Throughput Optimization via Association Control in Wireless LANs

With the rapid development of the mobile computing, accessing the Internet everywhere is important for mobile device users. Wireless LAN is a stable and reliable technique to provide network access for mobile devices. The Wireless LAN Access Points(APs) have been densely deployed so that a user can access the Internet almost everywhere. However, this fact brings some new challenges. Since the regular AP association strategy is signal-based when a user receive the signals of multiple APs. The APs with strong signal will be too overloaded while the bandwidth resource in other APs is wasted. The throughput of the whole WLAN is not optimized. Moreover, the diverse bandwidth demands among users further exacerbate the situation. In this paper, aiming at optimizing the throughput over the whole WLAN, a joint AP association and bandwidth allocation problem is formulated. The different users’ bandwidth demands are added as new constraints. We comprehensively analyze the solution space and prove the problem NP-hard. Our trace-driven evaluations show that the throughput is improved about 23.1 % compared to the conventional schemes.     

500kV顺德站VQC软件使用需求调研及实用化方案

500kV顺德站VQC软件实用化将大大减轻运行人员的工作量,为500kV顺德站以后实现无人值班提供的技术保障。本文对顺德站VQC软件使用进行需求调研以及实用化的过程详细介绍。对500kV变电站VQC软件使用的可行性、技术要求、现场测试、改进措施等进行了介绍,为500kV变电站VQC软件推广应用提供了借鉴及应用经验。     

Dual-material gate (DMG) field effect transistor

A generic new type of field effect transistor (FET), the dual material gate (DMG) FET, is proposed and demonstrated. The gate of the DMGFET consists of two laterally contacting materials with different work functions. This novel gate structure takes advantage of material work function difference in such a way that the threshold voltage near the source is more positive than that near the drain (for n-channel FET, the opposite for p-channel FET), resulting in a more rapid acceleration of charge carriers in the channel and a screening effect to suppress short-channel effects. Using the heterostructure FET as a vehicle, the principle, computer simulation results, design guidelines, processing, and characterization of the DMGFET are discussed in detail     

ENIG的耐蚀性：一种改进的浸金工艺

为了了解ENIG化学变化对浸金耐蚀性的形响,探讨了浸金电镀溶液的pH值和化学性质与结果所得到的浸金层的耐蚀性之间的关系。     

The role of cesium fluoride as an n-type dopant on electron transport layer in organic light-emitting diodes

We report on the role of cesium fluoride (CsF) doping on the enhanced electron transport properties of tris-(8-hydroxyquinolin) aluminum (Alq₃) for organic light-emitting diodes. The electronic structures of CsF-doped Alq₃ layers with various doping concentration are characterized by in situ ultraviolet and X-ray photoelectron spectroscopies, showing an n-type electrical doping effect with Fermi level shift towards unoccupied molecular orbital and the formation of chemistry-induced gap-states. The increase in conductivity and reduction in electron injection barrier in CsF-doped Alq₃ layer with optimal doping concentration lead to the enhanced electron injection and transport, which are consistent with the improved electrical characteristics of OLEDs.     

Ge-nanoclusters embedded in Ge-doped silica-on-silicon waveguides

Ge-nanoclusters were formed by electron-beam irradiation in Ge-doped silica-on-silicon thin films. The size and density of the clusters can be controlled by the irradiation intensity and time.     

Automatic generation of boundary conditions using demons nonrigid image registration for use in 3-D modality-independent elastography

Modality-independent elastography (MIE) is a method of elastography that reconstructs the elastic properties of tissue using images acquired under different loading conditions and a biomechanical model. Boundary conditions are a critical input to the algorithm and are often determined by time-consuming point correspondence methods requiring manual user input. This study presents a novel method of automatically generating boundary conditions by nonrigidly registering two image sets with a demons diffusion-based registration algorithm. The use of this method was successfully performed in silico using magnetic resonance and X-ray-computed tomography image data with known boundary conditions. These preliminary results produced boundary conditions with an accuracy of up to 80% compared to the known conditions. Demons-based boundary conditions were utilized within a 3-D MIE reconstruction to determine an elasticity contrast ratio between tumor and normal tissue. Two phantom experiments were then conducted to further test the accuracy of the demons boundary conditions and the MIE reconstruction arising from the use of these conditions. Preliminary results show a reasonable characterization of the material properties on this first attempt and a significant improvement in the automation level and viability of the method.     

A new method of Frequency-Hopping (FH) signal detection

A new Frequency-Hopping (FH) signal detection method is proposed. Different from previous methods which need to monitor the total band, it can monitor part of the band and decrease the range of the bandwidth. According to this method, a new detection model is set and the computation formulas of the detection probability and false-alarm probability are given. The parameters of a VHF radio are used to prove the validity of the method. Simulation results show that this method can decrease the range of the bandwidth and detect the FH signal with some penalty on the SNR and signal loss.     

基于移动支付的自动售货机

主要介绍一种采用SIEMENS MC35模块实现移动支付功能的自动售货机设计方案。文中简要说明了MC35模块、移动支付流程及MDB总线；设计了一种基于MC35模块的自动售货机结构，并给出总线转换接口的软硬件实现思路。