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This paper proposes a scalable lattice-Boltzmann computational framework (SBoTFlow) for simulations of flexible moving objects in an incompressible fluid flow. Behavior of fluid flow formed from moving boundaries of flexible-object motions is obtained through the multidirect forcing immersed boundary scheme associated with the lattice Boltzmann equation with a parallel topology-confined block refinement framework. We first demonstrate that the hydrodynamic quantities computed in this manner for standard benchmarks, including the Tayler-Green vortex flow and flow over an obstacle-embedded lid-driven cavity and an isolated circular cylinder, agree well with those previously published in the literature. We then exploit the framework to probe the underlying dynamic properties contributing to fluid flow under flexible motions at different Reynolds numbers by simulating large-scale flapping wing motions of both amplitude and frequency. The analysis shows that the proposed numerical framework for pitching and flapping motions has a strong ability to accurately capture high amplitudes, specifically up to $64^\circ$, and a frequency of $f=1/2.5\pi$. This suggests that the present parallel numerical framework has the potential to be used in studying flexible motions, such as insect flight or wing aerodynamics.

We present a differentiable greenhouse simulation model based on physical processes whose parameters can be obtained by training from real data. The physics-based simulation model is fully interpretable and is able to do state prediction for both climate and crop dynamics in the greenhouse over very a long time horizon. The model works by constructing a system of linear differential equations and solving them to obtain the next state. We propose a procedure to solve the differential equations, handle the problem of missing unobservable states in the data, and train the model efficiently. Our experiment shows the procedure is effective. The model improves significantly after training and can simulate a greenhouse that grows cucumbers accurately., Comment: Accepted at the Machine Learning and the Physical Sciences workshop, NeurIPS 2022. 7 pages, 2 figures

This paper studies a Group Influence with Minimum cost which aims to find a seed set with smallest cost that can influence all target groups, where each user is associated with a cost and a group is influenced if the total score of the influenced users belonging to the group is at least a certain threshold. As the group-influence function is neither submodular nor supermodular, theoretical bounds on the quality of solutions returned by the well-known greedy approach may not be guaranteed. To address this challenge, we propose a bi-criteria polynomial-time approximation algorithm with high certainty. At the heart of the algorithm is a novel group reachable reverse sample concept, which helps speed up the estimation of the group influence function. Finally, extensive experiments conducted on real social networks show that our proposed algorithm outperform the state-of-the-art algorithms in terms of the objective value and the running time., Comment: The paper contains some errors

Cost-aware Targeted Viral Marketing (CTVM), a generalization of Influence Maximization (IM), has received a lot of attentions recently due to its commercial values. Previous approximation algorithms for this problem required a large number of samples to ensure approximate guarantee. In this paper, we propose an efficient approximation algorithm which uses fewer samples but provides the same theoretical guarantees based on generating and using important samples in its operation. Experiments on real social networks show that our proposed method outperforms the state-of-the-art algorithm which provides the same approximation ratio in terms of the number of required samples and running time.

We compare the branching ratios for $b\rightarrow s\gamma$ and $\mu\rightarrow e\gamma$ in terms of constraining the parameter space in supersymmetric SO(10) grand unification models where supersymmetry is broken softly near the Planck scale by generationally symmetric operators. We observe two general cases. One with small $\tan\beta =2$ and the other one with large $\tan\beta$ having third generation Yukawa coupling unification at the GUT scale. \newline\indent We show that for small $\tan\beta$ the branching ratio constraints allow only a smaller region of parameter space for $\mu>0$ compared to $\mu<0$ for gluino mass $\alt$ 500 GeV. With large $\tan\beta$, we find acceptable regions of parameter space with $\left|\mu \right|\alt 1$ TeV only for $\mu<0$. The dominant constraint on large $\tan\beta$ with $\mu >0$ parameter space is found to be given by the $b\rightarrow s\gamma$ branching ratio, while for large $\tan\beta$ with $\mu <0$ it is found to be given by the $\mu\rightarrow e\gamma$ branching ratio. In many of these acceptable regions, we find that the $\mu\rightarrow e\gamma$ branching ratio is predicted to be within one order of magnitude of its current experimental bound. We also show that the usually neglected gluino mediated diagrams in $b\rightarrow s\gamma$ can not be ignored in some regions of parameter space, especially for large $\tan\beta$ scenarios when the gluino mass is near its lower experimental bound., Comment: 14 pages (Latex), 4 PS figs (uuencoded, epsf.tex), slight modification in text, as to appear in Physics Letters B

If the standard electroweak gauge model is extended to include two or more Higgs doublets, there may be a neutral Higgs boson $h$ which is light (with a mass of say 10 GeV) but the $hZZ$ coupling is suppressed so that it has so far escaped experimental detection. However, the effective $hhZZ$ coupling is generally unsuppressed, hence the decay of Z into two light Higgs bosons plus a fermion-antifermion pair may have an observable branching fraction, especially if $h$ decays invisibly as for example in the recently proposed doublet Majoron model., Comment: 10 pages, LaTex, figures available upon request to evan@ucrphh.ucr.edu

In two recently proposed supersymmetric extended electroweak gauge models, the reduced Higgs sector at the 100-GeV energy scale consists of only two doublets, but they have quartic scalar couplings different from those of the minimal supersymmetric standard model. In the SU(2) X SU(2) X U(1) model, there is an absolute upper bound of about 145 GeV on the mass of the lightest neutral scalar boson. In the SU(3) X U(1) model, there is only a parameter-dependent upper bound which formally goes to infinity in a particular limit, Comment: 9 pages (6 figures not included), UCRHEP-T128 (July 1994)

We consider a supersymmetric version of the recently proposed SU(3) X U(1) extended gauge model. We show that it is possible to have only two Higgs doublets at the SU(2) X U(1) energy scale but they are not those of the minimal supersymmetric standard model. In particular, the upper bound on the lightest scalar boson of this model is $4 M_Z \sin \theta_W$ at tree level and goes up to 189 GeV after radiative corrections., Comment: 9 pages, Univ. of California, Riverside Report No. UCRHEP-T111, June 1993

In extensions of the standard model, light scalar particles are often possible because of symmetry considerations. We study the decay of the Z boson into such particles. In particular, we consider for illustration the scalar sector of a recently proposed model of the 17-keV neutrino which satisfies all laboratory, astrophysical, and cosmological constraints., Comment: 11 pages (2 figures, not included) (Revised, Oct 1992). Some equations have been corrected and 1 figure has been eliminated