Search results for "racking"

Dynamic Regret Analysis for Online Tracking of Time-varying Structural Equation Model Topologies

2020

Identifying dependencies among variables in a complex system is an important problem in network science. Structural equation models (SEM) have been used widely in many fields for topology inference, because they are tractable and incorporate exogenous influences in the model. Topology identification based on static SEM is useful in stationary environments; however, in many applications a time-varying underlying topology is sought. This paper presents an online algorithm to track sparse time-varying topologies in dynamic environments and most importantly, performs a detailed analysis on the performance guarantees. The tracking capability is characterized in terms of a bound on the dynamic re…

Particle Group Metropolis Methods for Tracking the Leaf Area Index

2020

Monte Carlo (MC) algorithms are widely used for Bayesian inference in statistics, signal processing, and machine learning. In this work, we introduce an Markov Chain Monte Carlo (MCMC) technique driven by a particle filter. The resulting scheme is a generalization of the so-called Particle Metropolis-Hastings (PMH) method, where a suitable Markov chain of sets of weighted samples is generated. We also introduce a marginal version for the goal of jointly inferring dynamic and static variables. The proposed algorithms outperform the corresponding standard PMH schemes, as shown by numerical experiments.

Timing performance of the silicon PET insert probe

2010

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 2…

Comparison of Intensity-based B-splines and Point-to-Pixel Tracking Techniques for Motion Reduction in Optical Mapping

2016

Suppression of motion artifacts (MA) in cardiac optical mapping usually requires uncoupling of cardiac contraction by restriction techniques, which are known to have important effects on cardiac physiology deteriorating the quality of acquisitions and their interpretation. In this study, we propose to assess the performance of two independent intensity-based post-processing strategies to minimize MAs during registration. A point-to-pixel block-matching classical similarity-based tracking with displacement interpolation is compared to a well-known non-rigid registration algorithm where the deformation field is obtained using cubic splines. Both strategies were tested on synthetic and real op…

A PV plant simulator for testing MPPT techniques

2013

This paper introduces a versatile and reliable photovoltaic systems simulator. It includes the main components of a photovoltaic plant: a PV string and a PWM controlled boost chooper. The key feature of this simulator is the ability to consider different and non-uniform irradiation and temperature conditions (partial shading and partial heating of the strings). All the different I-V and P-V or P-I characteristics can then be determined in such non-uniform irradiation and temperature conditions, with the aim to try different MPPT algorithms. The simulator also allows to verify an enhanced version of the Incremental Conductance algorithm (IncCond) where, in order to reach the real absolute ma…

Autonomous maritime ecosystem : digital concepts and business case : results from the JYU TJTSM54 course on advanced topics on systems development

2019

Quantifying residential PV feed-in power in low voltage grids based on satellite-derived irradiance data with application to power flow calculations

2016

AbstractA scheme using satellite-derived irradiance measurements to model the feed-in power of residential photovoltaic (PV) systems in a low voltage distribution grid is described. It is validated against smart meter measurements from a test site with 12 residential PV systems in the city of Ulm, Germany, during May 2013 to December 2014. The PV feed-in power is simulated in a 15-min time resolution based on irradiance data derived from Meteosat Second Generation satellite images by the physically based retrieval scheme Heliosat-4. The PV simulation is based on the nominal power and location of the PV systems as provided by the distribution system operator. Orientation angles are taken fro…

Faster GPU-Accelerated Smith-Waterman Algorithm with Alignment Backtracking for Short DNA Sequences

2014

In this paper, we present a GPU-accelerated Smith-Waterman (SW) algorithm with Alignment Backtracking, called GSWAB, for short DNA sequences. This algorithm performs all-to-all pairwise alignments and retrieves optimal local alignments on CUDA-enabled GPUs. To facilitate fast alignment backtracking, we have investigated a tile-based SW implementation using the CUDA programming model. This tiled computing pattern enables us to more deeply explore the powerful compute capability of GPUs. We have evaluated the performance of GSWAB on a Kepler-based GeForce GTX Titan graphics card. The results show that GSWAB can achieve a performance of up to 56.8 GCUPS on large-scale datasets. Furthermore, ou…

Avoiding minorities: Social invisibility

2012

Three experiments examined how self-consciousness has an impact on the visual exploration of a social field. The main hypothesis was that merely a photograph of people can trigger a dynamic process of social visual interaction such that minority images are avoided when people are in a state of self-reflective consciousness. In all three experiments, pairs of pictures—one with characters of social minorities and one with characters of social majorities—were shown to the participants. By means of eye-tracking technology, the results of Experiment 1 (n=20) confirmed the hypothesis that in the reflective consciousness condition, people look more at the majority than minority characters. The res…

Selective attention in the news feed: An eye-tracking study on the perception and selection of political news posts on Facebook

2018

Social networking sites such as Facebook are becoming increasingly important as a source for news. However, few studies have investigated what drives attention to content within the news feed and what influences the selection of news posts. We hypothesized that attitude consistency, the credibility of a source, and comments of other users raise interest in a news post in the news feed and influence the selection decision. A 2 × 2 × 2 laboratory experiment ( N = 103) using eye-tracking measurement showed that attitude consistency did not influence attention distribution in the news feed, but users preferred to select news posts with content reinforcing their attitudes. Participants spent mor…