Spin-Dynamics in Cold Gases of 87Rb and Atomic Hydrogen. The spins they are a-changin’

In this thesis the dynamics of cold gaseous atoms is studied. Two different atomic species and two different experimental techniques have been used. In the first part of the thesis experiments with Bose-Einstein condensates of Rb-87 are presented. In these experiments the methods of laser cooling and magnetic trapping of atoms were utilized. An atom chip was used as the experimental technique for implementation of magnetic trapping. The atom chip is a small integrated instrument allowing accurate and detailed manipulation of the atoms. The experiments with Rb-87 probed the behaviour of a falling beam of atoms outcoupled from the Bose-Einstein condensate by electromagnetic field induced spin flips. In the experiments a correspondence between the phases of the outcoupling radio frequency field and the falling beam of atoms was found. In the second part of the thesis experiments of spin dynamics in cold atomic hydrogen gas are discussed. The experiments with atomic hydrogen are conducted in a cryostat using a dilution refrigerator as the cooling method. These experiments concentrated on explaining and quantifying modulations in the electron spin resonance spectra of doubly polarized atomic hydrogen. The modifications to the previous experimental setup are described and the observation of electron spin waves is presented. The observed spin wave modes were caused by the identical spin rotation effect. These modes have a strong dependence on the spatial profile of the polarizing magnetic field. We also demonstrated confinement of these modes in regions of strong magnetic field and manipulated their spatial distribution by changing the position of the field maximum.

Peltipoliisista hengenpelastajaksi : Automaattisen liikenneturvallisuusvalvonnan tarveselvitys 2011 – 2015

Työssä laadittiin automaattisen liikenneturvallisuusvalvonnan kehittämis- ja investointisuunnitelma vuosille 2011-2015 Varsinais-Suomen ja Satakunnan maantieverkolle. Suunnitelmaan kuului nykyisen toimintamallin ja kehittämistarpeiden arviointi sekä vuosina 2011-2015 toteutettavien automaattivalvontajaksojen ja hankkeiden priorisointi. Lisäksi työssä kuvattiin Ruotsissa käytössä olevaa automaattivalvontatekniikkaa ja -toimintamallia sekä esitettiin toimenpide-ehdotuksia automaattivalvonnan hyväksyttävyyden lisäämiseksi. Nykyistä toimintamallia ja automaattivalvonnan kehittämistarpeita arvioitiin asiantuntijahaastattelujen perusteella. Asiantuntijat pitivät nykyistä toimintamallia pääasiassa toimivana ja tehokkaana, sillä suhteellisen pienillä kustannuksilla on päästy tehokkaisiin tuloksiin. Automaattivalvonnassa on kuitenkin asiantuntijoiden mielestä vielä kehitettävää ja Ruotsin toimintamallia pidettiin hyvänä suuntana ja esimerkkinä. Suurimpina kehittämiskohteina pidettiin tekniikan kehittämistä sekä tiedon käsittelyn nopeuttamista ja automatisointia, mikä lisäisi poliisin resursseja valvonnan suorittamiseen. Vuosina 2011-2015 toteutettavat automaattivalvotut tiejaksot priorisoitiin ensisijaisesti onnettomuustiheyksien, onnettomuusmäärien, Tarva-laskentatulosten, nopeustietojen ja liikennemäärien perusteella. Onnettomuustilastoista huomioitiin lähinnä henkilövahinkoon johtaneet onnettomuudet. Lisäksi Tarva-laskentatuloksia hyödynnettiin automaattivalvonnan vaikutusten ja tehokkuuden arvioinnissa. Haastateltujen asiantuntijoiden mielestä tärkeimmät keinot hyväksyttävyyden lisäämiseksi olivat valvonnan avoimuus, valvontalaitteiden näkyvyys ja jatkuva valvonnasta tiedottaminen. Tiedottamisella tuodaan esille järjestelmän hyödyt ja sen merkitys liikenteelle ja liikenneturvallisuuteen. Myös automaattivalvontakameran brändin muuttamista Ruotsin mallin mukaisesti turvallisuuskameraksi pidettiin hyvänä. Tässä työssä esitettiin suunnitelma automaattivalvonnan hyväksyttävyyden lisäämiseksi.

Telerobotics: Methodology for the Development of a Through-the-Internet Robotic Teleoperated System

This work presents a methodology for the development of Teleoperated Robotic Systems through the Internet. Initially, it is presented a bibliographical review of the Telerobotic systems that uses Internet as way of control. The methodology is implemented and tested through the development of two systems. The first is a manipulator with two degrees of freedom commanded remotely through the Internet denominated RobWebCam (http://www.graco.unb.br/robwebcam). The second is a system which teleoperates an ABB (Asea Brown Boveri) Industrial Robot of six degrees of freedom denominated RobWebLink (http://webrobot.graco.unb.br). RobWebCam is composed of a manipulator with two degrees of freedom, a video camera, Internet, computers and communication driver between the manipulator and the Unix system; and RobWebLink composed of the same components plus the Industrial Robot. With the use of this technology, it is possible to move far distant positioning objects minimizing transport costs, materials and people; acting in real time in the process that is wanted to be controller. This work demonstrates that the teleoperating via Internet of robotic systems and other equipments is viable, in spite of using rate transmission data with low bandwidth. Possible applications include remote surveillance, control and remote diagnosis and maintenance of machines and equipments.

Experimental validation of a 3-D vision-based measurement system applied to robot calibration

One of the problems that slows the development of off-line programming is the low static and dynamic positioning accuracy of robots. Robot calibration improves the positioning accuracy and can also be used as a diagnostic tool in robot production and maintenance. A large number of robot measurement systems are now available commercially. Yet, there is a dearth of systems that are portable, accurate and low cost. In this work a measurement system that can fill this gap in local calibration is presented. The measurement system consists of a single CCD camera mounted on the robot tool flange with a wide angle lens, and uses space resection models to measure the end-effector pose relative to a world coordinate system, considering radial distortions. Scale factors and image center are obtained with innovative techniques, making use of a multiview approach. The target plate consists of a grid of white dots impressed on a black photographic paper, and mounted on the sides of a 90-degree angle plate. Results show that the achieved average accuracy varies from 0.2mm to 0.4mm, at distances from the target from 600mm to 1000mm respectively, with different camera orientations.

Performance evaluation of 3D computer vision techniques

This work presents the implementation and comparison of three different techniques of three-dimensional computer vision as follows: • Stereo vision - correlation between two 2D images • Sensorial fusion - use of different sensors: camera 2D + ultrasound sensor (1D); • Structured light The computer vision techniques herein presented took into consideration the following characteristics: • Computational effort ( elapsed time for obtain the 3D information); • Influence of environmental conditions (noise due to a non uniform lighting, overlighting and shades); • The cost of the infrastructure for each technique; • Analysis of uncertainties, precision and accuracy. The option of using the Matlab software, version 5.1, for algorithm implementation of the three techniques was due to the simplicity of their commands, programming and debugging. Besides, this software is well known and used by the academic community, allowing the results of this work to be obtained and verified. Examples of three-dimensional vision applied to robotic assembling tasks ("pick-and-place") are presented.

Hot tool temperature analysis though infrared images

Textile manufacture occupies a prominent place in the national economy. Because of its importance researches have been made on the development of new materials, equipment and methods used in the production process. The cutting of textiles starts in the basic stage, to be followed by the process of the making of clothes and other articles. In the hot cutting of fabric, one of the variables of great importance in the control of the process is the contact temperature between the tool and the fabric. This work presents a technique for the measurement of the temperature based on the processing of infrared images. With this purpose, it was developed a system which is composed of an infrared camera, a framegrabber PC board and a software which analyses the punctual temperature in the cut area enabling the operator to achieve the necessary control of other variables involved in the process.

Indoor Localization Solutions for a Marine Industry Augmented Reality Tool

In this report are described means for indoor localization in special, challenging circum-stances in marine industry. The work has been carried out in MARIN project, where a tool based on mobile augmented reality technologies for marine industry is developed. The tool can be used for various inspection and documentation tasks and it is aimed for improving the efficiency in design and construction work by offering the possibility to visualize the newest 3D-CAD model in real environment. Indoor localization is needed to support the system in initialization of the accurate camera pose calculation and auto-matically finding the right location in the 3D-CAD model. The suitability of each indoor localization method to the specific environment and circumstances is evaluated.

Acceleration of Solar Energetic Particles in coronal shocks through self-generated turbulence

The acceleration of solar energetic particles (SEPs) by flares and coronal mass ejections (CMEs) has been a major topic of research for the solar-terrestrial physics and geophysics communities for decades. This thesis discusses theories describing first-order Fermi acceleration of SEPs through repeated crossings at a CME-driven shock. We propose that particle trapping occurs through self-generated Alfvén waves, leading to a turbulent trapping region in front of the shock. Decelerating coronal shocks are shown to be capable of efficient SEP acceleration, provided seed particle injection is sufficient. Quasi-parallel shocks are found to inject thermal particles with good efficiency. The roles of minimum injection velocities, cross-field diffusion, downstream scattering efficiency and cross-shock potential are investigated in detail, with downstream isotropisation timescales having a major effect on injection efficiency. Accelerated spectra of heavier elements up to iron are found to exhibit significantly harder spectra than protons. Accelerated spectra cut-off energies are found to scale proportional to (Q/A)^1.5, which is explained through analysis of the spectral shape of amplified Alfvénic turbulence. Acceleration times to different threshold energies are found to be non-linear, indicating that self-consistent time-dependent simulations are required in order to expose the full extent of acceleration dynamics. The well-established quasilinear theory (QLT) of particle scattering is investigated by comparing QLT scattering coefficients with those found via full-orbit simulations. QLT is found to overemphasise resonance conditions. This finding supports the simplifications implemented in the presented coronal shock acceleration (CSA) simulation software. The CSA software package is used to simulate a range of acceleration scenarios. The results are found to be in agreement with well-established particle acceleration theory. At the same time, new spatial and temporal dynamics of particle population trapping and wave evolution are revealed.

Elever syns på nätet : multimodala texter och autentiska mottagare

This study is based on the notion that all students are likely to have a computer of some kind as their primary tool at school within a few years. The overall aim is to contribute to the knowledge of what this development of computer-assisted multimodal text production and communication on and over the net may entail in a school context. The study has an abductive approach drawing on theory from Media and Communication studies and from Pedagogy - particularly on media peda-gogy, multimodality, storytelling, conversation research and deliberative democracy – and is based on a DBR project in three schools. The empirical data are retrieved from four school classes, school years 4 and 5, with good access to computers and digital cameras. The classes have used the class blogs to tell the blog visitors about their school work and Skype to communicate with other classes in Sweden and Tanzania. A variety of research methods was employed: content analysis of texts, observations with field notes and camera documentation, interviews with individual students, group interviews with teachers and students, and a small survey. The study is essentially qualitative, focusing on students’ different perceptions. A small quantitative study was conducted to determine if any factors and variables could be linked to each other and to enable comparisons of the surveyed group with other research results. The results suggest that more computers at school offer more opportunities for real-life assignments and the chance to secure an authentic audience to the students’ production; primarily the students’ parents and relatives, students in the same class and at other schools. A theoretical analysis model to determine the degree of reality and authenticity in various school assignments was developed. The results also indicate that having access to cameras for documenting various events in the classes and to an authentic audience can create new opportunities for storytelling that have not been practiced previously at school. The documentary photo invites a viewer into the present tense of the image and the location where the picture was taken, whoever took the picture. It is used by the students and here too, a model has been developed to describe this relationship. The study also focuses on the freedom of expression and democracy. One of the more unexpected findings is that the students in the study did not see that they can influence other people’s perceptions or change various power structures through communication on the web, neither in nor outside of school.

Från plåtpolis till livräddare : Behovsanalys för automatisk trafiksäkerhetskontroll 2011 – 2015

I det här arbetet utformades en utvecklings- och investeringsplan för automatisk trafiksäkerhetsövervakning för åren 2011-2015 för landsvägsnätet i Egentliga Finland och Satakunta. Planen innehåller analys av den nuvarande verksamhetsmodellen och förslag hur verksamhetsmodellen kunde förbättras samt förslag om vilka vägavsnitt som ska få automatisk övervakning och vilka projekt som ska prioriteras under åren 2011-2015. Vidare beskrivs i planen den automatiska övervakningsteknik och verksamhetsmodell som används i Sverige samt åtgärdsförslag för att öka den automatiska trafikövervakningens acceptans. Den nuvarande verksamhetsmodellen och behovet av att utveckla den automatiska trafikövervakningen har utvärderats på basis av intervjuer med experter. Experterna ansåg att den nuvarande verksamhetsmodellen i huvudsak är funktionell och effektiv, eftersom man med relativt små kostnader har uppnått effektiva resultat. Den automatiska trafikövervakningen måste dock fortfarande utvecklas och Sveriges verksamhetsmodell ansågs vara en bra förebild och ett gott exempel. De viktigaste utvecklingsområdena ansågs vara utveckling av tekniken, snabbare informationsbehandling och automatisering, vilket skulle öka polisens resurser att verkställa övervakningen. Vägavsnitten som ska få automatisk övervakning under åren 2011-2015 prioriterades främst på basis av olycksfrekvens, antal olyckor, Tarva-beräkningsresultat, hastighetsdata och trafikmängder. Av olycksstatistiken har man främst uppmärksammat personskadeolyckor. Tarva-beräkningarna användes också för att utvärdera den automatiska trafikövervakningens inverkan och effektivitet. Enligt de intervjuade experterna är öppenhet kring övervakningen, synlig övervakningsapparatur och kontinuerlig informationsförmedling bland de viktigaste sätten att öka acceptansen. Genom att informera för man fram systemets fördelar och dess betydelse för trafiksäkerheten. Att förändra övervakningskamerans varumärke till säkerhetskamera enligt Sveriges modell ansågs även vara bra. I detta arbete presenteras en plan för att utveckla acceptansen för automatisk trafiksäkerhetsövervakning.

Scalable algorithms for height field illumination

Global illumination algorithms are at the center of realistic image synthesis and account for non-trivial light transport and occlusion within scenes, such as indirect illumination, ambient occlusion, and environment lighting. Their computationally most difficult part is determining light source visibility at each visible scene point. Height fields, on the other hand, constitute an important special case of geometry and are mainly used to describe certain types of objects such as terrains and to map detailed geometry onto object surfaces. The geometry of an entire scene can also be approximated by treating the distance values of its camera projection as a screen-space height field. In order to shadow height fields from environment lights a horizon map is usually used to occlude incident light. We reduce the per-receiver time complexity of generating the horizon map on N N height fields from O(N) of the previous work to O(1) by using an algorithm that incrementally traverses the height field and reuses the information already gathered along the path of traversal. We also propose an accurate method to integrate the incident light within the limits given by the horizon map. Indirect illumination in height fields requires information about which other points are visible to each height field point. We present an algorithm to determine this intervisibility in a time complexity that matches the space complexity of the produced visibility information, which is in contrast to previous methods which scale in the height field size. As a result the amount of computation is reduced by two orders of magnitude in common use cases. Screen-space ambient obscurance methods approximate ambient obscurance from the depth bu er geometry and have been widely adopted by contemporary real-time applications. They work by sampling the screen-space geometry around each receiver point but have been previously limited to near- field effects because sampling a large radius quickly exceeds the render time budget. We present an algorithm that reduces the quadratic per-pixel complexity of previous methods to a linear complexity by line sweeping over the depth bu er and maintaining an internal representation of the processed geometry from which occluders can be efficiently queried. Another algorithm is presented to determine ambient obscurance from the entire depth bu er at each screen pixel. The algorithm scans the depth bu er in a quick pre-pass and locates important features in it, which are then used to evaluate the ambient obscurance integral accurately. We also propose an evaluation of the integral such that results within a few percent of the ray traced screen-space reference are obtained at real-time render times.

Ring Dark Solitons in Toroidal Bose-Einstein Condensates

In this Thesis, we study various aspects of ring dark solitons (RDSs) in quasi-two-dimensional toroidally trapped Bose-Einstein condensates, focussing on atomic realisations thereof. Unlike the well-known planar dark solitons, exact analytic expressions for RDSs are not known. We address this problem by presenting exact localized soliton-like solutions to the radial Gross-Pitaevskii equation. To date, RDSs have not been experimentally observed in cold atomic gases, either. To this end, we propose two protocols for their creation in experiments. It is also currently well known that in dimensions higher than one, (ring) dark solitons are susceptible, in general, to an irreversible decay into vortex-antivortex pairs through the snake instability. We show that the snake instability is caused by an unbalanced quantum pressure across the soliton's notch, linking the instability to the Bogoliubov-de Gennes spectrum. In particular, if the angular symmetry is maintained (or the toroidal trapping is restrictive enough), we show that the RDS is stable (long-lived with a lifetime of order seconds) in two dimensions. Furthermore, when the decay does take place, we show that the snake instability can in fact be reversible, and predict a previously unknown revival phenomenon for the original (many-)RDS system: the soliton structure is recovered and all the point-phase singularities (i.e. vortices) disappear. Eventually, however, the decay leads to an example of quantum turbulence; a quantum example of the laminar-to-turbulent type of transition.

Model-Based Tracking Initialization in Ship Building Environment

An augmented reality (AR) device must know observer’s location and orientation, i.e. observer’s pose, to be able to correctly register the virtual content to observer’s view. One possible way to determine and continuously follow-up the pose is model-based visual tracking. It supposes that a 3D model of the surroundings is known and that there is a video camera that is fixed to the device. The pose is tracked by comparing the video camera image to the model. Each new pose estimate is usually based on the previous estimate. However, the first estimate must be found out without a prior estimate, i.e. the tracking must be initialized, which in practice means that some model features must be identified from the image and matched to model features. This is known in literature as model-to-image registration problem or simultaneous pose and correspondence problem. This report reviews visual tracking initialization methods that are suitable for visual tracking in ship building environment when the ship CAD model is available. The environment is complex, which makes the initialization non-trivial. The report has been done as part of MARIN project.

INFLUENCE OF THE GLYPHOSATE FORMULATIONS ON WETTABILITY AND EVAPORATION TIME OF DROPLETS ON DIFFERENT TARGETS

ABSTRACTEfficiency of weed control can be increased if the herbicide formulation provides higher target coverage and evaporation time that enable an adequate distribution of herbicide on the target plant, allowing the absorption to continue even after the droplets evaporation. The aim of this research was to assess the influence of glyphosate formulations on the wetted area and evaporation time of droplets on different targets. Tests were conducted with droplets sizing from 500 μm containing three formulations of glyphosate (isopropylamine salt, ammonium salt and potassium salt) deposited on three surfaces, two leaves (Bidens pilosa and Cenchrus echinatus) and glass slides. Sequential images analyses were used to quantify the evaporation time and the wetted area. An experimental system was utilized that was composed of a droplet generator, a stereo microscope with a camera to capture images, as well as an environmental chamber controlled for temperature and relative humidity. The kind of glyphosate formulations and target surfaces are crucial in the wetted area and evaporation time. The isopropylamine salt decreased the wetted area and evaporation time when compared with ammonium salt and potassium salt for all the surfaces deposited on. Bidens pilosa allows an increased wetted area for all the glyphosate formulations when compared to Cenchrus echinatus and glass slides.

The renal and hepatic distribution of Bence Jones proteins depends on glycosylation: a scintigraphic study in rats

The aim of the present study was to evaluate renal and liver distribution of two monoclonal immunoglobulin light chains. The chains were purified individually from the urine of patients with multiple myeloma and characterized as lambda light chains with a molecular mass of 28 kDa. They were named BJg (high amount of galactose residues exposed) and BJs (sialic acid residues exposed) on the basis of carbohydrate content. A scintigraphic study was performed on male Wistar rats weighing 250 g for 60 min after iv administration of 1 mg of each protein (7.4 MBq), as the intact proteins and also after carbohydrate oxidation. Images were obtained with a Siemens gamma camera with a high-resolution collimator and processed with a MicroDelta system. Hepatic and renal distribution were established and are reported as percent of injected dose. Liver uptake of BJg was significantly higher than liver uptake of BJs (94.3 vs 81.4%) (P<0.05). This contributed to its greater removal from the intravascular compartment, and consequently lower kidney accumulation of BJg in comparison to BJs (5.7 vs 18.6%) (P<0.05). After carbohydrate oxidation, there was a decrease in hepatic accumulation of both proteins and consequently a higher renal overload. The tissue distribution of periodate-treated BJg was similar to that of native BJs: 82.7 vs 81.4% in the liver and 17.3 vs 18.6% in the kidneys. These observations indicate the important role of sugar residues of Bence Jones proteins for their recognition by specific membrane receptors, which leads to differential tissue accumulation and possible toxicity