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© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., [EN] This paper gathers experiences and results from several demonstration projects in the field of grid integration of electric vehicles. The analyzed research projects are selected among research institutes and universities that are part of the European Energy Research Alliance Joint Program on Smart Grids. The paper provides an overview of recent trends in the field of electric vehicles integration issues and then dives deeper into specific aspects of each project. Twelve research projects are presented in general terms, while detailed information can be retrieved from the references and the websites. Although each project has its focus, a common element that can be devised is that the charging process can be technically controlled based on different interests and algorithms, but its role in the market is still under development. Particular focus is always given to the behavior of the user, which ultimately determines the possible level of flexibility that the electric vehicle can provide to the grid.

[EN] Generalized Spatial Modulation (GSM) is a trans-mission technique used in wireless communications in which only part of the transmitter antennas are activated during each time signaling period. A low complexity Sphere Decoding (SD) algorithm to achieve maximum likelihood (ML) detection has recently been proposed by using subproblem partitions, sorting preprocessing and radius updating. However, the ordering method has a serious limitation when the number of activated antennas is equal to the number of received antennas. Therefore, alternative sorting methods are studied in the present paper. In addition, the computational cost of the ML algorithm can be high when the system sizes increases. In this paper a suboptimal version is proposed where only the first L SD subproblems are carried out. The results show that the proposed algorithm achieves near optimal performance at lower computational cost than ML algorithms.

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., [EN] This paper gathers experiences and results from several demonstration projects in the field of grid integration of electric vehicles. The analyzed research projects are selected among research institutes and universities that are part of the European Energy Research Alliance Joint Program on Smart Grids. The paper provides an overview of recent trends in the field of electric vehicles integration issues and then dives deeper into specific aspects of each project. Twelve research projects are presented in general terms, while detailed information can be retrieved from the references and the websites. Although each project has its focus, a common element that can be devised is that the charging process can be technically controlled based on different interests and algorithms, but its role in the market is still under development. Particular focus is always given to the behavior of the user, which ultimately determines the possible level of flexibility that the electric vehicle can provide to the grid.

[EN] Generalized Spatial Modulation (GSM) is a trans-mission technique used in wireless communications in which only part of the transmitter antennas are activated during each time signaling period. A low complexity Sphere Decoding (SD) algorithm to achieve maximum likelihood (ML) detection has recently been proposed by using subproblem partitions, sorting preprocessing and radius updating. However, the ordering method has a serious limitation when the number of activated antennas is equal to the number of received antennas. Therefore, alternative sorting methods are studied in the present paper. In addition, the computational cost of the ML algorithm can be high when the system sizes increases. In this paper a suboptimal version is proposed where only the first L SD subproblems are carried out. The results show that the proposed algorithm achieves near optimal performance at lower computational cost than ML algorithms.

[EN] True, the scientific community still has a lot to investigate on how to get 5G to have a satisfactory journey in the development of standards. However, it is now that we must begin to glimpse the future of mobile technology, it is time to imagine what 6G will be. This paper offers a realistic view of what this technology might be. In this case, the experience of one of the most important groups in Europe dedicated to the mobile communication systems design, the iTEAM research institute, is combined with the one of the world's leading manufacturers of femtocells, Casa Systems. From the belief that the deployment of SG will come from homes, this paper analyzes the new use cases of the 6G, as well as the three technological pillars of this future technology.

[EN] Generalized Spatial Modulation (GSM) is a trans-mission technique used in wireless communications in which only part of the transmitter antennas are activated during each time signaling period. A low complexity Sphere Decoding (SD) algorithm to achieve maximum likelihood (ML) detection has recently been proposed by using subproblem partitions, sorting preprocessing and radius updating. However, the ordering method has a serious limitation when the number of activated antennas is equal to the number of received antennas. Therefore, alternative sorting methods are studied in the present paper. In addition, the computational cost of the ML algorithm can be high when the system sizes increases. In this paper a suboptimal version is proposed where only the first L SD subproblems are carried out. The results show that the proposed algorithm achieves near optimal performance at lower computational cost than ML algorithms.

[EN] True, the scientific community still has a lot to investigate on how to get 5G to have a satisfactory journey in the development of standards. However, it is now that we must begin to glimpse the future of mobile technology, it is time to imagine what 6G will be. This paper offers a realistic view of what this technology might be. In this case, the experience of one of the most important groups in Europe dedicated to the mobile communication systems design, the iTEAM research institute, is combined with the one of the world's leading manufacturers of femtocells, Casa Systems. From the belief that the deployment of SG will come from homes, this paper analyzes the new use cases of the 6G, as well as the three technological pillars of this future technology.

[EN] True, the scientific community still has a lot to investigate on how to get 5G to have a satisfactory journey in the development of standards. However, it is now that we must begin to glimpse the future of mobile technology, it is time to imagine what 6G will be. This paper offers a realistic view of what this technology might be. In this case, the experience of one of the most important groups in Europe dedicated to the mobile communication systems design, the iTEAM research institute, is combined with the one of the world's leading manufacturers of femtocells, Casa Systems. From the belief that the deployment of SG will come from homes, this paper analyzes the new use cases of the 6G, as well as the three technological pillars of this future technology.

[EN] The objective of this paper is to demonstrate how inline combline filters can be designed to implement transmission zeros in the filter transfer function. Following the design procedure described in this paper, up to N-1 transmission zeros can be implemented with a filter of order N. In addition to theory, comparisons between simulated and measured results are also presented. The agreement between simulation and measurements is indeed good, thereby fully validating the new combline filter topology, and the proposed design technique.

[EN] The objective of this paper is to demonstrate how inline combline filters can be designed to implement transmission zeros in the filter transfer function. Following the design procedure described in this paper, up to N-1 transmission zeros can be implemented with a filter of order N. In addition to theory, comparisons between simulated and measured results are also presented. The agreement between simulation and measurements is indeed good, thereby fully validating the new combline filter topology, and the proposed design technique.

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Handwritten text recognition of Bengali is a difficult task because of complex character shapes due to the presence of modified/compound characters as well as zone-wise writing styles of different individuals. Most of the research published so far on Bengali handwriting recognition deals with either isolated character recognition or isolated word recognition, and just a few papers have researched on recognition of continuous handwritten Bengali. In this paper we present a research on continuous handwritten Bengali. We follow a classical line-based recognition approach with a system based on hidden Markov models and n-gram language models. These models are trained with automatic methods from annotated data. We research both on the maximum likelihood approach and the minimum error phone approach for training the optical models. We also research on the use of word-based language models and characterbased language models. This last approach allow us to deal with the out-of-vocabulary word problem in the test when the training set is of limited size. From the experiments we obtained encouraging results.

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Handwritten text recognition of Bengali is a difficult task because of complex character shapes due to the presence of modified/compound characters as well as zone-wise writing styles of different individuals. Most of the research published so far on Bengali handwriting recognition deals with either isolated character recognition or isolated word recognition, and just a few papers have researched on recognition of continuous handwritten Bengali. In this paper we present a research on continuous handwritten Bengali. We follow a classical line-based recognition approach with a system based on hidden Markov models and n-gram language models. These models are trained with automatic methods from annotated data. We research both on the maximum likelihood approach and the minimum error phone approach for training the optical models. We also research on the use of word-based language models and characterbased language models. This last approach allow us to deal with the out-of-vocabulary word problem in the test when the training set is of limited size. From the experiments we obtained encouraging results.

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Handwritten text recognition of Bengali is a difficult task because of complex character shapes due to the presence of modified/compound characters as well as zone-wise writing styles of different individuals. Most of the research published so far on Bengali handwriting recognition deals with either isolated character recognition or isolated word recognition, and just a few papers have researched on recognition of continuous handwritten Bengali. In this paper we present a research on continuous handwritten Bengali. We follow a classical line-based recognition approach with a system based on hidden Markov models and n-gram language models. These models are trained with automatic methods from annotated data. We research both on the maximum likelihood approach and the minimum error phone approach for training the optical models. We also research on the use of word-based language models and characterbased language models. This last approach allow us to deal with the out-of-vocabulary word problem in the test when the training set is of limited size. From the experiments we obtained encouraging results.

[EN] Electric Vehicles (EVs) have gained increased attention courtesy their potential to mitigate environmental issues associated with transportation. To integrate EVs in transportation and power networks, it is essential to properly perform the siting and sizing of charging stations. In particular, this task is more challenging for users that have more rigid schedules such as taxi drivers. This paper proposes a coordinated siting and sizing methodology for electric taxi (ET) charging stations considering both transportation and power system constraints. The case of Quito, Ecuador has been analyzed. The results indicate the optimal placement of the ET charging stations and the number of charging spots to be installed.

[EN] In this paper, we present a self-training-based framework for glaucoma grading using OCT B-scans under the presence of domain shift. Particularly, the proposed two-step learning methodology resorts to pseudo-labels generated during the first step to augment the training dataset on the target domain, which is then used to train the final target model. This allows transferring knowledge-domain from the unlabeled data. Additionally, we propose a novel glaucoma-specific backbone which introduces residual and attention modules via skip-connections to refine the embedding features of the latent space. By doing this, our model is capable of improving state-of-the-art from a quantitative and interpretability perspective. The reported results demonstrate that the proposed learning strategy can boost the performance of the model on the target dataset without incurring in additional annotation steps, by using only labels from the source examples. Our model consistently outperforms the baseline by 1¿3% across different metrics and bridges the gap with respect to training the model on the labeled target data.

[Otros] Neuropsychological assessment has been traditionally made through paper-and-pencil batteries which usually are time-consuming, decontextualized, and nonecological. These abilities play a critical role in education since they are very related to learning capacity, academic achievement, social functioning, as well as the inhibition of maladaptive behaviors. Meanwhile, serious games are being used in education and psychology to achieve assessments without these limitations, including neuropsychological assessments. While traditional tests can be analyzed with classical statistics, a large number of variables can be extracted from serious games, the analysis of which can be more complex. Machine learning can handle this large amount of information and find patterns that allow us to recognize behaviors. This study aimed to investigate whether machine learning could be used to improve predictive validity in applying a serious game for neuropsychological assessment. Results were based on 60 subjects, including 42 cognitive activities. The validation process showed best results on attention, memory, planning, and cognitive flexibility, achieving accuracies higher or equal to 0.8 and Cohen¿s Kappas higher than 0.55, which implies that the Virtual Serious Game could be a valid tool to perform a neuropsychological evaluation along with traditional tests.

[EN] Design education and practice are continuously evolving. Educational institutions must include intellectual complexities and new curriculum to support good design education. The design education future emerges multidisciplinary knowledge, teaching innovation and employment necessities. This paper describes a methodology centered in product validation with industrial design students. Focusing on discovering the student experience during the project execution, in addition to observing closely the female design student's perception on the methodology and process developed. The academic project was the design of a novel tool board. The students developed the proposed project in a period of eight weeks. Sixteen students participated as a sample of this research. The methodology consisted of eight phases that spanned from project brief to project conclusion, introducing two phases focused on validation exercises for the elements created to reach the solution of the tool board. During the end of the two evaluation phases, two surveys were applied asking for information on his previous experience during his design education and three elements that assessment the design methodology implementation: utility, novelty, and relevance. Using multiple choice and Likert scale answers the students answered the surveys. The survey's findings revealed relevant information on the project implementation focused on evaluation phases during the product design. The results revealed how students reflected on their previous experience developing projects, and how the design tool board integrate important phases like validation. Also, the students evaluated with a positive value the utility, novelty, and relevance of the developed project. However, the most important finding was the female perception comparing male students. The female assessment of novelty and relevance increased during project implementation, highlighting novelty as a perceived element to a greater range than men. This

[EN] In this paper, we present a self-training-based framework for glaucoma grading using OCT B-scans under the presence of domain shift. Particularly, the proposed two-step learning methodology resorts to pseudo-labels generated during the first step to augment the training dataset on the target domain, which is then used to train the final target model. This allows transferring knowledge-domain from the unlabeled data. Additionally, we propose a novel glaucoma-specific backbone which introduces residual and attention modules via skip-connections to refine the embedding features of the latent space. By doing this, our model is capable of improving state-of-the-art from a quantitative and interpretability perspective. The reported results demonstrate that the proposed learning strategy can boost the performance of the model on the target dataset without incurring in additional annotation steps, by using only labels from the source examples. Our model consistently outperforms the baseline by 1¿3% across different metrics and bridges the gap with respect to training the model on the labeled target data.

[EN] Design education and practice are continuously evolving. Educational institutions must include intellectual complexities and new curriculum to support good design education. The design education future emerges multidisciplinary knowledge, teaching innovation and employment necessities. This paper describes a methodology centered in product validation with industrial design students. Focusing on discovering the student experience during the project execution, in addition to observing closely the female design student's perception on the methodology and process developed. The academic project was the design of a novel tool board. The students developed the proposed project in a period of eight weeks. Sixteen students participated as a sample of this research. The methodology consisted of eight phases that spanned from project brief to project conclusion, introducing two phases focused on validation exercises for the elements created to reach the solution of the tool board. During the end of the two evaluation phases, two surveys were applied asking for information on his previous experience during his design education and three elements that assessment the design methodology implementation: utility, novelty, and relevance. Using multiple choice and Likert scale answers the students answered the surveys. The survey's findings revealed relevant information on the project implementation focused on evaluation phases during the product design. The results revealed how students reflected on their previous experience developing projects, and how the design tool board integrate important phases like validation. Also, the students evaluated with a positive value the utility, novelty, and relevance of the developed project. However, the most important finding was the female perception comparing male students. The female assessment of novelty and relevance increased during project implementation, highlighting novelty as a perceived element to a greater range than men. This

[Otros] Neuropsychological assessment has been traditionally made through paper-and-pencil batteries which usually are time-consuming, decontextualized, and nonecological. These abilities play a critical role in education since they are very related to learning capacity, academic achievement, social functioning, as well as the inhibition of maladaptive behaviors. Meanwhile, serious games are being used in education and psychology to achieve assessments without these limitations, including neuropsychological assessments. While traditional tests can be analyzed with classical statistics, a large number of variables can be extracted from serious games, the analysis of which can be more complex. Machine learning can handle this large amount of information and find patterns that allow us to recognize behaviors. This study aimed to investigate whether machine learning could be used to improve predictive validity in applying a serious game for neuropsychological assessment. Results were based on 60 subjects, including 42 cognitive activities. The validation process showed best results on attention, memory, planning, and cognitive flexibility, achieving accuracies higher or equal to 0.8 and Cohen¿s Kappas higher than 0.55, which implies that the Virtual Serious Game could be a valid tool to perform a neuropsychological evaluation along with traditional tests.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., This paper shows part of the work carried out to develop parallel versions of the SLICOT routines for model reduction of stable systems. In particular, the routines that have been parallelised are those based on the solution of Lyapunov equations. The goal is to be able to work with larger unreduced models and also to obtain better performance in the reduction process. New routines have been developed using standard libraries to improve portability and efficiency. A preliminary version was released previously by the authors, which achieved high performance. However, accuracy improvements have been necessary in order to make the new routines similar to the sequential ones in this aspect. Routines presented in this paper preserve good performance obtained by the previous parallel implementation while maintaining high accuracy of sequential SLICOT routines.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., This paper describes the research work in the context of the CLUVIEM project towards achieving migrat- able, self-managed virtual elastic clusters on hybrid Cloud infrastructures. These virtual clusters can span across on- premises and public Cloud infrastructures thus leveraging hybrid Cloud platforms. They are elastic since working nodes are automatically provisioned and relinquished to dynamically adapt the capacity of the virtual cluster (in terms of number of nodes) according to the current workload. They are self- managed since the elasticity rules are managed via the head node without requiring any external software entity for mon- itoring and deciding when to scale in and out. Finally, they are migratable since they consider both application migration, via application checkpointing, and infrastructure migration, by cloning infrastructures across multi-Clouds. These features introduce unprecedented flexibility for cost-effective cluster- based computing with minimal impact for cluster users. The paper summarises the current state of developments and future roads to achieve this vision.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., This paper shows part of the work carried out to develop parallel versions of the SLICOT routines for model reduction of stable systems. In particular, the routines that have been parallelised are those based on the solution of Lyapunov equations. The goal is to be able to work with larger unreduced models and also to obtain better performance in the reduction process. New routines have been developed using standard libraries to improve portability and efficiency. A preliminary version was released previously by the authors, which achieved high performance. However, accuracy improvements have been necessary in order to make the new routines similar to the sequential ones in this aspect. Routines presented in this paper preserve good performance obtained by the previous parallel implementation while maintaining high accuracy of sequential SLICOT routines.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., This paper describes the research work in the context of the CLUVIEM project towards achieving migrat- able, self-managed virtual elastic clusters on hybrid Cloud infrastructures. These virtual clusters can span across on- premises and public Cloud infrastructures thus leveraging hybrid Cloud platforms. They are elastic since working nodes are automatically provisioned and relinquished to dynamically adapt the capacity of the virtual cluster (in terms of number of nodes) according to the current workload. They are self- managed since the elasticity rules are managed via the head node without requiring any external software entity for mon- itoring and deciding when to scale in and out. Finally, they are migratable since they consider both application migration, via application checkpointing, and infrastructure migration, by cloning infrastructures across multi-Clouds. These features introduce unprecedented flexibility for cost-effective cluster- based computing with minimal impact for cluster users. The paper summarises the current state of developments and future roads to achieve this vision.

In mathematical expression recognition, symbol classification is a crucial step. Numerous approaches for recognizing handwritten math symbols have been published, but most of them are either an online approach or a hybrid approach. There is an absence of a study focused on offline features for handwritten math symbol recognition. Furthermore, many papers provide results difficult to compare. In this paper we assess the performance of several well-known offline features for this task. We also test a novel set of features based on polar histograms and the vertical repositioning method for feature extraction. Finally, we report and analyze the results of several experiments using recurrent neural networks on a large public database of online handwritten math expressions. The combination of online and offline features significantly improved the recognition rate.

In mathematical expression recognition, symbol classification is a crucial step. Numerous approaches for recognizing handwritten math symbols have been published, but most of them are either an online approach or a hybrid approach. There is an absence of a study focused on offline features for handwritten math symbol recognition. Furthermore, many papers provide results difficult to compare. In this paper we assess the performance of several well-known offline features for this task. We also test a novel set of features based on polar histograms and the vertical repositioning method for feature extraction. Finally, we report and analyze the results of several experiments using recurrent neural networks on a large public database of online handwritten math expressions. The combination of online and offline features significantly improved the recognition rate.

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper describes experiences that combine digital peer production with digital ink affordances. Rather than preparing papers to obtain a summative final mark, students work over the course of the term producing different small learning resources such as short engineering problems, reasoning or synthesis where the lecturer acts as manager and supervisor. Teacher intervention is carried out using digital ink over each individual student production being possible to share the results throughout a public or group repository and in class offering a pro-active argument about preventing common mistakes. In order to enhance students programming skills important efforts are oriented to produce learning objects in the form of Java applets. It has the additional advantage of fostering collaborative knowledge construction because any object serves to the whole group as learning material as soon as it is already produced and validated. Qualitative and quantitative results show both an overall satisfaction from students participating in the experiences, and better results in the common written exams, when compared to the other groups following the traditional method.

The increasing interest of online learning is unquestionable nowadays, with MOOCs being taken by thousands of students. However, for online learning to go mainstream it is necessary that professors perceive that the effort required to prepare and manage an online course is manageable. Today, a myriad of inexpensive tools and services can be used to produce and manage online courses with unprecedented ease and without distressing the professor. For that, this paper proposes an architecture based on Cloud services that simplifies the process of managing an online course, from delivering on-demand fully customized remote laboratories to communication automation for student engagement and feedback gathering. This approach has been applied to produce, distribute and manage an Online Course on Cloud Computing with Amazon Web Services. The paper describes the methodology, tools and results of this experience to point out that it is possible to deliver online courses with automatically provisioned labs, with minimal management overhead, while still providing a high quality learning experience to a worldwide audience.

In mathematical expression recognition, symbol classification is a crucial step. Numerous approaches for recognizing handwritten math symbols have been published, but most of them are either an online approach or a hybrid approach. There is an absence of a study focused on offline features for handwritten math symbol recognition. Furthermore, many papers provide results difficult to compare. In this paper we assess the performance of several well-known offline features for this task. We also test a novel set of features based on polar histograms and the vertical repositioning method for feature extraction. Finally, we report and analyze the results of several experiments using recurrent neural networks on a large public database of online handwritten math expressions. The combination of online and offline features significantly improved the recognition rate.

The increasing interest of online learning is unquestionable nowadays, with MOOCs being taken by thousands of students. However, for online learning to go mainstream it is necessary that professors perceive that the effort required to prepare and manage an online course is manageable. Today, a myriad of inexpensive tools and services can be used to produce and manage online courses with unprecedented ease and without distressing the professor. For that, this paper proposes an architecture based on Cloud services that simplifies the process of managing an online course, from delivering on-demand fully customized remote laboratories to communication automation for student engagement and feedback gathering. This approach has been applied to produce, distribute and manage an Online Course on Cloud Computing with Amazon Web Services. The paper describes the methodology, tools and results of this experience to point out that it is possible to deliver online courses with automatically provisioned labs, with minimal management overhead, while still providing a high quality learning experience to a worldwide audience.

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, This paper describes experiences that combine digital peer production with digital ink affordances. Rather than preparing papers to obtain a summative final mark, students work over the course of the term producing different small learning resources such as short engineering problems, reasoning or synthesis where the lecturer acts as manager and supervisor. Teacher intervention is carried out using digital ink over each individual student production being possible to share the results throughout a public or group repository and in class offering a pro-active argument about preventing common mistakes. In order to enhance students programming skills important efforts are oriented to produce learning objects in the form of Java applets. It has the additional advantage of fostering collaborative knowledge construction because any object serves to the whole group as learning material as soon as it is already produced and validated. Qualitative and quantitative results show both an overall satisfaction from students participating in the experiences, and better results in the common written exams, when compared to the other groups following the traditional method.

[EN] This paper presents a compact multimode antenna for GPS applications, where multiple modes are excited in order to achieve radiation pattern diversity. Based on the Characteristic Mode Analysis of a rectangular plate of 80 mm x 54 mm, a practical implementation of the excitation network is presented.

[EN] Multi-element antenna beam steering in free-licence higher frequency bands is one of the crucial features of 5G networks enabling better tracking of the users. In this paper, we present an experimental microwave photonics transmission system operating at 26 GHz where beamforming is fully realized in the optical domain. The system is designed to be deployed as a part of the mobile fronthaul network with an optical fiber span of 15 km. As a proof of concept, a planar 3-element antenna array has been developed and radiation patterns were measured in an anechoic chamber with high agreement between experimental and simulation results

[EN] This paper investigates integrated radio-over-fiber and radio-over-free-space optic links in a passive optical network architecture for ubiquitous wireless coverage. Two optical millimeter-wave generation techniques, namely optical heterodyning and optical modulator-based up-conversion are used. In the first configuration, simulation results are achieved for transmission of 20-40 Gb/s 4-PAM over the 60 GHz heterodyned hybrid link. In the second configuration, transmission of 20 MHz 4-QAM over the up-converted 25 GHz hybrid system is examined. System performance evaluation and practical feasibility is carried out in terms of the received optical powers, bit error rates, eye diagrams, error vector magnitude and constellation diagrams.

[EN] The growth of the Internet worldwide has been fuelled by the development of the National Research and Education Networks (NRENs), i.e., networks of academic and educational institutions. In Africa the establishment of NRENs is more recent. In this paper we analyse the readiness of African NRENs to be part of The Things Network (TTN), a network of IoT gateways that has fostered the growth of IoT in Europe by adopting a community network model. We analyse RTT and packet loss toward the nearest TTN network server, in African countries where RIPE Atlas (RIPE - Réseaux IP Européens, French for ¿European IP Networks) probes are hosted both in academic and commercial networks. Our conclusion is that NRENs and commercial ISPs are on an equal foot in hosting TTN gateways in most countries we considered.

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., [EN] This paper investigates an optical transmission architecture of a passive optical network (PON), which is compatible with the millimeter-wave radio-over-fiber and free-space optics systems (RoF-FSO) under weak-to-strong atmospheric turbulence (AT) regimes to enable seamless connectivity as part of next-generation broadband wireless access networks. We first analyze and evaluate in simulation the transmission performance of the integrated system at 40 GHz for 10 Gb/s N-pulse amplitude modulation (N-PAM) with N = 2, 4. Link performance shows that, 4-PAM outperforms 2-PAM in terms of tolerance to the combined impairment of fiber chromatic dispersion and AT. We then experimentally demonstrate the proof-of-concept integrated RoF-FSO-PON at 25 GHz using 20 MHz M-quadrature amplitude modulation (M-QAM) signals with M = 4, 16, 64. We show that, for QAM with a higher-order M, the link performance is being more affected by the combined impairments.

[EN] The Internet of Things (IoT) enables to connect the physical world to digital business processes (BP). By using the IoT, a BP can, e.g.: 1) take into account real-world data to take more informed business decisions, and 2) automate and/or improve BP tasks. To achieve these benefits, the integration of IoT and BPs needs to be successful. The first step to this end is to support the modeling of IoT-enhanced BPs. Although numerous researchers have studied this subject, it is unclear what is the current state of the art in terms of current modeling solutions and gaps. In this work, we carry out a Systematic Mapping Study (SMS) to find out how current solutions are modelling IoT into business processes. After studying 600 papers, we identified and analyzed in depth a total of 36 different solutions. In addition, we report on some important issues that should be addressed in the near future, such as, for instance the lack of standardization.

[EN] The use of Convolutional Neural Networks (CNN) has experienced a huge rise over the last recent years and its popularity has increased exponentially, mainly due to its application both for image recognition and certain applications related to artificial intelligence. The new applications of CNN request computing demands that are difficult to address by conventional processors. As a consequence, accelerators ¿both prototypes and commercial products¿ focusing on CNN computation have been proposed. Among these accelerators, those based on systolic arrays have acquired a special relevance; some examples are the Google¿s TPU and Eyeriss. Current research has focused on regular squared systolic arrays and most existing work assumes that there is enough memory bandwidth to feed the systolic array with input data. In this paper we explore the design of non-squared systolic arrays and address the impact of the memory bandwidth from a performance perspective. This work makes two main contributions. First, we found that some workloads with non-squared arrays achieve similar performance to systolic arrays twice as large, which can translate in area and/or energy benefits. Second, we present a performance comparison varying the main memory bandwidth for current DRAM devices. The analysis reveals that main memory bandwidth has a great impact on performance and that the decision of which technology use is key for the system performance. For the 64x64 array size it is necessary to use HBM2 memory to avoid the slowdown that would introduce cheaper technologies (e.g. DDR5 and DDR4).

[EN] The importance of Millimeter Waves (mmW) band for the Fifth Generation (5G) of mobile and wireless communications has motivated a lot of work in mmW channel modelling. In this paper, we assess the use of the light physics modelling of a game engine to calculate the propagation losses at mmW band in an indoor scenario. With that aim, we propose a model that we refer to as Light Intensity Model (LIM), in which a detailed 3D scenario is created in a game engine, radio transmitters and receivers are replaced by light sources and detectors, and the received light intensities are translated to received radio signal power through a translation function which is the key of the model. The results obtained corroborate the validity of the assessed approach to model propagation losses in indoor scenarios

[EN] This paper presents a compact multimode antenna for GPS applications, where multiple modes are excited in order to achieve radiation pattern diversity. Based on the Characteristic Mode Analysis of a rectangular plate of 80 mm x 54 mm, a practical implementation of the excitation network is presented.

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., [EN] This paper investigates an optical transmission architecture of a passive optical network (PON), which is compatible with the millimeter-wave radio-over-fiber and free-space optics systems (RoF-FSO) under weak-to-strong atmospheric turbulence (AT) regimes to enable seamless connectivity as part of next-generation broadband wireless access networks. We first analyze and evaluate in simulation the transmission performance of the integrated system at 40 GHz for 10 Gb/s N-pulse amplitude modulation (N-PAM) with N = 2, 4. Link performance shows that, 4-PAM outperforms 2-PAM in terms of tolerance to the combined impairment of fiber chromatic dispersion and AT. We then experimentally demonstrate the proof-of-concept integrated RoF-FSO-PON at 25 GHz using 20 MHz M-quadrature amplitude modulation (M-QAM) signals with M = 4, 16, 64. We show that, for QAM with a higher-order M, the link performance is being more affected by the combined impairments.

[EN] This paper investigates integrated radio-over-fiber and radio-over-free-space optic links in a passive optical network architecture for ubiquitous wireless coverage. Two optical millimeter-wave generation techniques, namely optical heterodyning and optical modulator-based up-conversion are used. In the first configuration, simulation results are achieved for transmission of 20-40 Gb/s 4-PAM over the 60 GHz heterodyned hybrid link. In the second configuration, transmission of 20 MHz 4-QAM over the up-converted 25 GHz hybrid system is examined. System performance evaluation and practical feasibility is carried out in terms of the received optical powers, bit error rates, eye diagrams, error vector magnitude and constellation diagrams.

[EN] The Internet of Things (IoT) enables to connect the physical world to digital business processes (BP). By using the IoT, a BP can, e.g.: 1) take into account real-world data to take more informed business decisions, and 2) automate and/or improve BP tasks. To achieve these benefits, the integration of IoT and BPs needs to be successful. The first step to this end is to support the modeling of IoT-enhanced BPs. Although numerous researchers have studied this subject, it is unclear what is the current state of the art in terms of current modeling solutions and gaps. In this work, we carry out a Systematic Mapping Study (SMS) to find out how current solutions are modelling IoT into business processes. After studying 600 papers, we identified and analyzed in depth a total of 36 different solutions. In addition, we report on some important issues that should be addressed in the near future, such as, for instance the lack of standardization.

[EN] The growth of the Internet worldwide has been fuelled by the development of the National Research and Education Networks (NRENs), i.e., networks of academic and educational institutions. In Africa the establishment of NRENs is more recent. In this paper we analyse the readiness of African NRENs to be part of The Things Network (TTN), a network of IoT gateways that has fostered the growth of IoT in Europe by adopting a community network model. We analyse RTT and packet loss toward the nearest TTN network server, in African countries where RIPE Atlas (RIPE - Réseaux IP Européens, French for ¿European IP Networks) probes are hosted both in academic and commercial networks. Our conclusion is that NRENs and commercial ISPs are on an equal foot in hosting TTN gateways in most countries we considered.

[EN] Multi-element antenna beam steering in free-licence higher frequency bands is one of the crucial features of 5G networks enabling better tracking of the users. In this paper, we present an experimental microwave photonics transmission system operating at 26 GHz where beamforming is fully realized in the optical domain. The system is designed to be deployed as a part of the mobile fronthaul network with an optical fiber span of 15 km. As a proof of concept, a planar 3-element antenna array has been developed and radiation patterns were measured in an anechoic chamber with high agreement between experimental and simulation results

[EN] A dual circularly-polarized slot-array antenna fed by a Groove Gap Waveguide (GGW) and operating in the KaBand is presented in this paper. A simple mechanism is proposed to switch the polarization, from RHCP to LHCP, and viceversa. The lid of the antenna has two pieces: one fixed and one sliding. The fixed piece hosts T-shaped slots, and the sliding block is in charge of adjusting the offset of the perpendicular grooves with respect to the longitudinal slots. Preliminary results show an axial ratio below 1.5 dB for both, RHCP and LHCP, within a bandwidth of 1 GHz centered at 30 GHz.

[EN] This contribution presents a low-loss mechanical phase shifter in gap-waveguide technology. The phase shifter is aimed at ground terminals for Ka-band satellite on-the-move applications. The use of the gap-waveguide technology allows to divide the device into two main blocks distributed in two levels: a lower-rotatable block, in charge of the power distribution and the phase shifting; and an upper-fixed block with the output waveguides. In this paper, the lower and upper blocks are designed using Groove-gap waveguides (GGW), and Ridge-gap waveguides, respectively, connected to each other by coupling slots. Results show a good performance within the operating frequency band in terms of the phase shift between consecutive output ports (suitable for array feeding), and the return loss level at the input port.

[EN] A T-shaped slot-array antenna fed through a Groove Gap Waveguide (GGW) is presented in this paper. The array antenna operates at 30 GHz. The way the slots are excited, along with the T-shape on its lid allows a compact single-layer architecture. A uniform linear array of 12 elements is designed to demonstrate the viability of this concept for high-efficient singlelayer slot-array antennas. Preliminary results show a frequency bandwidth of 1 GHz with input reflection coefficient better than ¿12 dB. In addition, being a full-metal antenna, the expected efficiency is high. It is worth stressing the good polarization purity achieved, being below 1.5 dB within the band of interest.

[EN] In this paper we present a new method to compute singular integrals and nearly singular integrals in the context of boundary integral equations for electromagnetism. In particular the method is well suited for integral equations of the second kind. The method consist of splitting the integral in two parts, one regular, which is computed via adaptive integration, and another singular and local (with very small support of the integrand) which is computed using asymptotic expansion. This method can be applied to any second kind integral equation arising in CEM, like MFIE, Charge-Current integral equation, Non Resonant Charge Current Integral Equation (NRCCIE),...

[EN] A preliminary numerical magnetic field study of a wireless power transfer system composed of two interconnected source loops is addressed in this paper. The key feature of this study is to propose a new configuration capable of maintaining a uniform magnetic field density between the two loops. Furthermore, it has been shown that the Theory of Characteristic Modes is a helpful tool for investigating the near field of the magnetically-coupled loops.