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Applications of A Numerical Model to Wave Propagation on Mild Slopes

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China Ocean Engineering 2002年第4期17卷 569-576页

作者： Asu Inan Lale balas Civil Engineering Department Faculty of Engineering and Architecture Gazi University 06570 Ankara Turkey Civil Engineering Department Faculty of Engineering and Architecture Gazi University 06570 Ankara Turkey

Based on the mild slope equation that has heen deeomposed inlo three equations related to wave phase function, wave amplitude and wave approach angle, a refraction-diffraction model is developed. The finite difference method has been selected as the solution method. The model results are compared with experimental results and the model is applied to coastal waters of the Fethiye Bay, whieh is located at the Mediterranean Sea of Turkey.

关键词： numerical model wave propagation mild slope refraction-difjraction

Robust Adaptive Model Tracking for Distributed Parameter Control of Linear Infinite-dimensional Systems in Hilbert Space

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IEEE/CAA Journal of Automatica Sinica 2014年第3期1卷 294-301页

作者： Mark J.balas Susan A.Frost the Embry-Riddle Aeronautical University the NASA Ames Research Center

This paper is focused on adaptively controlling a linear infinite-dimensional system to track a finite-dimensional reference *** a linear continuous-time infinite-dimensional plant on a Hilbert space with disturbances of known waveform but unknown amplitude and phase,we show that there exists a stabilizing direct model reference adaptive control law with the properties of certain disturbance rejection and *** plant is described by a closed,densely defined linear operator that generates a continuous semigroup of bounded operators on the Hilbert space of *** central result will show that all errors will converge to a prescribed neighborhood of zero in an infinitedimensional Hilbert *** result will not require the use of the standard Barbalat’s lemma which requires certain signals to be uniformly *** result is used to determine conditions under which a linear infinite-dimensional system can be directly adaptively controlled to follow a reference *** particular,we examine conditions for a set of ideal trajectories to exist for the tracking *** results are applied to adaptive control of general linear diffusion systems described by self-adjoint operators with compact resolvent.

关键词： Robustness Adaptation models Adaptive control Hilbert space Trajectory Learning (artificial intelligence)

A Composite State Convergence Scheme for Bilateral Teleoperation Systems

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1166-1178页

作者： Muhammad Usman Asad Umar Farooq Jason Gu Ghulam Abbas Rong Liu Valentina E.balas the Department of Electrical &Computer Engineering Dalhousie UniversityN.S.Canada the Department of Electrical & Computer Engineering Dalhousie UniversityN.S.Canada the Department of Electrical Engineering University of the Punjab LahorePakistan the Department of Electrical Engineering The University of LahorePakistan the Department of Biomedical Engineering Dalian University of TechnologyChina the Department of Automatics &Applied Software “Aurel Vlaicu” University of AradRomania

State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator's force channel intact. We show that,with these composite and force variables;it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.

关键词： Composite variables linear control systems state convergence teleoperation time delay

基于Floquet理论的旋转风机叶片动力失速气弹稳定性研究

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振动与冲击 2015年第24期34卷 82-88页

作者：李迺璐穆安乐 balas M J 扬州大学水利与能源动力工程学院江苏扬州225127 西安理工大学机械与精密仪器工程学院西安710048 美国安柏瑞德航空航天大学航空学院美国32114

研究旋转风力机叶片动力失速气弹稳定性问题。叶片结构采用标量化的挥舞和扭转自由度耦合的振动运动模型,旋转风机叶片的气动力由Beddoes-Leishman失速模型来模拟,通过攻角在深度失速区域内的变化来计算出周期时变的非线性气动失速负载... 详细信息

研究旋转风力机叶片动力失速气弹稳定性问题。叶片结构采用标量化的挥舞和扭转自由度耦合的振动运动模型,旋转风机叶片的气动力由Beddoes-Leishman失速模型来模拟,通过攻角在深度失速区域内的变化来计算出周期时变的非线性气动失速负载。在系统静平衡点附近对非线性气弹系统进行线性化,采用Floquet理论分析旋转叶片动力失速气弹稳定性,其结果得到系统时域响的验证。通过数值分析,揭示了挥舞扭转固有频率比和结构阻尼对颤振边界的影响。

关键词：旋转风机叶片气动失速 Floquet理论 Beddoes-Leishman模型

基于B-L气动模型的旋转水平风机叶片经典颤振稳定性分析

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振动与冲击 2015年第23期34卷 171-176页

研究旋转水平轴风力机叶片周期时变气弹系统的经典颤振稳定性特性。叶片结构采用具有挥舞和扭转耦合的典型界面振动模型,引入Beddoes-Leishman气动模型为旋转叶片提供低攻角处周期时变的非定常气动力;为了研究颤振边界,利用标量风速和挥... 详细信息

研究旋转水平轴风力机叶片周期时变气弹系统的经典颤振稳定性特性。叶片结构采用具有挥舞和扭转耦合的典型界面振动模型,引入Beddoes-Leishman气动模型为旋转叶片提供低攻角处周期时变的非定常气动力;为了研究颤振边界,利用标量风速和挥舞/扭转固有频率比对所建立的旋转叶片气弹模型进行变型。在此基础上,通过时域响应曲线分析旋转叶片挥舞自由度和扭转自由度气弹稳定性特性,分析了标量速度,叶片刚度,挥舞/扭转固有频率比和结构阻尼的影响,揭示了旋转叶片经典颤振边界的变化规律且其准确性得到验证。

关键词：旋转风机叶片经典颤振气弹模型稳定性

Vessels Segmentation in Angiograms Using Convolutional Neural Network: A Deep Learning Based Approach

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Computer Modeling in Engineering & Sciences 2023年第7期136卷 241-255页

作者： Sanjiban Sekhar Roy Ching-Hsien Hsu Akash Samaran Ranjan Goyal Arindam Pande Valentina E.balas School of Computer Science and Engineering Vellore Institute of TechnologyVellore632014India Department of Computer Science and Information Engineering Asia UniversityTaichung41354Taiwan Department of Medical Research China Medical University HospitalChina Medical UniversityTaichung406Taiwan Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-nano Optoelectronic Technology School of Mathematics and Big DataFoshan UniversityFoshan528000China Medica Superspecialty Hospital Kolkata700099India Automation and Applied Informatics Aurel Vlaicu University of AradArad310130Romania

Coronary arterydisease(CAD)has become a significant causeof heart attack,especially amongthose 40yearsoldor *** is a need to develop new technologies andmethods to deal with this *** researchers have proposed image processing-based solutions for CADdiagnosis,but achieving highly accurate results for angiogram segmentation is still a *** different types of angiograms are adopted for CAD *** paper proposes an approach for image segmentation using ConvolutionNeuralNetworks(CNN)for diagnosing coronary artery disease to achieve state-of-the-art *** have collected the 2D X-ray images from the hospital,and the proposed model has been applied to *** augmentation has been performed in this research as it’s the most significant task required to be initiated to increase the dataset’s ***,the images have been enhanced using noise removal techniques before being fed to the CNN model for segmentation to achieve high *** the output,different settings of the network architecture undoubtedly have achieved different accuracy,among which the highest accuracy of the model is 97.61%.Compared with the other models,these results have proven to be superior to this proposed method in achieving state-of-the-art results.

关键词： Angiogram convolution neural network coronary artery disease diagnosis of CAD image segmentation

Design of a Proportional-Integral-Derivative Controller for an Automatic Generation Control of Multi-area Power Thermal Systems Using Firefly Algorithm

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IEEE/CAA Journal of Automatica Sinica 2019年第2期6卷 503-515页

作者： K.Jagatheesan B.Anand Sourav Samanta Nilanjan Dey Amira S.Ashour Valentina E.balas the Department of Electrical & Electronics Eng. Mahendra Institute of Eng. & Tech. the Department of Electrical & Electronics Eng. Hindusthan College of Eng. & Tech. the Department of Computer Science & Engineering University Institute of Technology The University of Burdwan the Department of Information Technology Techno India College of Technology the Department of Electronics and Electrical Communications Engineering Faculty of Engineering Tanta University the Faculty of Engineering Aurel Vlaicu University of Arad

Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.

关键词： Automatic generation control(AGC) firefly algorithm genetic algorithm(GA) particle swarm optimization(PSO) proportional-integral-derivative(PID) controller

WU Ying-kai, a pioneer in cardiothoracic surgery in China

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Chinese Medical Journal 2008年第2期121卷 190-191页

作者： WANG Zhong-gao Panagiotis balas Department of Vascular Surgery Xuan Wu Hospital Capital Medical University Beijing 100053 China Adviser and Past Vice President of International Union of Angiology Athens University Hospital University of Athens Athens Greece Past President of International Union of Angiology Past Chief Editor of International Angiology

When you ask who are the pioneers of surgery in China in the last centuary, the late professor WU Ying-kai is one of ***. Wu was an outstanding medical scientist, perhaps is one of few surgeons well known to many in the field of thoracic surgery outside China in that period. His name is related to the development of thoracic and cardiovascular surgery in this country.

关键词：胸外科学医学家人类

基于抗干扰自适应算法的颤振系统的研究与仿真

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测控技术 2014年第9期33卷 125-127页

作者：李迺璐 Mark J.balas 扬州大学水利与能源动力学院江苏扬州225127 怀俄明大学电子工程系美国怀俄明州82072

颤振抑制系统中非线性扰动的干扰是影响抑制效果的一个重要因素,同时对颤振位移等被控量精确测量的能力有限也影响了抑制效果。为了消除扰动影响和减小测量被控量的难度,提出了设计基于抗干扰自适应算法的控制器,对二阶弹性气动模型进... 详细信息

颤振抑制系统中非线性扰动的干扰是影响抑制效果的一个重要因素,同时对颤振位移等被控量精确测量的能力有限也影响了抑制效果。为了消除扰动影响和减小测量被控量的难度,提出了设计基于抗干扰自适应算法的控制器,对二阶弹性气动模型进行颤振控制。Matlab仿真结果表明,构建的自适应控制器只需要较少并易于测量的被控量,与PID控制器相比能更有效精确地抑制扰动,控制颤振并消除了抑制误差。

关键词：抗干扰自适应颤振系统