scholarly journals Analysis of Factors Affecting Safety Performance in Iranian Power Distribution Companies - Hybrid Approach of DEMATEL and ISM

2021 ◽  
Vol 18 (1) ◽  
pp. 169-185
Author(s):  
Maryam Rezapour ◽  
saeed safari ◽  
Alihossein Keshavarzi ◽  
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1999 ◽  
Vol 17 (5) ◽  
pp. 309-315 ◽  
Author(s):  
Edwin Sawacha ◽  
Shamil Naoum ◽  
Daniel Fong

Author(s):  
Prashant Kumar ◽  
Sabha Raj Arya ◽  
Khyati D. Mistry

Abstract In this article, a hybrid approach is implemented namely, neural network training (NNT) based machine learning (ML) estimator inspired by artificial neural network (ANN) and self-adaptive neuro-fuzzy inference system (ANFIS) to tackle the voltage aggravations in the power distribution network (DN). In this work, potential of swarm intelligence technique namely particle swam optimization (PSO) is analysed to obtain an optimum prediction model with certain modifications in training algorithm parameters. In practice, when the systems are continuously subjected to parametric changes or external disturbances, then ample time is dedicated to tune the system to regain its stable performance. To improve the dynamic performance of the system intelligence-based techniques are proposed to overcome the shortcomings of conventional controllers. So, gain tuning process based on the intelligence system is a desirable choice. The statistical tools are used to proclaim the effectiveness of the controllers. The obtained MSE, RMSE, ME, SD and R were evaluated as 0.0015959, 0.039949, −0.00089838, 0.039941 and 1 in the training phase and 0.0015372, 0.039207, −0.0005657, 0.039203 and 1 in the testing phase, respectively. The results revealed that the ANFIS-PSO network model could accomplish a better DC voltage regulation performance when it is compared to the conventional PI. The proposed intelligence strategies confirm that the predicted DVR model based on NNT-ML and ANFIS has faster convergence speed and reliable prediction rate. Moreover, the simulation results show that the dynamic response is improved with proposed PSO based NNT based ML and ANFIS (Takagi-Sugeno) that significantly compensates the voltage based PQ issues. The proposed DVR is actualized in MATLAB/SIMULINK platform.


2020 ◽  
Vol 10 (2) ◽  
pp. 108-14
Author(s):  
Majed M Moosa ◽  
Leo P. Oriet ◽  
Abdulrahman M Khamaj

Introduction: Research indicate that construction site accidents are a global concern, and rates are rapidly increasing. In developing countries such as Saudi Arabia, safety issues are frequently ignored, and little is known about their causes. Objectives: This study aimed to shed light on factors causing accidents in Saudi Arabian construction companies. Methods: An online detailed survey, using Google Form, of accident features was distributed randomly to potential employees in 35 construction companies in Saudi Arabia, where one of the top administrators or safety officers were required to respond to the survey. It was conducted from 1st June to 31st August, 2013. The safety practices and perceptions of accident causes were assessed. Results: The response rate was 63%. Over half of the surveyed organizations encountered all of the selected accident types. While 19 (86%) of the construction companies maintained the equipment regularly, 15 (68%) had regular maintenance staff and 13 (59%) inspected the equipment before use. Although 18 (82%) of the workers were supplied with personal protective equipment (PPE), only 12 (55%) emphasized its use and offered site orientation for new employees.  In the last part of the survey, respondents were requested to rate 25 factors affecting safety performance at the construction sites on a scale of 1 to 5, with 5 being the most important. The three most important factors of poor safety performance were the firm's top leaders, a lack of training, and the reckless operation of equipment. Conclusion: Changing attitudes of surrounding safety culture have the potential to significantly improve safety outcomes in the Saudi Arabian construction industry. Two Saudi Arabian corporations, Saudi Aramco and Saudi Chevron Petrochemical provide a positive model for increasing construction safety in the country, but there is a paucity of industry-level data. Further scholarly attention is strongly indicated.


2021 ◽  
Vol 3 (27) ◽  
pp. 101-115
Author(s):  
Massoud Danishmal ◽  

The design of power distribution systems should be such that it can technically respond to the increase in electricity demand properly and economically, optimally designed and high network reliability. In order to respond to the increase in electricity demand, load forecasting must be done so that in addition to providing the electricity needed by customers, expansion of power generation centers, expansion of substations, expansion of transformer stations and selection of their appropriate location can be done optimally. In this article, we first examine the definitions and factors that are technically and economically effective in the economic design of energy distribution systems. And in the next stage, we will see whether these above-mentioned effective factors are considered in the 0.4 kV distribution network of Ghazni city or not.


Author(s):  
Ossama E Gouda ◽  
Adel Z. El Dein ◽  
Ghada M Amer

As it is known, there are many factors affecting underground power distribution cables' loadings such as ambient temperature, cable depth laying, number of cable parallel circuits and thermal resistivity of the soil. One important factor usually ignored is the formation of dry zones around the underground power cables due to cable loading. Dry zones usually form around underground power cables under loading condition due to the migration of soil moisture content. In this paper the effect of dry zone formation on the underground power cables ampacity is investigated. De-rating factor for the formation of dry zone around underground power cables is suggested and calculated for different types of natural backfill soils. IEC 60287-1-3 is taken as reference. Experimental work is done to study the dry zone phenomena of each type of soil.


Author(s):  
Shahram Heydari ◽  
Liping Fu

Although accident frequencies at railway grade crossings have shown a decreasing trend over the last two decades (partly due to implemented safety improvements and technological advances), safety at grade crossings is still a major concern since crossing accidents are usually associated with devastating consequences. This paper investigates the effect of various site attributes on railway crossing safety outcomes using recent Canada wide data from a 6-year period (2008–2013). The new data sets allow adjusting previous accident models according to latest circumstances (e.g., vehicles’ improved safety features) affecting safety dynamics at crossings. Employing Bayesian hierarchical models including the non-conventional Poisson-Weibull model, different safety performance functions were separately developed for crossings with the following major warning systems: (1) flashing light and bell (FLB), (2) flashing light, bell, and gate (FLBG), (3) standard reflectorized crossing sign (SRCS), and (4) standard reflectorized crossing sign and stop sign (SRCS & STOP). Among other findings, the results indicated that traffic exposure (product of train and vehicle), number of lanes, whistle prohibition, train speed, and road speed were the most important factors affecting accident frequencies at Canadian railway crossings. It should be also noted that safety performance functions vary, in terms of independent variables and their associated coefficients, between the aforementioned warning devices.


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