423 research outputs found
Robust Component-based Network Localization with Noisy Range Measurements
Accurate and robust localization is crucial for wireless ad-hoc and sensor
networks. Among the localization techniques, component-based methods advance
themselves for conquering network sparseness and anchor sparseness. But
component-based methods are sensitive to ranging noises, which may cause a huge
accumulated error either in component realization or merging process. This
paper presents three results for robust component-based localization under
ranging noises. (1) For a rigid graph component, a novel method is proposed to
evaluate the graph's possible number of flip ambiguities under noises. In
particular, graph's \emph{MInimal sepaRators that are neaRly cOllineaR
(MIRROR)} is presented as the cause of flip ambiguity, and the number of
MIRRORs indicates the possible number of flip ambiguities under noise. (2) Then
the sensitivity of a graph's local deforming regarding ranging noises is
investigated by perturbation analysis. A novel Ranging Sensitivity Matrix (RSM)
is proposed to estimate the node location perturbations due to ranging noises.
(3) By evaluating component robustness via the flipping and the local deforming
risks, a Robust Component Generation and Realization (RCGR) algorithm is
developed, which generates components based on the robustness metrics. RCGR was
evaluated by simulations, which showed much better noise resistance and
locating accuracy improvements than state-of-the-art of component-based
localization algorithms.Comment: 9 pages, 15 figures, ICCCN 2018, Hangzhou, Chin
Computing a Compact Spline Representation of the Medial Axis Transform of a 2D Shape
We present a full pipeline for computing the medial axis transform of an
arbitrary 2D shape. The instability of the medial axis transform is overcome by
a pruning algorithm guided by a user-defined Hausdorff distance threshold. The
stable medial axis transform is then approximated by spline curves in 3D to
produce a smooth and compact representation. These spline curves are computed
by minimizing the approximation error between the input shape and the shape
represented by the medial axis transform. Our results on various 2D shapes
suggest that our method is practical and effective, and yields faithful and
compact representations of medial axis transforms of 2D shapes.Comment: GMP14 (Geometric Modeling and Processing
Transition metal oxides for high performance sodium ion battery anodes
Sodium-ion batteries (SIBs) are attracting considerable attention with expectation of replacing lithium-ion batteries (LIBs) in large-scale energy storage systems (ESSs). To explore high performance anode materials for SIBs is highly desired subject to the current anode research mainly limited to carbonaceous materials. In this study, a series of transition metal oxides (TMOs) is successfully demonstrated as anodes for SIBs for the first time. The sodium uptake/extract is confirmed in the way of reversible conversion reaction. The pseudocapacitance-type behavior is also observed in the contribution of sodium capacity. For Fe2O3anode, a reversible capacity of 386 mAh g-1at 100 mA g-1 is achieved over 200 cycles; as high as 233 mAhg-1is sustained even cycling at a large current-density of 5 A g-1
What kind of doctor looks more popular? A multi-dimensional study on online healthcare consultation
With the development of Web 2.0 technology, the healthcare industry is undergoing a digital transformation that has led to the emergence of online healthcare consulting, revolutionizing the patient consulting experience in several ways. Despite substantial literature on patient behavior, there is limited understanding of how the appearance of physicians, as conveyed by their portraits, affects patients\u27 online decision-making. To bridge this gap, this study aims to develop a four-dimensional facial impression model to systematically analyze physicians\u27 faces. Three stages of patient decision-making, including search, selection, and evaluation decisions, were examined using data collected from Haodf.com. Preliminary results indicate that seeing the true appearance of the physician positively influences patient experience, leading to increased consulting willingness and satisfaction. Diverse moderating role of service price suggesting the substitution and enhancement between price and real person portraits. Our study contributes to the literature on user behavior and facial impression in digitalized healthcare
Dual Process, Buffering/Coping Effects, and Reciprocal Dynamics: A Social Demands-Resources Model of SNS Discontinuance
Prior studies on social networking sites (SNSs) discontinuance focus on the demand side (e.g., social overload) while neglect the resource side. To address this problem, drawing upon the job demandsâresources (JDâR) model, we develop the social demandsâresources (SDâR) model of SNS discontinuance. Specifically, social overload and social support, as social demands and social resources, are proposed to affect discontinuance through the energetic process and the motivational process respectively. The buffering effect and the coping effect are proposed to explain the cross-links between the dual processes. We also propose the mechanism of reciprocal dynamics to capture the relationship between social support and social overload. Through a study of 479 WeChat users, the results confirm the proposed SDâR model of SNS discontinuance. The implications for research and practice are also discussed
A Label-Free Electrochemical Immunosensor for Carbofuran Detection Based on a Sol-Gel Entrapped Antibody
In this study, an anti-carbofuran monoclonal antibody (Ab) was immobilized on the surface of a glassy carbon electrode (GCE) using silica sol-gel (SiSG) technology. Thus, a sensitive, label-free electrochemical immunosensor for the direct determination of carbofuran was developed. The electrochemical performance of immunoreaction of antigen with the anti-carbofuran monoclonal antibody was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), in which phosphate buffer solution containing [Fe(CN)6]3â/4â was used as the base solution for test. Because the complex formed by the immunoreaction hindered the diffusion of [Fe(CN)6]3â/4â on the electrode surface, the redox peak current of the immunosensor in the CV obviously decreased with the increase of the carbofuran concentration. The pH of working solution, the concentration of Ab and the incubation time of carbofuran were studied to ensure the sensitivity and conductivity of the immunosensor. Under the optimal conditions, the linear range of the proposed immunosensor for the determination of carbofuran was from 1 ng/mL to 100 ÎŒg/mL and from 50 ÎŒg/mL to 200 ÎŒg/mL with a detection limit of 0.33 ng/mL (S/N = 3). The proposed immunosensor exhibited good high sensitivity and stability, and it was thus suitable for trace detection of carbofuran pesticide residues
pH-sensitive polymeric micelles triggered drug release for extracellular and intracellular drug targeting delivery
AbstractMost of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy. Based on physiological differences between the normal tissue and the tumor tissue, one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems. The copolymers with reversible protonationâdeprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release. These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect, or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway. The pH-sensitive micelles have been proved the specific tumor cell targeting, enhanced cellular internalization, rapid drug release, and multidrug resistance reversal. The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting. The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells, which reverses multidrug resistance. The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy, and is a novel promising platform for tumor-targeting drug delivery
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