23 research outputs found
Super-NeRF: View-consistent Detail Generation for NeRF super-resolution
The neural radiance field (NeRF) achieved remarkable success in modeling 3D
scenes and synthesizing high-fidelity novel views. However, existing NeRF-based
methods focus more on the make full use of the image resolution to generate
novel views, but less considering the generation of details under the limited
input resolution. In analogy to the extensive usage of image super-resolution,
NeRF super-resolution is an effective way to generate the high-resolution
implicit representation of 3D scenes and holds great potential applications. Up
to now, such an important topic is still under-explored. In this paper, we
propose a NeRF super-resolution method, named Super-NeRF, to generate
high-resolution NeRF from only low-resolution inputs. Given multi-view
low-resolution images, Super-NeRF constructs a consistency-controlling
super-resolution module to generate view-consistent high-resolution details for
NeRF. Specifically, an optimizable latent code is introduced for each
low-resolution input image to control the 2D super-resolution images to
converge to the view-consistent output. The latent codes of each low-resolution
image are optimized synergistically with the target Super-NeRF representation
to fully utilize the view consistency constraint inherent in NeRF construction.
We verify the effectiveness of Super-NeRF on synthetic, real-world, and
AI-generated NeRF datasets. Super-NeRF achieves state-of-the-art NeRF
super-resolution performance on high-resolution detail generation and
cross-view consistency
ImmersiveNeRF: Hybrid Radiance Fields for Unbounded Immersive Light Field Reconstruction
This paper proposes a hybrid radiance field representation for unbounded
immersive light field reconstruction which supports high-quality rendering and
aggressive view extrapolation. The key idea is to first formally separate the
foreground and the background and then adaptively balance learning of them
during the training process. To fulfill this goal, we represent the foreground
and background as two separate radiance fields with two different spatial
mapping strategies. We further propose an adaptive sampling strategy and a
segmentation regularizer for more clear segmentation and robust convergence.
Finally, we contribute a novel immersive light field dataset, named
THUImmersive, with the potential to achieve much larger space 6DoF immersive
rendering effects compared with existing datasets, by capturing multiple
neighboring viewpoints for the same scene, to stimulate the research and AR/VR
applications in the immersive light field domain. Extensive experiments
demonstrate the strong performance of our method for unbounded immersive light
field reconstruction
Reflare in MAXI J1348-630]{Evolution of disc and corona in MAXI J1348-630 during the 2019 reflare: NICER and Insight-HXMT view
In this work, using \textit{NICER} and \textit{Insight}-HXMT observations, we
present a study of the broadband spectral and timing evolution of the source
throughout the first reflare, which occurred about 4 months after the major
outburst. Our findings suggest that during the reflare, below a critical
luminosity (D/2.2 kpc) erg s,
the scale of the corona shrinks in the radial direction, whereas the inner
radius of the disk does not change considerably; however, the inner radius of
the disk starts to move inward when the source exceeds the critical luminosity.
We conclude that at low luminosity the increase in accretion rate only heats up
the inner zone of the accretion disc without the transfer of angular momentum
which occurs above a certain luminosity
Service utilization in community health centers in China: a comparison analysis with local hospitals
BACKGROUND: Being an important part of China's Urban Health Care Reform System, Community Health Centers (CHCs) have been established throughout the entire country and are presently undergoing substantial reconstruction. However, the services being delivered by the CHCs are far from reaching their performance targets. In order to assess the role of the CHCs, we examined their performance in six cities located in regions of South-East China. The purpose of this investigation was to identify the utilization and the efficiency of community health resources that are able to provide basic medical and public health services. METHODS: The study was approved by Peking University Health Science Center Institutional Reviewing Board (NO: IRB00001052-T1). Data were collected from all the local health bureaux and processed using SPSS software. Methods of analysis mainly included: descriptive analysis, paired T-test and one-way ANOVA. RESULTS: The six main functions of the CHCs were not fully exploited and the surveys that were collected on their efficiency and utilization of resources indicate that they have a low level of performance and lack the trust of local communities. Furthermore, the CHCs seriously lack funding support and operate under difficult circumstances, and residents have less positive attitudes towards them. CONCLUSION: The community health service must be adjusted according to the requirements of urban medical and health reform, taking into account communities' health needs. More research is required on the living standards and health needs of residents living within the CHC's range, taking into consideration the users' needs in expanding the newly implemented service, and at the same time revising the old service system so as to make the development of CHCs realistic and capable of providing a better service to patients. Several suggestions are put forward for an attainable scheme for developing a community health service