Prepare a short report for the company which covers both electrical resistance strain gauging and digital image correlation for use in experimental stress analysis. The report should briefly introduce experimental stress analysis and its relevance, introduce strain gauges and digital image correlation methods and give relevant background to each. You should then cover the fundamental concepts and mode of operation (how it works!) associated with each technique and give guidance for obtaining accurate measurements. Finally, critically compare the methods, give suitable applications for each technique in aircraft engineering and offer conclusions and recommendations to the aerospace company using the information you have gathered as evidence.