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Measuring human perception to improve handwritten document transcription

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arXiv 2019年

作者： Grieggs, Samuel Shen, Bingyu Rauch, Greta Li, Pei Ma, Jiaqi Chiang, David Price, Brian Scheirer, Walter J. Department of Computer Science and Engineering University of Notre Dame Notre DameIN46556 United States Zoom Video Communications Department of Classics Yale University Adobe Research

In this paper, we consider how to incorporate psychophysical measurements of human visual perception into the loss function of a deep neural network being trained for a recognition task, under the assumption that such information can reduce errors. As a case study to assess the viability of this approach, we look at the problem of handwritten document transcription. While good progress has been made towards automatically transcribing modern handwriting, significant challenges remain in transcribing historical documents. Here we describe a general enhancement strategy, underpinned by the new loss formulation, which can be applied to the training regime of any deep learning-based document transcription system. Through experimentation, reliable performance improvement is demonstrated for the standard IAM and RIMES datasets for three different network architectures. Further, we go on to show feasibility for our approach on a new dataset of digitized Latin manuscripts, originally produced by scribes in the Cloister of St. Gall in the the 9th century. Copyright © 2019, The Authors. All rights reserved.

关键词： Network architecture

on the Use of Class Activation Map for Land Cover Mapping

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on the Use of Class Activation Map for Land Cover Mapping

International Conference on Electrical engineering/Electronics, computer, Telecommunications and Information Technology, ECTI-CON

作者： P. Charuchinda T. Kasetkasem I. Kumazawa T. Chanwimaluang Department of Electrical Engineering Kasetsart University Bangkok Thailand Department of Information and Communications Engineering Tokyo Institute of Technology Tokyo Japan National Electronics and Computer Technology Center (NECTEC) Pathumthani Thailand

In a supervised classification of a remote sensing image, a ground survey is needed to collect sufficient training data to train a classifier. The ground survey is expensive and time consuming. Thus, the idea of the class activation map (CAM) is proposed for land cover mapping in this paper. Here, instead of training with ground data where the underlying class label of each training pixels must be identified, our goal is to classify every pixel in an image with a training set, where a training sample is the association between an image and their class composition. The identification of class composition with an image is an easier task to perform, since human perception can accurately detect the composition of objects. The CAM is a collection of “heatmap” images associated with different combinations of land cover classes, where the high value indicates a high probability that a pixel belongs to that class. Next, we label a pixel to the class where the corresponding CAM is maximum.

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A Cross-layer Algorithm for Improving AODV Protocol over Vehicular Ad-hoc Networks

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A Cross-layer Algorithm for Improving AODV Protocol over Veh...

International Conference on Wireless communications, Signal Processing and Networking (WiSPNET)

作者： Khalid A. Darabkh Mohammad G. Alfawares Saud Althunibat Ala’ F. Khalifeh Department of Computer Engineering The University of Jordan Amman Jordan Department of Communications Engineering Al-Hussein Bin Talal University Ma’an Jordan Electrical Engineering and Information Technology German Jordanian University Madaba Jordan

ISBN: (数字)9781538692790

ISBN: (纸本)9781538692806

Developing an efficient routing protocol over Vehicular Ad-hoc Networks (VANETs) is a very challenging topic and consequently increases the attention of a lot of current researchers. In this work, we propose a cross-layer algorithm for improving Ad-hoc on Demand Distance Vector (AODV) routing protocol over VANETs. Our algorithm is named as Multi Rate Mobility Aware Routing (MRMAR). It primarily concentrates on establishing routes considering the links available transmission rates and vehicles' speed with respect to source vehicles, thereby establishing fast forwarding and more stable routes. Our algorithm has been evaluated in terms of packet delivery ratio and route losses using NS3 simulator.

关键词： Ad hoc networks Routing protocols Routing Data communication Mobile computing Wireless communication

Non-stationarities in extra-large scale massive MIMO

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arXiv 2019年

作者： de Carvalho, Elisabeth Ali, Anum Amiri, Abolfazl Angjelichinoski, Marko Heath, Robert W. Department of Elec-tronic Systems Aalborg University Aalborg9220 Denmark Department of Electrical and Computer Engineering Duke University DurhamNC27708 United States Wireless Networking and Communications Group Department of Electrical and Computer Engineering University of Texas at Austin AustinTX78712 United States

Massive MIMO, a key technology for increasing area spectral efficiency in cellular systems, was developed assuming moderately sized apertures. In this paper, we argue that massive MIMO systems behave differently in large-scale regimes due to spatial non-stationarity. In the large-scale regime, with arrays of around fifty wavelengths, the terminals see the whole array but non-stationarities occur because different regions of the array see different propagation paths. At even larger dimensions, which we call the extra-large scale regime, terminals see a portion of the array and inside the first type of non-stationarities might occur. We show that the non-stationarity properties of the massive MIMO channel change several important MIMO design aspects. In simulations, we demonstrate how non-stationarity is a curse when neglected but a blessing when embraced in terms of computational load and multi-user transceiver design. Copyright © 2019, The Authors. All rights reserved.

关键词： MIMO systems

Wideband Bandpass Filters Using a Novel Thick Metallization Technology

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arXiv 2019年

作者： Gomez-Molina, Celia Pons-Abenza, Alejandro Do, James Quesada-Pereira, Fernando Liu, Xiaoguang Gomez-Diaz, Juan Sebastian Alvarez-Melcon, Alejandro Department of Information Technologies and Communications Universidad Politécnica de Cartagena Cartagena30202 Spain Department of Electrical and Computer Engineering University of California Davis United States

—A new class of wideband bandpass filters based on using thick metallic bars as microwave resonators, instead of common microstrip lines, is presented. These bars provide a series of advantages over fully planar printed technologies, including higher coupling levels between resonators, better unloaded quality factors QU, and larger bandwidths, implemented with more compact structures. Moreover, thick bar resonators can easily be coupled to an additional resonance excited in a box used for shielding, allowing to realize transversal topologies able to implement transmission zeros at desired frequencies. To illustrate the capabilities of this technology, two microwave filters with different bandwidths and one transmission zero have been designed. One of the filters has been manufactured and tested using copper bars inside an aluminum housing partially filled with Teflon. Measured data demonstrates a fractional bandwidth about FBW = 32%, spurious free range SFR > 50%, unloaded quality factor of QU = 1180 and return losses over 20 dB without requiring any post-tuning on the prototype, confirming the exciting performance of the proposed technology. Copyright © 2019, The Authors. All rights reserved.

关键词： Microwave filters

Non-Linear Diode Rectifier Analysis for Multi-Tone Wireless Power Harvesting

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Non-Linear Diode Rectifier Analysis for Multi-Tone Wireless ...

IEEE International Conference on Microwaves, communications, Antennas and Electronic Systems, COMCAS

作者： Ana López-Yela Alberto López-Yela Daniel Segovia-Vargas Zoya Popović Department of Signal Theory and Communications University Carlos III of Madrid Leganés Spain Department of Electrical Computer and Energy Engineering University of Colorado Boulder Colorado USA

This paper presents an analysis of the non-linear performance of a zero-bias Schottky diode under multi-tone excitation for wireless power harvesting applications. At low incident power levels, it has been shown that multi-tone inputs increase RF-DC conversion efficiency. Here we extend the theoretical analysis to include a more practical diode model which includes series resistance essential for determining efficiency. We show that the more complex theory approximates the real diode IV curve more accurately at low input power levels than previous models which neglect the series resistance.

关键词： Schottky diodes Resistance Energy harvesting Microwave antennas Taylor series Wireless communication Microwave communication

Optimized deployment of millimeter wave networks for in-venue regions with stochastic users' orientation

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arXiv 2019年

作者： Soorki, Mehdi Naderi Saad, Walid Bennis, Mehdi Wireless-VT Bradley Department of Electrical and Computer Engineering Virginia Tech BlacksburgVA United States Centre for Wireless Communications University of Oulu Finland

Millimeter wave (mmW) communication is a promising solution for providing high-capacity wireless network access. However, the benefits of mmW are limited by the fact that the channel between a mmW access point and the user equipment can stochastically change due to severe blockage of mmW links by obstacles such as the human body. Thus, one main challenge of mmW network coverage is to enable directional line-of-sight links between access points and mobile devices. In this paper, a novel framework is proposed for optimizing mmW network coverage within hotspots and in-venue regions, while being cognizant of the body blockage of the network's users. In the studied model, the locations of potential access points and users are assumed as predefined parameters while the orientation of the users is assumed to be stochastic. Hence, a joint stochastic access point placement and beam steering problem subjected to stochastic users' body blockage is formulated, under desired network coverage constraints. Then, a greedy algorithm is introduced to find an approximation solution for the joint deployment and assignment problem using a new "size constrained weighted set cover" approach. A closed-form expression for the ratio between the optimal solution and approximate one (resulting from the greedy algorithm) is analytically derived. The proposed algorithm is simulated for three in-venue regions: the meeting room in the Alumni Assembly Hall of Virginia Tech, an airport gate, and one side of a stadium football. Simulation results show that, in order to guarantee network coverage for different in-venue regions, the greedy algorithm uses at most three more access points (APs) compared to the optimal solution. The results also show that, due to the use of the additional APs, the greedy algorithm will yield a network coverage up to 11:7% better than the optimal, AP-minimizing solution. Copyright © 2019, The Authors. All rights reserved.

关键词： Stochastic systems

A regression approach to certain information transmission problems

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arXiv 2019年

作者： Zhang, Wenyi Wang, Yizhu Shen, Cong Liang, Ning CAS Key Laboratory of Wireless-Optical Communications University of Science and Technology of China China Department of Electrical and Computer Engineering University of Virginia United States

A general information transmission model, under independent and identically distributed Gaussian codebook and nearest neighbor decoding rule with processed channel output, is investigated using the performance metric of generalized mutual information. When the encoder and the decoder know the statistical channel model, it is found that the optimal channel output processing function is the conditional expectation operator, thus hinting a potential role of regression, a classical topic in machine learning, for this model. Without utilizing the statistical channel model, a problem formulation inspired by machine learning principles is established, with suitable performance metrics introduced. A data-driven inference algorithm is proposed to solve the problem, and the effectiveness of the algorithm is validated via numerical experiments. Extensions to more general information transmission models are also discussed. Copyright © 2019, The Authors. All rights reserved.

关键词： Regression analysis

New Construction of Optimal Type-II Binary Z-Complementary Pairs

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arXiv 2020年

作者： Gu, Zhi Zhou, Zhengchun Wang, Qi Fan, Pingzhi School of Information Science and Technology Southwest Jiaotong University Chengdu611756 China School of Mathematics Southwest Jiaotong University Chengdu611756 China Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen518055 China Institute of Mobile Communications Southwest Jiaotong University Chengdu611756 China

A pair of sequences is called a Z-complementary pair (ZCP) if it has zero aperiodic autocorrelation sums at each of the non-zero time-shifts within a certain region, called the zero correlation zone (ZCZ). ZCPs are categorised into two types: Type-I ZCPs and Type-II ZCPs. Type-I ZCPs have the ZCZ around the in-phase position and Type-II ZCPs have the ZCZ around the end-shift position. Till now only a few constructions of Type-II ZCPs are reported in the literature, and all have lengths of the form 2m±1 or N + 1 where N = 2a10b26c and a, b, c are non-negative integers. In this paper, we propose a recursive construction of ZCPs based on concatenation of sequences. Inspired by Turyn’s construction of Golay complementary pairs, we also propose a construction of Type-II ZCPs from known ones. The proposed constructions can generate optimal Type-II ZCPs with new flexible parameters and Z-optimal Type-II ZCPs with any odd length. In addition, we give upper bounds for the PMEPR of the proposed ZCPs. It turns out that our constructions lead to ZCPs with low PMEPR. Copyright © 2020, The Authors. All rights reserved.

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