48 research outputs found
Filipinas y su perpetua especialidad. La realidad de las Islas Filipinas y los filipinos durante el siglo XIX (1837-1898).
[ES]Las modificaciones constitucionales del siglo XIX tuvieron un profundo impacto sobre la organización de la colonia. En el presente trabajo se exponen los efectos jurídicos que dichos cambios tuvieron sobre Filipinas y los filipinos entre 1837 y 1898. Para ello, analizo el fenómeno de la especialidad y su repercusión tanto en los órganos de gobierno filipinos como en la sociedad de las Islas Filipinas. Prestando especial atención tanto a las causas como a las consecuencias del empleo del discurso de inferioridad así como el uso de diminutivos para referirse a los cargos ejercidos por nativos
Stereoscopic Omnidirectional Image Quality Assessment Based on Predictive Coding Theory
Objective quality assessment of stereoscopic omnidirectional images is a
challenging problem since it is influenced by multiple aspects such as
projection deformation, field of view (FoV) range, binocular vision, visual
comfort, etc. Existing studies show that classic 2D or 3D image quality
assessment (IQA) metrics are not able to perform well for stereoscopic
omnidirectional images. However, very few research works have focused on
evaluating the perceptual visual quality of omnidirectional images, especially
for stereoscopic omnidirectional images. In this paper, based on the predictive
coding theory of the human vision system (HVS), we propose a stereoscopic
omnidirectional image quality evaluator (SOIQE) to cope with the
characteristics of 3D 360-degree images. Two modules are involved in SOIQE:
predictive coding theory based binocular rivalry module and multi-view fusion
module. In the binocular rivalry module, we introduce predictive coding theory
to simulate the competition between high-level patterns and calculate the
similarity and rivalry dominance to obtain the quality scores of viewport
images. Moreover, we develop the multi-view fusion module to aggregate the
quality scores of viewport images with the help of both content weight and
location weight. The proposed SOIQE is a parametric model without necessary of
regression learning, which ensures its interpretability and generalization
performance. Experimental results on our published stereoscopic omnidirectional
image quality assessment database (SOLID) demonstrate that our proposed SOIQE
method outperforms state-of-the-art metrics. Furthermore, we also verify the
effectiveness of each proposed module on both public stereoscopic image
datasets and panoramic image datasets
SymmNeRF: Learning to Explore Symmetry Prior for Single-View View Synthesis
We study the problem of novel view synthesis of objects from a single image.
Existing methods have demonstrated the potential in single-view view synthesis.
However, they still fail to recover the fine appearance details, especially in
self-occluded areas. This is because a single view only provides limited
information. We observe that manmade objects usually exhibit symmetric
appearances, which introduce additional prior knowledge. Motivated by this, we
investigate the potential performance gains of explicitly embedding symmetry
into the scene representation. In this paper, we propose SymmNeRF, a neural
radiance field (NeRF) based framework that combines local and global
conditioning under the introduction of symmetry priors. In particular, SymmNeRF
takes the pixel-aligned image features and the corresponding symmetric features
as extra inputs to the NeRF, whose parameters are generated by a hypernetwork.
As the parameters are conditioned on the image-encoded latent codes, SymmNeRF
is thus scene-independent and can generalize to new scenes. Experiments on
synthetic and real-world datasets show that SymmNeRF synthesizes novel views
with more details regardless of the pose transformation, and demonstrates good
generalization when applied to unseen objects. Code is available at:
https://github.com/xingyi-li/SymmNeRF.Comment: Accepted by ACCV 202
PMC-VQA: Visual Instruction Tuning for Medical Visual Question Answering
In this paper, we focus on the problem of Medical Visual Question Answering
(MedVQA), which is crucial in efficiently interpreting medical images with
vital clinic-relevant information. Firstly, we reframe the problem of MedVQA as
a generation task that naturally follows the human-machine interaction, we
propose a generative-based model for medical visual understanding by aligning
visual information from a pre-trained vision encoder with a large language
model. Secondly, we establish a scalable pipeline to construct a large-scale
medical visual question-answering dataset, named PMC-VQA, which contains 227k
VQA pairs of 149k images that cover various modalities or diseases. Thirdly, we
pre-train our proposed model on PMC-VQA and then fine-tune it on multiple
public benchmarks, e.g., VQA-RAD and SLAKE, outperforming existing work by a
large margin. Additionally, we propose a test set that has undergone manual
verification, which is significantly more challenging, even the best models
struggle to solve
Designs and Implementations in Neural Network-based Video Coding
The past decade has witnessed the huge success of deep learning in well-known
artificial intelligence applications such as face recognition, autonomous
driving, and large language model like ChatGPT. Recently, the application of
deep learning has been extended to a much wider range, with neural
network-based video coding being one of them. Neural network-based video coding
can be performed at two different levels: embedding neural network-based
(NN-based) coding tools into a classical video compression framework or
building the entire compression framework upon neural networks. This paper
elaborates some of the recent exploration efforts of JVET (Joint Video Experts
Team of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC29) in the name of neural
network-based video coding (NNVC), falling in the former category.
Specifically, this paper discusses two major NN-based video coding
technologies, i.e. neural network-based intra prediction and neural
network-based in-loop filtering, which have been investigated for several
meeting cycles in JVET and finally adopted into the reference software of NNVC.
Extensive experiments on top of the NNVC have been conducted to evaluate the
effectiveness of the proposed techniques. Compared with VTM-11.0_nnvc, the
proposed NN-based coding tools in NNVC-4.0 could achieve {11.94%, 21.86%,
22.59%}, {9.18%, 19.76%, 20.92%}, and {10.63%, 21.56%, 23.02%} BD-rate
reductions on average for {Y, Cb, Cr} under random-access, low-delay, and
all-intra configurations respectively
Subjective quality assessment of stereoscopic omnidirectional image
Stereoscopic omnidirectional images are eye-catching because they can provide realistic and immersive experience. Due to the extra depth perception provided by stereoscopic omnidirectional images, it is desirable and urgent to evaluate the overall quality of experience (QoE) of these images, including image quality, depth perception, and so on. However, most existing studies are based on 2D omnidirectional images and only image quality is taken into account. In this paper, we establish the very first Stereoscopic OmnidirectionaL Image quality assessment Database (SOLID). Three subjective evaluating factors are considered in our database, namely image quality, depth perception, and overall QoE. Additionally, the relationship among these three factors is investigated. Finally, several well-known image quality assessment (IQA) metrics are tested on our SOLID database. Experimental results demonstrate that the objective overall QoE assessment is more challenging compared to IQA in terms of stereoscopic omnidirectional images. We believe that our database and findings will provide useful insights in the development of the QoE assessment for stereoscopic omnidirectional images
Synthesis of Indolo[2,1‑<i>a</i>]isoquinolines by Nickel-Catalyzed Mizoroki–Heck/Amination Cascade Reaction
An efficient Mizoroki–Heck/amination cascade reaction
of o-dihaloarenes with cyclic imines was realized
by combining
nickel and a sterically bulky N-heterocyclic carbene ligand. This
protocol provides access to a variety of indole[2,1-a]isoquinolines from readily available starting materials. This cascade
approach could be applied to produce straightforward synthesis of
the natural product cryptowoline
Recovery of K by NH4HSO4 low-temperature roasting from brown corundum Fly Ash
Brown corundum dust ash(BCFA) is an industrial solid waste from the brown corundum production process. The alkali metal is a key factor limiting its comprehensive use. Currently, BCFA is mainly stockpiled and occupies a large amount of land. Its fine particles are easy to cause air pollution. The addition of NH _4 HSO _4 allows for the effective extraction of K from BCFA and the efficient use of BCFA. Under optimum conditions: NH _4 HSO _4 to BCFA mass ratio of 1.2:1, the roasting temperature of 240 °C, roasting time of 2 h, water leaching time of 90 min, water leaching temperature of 65 °C water leaching liquid to solid ratio of 3:1, the leaching rate of K from BCFA reached 97%. The leachate was crystallised by evaporation to obtain K, N compound fertiliser for agricultural use. The leaching residue is mainly Al and Si, which can be used for the preparation of refractory materials, aluminium and silicon molecular sieves, construction materials and other raw materials