检索结果-内蒙古大学图书馆

Generation and time jitter of the loose soliton bunch in a passively mode-locked fiber laser

Chinese Optics Letters 2017年第8期15卷 26-29页

作者：王振洪王志刘艳格贺瑞敬王光斗杨光韩思濛 Key Laboratory of Optical Information and Technology Ministry of EducationTianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology and Institute of Modern Optics Nankai University Tianjin 300350 China

Passively mode-locked fiber lasers （PMLFLs） could be not only used as simple and economic ultrashort pulse sources but also as an ideal platform for exploring the nonlinear dynamics of dissipative solitons such as b... 详细信息

关键词： mode Generation and time jitter of the loose soliton bunch in a passively mode-locked fiber laser time

来源：评论

学校读者我要写书评

暂无评论

Coverage Performance Analysis of Grid Distribution in Heterogeneous network

Coverage Performance Analysis of Grid Distribution in Hetero...

引用

2017 17th IEEE International Conference on Communication technology (ICCT 2017)

作者： Xueming Sui Hui Zhang Yuanhong Lv Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Nankai University

With the growth of wireless communication services, large base stations will not only produce a lot of electromagnetic radiation, but also bring huge energy consumption, resulting in a large number of greenhouse gases. The fifth generation mobile communication will deploy the macro base stations and the micro base stations in multi-layer heterogeneous network to enhance the system network performance, reducing the negative impact of abovementioned factors. According to the theory of cell communication, in this paper, by adding the micro base stations distributed in different grid modes in the surrounding area of the macro base station, the purpose is to maximize the total area covered by the base stations in the cell under the condition that the total power consumption of the base stations is not increased.

关键词： heterogeneous network base station distribution cellular network Voronoi diagram coverage performance

来源：评论

学校读者我要写书评

暂无评论

Analysis of Base Stations Deployment on Power Saving for Heterogeneous network

Analysis of Base Stations Deployment on Power Saving for Het...

引用

2017 17th IEEE International Conference on Communication technology (ICCT 2017)

作者： Yuanhong Lv Hui Zhang Sui Xueming NanKai University Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology

With the increasing of energy consumption in the wireless network, Heterogeneous network(Het Net) is used to improve the capability of communication networks, save transmitting power of base stations(BSs), enhance the coverage of communication network and so on. Designing an energy efficient network should not only consider the energy efficient operation of BSs, but also take the energy efficiency of mobile devices(MDs) into account. This paper considers the energy efficiency of BSs and MDs and studies the power saving of Het Net from a more comprehensive and systematic perspective. This paper mainly analyzes the deployment of a certain number of micro BSs in the region which has a certain number of macro BSs, and compares the power saving indicator at different radius of the micro BSs in three algorithms, which are that the region-based deployment algorithm, the grid-based deployment algorithm and the greedy BSs deployment algorithm. The greedy BSs deployment algorithm is used to determine the most suitable positions of micro BSs, in order to maximize the overall power saving indicator of the entire Het Net.

关键词： HetNet energy efficiency power saving Base Stations Deployment mobile device

来源：评论

学校读者我要写书评

暂无评论

Corrections to “Label-Free Detection of DNA Hybridization Utilizing Dual S-Tapered Thin-Core Fiber Interferometer”

引用

Journal of Lightwave technology 2019年第19期37卷 5158-5158页

作者： Xu Zhang Bo Liu Hao Zhang Binbin Song Jixuan Wu Shaoxiang Duan Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University Tianjin China Key Laboratory of Computer Vision and Systems Ministry of Education School of Computer Science and Engineering Tianjin University of Technology Tianjin China College of Electronic and Information Engineering Tianjin Polytechnic University Tianjin China

Presents corrections to above named paper.

关键词： Biosensors DNA Optical fiber sensors Molecular biophysics Microsensors

来源：评论

学校读者我要写书评

暂无评论

Coupled dielectric-metal subwavelength gratings for terahertz polarization converter and one-way transmission

Coupled dielectric-metal subwavelength gratings for terahert...

引用

optoelectronics and Communications Conference, OECC

作者： Shi-Tong Xu Fei Fan Xiang-Hui Wang Sheng-Jiang Chang Key Laboratory of Optical Information Science and Technology Nankai University Tianjin Tianjin China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin Tianjin China

A dielectric-metal double layer grating structure is proposed for high performance of polarization converter and one-way transmission in the terahertz (THz) region. The results show that this composite grating structure achieves a high polarization conversion of 90% and a broadband one-way transmission with an extinction nearly 30dB from 0.2 to 1.2THz. It provides a simple way towards practical applications for THz polarization control and one-way transmission.

关键词： Gratings Metals Dielectrics Polarization Broadband communication Silicon Wires

来源：评论

学校读者我要写书评

暂无评论

Towards clinical diagnosis: Automated stroke lesion segmentation on multimodal MR image using convolutional neural network

arXiv

引用

arXiv 2018年

作者： Liu, Zhiyang Cao, Chen Ding, Shuxue Han, Tong Wu, Hong Liu, Sheng Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University Tianjin300071 China Key Laboratory for Cerebral Artery and Neural Degeneration of Tianjin Department of Medical Imaging Tianjin Huanhu Hospital Nankai University Tianjin300350 China School of Computer Science and Engineering University of Aizu Aizu-Wakamatsu Fukushima965-8580 Japan School of Basic Medical Sciences Tianjin Medical University Tianjin300071 China

The patient with ischemic stroke can benefit most from the earliest possible definitive diagnosis. While the high quality medical resources are quite scarce across the globe, an automated diagnostic tool is expected in analyzing the magnetic resonance (MR) images to provide reference in clinical diagnosis. In this paper, we propose a deep learning method to automatically segment ischemic stroke lesions from multi-modal MR images. By using atrous convolution and global convolution network, our proposed residual-structured fully convolutional network (Res-FCN) is able to capture features from large receptive fields. The network architecture is validated on a large dataset of 212 clinically acquired multi-modal MR images, which is shown to achieve a mean dice coefficient of 0.645 with a mean number of false negative lesions of 1.515. The false negatives can reach a value that close to a common medical image doctor, making it exceptive for a real clinical application. Copyright © 2018, The Authors. All rights reserved.

关键词： Magnetic resonance imaging

来源：评论

学校读者我要写书评

暂无评论

An improved time-domain channel estimation using compressive sensing based on wavelet transform multicarrier modulation system

An improved time-domain channel estimation using compressive...

引用

International Conference on Computer and Communications (ICCC)

作者： Yuting Zhang Hong Wu Bing Liu Sicong Zhang Yu Zhang Yingxin Zhao Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin China College of Electronic Information and Optical Engineering Nankai University Tianjin China

ISBN: (纸本)9781509063536;9781509063529

Compared with OFDM, wavelet-based multi-carrier modulation system, due to the utilization of wavelet basis to construct the channels, have not only the orthogonal sub-channels but also the orthogonal transmission symbols of each sub-channel, which means it can resist ICI effectively without inserting CP. These characteristics brings great improvement of the system spectrum utilization and makes wavelet-based multi-carrier modulation system get wide attention. But the widespread use of the system is limited by high complexity of its channel estimation technology. In this paper, an improved time-domain channel estimation technique based on compressive sensing is proposed. According to the estimation feature of compressive sensing, pilot symbols are randomly inserted in time-domain, and the number of pilot symbols depends on the channel sparseness. Using the quasi-Toeplitz to construct the observation matrix makes CS channel estimation has better BER performance than traditional method. Furthermore, constructing index set using the received pilot signal and the local pilot by cross-correlation and estimating the number of iterations of the OMP reconstruction algorithm that reduces the number of iterations and the time required for the algorithm under the same reconstruction rate. In general, an improved time-domain CS channel estimation for wavelet transform multi-carrier modulation effectively reduces the system overhead and improves the precision of spectrum utilization, greatly improves the accuracy of channel estimation.

关键词： Channel estimation Wavelet transforms Modulation Time-domain analysis OFDM Finite impulse response filters

来源：评论

学校读者我要写书评

暂无评论

Group sparse precoding for cloud-RAN with multiple user antennas

arXiv

引用

arXiv 2017年

作者： Liu, Zhiyang Zhao, Yingxin Wu, Hong Ding, Shuxue Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Department of Communication Engineering Nankai University 38 Tongyan Road Jinnan District Tianjin300350 China

Cloud radio access network (C-RAN) has become a promising network architecture to support the massive data traffic in the next generation cellular networks. In a C-RAN, a massive number of low-cost remote antenna ports (RAPs) are connected to a single baseband unit (BBU) pool via high-speed low-latency fronthaul links, which enables efficient resource allocation and interference management. As the RAPs are geographically distributed, group sparse beamforming schemes attract extensive studies, where a subset of RAPs is assigned to be active and a high spectral efficiency can be achieved. However, most studies assume that each user is equipped with a single antenna. How to design the group sparse precoder for the multiple antenna users remains little understood, as it requires the joint optimization of the mutual coupling transmit and receive beamformers. This paper formulates an optimal joint RAP selection and precoding design problem in a C-RAN with multiple antennas at each user. Specifically, we assume a fixed transmit power constraint for each RAP, and investigate the optimal tradeoff between the sum rate and the number of active RAPs. Motivated by the compressive sensing theory, this paper formulates the group sparse precoding problem by inducing the 0-norm as a penalty and then uses the reweighted 1heuristic to find a solution. By adopting the idea of block diagonalization precoding, the problem can be formulated as a convex optimization, and an efficient algorithm is proposed based on its Lagrangian dual. Simulation results verify that our proposed algorithm can achieve almost the same sum rate as that obtained from an exhaustive search. Copyright © 2017, The Authors. All rights reserved.

关键词： Beamforming

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

Deterministic realization of collective measurements via pho...

引用

第十八届全国量子光学学术会议

作者：侯志博 Jun-Feng Tang Yuan Yuan Kang-Da Wu Guo-Yong Xiang Chuan-Feng Li Guang-Can Guo Jiangwei Shang Huangjun Zhu Jian Li 中科大 Key Laboratory of Quantum Information University of Science and Technology of ChinaCAS Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Naturwissenschaftlich-Technische Fakult?t Universit?t Siegen Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of Technology Institute for Theoretical Physics University of Cologne Department of Physics and Center for Field Theory and Particle Physics Fudan University State Key Laboratory of Surface Physics Fudan University Collaborative Innovation Center of Advanced Microstructures Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of Education

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.

关键词： Deterministic realization of collective measurements via photonic quantum walks

来源：评论

学校读者我要写书评

暂无评论

Whispering-gallery-mode tuning in a magnetic-fluid-infiltrated microbubble resonator based on laser-induced photo-thermal effect

Whispering-gallery-mode tuning in a magnetic-fluid-infiltrat...

引用

Asia-Pacific Optical sensors Conference, APOS 2016

作者： Li, Yuetao Zhang, Hao Liu, Bo Li, Yuhan Song, Binbin Key Laboratory of Optical Information Science and Technology Ministry of Education Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Institute of Modern Optics Nankai University Tianjin300071 China

A magnetic-fluids-infiltrated microbubble resonator is proposed and experimentally demonstrated. WGM tuning property of this microresonator under different pump laser power densities has been investigated, showing its... 详细信息

ISBN: (纸本)9780960038053

关键词： Pumping (laser)

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：