A theoretical model for array patterns of variable inclination continuous transverse stub(VICTS) antenna is proposed. The theoretical model is utilized to reveal the nonlinearrelationship in beam scanning between the...
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A theoretical model for array patterns of variable inclination continuous transverse stub(VICTS) antenna is proposed. The theoretical model is utilized to reveal the nonlinearrelationship in beam scanning between the angular position of beam and the rotation angle of the radiation layer. A dynamic coordination system is used to simplify the theoretical model andreduce errors. Based on the dynamic coordination system, array pattern of VICTS antenna with arbitrary amplitude distribution and arbitrary aperture shape can be calculated by the theoretical model. Both the full-wave simulations and computation of the theoretical model are carried out. The calculation errors of the angular position of beam between the proposed method and the full-wave simulation are less than 1°. By using the proposed method, the problem of nonlinear anddynamic beam steering in the VICTS antenna servo control system can be solved.
A dumbbell-shape 90° step twist waveguide with the performance of band-pass filtering is proposed. Not only could the smooth dumbbell-shape structure be easily manufactured but also avoid high-strength electric f...
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A dumbbell-shape 90° step twist waveguide with the performance of band-pass filtering is proposed. Not only could the smooth dumbbell-shape structure be easily manufactured but also avoid high-strength electric field that excited by corner point. Traditional metal waveguide section is replaced by medium substrate. This waveguide can achieve the 90° polarization rotation of electromagnetic wave, also can be regarded as a filter with 190 MHz bandwidth. The twist waveguide has the features of high Q factor, small size and low manufacturing costs. The measured insertion loss is 0.9 dB and the relative bandwidth compared with the bandwidth of the structure with similar function is broadened by 58%. The total length of the twist section is only 1.6 mm and it achieves the miniaturization of device dramatically.
due to the problem of high hardware cost and low yield of the TSV in 3 d No C,the vertically partially connected 3 d No C with limit number of TSV has been researched *** respect to little research on micro-bufferedr...
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due to the problem of high hardware cost and low yield of the TSV in 3 d No C,the vertically partially connected 3 d No C with limit number of TSV has been researched *** respect to little research on micro-bufferedrouter which is suitable for this topology and can furtherreduce hardware cost,a micro bufferedrouter in vertically partially connected 3 d No C is *** router is the 3 d extension of Min Bd and modifies side-bufferdesign in Min Bd at the same *** a deflection routing algorithm based on this router is *** productive output ports of the intra-layer communication packet are calculated according to the direction of destination node and the productive output ports of the inter-layer communication packet are calculated according to the distribution of TSV in current *** experimental results show that the network performance of ourrouter is better than reference micro bufferedrouters',while even is similar to traditional bufferedrouters in low and medium network traffic environment.
In order to solve the cover source mismatch problem, a new blind universal image steganalysis algorithm combining camera source identification and outlierdetection is proposed in this paper. Cover im
ISBN:
(纸本)9781467389808
In order to solve the cover source mismatch problem, a new blind universal image steganalysis algorithm combining camera source identification and outlierdetection is proposed in this paper. Cover im
Space debris classification is significant fordebris catalog and early warning.A space debris classification method using photometric sequence obtained from ground based optical telescopes was ***,the photometric dat...
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Space debris classification is significant fordebris catalog and early warning.A space debris classification method using photometric sequence obtained from ground based optical telescopes was ***,the photometric data was analyzed and the debris size was estimated from *** 2 characteristic values could be obtained,namely the size mean value and *** motion attitude was divided into three-axis-stabilized,spin-stabilized andrandom-tumbling by frequency-domain characteristics of estimated size,and it was used as the 3 rd ***,the normalization and credibility methods were introduced to equalize 3 characteristics when constructing characteristic ***,debris was classified using maximum probably criterion with Gaussian mixture models,due to the debris’ variety of observation arcs with different *** simulation shows that success rate is more than 90% in classification of 4 kinds of debris.
data center Networks(dCNs) should provide low latency and high throughput to meet users' demands. However the coexistence of mice and elephant flows may jeopardize achieving both performance objectives simultaneou...
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data center Networks(dCNs) should provide low latency and high throughput to meet users' demands. However the coexistence of mice and elephant flows may jeopardize achieving both performance objectives simultaneously. Existing load agnostic routing techniques work well for mice flows but make elephant flows collide on the same output port, creating an avoidable bottleneck. In this paper, we present an SdN based Fast rerouting Mechanism(SFrM) forrescheduling elephant flows in a load-aware manner. An elephant flow selecting module is added into the controller to reschedule elephant flows selectively andreroutes a few elephant flows by Segment routing(Sr) technique. Simulations show that SFrM improves the network throughput andreduces the Flow Completion Time(FCT) significantly.
In order to solve the problem of the popular item ratings interfering in similarity calculation,we proposed the ratings distribution recommendation *** on this model,we designed a new collaborative filtering *** to ra...
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In order to solve the problem of the popular item ratings interfering in similarity calculation,we proposed the ratings distribution recommendation *** on this model,we designed a new collaborative filtering *** to ratings distribution,this algorithm firstly get the amount of information carried(The Shannon Entropy).Then,it calculated the rating weights to filter into traditional similarity *** experimental results show that the algorithm can effectively alleviate the above problem and improve the performance of the algorithm.
While there has been a belief over the past few years that virtual network functions(VNFs) should be built on common servers, we argue that it can lead to limited performance and large up/down traffic. This paper prop...
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While there has been a belief over the past few years that virtual network functions(VNFs) should be built on common servers, we argue that it can lead to limited performance and large up/down traffic. This paper proposes a new idea of shifting part of NFV functions from software packages to common hardware devices to promote overall performance. Then we present the design and implementation of PPAP, a Packets Processing Acceleration Platform for NFV. It offers high flexibility by allowing functions to control the processing flow of *** match tables and virtualization techniques ensure isolation among VNF instances.
Elastic control could balance the distributed control plane in Software-defined Networking(SdN). dynamic switch migration has been proposed to achieve it. However, existing schemes mainly focus on how to execute migra...
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Elastic control could balance the distributed control plane in Software-defined Networking(SdN). dynamic switch migration has been proposed to achieve it. However, existing schemes mainly focus on how to execute migration operation, but not why. This paperdesigns a decision-making mechanism based on zero-sum game theory to reelect a new controller as the master for migrated switches. It first chooses a switch for migration in the heavy controller which invites its neighbors as the game players to compete for the masterrole of this switch in the game-playing field(GPF) which is an occasional and loose domain for game-playing. Second, based on the concept of GPF, we design a decentralized strategy to play the game anddetermine which player as the final master. We implement it by extending the Open Flow protocol. Finally, numerical results demonstrate that ourdistributed strategy can approach elastic control plane with better performance.
For preventing the leakage of confidential messages sent to a marcocell user in dense heterogeneous networks, a physical layer security scheme based on base station cooperation is proposed in the paper. To improve tra...
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For preventing the leakage of confidential messages sent to a marcocell user in dense heterogeneous networks, a physical layer security scheme based on base station cooperation is proposed in the paper. To improve transmission rate of confidential messages and make the downlink signals of other legitimate users interfere with eavesdroppers, the beamforming vectors at a macrocell base station and femtocell base stations are jointly optimized. The problem of maximizing the secrecy rate is modeled under the limitations of quality of service(QoS) and base station power. due to the intractability, this problem is recast into a convex Semidefinite Program(SdP) problem using the Semidefinite relaxation(Sdr) technique and the successive convex approximation(SCA) algorithm. Simulation results validate the efficacy and the security of the scheme.
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