- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Energy-Efficient QoS-based OCDMA Networks Aided by Nonlinear Programming Methods
摘要： One of the advantages of the optical code division multiple access (OCDMA) system networks over other multiple access methods is the ability to provide differentiated classes of quality of service (QoS) for different users. The performance of the OCDMA networks is mainly limited by the multi-access interference (MAI) coming from other users sharing the same spectral resources. The suitable resource allocation in OCDMA networks allows greater capacity and the reliable deployment of the available resources in the network. This work aiming at applying and analyzing four analytical optimization methods applied to energy efficiency (EE) maximization of OCDMA networks. Hence, such optimization methods were applied and their performance-complexity tradeoffs are compared, namely the augmented Lagrangian method (ALM) [18], sequential quadratic programming method (SQP), majoration-minimization (MaMi) approach [23], [24], as well as Dinkelbach’s method (DK). Tests were performed considering practical and realistic OCDMA networks with a wide range of nodes, typically K = {8; 16; 32} nodes. The evaluated optimization methods were able to achieve convergence and perform suitably to solve the optical EE-OCDMA optimization problem. However, in a few specific high loading system configurations, the DK method did not reach full convergence; besides DK processing time was much greater compared to the promising ALM, SQP and MaMi EE-OCDMA optimization approaches.
关键词： CvX,OCDMA networks,Energy efficiency,Majoration-minimization,Sequential quadratic Programming method,Augmented Lagrangian method,Dinkelbach’s fractional optimization method
更新于2025-09-23 15:21:01
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Versatile relative entropy bounds for quantum networks
摘要： We provide a versatile upper bound on the number of maximally entangled qubits, or private bits, shared by two parties via a generic adaptive communication protocol over a quantum network when the use of classical communication is not restricted. Although our result follows the idea of Azuma et al (2016 Nat. Commun. 7 13523) of splitting the network into two parts, our approach relaxes their strong restriction, consisting of the use of a single entanglement measure in the quanti?cation of the maximum amount of entanglement generated by the channels. In particular, in our bound the measure can be chosen on a channel-by-channel basis, in order to make it as tight as possible. This enables us to apply the relative entropy of entanglement, which often gives a state-of-the-art upper bound, on every Choi-simulable channel in the network, even when the other channels do not satisfy this property. We also develop tools to compute, or bound, the max-relative entropy of entanglement for channels that are invariant under phase rotations. In particular, we present an analytical formula for the max-relative entropy of entanglement of the qubit amplitude damping channel.
关键词： quantum networks,quantum communication,quantum information
更新于2025-09-23 15:21:01
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Stability of glassy hierarchical networks
摘要： The structure of interactions in most animal and human societies can be best represented by complex hierarchical networks. In order to maintain close-to-optimal function both stability and adaptability are necessary. Here we investigate the stability of hierarchical networks that emerge from the simulations of an organization type with an efficiency function reminiscent of the Hamiltonian of spin glasses. Using this quantitative approach we find a number of expected (from everyday observations) and highly non-trivial results for the obtained locally optimal networks, including, for example: (i) stability increases with growing efficiency and level of hierarchy; (ii) the same perturbation results in a larger change for more efficient states; (iii) networks with a lower level of hierarchy become more efficient after perturbation; (iv) due to the huge number of possible optimal states only a small fraction of them exhibit resilience and, finally, (v) ‘attacks’ targeting the nodes selectively (regarding their position in the hierarchy) can result in paradoxical outcomes.
关键词： spin-glasses,hierarchy,stability,networks
更新于2025-09-23 15:21:01
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[IEEE 2018 International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR) - Chengdu, China (2018.7.15-2018.7.18)] 2018 International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR) - Spectral-Spatial Graph Convolutional Networks for Semel-Supervised Hyperspectral Image Classification
摘要： Collecting label samples is quite costly and time consuming for hyperspectral image (HSI) classification tasks. Semi-supervised learning framework, which combines the intrinsic information of labeled and unlabeled samples can alleviate the deficient labeled samples and increase the accuracy of HSI classification. In this paper, we propose a novel framework for semi-supervised learning on multiple spectral-spatial graphs that is based on graph convolutional networks (SGCN). In the filtering operation on graphs we consider the spatial information and spectral signatures of HSI simultaneously. The experimental results on three real-life HSI data sets, i.e. Botswana Hyperion, Kennedy Space Center, and Indian Pines, show that the proposed SGCN can significantly improve the classification accuracy. For instance, the over accuracy on Indian Pine data is increased from 78% to 93%.
关键词： Hyperspectral image classification,Graph fourier transform,Graph convolutional,Neural networks,Semi-supervised learning
更新于2025-09-23 15:21:01
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High-Resolution, High-Aspect-Ratio Printed and Plated Metal Conductors Utilizing Roll-to-Roll Microscale UV Imprinting with Prototype Imprinting Stamps
摘要： Micron-scale, high-aspect-ratio features were imprinted by a roll-to-roll process into a UV-curable polymer and used to create high-current-carrying conductive networks on plastic substrates. A stamp fabrication method was developed to create low-cost, rapidly produced roll-to-roll imprinting stamps, which can mold features from 3 μm to 1 mm wide. Isolated raised features 50 μm high were molded from a 25-μm-thick layer of UV-curable resin by displacing resin into raised features in the stamp. Substrates with imprinted capillary channels were used to form electrical conductors by printing a silver ink into reservoirs connected to the channels and allowing capillary flow to coat the channel. Copper electroless plating then filled the channels. The conductors demonstrate high resolution, high aspect ratio (～5:1 height:width), low resistance per length, and easy integration into networks. This roll-to-roll imprinting process provides a foundation for high-throughput manufacturing of high-resolution printed electronics.
关键词： high-aspect-ratio,conductive networks,roll-to-roll imprinting,UV-curable polymer,printed electronics
更新于2025-09-23 15:21:01
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Human sensitivity to perturbations constrained by a model of the natural image manifold
摘要： Humans are remarkably well tuned to the statistical properties of natural images. However, quantitative characterization of processing within the domain of natural images has been difficult because most parametric manipulations of a natural image make that image appear less natural. We used generative adversarial networks (GANs) to constrain parametric manipulations to remain within an approximation of the manifold of natural images. In the first experiment, seven observers decided which one of two synthetic perturbed images matched a synthetic unperturbed comparison image. Observers were significantly more sensitive to perturbations that were constrained to an approximate manifold of natural images than they were to perturbations applied directly in pixel space. Trial-by-trial errors were consistent with the idea that these perturbations disrupt configural aspects of visual structure used in image segmentation. In a second experiment, five observers discriminated paths along the image manifold as recovered by the GAN. Observers were remarkably good at this task, confirming that observers are tuned to fairly detailed properties of an approximate manifold of natural images. We conclude that human tuning to natural images is more general than detecting deviations from natural appearance, and that humans have, to some extent, access to detailed interrelations between natural images.
关键词： natural images,image recognition,noise perturbations,artificial neural networks,generative adversarial nets
更新于2025-09-23 15:21:01
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Overview of South-Bound Interfaces for Software-Defined Optical Networks
摘要： In SDN-enabled networks, the control plane and data plane interaction relies on open SouthBound Interfaces (SBIs) so that the SDN controller exercises direct control over the data plane elements. In this paper, we review current initiatives of SBI to control optical components which include ad-hoc extensions of OpenFlow and YANG modelling proposals combined with the NETCONF / RESTCONF protocols. Then we overview different tools and frameworks available for quick prototyping and deployment of software services that are compliant with such interfaces. Finally, we discuss the advantages and drawbacks of the reviewed initiatives considered key enablers for standardized end-to-end network programmability.
关键词： optical networks,software defined networking,programmatic interfaces
更新于2025-09-23 15:21:01
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - A New DSP-Based Physical Layer Encryption Technique Applied to Passive Optical Networks
摘要： Point-to-multipoint architecture poses serious security problems to passive optical networks (PONs). In this paper, we propose the use of a new digital signal processing (DSP)-based technique to improve the confidentiality of signals traveling through PONs. The technique consists of phase-shifting and delaying the spectral components of baseband signals that further modulate optical carriers. Our simulation analysis encompasses the application of the technique to binary phase-shift keying (BPSK) in an intensity modulated- direct detection (IM-DD) system. Results reveal that the encrypted signals may be properly decoded even when 64 PON users are considered and suggest the potential of the proposed technique for practical implementations. From a security point of view, we show that the proposed technique utterly outperforms the Advanced Encryption Standard (AES) in brute force attacks.
关键词： passive optical networks,physical layer security,digital signal processing
更新于2025-09-23 15:21:01
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Simultaneous Spectrum Sensing and Energy Harvesting
摘要： This paper proposes a new simultaneous spectrum sensing (SS) and energy harvesting (EH) scheme, called integrated SS-EH, where all of the incoming radio frequency (RF) power is used for EH. Then, SS is performed based on a fraction of the harvested power. The proposed approach does not require a separate energy detector which needs a power-hungry radio front end. Therefore, the energy consumption and hardware complexity for SS can be reduced significantly. Furthermore, it can increase the harvested energy over the conventional separated SS-EH scheme, where SS and EH are performed separately and thus only a fraction of incoming RF power can be used for EH. The combined benefit of reduced energy consumption for SS and increased energy harvest allows more energy to be available for communication, which results in an increase of the throughput. The probability of false alarm and missed detection, the average harvested energy, and the average throughput are analyzed in Rayleigh fading channel and compared with the conventional separated SS-EH scheme. Mixed SS and EH scheme is proposed in cooperative SS and EH environment where each sensor operates in either the integrated SS-EH or the separated SS-EH mode to improve the sensing accuracy at the fusion center.
关键词： mixed cooperative spectrum sensing,RF-powered cognitive radio networks,Integrated spectrum sensing and energy harvesting
更新于2025-09-23 15:21:01
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[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - HESCNET: A Synthetically Pre-Trained Convolutional Neural Network for Human Embryonic Stem Cell Colony Classification
摘要： This paper proposes a method for improving the results of deep convolutional neural network classification using synthetic image samples. Generative adversarial networks are used to generate synthetic images from a dataset of phase-contrast, human embryonic stem cell (hESC) microscopy images. hESCnet, a deep convolutional neural network is trained, and the results are shown on various combinations of synthetic and real images in order to improve the classification results with minimal data.
关键词： Image Processing,Generative Adversarial Networks,Deep Learning,Computer Vision,Video Bioinformatics
更新于2025-09-23 15:21:01