627 research outputs found
Rapid Determination of Saponins in the Honey-Fried Processing of Rhizoma Cimicifugae by Near Infrared Diffuse Reflectance Spectroscopy.
ObjectiveA model of Near Infrared Diffuse Reflectance Spectroscopy (NIR-DRS) was established for the first time to determine the content of Shengmaxinside I in the honey-fried processing of Rhizoma Cimicifugae.MethodsShengmaxinside I content was determined by high-performance liquid chromatography (HPLC), and the data of the honey-fried processing of Rhizoma Cimicifugae samples from different batches of different origins by NIR-DRS were collected by TQ Analyst 8.0. Partial Least Squares (PLS) analysis was used to establish a near-infrared quantitative model.ResultsThe determination coefficient R² was 0.9878. The Cross-Validation Root Mean Square Error (RMSECV) was 0.0193%, validating the model with a validation set. The Root Mean Square Error of Prediction (RMSEP) was 0.1064%. The ratio of the standard deviation for the validation samples to the standard error of prediction (RPD) was 5.5130.ConclusionThis method is convenient and efficient, and the experimentally established model has good prediction ability, and can be used for the rapid determination of Shengmaxinside I content in the honey-fried processing of Rhizoma Cimicifugae
DIP: Differentiable Interreflection-aware Physics-based Inverse Rendering
We present a physics-based inverse rendering method that learns the
illumination, geometry, and materials of a scene from posed multi-view RGB
images. To model the illumination of a scene, existing inverse rendering works
either completely ignore the indirect illumination or model it by coarse
approximations, leading to sub-optimal illumination, geometry, and material
prediction of the scene. In this work, we propose a physics-based illumination
model that explicitly traces the incoming indirect lights at each surface point
based on interreflection, followed by estimating each identified indirect light
through an efficient neural network. Furthermore, we utilize the Leibniz's
integral rule to resolve non-differentiability in the proposed illumination
model caused by one type of environment light -- the tangent lights. As a
result, the proposed interreflection-aware illumination model can be learned
end-to-end together with geometry and materials estimation. As a side product,
our physics-based inverse rendering model also facilitates flexible and
realistic material editing as well as relighting. Extensive experiments on both
synthetic and real-world datasets demonstrate that the proposed method performs
favorably against existing inverse rendering methods on novel view synthesis
and inverse rendering
D-IF: Uncertainty-aware Human Digitization via Implicit Distribution Field
Realistic virtual humans play a crucial role in numerous industries, such as
metaverse, intelligent healthcare, and self-driving simulation. But creating
them on a large scale with high levels of realism remains a challenge. The
utilization of deep implicit function sparks a new era of image-based 3D
clothed human reconstruction, enabling pixel-aligned shape recovery with fine
details. Subsequently, the vast majority of works locate the surface by
regressing the deterministic implicit value for each point. However, should all
points be treated equally regardless of their proximity to the surface? In this
paper, we propose replacing the implicit value with an adaptive uncertainty
distribution, to differentiate between points based on their distance to the
surface. This simple ``value to distribution'' transition yields significant
improvements on nearly all the baselines. Furthermore, qualitative results
demonstrate that the models trained using our uncertainty distribution loss,
can capture more intricate wrinkles, and realistic limbs. Code and models are
available for research purposes at https://github.com/psyai-net/D-IF_release
Learning Procedure-aware Video Representation from Instructional Videos and Their Narrations
The abundance of instructional videos and their narrations over the Internet
offers an exciting avenue for understanding procedural activities. In this
work, we propose to learn video representation that encodes both action steps
and their temporal ordering, based on a large-scale dataset of web
instructional videos and their narrations, without using human annotations. Our
method jointly learns a video representation to encode individual step
concepts, and a deep probabilistic model to capture both temporal dependencies
and immense individual variations in the step ordering. We empirically
demonstrate that learning temporal ordering not only enables new capabilities
for procedure reasoning, but also reinforces the recognition of individual
steps. Our model significantly advances the state-of-the-art results on step
classification (+2.8% / +3.3% on COIN / EPIC-Kitchens) and step forecasting
(+7.4% on COIN). Moreover, our model attains promising results in zero-shot
inference for step classification and forecasting, as well as in predicting
diverse and plausible steps for incomplete procedures. Our code is available at
https://github.com/facebookresearch/ProcedureVRL.Comment: Accepted to CVPR 202
Introduction to (p × n)-Type Transverse Thermoelectrics
This chapter will review (p × n)-type transverse thermoelectrics (TTE). Starting with the device advantages of single-leg (p × n)-type TTE’s over other thermoelectric paradigms, the theory of (p × n)-type TTE materials is given. Then, the figure of merit, transport equations, and thermoelectric tensors are derived for an anisotropic effective-mass model in bulk three-dimensional materials (3D), quasi-two-dimensional (2D), and quasi-one-dimensional (1D) materials. This chapter concludes with a discussion of the cooling power for transverse thermoelectrics in terms of universal heat flux and electric field scales. The importance of anisotropic ambipolar conductivity for (p × n)-type TTEs highlights the need to explore noncubic, narrow-gap semiconductor or semimetallic candidate materials
Putting Humans in a Scene: Learning Affordance in 3D Indoor Environments
Affordance modeling plays an important role in visual understanding. In this
paper, we aim to predict affordances of 3D indoor scenes, specifically what
human poses are afforded by a given indoor environment, such as sitting on a
chair or standing on the floor. In order to predict valid affordances and learn
possible 3D human poses in indoor scenes, we need to understand the semantic
and geometric structure of a scene as well as its potential interactions with a
human. To learn such a model, a large-scale dataset of 3D indoor affordances is
required. In this work, we build a fully automatic 3D pose synthesizer that
fuses semantic knowledge from a large number of 2D poses extracted from TV
shows as well as 3D geometric knowledge from voxel representations of indoor
scenes. With the data created by the synthesizer, we introduce a 3D pose
generative model to predict semantically plausible and physically feasible
human poses within a given scene (provided as a single RGB, RGB-D, or depth
image). We demonstrate that our human affordance prediction method consistently
outperforms existing state-of-the-art methods.Comment: https://sites.google.com/view/3d-affordance-cvpr1
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