13,899 research outputs found
Participatory varietal selection of potato using the mother & baby trial design: A gender-responsive trainer’s guide.
This guide aims to provide step-by-step guidance on facilitating and documenting the PVS dynamics using the MBT design to select, and eventually release, potato varieties preferred by end-users that suit male and female farmers ’different needs, diverse agro-systems, and management practices, as well as traders ’and consumers’ preferences
WCAM: secured video surveillance with digital rights management
The WCAM project aims to provide an integrated system for secure delivery of video surveillance data over a wireless network, while remaining scalable and robust to transmission errors. To achieve these goals., the content is encoded in Motion-JPEG2000 and streamed with a specific RTP protocol encapsulation to prevent the loss of packets containing the most essential data. Protection of the video data is performed at content level using the standardized JPSEC syntax along with flexible encryption of quality layers or resolution levels. This selective encryption respects the JPEG2000 structure of the stream, not only ensuring end-to-end ciphered delivery, but also enabling dynamic content adaptation within the wireless network (quality of service, adaptation to the user's terminal). A DRM (Digital Rights Management) solution, called OpenSDRM is added to manage all authenticated peers on the WLAN (from end-users to cameras), as well as to manage the rights to access and display conditionally the video data. This whole integrated architecture addresses several security problems such as data encryption, integrity, access control and rights management. Using several protection lavers, the level of confidentiality can depend both on content characteristics and user rights, thus also addressing the critical issue of privacy.info:eu-repo/semantics/acceptedVersio
Entanglement and the nonlinear elastic behavior of forests of coiled carbon nanotubes
Helical or coiled nanostructures have been object of intense experimental and
theoretical studies due to their special electronic and mechanical properties.
Recently, it was experimentally reported that the dynamical response of
foamlike forest of coiled carbon nanotubes under mechanical impact exhibits a
nonlinear, non-Hertzian behavior, with no trace of plastic deformation. The
physical origin of this unusual behavior is not yet fully understood. In this
work, based on analytical models, we show that the entanglement among
neighboring coils in the superior part of the forest surface must be taken into
account for a full description of the strongly nonlinear behavior of the impact
response of a drop-ball onto a forest of coiled carbon nanotubes.Comment: 4 pages, 3 figure
A development approach to industrial robots programming
This paper proposes a development approach to industrial
robot programming, that includes: a truly high
level and declarative language; an easy-to-use frontend;
an intermediate representation; an automatic generator
of the robot code generators. So, we introduce
a new paradigm to program industrial robots, that focus
on the modeling of the system, rather than on the
robot. It will improve the programming and maintenance
tasks, allowing the reuse of source code, because
this source code will be machine independent
Uma proposta de linguagem de programação para robótica
Este artigo destina-se a apresentar alguns problemas existentes nas
linguagens de programacĂŁo de robĂ´s, e uma possĂvel solucĂŁo dos mesmos atravĂ©s da utilização da linguagem Reativa SĂncrona RS. Uma implementacĂŁo prática
será apresentada a fim de mostrar como o uso desta linguagem pode facilitar
o desenvolvimento de programas para os robĂ´s, neste caso, industriais. Entretanto,
verifica-se a necessidade da existência de um módulo intermediário responsável por traduzir uma linguagem declarativa para código final de diferentes
robĂ´s, a fim de garantir a portabilidade de cĂłdigo.This paper presents some existing problems in robotics programming
languages and a possible solution using a reactive and synchronous language
called RS. An implementation will show how the RS language can facilitate
the robot´s programming, in this case, industrial robots. However, it should be
necessary to create an intermediate module responsible for translating a declarative
language to assembly code, in different robots, granting code portability
Young Measures Generated by Ideal Incompressible Fluid Flows
In their seminal paper "Oscillations and concentrations in weak solutions of
the incompressible fluid equations", R. DiPerna and A. Majda introduced the
notion of measure-valued solution for the incompressible Euler equations in
order to capture complex phenomena present in limits of approximate solutions,
such as persistence of oscillation and development of concentrations.
Furthermore, they gave several explicit examples exhibiting such phenomena. In
this paper we show that any measure-valued solution can be generated by a
sequence of exact weak solutions. In particular this gives rise to a very
large, arguably too large, set of weak solutions of the incompressible Euler
equations.Comment: 35 pages. Final revised version. To appear in Arch. Ration. Mech.
Ana
A graphical interface based on grafcet for programming industrial robots off-line
This paper presents the current development stage of our approach to industrial robot programming, that is the graphical interface for our environment, that is based on the well-known Grafcet. Our approach focus on
the modelling of the system, rather than on the robot. So, it will improve the programming and maintenance tasks, allowing the reuse of source code.Fundação para a Ciência e a Tecnologia (FCT
Coherent photon assisted cotunneling in a Coulomb blockade device
We study cotunneling in a double junction Coulomb blockade device under the
influence of time dependent potentials. It is shown that the ac-bias leads to
photon assisted cotunneling which in some cases may dominate the transport. We
derive a general non-perturbative expression for the tunneling current in the
presence of oscillating potentials and give a perturbative expression for the
photon assisted cotunneling current.Comment: Replaced with a longer paper which includes a non-perturbative
calculation. 13 pages with 1 figure. To be published in Physical Review
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