1,378 research outputs found

    Image Reconstruction from Bag-of-Visual-Words

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    The objective of this work is to reconstruct an original image from Bag-of-Visual-Words (BoVW). Image reconstruction from features can be a means of identifying the characteristics of features. Additionally, it enables us to generate novel images via features. Although BoVW is the de facto standard feature for image recognition and retrieval, successful image reconstruction from BoVW has not been reported yet. What complicates this task is that BoVW lacks the spatial information for including visual words. As described in this paper, to estimate an original arrangement, we propose an evaluation function that incorporates the naturalness of local adjacency and the global position, with a method to obtain related parameters using an external image database. To evaluate the performance of our method, we reconstruct images of objects of 101 kinds. Additionally, we apply our method to analyze object classifiers and to generate novel images via BoVW

    Neural 3D Mesh Renderer

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    For modeling the 3D world behind 2D images, which 3D representation is most appropriate? A polygon mesh is a promising candidate for its compactness and geometric properties. However, it is not straightforward to model a polygon mesh from 2D images using neural networks because the conversion from a mesh to an image, or rendering, involves a discrete operation called rasterization, which prevents back-propagation. Therefore, in this work, we propose an approximate gradient for rasterization that enables the integration of rendering into neural networks. Using this renderer, we perform single-image 3D mesh reconstruction with silhouette image supervision and our system outperforms the existing voxel-based approach. Additionally, we perform gradient-based 3D mesh editing operations, such as 2D-to-3D style transfer and 3D DeepDream, with 2D supervision for the first time. These applications demonstrate the potential of the integration of a mesh renderer into neural networks and the effectiveness of our proposed renderer

    Viscous characteristics of ETFE film sheetunder temperature change

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    Because ETFE film is a high polymer material its visco-elastic characteristics are observed by the researchers. Besides, the linear expansion coefficient of the ETFE is 10 times greater compared to steel products or the like. For that reason, due to change in temperature, there are cases where expansion and contraction are regarded as an issue. Therefore, in order to design and construct ETFE film membrane structures, research focused on its visco-elastic characteristics has been done. For research focused on viscosity of ETFE film, in addition to that carried out by the authors, there is research by Moriyama and Kawabata1,2, by Jeongand Kawabata3, by Wu4, by Galliot and Luchsinger5 and by Li and Wu6 and so on. These studies take into account either the viscosity, the change in temperature or introducing the constitutive equation of FEM. There is no research that takes into account all of them

    Effects of laser wavelength and density scalelength on absorption of ultrashort intense lasers on solid-density targets

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    Hot electron temperatures and electron energy spectra in the course of interaction between intense laser pulse and overdense plasmas are reexamined from a viewpoint of the difference in laser wavelength. The hot electron temperature measured by a particle-in-cell simulation is scaled by II rather than Iλ2I \lambda^2 at the interaction with overdense plasmas with fixed ions, where II and λ\lambda are the laser intensity and wavelength, respectively.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

    Prediction of RNA secondary structure with pseudoknots using integer programming

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    <p>Abstract</p> <p>Background</p> <p>RNA secondary structure prediction is one major task in bioinformatics, and various computational methods have been proposed so far. Pseudoknot is one of the typical substructures appearing in several RNAs, and plays an important role in some biological processes. Prediction of RNA secondary structure with pseudoknots is still challenging since the problem is NP-hard when arbitrary pseudoknots are taken into consideration.</p> <p>Results</p> <p>We introduce a new method of predicting RNA secondary structure with pseudoknots based on integer programming. In our formulation, we aim at minimizing the value of the objective function that reflects free energy of a folding structure of an input RNA sequence. We focus on a practical class of pseudoknots by setting constraints appropriately. Experimental results for a set of real RNA sequences show that our proposed method outperforms several existing methods in sensitivity. Furthermore, for a set of sequences of small length, our approach achieved good performance in both sensitivity and specificity.</p> <p>Conclusion</p> <p>Our integer programming-based approach for RNA structure prediction is flexible and extensible.</p

    Purification of functional baculovirus particles from silkworm larval hemolymph and their use as nanoparticles for the detection of human prorenin receptor (PRR) binding

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    <p>Abstract</p> <p>Background</p> <p>Baculovirus, which has a width of 40 nm and a length of 250-300 nm, can display functional peptides, receptors and antigens on its surface by their fusion with a baculovirus envelop protein, GP64. In addition, some transmembrane proteins can be displayed without GP64 fusion, using the native transmembrane domains of the baculovirus. We used this functionality to display human prorenin receptor fused with GFP<sub>uv </sub>(GFP<sub>uv</sub>-hPRR) on the surface of silkworm <it>Bombyx mori </it>nucleopolyhedrovirus (BmNPV) and then tested whether these baculovirus particles could be used to detect protein-protein interactions.</p> <p>Results</p> <p>BmNPV displaying GFP<sub>uv</sub>-hPRR (BmNPV-GFP<sub>uv</sub>-hPRR) was purified from hemolymph by using Sephacryl S-1000 column chromatography in the presence of 0.01% Triton X-100. Its recovery was 86% and the final baculovirus particles number was 4.98 × 10<sup>8 </sup>pfu. Based on the results of enzyme-linked immunosorbent assay (ELISA), 3.1% of the total proteins in BmNPV-GFP<sub>uv</sub>-hPRR were GFP<sub>uv</sub>-hPRR. This value was similar to that calculated from the result of western blot by a densitometry (2.7%). To determine whether BmNPV-GFP<sub>uv</sub>-hPRR particles were bound to human prorenin, ELISA results were compared with those from ELISAs using protease negative BmNPV displaying β1,3-<it>N</it>-acetylglucosaminyltransferase 2 fused with the gene encoding GFP<sub>uv </sub>(GGT2) (BmNPV-<it>CP</it><sup>-</sup>-GGT2) particles, which do not display hPRR on their surfaces.</p> <p>Conclusion</p> <p>The display of on the surface of the BmNPV particles will be useful for the detection of protein-protein interactions and the screening of inhibitors and drugs in their roles as nanobioparticles.</p

    How Plasma Membrane and Cytoskeletal Dynamics Influence Single-Cell Wound Healing: Mechanotransduction, Tension and Tensegrity

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    Organisms are able to recover from injuries by replacing damaged tissues, which recover by replacing damaged cells and extracellular structures. Similarly, a cell recovers from injuries by replacing damaged components of its structural integrity: its plasma membrane and cytoskeletal structures. Cells can be thought of as tensegral structures, their structural integrity relying on the interplay between tensile forces generated within and without the cell, and the compressive elements that counteracts them. As such, direct or indirect insults to the plasma membrane or cytoskeleton of a cell may not only result in the temporary loss of structural integrity, but also directly impact its ability to respond to its environment. This chapter will focus on the various aspects linking tensile forces and single-cell wound healing: where and how are they generated, how does the cell counteract them and how does the cell return to its previous tensegrity state? These questions will be explored using ubiquitous and cell-type specific examples of single-cell repair processes. Special attention will be given to changes in plasma membrane composition and area to cytoskeletal dynamics, and how these factor each other to influence and effect single-cell repair
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