Bridge maintenance robotic arm: Capacitive sensor for obstacle ranging in particle laden air

This paper describes an Adaptive Capacitive Sensor Network for Obstacle Ranging (ACSOR) that is intended to provide entire arm encompassing obstacle range data for a robotic arm conducting the task of sandblasting a bridge. A multi-channel capacitive sensor capable of dynamic obstacle ranging in air heavily laden with lead contaminated sandblasting refuse has been developed. Experimental results have shown the ACSOR's working range to be 50cm, that it is relatively immune from airborne lead contaminated sandblasting refuse and that it is capable of ranging an obstacle 21cm away whilst fitted to a robotic arm moving at 2cm/s with an obstacle range error of less than 1cm

Factors Influencing Tax Evasion: The Perception of Sri Lankan Medium-Sized Taxpayers

This quantitative study investigates the taxpayers’ perceptions of tax evasion. The tax evasion determinants were considered as institutional, economic, socio-psychological, and political and legal factors. Using a 5-point Likert scale, this study looked at 436 medium-sized entrepreneurs in the Colombo district to determine the most influential determinant of tax evasion. The survey responses were gathered through a questionnaire. The results show that socio-psychological and economic factors have a significant and negative impact on medium-sized taxpayers’ income tax evasion behaviour while institutional and political and legal factors have a weak association on tax evasion. The findings show that tax evasion is influenced by socio-psychological factors such as fairness of the tax system, moral obligation, and social influences, as well as economic factors such as tax rates, penalties, audit, and taxpayer privileges. The results highlight that in the Sri Lankan context, socio-psychosocial factors are regarded as a very crucial determinant that impacts individual income tax evasion. In addition, it offers insight into the influence of gender of business owner on tax evasion behaviour. Results suggest that medium-sized taxpayers’ tax evasion behaviors could be changed if tax policy decisions contemplate more on taxpayer’s psychological condition and affordability to pay tax. Distributing the tax burden to a greater number of taxpayers will help to increase tax compliance.     DOI: http://doi.org/10.31357/fhss/vjhss.v09i01.0

Planning under uncertainty using model predictive control for information gathering

This paper considers trajectory planning problems for autonomous robots in information gathering tasks. The objective of the planning is to maximize the information gathered within a finite time horizon. It is assumed that either the Extended Kalman Filter (EKF) or the Extended Information Filter (EIF) is applied to estimate the features of interest and the information gathered is expressed by the covariance matrix or information matrix. It is shown that the planning process can be formulated as an optimal control problem for a nonlinear control system with a gradually identified model. This naturally leads to the Model Predictive Control (MPC) planning strategy, which uses the updated knowledge about the model to solve a finite horizon optimal control problem at each time step and only executes the first control action. The proposed MPC framework is demonstrated through solutions to two challenging information gathering tasks: (1) Simultaneous planning, localization, and map building (SPLAM) and (2) Multi-robot Geolocation. It is shown that MPC can effectively deal with dynamic constraints, multiple robots/features and a range of objective functions. © 2006 Elsevier Ltd. All rights reserved

Wireless Power Technology for Biomedical Implants

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Wideband Technology for Medical Detection and Monitoring

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Multi-Step Look-Ahead Trajectory Planning in SLAM: Possibility and Necessity

In this paper, the possibility and necessity of multistep trajectory planning in Extended Kalman Filter (EKF) based SLAM is investigated. The objective of the trajectory planning here is to minimize the estimation error of the robot and landmark locations subject to a given time horizon. We show that the problem can be regarded as an optimization problem for a gradually identified model. A numerical method is proposed for trajectory planning using a variant of the nonlinear Model Predictive Control (MPC). The proposed method is optimal in the sense that the control action is computed using all the information available at the time of decision making. Simulation results are included to compare the results from the one-step look-ahead trajectory planning and the proposed multi-step lookahead techniqu

Designing a pulsed eddy current sensing set-up for cast iron thickness assessment

© 2017 IEEE. Pulsed Eddy Current (PEC) sensors possess proven functionality in measuring ferromagnetic material thickness. However, most commercial PEC service providers as well as researchers have investigated and claim functionality of sensors on homogeneous structural steels (steel grade Q235 for example). In this paper, we present design steps for a PEC sensing set-up to measure thickness of cast iron, which is unlike steel, is a highly inhomogeneous and non-linear ferromagnetic material. The setup includes a PEC sensor, sensor excitation and reception circuits, and a unique signal processing method. The signal processing method yields a signal feature which behaves as a function of thickness. The signal feature has a desirable characteristic of being lowly influenced by lift-off. Experimental results show that the set-up is usable for Non-destructive Evaluation (NDE) applications such as cast iron water pipe assessment

Design of a lock-in amplifier integrated with a coil system for eddy-current non-destructive inspection

© 2017 IEEE. Eddy-current non-destructive inspections of conductive components are of great interest in several industries including civil infrastructure and the mining industry. In this work, we have used a driver-pickup coil system as the probe to carry out inspection of ferromagnetic plates. The specific geometric configuration of the probe generates weak electric signals that are buried in a noisy environment. In order to detect these weak signals, we have designed and implemented a lock-in amplifier as part of the signal processing technique to increase the signal-to-noise ratio and also improve the sensitivity of the probe. We have used Comsol as a finite element method (FEM) to design the probe and conducted experiments with the probe and the lock-in amplifier. The experimental results, which are in agreement with the FEM results, indicate that the designed probe along with a lock-in amplifier can potentially be used to estimate the thickness of thin plates

Spectrum of sputum culture isolates and their antibiotic susceptibility pattern in adult cancer patients receiving empirical antibiotics at Apeksha Hospital, Maharagama, Sri Lanka

Background: Infections are the second commonest cause of non-cancer deaths among patients with malignancies. Both lower respiratory tract infections (LRTI) and blood stream infections have shown near equal prevalence in these populations.Objective: To determine the spectrum and the antibiotic susceptibility pattern of the bacteria isolated from sputum of cancer patients receiving empirical antibiotics for LRTI at the time of the specimen collection.Methods: Fifty five patients who were diagnosed clinically and/or radiologically to have LRTIs were included in the study from May, 2018 to January, 2019 at Apeksha Hospital, Maharagama. Sputum culture was done and ABST was performed for isolated pathogens.Results: Klebsiella pneumoniae was the commonest pathogen (49.1%, 27/55) isolated followed by multi-drug resistant Acinetobacter spp. (16.4%, 9/55). Overall proportion of coliforms was found to be 63.6% (35/55). All the isolated Staphylococcus aureus (12.7%, 7/55) were methicillin-resistant (MRSA) and inducible clindamycin resistant was detected among three of those. Coliforms showed the highest sensitivity to amikacin (71.4%, 25/35) and gentamicin (68.6%, 24/35). Colistin was the only antibiotic detected sensitive against eight Acinetobacter baumannii /A. calcoaceticus isolates. One A. iwoffii isolate was resistant to all the tested antibiotics including colistin. Extended spectrum beta lactamase (ESBL) production was detected in 22.8% (8/35) and carbapenem resistance in 54.3% (19/35). Meropenem was the empirical antibiotic of choice in this patient population which had been given to 34.5% (19/55). The isolated pathogen in 54.5% (30/55) of the patients was resistant to the selected empirical antibiotic.Conclusion: Sputum culture isolates show a very high resistance to multiple antibiotics which results in limitations of appropriate empirical antibiotic selection.Acknowledgement: University of Sri Jayewardenepura, research grant No. ASP/MED/2017/36