Investigating SAR algorithm for spaceborne interferometric oil spill detection

The environmental damages and recovery of terrestrial ecosystems from oil spills can last decades. Oil spills have been responsible for loss of aquamarine lives, organisms, trees, vegetation, birds and wildlife. Although there are several methods through which oil spills can be detected, it can be argued that remote sensing via the use of spaceborne platforms provides enormous benefits. This paper will provide more efficient means and methods that can assist in improving oil spill responses. The objective of this research is to develop a signal processing algorithm that can be used for detecting oil spills using spaceborne SAR interferometry (InSAR) data. To this end, a pendulum formation of multistatic smallSAR carrying platforms in a near equatorial orbit is described. The characteristic parameters such as the effects of incidence angles on radar backscatter, which support the detection of oil spills, will be the main drivers for determining the relative positions of the small satellites in formation. The orbit design and baseline distances between each spaceborne SAR platform will also be discussed. Furthermore, results from previous analysis on coverage assessment and revisit time shall be highlighted. Finally, an evaluation of automatic algorithm techniques for oil spill detection in SAR images will be conducted and results presented. The framework for the automatic algorithm considered consists of three major steps. The segmentation stage, where techniques that suggest the use of thresholding for dark spot segmentation within the captured InSAR image scene is conducted. The feature extraction stage involves the geometry and shape of the segmented region where elongation of the oil slick is considered an important feature and a function of the width and the length of the oil slick. For the classification stage, where the major objective is to distinguish oil spills from look-alikes, a Mahalanobis classifier will be used to estimate the probability of the extracted features being oil spills. The validation process of the algorithm will be conducted by using NASA’s UAVSAR data obtained over the Gulf of coast oil spill and RADARSAT-1 dat

Physical Layer Security in Vehicular Communication Networks in the Presence of Interference

This paper studies the physical layer security of a vehicular communication network in the presence of interference constraints by analysing its secrecy capacity. The system considers a legitimate receiver node and an eavesdropper node, within a shared network, both under the effect of interference from other users. The double-Rayleigh fading channel is used to capture the effects of the wireless communication channel for the vehicular network. We present the standard logarithmic expression for the system capacity in an alternate form, to facilitate analysis in terms of the joint moment generating functions (MGF) of the random variables representing the channel fading and interference. Closed-form expressions for the MGFs are obtained and Monte-Carlo simulations are provided throughout to validate the results. The results show that performance of the system in terms of the secrecy capacity is affected by the number of interferers and their distances. The results further demonstrate the effect of the uncertainty in eavesdropper location on the analysis

Management support as a Critical Success Factor (CSF) for changing worker’s safety behaviour: a case of the Nigerian construction industry

Work-related deaths, injuries, and diseases are still prevalent among workers in the construction industry especially in developing countries due to due several factors that encourage poor safety practices on site. The study appraised workers perception of management engagement as a critical success factor for the improvement of Nigerian construction worker’s safety attitude using Nordic Occupational Safety Climate Questionnaire (NOSACQ-50). Findings from the study reveal small and medium scale firms dominate the industry, and a sizable number (20.4%) of the study participants are between 18-27 years of age with majority (74.7%) having work experience of 1-10 years. Management safety priority, commitment, and competence and management safety empowerment was found to have strong positive correlation (r =.739, n = 292, p <.001). However, management safety commitment disparity existed between management of public and private construction projects [F (1,391) = 12.04, p <.001]. To advance positive safety behaviour and attitude across the construction industry in Nigeria, management commitment should be prioritised, while further study on workplace safety measures and worker’s safety engagement should be considered

Drivers and barriers of virtual reality adoption in UK AEC industry

Purpose: Virtual reality (VR) offers unique features of a three-dimensional (3D) model during early design stages in the virtual environment with immersive functions. Although the potential of VR is to increase the effectiveness and productivity of the project phases from initial concept design to detailed design preparation. VR adoption in the United Kingdom (UK) Architectural Engineering and Construction (AEC) sector is slow compared to other sectors. This research focuses on ascertaining the drivers and barriers of VR in construction projects in the UK. Design/methodology/approach: The study adopts an online survey design. It uses Bristol Online Survey (BOS) to create a structured questionnaire that is used to assess UK construction professionals using a convenience sampling technique. Therefore, researcher uses descriptive and inferential technique for data analysis and presentation based on Statistical Package for Social Sciences (SPSS) to analyze the questionnaire. Findings: The research findings revealed the most significant barriers to VR adoption in UK construction industry were lack of skills/expertise and cultural change. Hence, the main drivers of VR adoption as rated by the professionals in the UK construction industry are improved safety, improved quality and improved productivity. Practical implications: The identification and assessment of the drivers and barriers to VR adoption could advance VR adoption among construction professionals and other stakeholders of the UK AEC sector. This could also be extended to developing countries, given the status of VR as being in the developing stage. Originality/value: This study provides valuable insights to construction professionals and stakeholders to plan actions that could enhance the drivers and mitigate the barriers of VR. This study's main contribution is to group and classify various drivers and barriers into easily understood categories, in order to potentiate the drivers and reduce the barriers effectively. The groupings could be used as benchmarks in similar studies in developing countries

Reconfigurable Intelligent Surface Enabled IoT Networks in Generalized Fading Channels

This paper studies an Internet-of-Things (IoT) network employing a reconfigurable intelligent surface (RIS) over generalized fading channels. Inspired by the promising potential of RIS-based transmission, we investigate a RIS-enabled IoT network with the source node employing a RIS-based access point. The system is modelled with reference to a receivertransmitter pair and the Fisher-Snedecor F model is adopted to analyse the composite fading and shadowing channel. Closedform expressions are derived for the system with regards to the average capacity, average bit error rate (BER) and outage probability. Monte-Carlo simulations are provided throughout to validate the results. The results investigated and reported in this study extend early results reported in the emerging literature on RIS-enabled technologies and provides a framework for the evaluation of a basic RIS-enabled IoT network over the most common multipath fading channels. The results indicate the clear benefit of employing a RIS-enabled access point, as well as the versatility of the derived expressions in analysing the effects of fading and shadowing on the network. The results further demonstrate that for a RIS-enabled IoT network, there is the need to balance between the cost and benefit of increasing the RIS cells against other parameters such as increasing transmit power, especially at low SNR and/or high to moderate fading/shadowing severity

Towards Physical Layer Security for Internet of Vehicles: Interference Aware Modelling

The physical-layer security (PLS) of wireless networks has witnessed significant attention in next-generation communication systems due to its potential toward enabling protection at the signal level in dense network environments. The growing trends toward smart mobility via sensor-enabled vehicles are transforming today’s traffic environment into Internet of Vehicles (IoVs). Enabling PLS for IoVs would be a significant development considering the dense vehicular network environment in the near future. In this context, this article presents a PLS framework for a vehicular network consisting a legitimate receiver and an eavesdropper, both under the effect of interfering vehicles. The double-Rayleigh fading channel is used to capture the effect of mobility within the communication channel. The performance is analyzed in terms of the average secrecy capacity (ASC) and secrecy outage probability (SOP). We present the standard expressions for the ASC and SOP in alternative forms, to facilitate analysis in terms of the respective moment generating function (MGF) and characteristic function of the joint fading and interferer statistics. Closed-form expressions for the MGFs and characteristic functions were obtained and Monte Carlo simulations were provided to validate the results. Approximate expressions for the ASC and SOP were also provided, for easier analysis and insight into the effect of the network parameters. The results attest that the performance of the considered system was affected by the number of interfering vehicles as well as their distances. It was also demonstrated that the system performance closely correlates with the uncertainty in the eavesdropper’s vehicle location