| 1. |
- Bin, Jiang, 1965-, et al.
(författare)
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Automatic generation of the axial lines of urban environments to capture what we perceive
- 2010
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Ingår i: International Journal of Geographical Information Science. - London : Taylor & Francis Group. - 1365-8816 .- 1365-8824 .- 1362-3087. ; 24:4, s. 545-558
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Tidskriftsartikel (refereegranskat)abstract
- Based on the concepts of isovists and medial axes, we developed a set of algorithms that can automatically generate axial lines for representing individual linearly stretched parts of open space of an urban environment. Open space is the space between buildings, where people can freely move around. The generation of the axial lines has been a key aspect of space syntax research, conventionally relying on hand-drawn axial lines of an urban environment, often called axial map, for urban morphological analysis. Although various attempts have been made towards an automatic solution, few of them can produce the axial map that consists of the least number of longest visibility lines, and none of them really works for different urban environments. Our algorithms provide a better solution than existing ones. Throughout this paper, we have also argued and demonstrated that the axial lines constitute a true skeleton, superior to medial axes, in capturing what we perceive about the urban environment.
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| 2. |
- Petersson, Jesper, 1974
(författare)
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Geographies of eHealth: Studies of Healthcare at a Distance
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis examines the proliferation of healthcare services using information and communication technology to overcome spatial and temporal obstacles. These services are given such names as telemedicine and telecare, which are sometimes grouped together as telehealthcare under the umbrella term eHealth. My main argument is that a prevalent and overoptimistic rhetoric of how the possibilities of digitalization are expected to produce a homogenous and ubiquitous healthcare space conceals many of the spatiotemporal complexities involved in introducing telehealthcare and in the overall organizing of healthcare. To counteract such simplifications, I contend that we need a relational understanding of the technical and the geographical as always nested in the social and vice versa. With such an approach, it is arguably possible to begin to tease apart the many spatiotemporal entanglements of these innovations and to trace their political ramifications. This position is developed by integrating perspectives from science and technology studies with insights from human geography. The four constituent papers of this thesis pursue this argument in qualitatively grounded case studies of telehealthcare and its geographies. Paper I looks at various initiatives for fetal tele-ultrasonography, demonstrating that this practice cannot be reduced to a mere transparent relay for the speedy transmission of digital information across space and time. The paper investigates how its introduction could affect medical knowledge production, power hierarchies, and subject positions, for example, the status attributed to the fetal figure. Paper II traces Swedish transformations of telehealthcare. The use of telemedicine to reach those outside medicine’s range has arguably been accompanied by efforts to achieve intra-organizational streamlining via telemedicine. This process has continued with the emergence of telecare for personal use directed toward the overlapping groups of the elderly people and patients with chronic conditions. I contend that this shift can be understood through a geographical lens as attempts to save space and time by keeping as many patients as possible out of costly hospitalization and preventing them from engaging scarce specialist resources. Paper III compares four telemedicine projects in Sweden. In detailing how the purpose of practicing telemedicine differed between these projects in relation to, for example, the specifics of distance, care availability, and treated medical conditions, the paper demonstrates the existence of many versions of telemedicine. Whereas this fluidity could further the spread of telemedicine, it could also cause problems. To various actors wanting to use telemedicine in a homogenous and fixed way for national streamlining purposes, this diversity has generated confusion when they wished to align telemedicine in a preferred direction. The paper concludes that technology travels best when it can contain both fluid and fixed relationships. Paper IV argues that, whatever is claimed about creating a space- and time-independent healthcare by means of telehealthcare, the use of telecare to connect the standardized spaces of healthcare with the fluid everyday lives of elderly people and patients with chronic conditions actually works by unfolding new spaces of visibilities and establishing new temporalities as well. By investigating these spatiotemporalities, I demonstrate how these applications draw together discourses on individual freedom with medically derived algorithms and concerns about how to make best use of scarce healthcare resources.
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| 3. |
- Navas, Byron, et al.
(författare)
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On providing scalable self-healing adaptive fault-tolerance to RTR SoCs
- 2014
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Ingår i: Proceedings of ReConFigurable Computing and FPGAs (ReConFig), 2014 International Conference on. - 9781479959440 ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- The dependability of heterogeneous many-core FPGA based systems are threatened by higher failure rates caused by disruptive scales of integration, increased design complexity, and radiation sensitivity. Triple-modular redundancy (TMR) and run-time reconfiguration (RTR) are traditional fault-tolerant (FT) techniques used to increase dependability. However, hardware redundancy is expensive and most approaches have poor scalability, flexibility, and programmability. Therefore, innovative solutions are needed to reduce the redundancy cost but still preserve acceptable levels of dependability. In this context, this paper presents the implementation of a self-healing adaptive fault-tolerant SoC that reuses RTR IP-cores in order to self-assemble different TMR schemes during run-time. The presented system demonstrates the feasibility of the Upset-Fault-Observer concept, which provides a run-time self-test and recovery strategy that delivers fault-tolerance over functions accelerated in RTR cores, at the same time reducing the redundancy scalability cost by running periodic reconfigurable TMR scan-cycles. In addition, this paper experimentally evaluates the trade-off of the implemented reconfigurable TMR schemes by characterizing important fault tolerant metrics i.e., recovery time (self-repair and self-replicate), detection latency, self-assembly latency, throughput reduction, and increase of physical resources.
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| 4. |
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| 5. |
- Buehler, Stefan A., et al.
(författare)
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Efficient radiative transfer simulations for a broadband infrared radiometer—Combining a weighted mean of representative frequencies approach with frequency selection by simulated annealing
- 2010
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Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier BV. - 0022-4073 .- 1879-1352. ; 111:4, s. 602-615
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Tidskriftsartikel (refereegranskat)abstract
- We present a method to efficiently simulate the measurements of a broadband infrared instrument. The High Resolution Infrared Radiation Sounder (HIRS) instrument is used as example to illustrate the method. The method uses two basic ideas. Firstly, the channel radiance can be approximated by a weighted mean of the radiance at some representative frequencies, where the weights can be determined by linear regression. Secondly, a near-optimal set of representative frequencies can be found by simulated annealing.The paper does not only describe and analyze the method, it also describes how the method was used to derive optimized frequency grids for the HIRS instruments on the satellites TIROS N, NOAA 6-19, and Metop A. The grids and weights, as well as the optimization algorithm itself are openly available under a GNU public license.
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| 6. |
- Eriksson, Patrick, 1964, et al.
(författare)
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On cloud ice induced absorption and polarisation effects in microwave limb sounding
- 2011
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 4:6, s. 1305-1318
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Tidskriftsartikel (refereegranskat)abstract
- Microwave limb sounding in the presence of ice clouds was studied by detailed simulations, where clouds and other atmospheric variables varied in three dimensions and the full polarisation state was considered. Scattering particles were assumed to be horizontally aligned oblate spheroids with a size distribution parameterized in terms of temperature and ice water content. A general finding was that particle absorption is significant for limb sounding, which is in contrast to the down-looking case, where it is usually insignificant. Another general finding was that single scattering can be assumed for cloud optical paths below about 0.1, which is thus an important threshold with respect to the complexity and accuracy of retrieval algorithms. The representation of particle sizes during the retrieval is also discussed. Concerning polarisation, specific findings were as follows: Firstly, no significant degree of circular polarisation was found for the considered particle type. Secondly, for the +/- 45 degrees polarisation components, differences of up to 4 K in brightness temperature were found, but differences were much smaller when single scattering conditions applied. Thirdly, the vertically polarised component has the smallest cloud extinction. An important goal of the study was to derive recommendations for future limb sounding instruments, particularly concerning their polarisation setup. If ice water content is among the retrieval targets (and not just trace gas mixing ratios), then the simulations show that it should be best to observe any of the +/- 45 degrees and circularly polarised components. These pairs of orthogonal components also make it easier to combine information measured from different positions and with different polarisations
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| 7. |
- Eriksson, Anders
(författare)
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Quasi-static simulations of thin space membranes, aiming at stability analyses of balloon-like structures
- 2011
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Ingår i: ECCOMAS Thematic Conference - COMPDYN 2011.
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the evaluation of quasi-static equilibrium solutions for inflatable space membrane structures, such as balloons. A flat linearly interpolated triangular element is used for simulations, with a Mooney-Rivlin hyper-elastic material model, with variable constitutive constants. A compressible medium is used to introduce a one-parametric over-pressure loading within the membrane. Complex path-following procedures are used to find generalized equilibrium paths, with different parameterizations. Numerical examples show that the methods developed can give information on the stability of the structures, but that the medium and means for introducing the internal pressure is of importance for the interpretation of stability.
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| 8. |
- Marcus, Lars, 1962, et al.
(författare)
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Can spatial form support urban ecosystem services: Developing descriptions and measures to capture the spatial demands for pollination using the framework of space syntax
- 2014
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Ingår i: A|Z ITU Journal of Faculty of Architecture. - 1302-8324. ; 11:2, s. 255-270
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Tidskriftsartikel (refereegranskat)abstract
- For sustainable urban development the idea of ecosystem services (ESS) is crucial, since it pinpoints how cities are dependent on local ecosystems and the wide range of services they provide for their welfare and survival. Pollination is an essential ESS for the majority of food production in the world and therefore also represents a tremendous monetary value that is provided by ecosystems for free. That wild pollinators are facing increasing threats due to urbanization and habitat fragmentation is therefore a distressing development. At the same time, it is also pointed out how cities have a great potential to sustain pollinator populations if properly designed and managed. However, the role of spatial form in supporting ecosystems services has so far not been studied. This is unfortunate, since it is at this scale that urban designers need knowledge if they are to support ESS. This paper presents, firstly, a conceptual discussion on the topic of spatial form of ESS and, secondly, a principal description of a methodological approach in which we propose to capture the spatial demands for pollination by developing descriptions and measures used in the framework of Space syntax. Thirdly, some preliminary results from a study in Stockholm will be presented as the ground for a discussion about the principal potentials of a spatial morphology of urban ecosystems.
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| 9. |
- Xu, Lei, 1988, et al.
(författare)
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Analysis of an Intercooled Recuperated Aero-engine
- 2011
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Ingår i: ISABE 2011 Proceedings, ISABE-2011-1318.
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Konferensbidrag (refereegranskat)abstract
- The multi-disciplinary tool TERA2020 is employed to explore the design space of the Intercooled Recuperated Aero-engine being studied in the NEWAC project. To have a better understanding of the design space, a parametric analysis was conducted. This allows selecting of an engine close to optimal performance. Within the constraints, a 4.61% of fuel saving was observed compared to the baseline engine.
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| 10. |
- Bannova, Olga, 1964, et al.
(författare)
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TECHNOLOGY TRANSFER: CURRENT TRENDS IN INCORPORATING NEW TECHNOLOGIES INTO HOUSING INDUSTRY
- 2014
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Ingår i: 65th International Astronautical Congress, Proceedings.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In current world technological improvements and innovations are inseparable from everyday lifestyles everywhere around the world. There are some obvious and not so obvious correlations and analogies between approaches to sustainable living in space and on earth. These environments have many similar kinds of technical and operational priorities. Key among these are needs for appropriate transportation and construction systems, efficient energy, effective and environmentally-responsive waste management and life support systems, maintenance and repair provisions, and emergency accommodations. Space technologies have been and continue being implemented in housing and construction industry. Understanding current problems and challenges in construction and housing helps to form and outline strategies and techniques those industries require to be developed and implemented in order to meet sustainability criteria and help to shape responsible living practices. This paper investigates levels of feasibility of making cutting edge technologies be a part of our everyday life. To do so several common for space applications techniques are compared and analyzed.
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