2,428 research outputs found
Knowledge representation system for assembly using robots
Assembly robots combine the benefits of speed and accuracy with the capability of adaptation to changes in the work environment. However, an impediment to the use of robots is the complexity of the man-machine interface. This interface can be improved by providing a means of using a priori-knowledge and reasoning capabilities for controlling and monitoring the tasks performed by robots. Robots ought to be able to perform complex assembly tasks with the help of only supervisory guidance from human operators. For such supervisory quidance, it is important to express the commands in terms of the effects desired, rather than in terms of the motion the robot must undertake in order to achieve these effects. A suitable knowledge representation can facilitate the conversion of task level descriptions into explicit instructions to the robot. Such a system would use symbolic relationships describing the a priori information about the robot, its environment, and the tasks specified by the operator to generate the commands for the robot
Quantum information in base n defined by state partitions
We define a "nit" as a radix n measure of quantum information which is based
on state partitions associated with the outcomes of n-ary observables and
which, for n>2, is fundamentally irreducible to a binary coding. Properties of
this measure for entangled many-particle states are discussed. k particles
specify k nits in such a way that k mutually commuting measurements of
observables with n possible outcomes are sufficient to determine the
information.Comment: 4 pages, 2 figure
Different approaches to community detection
A precise definition of what constitutes a community in networks has remained
elusive. Consequently, network scientists have compared community detection
algorithms on benchmark networks with a particular form of community structure
and classified them based on the mathematical techniques they employ. However,
this comparison can be misleading because apparent similarities in their
mathematical machinery can disguise different reasons for why we would want to
employ community detection in the first place. Here we provide a focused review
of these different motivations that underpin community detection. This
problem-driven classification is useful in applied network science, where it is
important to select an appropriate algorithm for the given purpose. Moreover,
highlighting the different approaches to community detection also delineates
the many lines of research and points out open directions and avenues for
future research.Comment: 14 pages, 2 figures. Written as a chapter for forthcoming Advances in
network clustering and blockmodeling, and based on an extended version of The
many facets of community detection in complex networks, Appl. Netw. Sci. 2: 4
(2017) by the same author
MEASURING CONSUMER PREFERENCES FOR ECOLABELED SEAFOOD: AN INTERNATIONAL COMPARISON
An analysis of consumer preferences for seafood labeled with information about environmental production attributes is introduced into the food labeling literature. International seafood ecolabeling programs have proposed to create market-based incentives for fisheries managers to promote sustainable fisheries. We investigate differences in consumer preferences for ecolabeled seafood across the United States and Norway. Using a contingent-choice telephone survey of random households in each nation, a wide range of factors is found to influence consumers' likelihood of purchasing ecolabeled seafood. Consumer preferences differ by price premium, species, consumer group, and certifying agency. The effect of these factors often differs between the United States and Norway, suggesting heterogeneity in international reactions to seafood ecolabels.Consumer/Household Economics,
Protection of Nonimmune Volunteers against Rubella by Intravenous Administration of Normal Human Gamma Globulin
Standard gamma globulin, treated with pepsin and injected intravenously five days after infection, conferred passive protection against rubella on five volunteers. Intravenous injection of gamma globulin is superior to intramuscular injection, because the antibodies enter the bloodstream immediately, and an amount of antibody sufficient for protection can be given. Injection of standard gamma globulin is recommended when gamma globulin hyperimmune to rubella virus is unavailabl
Towards the H.E.S.S. Galactic Plane Survey Gamma-Ray Source Catalog
This thesis deals with the creation of a catalog of Galactic gamma-ray sources using a multiscale detection and morphology characterisation method. The analysis is based on maps of the H.E.S.S. Galactic Plane Survey (HGPS), generated from observations between 2004 and 2013. The emission of the Galactic plane is modelled with a Likelihood-Fit procedure, assuming a Gaussian source morphology. The identified shell-type supernova remnants Vela Junior, HESS J1731-347 and RX J1713.7-3946 are excluded from the analysis. Applying a detection threshold of TS = 30 a total number of 112 source components is obtained. The existence of large, low surface brightness emission underneath known sources is revealed. The origin of this unresolved emission is not known. Furthermore it is observed, that bright extended sources decompose into multiple components, because the morphology assumption does not match the data well enough. First a reference catalog is defined, dealing with these issues by manually classifying and merging source components, using previous H.E.S.S. publications as guidance. A total number of 78 sources in the survey region is found. For all sources the position, extension and ux with uncertainties are determined. The brightness of the sources varies between 0:7% Crab and 80% Crab. The size of the source ranges between σ=0:006° and σ=0:64°. In a second step automatic methods are developed and examined to classify unresolved components by simple cuts in size and significance and to merge components into sources by defining a suitable overlap criterion. The reference catalog can be reproduced except for a few cases, which are discussed in detail
Study of effect of arbuscular mycorrhiza (Glomus intraradices) fungus on wheat under nickel stress
ArticleIn many regions of the world soils are contaminated with heavy metals and therefore
restricted in their use. For instance, the absorption of nickel (Ni) in the tissue
of plants increase
the plant’s metabolism and cause physiological disorders or even death. Arbuscular mycorrhizal
fungi are known to enhance the tolerance of host plants to abiotic and biotic stress. Thus, we
investigated the potential of the arbuscular m
ycorrhizal fungi
Glomus intraradices
to mitigate
deleterious effects of Ni in wheat. The experiment was conducted using four levels of Ni (0, 60,
120 and 180
mg
per
kg of soil) and two levels of mycorrhizal fungi application (with and without
Glomus intrar
adices
). Nickel stress significantly decreased seed number per spike, thousand
-
seed
weight, seed yield per plant, concentration of chlorophyll a and b. At the same time, we found
increased catalase (CAT) enzyme activity and dityrosine (DT) treatments.
Mycorrhizal fungi
application attenuated Ni effects, i.e. fungal presence increased seed number per spike, thousand
-
seed weight, chlorophyll a and b. Furthermore mycorrhizal fungi application reduce CAT enzyme
activity and DT. In general, our results sugge
st that mycorrhizal fungi application reduces harmful
effects of Ni stress in wheat
- …