187 research outputs found
The Role of Human-Automation Consensus in Multiple Unmanned Vehicle Scheduling
Objective: This study examined the impact of increasing automation replanning rates on operator performance and workload when supervising a decentralized network of heterogeneous unmanned vehicles. Background: Futuristic unmanned vehicles systems will invert the operator-to-vehicle ratio so that one operator can control multiple dissimilar vehicles connected through a decentralized network. Significant human-automation collaboration will be needed because of automation brittleness, but such collaboration could cause high workload. Method: Three increasing levels of replanning were tested on an existing multiple unmanned vehicle simulation environment that leverages decentralized algorithms for vehicle routing and task allocation in conjunction with human supervision. Results: Rapid replanning can cause high operator workload, ultimately resulting in poorer overall system performance. Poor performance was associated with a lack of operator consensus for when to accept the automation’s suggested prompts for new plan consideration as well as negative attitudes toward unmanned aerial vehicles in general. Participants with video game experience tended to collaborate more with the automation, which resulted in better performance. Conclusion: In decentralized unmanned vehicle networks, operators who ignore the automation’s requests for new plan consideration and impose rapid replans both increase their own workload and reduce the ability of the vehicle network to operate at its maximum capacity. Application: These findings have implications for personnel selection and training for futuristic systems involving human collaboration with decentralized algorithms embedded in networks of autonomous systems.Aurora Flight Sciences Corp.United States. Office of Naval Researc
Spinodal Decomposition in a Binary Polymer Mixture: Dynamic Self Consistent Field Theory and Monte Carlo Simulations
We investigate how the dynamics of a single chain influences the kinetics of
early stage phase separation in a symmetric binary polymer mixture. We consider
quenches from the disordered phase into the region of spinodal instability. On
a mean field level we approach this problem with two methods: a dynamical
extension of the self consistent field theory for Gaussian chains, with the
density variables evolving in time, and the method of the external potential
dynamics where the effective external fields are propagated in time. Different
wave vector dependencies of the kinetic coefficient are taken into account.
These early stages of spinodal decomposition are also studied through Monte
Carlo simulations employing the bond fluctuation model that maps the chains --
in our case with 64 effective segments -- on a coarse grained lattice. The
results obtained through self consistent field calculations and Monte Carlo
simulations can be compared because the time, length, and temperature scales
are mapped onto each other through the diffusion constant, the chain extension,
and the energy of mixing. The quantitative comparison of the relaxation rate of
the global structure factor shows that a kinetic coefficient according to the
Rouse model gives a much better agreement than a local, i.e. wave vector
independent, kinetic factor. Including fluctuations in the self consistent
field calculations leads to a shorter time span of spinodal behaviour and a
reduction of the relaxation rate for smaller wave vectors and prevents the
relaxation rate from becoming negative for larger values of the wave vector.
This is also in agreement with the simulation results.Comment: Phys.Rev.E in prin
Adiabatic evolution of a coupled-qubit Hamiltonian
We present a general method for studying coupled qubits driven by
adiabatically changing external parameters. Extended calculations are provided
for a two-bit Hamiltonian whose eigenstates can be used as logical states for a
quantum CNOT gate. From a numerical analysis of the stationary Schroedinger
equation we find a set of parameters suitable for representing CNOT, while from
a time-dependent study the conditions for adiabatic evolution are determined.
Specializing to a concrete physical system involving SQUIDs, we determine
reasonable parameters for experimental purposes. The dissipation for SQUIDs is
discussed by fitting experimental data. The low dissipation obtained supports
the idea that adiabatic operations could be performed on a time scale shorter
than the decoherence time.Comment: 10 pages, 4 figures, to be pub.in Phys Rev
Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives
Purpose
This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care.
Design/methodology/approach
A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld.
Findings
This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation.
Research limitations/implications
This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only.
Practical implications
This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food.
Social implications
It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage.
Originality/value
This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence
Physical and emotional nourishment: Food as the embodied component of loving care of elderly family relatives
Purpose
This purpose of this study is to examine the fluidity of family life which continues to attract attention. This is increasingly significant for the intergenerational relationship between adult children and their elderly parents. Using practice theory, the aims are to understand the role of food in elderly families and explore how family practices are maintained when elderly transition into care.
Design/methodology/approach
A phenomenological research approach was used as the authors sought to build an understanding of the social interactions between family and their lifeworld.
Findings
This study extends theory on the relationship between the elderly parent and their family and explores through practice theory how families performed their love, how altered routines and long standing rituals provided structure to the elderly relatives and how care practices were negotiated as the elderly relatives transitioned from independence to dependence and towards care. A theoretical framework is introduced that provides guidance for the transition stages and the areas for negotiation.
Research limitations/implications
This research has implications for food manufacturers and marketers, as the demand for healthy food for the elderly is made more widely available, healthy and easy to prepare. The limitations of the research are due to the sample located in East Yorkshire only.
Practical implications
This research has implications for brand managers of food manufacturers and supermarkets that need to create product lines that target this segment by producing healthy, convenience food.
Social implications
It is also important for health and social care policy as the authors seek to understand the role of food, family and community and how policy can be devised to provide stability in this transitional and uncertain lifestage.
Originality/value
This research extends the body of literature on food and the family by focussing on the elderly cared for and their family. The authors show how food can be construed as loving care, and using practice theory, a theoretical framework is developed that can explain the transitions and how the family negotiates the stages from independence to dependence
Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA
An investigation of the hadronic final state in diffractive and
non--diffractive deep--inelastic electron--proton scattering at HERA is
presented, where diffractive data are selected experimentally by demanding a
large gap in pseudo --rapidity around the proton remnant direction. The
transverse energy flow in the hadronic final state is evaluated using a set of
estimators which quantify topological properties. Using available Monte Carlo
QCD calculations, it is demonstrated that the final state in diffractive DIS
exhibits the features expected if the interaction is interpreted as the
scattering of an electron off a current quark with associated effects of
perturbative QCD. A model in which deep--inelastic diffraction is taken to be
the exchange of a pomeron with partonic structure is found to reproduce the
measurements well. Models for deep--inelastic scattering, in which a
sizeable diffractive contribution is present because of non--perturbative
effects in the production of the hadronic final state, reproduce the general
tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil
A Search for Selectrons and Squarks at HERA
Data from electron-proton collisions at a center-of-mass energy of 300 GeV
are used for a search for selectrons and squarks within the framework of the
minimal supersymmetric model. The decays of selectrons and squarks into the
lightest supersymmetric particle lead to final states with an electron and
hadrons accompanied by large missing energy and transverse momentum. No signal
is found and new bounds on the existence of these particles are derived. At 95%
confidence level the excluded region extends to 65 GeV for selectron and squark
masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure
- …