I will cover two different topics coming from my research: evaluation of machine learning algorithms for recognizing motion contexts of smartphone users and development of an ice-aware navigation system for ice-going ships. I will firstly describe the overall research questions related to these two topics, as well as some background about the applications. I will then cover at the algorithm level the approach that I have taken to solving these problems (supervized machine learning for the first problem and A* algorithm for the second problem). I also plan to have a brief overview of my institute (Finnish Geodetic Institute) and the various research areas where we are working.