检索结果-内蒙古大学图书馆

European Conference on Antennas and Propagation, EuCAP

作者： Daniel Martinez-de-Rioja Eduardo Martinez-de-Rioja Yolanda Rodriguez-Vaqueiro Antonio Pino Carlos Mosquera Jose A. Encinar Giovanni Toso Information Processing and Telecommunications Center Universidad Politécnica de Madrid Madrid Spain Department of Signal Theory and Communications and Telematic Systems and Computing Universidad Rey Juan Carlos Fuenlabrada Spain AtlantTic Research Center Universidade de Vigo Vigo Spain Antenna and Sub-Millimeter Wave Section Electromagnetics Division European Space Agency ESTEC Noordwijk The Netherlands

This contribution describes the design of a dual-reflector multibeam antenna based on a parabolic polarizing main reflector with a flat reflectarray subreflector. This antenna concept is proposed to produce multiple beams in orthogonal CP for enabling broadband satellite communications in Ka-band. The antenna generates two orthogonal beams per feed at transmit (19.7 GHz) and receive (29.5 GHz) frequencies in Ka-band, which would make it possible to reduce by half the number of conventional reflector antennas required onboard the satellite to produce the same multispot coverage. The antenna generates a set of high-gain circularly polarized beams when illuminated by dual-linearly polarized feed-horns, which avoids the use of linear-to-circular polarizers in the feed-chains.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Different Ventricular Fibrillation Types in Low-Dimensional Latent Spaces

SSRN

引用

SSRN 2022年

作者： Bernal-Oñate, Carlos Paúl Melgarejo-Meseguer, Francisco Manuel Carrera, Enrique Vinicio Sánchez-Muñoz, Juan José García-Alberola, Arcadi Rojo-Álvarez, José Luis Departamento de Eléctrica Electrónica y Telecomunicaciones Universidad de las Fuerzas Armadas – ESPE Sangolqui Ecuador Department of Signal Theory and Communications Telematics and Computing Systems Universidad Rey Juan Carlos Madrid Spain Unidad de Arritmias Hospital Clínico Universitario Virgen de la Arrixaca Murcia Spain

The causes of ventricular fibrillation (VF) are not yet elucidated, and it has been proposed that even different mechanisms might exist. Moreover, conventional analysis methods do not seem to provide time or frequency domain features capable of recognizing different VF patterns in electrode-recorded biopotentials. The present work aims to determine whether low-dimensional latent spaces could exhibit discriminative features for different mechanisms or conditions during VF episodes. For this purpose, manifold learning using autoencoder neural networks was analyzed on surface ECG recordings from the onset of the VF episode and lasting 6 minutes in an experimental database (based on an animal model) with five situations, including control, drug intervention (amiodarone, diltiazem, and flecainide), and autonomic nervous system blockade (ANSB). Latent spaces from unsupervised schemes yielded moderate but noticeable separability among the different types of VF according to their type or intervention, reaching a multi-class classification accuracy of 66%. At the same time, supervised structures improved the separability of the generated latent spaces providing a classification accuracy of up to 74%. In addition, conventional audio features in the frequency domain yielded separability for both the unsupervised and supervised manifolds, reaching 58% multi-class accuracy. We can conclude that manifold learning schemes can provide a valuable tool for studying different types of VF while working in low-dimensional latent spaces. Hence, these techniques can be helpful in current research towards elucidating the existence of different VF underlying mechanisms. © 2022, The Authors. All rights reserved.

关键词： Frequency domain analysis

来源：评论

学校读者我要写书评

暂无评论

Deep Learning Approaches for Image Captioning: Opportunities, Challenges and Future Potential

引用

IEEE Access 2024年 1-1页

作者： Jamil, Azhar Saif-Ur-Rehman Mahmood, Khalid Villar, Monica Gracia Prola, Thomas Diez, Isabel De La Torre Samad, Md Abdus Ashraf, Imran Department of Computer Science Barani Institute of Information Technology PMAS-Arid Agriculture University Rawalpindi Pakistan Department of Computer Science University Institute of Information Technology PMAS-Arid Agriculture University Rawalpindi Pakistan Institute of Computing and Information Technology Gomal University D.I.Khan Pakistan Universidad Europea del Atlántico. Isabel Torres 21 Santander Spain Department of Signal Theory Communications and Telematics Engineering Unviersity of Valladolid Paseo de Belén 15 Valladolid Spain Department of Information and Communication Engineering Yeungnam University Gyeongsan Republic of Korea

Generative intelligence relies heavily on the integration of vision and language. Much of the research has focused on image captioning, which involves describing images with meaningful sentences. Typically, when generating sentences that describe the visual content, a language model and a vision encoder are commonly employed. Because of the incorporation of object areas, properties, multi-modal connections, attentive techniques, and early fusion approaches like bidirectional encoder representations from transformers (BERT), these components have experienced substantial advancements over the years. This research offers a reference to the body of literature, identifies emerging trends in an area that blends computer vision as well as natural language processing in order to maximize their complementary effects, and identifies the most significant technological improvements in architectures employed for image captioning. It also discusses various problem variants and open challenges. This comparison allows for an objective assessment of different techniques, architectures, and training strategies by identifying the most significant technical innovations, and offers valuable insights into the current landscape of image captioning research. Authors

关键词： Feature extraction

来源：评论

学校读者我要写书评

暂无评论

Learning analytics summer institute Spain 2020: Learning analytics. time for adoption?

Learning analytics summer institute Spain 2020: Learning ana...

引用

2020 Learning Analytics Summer Institute Spain: Learning Analytics. Time for Adoption?, LASI-SPAIN 2020

作者： Martínez-Monés, Alejandra Álvarez, Aihnoa Caeiro, Manuel Dimitriadis, Yannis Department of Computer Science Universidad de Valladolid Spain Department of Computer Languages and Systems Universidad Del País Vasco UPV/EHU Spain Department of Telematics Engineering Universidade de Vigo Spain Department of Theory of Signal and Communications and Telematics Engineering Universidad de Valladolid Spain

来源：评论

学校读者我要写书评

暂无评论

Wideband Hybrid Dielectric Resonator Antenna Array for 5G mmWave Mobile Applications

Wideband Hybrid Dielectric Resonator Antenna Array for 5G mm...

引用

Global Power, Energy and Communication Conference (GPECOM)

作者： Ali Zidour Mohammad Alibakhshikenari Mouloud Ayad Chan Hwang See Ernesto Limiti Department of Electrical Systems Engineering Faculty of Technology University of M’Hamed Bougara Boumerdes Algeria Department of Signal Theory and Communications Universidad Carlos III de Madrid Leganés Madrid Spain Department of Electronics Faculty of Technology Ferhat Abbas University of Setif1 Setif Algeria School of Computing Engineering and the Built Environment Edinburgh Napier University Edinburgh UK Electronic Engineering Department University of Rome “Tor Vergata” Rome Italy

ISBN: (数字)9798350351088

ISBN: (纸本)9798350351095

In this paper, a wideband hybrid dielectric resonator antenna (HDRA) array design is presented for fifth-generation (5G) millimeter wave (mmWave) applications. The hybrid antenna integrates three resonant radiators of feeding slot, ring patch, and DRA to generate four resonances around 28 and 38 GHz frequency bands. The antenna element within an overall size of 0.46λ L × 0.46λ L × 0.1λ L (λ L is the free-space wavelength at 28 GHz) can achieve wide impedance bandwidth, covering n257, n259, n260 and n261, simultaneously. The 1 × 4 HDRA array is designed and simulated based on the antenna element which can achieve high realized gain varies between 10.3 to 12.5 dBi and wide beam scanning angles of ±55° and ±40° at 28 and 38 GHz frequency bands, respectively.

关键词： Slot antennas 5G mobile communication Resonant frequency Mobile antennas Dielectric resonator antennas Dielectrics Broadband antennas

来源：评论

学校读者我要写书评

暂无评论

A Vertex Function-Based Radial-Angular Quadrature for the Numerical Evaluation of Surface Test Integrals in the Method of Moments

引用

IEEE Transactions on Antennas and Propagation 2025年

作者： Rivero, J. Martin, V.F. Wilton, D.R. Johnson, W.A. Vipiana, F. Politecnico di Torino Department of Electronics and Telecommunications Torino10129 Italy Universidad de Extremadura Dept. de Tecnologias de Computadores y Comunicaciones Caceres10003 Spain Politecnico di Torino Dept. of Electronics and Telecommunications Torino10129 Italy Universidad Rey Juan Carlos Dept. of Signal Theory and Communications Telematic Systems and Computing Fuenlabrada28942 Spain University of Houston Department of Electrical and Computer Engineering HoustonTX77204-4005 United States Jemez Springs NM87025 United States

A novel integration scheme is proposed for the accurate numerical evaluation of test (reaction) integrals needed for solving complex direct or inverse electromagnetic problems using surface integral equation formulations and the method of moments. Significant effort has already been devoted to improving the numerical evaluation of source integrals yielding potentials (or their derivatives), especially for triangular elements. But numerical techniques for accurately evaluating the subsequent test integrals have been largely neglected, with simple numerical integration schemes being used that either ignore or are developed with incomplete knowledge of the detailed behavior of potentials (or their derivatives) near edges and vertices. Consequently, simple numerical quadrature schemes are found to be either of limited accuracy or slowly convergent with respect to increasing the sampling for self, edge- or vertex-adjacent source and test triangle pairs. Here we describe a simple model derived from static potential integrals that properly describes and bounds the potentials and their derivatives near vertices. From it, we are able to construct appropriate, separable radial-angular quadrature schemes that are both exponentially convergent and applicable to all potential forms of interest arising from both EFIE and MFIE operators. Numerical results are presented that demonstrate the wide-ranging applicability and improved convergence rates of the proposed scheme, and these are compared to some previously reported testing schemes. The method’s sensitivity to test triangle shape and the ratio choice of angular-to-radial sampling rates is also briefly explored. © 1963-2012 IEEE.

关键词： integral equations moments method numerical analysis singular integrals vertex functions

来源：评论

学校读者我要写书评

暂无评论

Modelling temporal relationships in pseudomonas aeruginosa antimicrobial resistance prediction in intensive care unit 1

Modelling temporal relationships in pseudomonas aeruginosa a...

引用

1st International AAI4H - Advances in Artificial Intelligence for Healthcare Workshop, AAI4H 2020

作者： Hernandez-Carnerero, Alvar Sanchez-Marre, Miquel Mora-Jimenez, Inmaculada Soguero-Ruiz, Cristina Martinez-Aguero, Sergio Alvarez-Rodriguez, Joaquin Campus Del Poblenou Universitat Pompeu Fabra Barcelona08018 Spain Dept. of Computer Science Universitat Politecnica de Catalunya Spain Department of Signal Theory and Communications Telematics and Computing Systems Rey Juan Carlos University Madrid28943 Spain Intensive Care Department University Hospital of Fuenlabrada Madrid28942 Spain

In this paper, the prediction of antimicrobial resistance of Pseudomonas aeruginosa bacteria caused by nosocomial infections in the Intensive Care Unit (ICU) was considered. It was trained a Logistic Regression model using health records information from patients together with the history of past sensitivity tests (antibiograms). To predict the antimicrobial resistance for a certain patient, this study proposes to model the temporal relationships using bacterial information from the rest of the patients who are at the same time in the ICU. Furthermore, a training window with incremental size is used so that training set is always temporarily as near as possible to test instances to be predicted. Using these contributions, experiments show promising results to predict antimicrobial resistance even when few training data is available. From these results it is further inferred that resistant bacteria may be spreading among patients in the ICU and their populations rapidly mutate, changing the underlying data distribution, along time. Copyright © 2020 for this paper by its authors.

关键词： Intensive care units

来源：评论

学校读者我要写书评

暂无评论

Reference-Plane Invariant Free Space Dielectric Material Characterization up to 330 GHz

Reference-Plane Invariant Free Space Dielectric Material Cha...

引用

URSI Atlantic Radio Science Conference (URSI AT-RASC)

作者： Salvador Moreno-Rodríguez Mario Pérez-Escribano Sergio Ortiz-Ruiz Antonio Alex-Amor Borja Plaza-Gallardo Francisco G. Ruiz Carlos Molero Department of Signal Theory Telematics and Communications Research Centre for Information and Communication Technologies (CITIC-UGR) University of Granada Granada Spain Telecommunication Research Institute (TELMA) Universidad de Málaga E.T.S. Ingeniería de Telecomunicación Málaga Spain Department of Electronics and Computer Science Pervasive Electronics Advanced Research Laboratory (PEARL) University of Granada Granada Spain Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia Pennsylvania United States Radiofrequency Area National Institute for Aerospace Technology (INTA) Madrid Spain

ISBN: (数字)9789463968102

ISBN: (纸本)9798350360257

This paper describes the process followed to implement a system to characterize the complex permittivity of materials in the 10-330 GHz frequency band. Firstly, the method used and the system’s calibration process are shown, consisting of a double calibration TRL (Thru-Reflect-Line) and GRL (Gated-Reflect-Line). Subsequently, a smoothing technique is used to improve the accuracy of the results. Finally, a test is performed on quartz and glass fiber samples, showing that the results are quite reliable over the entire measured bandwidth.

关键词： Accuracy Smoothing methods Permittivity measurement Glass Bandwidth Position measurement Reflection

来源：评论

学校读者我要写书评

暂无评论

Active learning and margin strategies for arrhythmia classification in implantable devices

引用

Computers in Biology and Medicine 2025年 188卷 109747-109747页

作者： Lillo-Castellano, José-María Mora-Jiménez, Inmaculada Martín-Méndez, María Cerdá, Laia García-Alberola, Arcadi Rojo-Álvarez, José Luis Tuia, Devis Universidad Rey Juan Carlos Department of Signal Theory and Communications Telematics and Computing Systems Camino del Molino 5. Fuenlabrada Madrid28942 Spain Medtronic Ibérica ®S.A Dep. Cardiac Rhythm and Heart Failure C/ María de Portugal 9 Madrid28050 Spain Hospital CU Virgen de la Arrixaca. Arrhythmia Unit Ctra. Madrid-Cartagena s/n. 30120-El Palmar Murcia Spain D!lemma Ltd startup Camino del Molino 5. 28942-Fuenlabrada Madrid Spain Ecole Polytechnique Fédérale de Lausanne Environmental Computational Science and Earth Observation Laboratory 1950-Sion Switzerland

Background and Objectives: The massive storage of cardiac arrhythmic episodes from Implantable Cardioverter Defibrillators (ICD) and the advent of new artificial intelligence algorithms are opening up new opportunities for electrophysiological knowledge extraction. However, in this context, accurate and reliable episode labeling by expert cardiologists still remains a manual, costly, and time-consuming process. Methods: In this work, we propose using Active Learning (AL) to design classification models that streamline the manual labeling of cardiac arrhythmic episodes. When AL is used, relevant episodes for classification are selected and then presented to the human expert for labeling, thereby dramatically reducing the manual labeling burden. Results: We adapted four large-margin-based AL strategies to a previously proposed classification methodology. We benchmarked them on problems involving 3 and 8 arrhythmia types using 9908 episodes from a massive national ICD data repository. Specifically, the relevance of episode–patient diversity for classification was evaluated. Results showed that the gold standard performance, achieved using all episodes, was reached by using approximately 20% (50%) of episodes from 60% (85%) of patients in the 3-class (8-class) model design. Conclusions: We can conclude that AL techniques are advantageous for designing classification models and can streamline the human labeling process of large ICD datasets. © 2025 Elsevier Ltd

关键词： Implantable cardioverter defibrillator Multi-signal Heterogeneous data Patient diversity Episode of cardiac arrhythmia Support vector machine Expert labeling

来源：评论

学校读者我要写书评

暂无评论

A data-driven model based on support vector machine to identify chronic hypertensive and diabetic patients 1

引用

3rd International Conference on Physiological computing systems, PhyCS 2016, 4th International Conference on Physiological computing systems, PhyCS 2017 and 5th International Conference on Physiological computing systems, PhyCS 2018

作者： Soguero-Ruiz, Cristina de Miguel-Bohoyo, Pablo Mora-Jiménez, Inmaculada Department of Signal Theory and Communications Telematics and Computing Universidad Rey Juan Carlos Madrid Spain University Hospital of Fuenlabrada FuenlabradaMadrid Spain

ISBN: (数字)9783030279509

ISBN: (纸本)9783030279493

Hypertension and diabetes are chronic conditions that have a considerable prevalence in the elderly. It is estimated that both hypertensive patients and people with diagnosed diabetes double cost of normotensive individuals and those in the absence of diabetes, respectively. It is therefore important to pay attention to these chronic conditions, both from a health and economical point of view, especially in scenarios with budget limitations. Clinical identification of chronic patients can be performed by feeding data of the patient encounters with the healthcare system to population classification systems such as Clinical Risk Groups (CRGs). CRGs classify individuals in unique and excluding health status categories taking both demographic and clinical information during certain period of time. In this work, we characterize healthy and chronic hypertensive and diabetic population at different chronic statuses (CRG) according to gender, age, diagnoses and drugs. After this characterization, we propose to use a supervised machine learning approach, in particular Support Vector Machines, to construct a data-driven model identifying the patient health status. We conclude that drugs and diagnoses are quite informative to discriminate patients with hypertension and diabetes, achieving promising results with the use of data-driven models. © Springer Nature Switzerland AG 2019.

关键词： Diagnosis

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：