Small-scale distributions in an indoor environment at 94GHz

[EN] In this paper, an extensive multiple-input multiple-output measurement campaign in a lab environment has been conducted at the 94GHz band. Using a vector network analyzer, updown converters, and omnidirectional antennas displaced in virtual arrays, we have obtained an estimation of the distribution parameters for the most usual distributions employed in the small-scale fading modeling, i.e., Rayleigh, Rice, Nakagami-m and -, by using statistical inference techniques. Moreover, in this scenario the best fit distribution to the experimental data is the Weibull distribution, using the Kolmogorov-Smirnov test. However, the - distribution provides the best fitting to the experimental results in terms of the lower tails of the distributions.This work was supported by the Ministerio de Economia y Competitividad MINECO, Spain (TEC2016-78028-C3-2-P) and by the European FEDER funds. Further information regarding the data obtained and included in this paper can be attained by contacting the author, Jose M. Molina ([email protected]).Reig, J.; Martinez-Ingles, M.; Molina-Garcia-Pardo, J.; Rubio Arjona, L.; Rodrigo Peñarrocha, VM. (2017). Small-scale distributions in an indoor environment at 94GHz. Radio Science. 52(7):852-861. https://doi.org/10.1002/2017RS006335S852861527Cudak, M., Ghosh, A., Kovarik, T., Ratasuk, R., Thomas, T. A., Vook, F. W., & Moorut, P. (2013). Moving Towards Mmwave-Based Beyond-4G (B-4G) Technology. 2013 IEEE 77th Vehicular Technology Conference (VTC Spring). doi:10.1109/vtcspring.2013.6692638Everitt, B. S., & Skrondal, A. (2010). The Cambridge Dictionary of Statistics. doi:10.1017/cbo9780511779633Helminger, J., Detlefsen, J., & Groll, H. (s. f.). Propagation properties of an indoor-channel at 94 GHz. ICMMT’98. 1998 International Conference on Microwave and Millimeter Wave Technology. Proceedings (Cat. No.98EX106). doi:10.1109/icmmt.1998.768215Moon-Soon Choi, Grosskopf, G., & Rohde, D. (s. f.). Statistical Characteristics of 60 GHz Wideband Indoor Propagation Channel. 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications. doi:10.1109/pimrc.2005.1651506Kajiwara, A. (s. f.). Indoor propagation measurements at 94 GHz. Proceedings of 6th International Symposium on Personal, Indoor and Mobile Radio Communications. doi:10.1109/pimrc.1995.477099Maccartney, G. R., Rappaport, T. S., Sun, S., & Deng, S. (2015). Indoor Office Wideband Millimeter-Wave Propagation Measurements and Channel Models at 28 and 73 GHz for Ultra-Dense 5G Wireless Networks. IEEE Access, 3, 2388-2424. doi:10.1109/access.2015.2486778Marcum J. I. 1950 Table of Q functionsMartinez-Ingles, M.-T., Gaillot, D. P., Pascual-Garcia, J., Molina-Garcia-Pardo, J.-M., Rodríguez, J.-V., Rubio, L., & Juan-Llácer, L. (2016). Channel sounding and indoor radio channel characteristics in the W-band. EURASIP Journal on Wireless Communications and Networking, 2016(1). doi:10.1186/s13638-016-0530-7Rangan, S., Rappaport, T. S., & Erkip, E. (2014). Millimeter-Wave Cellular Wireless Networks: Potentials and Challenges. Proceedings of the IEEE, 102(3), 366-385. doi:10.1109/jproc.2014.2299397Reig, J., Martínez-Inglés, M.-T., Rubio, L., Rodrigo-Peñarrocha, V.-M., & Molina-García-Pardo, J.-M. (2014). Fading Evaluation in the 60 GHz Band in Line-of-Sight Conditions. International Journal of Antennas and Propagation, 2014, 1-12. doi:10.1155/2014/984102Thomas, H. J., Cole, R. S., & Siqueira, G. L. (1994). An experimental study of the propagation of 55 GHz millimeter waves in an urban mobile radio environment. IEEE Transactions on Vehicular Technology, 43(1), 140-146. doi:10.1109/25.282274Thomas, T. A., Vook, F. W., & Sun, S. (2015). Investigation into the effects of polarization in the indoor mmWave environment. 2015 IEEE International Conference on Communications (ICC). doi:10.1109/icc.2015.724851

The Folded Normal Distribution: A New Model for the Small-Scale Fading in Line-of-Sight (LOS) Condition

(c) 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, 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 components of this work in other works.[EN] In this paper, a novel form of the folded normal (FN) distribution has been proposed to model the small-scale fading in wireless communications. From a multiple-input multiple-output (MIMO) measurement campaign conducted in a lab environment with the line-of-sight (LOS) conditions at both the 60 and the 94 GHz bands, the authors obtain the parameters of the Rician, FN, and kappa-mu distributions. These parameters have been calculated by using the least square (LS) approximation and with techniques of statistical inference. The FN distribution provides the best fitting to the experimental results using the Kolmogorov-Smirnov (K-S) test for the inferred estimators with values of the ful llment of 100% and 69.82% at the 60 and 94 GHz bands, respectively, for a significance level of 1%.This work was supported by the Ministerio de Economia, Industria y Competitividad of the Spanish Government under the national projects TEC2017-86779-C2-2-R and TEC2016-78028-C3-2-P, through the Agencia Estatal de Investigacion (AEI) and the Fondo Europeo de Desarrollo Regional (FEDER).Reig, J.; Rodrigo Peñarrocha, VM.; Rubio Arjona, L.; Martínez-Inglés, MT.; Molina-García-Pardo, JM. (2019). The Folded Normal Distribution: A New Model for the Small-Scale Fading in Line-of-Sight (LOS) Condition. IEEE Access. 7:77328-77339. https://doi.org/10.1109/ACCESS.2019.2921340S7732877339

Electrolytic synthesis of chloroacetic acids in a filter-press reactor from polychloromethanes

Electrochemical carboxylation of carbon tetrachloride and chloroform to synthesize chloroacetic acids in mild conditions has been investigated by galvanostatic electrolyses using a homemade electrochemical filter-press reactor. Undivided filter-press reactor consisting of a planar Zn cathode and a planar Al sacrificial anode has been shown to be an optimal electrochemical device for the electrocarboxylation reaction. The influence of some operative parameters, such as current density and concentration of supporting electrolyte, on the efficiency and selectivity of the synthetic process has been investigated. Highly current efficiencies and target products yields (both of them > 85%) were achieved in all cases, whereas byproducts formation was minimal.Dirección General de Ciencia y Tecnología de España. CTQ2004-0036

Diffusion tensor imaging in orthostatic tremor: a tract‐based spatial statistics study

[Abstract] Objective The pathogenesis of orthostatic tremor (OT) is unknown. We investigated OT‐related white matter changes and their correlations with scores from a neuropsychological testing battery. Methods Diffusion tensor imaging measures were compared between 14 OT patients and 14 age‐ and education‐matched healthy controls, using whole‐brain tract‐based spatial statistics analysis. Correlations between altered diffusion metrics and cognitive performance in OT group were assessed. Results In all cognitive domains (attention, executive function, visuospatial ability, verbal memory, visual memory, and language), OT patients’ cognitive performance was significantly worse than that of healthy controls. OT patients demonstrated altered diffusivity metrics not only in the posterior lobe of the cerebellum (left cerebellar lobule VI) and in its efferent cerebellar fibers (left superior cerebellar peduncle), but also in medial lemniscus bilaterally (pontine tegmentum), anterior limb of the internal capsule bilaterally, right posterior limb of the internal capsule, left anterior corona radiata, right insula, and the splenium of corpus callosum. No relationship was found between diffusion measures and disease duration in OT patients. Diffusion white matter changes, mainly those located in right anterior limb of the internal capsule, were correlated with poor performance on tests of executive function, visuospatial ability, verbal memory, and visual memory in OT patients. Interpretation White matter changes were preferentially located in the cerebellum, its efferent pathways, as well as in the pontine tegmentum and key components of the frontal–thalamic–cerebellar circuit. Further work needs to be done to understand the evolution of these white matter changes and their functional consequences.National Institutes of Health; R01 NS39422National Institutes of Health; R01 NS094607National Institutes of Health; R01 NS085136National Institutes of Health; R01 NS073872National Institutes of Health; R01 NS088257European Commission. Grant Number: ICT‐2011‐287739Ministerio de Ecnomía y Competitividad; RTC‐2015‐3967‐1Spanish Health Research Agency; FIS PI12/01602Spanish Health Research Agency; FIS PI16/00451Ministerio de Ecnomía y Competitividad; DPI‐2015‐68664‐C4‐1‐

A multi-perspective comparison of ESA Academy’s Training and Learning Programme experiences before and throughout COVID-19 pandemic through the eyes of 6 students

The forced transition from fully in-person learning to online methodologies incurred by the proliferation of the COVID-19 pandemic has been a major blow to most organisations worldwide. The aim of the present paper is to analyse the impact of the COVID-19 in ESA educational activities from students' perspective, in order to stimulate the future creation of both online and on-site courses. The participation of the authors in the ESA Academy training sessions covers the period from February 2019 to September 2021, thus experiencing not only both on-site and online courses, but also pre- and mid-pandemic learning experiences and course adaptations due to the impact of COVID-19. The wide range of space education experiences gathered by the authors enables a multi-perspective comparison of a variety of topics involving the ESA Academy training sessions such as networking possibilities, course dynamics and content, motivation induced by the course environment, impact on the future career and professional development of the participants, as well as compared to the academic experience of the students at their home universities. The analysis and comparison of the authors' experiences allow to establish correlations between the learning method (in-person or online) and the specific experience outcomes of attending an ESA Academy training session. Finally, some recommendations are provided to further mitigate the COVID-19 impact on space educational activities

Event-related potentials associated to N-back test performance in schizophrenia

Producción CientíficaMapping of Event-Related Potentials (ERP) associated with auditory and visual odd-ball paradigms has shown consistent differences between healthy controls and schizophrenia patients. It may be hypothesized that higher task attentional/cognitive demand will result in larger differences in these paradigms, which may help understanding the substrates of cognitive deficits in this syndrome. To this aim, we performed an EEG study comparing the effects of increasing the attentional/cognitive load of an auditory N-back task on the Event-Related Potential in 50 subjects with schizophrenia (11 first episodes) and 35 healthy controls. We considered a post-target window of 1000 ms to explore possible between groups differences in N100, P300, and Late Slow Wave (LSW), and compared these components between 0-back (‘lower attentional/cognitive load) and 1-back (‘higher attentional/cognitive load’) conditions. Our results showed that N100 and LSW amplitude increase from 0- to 1-back condition was significantly larger in healthy controls compared to schizophrenia patients. Furthermore, LSW amplitude difference between 0- and 1-back conditions positively correlated with performance in the behavioral cognitive assessment. Taken together, these results support that higher task attentional/cognitive load (0-back vs. 1-back condition) increase N100 amplitude differences and reveal new findings related to the LSW component in schizophrenia.Junta de Castilla y León (project VA057P17)Instituto de Salud Carlos III (project PI18/00178

Diffusion tensor imaging in orthostatic tremor: a tract-based spatial statistics study.

Objective: The pathogenesis of orthostatic tremor (OT) is unknown. We investigated OT-related white matter changes and their correlations with scores from a neuropsychological testing battery. Methods: Diffusion tensor imaging measures were compared between 14 OT patients and 14 age- and educationmatched healthy controls, using whole-brain tract-based spatial statistics analysis. Correlations between altered diffusion metrics and cognitive performance in OT group were assessed. Results: In all cognitive domains (attention, executive function, visuospatial ability, verbal memory, visual memory, and language), OT patients’ cognitive performance was significantly worse than that of healthy controls. OT patients demonstrated altered diffusivity metrics not only in the posterior lobe of the cerebellum (left cerebellar lobule VI) and in its efferent cerebellar fibers (left superior cerebellar peduncle), but also in medial lemniscus bilaterally (pontine tegmentum), anterior limb of the internal capsule bilaterally, right posterior limb of the internal capsule, left anterior corona radiata, right insula, and the splenium of corpus callosum. No relationship was found between diffusion measures and disease duration in OT patients. Diffusion white matter changes, mainly those located in right anterior limb of the internal capsule, were correlated with poor performance on tests of executive function, visuospatial ability, verbal memory, and visual memory in OT patients. Interpretation: White matter changes were preferentially located in the cerebellum, its efferent pathways, as well as in the pontine tegmentum and key components of the frontal–thalamic–cerebellar circuit. Further work needs to be done to understand the evolution of these white matter changes and their functional consequences.post-print404 K

Millimeter Wave MISO-OFDM Transmissions in an Intra-Wagon Environment

[EN] In this paper, the maximum achievable throughput is analyzed in the intra-wagon channel when multiple-input single-output (MISO) and orthogonal frequency division multiplexing (OFDM), MISO-OFDM, techniques are used. This analysis is performed from real wideband propagation channel measurements at 28 and 37 GHz, two potential frequency bands to deploy the future fifth-generation (5G) wireless communications networks. Four different scenarios in terms of the access point (AP) and user equipment (UE) positions inside the wagon have been considered, using 4 and 8 antennas at the AP. The performance of both quasi-orthogonal space-time block code (QSTBC), combined with Hadamard matrices, and transmit beamforming techniques is studied and evaluated from simulation results. The simulation results take into account the signal-to-noise ratio (SNR) and the antenna correlation for each antenna array configuration at the AP. These results provide useful insight to better understand the intra-wagon channel properties and deploy the future 5G wireless networks in this particular scenario at mmWave frequencies, where high-data-rates are expected to support different types of digital applications.This work was supported in part by the Ministerio de Economia y Competitividad MINECO, Spain, under Grant TEC2016-78028C3-2-P and Grant TEC2017-86779-C2-2-R and in part by the European FEDER Funds.Sanchis Borrás, C.; Molina-García-Pardo, J.; Rubio Arjona, L.; Pascual-García, J.; Rodrigo Peñarrocha, VM.; Juan Llacer, L.; Reig, J. (2021). Millimeter Wave MISO-OFDM Transmissions in an Intra-Wagon Environment. IEEE Transactions on Intelligent Transportation Systems. 22(8):4899-4908. https://doi.org/10.1109/TITS.2020.2983028S4899490822

Millimeter Wave Channel Measurements in an Intra-Wagon Environment

© 2019 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng 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] In this correspondence, useful measurement results of the propagation channel characteristics in an intra-wagon environment at millimeter wave (mmWave) frequencies are presented. The measurements were collected inside an underground convoy from 25 to 40 GHz in the frequency domain. A broadband radio over fiber (RoF) link was used in order to avoid the high losses introduced by cables at these frequencies, thus allowing long distances between the transmitter and receiver antennas. Values of the path loss exponent and delay spread are reported at the potential 26, 28 and 38 GHz bands to deploy the future fifth-generation (5G) systems. These results allow us to have a better knowledge of the path loss and time dispersion characteristics of the propagation channel in this particular environment, characterized by rich-scattering with long delays.This work was supported by the Ministerio de Economia, Industria y Competitividad of the Spanish Government under the National Projects TEC2016-78028-C3-2-P and TEC2017-86779-C2-2-R, through the Agencia Estatal de Investigacion (AEI) and the Fondo Europeo deDesarrollo Regional (FEDER). The review of this article was coordinated by Prof. J. F. Paris. The authors would like to thank the staff of FGV who have facilitated the realization of the measurements campaing, in particular J. Iserte Villalba and F. M. Brox López.Rubio Arjona, L.; Rodrigo Peñarrocha, VM.; Molina-García-Pardo, JM.; Juan Llacer, L.; Pascual Garcia, J.; Reig, J.; Sanchis Borrás, C. (2019). Millimeter Wave Channel Measurements in an Intra-Wagon Environment. IEEE Transactions on Vehicular Technology. 68(12):12427-12431. https://doi.org/10.1109/TVT.2019.2947205S1242712431681

Analysis of the functional EEG network in an Ecuadorian schizophrenia sample

Background and objectives Higher mental functions depend on global functional coordination of the brain. Our aim was to study the baseline condition and modulation of functional networks in a previously unevaluated clinical population, compare the results with a population from another country, and analyze their relationship with cognitive functioning. Methods We evaluated the functioning of brain networks by EEG in 24 patients with schizophrenia and 32 healthy Ecuadorian controls. EEG recordings were made at rest and while performing a P300 task. Small world (SW), Path Length (PL), clustering coefficient (CLC) and connective strength (CS) values were calculated in both conditions. The values obtained were compared between groups, with the results of Spanish patients, and the relationship between the connective parameters and the cognitive performance of the participants was analyzed. Results Higher PL, CLC and CS values were identified in patients diagnosed with schizophrenia compared to controls (in basal condition) and lower SW values in this same condition. Ecuadorian patients obtained higher values than Spanish patients in the PL and CLC parameters and lower values for the SW parameter, despite these differences, the pattern of alteration in both samples followed the same trend. Finally, the alteration of CS, SW, CLC and PL parameters at baseline was related to cognitive performance. Conclusion The connective alterations identified in Ecuadorian schizophrenic patients are consistent with those found in another sample with different genetic, environmental and cultural conditions. In addition, these alterations were associated with worse performance in different cognitive domains