Petri Makkonen

Early design evaluation of products artifacts’: An approach based on dimensional analysis for combined analysis of environmental, technical and cost requirements

The early development process of products imposes to fulfill numerous types of requirements simultaneously. Those requirements are often qualitative and imprecise. The main tasks of a development team consist of grasping and understanding customer needs, refining these needs, synthesizing concepts of solutions, evaluating and selecting appropriate solutions. Evaluating and selecting solutions is a critical stage because various types of metrics are used to measure performances of concepts. This paper presents both theoretical contributions and practical implementations. This article presents a theoretical analysis of resource consumption and environmental impact from the viewpoint of exergy. In addition, this article provides a theoretical answer to the issue of qualitative modeling of early design concepts of solutions. This article opens a fruitful perspective for combining heterogeneous requirements in a coherent and systematic manner by using dimensional analysis calculus.

Environmental analysis of the Product Life Cycle by using an aggregated metric based on exergy

Environmental accountancy and environmental impacts analysis are characterised by fragmented approaches encompassing a number of different perspectives and analytical techniques. Although Life Cycle Assessment (LCA) method is the most commonly used tool by which environmentally conscious design is carried out, the scientific reliability of LCA techniques has been questioned. Indeed, LCA techniques include limitations such as a lack of adequate inventory data, disparate underlying assumptions and environmental assessment made in terms that are not directly comparable. Those restrictions limit the applicability of LCA methods during early development stages. This article addresses this shortcoming by outlining previous researches in life cycle analysis and thermodynamics. It is argued herein that the early development phases require a simplified approach based on exergy. It is argued that the concept of exergy is a broad-based measure assessing the environmental impact and resource consumption of the Product Life Cycle (PLC). In addition, the article addresses a more ambitious research problem by integrating environmental impact and resource consumption into a broader design framework, described briefly in this article. The aim of the design framework presented herein is to optimise the comparison and evaluation process, which ends the early design process. This is in our viewpoint the first step of our work toward unified design theory based on topological principles.

Measurement Theory and Dimensional Analysis: Methodological Impact on the Comparison and Evaluation Process

Comparison and ranking of solutions are central tasks of the design process. Designers have to deal with decisions simultaneously involving multiple criteria. Those criteria are often inconsistent in the sense that they are expressed according to different types of metrics. This means that usual engineering performance indicators are expressed according to physical quantities (i.e. SI system) and indicators such as preference functions can be “measured” by using other type of qualitative metrics. This aspect limits the scientific consistency of design because a coherent scientific framework will at first require the creation of a unified list of fundamental properties. A combined analysis of the measurement theory, the General Design Theory (GDT) and the dimensional analysis theory give an interesting insight in order to create guidelines for establishing a coherent measurement system. This article establishes a list of fundamental requirements. We expect that these guidelines can help engineers and designers to be more aware of the drawbacks linked with the use of wrong comparison procedures and limitations associated with the use of weak measurement scales. This article makes an analysis of the fundamental aspects available in major scientific publications related to comparison, provides a synthesis of these basic concepts and unifies those concepts together from a designing perspective. A practical design methodology using the fundamental results of this article as prerequisites has been implemented by the authors.Copyright

Overview of EMAC-95 snow and ice airborne campaign in Finland

The 1995 European Multisensor Airborne Campaign (EMAC-95) on snow and ice was funded by European Space Agency (ESA) and national authorities. The main test sites were in Finland (sea ice, snow in boreal areas) and Norway (land ice, snow in mountainous areas). The airborne instruments included two microwave radiometer systems (Helsinki University of Technology HUTRAD and UK Meteorological Office system) and two SAR sensors (ESAR from DLR (Germany) and EMISAR from Technical University of Denmark). This paper summarizes the activities in the Finnish test sites. Results from the HUT microwave radiometer measurements in the Campaign are given.