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51.
Scheidegger C Vo H Koop D Freire J Silva C 《IEEE transactions on visualization and computer graphics》2007,13(6):1560-1567
While there have been advances in visualization systems, particularly in multi-view visualizations and visual exploration, the process of building visualizations remains a major bottleneck in data exploration. We show that provenance metadata collected during the creation of pipelines can be reused to suggest similar content in related visualizations and guide semi-automated changes. We introduce the idea of query-by-example in the context of an ensemble of visualizations, and the use of analogies as first-class operations in a system to guide scalable interactions. We describe an implementation of these techniques in VisTrails, a publicly-available, open-source system. 相似文献
52.
Tarini M Cignoni P Montani C 《IEEE transactions on visualization and computer graphics》2006,12(5):1237-1244
The paper presents a set of combined techniques to enhance the real-time visualization of simple or complex molecules (up to order of 106 atoms) space fill mode. The proposed approach includes an innovative technique for efficient computation and storage of ambient occlusion terms, a small set of GPU accelerated procedural impostors for space-fill and ball-and-stick rendering, and novel edge-cueing techniques. As a result, the user's understanding of the three-dimensional structure under inspection is strongly increased (even for still images), while the rendering still occurs in real time. 相似文献
53.
In this paper, we introduce two algorithms to address the two-echelon capacitated location-routing problem (2E-CLRP). We introduce a branch-and-cut algorithm based on the solution of a new two-index vehicle-flow formulation, which is strengthened with several families of valid inequalities. We also propose an adaptive large-neighbourhood search (ALNS) meta-heuristic with the objective of finding good-quality solutions quickly. The computational results on a large set of instances from the literature show that the ALNS outperforms existing heuristics. Furthermore, the branch-and-cut method provides tight lower bounds and is able to solve small- and medium-size instances to optimality within reasonable computing times. 相似文献
54.
55.
Dohnal Vlastislav Gennaro Claudio Savino Pasquale Zezula Pavel 《Multimedia Tools and Applications》2003,21(1):9-33
In order to speedup retrieval in large collections of data, index structures partition the data into subsets so that query requests can be evaluated without examining the entire collection. As the complexity of modern data types grows, metric spaces have become a popular paradigm for similarity retrieval. We propose a new index structure, called D-Index, that combines a novel clustering technique and the pivot-based distance searching strategy to speed up execution of similarity range and nearest neighbor queries for large files with objects stored in disk memories. We have qualitatively analyzed D-Index and verified its properties on actual implementation. We have also compared D-Index with other index structures and demonstrated its superiority on several real-life data sets. Contrary to tree organizations, the D-Index structure is suitable for dynamic environments with a high rate of delete/insert operations. 相似文献
56.
57.
Francesco Calvetti Claudio di Prisco Roberto Nova 《Canadian Metallurgical Quarterly》2004,130(12):1292-1299
Cases of pipeline damage caused by landslides are common in coastal or mountainous regions, where a continuous monitoring/repair activity is planned in order to maintain their serviceability. The analysis of the soil–structure interaction phenomenon can be invoked to improve the planning and design of buried pipelines, to guide monitoring, and to reduce the risk of damage or failure. Two different approaches are considered in this paper: small scale laboratory tests and numerical simulations using the distinct element method (DEM). The experimental setup consists of a box filled with sand and water. Several experiments were performed, in which the diameter and the depth of the tube varied. The numerical simulations are divided in two separate series: in the first, the numerical model is calibrated and its reliability in reproducing the experimental tests is checked; in the second series, the direction of the relative displacement between the tube and the surrounding “numerical soil” varies over the range ±90° with respect to the horizontal. In the latter, both vertical and horizontal components of the drag force are measured and the corresponding interaction diagrams are constructed. The DEM simulations provide useful information about the shape of the failure mechanisms and the force transfer within the soil. 相似文献
58.
The paper is about some families of rewriting P systems, where the application of evolution rules is extended from the classical
sequential rewriting to the parallel one (as, for instance, in Lindenmayer systems). As a result, consistency problems for
the communication of strings may arise. Three variants of parallel rewriting P systems (already present in the literature)
are considered here, together with the strategies they use to face the communication problem, and some parallelism methods
for string rewriting are defined. We give a survey of all known results about each variant and we state some relations among
the three variants, thus establishing hierarchies of parallel rewriting P systems. Various open problems related to the subject
are also presented.
Danicla Besozzi: She is assistant professor at the University of Milano. She received her M.S. in Mathematics (2000) from the University
of Como and Ph.D. in Computer Science (2004) from the University of Milano. Her research interests cover topics in Formal
Language Theory, Molecular Computing, Systems Biology. She is member of EATCS (European Association for Theoretical Computer
Science) and EMCC (European Molecular Computing Consortium).
Giancarlo Mauri: He is full professor of Computer Science at the University of Milano-Bicocca. His research interests are mainly in the area
of theoretical computer science, and include: formal languages and automata, computational complexity, computational learning
theory, soft computing techniques, cellular automata, bioinformatics and molecular computing. On these subjects, he published
more than 150 scientific papers in international journals, contributed volumes and conference proceedings.
Claudio Zandron: He received Ph.D. in Computer Science at the University of Milan, Italy, in 2001. Since 2002 he is assistant professor at
the University of Milano-Bicocca, Italy. He is member of the EATCS (European Association for Theoretical Computer Science)
and of EMCC (European Molecular Computing Consortium). His research interests are Molecular Computing (DNA and Membrane Computing)
and Formal Languages. 相似文献
59.
Claudio Bonivento Author Vitae Author Vitae Lorenzo Marconi Author Vitae Andrea Paoli Author Vitae 《Automatica》2004,40(3):355-371
In this paper we propose an innovative way of dealing with the design of fault-tolerant control systems. We show how the nonlinear output regulation theory can be successfully adopted in order to design a regulator able to offset the effect of all possible faults which can occur and, in doing so, also to detect and isolate the occurred fault. The regulator is designed by embedding the (possible nonlinear) internal model of the fault. This idea is applied to the design of a fault-tolerant controller for induction motors in presence of both rotor and stator mechanical faults. 相似文献
60.
Kotoni D Ciogli A Molinaro C D'Acquarica I Kocergin J Szczerba T Ritchie H Villani C Gasparrini F 《Analytical chemistry》2012,84(15):6805-6813
A new chiral stationary phase for ultrahigh-pressure liquid chromatography (UHPLC) applications was prepared by covalent attachment of the Whelk-O1 selector to spherical, high-surface-area 1.7-μm porous silica particles. Columns of varying dimensions (lengths of 50, 75, 100, and 150 mm and internal diameters of 3.0 or 4.6 mm) were packed and characterized in terms of permeability, efficiency, retention, and enantioselectivity, using both organic and water-rich mobile phases. A conventional HPLC Whelk-O1 column based on 5.0-μm porous silica particles and packed in a 250 mm × 4.6 mm column was used as a reference. Van Deemter curves, generated with low-molecular-weight solutes on a 100 mm × 4.6 mm column packed with the 1.7-μm particles, showed H(min) (μm) and μ(opt) (mm/s) values of 4.10 and 5.22 under normal-phase and 3.74 and 4.34 under reversed-phase elution conditions. The flat C term of the van Deemter curves observed with the 1.7-μm particles allowed the use of higher-than-optimal flow rates without significant efficiency loss. Kinetic plots constructed from van Deemter data confirmed the ability of the column packed with the 1.7-μm particles to afford subminute separations with good efficiency and its superior performances in the high-speed regime, compared to the column packed with 5.0-μm particles. Resolutions in the time scale of seconds were obtained using a 50-mm-long column in the normal phase or polar organic mode. The intrinsic kinetic performances of 1.7-μm silica particles are retained in the Whelk-O1 chiral stationary phase, clearly demonstrating the potentials of enantioselective UHPLC in terms of high speed, throughput, and resolution. 相似文献