scholarly journals The Use of Dijkstra’s Algorithm in Assessing the Correctness of Imaging Brittle Damage in Concrete Beams by Means of Ultrasonic Transmission Tomography

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 551 ◽  
Author(s):  
Zbigniew Perkowski ◽  
Karolina Tatara
Keyword(s):  
Wave Propagation ◽  
Damage Mechanics ◽  
Concrete Beams ◽  
Tomographic Reconstruction ◽  
Ultrasonic Tomography ◽  
Dijkstra’S Algorithm ◽  
Brittle Damage ◽  
Dijkstra's Algorithm ◽  
Propagation Paths ◽  
Damage In Concrete

The accuracy of transmission ultrasonic tomography for the detection of brittle damage in concrete beams can be effectively supported by the graph theory and, in particular, by Dijkstra’s algorithm. It allows determining real paths of the fastest ultrasonic wave propagation in concrete containing localized elastically degraded zones at any stage of their evolution. This work confronts this type of approach with results that can be obtained from non-local isotropic damage mechanics. On this basis, the authors developed a method of reducing errors in tomographic reconstruction of longitudinal wave velocity maps which are caused by using the simplifying assumptions of straightness of the fastest wave propagation paths. The method is based on the appropriate elongation of measured propagation times of the wave transmitted between opposite sending-receiving transducers if the actual propagation paths deviate from straight lines. Thanks to this, the mathematical apparatus used typically in the tomography, in which the straightness of the fastest paths is assumed, can be still used. The work considers also the aspect of using fictitious wave sending-receiving points in ultrasonic tomography for which wave propagation times are calculated by interpolation of measured ones. The considerations are supported by experimental research conducted on laboratory reinforced concrete (RC) beams in the test of three-point bending and a prefabricated damaged RC beam.

Real-time localization of micro-damage in concrete beams using DIC technology and wavelet packet analysis

2021 ◽  
pp. 104198
Author(s):  
Kaiyang Zhou ◽  
Dong Lei ◽  
Jintao He ◽  
Pei Zhang ◽  
Pengxiang Bai ◽  
...  
Keyword(s):  
Real Time ◽  
Concrete Beams ◽  
Wavelet Packet ◽  
Wavelet Packet Analysis ◽  
Damage In Concrete

scholarly journals Railway timetabling: a maximum bottleneck path algorithm for finding an additional train path

2020 ◽  
Author(s):  
Fredrik Ljunggren ◽  
Kristian Persson ◽  
Anders Peterson ◽  
Christiane Schmidt
Keyword(s):  
Experimental Evaluation ◽  
Temporal Distance ◽  
Dijkstra’S Algorithm ◽  
Passenger Traffic ◽  
Dijkstra's Algorithm ◽  
Railway Timetabling

Abstract We present an algorithm to insert a train path in an existing railway timetable close to operation, when we want to affect the existing (passenger) traffic as little as possible. Thus, we consider all other trains as fixed, and aim for a resulting train path that maximizes the bottleneck robustness, that is, a train path that maximizes the temporal distance to neighboring trains in the timetable. Our algorithm is based on a graph formulation of the problem and uses a variant of Dijkstra’s algorithm. We present an extensive experimental evaluation of our algorithm for the Swedish railway stretch from Malmö to Hallsberg. Moreover, we analyze the size of our constructed graph.

Smart Shopping Robot for Supermarkets using Dijkstra’s Algorithm with user Interface

2020 ◽  
pp. 193-203
Author(s):  
Stevens Johnson ◽  
V.M. Midhun ◽  
Nithin Issac ◽  
Ann Mariya Mathew ◽  
Shinosh Mathew
Keyword(s):  
User Interface ◽  
Dijkstra’S Algorithm ◽  
Dijkstra's Algorithm

scholarly journals Optimal power flow-path determination for voltage control in electricity distribution using the modified dijkstra’s algorithm

2021 ◽  
Vol 10 (2) ◽  
pp. 108
Author(s):  
Ofem Ajah Ofem ◽  
Moses Adah Agana ◽  
Ejogobe Owai E.
Keyword(s):  
Power Flow ◽  
Optimal Power Flow ◽  
Distribution Network ◽  
Flow Path ◽  
Path Model ◽  
Electricity Distribution ◽  
Dijkstra’S Algorithm ◽  
Shortest Path Problems ◽  
Dijkstra's Algorithm ◽  
Optimal Power

This paper examines the electric power distribution network system of the Port Harcourt Electricity Distribution Company (PHEDC); its shortcomings, costs and voltage loss in distribution with a view to finding optimal solution through determination of optimal power flow path. The Modified Dijsktra’s Algorithm was applied to generate optimal flow path model of the distribution network with seven (7) nodes from Afam Thermal Power Station (source) to the Calabar Distribution Centre (destination) via the interconnected substations. The structural design of the PHEDC distribution network and a review of relevant literatures on shortest path problems were adopted. The modified Dijkstra’s algorithm was simulated using JavaScript and is able to run on any web browser (Google Chrome, Mozilla Firefox, etc). It was applied to a practical 330kV network using the relevant data obtained from the company and the result shows the negative effect of distance on voltage quality. It was observed that the Modified Dijkstra’s Algorithm is suitable for determining optimal power flow path with up to 98 percent level of accuracy because of its suitability for determining the shortest route in both transportation and power energy distribution as well as its overall performance with minimal memory space and fast response time.  

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