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Chinese Automation Congress (CAC)

作者： Yunong Zhang Kangze Zheng Jinjin Guo School of Computer Science and Engineering Sun Yat-sen University Guangzhou P. R. China Guangdong Key Laboratory of Modern Control Technology Guangzhou P. R. China Research Institute of Sun Yat-sen University in Shenzhen Shenzhen P. R. China Key Laboratory of Machine Intelligence and Advanced Computing Ministry of Education Guangzhou P. R. China

ISBN: (数字)9781665426473

ISBN: (纸本)9781665426480

Since 2014, Zhang time discretization (ZTD, also termed Zhang et al. discretization) formulas have been put forward as a new method for time discretization by Zhang et al. Originally, ZTD formulas were used to obtain discrete Zhang neural network (ZNN) model from continuous ZNN one. ZTD formulas were also used later to discretize other continuous-time systems. So far, ZTD formulas with various number of instants have been proposed and applied, and the highest precisions of the 2-instant ZTD formula to 7-instant ZTD formulas have been discovered. Instinctively, we want to find out the highest precision of 8-instant ZTD formulas. During our investigation, we ascertain that any convergent 8-instant ZTD formula cannot possess quintic precision or higher. Combined with previous work, we conclude that any 8-instant ZTD formula converges with a truncation error in proportion to the 4-th power of the sampling interval or greater. The conclusion is proved in our paper.

关键词： Automation Stability criteria Neural networks Finite wordlength effects Thermal stability

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AI and Reading Fluency for Brazilian Portuguese: A Preliminary Study

SSRN

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SSRN 2023年

作者： Rodrigues, Aline Do Nascimento Ribeiro, Gabriela L. Silva, Victor H.A. Carvalho, Wesley S. Ramírez, Miguel A. Alves, Luciana M. Finger, Marcelo Navas, Ana Luiza G.P. Ribeiro, Carlos H.C. Computer Science Division Aeronautics Institute of Technology Praça Mal. Eduardo Gomes 50 SP Sao Jose dos Campos12228-900 Brazil Federal University of Minas Gerais Medicine Faculty Department of Speech Therapy Av. Prof. Alfredo Balena 190 MG Belo Horizonte30130-100 Brazil University of Sao Paulo Escola Politecnica Department of Telecommunications and Control Engineering Av. Prof. Luciano Gualberto trav. 3 158 SP Sao Paulo05508-010 Brazil University of Sao Paulo Institute of Mathematics and Statistics Department of Computer Science Rua do Matao 1010 SP Sao Paulo05508-090 Brazil University of Sao Paulo Escola Politecnica Department of Electronic Systems Engineering Av. Prof. Luciano Gualberto trav. 3 158 SP Sao Paulo05508-010 Brazil School of Medical Sciences of Santa Casa de Sao Paulo Department of Speech Therapy R. Dr. Cesario Motta Jr. 61 SP Sao Paulo01221-020 Brazil

Automatic assessment of oral reading fluency — either for completely autonomous operation or as a facilitator for human decision making — is a likely requirement for timely interventions regarding educational policies for Literacy, especially at the initial years of formal Education. Countries with huge populations such as Brazil have a more urgent demand for such automated procedures, considering the scale of the evaluation needs and the disproportional lack of specialized personnel, compared to more advanced countries. Nevertheless, computational methods as educational aids for Literacy evaluation have been developed mainly for English and other languages associated with those high income countries. Therefore there is an obvious need for studies on languages and countries (especially those with large educational populations) that are less developed. We report on a computational model for fluency assessment based on an automatic speech recognizer (ASR) readily available in the software literature, trained via a deep learning model on a publicly available dataset for Brazilian Portuguese. The model was previously trained for ASR purposes, and therefore was not designed for Literacy assessment of children, this aspect was dealt with through a series of pre and post-processing of the audio samples. Extensive comparative results on reading oral fluency for standardized assessment texts considering the proposed automated process compared to a benchmark by human expert annotations showed a high matching for measures on word and word error rates, despite the fact that the learning model did not include samples from the target population. © 2023, The Authors. All rights reserved.

关键词： Computational methods

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Sample Complexity Lower Bounds for Linear System Identification

Sample Complexity Lower Bounds for Linear System Identificat...

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IEEE Annual Conference on Decision and control

作者： Yassir Jedra Alexandre Proutiere Division of Decision and Control Systems School of Electrical Engineering and Computer Science Royal institute of Technology (KTH) Stockholm Sweden

ISBN: (数字)9781728113982

ISBN: (纸本)9781728113999

This paper establishes problem-specific sample complexity lower bounds for linear system identification problems. The sample complexity is defined in the PAC framework: it corresponds to the time it takes to identify the system parameters with prescribed accuracy and confidence levels. By problem-specific, we mean that the lower bound explicitly depends on the system to be identified (which contrasts with minimax lower bounds), and hence really captures the identification hardness specific to the system. We consider both uncontrolled and controlled systems. For uncontrolled systems, the lower bounds are valid for any linear system, stable or not, and only depend on the system finite-time controllability gramian. A simplified lower bound depending on the spectrum of the system only is also derived. In view of recent finite-time analysis of classical estimation methods (e.g. ordinary least squares), our sample complexity lower bounds are tight for many systems. For controlled systems, our lower bounds are not as explicit as in the case of uncontrolled systems, but could well provide interesting insights into the design of control policy with minimal sample complexity.

关键词： Complexity theory Linear systems Estimation Optimization Heuristic algorithms controllability

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Robust Trajectory Tracking control for Underactuated Autonomous Underwater Vehicles

Robust Trajectory Tracking Control for Underactuated Autonom...

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IEEE Conference on Decision and control

作者： Shahab Heshmati-alamdari Alexandros Nikou Dimos V. Dimarogonas Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden

ISBN: (数字)9781728113982

ISBN: (纸本)9781728113999

This paper addresses the tracking control problem of 3D trajectories for underactuated underwater robotic vehicles operating in an uncertain workspace including obstacles. In particular, a robust Nonlinear Model Predictive control (NMPC) scheme is presented for the case of underactuated Autonomous Underwater Vehicles (AUVs) (i.e., vehicles actuated only in surge, heave and yaw). The purpose of the controller is to steer the underactuated AUV to a desired trajectory with guaranteed input and state constraints inside a dynamic environment where the knowledge of the operating workspace is constantly updated on-line via the vehicle's on-board sensors. In particular, obstacle avoidance with any of the detected obstacles is guaranteed, despite the model dynamic uncertainties and the presence of external disturbances representing ocean currents and waves. The proposed feedback control law consists of two parts: an online law which is the outcome of a Finite Horizon Optimal control Problem (FHOCP) solved for the nominal dynamics; and a state feedback law which is tuned offline and guarantees that the real trajectories remain bounded in a hyper-tube centered along the nominal trajectories for all times. Finally, a simulation study verifies the performance and efficiency of the proposed approach.

关键词： Trajectory Underwater vehicles Vehicle dynamics Robot sensing systems Robustness

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Exploring the Pan-Relationship Between Disease and Symptom Related to Coronary Heart Disease from Chinese Electronic Medical Records 15th

Exploring the Pan-Relationship Between Disease and Symptom R...

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15th International Conference on Intelligent Computing, ICIC 2019

作者： Yang, Ronggen Wang, Yichen Wang, Bo Gong, Lejun Faculty of Intelligent Science and Control Engineering Jinling Institute of Technology Nanjing211169 China Jiangsu Key Lab of Big Data Security and Intelligent Processing School of Computer Science Nanjing University of Posts and Telecommunications Nanjing210046 China School of Geography and Bioinformatics Nanjing University of Posts and Telecommunication Nanjing China

ISBN: (纸本)9783030267650

Electronic Medical Records (EMRs) arises from the clinical treatment process, which reflects a patient’s physical condition, the disease, the treatment process, etc. It has an important significance for the recovery of the patient. As the amount of electronic medical records continues to increase, people are actively looking for ways to get the valid data contained in electronic medical records. More effective methods are urgently needed for processing EMRs. In this paper, 108 real EMRs of coronary heart disease were analyzed, through named entity recognition and entity relation extraction. Pan-relationship between entities was defined in the process. Experimental results showed the analysis of pan-relation between coronary heart disease and symptom is helpful for treatment of coronary heart disease. © 2019, Springer Nature Switzerland AG.

关键词： Diseases

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Toward Tractable Global Solutions to Maximum-Likelihood Estimation Problems via Sparse Sum-of-Squares Relaxations

Toward Tractable Global Solutions to Maximum-Likelihood Esti...

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IEEE Annual Conference on Decision and control

作者： Diogo Rodrigues Mohamed R. Abdalmoaty Hakan Hjalmarsson Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden

ISBN: (数字)9781728113982

ISBN: (纸本)9781728113999

In system identification, the maximum-likelihood method is typically used for parameter estimation owing to a number of optimal statistical properties. However, in many cases, the likelihood function is nonconvex. The solutions are usually obtained by local numerical optimization algorithms that require good initialization and cannot guarantee global optimality. This paper proposes a computationally tractable method that computes the maximum-likelihood parameter estimates with posterior certification of global optimality via the concept of sum-of-squares polynomials and sparse semidefinite relaxations. It is shown that the method can be applied to certain classes of discrete-time linear models. This is achieved by taking advantage of the rational structure of these models and the sparsity in the maximum-likelihood parameter estimation problem. The method is illustrated on a simulation model of a resonant mechanical system where standard methods struggle.

关键词： Optimization Maximum likelihood estimation Computational modeling Parameter estimation Random variables Convergence

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A Non-Stop Double Buffering Mechanism for Dataflow Architecture

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Journal of computer Science & Technology 2018年第1期33卷 145-157页

作者： Xu Tan Xiao-Wei Shen Xiao-Chun Ye Da Wang Dong-Rui Fan Lunkai Zhang Wen-Ming Li Zhi-Min Zhang Zhi-Min Tang State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China School of Computer and Control Engineering University of Chinese Academy of Sciences Beijing 100049 China State Key Laboratory of Mathematical Engineering and Advanced Computing Wuxi 214125 China Department of Computer Science The University of Chicago Chicago IL 60637 U.S.A.

Double buffering is an effective mechanism to hide the latency of data transfers between on-chip and off-chip memory. However, in dataflow architecture, the swapping of two buffers during the execution of many tiles decreases the performance because of repetitive filling and draining of the dataflow accelerator. In this work, we propose a non-stop double buffering mechanism for dataflow architecture. The proposed non-stop mechanism assigns tiles to the processing element array without stopping the execution of processing elements through optimizing control logic in dataflow architecture. Moreover, we propose a work-flow program to cooperate with the non-stop double buffering mechanism. After optimizations both on control logic and on work-flow program, the filling and draining of the array needs to be done only once across the execution of all tiles belonging to the same dataflow graph. Experimental results show that the proposed double buffering mechanism for dataftow architecture achieves a 16.2% average efficiency improvement over that without the optimization.

关键词： non-stop double buffering dataflow architecture high-performance computing

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Realization of Nonlinear Adaptive Compliance: Towards Energy Efficiency in Cyclic Tasks

Realization of Nonlinear Adaptive Compliance: Towards Energy...

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RSI/ISM International Conference on Robotics and Mechatronics (ICROM)

作者： Rezvan Nasiri Arjang Ahmadi Majid Nili Ahmadabadi Cognitive Systems Laboratory Control and Intelligent Processing Center of Excellence (CIPCE) School of Electrical and Computer Engineering College of Engineering University of Tehran Iran

ISBN: (数字)9781728166049

ISBN: (纸本)9781728166056

Due to the nonlinearity of dynamical equations in robotic systems, nonlinear compliance has more potential for energy consumption reduction. Moreover, the legged robots require adaptive structures so as to maximize their efficiency w.r.t. the new environments and gaits. Therefore, having nonlinear adaptive compliance is essential in legged robots. In this paper, we take one step towards the realization of nonlinear compliances with adaptable torque-deflection profiles. So as to achieve this goal, we present a mechanism which consists of four linear extension springs. Changing the arrangement of linear springs can adapt the compliance profile to the desired one. In addition, to optimize the arrangement of linear springs in an online manner, an adaptation rule is presented. The proposed adaptation rule adapts the compliance profile such that the actuator's torque and consequently the energy consumption are reduced. The performance of presented adaptation rule for actuator's torque minimization is analyzed by means of simulations. In simulations, we observed that the adaptation rule not only minimizes the energy consumption but also improves the tracking performance of the controller. Finally, to realize nonlinear adaptive compliance, a prototype of the presented mechanism is designed and constructed.

关键词： Torque Springs Robots Actuators Energy consumption Task analysis Mathematical model

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Stochastic phase-cohesiveness of discrete-time kuramoto oscillators in a frequency-dependent tree network

arXiv

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arXiv 2019年

作者： Jafarian, Matin Mamduhi, Mohammad H. Johansson, Karl H. Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden

This paper presents the notion of stochastic phasecohesiveness based on the concept of recurrent Markov chains and studies the conditions under which a discrete-time stochastic Kuramoto model is phase-cohesive. It is assumed that the exogenous frequencies of the oscillators are combined with random variables representing uncertainties. A bidirectional tree network is considered such that each oscillator is coupled to its neighbors with a coupling law which depends on its own noisy exogenous frequency. In addition, an undirected tree network is studied. For both cases, a sufficient condition for the common coupling strength (κ) and a necessary condition for the sampling-period are derived such that the stochastic phase-cohesiveness is achieved. The analysis is performed within the stochastic systems framework and validated by means of numerical simulations. Copyright © 2019, The Authors. All rights reserved.

关键词： Stochastic systems

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Ultra-short-term wind speed forecast based on WD-ARIMAX-GARCH model 2

Ultra-short-term wind speed forecast based on WD-ARIMAX-GARC...

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2nd IEEE International Conference on Automation, Electronics and Electrical engineering, AUTEEE 2019

作者： Xu, Qiang Li, Wei Kong, Dean Zhao, Xiang Wang, Xiaoyu Li, Yongji Shen, Yong Wang, Xiangshuo Zhao, Zheng State Grid Xinjiang Company Limited Electric Power Research Institute Urumqi China Xinjiang Electric Power Construction and Commissioning Co. Ltd Urumqi China School of Control Engineering and Computer North China Electric-Power University Baoding China

ISBN: (纸本)9781728150291

With the increasing proportion of wind energy in the energy structure, the high-precision prediction model has become an indispensable link. An ultra-short-term wind speed forecasting model based on WD-ARIMAX-GARCH is proposed. For some time series, they are often influenced by external factors, and the ARIMA model is only a regression of historical time series, which cannot reflect the influence of external factors. In order to obtain exogenous variables, the wind speed time series is decomposed into several subsequences by introducing wavelet decomposition, and the ARIMA-GARCH model is established for each subsequence. The predicted result is recombined as an exogenous variable and the decomposed data, and an ARIMAX model is established for the new time series. The WD-ARIMAX-GARCH model experiment results show that the prediction accuracy is high. © 2019 IEEE.

关键词： Wavelet decomposition

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