Multiscale Representation for Real-Time Anti-Aliasing Neural Rendering

The rendering scheme in neural radiance field (NeRF) is effective in rendering a pixel by casting a ray into the scene. However, NeRF yields blurred rendering results when the training images are captured at non-uniform scales, and produces aliasing artifacts if the test images are taken in distant views. To address this issue, Mip-NeRF proposes a multiscale representation as a conical frustum to encode scale information. Nevertheless, this approach is only suitable for offline rendering since it relies on integrated positional encoding (IPE) to query a multilayer perceptron (MLP). To overcome this limitation, we propose mip voxel grids (Mip-VoG), an explicit multiscale representation with a deferred architecture for real-time anti-aliasing rendering. Our approach includes a density Mip-VoG for scene geometry and a feature Mip-VoG with a small MLP for view-dependent color. Mip-VoG encodes scene scale using the level of detail (LOD) derived from ray differentials and uses quadrilinear interpolation to map a queried 3D location to its features and density from two neighboring downsampled voxel grids. To our knowledge, our approach is the first to offer multiscale training and real-time anti-aliasing rendering simultaneously. We conducted experiments on multiscale datasets, and the results show that our approach outperforms state-of-the-art real-time rendering baselines

Improving Shape Retrieval by Integrating AIR and Modified Mutual k

In computer vision, image retrieval remained a significant problem and recent resurgent of image retrieval also relies on other postprocessing methods to improve the accuracy instead of solely relying on good feature representation. Our method addressed the shape retrieval of binary images. This paper proposes a new integration scheme to best utilize feature representation along with contextual information. For feature representation we used articulation invariant representation; dynamic programming is then utilized for better shape matching followed by manifold learning based postprocessing modified mutual kNN graph to further improve the similarity score. We conducted extensive experiments on widely used MPEG-7 database of shape images by so-called bulls-eye score with and without normalization of modified mutual kNN graph which clearly indicates the importance of normalization. Finally, our method demonstrated better results compared to other methods. We also computed the computational time with another graph transduction method which clearly shows that our method is computationally very fast. Furthermore, to show consistency of postprocessing method, we also performed experiments on challenging ORL and YALE face datasets and improved baseline results

Reactive Oxygen Species and Gibberellin Acid Mutual Induction to Regulate Tobacco Seed Germination

Seed germination is a complex process controlled by various mechanisms. To examine the potential contribution of reactive oxygen species (ROS) and gibberellin acid (GA) in regulating seed germination, diphenylene iodonium chloride (DPI) and uniconazole (Uni), as hydrogen peroxide (H2O2) and GA synthesis inhibitor, respectively, were exogenously applied on tobacco seeds using the seed priming method. Seed priming with DPI or Uni decreased germination percentage as compared with priming with H2O, especially the DPI + Uni combination. H2O2 and GA completely reversed the inhibition caused by DPI or Uni. The germination percentages with H2O2 + Uni and GA + DPI combinations kept the same level as with H2O. Meanwhile, GA or H2O2 increased GA content and deceased ABA content through corresponding gene expressions involving homeostasis and signal transduction. In addition, the activation of storage reserve mobilization and the enhancement of soluble sugar content and isocitrate lyase (ICL) activity were also induced by GA or H2O2. These results strongly suggested that H2O2 and GA were essential for tobacco seed germination and by downregulating the ABA/GA ratio and inducing reserve composition mobilization mutually promoted seed germination. Meanwhile, ICL activity was jointly enhanced by a lower ABA/GA ratio and a higher ROS concentration

Key residues in the nicotinic acetylcholine receptor β2 subunit contribute to α-conotoxin LvIA binding

alpha-Conotoxin LvIA (alpha-CTx LvIA) is a small peptide from the venom of the carnivorous marine gastropod Conus lividus and is the most selective inhibitor of alpha 3 beta 2 nicotinic acetylcholine receptors (nAChRs) known to date. It can distinguish the alpha 3 beta 2 nAChR subtype from the alpha 6 beta 2* (*indicates the other subunit) and alpha 3 beta 4 nAChR subtypes. In this study, we performed mutational studies to assess the influence of residues of the beta 2 subunit versus those of the beta 4 subunit on the binding of alpha-CTx LvIA. Although two beta 2 mutations, alpha 3 beta 2[F119Q] and alpha 3 beta 2[T59K], strongly enhanced the affinity of LvIA, the beta 2 mutation alpha 3 beta 2[V111I] substantially reduced the binding of LvIA. Increased activity of LvIA was also observed when the beta 2-T59L mutant was combined with the alpha 3 subunit. There were no significant difference in inhibition of alpha 3 beta 2[T59I], alpha 3 beta 2[Q34A], and alpha 3 beta 2[K79A] nAChRs when compared with wild-type alpha 3 beta 2 nAChR. alpha-CTx LvIA displayed slower off-rate kinetics at alpha 3 beta 2[F119Q] and alpha 3 beta 2[T59K] than at the wild-type receptor, with the latter mutant having the most pronounced effect. Taken together, these data provide evidence that the beta 2 subunit contributes to alpha-CTx LvIA binding and selectivity. The results demonstrate that Val(111) is critical and facilitates LvIA binding; this position has not previously been identified as important to binding of other 4/7 framework alpha-conotoxins. Thr(59) and Phe(119) of the beta 2 subunit appear to interfere with LvIA binding, and their replacement by the corresponding residues of the beta 4 subunit leads to increased affinity

Characterization of a novel alpha-conotoxin TxID from Conus textile that potently blocks rat alpha3/beta4 nicotinic acetylcholine receptors

The alpha 3 beta 4 nAChRs are implicated in pain sensation in the PNS and addiction to nicotine in the CNS. We identified an alpha-4/6-conotoxin (CTx) TxID from Conus textile. The new toxin consists of 15 amino acid residues with two disulfide bonds. TxID was synthesized using solid phase methods, and the synthetic peptide was functionally tested on nAChRs heterologously expressed in Xenopus laevis oocytes. TxID blocked rat alpha 3 beta 4 nAChRs with a 12.5 nM IC50, which places it among the most potent alpha 3 beta 4 nAChR antagonists. TxID also blocked the closely related alpha 6/alpha 3 beta 4 with a 94 nM IC50 but showed little activity on other nAChR subtypes. NMR analysis showed that two major structural isomers exist in solution, one of which adopts a regular alpha-CTx fold but with different surface charge distribution to other 4/6 family members. alpha-CTx TxID is a novel tool with which to probe the structure and function of alpha 3 beta 4 nAChRs

A High Precison Phase Extraction Algorithm from a Single Shot Interferogram

Abstract. Phase shifting interferometry is an optical metrology with a high precision, but it usually requires the expensive high precision phase shifter. Therefore, low cost methods of extracting phase from a single shot interferogram were very valuable, but available algorithms are usually effective only in a limited conditions. To solve these problems, a novel method is presented in this work. Based on this method, the interference fringe is retrieved to a wrapped phase and divided into different regions and the index of the pixel is calculated. The pixels in the same region have the same parity and the PSF’s gravity center of part wavefront so as to solve the sign ambiguity. The theoretical simulation results indicate that the PV of wavefront error is 0.00054λ and the rms is 0.000125λ,which is much better than the results from the Fast Fourier Transformation method. The experimentally measured interferogram is also used to validate the method. It has the advantages of simplicity, high precision and effective for both open and closed interferometer fringes

Hydrolysis of corn stover pretreated by DESs with carbon-based solid acid catalyst

Abstract This study evaluated two hydrolysis strategies that involve a two-step and a one-pot process for the hydrolysis of cellulose. The two-step process consisted of cellulose pretreatment with deep eutectic solvent, followed by hydrolysis promoted by the carbon-based solid acid catalyst. The obtained results showed that the xylose and glucose yields were 33.9% and 6.9%, respectively, from corn stover based on this two-step strategy with ChCl ·Formic acid used as the pretreatment solvent. For one-pot hydrolysis, side reactions occurred and less glucose accumulated in the reaction system. In this case, the maximum achieved glucose yield was 21.1% for the hydrolysis of microcrystalline cellulose. Graphic abstract The corn stover was pretreated with DES and then hydrolysed by carbon-based solid acid catalyst. Approximately 33.9% of xylose and 6.9% of glucose was recovered from corn stover with ChCl·Formic acid as the pretreatment solvent

Improving Shape Retrieval by Integrating AIR and Modified Mutual NN Graph

In computer vision, image retrieval remained a significant problem and recent resurgent of image retrieval also relies on other postprocessing methods to improve the accuracy instead of solely relying on good feature representation. Our method addressed the shape retrieval of binary images. This paper proposes a new integration scheme to best utilize feature representation along with contextual information. For feature representation we used articulation invariant representation; dynamic programming is then utilized for better shape matching followed by manifold learning based postprocessing modified mutual NN graph to further improve the similarity score. We conducted extensive experiments on widely used MPEG-7 database of shape images by so-called bulls-eye score with and without normalization of modified mutual NN graph which clearly indicates the importance of normalization. Finally, our method demonstrated better results compared to other methods. We also computed the computational time with another graph transduction method which clearly shows that our method is computationally very fast. Furthermore, to show consistency of postprocessing method, we also performed experiments on challenging ORL and YALE face datasets and improved baseline results

RISK-INFORMED STRENGTH DESIGN OF HOT MOLTEN SALT STORAGE TANK FOR CSP PLANTS

Hot molten salt storage tank is the key energy storage equipment in solar thermal power stations. The accidents of similar equipment indicates that there is a risk of periodic cracking for storage tanks based on general strength design specifications. Based on the high-temperature structural strength design theory, risk-informed design methods were introduced to a 100 MW CSP plant. Quantitative control indicators for risk sources were reversely calculated. The results show that when the equivalent friction coefficient of bottom plate is greater than 0.65, the tank could have ratchet damage during heat-up stage. When the thickness of sand layer is greater than 60 mm, the sidewall of the storage tank could be instantaneously fractured. The range of temperature fluctuation should be limited between-20℃ and +25℃ to avoid high cycle fatigue fracture and buckling. Meanwhile, it is recommended to appropriately increase the center height of the tank bottom（<29 mm） to prevent thermal stress failure