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作者： Wu, Ling Noels, L. Rochus, V. Pustan, M. Golinval, J.C. University of Liege Aerospace and Mechanical Engineering Department Belgium Northwestern Polytechnical University School of Aeronautics 710072 Xi'an China Technical University of Cluj-Napoca Cluj-Napoca Romania

ISBN: (纸本)9781441988249

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but leads to an increase of the actuation voltage so that the switch's efficiency is threatened. A statistical rough surfaces interaction model, based on Maugis' and Kim's formulations is applied to estimate the adhesive forces in MEMS switches. Based on the knowledge of these forces, the proper design range of the equivalent spring constant, which is the main factor of restoring force in MEMS switches, can be determined. The upper limit of equivalent spring constant depends mainly on the expected actuator voltage and on the geometric parameters, such as initial gap size and thickness of dielectric layer. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. It mainly depends on the adhesive work of contact surfaces and on the surfaces' roughness. In order to study more complicated structures, this framework will be used in a multiscale model: resulting unloading micro adhesive contact-distance curves of two rough surfaces will be used as contact forces in a finite-element model. In this paper the extraction of these curves for the particular case of gold to gold micro-switches is pursued. ©2010 Society for Experimental mechanics Inc.

关键词： Finite element method

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Analysis of the adhesion effect in RF-MEMS switches using atomic force microscope

Analysis of the adhesion effect in RF-MEMS switches using at...

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2014 Symposium on Design, Test, Integration and Packaging of MEMS/MOEMS, DTIP 2014

作者： Birleanu, Corina Pustan, Marius Technical University of Cluj-Napoca Department of Mechanical System Engineering Micro and Nano Systems Laboratory Bd. Muncii 103-105 Cluj-Napoca400641 Romania

ISBN: (纸本)9782355000287

The main scope of this paper is to investigate the adhesion effect on the mechanical response of MEMS components from RF switch application by using an atomic force microscope (AFM). The occurrence and strength of adhesion effects in MEMS devices depend on a variety of environmental, geometrical and operational parameters (temperature, relative humidity, contact area, surface energies of contact materials, surface roughness and shape of contact surfaces) - so-called adhesion parameters should be taken into account when investigating the reliability of MEMS devices with respect to adhesion-induced failures. After, the temperature influence on adhesion is experimentally analyzed considering commonly used MEMS materials to fabricate RF switches. The adhesion force is the main factor with influence on stiction. In fact, stiction is the adhesion occurring between the contact surfaces due to surface forces including van der Waals, capillary forces, Casmir forces, and electrostatic forces. First, the adhesion between AFM tip and the materials under interest is investigated using the spectroscopy in point of an atomic force microscope. Different coated AFM tip is considered for tests. The AFM spectroscopy-in-point curve gives the direct measurement of tip-sample interaction force as a function of the gap between the tip and sample. The adhesion between tip and sample is characterized by so-called pull-off or pull-out force. The pull-off force is related in current continuum contact mechanics model to the work of adhesion. Using a thermal controller stage the temperature of investigated materials is changed from 0°C to 80°C. The mechanical properties variation of MEMS materials as a function of temperature is monitored and the temperature influence on adhesion is analyzed. The influence of the surface roughness on the adhesion forces between AFM tip and samples is determined. Different roughness (Ra) of investigated polysilicon samples is varied in the range of ∼5-15 nm. The

关键词： Adhesion

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Enhancing Learning Experiences in Erasmus Blended Intensive Programs 21

Enhancing Learning Experiences in Erasmus Blended Intensive ...

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21st International Conference on Information Technology Based Higher Education and Training, ITHET 2024

作者： Grindei, Laura Holonec, Rodica Clavero, Sara Blanc Benlloch-Dualde, Jose Vicente Technical University of Cluj Napoca Faculty of Electrical Engineering Cluj Napoca Romania Universitat Politècnica de València Department of Computer Engineering Valencia Spain

ISBN: (纸本)9798331516635

This paper outlines an approach to enhance the learning experiences of students beginning their bachelor's studies in Electrical and Computer Science Engineering by working in international teams on practical projects. The paper presents details on implementation of this approach supported by two Erasmus+ BIP projects aimed at improving students' knowledge in Electronics, Arduino programming, IoT, Communication Technologies and other related fields. The paper outlines the activities carried out within the ELSE PRO Eramus BIP project, including its virtual and physical components, provides details on student projects completed during the summer camp, and discusses the evaluation and dissemination of the project outcomes. © 2024 IEEE.

关键词： Collaborative learning

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Developing Embedded Control System Platform for Testing PMSM Drives 8

Developing Embedded Control System Platform for Testing PMSM...

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8th International Conference And Exposition On Electrical And Power Engineering (EPE)

作者： Rusu, Calin Birou, Iulian Radulescu, Mircea M. Bara, Alexandru Department of Electrical Machines and Drives Technical University of Cluj-Napoca 27 Memorandumului Street 4000020 Romania

ISBN: (纸本)9781479958498

The paper presents an Embedded Motor Drive Prototyping test bench for developing and study energy efficient of the motor drives. The development platform uses an eZdsp target controller with power stage converter that employs Targeted Code Generation from Matlab-Simulink and the Target Support Package for the TI C2000 microcontrollers. Computer Aided Control System Design (CACSD) tools are used to generate real-time code automatically. The reason is to simplify the programming process by making it more graphical and thus more intuitive. Application performances of the electrical drives require energy efficiency, flexibility, outstanding reliability and robust control. Servo drives with Permanent Magnet Synchronous Motors (PMSM) have wide industrial applications where the speed and torque response with high-performance operations are required. The controller drives are implemented by field-orientation control mode (FOC) since the method laid the motors at maximum theoretical performances. A graphical programming interface with hardware-in-loop design processes is used for testing the algorithms controller. The performances are tested in a rapid prototyping approach using Matlab/Simulink and the Real Time Workshop (RTW) toolbox and represent a solution for educational purposes.

关键词： Graphical programming Automatic Code Generation PM Synchronous Motor Drive Field Oriented Control eZdsp F2812 Controller with Power Stage

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Natural periods of vibration of outrigger braced shear walls

Natural periods of vibration of outrigger braced shear walls

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6th European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2012

作者： Nicoreac, M.P. Hoenderkamp, J.C.D. Department of Structural Mechanics Technical University of Cluj-Napoca C. Daicoviciu Street 15 400020 Cluj-Napoca Romania Department of the Built Environment Eindhoven University of Technology PO Box 513 5600 MB Eindhoven Netherlands

ISBN: (纸本)9783950353709

This paper presents simple equations for the natural lateral and rotational periods of vibration of tall buildings comprising shear walls with outrigger trusses. The structural floor plan may consist of a symmetric or asymmetric combination of identical bents. For a planar analysis the outrigger braced shear wall is replaced by an equivalent column with a rotational spring at outrigger level. There are four stiffnesses taken into account for the individual bracing elements: the flexural stiffness of the walls, the bending and racking shear stiffness of the outriggers and the axial stiffness of the exterior columns. The last three are combined to give the rotational spring stiffness. The natural periods of vibration will be obtained by two methods: an approximate method and an analytical method. The first relates the natural frequency of the structure to the top deflection when the self-weight is taken as a distributed horizontal load. The second method gives the frequency equation for a cantilever beam with an intermediate rotational spring. For a torsional analysis, the bending stiffness and the spring stiffness parameters of the high rise structure each are combined to yield a warping stiffness and a warping spring stiffness. This allows the torsional natural periods of vibration to be obtained from the approximate method and the analytical method.

关键词： Stiffness

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Experimental results of a fractional order PDλ controller for vibration suppresion

Experimental results of a fractional order PDλ controller f...

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International Conference on Control, Automation, Robotics and Vision (ICARCV)

作者： Cristina I. Muresan Isabela R. Birs Silviu Folea Eva H. Dulf Ovidiu Prodan Department of Automation Technical University of Cluj-Napoca Cluj-Napoca Romania Department of Structural Mechanics Technical University of Cluj-Napoca Cluj-Napoca Romania

ISBN: (纸本)9781509035502

Vibration occurs in numerous important domains, such as the aerospace industry, and has negative effects since it can limit the life span of the devices, cause malfunctioning or even system instability. The necessity of research on vibration suppression in aeroplane wings is important from a scientific and technologic point of view: to provide better, more efficient, robust, cheaper solutions to eliminate vibrations effects, which triggers the socioeconomic aspect regarding the increase of flight safety and passenger comfort. Vibration suppression can be achieved using passive techniques, but they come along with certain disadvantages related to efficiency/costs. An alternative solution is to use active control. Several active control strategies have been proposed so far, with aeroplane wings/helicopter blades simulated as smart cantilever beams. The present paper proposes a fractional order Proportional Derivative controller, designed using frequency domain specifications. The case study consists in a smart beam equipped with dedicated sensors and actuators. The experimental results, considering both passive and active control responses of the smart beam, show that the proposed method leads to significant improvement of the closed loop behavior.

关键词： Vibrations PD control Robustness Transfer functions Frequency-domain analysis Tuning Sensors

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Education in electronics -A multimedia implementation 6

Education in electronics -A multimedia implementation

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6th International Conference on Optimization of Electrical and Electronic Equipments, OPTIM 1998

作者： Kayafas, Eleftherios A. Fazakas, Albert A. National Technical University of Athens Department of Electrical and Computer Engineering Division of Computer Science Zografou Athens15773 Greece Technical University of Cluj-Napoca Department of Bases of Electronics Cluj-Napoca3400 Romania

ISBN: (纸本)9739851126

Education, by means of computers that was introduced in the late 50's passed through stages of success and failure and faced much criticism. Nevertheless, some of its advantages were obvious. In most cases educational material was developed by software companies which had the necessary experience in programming-something which teacher's didn't- but they had little experience in education procedures. Eventually it became clear, that mainly teachers should develop the structure of such educational environment and the interaction with it. In these early days, the cost of constructing educational software was high and therefore the necessary revisions were hard to accomplish. Recently, multimedia tools and authoring language developments have overcome this difficulty. These techniques offer many abilities for users, aiming in substantial reduction of programming skills. This argument is applicable in cases where a teacher is preparing the material for his class students. On the other hand, if special skills and tasks are required, such aiding tools are becoming rather inflexible and other particular approaches may be applied. Therefore, the research on educational aiding tools is still an open area for development. © 1998 Institute of Electrical and Electronics Engineers Inc. All rights reserved.

关键词： E-learning

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Testing of a mechatronic inspection system's prototype

Romanian Review Precision Mechanics, Optics and Mechatronics

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Romanian Review Precision mechanics, Optics and Mechatronics 2011年第39期 153-156页

作者： Adrian, Aluţei Vistrian, MǍties Olimpiu, TǍtar M. Claudiu, Cirebea I. Technical University of Cluj-Napoca Mechanisms Precision Mechanics and Mechatronics Department Cluj-Napoca 400641 Romania

The aim of the paper is to investigate some of the most important parameters of an inspection mechatronic system and to test the developed prototype for validation purpose. In the introduction of the paper some important details about the inspection mechatronic systems are presented. In the second part the developed prototype along with the test conditions are presented. In the third chapter theoretical aspects about the locomotion of the system inside pipelines are discussed. Test condition and results are presented in chapter four and five of the paper.

关键词： Inspection

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Compilation to quantum circuits for a language with quantum data and control

Compilation to quantum circuits for a language with quantum ...

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2013 Federated Conference on Computer Science and Information Systems, FedCSIS 2013

作者： Rouselakis, Yannis Papaspyrou, Nikolaos S. Tsiouris, Yiannis Todoran, Eneia N. School of Electrical and Computer Engineering National Technical University of Athens Polytechnioupoli 15780 Zografou Greece Computer Science Department Technical University of Cluj-Napoca Baritiu Street 28 400027 Cluj-Napoca Romania

ISBN: (纸本)9781467344715

In this paper we further investigate nQML, a functional quantum programming language that follows the 'quantum data and control' paradigm. We define a semantics for nQML, which translates programs to quantum circuits in the category FQC of finite quantum computations, following the approach of Altenkirch and Grattage's QML. This semantics, which coincides with the denotational semantics for nQML over density matrices and unitary transformations, serves as a compiler from nQML programs to quantum circuits. We also provide an implementation of this compiler, written in Haskell, as well as an interpreter for quantum circuits. © 2013 Polish Information Processing Society.

关键词： Semantics

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Application software for processing Weigh-in-Motion traffic data

Application software for processing Weigh-in-Motion traffic ...

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作者： Ciont, N. Cadar, R.D. Iliescu, M. Department of Railways Roads and Bridges Technical University of Cluj Napoca Romania

This paper presents the functionality of an application software designed to process and report weigh-in-motion traffic data. The study is focused on flexible road pavement design. The traffic data is collected by a high-speed weigh-in-motion system installed in Romania, which provides separate files for each day. The application software uses the Microsoft Access 2010 database management system, which is based on the Visual Basic for Applications programming language. Dedicated software functions were designed to provide information on a wide range of traffic engineering parameters. The application also evaluates road pavement design parameters. The main achievement of the work described in this paper is the software's ability to process, analyse and report the collected traffic data, according to the user function request. The software provides essential results and information, used in both traffic studies and pavement design, for single facilities or an entire network. A comparative flexible pavement design was carried out in two hypotheses, based on standardised design values and application-processed factors, respectively. The study used data collected between April 2013 and February 2015, concluding that different design approaches may lead to significant advantages and that the designed application software is an essential data processing tool. © Civil-Comp Press, 2015.

关键词： Application programs

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