检索结果-内蒙古大学图书馆

arXiv 2021年

作者： Xue, Lianjie Liu, Song Hang, Yang Summers, Adam M. Wilson, Derrek J. Wang, Xinya Chen, Pingping Folland, Thomas G. Hachtel, Jordan A. Shi, Hongyu Hosseini-Zavareh, Sajed Das, Suprem R. Lei, Shuting Zhang, Zhuhua Sorensen, Christopher M. Guo, Wanlin Caldwell, Joshua D. Edgar, James H. Blaga, Cosmin I. Trallero-Herrero, Carlos A. Department of Physics Kansas State University ManhattanKS66506 United States Tim Taylor Department of Chemical Engineering Kansas State University ManhattanKS66506 United States J. R. Macdonald Laboratory Department of Physics Kansas State University ManhattanKS66506 United States State Key Laboratory of Mechanics and Control of Mechanical Structures Institute of Nano Science Nanjing University of Aeronautics and Astronautics Nanjing210016 China Advanced Laser Light Source and few-cycle Inc. Institut Nationale de la Recherche Scientifique 1650 Boul. Lionel-Boulet VarennesQCJ3X 1P7 Canada Department of Industrial and Manufacturing Systems Engineering Kansas State University ManhattanKS66506 United States Department of Mechanical Engineering Vanderbilt University NashvilleTN37212 United States Center for Nanophase Materials Science Oak Ridge National Laboratory Oak Ridge37830 United States Department of Electrical and Computer Engineering Kansas State University ManhattanKS66506 United States Department of Physics University of Connecticut StorrsCT06269 United States

The non-linear response of dielectrics to intense, ultrashort electric fields has been a sustained topic of interest for decades with one of its most important applications being femtosecond laser micro/nano-machining. More recently, renewed interests in strong field physics of solids were raised with the advent of mid-infrared femtosecond laser pulses, such as high-order harmonic generation, optical-field-induced currents, etc. All these processes are underpinned by photoionization (PI), namely the electron transfer from the valence to the conduction bands, on a time scale too short for phononic motion to be of relevance. Here, in hexagonal boron nitride, we reveal that the bandgap can be finely manipulated by femtosecond laser pulses as a function of field polarization direction with respect to the lattice, in addition to the field’s intensity. It is the modification of bandgap that enables the ultrafast PI processes to take place in dielectrics. We further demonstrate the validity of the Keldysh theory in describing PI in dielectrics in the few TW/cm2 regime. © 2021, CC BY.

关键词： Photoionization

来源：评论

学校读者我要写书评

暂无评论

Fault-tolerant Individual Pitch control using Adaptive Sliding Mode Observer

引用

IFAC-PapersOnLine 2018年第24期51卷 1127-1132页

作者： Liu, Yanhua Patton, Ron J. Lan, Jianglin School of Engineering and Computer Science University of Hull Cottingham Road HullHUG 7RX United Kingdom Department of Automatic Control and Systems Engineering University of Sheffield Portobello Street SheffieldS1 3JD United Kingdom

Due to the increasing size of wind turbines, the unbalanced loads caused by the uneven spatial distribution of wind speed and turbulence are becoming larger and larger. As has been proved, individual pitch control (IPC) can mitigate the blade asymmetric loads greatly in region 3. On the other hand, the pitch actuator faults can affect the pitching performance with slow dynamics, resulting in generator power instability and even deteriorating the unbalanced loads of blades. However, the effects of unbalanced blade loads deterioration caused by pitch actuator faults have not been taken into account by the traditional IPC design. In the present paper, a fault-tolerant control (FTC) strategy using adaptive sliding mode estimation is combined with a traditional IPC system based on two different control methods (Proportional-Integral and H∞ loop-shaping). It maintains the nominal pitch performance and removes the negative effects of pitch actuator faults on generator power and unbalanced blade loads perfectly. The effectiveness of the proposed strategy is verified on the 5MW NREL wind turbine system. © 2018

关键词： Adaptive control systems Actuators Deterioration Fault tolerance Sliding mode control Two term control systems Wind Wind turbines Actuator fault Adaptive sliding mode Adaptive sliding mode observer Fault tolerant control Individual pitch control Load reduction Proportional integral Sliding mode observers

来源：评论

学校读者我要写书评

暂无评论

Exploring the use of AI in marine acoustic sensor management

引用

Proceedings of Meetings on Acoustics 2022年第1期47卷

作者： Edward Clark Alan Hunter Olga Isupova Marcus Donnelly 1Department of Mechanical Engineering University of Bath Bath BA2 7AY UNITED KINGDOM eprc20@bath.ac.uk A.J.Hunter@bath.ac.uk 2Department of Computer Science University of Bath Bath UNITED KINGDOM oi260@bath.ac.uk 3Systems Engineering & Assesment Ltd Beckington Somerset BA116TA UNITED KINGDOM marcus.donnelly@sea.co.uk

Underwater passive acoustic source detection and tracking is important for various marine applications, including marine mammal monitoring and naval surveillance. The performance in these applications is dependent on the placement and operation of sensing assets, such as autonomous underwater vehicles. Conventionally, these decisions have been made by human operators aided by acoustic propagation modelling tools, situational and environmental data, and experience. However, this is time-consuming and computationally expensive. We consider a ‘toy problem’ of a single autonomous vehicle (agent) in search of a stationary source of low frequency within a reinforcement learning (RL) architecture. We initially choose the observation space to be the agent’s current position. The agent is allowed to explore the environment with a limited action space, taking equal distance steps in one of $n$ directions. Rewards are received for positive detections of the source. Using OpenAI’s PPO algorithm an increase in median episode reward of approximately 20 points in the RL environment developed is seen when the agent is given a history of it’s previous moves and signal-to-noise ratio compared to the simple state. The future expansion of the RL framework is discussed in terms of the observation and action spaces, reward function and RL architecture.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Natural convection flow of nanofluids over horizontal circular cylinder with uniform surface heat flux

引用

AIP Conference Proceedings 2021年第1期2324卷

作者： Sadia Afsana Preetom Nag Md Mamun Molla Sharaban Thohura 1Department of Electrical and Computer Engineering North South University Dhaka 1229 Bangladesh 2Department of Mathematics and Physics North South University Dhaka 1229 Bangladesh 3Center for Applied Scientific Computing North South University Dhaka 1229 Bangladesh 4Department of Mathematics Jagannath University Dhaka 1100 Bangladesh

The behavior of natural convection laminar flow of Nanofluids over a horizontal circular cylinder with uniform surface heat flux has been examined. In this study, Copper-Water (Cu-H2O) nanofluid has been chosen with different volume fractions ranging from 0% to 10%. In the present study, the governing boundary layer equations are converted into a dimensionless form, and the resultant non-dimensional set of equations has been transformed into a parabolic system of partial differential equations by applying a specific set of variables. The set of parabolic equations has been numerically solved using an implicit finite difference method. The outcomes of the numerical simulation have been compared and validated with an excellent agreement with the previously published work. The numerical results have been depicted in terms of the velocity and temperature profiles. Finally, the skin friction coefficient (Cf) and the local Nusselt number (Nu) has been outlined to understand the feature of the wall shear stress and the surface heat transfer rate, respectively.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A secure cloud based image processing technique

引用

AIP Conference Proceedings 2020年第1期2277卷

作者： G. Usha N. A. S Vinoth Veena Maria Nancy Domi Evangeline 1Department of Software Engineering SRMIST Kanchipuram Dt. Kattankulathur – 603 203 India 2Department of Computer Science and Engineering SRMIST Kanchipuram Dt. Kattankulathur – 603 203 India

With the media industry in its full swing, the need for video editing and censoring has increased in drastic proportions. But as every sector has its own advancements, there are also certain areas where it lags. With more number of media items pouring in, the need to segregate the categories has also increased. Presently, this censoring is done manually by viewer’s who view the content. Though there are strict rules as to which videos should fall under which category, discrepancies occur due to difference in perspectives. Moreover, a content running for 3 min would be judged by an algorithm at faster rates than what is being done manually. Therefore, there is a need for a platform where end users need only upload the content while the sorting would be done automatically. The data sets available from ImageNet API would make it easier for training the model for convolutional neural networks.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Development of the software to improve the accuracy of emotion recognition

引用

AIP Conference Proceedings 2022年第1期2647卷

作者： E. V. Soboleva T. N. Suvorova E. V. Lebedeva M. V. Petukhova T. V. Masharova 1Department of Digital Technologies in Education Vyatka State University Kirov Russia 2Department of Informatization of Education Institute of Digital Education Moscow City University Moscow Russia 3Department of Algebra and Mathematical Methods in Economy of Orel State University named after I.S. Turgenev Orel Russia 4Department of Computer Aided Design and Engineering Calculation Russian State Agrarian University–Moscow Timiryazev Agricultural Academy Moscow Russia 5Department of Pedagogy Institute of Pedagogy and Psychology of Education Moscow City Pedagogical University Moscow Russia

The theory of pattern recognition is one of the directions of scientific and technical development in the field of image analysis and machine vision, etc. The authors consider the possibility of using information systems to improve the quality and accuracy of recognizing emotions on faces from images. The purpose of the research is to develop an application that uses the most effective algorithm for detecting faces and recognizing emotions. The methodology is based on the principles of deep learning, includes the use of convolutional neural networks, their software embodiments. The functional scheme is implemented in the application using the methods of the library of computer vision. Result of the research, a module was developed with the ability to determine the user’s emotions from an image from a webcam in real time. At the testing stage a data set for training was formed. A convolutional neural network was trained. The functional for generating graphs describing the emotional portrait of the user for the entire time of using the module was implemented. In the future, it is planned to improve the quality of neural network recognition, and prepare a web service for integration into mobile applications.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Cost optimization of a M/G/k queue with server vacation

引用

AIP Conference Proceedings 2020年第1期2277卷

作者： Lavanya Gowrishankar Vidhyacharan Bhaskar K. Sundarammal 1Department of Mathematics SRM Institute of Science and Technology Kattankulathur 603203 India 2Dept. of Electrical and Computer Engineering San Francisco State University USA

Queueing optimization is a science currently gaining importance in view of its contribution to operations research and marketing management. Capacity of the queue, service policy followed and the job flow into the system are the key variables which affect the cost efficiency of a system. In this proposed model we use Kingman relation to optimize M/G/k queue where the servers returns to function only if there are L jobs and also L is less than k. An expression for the expected cost for one execution cycle per unit time and the average time required for the execution of one cycle is obtained. The average cost incurred per unit time is also obtained.

关键词：

来源：评论

学校读者我要写书评

暂无评论

CenterNet3D: An anchor free object detector for point cloud

arXiv

引用

arXiv 2020年

作者： Wang, Guojun Wu, Jian Tian, Bin Teng, Siyu Chen, Long Cao, Dongpu The State Key Laboratory of Automotive Simulation and Control Jilin University Changchun130022 China The State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing100190 China The School of Artificial Intelligence University of Chinese Academy of Sciences Beijing100190 China The Department of Computer Science Hong Kong Baptist University Hong Kong The School of Data and Computer Science Sun Yat-Sen University Guangdong Guangzhou510275 China The Department of Mechanical and Mechatronics Engineering University of Waterloo WaterlooONN2L 3G1 Canada

Accurate and fast 3D object detection from point clouds is a key task in autonomous driving. Existing one-stage 3D object detection methods can achieve real-time performance, however, they are dominated by anchor-based detectors which are inefficient and require additional post-processing. In this paper, we eliminate anchors and model an object as a single point-the center point of its bounding box. Based on the center point, we propose an anchor-free CenterNet3D network that performs 3D object detection without anchors. Our CenterNet3D uses keypoint estimation to find center points and directly regresses 3D bounding boxes. However, because inherent sparsity of point clouds, 3D object center points are likely to be in empty space which makes it difficult to estimate accurate boundaries. To solve this issue, we propose an extra corner attention module to enforce the CNN backbone to pay more attention to object boundaries. Besides, considering that one-stage detectors suffer from the discordance between the predicted bounding boxes and corresponding classification confidences, we develop an efficient keypoint-sensitive warping operation to align the confidences to the predicted bounding boxes. Our proposed CenterNet3D is non-maximum suppression free which makes it more efficient and simpler. We evaluate CenterNet3D on the widely used KITTI dataset and more challenging nuScenes dataset. Our method outperforms all state-of-the-art anchor-based one-stage methods and has comparable performance to two-stage methods as well. It has an inference speed of 20 FPS and achieves the best speed and accuracy trade-off. Our source code will be released at https://***/wangguojun2018/CenterNet3d. Copyright © 2020, The Authors. All rights reserved.

关键词： Autonomous vehicles

来源：评论

学校读者我要写书评

暂无评论

A study for Motion-Planning Method Resident-tracking Robot based on Reinforcement Learning 30

A study for Motion-Planning Method Resident-tracking Robot b...

引用

30th International Symposium on Micro-NanoMechatronics and Human Science, MHS 2019

作者： Sugimoto, Masashi Yoshioka, Takashi Ishii, Kohei Nonaka, Shogo Deguchi, Mikio Tsuzuki, Shinji Hiran, Masatsugu Electrical and Electronic Engineering Course Ehime University Division of Electrical and Electronic Engineering and Computer Science 3 Bunkyo-cho Matsuyama City Ehime Pref.790-8577 Japan National Institute of Technology Kagawa College Department of Electrical and Computer Engineering 355 Chokushi-cho Takamatsu City Kagawa Pref.761-8058 Japan National Institute of Technology Kagawa College. Department of Electro-Mechanical Systems Engineering 355 Chokushi-cho Takamatsu City Kagawa Pref.761-8058 Japan National Institute of Technology Tsuyama College Department of Integrated Science and Technology 624-1 Numa Tsuyama City Okayama Pref.790-8577 Japan National Institute of Technology Niihama College Department of Electronics and Control Engineering 7-1 Yakumo-cho Niihama City Ehime Pref.790-8580 Japan National Institute of Technology Niihama College Department of Electrical Engineering and Information Science 7-1 Yakumo-cho Niihama City Ehime Pref.792-8580 Japan

ISBN: (纸本)9781728126746

Among the advanced countries, especially in Japan, we are facing on the decreasing birthrate and aging population ahead of the world. In recent, population of single-living elder, and elderly people have been taking care by same-aged person, have been actualized. Unfortunately, the population of caregivers is decreasing according to year. In this situation, the Elderly Person Watching System has been focused on. Especially, Robotics, Internet of Things, and Artificial Intelligence technology have been having high affinity with this system. In this study, firstly, the person watching robot system will be developed. In detail, in this paper, the flexible-analyze system will be focused on. In the algorithm, a resident-tracking task and an energy-saving task are holding. The whole tasks are working based on Reinforcement Learning. Thus, the behavior algorithm of the person watching robot system will be developed. In detail, in this paper, the flexible-analyze system will be focused on. In the algorithm, a resident-tracking task and an energy-saving task are holding. From the verification experiment, the simulation results showed the proposed method has been acquired actions to switch the desired task. © 2019 IEEE.

关键词： Reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Advanced NOMA Assisted Semi-Grant-Free Transmission Schemes for Randomly Distributed Users

arXiv

引用

arXiv 2020年

作者： Lu, Huabing Xie, Xianzhong Shi, Zhaoyuan Lei, Hongjiang Yang, Helin Cai, Jun The Key Laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of Education Dalian University of Technology Dalian116024 China The School of Computer Science and Technology Chongqing University of Posts and Telecommunications Chongqing400065 China The Key Laboratory of Intelligent Perception and Computing of Anhui Province Anqing Normal University Anqing246011 China The School of Communication and Information Engineering Chongqing University of Posts and Telecommunications Chongqing400065 China The Department of Information and Communication Engineering School of Informatics Xiamen University Xiamen361005 China Department of Electrical and Computer Engineering Concordia University MontrealQCH3G 1M8 Canada

Non-orthogonal multiple access (NOMA) assisted semi-grant-free (SGF) transmission has recently received significant research attention due to its outstanding ability of serving grant-free (GF) users with grant-based (GB) users' spectrum, which greatly improves the spectrum efficiency and effectively relieves the massive access problem of 5G and beyond networks. In this paper, we first study the outage performance of the greedy best user scheduling SGF scheme (BU-SGF) by considering the impacts of Rayleigh fading, path loss, and random user locations. In order to tackle the admission fairness problem of the BU-SGF scheme, we propose a fair SGF scheme by applying cumulative distribution function (CDF)-based scheduling (CS-SGF), in which the GF user with the best channel relative to its own statistics will be admitted. Moreover, by employing the theories of order statistics and stochastic geometry, the outage performances of both BU-SGF and CS-SGF schemes are analyzed. Theoretical results show that both schemes can achieve full diversity orders only when the served users' data rate is capped, which severely limits the rate performance of SGF schemes. To further address this issue, we propose a distributed power control strategy to relax such data rate constraint, and derive analytical expressions of the two schemes' outage performances under this strategy. Finally, simulation results validate the fairness performance of the proposed CS-SGF scheme, the effectiveness of the power control strategy, and the accuracy of the theoretical analyses. Copyright © 2020, The Authors. All rights reserved.

关键词： Spectrum efficiency

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：