7 research outputs found
BackTrack: Robust template update via Backward Tracking of candidate template
Variations of target appearance such as deformations, illumination variance,
occlusion, etc., are the major challenges of visual object tracking that
negatively impact the performance of a tracker. An effective method to tackle
these challenges is template update, which updates the template to reflect the
change of appearance in the target object during tracking. However, with
template updates, inadequate quality of new templates or inappropriate timing
of updates may induce a model drift problem, which severely degrades the
tracking performance. Here, we propose BackTrack, a robust and reliable method
to quantify the confidence of the candidate template by backward tracking it on
the past frames. Based on the confidence score of candidates from BackTrack, we
can update the template with a reliable candidate at the right time while
rejecting unreliable candidates. BackTrack is a generic template update scheme
and is applicable to any template-based trackers. Extensive experiments on
various tracking benchmarks verify the effectiveness of BackTrack over existing
template update algorithms, as it achieves SOTA performance on various tracking
benchmarks.Comment: 14 pages, 7 figure
Integrated Analysis of Permeability Reduction Caused by Polymer Retention for Better Understanding Polymer Transport
Polymer retention is one of the most important factors to govern polymer propagation through porous media, determining whether successful or not. The focus of previous studies has been limited to polymer concentration loss caused by the retention; not only change in polymer concentration, but also reduction in reservoir permeability is the main issue for theoretical transport study. Due to the lack of accuracy of Langmuir isotherm describing the polymer retention mechanisms, this study proposes a new type of matching interpretation method to correlate the permeability reduction factors from experiments to permeability. In order to solve the problem of poorly matching results between estimation and observation, use of nonadsorptive constant conditionally selected in matching process was made. Based on the threshold permeability reduction factors, approximate critical permeability can be calculated to which nonadsorptive constant would be applied. Results showed significant improvements in the estimation of permeability reduction for both low and high permeability cores. In addition, effects of permeability reduction on polymer transport in field scale were analyzed using the proposed matching model. Thus, not only does this interpretation method help to evaluate prediction for accurate flow behavior, but also unwanted risk can be evaluated
Numerical investigation of CO2-carbonated water-alternating-gas on enhanced oil recovery and geological carbon storage
This study investigates the potential of a novel CO2-carbonated water-alternating-gas (CWAG) injection method for enhanced oil recovery (EOR) and geological carbon storage. The Weyburn fluid data acquired from Canada are used in a compositional reservoir simulation of a CO2-CWAG case study with seven cycles in order to analyze the effects of carbonated water (CW) upon the oil recovery and CO2 storage capacity of a multi-phase CO2/brine/oil system. The study includes an assessment of the CO2 plume propagation and retention via structural, residual, and solubility trapping mechanisms. The numerical results demonstrate that CO2-CWAG yields a 6.7% increase in oil recovery compared to continuous CO2 flooding (from 68.4% to 73.0%) and a 1.4% increase compared to CO2-WAG (from 72.0% to 73.0%). During the CO2-CWAG operation, increasing the molarity of CO2 from 0.0 mol/L to 1.2 mol/L in carbonated water results in a 6.7% increase in the amount of geologically stored CO2 (from 6191 tons to 6608 tons). In brief, CO2-CWAG improves not only oil recovery but also CO2 storage capacity in terms of the three trapping mechanisms, thus making it a promising low-carbon EOR method that could help reduce CO2 emissions in the oil and gas industry
Influence of Intercell Trapped Charge on Vertical NAND Flash Memory
The influence of intercell trapped charge (ITC)-the charge trapped at the inter-cell nitride regions by fringe electric fields during programand erase operations-on vertical NAND (VNAND) flash memory is investigated. In addition to conventional degradation mechanisms such as tunnel oxide damage, ITC deteriorates the transconductance and read current of VNAND flash memory cells. The influence of ITC-induced degradationon VNAND flashmemory is discussed, using both simulation and experimental results. A solution for ITC suppression is also proposed: the use of low-k intercell regions.N
Effects of abnormal cell-to-cell interference on p-type floating gate and control gate NAND flash memory
Abnormal cell-to-cell interference occurring in NAND flash memory has been investigated. In the case of extremely downscaled NAND flash memory, cell-to-cell interference increases abnormally. The abnormal cell-to-cell interference has been observed in a p-type floating gate (FG)/control gate (CG) cells for the first time. It has been found that the depletion region variation leads to the abnormal cell-to-cell interference. The depletion region variation of FG and CG is determined by state of neighbor cells. The depletion region variation affects CG-to-FG coupling capacitance and threshold voltage variation (Delta V-T). Finally, it is observed that there is a symmetrical relationship between n- and p-type FG/CG NAND flash memory in terms of cell-to-cell interference. (C) 2014 The Japan Society of Applied PhysicsN