检索结果-南通市图书馆

Compact all-optical switches based on photon-induced suppression of mode interference

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2006年第2期4卷 93-95页

作者：李龙志唐奕杨建义王明华江晓清 department of information and Electronic Engineering

An optically activated optical switch based on suppression of mode interference （SMI） is presented. The imaging properties of multi-mode interference （MMI） section in the switch with Y-branch can be modified by a controlling light injection. The switch was simulated by finite difference beam propagation method （FD-BPM） and fabricated on GaAlAs/GaAs epitaxial materials. At the wavelength of 1.31 μm, the primary experiment showed an extinction ratio of about 8 dB with controlling light power density of 73.5 W/mm^2.

关键词： Computer simulation Finite difference method Image quality Interference suppression Light extinction Photons Semiconducting gallium arsenide Semiconducting gallium compounds

Recommendation application for video head impulse test based on fuzzy logic control

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第5期23卷 1208-1214页

作者： NGUYEN Thi Anh Dao KIM Dae Young LEE Sang Min KIM Kyu Sung Seong Ro Lee KWON Jang Woo department of Computer and information Engineering Inha University department of Otorhinolaryngology Inha University Hospital department of Electronic Engineering Inha University department of information and Electronics Engineering Mokpo National University

Vestibulo-ocular reflex(VOR) is an important biological reflex that controls eye movement to ensure clear vision while the head is in ***,VOR measurement is commonly done with a video head impulse test based on a velocity gain algorithm or a position gain algorithm,in which velocity gain is a VOR calculation on head and eye velocity,whereas position gain is calculated from head and eye *** aim of this work is first to compare the two algorithms' performance and to detect covert catch-up saccade,then to propose a stand-alone recommendation application for the patient's *** the first experiment,for ipsilesional and contralesional sides,the calculated position gain(0.94±0.17) is higher than velocity gain(0.84±0.19).Moreover,gain asymmetry of both lesion and intact sides using velocity gain is mostly higher than that from using position gain(four out of five subjects).Consequently,for subjects who have unilateral vestibular neuritis diagnosed from clinical symptoms and a vestibular function test,vestibular weakness is depicted by velocity gain much better than by position *** catch-up saccade and position gain then are used as inputs for recommendation applications.

关键词： vestibulo-ocular response video head impulse velocity gain position gain desaccade

Affine & Scale-Invariant Heterogeneous Pyramid Features for Automatic Matching of High Resolution Pushbroom Imagery from Chang'e 2 Satellite

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2016年第4期27卷 716-726页

作者： Sheng Yang Shibing Zhu Zhenju Li Xuejun Li Tao Liu Jue Wang Jianwei Xie department of information Equipment the Equipment Academy

The automatic feature extracting and matching for large amount of linear pushbroom imagery with higher and higher resolution is urgent and challenging in three dimensional reconstructions, remote sensing and mapping. Affine ＆ scale-invariant heterogeneous pyramid feature is proposed in this paper, along with the new scale-invariant analysis method, the detecting of the key points, the affine ＆ scale-invariant descriptor, the steering method of the matching, and the quasi-dense matching algorithm based on the extensive epipolar geometry. The automatic matching is devised for the linear pushbroom imagery. The whole process is executed on lunar images of the highest resolution of ~7 m/pixel（or ~1 m/pixel in the lower orbits） from the Chinese Chang＇e 2 satellite, it runs robustly at present, and resulting in large amounts of well-distributed-correspondences with accuracy of 0.3 pixels and excellent reliability, which gives great support for the further exploration both on the Moon and the Earth.

关键词： image matching linear pushbroom imagery epipolar geometry quasi-dense matching.

A Novel Goodness of Fit Test Spectrum Sensing Using Extreme Eigenvalues

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第6期29卷 1201-1206页

作者： LI He ZHAO Wenjing LIU Chang JIN Minglu YOO Sang-Jo School of information and Communication Engineering Dalian University of Technology department of information and Communication Engineering Inha University

The existing Goodness of fit(GoF) test based spectrum sensing algorithms mostly use samples or energies as observations to make decisions,which can hardly achieve satisfactory performance especially when the Primary user(PU) signals are highly ***,the eigenvalue of covariance matrix can reflect signal correlations *** by this,we study the distribution of eigenvalue and propose an eigenvalue based GoF spectrum sensing *** the proposed scheme,we use the ratios of maximum to minimum eigenvalue as observations and thus it can bring performance improvements through capturing correlation of PU *** also provide the related theoretical analysis for the proposed *** results show that the proposed method overcomes the problem of noise uncertainty and achieves performance improvement over the classical samples-based GoF test.

关键词： correlation methods covariance matrices eigenvalues and eigenfunctions radio spectrum management signal denoising signal detection signal sampling eigenvalue based GoF spectrum sensing algorithm goodness of fit test spectrum sensing algorithm GoF test based spectrum sensing algorithm primary user signal covariance matrix eigenvalue signal correlation Cognitive radio spectrum sensing goodness of fit test eigenvalue

Prediction Model for Coronavirus Pandemic Using Deep Learning

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2022年第3期40卷 947-961页

作者： Mamoona Humayun Ahmed Alsayat department of information Systems College of Computer and Information SciencesJouf UniversityKSA department of Computer Science College of Computer and Information SciencesJouf UniversityKSA

The recent global outbreak of COVID-19 damaged the world health systems,human health,economy,and daily life *** of the countries was ready to face this emerging health *** professionals were not able to predict its rise and next move,as well as the future curve and impact on lives in case of a similar pandemic situation *** created huge chaos globally,for longer and the world is still struggling to come up with any suitable *** the better use of advanced technologies,such as artificial intelligence and deep learning,may aid healthcare practitioners in making reliable COVID-19 *** proposed research would provide a prediction model that would use Artificial Intelligence and Deep Learning to improve the diagnostic process by reducing unreliable diagnostic interpretation of chest CT scans and allowing clinicians to accurately discriminate between patients who are sick with COVID-19 or pneumonia,and also empowering health professionals to distinguish chest CT scans of healthy *** efforts done by the Saudi government for the management and control of COVID-19 are remarkable,however;there is a need to improve the diagnostics process for better *** used a data set from Saudi regions to build a prediction model that can help distinguish between COVID-19 cases and regular cases from CT *** proposed methodology was compared to current models and found to be more accurate(93 percent)than the existing methods.

关键词： Artificial Intelligence(AI) deep learning(DL) COVID-19 pandemic

Photonic crystal fibre Brillouin laser based on Bragg grating Fabry-Perot cavity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第3期17卷 1020-1024页

作者：耿丹杨冬晓沈国锋章献民 department of information & Electronic Engineering Zhejiang University

A photonic crystal fibre Brillouin laser based on fibre Bragg grating Fabr-Perot cavity is presented. A highly nonlinear photonic crystal fibre 25 m in length is used as Brillouin gain medium and fibre Bragg grating Fabry-Perot cavity is chosen in order to enhance the laser conversion efficiency and suppress the higher-order Stokes waves. The laser reaches the threshold at input power of 35 mW, and the experimental laser conversion efficiency achieves 18% of the input power of 140 mW and does not show higher-order Stokes waves. A photonic crystal fibre Brillouin laser with shorter fibre length and lower threshold is experimentally realized.

关键词： photonic crystal fibre two-frequency laser stimulated Brillouin scattering

To narrow laser linewidth by utilizing dispersion characteristics of Gires-Tournois etalon

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第7期7卷 608-610页

作者：胡宗福 department of information and Communication Engineering Tongji University

A longer laser resonator length is benefit for laser linewidth, but harmful for single-frequency operation. A novel way is suggested to narrow the bandwidth of a Fabry-Perot （FP） cavity through increasing the derivative of one round-trip phase shift with respect to the frequency. It can be implemented by replacing one of two FP mirrors with a Gires-Tournois etalon （GTE）, called FPCT, as a dispersion element. FPGT resonator has additional axial modes due to the GTE reflection phase shift. Theoretical analyses show that the bandwidth of additional axial modes can be 1% of that of a conventional FP cavity. A distributed feedback （DFB） laser diode can employ FPGT resonator to achieve ultra-narrow linewidth laser. It is shown that the effect of refractivity fluctuation in the gain medium on the linewidth is little, and kilohertz linewidth is achievable for such a device.

关键词： Dispersions Etalons Laser resonators Phase shift Resonators

Quantum entanglement and nonlocality properties of two-mode Gaussian squeezed states

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第2期18卷 418-425页

作者：向少华邵彬宋克慧 department of Physics Beijing Institute of Technology Research Institute of information Science Huaihua University department of Physics and Electronic information Science Huaihua University

Quantum entanglement and nonlocality properties of a family of two-mode Gaussian pure states have been investigated. The results show that the entanglement of these states is determined by both the two-mode squeezing parameter and the difference of the two single-mode squeezing parameters. For the same two-mode squeezing parameter, these states show larger entanglement than the usual two-mode squeezed vacuum state. The violation of Bell inequality depends strongly on all the squeezing parameters of these states and disappears completely in the limit of large squeezing. In particular, these states can exhibit much stronger violation of local realism than two-mode squeezed vacuum state in the range of experimentally available squeezing values.

关键词： entanglement nonlocality Gaussian state

Enhancing synchronizability by rewiring networks

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2010年第8期19卷 72-79页

作者：王立夫王庆利孔芝井元伟 department of Automation and Engineering Northeastern University at Qinhuangdao School of information Science and Engineering Northeastern University department of information and Engineering Shenyang Institute of Engineering

According to different forms of synchronized region, complex networks are divided into type Ⅰ （unbounded synchronization region） and type Ⅱ （bounded synchronization region） networks. This paper presents a rewiring algorithm to enhance the synchronizability of type Ⅰ and type Ⅱ networks. By utilizing the algorithm for an unweighted and undirected network, a better synchronizability of network with the same number of nodes and edges can be obtained. Numerical simulations on several different network models are used to support the proposed procedure. The relationship between different topological properties of the networks and the number of rewirings are shown. It finds that the final optimized network is independent of the initial network, and becomes homogeneous. In addition the optimized networks have similar structural properties in the sense of degree, and node and edge betweenness centralities. However, they do not have similar cluster coefficients for type Ⅱ networks. The research may be useful for designing more synchronizable networks and understanding the synchronization behaviour of networks.

关键词： synchronizability rewire networks complex networks optimized network network structural property