Rotation Averaging and Strong Duality

In this paper we explore the role of duality principles within the problem of rotation averaging, a fundamental task in a wide range of computer vision applications. In its conventional form, rotation averaging is stated as a minimization over multiple rotation constraints. As these constraints are non-convex, this problem is generally considered challenging to solve globally. We show how to circumvent this difficulty through the use of Lagrangian duality. While such an approach is well-known it is normally not guaranteed to provide a tight relaxation. Based on spectral graph theory, we analytically prove that in many cases there is no duality gap unless the noise levels are severe. This allows us to obtain certifiably global solutions to a class of important non-convex problems in polynomial time. We also propose an efficient, scalable algorithm that out-performs general purpose numerical solvers and is able to handle the large problem instances commonly occurring in structure from motion settings. The potential of this proposed method is demonstrated on a number of different problems, consisting of both synthetic and real-world data

From Apprenticeship Genres to Academic Literacy: Problematising Students’ and Teachers’ Perceptions of Communication Activities in an ICL Environment

Comparatively little research has been done on students’ perceptions of communication and communication activities in integrated content and language (ICL) environments. In the present study, student statements about communication and communication activities have been collected via interviews and surveys from students attending a mechanical engineering programme in Sweden. These statements are compared with statements from content teachers at the same programme. Results suggest that students and teachers share a common perspective that communication activities should address a couple of apprenticeship genres that students will use in their future professions. Consequently, there seem to be good reasons for identifying and practising the use of apprenticeship genres. However, the focus on a few genres is problematised as some students show frustration when encountering unfamiliar genres. The article therefore also discusses the potential need for a role where communication teachers facilitate communication activities such that students enhance their perceptions of communication and communication activities in order to better prepare themselves for addressing various types of communicative situations

The Data Driven Decision RACE in eRetailing

This study takes a customer centric approach to investigate small eRetailers’ data driven decisions. The research is based on an edited version of Chaffey and Smith´s (2013) RACE framework and an edited version of the business analytics framework by Delen and Demirkan (2012a), divided in knowledge and data driven decision-making. By combining these two frameworks we create the Data Driven Decision RACE model. The empirical research is a survey among small Finnish eRetailers. The findings indicate that a majority of the studied eRetailers do analyze data and understand customer online behavior especially in the Reach and Engage stages of the Data Driven Decision RACE model. However, the study also indicates that the data driven decision-making is fairly low within all three stages of the model, which implies that small eRetailers primarily rely on experience and gut instinct rather than on customer data when they make decisions concerning their online activities

A description of an e-Commerce Lab in Finland

International online retail stores are increasingly challenging Finnish retailers. In order to strengthen the Finnish e‐retailing competence and to educate the retailers of tomorrow an e‐Commerce Lab was created. The Lab is the first of its kind in Finland and it is built around a concept that we call “reality‐based simulation before a live audience”. This paper describes the e‐Commerce Lab, shows the simulated business processes and provides lessons learned on what is gained by setting up an e‐ Commerce Lab together with different stakeholders of e‐Commerce in Finland. We also propose some initial thoughts on how to further develop the Lab

Smoothing out peaks of ranwather flood in the courtyards : with open stormwather system

Att drabbas av översvämningar är kostsamt både för den enskilde och för samhället. I takt med städers tillväxt och klimatförändringar förväntas befintliga ledningar som omhändertar dagvatten att överbelastas om inga åtgärder vidtas. Ett sett att minska risken för översvämningar är att omhänderta en del av dagvattnet via öppna dagvattensystem. Detta system fördröjer och reducerar mängden dagvatten men har fler fördelar så som rening och estetiska värden. Nedan beskrivs dessa öppna dagvattensystem och 11 bostadsgårdar undersökts i en fallstudie där förslagna åtgärder redovisas. Alla bostadsgårdar kan tilldelas förslag på olika dagvattenlösningar. Hur stor andel av dagvattnet som kan omhändertas i öppna dagvattensystem beror på hur stora anläggningar det finns möjlighet att bygga, på den specifika platsen samt topografiska och hydrologiska förutsättningar

Samhällsekonomiska vinster med regionala fjärrvärmenät, (En fallstudie på västra Skåne)

Syftet var att undersöka vilka samhällsekonomiska vinster som kan fås utav regionala nät ur ett ekonomiskt, miljömässigt och socialt perspektiv. Projektet syftade också till att utreda var det finns förutsättningar för regionala nät och utnyttjande av spillvärme samt vilka hinder som finns. För att utreda vilka vinster som kan uppnås skapades två olika modeller som sedan jämfördes.Målsättning var att projektet skulle resultera i en metodik som kan användas för att beskriva de förmodade samhällsekonomiska vinsterna med regionala nät. Metodiken skulle vara av sådan karaktär att den kan tillämpas på fler regionala nät än det för studien undersökta området

Sustainable Writing Support: A Campus-wide Module to Support Bachelor Thesis Writing at a University of Technology

Higher education is today characterised by increasing student groups and high pressure on teaching staff. In these circumstances, it may be difficult to provide appropriate scaffolding of activities that many students find challenging, for example, academic and discipline-specific writing. It may also be difficult to align such support with principles associated with effective learning. In this paper, we present the design of the bachelor thesis writing support for students at a university of technology. The support is delivered by a communication division and reaches approximately 900 students each year. The paper describes the principles guiding the design and use results from a student survey to illuminate the challenges and affordances of the approach. The survey results show that students appreciate the module and its focus on dialogic feedback, student engagement and student activity. Our results also show that one of the challenges for some students is to negotiate advice from multiple sources, primarily content supervisors and writing staff. Despite such challenges, the design is an example of a sustainable, large-scale writing module based on research on feedback and learning

Alternative promoter usage of the membrane glycoprotein CD36

BACKGROUND: CD36 is a membrane glycoprotein involved in a variety of cellular processes such as lipid transport, immune regulation, hemostasis, adhesion, angiogenesis and atherosclerosis. It is expressed in many tissues and cell types, with a tissue specific expression pattern that is a result of a complex regulation for which the molecular mechanisms are not yet fully understood. There are several alternative mRNA isoforms described for the gene. We have investigated the expression patterns of five alternative first exons of the CD36 gene in several human tissues and cell types, to better understand the molecular details behind its regulation. RESULTS: We have identified one novel alternative first exon of the CD36 gene, and confirmed the expression of four previously known alternative first exons of the gene. The alternative transcripts are all expressed in more than one human tissue and their expression patterns vary highly in skeletal muscle, heart, liver, adipose tissue, placenta, spinal cord, cerebrum and monocytes. All alternative first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins. The alternative promoters lack TATA-boxes and CpG islands. The upstream region of exon 1b contains several features common for house keeping gene and monocyte specific gene promoters. CONCLUSION: Tissue-specific expression patterns of the alternative first exons of CD36 suggest that the alternative first exons of the gene are regulated individually and tissue specifically. At the same time, the fact that all first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins may suggest that the alternative first exons are coregulated in this cell type and environmental condition. The molecular mechanisms regulating CD36 thus appear to be unusually complex, which might reflect the multifunctional role of the gene in different tissues and cellular conditions

Produktionsjämförelse av genetiskt förädlad vårtbjörk med finskt och svenskt ursprung

Genetisk förädling av ett trädslag innebär förbättring av tillväxtegenskaper och förbättring av kvalitén, det kan även leda till bättre anpassning till miljön vilket är viktigt då klimatet ändras. I Sverige har förädlingen av barrträd lett till högre avkastning av skogsproduktion, men för björk finns endast förädlat material från ett första generationens plantage i södra Sverige. Finland däremot har sedan 60-talet producerat förädlade björkfrön och detta har pågått i flera generationer. 1997 anlade Skogforsk ett trädslagsförsök i syfte att jämföra finska björkfrön med de svenska. Försöket anlades på fyra olika platser i Sverige, Norrbotten, Västerbotten, Västernorrland och Värmland. Femton olika frösorter av både glas- och vårtbjörk samt med olika grad av förädling planterades. Syftet med denna studie var att analysera de mätdata som detta försök har genererat under de första 20 åren och endast för vårtbjörk. Det som har analyserats är om den högre förädlingsgraden hos Finlands material ger upphov till positiva skillnader när det gäller produktionsegenskaper. Resultatet påvisar att det finska materialet växer signifikant bättre på höjden på försökets tre sydligaste lokaler. Finska materialet växer också bättre på diametern på samtliga lokaler men är endast statistiskt signifikant på en av de fyra lokalerna. Däremot kan inga signifikanta skillnader i kvalitativa egenskaper påvisas mellan olika de olika sorterna. Slutsatsen blir därmed att det finska materialet växer bättre utan att vara sämre vad gäller kvalitén och därmed erhåller bättre produktionsegenskaper.Tree breeding aims to improve tree growth and improved quality of a chosen species, it can also lead to better adaption to the environment which is important due to climate changes. In Sweden tree breeding of conifers has led to increased incomes in the forestry industry, but for birch there is only bred material from the first generation in the south. Finland on the other hand has produced improved birch-seeds since around 1960 and during these years they have been doing birch-breeding for some generations. In 1997 Skogforsk set up a test to compare Finnish birch-seeds to Swedish ones. This test was set up on different locations in Sweden, Norrbotten, Västerbotten, Västernorrland and Värmland. Fifteen different types of both downy- and silverbirch. The purpose of this study was to analyse the data this test has produced over the first 20 years and only for the silverbirch. In the study the breeding grade was analysed and if the Finnish material, with a higher breeding grade than the Swedish material, would give positive effects on tree growth and quality. The result shows that the Finnish seeds grow significantly better on three of the four sites of the test. The diameter was also bigger on every local but only a significant difference on one of four locals. On the other hand, no differences can be shown on quality. The conclusion is therefore that the Finnish material grows faster but does not have worse quality therefore it holds better attributes for production