A cross-layer heuristic algorithm for addressing shadowing problem in optical attocell networks

The performance of visible light communication (VLC)-based optical attocell networks degrades due to shadowing caused by opaque objects. In order to improve reliability, we propose a cross-layer algorithm to find the optimal routing and resource allocation schemes when shadowing occurs. Simulation results show that the optimal scheme found by the proposed algorithm significantly improves the performance of optical attocell networks with one randomly shadowed link

Analysis of the impact of misaligned wireless backhaul links on optical Attocell networks

Wireless solutions based on visible light communication (VLC) have been proposed for backhaul transmission in optical attocell networks. Perfect alignment of auxiliary transceivers is important for wireless backhaul links due to the requirement of direct line-of-sight (LOS) and the first-bounce specular reflection of mirror-aided non-LOS. However, the perfect alignment may not be guaranteed due to the limitation of the layout of BSs or installation mistakes. In this article, we investigate the impact of misalignment on the overall network performance. Two VLC backhaul link configurations have been considered and compared. Performance of using different frequency reuse schemes and channel allocation schemes are compared

Hybrid traceback-filtering (HTF): An efficient DoS/DDoS defense mechanism

Master'sMASTER OF SCIENC

Enhancing a Sense of Competence at Work by Engaging in Proactive Behavior: The Role of Proactive Personality

To understand how individuals’ senses of competence are cultivated, scholars have primarily focused on situational factors such as job autonomy and supervisor support. Against this backdrop, we propose that individuals can work as active agents and enhance their sense of competence by initiating actions that aim to master the environment. We adopt the behavioral concordance model and propose that people higher in proactive personality are more likely to engage in proactive behavior that elevates their senses of competence over time. We further propose that such behavioral concordance contributes to boosting a sense of competence is more prominent among those with higher proactive personality. Our predictions are supported by data from 172 employees and their direct supervisors in China, after controlling for the effect of job autonomy and supervisor support for autonomy. Specifically, only those higher in proactive personality engaged in more proactive behavior and increased their sense of competence over time. This study highlights both a self-initiated and a behavioral perspective on understanding the development of a sense of competence

Mirror-aided non-LOS VLC channel characterizations with a time-efficient simulation model

The emerging cost-efficient visible light communication (VLC)-based indoor wireless network requires an economical solution for backhaul transmission. Non-line-of-sight (non-LOS) VLC links are generally applicable candidates to set up a backhaul network without rearrangement of existing lighting fixtures. Here, we describe non-LOS channels aided by the first-order specular reflection from mirrors, which can be used to overcome the multipath effect of purely diffuse non-LOS channels. Characterizations of purely diffuse and mirror-aided non-LOS channels are conducted with a time-efficient simulation model based on an iterative algorithm. Any bounce of reflections combined with specular and diffuse reflections can be simulated using the proposed iterative VLC model in polynomial time. Simulation results show that mirror-aided non-LOS channels outperform purely diffuse non-LOS links regardless of the link configuration. The effect of concentration and directionality of non-LOS VLC channels is also shown and discussed

Gene Transfer of Calcitonin Gene-Related Peptide Inhibits Macrophages and Inflammatory Mediators in Vein Graft Disease

Vein graft disease is a chronic inflammatory disease and limits the late results of coronary revascularization. Calcitonin gene-related peptide (CGRP) inhibits macrophages infiltrated and inflammatory mediators, we hypothesized that transfected CGRP gene inhibits macrophages infiltrated and inflammatory mediators in vein graft disease. Autologous rabbit jugular vein grafts were incubated ex vivo in a solution of mosaic adeno-associated virus vectors containing CGRP gene (AAV2/1.CGRP) 、escherichia coli lac Z gene (AAV2/1.LacZ) or saline and then interposed in the carotid artery. Intima/media ratio were evaluated at postoperative 4 weeks, Macrophages were marked with CD68 antibody by immunocytochemistry. Inflammatory mediators were mensurated with real-time PCR. Neointimal thickening was significantly suppressed in AAV2/1.CGRP group. Macrophages infiltrated and inflammatory mediators monocyte chemoattractant protein-1 (MCP-1)、tumor necrosis factorα(TNF-α)、inducible nitricoxide synthase (iNOS)、matrix metalloproteinase-9 (MMP-9) was significantly suppressed in AAV2/1.CGRP group.Gene transfected AAV2/1.CGRP suppressed neointimal hyperplasia in vein graft disease by suppressed macrophages infiltrated and inflammatory mediators

Evolution-Operator-Based Single-Step Method for Image Processing

This work proposes an evolution-operator-based single-time-step method for image and signal processing. The key component of the proposed method is a local spectral evolution kernel (LSEK) that analytically integrates a class of evolution partial differential equations (PDEs). From the point of view PDEs, the LSEK provides the analytical solution in a single time step, and is of spectral accuracy, free of instability constraint. From the point of image/signal processing, the LSEK gives rise to a family of lowpass filters. These filters contain controllable time delay and amplitude scaling. The new evolution operator-based method is constructed by pointwise adaptation of anisotropy to the coefficients of the LSEK. The Perona-Malik-type of anisotropic diffusion schemes is incorporated in the LSEK for image denoising. A forward-backward diffusion process is adopted to the LSEK for image deblurring or sharpening. A coupled PDE system is modified for image edge detection. The resulting image edge is utilized for image enhancement. Extensive computer experiments are carried out to demonstrate the performance of the proposed method. The major advantages of the proposed method are its single-step solution and readiness for multidimensional data analysis