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Guaranteed feasible control allocation using model predictive control

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Control Theory and Technology 2019年第3期17卷 252-264页

作者： Mehdi NADERI ali khaki sedigh Tor Arne JOHANSEN Center of Excellence in Industrial Control Faculty of Electrical Engineering K. N. Toosi University of Technology Seyyed Khandan Bridge Shariati Ave. Tehran Iran Center for Autonomous Marine Operation and Systems Department of Engineering Cybernetics Norwegian University of Science and Technology N7491 Trondheim Norway

This paper proposes a guaranteed feasible control allocation method based on the model predictive control. Feasible region is considered to guarantee the determination of the desired virtual control signal using the pseudo inverse methodology and is described as a set of constraints of an MPC problem. With linear models and the given constraints, feasible region defines a convex polyhedral in the virtual control space. In order to reduce the computational time, the polyhedral can be approximated by a few axis alig ned hypercubes. Employing the MPC with rectangular constraints substantially reduces the computational complexity .In two dimensions, the feasible region can be approximated by a few rectangles of the maximum area using numerical geometry techniques which are considered as the constraints of the MPC problem. Also, an active MPC is defined as the controller to minimize the cost function in the control horizon. Finally, several simulation examples are employed to illustrate the effectiveness of the proposed techniques.

关键词： Control allocation feasible region actuator constraints model predictive control

Enhancement of Multi-Objective Control Performance via Switching

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Enhancement of Multi-Objective Control Performance via Switc...

2009中国控制与决策会议

作者： Laven Soltanian ali khaki sedigh Omid Namaki-Shoushtari Advanced Process Automation & Control(APAC) Research Group K.N.Toosi University of TechnologyTehranIran Control Engineering Department K.N.Toosi University of TechnologyTehranIran

＜正＞Control system design for a complex system encompasses the optimization of different and often conflicting objectives leading to a multiple objective design *** this paper,a switching strategy is proposed to solve the multiple objective controller *** controller is designed based on a set of performance *** realization considerations are used to ensure overall closed loop *** matrix inequalities are employed in the controller design *** objective designs are always prone to over conservatism,which is greatly reduced by the switching *** results are used to show the effectiveness of the design methodology.

关键词： multi-objective control switching stability state space realization linear matrix inequalities(LMI)

An Adaptive Observer for Linear Systems with Reduced Adaptation Laws and Measurement Faults

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An Adaptive Observer for Linear Systems with Reduced Adaptat...

2011 Chinese Control and Decision Conference（CCDC）

作者： Amirhossein Nikoofard Farzad R.Salmasi ali khaki sedigh Control and Intelligent Processing Center of Excellence ECE Department College of EngineeringUniversity of Tehran Faculty of Electrical Engineering Khajeh Nasir Toosi University of Technology

In this note,an adaptive observer is considered for simultaneous estimation of the states and unknown parameters of linear stationary systems with faulty *** entries of system matrices are functions of only a few parameters,it is enough to tune those parameters,instead of adapting all *** leads to reduced adaptation ***,the problem of measurement offset and gain faults are also *** stability and convergence of the proposed adaptive observer is *** results validate the performance of the proposed adaptive observer.

关键词： Adaptive observer parameter estimation measurement fault induction motor

A Fault-Tolerant Control Technique for Accommodation of Partial Actuator Faults

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A Fault-Tolerant Control Technique for Accommodation of Part...

2010 Chinese Control and Decision Conference

作者： Behnam Allahverdi Charandabi ali khaki sedigh Farzad R.Salmasi School of Electrical Engineering Faculty of EngineeringTehran UniversityTehranIran Faculty of Electrical Engineering Khajeh Nasir Toosi University of TechnologyTehranIran

＜正＞In this paper,a robust adaptive controller for accommodation of partial actuator faults is *** proposed controller is based on the robust adaptive model-reference control scheme with improved dead zone *** common problem of steady state error in robust adaptive systems with simple dead zone modification is resolved by tuning a specific parameter inside the dead zone with a different adaptive *** types of actuator faults including output offset,loss of efficiency,and output delay are compensated with the proposed *** behave these faults as uncertainties and disturbances. The proposed technique does not need an extra unit for fault detection and *** simulation studies are performed to illustrate the effectiveness of the proposed control technique versus the robust adaptive controller with simple dead zone modification.

关键词： Fault-tolerant control Robust adaptive control Dead zone Uncertainty

Effects of sphere size on the microstructure and mechanical properties of ductile iron–steel hollow sphere syntactic foams

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 676-682页

作者： Hamid Sazegaran ali-Reza Kiani-Rashid Jalil Vahdati khaki Department of Metallurgical and Materials Engineering Faculty of Engineering Ferdowsi University of Mashhad

The effects of sphere size on the microstructural and mechanical properties of ductile iron–steel hollow sphere（DI–SHS） syntactic foams were investigated in this study. The SHSs were manufactured by fluidized-bed coating via the Fe-based commercial powder–binder suspension onto expanded polystyrene spheres（EPSs）. Afterwards, the DI–SHS syntactic foams were produced via a sand-mold casting process. The microstructures of specimens were investigated by optical microscopy, scanning electron microscopy（SEM）, and energy-dispersive X-ray spectroscopy（EDS）. The microscopic evaluations of specimens reveal distinct regions composed of the DI matrix, SHS shells, and compatible interface. As a result, the microstructures and graphite morphologies of the DI matrix depend on sphere size. When the sphere size decreases, the area fractions of cementite and graphite phases are observed to increase and decrease, respectively. Compression tests were subsequently conducted at ambient temperature on the DI–SHS syntactic foams. The results reveal that the compression behavior of the syntactic foams is enhanced with increasing sphere size. Furthermore, the compressed specimens demonstrate that microcracks start and grow from the interface region.

关键词： ductile iron steel syntactic foams microstructure mechanical properties

Effects of copper content on the shell characteristics of hollow steel spheres manufactured using an advanced powder metallurgy technique

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International Journal of Minerals,Metallurgy and Materials 2016年第4期23卷 434-441页

作者： Hamid Sazegaran ali-Reza Kiani-Rashid Jalil Vahdati khaki Department of Materials Science and Metallurgical Engineering Engineering Faculty Ferdowsi University of Mashhad

Metallic hollow spheres are used as base materials in the manufacture of hollow sphere structures and metallic foams. In this study, steel hollow spheres were successfully manufactured using an advanced powder metallurgy technique. The spheres＇ shells were characterized by optical microscopy in conjunction with microstructural image analysis software, scanning electron microscopy（SEM）, energy-dispersive X-ray spectroscopy（EDX）, and X-ray diffraction（XRD）. The microscopic evaluations revealed that the shells consist of sintered iron powder, sintered copper powder, sodium silicate, and porosity regions. In addition, the effects of copper content on various parameters such as shell defects, microcracks, thickness, and porosities were investigated. The results indicated that increasing the copper content results in decreases in the surface fraction of shell porosities and the number of microcracks and an increase in shell thickness.

关键词： steel hollow spheres powder metallurgy copper content shell characteristics

Determinants of prognosis in metastatic urothelial carcinoma:a review of the literature

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Journal of Cancer Metastasis and Treatment 2022年第1期8卷 240-252页

作者： Gavin Hui ali Raza khaki Petros Grivas Department of Medicine Stanford UniversityStanfordCA 94304USA Division of Oncology Department of MedicineStanford UniversityStanfordCA 94304USA Division of Medical Oncology Department of MedicineUniversity of WashingtonFred Hutchinson Cancer CenterSeattleWA 98109USA

The treatments for metastatic urothelial carcinoma(mUC)have advanced substantially since *** tools have been used to inform clinical trial designs and treatment ***,prognostic tools were developed for mUC based on older clinical trials involving cytotoxic *** novel therapies emerged,there are studies investigating prognostic factors in the era of immune checkpoint inhibitors(ICI),antibody-drug conjugates,and targeted *** review aims to highlight prognostic factors in mUC and their potential in clinical decision-making and *** the setting of chemotherapy,patient performance status,site of metastatic burden,and specific laboratory findings were found to have prognostic value in *** the era of ICI,newer models identified variables such as neutrophil to lymphocyte ratio,platelet count,and lactate dehydrogenase to also have potential prognostic *** addition to clinical biomarkers,molecular biomarkers,such as PD-L1 assay and fibroblast growth factor receptor 2 and 3 genomic testings,may have promising prognostic and predictive *** methods of identifying clinical and molecular prognostic factors involve clinician *** large complex datasets emerge,machine learning and artificial intelligence may help data analysis and detect important prognostic *** careful validation,such machine learning-based strategies may help create more robust prognostic and/or predictive models in the future.

关键词： Bladder cancer biomarkers health outcomes nomogram prediction prognosis urothelial carcinoma urinary tract cancers

Predictive Control of Non-minimum Phase Motor with Backlash in an Earth Station Antenna

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Predictive Control of Non-minimum Phase Motor with Backlash ...

第25届中国控制会议

作者： Mohammadzaman Iman khaki sedigh ali Nasirian Mehrzad Faculty of Electrical Engineering Malek Ashtar University of Technology TehranIran Faculty of Electrical Engineering K．N．Toosi University of Technology TehranIran Faculty of Electrical Engineering K．N．Toosi University of Technology TehranIran

＜正＞In this paper, Generalized Predictive Control （GPC） algorithm is implemented to control an earth station antenna with a non-minimum phase motor. Nonlinear term in motors caused by gearbox or other parts is modeled by a backlash block. Simulation results show the effectiveness of GPC method for robust control in the presence of backlash nonlinearity without a priori knowledge about upper and lower bounds of backlash. Also, adaptation mechanism as a self tuning predictive control is used to conquer environment changing.

关键词： Generalized Predictive Control Non-minimum Phase Motor Backlash Earth Station Antenna

PERCEPOLIS: Pervasive Cyberinfrastructure for Personalized Learning and Instructional Support

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Intelligent Information Management 2010年第10期2卷 586-596页

作者： ali R. Hurson Sahra sedigh 不详

This paper describes PERCEPOLIS, an educational platform that leverages technological advances, in particular in pervasive computing, to facilitate personalized learning in higher education, while supporting a networked curricular model. Fundamental to PERCEPOLIS is the modular approach to course development. Blended instruction, where students are responsible for perusing certain learning objects outside of class, used in conjunction with the cyberinfrastructure will allow the focus of face-to-face meetings to shift from lecture to active learning, interactive problem-solving, and reflective instructional tasks. The novelty of PERCEPOLIS lies in its ability to leverage pervasive and ubiquitous computing and communication through the use of intelligent software agents that use a student’s academic profile and interests, as well as supplemental information such as his or her learning style, to customize course content. Assessments that gauge the student’s mastery of concepts are used to allow self-paced progression through the course. Furthermore, the cyberinfrastructure facilitates the collection of data on student performance and learning at a resolution that far exceeds what is currently available. We believe that such an infrastructure will accelerate the acquisition of knowledge and skills critical to professional engineering practice, while facilitating the study of how this acquisition comes about, yielding insights that may lead to significant changes in pedagogy.

关键词： Learning Technology Personalized Learning Cyberinfrastructure Pervasive Computing.