scholarly journals Superlinear convergence using block preconditioners for the real system formulation of complex Helmholtz equations

2018 ◽  
Vol 340 ◽  
pp. 424-431 ◽  
Author(s):  
Owe Axelsson ◽  
János Karátson ◽  
Fréderic Magoulès
Keyword(s):  
Superlinear Convergence ◽  
Real System ◽  
Helmholtz Equations ◽  
The Real ◽  
Block Preconditioners

scholarly journals A Tool for the Analysis and Characterization of School Mathematical Models

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1569
Author(s):  
Jesús Montejo-Gámez ◽  
Elvira Fernández-Ahumada ◽  
Natividad Adamuz-Povedano
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Models ◽  
Educational Research ◽  
Analysis Procedure ◽  
Real System ◽  
The Real ◽  
School Model ◽  
Corresponding Analysis ◽  
Three Components

This paper shows a tool for the analysis of written productions that allows for the characterization of the mathematical models that students develop when solving modeling tasks. For this purpose, different conceptualizations of mathematical models in education are discussed, paying special attention to the evidence that characterizes a school model. The discussion leads to the consideration of three components, which constitute the main categories of the proposed tool: the real system to be modeled, its mathematization and the representations used to express both. These categories and the corresponding analysis procedure are explained and illustrated through two working examples, which expose the value of the tool in establishing the foci of analysis when investigating school models, and thus, suggest modeling skills. The connection of this tool with other approaches to educational research on mathematical modeling is also discussed.

scholarly journals Hardware in the Loop Platform for Testing Photovoltaic System Control

2020 ◽  
Vol 10 (23) ◽  
pp. 8690
Author(s):  
Víctor Samano-Ortega ◽  
Alfredo Padilla-Medina ◽  
Micael Bravo-Sanchez ◽  
Elías Rodriguez-Segura ◽  
Alonso Jimenez-Garibay ◽  
...  
Keyword(s):  
Control Systems ◽  
Operating Conditions ◽  
Real System ◽  
Photovoltaic System ◽  
Hill Climbing ◽  
Integration Time ◽  
System Control ◽  
Hardware In The Loop ◽  
The Real ◽  
Point Tracking

The hardware in the loop (HIL) technique allows you to reproduce the behavior of a dynamic system or part of it in real time. This quality makes HIL a useful tool in the controller validation process and is widely used in multiple areas including photovoltaic systems (PVSs). This study presents the development of an HIL system to emulate the behavior of a PVS that includes a photovoltaic panel (PVP) and a DC-DC boost converter connected in series. The emulator was embedded into an NI-myRIO development board that operates with an integration time of 10 µs and reproduces the behavior of the real system with a mean percent error of 2.0478%, compared to simulation results. The implemented emulator is proposed as a platform for the validation of control systems. With it, the experimental stage is carried out on two controllers connected to the PVS without having the real system and allowing to emulate different operating conditions. The first controller is based on the Hill Climbing algorithm for the maximum power point tracking (MPPT), the second is a proportional integral (PI) controller for voltage control. Both controllers generate settling times of less than 3 s; the MPPT controller generates variations in the output in steady state inherent to the algorithm used. For both cases, the comparison of the experimental results with those obtained through software simulation show that the platform fulfills its usefulness when evaluating control systems.

Earth–Moon low energy trajectory optimization in the real system

2013 ◽  
Vol 51 (5) ◽  
pp. 917-929 ◽  
Author(s):  
Hanlun Lei ◽  
Bo Xu ◽  
Yisui Sun
Keyword(s):  
Trajectory Optimization ◽  
Low Energy ◽  
Real System ◽  
The Real

Simulation and Experimentation of a Precise Nonlinear Tracking Control Algorithm for a Rotary Servo-Hydraulic System With Minimum Sensors

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
M. H. Toufighi ◽  
S. H. Sadati ◽  
F. Najafi ◽  
A. A. Jafari
Keyword(s):  
Singular Perturbation ◽  
Hydraulic System ◽  
Control Algorithm ◽  
Small Error ◽  
Least Square ◽  
Real System ◽  
Singular Perturbation Theory ◽  
Control Analysis ◽  
Recursive Least Square ◽  
The Real

The dynamics of hydraulic systems involves slow and fast modes. These modes are associated with the mechanical components and those involving fluid flow, respectively. As such, controllers for electro-hydraulic servo systems (EHSS) can be designed and analyzed using singular perturbation theory. In this paper, a singular perturbation control (SPC) algorithm is proposed and investigated on a rotary EHSS modeled based on a two-time-scale behavior of the system. For modeling, the components of the hydraulic system, specifically the nonlinear model of the orifice in servo valve, are modeled. A mathematical modeling and nonlinear control analysis that validated by experiment is presented. The controlled system with the SPC algorithm tracks a fairly smooth trajectory with very small error. As well, the control algorithm is successfully verified by experiment as the main contribution of the paper. In addition, this is robust to variations in the hydraulic fluid bulk modulus such that only its nominal value is sufficient. Furthermore, the proposed control design will not require derivatives of the control pressures and any output acceleration feedback. Hence, it can be implemented easier in the real system setup. The controller design approach addresses the nonlinearities of the rotary EHSS. The parameters of the real system model are experimentally identified using the continuous recursive least square method.

Robust optimal attitude control of a laboratory helicopter without angular velocity feedback

Robotica ◽  
2014 ◽  
Vol 33 (2) ◽  
pp. 282-294 ◽  
Author(s):  
Hao Liu ◽  
Jianxiang Xi ◽  
Yisheng Zhong
Keyword(s):  
Angular Velocity ◽  
Attitude Control ◽  
Control Method ◽  
Linear Time ◽  
Real System ◽  
Velocity Feedback ◽  
The Real ◽  
Linear Time Invariant ◽  
Optimal Output ◽  
Asymptotic Tracking

SUMMARYIn this paper, the robust, optimal, output control problem is dealt with for a 3-degree-of-freedom laboratory helicopter. The control goal is to achieve the practical tracking of the desired elevation and pitch angles without the angular velocity feedback. A nominal linear time-invariant system is introduced and the real system is considered as the nominal one with uncertainties, including parameter perturbations, nonlinear time-varying uncertainties, and external disturbances. An observer is first used to estimate angular velocity. Then a nominal controller based on the optimal control method is designed for the nominal system to achieve the desired tracking properties. Lastly, a robust output compensator is added to restrain the effects of uncertainties in the real system. It is shown that asymptotic tracking properties and robust stability can be achieved. Experimental results on the laboratory helicopter are shown to verify the effectiveness of the proposed control method.

scholarly journals A novel similarity measure for mining missing links in long-path networks

2021 ◽  
Author(s):  
Yijun Ran ◽  
Tianyu Liu ◽  
Tao Jia ◽  
Xiao-Ke Xu
Keyword(s):  
Link Prediction ◽  
Real Life ◽  
Structural Evolution ◽  
Poor Performance ◽  
Real System ◽  
Machine Learning Techniques ◽  
Information Mining ◽  
The Real ◽  
Network Information ◽  
Maximal Information Coefficient

Abstract Network information mining is the study of the network topology, which may answer a large number of application-based questions towards the structural evolution and the function of a real system. The question can be related to how the real system evolves or how individuals interact with each other in social networks. Although the evolution of the real system may seem to be found regularly, capturing patterns on the whole process of evolution is not trivial. Link prediction is one of the most important technologies in network information mining, which can help us understand the evolution mechanism of real-life network. Link prediction aims to uncover missing links or quantify the likelihood of the emergence of nonexistent links from known network structures. Currently, widely existing methods of link prediction almost focus on short-path networks that usually have a myriad of close triangular structures. However, these algorithms on highly sparse or long-path networks have poor performance. Here, we propose a new index that is associated with the principles of Structural Equivalence and Shortest Path Length (SESPL) to estimate the likelihood of link existence in long-path networks. Through 548 real networks test, we find that SESPL is more effective and efficient than other similarity-based predictors in long-path networks. Meanwhile, we also exploit the performance of SESPL predictor and of embedding-based approaches via machine learning techniques. The results show that the performance of SESPL can achieve a gain of 44.09% over GraphWave and 7.93% over Node2vec. Finally, according to the matrix of Maximal Information Coefficient (MIC) between all the similarity-based predictors, SESPL is a new independent feature in the space of traditional similarity features.

scholarly journals SISTEM ADMINISTRASI AKADEMIK JURUSAN D3 AKUNTANSI BERBASIS TEKNOLOGI INFORMASI

2016 ◽  
Vol 13 (2) ◽  
Author(s):  
Lucy Sri Musmini ◽  
Ni Ketut Kertiasih
Keyword(s):  
Information Technology ◽  
Real System ◽  
Administration System ◽  
Academic Administration ◽  
Development Method ◽  
The Real ◽  
Academic Activities ◽  
System Input ◽  
System Output

AbstrakPerkembangan teknologi informasi dapat mempermudah dan mempercepat kegiatan yang dilakukan oleh sistem administrasi akademik. Tujuan penelitian ini adalah mengembangkan sistem administrasi akademik berbasis teknologi informasi Jurusan D3 Akuntansi Undiksha.Metode yang digunakan pada penelitian ini adalah metode pengembangan, dalam hal ini studi kasus pengembangan sebuah sistem administrasi akademik berbasis teknologi pada Jurusan D3 Akuntansi.Hasil penelitian ini adalah analisis sistem, yang terdiri dari analisis kelemahan dan kebutuhan sistem, dan desain sistem, yang terdiri dari desain konteks, flowchart, dan desain sistem riil. Sistem yang dikembangkan terkait dengan kegiatan akademik mahasiswa, dosen, dan jurusan. Akses input sistem dapat dilakukan oleh mahasiswa, dosen, dan administrasi, sedangkan akses output sistem dapat dilakukan oleh dosen dan administrasi. Administrasi jurusan dalam penelitian ini adalah sekretaris jurusan. Informasi yang diperoleh dari sistem adalah kegiatan akademik mahasiswa, dosen, dan jurusan pada Jurusan D3 Akuntansi. Implikasi penelitian ini adalah sistem adminstrasi akademik jurusan yang semakin efektif dan efisien. Kata kunci: Sistem, Administrasi Akademik, dan Teknologi Informasi AbstractThe purpose of this research is to develop academic administration system based on technology information for D3 Accounting Department, Undiksha.The method used in this research is the development method with case study to develop academic administration system based on technology information at the Department of Accounting D3.The results are the analysis of the system, which consists of the analysis of the weaknesses and needs of the system, and the design of the system, which consists of the design context, flowchart, and the design of the real system. The system developed and obtained information related to academic activities of students, lecturer, and department. Access to system input can be done by students, lecturer, and administration, while access to the system output can be done by the lecturer and administration. Administration majoring in this research is the department secretary. Implication of this research is the major system of academic administration more effective and efficient. Keywords : Systems, Academic Administration, and Information Technology

scholarly journals PENJADWALAN PERALATAN UNTUK MENINGKATKAN KINERJA SISTEM MANUFAKTUR DENGAN PENDEKATAN SIMULASI SISTEM DISKRIT

2017 ◽  
Author(s):  
Abdurrozzaq Hasibuan
Keyword(s):  
Development Strategy ◽  
Real System ◽  
Product Cycle ◽  
Manufacturing Companies ◽  
Productivity Level ◽  
The Real ◽  
High Productivity ◽  
Work In Process ◽  
System P ◽  
System Variables

Facing the thight business competition era, the manufacturing companies have to development their industrial system preformances to the high productivity level. This paper explain three manufacturing system indicator; amount of standart output in a periode of time, product cycle time, and the amount of work in process (unfinish) product. Those three indicators will be viewed as a result of tools and production machine resources allocation in each work station.The Discrete system simulation was used to represent the real system that is examined. This method can give a details information about the characteristic of each system variables when try to make an experiment to improve the system performances without bothering and interrupt the real system it self. This situation will exactly reduce the unpredictable risk when implement the development strategy in the real system.

Structural Optimization of Microfluidic Gate Controlled Magnetic Bead System for DNA Sequencing-by-Synthesis

2008 ◽  
Author(s):  
Hesaam Esfandyarpour ◽  
Ronald W. Davis
Keyword(s):  
Structural Optimization ◽  
Dna Sequencing ◽  
Intermediate Layer ◽  
Detection Efficiency ◽  
Magnetic Bead ◽  
Real System ◽  
The Real ◽  
Structure Geometry ◽  
Sequencing By Synthesis ◽  
And Control

In this paper we present a structural and geometrical optimization of a microfluidic gate-controlled magnetic bead system for DNA Sequencing by Synthesis technology. To optimize the efficiency of the technology, we designed, fabricated and tested several structures of the GCMB platform. Different designs of the system were created to study the effects of the pressure, structure, geometry, materials, thickness of intermediate layer between flow and control lines; Toward optimization of the system for a better sensing and to concentrate signal (e.g. heat in Thermosequencing [4–9]) into specific regions for detection in the real system, we recommend an optimized modified gated structure for the microfluidic detection platform and show how this new platform could improve the detection efficiency.

scholarly journals A Hybrid Methodology for Validation of Optimization Solutions Effects on Manufacturing Sustainability with Time Study and Simulation Approach for SMEs

2019 ◽  
Vol 11 (5) ◽  
pp. 1454 ◽  
Author(s):  
Poorya Ghafoorpoor Yazdi ◽  
Aydin Azizi ◽  
Majid Hashemipour
Keyword(s):  
System Performance ◽  
Industry 4.0 ◽  
Material Handling ◽  
Synergistic Effects ◽  
Production Quality ◽  
Real System ◽  
The Other ◽  
Time Study ◽  
The Real ◽  
Hybrid Methodology

The properties of small- and medium-sized enterprises (SMEs) make them one of the most important categories of enterprises for the economics of challenging world. SMEs, in most countries, are still enterprises with marketing and financial challenges. In addition, most of these challenges are related to their production and product characteristics. On the other hand, SMEs should fulfil the costumer’s demands. In order to reach these goals, SMEs must reach the highest level of production quality and quantity and successfully sustain them. Consequently, various manufacturing paradigms have been offered by an Industry 4.0 concept, which offers a variety of solutions to increase the productivity and enhance the performance of SMEs. It should be noted that implementation of these manufacturing paradigms for SMEs is quite difficult and sometimes risky for several reasons. Still, amidst all these difficulties and challenges, the benefits and idealism of the Industry 4.0 paradigms prevail. From productivity to market, it is difficult to deny that SMEs are frightened by the challenges they face and fleeing from the potential of overcoming them. This paper is an extended version of the research by Ghafoorpoor Yazdi et al. (2018) and conducts a hybrid methodology to satisfy the SMEs by validating and verifying any optimization idea before implementing the Industry 4.0 concept. To reach the study goals, an intelligent Material Handling System (MHS) with agent-based control architecture has been developed. The developed MHS has been utilized for auto parts distribution. The system performance has been evaluated, and some solutions have been provided to optimize the performance of system. To evaluate the target system’s performance, an analytical time study method has been utilized. The time study has an Overall Equipment Effectiveness (OEE) standard approach to identifying the matters that need to be resolved and optimized to increase system performance. The other part of the methodology is generating a simulation model of the real system by use of ARENA® software to evaluate the system’s performance before implementing the optimization idea and modifying the real system. Furthermore, as the sustainability strategies create many synergistic effects for SMEs, after evaluating the effects of the optimization ideas on OEE percentage, the influence of the OEE changes on manufacturing sustainability has been investigated. The results show that optimizing the OEE in SMEs with sustainability approaches can create competitive advantages, rather than simply focusing on reducing unsustainability.

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