Binary Matrices under the Microscope: A Tomographical Problem

A binary matrix can be scanned by moving a fixed rectangular window (submatrix) across it, rather like examining it closely under a microscope. With each viewing, a convenient measurement is the number of 1s visible in the window, which might be thought of as the luminosity of the window. The rectangular scan of the binary matrix is then the collection of these luminosities presented in matrix form. We show that, at least in the technical case of a smooth m x n binary matrix, it canbe reconstructed from its rectangular scan in polynomial time in the parameters m and n, where the degree of the polynomial depends on the size of the window of inspection. For an arbitrary binary matrix, we then extend this result by determining the entries in its rectangular scan that preclude the smoothness of the matrix.Comment: 25 pages, 15 figures, submitte

Activity In Vitro of Clotrimazole against Canine Methicillin-Resistant and Susceptible Staphylococcus pseudintermedius

Emergence of multidrug-resistance in Staphylococcus pseudintermedius (SP) has increased interest in topical therapy as an alternative to systemic antibiotics in canine pyoderma. The antifungal imidazole, clotrimazole, is contained in numerous licensed canine ear preparations. Its in vitro activity against SP has not been evaluated, although previous studies have shown that the related imidazole, miconazole, has significant anti-staphylococcal efficacy. We therefore determined minimum inhibitory concentrations (MICs) of clotrimazole amongst 50 SP isolates (25 methicillin-resistant [MR]SP and susceptible [MS]SP) collected from dogs in Germany during 2010–2011 using an agar dilution method (CLSI VET01-A4). MICs amongst MRSP and MSSP were comparable (MIC50 and MIC90 = 1mg/L for both groups, p = 0.317); overall, 49 isolates had MIC = 1 mg/L and one had MIC = 0.5 mg/L. The relatively low MICs obtained in this study are likely to be exceeded by topical therapy and thus further clinical evaluation of clotrimazole use in canine superficial pyoderma and otitis externa caused by MRSP and MSSP is now warranted

Measurement of the time alignment between muon detector and calorimeters with the 2008 cosmic runs

The aim of the note is to present some results concerning the time alignment between the LHCb Muon Detector and the Calorimeter system. The analysis is performed by computing the time residuals between the two detectors on a sample of cosmic muons acquired by the experiment during September 2008. To have a more detailed description of the current state of the time alignment, time residuals have been separated according to the station and region of the Muon Detector crossed by the cosmic rays. The estimated misalignment of the Muon Detector with respect to the Electromagnetic Calorimeter is about 4 - 7 ns while the misalignment with respect to the Hadronic Calorimeter is about 1 - 4 ns. Using the external time reference provided by the Calorimeters, the R4 region is found to be misaligned with respect to the other regions by about 2 - 3 ns. This behaviour has been seen to be independent both from the choice among Electromagnetic and Hadronic calorimeters, and from the calorimeter's region intercepted by the tracks

J/ψ production cross section and polarization with LHCb

Despite the large experimental and theoretical efforts, the J/ψ production rate and states in hadronic collisions are not yet satisfactorily understood. The comparison between the J/ψ differential cross section measurement and the most recent theoretical models shows a general good Agreement but it is still unsatisfactory. The double differential J/ψ cross section has been measured at LHCb with 5 pb−1 out of the 37 pb−1 data sample recorded during the 2010 data taking, disentangling the prompt component and the component coming from the b-hadrons decays. With the full data sample LHCb aims to give a measurement of the prompt J/ψ polarization with a full angular analysis, in both the polar and azimuthal angle

Prospects in quarkonium studies at LHCb

Quarkonium production mechanism is not yet completely understood. CDF data have demonstrated that both Colour Singlet and Octet Model fail to explain the production of quarkonium prompt component. LHCb has the possibility to explore a pseudo-rapidity range complementary to the other LHC and Tevatron experiments. In this paper the quarkonium program at LHCb will be presented, together with the prospects and the possible measurements

Analysis and design of innovative magnetic wedges for high efficiency permanent magnet synchronous machines

The global decarbonization targets require increasingly higher levels of efficiency from the designers of electrical machines. In this context, the opportunity to employ magnetic or semi-magnetic wedges in surface-mounted permanent magnet machines with fractional-slot concentrated winding has been evaluated in this paper, with the aim to reduce the power losses, especially in the magnets. Since an analytical calculation is not sufficient for this evaluation, finite element methods with two different software have been employed, by using a model experimentally validated on a real motor. The effects of wedges with different values of permeability and different magnetization characteristics have been evaluated on flux density, back electromotive force, and inductances, in order to choose the more suitable wedge for the considered motor. Furthermore, a new wedge consisting of different portions of materials with different magnetic permeability values is proposed. The effects of both conventional and unconventional magnetic wedges were assessed to optimize the motor performance in all working conditions

Combining Flexible Queries and Knowledge Anchors to facilitate the exploration of Knowledge Graphs

Semantic web and information extraction technologies are enabling the creation of vast information and knowledge repositories, particularly in the form of knowledge graphs comprising entities and the relationships between them. Users are often unfamiliar with the complex structure and vast content of such graphs. Hence, users need to be assisted by tools that support interactive exploration and flexible querying. In this paper we draw on recent work in flexible querying for graph-structured data and identifying good anchors for knowledge graph exploration in order to demonstrate how users can be supported in incrementally querying, exploring and learning from large complex knowledge graphs. We demonstrate our techniques through a case study in the domain of lifelong learning and career guidance

Comparing persistence diagrams through complex vectors

The natural pseudo-distance of spaces endowed with filtering functions is precious for shape classification and retrieval; its optimal estimate coming from persistence diagrams is the bottleneck distance, which unfortunately suffers from combinatorial explosion. A possible algebraic representation of persistence diagrams is offered by complex polynomials; since far polynomials represent far persistence diagrams, a fast comparison of the coefficient vectors can reduce the size of the database to be classified by the bottleneck distance. This article explores experimentally three transformations from diagrams to polynomials and three distances between the complex vectors of coefficients.Comment: 11 pages, 4 figures, 2 table