A Microdata Analysis Approach to Transport Infrastructure Maintenance

Maintenance of transport infrastructure assets is widely advocated as the key in minimizing current and future costs of the transportation network. While effective maintenance decisions are often a result of engineering skills and practical knowledge, efficient decisions must also account for the net result over an asset's life-cycle. One essential aspect in the long term perspective of transport infrastructure maintenance is to proactively estimate maintenance needs. In dealing with immediate maintenance actions, support tools that can prioritize potential maintenance candidates are important to obtain an efficient maintenance strategy. This dissertation consists of five individual research papers presenting a microdata analysis approach to transport infrastructure maintenance. Microdata analysis is a multidisciplinary field in which large quantities of data is collected, analyzed, and interpreted to improve decision-making. Increased access to transport infrastructure data enables a deeper understanding of causal effects and a possibility to make predictions of future outcomes. The microdata analysis approach covers the complete process from data collection to actual decisions and is therefore well suited for the task of improving efficiency in transport infrastructure maintenance. Statistical modeling was the selected analysis method in this dissertation and provided solutions to the different problems presented in each of the five papers. In Paper I, a time-to-event model was used to estimate remaining road pavement lifetimes in Sweden. In Paper II, an extension of the model in Paper I assessed the impact of latent variables on road lifetimes; displaying the sections in a road network that are weaker due to e.g. subsoil conditions or undetected heavy traffic. The study in Paper III incorporated a probabilistic parametric distribution as a representation of road lifetimes into an equation for the marginal cost of road wear. Differentiated road wear marginal costs for heavy and light vehicles are an important information basis for decisions regarding vehicle miles traveled (VMT) taxation policies. In Paper IV, a distribution based clustering method was used to distinguish between road segments that are deteriorating and road segments that have a stationary road condition. Within railway networks, temporary speed restrictions are often imposed because of maintenance and must be addressed in order to keep punctuality. The study in Paper V evaluated the empirical effect on running time of speed restrictions on a Norwegian railway line using a generalized linear mixed model.

Colorizing Grey Scale Images

The purpose of this thesis is to develop a working methodology to color a grey scale image. This thesis is based on approach of using a colored reference image. Coloring grey scale images has no exact solution till date and all available methods are based on approximation. This technique of using a color reference image for approximating color information in grey scale image is among most modern techniques.Method developed here in this paper is better than existing methods of approximation of color information addition in grey scale images in brightness, sharpness, color shade gradients and distribution of colors over objects.Color and grey scale images are analyzed for statistical and textural features. This analysis is done only on basis of luminance value in images. These features are then segmented and segments of color and grey scale images are mapped on basis of distances of segments from origin. Then chromatic values are transferred between these matched segments from color image to grey scale image.Technique proposed in this paper uses better mechanism of mapping clusters and mapping colors between segments, resulting in notable improvement in existing techniques in this category.

Hur grafiska formgivare runt om i världen uppfattar skandinavisk grafisk design

Syftet med föreliggande studie har varit att kartlägga hur grafiska formgivare runt om i världen uppfattar skandinavisk grafisk design. 53 deltagare från industriländer deltog i studien som använde en kombination av mail-intervjuer och enkäter. Resultaten från denna studie indikerar att, oavsett kontinent, upplevs skandinavisk grafisk design som enkel och funktionell. Layouten uppfattades som rutnätsbaserad med mycket ljusrum och få grafiska element. Monokroma färger som svart, vit och grå utan gradienter och skuggor uppfattades som typiska för skandinavisk grafisk design; följt av jord- och pastellfärger. Sanserifer var mest förknippade med skandinavisk grafisk design. Motiv ansågs i denna studie att användas sparsamt, men när de används avbildar de naturen eller geometriska former. Foton och illustrationer ansågs användas ungefär lika mycket, illustrationer hade en smärre större preferens. Den upplevda påverkan av skandinavisk grafisk design varierade mellan deltagarna. Deltagarna som tyckte att påverkan var stor, ansåg att detta berodde på förespråkandet av enkelhet och funktion, sammanflätning av designområden och/eller frammaning av hållbar grafisk design. Deltagarna som ansåg att påverkan var låg, tyckte att för lite publicitet var en bidragande faktor.De flesta deltagarna i denna undersökning ansåg att skandinavisk grafisk design var enklare i jämförelse med vad de kunde se i sina hemländer. Vidare tyckte afrikanska, asiatiska och sydamerikanska deltagare  att färgerna hade lägre kroma.