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Straightness and flatness evaluation using data envelopment analysis

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2012年第5-8期63卷 731-740页

作者： Cho, Sohyung Kim, Joon-Young So Illinois Univ Edwardsville IL 62026 USA Korea Maritime Univ Div Marine Equipment Engn Pusan 606791 South Korea

In today's world of precision engineering, robustness and accuracy in the evaluation of the form tolerances are considered as competitive advantages for manufacturing enterprises. Amongst various methods for accurate and robust evaluation, which have been studied, nonlinear optimization methods based on operational research have proved to be successful as far as they can ensure unique and global convergence in practical applications. However, it is well known that ensuring the convergence is the most difficult thing to deal with for a nonlinear optimization technique because the performance is in general highly sensitive to parameter setting. Therefore, this paper introduces a robust linear programming formulation-based algorithm in which the performance is not dependent on the quality of parameters. Interestingly, in this algorithm, the data envelopment analysis technique is used to form a convex hull that decides the minimum enclosed zone in a robust manner. From the computational experiments, it is shown that the proposed algorithm can be a promising alternative to the traditional nonlinear optimization method for straightness and flatness evaluation.

关键词： Form tolerance robust algorithm Data envelopment analysis

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Dominating Induced Matchings for P₇-Free Graphs in Linear Time

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algorithmICA 2014年第4期68卷 998-1018页

作者： Brandstaedt, Andreas Mosca, Raffaele Univ Rostock Fachbereich Informat D-18051 Rostock Germany Univ G DAnnunzio Dipartimento Sci I-65121 Pescara Italy

Let G be a finite undirected graph with edge set E. An edge set E'aS dagger E is an induced matching in G if the pairwise distance of the edges of E' in G is at least two;E' is dominating in G if every edge eaEa-E' intersects some edge in E'. The Dominating Induced Matching Problem (DIM, for short) asks for the existence of an induced matching E' which is also dominating in G;this problem is also known as the Efficient Edge Domination Problem. The DIM problem is related to parallel resource allocation problems, encoding theory and network routing. It is -complete even for very restricted graph classes such as planar bipartite graphs with maximum degree three. However, its complexity was open for P (k) -free graphs for any ka parts per thousand yen5;P (k) denotes a chordless path with k vertices and k-1 edges. We show in this paper that the weighted DIM problem is solvable in linear time for P (7)-free graphs in a robust way.

关键词： Dominating induced matching Efficient edge domination P-7-free graphs Linear time algorithm robust algorithm

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Intergrid-boundary definition method for overset unstructured grid approach

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AIAA JOURNAL 2000年第11期38卷 2077-2084页

作者： Nakahashi, K Togashi, F Sharov, D Tohoku Univ Dept Aeronaut & Space Engn Sendai Miyagi 9808579 Japan Sci Applicat Int Corp Ctr Appl Computat Sci Adv Technol Grp Mclean VA 22102 USA

The use of the overset concept for the unstructured grid method is relatively unexplored. However, the overset approach can extend the applicability of the unstructured grid method for real engineering problems without much need for code development. The multiple moving-body problem is one of those applications. Improvement in local resolution for Euler/Navier-Stokes computations on unstructured grids is another use of the overset concept. An efficient and robust algorithm to localize the intergrid boundaries for the overset unstructured grid method is proposed. Simplicity and automation in the intergrid-boundary definition are realized using the wall distance as a basic parameter. The neighbor-to-neighbor jump search algorithm is efficiently utilized in the method. The robustness and efficiency of the search is improved by the use of subsidiary grids that are generated as a byproduct of the Delaunay triangulation method. The basic procedure of the present method is described for a multielement airfoil problem. The effects of the overset method on the solution accuracy and the convergence are tested by ONERA M6-wing. The capability of the method is demonstrated by application to an airplane-rocket boaster separation problem.

关键词： Unstructured Grid Supersonic Airplane Rockets Search algorithm robust algorithm Airfoil Angle of Attack Freestream Mach Number Courant Friedrichs Lewy Stokes Problem

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H-INFINITY SYNTHESIS USING A BILINEAR POLE SHIFTING TRANSFORM

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1992年第5期15卷 1111-1117页

作者： CHIANG, RY SAFONOV, MG UNIV SO CALIF DEPT ELECT ENGNLOS ANGELESCA 90089

An H(infinity) control law design is presented for a benchmark problem consisting of an undamped pair of spring-coupled masses with a sensor and actuator that are not collocated. This simple mechanical system captures many of the salient features of more complex aircraft and space structure vibration control problems. The H(infinity) problem formulation enables the issue of stability robustness in the face of large mass and spring constant variation to be directly addressed. Constraints on closed-loop dominant pole locations and settling time are accommodated via a simple s-plane bilinear transform. The transform parameter can give direct control of closed-loop disturbance settling time and controller open-loop pole-zero locations. A four-state H(infinity) minimum phase controller was found to meet the given specifications of each design. Detailed analysis on the tradeoffs of sensor noise vs control energy are also presented.

关键词： Closed Loop Transfer Function Sensor Systems Actuators Vibration Control Space Structures Full State Feedback Linear Quadratic Gaussian Frequency Domain Riccati Equations robust algorithm

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Boundary Defense Against Cyber Threat for Power System State Estimation

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IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY 2021年 16卷 1752-1767页

作者： Jin, Ming Lavaei, Javad Sojoudi, Somayeh Baldick, Ross Virginia Tech Blacksburg VA 24061 USA Univ Calif Berkeley Dept Ind Engn & Operat Res Berkeley CA 94710 USA Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94710 USA Univ Texas Austin Dept Elect & Comp Engn Austin TX 78712 USA

The operation of power grids is becoming increasingly data-centric. While the abundance of data could improve system efficiency, it poses major reliability challenges. In particular, state estimation aims to find the operating state of a network from the telemetered data, but an undetected attack on the data could lead to making wrong operational decisions for the system and trigger a large-scale blackout. Nevertheless, understanding the vulnerability of state estimation with regards to cyberattacks, which is a special instance of graph-structured quadratic sensing problem, has been hindered by the lack of tools for studying the topological and data-analytic aspects of networks. algorithmic robustness is critical in extracting reliable information from abundant but untrusted grid data. For a large-scale power grid, we quantify, analyze, and visualize the regions of the network that are not robust to cyberattacks in the sense that there exists a data manipulation strategy for each of those local regions that misleads the operator at the global scale and yields a wrong estimation of the state of the network at almost all buses. We also propose an optimization-based graphical boundary defense mechanism to identify the border of the geographical area in which data have been manipulated. The proposed method does not allow a local attack to have a global effect on the data analysis of the entire network, which enhances the situational awareness of the grid, especially in the face of adversity. The developed mathematical framework reveals key geometric and algebraic factors that can affect algorithmic robustness and is used to study the vulnerability of the U.S. power grid in this paper.

关键词： Power grids robustness Sensors Power system reliability State estimation Computer crime Optimization Power system state estimation CPS security robust algorithm smart grid

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An improved constrained differential evolution for optimal design of steel frames with discrete variables

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MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES 2020年第6期48卷 697-723页

作者： Babaei, Mehdi Mollayi, Masoud Univ Zanjan Fac Engn Dept Civil Engn Zanjan Iran

New metaheuristic algorithms have been shown to be robust and effective for engineering optimization problems. Differential Evolution (DE), which is one of the most famous optimization approaches developed for optimal design problems with continuous design variables, is, in fact, inappropriate for constrained problems containing discrete design variables. In this article, an improved constrained differential evolution (iCDE) algorithm is proposed for optimization of steel frames with discrete design variables, followed by comprehensive testing of iCDE to validate the results. In order to make iCDE more efficient, two novel mutation approaches are proposed and tested. Three benchmark structural optimization problems are evaluated by the algorithm and compared against those reported in the literature obtained by GA, ACO, IACO, ICA, HS, and SBO. The total weight of the frame is considered as the objective function and the cross sections of the elements are taken as design variables. Constraints are based on the stress and displacement requirements conforming to the AISC-LRFD specifications. Moreover, to demonstrate the robustness of the algorithm, eight benchmark test functions of CEC-2017 are evaluated. The results show that the iCDE algorithm is computationally efficient and robust enough to find the global optima. Communicated by Janos Logo.

关键词： Improved differential evolution discrete optimization metaheuristic algorithms steel frames structural optimization robust algorithm

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robustification of fault detection algorithm in a three-phase induction motor using MCSA for various single and multiple faults

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IET ELECTRIC POWER APPLICATIONS 2021年第5期15卷 593-615页

作者： Kompella, K. C. Deekshit Rongala, Naga Sreenivasu Rayapudi, Srinivasa Rao Mannam, Venu Gopala Rao SNIST EEE Dept Hyderabad India IRSEE Southern Railways Tamil Nadu India JNTUK Dept Elect Engn Kakinada India PVPSIT Dept EEE Vijayawada India

Fault diagnosis in induction machines, particularly at a premature stage, has become necessary to avoid unexpected interruption of the industrial process. Moreover, a reliable and cost-effective fault detection process is highly essential to avoid inappropriate shut down of the machine. Thus, a critical comparison is done between two popular pre-fault component cancellation techniques and a reliability test is performed to develop a robust algorithm for fault diagnosis in three-phase induction motor. To achieve this, various single and multiple faults experienced by induction motor are created and tested to examine the effectiveness of developed algorithm. Evaluation of the proposed topology based on motor current signature analysis is done by repeating the process for several times and tested for consistency. As a part of this, various feature extraction parameters are computed and compared to identify the best estimate of fault and its seriousness. The proposed technique is examined in MATLAB and LabVIEW environment and experiments on a three-phase, 1.5-kW induction motor.

关键词： fault diagnosis popular pre-fault component cancellation techniques reliable cost-effective fault detection process industrial process power 1.5 kW premature stage robust algorithm induction motors machine testing induction machines motor current signature analysis feature extraction Asynchronous machines fault detection algorithm Reliability reliability test single faults MCSA reliability three-phase induction motor

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Low-Complexity Distributed Beamforming for Relay Networks With Real-Valued Implementation

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2013年第20期61卷 5039-5048页

作者： Zhang, Lei Liu, Wei Li, Jian Huawei Technol Co Ltd Commun Technol Lab Shenzhen Peoples R China Univ Sheffield Commun Res Grp Dept Elect & Elect Engn Sheffield S10 2TN S Yorkshire England Univ Florida Dept Elect & Comp Engn Gainesville FL 32601 USA

The distributed beamforming problem for amplify-and-forward relay networks is studied. Maximizing output SNR (signal-to-noise ratio) for distributed beamforming can be considered as a generalized eigenvector problem (GEP) and the principal eigenvector and its eigenvalue can be derived with a standard closed-form solution. In this paper, four classes of beamforming algorithms are derived based on different design criteria and constraints, including maximizing output SNR subject to a constraint on the total transmitted signal power, minimizing the total transmitted signal power subject to certain level of output SNR, minimizing the relay node number subject to constraints on the total signal power and output SNR, and a robust algorithm to deal with channel estimation errors. All of the algorithms have a low computational complexity due to the proposed real-valued implementation.

关键词： Distributed beamforming relay networks generalized eigenvector problem robust algorithm

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A fuzzy paradigmatic clustering algorithm

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IFAC-PapersOnLine 2019年第13期52卷 2360-2365页

作者： Amirjavid, Farzad Barak, Sasan Nemati, Hamidreza Edward S. Rogers Department of Electrical and Computer Engineering University of Toronto Toronto Canada Department of Management Science Lancaster University Management School Lancaster United Kingdom Engineering Department Lancaster University Lancaster United Kingdom

Clustering algorithms resume the datasets into few number of data points such as centroids or medoids, which explain the entire dataset briefly. In the domain of data-driven machine learning, the more precision with the clustering rule leads directly to more precise classification, prediction, and recognition. We propose an efficient clustering method, which applies the paradigms - mainly 3D Gaussian model - to estimate the optimum cluster number, cluster border, and congestion coordinates to model the datasets of the natural distributions. This approach considers both qualitative and quantitative features of the dataset and calculates the best scale to analyze it. We used fuzzy logic to compare the models with data, to generate and rank the hypotheses, and finally to reject or accept the assumptions. The proposed approach which is called Fuzzy Gaussian Paradigmatic Clustering (FGPC) algorithm is used as the basis of a fast (with the complexity order of O(n)) and robust algorithm for identifying fuzzy models. © 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Clustering algorithms 3D modeling Cluster analysis Computer circuits Fuzzy logic Gaussian distribution Cluster numbers Clustering methods Clustering rules Complexity orders Natural distribution Paradigmatic clustering Quantitative features robust algorithm

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Verification of the Relative Distance Measurement Method for Pico-satellites in Constellation

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IFAC-PapersOnLine 2018年第12期51卷 100-105页

作者： Nebylov, A. Padron, A. Medina Knyazhsky, A. State University of Aerospace Instrumentation 67 Bolshaya Morskaya Saint-Petersburg190000 Russia Polytechnique de Montréal Département Génie électrique 2900 Edouard-Monpetit MontrealQCH3T 1J4 Canada

This paper considers the optical relative navigation method for the small satellites, describes the algorithms of the image processing and calculating the relative distance and orientation. Different methods and approaches exist but need to be adapted or improved based on robust algorithms for both detection and range of multiple space crafts. Originality of the solution is to extend optical with image processing and vision algorithms to space relative navigation, some experimental and preliminary results are also reported at the article. © 2018

关键词： Image processing Optical data processing Satellites Motion parameters pico satellited Relative distances Relative motion Relative navigation robust algorithm Vision algorithms

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