Motivation: DNA methylation analysis suffers from very long processing time, as the advent of Nex... more Motivation: DNA methylation analysis suffers from very long processing time, as the advent of Next-Generation Sequencers has shifted the bottleneck of genomic studies from the sequencers that obtain the DNA samples to the software that performs the analysis of these samples. The exist-ing software for methylation analysis does not seem to scale efficiently neither with the size of the dataset nor with the length of the reads to be analyzed. As it is expected that the sequencers will provide longer and longer reads in the near future, efficient and scalable methylation software should be developed. Results: We present a new software tool, called HPG-Methyl, which efficiently maps bisulphite sequencing reads on DNA, analyzing DNA methylation. The strategy used by this software consists of leveraging the speed of the Burrows–Wheeler Transform to map a large number of DNA fragments (reads) rapidly, as well as the accuracy of the Smith–Waterman algorithm, which is exclusively employed to...
Networks of Workstations have become a cost-effective alternative to parallel computers. The char... more Networks of Workstations have become a cost-effective alternative to parallel computers. The characterization of these networks results quite difficult, since the traditional parameters used for regular topologies (node degree, diameter, average distance, etc.) do not provide information about the arrangement of the links. In this paper, we propose a new model of communication cost between network nodes. This model takes into account both the network topology and the routing algorithm, but it does not depend on the traffic pattern generated by the application running on the machine. The evaluation results show that our communication cost model is highly correlated with network performance. Since it provides a metric based on internode distance, our model can be used as the basis for both an efficient characterization of networks as well as an efficient mapping of processes to processors. 1
Modern scientific collaborations, like the ATLAS experiment at CERN, produce large amounts of dat... more Modern scientific collaborations, like the ATLAS experiment at CERN, produce large amounts of data that need cataloging to meet multiple use cases and search criteria. Challenges arise in indexing and collecting billions of events, or particle collisions, from hundred of grid sites worldwide. In addition we face challenges in the organization of the data storage layer of the catalog, that should be capable of handling mixed OLTP (high-volume transaction processing updates ) and OLAP (real-time analytical queries) use cases. In order to overcome the challenge on the distributed data collection of events, we have designed and implemented a distributed producer/consumer architecture, based on an Object Store as a shared storage, and with dynamic data selection. Producers run at hundreds of grid sites worldwide indexing millions of files summing up Petabytes of data, and store a small quantity of metadata per event in an ObjectStore. Then a reference to the data is sent to a supervisor,...
The use of authoring tools has become a valuable trend for the fast development of Augmented Real... more The use of authoring tools has become a valuable trend for the fast development of Augmented Reality (AR) applications in industrial organizations. However, most of current AR authoring tools are actually programming interfaces that are exclusively suitable for programmers, and they do not provide advanced visual effects. In this paper, we propose an easy-to-use AR authoring tool oriented to the development of AR applications for the execution of industrial sequential procedures. Unlike other recent easy-to-use AR authoring tools, this software framework allows non-programming users to develop low-cost AR applications, including occlusion capabilities, by means of the use of a Kinect sensor. The evaluation results show that overlaying 3D instructions on the actual work pieces reduces the error rate for an assembly task by more than a 75%, particularly diminishing cumulative errors common in sequential procedures. Also, the results show that the time required by non-programming users...
The Large Hadron Collider (LHC) is about to enter its third run at unprecedented energies. The ex... more The Large Hadron Collider (LHC) is about to enter its third run at unprecedented energies. The experiments at the LHC face computational challenges with enormous data volumes that need to be analysed by thousands of physics users. The ATLAS EventIndex project, currently running in production, builds a complete catalogue of particle collisions, or events, for the ATLAS experiment at the LHC. The distributed nature of the experiment data model is exploited by running jobs at over one hundred Grid data centers worldwide. Millions of files with petabytes of data are indexed, extracting a small quantity of metadata per event, that is conveyed with a data collection system in real time to a central Hadoop instance at CERN. After a successful first implementation based on a messaging system, some issues suggested performance bottlenecks for the challenging higher rates in next runs of the experiment. In this work we characterize the weaknesses of the previous messaging system, regarding co...
The International Journal of High Performance Computing Applications
DNA methylation (mC) and hydroxymethylation (hmC) can significantly affect the normal human devel... more DNA methylation (mC) and hydroxymethylation (hmC) can significantly affect the normal human development, as well as health and disease status. hmC studies require not only specific treatment of DNA, but also software tools for their analysis. However, there are no software tools capable of analyzing DNA hmC currently. In this article, we propose HPG-HMapper, a parallel software tool for analyzing the DNA hmC data obtained by ten-eleven translocation–assisted bisulfite sequencing. This tool takes as input data the output files of mC aligner tools, and it yields mC maps and the accounting of methylated and hydroxymethylated bases on each chromosome. The design of this tool includes the consideration of different approaches, one of them based on binary trees and the other one based on bit arrays. The performance evaluation results show that a hybrid implementation is the most efficient option, allowing fast read and update operations while keeping a small memory footprint.
Interactive 3D terrain visualization plays an important role in multiple networked applications l... more Interactive 3D terrain visualization plays an important role in multiple networked applications like virtual worlds visualization, multiplayer games or distributed simulators. Since the client/server architecture has obvious scalability limitations, different peer-to-peer schemes have been proposed as trade-off solutions that yield good robustness, availability and scalability for this kind of systems. In this paper, we propose a new hybrid distributed architecture that significantly improves the scalability and performance of the existing proposals. The proposed scheme redesigns the relationships between the different elements of a hybrid architecture, modifies the information shared by each client with its neighboring peers and varies the messages exchanged among them, providing a larger number of users with a fluid navigation experience over a large virtual terrain.
Proceedings 2000 International Conference on Parallel Processing, 2000
Many research activities have focused on the problem of task scheduling in heterogeneous systems ... more Many research activities have focused on the problem of task scheduling in heterogeneous systems from the computational point of view. However, an ideal scheduling strategy would also take into account the communication requirements of the applications and the communication bandwidth that the network can offer. In this paper, we first propose a criterion to measure the suitability of each allocation of network resources to each parallel application, according to the communication requirements. Second, we propose a scheduling technique based exclusively on this criterion that provides a near-optimal mapping of processes to processors according to the communication requirements. Evaluation results show that the use of this scheduling technique fully exploits the available network bandwidth, greatly improving network performance. Therefore, the proposed scheduling technique may be used in the design of communication-aware scheduling strategies for those situations where the communication requirements are the system performance bottleneck.
Optical three-dimensional shape measurement based on structured light has been widely used for 3D... more Optical three-dimensional shape measurement based on structured light has been widely used for 3D measurement in many different applications. Although many different methods for 3D object reconstruction have been proposed last years, surprisingly none of the proposals includes a parallelization study of the tasks executed on computers, preventing these methods from reaching their maximum performance. In this paper, we propose first the computational evaluation of a previously proposed 3D object reconstruction method. Based on that evaluation, we also propose the parallelization of the reconstruction method using the OpenMP API specification for shared-memory parallel programming. The results show that most of the execution time is consumed by the tasks depending on the I/O hardware (camera, projector, hard disk, etc.), in such a way that the tasks performed by the computer should be overlapped as much as possible with the tasks performed by the I/O hardware, for those scenarios where the acquisition of the images should be performed on-line. For those scenarios where all the images are already available, then the inherent parallelism of the application increases, allowing a reduction of the execution time that can reach up to a 82 %. These results validate the proposed parallelization as a valuable implementation for data centers that provide web services for 3D object reconstruction purposes.
Journal of Network and Computer Applications, 2009
Crowd simulation requires both rendering visually plausible images and managing the behavior of a... more Crowd simulation requires both rendering visually plausible images and managing the behavior of autonomous agents. Therefore, these applications need an efficient design that allow them to simultaneously tackle these two requirements. Although several proposals have focused on the software architectures for these systems, no proposals have focused on the computer systems supporting them. In this paper, we analyze the computer architectures used in the literature to support virtual environments. Also, we propose a distributed computer architecture efficient enough to support simulations of thousand of autonomous agents. This proposal consists of a cluster of interconnected computers in order to improve flexibility and robustness, as well as a hierarchical software architecture that efficiently provides consistency. Performance evaluation results show that the trade-off between flexibility and consistency allows to efficiently manage thousands of autonomous agents. Therefore, this network-based system architecture can provide the required scalability for large-scale crowd simulations.
La propuesta de trabajar por competencias en lugar de hacerlo como se hacia tradicionalmente, por... more La propuesta de trabajar por competencias en lugar de hacerlo como se hacia tradicionalmente, por objetivos, ha hecho proliferar propuestas y alternativas metodologicas para favorecer un cambio en la Educacion Superior. Una de estas metodologias es el aprendizaje basado en problemas (ABP). El ABP es una metodologia de aprendizaje en la cual el punto de partida es un problema construido por el profesor que permite al estudiante identificar necesidades para comprender mejor ese problema/situacion, identificar principios que sustentan el conocimiento y cumplir objetivos de aprendizaje relacionados con cada porcion del contenido de la materia. En el caso de las tecnologias de la informacion y las comunicaciones es especialmente relevante, ya que permite desarrollar simultaneamente conocimientos teoricos y estrategias para resolver problemas practicos en pequenos grupos, similares a los que se encuentran en la practica profesional. Esta metodologia se ha implementado en la asignatura de ...
The market of luxury watches has been continuously growing across the world, regardless of econom... more The market of luxury watches has been continuously growing across the world, regardless of economic crisis. However, consumers can purchase online, on the web pages of the luxury watchmakers, the same product they can acquire in physical retail stores, producing a significant reduction in the overall sales of the latter ones. To reduce this trend, retail stores should increase their added-value services, one of which could be the use of virtual exhibitors in the shop. In this paper, we have developed two multimedia solutions (an Augmented Reality application and a pseudo-holographic system) for the creation of virtual exhibitors, and we have carried out a comparative study (based on real users) to measure which system would produce the best impact on users when used in traditional luxury watch retail stores. Our primary hypothesis was that there would be significant differences between the use of the mobile AR application and the use of the pseudo-holographic system. Our secondary hypothesis was that user preference for the mobile AR application would be higher than for the pseudo-holographic system.
Collaborative Augmented Reality (CAR) systems allow multiple users to share a real world environm... more Collaborative Augmented Reality (CAR) systems allow multiple users to share a real world environment including computer-generated images in real time. The hardware features of most current mobile phones include wireless network capabilities that offer a natural platform for CAR systems. However, the potential number of clients in CAR systems based on mobile phones is much larger than on CAR systems based on other kind of mobile devices, requiring a system design that takes into account scalability issues. This paper presents the experimental comparison of different CAR systems based on mobile phones with different server implementations. The performance evaluation results show that the best implementation is the one based on UDP messages instead of classical TCP connections, in order to improve the system throughput. The UDPbased implementation provides a significant improvement in system throughput, at the cost of loosing a very small percentage of updating messages. However, the effects of these small quantities of dropped messages cannot expand beyond some jitter (bounded within a short period of time) in a reduced number of clients of the CAR application. These results validate the proposed UDP-based implementation as the best option for large-scale CAR systems based on mobile phones.
Communications in Computer and Information Science, 2013
Augmented Reality (AR) applications have been emerged last years as a valuable tool for saving si... more Augmented Reality (AR) applications have been emerged last years as a valuable tool for saving significant costs in maintenance and process control tasks in industry. This trend has been stimulated by the appearance of authoring tools that allow the fast and easy development of AR applications. However, most of current AR authoring tools are actually programming interfaces that are exclusively suitable for programmers, and they do not provide advanced visual effects such as occlusion or object collision detection.
Abstract. In recent years, distributed virtual environments (DVEs) have become a major trend in d... more Abstract. In recent years, distributed virtual environments (DVEs) have become a major trend in distributed applications, mainly due to the enormous,popularity of multiplayer online games,in the entertainment industry. Although the workload generated by avatars in a DVE system has already been characterized, the special features of multiplayer online games make,these applications to require a particular workload characterization. This paper presents
Many research activities have focused on the problem of task scheduling in heterogeneous systems ... more Many research activities have focused on the problem of task scheduling in heterogeneous systems from the computa-tional point of view. Howevel; an ideal scheduling strategy would also take into account the communication require-ments of the applications and the ...
The study of Deoxyribonucleic Acid (DNA) methylation has allowed important advances in the unders... more The study of Deoxyribonucleic Acid (DNA) methylation has allowed important advances in the understanding of genetic diseases related to abnormal cell behavior. DNA methylation analysis tools have become especially relevant in recent years. However, these tools have a high computational cost and some of them require the configuration of specific hardware and software, extending the time for research and diagnosis. In previous works, we proposed some tools for DNA methylation analysis and a new tool, called HPG-DHunter, for the detection and visualization of Differentially Methylated Regions (DMRs). Even though this tool offers a user-friendly interface, its installation and maintenance requires the information technology knowledge specified above. In this paper, we propose our tool as a web-based application, which allows biomedical researchers the use of a powerful tool for methylation analysis, even for those not specialized in the management of Graphics Processing Units (GPUs) and...
Background: Software tools for analyzing DNA methylation do not provide graphical results which c... more Background: Software tools for analyzing DNA methylation do not provide graphical results which can be easily identified, but huge text files containing the alignment of the samples and their methylation status at a resolution of base pairs. There have been proposed different tools and methods for finding Differentially Methylated Regions (DMRs) among different samples, but the execution time required by these tools is large, and the visualization of their results is far from being interactive. Additionally, these methods show more accurate results when identifying simulated DM regions that are long and have small within-group variation, but they have low concordance when used with real datasets, probably due to the different approaches they use for DMR identification. Thus, a tool which automatically detects DMRs among different samples and interactively visualizes DMRs at different scales (from a bunch to ten of millions of DNA locations) can be the key for shortening the DNA methylation analysis process in many studies. Results: In this paper, we propose a software tool based on the wavelet transform. This mathematical tool allows the fast automatic DMR detection by simple comparison of different signals at different resolution levels. Also, it allows an interactive visualization of the DMRs found at different resolution levels. The tool is publicly available at https://grev-uv.github.io/, and it is part of a complete suite of tools which allow to carry out the complete process of DNA alignment and methylation analysis, creation of methylation maps of the whole genome, and the detection and visualization of DMRs between different samples. Conclusions: The validation of the developed software tool shows similar concordance with other well-known and extended tools when used with real and synthetic data. The batch mode of the tool is capable of automatically detecting the existing DMRs for half (twelve) of the human chromosomes between two sets of six samples (whose .csv files after the alignment and mapping procedures have an aggregated size of 108 Gigabytes) in around three hours and a half. When compared to
Current software tools for analyzing the DNA methylation yield the results as text files whose si... more Current software tools for analyzing the DNA methylation yield the results as text files whose sizes reach tens or hundreds of GBytes, and they are not useful by themselves to biomedical researchers, who need to compare methylation information at different scales. Several tools for discovering differentially methylated regions have been proposed, but they are based on statistical techniques, requiring huge computations for finding differences in small DNA segments. In this paper, we propose a different strategy based on treating the DNA methylation as a signal. We propose to translate the DNA methylation results into a methylation signal, and the wavelet transformation of that signal for the displaying of the methylation results at the required scale. The results show that this approach not only yields the same visualization results than other existing tools, but it also yields signals with different resolution levels, which can be used to easily detect Differentially Methylated Regions in much faster way than using statistical techniques.
Motivation: DNA methylation analysis suffers from very long processing time, as the advent of Nex... more Motivation: DNA methylation analysis suffers from very long processing time, as the advent of Next-Generation Sequencers has shifted the bottleneck of genomic studies from the sequencers that obtain the DNA samples to the software that performs the analysis of these samples. The exist-ing software for methylation analysis does not seem to scale efficiently neither with the size of the dataset nor with the length of the reads to be analyzed. As it is expected that the sequencers will provide longer and longer reads in the near future, efficient and scalable methylation software should be developed. Results: We present a new software tool, called HPG-Methyl, which efficiently maps bisulphite sequencing reads on DNA, analyzing DNA methylation. The strategy used by this software consists of leveraging the speed of the Burrows–Wheeler Transform to map a large number of DNA fragments (reads) rapidly, as well as the accuracy of the Smith–Waterman algorithm, which is exclusively employed to...
Networks of Workstations have become a cost-effective alternative to parallel computers. The char... more Networks of Workstations have become a cost-effective alternative to parallel computers. The characterization of these networks results quite difficult, since the traditional parameters used for regular topologies (node degree, diameter, average distance, etc.) do not provide information about the arrangement of the links. In this paper, we propose a new model of communication cost between network nodes. This model takes into account both the network topology and the routing algorithm, but it does not depend on the traffic pattern generated by the application running on the machine. The evaluation results show that our communication cost model is highly correlated with network performance. Since it provides a metric based on internode distance, our model can be used as the basis for both an efficient characterization of networks as well as an efficient mapping of processes to processors. 1
Modern scientific collaborations, like the ATLAS experiment at CERN, produce large amounts of dat... more Modern scientific collaborations, like the ATLAS experiment at CERN, produce large amounts of data that need cataloging to meet multiple use cases and search criteria. Challenges arise in indexing and collecting billions of events, or particle collisions, from hundred of grid sites worldwide. In addition we face challenges in the organization of the data storage layer of the catalog, that should be capable of handling mixed OLTP (high-volume transaction processing updates ) and OLAP (real-time analytical queries) use cases. In order to overcome the challenge on the distributed data collection of events, we have designed and implemented a distributed producer/consumer architecture, based on an Object Store as a shared storage, and with dynamic data selection. Producers run at hundreds of grid sites worldwide indexing millions of files summing up Petabytes of data, and store a small quantity of metadata per event in an ObjectStore. Then a reference to the data is sent to a supervisor,...
The use of authoring tools has become a valuable trend for the fast development of Augmented Real... more The use of authoring tools has become a valuable trend for the fast development of Augmented Reality (AR) applications in industrial organizations. However, most of current AR authoring tools are actually programming interfaces that are exclusively suitable for programmers, and they do not provide advanced visual effects. In this paper, we propose an easy-to-use AR authoring tool oriented to the development of AR applications for the execution of industrial sequential procedures. Unlike other recent easy-to-use AR authoring tools, this software framework allows non-programming users to develop low-cost AR applications, including occlusion capabilities, by means of the use of a Kinect sensor. The evaluation results show that overlaying 3D instructions on the actual work pieces reduces the error rate for an assembly task by more than a 75%, particularly diminishing cumulative errors common in sequential procedures. Also, the results show that the time required by non-programming users...
The Large Hadron Collider (LHC) is about to enter its third run at unprecedented energies. The ex... more The Large Hadron Collider (LHC) is about to enter its third run at unprecedented energies. The experiments at the LHC face computational challenges with enormous data volumes that need to be analysed by thousands of physics users. The ATLAS EventIndex project, currently running in production, builds a complete catalogue of particle collisions, or events, for the ATLAS experiment at the LHC. The distributed nature of the experiment data model is exploited by running jobs at over one hundred Grid data centers worldwide. Millions of files with petabytes of data are indexed, extracting a small quantity of metadata per event, that is conveyed with a data collection system in real time to a central Hadoop instance at CERN. After a successful first implementation based on a messaging system, some issues suggested performance bottlenecks for the challenging higher rates in next runs of the experiment. In this work we characterize the weaknesses of the previous messaging system, regarding co...
The International Journal of High Performance Computing Applications
DNA methylation (mC) and hydroxymethylation (hmC) can significantly affect the normal human devel... more DNA methylation (mC) and hydroxymethylation (hmC) can significantly affect the normal human development, as well as health and disease status. hmC studies require not only specific treatment of DNA, but also software tools for their analysis. However, there are no software tools capable of analyzing DNA hmC currently. In this article, we propose HPG-HMapper, a parallel software tool for analyzing the DNA hmC data obtained by ten-eleven translocation–assisted bisulfite sequencing. This tool takes as input data the output files of mC aligner tools, and it yields mC maps and the accounting of methylated and hydroxymethylated bases on each chromosome. The design of this tool includes the consideration of different approaches, one of them based on binary trees and the other one based on bit arrays. The performance evaluation results show that a hybrid implementation is the most efficient option, allowing fast read and update operations while keeping a small memory footprint.
Interactive 3D terrain visualization plays an important role in multiple networked applications l... more Interactive 3D terrain visualization plays an important role in multiple networked applications like virtual worlds visualization, multiplayer games or distributed simulators. Since the client/server architecture has obvious scalability limitations, different peer-to-peer schemes have been proposed as trade-off solutions that yield good robustness, availability and scalability for this kind of systems. In this paper, we propose a new hybrid distributed architecture that significantly improves the scalability and performance of the existing proposals. The proposed scheme redesigns the relationships between the different elements of a hybrid architecture, modifies the information shared by each client with its neighboring peers and varies the messages exchanged among them, providing a larger number of users with a fluid navigation experience over a large virtual terrain.
Proceedings 2000 International Conference on Parallel Processing, 2000
Many research activities have focused on the problem of task scheduling in heterogeneous systems ... more Many research activities have focused on the problem of task scheduling in heterogeneous systems from the computational point of view. However, an ideal scheduling strategy would also take into account the communication requirements of the applications and the communication bandwidth that the network can offer. In this paper, we first propose a criterion to measure the suitability of each allocation of network resources to each parallel application, according to the communication requirements. Second, we propose a scheduling technique based exclusively on this criterion that provides a near-optimal mapping of processes to processors according to the communication requirements. Evaluation results show that the use of this scheduling technique fully exploits the available network bandwidth, greatly improving network performance. Therefore, the proposed scheduling technique may be used in the design of communication-aware scheduling strategies for those situations where the communication requirements are the system performance bottleneck.
Optical three-dimensional shape measurement based on structured light has been widely used for 3D... more Optical three-dimensional shape measurement based on structured light has been widely used for 3D measurement in many different applications. Although many different methods for 3D object reconstruction have been proposed last years, surprisingly none of the proposals includes a parallelization study of the tasks executed on computers, preventing these methods from reaching their maximum performance. In this paper, we propose first the computational evaluation of a previously proposed 3D object reconstruction method. Based on that evaluation, we also propose the parallelization of the reconstruction method using the OpenMP API specification for shared-memory parallel programming. The results show that most of the execution time is consumed by the tasks depending on the I/O hardware (camera, projector, hard disk, etc.), in such a way that the tasks performed by the computer should be overlapped as much as possible with the tasks performed by the I/O hardware, for those scenarios where the acquisition of the images should be performed on-line. For those scenarios where all the images are already available, then the inherent parallelism of the application increases, allowing a reduction of the execution time that can reach up to a 82 %. These results validate the proposed parallelization as a valuable implementation for data centers that provide web services for 3D object reconstruction purposes.
Journal of Network and Computer Applications, 2009
Crowd simulation requires both rendering visually plausible images and managing the behavior of a... more Crowd simulation requires both rendering visually plausible images and managing the behavior of autonomous agents. Therefore, these applications need an efficient design that allow them to simultaneously tackle these two requirements. Although several proposals have focused on the software architectures for these systems, no proposals have focused on the computer systems supporting them. In this paper, we analyze the computer architectures used in the literature to support virtual environments. Also, we propose a distributed computer architecture efficient enough to support simulations of thousand of autonomous agents. This proposal consists of a cluster of interconnected computers in order to improve flexibility and robustness, as well as a hierarchical software architecture that efficiently provides consistency. Performance evaluation results show that the trade-off between flexibility and consistency allows to efficiently manage thousands of autonomous agents. Therefore, this network-based system architecture can provide the required scalability for large-scale crowd simulations.
La propuesta de trabajar por competencias en lugar de hacerlo como se hacia tradicionalmente, por... more La propuesta de trabajar por competencias en lugar de hacerlo como se hacia tradicionalmente, por objetivos, ha hecho proliferar propuestas y alternativas metodologicas para favorecer un cambio en la Educacion Superior. Una de estas metodologias es el aprendizaje basado en problemas (ABP). El ABP es una metodologia de aprendizaje en la cual el punto de partida es un problema construido por el profesor que permite al estudiante identificar necesidades para comprender mejor ese problema/situacion, identificar principios que sustentan el conocimiento y cumplir objetivos de aprendizaje relacionados con cada porcion del contenido de la materia. En el caso de las tecnologias de la informacion y las comunicaciones es especialmente relevante, ya que permite desarrollar simultaneamente conocimientos teoricos y estrategias para resolver problemas practicos en pequenos grupos, similares a los que se encuentran en la practica profesional. Esta metodologia se ha implementado en la asignatura de ...
The market of luxury watches has been continuously growing across the world, regardless of econom... more The market of luxury watches has been continuously growing across the world, regardless of economic crisis. However, consumers can purchase online, on the web pages of the luxury watchmakers, the same product they can acquire in physical retail stores, producing a significant reduction in the overall sales of the latter ones. To reduce this trend, retail stores should increase their added-value services, one of which could be the use of virtual exhibitors in the shop. In this paper, we have developed two multimedia solutions (an Augmented Reality application and a pseudo-holographic system) for the creation of virtual exhibitors, and we have carried out a comparative study (based on real users) to measure which system would produce the best impact on users when used in traditional luxury watch retail stores. Our primary hypothesis was that there would be significant differences between the use of the mobile AR application and the use of the pseudo-holographic system. Our secondary hypothesis was that user preference for the mobile AR application would be higher than for the pseudo-holographic system.
Collaborative Augmented Reality (CAR) systems allow multiple users to share a real world environm... more Collaborative Augmented Reality (CAR) systems allow multiple users to share a real world environment including computer-generated images in real time. The hardware features of most current mobile phones include wireless network capabilities that offer a natural platform for CAR systems. However, the potential number of clients in CAR systems based on mobile phones is much larger than on CAR systems based on other kind of mobile devices, requiring a system design that takes into account scalability issues. This paper presents the experimental comparison of different CAR systems based on mobile phones with different server implementations. The performance evaluation results show that the best implementation is the one based on UDP messages instead of classical TCP connections, in order to improve the system throughput. The UDPbased implementation provides a significant improvement in system throughput, at the cost of loosing a very small percentage of updating messages. However, the effects of these small quantities of dropped messages cannot expand beyond some jitter (bounded within a short period of time) in a reduced number of clients of the CAR application. These results validate the proposed UDP-based implementation as the best option for large-scale CAR systems based on mobile phones.
Communications in Computer and Information Science, 2013
Augmented Reality (AR) applications have been emerged last years as a valuable tool for saving si... more Augmented Reality (AR) applications have been emerged last years as a valuable tool for saving significant costs in maintenance and process control tasks in industry. This trend has been stimulated by the appearance of authoring tools that allow the fast and easy development of AR applications. However, most of current AR authoring tools are actually programming interfaces that are exclusively suitable for programmers, and they do not provide advanced visual effects such as occlusion or object collision detection.
Abstract. In recent years, distributed virtual environments (DVEs) have become a major trend in d... more Abstract. In recent years, distributed virtual environments (DVEs) have become a major trend in distributed applications, mainly due to the enormous,popularity of multiplayer online games,in the entertainment industry. Although the workload generated by avatars in a DVE system has already been characterized, the special features of multiplayer online games make,these applications to require a particular workload characterization. This paper presents
Many research activities have focused on the problem of task scheduling in heterogeneous systems ... more Many research activities have focused on the problem of task scheduling in heterogeneous systems from the computa-tional point of view. Howevel; an ideal scheduling strategy would also take into account the communication require-ments of the applications and the ...
The study of Deoxyribonucleic Acid (DNA) methylation has allowed important advances in the unders... more The study of Deoxyribonucleic Acid (DNA) methylation has allowed important advances in the understanding of genetic diseases related to abnormal cell behavior. DNA methylation analysis tools have become especially relevant in recent years. However, these tools have a high computational cost and some of them require the configuration of specific hardware and software, extending the time for research and diagnosis. In previous works, we proposed some tools for DNA methylation analysis and a new tool, called HPG-DHunter, for the detection and visualization of Differentially Methylated Regions (DMRs). Even though this tool offers a user-friendly interface, its installation and maintenance requires the information technology knowledge specified above. In this paper, we propose our tool as a web-based application, which allows biomedical researchers the use of a powerful tool for methylation analysis, even for those not specialized in the management of Graphics Processing Units (GPUs) and...
Background: Software tools for analyzing DNA methylation do not provide graphical results which c... more Background: Software tools for analyzing DNA methylation do not provide graphical results which can be easily identified, but huge text files containing the alignment of the samples and their methylation status at a resolution of base pairs. There have been proposed different tools and methods for finding Differentially Methylated Regions (DMRs) among different samples, but the execution time required by these tools is large, and the visualization of their results is far from being interactive. Additionally, these methods show more accurate results when identifying simulated DM regions that are long and have small within-group variation, but they have low concordance when used with real datasets, probably due to the different approaches they use for DMR identification. Thus, a tool which automatically detects DMRs among different samples and interactively visualizes DMRs at different scales (from a bunch to ten of millions of DNA locations) can be the key for shortening the DNA methylation analysis process in many studies. Results: In this paper, we propose a software tool based on the wavelet transform. This mathematical tool allows the fast automatic DMR detection by simple comparison of different signals at different resolution levels. Also, it allows an interactive visualization of the DMRs found at different resolution levels. The tool is publicly available at https://grev-uv.github.io/, and it is part of a complete suite of tools which allow to carry out the complete process of DNA alignment and methylation analysis, creation of methylation maps of the whole genome, and the detection and visualization of DMRs between different samples. Conclusions: The validation of the developed software tool shows similar concordance with other well-known and extended tools when used with real and synthetic data. The batch mode of the tool is capable of automatically detecting the existing DMRs for half (twelve) of the human chromosomes between two sets of six samples (whose .csv files after the alignment and mapping procedures have an aggregated size of 108 Gigabytes) in around three hours and a half. When compared to
Current software tools for analyzing the DNA methylation yield the results as text files whose si... more Current software tools for analyzing the DNA methylation yield the results as text files whose sizes reach tens or hundreds of GBytes, and they are not useful by themselves to biomedical researchers, who need to compare methylation information at different scales. Several tools for discovering differentially methylated regions have been proposed, but they are based on statistical techniques, requiring huge computations for finding differences in small DNA segments. In this paper, we propose a different strategy based on treating the DNA methylation as a signal. We propose to translate the DNA methylation results into a methylation signal, and the wavelet transformation of that signal for the displaying of the methylation results at the required scale. The results show that this approach not only yields the same visualization results than other existing tools, but it also yields signals with different resolution levels, which can be used to easily detect Differentially Methylated Regions in much faster way than using statistical techniques.
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Papers by Juan M. Orduña