue: arXiv cs.IT 2015
Year: 2015

In this paper, a new state-of-the-art multi-cell MMSE scheme is proposed for massive MIMO networks, which includes an uplink MMSE detector and a downlink MMSE precoder. The main novelty is that it exploits all available pilots for interference suppression. Specifically, let $K$ and $B$ denote the number of users per cell and the number of orthogonal pilot sequences in the network, respectively, where $β= B/K$ is the pilot reuse factor. Then our multi-cell MMSE scheme utilizes all $B$ channel directions, that can be estimated locally at each base station, to actively suppress both intra-cell and inter-cell interference. The proposed scheme is particularly practical and general, since power control for the pilot and payload, imperfect channel estimation and arbitrary pilot allocation are all accounted for. Simulations show that significant spectral efficiency (SE) gains are obtained over the single-cell MMSE scheme and the multi-cell ZF, particularly for large $β$ and/or $K$. Furthermore, large-scale approximations of the uplink and downlink SINRs are derived, which are asymptotically tight in the large-system limit. The approximations are easy to compute and very accurate even for small system dimensions. Using these SINR approximations, a low-complexity power control algorithm is also proposed to maximize the sum SE.
Parse Concurrent Data Structures: BST as an Example
Venue: arXiv cs.DC 2015
Year: 2015

Designing concurrent data structures should follow some basic rules. By separating the algorithms into two phases, we present guidelines for scalable data structures, with a analysis model based on the Amadal's law. To the best of our knowledge, we are the first to formalize a practical model for measuring concurrent structures' speedup. We also build some edge-cutting BSTs following our principles, testing them under different workloads. The result provides compelling evidence to back the our guidelines, and shows that our theory is useful for reasoning the varied speedup.