16,129 research outputs found
Fast parallel volume visualization on cuda technology
In the medical diagnosis and treatment planning, radiologists and surgeons rely
heavily on the slices produced by medical imaging scanners. Unfortunately, most of
these scanners can only produce two dimensional images because the machines that
can produce three dimensional are very expensive. The two dimensional images from
these devices are difficult to interpret because they only show cross-sectional views
of the human structure. Consequently, such circumstances require highly qualified
doctors to use their expertise in the interpretation of the possible location, size or
shape of the abnormalities especially for large datasets of enormous amount of slices.
Previously, the concept of reconstructing two dimensional images to three
dimensional was introduced. However, such reconstruction model requires high
performance computation, may either be time-consuming or costly. Furthermore,
detecting the internal features of human anatomical structure, such as the imaging of
the blood vessels, is still an open topic in the computer-aided diagnosis of disorders
and pathologies. This study proposed, designed and implemented a visualization
framework named SurLens with high performance computing using Compute
Unified Device Architecture (CUDA), augmenting the widely proven ray casting
technique in terms of superior qualities of images but with slow speed. Considering
the rapid development of technology in the medical community, our framework is
implemented on Microsoft .NET environment for easy interoperability with other
emerging revolutionary tools. The Visualization System was evaluated with brain
datasets from the department of Surgery, University of North Carolina, United
States, containing 109 datasets of MRA, T1-FLASH, T2-Weighted, DTI and
T1-MPRAGE. Significantly, at a reasonably cheaper cost, SurLens Visualization
System achieves immediate reconstruction and obvious mappings of the internal
features of the human brain, reliable enough for instantaneously locate possible
blockages in the brain blood vessels without any prior segmentation of the datasets
Tasks, cognitive agents, and KB-DSS in workflow and process management
The purpose of this paper is to propose a nonparametric interest rate term structure model and investigate its implications on term structure dynamics and prices of interest rate derivative securities. The nonparametric spot interest rate process is estimated from the observed short-term interest rates following a robust estimation procedure and the market price of interest rate risk is estimated as implied from the historical term structure data. That is, instead of imposing a priori restrictions on the model, data are allowed to speak for themselves, and at the same time the model retains a parsimonious structure and the computational tractability. The model is implemented using historical Canadian interest rate term structure data. The parametric models with closed form solutions for bond and bond option prices, namely the Vasicek (1977) and CIR (1985) models, are also estimated for comparison purpose. The empirical results not only provide strong evidence that the traditional spot interest rate models and market prices of interest rate risk are severely misspecified but also suggest that different model specifications have significant impact on term structure dynamics and prices of interest rate derivative securities.
Tasks, cognitive agents, and KB-DSS in workflow and process management
The purpose of this paper is to propose a nonparametric interest rate term structure model and investigate its implications on term structure dynamics and prices of interest rate derivative securities. The nonparametric spot interest rate process is estimated from the observed short-term interest rates following a robust estimation procedure and the market price of interest rate risk is estimated as implied from the historical term structure data. That is, instead of imposing a priori restrictions on the model, data are allowed to speak for themselves, and at the same time the model retains a parsimonious structure and the computational tractability. The model is implemented using historical Canadian interest rate term structure data. The parametric models with closed form solutions for bond and bond option prices, namely the Vasicek (1977) and CIR (1985) models, are also estimated for comparison purpose. The empirical results not only provide strong evidence that the traditional spot interest rate models and market prices of interest rate risk are severely misspecified but also suggest that different model specifications have significant impact on term structure dynamics and prices of interest rate derivative securities.
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Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: NL
Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: N
Do Process Modelling Techniques Get Better? A Comparative Ontological Analysis of BPMN
Current initiatives in the field of Business Process Management (BPM) strive for the development of a BPM standard notation by pushing the Business Process Modeling Notation (BPMN). However, such a proposed standard notation needs to be carefully examined. Ontological analysis is an established theoretical approach to evaluating modelling techniques. This paper reports on the outcomes of an ontological analysis of BPMN and explores identified issues by reporting on interviews conducted with BPMN users in Australia. Complementing this analysis we consolidate our findings with previous ontological analyses of process modelling notations to deliver a comprehensive assessment of BPMN
What value do consumers really expect from Product Service Systems? : Reflections on how a different conception of value could facilitate the implementation of PSS in consumer markets
Purpose – This paper explores how PSS may create value in consumer markets in urban environment and how consumers value PSS beyond a narrow focus on functionality. Design/ methodology/approach – Within a case study of a use orientated PSS based on baby products, we conducted ten ethnographic interviews of current users of the scheme. Findings – Our data gives evidence that some of these products are important possessions for consumers’ identity construction. In contrast with highly visible products such as push-chairs, however, baby cots and car seats are seen by consumers from a more utilitarian perspective. Practical implications – The design of a PSS provision around products which are highly symbolic is problematic because of a need to fully understand the complex symbolism and hedonic value consumers attribute to these products. Originality /value – We fill a gap in PSS research by adopting a constructivist perspective to explore the multidimensional value consumers co-create around a baby products PSS.Non peer reviewedFinal Accepted Versio
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