676 research outputs found

    2D multi-objective placement algorithm for free-form components

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    This article presents a generic method to solve 2D multi-objective placement problem for free-form components. The proposed method is a relaxed placement technique combined with an hybrid algorithm based on a genetic algorithm and a separation algorithm. The genetic algorithm is used as a global optimizer and is in charge of efficiently exploring the search space. The separation algorithm is used to legalize solutions proposed by the global optimizer, so that placement constraints are satisfied. A test case illustrates the application of the proposed method. Extensions for solving the 3D problem are given at the end of the article.Comment: ASME 2009 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, San Diego : United States (2009

    Superpartners at LHC and Future Colliders: Predictions from Constrained Compactified M-Theory

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    We study a realistic top-down M-theory compactification with low-scale effective Supersymmetry, consistent with phenomenological constraints. A combination of top-down and generic phenomenological constraints fix the spectrum. The gluino mass is predicted to be about 1.5 TeV. Three and only three superpartner channels, g~g~\tilde{g} \tilde{g}, χ20χ1±\chi_2^0 \chi_1^\pm and χ1+χ1\chi_1^+ \chi_1^- (where χ20,χ1±\chi_2^0, \chi_1^\pm are Wino-like), are expected to be observable at LHC-14. We also investigate the prospects of finding heavy squarks and Higgsinos at future colliders. Gluino-stop-top, gluino-sbottom-bottom associated production and first generation squark associated production should be observable at a 100 TeV collider, along with direct production of heavy Higgsinos. Within this framework the discovery of a single sparticle is sufficient to determine uniquely the SUSY spectrum, yielding a number of concrete testable predictions for LHC-14 and future colliders, and determination of M3/2M_{3/2} and thereby other fundamental quantities.Comment: 19 pages, 4 figure

    Knowledge-based vision for space station object motion detection, recognition, and tracking

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    Computer vision, especially color image analysis and understanding, has much to offer in the area of the automation of Space Station tasks such as construction, satellite servicing, rendezvous and proximity operations, inspection, experiment monitoring, data management and training. Knowledge-based techniques improve the performance of vision algorithms for unstructured environments because of their ability to deal with imprecise a priori information or inaccurately estimated feature data and still produce useful results. Conventional techniques using statistical and purely model-based approaches lack flexibility in dealing with the variabilities anticipated in the unstructured viewing environment of space. Algorithms developed under NASA sponsorship for Space Station applications to demonstrate the value of a hypothesized architecture for a Video Image Processor (VIP) are presented. Approaches to the enhancement of the performance of these algorithms with knowledge-based techniques and the potential for deployment of highly-parallel multi-processor systems for these algorithms are discussed

    Distributed Query Monitoring through Convex Analysis: Towards Composable Safe Zones

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    Continuous tracking of complex data analytics queries over high-speed distributed streams is becoming increasingly important. Query tracking can be reduced to continuous monitoring of a condition over the global stream. Communication-efficient monitoring relies on locally processing stream data at the sites where it is generated, by deriving site-local conditions which collectively guarantee the global condition. Recently proposed geometric techniques offer a generic approach for splitting an arbitrary global condition into local geometric monitoring constraints (known as "Safe Zones"); still, their application to various problem domains has so far been based on heuristics and lacking a principled, compositional methodology. In this paper, we present the first known formal results on the difficult problem of effective Safe Zone (SZ) design for complex query monitoring over distributed streams. Exploiting tools from convex analysis, our approach relies on an algebraic representation of SZs which allows us to: (1) Formally define the notion of a "good" SZ for distributed monitoring problems; and, most importantly, (2) Tackle and solve the important problem of systematically composing SZs for monitored conditions expressed as Boolean formulas over simpler conditions (for which SZs are known); furthermore, we prove that, under broad assumptions, the composed SZ is good if the component SZs are good. Our results are, therefore, a first step towards a principled compositional solution to SZ design for distributed query monitoring. Finally, we discuss a number of important applications for our SZ design algorithms, also demonstrating how earlier geometric techniques can be seen as special cases of our framework

    Accurately scaled 3-D scene reconstruction using a moving monocular camera and a single-point depth sensor

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    Abstract: A 3-D reconstruction produced using only a single camera and Structure from Motion (SfM) is always up to scale i.e. without real world dimensions. Real-world dimensions are necessary for many applications that require 3-D reconstruction since decisions are made based on the accuracy of the reconstruction and the estimated camera poses. Current solutions to the absence of scale require prior knowledge of or access to the imaged environment in order to provide absolute scale to a reconstruction. It is often necessary to obtain a 3-D reconstruction of an inaccessible or unknown enviroment. This research proposes the use of a basic SfM pipeline for 3-D reconstruction with a single camera while augmenting the camera with a depth measurement for each image by way of a laser point marker. The marker is identified in the image and projected such that its location is determined as the point with highest point density along the projection in the up to scale reconstruction. The known distance to this point provides a scale factor that can be applied to the up to scale reconstruction. The results obtained show that the proposed augmentation does provide better scale accuracy. The SfM pipeline has room for improvement especially in terms of two-view geometry and structure estimations. A proof of concept is achieved that may open the door to improved algorithms for more demanding applications.M.Ing. (Electrical and Electronic Engineering

    Combining High-Resolution Images With Low-Quality Videos

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    Iso-entangled bases and joint measurements

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    While entanglement between distant parties has been extensively studied, entangled measurements have received relatively little attention despite their significance in understanding non-locality and their central role in quantum computation and networks. We present a systematic study of entangled measurements, providing a complete classification of all equivalence classes of iso-entangled bases for projective joint measurements on 2 qubits. The application of this classification to the triangular network reveals that the Elegant Joint Measurement, along with white noise, is the only measurement resulting in output permutation invariant probability distributions when the nodes are connected by Werner states. The paper concludes with a discussion of partial results in higher dimensions.Comment: 5 pages + appendice

    Theoretical Spectra and Atmospheres of Extrasolar Giant Planets

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    We present a comprehensive theory of the spectra and atmospheres of irradiated extrasolar giant planets. We explore the dependences on stellar type, orbital distance, cloud characteristics, planet mass, and surface gravity. Phase-averaged spectra for specific known extrasolar giant planets that span a wide range of the relevant parameters are calculated, plotted, and discussed. The connection between atmospheric composition and emergent spectrum is explored in detail. Furthermore, we calculate the effect of stellar insolation on brown dwarfs. We review a variety of representative observational techniques and programs for their potential for direct detection, in light of our theoretical expectations, and we calculate planet-to-star flux ratios as a function of wavelength. Our results suggest which spectral features are most diagnostic of giant planet atmospheres and reveal the best bands in which to image planets of whatever physical or orbital characteristics.Comment: 47 pages, plus 36 postscript figures; with minor revisions, accepted to the Astrophysical Journal, May 10, 2003 issu
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