scholarly journals Dynamic PET Reconstruction on the GPU

2018 ◽  
Vol 62 (4) ◽  
pp. 134-143 ◽  
Author(s):  
László Szirmay-Kalos ◽  
Ágota Kacsó ◽  
Milán Magdics ◽  
Balázs Tóth
Keyword(s):  
Parallel Architecture ◽  
Concentration Function ◽  
Space Time ◽  
Massively Parallel ◽  
Graphics Processors ◽  
Gamma Photon ◽  
Likelihood Principle ◽  
Positron Emission ◽  
Spatio Temporal ◽  
Pet Reconstruction

Dynamic Positron Emission Tomography (PET) reconstructs the space-time concentration function of a radiotracer by observing the detector hits of gamma-photon pairs born during the radiotracer decay. The computation is based on the maximum likelihood principle, i.e. we look for the space-time function that maximizes the probability of the actual measurements. The number of finite elements representing the spatio-temporal concentration and the number of events detected by the tomograph may be higher than a billion, thus the reconstruction requires supercomputer performance. The enormous computational burden can be handled by graphics processors (GPU) if the algorithm is decomposed to parallel, independent threads, and the storage requirements are kept under control. This paper proposes a scalable dynamic reconstruction system where the algorithm is decomposed to phases where each phase is efficiently mapped onto the massively parallel architecture of the GPU.

Study of the Spatio-Temporal Data Model in Sea Battlefield

2012 ◽  
Vol 246-247 ◽  
pp. 744-748
Author(s):  
Yue Lin Sun ◽  
Lei Bao ◽  
Yi Hang Peng
Keyword(s):  
Data Model ◽  
Object Oriented ◽  
Space Time ◽  
Comprehensive Analysis ◽  
Temporal Data ◽  
Data Types ◽  
Spatio Temporal ◽  
The Right ◽  
Effective Analysis

An effective analysis of the battlefield situation and spatio-temporal data model in a sea battlefield has great significance for the commander to perceive the battlefield situation and to make the right decisions. Based on the existing spatio-temporal data model, the present paper gives a comprehensive analysis of the characteristics of sea battlefield data, and chooses the object-oriented spatio-temporal data model to modify it; at the same time this paper introduces sea battlefield space-time algebra system to define various data types formally, which lays the foundation for the establishment of the sea battlefield spatio-temporal data model.

The physical basis of application of positron emission tomography and modern radiopharms

2021 ◽  
Vol 4 ◽  
Author(s):  
L.I. , Galchenko ◽  
◽  
A.N. Kalyagin
Keyword(s):  
Positron Emission Tomography ◽  
Time Distribution ◽  
Space Time ◽  
Physical Basis ◽  
Emission Tomography ◽  
Annihilation Radiation ◽  
Review Of The Literature ◽  
Diagnostic Practice ◽  
Positron Emission

This article provides a review of the literature on the history, physical and technical foundations and features of the application of positron emission tomography (PET), which came into practice in the 1970s. PET is a method of visualizing the space-time distribution of a positron-emitting radiopharmaceutical (RP) in the patient‘s body by annihilation radiation. The classification of radiopharmaceuticals that are used in clinical and diagnostic practice is considered.

scholarly journals SPACE-TIME TRANSFORMATIONS IN THE UPPER XINGU AND UPPER RIO NEGRO

2015 ◽  
Vol 5 (3) ◽  
pp. 699-724
Author(s):  
Geraldo Andrello ◽  
Antonio Guerreiro ◽  
Stephen Hugh-Jones
Keyword(s):  
Social Organization ◽  
Social Life ◽  
Space Time ◽  
Unequal Distribution ◽  
Rio Negro ◽  
The People ◽  
The Social ◽  
Esoteric Knowledge ◽  
Spatio Temporal ◽  
Time Transformations

Abstract The multi-ethnic and multilingual complexes of the Upper Rio Negro and the Upper Xingu share common aspects that frequently emerge in ethnographies, including notions of descent, hierarchical social organization and ritual activities, as well as a preference for forms of exogamy and the unequal distribution of productive and ritual specialties and esoteric knowledge. In this article we investigate how the people of both regions conceive of their humanity and that of their neighbours as variations on a shared form, since in both regions ritual processes for negotiating positions and prerogatives seems to take the place of the latent state of warfare typical of the social life of other Amazonian peoples. In this article we will synthesize, for each region, the spatio-temporal processes that underscore the eminently variable constitution of collectivities, seeking, in conclusion, to isolate those elements that the two regions have in common.

scholarly journals Space-Time Cube and Mixed Reality – New Approaches to Support Understanding Historical Landscape Changes

2019 ◽  
Vol 2 ◽  
pp. 1-7
Author(s):  
Mathias Jahnke ◽  
Edyta P. Bogucka ◽  
Maria Turchenko
Keyword(s):  
Cultural Landscape ◽  
Mixed Reality ◽  
New Technology ◽  
Space Time ◽  
Field Of View ◽  
Landscape Changes ◽  
Huge Amount ◽  
Visual Variables ◽  
Spatio Temporal ◽  
Microsoft Hololens

<p><strong>Abstract.</strong> Mixed reality is a rather new technology but came to its nowadays success through the availability of devices like Microsoft HoloLens which easily support the users and developers to use such devices. Therefore, visualization specialists like cartographers paid attention due to interaction possibilities such devices provide. In particular, to utilize the huge amount of opportunities such device gave. The applicability within the cartographic domain needs to be further investigated.</p><p>The main goal of this contribution is to evaluate the applicability of a mixed reality device in the domain of spatio-temporal representations on the example of the space-time cube to show cultural landscape changes. The hologram of the space-time cube provides the changes of the Royal Castle in Warsaw and their surrounding elements. The hologram therefore incorporated the different buildings of the castle, space-time prisms and space-time links to connect building elements over the years. The visual variables colour hue, colour value and transparency are mainly used to feature distinguishable space-time prisms and to show the space-time links. Different colour schemes are developed which features the characteristics of a mixed reality device. The possibilities of input actions are ranging from gaze/head movement, to gesture and voice.</p><p>The usability evaluation of the mixed reality hologram showed the overall comfort of interactions, perception of the visual components of the space-time cube and determines advantageous features and limitations of the technology. Most of the found limitations are connected to current devices, like e.g. resolution or field of view. An important aspect which came out is, that the experience the user has which such devices/technology plays an important role in successfully use and knowledge discovery from such applications.</p>

scholarly journals The First Lumpy Skin Disease Outbreak in Thailand (2021): Epidemiological Features and Spatio-Temporal Analysis

2022 ◽  
Vol 8 ◽  
Author(s):  
Orapun Arjkumpa ◽  
Minta Suwannaboon ◽  
Manoch Boonrod ◽  
Issara Punyawan ◽  
Supawadee Liangchaisiri ◽  
...  
Keyword(s):  
Skin Disease ◽  
Temporal Analysis ◽  
Space Time ◽  
Effective Control ◽  
Outbreak Response ◽  
Lumpy Skin Disease ◽  
Epidemiological Features ◽  
Spatio Temporal ◽  
Epidemiological Characteristics ◽  
Cattle Farms

The first outbreak of lumpy skin disease (LSD) in Thailand was reported in March 2021, but information on the epidemiological characteristics of the outbreak is very limited. The objectives of this study were to describe the epidemiological features of LSD outbreaks and to identify the outbreak spatio-temporal clusters. The LSD-affected farms located in Roi Et province were investigated by veterinary authorities under the outbreak response program. A designed questionnaire was used to obtain the data. Space-time permutation (STP) and Poisson space-time (Poisson ST) models were used to detect areas of high LSD incidence. The authorities identified 293 LSD outbreak farms located in four different districts during the period of March and the first week of April 2021. The overall morbidity and mortality of the affected cattle were 40.5 and 1.2%, respectively. The STP defined seven statistically significant clusters whereas only one cluster was identified by the Poisson ST model. Most of the clusters (n = 6) from the STP had a radius &lt;7 km, and the number of LSD cases in those clusters varied in range of 3–51. On the other hand, the most likely cluster from the Poisson ST included LSD cases (n = 361) from 198 cattle farms with a radius of 17.07 km. This is the first report to provide an epidemiological overview and determine spatio-temporal clusters of the first LSD outbreak in cattle farms in Thailand. The findings from this study may serve as a baseline information for future epidemiological studies and support authorities to establish effective control programs for LSD in Thailand.

scholarly journals INTERESTING SPATIO-TEMPORAL REGION DISCOVERY COMPUTATIONS OVER GPU AND MAPREDUCE PLATFORMS

2015 ◽  
Vol II-4/W2 ◽  
pp. 35-41 ◽  
Author(s):  
M. McDermott ◽  
S. K. Prasad ◽  
S. Shekhar ◽  
X. Zhou
Keyword(s):  
Parallel Architecture ◽  
Computation Time ◽  
Data Sets ◽  
Temporal Region ◽  
Data Set ◽  
Atmospheric Sciences ◽  
3 Dimensional ◽  
Linear Speedup ◽  
Spatio Temporal ◽  
Mapreduce Model

Discovery of interesting paths and regions in spatio-temporal data sets is important to many fields such as the earth and atmospheric sciences, GIS, public safety and public health both as a goal and as a preliminary step in a larger series of computations. This discovery is usually an exhaustive procedure that quickly becomes extremely time consuming to perform using traditional paradigms and hardware and given the rapidly growing sizes of today’s data sets is quickly outpacing the speed at which computational capacity is growing. In our previous work (Prasad et al., 2013a) we achieved a 50 times speedup over sequential using a single GPU. We were able to achieve near linear speedup over this result on interesting path discovery by using Apache Hadoop to distribute the workload across multiple GPU nodes. Leveraging the parallel architecture of GPUs we were able to drastically reduce the computation time of a 3-dimensional spatio-temporal interest region search on a single tile of normalized difference vegetative index for Saudi Arabia. We were further able to see an almost linear speedup in compute performance by distributing this workload across several GPUs with a simple MapReduce model. This increases the speed of processing 10 fold over the comparable sequential while simultaneously increasing the amount of data being processed by 384 fold. This allowed us to process the entirety of the selected data set instead of a constrained window.

scholarly journals FDTD Computation of Space/Time Integrated Electromagnetic Lagrangian: New Insights on Mutually Coupled Wide-band Antenna Design

2021 ◽  
Author(s):  
Debdeep Sarkar ◽  
Yahia Antar
Keyword(s):  
Electromagnetic Interference ◽  
Interference Mitigation ◽  
Near Field ◽  
Time Integration ◽  
Wide Band ◽  
Space Time ◽  
Ultra Wideband ◽  
Mimo Antennas ◽  
Electric And Magnetic Fields ◽  
Spatio Temporal

In this paper, we develop a formalism based on either spatially or temporally integrated electromagnetic (EM) Lagrangian, which provides new insights about the near-field reactive energy around generic antennas for arbitrary spatio-temporal excitation signals. Using electric and magnetic fields calculated via FDTD technique and interpolation routines, we compute and plot the normalized values of space/time integrated EM Lagrangian around antennas. While the time-integration of EM Lagrangian sheds light onto the spatial distribution of inductive/capacitive reactive energy, time-variation of spatially integrated EM Lagrangian can help in design of ultra-wideband (UWB) MIMO antennas with low mutual coupling. The EM Lagrangian approach can assist in design of energy harvesting and wireless power transfer systems, as well as for electromagnetic interference mitigation applications.

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