检索结果-内蒙古大学图书馆

Improvement of K-means Cluster Quality by Post Processing Resulted Clusters

Procedia Computer Science 2022年 199卷 63-70页

作者： Ioan-Daniel Borlea Radu-Emil Precup Alexandra-Bianca Borlea Politehnica University of Timişoara Dept. Automation and Applied Informatics Bd. V. Parvan 2 300223 Timişoara Romania

A big volume of new data is generated in every moment of the day by different devices and domains as social network, mobile and desktop devices, financial transaction, online websites, different search engines and a lot of smart home devices. The generated data is diversified and can be structured or unstructured. Clustering is the process of categorizing a dataset in groups of records that are similar and are called clusters, the grouping process being performed using a specific criterion. The K-means clustering algorithm is still popular after many years. Different versions of the K-means algorithm emerged along the time and were focused on improving the K-means algorithm by performing some preprocessing steps or by reducing the number of iterations having as a final objective the improvement of the processing time. This paper presents a way of improving the resulted clusters generated by the K-means algorithm by post processing the resulted clusters with a supervised learning algorithm. The proposed approach is focused on improving the quality of the resulting clusters and not on reducing the processing time.

关键词： Clustering algorithms hybrid K-means improved K-means K-means post processing

来源：评论

学校读者我要写书评

暂无评论

Secure handwriting using a robot arm for educational purpose

Secure handwriting using a robot arm for educational purpose

引用

International Conference on Methods and Models in automation and Robotics (MMAR)

作者： Marius-Florin Crainic Stefan Preitl Lucian Alexandru Şandru Valer Dolga Dept. of Automation and Applied Informatics “Politehnica” University of Timisoara Timisoara Romania Dept. of Mechatronics “Politehnica” University of Timisoara Timisoara Romania

As the educational system is growing there is a lot of paperwork to do like completing different types of certificates, or traditional gradebook. The paper presents a different approach to facilitate and secure the writing of certificates or traditional gradebooks. This system uses a robot arm, RV-2AJ, which has a pen attached. The setups are easy to be made because they involve the reading of only three points for calibration which forms a right-angled triangle. After the calibration the robotic arm can write even if the writing surface is on an inclined plane, or the paper is rotated. This system is more secure than the one that uses the ink printer, because the movement of the robot arm to reproduce the font on the paper is unique. Another secure element is the embossing stamp. The embossing stamp is created by changing the pen with a needle. The needle creates small closed holes using a pattern in which the information used for writing is encrypted.

关键词： Robot kinematics Writing Calibration Embossing Software Mathematical model

来源：评论

学校读者我要写书评

暂无评论

Second Order Intelligent Proportional-Integral Fuzzy Control of Twin Rotor Aerodynamic Systems

引用

Procedia Computer Science 2018年 139卷 372-380页

作者： Raul-Cristian Roman Radu-Emil Precup Radu-Codrut David Politehnica University of Timişoara Dept. Automation and Applied Informatics Bd. V. Parvan 2 300223 Timişoara Romania

This paper proposes a hybrid controller that consists of a second order data–driven Model–Free Control (MFC), also known as intelligent proportional–integral (iPI), and a Takagi-Sugeno Fuzzy (TSF) logic controller for nonlinear Multi Input–Multi Output (MIMO) twin rotor aerodynamic systems (TRASs). The pitch position control is carried out using a single input–single output control system structure. The hybrid controller (the second order MFC algorithm and the TSF logic controller) is referred to as second order MFC–TSF controller. The performance of the control system structure (CSS) with the new second order MFC–TSF controller is compared with the performance of a CSS with the second order MFC controller, which is optimally tuned in a model-based manner by a Grey Wolf Optimizer algorithm. Experimental validation results on a nonlinear TRAS laboratory equipment are included.

关键词： Fuzzy control model-free control grey wolf optimization experimental results twin rotor aerodynamic systems

来源：评论

学校读者我要写书评

暂无评论

Combined Model-Free Adaptive Control with Fuzzy Component by Virtual Reference Feedback Tuning for Tower Crane Systems

引用

Procedia Computer Science 2019年 162卷 267-274页

作者： Raul-Cristian Roman Radu-Emil Precup Claudia-Adina Bojan-Dragos Alexandra-Iulia Szedlak-Stinean Politehnica University of Timişoara Dept. Automation and Applied Informatics Bd. V. Parvan 2 300223 Timişoara Romania

A novel mix of two data-driven algorithms is proposed in this paper. The mix of the algorithms aims to exploit the main advantage of data-driven Virtual Reference Feedback Tuning (VRFT) algorithm, that is represented by the automatic computation of the optimal parameters using a metaheuristic Grey Wolf Optimizer (GWO) for the Compact Form Dynamic Linearization (CFDL) version of the authors’ Model-Free Adaptive Control Takagi-Sugeno Fuzzy Algorithm (CFDL-PDTSFA), so the parameters of the CFDL-PDTSFA are optimally tuned in a model-free manner via VRFT. Three specific optimization problems are defined and solved by Model-Free Adaptive Control, VRFT and GWO algorithms. The new resulted algorithm is validated using experimental results to the arm angular position of the nonlinear tower crane system laboratory equipment.

关键词： Data-driven algorithms model-free adaptive fuzzy control tower crane systems virtual reference feedback tuning

来源：评论

学校读者我要写书评

暂无评论

Mathematical modeling of flow washing of preserved rawhides 26

Mathematical modeling of flow washing of preserved rawhides

引用

26th International Conference on Circuits, Systems, Communications and Computers, CSCC 2022

作者： Janacova, Dagmar Mokrejs, Pavel Vasek, Vladimir Drga, Rudolf Dept. of Automation and Control Engineering Faculty of Applied Informatics Tomas Bata University in Zlín Nad Stráněmi 4511 Zlín760 01 Czech Republic Dept. of Polymer Engineering Faculty of Technology Tomas Bata University in Zlín Vavrekova 5669 Zlín760 01 Czech Republic Dept. of Security Engineering Faculty of Applied Informatics Tomas Bata University in Zlín Nad Stráněmi 4511 Zlín760 01 Czech Republic

ISBN: (纸本)9781665481861

This paper presents a mathematical model of flow washing with the initial volume of the washing bath of preserved raw hides by salt. The main result of this work is the determination of the concentration field of the preservative in the raw material depending on the washing time and the size of the washing water flow, based on the correct laboratory-determined diffusion coefficient of the preservative using a tortuous factor. The paper points out the usefulness of applying theoretical tools of chemical engineering in areas such as the tanning industry. © 2022 IEEE.

关键词： Washing

来源：评论

学校读者我要写书评

暂无评论

Hybrid design tools - Making of a digitally augmented blackboard

arXiv

引用

arXiv 2018年

作者： Milincu, Camil Octavian Tudoran, Otilia Alexandra Tarce, Paul-Florin Banias, Ovidiu Politehnica University of Timisoara Faculty of Arhitecture and Urbanism Architecture Dept. Romania Politehnica University of Timisoara Faculty of Automation and Computer Science Automation and Applied Informatics Dept. Romania

The way that design is being taught is continuously changing under the pressure of the transition from analogical to digital environments. This becomes even more important as the novelty and the alleged superiority of the digital world is used as a marketing tool by competing universities. Even though in some fields of application this approach is desirable, some particular aspects of teaching design and architecture make this transition debatable. The advantages of drawing on blackboards over drawing on whiteboard surfaces in regards of line aesthetic and expression possibilities were previously identified, along with the complementary necessary features for improvement. This study showcases a proof of concept in digitally augmenting a blackboard surface. The system allows the capturing, processing and making real time projections of images over the blackboard surface as trace references. Such a hybrid system, along with providing support for design and architecture related presentations and discussions could also mediate the contradictory relation towards technology that students and teachers have. Copyright © 2018, The Authors. All rights reserved.

关键词： E-learning

来源：评论

学校读者我要写书评

暂无评论

Two Discrete-Time Data-Driven Sliding Mode Controllers for Tower Crane Systems

Two Discrete-Time Data-Driven Sliding Mode Controllers for T...

引用

International Conference on System Theory, Control, and Computing (ICSTCC)

作者： Anamaria-Ioana Borlea Radu-Emil Precup Raul-Cristian Roman Dept. Automation and Applied Informatics Politehnica University of Timisoara Timisoara Romania Dept. Automation and Applied Informatics Center Fundam. Adv. Tech. Res. Romanian Academy - Timisoara Branch Politehnica University of Timisoara Timisoara Romania

This paper merges the advantages of data-driven control and sliding mode control in terms of applying and modifying two combinations of model-free adaptive control and sliding mode control suggested by Ebrahimi et al. in 2018 to the position control of tower crane systems. The modifications concern the classical definition of the control error or the tracking error and appropriate proofs are adapted and summarized. The two controllers are validated experimentally and compared in the control of the three positions specific to tower crane system laboratory equipment.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A new pattern of knowledge based on experimenting the causality relation

A new pattern of knowledge based on experimenting the causal...

引用

14th International Conference on Intelligent Engineering Systems, INES 2010

作者： Pozna, C. Prahovean, V. Precup, R.-E. Department of Product Design and Robotics Transilvania University of Brasov Brasov Romania Dept. of Political and Administrative Sciences Babes-Bolyai University of Cluj Napoca Cluj-Napoca Romania Department of Automation and Applied Informatics Politehnica University of Timisoara Timisoara Romania

ISBN: (纸本)9781424476527

This paper suggests a new pattern of human knowledge. Its execution represents an important stage in the general framework of aiming the building of an artificial cognitive system. First the general presentation of the artificial cognitive system, its objective, main principles and implementation phases are highlighted. The known patterns, which have a cultural (philosophical, psychological and linguistic) origin are then analyzed. Finally the details concerning the proposed pattern are pointed out. © 2010 IEEE.

关键词： Cognitive systems

来源：评论

学校读者我要写书评

暂无评论

Optimization of PWM for overmodulation region of two-level inverters

Optimization of PWM for overmodulation region of two-level i...

引用

International (EPE-PEMC) Power Electronics and Motion Control Conference

作者： Péter Stumpf Sándor Halász Dept. of Automation and Applied Informatics (AAI) Budapest University of Technology and Economics Dept. of Electric Power Engineering Budapest University of Technology and Economics

ISBN: (纸本)9781509017997

Two optimized PWM techniques for the overmodulation region of two-level inverter-fed ac drives are investigated from harmonic loss minimization point of view. The optimization is elaborated for the lowest loss-factor, which is proportional to the square of rms value of current harmonics. The loss-factors are computed for different switching numbers as the function of the motor fundamental voltage. It is shown that, respect to the motor heating and torque ripples, the acceptable drive condition can be guaranteed by relatively low value of inverter switching frequency up to 96-97% of maximal possible motor voltage. Furthermore, it is shown that, the so-called Three vector method, introduced in the paper, has considerably better performance in the lower part of the overmodulation region than the so-called Two vector method or the standard PWM techniques for the same number of switching. The theoretical results are verified by experimental tests.

关键词： Harmonic analysis Pulse width modulation Inverters Switching frequency Switches Torque AC motors

来源：评论

学校读者我要写书评

暂无评论

FEM assisted position and speed observer for BLDC PM motor drive sensorless control, with experiments

FEM assisted position and speed observer for BLDC PM motor d...

引用

14th International Power Electronics and Motion Control Conference, EPE-PEMC 2010

作者： Ştirban, Alin Boldea, Ion Andreescu, Gheorghe-Daniel Iles, Dorin Blaabjerg, Frede Dept. of Electrical Machines and Drives University Politehnica of Timisoara Timisoara Romania Dept. of Automation and Applied Informatics University Politehnica of Timisoara Timisoara Romania Ebm-papst St. Georgen GmbH and Co. KG. 78112 St. Georgen Germany Institute of Energy Technology Aalborg University Aalborg Denmark

ISBN: (纸本)9781424478545

In this paper, the authors propose and investigate a FEM assisted position and speed observer for brushless d.c. PM motor drive sensorless control, based on the line-to-line PM flux linkage estimation. The line-to-line PM flux may be estimated using measured currents and line-toline voltages. The zero-crossing of the line-to-line PM flux linkage occurs right in the middle of two commutation points. The time period from one commutation point to zero-crossing is equal with the time period from zero-crossing to the next commutation point, at constant or slowly varying speed. This is used as a basis for the position and speed observer. For performance applications, in the present paper, the position between commutation points is obtained by comparing the estimated line-to-line PM flux with a look-up table, which contains the position versus FEM calculated line-to-line PM flux. A simulation model and experimental results are shown, demonstrating the reliability of FEM assisted position and speed observer for BLDC PM motor. © 2010 IEEE.

关键词： Sensorless control

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：