20,962 research outputs found
SmartMirror: A Glance into the Future
In todays society, information is available to us at a glance through our phones, our laptops, our desktops, and more. But an extra level of interaction is required in order to access the information. As technology grows, technology should grow further and further away from the traditional style of interaction with devices. In the past, information was relayed through paper, then through computers, and in todays day and age, through our phones and multiple other mediums. Technology should become more integrated into our lives - more seamless and more invisible. We hope to push the envelope further, into the future. We propose a new simple way of connecting with your morning newspaper. We present our idea, the SmartMirror, information at a glance. Our system aims to deliver your information quickly and comfortably, with a new modern aesthetic. While modern appliances require input through modules such as keyboards or touch screen, we hope to follow a model that can function purely on voice and gesture. We seek to deliver your information during your morning routine and throughout the day, when taking out your phone is not always possible. This will cater to a larger audience base, as the average consumer nowadays hopes to accomplish tasks with minimal active interaction with their adopted technology. This idea has many future applications, such as integration with new virtual or augmented reality devices, or simplifying consumer personal media sources
Seeing in Color: Jet Superstructure
A new class of observables is introduced which aims to characterize the
superstructure of an event, that is, features, such as color flow, which are
not determined by the jet four-momenta alone. Traditionally, an event is
described as having jets which are independent objects; each jet has some
energy, size, and possible substructure such as subjets or heavy flavor
content. This description discards information connecting the jets to each
other, which can be used to determine if the jets came from decay of a color
singlet object, or if they were initiated by quarks or gluons. An example
superstructure variable, pull, is presented as a simple handle on color flow.
It can be used on an event-by-event basis as a tool for distinguishing
previously irreducible backgrounds at the Tevatron and the LHC.Comment: 4 pages, 5 figures. Published version. Some clarifications and
references adde
Resilient Understanding: The Value of Seeing for Oneself
The primary aim of this paper is to argue that the value of understanding derives in part from a kind of subjective stability of belief that we call epistemic resilience. We think that this feature of understanding has been overlooked by recent work, and we think it’s especially important to the value of understanding for social cognitive agents such as us. We approach the concept of epistemic resilience via the idea of the experience of epistemic ownership and argue that the former concept has Platonic pedigree. Contrary to longstanding exegetical tradition, we think that Plato solves the “Meno problem” with an appeal to the epistemic resilience characteristic of understanding, not the well-groundedness characteristic of canonical cases of propositional knowledge. Finally, we apply our discussion to the case of science outreach and the challenge of global warming skepticism and conclude with directions for future research
Quark and Gluon Tagging at the LHC
Being able to distinguish light-quark jets from gluon jets on an
event-by-event basis could significantly enhance the reach for many new physics
searches at the Large Hadron Collider. Through an exhaustive search of existing
and novel jet substructure observables, we find that a multivariate approach
can filter out over 95% of the gluon jets while keeping more than half of the
light-quark jets. Moreover, a combination of two simple variables, the charge
track multiplicity and the -weighted linear radial moment (girth), can
achieve similar results. While this pair appears very promising, our study is
only Monte Carlo based, and other discriminants may work better with real data
in a realistic experimental environment. To that end, we explore many other
observables constructed using different jet sizes and parameters, and highlight
those that deserve further theoretical and experimental scrutiny. Additional
information, including distributions of around 10,000 variables, can be found
on this website http://jets.physics.harvard.edu/qvg .Comment: 5 pages, 3 figures. v2 published versio
MD boundary conditions for pressure gradient flows : nano-mixing and nano-droplet deformation in extensional flows
We present new algorithms for simulating pressure gradient flows in molecular dynamics (MD) simulations. Nano-channel inlet and outlet non-periodic boundary conditions are implemented using hydrodynamic state reservoirs and flux boundary models at arbitrary boundaries of the domain geometry. We demonstrate the new method in a complex nano-mixer configuration and for droplet deformation in extensional flow channels. The technique which we propose is applicable to any complex nano-channel configuration, and may serve as a useful tool in engineering design of nano-scale applications
Holographic Holes and Differential Entropy
Recently, it has been shown by Balasubramanian et al. and Myers et al. that
the Bekenstein-Hawking entropy formula evaluated on certain closed surfaces in
the bulk of a holographic spacetime has an interpretation as the differential
entropy of a particular family of intervals (or strips) in the boundary theory.
We first extend this construction to bulk surfaces which vary in time. We then
give a general proof of the equality between the gravitational entropy and the
differential entropy. This proof applies to a broad class of holographic
backgrounds possessing a generalized planar symmetry and to certain classes of
higher-curvature theories of gravity. To apply this theorem, one can begin with
a bulk surface and determine the appropriate family of boundary intervals by
considering extremal surfaces tangent to the given surface in the bulk.
Alternatively, one can begin with a family of boundary intervals; as we show,
the differential entropy then equals the gravitational entropy of a bulk
surface that emerges from the intersection of the neighboring entanglement
wedges, in a continuum limit.Comment: 62 pages; v2: minor improvements to presentation, references adde
Molecular dynamics simulations of liquid flow in and around carbon nanotubes
Using recently-developed fluid state controllers [1], we apply continuum fluid boundary conditions to molecular dynamics (MD) simulations of liquid argon flow past a carbon nanotube (CNT) and through a CNT membrane. Advantages of this method are that it: is not dependent on periodic boundary conditions; can accurately generate fluid transport without any geometrical constraints; and is capable of performing as an essential part of a hybrid continuum/atomistic technique. In our simulations, a pressure gradient is applied across a CNT membrane by controlling the densities of two reservoirs located either side of the membrane. Fluid velocity and density distributions are reported and compared to other published data where possible
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