456 research outputs found
Seismic and stability analysis of component-based extraterrestrial vaults
No full textFor the first time since the 1970s, concrete plans are in motion to bring humans back to the Moon through the Artemis programme. The dawning era of space exploration aims to set the groundwork for long-term off-Earth settlement, with sights on bringing the first humans to Mars. In order to provide a safe means of inhabiting extraterrestrial (ET) environments, a self-supporting habitat shield concept has been developed by the Specialist Modelling Group at Foster + Partners, which is based on the use of mechanically interlocking masonry manufactured from in-situ resources. Significant progress must still be made in the structural design and validation of such systems, however, before they can be safely implemented. Due to the novelty of the proposed structure, existing research does not provide numerical evidence of its stability under self-weight, or under seismic loading. Research in this direction is valuable, as it explores alternatives to popular design concepts based on monolithic additive manufacturing and addresses research gaps related to the analysis of mechanically interlocking structures. The aim of this project is to provide novel insight into the stability of self-supporting dry-stone vaults under the influence of microgravity and ground motions. This is achieved through a three-part analysis approach, which starts with an investigation into the fundamental structural behaviour of dry-stone, Nubian-type vaults based on a series of parametric studies. Key geometric parameters of the vaults are varied, and the resulting distinct element models are subjected to quasi-static pushover-type analysis in 3DEC. The parametric studies indicate what configuration of the vault geometry can maximise seismic capacity. This optimal vault geometry is modelled in Rhino using geometric constraint solving, which is used to produce a model which can be assembled from mechanically interlocking components. Through pushover-type testing and dynamic time history analysis, the performance of the resulting vault model is assessed with respect to possible moonquake loading. The final part of the design process accounts for uncertainties in material properties by conducting sensitivity studies, which indicate what degree of variation in performance is possible. After completing the three mains sets of analysis needed to design a moonquake-resistant vault, several comparative analyses are carried out to provide context to the structural performance of the Nubian-type vault. The first of these additional investigations models an equivalent monolithic vault geometry in DIANA and conducts finite element analysis to determine its capacity for lateral acceleration. The second comparative study determines how covering the vault in loose regolith may influence its structural performance. The third study investigates how the variation of gravity affects the stability and seismic performance of the vault. Several key findings are obtained in this project, leading to an understanding of the structural behaviour of Nubian-type vaults and how they may be a possible solution to shielding demands in ET contexts. The final vault model was shown to remain stable under a uniform lateral acceleration equivalent to the PGA for a possible moonquake with a 475 year return period. Dynamic analysis conducted using an artificial ground motion record obtained for the same return period produced less favourable results, resulting in partial collapse of the outermost six courses of the vault. Computational constraints necessitated the implementation of an undamped analysis, however, so these results are considered to be conservative. Further analysis is needed, but these results suggest that with minor adjustments, the vault may be able to safely resist moonquake loading. The comparative monolithic vault analysis demonstrates that an additively manufactured vault may provide slightly better resistance to static lateral acceleration than a component-based vault. When considering the structural redundancy and energy dissipation necessary for safe seismic design, however, the discrete vault is expected to perform better. Results show that covering the vault in loose regolith is expected to reduce its overall stiffness. Conclusions about changes in stability cannot be made with confidence due to modelling issues at the interface between the regolith and the structure. By studying the influence of gravitational variation on the vault, results indicate that it may perform favourably on the Earth or on Mars, though the possibility of material damage must be studied further.Civil Engineerin
ADCP data from Poseidon E1-M3A observatory
No full text<p>Acoustic Doppler current profiler data from Poseidon E1-M3A observatory.</p>
<ul>
<li>Instrument: Teledyne RD Instruments Longranger 75 kHz ADCP</li>
<li>Location: Cretan Sea, 25.12° E 35.74° N</li>
<li>Time span: 15 Nov 2012 – 02 Jun 2015 </li>
</ul>
<p>A data description is available in "ADCP observations of migration patterns of zooplankton in the Cretan Sea" by Potiris E, Frangoulis C, Kalampokis A, Ntoumas M, Pettas M, Petihakis G and Zervakis V (2018), https://doi.org/10.5194/os-2018-10.</p>
Corrigendum to “A novel method to assess the dilution of complex mixtures in the marine environment: Application to marine scrubber water effluents” [Mar. Pollut. Bull. (2025) 117956]
No full textThe authors would like to apologise for any inconvenience caused. We realized that the “Funding” section in the published version of the paper is incomplete. Accordingly, we would like to add the following “Funding” section to the paper. This work has received funding from the European Union's Horizon 2020 Research and Innovation Program under Grant Agreement No 874990 (“Evaluation, control and Mitigation of the EnviRonmental impacts of shippinG Emissions” - EMERGE project). This work reflects only the authors' view and CINEA is not responsible for any use that may be made of the information it contains. One author (L.C.) was partially funded by the “ Interconnected Nord-Est Innovation Ecosystem (iNEST)” project and received funding from the European Union Next-GenerationEU - National Recovery and Resilience Plan (NRRP) – MISSION 4 COMPONENT 2, INVESTIMENT N. ECS00000043 – CUP N. H43C22000540006. This manuscript reflects only the authors' views and opinions, neither the European Union nor the European Commission can be considered responsible for them. This work took place within the framework of the DoE 2023–2027 (MUR, AIS.DIP.ECCELLENZA2023_27.FF project)
Apuntes de José Antonio Valverde sobre manos
No full textApuntes sobre manos, que el autor utilizó para elaborar su conferencia "L'Evolution Humaine Apercue Generale", impartida en el Musèe de l'Homme de París, y patrocinada por la Société d’Anthropologie de Paris, el 21 de marzo de 1963.Notes about hands, that the author used to prepare his conference: "L'Evolution Humaine Apercue Generale", given at the Musèe de l'Homme de París, and represented by the Société d’Anthropologie of Paris, the 21st of March of 1963
A novel method to assess the dilution of complex mixtures in the marine environment: Application to marine scrubber water effluents
No full textA new method is introduced that, using water-quality modelling results focused on single substances, estimates the degree of the progressive dilution and degradation of a complex mixture after discharge in the marine environment, until its consistency is modified due to different biogeochemical processes acting on its constituents. The method is based on the variance between the dilution ratios of scrubber water constituents and is applied to scrubber water effluents in two case studies in the Mediterranean Sea, using both Eulerian and Lagrangian frameworks. Results reveal that, prior to the onset of biogeochemical transformations, scrubber water behaves as a homogeneous mixture through turbulent mixing with surrounding water, gradually diluting to
10 5–10 10 ratios, in spatiotemporal scales ranging from 2 to 25 km and 2 to 60 h. The proposed method generates scrubber-water dilution maps, directly comparable to the results of “whole effluent” ecotoxicological experiments, making them suitable for risk and impact assessment studies
Autoficción y decadencia: un diálogo con la escuela buraiha japonesa, en “Manos de diamante” de Andrés Felipe Solano
No full textThis article examines the short story “Manos de diamante” by Andrés Felipe Solano, pointing out the dialogue constructed between an autobiographical narrator and the concept of decadence of the Japanese school of the buraiha, which constitute a oneself-writing in confrontation with the modernity signs of our time. First, the trajectory and historical context of the buraiha writers are reviewed to understand, in a second moment, how the Colombian author configures an unstable reader-writer pact in the story that moves between a buraiha-style fiction and the chronicle of the author-narrator’s existential drift. Finally, it is ex-posed how these elements of the autofiction genre allow the story to reveal the self-disintegration and the loss of identity in our present times.En este artículo se examina el cuento “Manos de diamante” de Andrés Felipe Solano, analizando la configuración del diálogo entre el narrador autobiográfico y el concepto de decadencia de la escuela japonesa buraiha, mediante el cual se estructura una narrativa del yo en confrontación con los signos de los tiempos de la modernidad actual. Se revisa, primeramente, la trayectoria y el contexto histórico de los escritores buraiha para comprender, en un segundo momento, cómo el autor colombiano construye en el relato un pacto ambiguo de lectura que transita entre una ficción al estilo buraiha y una crónica de la deriva existencial del narrador-autor. Finalmente, se expone de qué manera los elementos propios de la autoficción permiten revelar en el cuento la desintegración del yo y la deriva identitaria en nuestra época
Makunaima comeu Mário de Andrade: pós-humano, antropofagia e o fantástico no conto “Makunaima e os Manos Deuses” de Julie Dorrico
No full textThis paper analyzed the short story Makunaíma e os Manos Deuses, by author and indigenous scholar Julie Dorrico, and its anthropophagic relationship with Mário de Andrade’s novel Macunaíma, o herói sem nenhum caráter, in which it perfumes vengeful echoes of an “oral-cannibal complex”. The article sought to define whether Makunaíma e os Manos Deuses belongs to a new decolonial and minor Brazilian literature that eschews the failed attempts to create a national literature aligned with the Western canon and makes peace with its indigenous, African, and popular roots. The present analysis takes place through the keys of posthumanism, Amerindian perspectivism, literary minority, anthropophagy, and the fantastic.El presente artículo analizó el cuento Makunaíma e os Manos Deuses, de la autora y estudiosa indígena Julie Dorrico, y su relación antropofágica con Macunaíma, o herói sem nenhum caráter, de Mário de Andrade, en la que realiza ecos vengativos del “complejo oral-caníbal”. El artículo buscó definir si Makunaíma e os Manos Deuses pertenece a una nueva literatura brasileña decolonial y menor que evita los intentos frustrados de crear una literatura nacional alineada con el canon occidental y hace las paces con sus raíces indígenas, africanas y populares. El presente análisis se realiza a través de las claves del posthumanismo, el perspectivismo amerindio, la minoridad literaria, la antropofagia y lo fantástico.O presente artigo analisa o conto Makunaíma e os Manos Deuses, da autora e acadêmica indígena Julie Dorrico, e sua relação antropofágica com a novela Macunaíma, o herói sem nenhum caráter, de Mário de Andrade, na qual performa ecos vingativos de complexo oral-canibal. O artigo procura definir se Makunaíma e os Manos Deuses pertence a uma nova literatura brasileira decolonial e menor que foge das tentativas frustradas de criar uma literatura nacional alinhada ao cânone ocidental e faz as pazes com suas raízes indígenas, africanas e populares. A presente análise dá-se por meio das chaves do pós-humanismo, do perspectivismo ameríndio, da menoridade literária, da antropofagia e do fantástico
En las manos
No full textTreball Final de Grau en Comunicació Audiovisual. Codi: CA0932. Curs acadèmic: 2017-2018Cuba ha sido siempre un país en el punto de mira para el resto del mundo. No solo
desde el bloqueo endurecido por Estados Unidos en el año 1962, sino ya desde sus
orígenes, los cuales no se conocen plenamente.
Son muchos los países que han intentado apropiarse de la riqueza de las Antillas y,
en general, de América Latina durante muchos años. El punto estratégico en el que
está situada esta isla, el valor de sus tierras y la imposición de un sistema
radicalmente distinguido del resto, son las que han situado a Cuba en el foco de
atención de las grandes potencias económicas del mundo.
El sistema capitalista necesita de los medios de comunicación para consolidar sus
bases y por ello, son una herramienta fundamental en la construcción del imaginario
colectivo de las sociedades a las que va dirigida dicha información.
Como pasa con otros países que también tienen un sistema alejado del capitalismo
consumista, así como Corea del Norte o Venezuela, estos medios emiten mensajes
que en numerosas ocasiones no representan una imagen fiel de las sociedades que
habitan en estos sistemas.
En las manos pretende mostrar una visión de la sociedad cubana que queda alejada
del eco que hacen los mass media. Para ello, se presentan una serie de fotografías
acompañadas de unos textos que reflejan las reflexiones personales de la autora
tras unos días en distintos puntos de la isla caribeña.
En las manos, es un fotolibro realizado durante el curso académico 2017/2018 para
el Trabajo de Fin de Grado de Comunicación Audiovisual.Cuba has always been a country in the spotlight for the rest of the world. Not only
since the blockade hardened by the United States in 1962, but since its origins,
which are not fully known.
Many countries have tried to appropriate the wealth of the Antilles and, in general, of
Latin America for many years. The strategic point in which this island is located, the
value of its lands and the imposition of a system radically distinguished from the rest,
are those that have placed Cuba in the focus of attention of the great economic
powers of the world.
The capitalist system needs the means of communication to consolidate its bases
and, therefore, is a fundamental tool in the construction of the collective imagination
of the societies to which this information is addressed.
As happens with other countries that also have a system far from consumer
capitalism, as well as North Korea or Venezuela, these media emit messages that in
many occasions do not represent a true image of the societies that inhabit these
systems.
In his hands he tries to show a vision of Cuban society that is far from the echo that
the mass media make. To do this, a series of photographs accompanied by texts
that reflect the personal reflections of the author after a few days in different parts of
the Caribbean island are presented.
In the hands, is a photobook made during the academic year 2017/2018 for the Final
Project of Audiovisual Communication Degree
Ultra-Low Energy Time-Mode ADC with Background Calibration for Biomedical Sensing Applications
No full textBiomedical engineering focuses in advancing health care by taking advantage of the technological improvement. An important part of biomedical engineering is biomedical sensing, that focuses in the acquisition of biopotential signals. Through time, a lot of research has been done on the acquisition of biopotential signals and a variety of methods has been presented. The main goal of the front-end circuits of the biomedical sensing devices is to convert the analog value obtained by a sensor to its digital equivalent. In order to achieve an accurate conversion, the analog-to-digital converters used, need to achieve a medium resolution and a sampling frequency at the kilohertz range. Another important aspect in biomedical sensing devices is to achieve minimum power and area consumption. The properties of the biopotential signals and the requirements set by the biomedical applications, make the design of ADCs based on classical mixed architectures increasingly difficult, as technology scaling deteriorates the performance of the analog part of the devices. In the presented thesis, time-domain signal processing techniques have been used in order to develop a programmable resolution, low-voltage, low-power and small-area time-mode ADC for biomedical applications. The proposed time-mode ADC is a novel architecture and it is composed of a voltagecontrolled ring oscillator based analog-to-time converter, followed by an asynchronous, unfolded SAR, coarse TDC and an asynchronous, enhanced range. fine flash TDC, As the input is sensed, the analog-to-time converter, embeds the analog informationwithin the time period between a rising and a falling edge of the output signal. Following, the output time pulse is fed to the TDC that quantizes the pulse and produces the digital equivalent representation of the sensed value. The resolution of the ADC can be programmed from 8 to 10 bits. The delay elements of the coarse TDC are based on a novel modified version of Dynamic Leakage Suppresion delay elements. Moreover, a novel background calibration mechanism is introduced to correct the errors due to process variation. The calibration removes the offset and gain error of the ADC and achieves DNL and INL reduction. The integrated circuit has been implemented in a 65nm TSMC process and its performance has been evaluated through Cadence and Synopsys tools. The ADC uses a 0.5V supply voltage and consumes 771 nW for 10-bit resolution. The total area of the ADC is 0.01342 mm2. The maximum sampling rate is 2.2 KS/s. The DNL and INL of the 10 bit converter are +0.86/-0.83 and +0.88/-1.79 respectively. The simulation results indicate an SNDR of 61.3 dB and an ENOB of 9.8 bit for a 10mV peak-to-peak 1kHz input frequency.Electrical Engineering | Bioelectronic
Semantic segmentation of the AHN dataset with the Random Forest Classifier
No full textThree-dimensional (3D) city models are of great significance and are high in demand. They can be used for various useful applications such as urban planning, visibility analysis and estimating the solar irradiation and energy demand of buildings throughout the day. Nowadays, Light Detection And Ranging (LiDAR) sensors are one of the most commonly used technologies for the acquisition of cheap, fast, dense, and reliable 3D point cloud datasets. At the same time, increasing attention has been focused lately on the utilization of these 3D point cloud datasets for the reconstruction of 3D city models. The 3D representation of a scene in the form of a 3D point cloud facilitates a variety of analysis tasks like object recognition, segmentation, and classification, which are an important prerequisite for many building reconstruction methods. Thus, having an accurate classifier that can automatically assign 3D points a respective semantic class label is of utmost importance as it can significantly reduce the time and cost required to analyse 3D scenes. Training machine learning and deep learning algorithms to perform this task has been the focus of many recent scientific works that provide promising results and insights for future work.This thesis attempted to create an accurate Random Forest Classifier for LiDAR point cloud datasets using the Actueel Hoogtebestand Nederland 3 (AHN3) dataset as training data. The aim was to assist building reconstruction methods, and for this reason, only three semantic class labels are assigned to the points by the classifier, namely ground, building and other. Multiple experiments were conducted to test how large the training dataset needs to be, what features should be included and what point density the input point cloud needs to have for the classifier to perform well. Tests were also made using the DALES dataset to evaluate the performance of the classifier for different datasets and environments. Moreover, the time and memory required to train and test the various Random Forests models and the evaluation metrics of the results were stored as benchmarking research to provide insights and guide future work.The classification approach that was used consists of five major steps. First, the input point cloud is uniformly sampled and then spherical local neighbourhoods of the points are computed in multiple scales. Height and eigen-based features are then extracted for each local neighbourhood, and the best subset of features is then used to train the Random Forest Classifier. Finally, each point of the input point cloud is assigned to the same class as its nearest neighbour in the sampled point cloud. A comparative analysis shows that the performance of our final Random Forest model stands in parallel with that of other available, more complex, deep learning algorithms if we take into consideration its simplicity and efficiency.Geomatic
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