9,420 research outputs found

    Fine-grained sketch-based image retrieval by matching deformable part models

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    (c) 2014. The copyright of this document resides with its authors. It may be distributed unchanged freely in print or electronic forms.© 2014. The copyright of this document resides with its authors. An important characteristic of sketches, compared with text, rests with their ability to intrinsically capture object appearance and structure. Nonetheless, akin to traditional text-based image retrieval, conventional sketch-based image retrieval (SBIR) principally focuses on retrieving images of the same category, neglecting the fine-grained characteristics of sketches. In this paper, we advocate the expressiveness of sketches and examine their efficacy under a novel fine-grained SBIR framework. In particular, we study how sketches enable fine-grained retrieval within object categories. Key to this problem is introducing a mid-level sketch representation that not only captures object pose, but also possesses the ability to traverse sketch and image domains. Specifically, we learn deformable part-based model (DPM) as a mid-level representation to discover and encode the various poses in sketch and image domains independently, after which graph matching is performed on DPMs to establish pose correspondences across the two domains. We further propose an SBIR dataset that covers the unique aspects of fine-grained SBIR. Through in-depth experiments, we demonstrate the superior performance of our SBIR framework, and showcase its unique ability in fine-grained retrieval

    The preparation, characterization, and pharmacokinetic studies of chitosan nanoparticles loaded with paclitaxel/dimethyl-β-cyclodextrin inclusion complexes.

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    A novel biocompatible and biodegradable drug-delivery nanoparticle (NP) has been developed to minimize the severe side effects of the poorly water-soluble anticancer drug paclitaxel (PTX) for clinical use. PTX was loaded into the hydrophobic cavity of a hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD), using an aqueous solution-stirring method followed by lyophilization. The resulting PTX/DM-β-CD inclusion complex dramatically enhanced the solubility of PTX in water and was directly incorporated into chitosan (CS) to form NPs (with a size of 323.9–407.8 nm in diameter) using an ionic gelation method. The formed NPs had a zeta potential of +15.9–23.3 mV and showed high colloidal stability. With the same weight ratio of PTX to CS of 0.7, the loading efficiency of the PTX/DM-β-CD inclusion complex-loaded CS NPs was 30.3-fold higher than that of the PTX-loaded CS NPs. Moreover, it is notable that PTX was released from the DM-β-CD/CS NPs in a sustained-release manner. The pharmacokinetic studies revealed that, compared with reference formulation (Taxol(®)), the PTX/DM-β-CD inclusion complex-loaded CS NPs exhibited a significant increase in AUC(0→24h) (the area under the plasma drug concentration–time curve over the period of 24 hours) and mean residence time by 2.7-fold and 1.4-fold, respectively. Therefore, the novel drug/DM-β-CD inclusion complex-loaded CS NPs have promising applications for the significantly improved delivery and controlled release of the poorly water-soluble drug PTX or its derivatives, thus possibly leading to enhanced therapeutic efficacy and less severe side effects

    Development of a Modular and Submersible Soft Robotic Arm and Corresponding Learned Kinematics Models

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    Most soft-body organisms found in nature exist in underwater environments. It is helpful to study the motion and control of soft robots underwater as well. However, a readily available underwater soft robotic system is not available for researchers to use because they are difficult to design, fabricate, and waterproof. Furthermore, submersible robots usually do not have configurable components because of the need for sealed electronics packages. This work presents the development of a submersible soft robotic arm driven by hydraulic actuators which consists of mostly 3D printable parts which can be assembled in a short amount of time. Also, its modular design enables multiple shape configurations and easy swapping of soft actuators. As a first step to exploring machine learning control algorithms on this system, two deep neural network models were developed, trained, and evaluated to estimate the robot's forward and inverse kinematics. The techniques developed for controlling this underwater soft robotic arm can help advance understanding on how to control soft robotic systems in general.Comment: 12 pages, 10 figure

    Current–Voltage Characteristics in Individual Polypyrrole Nanotube, Poly(3,4-ethylenedioxythiophene) Nanowire, Polyaniline Nanotube, and CdS Nanorope

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    In this paper, we focus on current–voltage (I–V) characteristics in several kinds of quasi-one-dimensional (quasi-1D) nanofibers to investigate their electronic transport properties covering a wide temperature range from 300 down to 2 K. Since the complex structures composed of ordered conductive regions in series with disordered barriers in conducting polymer nanotubes/wires and CdS nanowires, all measured nonlinearI–Vcharacteristics show temperature and field-dependent features and are well fitted to the extended fluctuation-induced tunneling and thermal excitation model (Kaiser expression). However, we find that there are surprisingly similar deviations emerged between theI–Vdata and fitting curves at the low bias voltages and low temperatures, which can be possibly ascribed to the electron–electron interaction in such quasi-1D systems with inhomogeneous nanostructures

    Sums of products of two reciprocal Fibonacci numbers

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    Identification of non-Gaussian parametric model with time-varying coefficients using wavelet basis

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    Many time series in practice turn to be the time-varying (TV) non-Gaussian processes. In this paper, we address the problem of how to describe these non-stationary non-Gaussian time series. A non-Gaussian AR model with TV parameters is proposed to track the non-stationary non-Gaussian characteristics of the signal. Since wavelet has flexibility in capturing the signal's transient characteristics at different scales, a set of wavelet basis is employed so that the model parameters can effectively track the variations of TV signals and be used to estimate the corresponding TV bispectrum. The experiments results confirm the superior performance of the presented model over the previous method.published_or_final_versio

    转铁蛋白-转铁蛋白受体系统在药物运输和定向给药中的应用

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Designing bus routes and frequencies for Tin Shui Wai, Hong Kong

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    A real bus network design problem for a suburban residential area, Tin Shui Wai, Hong Kong, is investigated. The problem considers bus service from origins inside this area to destinations in the city. The aim is to improve the existing bus network by reducing the number of transfers and total travel time of users. This is achieved by the proposed integrated solution method, which simultaneously solves the route design and frequency setting problems. In the proposed method, a genetic algorithm that tackles the route design problem is hybridized with a neighborhood search heuristic that addresses the frequency setting problem. A new representation scheme and specific genetic operators are developed so that the genetic algorithm can search all possible route structures rather than selecting from an initial set of predefined routes. The proposed method reduces the number of transfers and total travel time by 20.6% and 7.0%, respectively.postprintThe 2010 HKIE Civil Division Conference on Infrastructure Solutions for Tomorrow, Hong Kong, 12-14 April 2010. In Proceedings of the HKIE Civil Division Conference 2010: Infrastructure Solutions for Tomorrow, 201

    An artificial bee colony algorithm for the capacitated vehicle routing problem

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    Session MF-03: Population-based metaheuristics for routing problems - Stream: Metaheuristics - Invited session no. 3This paper introduces an artificial bee colony heuristic for the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. The performance of the heuristic is evaluated on two sets of benchmark instances. A new scheme is also developed to improve the performance of the artificial bee colony heuristic. Computational results show that the heuristic with the new scheme produces good solutions.postprintThe 24th European Conference on Operational Research (EURO 24), Lisbon, Portual, 11-14 July 2010. In Abstract Book of EURO 24, 2010, p. 89, MF-03-
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