365 research outputs found
Padding Ain't Enough: Assessing the Privacy Guarantees of Encrypted DNS – Web Scans
No full textThis dataset contains the main data set of our FOCI 2020 paper "Padding Ain’t Enough: Assessing the Privacy Guarantees of Encrypted DNS".
https://www.usenix.org/conference/foci20/presentation/bushart
You can find the source code for this project on GitHub: https://github.com/jonasbb/padding-aint-enough
When using this software or our dataset, please cite our FOCI 20 paper.
@inproceedings {PaddingAintEnough,
author = {Jonas Bushart and Christian Rossow},
booktitle = {10th {USENIX} Workshop on Free and Open Communications on the Internet ({FOCI} 20)},
month = aug,
publisher = {{USENIX} Association},
title = {Padding Ain{\textquoteright}t Enough: Assessing the Privacy Guarantees of Encrypted {DNS}},
year = {2020},
Padding Ain't Enough: Assessing the Privacy Guarantees of Encrypted DNS – Subpage-Agnostic Domain Classification Tor Browser
No full textThis dataset contains the second part of the "Subpage-Agnostic Domain Classification" section of our FOCI 2020 paper "Padding Ain’t Enough: Assessing the Privacy Guarantees of Encrypted DNS".
https://www.usenix.org/conference/foci20/presentation/bushart
You can find the source code for this project on GitHub: https://github.com/jonasbb/padding-aint-enough
When using this software or our dataset, please cite our FOCI 20 paper.
@inproceedings {PaddingAintEnough,
author = {Jonas Bushart and Christian Rossow},
booktitle = {10th {USENIX} Workshop on Free and Open Communications on the Internet ({FOCI} 20)},
month = aug,
publisher = {{USENIX} Association},
title = {Padding Ain{\textquoteright}t Enough: Assessing the Privacy Guarantees of Encrypted {DNS}},
year = {2020},
Padding Ain't Enough: Assessing the Privacy Guarantees of Encrypted DNS – Subpage-Agnostic Domain Classification Firefox
No full textThis dataset contains one part for the "Subpage-Agnostic Domain Classification" section of our FOCI 2020 paper "Padding Ain’t Enough: Assessing the Privacy Guarantees of Encrypted DNS".
https://www.usenix.org/conference/foci20/presentation/bushart
You can find the source code for this project on GitHub: https://github.com/jonasbb/padding-aint-enough
When using this software or our dataset, please cite our FOCI 20 paper.
@inproceedings {PaddingAintEnough,
author = {Jonas Bushart and Christian Rossow},
booktitle = {10th {USENIX} Workshop on Free and Open Communications on the Internet ({FOCI} 20)},
month = aug,
publisher = {{USENIX} Association},
title = {Padding Ain{\textquoteright}t Enough: Assessing the Privacy Guarantees of Encrypted {DNS}},
year = {2020},
Coarse-grained simulations of entangled star polyethylene melts
No full textIn this paper, a previous coarse-grain model [J. T. Padding and W. J. Briels, J. Chem. Phys. 117, 925 (2002)]10.1063/1.1481859 to simulate melts of linear polymers has been adapted to simulate polymers with more complex hierarchies. Bond crossings between highly coarse-grained soft particles are prevented by applying an entanglement algorithm. We first test our method on a virtual branch point inside a linear chain to make sure it works effectively when linking two linear arms. Next, we apply our method to study the diffusive and rheological behaviors of a melt of three-armed stars. We find that the diffusive behavior of the three-armed star is very close to that of a linear polymer with the same molecular weight, while its rheological properties are close to those of a linear chain with molecular mass equal to that of the longest linear sub-chain in the star
The role of collective motion in examples of coarsening and self-assembly
No full textThe simplest prescription for building a patterned structure from its constituents is to add particles, one at a time, to an appropriate template. However, self-organizing molecular and colloidal systems in nature can evolve in much more hierarchical ways. Specifically, constituents (or clusters of constituents) may aggregate to form clusters (or clusters of clusters) that serve as building blocks for later stages of assembly. Here we evaluate the character and consequences of such collective motion in a set of prototypical assembly processes. We do so using computer simulations in which a system's capacity for hierarchical dynamics can be controlled systematically. By explicitly allowing or suppressing collective motion, we quantify its effects. We find that coarsening within a two dimensional attractive lattice gas (and an analogous off-lattice model in three dimensions) is naturally dominated by collective motion over a broad range of temperatures and densities. Under such circumstances, cluster mobility inhibits the development of uniform coexisting phases, especially when macroscopic segregation is strongly favored by thermodynamics. By contrast, the assembly of model viral capsids is not frustrated but is instead facilitated by collective moves, which promote the orderly binding of intermediates consisting of several monomers
Eijndhoven. Hardwired MPEG-4 Repetitive Padding
No full textAbstract—We consider two hardwired solutions for repetitive padding, a performance restricting algorithm for real time MPEG-4 execution. The first solution regards application specific implementations, the second regards general purpose processing. For the application specific implementations we propose a systolic array structure. To determine the chip area and speed, we have synthesized its VHDL models for two field-programmable gate array families—Xilinx and Altera. Depending on the implemented configuration, the unit can process between 77 K and 950 K macroblocks per second (MB/s) when mapped on FPGA chips containing less than 10 K logical gates and frequency capabilities below 100 MHz. The second approach regards an augmentation of a general-purpose arithmetic logical units with an extra functionality added to perform repetitive padding. At trivial hardware costs of a few hundred 2 2 AND-OR logic gates, we achieve an order of magnitude speed-up compared to nonaugmented general purpose processor padding. The proposed hardware solutions meet the requirements of all MPEG-4 visual profile levels. Both approaches have been proven to be scalable and fit into different architectural concepts and operand widths. Index Terms—Arithmetic-logical-unit (ALU) augmentation, field-programmable gate array (FPGA), hardwired repetitive padding, MPEG-4, systolic structure. I
Performance of the 0-padding optimal filter method in non-linear gain calibration
No full textArtículo firmado por 17 autoresThe focal-plane detector, the X-ray Integral Field Unit (X-IFU), on-board ESA’s Athena space telescope is a transition edge sensor (TES) microcalorimeter array with 1.5k pixels, designed to provide spatially-resolved, high-resolution spectroscopy over the energy range 0.2-12 keV. The onboard event processor uses a digital optimal filter to determine the pulse-height of the measured current pulse from every X-ray photon striking the array. A modified optimal filter called the 0-padding filter has recently been proposed. This is a truncated version of the standard optimal filter and has been shown to provide comparable energy resolution but with the benefit of reduced computational expense. Whereas the standard optimal filter has zero integral and is not sensitive to variations in the DC level of the measured signal, the integral of the 0-padded version is non-zero and thus is more sensitive to fluctuations in DC signal over time. In this work, we explore the effect of 0-padding on the energy scale calibration using data from 250-pixels in a prototype Athena X-IFU array, measured over the range 1.3-12 keV.Ministerio de Ciencia e Innovación (España)ERDF A way of making EuropeNational Aeronautics & Space Administration (NASA)Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu
On analysing sea level rise in the German Bight since 1844
No full textIn this paper, a methodology to analyse observed sea level rise (SLR) in the German Bight, the shallow south-eastern part of the North Sea, is presented. The paper focuses on the description of the methods used to generate and analyse mean sea level (MSL) time series. Parametric fitting approaches as well as non-parametric data adaptive filters, such as Singular System Analysis (SSA) are applied. For padding non-stationary sea level time series, an advanced approach named Monte-Carlo autoregressive padding (MCAP) is introduced. This approach allows the specification of uncertainties of the behaviour of smoothed time series near the boundaries. As an example, the paper includes the results from analysing the sea level records of the Cuxhaven tide gauge and the Heligoland tide gauge, both located in the south-eastern North Sea. For comparison, the results from analysing a worldwide sea level reconstruction are also presented. The results for the North Sea point to a weak negative acceleration of SLR since 1844 with a strong positive acceleration at the end of the 19th century, to a period of almost no SLR around the 1970s with subsequent positive acceleration and to high recent rates
Multiple description video coding based on zero padding
No full textThis paper proposes a simple multiple description video coding approach based on zero padding theory. It is completely based on pre- and post-processing, which require no modifications to the source codec. Redundancy is added by padding zeros in the DCT domain, which results in interpolation of the original frame and increases correlations between pixels. Methods based on 1D and 2D DCT are presented. We also investigate two sub-sampling methods, which are interleaved and quincunx, to generate multiple descriptions. Results are presented for two zero padding approaches using H.264, which shows that the 1D approach performs much better than 2D padding techniques, at a much lower computational complexity. For 1D zero padding, results show that interleaved sub-sampling is better than quincunx.This paper proposes a simple multiple description video coding approach based on zero padding theory. It is completely based on pre- and post-processing, which require no modifications to the source codec. Redundancy is added by padding zeros in the DCT domain, which results in interpolation of the original frame and increases correlations between pixels. Methods based on 1D and 2D DCT are presented. We also investigate two sub-sampling methods, which are interleaved and quincunx, to generate multiple descriptions. Results are presented for two zero padding approaches using H.264, which shows that the 1D approach performs much better than 2D padding techniques, at a much lower computational complexity. For 1D zero padding, results show that interleaved sub-sampling is better than quincunx
The effects of postural support padding modifications to child restraints for children with disability on crash protection
No full textObjective: Many children with physical disabilities need additional postural support when sitting and supplementary padding is used on standards approved child restraints to achieve this when traveling in a motor vehicle. However, the effect of this padding on crash protection for a child is unknown. This study aimed to investigate the effect of additional padding for postural support on crash protection for child occupants in forward facing child restraints. Methods: Forty frontal sled tests at 49 km/h were conducted to compare Q1 anthropometric test device (ATD) responses in a forward-facing restraint, with and without additional padding in locations to increase recline of the restraint, and/or support the head, trunk and pelvis. Three padding materials were tested: cloth toweling, soft foam, and expanded polystyrene (EPS). The influence of padding on head excursion, peak 3 ms head acceleration, HIC15, peak 3 ms chest acceleration and chest deflection were analyzed. Results: The influence of padding varied depending on the location of use. Padding used under the restraint to increase the recline angle increased head injury metrics. Toweling in multiple locations which included behind the head increased head excursion and chest injury metrics. There was minimal effect on injury risk measures with additional padding to support the sides of the head or the pelvis position. Rigid EPS foam, as recommended in Australian standards and guidelines, had minimal effect on injury metrics when used inside the restraint, as did tightly rolled or folded toweling secured to the restraint at single locations around the body of the child. Conclusions: This study does not support the use of postural support padding to increase recline of a forward-facing restraint or padding behind the head. Recommendations in published standards and guidelines to not use foam that is spongy, soft or easily compressed, with preference for secured firm foam or short-term use of tightly rolled or folded toweling under the child restraint cover is supported. This study also highlights the importance of considering the whole context of child occupant protection when using additional padding, particularly the change in the child’s seated position when adding padding in relation to the standard safety features of the restraint
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