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61.
Peter Burns 《Journal of Urban Affairs》2003,25(3):285-303
Abstract State government possesses the resources and authority to directly shape urban education policy but regime theorists understate the roles governors, state legislatures, and other state actors play as members of urban education regimes. This article examines the state takeover of schools in Newark, New Jersey to demonstrate why and how a state government leads an urban education regime. The Newark case illustrates how politics and structural conditions motivated state government to change the nature of the education regime and directly shape education policy at the local level. It highlights the role state government played in reshaping an educator‐centered coalition that operated a poorly performing school district. Despite the existence of a new regime, Newark students’ achievement scores have not significantly improved, and in some instances they have declined under the state‐led regime. This article encourages scholars of city politics to continue to investigate state government's role in urban governing coalitions because state political players maintain the capacity and motivation to join urban regimes. 相似文献
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An exact mass measurement ESI TOF mass spectrometer has been developed for fast pathogen identification and strain typing. This unique technology relies on mass spectrometry-derived base composition signatures of amplicons from PCR (Polymerase Chain Reaction) products, and “intelligent PCR primers” that target broadly conserved regions of microbial genomes that flank variable regions. This rapid detection (30 seconds per sample) and identification of microorganism methodology also associates with a potential biological warfare attack or a natural outbreak of an emerging infectious disease. The strategy to build a high end and low cost ESI TOF machine will be discussed. The performance data particularly in accurate mass measurement, high resolving power and 24 hours stability test will be presented. The discovery of Swine flu virus H1N1 will be presented as an example to illustrate the procedure of detection and identification of microoganisms. 相似文献
65.
Highly accurate real‐time localization is of fundamental importance for the safety and efficiency of planetary rovers exploring the surface of Mars. Mars rover operations rely on vision‐based systems to avoid hazards as well as plan safe routes. However, vision‐based systems operate on the assumption that sufficient visual texture is visible in the scene. This poses a challenge for vision‐based navigation on Mars where regions lacking visual texture are prevalent. To overcome this, we make use of the ability of the rover to actively steer the visual sensor to improve fault tolerance and maximize the perception performance. This paper answers the question of where and when to look by presenting a method for predicting the sensor trajectory that maximizes the localization performance of the rover. This is accomplished by an online assessment of possible trajectories using synthetic, future camera views created from previous observations of the scene. The proposed trajectories are quantified and chosen based on the expected localization performance. In this study, we validate the proposed method in field experiments at the Jet Propulsion Laboratory (JPL) Mars Yard. Furthermore, multiple performance metrics are identified and evaluated for reducing the overall runtime of the algorithm. We show how actively steering the perception system increases the localization accuracy compared with traditional fixed‐sensor configurations. 相似文献
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T. Wilkinson S. Ward‐Foxton A. Menon W. H. Reeves S. E. Burns 《Journal of the Society for Information Display》2005,13(7):605-608
Abstract— In this paper, we present results from a new liquid crystal over plastic printed thin‐film‐transistor (TFT) display. The display demonstrator shows that the processing incompatibilities between the plastic TFT backplane and the liquid‐crystal materials can be addressed to make a stable twisted‐nematic structure. New fabrication processes such as the photo‐alignment of liquid crystals have made it possible to create a new generation of displays, which pave the way towards fully integrated plastic liquid‐crystal‐display technologies. 相似文献
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Whang K.-Y. Malhotra A. Sockut G.H. Burns L. Choi K.-S. 《IEEE transactions on pattern analysis and machine intelligence》1992,18(3):216-224
A technique is proposed for specifying universal quantification and existential quantification (combined with negation) in a two-dimensional (graphical) database query language. Unlike other approaches that provide set operators to simulate universal quantification, this technique allows a direct representation of universal quantification. Syntactic constructs for specifying universal and existential quantifications, two-dimensional translation of universal quantification to existential quantification (with negation), and translation of existentially quantified two-dimensional queries to relational queries are presented. The resulting relational queries can be processed directly by many existing database systems. The authors claim that this technique renders universal quantifications easy to understand. To substantiate this claim, they provide a simple, easy-to-follow guideline for constructing universally quantified queries 相似文献
70.
This work focuses on simultaneous approximation terms (SATs) for multidimensional summation-by-parts (SBP) discretizations of linear second-order partial differential equations with variable coefficients. Through the analysis of adjoint consistency and stability, we present several conditions on the SAT penalties for general operators, including those operators that do not have nodes on their boundary or do not correspond with a collocation discontinuous Galerkin method. Based on these conditions, we generalize the modified scheme of Bassi and Rebay and the symmetric interior penalty Galerkin method to SBP-SAT discretizations. Numerical experiments are carried out on unstructured grids with triangular elements to verify the theoretical results. 相似文献