Wireless sensor networks provide a wide range of applications, such as environment surveillance, hazard monitoring, traffic control, and other commercial or military applications. The quality of service provided by a sensor network relies on its coverage, i.e., how well an event can be tracked by sensors. This research studies issues about sensor coverage: (1) how to optimally deploy new sensors in order to improve the coverage of an existing network, (2) how to properly measure the coverage when the path is a line. The best- and worst-case coverage problems that are related to the observability of a path are addressed and formulated into computational geometry problems. We prove that there exists a duality between the two coverage problems, and then solve the two problems together. The presented new-node placement algorithm is shown to deploy new nodes optimally in polynomial time. However, in some applications, such as highway monitoring and anti-missile interception systems, the trajectory of a target is linear but we can not find suitable coverage measurement for the straight-line path in previous research. Therefore, this research presents novel algorithms for coverage measurement of straight-line paths. Based on computational geometry and graph theory, we propose plane sweep algorithms to find the optimal straight-line paths for both the best-case and worst-case coverage problems in polynomial time. Both mathematical analysis and simulations are used to prove the optimality of our algorithms.

Test coverage is an important parameter of analyzing how well the product is being tested in any domain within the IT industry. Unit testing is one of the important processes that have gained even more popularity with the rise in Test driven development (TDD) culture.This degree project, conducted at NASDAQ Technology AB, analyzes the existing unit tests in one of the products, and compares various coverage models in terms of quality. Further, the study examines the factors that affect code coverage, presents the best practices for unit testing, and a proven test process used in a real world project.To conclude, recommendations are given to NASDAQ based on the findings of this study and industry standards. / Testtäckning är en viktig parameter för att analysera hur väl en produkt är testad inom alla domäner i IT-industrin. Enhetstestning är en av de viktiga processerna som har ökat sin popularitet med testdriven utveckling. Detta examensarbete, utfört på NASDAQ Technology AB, analyserar de befintliga testen i en av produkterna, och jämför olika kvalitetsmodeller. Vidare undersöker undersökningen de faktorer som påverkar koddekning, presenterar de bästa metoderna för enhetstestning och en beprövad testprocess som används i ett verkligt världsprojekt. Avslutningsvis ges rekommendationer till NASDAQ baserat på resultaten från denna studie och industristandarder.