Automated Bridge Inspection for Concrete Surface Defect Detection Using Deep Neural Network Based on LiDAR Scanning

Structural inspection and maintenance of bridges are essential to improve the safety and sustainability of the infrastructure systems. Visual inspection using non-equipped eyes is the principal method of detecting surface defects of bridges, which is time-consuming, unsafe, and encounters inspectors falling risks. Therefore, there is a need for automated bridge inspection. Recently, Light Detection and Ranging (LiDAR) scanners are used for detecting surface defects. LiDAR scanners can collect high-quality 3D point cloud datasets. In order to automate the process of structural inspection, it is important to collect proper datasets and use an efficient approach to analyze them and find the defects. Deep Neural Networks (DNNs) have been recently used for detecting 3D objects within 3D point clouds. PointNet and PointNet++ are deep neural networks for classification, part segmentation, and semantic segmentation of point clouds that are modified and adapted in this work to detect surface concrete defects. The research contributions are: (1) Designing a LiDAR-equipped UAV platform for structural inspection using an affordable 2D scanner for data collection, and (2) Proposing a method for detecting concrete surface defects using deep neural networks based on LiDAR generated point clouds. Training and testing datasets are collected from four concrete bridges in Montréal and annotated manually. The point cloud dataset prepared in five areas, which contain more than 51 million points and 2,572 annotated defects in four classes of crack, light spalling, medium spalling, and severe spalling. The accuracies of 75% (adapted PointNet) and 79% (adapted PointNet++) in detecting defects are achieved in binary semantic segmentation

Investigation of the Relation between Economic Globalization and Government Size in Asian Developing Countries

The purpose of this paper is to examine the relation between government size and openness for a 26-years panel of 30 Asian developing countries. It is argued that there is a negative relation between country size and government size and also between country size and openness. Considering that, some researchers concluded that there is a positive relationship between openness and the size of government. To reveal the relation between these two variables, we used two proxies for measuring the extent of openness. The proxy used for openness is the economic dimension of KOF index of globalization. Employing a non-stationary panel data technique and DOLS estimator, the results show that there is a positive relationship between economic globalization and government size

Codification of indicators of the resilience of Iranian news agencies in the stage of reconstruction and rehabilitation of natural crises management

Mass media such as news agencies, due to their ability to direct public opinion, play a key role in various stages of the crisis, including the reconstruction and recovery phase, so that by defining and implementing their positive and intrinsic roles, they can increase the resilience capacity of society. However, the prerequisite for this assistance is that they can maintain their original status after the emergency and continue to provide services; In other words, be resilient. To make media resilient, the first step can be to measure how well they perform, and in fact, how resilient that media is in the face of crises. This issue is based on providing indicators that show the performance of the media in the face of crises. Therefore, the purpose of this study is to develop the performance indicators of the resilience of Iranian news agencies in natural crises in the reconstruction and recovery phase. In this qualitative research, the data were collected using a systematic review of resources and also a semi-structured interview with 12 subject matter experts and analyzed using thematic analysis. The analysis of research data led to the introduction of 3 comprehensive themes (as dimensions) including "learning development", "news continuity", and "monitoring and follow-up", under which 5 components are "monitoring the actions of officials", "take care of the environment and public opinion ", "Experience Writing", "Futuristic Education" and "Situational Reporting". Finally, 12 indicators were identified and presented as performance indicators of the resilience of Iranian news agencies in the stage of reconstruction and recovery of natural crises

Optimization of water pressure of a distribution network within the water-energy Nexus

Pressure control in water distribution networks (WDNs) reduces leaks and bursting. Thus, it is regarded as a valuable solution to cut costs related to the operation and maintenance of WDNs and it is recommended for use in deteriorated water distribution pipes. However, growing consumer demand for satisfactory performance from faucets, combined with reduced water pressure from water supply companies, has resulted in an increased need for domestic water pressure booster systems (WPBSs) and has led to an increase in the energy demand. This misalignment of interests between water companies and energy consumers highlights the water¿energy nexus perspective. This research aims to find a solution for optimizing the pressure of any WDN through the application of WPBSs to simultaneously minimize the cost associated with water leaks, repairs of burst pipes, and energy consumption. This methodology is applied to Baharestan city, where an optimum pressure of 47.6 mH2O is calculated. According to the sensitivity analysis of the inputs, the optimized pressure and cost are most sensitive to water loss and leakage exponent, respectively. Moreover, the hourly optimization of water pressure based on changes in demand and energy prices throughout the day is estimated to cut costs by 41%

Investigation of pipe shear connectors using push out test

Mechanical shear connectors are commonly used to transfer longitudinal shear forces across the steel-concrete interface in composite beams. Steel pipe as a new shear connector is proposed in this research and its performance to achieve composite strength is investigated. Experimental monotonic push-out tests were carried out for this connector. Then, a nonlinear finite element model of the push-out specimens is developed and verified against test results. Further, the finite element model is used to investigate the effects of pipe thickness, length and diameter on the shear strength of the connectors. The ultimate strengths of these connectors are reported and their respective failure modes are discussed. This paper comprises of the push-out tests of ten specimens on this shear connector in both the vertical and horizontal positions in different reinforced concretes. The results of experimental tests are given as load-deformation plots. It is concluded that the use of these connectors is very effective and economical in the medium shear demand range of 150-350 KN. The dominant failure modes observed were either failure of concrete block (crushing and splitting) or shear failure of pipe connector. It is shown that the horizontal pipe is not as effective as vertical pipe shear connector and is not recommended for practical use. It is shown that pipe connectors are more effective in transferring shear forces than channel and stud connectors. Moreover, based on the parametric study, a formula is presented to predict the pipe shear connectors' capacity

Unraveling the Water-Energy-Food-Environment Nexus for Climate Change Adaptation in Iran: Urmia Lake Basin Case-Study

A holistic approach to the management of water, energy, food, and the environment is required to both meet the socioeconomic demands of the future as well as sustainable development of these limited resources. The Urmia Lake Basin has faced environmental, social, and economic challenges in recent years, and this situation is likely to worsen under the impacts of climate change. For this study, an adaptability analysis of this region is proposed for the 2040 horizon year. Two models, the water evaluation and planning (WEAP (Stockholm Environmental Institute, Stockholm, Sweden)) and the low emissions analysis platform (LEAP (Stockholm Environmental Institute, Boston, MA, USA)), are integrated to simulate changes in water, energy, food, and the environment over these 20 years. Two climate scenarios and nine policy scenarios are combined to assess sustainable development using a multi-criteria decision analysis (MCDA) approach. Results show that, through pursuing challenging goals in agricultural, potable water, energy, and industrial sectors, sustainable development will be achieved. In this scenario, the Lake Urmia water level will reach its ecological water level in 2040. However, social, technical, and political challenges are considered obstacles to implementing the goals of this scenario. In addition, industry growth and industry structure adjustment have the most impact on sustainable development achievement

Review on Waste-to-Energy Approaches toward a Circular Economy in Developed and Developing Countries

International interest in using waste-to-energy (WtE) technology toward a circular economy (CE) is developing, spurred by environmental challenges such as inefficient solid waste dumping, pollution, and resource depletion. Incineration, pyrolysis, gasification, landfill, and anaerobic digestion are standard WtE technologies. Although these methods have been used for many decades, all countries try to implement the best plans based on their technologies and capacities. Therefore, an up-to-date comprehensive study is needed to evaluate the existing barriers to draw a logical roadmap for WtE to CE. Therefore, this review addresses the recent policies adopted by developed and developing countries for WtE technologies. Based on the findings, most countries seek the most cost-effective and environmentally sustainable pathways in WtE to CE; meanwhile, international collaboration and governmental support are needed to overcome the existing barriers and find a sustainable and economically viable plan for both developed and developing countries in the future