1,055 research outputs found
Pulse-based, Periodic MPC for Irrigation in Smart and Sustainable Agriculture
Growing population together with global warm- ing and difficulty of access to water makes the increase of efficient and sustainable agriculture a priority. Undoubtedly, the recent development of low-cost IoT-based sensors and actuators entail great opportunities in this direction, since these devices can be easily deployed to implement advanced monitoring and irrigation control techniques at a farm scale. This paper proposes a pulse-based, periodic, economic pre- dictive controller. Its goal is to find the irrigation pulse trains that optimize water and energy consumption while ensuring adequate levels of soil moisture for the crops. To this purpose, the developed MPC makes use of soil moisture data at different depths, sent by a set of field sensors, and formulate a constrained optimization problem that takes into account water costs, electricity prices, and an accurate dynamical nonlinear agro-hydrological model. Its performance is tested by simulating real case-study, tests and shows that water and energy consumption can be significantly reduced
Integrating the RTO in the MPC: an adaptive gradient-based approach
Model Predictive Control (MPC) is the most used advanced control technique in process industries, since it ensures stability, constraints satisfaction and convergence to the setpoint. The optimal setpoint is calculated by the Real Time Optimizer (RTO), minimizing the economic objective taking into account the operational limits of the plant. Since RTO employs complex stationary nonlinear models to perform the optimization and a larger sampling time than the controller, the economic setpoints calculated by the RTO may be inconsistent for the MPC layer and the economic performance of the overall
controller may be worse than expected. The aim of this work is to propose an MPC controller that explicitly integrates the RTO into the MPC control layer. The proposed strategy is based on
the MPC for tracking; the optimization problem to be solved only requires one evaluation of the gradient of the economic cost function at each sampling time. Based on this gradient, a second
order approximation of the economic function is obtained and used in the MPC optimization problem resulting in a convex optimization problem. Recursive feasibility and convergence to the optimal equilibrium point is ensured
Pulse-based, Periodic MPC for Irrigation in Smart and Sustainable Agriculture
The growing population, together with global warming and the difficulty of accessing water, makes the
increase of efficient and sustainable agriculture a priority. Undoubtedly, the recent development of low-cost IoT-based sensors and actuators presents great opportunities in this direction, since these devices can be easily deployed to implement advanced monitoring and irrigation control techniques
at a farm scale. This paper proposes a pulse-based, periodic, economic predictive controller. Its goal is to find the irrigation pulse trains that optimize water and energy consumption while ensuring adequate levels of soil moisture for the crops. For this purpose, the developed MPC makes use of soil
moisture data at different depths, sent by a set of field sensors, and formulates a constrained optimization problem that takes into account water costs, electricity prices, and an accurate dynamical nonlinear agro-hydrological model. Its performance is tested by simulating real case studies, which
show that water and energy consumption can be significantly reduced
First detection of the 448 GHz H2O transition in space
We present the first detection of the ortho-H2O 4_23-3_30 transition at 448
GHz in space. We observed this transition in the local (z = 0.010) luminous
infrared (IR) galaxy ESO 320-G030 (IRAS F11506-3851) using the Atacama Large
Millimeter/submillimeter Array (ALMA). The water 4_23-3_30 emission, which
originates in the highly obscured nucleus of this galaxy, is spatially resolved
over a region of ~65 pc in diameter and shows a regular rotation pattern
compatible with the global molecular and ionized gas kinematics. The line
profile is symmetric and well fitted by a Gaussian with an integrated flux of
37.0 +- 0.7 Jy km s-1 . Models predict this water transition as a potential
collisionally excited maser transition. On the contrary, in this galaxy, we
find that the 4_23-3_30 emission is primarily excited by the intense far-IR
radiation field present in its nucleus. According to our modeling, this
transition is a probe of deeply buried galaxy nuclei thanks to the high dust
optical depths (tau_100{\mu}m > 1, N_H > 1e24 cm-2) required to efficiently
excite it.Comment: Accepted for publication in A&A Letters; 4 pages, 5 figure
Efecto de la motivación del entrenador sobre la carga interna y el rendimiento físico de un juego de fútbol reducido 3x3
Los juegos reducidos de fútbol son una estrategia de entrenamientomuy empleada en la actualidad. Manipulando sus parámetros configuradores,el entrenador puede conseguir diferentes propósitos. El objetivo del trabajofue analizar la influencia de la motivación del entrenador sobre la intensidad de un juego reducido (JR) de 3 contra 3 y su efecto sobre el rendimiento físico de jugadores de categoría alevín. Doce futbolistas realizaron el mismo juego reducido con motivación del entrenador (JME) y sin motivación del técnico(JSME). La carga interna de cada tarea fue cuantificada mediante el registro de la frecuencia cardíaca. Antes y después del JR los jugadores realizaron un test de velocidad (sprint de 30-m), un test de fuerza explosiva de piernas (testtriple Hop) y un test de agilidad (test de Illinois). La participación motivante del entrenador provoca una frecuencia cardíaca media, expresada como porcentaje de la frecuencia cardíaca máxima, significativamente mayor quela obtenida sin la motivación del entrenador (89.12±4.29% vs. 82.15±3.12%respectivamente). Además, se ha observado una pérdida significativa de rendimiento en el test de velocidad (5.15±0.21s pre-test y 5.43±0.27 s post-test),agilidad (20.25 ± 0.86s pre-test y 21.01±0.99s post-test) y salto con pierna hábil (4.88±0.43 m pre-test y 4.58±0.41 m post-test) tras realizar el JME.El JSME sólo provoca un descenso significativo del rendimiento en el testde velocidad (5.28±0.27s pre-test y 5.51±0.22s post-test). La motivación delentrenador aumenta la intensidad del JR 3 contra
Multi-phase feedback processes in the Sy2 galaxy NGC 5643
We study the multi-phase feedback processes in the central ~3 kpc of the
barred Sy 2 galaxy NGC 5643. We use observations of the cold molecular gas
(ALMA CO(2-1)) and ionized gas (MUSE IFU). We study different regions along the
outflow zone which extends out to ~2.3 kpc in the same direction (east-west) as
the radio jet, as well as nuclear/circumnuclear regions in the host galaxy
disk. The deprojected outflowing velocities of the cold molecular gas (median
Vcentral~189 km s^-1) are generally lower than those of the outflowing ionized
gas, which reach deprojected velocities of up to 750 km s^-1 close to the AGN,
and their spatial profiles follow those of the ionized phase. This suggests
that the outflowing molecular gas in the galaxy disk is being entrained by the
AGN wind. We derive molecular and ionized outflow masses of ~5.2x10^7 Msun and
8.5x10^4 Msun and molecular and ionized outflow mass rates of ~51 Msun yr^-1
and 0.14 Msun yr^-1. Therefore, the molecular phase dominates the outflow mass
and outflow mass rate, while the outflow kinetic power and momentum are similar
in both phases. However, the wind momentum load for the molecular and ionized
outflow phases are ~27-5 and <1, which suggests that the molecular phase is not
momentum conserving while the ionized one most certainly is. The molecular gas
content (~1.5x10^7 Msun) of the eastern spiral arm is approximately 50-70% of
the content of the western one. We interpret this as destruction/clearing of
the molecular gas produced by the AGN wind impacting in the host galaxy. The
increase of the molecular phase momentum implies that part of the kinetic
energy from the AGN wind is transmitted to the molecular outflow. This suggest
that in Sy-like AGN such as NGC 5643, the radiative/quasar and the
kinetic/radio AGN feedback modes coexist and may shape the host galaxies even
at kpc-scales via both positive and (mild) negative feedback.Comment: 26 pages, 21 figures, 5 tables. Astronomy and Astrophysics, Accepted
2020 September 11, in pres
Reproducibility of peak power output during a 10-s cycling maximal effort using different sampling rates
Compact molecular gas emission in local LIRGs among low- and high-z galaxies
We present new CO(2–1) observations of a representative sample of 24 local (z < 0.02) luminous infrared galaxies (LIRGs) at high spatial resolution (< 100 pc) from the Atacama Large Millimeter/submillimeter Array (ALMA). Our LIRGs lie above the main sequence (MS), with typical stellar masses in the range 1010–1011 M⊙ and SFR ∼ 30 M⊙ yr−1. We derive the effective radii of the CO(2–1) and the 1.3 mm continuum emissions using the curve-of-growth method. LIRGs show an extremely compact cold molecular gas distribution (median RCO ∼ 0.7 kpc), which is a factor 2 smaller than the ionized gas (median RHα ∼ 1.4 kpc), and 3.5 times smaller than the stellar size (median Rstar ∼ 2.4 kpc). The molecular size of LIRGs is similar to that of early-type galaxies (ETGs; RCO ∼ 1 kpc) and about a factor of 6 more compact than local spiral galaxies of similar stellar mass. Only the CO emission in low-z ULIRGs is more compact than these local LIRGs by a factor of 2. Compared to high-z (1 < z < 6) systems, the stellar sizes and masses of local LIRGs are similar to those of high-z MS star-forming galaxies (SFGs) and about a factor of 2–3 lower than submillimeter (submm) galaxies (SMGs). The molecular sizes of high-z MS SFGs and SMGs are larger than those derived for LIRGs by a factor of ∼3 and ∼8, respectively. Contrary to high-z SFGs and SMGs, which have comparable molecular and stellar sizes (median Rstar/RCO = 1.8 and 1.2, respectively), local LIRGs show more centrally concentrated molecular gas distribution (median Rstar/RCO = 3.3). A fraction of the low-z LIRGs and high-z galaxies share a similar range in the size of the ionized gas distribution, from 1 to 4 kpc. However, no LIRGs with a very extended (above 4 kpc) radius are identified, while for high-z galaxies no compact (less than 1 kpc) emission is detected. These results indicate that while low-z LIRGs and high-z MS SFGs have similar stellar masses and sizes, the regions of current star formation (traced by the ionized gas) and of potential star formation (traced by the molecular gas) are substantially smaller in LIRGs, and constrained to the central kiloparsec (kpc) region. High-z galaxies represent a wider population but their star-forming regions are more extended, even covering the entire extent of the galaxy. High-z galaxies have larger fractions of gas than low-z LIRGs, and therefore the formation of stars could be induced by interactions and mergers in extended disks or filaments with sufficiently large molecular gas surface density involving physical mechanisms similar to those identified in the central kpc of LIRGs
Generating Functions for Coherent Intertwiners
We study generating functions for the scalar products of SU(2) coherent
intertwiners, which can be interpreted as coherent spin network evaluations on
a 2-vertex graph. We show that these generating functions are exactly summable
for different choices of combinatorial weights. Moreover, we identify one
choice of weight distinguished thanks to its geometric interpretation. As an
example of dynamics, we consider the simple case of SU(2) flatness and describe
the corresponding Hamiltonian constraint whose quantization on coherent
intertwiners leads to partial differential equations that we solve.
Furthermore, we generalize explicitly these Wheeler-DeWitt equations for SU(2)
flatness on coherent spin networks for arbitrary graphs.Comment: 31 page
Gravitational collapse and naked singularities
Gravitational collapse is one of the most striking phenomena in gravitational
physics. The cosmic censorship conjecture has provided strong motivation for
researches in this field. In the absence of general proof for the censorship,
many examples have been proposed, in which naked singularity is the outcome of
gravitational collapse. Recent development has revealed that there are examples
of naked singularity formation in the collapse of physically reasonable matter
fields, although the stability of these examples is still uncertain. We propose
the concept of ``effective naked singularities'', which will be quite helpful
because general relativity has the limitation of its application for
high-energy end. The appearance of naked singularities is not detestable but
can open a window for new physics of strongly curved spacetimes.Comment: 12 pages, to appear in the Proceedings of the International
Conference on Gravitation and Cosmology (ICGC-2004), ed. by B.R. Iyer, V.
Kuriakose and C.V. Vishveshwara, published by Pramana, minor correction
- …