734 research outputs found
A 17 degree of freedom anthropomorphic manipulator
A 17 axis anthropomorphic manipulator, providing coordinated control of two seven degree of freedom arms mounted on a three degree of freedom torso-waist assembly, is presented. This massively redundant telerobot, designated the Robotics Research K/B-2017 Dexterous Manipulator, employs a modular mechanism design with joint-mounted actuators based on brushless motors and harmonic drive gear reducers. Direct joint torque control at the servo level causes these high-output joint drives to behave like direct-drive actuators, facilitating the implementation of an effective impedance control scheme. The redundant, but conservative motion control system models the manipulator as a spring-loaded linkage with viscous damping and rotary inertia at each joint. This approach allows for real time, sensor-driven control of manipulator pose using a hierarchy of competing rules, or objective functions, to avoid unplanned collisions with objects in the workplace, to produce energy-efficient, graceful motion, to increase leverage, to control effective impedance at the tool or to favor overloaded joints
AI Extenders
Humans and AI systems are usually portrayed as separate sys- tems that we need to align in values and goals. However, there is a great deal of AI technology found in non-autonomous systems that are used as cognitive tools by humans. Under the extended mind thesis, the functional contributions of these tools become as essential to our cognition as our brains. But AI can take cognitive extension towards totally new capabil- ities, posing new philosophical, ethical and technical chal- lenges. To analyse these challenges better, we define and place AI extenders in a continuum between fully-externalized systems, loosely coupled with humans, and fully-internalized processes, with operations ultimately performed by the brain, making the tool redundant. We dissect the landscape of cog- nitive capabilities that can foreseeably be extended by AI and examine their ethical implications. We suggest that cognitive extenders using AI be treated as distinct from other cognitive enhancers by all relevant stakeholders, including developers, policy makers, and human users.Leverhulme Centre for the Future of Intelligence, Leverhulme Trust, under Grant RC-2015-06
Finite Element Model Update via Bayesian Estimation and Minimization of Dynamic Residuals
Flipped gaming-testing three simulation games
© 2018 IEEE. At the Inland Norway University of Applied Sciences 'flipped gaming' has been tested with two student groups (in 2017). This paper will present a newer version of the 'flipping' and also how a total of eight groups utilized tree different types of simulators to play the scenarios. The scenarios were developed by the student themselves as this was their mandatory assignment. The mandatory assignment was handed out in January. The assignment was about making a playable script for an incident, in addition to conduct the planning, execution and evaluation of a complete exercise in crisis management. They were given feedback once before the workshop where they presented and played the script. The tools that were used was Rayvn (https://rayvn.global/), Microsoft HoloLens (https://www.microsoft.com/nb-no/hololens) and a simulator based on a platform from Bohemia Interactive Solutions (https://bisimulations.com/)-the same platform as Virtual Battle Space 3 uses. Rayvn is an incident management tool, mainly for communication. The written messages can then be logged and stored for later reflections. Microsoft HoloLens is a tool for 3D vision, a tool that can show environments in 3D and allow the player to carry out operations using movements that are recorded and executed. This was a prototype. The game based simulator is computer based. The different views are 2D maps and 3D environments. The players use the keyboard and mouse to move the vehicles and avatars around. This in a 'disaster town', called 'Lyngvik', a very poor planned city centre with a large accident/crisis potential. The study is based on the previous study of the learning outcome from assignment that is based on student input. The mandatory assignment was to develop a playable scenario and they could choose in which of the three different simulation tools they were to play their scenario. Two by two, the groups are to play each other's scenario. They have received some supervision and the lecturers have remarked on that the students may lack insight in what a 'playable scenario' require. One of the groups operates as the exercise management staff(the ones that makes the incidents happen and 'play out') and the other group is the ones who man the different roles in handling the scenario e.g.,-different call out services. This group is also calledmain training audience (MTA). The students are in their 6th and last semester in their Bachelor in Crisis Management. The students have been subjected to diverse teaching methods, but this is the first time they have a simulation tool to work with in order to enhance their learning outcome. The preliminary reports from the reflections after the simulating are very positive. The students report on a learning outcome, both from making the scenarios and from simulating. There is also a final report to be written where the students are to reflect on their learning outcome from the simulation and the work on the assignment. The paper shows the results from the whole undertaking and presents further details from the different phases. We also present the theoretical backdrop and the methodological reasoning behind the data collection and analysis
Crossover effects in a discrete deposition model with Kardar-Parisi-Zhang scaling
We simulated a growth model in 1+1 dimensions in which particles are
aggregated according to the rules of ballistic deposition with probability p or
according to the rules of random deposition with surface relaxation (Family
model) with probability 1-p. For any p>0, this system is in the
Kardar-Parisi-Zhang (KPZ) universality class, but it presents a slow crossover
from the Edwards-Wilkinson class (EW) for small p. From the scaling of the
growth velocity, the parameter p is connected to the coefficient of the
nonlinear term of the KPZ equation, lambda, giving lambda ~ p^gamma, with gamma
= 2.1 +- 0.2. Our numerical results confirm the interface width scaling in the
growth regime as W ~ lambda^beta t^beta, and the scaling of the saturation time
as tau ~ lambda^(-1) L^z, with the expected exponents beta =1/3 and z=3/2 and
strong corrections to scaling for small lambda. This picture is consistent with
a crossover time from EW to KPZ growth in the form t_c ~ lambda^(-4) ~ p^(-8),
in agreement with scaling theories and renormalization group analysis. Some
consequences of the slow crossover in this problem are discussed and may help
investigations of more complex models.Comment: 16 pages, 7 figures; to appear in Phys. Rev.
imported berry mix cake suspected to be the source of infection in Norway
Ongoing hepatitis A outbreak in Europe 2013 to 2014
Abrupt grain boundary melting in ice
The effect of impurities on the grain boundary melting of ice is investigated
through an extension of Derjaguin-Landau-Verwey-Overbeek theory, in which we
include retarded potential effects in a calculation of the full frequency
dependent van der Waals and Coulombic interactions within a grain boundary. At
high dopant concentrations the classical solutal effect dominates the melting
behavior. However, depending on the amount of impurity and the surface charge
density, as temperature decreases, the attractive tail of the dispersion force
interaction begins to compete effectively with the repulsive screened Coulomb
interaction. This leads to a film-thickness/temperature curve that changes
depending on the relative strengths of these interactions and exhibits a
decrease in the film thickness with increasing impurity level. More striking is
the fact that at very large film thicknesses, the repulsive Coulomb interaction
can be effectively screened leading to an abrupt reduction to zero film
thickness.Comment: 8 pages, 1 figur
Nucleon Edm from Atomic Systems and Constraints on Supersymmetry Parameters
The nucleon EDM is shown to be directly related to the EDM of atomic systems.
From the observed EDM values of the atomic Hg system, the neutron EDM can be
extracted, which gives a very stringent constraint on the supersymmetry
parameters. It is also shown that the measurement of Nitrogen and Thallium
atomic systems should provide important information on the flavor dependence of
the quark EDM. We perform numerical analyses on the EDM of neutron, proton and
electron in the minimal supersymmetric standard model with CP-violating phases.
We demonstrate that the new limit on the neutron EDM extracted from atomic
systems excludes a wide parameter region of supersymmetry breaking masses above
1 TeV, while the old limit excludes only a small mass region below 1 TeV.Comment: 10 pages, 7 figure file
The Parallel Complexity of Growth Models
This paper investigates the parallel complexity of several non-equilibrium
growth models. Invasion percolation, Eden growth, ballistic deposition and
solid-on-solid growth are all seemingly highly sequential processes that yield
self-similar or self-affine random clusters. Nonetheless, we present fast
parallel randomized algorithms for generating these clusters. The running times
of the algorithms scale as , where is the system size, and the
number of processors required scale as a polynomial in . The algorithms are
based on fast parallel procedures for finding minimum weight paths; they
illuminate the close connection between growth models and self-avoiding paths
in random environments. In addition to their potential practical value, our
algorithms serve to classify these growth models as less complex than other
growth models, such as diffusion-limited aggregation, for which fast parallel
algorithms probably do not exist.Comment: 20 pages, latex, submitted to J. Stat. Phys., UNH-TR94-0
Growth model with restricted surface relaxation
We simulate a growth model with restricted surface relaxation process in d=1
and d=2, where d is the dimensionality of a flat substrate. In this model, each
particle can relax on the surface to a local minimum, as the Edwards-Wilkinson
linear model, but only within a distance s. If the local minimum is out from
this distance, the particle evaporates through a refuse mechanism similar to
the Kim-Kosterlitz nonlinear model. In d=1, the growth exponent beta, measured
from the temporal behavior of roughness, indicates that in the coarse-grained
limit, the linear term of the Kardar-Parisi-Zhang equation dominates in short
times (low-roughness) and, in asymptotic times, the nonlinear term prevails.
The crossover between linear and nonlinear behaviors occurs in a characteristic
time t_c which only depends on the magnitude of the parameter s, related to the
nonlinear term. In d=2, we find indications of a similar crossover, that is,
logarithmic temporal behavior of roughness in short times and power law
behavior in asymptotic times
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