DSpace Community:
http://hdl.handle.net/2117/208
Sun, 05 Jul 2015 04:44:37 GMT20150705T04:44:37Zwebmaster.bupc@upc.eduUniversitat Politècnica de Catalunya. Servei de Biblioteques i DocumentaciónoConditions of consistency for multicomponent stellar systems. II. Is a pointaxial symmetric model suitable for the Galaxy?
http://hdl.handle.net/2117/28482
Title: Conditions of consistency for multicomponent stellar systems. II. Is a pointaxial symmetric model suitable for the Galaxy?
Authors: Cubarsí Morera, Rafael
Abstract: Under a common potential, a finite mixture of ellipsoidal velocity distributions satisfying the Boltzmann collisionless
equation provides a set of integrability conditions that may constrain the population kinematics. They are referred to as
conditions of consistency and were discussed in a previous paper on mixtures of axisymmetric populations. As a corollary,
these conditions are now extended to pointaxial symmetry, that is, point symmetry around the rotation axis or bisymmetry,
by determining which potentials are connected with a more flexible superposition of stellar populations. Under pointaxial
symmetry, the potential is still axisymmetric, but the velocity and mass distributions are not necessarily. A pointaxial stellar
system is, in a natural way, consistent with a flat velocity distribution of a disc population. Therefore, no additional integrability
conditions are required to solve the Boltzmann collisionless equation for such a population. For other populations, if the
potential is additively separable in cylindrical coordinates, the populations are not kinematically constrained, although under
pointaxial symmetry, the potential is reduced to the harmonic function, which, for the Galaxy, is proven to be nonrealistic.
In contrast, a nonseparable potential provides additional conditions of consistency. When mean velocities for the populations
are unconstrained, the potential becomes quasistationary, being a particular case of the axisymmetric model. Then, the radial
and vertical mean velocities of the populations can differ and produce an apparent vertex deviation of the whole velocity
distribution. However, single population velocity ellipsoids still have no vertex deviation in the Galactic plane and no tilt in
their intersection with a meridional Galactic plane. If the thick disc and halo ellipsoids actually have nonvanishing tilt, as the
surveys of the solar neighbourhood that include RAdial Velocity Experiment (RAVE) data seem to show, the pointaxial model
is unable to fit the local velocity distribution. Conversely, the axisymmetric model is capable of making a better approach. If,
in the end, more accurate data confirm a negligible tilt of the populations, then the pointaxisymmetric model will be able to
describe nonaxisymmetric mass and velocity distributions, although in the Galactic plane the velocity distribution will still be
axisymmetric.Wed, 01 Jul 2015 08:38:01 GMThttp://hdl.handle.net/2117/2848220150701T08:38:01ZCubarsí Morera, Rafaelnogalaxies: kinematics and dynamics – Galaxy: solar neighbourhood – galaxies: statisticsUnder a common potential, a finite mixture of ellipsoidal velocity distributions satisfying the Boltzmann collisionless
equation provides a set of integrability conditions that may constrain the population kinematics. They are referred to as
conditions of consistency and were discussed in a previous paper on mixtures of axisymmetric populations. As a corollary,
these conditions are now extended to pointaxial symmetry, that is, point symmetry around the rotation axis or bisymmetry,
by determining which potentials are connected with a more flexible superposition of stellar populations. Under pointaxial
symmetry, the potential is still axisymmetric, but the velocity and mass distributions are not necessarily. A pointaxial stellar
system is, in a natural way, consistent with a flat velocity distribution of a disc population. Therefore, no additional integrability
conditions are required to solve the Boltzmann collisionless equation for such a population. For other populations, if the
potential is additively separable in cylindrical coordinates, the populations are not kinematically constrained, although under
pointaxial symmetry, the potential is reduced to the harmonic function, which, for the Galaxy, is proven to be nonrealistic.
In contrast, a nonseparable potential provides additional conditions of consistency. When mean velocities for the populations
are unconstrained, the potential becomes quasistationary, being a particular case of the axisymmetric model. Then, the radial
and vertical mean velocities of the populations can differ and produce an apparent vertex deviation of the whole velocity
distribution. However, single population velocity ellipsoids still have no vertex deviation in the Galactic plane and no tilt in
their intersection with a meridional Galactic plane. If the thick disc and halo ellipsoids actually have nonvanishing tilt, as the
surveys of the solar neighbourhood that include RAdial Velocity Experiment (RAVE) data seem to show, the pointaxial model
is unable to fit the local velocity distribution. Conversely, the axisymmetric model is capable of making a better approach. If,
in the end, more accurate data confirm a negligible tilt of the populations, then the pointaxisymmetric model will be able to
describe nonaxisymmetric mass and velocity distributions, although in the Galactic plane the velocity distribution will still be
axisymmetric.An application of chanceconstrained model predictive control to inventory management in hospitalary pharmacy
http://hdl.handle.net/2117/28475
Title: An application of chanceconstrained model predictive control to inventory management in hospitalary pharmacy
Authors: Maestre Torreblanca, José María; Velarde, Pablo; Jurado, Isabel; OcampoMartínez, Carlos; Isla Tejera, Beatriz; del Prado, José Ramón
Abstract: Inventory management is one of the main tasks that the pharmacy department has to carry out in a hospital. It is a complex problem that requires to establish a tradeoff between different and contradictory optimization criteria. The complexity of the problem is increased due to the constraints
that naturally arise in this type of applications. In this paper, which corresponds to preliminary works performed to implement advanced control techniques for pharmacy management in two Spanish hospitals, we propose and assess chanceconstrained model predictive control (CCMPC) as a mean to relieve this issue.Tue, 30 Jun 2015 16:31:40 GMThttp://hdl.handle.net/2117/2847520150630T16:31:40ZMaestre Torreblanca, José María; Velarde, Pablo; Jurado, Isabel; OcampoMartínez, Carlos; Isla Tejera, Beatriz; del Prado, José Ramónnocontrol theory, optimisation, predictive control, pharmacy stocks, MPC, chance constraints, robust controlInventory management is one of the main tasks that the pharmacy department has to carry out in a hospital. It is a complex problem that requires to establish a tradeoff between different and contradictory optimization criteria. The complexity of the problem is increased due to the constraints
that naturally arise in this type of applications. In this paper, which corresponds to preliminary works performed to implement advanced control techniques for pharmacy management in two Spanish hospitals, we propose and assess chanceconstrained model predictive control (CCMPC) as a mean to relieve this issue.Conditions of consistency for multicomponent axisymmetric stellar systems. Is an axisymmetric model suitable yet?
http://hdl.handle.net/2117/28464
Title: Conditions of consistency for multicomponent axisymmetric stellar systems. Is an axisymmetric model suitable yet?
Authors: Cubarsí Morera, Rafael
Abstract: Solving the Boltzmann collisionless equatio n under the axisymmetric hypot hesis introduces serious lim itations on describing the kinematics of a single stellar system according to the local Galactic observables. Instead of relaxing the hypothesis of axisymmetry, one alternative is to assume a mixture model. For a finite mixture of ellipsoidal velocity distributions, the coexistence of several stellar populations sharing a co mmon potential introduces a set of conditions of consistency that m ay also constrain the population kinematics. For only a few potentials, the populations may have independent mean veloc ities and unconstrained velocity ellipsoids. In this paper, we determine which axisymmetric potentials are connect ed with a more flexible superposition of the stellar populations. The conditions of consistency are checked against recent results derived from kinematic surveys of the solar neighbourhood that include RAdial Velocity Experiment (RAVE) data. Several key observables are used to determine whether the axisymmetric mixture model is able to account for the main features of the local velocity distribution, such as the vertex deviation associated with the second central moment µ ¿ , the population radial mean velocities, the radial gradient of the moment µ z , the tilt of the velocity ellipsoids, and the existence of stars with no net rotation. In addition, the mixture moments for an arbitrary number of populations are derived in terms of the onetoone mean velocity di ff erences in order to study whether a more populated mixture could add any new features to the velocity distribution that remain unnoticed in a twocomponent mixture. According to this analysis, the quasistationary potential is the only potential allowing arbitrary directions of the population mean velocities. Then, the apparent vertex deviation of the total velocity distribution is due to the di ff erence of the mean velocities of the populations whose velocity ellipsoids hav e no vertex deviation. For a nonseparable pot ential, the population v elocity ellipsoids have the same orientation and point towards the Galactic centre. For a potential separable in addition in cylindrical coordinates, the population velocity ellipsoids may ha ve arbitrary tilt.Tue, 30 Jun 2015 08:51:39 GMThttp://hdl.handle.net/2117/2846420150630T08:51:39ZCubarsí Morera, Rafaelnogalaxies: kinematics and dynamics  Galaxy: solar neighbourhood  galaxies: statisticsSolving the Boltzmann collisionless equatio n under the axisymmetric hypot hesis introduces serious lim itations on describing the kinematics of a single stellar system according to the local Galactic observables. Instead of relaxing the hypothesis of axisymmetry, one alternative is to assume a mixture model. For a finite mixture of ellipsoidal velocity distributions, the coexistence of several stellar populations sharing a co mmon potential introduces a set of conditions of consistency that m ay also constrain the population kinematics. For only a few potentials, the populations may have independent mean veloc ities and unconstrained velocity ellipsoids. In this paper, we determine which axisymmetric potentials are connect ed with a more flexible superposition of the stellar populations. The conditions of consistency are checked against recent results derived from kinematic surveys of the solar neighbourhood that include RAdial Velocity Experiment (RAVE) data. Several key observables are used to determine whether the axisymmetric mixture model is able to account for the main features of the local velocity distribution, such as the vertex deviation associated with the second central moment µ ¿ , the population radial mean velocities, the radial gradient of the moment µ z , the tilt of the velocity ellipsoids, and the existence of stars with no net rotation. In addition, the mixture moments for an arbitrary number of populations are derived in terms of the onetoone mean velocity di ff erences in order to study whether a more populated mixture could add any new features to the velocity distribution that remain unnoticed in a twocomponent mixture. According to this analysis, the quasistationary potential is the only potential allowing arbitrary directions of the population mean velocities. Then, the apparent vertex deviation of the total velocity distribution is due to the di ff erence of the mean velocities of the populations whose velocity ellipsoids hav e no vertex deviation. For a nonseparable pot ential, the population v elocity ellipsoids have the same orientation and point towards the Galactic centre. For a potential separable in addition in cylindrical coordinates, the population velocity ellipsoids may ha ve arbitrary tilt.Chanceconstrained model predictive control applied to inventory management in hospitalary pharmacy
http://hdl.handle.net/2117/28328
Title: Chanceconstrained model predictive control applied to inventory management in hospitalary pharmacy
Authors: Maestre Torreblanca, José María; OcampoMartínez, Carlos
Abstract: This extended abstract addresses the preliminary results of applying uncertainty handling strategies and advanced control techniques to the inventary management of hospitality pharmacy. Inventory management is one of the main tasks that a pharmacy department has to carry out in a hospital. It is a complex problem because it requires to establish a tradeoff between contradictory optimization criteria. The final goal of the proposed research is to update the inventory management system of hospitals such that it is possible to reduce the average inventory while maintaining preestablished clinical guarantees.Tue, 16 Jun 2015 17:31:57 GMThttp://hdl.handle.net/2117/2832820150616T17:31:57ZMaestre Torreblanca, José María; OcampoMartínez, Carlosnoautomation, optimisation, stochastic programming, pharmacy inventary management, uncertainty handling, model predictive control, optimizationThis extended abstract addresses the preliminary results of applying uncertainty handling strategies and advanced control techniques to the inventary management of hospitality pharmacy. Inventory management is one of the main tasks that a pharmacy department has to carry out in a hospital. It is a complex problem because it requires to establish a tradeoff between contradictory optimization criteria. The final goal of the proposed research is to update the inventory management system of hospitals such that it is possible to reduce the average inventory while maintaining preestablished clinical guarantees.Hybrid modeling and receding horizon control of sewer networks
http://hdl.handle.net/2117/28327
Title: Hybrid modeling and receding horizon control of sewer networks
Authors: Joseph Duran, Bernat; OcampoMartínez, Carlos; Cembrano Gennari, Gabriela
Abstract: In this work, a controloriented sewer network model is presented based on a hybrid linear modeling framework. The model equations are described independently for each network element, thus allowing the model to be applied to a broad class of networks. A parameter calibration procedure using data obtained from simulation software that solves the physically based model equations is described and validation results are given for a case study. Using the control model equations, an optimal control problem to minimize flooding and pollution is formulated to be solved by means of mixedinteger linear or quadratic programming. A receding horizon control strategy based on this optimal control problem is applied to the case study using the simulation software as a virtual reality. Results of this closedloop simulation tests show the effectiveness of the proposed approach in fulfilling the control objectives while complying with physical and operational constraints.Tue, 16 Jun 2015 16:59:47 GMThttp://hdl.handle.net/2117/2832720150616T16:59:47ZJoseph Duran, Bernat; OcampoMartínez, Carlos; Cembrano Gennari, GabrielanoREALTIME CONTROL, URBAN DRAINAGE SYSTEMS, WASTEWATER SYSTEMS, PREDICTIVE CONTROL, SURROGATE MODELS, SIMULATION, OVERFLOWIn this work, a controloriented sewer network model is presented based on a hybrid linear modeling framework. The model equations are described independently for each network element, thus allowing the model to be applied to a broad class of networks. A parameter calibration procedure using data obtained from simulation software that solves the physically based model equations is described and validation results are given for a case study. Using the control model equations, an optimal control problem to minimize flooding and pollution is formulated to be solved by means of mixedinteger linear or quadratic programming. A receding horizon control strategy based on this optimal control problem is applied to the case study using the simulation software as a virtual reality. Results of this closedloop simulation tests show the effectiveness of the proposed approach in fulfilling the control objectives while complying with physical and operational constraints.A faulthiding approach for the switching quasiLPV faulttolerant control of a fourwheeled omnidirectional mobile robot
http://hdl.handle.net/2117/28323
Title: A faulthiding approach for the switching quasiLPV faulttolerant control of a fourwheeled omnidirectional mobile robot
Authors: Rotondo, Damiano; Puig Cayuela, Vicenç; Nejjari AkhiElarab, Fatiha; Romera Formiguera, Juli
Abstract: This paper proposes a reference model approach for the trajectory tracking of a fourwheeled omnidirectional mobile robot. In particular, the error model is brought to a quasilinearparametervarying (LPV) form suitable for designing an errorfeedback controller. It is shown that, if polytopic techniques are used to reduce the number of constraints from infinite to finite, a solution within the standard LPV framework could not exist due to a singularity that appears in the possible values of the input matrix. Adding a switching component to the controller allows solving this problem. Moreover, a switching LPV virtual actuator is added to the control loop in order to obtain fault tolerance within the faulthiding paradigm, keeping the stability and some desired performances under the effect of actuator faults without the need of retuning the nominal controller. The effectiveness of the proposed approach is shown and proved through simulation and experimental results.Tue, 16 Jun 2015 12:15:54 GMThttp://hdl.handle.net/2117/2832320150616T12:15:54ZRotondo, Damiano; Puig Cayuela, Vicenç; Nejjari AkhiElarab, Fatiha; Romera Formiguera, JulinoFaulttolerant control (FTC), identification, linear parametervarying (LPV) systems, mobile robots, model reference, switched systems, tracking, virtual actuators, CONTROLSYSTEMS, LEASTSQUARES, ACTUATOR, DESIGN, MODEL, ACCOMMODATION, OPTIMIZATION, CONSTRAINTS, PARAMETERS, ALGORITHMThis paper proposes a reference model approach for the trajectory tracking of a fourwheeled omnidirectional mobile robot. In particular, the error model is brought to a quasilinearparametervarying (LPV) form suitable for designing an errorfeedback controller. It is shown that, if polytopic techniques are used to reduce the number of constraints from infinite to finite, a solution within the standard LPV framework could not exist due to a singularity that appears in the possible values of the input matrix. Adding a switching component to the controller allows solving this problem. Moreover, a switching LPV virtual actuator is added to the control loop in order to obtain fault tolerance within the faulthiding paradigm, keeping the stability and some desired performances under the effect of actuator faults without the need of retuning the nominal controller. The effectiveness of the proposed approach is shown and proved through simulation and experimental results.Operating cost based cruise speed reduction for ground delay programs: Effect of scope length
http://hdl.handle.net/2117/28107
Title: Operating cost based cruise speed reduction for ground delay programs: Effect of scope length
Authors: Delgado Muñoz, Luis; Prats Menéndez, Xavier
Abstract: Ground delay programs typically involve the delaying of aircraft that are departing from origin airports within some set distance of a capacity constrained destination airport. Long haul flights are not delayed in this way. A tradeoff exists when fixing the distance parameter: increasing the 'scope' distributes delay among more aircraft and may reduce airborne holding delay but could also result in unnecessary delay in the (frequently observed) case of early program cancellation. In order to overcome part of this drawback, a fuel based cruise speed reduction strategy aimed at realizing airborne delay, was suggested by the authors in previous publications. By flying slower, at a specific speed, aircraft that are airborne can recover part of their initially assigned delay without incurring extra fuel consumption if the ground delay program is canceled before planned. In this paper, the effect of the scope of the program is assessed when applying this strategy. A case study is presented by analyzing all the ground delay programs that took place at San Francisco, Newark Liberty and Chicago O'Hare International airports during one year. Results show that by the introduction of this technique it is possible to define larger scopes, partially reducing the amount of unrecovered delay. (C) 2014 Elsevier Ltd. All rights reserved.Sat, 30 May 2015 10:47:18 GMThttp://hdl.handle.net/2117/2810720150530T10:47:18ZDelgado Muñoz, Luis; Prats Menéndez, XaviernoGround delay program, Speed reduction, Ground delay program scope, Delay savings, Airborne delay, TRAFFIC FLOW MANAGEMENTGround delay programs typically involve the delaying of aircraft that are departing from origin airports within some set distance of a capacity constrained destination airport. Long haul flights are not delayed in this way. A tradeoff exists when fixing the distance parameter: increasing the 'scope' distributes delay among more aircraft and may reduce airborne holding delay but could also result in unnecessary delay in the (frequently observed) case of early program cancellation. In order to overcome part of this drawback, a fuel based cruise speed reduction strategy aimed at realizing airborne delay, was suggested by the authors in previous publications. By flying slower, at a specific speed, aircraft that are airborne can recover part of their initially assigned delay without incurring extra fuel consumption if the ground delay program is canceled before planned. In this paper, the effect of the scope of the program is assessed when applying this strategy. A case study is presented by analyzing all the ground delay programs that took place at San Francisco, Newark Liberty and Chicago O'Hare International airports during one year. Results show that by the introduction of this technique it is possible to define larger scopes, partially reducing the amount of unrecovered delay. (C) 2014 Elsevier Ltd. All rights reserved.Realtime aircraft continuous descent trajectory optimization with ATC time constraints using direct collocation methods.
http://hdl.handle.net/2117/28057
Title: Realtime aircraft continuous descent trajectory optimization with ATC time constraints using direct collocation methods.
Authors: Verhoeven, Ronald; Dalmau Codina, Ramon; Prats Menéndez, Xavier; de Gelder, Nico
Abstract: 1
Abstract
In this paper an initial implementation of
a real

time aircraft trajectory optimization
algorithm
is
presented
. The aircraft trajectory
for descent and approach is
computed
for
minimum use of thrust and speed brake in
support of a “green” continuous descent and
approach flight operation, while complying with
ATC time constraints for maintaining runway
throughput and considering realistic wind
conditions. The trajectory opti
mizer forms an
important part of a new integrated, planning
and guidance concept name
d
TEMO (Time and
Energy Managed Operations) developed in the
Systems for Green Operat
ions (SGO) Clean Sky
EU

program
. It
is
compared with a
typical
A320
Flight Mana
gement System
(
FMS
)
showing
improvement
s
regarding
time adherence
performance and environmental impact.Tue, 26 May 2015 12:22:14 GMThttp://hdl.handle.net/2117/2805720150526T12:22:14ZVerhoeven, Ronald; Dalmau Codina, Ramon; Prats Menéndez, Xavier; de Gelder, Nicono1
Abstract
In this paper an initial implementation of
a real

time aircraft trajectory optimization
algorithm
is
presented
. The aircraft trajectory
for descent and approach is
computed
for
minimum use of thrust and speed brake in
support of a “green” continuous descent and
approach flight operation, while complying with
ATC time constraints for maintaining runway
throughput and considering realistic wind
conditions. The trajectory opti
mizer forms an
important part of a new integrated, planning
and guidance concept name
d
TEMO (Time and
Energy Managed Operations) developed in the
Systems for Green Operat
ions (SGO) Clean Sky
EU

program
. It
is
compared with a
typical
A320
Flight Mana
gement System
(
FMS
)
showing
improvement
s
regarding
time adherence
performance and environmental impact.Enhancement of a time and energy management algorithm for continuous descent operations
http://hdl.handle.net/2117/28055
Title: Enhancement of a time and energy management algorithm for continuous descent operations
Authors: Prats Menéndez, Xavier; Pérez Batlle, Marcos; Barrado Muxí, Cristina; Vilardaga GarcíaGascon, Santi; Bas, Isidro; Birling, Florent; Verhoeven, Ronald; Marsman, Adri
Abstract: In previous research, an aircraft trajectory planning algorithm was developed aiming at
optimizing continuous descent operations with required times of arrival at given waypoints.
A nonlinear optimal control problem was solved by using direct transcription methods.
In this paper, enhanced models for the same optimization framework are presented, im
proving the accuracy of the optimized trajectories. These new models take into account
wind, realistic atmospheric conditions, curved trajectories and general improvements in the
aircraft dynamics model. Preliminary results are shown in a hypothetical scenario where
trajectories are optimized from cruise altitude to the runway with different required times
of arrival at the threshold. The effects of wind and nonstandard atmospheres can be easily
appreciated.Tue, 26 May 2015 11:58:05 GMThttp://hdl.handle.net/2117/2805520150526T11:58:05ZPrats Menéndez, Xavier; Pérez Batlle, Marcos; Barrado Muxí, Cristina; Vilardaga GarcíaGascon, Santi; Bas, Isidro; Birling, Florent; Verhoeven, Ronald; Marsman, AdrinoIn previous research, an aircraft trajectory planning algorithm was developed aiming at
optimizing continuous descent operations with required times of arrival at given waypoints.
A nonlinear optimal control problem was solved by using direct transcription methods.
In this paper, enhanced models for the same optimization framework are presented, im
proving the accuracy of the optimized trajectories. These new models take into account
wind, realistic atmospheric conditions, curved trajectories and general improvements in the
aircraft dynamics model. Preliminary results are shown in a hypothetical scenario where
trajectories are optimized from cruise altitude to the runway with different required times
of arrival at the threshold. The effects of wind and nonstandard atmospheres can be easily
appreciated.Conflict Free Trajectory Optimisation with Target Tracking and Conformance Monitoring
http://hdl.handle.net/2117/28054
Title: Conflict Free Trajectory Optimisation with Target Tracking and Conformance Monitoring
Authors: Vilardaga GarcíaGascon, Santi; Prats Menéndez, Xavier; Duan, Pengfei; Uijt de Haag, Maarten
Abstract: In an effort to improve the effciency of air traffic operations, whilst reducing the envi
ronmental impact on aviation and increase capacity, 4D trajectory optimisation has shown
good potential. In previous research the authors have described a framework where com
plex departure routes can be optimised, producing con
ict free fuel optimal trajectories.
The research in this paper extends this concept to account for prediction uncertainty of
future states of intruding traffic. It is proposed to continuously monitor the surounding
traffic and recompute the ownship trajectory whenever a deviation from nominal traffic
behavior arises. The effectiveness of the conformance monitoring function is evalutated in
a scenario with two aircraft
ying standard departing procedures from Barcelona and Reus
airports.Tue, 26 May 2015 11:46:27 GMThttp://hdl.handle.net/2117/2805420150526T11:46:27ZVilardaga GarcíaGascon, Santi; Prats Menéndez, Xavier; Duan, Pengfei; Uijt de Haag, MaartennoIn an effort to improve the effciency of air traffic operations, whilst reducing the envi
ronmental impact on aviation and increase capacity, 4D trajectory optimisation has shown
good potential. In previous research the authors have described a framework where com
plex departure routes can be optimised, producing con
ict free fuel optimal trajectories.
The research in this paper extends this concept to account for prediction uncertainty of
future states of intruding traffic. It is proposed to continuously monitor the surounding
traffic and recompute the ownship trajectory whenever a deviation from nominal traffic
behavior arises. The effectiveness of the conformance monitoring function is evalutated in
a scenario with two aircraft
ying standard departing procedures from Barcelona and Reus
airports.A methodology to assess ionospheric models for GNSS
http://hdl.handle.net/2117/27981
Title: A methodology to assess ionospheric models for GNSS
Authors: Rovira Garcia, Adrià; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; González Casado, Guillermo; Ibáñez Segura, Marcos  DeimosWed, 20 May 2015 12:32:18 GMThttp://hdl.handle.net/2117/2798120150520T12:32:18ZRovira Garcia, Adrià; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; González Casado, Guillermo; Ibáñez Segura, Marcos  DeimosnoNonlinear model of leachate anaerobic digestion treatment process
http://hdl.handle.net/2117/27973
Title: Nonlinear model of leachate anaerobic digestion treatment process
Authors: Alzate Ibáñez, Angélica María; OcampoMartínez, Carlos
Abstract: In this report a continuous adaptive highgain observer method is presented for the estimation of state variables that could not be measurable online and unknown timevarying parameters of leachate anaerobic digestion treatment process. The highgain observer is a variant of the Luenberger extended observer and involves an adjustable gain parameter. It is characterized by easy implementation and calibration, is stable and exhibit exponential convergence. The observer is based on a simplified mathematical model of the system. Calibration of the model was performed with real data from the Upflow Anaerobic Sludge Blanket (UASB) reactor for landfill leachate treatment in open loop under normal operational conditions. The model performance is evaluated via numerical simulations showing adequate results. The criteria used for considering the model as acceptable is to calculate the values of Mean Magnitude of Relative Error (MMRE) and Prediction at level l.Tue, 19 May 2015 18:14:16 GMThttp://hdl.handle.net/2117/2797320150519T18:14:16ZAlzate Ibáñez, Angélica María; OcampoMartínez, Carlosnoautomation, mathematical programming, nonlinear programming.In this report a continuous adaptive highgain observer method is presented for the estimation of state variables that could not be measurable online and unknown timevarying parameters of leachate anaerobic digestion treatment process. The highgain observer is a variant of the Luenberger extended observer and involves an adjustable gain parameter. It is characterized by easy implementation and calibration, is stable and exhibit exponential convergence. The observer is based on a simplified mathematical model of the system. Calibration of the model was performed with real data from the Upflow Anaerobic Sludge Blanket (UASB) reactor for landfill leachate treatment in open loop under normal operational conditions. The model performance is evaluated via numerical simulations showing adequate results. The criteria used for considering the model as acceptable is to calculate the values of Mean Magnitude of Relative Error (MMRE) and Prediction at level l.Novel ionospheric activity indicator specifically tailored for GNSS users
http://hdl.handle.net/2117/27928
Title: Novel ionospheric activity indicator specifically tailored for GNSS users
Authors: Sanz Subirana, Jaume; Juan Zornoza, José Miguel; González Casado, Guillermo; Prieto Cerdeira, Roberto; Schlüter, S.; Orús Pérez, Raul
Abstract: This work introduces a novel ionospheric activity indicator useful for identifying disturbed periods affecting performance for GNSS users, at regional level. This indicator is based in the “Along Arc TEC Rate (AATR) and can be easily computed from GNSS data. The AATR indicator has been assessed over more than one Solar Cycle (20022013) involving 140 receivers distributed worldwide. Results show that it is well correlated with the ionospheric activity and, unlike other global indicators linked to the geomagnetic activity (i.e. DST, Ap), it is sensitive to regional behaviour the ionosphere and identifies specific effects on GNSS users. Moreover from a devoted analysis of EGNOS performances in different ionospheric conditions, it follows that the AATR indicator is able to predict SBAS user availability anomalies linked to the ionosphere. The AATR indicator has been chosen as the metric to characterise the ionosphere operational conditions in the frame of EGNOS activities. This indicator has been also proposed for joint analysis in the International SBASIonosphere Working Group.Fri, 15 May 2015 08:41:11 GMThttp://hdl.handle.net/2117/2792820150515T08:41:11ZSanz Subirana, Jaume; Juan Zornoza, José Miguel; González Casado, Guillermo; Prieto Cerdeira, Roberto; Schlüter, S.; Orús Pérez, RaulnoThis work introduces a novel ionospheric activity indicator useful for identifying disturbed periods affecting performance for GNSS users, at regional level. This indicator is based in the “Along Arc TEC Rate (AATR) and can be easily computed from GNSS data. The AATR indicator has been assessed over more than one Solar Cycle (20022013) involving 140 receivers distributed worldwide. Results show that it is well correlated with the ionospheric activity and, unlike other global indicators linked to the geomagnetic activity (i.e. DST, Ap), it is sensitive to regional behaviour the ionosphere and identifies specific effects on GNSS users. Moreover from a devoted analysis of EGNOS performances in different ionospheric conditions, it follows that the AATR indicator is able to predict SBAS user availability anomalies linked to the ionosphere. The AATR indicator has been chosen as the metric to characterise the ionosphere operational conditions in the frame of EGNOS activities. This indicator has been also proposed for joint analysis in the International SBASIonosphere Working Group.On the comparison of predictive control and command governor approaches for operational management of drinking water networks: a case study
http://hdl.handle.net/2117/27912
Title: On the comparison of predictive control and command governor approaches for operational management of drinking water networks: a case study
Authors: Tedesco, Francesco; OcampoMartínez, Carlos; Cassavola, Alessandro; Puig Cayuela, Vicenç
Abstract: This paper evaluates the application of command governor (CG) strategy for the operational control of drinking water networks (DWN) given their largescale and complex nature, the permanent and relevant effect of the disturbances (water demands) and their marginal stability feature. Moreover, the performance improvement offered by CG is compared with the application of model predictive control for the same management purposes and in the same context. The paper also discusses the effectiveness of both strategies and highlights the advantages of each approach. The Barcelona DWN is considered as case study for the undertaken assessment analysis.Wed, 13 May 2015 18:18:36 GMThttp://hdl.handle.net/2117/2791220150513T18:18:36ZTedesco, Francesco; OcampoMartínez, Carlos; Cassavola, Alessandro; Puig Cayuela, Vicençnoautomation, control theory, dynamic programming, optimisation, model predictive contro, command governor, centralised control, drinking water networksThis paper evaluates the application of command governor (CG) strategy for the operational control of drinking water networks (DWN) given their largescale and complex nature, the permanent and relevant effect of the disturbances (water demands) and their marginal stability feature. Moreover, the performance improvement offered by CG is compared with the application of model predictive control for the same management purposes and in the same context. The paper also discusses the effectiveness of both strategies and highlights the advantages of each approach. The Barcelona DWN is considered as case study for the undertaken assessment analysis.A Worldwide ionospheric model for fast precise point positioning
http://hdl.handle.net/2117/27895
Title: A Worldwide ionospheric model for fast precise point positioning
Authors: Rovira Garcia, Adrià; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; González Casado, Guillermo
Abstract: Fast precise point positioning (FastPPP) is a satellitebased navigation technique using an accurate realtime ionospheric modeling to achieve high accuracy quickly. In this paper, an endtoend performance assessment of FastPPP is presented in nearmaximum Solar Cycle conditions; from the accuracy of the Central Processing Facility corrections, to the user positioning. A planetary distribution of permanent receivers including challenging conditions at equatorial latitudes, is navigated in pure kinematic mode, located from 100 to 1300 km away from the nearest reference station used to derive the ionospheric model.
It is shown that satellite orbits and clocks accurate to few centimeters
and few tenths of nanoseconds, used in conjunction with an ionosphere with an accuracy better than 1 Total Electron Content Unit (16 cm in L1) reduce the convergence time of dualfrequency Precise Point Positioning, to decimeterlevel (3D) solutions. Horizontal convergence times are shortened 40% to 90%, whereas the vertical components are reduced by 20% to 60%. A metric to evaluate the quality of any ionospheric model for Global Navigation Satellite System is also proposed. The ionospheric modeling accuracy is directly translated to massmarket singlefrequency
users. The 95th percentile of horizontal and vertical accuracies is shown to be 40 and 60 cm for singlefrequency users and 9 and 16 cm for dualfrequency users. The tradeoff between the formal and actual positioning errors has been carefully studied to set realistic confidence levels to the corrections.Tue, 12 May 2015 11:44:15 GMThttp://hdl.handle.net/2117/2789520150512T11:44:15ZRovira Garcia, Adrià; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; González Casado, GuillermonoGlobal Navigation Satellite System (GNSS), precise point positioning (PPP), realtime ionospheric corrections, undifferenced ambiguity fixing.Fast precise point positioning (FastPPP) is a satellitebased navigation technique using an accurate realtime ionospheric modeling to achieve high accuracy quickly. In this paper, an endtoend performance assessment of FastPPP is presented in nearmaximum Solar Cycle conditions; from the accuracy of the Central Processing Facility corrections, to the user positioning. A planetary distribution of permanent receivers including challenging conditions at equatorial latitudes, is navigated in pure kinematic mode, located from 100 to 1300 km away from the nearest reference station used to derive the ionospheric model.
It is shown that satellite orbits and clocks accurate to few centimeters
and few tenths of nanoseconds, used in conjunction with an ionosphere with an accuracy better than 1 Total Electron Content Unit (16 cm in L1) reduce the convergence time of dualfrequency Precise Point Positioning, to decimeterlevel (3D) solutions. Horizontal convergence times are shortened 40% to 90%, whereas the vertical components are reduced by 20% to 60%. A metric to evaluate the quality of any ionospheric model for Global Navigation Satellite System is also proposed. The ionospheric modeling accuracy is directly translated to massmarket singlefrequency
users. The 95th percentile of horizontal and vertical accuracies is shown to be 40 and 60 cm for singlefrequency users and 9 and 16 cm for dualfrequency users. The tradeoff between the formal and actual positioning errors has been carefully studied to set realistic confidence levels to the corrections.