What governs star formation in galaxies? A modern statistical approach

Understanding the process of star formation is one of the key steps in understanding the formation and evolution of galaxies. In this thesis, I address the empirical star formation laws, and study the properties of galaxies that can affect the star formation rate. The Andromeda galaxy (M31) is the nearest large spiral galaxy, and Therefore, high resolution images of this galaxy are available. These images provide data from various regions with different physical properties. Star formation rate and gas mass surface densities of M31have been measured using three different methods, and have been used to compare different star formation laws over the whole galaxy and in spatially-resolved regions. Using hierarchical Bayesian regression analysis, I conclude that there is a correlation between surface density of star formation and the stellar mass surface density. A weak correlation between star formation rate, stellar mass and metallicity is also found. To study the effect of other properties a galaxy on the star formation rate, I utilize an unsupervised data mining method (specifically the self-organizing map) on measurements of both nearby and high-redshift galaxies. Both observed data and derived quantities (e.g. star formation rate, stellar mass) of star-forming regions in M31 and the nearby spiral galaxy M101 are used as inputs to the self-organizing map. Clustering the M31 regions in the feature space reveals some (anti)-correlations between the properties the galaxy, which are not apparent when considering data from all regions in the galaxy. The self-organizing map can be used to predict star formation rates for spatially-resolved regions in galaxies using other properties of those regions. I also apply the self-organizing map method to spectral energy distributions of high-redshift galaxies. Template spectra made from galaxies with known morphological type are used to train self-organizing maps. The trained maps are used to classify a sample of galaxy spectral energy distributions derived from fitting models to photometry data of 142 high-redshift galaxies. The grouped properties of the classified galaxies are found to be more tightly correlated in mean values of age, specific star formation rate, stellar mass, and far-UV extinction than in previous studies

The State of the Art in Cartograms

Cartograms combine statistical and geographical information in thematic maps, where areas of geographical regions (e.g., countries, states) are scaled in proportion to some statistic (e.g., population, income). Cartograms make it possible to gain insight into patterns and trends in the world around us and have been very popular visualizations for geo-referenced data for over a century. This work surveys cartogram research in visualization, cartography and geometry, covering a broad spectrum of different cartogram types: from the traditional rectangular and table cartograms, to Dorling and diffusion cartograms. A particular focus is the study of the major cartogram dimensions: statistical accuracy, geographical accuracy, and topological accuracy. We review the history of cartograms, describe the algorithms for generating them, and consider task taxonomies. We also review quantitative and qualitative evaluations, and we use these to arrive at design guidelines and research challenges

Maneuvering the Dual Mode Manned/Automated Lunar Roving Vehicle, June 1969 - March 1970

Digital maps of hazards to movement for dual mode Lunar Roving Vehicl

Consumer flexibility in the power market

Tradisjonelt sett har kraftproduksjonen vært tilpasset kraftforbruket, men i en tid med økende elektrifisering, underskudd på kraft og økende kraftpriser er det viktig med forskning og kunnskap om metoder for å kunne møte fremtidens kraftbehov på en samfunnsøkonomisk måte. For å spare kostnader og natur fra utbygging av kraftnett, kan forbrukerfleksibilitet, der kraftforbrukene tilpasser seg produksjonen, bli viktig i fremtiden. Ved hjelp av en kvantitativ spørreundersøkelse til private strømforbrukere har denne oppgaven som formål å undersøke hvordan private strømforbrukere kan bidra til et mer fleksibelt kraftmarked. For å besvare problemstillingen er det spesifisert tre forskningsspørsmål. Det første forskningsspørsmålet undersøker sammenhengen mellom strømpris og fleksibilitet hos respondentene. Resultatene viser at det er en signifikant sammenheng mellom strømpris og hvor villig respondentene er til å spare strøm, og hvor mye de følger med på variasjon i strømpris. Det andre forskningsspørsmålet undersøker hvor mye kunnskap respondentene har om eget strømforbruk. Resultatene viser at mange har kunnskap om hva som er effektive måter å spare strøm på, men at det er kunnskapshull i hvor mye hvert av tiltakene faktisk utgjør på strømregningen. Høyere kunnskap om hvilke tiltak som gir mest økonomisk gevinst for strømforbrukerne kan bidra til økt motivasjon for å redusere strømforbruket. Det tredje forskningsspørsmålet undersøker hvordan elektriske biler kan bidra til et mer fleksibelt kraftmarked i fremtiden. Vehicle-to-grid ser ut til å være mest aktuell i fremtiden, der elbiler bidrar i markedet via en tredjeparts aggregator. I dag er ikke forbrukerfleksibilitet en pålitelig ressurs til fleksibilitet i kraftmarkedet, men forskning og tilrettelegging kan gjøre det viktig i fremtiden.Traditionally, power production has been adapted to power consumption, but in a time of increasing electrification, power deficits and rising power prices, it is important to conduct research and knowledge about methods to meet future power needs in a socio-economic way. To save costs and nature from the development of the power grid, consumer flexibility, where power consumption adapts to production, may be important in the future. Using a quantitative survey to private electricity consumers, this task aims to investigate how private electricity consumers can contribute to a more flexible power market. To answer this, three research questions have been specified. The first research question examines the relationship between electricity prices and flexibility among respondents. The results show that there is a significant correlation between electricity prices and how willing respondents are to save electricity, and how much they pay attention to variations in electricity prices. The second research question examines how much knowledge respondents have about their own electricity consumption. The results show that many have knowledge about effective ways to save electricity, but there is a knowledge gap for the consumers in how much each of the measures amounts to on their electricity bills. Better knowledge about which measures provide the highest financial savings for consumers can contribute to increased motivation to reduce electricity consumption. The third research question concerns whether electric cars can contribute to a more flexible power market in the future. Owners of private electric cars can contribute to a more flexible power market, but this must be facilitated. Vehicle-to-grid is an upcoming technology which seems to be most promising if the consumer can take part in the flexibility market via a third-party aggregator. Today, consumer flexibility is not a reliable source, but research and facilitation can make it important in the future. Knowledge and facilitation about costumer flexibility can save society considerable financial costs in the development of power and power grids