84 research outputs found
Differential equation-based shape interpolation for surface blending and facial blendshapes.
Differential equation-based shape interpolation has been widely applied in geometric modelling and computer animation. It has the advantages of physics-based, good realism, easy obtaining of high- order continuity, strong ability in describing complicated shapes, and small data of geometric models. Among various applications of differential equation-based shape interpolation, surface blending and facial blendshapes are two active and important topics.
Differential equation-based surface blending can be time-independent and time-dependent. Existing differential equation-based surface blending only tackles time-dependen
Dataset Quantization
State-of-the-art deep neural networks are trained with large amounts
(millions or even billions) of data. The expensive computation and memory costs
make it difficult to train them on limited hardware resources, especially for
recent popular large language models (LLM) and computer vision models (CV).
Recent popular dataset distillation methods are thus developed, aiming to
reduce the number of training samples via synthesizing small-scale datasets via
gradient matching. However, as the gradient calculation is coupled with the
specific network architecture, the synthesized dataset is biased and performs
poorly when used for training unseen architectures. To address these
limitations, we present dataset quantization (DQ), a new framework to compress
large-scale datasets into small subsets which can be used for training any
neural network architectures. Extensive experiments demonstrate that DQ is able
to generate condensed small datasets for training unseen network architectures
with state-of-the-art compression ratios for lossless model training. To the
best of our knowledge, DQ is the first method that can successfully distill
large-scale datasets such as ImageNet-1k with a state-of-the-art compression
ratio. Notably, with 60% data from ImageNet and 20% data from Alpaca's
instruction tuning data, the models can be trained with negligible or no
performance drop for both vision tasks (including classification, semantic
segmentation, and object detection) as well as language tasks (including
instruction tuning tasks such as BBH and DROP).Comment: 9 page
CAFE Learning to Condense Dataset by Aligning Features
Dataset condensation aims at reducing the network training effort through
condensing a cumbersome training set into a compact synthetic one.
State-of-the-art approaches largely rely on learning the synthetic data by
matching the gradients between the real and synthetic data batches. Despite the
intuitive motivation and promising results, such gradient-based methods, by
nature, easily overfit to a biased set of samples that produce dominant
gradients, and thus lack global supervision of data distribution. In this
paper, we propose a novel scheme to Condense dataset by Aligning FEatures
(CAFE), which explicitly attempts to preserve the real-feature distribution as
well as the discriminant power of the resulting synthetic set, lending itself
to strong generalization capability to various architectures. At the heart of
our approach is an effective strategy to align features from the real and
synthetic data across various scales, while accounting for the classification
of real samples. Our scheme is further backed up by a novel dynamic bi-level
optimization, which adaptively adjusts parameter updates to prevent
over-/under-fitting. We validate the proposed CAFE across various datasets, and
demonstrate that it generally outperforms the state of the art: on the SVHN
dataset, for example, the performance gain is up to 11%. Extensive experiments
and analyses verify the effectiveness and necessity of proposed designs.Comment: The manuscript has been accepted by CVPR-2022
Ithaca365: Dataset and Driving Perception under Repeated and Challenging Weather Conditions
Advances in perception for self-driving cars have accelerated in recent years
due to the availability of large-scale datasets, typically collected at
specific locations and under nice weather conditions. Yet, to achieve the high
safety requirement, these perceptual systems must operate robustly under a wide
variety of weather conditions including snow and rain. In this paper, we
present a new dataset to enable robust autonomous driving via a novel data
collection process - data is repeatedly recorded along a 15 km route under
diverse scene (urban, highway, rural, campus), weather (snow, rain, sun), time
(day/night), and traffic conditions (pedestrians, cyclists and cars). The
dataset includes images and point clouds from cameras and LiDAR sensors, along
with high-precision GPS/INS to establish correspondence across routes. The
dataset includes road and object annotations using amodal masks to capture
partial occlusions and 3D bounding boxes. We demonstrate the uniqueness of this
dataset by analyzing the performance of baselines in amodal segmentation of
road and objects, depth estimation, and 3D object detection. The repeated
routes opens new research directions in object discovery, continual learning,
and anomaly detection. Link to Ithaca365: https://ithaca365.mae.cornell.edu/Comment: Accepted by CVPR 202
C2 Continuous Blending of Time-Dependent Parametric Surfaces.
Surface blending is widely applied in mechanical engineering. Creating a smooth transition surface of C2 continuity between time-dependent parametric surfaces that change their positions and shapes with time is an important and unsolved topic in surface blending. In order to address this issue, this paper develops a new approach to unify both time-dependent and time-independent surface blending with C2 continuity. It proposes a new surface blending mathematical model consisting of a vector-valued sixth-order partial differential equation and blending boundary constraints and investigates a simple and efficient approximate analytical solution of the mathematical model. A number of examples are presented to demonstrate the effectiveness and applications. The proposed approach has the advantages of (1) unifying time-independent and time-dependent surface blending, (2) always maintaining C2 continuity at trimlines when parametric surfaces change their positions and shapes with time, (3) providing effective shape control handles to achieve the expected shapes of blending surfaces but still exactly satisfy the given blending boundary constraints, and (4) quickly generating C2 continuous blending surfaces from the approximate analytical solution with easiness, good accuracy, and high efficiency
Functionally Orthologous Viral and Cellular MicroRNAs Studied by a Novel Dual-Fluorescent Reporter System
Recent research raised the possibility that some viral microRNAs (miRNAs) may function as orthologs of cellular miRNAs. In the present work, to study the functional orthologous relationships of viral and cellular miRNAs, we first constructed a dual-fluorescent protein reporter vector system for the easy determination of miRNA function. By expressing the miRNAs and the indicator and internal control fluorescent proteins individually from a single vector, this simple reporter system can be used for miRNA functional assays that include visualizing miRNA activity in live cells. Sequence alignments indicated that the simian virus 40 (SV40) encoded miRNA sv40-mir-S1-5p contains a seed region identical to that of the human miRNA hsa-miR423-5p. Using the new reporter system, it was found that sv40-mir-S1-5p and hsa-miR423-5p downregulate the expression of common artificial target mRNAs and some predicted biological targets of hsa-miR423-5p, demonstrating that they are functional orthologs. The human immunodeficiency virus 1 (HIV-1) encoded hiv1-miR-N367 also contains a seed sequence identical to that of the human miRNA hsa-miR192. Functional assays showed that hiv1-miR-N367 and hsa-miR192 could downregulate common artificial and predicted biological targets, suggesting that these miRNAs may also act as functional orthologs. Thus, this study presents a simple and universal system for testing miRNA function and identifies two new pairs of functional orthologs, sv40-mir-S1-5p and hsa-miR423-5p as well as hiv-1-miR-N367 and hsa-miR192. These findings also expand upon our current knowledge of functional homology and imply that a more general phenomenon of orthologous relationships exists between viral and cellular miRNAs
Purification and In Situ Immobilization of Papain with Aqueous Two-Phase System
Papain was purified from spray-dried Carica papaya latex using aqueous two-phase system (ATPS). Then it was recovered from PEG phase by in situ immobilization or preparing cross-linked enzyme aggregates (CLEAs). The Plackett-Burman design and the central composite design (CCD) together with the response surface methodology (RSM) were used to optimize the APTS processes. The highly purified papain (96–100%) was achieved under the optimized conditions: 40% (w/w) 15 mg/ml enzyme solution, 14.33–17.65% (w/w) PEG 6000, 14.27–14.42% (w/w) NaH2PO4/K2HPO4 and pH 5.77–6.30 at 20°C. An in situ enzyme immobilization approach, carried out by directly dispersing aminated supports and chitosan beads into the PEG phase, was investigated to recover papain, in which a high immobilization yield (>90%) and activity recovery (>40%) was obtained. Moreover, CLEAs were successfully used in recovering papain from PEG phase with a hydrolytic activity hundreds times higher than the carrier-bound immobilized papain
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