Consensus Message Passing for Layered Graphical Models

Generative models provide a powerful framework for probabilistic reasoning. However, in many domains their use has been hampered by the practical difficulties of inference. This is particularly the case in computer vision, where models of the imaging process tend to be large, loopy and layered. For this reason bottom-up conditional models have traditionally dominated in such domains. We find that widely-used, general-purpose message passing inference algorithms such as Expectation Propagation (EP) and Variational Message Passing (VMP) fail on the simplest of vision models. With these models in mind, we introduce a modification to message passing that learns to exploit their layered structure by passing 'consensus' messages that guide inference towards good solutions. Experiments on a variety of problems show that the proposed technique leads to significantly more accurate inference results, not only when compared to standard EP and VMP, but also when compared to competitive bottom-up conditional models.Comment: Appearing in Proceedings of the 18th International Conference on Artificial Intelligence and Statistics (AISTATS) 201

Integrating e-commerce standards and initiatives in a multi-layered ontology

The proliferation of different standards and joint initiatives for the classification of products and services (UNSPSC, e-cl@ss, RosettaNet, NAICS, SCTG, etc.) reveals that B2B markets have not reached a consensus on the coding systems, on the level of detail of their descriptions, on their granularity, etc. This paper shows how these standards and initiatives, which are built to cover different needs and functionalities, can be integrated in an ontology using a common multi-layered knowledge architecture. This multi-layered ontology will provide a shared understanding of the domain for applications of e-commerce, allowing the information sharing between heterogeneous systems. We will present a method for designing ontologies from these information sources by automatically transforming, integrating and enriching the existing vocabularies with the WebODE platform. As an illustration, we show an example on the computer domain, presenting the relationships between UNSPSC, e-cl@ss, RosettaNet and an electronic catalogue from an e-commerce platform

Dual Regulation, Collaborative Management or Layered Federalism: Can Cooperative Federalism Models From Other Laws Save Our Public Lands?

Few would assert that the current governance model for managing the nation\u27s public lands, which grants exclusive authority to the federal government, has protected the natural resource values of those lands or provided a framework for the harmonious resolution of conflicts over their use. Dissatisfaction is apparent from recurrent proposals to privatize public lands or to devolve their ownership to the states. The emergence of the wise use and county supremacy movements directly challenges the authority of the federal government to manage its land. While this new state and local assertiveness is not without historical basis nor completely without merit, its proponents have yet to offer a workable solution other than complete ouster of the federal sovereign

c-Axis Phase Coherence and Spin Fluctuations in Cuprates

There is a consensus that superconductivity (SC) in cuprates is two-dimensional. It is widely believed that the long-range phase coherence appears at T_{c} due to the Josephson coupling between SC CuO_{2} (bi-, tri-, >...)layers. Recent T_{c} and resistivity measurements in Tl2212 as a function of applied pressure (Salvetat J.-P. et al., Europhys. Lett., 52 (2000) 584) show that the interlayer Josephson-coupling mechanism does not fit the data. Here we analyze data obtained in Andreev reflection, neutron scattering, microwave, muon spin relaxation, tunneling and resistivity measurements performed on different cuprates, mainly, on YBCO, Bi2212 and LSCO. The analysis of the data shows that the long-range phase coherence in the cuprates intimately relates to antiferromagnetic interactions along the c axis. At the same time, it seems that the in-plane mechanism of the SC has no or little relations to the magnetic interactions along the c axis.Comment: 5 pages including 3 figures, Europhys. Let

Towards a Layered Architectural View for Security Analysis in SCADA Systems

Supervisory Control and Data Acquisition (SCADA) systems support and control the operation of many critical infrastructures that our society depend on, such as power grids. Since SCADA systems become a target for cyber attacks and the potential impact of a successful attack could lead to disastrous consequences in the physical world, ensuring the security of these systems is of vital importance. A fundamental prerequisite to securing a SCADA system is a clear understanding and a consistent view of its architecture. However, because of the complexity and scale of SCADA systems, this is challenging to acquire. In this paper, we propose a layered architectural view for SCADA systems, which aims at building a common ground among stakeholders and supporting the implementation of security analysis. In order to manage the complexity and scale, we define four interrelated architectural layers, and uses the concept of viewpoints to focus on a subset of the system. We indicate the applicability of our approach in the context of SCADA system security analysis.Comment: 7 pages, 4 figure

A new genus, Desertispora, and a new species, Diversispora sabulosa, in the family Diversisporaceae (order Diversisporales, subphylum Glomeromycotina)

Phylogenetic analyses of sequences of the SSU-ITS-LSU nrDNA segment and the RPB1 gene showed that the arbuscular mycorrhizal fungus originally described as Diversispora omaniana does not belong to the genus Diversispora, but represents a separate clade at the rank of genus in the family Diversisporaceae of the order Diversisporales. The closest natural relatives of the fungus proved to be species of the genera Corymbiglomus and Redeckera. Consequently, the new genus was named Desertispora, and Di. omaniana was renamed De. omaniana comb. nov. In addition, the morphological and histochemical features of spores and mycorrhizal structures of a new Diversispora sp., Di. sabulosa, were described and the closest relatives of the species were determined based on phylogenetic analyses of sequences of the two loci mentioned above. The new fungus was grown in single-species cultures established from spores extracted from a trap culture inoculated with a mixture of the rhizosphere soil and root fragments of Ammophila arenaria that had colonized maritime sand dunes of the Curonian Spit located in the north of Lithuania. Diversispora sabulosa was never found before in many different sites of the world which were sampled during the last 34 years by the last author of the paper. Also, the lack of molecular sequences in public databases of identity ≥ 97% to sequences of Di. sabulosa suggests that the fungus is rare on the Earth

Chimera order in spin systems

Homogeneous populations of oscillators have recently been shown to exhibit stable coexistence of coherent and incoherent regions. Generalizing the concept of chimera states to the context of order-disorder transition in systems at thermal equilibrium, we show analytically that such complex ordering can appear in a system of Ising spins, possibly the simplest physical system exhibiting this phenomenon. We also show numerically the existence of chimera ordering in 3-dimensional spin systems that model layered magnetic materials, suggesting possible means of experimentally observing such states.Comment: 5 pages, 3 figure

Implementation of UAV Coordination Based on a Hierarchical Multi-UAV Simulation Platform

In this paper, a hierarchical multi-UAV simulation platform,called XTDrone, is designed for UAV swarms, which is completely open-source 4 . There are six layers in XTDrone: communication, simulator,low-level control, high-level control, coordination, and human interac-tion layers. XTDrone has three advantages. Firstly, the simulation speedcan be adjusted to match the computer performance, based on the lock-step mode. Thus, the simulations can be conducted on a work stationor on a personal laptop, for different purposes. Secondly, a simplifiedsimulator is also developed which enables quick algorithm designing sothat the approximated behavior of UAV swarms can be observed inadvance. Thirdly, XTDrone is based on ROS, Gazebo, and PX4, andhence the codes in simulations can be easily transplanted to embeddedsystems. Note that XTDrone can support various types of multi-UAVmissions, and we provide two important demos in this paper: one is aground-station-based multi-UAV cooperative search, and the other is adistributed UAV formation flight, including consensus-based formationcontrol, task assignment, and obstacle avoidance.Comment: 12 pages, 10 figures. And for the, see https://gitee.com/robin_shaun/XTDron