Jorge Posada - Academia.edu (original) (raw)
Papers by Jorge Posada
Applied Sciences
Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz... more Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz, ortho-walls, gyroid, etc.) with each individual having distinct geometric grading. In the context of the design, analysis and manufacturing of lattice workpieces, the problem of rapidly assessing the mechanical behavior of large domains is relevant for pre-evaluation of designs. In this realm, two approaches can be identified: (1) numerical simulations which usually bring accuracy but limit the size of the domains that can be studied due to intractable data sizes, and (2) material homogenization strategies that sacrifice precision to favor efficiency and allow for simulations of large domains. Material homogenization synthesizes diluted material properties in a lattice, according to the volume occupancy factor of such a lattice. Preliminary publications show that material homogenization is reasonable in predicting displacements, but is not in predicting stresses (highly sensitive to lo...
Applied Sciences
The second volume of the Special Issue New Industry 4 [...]
Plasma Processes and Polymers
Compared to current c‐Si solar cell technologies, fired passivating contacts (FPCs) can reduce th... more Compared to current c‐Si solar cell technologies, fired passivating contacts (FPCs) can reduce the thermal budget of the solar cell fabrication process. In this study, a simplified process flow for the fabrication of these contacts is investigated along with the use of two hole transport materials: p‐type nanocrystalline silicon ((p) nc‐Si:H) and nanocrystalline silicon oxide ((p) nc‐SiOx:H). More specifically, the passivation properties provided by the FPC stack are assessed at different stages of the manufacturing. The hydrogenation process is studied using in situ modulated photoluminescence (MPL) which allows to measure in real time the effective minority carrier lifetime in the sample during a process step. The increase of passivation observed during the deposition of the capping silicon‐nitride (a‐SiNx:H) layer by plasma‐enhanced chemical vapor deposition is shown to be due to both annealing of the sample and the deposition in presence of silane in the plasma, while the exposu...
In the context of CAD CAM CAE (Computer-Aided Design, Manufacturing and Engineering) and Additive... more In the context of CAD CAM CAE (Computer-Aided Design, Manufacturing and Engineering) and Additive Manufacturing, the computation of level sets of closed 2-manifold triangular meshes (mesh slicing) is relevant for the generation of 3D printing patterns. Current slicing methods rely on the assumption that the function used to compute the level sets satisfies strong Morse conditions, rendering incorrect results when such a function is not a Morse one. To overcome this limitation, this manuscript presents an algorithm for the computation of mesh level sets under the presence of non-Morse degeneracies. To accomplish this, our method defines weak-Morse conditions, and presents a characterization of the possible types of degeneracies. This classification relies on the position of vertices, edges and faces in the neighborhood outside of the slicing plane. Finally, our algorithm produces oriented 1-manifold contours. Each contour orientation defines whether it belongs to a hole or to an exte...
Proceedings of the International Conference on Computer Graphics Theory and Applications, 2010
Surface reconstruction from unorganized point set is a common problem in computer graphics. Gener... more Surface reconstruction from unorganized point set is a common problem in computer graphics. Generation of the signed distance field from the point set is a common methodology for the surface reconstruction. The reconstruction of implicit surfaces is made with the algorithm of marching cubes, but the distance field of a point set can not be processed with marching cubes because the unsigned nature of the distance. We propose an extension to the marching cubes algorithm allowing the reconstruction of 0-level iso-surfaces in an unsigned distance field. We calculate more information inside each cell of the marching cubes lattice and then we extract the intersection points of the surface within the cell then we identify the marching cubes case for the triangulation. Our algorithm generates good surfaces but the presence of ambiguities in the case selection generates some topological mistakes.
International Journal for Simulation and Multidisciplinary Design Optimization, 2021
In the context of smart manufacturing, the concept of Visual Computing is a key enabling technolo... more In the context of smart manufacturing, the concept of Visual Computing is a key enabling technology for Industry 4.0. Visual Computing and Physically-based simulation enables the implementation of interactive, visual and (in most cases) non-disruptive solutions within the context of (a) the production process (off-line or in-line) the shop floor, (b) the interaction with customers and clients in the whole value chain, and/or (c) the product-service schemas. Technologies such as Industrial Big Data, Human-Robot Collaboration, IIOT & 5G, Cybersecurity, Cyber-Physical Systems, Semantic Technologies, Visual Computing and other related technologies have a strong impact in the new ways smart manufacturing is reconfiguring the production. This article presents a theoretical framework for the incorporation of Visual Computing and Physically-based Simulation technologies to Industry 4.0 and Operator 4.0 scenarios. This framework has been already implemented and supports different smart manuf...
Solar Energy Materials and Solar Cells, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial 4.0 International License
Research-Technology Management, 2020
Overview: Performance measurement systems are a fundamental concern for R&D managers and exec... more Overview: Performance measurement systems are a fundamental concern for R&D managers and executives. The main challenge is ensuring that R&D managers can match organizational key performance indicators with researchers’ interests. This article details a new approach to measuring the fuzzy parameter of researchers’ performance. It presents a case study on the implementation of a rating system in a research technology organization and reports the results the system achieved, including researcher satisfaction. We describe which researcher skills were selected for rating, the evaluation criteria developed, and the data collection system that supported the rating process. The rating system was developed to be objective and acceptable to researchers, and to support achievement of desired corporate results. We present lessons learned from implementation over four years.
Mathematics, 2019
In the context of CAD, CAM, CAE, and reverse engineering, the problem of mesh parameterization is... more In the context of CAD, CAM, CAE, and reverse engineering, the problem of mesh parameterization is a central process. Mesh parameterization implies the computation of a bijective map ϕ from the original mesh M ∈ R 3 to the planar domain ϕ ( M ) ∈ R 2 . The mapping may preserve angles, areas, or distances. Distance-preserving parameterizations (i.e., isometries) are obviously attractive. However, geodesic-based isometries present limitations when the mesh has concave or disconnected boundary (i.e., holes). Recent advances in computing geodesic maps using the heat equation in 2-manifolds motivate us to revisit mesh parameterization with geodesic maps. We devise a Poisson surface underlying, extending, and filling the holes of the mesh M. We compute a near-isometric mapping for quasi-developable meshes by using geodesic maps based on heat propagation. Our method: (1) Precomputes a set of temperature maps (heat kernels) on the mesh; (2) estimates the geodesic distances along the piecewis...
Thin Solid Films, 2017
Abstract In this work, we have synthetized ultra-thin Cu(In,Ga)Se 2 (CIGS) absorbers with an alte... more Abstract In this work, we have synthetized ultra-thin Cu(In,Ga)Se 2 (CIGS) absorbers with an alternative hybrid co-sputtering/evaporation process. Copper, indium and gallium are sputtered simultaneously with the thermal evaporation of selenium, thus avoiding the use of H 2 Se. Different CIGS absorbers with a thicknesses lower than 550 nm were deposited by a one-step stabilized process on Mo/soda lime glass substrates. Hence, the growth mechanisms of ultra-thin CIGS films when varying the power values during hybrid process has been studied. The temperature of the selenium effusion cell and the deposition temperature have been fixed to 190 °C and 550 °C respectively. Deposition time has also been fixed to 20 min. Ultra-thin CIGS solar cells with conversion efficiencies up to 6.5% have been fabricated with an absorber layer thickness of 470 nm.
Procedia Computer Science, 2015
A worldwide trend in advanced manufacturing countries is defining Industrie 4.0, Industrial Inter... more A worldwide trend in advanced manufacturing countries is defining Industrie 4.0, Industrial Internet and Factories of the Future as a new wave that can revolutionize the production and its associated services. Cyber-Physical Systems (CPS) are central to this vision and are entitled to be part of smart machines, storage systems and production facilities able to exchange information with autonomy and intelligence. Such systems should be able to decide and trigger actions, and control each other independently and for such reason it is required the use of Knowledge based and intelligent information approaches. In this paper we present our perspective on how to support Industrie 4.0 with Knowledge based and intelligent systems. We focus in the conceptual model, architecture and necessary elements we believe are required for a real world implementation. We base our conceptualization in the experiences gathered during the participation in different ongoing research projects where the presented architecture is being implemented.
Integrated Design and Manufacturing in Mechanical Engineering ’98, 1999
The 14th IEEE International Conference on Fuzzy Systems, 2005. FUZZ '05.
Abstract-This paper presents a type-2 fuzzy logic controller for a robotic agent intended to trac... more Abstract-This paper presents a type-2 fuzzy logic controller for a robotic agent intended to track a mobile object in the context of robot soccer games. The controller has two inputs and two outputs that are logically connected by four rules. Image processing is used to estimate the angle ...
GeoSpatial Visual Analytics, 2009
Page 1. and Visual Analytics for Environmental Security, © Springer Science + Business Media BV 2... more Page 1. and Visual Analytics for Environmental Security, © Springer Science + Business Media BV 2009 VISUAL PROCESSING OF GEOGRAPHIC AND ENVIRONMENTAL INFORMATION IN THE BASQUE COUNTRY: TWO BASQUE CASE STUDIES ...
Lecture Notes in Computer Science, 2009
Lecture Notes in Computer Science, 2005
2008 International Workshop on Content-Based Multimedia Indexing, 2008
How to best perform a search over a dataset is a common field of research in the scientific commu... more How to best perform a search over a dataset is a common field of research in the scientific community. Query engines are used when the information is handled by an ontology in order to obtain structured information semantically. A common issue that arises is when the same query is performed several times, as the query engine must check the domain
Volume 4: 24th Computers and Information in Engineering Conference, 2004
Inspecting large industrial plants in a virtual walkthrough environment has proven to be a valuab... more Inspecting large industrial plants in a virtual walkthrough environment has proven to be a valuable tool in Plant Design. Many CG techniques, such as various LOD and culling methods, have been developed to visualize complex models in VR environments. These techniques decide solely based on geometric properties how to optimize the scene. In this paper we introduce the concept of semantically controlled selection of those techniques and show how semantic considerations can enhance the CAD to VR conversion process for large model visualization (LMV) walkthroughs of Plant Design models, improving the performance and adapting the visualization to the users’ needs. A taxonomy, together with semantic considerations coming from the relationship between user, model, and resources is the basis to decide which rules should be applied for a specific visualization technique. By extending a LMV walkthrough system we are able to reduce the complexity of large industrial plant models by a factor of...
Lecture Notes in Computer Science, 2004
Multilingual 3D avatars combine rich emotion with multilingual speech gesticulation. They require... more Multilingual 3D avatars combine rich emotion with multilingual speech gesticulation. They require complex animation. The most performing facial animation engines for avatars have been developed using morphing techniques. Unfortunately, these techniques cannot be directly utilized to generate animation through the Internet. The information needed to make them work is over the capacities of the connections of most Internet users. This article presents a solution to this problem. We have elaborated the adaptation of a very performing multilingual face animation engine to fit it into the Internet. We also evaluate the pros and the cons of such an adaptation from the animation quality perspective.
Lecture Notes in Computer Science, 2006
... pp. 679686, 2006. © Springer-Verlag Berlin Heidelberg 2006 Knowledge Based Tools to Support ... more ... pp. 679686, 2006. © Springer-Verlag Berlin Heidelberg 2006 Knowledge Based Tools to Support the Structural Design Process Carlos Toro1, Jorge Posada1, Maite Termenón1, Joaquín Oyarzun2, and Juanjo Falcón3 1 VICOMTech ...
Applied Sciences
Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz... more Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz, ortho-walls, gyroid, etc.) with each individual having distinct geometric grading. In the context of the design, analysis and manufacturing of lattice workpieces, the problem of rapidly assessing the mechanical behavior of large domains is relevant for pre-evaluation of designs. In this realm, two approaches can be identified: (1) numerical simulations which usually bring accuracy but limit the size of the domains that can be studied due to intractable data sizes, and (2) material homogenization strategies that sacrifice precision to favor efficiency and allow for simulations of large domains. Material homogenization synthesizes diluted material properties in a lattice, according to the volume occupancy factor of such a lattice. Preliminary publications show that material homogenization is reasonable in predicting displacements, but is not in predicting stresses (highly sensitive to lo...
Applied Sciences
The second volume of the Special Issue New Industry 4 [...]
Plasma Processes and Polymers
Compared to current c‐Si solar cell technologies, fired passivating contacts (FPCs) can reduce th... more Compared to current c‐Si solar cell technologies, fired passivating contacts (FPCs) can reduce the thermal budget of the solar cell fabrication process. In this study, a simplified process flow for the fabrication of these contacts is investigated along with the use of two hole transport materials: p‐type nanocrystalline silicon ((p) nc‐Si:H) and nanocrystalline silicon oxide ((p) nc‐SiOx:H). More specifically, the passivation properties provided by the FPC stack are assessed at different stages of the manufacturing. The hydrogenation process is studied using in situ modulated photoluminescence (MPL) which allows to measure in real time the effective minority carrier lifetime in the sample during a process step. The increase of passivation observed during the deposition of the capping silicon‐nitride (a‐SiNx:H) layer by plasma‐enhanced chemical vapor deposition is shown to be due to both annealing of the sample and the deposition in presence of silane in the plasma, while the exposu...
In the context of CAD CAM CAE (Computer-Aided Design, Manufacturing and Engineering) and Additive... more In the context of CAD CAM CAE (Computer-Aided Design, Manufacturing and Engineering) and Additive Manufacturing, the computation of level sets of closed 2-manifold triangular meshes (mesh slicing) is relevant for the generation of 3D printing patterns. Current slicing methods rely on the assumption that the function used to compute the level sets satisfies strong Morse conditions, rendering incorrect results when such a function is not a Morse one. To overcome this limitation, this manuscript presents an algorithm for the computation of mesh level sets under the presence of non-Morse degeneracies. To accomplish this, our method defines weak-Morse conditions, and presents a characterization of the possible types of degeneracies. This classification relies on the position of vertices, edges and faces in the neighborhood outside of the slicing plane. Finally, our algorithm produces oriented 1-manifold contours. Each contour orientation defines whether it belongs to a hole or to an exte...
Proceedings of the International Conference on Computer Graphics Theory and Applications, 2010
Surface reconstruction from unorganized point set is a common problem in computer graphics. Gener... more Surface reconstruction from unorganized point set is a common problem in computer graphics. Generation of the signed distance field from the point set is a common methodology for the surface reconstruction. The reconstruction of implicit surfaces is made with the algorithm of marching cubes, but the distance field of a point set can not be processed with marching cubes because the unsigned nature of the distance. We propose an extension to the marching cubes algorithm allowing the reconstruction of 0-level iso-surfaces in an unsigned distance field. We calculate more information inside each cell of the marching cubes lattice and then we extract the intersection points of the surface within the cell then we identify the marching cubes case for the triangulation. Our algorithm generates good surfaces but the presence of ambiguities in the case selection generates some topological mistakes.
International Journal for Simulation and Multidisciplinary Design Optimization, 2021
In the context of smart manufacturing, the concept of Visual Computing is a key enabling technolo... more In the context of smart manufacturing, the concept of Visual Computing is a key enabling technology for Industry 4.0. Visual Computing and Physically-based simulation enables the implementation of interactive, visual and (in most cases) non-disruptive solutions within the context of (a) the production process (off-line or in-line) the shop floor, (b) the interaction with customers and clients in the whole value chain, and/or (c) the product-service schemas. Technologies such as Industrial Big Data, Human-Robot Collaboration, IIOT & 5G, Cybersecurity, Cyber-Physical Systems, Semantic Technologies, Visual Computing and other related technologies have a strong impact in the new ways smart manufacturing is reconfiguring the production. This article presents a theoretical framework for the incorporation of Visual Computing and Physically-based Simulation technologies to Industry 4.0 and Operator 4.0 scenarios. This framework has been already implemented and supports different smart manuf...
Solar Energy Materials and Solar Cells, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial 4.0 International License
Research-Technology Management, 2020
Overview: Performance measurement systems are a fundamental concern for R&D managers and exec... more Overview: Performance measurement systems are a fundamental concern for R&D managers and executives. The main challenge is ensuring that R&D managers can match organizational key performance indicators with researchers’ interests. This article details a new approach to measuring the fuzzy parameter of researchers’ performance. It presents a case study on the implementation of a rating system in a research technology organization and reports the results the system achieved, including researcher satisfaction. We describe which researcher skills were selected for rating, the evaluation criteria developed, and the data collection system that supported the rating process. The rating system was developed to be objective and acceptable to researchers, and to support achievement of desired corporate results. We present lessons learned from implementation over four years.
Mathematics, 2019
In the context of CAD, CAM, CAE, and reverse engineering, the problem of mesh parameterization is... more In the context of CAD, CAM, CAE, and reverse engineering, the problem of mesh parameterization is a central process. Mesh parameterization implies the computation of a bijective map ϕ from the original mesh M ∈ R 3 to the planar domain ϕ ( M ) ∈ R 2 . The mapping may preserve angles, areas, or distances. Distance-preserving parameterizations (i.e., isometries) are obviously attractive. However, geodesic-based isometries present limitations when the mesh has concave or disconnected boundary (i.e., holes). Recent advances in computing geodesic maps using the heat equation in 2-manifolds motivate us to revisit mesh parameterization with geodesic maps. We devise a Poisson surface underlying, extending, and filling the holes of the mesh M. We compute a near-isometric mapping for quasi-developable meshes by using geodesic maps based on heat propagation. Our method: (1) Precomputes a set of temperature maps (heat kernels) on the mesh; (2) estimates the geodesic distances along the piecewis...
Thin Solid Films, 2017
Abstract In this work, we have synthetized ultra-thin Cu(In,Ga)Se 2 (CIGS) absorbers with an alte... more Abstract In this work, we have synthetized ultra-thin Cu(In,Ga)Se 2 (CIGS) absorbers with an alternative hybrid co-sputtering/evaporation process. Copper, indium and gallium are sputtered simultaneously with the thermal evaporation of selenium, thus avoiding the use of H 2 Se. Different CIGS absorbers with a thicknesses lower than 550 nm were deposited by a one-step stabilized process on Mo/soda lime glass substrates. Hence, the growth mechanisms of ultra-thin CIGS films when varying the power values during hybrid process has been studied. The temperature of the selenium effusion cell and the deposition temperature have been fixed to 190 °C and 550 °C respectively. Deposition time has also been fixed to 20 min. Ultra-thin CIGS solar cells with conversion efficiencies up to 6.5% have been fabricated with an absorber layer thickness of 470 nm.
Procedia Computer Science, 2015
A worldwide trend in advanced manufacturing countries is defining Industrie 4.0, Industrial Inter... more A worldwide trend in advanced manufacturing countries is defining Industrie 4.0, Industrial Internet and Factories of the Future as a new wave that can revolutionize the production and its associated services. Cyber-Physical Systems (CPS) are central to this vision and are entitled to be part of smart machines, storage systems and production facilities able to exchange information with autonomy and intelligence. Such systems should be able to decide and trigger actions, and control each other independently and for such reason it is required the use of Knowledge based and intelligent information approaches. In this paper we present our perspective on how to support Industrie 4.0 with Knowledge based and intelligent systems. We focus in the conceptual model, architecture and necessary elements we believe are required for a real world implementation. We base our conceptualization in the experiences gathered during the participation in different ongoing research projects where the presented architecture is being implemented.
Integrated Design and Manufacturing in Mechanical Engineering ’98, 1999
The 14th IEEE International Conference on Fuzzy Systems, 2005. FUZZ '05.
Abstract-This paper presents a type-2 fuzzy logic controller for a robotic agent intended to trac... more Abstract-This paper presents a type-2 fuzzy logic controller for a robotic agent intended to track a mobile object in the context of robot soccer games. The controller has two inputs and two outputs that are logically connected by four rules. Image processing is used to estimate the angle ...
GeoSpatial Visual Analytics, 2009
Page 1. and Visual Analytics for Environmental Security, © Springer Science + Business Media BV 2... more Page 1. and Visual Analytics for Environmental Security, © Springer Science + Business Media BV 2009 VISUAL PROCESSING OF GEOGRAPHIC AND ENVIRONMENTAL INFORMATION IN THE BASQUE COUNTRY: TWO BASQUE CASE STUDIES ...
Lecture Notes in Computer Science, 2009
Lecture Notes in Computer Science, 2005
2008 International Workshop on Content-Based Multimedia Indexing, 2008
How to best perform a search over a dataset is a common field of research in the scientific commu... more How to best perform a search over a dataset is a common field of research in the scientific community. Query engines are used when the information is handled by an ontology in order to obtain structured information semantically. A common issue that arises is when the same query is performed several times, as the query engine must check the domain
Volume 4: 24th Computers and Information in Engineering Conference, 2004
Inspecting large industrial plants in a virtual walkthrough environment has proven to be a valuab... more Inspecting large industrial plants in a virtual walkthrough environment has proven to be a valuable tool in Plant Design. Many CG techniques, such as various LOD and culling methods, have been developed to visualize complex models in VR environments. These techniques decide solely based on geometric properties how to optimize the scene. In this paper we introduce the concept of semantically controlled selection of those techniques and show how semantic considerations can enhance the CAD to VR conversion process for large model visualization (LMV) walkthroughs of Plant Design models, improving the performance and adapting the visualization to the users’ needs. A taxonomy, together with semantic considerations coming from the relationship between user, model, and resources is the basis to decide which rules should be applied for a specific visualization technique. By extending a LMV walkthrough system we are able to reduce the complexity of large industrial plant models by a factor of...
Lecture Notes in Computer Science, 2004
Multilingual 3D avatars combine rich emotion with multilingual speech gesticulation. They require... more Multilingual 3D avatars combine rich emotion with multilingual speech gesticulation. They require complex animation. The most performing facial animation engines for avatars have been developed using morphing techniques. Unfortunately, these techniques cannot be directly utilized to generate animation through the Internet. The information needed to make them work is over the capacities of the connections of most Internet users. This article presents a solution to this problem. We have elaborated the adaptation of a very performing multilingual face animation engine to fit it into the Internet. We also evaluate the pros and the cons of such an adaptation from the animation quality perspective.
Lecture Notes in Computer Science, 2006
... pp. 679686, 2006. © Springer-Verlag Berlin Heidelberg 2006 Knowledge Based Tools to Support ... more ... pp. 679686, 2006. © Springer-Verlag Berlin Heidelberg 2006 Knowledge Based Tools to Support the Structural Design Process Carlos Toro1, Jorge Posada1, Maite Termenón1, Joaquín Oyarzun2, and Juanjo Falcón3 1 VICOMTech ...