1,606 research outputs found
Ball-Scale Based Hierarchical Multi-Object Recognition in 3D Medical Images
This paper investigates, using prior shape models and the concept of ball
scale (b-scale), ways of automatically recognizing objects in 3D images without
performing elaborate searches or optimization. That is, the goal is to place
the model in a single shot close to the right pose (position, orientation, and
scale) in a given image so that the model boundaries fall in the close vicinity
of object boundaries in the image. This is achieved via the following set of
key ideas: (a) A semi-automatic way of constructing a multi-object shape model
assembly. (b) A novel strategy of encoding, via b-scale, the pose relationship
between objects in the training images and their intensity patterns captured in
b-scale images. (c) A hierarchical mechanism of positioning the model, in a
one-shot way, in a given image from a knowledge of the learnt pose relationship
and the b-scale image of the given image to be segmented. The evaluation
results on a set of 20 routine clinical abdominal female and male CT data sets
indicate the following: (1) Incorporating a large number of objects improves
the recognition accuracy dramatically. (2) The recognition algorithm can be
thought as a hierarchical framework such that quick replacement of the model
assembly is defined as coarse recognition and delineation itself is known as
finest recognition. (3) Scale yields useful information about the relationship
between the model assembly and any given image such that the recognition
results in a placement of the model close to the actual pose without doing any
elaborate searches or optimization. (4) Effective object recognition can make
delineation most accurate.Comment: This paper was published and presented in SPIE Medical Imaging 201
Efficacy of Surrogate Measures in Performance-Based Design of Water Distribution Networks
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Raman and photoluminescence studies on thermally annealed porous silicon
We report Raman and Photoluminescence (PL) studies of porous silicon (PS) as a function of isochronal thermal annealing from room temperature to 900°C. The PL peak position and intensity show nonmonotonic variation with increasing temperature. The PL intensity first increases upto 100°C, then decreases till 550°C and recovers its intensity at 700 °C before it completely disappears at 800 °C. The red shifted asymmetric Raman line shape can be fitted by phonon confinement model along with the disordered silicon component. Our results clearly indicate that the origin of visible PL can be better explained by a new hybrid model which incorporates both nanostructures for quantum confinement and silicon complexes (such as SiHx and siloxene) and defects at Si/SiO2 interfaces as luminescent centres
Origin of visible photoluminescence from porous silicon as studied by Raman spectroscopy
In this paper we discuss the different models proposed to explain the visible luminescence in porous silicon (PS). We review our recent photoluminescence and Raman studies on PS as a function of different preparation conditions and isochronal thermal annealing. Our results can be explained by a hybrid model which incorporates both nanostructures for quantum confinement and silicon complexes (such as SiHx and siloxene) and defects at Si/SiO2 interfaces as luminescent centres
Unimpeded permeation of water through helium-leak-tight graphene-based membranes
Permeation through nanometer pores is important in the design of materials
for filtration and separation techniques and because of unusual fundamental
behavior arising at the molecular scale. We found that submicron-thick
membranes made from graphene oxide can be completely impermeable to liquids,
vapors and gases, including helium, but allow unimpeded permeation of water
(H2O permeates through the membranes at least 10^10 times faster than He). We
attribute these seemingly incompatible observations to a low-friction flow of a
monolayer of water through two dimensional capillaries formed by closely spaced
graphene sheets. Diffusion of other molecules is blocked by reversible
narrowing of the capillaries in low humidity and/or by their clogging with
water
Beneficiation of Manganese Ore Fines for the Production of Battery Grade MnO2
Though India is a leading producer of manganese ore, it is important battery grade manganese dioxide to meet the domestic requirements. The total consumption of manganese dioxide by 10 to 12 units of battery industry for the production of 1,214 million pieces of batteries per annum was around 21,521 tonnes in 1981-82, In 1980, the import of battery grade MnO2 was more than 50% of the total requirements of the industry
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