601 research outputs found

    A Four-Factor User Interaction Model for Content-Based Image Retrieval

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    In order to bridge the ā€œSemantic gapā€, a number of relevance feedback (RF) mechanisms have been applied to content-based image retrieval (CBIR). However current RF techniques in most existing CBIR systems still lack satisfactory user interaction although some work has been done to improve the interaction as well as the search accuracy. In this paper, we propose a four-factor user interaction model and investigate its effects on CBIR by an empirical evaluation. Whilst the model was developed for our research purposes, we believe the model could be adapted to any content-based search system

    Hysteretic behavior of angular dependence of exchange bias in FeNi/FeMn bilayers

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    For FeNi/FeMn bilayers, the angular dependence of exchange bias shows hysteresis between clockwise and counterclockwise rotations, as a new signature. The hysteresis decreases for thick antiferromagnet layers. Calculations have clearly shown that the orientation of antiferromagnet spins also exhibits hysteresis between clockwise and counterclockwise rotations. This furnishes an interpretation of the macroscopic behavior of the ferromagnetic layer in terms of the thermally driven evolution of the magnetic state of the antiferromagnet layer

    Can a workspace help to overcome the query formulation problem in image retrieval?

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    We have proposed a novel image retrieval system that incorporates a workspace where users can organise their search results. A task-oriented and user-centred experiment has been devised involving design professionals and several types of realistic search tasks. We study the workspaceā€™s effect on two aspects: task conceptualisation and query formulation. A traditional relevance feedback system serves as baseline. The results of this study show that the workspace is more useful with respect to both of the above aspects. The proposed approach leads to a more effective and enjoyable search experience

    Evaluating a workspace's usefulness for image retrieval

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    Image searching is a creative process. We have proposed a novel image retrieval system that supports creative search sessions by allowing the user to organise their search results on a workspace. The workspaceā€™s usefulness is evaluated in a task-oriented and user-centred comparative experiment, involving design professionals and several types of realistic search tasks. In particular, we focus on its effect on task conceptualisation and query formulation. A traditional relevance feedback system serves as a baseline. The results of this study show that the workspace is more useful in terms of both of the above aspects and that the proposed approach leads to a more effective and enjoyable search experience. This paper also highlights the influence of tasks on the usersā€™ search and organisation strategy

    Scattering mechanism in a step-modulated subwavelength metal slit: a multi-mode multi-reflection analysis

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    In this paper, the scattering/transmission inside a step-modulated subwavelength metal slit is investigated in detail. We firstly investigate the scattering in a junction structure by two types of structural changes. The variation of transmission and reflection coefficients depending on structural parameters are analyzed. Then a multi-mode multi-reflection model based on ray theory is proposed to illustrate the transmission in the step-modulated slit explicitly. The key parts of this model are the multi-mode excitation and the superposition procedure of the scatterings from all possible modes, which represent the interference and energy transfer happened at interfaces. The method we use is an improved modal expansion method (MEM), which is a more practical and efficient version compared with the previous one [Opt. Express 19, 10073 (2011)]. In addition, some commonly used methods, FDTD, scattering matrix method, and improved characteristic impedance method, are compared with MEM to highlight the preciseness of these methods.Comment: 25 pages, 9 figure

    An explorative study of interface support for image searching

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    In this paper we study interfaces for image retrieval systems. Current image retrieval interfaces are limited to providing query facilities and result presentation. The user can inspect the results and possibly provide feedback on their relevance for the current query. Our approach, in contrast, encourages the user to group and organise their search results and thus provide more fine-grained feedback for the system. It combines the search and management process, which - according to our hypothesis - helps the user to onceptualise their search tasks and to overcome the query formulation problem. An evaluation, involving young design-professionals and diĀ®erent types of information seeking scenarios, shows that the proposed approach succeeds in encouraging the user to conceptualise their tasks and that it leads to increased user satisfaction. However, it could not be shown to increase performance. We identify the problems in the current setup, which when eliminated should lead to more effective searching overall

    The Transformation from Translucent into Transparent Rare Earth Ions Doped Oxyfluoride Glass-Ceramics with Enhanced Luminescence

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    Article reporting a scenario where a translucent Er3+āˆ’Yb3+ doped oxyfluoride precursor glass-ceramic (P-GC) becomes transparent with increasing crystal size and crystallinity

    A minimum single-band model for low-energy excitations in superconducting Kx_xFe2_2Se2_2

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    We propose a minimum single-band model for the newly discovered iron-based superconducting Kx_xFe2_2Se2_2. Our model is found to be numerically consistent with the five-orbital model at low energies. Based on our model and the random phase approximation, we study the spin fluctuation and the pairing symmetry of superconducting gap function. The (Ļ€/2,Ļ€/2)(\pi/2,\pi/2) spin excitation and the dx2āˆ’y2d_{x^2-y^2} pairing symmetry are revealed. All of the results can well be understood in terms of the interplay between the Fermi surface topology and the local spin interaction, providing a sound picture to explain why the superconducting transition temperature is as high as to be comparable to those in pnictides and some cuprates. A common origin of superconductivity is elucidated for this compound and other high-Tc_c materials.Comment: 5 pages, 4 figure

    Prosemantic features for content-based image retrieval

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-18449-9_8Revised Selected Papers of 7th International Workshop, AMR 2009, Madrid, Spain, September 24-25, 2009We present here, an image description approach based on prosemantic features. The images are represented by a set of low-level features related to their structure and color distribution. Those descriptions are fed to a battery of image classifiers trained to evaluate the membership of the images with respect to a set of 14 overlapping classes. Prosemantic features are obtained by packing together the scores. To verify the effectiveness of the approach, we designed a target search experiment in which both low-level and prosemantic features are embedded into a content-based image retrieval system exploiting relevance feedback. The experiments show that the use of prosemantic features allows for a more successful and quick retrieval of the query images

    Split First Dose Administration of Intravenous Daratumumab for the Treatment of Multiple Myeloma (MM) : Clinical and Population Pharmacokinetic Analyses

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    Introduction: Daratumumab, a human immunoglobulin GĪŗ monoclonal antibody targeting CD38, is approved as monotherapy and in combination with standard-of-care regimens for multiple myeloma. In clinical studies, the median durations of the first, second, and subsequent intravenous infusions of daratumumab were 7.0, 4.3, and 3.4 h, respectively. Splitting the first intravenous infusion of daratumumab over 2 days is an approved alternative dosing regimen to reduce the duration of the first infusion and provide flexibility for patients and healthcare providers. Methods: The feasibility of splitting the first 16-mg/kg infusion into two separate infusions of 8 mg/kg on Days 1 and 2 of the first treatment cycle was investigated in two cohorts [daratumumab, carfilzomib, and dexamethasone (D-Kd) and daratumumab, carfilzomib, lenalidomide, and dexamethasone (D-KRd)] of the phase 1b MMY1001 study. Additionally, a population pharmacokinetic (PK) analysis and simulations were used to compare the PK profiles of the split first dose regimen with the recommended single first dose regimens of daratumumab in previously approved indications. Results: In MMY1001, following administration of the second half of a split first dose on Cycle 1 Day 2, postinfusion median (range) daratumumab concentrations were similar between split first dose [D-Kd, 254.9 (125.8-435.5) Āµg/ml; D-KRd, 277.2 (164.0-341.8) Āµg/ml; combined, 256.8 (125.8-435.5) Āµg/ml] and single first dose [D-Kd, 319.2 (237.5-394.7) Āµg/ml]. At the end of weekly dosing, median (range) Cycle 3 Day 1 preinfusion daratumumab concentrations were similar between split first dose [D-Kd, 663.9 (57.7-1110.7) Āµg/ml; D-KRd, 575.1 (237.9-825.5) Āµg/ml; combined, 639.2 (57.7-1110.7) Āµg/ml] and single first dose [D-Kd, 463.2 (355.9-792.9) Āµg/ml]. The population PK simulations demonstrated virtually identical PK profiles after the first day of treatment for all approved indications and recommended dosing schedules of daratumumab. Conclusion: These data support the use of an alternative split first dose regimen of intravenous daratumumab for the treatment of MM. Trial Registration: ClinicalTrials.gov number, NCT01998971
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