19 research outputs found

    Image reconstruction for Magnetic Particle Imaging using an Augmented Lagrangian Method

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    Magnetic particle imaging (MPI) is a relatively new imaging modality that images the spatial distribution of superparamagnetic iron oxide nanoparticles administered to the body. In this study, we use a new method based on Alternating Direction Method of Multipliers (a subset of Augmented Lagrangian Methods, ADMM) with total variation and l1 norm minimization, to reconstruct MPI images. We demonstrate this method on data simulated for a field free line MPI system, and compare its performance against the conventional Algebraic Reconstruction Technique. The ADMM improves image quality as indicated by a higher structural similarity, for low signal-to-noise ratio datasets, and it significantly reduces computation time. © 2017 IEEE

    BUSINNES MODEL OF CORS-TR (TUSAGA-AKTIF)

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    CORS-TR (TUSAGA-Aktif (Turkish National Permanent GNSS Network – Active)), serves location information at cm level accuracy in Turkey and TR Northern Cyprus in few seconds, where adequate numbers of GNSS satellites are observed and communication possibilities are present. No ground control points and benchmarks are necessary. There are 146 permanent GNSS stations within the CORS-TR System. Station data are transferred online to the main control center located in the Mapping Department of the General Directorate of Land Registry and Cadastre. CORS-TR System was established in 2008 and has been updated in software, hardware, communication and pricing areas from technical and administrative point of view in order to improve the system and provide better service to the users. Thus, the added value obtained from the CORS-TR System has been increased and contributed to the more efficient use of country resources. In this paper, how the technical, administrative and financial studies in the operation of the CORS-TR System were managed with a sustainable business model, studies for solving problems encountered in operating of the system, the cost / benefit analysis of the system and the sharing of experience gained from the perspective of how web-based applications are managed and the business model of the CORS-TR System are explained in detail

    Nonlinear chirped-pulse amplification of a solitonsimilariton laser to ~1 μJ at 1550 nm

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    We demonstrate all-fiber-integrated nonlinear CPA system operating at 1550 nm, seeded by a solitonsimilariton laser. Chirped 2-μJ pulses are compressed to 700-fs, 0.5-μJ pulses at 1 MHz. Amplifier output is through a strictly singlemode fiber. © OSA 2012

    Efficient sensing of single viruses and nanoparticles by nanomechanical sensors integrated with ion lenses

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    Nanoelectromechanical Systems (NEMS) resonators can be used to detect, weigh and identify single nanoparticles and viruses. Given their small footprint, however, NEMS are plagued by low analyte detection rate since the active sensing cross-sections to capture analyte particles is very small. Here we report on the development of an on-chip focusing lens operating in air and integrated with the NEMS sensor. The integrated system increases the capture efficiency by orders of magnitude, and allows for operation under ambient conditions to measure the mass of nanoparticles and virions. With this system, mass spectrum of nanoparticle samples and mammalian viruses at biologically relevant concentrations can be characterized within less than 30 minutes
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