4,967 research outputs found
Unsteady adjoint of pressure loss for a fundamental transonic turbine vane
High fidelity simulations, e.g., large eddy simulation are often needed for
accurately predicting pressure losses due to wake mixing in turbomachinery
applications. An unsteady adjoint of such high fidelity simulations is useful
for design optimization in these aerodynamic applications. In this paper we
present unsteady adjoint solutions using a large eddy simulation model for a
vane from VKI using aerothermal objectives. The unsteady adjoint method is
effective in capturing the gradient for a short time interval aerothermal
objective, whereas the method provides diverging gradients for long
time-averaged thermal objectives. As the boundary layer on the suction side
near the trailing edge of the vane is turbulent, it poses a challenge for the
adjoint solver. The chaotic dynamics cause the adjoint solution to diverge
exponentially from the trailing edge region when solved backwards in time. This
results in the corruption of the sensitivities obtained from the adjoint
solutions. An energy analysis of the unsteady compressible Navier-Stokes
adjoint equations indicates that adding artificial viscosity to the adjoint
equations can potentially dissipate the adjoint energy while potentially
maintain the accuracy of the adjoint sensitivities. Analyzing the growth term
of the adjoint energy provides a metric for identifying the regions in the flow
where the adjoint term is diverging. Results for the vane from simulations
performed on the Titan supercomputer are demonstrated.Comment: ASME Turbo Expo 201
Multiparticle Bell's inequalities involving many measurement settings
We present a prescription for obtaining Bell's inequalities for N>2 observers
involving more than two alternative measurement settings. We give examples of
some families of such inequalities. The inequalities are violated by certain
classes of states for which all standard Bell's inequalities with two
measurement settings per observer are satisfied.Comment: 4 pages, RevTeX
Detection of N-particle entanglement with generalized Bell inequalities
We show that the generalized Bell-type inequality, explicitly involving
rotational symmetry of physical laws, is very efficient in distinguishing
between true N-particle quantum correlations and correlations involving less
particles. This applies to various types of generalized partial separabilities.
We also give a rigorous proof that the new Bell inequalities are maximally
violated by the GHZ states, and find a very handy description of the N-qubit
correlation function.Comment: 5 pages, minor typos corrected, journal versio
Supporting the Algebra I Curriculum with an Introduction to Computational Thinking Course
The Louisiana Workforce Commission predicts a 33.6% increase in computer science and mathematical occupations by 2022 and the Bureau of Labor Statistics foresees a 16% increase in computer scientists from 2018-2028. Despite these opportunities for job and financial security, the number of Louisiana students enrolled in a nationally accredited computing course is less than 1%, compared to national leaders California and Texas which have 3% and 3.8% of students respectively. Furthermore, the international assessments of mathematical literacy, PISA and TIMMS, both report American students continue to fall further behind their international peers in mathematics achievement.
This thesis rejects these statistics as definitive and attempts to contribute to an expansion of the mathematical libraries of a computational thinking course that a teacher could use to support a standards-based Algebra I course. The framework presented in this thesis supports the Louisiana State University (LSU) STEM Pathway course entitled Introduction to Computational Thinking (ICT). The course introduces students to a systematic problem-solving approach in which they learn to solve problems computationally, that is, through abstraction, decomposition, and pattern recognition. ICT utilizes the functional programming language Haskell in the educational programming environment âCodeWorldâ in order to create pictures and animations.
Jean Piaget, the great child cognitive development psychologist, proclaimed âThe goal of intellectual education is not to know how to repeat or retain ready-made truthsâ; rather, one becomes educated by âlearning to master the truth by oneselfâ (Piaget, 1973). Because of the graphical outputs that one can easily code in CodeWorld, students have the ability to explore an algebraic concept with a computer programmed model, alongside the textbookâs given table, equation and graph. This thesis provides additional projects for supporting the Algebra I curriculum through LSUâs ICT course and an overview of the history of computing with an emphasis on highlighting some of the attempts that were undertaken within the past 80 years to use computational thinking and programming to support problem solving across disciplines, including the humanities, math and sciences
A Two-Coordinate Nickel Imido Complex That Effects CâH Amination
An exceptionally low coordinate nickel imido complex, (IPr*)NiâN(dmp) (2) (dmp = 2,6-dimesitylphenyl), has been prepared by the elimination of N_2 from a bulky aryl azide in its reaction with (IPr*)Ni(η^6-C_7H_8) (1). The solid-state structure of 2 features two-coordinate nickel with a linear CâNiâN core and a short NiâN distance, both indicative of multiple-bond character. Computational studies using density functional theory showed a NiâN bond dominated by Ni(dÏ)âN(pÏ) interactions, resulting in two nearly degenerate singly occupied molecular orbitals (SOMOs) that are NiâN Ï* in character. Reaction of 2 with CO resulted in nitrene-group transfer to form (dmp)NCO and (IPr*)Ni(CO)_3 (3). Net CâH insertion was observed in the reaction of 2 with ethene, forming the vinylamine (dmp)NH(CHâCH_2) (5) via an azanickelacyclobutane intermediate, (IPr*)Ni{N,C:Îș^2-N(dmp)CH_2CH_2} (4)
Yeah, Right, Uh-Huh: A Deep Learning Backchannel Predictor
Using supporting backchannel (BC) cues can make human-computer interaction
more social. BCs provide a feedback from the listener to the speaker indicating
to the speaker that he is still listened to. BCs can be expressed in different
ways, depending on the modality of the interaction, for example as gestures or
acoustic cues. In this work, we only considered acoustic cues. We are proposing
an approach towards detecting BC opportunities based on acoustic input features
like power and pitch. While other works in the field rely on the use of a
hand-written rule set or specialized features, we made use of artificial neural
networks. They are capable of deriving higher order features from input
features themselves. In our setup, we first used a fully connected feed-forward
network to establish an updated baseline in comparison to our previously
proposed setup. We also extended this setup by the use of Long Short-Term
Memory (LSTM) networks which have shown to outperform feed-forward based setups
on various tasks. Our best system achieved an F1-Score of 0.37 using power and
pitch features. Adding linguistic information using word2vec, the score
increased to 0.39
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