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Spray and wait routing algorithm based on historic throughput ratio of nodes in DTN

Journal of Computational Information Systems 2015年第19期11卷 6967-6974页

作者： Wang, Guizhu Li, Run Shao, Mei Ma, Yao Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University Hefei China

The performance of nodes shows great differences in Delay Tolerant Network (DTN). In order to estimate the performance of nodes in a more effective way, we put forwarded the concept of historic throughput ratio of nodes (HTR). Afterward, we proposed the Spray and Wait Routing algorithm based on historic throughput ratio of nodes (HTR-SW) in DTN Network. The algorithm uses the ratio of HTR to assign the number of message copies to the encounter nodes dynamically and to select the right length of messages sprayed to the encounter nodes. It not only solves the problem of being random and blind when using the Binary Spray and Wait (BSW) routing to spray the number of message copies, but also assigns the right length of messages according to the performance of the encounter nodes. The simulation results show that compared with the BSW algorithm, HTR-SW algorithm can enhance the message delivery probability, reduce the average latency and network overhead. At the same time, it can also reduce the number of messages forwarded by relay-nodes in the DTN network significantly. © 2015 by Binary Information Press.

关键词： Throughput

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Research on bearing micro deformation based on the frequency domain technique of white light speckle image

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Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument 2016年 37卷 46-52页

作者： Feng, Bo Xu, Chao Shao, Deyang Luo, Shixian Anhui Engineering Laboratory of Agro-Ecological Big Data Anhui University Hefei230601 China Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Hefei230601 China

In this paper, a new method of non contact and on-line measurement is presented for the change of the axis of the rotation axis. Under the condition of a constant light source, the image of the original position and the offset image in the original position are collected by the micro camera, These two pictures are calculated by the improved White light digital image point by point analysis method in this paper, and get the black and white stripes. The number and the angle of the fringe in the white light digital frequency domain interference image can be known as the offset and direction of the rotating shaft in the rotating process. Because this method only use a camera and a light source, and this method is very simple, and it can always detect, and it does not affect the normal work, so there is a wide range of industrial application prospects. This method can provide alarm before the plastic deformation occurs in the shaft, Reduce the risk of shaft damage. © 2016, Science Press. All right reserved.

关键词： Frequency domain analysis

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Design of hardware-in-the-loop simulation system for LTE-A system based on USRP

Design of hardware-in-the-loop simulation system for LTE-A s...

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IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Zhaoming Chen Yanjun Hu Xue Wang Haowen Wang Delin Cai Ministry of Education Key laboratory of Intelligent Computing & Signal Processing (Anhui University) Hefei P.R.China Shanghai Research Center for Wireless Communications Shanghai P.R.China China Electronics Technology Group Corporation No.38 Research Institute Hefei P.R.China

ISBN: (纸本)9781467386456

The traditional LTE-A algorithm validation is limited to pure computer software simulation, which can't simulate the actual link scenes, missing scene parameters, the simulation results is invaluable in practice. Therefore, this paper designs LTE-A hardware-in-the-loop simulation system based on software-defined radio device USRP, and the physical layer real-time test level downlink is designed on the system. The downlink scheduled by the scheduling algorithm of the PC simulation platform, with scene parameters feedback to MAC layer in real time. The downlink designed with power interference between cells and users simulate the actual scene. Compare to current design of LTE hardware-in-the-loop simulation, this design presents data interaction between MAC layer and physical layer, implement of specific requirements for physical layer link, instead of generation of vector signal only. The results show that the system is running normally with easy scalab.lity.

关键词： Physical layer Interference Long Term Evolution Downlink Real-time systems Hardware Atmospheric modeling

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Numerical Simulation of Infrared Photodetectors with Au Gratings by FDFD Method

Numerical Simulation of Infrared Photodetectors with Au Grat...

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The 6th International Symposium on Microwave,Antenna,Propagation,and Electromagnetic Compatibility Technologies(MAPE 2015)

作者： Lulu Cheng Zhixiang Huang Jie Xu Xianliang Wu Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University

Quantum-well infrared photodetectors have been studied extensively due to their night vision, astronomy and environmental monitoring research in recent years. However, responsivity and detectivity are relatively low in these photodetectors without the Au gratings. Therefore, the Au grating will be employed on the surface of photodetector with periodic structure due to the principle of spoof plasmon resonance. The new design mainly aims to enhance the absorption in the QW active region based on the Au grating and can be numerically simulated by using finite-difference frequency-domain method. With optimal grating parameters, the absorption can be enhanced by hundreds of times compared with that in the reference structure without grating. The theoretical results provide the realistic organic infrared photodetectors with theoretical basis and technical support.

关键词： Au grating photodetector finite-difference frequency-domain plasmon resonance

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A Novel Open Slot Wideband Antenna with Enhanced Bandwidth

A Novel Open Slot Wideband Antenna with Enhanced Bandwidth

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2015 International Conference on Electrical and Electronics: Techniques and Applications(EETA 2015)

作者： Yuan ZHU You DING Min-quan LI Key Laboratory of Intelligent Computing & Signal Processing Ministry of EducationAnhui University

In this paper, a novel open slot wideband antenna with enhanced bandwidth is presentedMultiple resonances are generated by the rectangular patch and a C-shaped slot etched on the groundFurthermore, a metal cylinder is used in antenna structure which leads to the bandwidth enhancement of the proposed antennaBoth the simulated and measured results show that the proposed antenna can provide a wide impedance bandwidth of 94.1% from 3.13 to 8.7 GHz with 10-dB return lossCompared with the conventional L-slot wideband antenna with an impedance bandwidth of 72.7%, ranging from 3.1 to 7.0GHz, the impedance bandwidth of the proposed antenna is increased by 21.4%Moreover, the impedance bandwidth can be altered by changing the dimension of the metal cylinder's radius within limits.

关键词： Bandwidth enhancement Impedance bandwidth Open slot Wideband antenna

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Dynamic Analysis of Urban Landscape Patterns of Vegetation Coverage Based on Multi-temporal Landsat Dataset

Dynamic Analysis of Urban Landscape Patterns of Vegetation C...

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The 9th International Conference on Computer and computing Technologies in Agriculture (CCTA 2015)

作者： Dong Liang Ling Teng Linsheng Huang Xinhua Xie Yan Zuo Jingling Zhao Key Laboratory of Intelligent Computing and Signal Processing Ministry of EducationAnhui University

ISBN: (纸本)9783319483566

Dynamic monitoring of vegetation coverage changes, especially on a relatively large temporal scale, have important practical significance in urban planning and environmental protection. The objective of this study is to dynamically investigate the urban landscape patterns of vegetation coverage based on remote sensing techniques. Multi-temporal Landsat images of 1990,2000 and 2013 were firstly used to produce three vegetation coverage maps of HefeiCity, AnhuiProvince, China with five grades using the NDVI(Normalized Difference Vegetation Index) dimidiate pixel model. Subsequently, a total of eight landscape pattern indictors in FRAGSTATS 4.2 were selected to analyze the dynamic characteristics of area, quantity and density for the study area with different vegetation coverage grades. The results showed that(1) the dominant vegetation coverage of 1990, 2000 and 2013 were the high vegetation coverage, the moderate vegetation coverage and the moderate-to-high vegetation coverage, respectively. The acreage of non-vegetation coverage increased by1.89 %, while the high vegetation coverage decreased by 10.48 % from 1990 to2013;(2) the quantity and density of patches decreased by 33.42 % and33.41 % during 1990–2013. Shannon's diversity index and Shannon's evenness index increased from 0.92 in 1990 to 0.97 in 2000, and then declined to 0.96 in2013;and(3) the contagion index had an upward trend and conversely the aggregation index showed no significant changes, but both of them were close to1 during 1990–2013. In comparison with natural in fluences, the primary driving forces causing the changes were ascribed to human factors including the rapid population growth and fast-growing urban areas.

关键词： Landscape pattern Vegetation coverage Normalized difference vegetation index (NDVI) Landsat Remote sensing Coverage Landsat satellites vegetation remote sensing Landscape Patterns Dynamic analysis urban landscape normalized difference vegetation index

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A Novel DGS to Bandpass Filter Design

A Novel DGS to Bandpass Filter Design

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2015 2nd International Workshop on Materials Engineering and Computer Sciences(IWMECS 2015)

作者： Hongqing He Minquan Li Yu Zhang Key Laboratory of Intelligent Computing & Signal Processing Ministry of EducationAnhui University

In this paper, a novel symmetrical split-ring resonators defected ground structure(DGS) wideband bandpass filter is proposedThis filter exhibits advantages such as miniaturization, large range of bandwidth and easy fabricationThis paper analyzes the symmetrical split-ring resonators DGS unit and the bandpass filter with three symmetrical split-ring resonators DGS is designedThe simulation and testing show that the bandpass filter with the novel DGS provides insertion loss of 0.9d B, return loss of-12.5d B, and the relative bandwidth achieves 7%.

关键词： bandpass filter defected ground structure miniaturization split-ring resonator

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A Novel Coplanar Waveguide Fed Ultra-Wideband Antenna With Dual Band-notched Characteristics

A Novel Coplanar Waveguide Fed Ultra-Wideband Antenna With D...

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2015 3rd International Conference on Machinery,Materials and Information Technology Applications(ICMMITA 2015)

作者： Ya-dong Wei Min-quan Li Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University

A novel ultra-wideband( UWB) antenna is proposed in this paper,which has a band-notched characteristic for the interference between the UWB applications and the IEEE802.11 a wireless local area network(WLAN) and the Wi MAX /C-band with combination of notched structures. The proposed antenna fed by coplanar waveguide( CPW),with modified U-slots and general U-slot in echelon patch which can be used to reject the frequency 5.15 to 5.825 GHz, 3.3 to 3.6GHz,and 3.7 to 4.2GHz. The simulation results show that the antenna has obvious band-notched characteristics in the notched band which can effectively prevent the interference of these narrow-band communication systems, and also has well radiation characteristics in the whole band.

关键词： UWB antenna dual-notched bands coplanar waveguide(CPW) combination of notched structures

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A logarithmic backoff algorithm based on dynamic contention window adjustment for IEEE 802.11 DCF

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Journal of Computational Information Systems 2014年第17期10卷 7609-7617页

作者： Xu, Lei Wang, Li Xun, Huili H., Zhang X., Li Key Lab. of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei China

IEEE 802.11 is a protocol standard widely used in wireless local area network (WLAN). For the distributed coordination function (DCF) of IEEE 802.11 MAC layer, the binary exponential backoff (BEB) algorithm has the defect of poor access fairness. To address this issue, the design criteria of backoff algorithm is generalized from the analysis of the key performance parameters of DCF, and then a logarithmic backoff (LB) algorithm based on dynamic contention window (CW) adjustment is proposed. The algorithm dynamically adjusts the initial value of CW and the backoff size of the CW by using the logarithmic function that takes the number of network competing nodes as the variable. Simulation results show that compared with the BEB algorithm, the LB algorithm can effectively improve the fairness performance and the throughput performance, and also reduce network delay.

关键词： IEEE Standards

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A full-rate cooperative relay transmission scheme with randomized cyclic delay diversity

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Journal of Computational Information Systems 2014年第1期10卷 275-284页

作者： Xu, Lei Bao, Menglin Jiang, Ran Zhang, Hongwei Li, Xiaohui Key Lab. of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei 230039 China

Randomized cyclic delay diversity (RCDD) is an effective means to capture both the space diversity and the frequency diversity with low complexity detection over frequency-selective fading channels. Since many existing full-rate cooperative relay transmission schemes have the disadvantages of low spectrum efficiency and high complexity detection, a practical and low complexity detection full-rate distributed cooperative relay transmission scheme is proposed in this paper by taking advantages of the randomized cyclic delay diversity method and the linear constellation precoding (LCP) technology. The bit error rate (BER) performance of the proposed scheme is superior to that of the system with fixed cyclic delay diversity (FCDD) when the number of subcarriers is sufficiently large. Moreover, the system diversity gain improves with the multipath number of the frequency-selective fading channel and the relay number increases. Copyright © 2014 Binary Information Press.

关键词： Cooperative communication

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