• Title/Summary/Keyword: Grid-based methods

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Further Development of Vision-Based Strain Measurement Methods to Verify Finite Element Analyses

  • Kim, Hyung jong;Lee, Daeyong
    • Transactions of Materials Processing
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    • v.5 no.4
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    • pp.343-352
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    • 1996
  • One of the preferred methods that can be used to verify the results of finite element analysis is to measure surface strains of the deformed part for purpose of direct comparison with simulation results. Instead of using the usual manual method the vision-based measurement method is capable of determining surface geometry and strain from the deformed grid pattern automatically with the help of a computer. To obtain strain distribution over an area, the coordinates of such a surface grid are determined from the multiple video images by applying the photogrammetry principle. Methods to improve the overall accuracy of the vision-based strain measurement system are explored and the possible accuracies that can be attained by such a measurement method are discussed. A major emphasis is placed on the initial grid application method its accuracy and ease of subsequent image processing. Finite element analyses of limiting dome height(LDH) test are carried out and the results of them are compared with exsperimen-tal data.

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Voltage Distortion Approach for Output Filter Design for Off-Grid and Grid-Connected PWM Inverters

  • Husev, Oleksandr;Chub, Andrii;Romero-Cadaval, Enrique;Roncero-Clemente, Carlos;Vinnikov, Dmitri
    • Journal of Power Electronics
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    • v.15 no.1
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    • pp.278-287
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    • 2015
  • This paper proposes a novel voltage distortion approach for output filter design based on the voltage transfer function for both off-grid and grid-connected Pulse Width Modulation (PWM) Inverters. The method explained in detail is compared to conventional methods. A comparative analysis is performed on an example of L and LCL-filter design. Simulation and experimental results for the off-grid and the grid-connected single phase inverter prove our theoretical predictions. It was found that conventional methods define redundant values of the output filter elements. Assumptions and limitations of the proposed approach are also discussed.

A method Based on Boundary Deformation for Planar Grid Generation

  • Liu, Xinru;Liu, Duanfeng;Han, Xuli
    • International Journal of CAD/CAM
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    • v.8 no.1
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    • pp.63-67
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    • 2009
  • This paper puts forward a method based on the boundary deformation for planar grid generation. Many methods start with the special properties of grid and switch to the solution of a direct optimization or a non-linear minimum cost flow. Though with high theoretical significance, it's hard to realize due to the extremely complicated computing process. This paper brings out the automatic generation of planar grid by studying the boundary deformational properties of planar grid, which leads to uniform grid and enjoys the simplicity of computation and realization.

Feature Map Construction using Orientation Information in a Grid Map (그리드지도의 방향정보 이용한 형상지도형성)

  • 송도성;강승균;임종환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1496-1499
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    • 2004
  • The paper persents an efficient method of extracting line segment in a grid map. The grid map is composed of 2-D grids that have both the occupancy and orientation probabilities based on the simplified Bayesian updating model. The probabilities and orientations of cells in the grid map are continuously updated while the robot explorers to their values. The line segments are, then, extracted from the clusters using Hough transform methods. The eng points of a line segment are evaluated from the cells in each cluster, which is simple and efficient comparing to existing methods. The proposed methods are illustrated by sets of experiments in an indoor environment.

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A study on the development of PCB automatic routing system using the mixing method of non-grid and grid (논-그리드와 그리드 혼합 방식을 이용한 PCB 자동 배선 시스템 개발)

  • Choe, Yeong-Gyu;Lee, Cheon-Hui
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.4
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    • pp.592-602
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    • 1995
  • Non-grid and grid method are used for modeling the routing region of the automatic routing system. In this study, we develop the automatic routing system by mixing the methods of non-grid and grid to improve the speed of routing. Grid method has a demerit which decreases the automatic routing speed because it is required a lot of memory by the limitation of the size of board and grid, although the electrical and physical elements are insufficient on the PCB, But non-grid is spent gurite less memory than grid method by using a shape-based patterns. Therefore, we used the methods of non-grid and grid altogether in this paper, In the former method, it is attributed to the improvement of speed, the latter one is applied only the connection of the failed routing in the former one, and it performs the complete automatic routing. This system was developed with C++language under the Windows NT environment of IBM 486DX2-66 Computer.

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The Digital Transformation of Power Grid under the Background of Artificial Intelligence

  • Li Liu;Zhiqi Li;Sujuan Deng;Yilei Zhao;Yuening Wang
    • Journal of Information Processing Systems
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    • v.19 no.3
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    • pp.302-309
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    • 2023
  • Artificial intelligence (AI) plays a crucial role in the intelligent development of China's power system. It is also an important part of the digital development of the power grid. The development of AI determines whether the digital transformation of China's power system can be successfully implemented. Therefore, this paper discusses the digital transformation of the power grid based on AI technologies. The author has established a digital evaluation index system to reflect the development of the power grid in one province. Both qualitative and quantitative methods have been adopted in the analysis, which delves into the economic effectiveness, quality, and coordination of power grid development in the province in a comprehensive way. Results show that, to meet the needs of the power grid's digital transformation, the correlation coefficient between the power grid's development and the province's overall coordination has been increasing in recent years.

Static Switch Controller Based on Artificial Neural Network in Micro-Grid Systems

  • Saeedimoghadam, Mojtaba;Moazzami, Majid;Nabavi, Seyed. M.H.;Dehghani, Majid
    • Journal of Electrical Engineering and Technology
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    • v.9 no.6
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    • pp.1822-1831
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    • 2014
  • Micro-grid is connected to the main power grid through a static switch. One of the critical issues in micro-grids is protection which must disconnect the micro-grid from the network in short-circuit contingencies. Protective methods of micro-grid mainly follow the model of distribution system protection. This protection scheme suffers from improper operation due to the presence of single-phase loads, imbalance of three-phase loads and occurrence of power swings in micro-grid. In this paper, a new method which prevents from improper performance of static micro-grid protection is proposed. This method works based on artificial neural network (ANN) and able to differentiate short circuit from power swings by measuring impedance and the rate of impedance variations in PCC bus. This new technique provides a protective system with higher reliability.

Ontology-based Grid Resource Selection System (온톨로지 기반의 그리드 자원선택 시스템)

  • Noh, Chang-Hyeon;Jang, Sung-Ho;Kim, Tae-Young;Lee, Jong-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.3
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    • pp.169-177
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    • 2008
  • Grid resources are composed of various communication networks and operation systems. When a grid system searches and selects grid resources, which meet requirements of a grid user, existing grid resource selection systems are limited due to their storage methods for resource information. In order to select grid resources suitable for requirements of a grid user and characteristics of data, this paper constructs an ontology for grid resources and proposes an ontology-based grid resource selection system. This system provides an inference engine based on rules defined by SWRL to create a resource list. Experimental results comparing the proposed system with existing grid resource selection systems, such as the Condor-G and the Nimrod-G, verify the effectiveness of the ontology-based grid resource selection system with improved job throughput and resource utilization and reduced job loss and job processing time.

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An Improved Face Recognition Method Using SIFT-Grid (SIFT-Grid를 사용한 향상된 얼굴 인식 방법)

  • Kim, Sung Hoon;Kim, Hyung Ho;Lee, Hyon Soo
    • Journal of Digital Convergence
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    • v.11 no.2
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    • pp.299-307
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    • 2013
  • The aim of this paper is the improvement of identification performance and the reduction of computational quantities in the face recognition system based on SIFT-Grid. Firstly, we propose a composition method of integrated template by removing similar SIFT keypoints and blending different keypoints in variety training images of one face class. The integrated template is made up of computation of similarity matrix and threshold-based histogram from keypoints in a same sub-region which divided by applying SIFT-Grid of training images. Secondly, we propose a computation method of similarity for identify of test image from composed integrated templates efficiently. The computation of similarity is performed that a test image to compare one-on-one with the integrated template of each face class. Then, a similarity score and a threshold-voting score calculates according to each sub-region. In the experimental results of face recognition tasks, the proposed methods is founded to be more accurate than both two other methods based on SIFT-Grid, also the computational quantities are reduce.

Enhancing Security Gaps in Smart Grid Communication

  • Lee, Sang-Hyun;Jeong, Heon;Moon, Kyung-Il
    • International Journal of Advanced Culture Technology
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    • v.2 no.2
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    • pp.7-10
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    • 2014
  • In order to develop smart grid communications infrastructure, a high level of interconnectivity and reliability among its nodes is required. Sensors, advanced metering devices, electrical appliances, and monitoring devices, just to mention a few, will be highly interconnected allowing for the seamless flow of data. Reliability and security in this flow of data between nodes is crucial due to the low latency and cyber-attacks resilience requirements of the Smart Grid. In particular, Artificial Intelligence techniques such as Fuzzy Logic, Bayesian Inference, Neural Networks, and other methods can be employed to enhance the security gaps in conventional IDSs. A distributed FPGA-based network with adaptive and cooperative capabilities can be used to study several security and communication aspects of the smart grid infrastructure both from the attackers and defensive point of view. In this paper, the vital issue of security in the smart grid is discussed, along with a possible approach to achieve this by employing FPGA based Radial Basis Function (RBF) network intrusion.