182,111 research outputs found
Automated weighing by sequential inference in dynamic environments
We demonstrate sequential mass inference of a suspended bag of milk powder
from simulated measurements of the vertical force component at the pivot while
the bag is being filled. We compare the predictions of various sequential
inference methods both with and without a physics model to capture the system
dynamics. We find that non-augmented and augmented-state unscented Kalman
filters (UKFs) in conjunction with a physics model of a pendulum of varying
mass and length provide rapid and accurate predictions of the milk powder mass
as a function of time. The UKFs outperform the other method tested - a particle
filter. Moreover, inference methods which incorporate a physics model
outperform equivalent algorithms which do not.Comment: 5 pages, 7 figures. Copyright IEEE (2015
Scaling universalities of kth-nearest neighbor distances on closed manifolds
Take N sites distributed randomly and uniformly on a smooth closed surface.
We express the expected distance from an arbitrary point on the
surface to its kth-nearest neighboring site, in terms of the function A(l)
giving the area of a disc of radius l about that point. We then find two
universalities. First, for a flat surface, where A(l)=\pi l^2, the k-dependence
and the N-dependence separate in . All kth-nearest neighbor distances
thus have the same scaling law in N. Second, for a curved surface, the average
\int d\mu over the surface is a topological invariant at leading and
subleading order in a large N expansion. The 1/N scaling series then depends,
up through O(1/N), only on the surface's topology and not on its precise shape.
We discuss the case of higher dimensions (d>2), and also interpret our results
using Regge calculus.Comment: 14 pages, 2 figures; submitted to Advances in Applied Mathematic
Experiences with Problem-Based Learning: Virginia Initiative for Science Teaching and Achievement
The Virginia Initiative for Science Teaching and Achievement (VISTA) provides high-quality professional development for teachers and administrators to enhance the quality of their science instructional programs. One emphasis of this program is helping teachers learn to implement Problem-Based Learning in the elementary science classroom. Problem-Based Learning (PBL) has the potential to produce significant positive outcomes for students, such as increased student engagement, and opportunities for in-depth critical thinking [1]. Teachers find PBL challenging because it does take additional time for planning and material acquisition, but experience has shown that the benefits outweigh these challenges. Setting clear goals, identifying specific learning objectives, and developing big questions that tie these together help increase the success of the unit. Additionally, administrators can help teachers succeed in implementing a Problem-Based Learning unit by understanding the dynamic nature of the PBL environment, providing flexibility with unit pacing, and setting aside time for refining, reflection, and revision of the unit
Dirac Triplet Extension of the MSSM
In this paper we explore extensions of the Minimal Supersymmetric Standard
Model involving two triplet chiral superfields that share a
superpotential Dirac mass yet only one of which couples to the Higgs fields.
This choice is motivated by recent work using two singlet superfields with the
same superpotential requirements. We find that, as in the singlet case, the
Higgs mass in the triplet extension can easily be raised to
without introducing large fine-tuning. For triplets that carry hypercharge, the
regions of least fine tuning are characterized by small contributions to the
parameter, and light stop squarks, ; the latter is a result of the dependence of
the triplet contribution to the Higgs mass. Despite such light stop masses,
these models are viable provided the stop-electroweakino spectrum is
sufficiently compressed.Comment: 26 pages, 4 figure
Study and applications of retrodirective and self-adaptive electromagnetic wave controls to a Mars probe First quarterly report
Antenna array studies for future Mars probe
Edge usage, motifs and regulatory logic for cell cycling genetic networks
The cell cycle is a tightly controlled process, yet its underlying genetic
network shows marked differences across species. Which of the associated
structural features follow solely from the ability to impose the appropriate
gene expression patterns? We tackle this question in silico by examining the
ensemble of all regulatory networks which satisfy the constraint of producing a
given sequence of gene expressions. We focus on three cell cycle profiles
coming from baker's yeast, fission yeast and mammals. First, we show that the
networks in each of the ensembles use just a few interactions that are
repeatedly reused as building blocks. Second, we find an enrichment in network
motifs that is similar in the two yeast cell cycle systems investigated. These
motifs do not have autonomous functions, but nevertheless they reveal a
regulatory logic for cell cycling based on a feed-forward cascade of activating
interactions.Comment: 9 pages, 9 figures, to be published in Phys. Rev.
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