Carlos Pérez | Universidad Politécnica de Madrid (original) (raw)
Papers by Carlos Pérez
Revista De La Union Matematica Argentina, 1991
Given a pseudo-differential operator L in the Hormander class L:;-:6 ' it is a classical resu... more Given a pseudo-differential operator L in the Hormander class L:;-:6 ' it is a classical result , (cf. [8] ) that the distribution kernel k(x, y) of L will be a Coo function away from the diagonal and will decay rapidly with all its derivatives as I x y l --t 00 , if 0 < p ::; 1 , 0 ::; b < 1 . Moreover, k(x, y) will coincide with a Cj function in all mn x mn , provided m+n+j < O . In [7], we completed the analysis, by proving a sharp estimate for k( x , y ) , when m + n +j ;::: O . \""Ie used, however, a non standard partition of unity, which forced us to consider separately the cases p = 1 , 0 < p < 1 .
Revista Geográfica de América Central, 2020
El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislado... more El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislados, en las regiones montañosas del centro del país. Para su desarrollo requiere de condiciones medioambientales específicas de temperaturas frescas y alta humedad. El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislados, en las regiones montañosas del centro del país. Para su desarrollo requiere de condiciones medioambientales específicas de temperaturas frescas y alta humedad. Los bosques de oyamel constituyen un gran reservorio de biodiversidad ya que albergan cientos de especies de flora y fauna. Así mismo, cumplen la función de importantes sumideros de carbono y captadores de agua, además de poseer un importante potencial económico puesto que proporcionan materias primas para varias industrias, entre otros servicios ambientales. A pesar de que el cambio climático no es un fenómeno inédito, la velocidad observada en la actualidad hace pensar q...
Contributions to science, 2006
Titles in this Working Paper series aim to disseminate interim climate change, agriculture and fo... more Titles in this Working Paper series aim to disseminate interim climate change, agriculture and food security research and practices and stimulate feedback from the scientific community.
2008 IEEE International Conference on Robotics and Automation, 2008
This paper presents a new bilateral control scheme for time-delayed teleoperation designed to ach... more This paper presents a new bilateral control scheme for time-delayed teleoperation designed to achieve transparency. The control scheme allows that the slave follows the master in spite of the time delay, ant that the force displayed to the operator was exactly the reaction force from the environment. In addition, the interaction force of the slave with the environment is adapted to the master/slave ratio when it is reflected to the operator, improving the transparency of the system. The bilateral control scheme can be used in contact situations or non-contact situations of the slave with the environment. Together with the control scheme, the paper describes an analytical design method that allows the obtaining of the control gains.
Lecture Notes in Computer Science, 2011
... CETpD - Technical Research Center for Dependency Care and Autonomous Living Neàpolis Building... more ... CETpD - Technical Research Center for Dependency Care and Autonomous Living Neàpolis Building, Rambla de l&amp;amp;amp;#x27;Exposició, 59-69, 08800 Vilanova i la Geltrú, Barcelona, Spain {albert.sama,francisco.javier.ruiz,carlos.perez_lopez, andreu.catala}@upc.edu Abstract. ...
Infectio, 2012
Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de ... more Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de la probabilidad ARTICULO ORIGINAL Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de la probabilidad. Aplicación clínica en poblaciones de leucocitos, linfocitos y CD4 de pacientes con VIH T CD4 Lymphocytes Prediction Based on the Theory of Probability. Clinical application on leukocytes, lymphocytes and CD4 populations of HIV patients Resumen Introducción. Objetivo. Métodos. Resultado. Conclusión.
This paper describes a method for recognizing real three-dimensional objects in non-controlled ba... more This paper describes a method for recognizing real three-dimensional objects in non-controlled backgrounds using independent component analysis to eliminate redundant image information present in each object image. The proposed method is a two-step process that allows a coarse color-based detection and an exact localization using shape information. The paper describes an efficient implementation, making this approach suitable for real-time applications.
Studia Mathematica, 2009
We consider two-weight estimates for singular integral operators and their commutators with bound... more We consider two-weight estimates for singular integral operators and their commutators with bounded mean oscillation functions. Hörmander type conditions in the scale of Orlicz spaces are assumed on the kernels. We prove weighted weak-type estimates for pairs of weights (u, Su) where u is an arbitrary nonnegative function and S is a maximal operator depending on the smoothness of the kernel. We also obtain sufficient conditions on a pair of weights (u, v) for the operators to be bounded from L p (v) to L p,∞ (u). One-sided singular integrals, as the differential transform operator, are under study. We also provide applications to Fourier multipliers and homogeneous singular integrals.
Medical & Biological Engineering & Computing, 2011
This study introduces the concept design and analysis of a robotic system for the assistance and ... more This study introduces the concept design and analysis of a robotic system for the assistance and rehabilitation of disabled people. Based on the statistical data of the most common types of disabilities in Spain and other industrialized countries, the different tasks that the device must be able to perform have been determined. In this study, different robots for rehabilitation and assistance previously introduced have been reviewed. This survey is focused on those robots that assist with gait, balance and standing up. The structure of the ROAD robot presents various advantages over these robots, we discuss some of them. The performance of the proposed architecture is analyzed when it performs the sit to stand activity.
Journal of Molecular Graphics and Modelling, 1997
We have used a published set of inhibitors of HIV-1 protease 1 to build a COMBINE-type structure-... more We have used a published set of inhibitors of HIV-1 protease 1 to build a COMBINE-type structure-based QSAR model with good predictive ability (r 2 ϭ 0.90, q 2 ϭ 0.69). 2 Since the compounds in the training series exhibit most of their structural variability on one-half of the pseudosymmetrical binding cavity and only one binding orientation was explored for each molecule, the model describes mainly the effect of the structural changes on interactions involving only one-half of the binding cavity (pockets S1Ј and S2Ј). Thus, the model cannot be expected to give accurate predictions for new compounds exhibiting structural variation in both halves. The model does in fact show a tendency to underpredict slightly the biological activity of the molecules in the external test set. In an attempt to improve the quality of the model, both possible orientations of the ligands are now considered so that structural variation takes place in all binding pockets. One possibility would have been to build an additional set of complexes with the inhibitors docked in a reversed orientation. The alternative we have explored, however, consists of manipulating the data matrix describing the interaction energies so that each row is duplicated and the order of the variables in the duplicated rows is swapped between subunits. This simple approach has produced a new model that is similar in quality to the original model (r 2 ϭ 0.89, q 2 ϭ 0.64) but lacks the tendency to underpredict the activity of the compounds in the external set. Moreover, since equivalent residues are assigned equivalent weights, the model is insensitive to ligand orientation and is easier to interpret.
![Research paper thumbnail of Identification of a Putative Binding Site for [2‘,5‘-Bis-O-(tert-butyldimethylsilyl)-β-d-ribofuranosyl]-3‘-spiro-5‘ ‘-(4‘ ‘-amino-1‘ ‘,2‘ ‘-oxathiole-2‘ ‘,2‘ ‘-dioxide)thymine (TSAO) Derivatives at the p51−p66 Interface of HIV-1 Reverse Transcriptase](https://attachments.academia-assets.com/89447580/thumbnails/1.jpg)
](Journal of Medicinal Chemistry, 2001
Journal of Materials Science Letters, 1996
El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido ... more El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido facilitado todavía por el investigador a cargo del archivo del mismo.
Journal of Functional Analysis, 1995
Institute of Mathematics of the Czech Academy of Sciences provides access to digitized documents ... more Institute of Mathematics of the Czech Academy of Sciences provides access to digitized documents strictly for personal use. Each copy of any part of this document must contain these Terms of use.
The Journal of Fourier Analysis and Applications, 1997
Journal of Allergy and Clinical Immunology, 2001
importance of screening for cross-reactivity with a molecule in the same pharmaceutical class whe... more importance of screening for cross-reactivity with a molecule in the same pharmaceutical class when a type I hypersensitivity mechanism has been demonstrated for one molecule of this class in order to use a molecule that has similar pharmacologic properties but does not share its immunological cross-reactivity. Only when results of tests (skin tests, LHRT) with the drug that caused the reaction are positive do negative tests with the related drugs have a strong negative value and indicate that they can be used safely, as has been previously demonstrated for muscle relaxants. 7 The mechanism by which this patient became sensitized to granisetron, given that she had never received it, remains unknown. This was certainly the first time that the patient had received this drug, which leaves us in the dark about the origin of sensitization. The absence of prior contact with the drug, usually required for sensitization, occurs more frequently than is realized. It is well known for muscle relaxants: 30% of patients who have an anaphylactic reaction to muscle relaxants are undergoing general anesthesia for the first time in their life.
Environmental Modelling & Software, 2008
CHIMERE is a chemical transport model widely used within the air quality scientific community. Th... more CHIMERE is a chemical transport model widely used within the air quality scientific community. The actual version of CHIMERE is coupled with the MM5 mesoscale meteorological model. To facilitate model development, MM5 is replaced here with the Weather Research and Forecasting (WRF) model. With the accuracy of air quality models being highly dependent on the quality of meteorological drivers, this coupling allows one to take advantage of relevant new developments in meteorological modelling.
Revista De La Union Matematica Argentina, 1991
Given a pseudo-differential operator L in the Hormander class L:;-:6 ' it is a classical resu... more Given a pseudo-differential operator L in the Hormander class L:;-:6 ' it is a classical result , (cf. [8] ) that the distribution kernel k(x, y) of L will be a Coo function away from the diagonal and will decay rapidly with all its derivatives as I x y l --t 00 , if 0 < p ::; 1 , 0 ::; b < 1 . Moreover, k(x, y) will coincide with a Cj function in all mn x mn , provided m+n+j < O . In [7], we completed the analysis, by proving a sharp estimate for k( x , y ) , when m + n +j ;::: O . \""Ie used, however, a non standard partition of unity, which forced us to consider separately the cases p = 1 , 0 < p < 1 .
Revista Geográfica de América Central, 2020
El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislado... more El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislados, en las regiones montañosas del centro del país. Para su desarrollo requiere de condiciones medioambientales específicas de temperaturas frescas y alta humedad. El oyamel (Abies religiosa) es una especie endémica de México; se distribuye en manchones aislados, en las regiones montañosas del centro del país. Para su desarrollo requiere de condiciones medioambientales específicas de temperaturas frescas y alta humedad. Los bosques de oyamel constituyen un gran reservorio de biodiversidad ya que albergan cientos de especies de flora y fauna. Así mismo, cumplen la función de importantes sumideros de carbono y captadores de agua, además de poseer un importante potencial económico puesto que proporcionan materias primas para varias industrias, entre otros servicios ambientales. A pesar de que el cambio climático no es un fenómeno inédito, la velocidad observada en la actualidad hace pensar q...
Contributions to science, 2006
Titles in this Working Paper series aim to disseminate interim climate change, agriculture and fo... more Titles in this Working Paper series aim to disseminate interim climate change, agriculture and food security research and practices and stimulate feedback from the scientific community.
2008 IEEE International Conference on Robotics and Automation, 2008
This paper presents a new bilateral control scheme for time-delayed teleoperation designed to ach... more This paper presents a new bilateral control scheme for time-delayed teleoperation designed to achieve transparency. The control scheme allows that the slave follows the master in spite of the time delay, ant that the force displayed to the operator was exactly the reaction force from the environment. In addition, the interaction force of the slave with the environment is adapted to the master/slave ratio when it is reflected to the operator, improving the transparency of the system. The bilateral control scheme can be used in contact situations or non-contact situations of the slave with the environment. Together with the control scheme, the paper describes an analytical design method that allows the obtaining of the control gains.
Lecture Notes in Computer Science, 2011
... CETpD - Technical Research Center for Dependency Care and Autonomous Living Neàpolis Building... more ... CETpD - Technical Research Center for Dependency Care and Autonomous Living Neàpolis Building, Rambla de l&amp;amp;amp;#x27;Exposició, 59-69, 08800 Vilanova i la Geltrú, Barcelona, Spain {albert.sama,francisco.javier.ruiz,carlos.perez_lopez, andreu.catala}@upc.edu Abstract. ...
Infectio, 2012
Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de ... more Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de la probabilidad ARTICULO ORIGINAL Predicción de la concentración de linfocitos T CD4 en sangre periférica con base en la teoría de la probabilidad. Aplicación clínica en poblaciones de leucocitos, linfocitos y CD4 de pacientes con VIH T CD4 Lymphocytes Prediction Based on the Theory of Probability. Clinical application on leukocytes, lymphocytes and CD4 populations of HIV patients Resumen Introducción. Objetivo. Métodos. Resultado. Conclusión.
This paper describes a method for recognizing real three-dimensional objects in non-controlled ba... more This paper describes a method for recognizing real three-dimensional objects in non-controlled backgrounds using independent component analysis to eliminate redundant image information present in each object image. The proposed method is a two-step process that allows a coarse color-based detection and an exact localization using shape information. The paper describes an efficient implementation, making this approach suitable for real-time applications.
Studia Mathematica, 2009
We consider two-weight estimates for singular integral operators and their commutators with bound... more We consider two-weight estimates for singular integral operators and their commutators with bounded mean oscillation functions. Hörmander type conditions in the scale of Orlicz spaces are assumed on the kernels. We prove weighted weak-type estimates for pairs of weights (u, Su) where u is an arbitrary nonnegative function and S is a maximal operator depending on the smoothness of the kernel. We also obtain sufficient conditions on a pair of weights (u, v) for the operators to be bounded from L p (v) to L p,∞ (u). One-sided singular integrals, as the differential transform operator, are under study. We also provide applications to Fourier multipliers and homogeneous singular integrals.
Medical & Biological Engineering & Computing, 2011
This study introduces the concept design and analysis of a robotic system for the assistance and ... more This study introduces the concept design and analysis of a robotic system for the assistance and rehabilitation of disabled people. Based on the statistical data of the most common types of disabilities in Spain and other industrialized countries, the different tasks that the device must be able to perform have been determined. In this study, different robots for rehabilitation and assistance previously introduced have been reviewed. This survey is focused on those robots that assist with gait, balance and standing up. The structure of the ROAD robot presents various advantages over these robots, we discuss some of them. The performance of the proposed architecture is analyzed when it performs the sit to stand activity.
Journal of Molecular Graphics and Modelling, 1997
We have used a published set of inhibitors of HIV-1 protease 1 to build a COMBINE-type structure-... more We have used a published set of inhibitors of HIV-1 protease 1 to build a COMBINE-type structure-based QSAR model with good predictive ability (r 2 ϭ 0.90, q 2 ϭ 0.69). 2 Since the compounds in the training series exhibit most of their structural variability on one-half of the pseudosymmetrical binding cavity and only one binding orientation was explored for each molecule, the model describes mainly the effect of the structural changes on interactions involving only one-half of the binding cavity (pockets S1Ј and S2Ј). Thus, the model cannot be expected to give accurate predictions for new compounds exhibiting structural variation in both halves. The model does in fact show a tendency to underpredict slightly the biological activity of the molecules in the external test set. In an attempt to improve the quality of the model, both possible orientations of the ligands are now considered so that structural variation takes place in all binding pockets. One possibility would have been to build an additional set of complexes with the inhibitors docked in a reversed orientation. The alternative we have explored, however, consists of manipulating the data matrix describing the interaction energies so that each row is duplicated and the order of the variables in the duplicated rows is swapped between subunits. This simple approach has produced a new model that is similar in quality to the original model (r 2 ϭ 0.89, q 2 ϭ 0.64) but lacks the tendency to underpredict the activity of the compounds in the external set. Moreover, since equivalent residues are assigned equivalent weights, the model is insensitive to ligand orientation and is easier to interpret.
Journal of Medicinal Chemistry, 2001
Journal of Materials Science Letters, 1996
El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido ... more El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido facilitado todavía por el investigador a cargo del archivo del mismo.
Journal of Functional Analysis, 1995
Institute of Mathematics of the Czech Academy of Sciences provides access to digitized documents ... more Institute of Mathematics of the Czech Academy of Sciences provides access to digitized documents strictly for personal use. Each copy of any part of this document must contain these Terms of use.
The Journal of Fourier Analysis and Applications, 1997
Journal of Allergy and Clinical Immunology, 2001
importance of screening for cross-reactivity with a molecule in the same pharmaceutical class whe... more importance of screening for cross-reactivity with a molecule in the same pharmaceutical class when a type I hypersensitivity mechanism has been demonstrated for one molecule of this class in order to use a molecule that has similar pharmacologic properties but does not share its immunological cross-reactivity. Only when results of tests (skin tests, LHRT) with the drug that caused the reaction are positive do negative tests with the related drugs have a strong negative value and indicate that they can be used safely, as has been previously demonstrated for muscle relaxants. 7 The mechanism by which this patient became sensitized to granisetron, given that she had never received it, remains unknown. This was certainly the first time that the patient had received this drug, which leaves us in the dark about the origin of sensitization. The absence of prior contact with the drug, usually required for sensitization, occurs more frequently than is realized. It is well known for muscle relaxants: 30% of patients who have an anaphylactic reaction to muscle relaxants are undergoing general anesthesia for the first time in their life.
Environmental Modelling & Software, 2008
CHIMERE is a chemical transport model widely used within the air quality scientific community. Th... more CHIMERE is a chemical transport model widely used within the air quality scientific community. The actual version of CHIMERE is coupled with the MM5 mesoscale meteorological model. To facilitate model development, MM5 is replaced here with the Weather Research and Forecasting (WRF) model. With the accuracy of air quality models being highly dependent on the quality of meteorological drivers, this coupling allows one to take advantage of relevant new developments in meteorological modelling.