A novel design and fabrication approach for a high fill-factor micro-electro-mechanical system （MEMS） micromirror array-based wavelength-selective switch （WSS） is presented. The WSS is composed of a polarization-i...
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A novel design and fabrication approach for a high fill-factor micro-electro-mechanical system （MEMS） micromirror array-based wavelength-selective switch （WSS） is presented. The WSS is composed of a polarization-independent transmission grating and a high fill-factor micromirror array. The WSS is successfully demonstrated based on the fabricated high fill-factor micromirror array. Test results show that the polarization-dependent loss （PDL） is less than 0.3 dB and that the insertion loss （IL） of the wavelength channel is about -6 dB. The switching function between the two output ports of WSS is measured. The forward switching time is recorded to be about 0.5 ms, whereas the backward switching time is about 7 ms.
Aiming at the small sample problem in the dual-frequency ultrasonic extraction process of liquorice,this paper proposes a virtual sample generation method to expand small sample *** method uses Box-Behnken Design(BBD)...
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ISBN:
(纸本)9781665431293
Aiming at the small sample problem in the dual-frequency ultrasonic extraction process of liquorice,this paper proposes a virtual sample generation method to expand small sample *** method uses Box-Behnken Design(BBD) to design experiments,in order to collect original small sample data for *** on this forecasting model,data is ***,by adding the Firework-Differential Evolution Algorithm with Levy Flight(L-FW-DE),reasonable and effective virtual samples are obtained and selected in the iterative process to expand the sample *** samples,consist of virtual samples and original small samples,are applied to establish a prediction model for dual-frequency ultrasonic extraction of liquiritin from ***,the optimal process parameters are obtained by an optimization ***,the experiment of extracting liquiritin by dual-frequency ultrasound verifies that under these optimized parameters,the extraction rate is the *** of the experiments show that this method can efficiently generate reasonable virtual samples,and the synthetic sample composed of small samples and virtual samples can enhance the accuracy of the prediction *** reliable optimal process parameters which are obtained by the forecasting model can provide guidance for the extraction process under the small sample condition.
The study on photon counting statistics is of fundamental importance in quantum optics. We theoretically analyzed the imperfect detection of an arbitrary quantum state. We derived photon counting formulae for six typi...
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The study on photon counting statistics is of fundamental importance in quantum optics. We theoretically analyzed the imperfect detection of an arbitrary quantum state. We derived photon counting formulae for six typical quantum states （i.e., Fock, coherent, squeeze-vacuum, thermal, odd and even coherent states） with finite quantum efficiencies and dark counts based on multiple on/off detector arrays. We applied the formulae to the simulation of multiphoton number detections and obtained both the simulated and ideal photon number distributions of each state. A comparison between the results by using the fidelity and relative entropy was carried out to evaluate the detection scheme and help select detectors for different quantum states.
Hardware security has become more and more important in current information security architecture. Recently collected reports have shown that there may have been considerable hardware attacks prepared for possible mil...
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Hardware security has become more and more important in current information security architecture. Recently collected reports have shown that there may have been considerable hardware attacks prepared for possible military usage from all over the world. Due to the intrinsic difference from software security, hardware security has some special features and challenges. In order to guarantee hardware security, academia has proposed the concept of trusted integrated circuits,which aims at a secure circulation of IC design, manufacture and chip using. This paper reviews the main problems of trusted integrated circuits, and concludes four key domains of the trusted IC, namely the trusted IC design, trusted manufacture,trusted IP protection, and trusted chip authentication. The main challenges in those domains are also analyzed based on the current known techniques. Finally, the main limitations of the current techniques and possible future trends are discussed.
The energy consumption in large-scale data centers is attracting more and more attention today with the increasing data center energy costs making the enhanced performance very expensive. This is becoming a bottleneck...
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The energy consumption in large-scale data centers is attracting more and more attention today with the increasing data center energy costs making the enhanced performance very expensive. This is becoming a bottleneck to further developments in terms of both scale and performance of cloud computing. Thus, the reduction of the energy consumption by data centers is becoming a key research topic in green IT and green computing. The web servers providing cloud service computing run at various speeds for different scenarios. By shifting among these states using speed scaling, the energy consumption is proportional to the workload, which is termed energy-proportionality. This study uses stochastic service decision nets to investigate energy-efficient speed scaling on web servers. This model combines stochastic Petri nets with Markov decision process models. This enables the model to dynamically optimize the speed scaling strategy and make performance evaluations. The model is graphical and intuitive enough to characterize complicated system behavior and decisions. The model is service-oriented using the typical service patterns to reduce the complex model to a simple model with a smaller state space. Performance and reward equivalent analyse substantially reduces the system behavior sub-net. The model gives the optimal strategy and evaluates performance and energy metrics more concisely.
Unmanned Aerial Vehicles (UAVs) are increasingly important in dynamic environments such as logistics transportation and disaster response. However, current tasks often rely on human operators to monitor aerial videos ...
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In this paper, retransmission strategies of the network-coding-based packet network are investigated. We propose two retransmission strategies, the packet-loss-edge-based retransmission strategy (PLERT) and the minimu...
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In this paper, retransmission strategies of the network-coding-based packet network are investigated. We propose two retransmission strategies, the packet-loss-edge-based retransmission strategy (PLERT) and the minimum retransmission strategy (MRT), which focus on optimizing the retransmission efficiency without the constraint on the encoding field size. We compared the performances of the proposed retransmission strategies with the traditional automatic repeat-request (ARQ) strategy and the random retransmission strategy. Simulation results showed that the PLERT strategy works well when the packet loss rate is small. Among these retransmission strategies, the performance of the MRT strategy is the best at the cost of the high complexity that is still polynomial. Furthermore, neither of the proposed strategies is sensitive to the encoding field size.
作者：
ZAHN, MMassachusetts Institute of Technology
Department of Electrical Engineering and Computer Science Laboratory for Electromagnetic and Electronic Systems Cambridge MA 02139 USA
Ferrofluid motion driven by a travelling wave magnetic field can be in the same or opposite direction to the direction of wave propagation. A net time average body force on a ferrofluid is produced when there is a tim...
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Ferrofluid motion driven by a travelling wave magnetic field can be in the same or opposite direction to the direction of wave propagation. A net time average body force on a ferrofluid is produced when there is a time phase lag between the ferrofluid magnetization M and the driving magnetic field H . With M and H not collinear, there is also a dipole torque exerted on each magnetic domain which is balanced by the fluid viscous drag. Conservation of linear and angular momentum equations are solved in the steady state for a ferrofluid layer stressed by a travelling wave magnetic field. This configuration can be easily set up as an experiment, allows closed form solutions for the time average flow and spin fields, and exemplifies the essential physics of ferrohydrodynamic interactions.
By means of introducing multi-auctioneer model, resources in the computational economic grid can be managed and allocated like in the auction. We research and put forward the corresponding solve schemes of three key i...
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ISBN:
(纸本)9780889866386
By means of introducing multi-auctioneer model, resources in the computational economic grid can be managed and allocated like in the auction. We research and put forward the corresponding solve schemes of three key issues of auctioneer system: preventing auctioneer from cheating, selection of auctioneer, setting of trading prices, and use computational grid modeling and simulation tools GridSim to simulate computational grid environment in the experiment which uses multiauctioneer system to manage and schedule, then we analyze the results of experiment in different conditions, and validate the feasibility of a multi-auctioneer system in computational grid.
3D dynamic datasets compression still poses two challenges. One is high time cost due to growing data and complex computation of compression algorithms. The other is low compression factor because of complex motions o...
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3D dynamic datasets compression still poses two challenges. One is high time cost due to growing data and complex computation of compression algorithms. The other is low compression factor because of complex motions of dynamic scenes and unknown motion equations. In this paper, composite rigid body construction for fast and compact compression of 3D dynamic datasets is proposed to solve these two problems. It accelerates the compression with a fast rigid body decomposition based on disjoint union, and avoids serial searching, comparing and merging of the rigid body decomposition. To increase the compression factor,composite rigid body is introduced with consideration of motion consistency among rigid bodies at different time periods. The results of the experiments show that our algorithm compresses dynamic datasets quickly and achieves a high compression factor.
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