Multi-Hazard Resilience of Steel MRF Buildings

Multi-hazard analyses can be used to create more sustainable and resilient structural designs by considering cascading hazards and the overall system performance of structures exposed to multiple hazard types. This dissertation develops a methodology to assess building resilience for seismic, wind, fire, and post-earthquake fire scenarios. Special emphasis is placed on understanding the interdependencies and relationships between earthquake and fire damage in the assessment of structures for post-earthquake fire. The proposed methodology includes designing a building structure according to the latest building codes, developing a three-dimensional (3D) finite element method (FEM) computer model to represent building behavior, and conducting incremental dynamic and incremental fire analyses as a means to assess building performance to multiple cascading hazards. The approach is articulated by analyzing two 10-story steel structures. These structures were designed for hazard levels in Chicago, IL and Los Angeles, CA. The buildings have the same geometry and gravity framing, but vary in the design of the perimeter moment resisting frames (MRFs). Detailed 3D FEM building models were developed in ABAQUS in order to more adequately simulate real-building behavior. The framing members are modeled using beam elements and the composite floor slabs are modeled as shell elements. This model provides building level response to earthquakes, wind, fires, and fires following earthquakes. It permits redistribution of loading through catenary action during column failure in a fire event and can simulate connection and member failures. In order to simulate seismic hazards, nonlinear time history ground displacement records were applied to the base of the building and Rayleigh damping was implemented. Because ABAQUS is not traditionally used to simulate seismic building behavior, the seismic response was validated using another computer program. Fire loads were modeled using parametric time-temperature curves from Eurocode to simulate compartment fires at the first, fifth and ninth stories of the buildings. Damage from the seismic structural model was imported into the fire structural model in order to capture post-earthquake fire behavior. The level of modeling within each model varied as necessary in order to adequately capture building behavior for each hazard, while maintaining computational efficiency. The findings of this study show that post-earthquake fire resilience for structures in high and low seismic areas are the same regardless of seismic damage, as long as moment frame connections have not fractured. For compartment fires where there is no seismic damage (no plastic hinging or fracture of members), the system responds the same as a fire-only scenario. Gravity columns are the most vulnerable components because of their high utilization ratio. Buckling of gravity columns can cause column, bay or system failures in the corner, edge and interior compartments, respectively. The perimeter moment frame system can help to prevent system collapse due to gravity column failure, but it cannot prevent the gravity column failure from occurring. In some cases, moment frame connection fractures may result in additional, subsequent failure modes (such as system collapse) that occur after gravity column failure initiates. Pilot studies show that increasing gravity column sizes or its fireproofing can increase the multi-hazard resilience of the system. These modifications can prevent gravity column failure from occurring and, in turn, any subsequent failures that may occur in response. In addition, implementing a rebar mat within the composite slab can help to redistribute loads and prevent progressive collapse in interior compartments. Studies were also performed to examine the effect of fireproofing damage on the fire resilience of the structure

Inclusions.

The paradigm based on the conceptual dichotomy between inclusion and exclusion – which has affected the modern era of political and legal thought – is definitely ineffective in portraying assets and institutions as well as political and social forms that currently frame the neoliberal governmentality

Novel supports to the assessment of cognitive functions through the combined use of technologies and subjective and objective measurements

Tesis por compendio[ES] Las funciones cognitivas incluyen todos los procesos a través de los cuales un individuo percibe, registra, mantiene, manipula, usa y expresa información que está involucrada en cualquier actividad cotidiana. Las principales herramientas estandarizadas se pueden dividir en tres grupos principales: escalas cortas de pruebas de seguimiento cognitivo: cuestionarios, baterías neuropsicológicas generales y pruebas específicas. Estas herramientas están bien validadas y son confiables, pero, en la última década, varias investigaciones han demostrado que algunos pacientes pueden realizar bien estas pruebas neuropsicológicas, incluso cuando tienen dificultades significativas para adaptar sus comportamientos a las actividades de la vida diaria. De acuerdo con esto, más recientemente, un nuevo enfoque ha aumentado sustancialmente, lo que podría proporcionar una mayor validez ecológica en la evaluación de las capacidades cognitivas funcionales que el enfoque estandarizado: el uso de sistemas tecnológicos avanzados para la evaluación neuropsicológica (STAEN). STAEN se refiere a un conjunto de dispositivos y aplicaciones de software tales como pruebas computarizadas, juegos divertidos e interactivos de fantasía (JS) y / o sistemas de realidad virtual simulada (RV) y / o aumentada (RA) que van más allá de las pruebas de evaluación tradicionales y que Brindar la posibilidad de entregar estímulos controlados y dinámicos, en entornos ecológicamente válidos y seguros. Partiendo de estas premisas, el objetivo principal de la tesis era diseñar, desarrollar y validar un SG 2D no inmersivo versus un JS 3D inmersivo y una actividad de la vida diaria en un entorno 3D RV inmersivo versus un RA para la evaluación de funciones cognitivas, comparando la eficacia y efectividad de ellos. El primer estudio 2D incluyó 354 sujetos sanos y se encontraron correlaciones entre el juego y los métodos tradicionales, lo que sugiere que el juego podría ser una herramienta válida para evaluar las funciones cognitivas en adultos. El segundo estudio, comparó la versión 2D versus una versión 3D STAEN, involucró a 94 sujetos sanos y mostró que la versión 3D fue capaz de generar tiempos más bajos y respuestas correctas más altas que la 2D, lo que sugiere evidencia inicial de la eficacia de un sistema más inmersivo en comparación con un sistema no-inmersivo. Aunque este resultado destaca una posible limitación en el uso de diferentes sistemas tecnológicos debido a las diferencias en los dos métodos de interacción (el sistema 2D aplicó el mouse y el teclado; los controladores de dos manos virtuales 3D) y el registro de datos de latencia de hardware y software. Con respecto a la variabilidad individual en edad, género y educación, los hallazgos mostraron consistencia con la literatura de referencia. Específicamente, los más jóvenes mostraron un mayor rendimiento que los mayores; niveles educativos más altos reflejados en una mejor puntuación y sobre género, los resultados mostraron un panorama más compuesto. Además, para mejorar la validez ecológica de la evaluación, el último estudio de esta tesis comparó el rendimiento conductual y las respuestas fisiológicas, durante una tarea de cocina ecológica, entre un sistema virtual y un sistema aumentado en 50 sujetos sanos. La tarea de cocinar consistió en 4 niveles que aumentaron en dificultad. A medida que el nivel aumentó, aparecieron actividades adicionales. Los resultados de comportamiento mostraron que los tiempos son siempre más bajos en realidad virtual que en RA, aumentando constantemente de acuerdo con la dificultad de las tareas. Con respecto a las respuestas fisiológicas, los hallazgos mostraron que la condición RA produjo más excitación y activación individual que la realidad virtual. Para concluir, STAEN está demostrando ser herramientas confiables y efectivas para la evaluación de las funciones cognitivas en adultos, proporcionando más validez ec[CA] Les funcions cognitives inclouen tots els processos a través dels quals un individu percep, registra, manté, manipula, usa i expressa informació que està involucrada en qualsevol activitat quotidiana. Les principals ferramentes estandarditzades es poden dividir en tres grups principals: escales curtes de proves de seguiment cognitiu: qüestionaris, bateries neuropsicológiques generals i proves específiques. Estes ferramentes estan ben validades i són confiables, però, en l'última dècada, diverses investigacions han demostrat que alguns pacients poden realitzar bé estes proves neuropsicológiques, inclús quan tenen dificultats significatives per a adaptar els seus comportaments a les activitats de la vida diària. D'acord amb açò, més recentment, un nou enfocament ha augmentat substancialment, la qual cosa podria proporcionar una major validesa ecològica en l'avaluació de les capacitats cognitives funcionals que l'enfocament estandarditzat: l'ús de sistemes tecnològics avançats per a l'avaluació neuropsicológica (STAEN). STAEN es referix a un conjunt de dispositius i aplicacions de software com ara proves computaritzades, jocs divertits i interactius de fantasia (JS) i / o sistemes de realitat virtual simulada (RV) i / o augmentada (RA) que van més enllà de les proves d'avaluació tradicionals i que brinden la possibilitat de presentar estímuls controlats i dinàmics, en entorns ecològicament vàlids i segurs. Partint d'estes premisses, l'objectiu principal de la tesi era dissenyar, desenrotllar i validar un SG 2D no inmersiu versus un JS 3D inmersiu i una activitat de la vida diària en un entorn 3D RV inmersiu versus un RA per a l'avaluació de funcions cognitives, comparant l'eficàcia i efectivitat d'ells. El primer estudi 2D va incloure 354 subjectes sans i es van trobar correlacions entre el joc i els mètodes tradicionals, la qual cosa suggerix que el joc podria ser una ferramenta vàlida per a avaluar les funcions cognitives en adults. El segon estudi, va comparar la versió 2D versus una versió 3D STAEN, va involucrar a 94 subjectes sans i va mostrar que la versió 3D va ser capaç de generar temps més baixos i respostes correctes més altes que la 2D, la qual cosa suggerix evidència inicial de l'eficàcia d'un sistema més inmersiu en comparació amb un sistema no-inmersiu. Encara que este resultat destaca una possible limitació en l'ús de diferents sistemes tecnològics a causa de les diferències en els dos mètodes d'interacció (el sistema 2D va aplicar el ratolí i el teclat; els controladors de dos mans virtuals 3D) i el registre de dades de latència de hardware i software. Respecte a la variabilitat individual en edat, gènere i educació, les troballes van mostrar consistència amb la literatura de referència. Específicament, els més jóvens van mostrar un major rendiment que els majors; nivells educatius més alts reflectits en una millor puntuació i sobre gènere, els resultats van mostrar un panorama més compost. A més, per a millorar la validesa ecològica de l'avaluació, l'últim estudi d'esta tesi va comparar el rendiment conductual i les respostes fisiològiques, durant una tasca de cuina ecològica, entre un sistema virtual i un sistema augmentat en 50 subjectes sans. La tasca de cuinar va consistir en 4 nivells que van augmentar en dificultat. A mesura que el nivell va augmentar, van aparéixer activitats addicionals. Els resultats de comportament van mostrar que els temps són sempre més baixos en realitat virtual que en RA, augmentant constantment d'acord amb la dificultat de les tasques. Respecte a les respostes fisiològiques, les troballes van mostrar que la condició RA va produir més excitació i activació individual que la realitat virtual. Per a concloure, STAEN està demostrant ser ferramentes confiables i efectives per a l'avaluació de les funcions cognitives en adults, proporcionant més validesa ecològica i objectivitat que els mètodes tradicio[EN] Cognitive functions include all the processes through which an individual perceives, records, maintains, manipulates, uses and expresses information that are involved in any everyday activity. The main standardized tools can be divided in three main groups: short scales of cognitive tracking tests - questionnaires, general neuropsychological batteries, and specific tests. These tools are well-validated and reliable but, in the last decade, several research have shown that some patients can perform these neuropsychological tests well, even when they have significant difficulties in adapting their behaviours to daily life activities. According to this, more recently, a new approach has substantially increased, potentially providing a higher ecological validity in functional cognitive abilities assessment than standardized approach: the use of advanced technological systems for neuropsychological assessment (ATSNA). ATSNA refer to a set of devices and software applications such as computerized tests, fun and interactive fantasy serious games (SG), and/or simulated virtual (VR) and/or augmented (AR) reality systems that go beyond traditional assessment tests and that supply the possibility to deliver controlled and dynamic stimuli, in ecologically valid, and secure environments. Starting from these premises, the main objective of the thesis was to design, develop, and validate a non-immersive 2D SG versus an immersive 3D SG and a daily life activity in an immersive 3D VR environment versus an AR for the assessment of cognitive functions, comparing the efficacy and effectiveness of them. The first 2D study involved 354 healthy subjects and correlations were found between the game and traditional methods, suggesting that the game could be a valid tool for assessing cognitive functions in adults. The second study, compared 2D versus a 3D ATSNA version, it involved 94 healthy subjects and showed that 3D version was able to generate lower times and higher correct answers that the 2D, suggesting initial evidence of efficacy of a more immersive system compared to a non-immersive system. Although this result highlights a potential limitation on using different technological systems due to the differences on the two interaction methods (the 2D system applied mouse and keyboard; the 3D two virtual hands' controllers) and hardware and software latency data recording. Regarding individual variability on age, gender, and education, the findings showed consistency with the reference literature. Specifically, younger showed higher performance that older; higher educational levels reflected on a better score and about gender, results showed a more composite panorama. Furthermore, to enhance the ecological validity of assessment, the last study of this thesis compared the behavioural performance and physiological responses, during an ecological cooking task, between a virtual and an augmented system on 50 healthy subjects. The cooking task consisted of 4 levels that increased in difficulty. As the level increased, additional activities appeared. The behavioural results showed that times are always lower in VR than in AR, increasing constantly in accordance with the difficulty of the tasks. Regarding physiological responses, the findings showed that AR condition produced more individual excitement and activation than VR. To conclude, ATSNA are proving to be reliable and effective tools for the assessment of cognitive functions in adults, providing more ecological validity and objectivity than traditional methods of assessment.Chicchi Giglioli, IAM. (2020). Novel supports to the assessment of cognitive functions through the combined use of technologies and subjective and objective measurements [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/139075TESISCompendi

Covid-19 Impact on Platform Economy. A Preliminary Outlook

With this report, PLUS consortium wants to contribute to a large debate on the role of platform economy and on how to deal with labour transformations after Covid-19 outbreak. Considering the ongoing very unpredictable situation, the observations contained in the report should be considered as explorative to further investigations. In any case, we would suggest to avoid framing Covid-19 outbreak in 2020 as outstanding event clearly dividing what occurred before from what will occur shortly after. Rather, one of the purposes of this report is to test if some of the hypothesis we produced during the first year and half of the project are still persuasive even after virus appearance. At first sight it seems that Covid-19 pandemic highlights and, if anything, emphasizes very well some platforms characteristics we had already identified: the lack of social protections for platform workers, the becoming essential infrastructures of platforms, the digitalization of services, the changing nature of urban economies

Post-Earthquake Fire Assessment of Steel Buildings

Resilience of structural systems after hazardous events is a crucial concern of building design. An abundance of research has focused on hazards such as seismic and fire separately. This project conducted a multi-hazard study on steel buildings considering both seismic and fire damage. A literature review of the behavior of steel-framed buildings due to fires after earthquakes, known as post-earthquake fires (PEF), is offered. The new PEF methodology, delivered in this study, starts with creating a three dimensional (3D) model of the examined steel building using the finite element method software, ABAQUS. Next, varying intensities of seismic and fire hazards were applied to the building models. Incremental dynamic analyses (IDA) were conducted to examine the progression of damage as peak ground accelerations increase. Similarly, incremental fire analyses (IFA) involved scaling the peak fire temperature and recording the vertical story deflection. Three primary failure modes were observed: compartment failure, column failure and bay failure. Preliminary results show that gravity columns are the most vulnerable component within the structure, regardless of seismic damage. Recommendations for improving building resilience are provided for future examination

How a student becomes a teacher: learning and forgetting through Spectral methods

In theoretical ML, the teacher-student paradigm is often employed as an effective metaphor for real-life tuition. The above scheme proves particularly relevant when the student network is overparameterized as compared to the teacher network. Under these operating conditions, it is tempting to speculate that the student ability to handle the given task could be eventually stored in a sub-portion of the whole network. This latter should be to some extent reminiscent of the frozen teacher structure, according to suitable metrics, while being approximately invariant across different architectures of the student candidate network. Unfortunately, state-of-the-art conventional learning techniques could not help in identifying the existence of such an invariant subnetwork, due to the inherent degree of non-convexity that characterizes the examined problem. In this work, we take a leap forward by proposing a radically different optimization scheme which builds on a spectral representation of the linear transfer of information between layers. The gradient is hence calculated with respect to both eigenvalues and eigenvectors with negligible increase in terms of computational and complexity load, as compared to standard training algorithms. Working in this framework, we could isolate a stable student substructure, that mirrors the true complexity of the teacher in terms of computing neurons, path distribution and topological attributes. When pruning unimportant nodes of the trained student, as follows a ranking that reflects the optimized eigenvalues, no degradation in the recorded performance is seen above a threshold that corresponds to the effective teacher size. The observed behavior can be pictured as a genuine second-order phase transition that bears universality traits.Comment: 10 pages + references + supplemental material. Poster presentation at NeurIPS 202

Biosignal comparison for autism assessment using machine learning models and virtual reality

: Clinical assessment procedures encounter challenges in terms of objectivity because they rely on subjective data. Computational psychiatry proposes overcoming this limitation by introducing biosignal-based assessments able to detect clinical biomarkers, while virtual reality (VR) can offer ecological settings for measurement. Autism spectrum disorder (ASD) is a neurodevelopmental disorder where many biosignals have been tested to improve assessment procedures. However, in ASD research there is a lack of studies systematically comparing biosignals for the automatic classification of ASD when recorded simultaneously in ecological settings, and comparisons among previous studies are challenging due to methodological inconsistencies. In this study, we examined a VR screening tool consisting of four virtual scenes, and we compared machine learning models based on implicit (motor skills and eye movements) and explicit (behavioral responses) biosignals. Machine learning models were developed for each biosignal within the virtual scenes and then combined into a final model per biosignal. A linear support vector classifier with recursive feature elimination was used and tested using nested cross-validation. The final model based on motor skills exhibited the highest robustness in identifying ASD, achieving an AUC of 0.89 (SD = 0.08). The best behavioral model showed an AUC of 0.80, while further research is needed for the eye-movement models due to limitations with the eye-tracking glasses. These findings highlight the potential of motor skills in enhancing objectivity and reliability in the early assessment of ASD compared to other biosignals

Application of Supervised Machine Learning for Behavioral Biomarkers of Autism Spectrum Disorder Based on Electrodermal Activity and Virtual Reality

Objective Sensory processing is the ability to capture, elaborate, and integrate information through the five senses and is impaired in over 90% of children with autism spectrum disorder (ASD). The ASD population shows hyper-hypo sensitiveness to sensory stimuli that can generate alteration in information processing, affecting cognitive and social responses to daily life situations. Structured and semi-structured interviews are generally used for ASD assessment, and the evaluation relies on the examiner's subjectivity and expertise, which can lead to misleading outcomes. Recently, there has been a growing need for more objective, reliable, and valid diagnostic measures, such as biomarkers, to distinguish typical from atypical functioning and to reliably track the progression of the illness, helping to diagnose ASD. Implicit measures and ecological valid settings have been showing high accuracy on predicting outcomes and correctly classifying populations in categories. Methods Two experiments investigated whether sensory processing can discriminate between ASD and typical development (TD) populations using electrodermal activity (EDA) in two multimodal virtual environments (VE): forest VE and city VE. In the first experiment, 24 children with ASD diagnosis and 30 TDs participated in both virtual experiences, and changes in EDA have been recorded before and during the presentation of visual, auditive, and olfactive stimuli. In the second experiment, 40 children have been added to test the model of experiment 1. Results The first exploratory results on EDA comparison models showed that the integration of visual, auditive, and olfactive stimuli in the forest environment provided higher accuracy (90.3%) on sensory dysfunction discrimination than specific stimuli. In the second experiment, 92 subjects experienced the forest VE, and results on 72 subjects showed that stimuli integration achieved an accuracy of 83.33%. The final confirmatory test set (n = 20) achieved 85% accuracy, simulating a real application of the models. Further relevant result concerns the visual stimuli condition in the first experiment, which achieved 84.6% of accuracy in recognizing ASD sensory dysfunction. Conclusion According to our studies' results, implicit measures, such as EDA, and ecological valid settings can represent valid quantitative methods, along with traditional assessment measures, to classify ASD population, enhancing knowledge on the development of relevant specific treatments

An Immersive Virtual Reality Game for Predicting Risk Taking through the Use of Implicit Measures

Featured ApplicationThe tool presented in this article can be applied as an ecological measure for evaluating decision-making processes in risky situations. It can be used in different contexts from both Occupational Safety and Health practices and for research purposes.Risk taking (RT) measurement constitutes a challenge for researchers and practitioners and has been addressed from different perspectives. Personality traits and temperamental aspects such as sensation seeking and impulsivity influence the individual's approach to RT, prompting risk-seeking or risk-aversion behaviors. Virtual reality has emerged as a suitable tool for RT measurement, since it enables the exposure of a person to realistic risks, allowing embodied interactions, the application of stealth assessment techniques and physiological real-time measurement. In this article, we present the assessment on decision making in risk environments (AEMIN) tool, as an enhanced version of the spheres and shield maze task, a previous tool developed by the authors. The main aim of this article is to study whether it is possible is to discriminate participants with high versus low scores in the measures of personality, sensation seeking and impulsivity, through their behaviors and physiological responses during playing AEMIN. Applying machine learning methods to the dataset we explored: (a) if through these data it is possible to discriminate between the two populations in each variable; and (b) which parameters better discriminate between the two populations in each variable. The results support the use of AEMIN as an ecological assessment tool to measure RT, since it brings to light behaviors that allow to classify the subjects into high/low risk-related psychological constructs. Regarding physiological measures, galvanic skin response seems to be less salient in prediction models