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1

Online parameter identification of SPMSM based on improved artificial bee colony algorithm

Wu Chunli, Jiang Shuai, Bian Chunyuan

Archives of Electrical Engineering

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2021

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Vol. 70, nr 4

777--790

EN

The artificial bee colony (ABC) intelligence algorithm is widely applied to solve multi-variable function optimization problems. In order to accurately identify the parameters of the surface-mounted permanent magnet synchronous motor (SPMSM), this paper proposes an improved ABC optimization method based on vector control to solve the multi-parameter identification problem of the PMSM. Because of the shortcomings of the existing parameter identification algorithms, such as high computational complexity and data saturation, the ABC algorithm is applied for the multi-parameter identification of the PMSM for the first time. In order to further improve the search speed of the ABC algorithm and avoid falling into the local optimum, Euclidean distance is introduced into the ABC algorithm to search more efficiently in the feasible region. Applying the improved algorithm to multi-parameter identification of the PMSM, this method only needs to sample the stator current and voltage signals of the motor. Combined with the fitness function, the online identification of the PMSM can be achieved. The simulation and experimental results show that the ABC algorithm can quickly identify the motor stator resistance, inductance and flux linkage. In addition, the ABC algorithm improved by Euclidean distance has faster convergence speed and smaller steady-state error for the identification results of stator resistance, inductance and flux linkage.

2

The evaluation of text string matching algorithms as an aid to image search

Ochelska-Mierzejewska J.

Journal of Applied Computer Science

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2018

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Vol. 26, nr 1

33--62

EN

The main goal of this paper is to analyse intelligent text string matching methods (like fuzzy sets and relations) and evaluate their usefulness for image search. The present study examines the ability of different algorithms to handle multi-word and multi-sentence queries. Eight different similarity measures (N-gram, Levenshtein distance, Jaro coefficient, Dice coefficient, Overlap coefficient, Euclidean distance, Cosine similarity and Jaccard similarity) are employed to analyse the algorithms in terms of time complexity and accuracy of results. The outcomes are used to develop a hierarchy of methods, illustrating their usefulness to image search. The search response time increases significantly in the case of data sets containing several thousand images. The findings indicate that the analysed algorithms do not fulfil the response-time requirements of professional applications. Due to its limitations, the proposed system should be considered only as an illustration of a novel solution with further development perspectives. The use of Polish as the language of experiments affects the accuracy of measures. This limitation seems to be easy to overcome in the case of languages with simpler grammar rules (e.g. English).

3

Evaluating organizational antifragility via fuzzy logic : the case of an Iranian company producing banknotes and security paper

Ghasemi A., Alizadeh M.

Operations Research and Decisions

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2017

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Vol. 27, No. 2

21--43

EN

The concept of antifragility has received much attention from researchers in recent years. Contrary to fragile systems which fail when exposed to stressors, antifragile systems prosper and improve in response to unpredictability, volatility, randomness, chaos and disturbance. The implications of antifragility goes beyond resilience or robustness. A resilient system resists stress and remains the same; while an antifragile system improves. Taleb argues that antifragility is required for dealing with events that he called black swans or X-events, which are scarce, unpredictable, and extreme events. Such events come as a surprise and have major consequences. The concept of antifragility was developed by Taleb in a socioeconomic context, not in industrial production. However, the authors think that this concept may have its greatest practical utilization when applied to industrial environments. Thus, they focused on this concept in the article aiming to investigate the level of antifragility in an organization. In order to perform this, the authors used a case study based on an Iranian manufacturer of banknotes and security paper (TAKAB). Firstly, a questionnaire was designed based on 7 criteria related to antifragility using the five-point Likert scale and a triangular fuzzy number for each linguistic term is defined. In the next phase, the weight of each component was obtained using the entropy technique. In the final stage, the Euclidean distance between the aggregated fuzzy antifragility index (FAI) and each linguistic term used during this case study was calculated. Finally, based on these results, the level of the organization’s antifragility was assessed as satisfactorily antifragile, based on the minimum Euclidean distance.

4

Yarn-Dyed Fabric Defect Detection Based On Autocorrelation Function And GLCM

Zhu D., Pan R., Gao W., Zhang J.

Autex Research Journal

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2015

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Vol. 15, no. 3

226--232

EN

In this study, a new detection algorithm for yarn-dyed fabric defect based on autocorrelation function and grey level co-occurrence matrix (GLCM) is put forward. First, autocorrelation function is used to determine the pattern period of yarn-dyed fabric and according to this, the size of detection window can be obtained. Second, GLCMs are calculated with the specified parameters to characterise the original image. Third, Euclidean distances of GLCMs between being detected images and template image, which is selected from the defect-free fabric, are computed and then the threshold value is given to realise the defect detection. Experimental results show that the algorithm proposed in this study can achieve accurate detection of common defects of yarn-dyed fabric, such as the wrong weft, weft crackiness, stretched warp, oil stain and holes.

5

Zastosowanie modeli dokładnych sieci do detekcji i lokalizacji wycieków

Tomasik P.

Problemy Eksploatacji

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2011

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nr 2

223-230

PL

W referacie opisano metodę wykorzystującą dokładne modele sieci wodociągowej do detekcji i lokalizacji wycieków. Metoda ta bazuje na prostej mierze podobieństwa pomiędzy rzeczywistymi i modelowymi danymi o przepływach w sieci wodociągowej.

EN

The paper describes a method of using accurate models of the water supply system for detecting and locating leaks. This method is based on a simple measure of similarity between real and simulated data on water flows in the water supply.