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Number of results: 6
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Abstract

Eye tracking recordings could reveal the visual behavior for different cartographic visualization techniques, such as hill-shading, while at the same time eye tracking metrics (ETMs) can summarize the associated complexity levels in a concise and quantitative manner. In the present study, three different hill-shading methods, including: (i) the standard method based on ideal diffuse reflection, (ii) the Multidirectional Oblique- Weighted method – MDOW and (iii) the combination of a MDOW’s variation with standard hill-shading, are evaluated and ranked in terms of their perceived visual complexity. The performed examination is based on both eye tracking techniques and expert judgement procedures. A weighted combination of basic ETMs has been used, implemented by the Landscape Rating Index – LRI. The weights resulted from an experts’ judgement process where the opinions of experts in geoinformatics, cartography, geovisualization, experimental psychology, cognitive science, neuroscience and eye tracking were analyzed. Fifteen (15) individuals participated in an eye tracking experiment with hill-shading images produced by the three methods under evaluation, while 41 experts participated in an online questionnaire in order to collect all the analysis data. The final evaluation was based on the computation of three LRI models. The outcomes indicate that implementing hill-shading with more than one light sources results in similar perceptual behaviors, allowing for a seamless exploitation of the advantages of using multidirectional illumination.
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Authors and Affiliations

Nikolaos Tzelepis
1
ORCID: ORCID
Alexandra Kaliakouda
1 2
ORCID: ORCID
Vassilios Krassanakis
3
ORCID: ORCID
Loukas-Moysis Misthos
1 3
ORCID: ORCID
Byron Nakos
1
ORCID: ORCID

  1. National Technical University of Athens, School of Rural and Surveying Engineering, Athens, Greece
  2. KTH Royal Institute of Technology, School of Architecture and Built Environment, Stocholm, Sweden
  3. University of West Attica, Department of Surveying and Geoinformatics Engineering, Athens, Greece
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Abstract

A transformer is an important part of power transmission and transformation equipment. Once a fault occurs, it may cause a large-scale power outage. The safety of the transformer is related to the safe and stable operation of the power system. Aiming at the problem that the diagnosis result of transformer fault diagnosis method is not ideal and the model is unstable, a transformer fault diagnosis model based on improved particle swarm optimization online sequence extreme learning machine (IPSO-OS-ELM) algorithm is proposed. The improved particle swarmoptimization algorithm is applied to the transformer fault diagnosis model based on the OS-ELM, and the problems of randomly selecting parameters in the hidden layer of the OS-ELM and its network output not stable enough, are solved by optimization. Finally, the effectiveness of the improved fault diagnosis model in improving the accuracy is verified by simulation experiments.

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Authors and Affiliations

Yuancheng Li
Longqiang Ma
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Abstract

This paper presents the application of Flexible Alternating Current Transmission System (FACTS) devices based on heuristic algorithms in power systems. The work proposes the Autonomous Groups Particle Swarm Optimization (AGPSO) approach for the optimal placement and sizing of the Static Var Compensator (SVC) to minimize the total active power losses in transmission lines. A comparative study is conducted with other heuristic optimization algorithms such as Particle Swarm Optimization (PSO), Timevarying Acceleration Coefficients PSO (TACPSO), Improved PSO (IPSO), Modified PSO (MPSO), and Moth-Flam Optimization (MFO) algorithms to confirm the efficacy of the proposed algorithm. Computer simulations have been carried out on MATLAB with the MATPOWER additional package to evaluate the performance of the AGPSO algorithm on the IEEE 14 and 30 bus systems. The simulation results show that the proposed algorithm offers the best performance among all algorithms with the lowest active power losses and the highest convergence rate.
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Bibliography

[1] Vera S.M., Nuez I., Hernandez-Tejera M., A FACTS devices allocation procedure attending to load share, Energies, vol. 13, no. 8 (2020), DOI: 10.3390/en13081976.
[2] Singh B., Kumar R., A comprehensive survey on enhancement of system performances by using different types of FACTS controllers in power systems with static and realistic load models, Energy Reports, vol. 6, pp. 55–79 (2020).
[3] Shehata A.A., Ahmed M.K., State estimation accuracy enhancement for optimal power system steady state modes, IOP Conference Series: Materials Science and Engineering, vol. 643 (2019), DOI: 10.1088/1757-899X/643/1/012049.
[4] Sreedharan S., Joseph T., Joseph S., Chandran C.V., Vishnu J., Das V., Power system loading margin enhancement by optimal STATCOM integration – A case study, Computers and Electrical Engineering, vol. 81, no. 106521 (2019).
[5] Al Ahmad A., Sirjani R., Optimal placement and sizing of multi-type FACTS devices in power systems using metaheuristic optimisation techniques: An updated review, Ain Shams Engineering Journal (2019), DOI: 10.1016/j.asej.2019.10.013.
[6] Belazzoug M., Boudour M., Sebaa K., FACTS location and size for reactive power system compensation through the multi-objective optimization, Archives of Control Sciences, vol. 20, no. 4, pp. 473–489 (2010).
[7] Kotsampopoulos P., Georgilakis P., Lagos D.T., Kleftakis V., Hatziargyriou N., FACTS providing grid services: applications and testing, Energies, vol. 12, no. 13 (2019), DOI: 10.3390/en12132554
[8] Kavitha K.,Neela R., Optimal allocation of multi-type FACTS devices and its effect in enhancing system security using BBO, WIPSO & PSO, Journal of Electrical Systems and Information Technology, vol. 5, no. 3, pp. 777–793 (2018).
[9] Shehata A.A., Korovkin N.V., An accuracy enhancement of optimization techniques containing fractional-polynomial relationships, 2020 International Youth Conference on Radio Electronics, Electrical and Power Engineering (REEPE), pp. 1–5 (2020).
[10] Dash S.P., Subhashini K.R., Satapathy J.K., Optimal location and parametric settings of FACTS devices based on JAYA blended moth flame optimization for transmission loss minimization in power systems, Microsystem Technologies, vol. 26, no. 5, pp. 1543–1552 (2020).
[11] Saurav S., Gupta V.K., Mishra S.K., Moth-flame optimization based algorithm for FACTS devices allocation in a power system, 2017 International Conference on Innovations in Information, Embedded and Communication Systems (ICIIECS), pp. 1–7 (2017).
[12] Jyotshna D.K., Madhuri N., Optimal allocation of SVC for enhancement of voltage stability using harmony search algorithm, International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering, vol. 4, no. 7, pp. 6693–6701 (2015).
[13] Ravi K., Rajaram M., Optimal location of FACTS devices using Improved Particle Swarm Optimization, International Journal of Electrical Power and Energy Systems, vol. 49, pp. 333–338 (2013).
[14] Mathad V.G., Ronad B.G., Jangamshetti S.H., Review on comparison of FACTS controllers for power system stability enhancement, International Journal of Scientific and Research Publications, vol. 3, no. 3, pp. 2250–3153 (2013).
[15] Murali D., Rajaram M., Reka N., Comparison of FACTS devices for power system stability enhancement, International Journal of Computer Applications, vol. 8, no. 4, pp. 30–35 (2010).
[16] Rezaee J.A., Particle swarm optimisation (PSO) for allocation of FACTS devices in electric transmission systems: A review, Renewable and Sustainable Energy Reviews, vol. 52, pp. 1260-1267 (2015).
[17] Shaheen A.M., Spea S.R., Farrag S.M., Abido M.A., A review of meta-heuristic algorithms for reactive power planning problem, Ain Shams Engineering Journal, vol. 9, no. 2, pp. 215–231 (2018).
[18] Suresh V., Janik P., Jasinski M., Metaheuristic approach to optimal power flow using mixed integer distributed ant colony optimization, Archives of Electrical Engineering, vol. 69, no. 2, pp. 335–348 (2020).
[19] Benchabira A., Khiat M., A hybrid method for the optimal reactive power dispatch and the control of voltages in an electrical energy network, Archives of Electrical Engineering, vol. 68, no. 3, pp. 535–551 (2019).
[20] Ziyu T., Dingxue Z., A modified particle swarm optimization with an adaptive acceleration coefficient, 2009 Asia-Pacific Conference on Information Processing, vol. 2, pp. 330–332 (2009).
[21] Mirjalili S., Lewis A., Sadiq A.S., Autonomous particles groups for particle swarm optimization, Arabian Journal for Science and Engineering, vol. 39, no. 6, pp. 4683–4697 (2014). [22] The IEEE 14 and 30 Bus Test Systems, available online at: http://labs.ece.uw.edu/pstca.
[23] Cui Z., Zeng J., Yin Y., An improved PSO with time-varying accelerator coefficients, 2008 8th International Conference on Intelligent Systems Design and Applications, vol. 2, pp. 638–643 (2008).
[24] Bao G.Q., Mao K.F., Particle swarmoptimization algorithm with asymmetric time varying acceleration coefficients, 2009 IEEE International Conference on Robotics and Biomimetics (ROBIO), no. 3, pp. 2134–2139 (2009).
[25] Mirjalili S., Moth-flame optimization algorithm: a novel nature-inspired heuristic paradigm, Knowledge-Based Systems, vol. 89, pp. 228–249 (2015).
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Authors and Affiliations

Ahmed A. Shehata
1
ORCID: ORCID
Ahmed Refaat
2
ORCID: ORCID
Mamdouh K. Ahmed
1
ORCID: ORCID
Nikolay V. Korovkin
1
ORCID: ORCID

  1. Institute of Energy, Peter the Great Saint-Petersburg Polytechnic University, Russia
  2. Electrical Engineering Department, Port-Said University, Egypt
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Abstract

The main topic of this article is apes’ intentional behaviour. I consider the Michael Tomasello’s concept of intentionality. I outline how different levels of intentionality presented by Tomasello could be applied to apes’ behaviour. To do so I examine few experiments and observations (in natural conditions) of apes’ behaviour and try to apply Tomasello’s intentionality concepts. My main concern is the possibility of group and shared intentionality in ape communities, which could suggest that there is some kind of culture oriented behaviour in non-human animals.

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Authors and Affiliations

Iwona Olejniczak
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Abstract

The paper presents the full transient, two-dimensional finite volume method numerical calculations of the classical involute scroll compressor geometry. The purpose of the study was to develop and evaluate an adaptable implementation of numerical fluid mechanics and thermodynamics modeling procedure with a mesh deformation. The methodology consisting in the compression chamber geometry preparation, mesh generation and governing equations solving was described. The evaluation was carried by simulating an adiabatic compression process and the results were compared with the theoretical zero-dimensional model and the existing research concerning the scroll chamber computational fluid dynamics modeling. It has been shown that the proposed modeling routine results in good accuracy for the scroll compressors study applications.

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Authors and Affiliations

Józef Rak
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Abstract

Buckling and postbuckling response of thin-walled composite plates investigated experimentally and determinated analytically and numerically is compared. Real dimension specimens of composite plates weakened by cut-out subjected to uniform compression in laboratory buckling tests have been modelled in the finite element method and examined analytically based on P-w2 and P-w3 methods. All results were obtained during the experimental investigations and the numerical FEM analysis of a thin-walled composite plate made of a carbon-epoxy laminate with a symmetrical eight-layer arrangement of [90/-45/45/0]s. The instrument used for this purpose was a numerical ABAQUS® program.

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Authors and Affiliations

K. Falkowicz

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