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Chinese Physics B 2011年第3期20卷 392-397页

作者：刘炳灿于丽逯志欣 School of Science Beijing University of Posts and Telecommunications department of Fundamental Courses Academy of Armored Force Engineering

The analytic surface plasmon polaritons （SPPs） dispersion relation is studied in a system consisting of a thin metallic film bounded by two sides media of nonlinear dielectric of arbitrary nonlinearity is studied by applying a generalised first integral approach. We consider both asymmetric and symmetric structures. Especially, in the symmetric system, two possible modes can exist： the odd mode and the even mode. The dispersion relations of the two modes are obtained. Due to the nonlinear dielectric, the magnitude of the electric field at the interface appears and alters the dispersion relations. The changes in SPPs dispersion relations depending on film thicknesses and nonlinearity are studied.

关键词： surface plasmon polariton nonlinear dispersion relation planar waveguide

Low-Brightness Object Recognition Based on Deep Learning

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Computers, Materials & Continua 2024年第5期79卷 1757-1773页

作者： Shu-Yin Chiang Ting-Yu Lin department of Information and telecommunications engineering Ming Chuan UniversityTaoyuan City333Taiwan

This research focuses on addressing the challenges associated with image detection in low-light environments,particularly by applying artificial intelligence techniques to machine vision and object recognition *** primary goal is to tackle issues related to recognizing objects with low brightness *** this study,the Intel RealSense Lidar Camera L515 is used to simultaneously capture color information and 16-bit depth information *** detection scenarios are categorized into normal brightness and low brightness *** the system determines a normal brightness environment,normal brightness images are recognized using deep learning *** low-brightness situations,three methods are proposed for *** first method is the SegmentationwithDepth image(SD)methodwhich involves segmenting the depth image,creating amask from the segmented depth image,mapping the obtained mask onto the true color(RGB)image to obtain a backgroundreduced RGB image,and recognizing the segmented *** second method is theHDVmethod(hue,depth,value)which combines RGB images converted to HSV images(hue,saturation,value)with depth images D to form HDV images for *** third method is the HSD(hue,saturation,depth)method which similarly combines RGB images converted to HSV images with depth images D to form HSD images for *** experimental results,in normal brightness environments,the average recognition rate obtained using image recognition methods is 91%.For low-brightness environments,using the SD method with original images for training and segmented images for recognition achieves an average recognition rate of over 82%.TheHDVmethod achieves an average recognition rate of over 70%,while the HSD method achieves an average recognition rate of over 84%.The HSD method allows for a quick and convenient low-light object recognition *** research outcome can be applied to nighttime surveillance systems or nighttime road safety systems

关键词： Low-brightness depth image image segmentation image recognition HDV HSD

Dynamic Channel Allocation Aided Random Access for SDN-Enabled LEO Satellite IoT

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Journal of Communications and Information Networks 2021年第2期6卷 134-141页

作者： Lanting Yan Xiaojin Ding Gengxin Zhang department of Communication engineering.Nanjing University of Posts and telecommunications Nanjing 210003China

Considering the global demands on Internet of things(IoT),and the limitation of constructing base stations for the terrestrial IoT,the satellite IoT approach is a realizable and powerful supplement to the terrestrial ***,in order to dynamically access the available terrestrial and satellite networks,IoT terminals may have the ability of accessing both the terrestrial IoT and the satellite IoT,leading to great challenges on the access-control of the *** this paper,we design a satellite-terrestrial integrated architecture for the IoT relying on the software defined network(SDN).Moreover,based on this architecture,we further propose a dynamic channel resource allocation algorithm to control the access of the IoT terminals with different *** results show that the demands on the probabilities of successful access of IoT terminals with various priorities can be simultaneously met if the access of the IoT terminals are well controlled.

关键词： satellite-terrestrial integrated network software defined network random access dynamic resource allocation

Inference and optimal design on step-stress partially accelerated life test for hybrid system with masked data

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Journal of Systems engineering and Electronics 2018年第5期29卷 1089-1100页

作者： SHI Xiaolin LU Pu SHI Yimin School of Electronic engineering Xi'an University of Posts and Telecommunications department of Applied Mathematics Northwestern Polytechnical University

Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality ***, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.

关键词： hybrid system step-stress partially accelerated life test Type-Ⅱ progressively hybrid censored and masked data statistical inference optimal test plan

Mechanism of laser-induced plasma shock wave evolution in air

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Chinese Physics B 2009年第5期18卷 1877-1883页

作者：赵瑞梁忠诚韩冰张宏超徐荣青陆建倪晓武 Center for Optofluidic Technology Nanjing University of Posts and Telecommunications department of Applied Physics Nanjing University of Science and Technology College of Optoelectronic engineering Nanjing University of Posts and Telecommunications

A theoretical model is proposed to describe the mechanism of laser-induced plasma shock wave evolution in air. To verify the validity of the theoretical model, an optical beam deflection technique is employed to track the plasma shock wave evolution process. The theoretical model and the experimental signals are found to be in good agreement with each other. It is shown that the laser-induced plasma shock wave undergoes formation, increase and decay processes; the increase and the decay processes of the laser-induced plasma shock wave result from the overlapping of the compression wave and the rarefaction wave, respectively. In addition, the laser-induced plasma shock wave speed and pressure distributions, both a function of distance, are presented.

关键词： laser shock wave optical beam deflection

Characteristics of drain-modulated generation current in n-type metal-oxide-semiconductor field-effect transistor

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Chinese Physics B 2015年第7期24卷 595-600页

作者：陈海峰过立新郑璞阳董钊张茜 School of Electronic engineering Xi’an University of Posts and Telecommunications

Drain-modulated generation current IDMGinduced by interface traps in an n-type metal-oxide-semiconductor fieldeffect transistor（n MOSFET） is investigated. The formation of IDMGascribes to the change of the Si surface potential φ*** change makes the channel suffer transformation from the inversion state, depletion I state to depletion II state. The simulation result agrees with the experiment in the inversion and depletion I states. In the depletion II state, the theoretical curve goes into saturation, while the experimental curve drops quickly as VDincreases. The reason for this unconformity is that the drain-to-gate voltage VDGlessens φs around the drain corner and controls the falling edge of the IDMG *** experiments of gate-modulated generation and recombination currents are also applied to verify the reasonability of the mechanism. Based on this mechanism, a theoretical model of the IDMGfalling edge is set up in which IDMGhas an exponential attenuation relation with VDG. Finally, the critical fitting coefficient t of the experimental curves is extracted. It is found that t = 80 m V = 3k T /q. This result fully shows the accuracy of the above mechanism.

关键词： interface trap generation surface potential nMOSFET

Degradation of the transconductance of a gate-modulated generation current in nMOSFET

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Chinese Physics B 2012年第8期21卷 564-569页

作者：陈海峰过立新杜慧敏 School of Electronic engineering Xi'an University of Posts and Telecommunications

The degradation of transconductance （G） of a gate-modulated generation current IGD in a LDD nMOSFET is investigated. The G curve shifts rightward under the single electron-injection-stress （EIS）. The trapped electrons located in the gate oxide over the LDD region （QL） makes the effective drain voltage diminish. Accordingly, the G peak in depletion （GMD） and that in weak inversion （GMw） decrease. It is found that △GMD and △GMw each have a linear relationship with the n-th power of stress time （tn） in a dual-log coordinate： △GMD octn, AGMD octn （n = 0.25）. During the alternate stress, the injected holes neutralize QL induced by the previous EIS. This neutralization makes the effective VD restore to the initial value and then the IGD peak recovers completely. Yet the threshold voltage recovery is incomplete due to the trapped electron located over the channel （Qc）. As a result, GMW only recovers to circa 50% of the initial value after the hole-injection-stress （HIS）. Instead, GMD almost recovers. The relevant mechanisms are given in detail.

关键词： generation current transconductance electron injection alternate stress degradation

Recent advances and future challenges for mobile network virtualization

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Science China(Information Sciences) 2017年第4期60卷 5-16页

作者： Xiaofeng TAO Yan HAN Xiaodong XU Ping ZHANG Victor C.M.LEUNG National engineering Lab for Mobile Network Technologies Beijing University of Posts and Telecommunications State Key Lab of Networking & Switching Technology Beijing University of Posts and Telecommunications department of Electrical and Computer engineering The University of British Columbia

Recently, network function virtualization(NFV) was proposed as a paradigm shift in the telecommunication industry. Both industry and academia have drawn significant attention in mobile network *** decouples the software implementation of network functions from the underlying hardware, leading to considerable reductions in operating expenses(OPEX) and capital expenses(CAPEX), and facilitating the network deployment. However, as an emerging technology, NFV brings both challenges and opportunities in developing new architectures, applying and deployment. In this paper, we first survey the related work of NFV, and then propose promising research directions in this area.

关键词： network function virtualization mobile networks software defined networking network functions 5G network slicing

Efficient closed-form solution for target localization using TDOA measurements in the presence of sensor position errors

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The Journal of China Universities of Posts and telecommunications 2017年第4期24卷 1-9,15页

作者： Yan Leibing Zhang Yerong Lu Yin School of Electronic Science and engineering Nanjing University of Posts and Telecommunications department of Electronics and Communication engineering Henan Institute of Technology

An efficient solution for locating a target was proposed, which by using time difference of arrival （TDOA） measurements in the presence of random sensor position errors to increase the accuracy of estimation. The cause of position estimation errors in two-stage weighted least squares （TSWLS） method is analyzed to develop a simple and effective method for improving the localization performance. Specifically, the reference sensor is selected again and the coordinate system is rotated according to preliminary estimated target position by using TSWLS method, and the final position estimation of the target is obtained by using weighted least squares （WLS）. The proposed approach exhibits a closed-form and is as efficient as TSWLS method. Simulation results show that the proposed approach yields low estimation bias and improved robustness with increasing sensor position errors and thus can easily achieve the Cramer-Rao lower bound （CRLB） easily and effectively improve the localization accuracy.

关键词： target localization TDOA sensor position errors CRLB

Flood Avoidance Mechanisms for Bridged Resilient Packet Rings

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Journal of Computer Science & Technology 2008年第5期23卷 815-824页

作者： Pisai Setthawong Surat Tanterdtid department of telecommunications Science Assumption University

Resilient Packet Ring （RPR）, or the Standard IEEE 802.17, is a new IP-based network technology proposed to replace SONET/SDH in metropolitan area networks. RPR is well-adapted to handle multimedia traffic and is efficient. However, when RPR networks are bridged, inter-ring packets, or packets with the destination on a remote RPR network other than on the source network, are flooded on the source and the destination networks, and also on the path of the intermediate networks between the source and the destination networks. This decreases the available bandwidth for other traffic in those networks and is inefficient. As a result, we propose two solutions based on topology discovery, global topology discovery （GTD） and enhanced topology discovery （ETD）, that prevent the flooding of inter-ring packets. GTD enables the bridges to determine the next-hop bridge for each destination. ETD enables the source node to determine a default ringlet, so that packets reach the next-hop bridge without flooding the source network. The proposed solutions were analyzed and the overhead bandwidth and stabilization time were shown to be bounded. Simulations performed showed that the proposed solutions successfully avoid flooding and achieve optimal efficiency in the intermediate and destination networks, and in the source networks with one bridge.

关键词： resilient packet rings IEEE 802.17 standard bridging topology discovery bandwidth efficiency