7,258 research outputs found
Shape similarity analysis by self-tuning locally constrained mixed-diffusion
Similarity analysis is a powerful tool for shape matching/retrieval and other computer vision tasks. In the literature, various shape (dis)similarity measures have been introduced. Different measures specialize on different aspects of the data. In this paper, we consider the problem of improving retrieval accuracy by systematically fusing several different measures. To this end, we propose the locally constrained mixeddiffusion method, which partly fuses the given measures into one and propagates on the resulted locally dense data space. Furthermore, we advocate the use of self-adaptive neighborhoods to automatically determine the appropriate size of the neighborhoods in the diffusion process, with which the retrieval performance is comparable to the best manually tuned kNNs. The superiority of our approach is empirically demonstrated on both shape and image datasets. Our approach achieves a score of 100% in the bull’s eye test on the MPEG-7 shape dataset, which is the best reported result to date.Lei Luo, Chunhua Shen, Chunyuan Zhang and Anton van den Henge
Unleashing the Power of Edge-Cloud Generative AI in Mobile Networks: A Survey of AIGC Services
Artificial Intelligence-Generated Content (AIGC) is an automated method for
generating, manipulating, and modifying valuable and diverse data using AI
algorithms creatively. This survey paper focuses on the deployment of AIGC
applications, e.g., ChatGPT and Dall-E, at mobile edge networks, namely mobile
AIGC networks, that provide personalized and customized AIGC services in real
time while maintaining user privacy. We begin by introducing the background and
fundamentals of generative models and the lifecycle of AIGC services at mobile
AIGC networks, which includes data collection, training, finetuning, inference,
and product management. We then discuss the collaborative cloud-edge-mobile
infrastructure and technologies required to support AIGC services and enable
users to access AIGC at mobile edge networks. Furthermore, we explore
AIGCdriven creative applications and use cases for mobile AIGC networks.
Additionally, we discuss the implementation, security, and privacy challenges
of deploying mobile AIGC networks. Finally, we highlight some future research
directions and open issues for the full realization of mobile AIGC networks
A Thermal Plume Model for the Martian Convective Boundary Layer
The Martian Planetary Boundary Layer [PBL] is a crucial component of the
Martian climate system. Global Climate Models [GCMs] and Mesoscale Models [MMs]
lack the resolution to predict PBL mixing which is therefore parameterized.
Here we propose to adapt the "thermal plume" model, recently developed for
Earth climate modeling, to Martian GCMs, MMs, and single-column models. The aim
of this physically-based parameterization is to represent the effect of
organized turbulent structures (updrafts and downdrafts) on the daytime PBL
transport, as it is resolved in Large-Eddy Simulations [LESs]. We find that the
terrestrial thermal plume model needs to be modified to satisfyingly account
for deep turbulent plumes found in the Martian convective PBL. Our Martian
thermal plume model qualitatively and quantitatively reproduces the thermal
structure of the daytime PBL on Mars: superadiabatic near-surface layer, mixing
layer, and overshoot region at PBL top. This model is coupled to surface layer
parameterizations taking into account stability and turbulent gustiness to
calculate surface-atmosphere fluxes. Those new parameterizations for the
surface and mixed layers are validated against near-surface lander
measurements. Using a thermal plume model moreover enables a first order
estimation of key turbulent quantities (e.g. PBL height, convective plume
velocity) in Martian GCMs and MMs without having to run costly LESs.Comment: 53 pages, 21 figures, paper + appendix. Accepted for publication in
Journal of Geophysical Research - Planet
The interpretation of the field angle dependence of the critical current in defect-engineered superconductors
We apply the vortex path model of critical currents to a comprehensive
analysis of contemporary data on defect-engineered superconductors, showing
that it provides a consistent and detailed interpretation of the experimental
data for a diverse range of materials. We address the question of whether
electron mass anisotropy plays a role of any consequence in determining the
form of this data and conclude that it does not. By abandoning this false
interpretation of the data, we are able to make significant progress in
understanding the real origin of the observed behavior. In particular, we are
able to explain a number of common features in the data including shoulders at
intermediate angles, a uniform response over a wide angular range and the
greater discrimination between individual defect populations at higher fields.
We also correct several misconceptions including the idea that a peak in the
angular dependence of the critical current is a necessary signature of strong
correlated pinning, and conversely that the existence of such a peak implies
the existence of correlated pinning aligned to the particular direction. The
consistency of the vortex path model with the principle of maximum entropy is
introduced.Comment: 14 pages, 7 figure
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