Adaptive MCMC methods with applications in environmental and geophysical models

This work presents new, efficient Markov chain Monte Carlo (MCMC) simulation methods for statistical analysis in various modelling applications. When using MCMC methods, the model is simulated repeatedly to explore the probability distribution describing the uncertainties in model parameters and predictions. In adaptive MCMC methods based on the Metropolis-Hastings algorithm, the proposal distribution needed by the algorithm learns from the target distribution as the simulation proceeds. Adaptive MCMC methods have been subject of intensive research lately, as they open a way for essentially easier use of the methodology. The lack of user-friendly computer programs has been a main obstacle for wider acceptance of the methods. This work provides two new adaptive MCMC methods: DRAM and AARJ. The DRAM method has been built especially to work in high dimensional and non-linear problems. The AARJ method is an extension to DRAM for model selection problems, where the mathematical formulation of the model is uncertain and we want simultaneously to fit several different models to the same observations. The methods were developed while keeping in mind the needs of modelling applications typical in environmental sciences. The development work has been pursued while working with several application projects. The applications presented in this work are: a winter time oxygen concentration model for Lake Tuusulanjärvi and adaptive control of the aerator; a nutrition model for Lake Pyhäjärvi and lake management planning; validation of the algorithms of the GOMOS ozone remote sensing instrument on board the Envisat satellite of European Space Agency and the study of the effects of aerosol model selection on the GOMOS algorithm.

Facilitating coordination improvement efforts in cross-functional process development programs

Business process improvement is a common approach in increasing the effectiveness of an organization. It can be seen as an effort to increase coordination between units. Process improvement has proved to be challenging, and most management consultation firms facilitate organizations in this kind of initiatives. Cross-functional improvement is one of the main areas for internal consultants as well. However, the needs, challenges and means of cross-functional help have been rarely discussed in the literature. The objective of this thesis is on one hand to present a conceptual and descriptive framework to help understand the challenges of facilitating coordination improvement efforts in cross-functional improvement programs, and on the other hand to develop and test feasible solutions for some facilitation situations. The research questions are: 1. Why and in what kind of situations do organizations need help in developing coordination in cross-functional processes? 2. How can a facilitator help organizations in improving coordination to develop cross-functional processes? The study consists of two parts. The first part is an overview of the dissertation, and the second part comprises six research publications. The theoretical background for the study are the differentiation causing challenges in cross-functional settings, the coordination needed to improve processes, change management principles, methods and tools, and consultation practises. Three of the publications introduce tools for helping in developing prerequisites, planning responsibilities and supporting learning during the cross-functional program. The three other papers present frameworks to help understand and analyse the improvement situation. The main methodological approaches used in this study are design science research, action research and case research. The research data has been collected from ten cases representing different kinds of organizations, processes and developing situations. The data has been collected mainly by observation, semi-structured interviews and questionnaires. The research contributes to the rare literature combining coordination theories and process improvement practises. It also provides additional understanding of a holistic point of view in process improvement situations. The most important contribution is the addition to the theories of facilitating change in process improvement situations. From the managerial point of view, this study gives advice to managers and consultants in planning and executing cross-functional programs. The main factors increasing the need for facilitation are the challenges for differentiation, challenges of organizational change in general, and the novelty of initiatives and improvement practices concerning process development. Organizations need help in creating the prerequisites to change, in planning initiatives, easing conflict management and collaboration between groups, as well as supporting the learning of cross-functional improvement. The main challenges of facilitation are combining the different roles as a consultant, maintaining the ownership for the improvement project with the client, and supporting learning in the client organization.