A Hybrid of Dual and Meet-in-the-Middle Attack on Sparse and Ternary Secret LWE

The dual attack is one of the most efficient attack algorithms for the Learning with Errors (LWE) problem. Recently, an efficient variant of the dual attack for sparse and small secret LWE was reported by Albrecht [Eurocrypt 2017], which forces some LWE-based cryptosystems, especially fully homomorphic encryptions (FHE), to change parameters. In this work, we propose a new hybrid of dual and meet-in-the-middle (MITM) attack, which outperforms the improved variant on the same LWE parameter regime. To this end, we adapt the MITM attack for NTRU due to Odlyzko to LWE, and give a rigorous analysis for it. The performance of our MITM attack depends on the relative size of error and modulus, and hence for a large modulus LWE samples, our MITM attack works well for quite large error. We then combine our MITM attack with Albrecht\u27s observation that understands the dual attack as dimension-error tradeoff, which finally yields our hybrid attack. We also implement a sage module that estimates the attack complexity of our algorithm upon {\sf LWE-estimator}, and our attack shows significant performance improvement for the LWE parameter for FHE. For example, for the LWE problem with dimension $n=2^{15}$, modulus $q=2^{628}$ and ternary secret key with Hamming weight 64 which is one parameter set used for {\sf HEAAN} bootstrapping [Eurocrypt 2018], our attack takes $2^{112.5}$ operations and $2^{70.6}$ bit memory while the previous best attack requires $2^{127.2}$ operations as reported by {\sf LWE-estimator}

Urodynamic and Histological Changes in a Sterile Rabbit Vesicoureteral Reflux Model

This study aimed to investigate pressure changes of renal pelvis and histological change of kidneys in a surgically induced sterile rabbit vesicoureteral reflux (VUR) model. Five rabbits served as a control group, 7 as the sham-operated group, and 8 served as the VUR group. Three weeks later, urodynamic studies were performed, and histological examinations evaluated degree of inflammation, fibrosis, and tubular damage in the kidneys. At a low infusion rate, renal pelvic pressure in the VUR group was stable until late filling phase and then increased slightly. At a high infusion rate, the renal pelvic pressures of the sham-operated and control groups were stable until late filling phase and then increased slightly, whereas the renal pelvic pressure in the VUR group steadily increased from mid filling phase. Focal thinning of the tubular epithelium and interstitial widening were observed in certain cortical areas of refluxing kidneys, without inflammatory cell infiltration. Obvious changes in the mean diameters of distal tubules and extracellular matrix volume fractions were observed in two highly refluxing kidneys. High pressure reflux with bladder instability may result in renal cortical changes

Investigation of Asphalt Pavement Analyzer Testing Program in Nebraska

The asphalt pavement analyzer (APA) has been widely used to evaluate hot-mix asphalt (HMA) rutting potential in mix design and quality control – quality assurance (QC-QA) applications, because the APA testing and its data analyses are relatively simple, rapid, and easy. However, as demonstrated in many studies and also experienced by the state of Nebraska, the APA testing is in question due to its high testing variability and a lack of sufficient correlation with actual filed performance. The primary objective of this research was to find critical materials and/or mixture design factors affecting APA test results so as to eventually improve current APA testing program in Nebraska. In addition to that, development of models to predict APA rut performance with given properties of HMA mixture ingredients and mixture design characteristics were also attempted. To find variables affecting APA rut results and the extent of these variables, SP-4 mixture data from Nebraska and HMA mixture data from Kentucky were statistically analyzed using the multiple linear regression method considering six factors (binder PG, aggregate gradation, nominal maximum aggregate size, aggregate angularity, air voids in mixture, and asphalt content in mixture) as probable candidates significantly affecting APA rut results. For a detailed characterization of gradation effects, three indicators (gradation density, fineness modulus, and restricted zone) were considered and each of them was used for each statistical analysis. Analyses results demonstrated that the binder PG was the only variable that always shows significant impact on APA rut results, which is in a good agreement with other studies. Predicting models developed through the results of multiple linear regression analysis and the artificial neural network technique presented a relatively low level of model adequacy which can be observed by the coefficients of determination and crossplots between predicted APA rut values and the measured APA rut data. More data would be helpful to confirm the findings from this research and also to develop a better prediction model

Representing Hydraulically-Based Stream-Hillslope Continuum in the National Water Model for Improved Hydrologic Predictions: Catchment-Scale Application of Boussinesq Theory

Although hydraulic groundwater theory (i.e., Boussinesq flow) has been understood as a viable approach for catchment-scale understanding of the role of the aquifer(s) in the terrestrial water and energy cycle, the land surface modeling (LSM) community still lacks a proper hydrologic structure to utilize the well-studied theory for large-scale terrestrial predictions. This study aims to present a new LSM framework that enables the Boussinesq equation-based depiction of the stream-hillslope two-way continuum (i.e., bidirectional interactions among the vadose zone-phreatic aquifer-river) for applying the Boussinesq groundwater theory in a large-scale model configuration. Specifically, this study developed a new numerical scheme representing the catchment-scale stream-hillslope continuum and integrated it into the National Water Model (NWM). The NWM-BE3S LSM was applied to three major basins in Texas (i.e., the Trinity, Brazos, and Colorado River basins) to test the effects of the novel physics on improving the predictability of terrestrial water/energy fluxes. We identified the implemented stream-hillslope continuum scheme showed 'more' noticeable improvements in land surface water/energy fluxes (e.g., evapotranspiration) as well as streamflow dynamics as aquifers exhibited higher nonlinearities in the observed streamflow recession curves. The varying degree of improvements in model outputs according to the streamflow recession characteristics demonstrates (1) the applicability of the Boussinesq theory-based depiction of the stream-hillslope exchange processes and (2) the algorithmic enhancement in the NWM-BE3S's structure/capability (compared to the original NWM). Overall, our results revealed the importance of catchment-scale conservation of hydraulic consistency among the vegetation-land surface-critical zone-aquifer-river for the improved predictability of terrestrial water and energy cycles

The Role of Intermolecular Interactions on the Performance of Organic Thermally Activated Delayed Fluorescence (TADF) Materials

In most instances, thermally activated delayed fluorescence (TADF) emitters are incorporated into a suitable host matrix at low doping concentration in order to reduce emission quenching and to improve organic light-emitting diode (OLED) efficiency. Here, a combination of molecular dynamics simulations and density functional theory calculations is performed for thin films of 1) the neat 4CzIPN TADF emitter and 2) the (guest–host) 4CzIPN:mCBP system, in order to determine how guest–guest and guest–host interactions influence the morphological, electronic, and luminescence properties of the TADF emitters. The red-shift in emission recently observed experimentally upon increasing the concentration in TADF emitters is attributed to the formation of guest–guest, i.e., dimer, intermolecular charge-transfer states. It is found that the radiative and reverse intersystem crossing rates associated with these dimer states are similar to those of monomers. Thus, the contributions from both the dimer and monomer states need to be considered to describe TADF within the emissive layer. The exciton diffusion processes are also characterized; singlet excitons are calculated to be the main contributors to the diffusion length, in contrast to recently proposed models. © 2021 Wiley-VCH GmbH12 month embargo; first published online 8 February 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Effect of LiCoO2 Cathode Nanoparticle Size on High Rate Performance for Li-Ion Batteries

The effect of LiCoO2 cathode nanoparticle size on high-rate performance in Li-ion batteries was investigated using hydrothermally prepared oleylamine-capped LiCoO2 nanoparticles with a particle size of 50 nm obtained at 200 degrees C. Upon annealing as-prepared LiCoO2 at 500, 700, and 900 degrees C, the particle size increased to 100 nm, 300 nm, and 1 mu m, respectively. Ex situ transmission electron microscopy and X-ray diffraction results indicated that the thickness of the solid electrolyte interface (SEI) affected the particle's electrochemical properties at high rates. A LiCoO2 cathode with a smaller particle size had a thicker SEI layer, which acted as a barrier for Li-ion diffusion, resulting in deteriorated rate capabilities at higher C rates. However, irrespective of the particle size, there was no structural degradation after cycling. Rate capability tests were performed under two different electrode densities (3.4 and 2.8 g/cm(3)), and LiCoO2 with a particle size of 300 nm demonstrated the best rate capability at higher C rates. Upon extended cycling at the 7 C rate, LiCoO2 with a particle size of 300 nm exhibited 87 and 150 mAh/g under 3.4 and 2.8 g/cm(3), respectively.close504