Purpose - The aim of the research project which resulted in this work is to achieve a cost-effective approach for instantaneous hyperspectral imaging. Design/methodology/approach - This paper presents a simulation study and an experimental evaluation of a novel imaging spectroscopy technique, where multi-channel image data are acquired instantaneously and transformed into spectra by using a statistical modelling approach. A digital colour camera equipped with an additional colour filter array was used to acquire an instantaneous single image that was demosaicked to generate a multi-channel image. A statistical transformation approach was employed to convert this image into a hyperspectral one. Findings - The feasibility of this method was investigated through extensive simulation and experimental tasks where promising results were obtained. Practical implications The small size of the initially acquired single instantaneous image makes this approach useful for applications where video-rate hyperspectral imaging is required. Originality/value - For the first time, a simplified prototype of this novel imaging spectroscopy technique was built and evaluated experimentally. And the results were compared with those of a more ideal simulation study. Recommendations for how to improve the prototype were also suggested as a result of the comparison between the simulation and the prototype evaluation results.
In this paper, we investigate the physics of the positron annihilation process, which occurs in a PET imaging system. In particular, the diffusion of beta particles (positrons) within water was addressed. Beta particles are emitted isotropically from the same source point with random directions and randomly chosen energy levels. After traversing a certain distance within water, beta particles lose a certain amount of its energy. The inelastic collisions with atomic electrons are mainly responsible for the energy dissipation of charged particles, such as electrons and positrons (that have low mass). The energy loss rate due to inelastic process is estimated by using the Beta-Bloch formula. These results help in understanding how to develop and implement a computationally efficient Monte Carlo Simulation of the positron annihilation process.
In this study, we present the exact solution of certain fractional partial differential equations (FPDE) by using a modified homotopy perturbation method (MHPM).The exact solutions are constructed by choosing an appropriate initial approximation and only one term of the series obtained by MHPM. The exact solutions for initial value problems of FPDE are analytically derived. The methods introduced an efficient tool for solving a wide class of time-fractional partial differential equations.
In this study, the Homo-Separation of Variables method is introduced to find the exact solution of somecoupled nonlinear partial differential equations. This analytical method is a new combination of two powerfuland popular methods; namely the homotopy perturbation method (HPM) and the separation of variables method.The exact solution is constructed by choosing an appropriate initial approximation in addition to retaining onlythe first term of the series obtained by HPM. The proposed method is capable of reducing the computational loadconsiderably when compared to other classical method.
Distributed authorization provides the ability to control access to resources spread over the Internet. Typical authorization systems consider a range of security information like user identities, role identities or even temporal, spatial and contextual information associated with the access requestor. However, the ability to include computing platform related information has been quite limited due to constraints in identification and validation of platforms when distributed. Trusted computing is an exciting technology that can provide new ways to bridge this gap. In this paper, we provide the first steps necessary to achieving distributed authorization using trusted computing platforms. We introduce the notion of a Property Manifest that can be used in the specification of authorization policies. We provide an overview of our authorization architecture, its components and functions. We then illustrate the applicability of our system by implementing it in a Web service oriented architecture.