Reconstruction of General Curves,Using Factorization and Bundle Adjustment

In this paper, we extend the notion of affine shape, introduced by Sparr, from finite point sets to curves. The extension makes it possible to reconstruct 3D-curves up to projective transformations, from a number of their 2D-projections. We also extend the bundle adjustment technique from point features to curves.The first step of the curve reconstruction algorithm is based on affine shape. It is independent of choice of coordinates, is robust, does not rely on any preselected parameters and works for an arbitrary number of images. In particular this means that, except for a small set of curves (e.g. a moving line), a solution is given to the aperture problem of finding point correspondences between curves. The second step takes advantage of any knowledge of measurement errors in the images. This is possible by extending the bundle adjustment technique to curves.Finally, experiments are performed on both synthetic and real data to show the performance and applicability of the algorithm.     

Rethinking competence systems for knowledge-based organizations

Existing competence systems are based on a rationalistic view of competence. While these competence systems might work in job-based organizations, we argue that in more dynamic settings, such as in knowledge-based organizations, the interest-informed actions that capture the emergent competencies of tomorrow require different types of information technology support. The main objective of this paper is to elaborate on the possibilities and implications of using interest-activated technology as a design rationale for competence systems. This paper is based on an action case study of an implemented interest-activated Intranet recommender system prototype at Volvo Information Technology AB in Gothenburg, Sweden. On the basis of how organizational members used this prototype to find information they were interested in, our research team was able to inquire into how personal interest, embodied in information-seeking activities, could be a means for identifying competence. Building on the relation between personal interest and competence, we discuss competence systems design and spell out explicit implications for managerial practice in knowledge-based organizations.     

High Order Finite Difference Approximations of Electromagnetic Wave Propagation Close to Material Discontinuities

Electromagnetic wave propagation close to a material discontinuity is simulated by using summation by part operators of second, fourth and sixth order accuracy. The interface conditions at the discontinuity are imposed by the simultaneous approximation term procedure. Stability is shown and the order of accuracy is verified numerically.     

Crafting interaction: The epistemology of modern programming

There is a long tradition in design of discussing materials and the craft of making artefacts. “Smart” and interactive materials affected what constitutes a material. Interaction design is a design activity that creates the appearance and behaviour of information technology, challenged by the illusiveness of interactive materials. With the increased design space of ubiquitous devices, designers can no longer rely on a design process based on known interaction idioms, especially for innovative highly interactive designs. This impedes the design process, because non-interactive materials, by which designers create sketches, storyboards, and mock-up prototypes, do not provide the essential talkbacks needed to make reliable assessments of the design characteristics. Without a well-defined design, the engineering process of artefacts has unclear ends, which are not encompassed in the rational epistemology of engineering. To value the experiential qualities of these artefacts, the prototypes need to be interactive and crafted in code. This paper investigates the materiality of information technology, specifically programming language code from which interactive artefacts are made. A study of users of programming languages investigates how they describe programming language code as a material. If you have a material, it is reasonable, because of the tradition in the material and craft fields, to say you have a craft. Thus, considering code a design material allows the metaphor of craft to be used for the activity of programming.     

Priorities of pedestrian protection—A real-life study of severe injuries and car sources

The aim of this study was to aid the optimisation of future, vehicle based, pedestrian injury countermeasures. The German In-Depth Accident Study (GIDAS) database was queried for pedestrians impacted by the front of a passenger car or van. A total of 1030 cases from 1998 to 2008 were studied including 161 severely (AIS3+) injured pedestrians. Considering the severe injuries, the most frequent injury mechanisms were “leg-to-front end”, “head-to-windscreen area”, “chest-to-bonnet area”, and “chest-to-windscreen area”. For children, a “head-to-bonnet area” impact was the second most common source of injury. With safety systems targeting these five injury mechanisms, 73% (95% confidence interval [CI], 65–81%) of the severely injured pedestrians would be provided protection from all of their vehicle-induced severe injuries. Omitting the windscreen area, this figure is decreased to 44% (CI, 36–53%). Furthermore, 31% of the surviving pedestrians were estimated to sustain a permanent medical impairment at any level. For more severe impairment, head was the dominating body region. The study shows that when developing countermeasures for the windscreen area to mitigate head injuries, attention should be paid to the structural parts of the windscreen area with a special focus on brain injuries. Finally, the incidence and risk of severe injury were derived as functions of impact speed for different body regions and injury sources.     

Use of Polyaminocarboxylic Acids as Hydrophilic Masking Agents for Fission Products in Actinide Partitioning Processes

During the partitioning of trivalent actinides from High Active Raffinate (HAR) solutions, most processes have to cope with an undesirable co-extraction of some of the fission products. Four hydrophilic complexing agents of the group of polyaminocarboxylic acids, namely EDTA, HEDTA, DTPA, and CTDA were tested and compared for their ability to complex fission products in a simulated PUREX raffinate solution, thereby preventing their extraction into an organic solvent. Several solvents, based on TODGA and the DIAMEX reference molecule DMDOHEMA, that are commonly known to show quite high Zr and Pd co-extraction, were studied. Our investigations ultimately resulted in a substitution of oxalic acid and HEDTA by cyclohexanediaminetetraacetic acid (CDTA). A small addition of this hydrophilic complexing agent to the feed decreased the distribution ratios of Zr from 100 to <0.01. The suppression of Pd was also very effective, resulting in >90% of the metal retained in the feed solution. The extraction of trivalent actinides and lanthanides was not negatively affected by the presence of CDTA. Furthermore, experiments with high concentrations of Zr proved the applicability of this new masking agent. The suppression of Zr and Pd extraction was also verified at a high Pu loading which makes CDTA as a masking agent attractive for grouped actinide extraction processes (GANEX) as well as DIAMEX-SANEX type separations.     

Experimental investigation of an industrial scale black liquor gasifier. 1. The effect of reactor operation parameters on product gas composition

A novel technology to mitigate the climate changes and improve energy security is Pressurized Entrained flow High Temperature Black Liquor Gasification (PEHT-BLG) in combination with an efficient fuel synthesis using the resulting syngas. In order to optimise the technology for use in a pulp and paper mill based biorefinery, it is of great importance to understand how the operational parameters of the gasifier affect the product gas composition. The present paper is based on experiments where gas samples were withdrawn from the hot part of a 3 MW entrained flow pressurized black liquor gasifier of semi industrial scale using a high temperature gas sampling system. Specifically, the influence of process conditions on product gas composition (CO₂, CO, H₂, CH₄, H₂S, and COS) were examined by systematically varying the operational parameters: system pressure, oxygen to black liquor equivalence ratio, black liquor flow rate to pressure ratio and black liquor pre-heat temperature. Due to the harsh environment inside the gasification reactor, gas sampling is a challenging task. However, for the purpose of the current study, a specially designed high temperature gas sampling system was successfully developed and used. The results, obtained from two separate experimental campaigns, show that all of the investigated operational parameters have a significant influence on the product gas composition and present valuable information about to the process characteristics.     

The Influence of Temperature on Oxide-Scale Formation during Erosion--Corrosion

Four steels (Fe2.25Cr1Mo, Fe9Cr1Mo, AISI 304, 353 MA) and one Ni-based superalloy (Inconel 625) were exposed in an erosion--corrosion test rig at the temperatures 20, 350, 550 and 700°C for 1 week. The atmosphere was air and the particle velocity 1.2 m/s. The composition and thickness of the developed surface layers were determined by Auger electron spectroscopy and X-ray photoelectron spectroscopy. The ferritic and Ni-based alloys investigated show a minimum in wastage rate around 350°C due to the development of a particle strengthened/toughened composite layer on the surface. The greatest wastage rates were measured at 700°C. Rapid diffusion paths created in the oxide from the particle bombardment results in the growth of oxide nodules at the oxide/metal-interface causing protruding oxide flakes which are chipped away. At this temperature the ferritic steel Fe9Cr1Mo is degraded to a larger extent than the austenitic steels.     

Thermal influence on torque transfer of wet clutches in limited slip differential applications

Wet clutches operating under low velocity and high load are studied with the aim of obtaining reliable models for the torque transfer during boundary lubrication conditions. A friction model which takes temperature, speed and nominal pressure into account is developed and used with temperature calculations to be able to simulate behavior of a wet clutch working in boundary lubrication regime. Predicted torque and temperatures from the model agree well with experimental data.