检索结果-内蒙古大学图书馆

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

来源：评论

学校读者我要写书评

暂无评论

A Novel DGS to Bandpass Filter Design

A Novel DGS to Bandpass Filter Design

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Image authentication and self-recovery scheme based on the rehashing model

引用

Journal of Information Hiding and Multimedia signal processing 2016年第3期7卷 460-474页

作者： Lyu, Wan-Li Chang, Chin-Chen Wang, Feng Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Computer Science and Technology Anhui University Hefei230039 China Department of Information Engineering and Computer Science Feng Chia University 100 Wenhwa Rd. Seatwen Taichung40724 Taiwan Department of Computer Science and Information Engineering Asia University Taichung41354 Taiwan Department of Mathematics and Physics Fujian University of Technology FuzhouFujian350108 China

An effective image tamper localization and self-recovery scheme that uses the rehashing model is proposed in this paper. The aim of the proposed scheme was to reduce the failure rate in detecting image tamper areas and achieve high rates of successful detection. To achieve this aim, the proposed scheme uses a set of hash functions which are called the rehashing model, gained an optimal decreasing collision method to detect tamper areas With an improved and accurate tamper detection rate, the tampered image can be recovered more accurately. The quality of the proposed scheme was tested with gray and color images. The experimental results indicated that the proposed scheme has good performance in locating tamper locations and allows image recovery with an acceptable visual quality up to 50% of the image content tampered. © 2016.

关键词： Hash functions

来源：评论

学校读者我要写书评

暂无评论

An integratable verifiable secret sharing mechanism

引用

International Journal of Network Security 2016年第4期18卷 617-624页

作者： Liu, Yanjun Chang, Chin-Chen Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Computer Science and Technology Anhui University No. 111 Jiulong Rd Hefei230601 China Department of Computer Science and Information Engineering Asia University No. 500 Lioufeng Rd Wufeng Taichung413 Taiwan Department of Information Engineering and Computer Science Feng Chia University No. 100 Wenhwa Rd Seatwen Taichung413 Taiwan

Threshold secret sharing (SS), also denoted as (t, n) SS, has been used extensively in the area of information se- curity, such as for group authentication, cloud storage schemes, secure parallel communication and wireless mul- tipath routing protocols. However, a (t, n) SS cannot de- tect any deceptions among the dealer and shareholders. Veriable secret sharing (VSS) overcomes the weakness of (t, n) SS in such a way that it is able to detect cheaters by verifying the validity of shares or the correctness of the recovered secret under the condition that both shares and the secret are not compromised. Recently, two non- interactive VSSs based on Asmuth-Bloom's SS were pro- posed by Harn et al. and Liu et al., respectively. Both VSSs require shareholders to examine the range of values of some integers related to the secret before recovering the secret, which is a time-consuming operation. In this paper, we propose a novel integratable VSS mechanism that integrates the concepts of the generalized Chinese remainder theorem (GCRT), Shamir's SS and Asmuth- Bloom's SS. Our proposed VSS can verify that the secret reconstructed by any t or more shareholders is the same as the one that the dealer has generated. Analysis shows that our proposed VSS can provide perfect secrecy and better efficiency.

关键词： Hash functions

来源：评论

学校读者我要写书评

暂无评论

Deterministic realization of collective measurements via photonic quantum walks

arXiv

引用

arXiv 2017年

作者： Hou, Zhibo Tang, Jun-Feng Shang, Jiangwei Zhu, Huangjun Li, Jian Yuan, Yuan Wu, Kang-Da Xiang, Guo-Yong Li, Chuan-Feng Guo, Guang-Can Key Laboratory of Quantum Information University of Science and Technology of China CAS Hefei230026 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei230026 China Naturwissenschaftlich-Technische Fakultät Universität Siegen Siegen57068 Germany Beijing Key Laboratory of Nanophotonics Ultrafine Optoelectronic Systems School of Physics Beijing Institute of Technology Beijing100081 China Institute for Theoretical Physics University of Cologne Cologne50937 Germany Department of Physics Center for Field Theory and Particle Physics Fudan University Shanghai200433 China Institute for Nanoelectronic Devices and Quantum Computing Fudan University Shanghai200433 China State Key Laboratory of Surface Physics Fudan University Shanghai200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing210093 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing210003 China

Collective measurements on identically prepared quantum systems can extract more information than local measurements, thereby enhancing information-processing efficiency. Although this nonclassical phenomenon has been known for two decades, it has remained a challenging task to demonstrate the advantage of collective measurements in experiments. Here we introduce a general recipe for performing deterministic collective measurements on two identically prepared qubits based on quantum walks. Using photonic quantum walks, we realize experimentally an optimized collective measurement with fidelity 0.9946 without post selection. As an application, we achieve the highest tomographic efficiency in qubit state tomography to date. Our work offers an effective recipe for beating the precision limit of local measurements in quantum state tomography and metrology. In addition, our study opens an avenue for harvesting the power of collective measurements in quantum information processing and for exploring the intriguing physics behind this power. Copyright © 2017, The Authors. All rights reserved.

关键词： Quantum optics

来源：评论

学校读者我要写书评

暂无评论

Distributed CoMP transmission for cell range expansion with almost blank subframe in downlink heterogeneous networks

Distributed CoMP transmission for cell range expansion with ...

引用

International Conference on intelligent computing and Internet of Things (ICIT)

作者： Yi Wang Yanjun Hu Key Laboratory of Intelligent Computing & Signal Processing Ministry of Education Anhui University Hefei Anhui Province China

ISBN: (纸本)9781479975358

The almost blank subframe (ABS) has been studied in 3GPP as a way to mitigate downlink interference experienced by cell range expansion (CRE) user equipments (UEs). However, the throughput of CRE UEs highly depends on the ratios of ABS which are statically configured in many situations. The coordinated multi-point (CoMP) is one of the key solutions standardized in LTE-A which can be implemented in CRE with ABS to exploit the abundant spatial resources. And distributed cell selection could help guarantee the UEs' performance under different range expansion biases. In this paper, a distributed CoMP method for CRE with ABS is proposed in heterogeneous networks. Simulation results show that our proposed algorithm provides considerable performance gains in the spectrum efficiency with different bias and users settings.

关键词： Algorithm design and analysis Macrocell networks Antennas

来源：评论

学校读者我要写书评

暂无评论

A distributed high-rate and low-detection complexity cooperative relay transmission scheme

引用

Journal of Information and Computational Science 2014年第18期11卷 6591-6599页

作者： Xu, Lei Jiang, Ran Zhang, Gongquan Zou, Mingquan Li, Xiaohui Key Lab of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei China

Since the existing full-rate cooperative transmission schemes have a serious defect in low Bit Error Rate (BER) performance while the existing high-rate cooperative transmission schemes have a serious defect in low spectral efficiency, a distributed high-rate cooperative relay transmission scheme based on full-rate cooperative communication model is proposed in this paper, in which Cyclic Delay Diversity (CDD) technology and Linear Constellation Precoding (LCP) technology are employed. Moreover, the proposed scheme addresses the issue of obtaining maximum spatial and multipath diversity with low decoding complexity and high transmission reliability. The BER performance of the proposed scheme is contrasted to that of the full-rate transmission scheme where better performance is achieved, and is improved when the number of the multipath or the relay nodes increases.

关键词： Bit error rate

来源：评论

学校读者我要写书评

暂无评论

A mixed structure of full-rate and low-detection complexity cooperative relay transmission scheme

引用

Journal of Computational Information Systems 2014年第21期10卷 9339-9349页

作者： Jiang, Ran Meng, Fanzhi Li, Xiaohui Key Lab of Intelligent Computing and Signal Processing of Ministry of Education Anhui University Hefei China

Since the single-antenna relay cooperative communication systems have a serious defect in reliability of data transmission, while the MIMO communication systems have difficulty in design and decoding, we propose a mixed structure of full-rate and low-detection complexity cooperative relay transmission scheme based on full-rate relay cooperative transmission model, which combines the advantages of cyclic delay diversity (CDD) technology and linear constellation precoding (LCP) technology. This scheme can excavation diversity gain by using single antenna terminal and multiple antenna simultaneously, moreover, the decoding complexity is low. The bit error rate (BER) performance is improved with the number of the antenna or the multipath or the relay nodes increases.

关键词： Cooperative communication

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：