8,623 research outputs found
Modeling user navigation
This paper proposes the use of neural networks as a tool for studying navigation within virtual worlds. Results indicate that the network learned to predict the next step for a given trajectory. The analysis of hidden layer shows that the network was able to differentiate between two groups of users identified on the basis of their performance for a spatial task. Time series analysis of hidden node activation values and input vectors suggested that certain hidden units become specialised for place and heading, respectively. The benefits of this approach and the possibility of extending the methodology to the study of navigation in Human Computer Interaction applications are discussed
Technologies for Beneficial Microorganisms Inocula Used as Biofertilizers
The increasing need for environmentaly friendly agricultural practices is driving the use of fertilizers based on beneficial microorganisms. The latter belong to a wide array of genera, classes, and phyla, ranging from bacteria to yeasts and fungi, which can support plant nutrition with different mechanisms. Moreover, studies on the interactions between plant, soil, and the different microorganisms are shedding light on their interrelationships thus providing new possible ways to exploit them for agricultural purposes. However, even though the inoculation of plants with these microorganisms is a well-known practice, the formulation of inocula with a reliable and consistent effect under field conditions is still a bottleneck for their wider use. The choice of the technology for inocula production and of the carrier for the formulation is key to their successful application. This paper focuses on how inoculation issues can be approached to improve the performance of beneficial microorganisms used as a tool for enhancing plant growth and yield
61 Planowanie leczenia raka piersi po tumorektomi z wykorzystaniem przystawki tomograficznej symulatora Ximatron
Uzyskanie przekrojów tomograficznych klatki piersiowej napromienianych chorych z rakiem piersi jest bardzo utrudnione, a czasem wręcz niemożliwe. Przyczyną są: specyficzne ułożenie pacjentki oraz zbyt mała standardowa średnica otworu gantry w klasycznym aparacie tomograficznym. Przekroje te można obecnie otrzymać za pomocą nowoczesnych stymulatorów wyposażonych w przystawki tomograficzne. Obrazy poprzecznych przekrojów pacjentki przesyłane są siecią komputerową do systemu planowania leczenia.Przedstawiono przykład sposobu unieruchomienia pacjentki podczas symulacji i napromieniania, obrazy tomograficzne uzyskane z wykorzystaniem przystawki tomograficznej symulatora Ximatron oraz przykład komputerowego planu 3D (CADPLN) leczenie raka piersi
Potential and current distribution in strongly anisotropic Bi(2)Sr(2) CaCu(2)O(8) single crystals at current breakdown
Experiments on potential differences in the low-temperature vortex solid
phase of monocrystalline platelets of superconducting Bi(2)Sr(2)CaCu(2)O(8)
(BSCCO) subjected to currents driven either through an "ab" surface or from one
such surface to another show evidence of a resistive/nonresistive front moving
progressively out from the current contacts as the current increases. The depth
of the resistive region has been measured by a novel in-depth voltage probe
contact. The position of the front associated with an injection point appears
to depend only on the current magnitude and not on its withdrawal point. It is
argued that enhanced nonresistive superconducting anisotropy limits current
penetration to less than the London length and results in a flat rectangular
resistive region with simultaneous "ab" and "c" current breakdown which moves
progressively out from the injection point with increasing current.
Measurements in "ab" or "c" configurations are seen to give the same
information, involving both ab-plane and c-axis conduction properties.Comment: 9 pages, 13 figures, typo error corrected, last section was refine
Life table analysis of Diaphorina citri (Hemiptera: Psyllidae) infesting sweet orange (Citrus sinensis) in São Paulo
An ecological life table for eggs and nymphs of Diaphorina citri Kuwayama (Hemiptera:
Psyllidae) was constructed with data obtained from orange orchards (Citrus sinensis Osbeck) in 2 regions of the State of São Paulo, over 4 generations in the period from XI-2006
to V-2007, comprising spring, summer, and fall seasons. Young growing shoots with D. citri
eggs present were identifed, and live individuals were counted until adult emergence. No
predatory arthropods were observed in association with D. citri eggs and nymphs during
the study. The mean parasitism of fourth- and ffth-instar nymphs by Tamarixia radiata
Waterston (Hymenoptera: Eulophidae) was 2.3%. The durations of the egg–adult period
were similar among the 4 generations, ranging from 18.0 to 24.7 d (at mean temperatures
ranging from 21.6 to 26.0 °C) and followed the temperature requirement models obtained
in the laboratory for D. citri. However, survival from the egg to the adult stage for the same
period varied considerably from 1.7 to 21.4%; the highest mortalities were observed in the
egg and small nymphal (frst- to thirdinstar) stages, which were considered to be key phases
for population growth of the pest.Uma tabela de vida ecológica foi construída para ovos e ninfas de Diaphorina citri Kuwayama (Hemiptera: Psyllidae) com dados obtidos em pomares de laranja (Citrus sinensis Osbeck) em 2 regiões do estado de São Paulo, com 4 gerações, no período de novembro de 2006
a maio de 2007, compreendendo as estações de primavera, verão e outono. Ramos jovens
em crescimento com a presença de ovos de D. citri foram identificados e os indivíduos vivos
foram contados até a emergência dos adultos. Nenhum predador foi observado associado a
ovos e ninfas de D. citri durante o estudo. A taxa média de parasitismo de ninfas de quarto
e quinto ínstares por Tamarixia radiata Waterson (Hymenoptera: Eulophidae) foi de 2.3%.
A duração do período de ovo a adulto foi semelhante entre as quatro gerações, variando de
18.0 a 24.7 dias (com temperaturas médias de 21.6 a 26.0 °C) e seguiram os modelos de
exigencias térmicas obtidas em laboratório para D. citri. Todavia, a sobrevivencia de ovo
até o estágio adulto variou consideravelmente para o mesmo período, de 1.7 a 21.4%, sendo
que as maiores mortalidades foram observadas nos estágios de ovos e ninfas pequenas (de
primeiro a terceiro ínstares), as quais foram consideradas fases chaves para o crescimento
populacional desta praga.info:eu-repo/semantics/publishedVersio
UNIMIB@NEEL-IT: Named Entity Recognition and Linking of Italian Tweets
Questo articolo descrive il sistema proposto dal gruppo UNIMIB per il task di Named Entity Recognition and Linking applicato a tweet in lingua italiana (NEEL-IT). Il sistema, che rappresenta un approccio iniziale al problema, \ue8 costituito da tre passaggi fondamentali: (1) Named Entity Recognition tramite l\u2019utilizzo di Conditional Random Fields, (2) Named Entity Linking considerando sia approcci supervisionati sia modelli di linguaggio basati su reti neurali, e (3) NIL clustering tramite un approccio basato su grafi.This paper describes the framework proposed by the UNIMIB Team for the task of Named Entity Recognition and Linking of Italian Tweets (NEEL-IT). The proposed pipeline, which represents an entry level system, is composed of three main steps: (1) Named Entity Recognition using Conditional Random Fields, (2) Named Entity Linking by considering both Supervised and Neural-Network Language models, and (3) NIL clustering byusing a graph-based approach
Determination of the residual life time of thin-walled structural elements under high temperature creep
A calculation model for evaluation of sub critical crack propagation hightemperature
creep in metallic plates is proposed. The model is based on the first low of
thermodynamics on energy balance and the balance of energy change velocity in a metallic
plate, containing a macro crack and subjected to long-term static loading tension under hightemperature
field effect, thus providing the process of stable creep in the process zone near
the crack tip. On the basis of above mentioned the equation with original and final conditions
are obtained that composed the mathematical model for determining the sub critical crack
growth period under high-temperature creep in metallic plates
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