1,028 research outputs found
Two New Upper Bounds for the Maximum k-plex Problem
A k-plex in a graph is a vertex set where each vertex is non-adjacent to at
most k vertices (including itself) in this set, and the Maximum k-plex Problem
(MKP) is to find the largest k-plex in the graph. MKP is a practical NP-hard
problem, and the k-plex model has many important real-world applications, such
as the analysis of various complex networks. Branch-and-bound (BnB) algorithms
are a type of well-studied and effective exact algorithms for MKP. Recent BnB
MKP algorithms involve two kinds of upper bounds based on graph coloring and
partition, respectively, that work in different perspectives and thus are
complementary with each other. In this paper, we first propose a new
coloring-based upper bound, termed Relaxed Graph Color Bound (RelaxGCB), that
significantly improves the previous coloring-based upper bound. Then we propose
another new upper bound, termed SeesawUB, inspired by the seesaw playing game,
that incorporates RelaxGCB and a partition-based upper bound in a novel way,
making use of their complementarity. We apply RelaxGCB and SeesawUB to
state-of-the-art BnB MKP algorithms and produce four new algorithms. Extensive
experiments show the excellent performance and robustness of the new algorithms
with our proposed upper bounds
KD-Club: An Efficient Exact Algorithm with New Coloring-based Upper Bound for the Maximum k-Defective Clique Problem
The Maximum k-Defective Clique Problem (MDCP) aims to find a maximum
k-defective clique in a given graph, where a k-defective clique is a relaxation
clique missing at most k edges. MDCP is NP-hard and finds many real-world
applications in analyzing dense but not necessarily complete subgraphs. Exact
algorithms for MDCP mainly follow the Branch-and-bound (BnB) framework, whose
performance heavily depends on the quality of the upper bound on the
cardinality of a maximum k-defective clique. The state-of-the-art BnB MDCP
algorithms calculate the upper bound quickly but conservatively as they ignore
many possible missing edges. In this paper, we propose a novel CoLoring-based
Upper Bound (CLUB) that uses graph coloring techniques ingeniously to detect
independent sets so as to detect missing edges ignored by the previous methods.
We then develop a new BnB algorithm for MDCP, called KD-Club, using CLUB in
both the preprocessing stage for graph reduction and the BnB searching process
for branch pruning. Extensive experiments show that KD-Club significantly
outperforms state-of-the-art BnB MDCP algorithms on the number of solved
instances within the cut-off time, having much smaller search tree and shorter
solving time on various benchmarks
Non-linear relationship between sleep duration and blood pressure in children with short stature
BackgroundEvidence regarding the relationship between sleep duration and blood pressure is controversial. Therefore, the aim of this study was to investigate the relationship between sleep duration and blood pressure in children with short stature.MethodsA total of 1,085 participants with short stature were enrolled from the Affiliated Hospital of Jining Medical University in China. The variables involved in this study included sleep duration, anthropometric indicators and biochemical parameters. Sleep duration was evaluated in a face-to-face interview.ResultsThe average age of the 1,085 selected participants was 10.2βΒ±β3.5 years old, and approximately 763 (70.32%) of them were male. The results of adjusted linear regression showed that sleep duration was negatively associated with systolic blood pressure z scores (SBP-Z) and diastolic blood pressure z scores (DBP-Z) after adjusting for confounders (Ξ² β0.07, 95% CI β0.13, β0.01 Pβ=β0.038; Ξ² β0.05, 95% CI β0.10, β0.01 Pβ=β0.035, respectively). A nonlinear relationship was detected between sleep duration and blood pressure, including SBP-Z, DBP-Z and mean arterial pressure z scores (MAP-Z). The inflection point of the nonlinear relationship between sleep duration and SBP-Z is 10β
h, and the inflection point of DBP-Z and MAP-Z is 8β
h.ConclusionThis study revealed a nonlinear relationship between sleep duration and blood pressure in children with short stature. The findings suggest that the optimal sleep duration in children with short stature was 8β10β
h, and sleep durations either too short or too long were associated with increased blood pressure levels
AvatarCraft: Transforming Text into Neural Human Avatars with Parameterized Shape and Pose Control
Neural implicit fields are powerful for representing 3D scenes and generating
high-quality novel views, but it remains challenging to use such implicit
representations for creating a 3D human avatar with a specific identity and
artistic style that can be easily animated. Our proposed method, AvatarCraft,
addresses this challenge by using diffusion models to guide the learning of
geometry and texture for a neural avatar based on a single text prompt. We
carefully design the optimization framework of neural implicit fields,
including a coarse-to-fine multi-bounding box training strategy, shape
regularization, and diffusion-based constraints, to produce high-quality
geometry and texture. Additionally, we make the human avatar animatable by
deforming the neural implicit field with an explicit warping field that maps
the target human mesh to a template human mesh, both represented using
parametric human models. This simplifies animation and reshaping of the
generated avatar by controlling pose and shape parameters. Extensive
experiments on various text descriptions show that AvatarCraft is effective and
robust in creating human avatars and rendering novel views, poses, and shapes.
Our project page is: https://avatar-craft.github.io/.Comment: ICCV 2023 Camera Read
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