598 research outputs found
A quantum interface between light and nuclear spins in quantum dots
The coherent coupling of flying photonic qubits to stationary matter-based
qubits is an essential building block for quantum communication networks. We
show how such a quantum interface can be realized between a traveling-wave
optical field and the polarized nuclear spins in a singly charged quantum dot
strongly coupled to a high-finesse optical cavity. By adiabatically eliminating
the electron a direct effective coupling is achieved. Depending on the laser
field applied, interactions that enable either write-in or read-out are
obtained.Comment: 10 pages, 5 figures, final versio
Social Network Privacy: Expectations vs Reality
This study is an initial step in a larger study which explores issues associated with security and privacy in social network sites (SNSs). Sites such as Facebook, MySpace, LinkedIn, Bebo, Ning and others have increased in popularity and are receiving increased attention from industry and academics as SNSs move beyond the youth market. Most SNSs are targeted towards individuals, yet they are impacting organizations and will change the way business is conducted in the future. Utilizing a survey of MBA students from two US institutions, this study explores the issue of privacy and proposes a model which addresses the risks, expectations, and reality of social networking privacy. It also outlines an agenda for future research
CLIPSwarm: Converting text into formations of robots
We present CLIPSwarm, an algorithm to generate robot swarm formations from
natural language descriptions. CLIPSwarm receives an input text and finds the
position of the robots to form a shape that corresponds to the given text. To
do so, we implement a variation of the Montecarlo particle filter to obtain a
matching formation iteratively. In every iteration, we generate a set of new
formations and evaluate their Clip Similarity with the given text, selecting
the best formations according to this metric. This metric is obtained using
Clip, [1], an existing foundation model trained to encode images and texts into
vectors within a common latent space. The comparison between these vectors
determines how likely the given text describes the shapes. Our initial proof of
concept shows the potential of this solution to generate robot swarm formations
just from natural language descriptions and demonstrates a novel application of
foundation models, such as CLIP, in the field of multi-robot systems. In this
first approach, we create formations using a Convex-Hull approach. Next steps
include more robust and generic representation and optimization steps in the
process of obtaining a suitable swarm formation.Comment: Please cite this article as "P. Pueyo, E. Montijano, A. C. Murillo,
and M. Schwager, CLIPSwarm: Converting text into formations of robots. ICRA
2023 Workshop on Multi-Robot Learning
CineTransfer: Controlling a Robot to Imitate Cinematographic Style from a Single Example
This work presents CineTransfer, an algorithmic framework that drives a robot
to record a video sequence that mimics the cinematographic style of an input
video. We propose features that abstract the aesthetic style of the input
video, so the robot can transfer this style to a scene with visual details that
are significantly different from the input video. The framework builds upon
CineMPC, a tool that allows users to control cinematographic features, like
subjects' position on the image and the depth of field, by manipulating the
intrinsics and extrinsics of a cinematographic camera. However, CineMPC
requires a human expert to specify the desired style of the shot (composition,
camera motion, zoom, focus, etc). CineTransfer bridges this gap, aiming a fully
autonomous cinematographic platform. The user chooses a single input video as a
style guide. CineTransfer extracts and optimizes two important style features,
the composition of the subject in the image and the scene depth of field, and
provides instructions for CineMPC to control the robot to record an output
sequence that matches these features as closely as possible. In contrast with
other style transfer methods, our approach is a lightweight and portable
framework which does not require deep network training or extensive datasets.
Experiments with real and simulated videos demonstrate the system's ability to
analyze and transfer style between recordings, and are available in the
supplementary video
An Examination of the Benefits of E-Business to Small and Medium Size Businesses
Small and Medium Sized Enterprises (SME) play a significant part in economies throughout the world. In the early developmental stages of e-commerce/e-business many believed that it would enable these SMEs to compete head-to-head with large companies. While much has been done to examine the adoption of e-commerce/e-business, few have addressed the benefit that it is providing these businesses. This study identifies the types of e-commerce that SMEs are using and examines the benefits that are received from this use
Asymmetric optical nuclear spin pumping in a single uncharged quantum dot
A highly asymmetric dynamic nuclear spin pumping is observed in a single self
assembled InGaAs quantum dot subject to resonant optical pumping of the neutral
exciton transition leading to a large maximum polarization of 54%. This dynamic
nuclear polarization is found to be much stronger following pumping of the
higher energy Zeeman state. Time-resolved measurements allow us to directly
monitor the buildup of the nuclear spin polarization in real time and to
quantitatively study the dynamics of the process. A strong dependence of the
observed dynamic nuclear polarization on the applied magnetic field is found,
with resonances in the pumping efficiency being observed for particular
magnetic fields. We develop a model that fully accounts for the observed
behaviour, where the pumping of the nuclear spin system is due to
hyperfine-mediated spin flip transitions between the states of the neutral
exciton manifold.Comment: published version; 4+ pages, 3 figures (eps
Recommended from our members
Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata
Background: The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results: In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions: Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc expression. The broader expression of Po-cnc with respect to Po-Dfd in chelicerates further suggests that the regulation of cnc by Dfd was also acquired at the base of Mandibulata. To test this hypothesis, future studies examining panarthropod cnc evolution should investigate expression of the cnc ortholog in arthropod outgroups, such as Onychophora and Tardigrada
SOCIAL NETWORK PRIVACY: EXPECTATIONS VS. REALITY (RESEARCH IN PROGRESS)
ABSTRACT This study is an initial step in a larger study which explores issues associated with security and privacy in social network sites (SNSs). Sites such as Facebook, MySpace, LinkedIn, Bebo, Ning and others have increased in popularity and are receiving increased attention from industry and academics as SNSs move beyond the youth market. Most SNSs are targeted towards individuals, yet they are impacting organizations and will change the way business is conducted in the future. Utilizing a survey of MBA students from two US institutions, this study explores the issue of privacy and proposes a model which addresses the risks, expectations, and reality of social networking privacy. It also outlines an agenda for future research
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