Tailored ensembles of neural networks optimize sensitivity to stimulus statistics

The dynamic range of stimulus processing in living organisms is much larger than a single neural network can explain. For a generic, tunable spiking network we derive that while the dynamic range is maximal at criticality, the interval of discriminable intensities is very similar for any network tuning due to coalescence. Compensating coalescence enables adaptation of discriminable intervals. Thus, we can tailor an ensemble of networks optimized to the distribution of stimulus intensities, e.g., extending the dynamic range arbitrarily. We discuss potential applications in machine learning.Comment: 6 pages plus supplemental materia

Description of spreading dynamics by microscopic network models and macroscopic branching processes can differ due to coalescence

Spreading processes are conventionally monitored on a macroscopic level by counting the number of incidences over time. The spreading process can then be modeled either on the microscopic level, assuming an underlying interaction network, or directly on the macroscopic level, assuming that microscopic contributions are negligible. The macroscopic characteristics of both descriptions are commonly assumed to be identical. In this work, we show that these characteristics of microscopic and macroscopic descriptions can be different due to coalescence, i.e., a node being activated at the same time by multiple sources. In particular, we consider a (microscopic) branching network (probabilistic cellular automaton) with annealed connectivity disorder, record the macroscopic activity, and then approximate this activity by a (macroscopic) branching process. In this framework, we analytically calculate the effect of coalescence on the collective dynamics. We show that coalescence leads to a universal non-linear scaling function for the conditional expectation value of successive network activity. This allows us to quantify the difference between the microscopic model parameter and established macroscopic estimates. To overcome this difference, we propose a non-linear estimator that correctly infers the model branching parameter for all system sizes.Comment: 13 page

Dialógus a megértésről - Ottlik Géza: Iskola a határon

School at the Frontier by Géza Ottlik is one of the most influential novels of Hungarian modernism. The concept of understanding is one of the most important topics of the novel, yet it has been neglected by previous research. In this paper, I explore the role and forms of understanding in the novel, especially in the case of the primary narrator, Bébé. I conclude that understanding in the novel is a more complex concept than what is explicitly presented in the narrative. The narrator states at the beginning of the novel that there is a complete understanding between him and his closest friends at the military school that formed as a part of a Wittgensteinian language-game. Still, the structure of the narrative disproves this concept. The forming of the narrative leads to a new concept of understanding that is not based on the complete identification of individuals but rather on interpretation

Regional polyphase deformation of the Eastern Sierras Pampeanas (Argentina Andean foreland): strengths and weaknesses of paleostress inversion

The Eastern Sierras Pampeanas of central Argentina are composed of a series of basement-cored ranges, located in the Andean foreland c. 600 km east of the Andean Cordillera. Although uplift of the ranges is partly attributed to the regional Neogene evolution (Ramos et al. 2002), many questions remain as to the timing and style of deformation. In fact, the Eastern Sierras Pampeanas show compelling evidence of a long lasting brittle history (spanning the Early Carboniferous to Present time), characterised by several deformation events reflecting different tectonic regimes. Each deformation phase resulted in further strain increments accommodated by reactivation of inherited structures and rheological anisotropies (Martino 2003). In the framework of such a polyphase brittle tectonic evolution affecting highly anisotropic basement rocks, the application of paleostress inversion methods, though powerful, suffers from some shortcomings, such as the likely heterogeneous character of fault slip datasets and the possible reactivation of even highly misoriented structures, and thus requires careful analysis. The challenge is to gather sufficient fault-slip data, to develop a proper understanding of the regional evolution. This is done by the identification of internally consistent fault and fracture subsets (associated to distinct stress states on the basis of their geometric and kinematic compatibility) in order to generate a chronologically-constrained evolutionary conceptual model. Based on large fault-slip datasets collected in the Sierras de Cordoba (Eastern Sierras Pampeanas), reduced stress tensors have been generated and interpreted as part of an evolutionary model by considering the obtained results against: (i) existing K\u2013Ar illite ages of fault gouges in the study area (Bense et al. 2013), (ii) the nature and orientation of pre-existing anisotropies and (iii) the present-day stress field due to the convergence of the Nazca and South America plates (main shortening oriented WSW-ENE). Although remarkable differences in reactivation mechanisms have been observed for the various studied lithological domains (schist, gneiss and granitic rocks), the brittle regional polyphase deformation of the Eastern Sierras Pampeanas appears to be dominated by two extensional episodes (sigma3 oriented NE/ENE and WNW, respectively), which can be associated with Middle-Late Permian to Early Cretaceous tectonism, followed by a compressional paleostress (sigma1 oriented ENE), which is compatible with the present day Andean convergence. Paleostress inversion techniques, despite all uncertainties involved, represent a robust approach to disentangle complex polyphase deformation histories both in term of reactivation mechanisms and strain partitioning

Pavement Information Modelling (PIM): Best Practice to Build a Digital Repository for Roads Asset Management

The application of BIM methods and tools plays a key role in transportation infrastructure asset management. Road pavements represent one of the main components of the asset, which greatly influences safety and quality of service for users. The work presented herein exploited the potentialities of BIM processes and methods for management of road pavement structures. The specific goal was to define best practice for development of a methodological framework for Pavement Information Modelling (PIM). The starting point of the process was the identification of the specific BIM use, as intended by Kreider and Messner [1]. In this case, the BIM use identified concerned the 3rd (3D), 4th (4D), and 5th (5D) dimensions of BIM. The adopted approach had the aim to define the steps to build PIM based on geometrical and structural parameters to be used as a database for different kinds of maintenance strategies. Within this context, the main objectives of the study can be summarized as follows:(1)Define the steps to develop a PIM including all the relevant information to be stored for management purposes, from data collection to data restitution,(2)Define a best practice for the integration among BIM tools and road pavement management methods in order to obtain a digital repository for predictive maintenance strategies,(3)Define a planning and cost database for the different technologies and materials involved in the different maintenance strategies.From a practical point of view, the methodological framework was divided into three main categories (Figure 1) dealing with data: (i) data collection and input definition, which includes the analysis of available data and the BIM tools to be used to develop specific workflows; (ii) data processing, by dividing the workflows and related tasks in sub-sections for the fulfilment of the previously enounced objectives; (iii) data output, by defining the final result of each workflow.QC 20230706</p

Perceptions, Beliefs, and Attitudes of First Year Third-Level Students: An Empirical Study of Portuguese, Russian, Polish, Finnish, and Irish Students

The contemporary skillset of undergraduates includes a degree of sophistication in the application of ICT within their daily lives as well as within the higher education environment. The assumption of the student as a digital native, with the ability to cognitively process information in an ICT focused educational environment, is omnipresent in higher education. It has been suggested this assumption does not aid learning and adds an additional burden on the student. This study investigated whether experiences and perceptions, of mathematics and online assessment, are common to students studying in different countries and their respective higher education systems. The purpose of the investigation was to determine what issues influence the attitudes of students in the application of ICT for the online assessment of mathematics in the first year of undergraduate programmes. The investigation was conducted online by means of a quantitative questionnaire, consisting of 16 survey items, using Google Forms to self-selecting students (n=374) across several academic disciplines including engineering, business studies, media, and tourism. The survey was delivered in English to the majority students and translated to Russian for the Russian students to enable each group to reply in their own native language. The questionnaire design utilized a 6-point Likert scale where students were asked to express their experiences and perceptions of mathematics and online assessment in their chosen programme of study. The data was exported to IBM SPSSv24 and regression analyses were conducted to ascertain possible associations and relationships between the two student groups in the case study. The results of the investigation reveal some peculiar features and the respective investigation outcomes of the investigation will be utilized in the design of learner-centered assessments and shared with international partners

Tackling the subsampling problem to infer collective properties from limited data

Complex systems are fascinating because their rich macroscopic properties emerge from the interaction of many simple parts. Understanding the building principles of these emergent phenomena in nature requires assessing natural complex systems experimentally. However, despite the development of large-scale data-acquisition techniques, experimental observations are often limited to a tiny fraction of the system. This spatial subsampling is particularly severe in neuroscience, where only a tiny fraction of millions or even billions of neurons can be individually recorded. Spatial subsampling may lead to significant systematic biases when inferring the collective properties of the entire system naively from a subsampled part. To overcome such biases, powerful mathematical tools have been developed in the past. In this perspective, we overview some issues arising from subsampling and review recently developed approaches to tackle the subsampling problem. These approaches enable one to assess, e.g., graph structures, collective dynamics of animals, neural network activity, or the spread of disease correctly from observing only a tiny fraction of the system. However, our current approaches are still far from having solved the subsampling problem in general, and hence we conclude by outlining what we believe are the main open challenges. Solving these challenges alongside the development of large-scale recording techniques will enable further fundamental insights into the working of complex and living systems.Comment: 20 pages, 6 figures, review articl

Passively morphing blades for load alleviation of tidal turbines

Tidal turbines are exposed to time variable loading that can lead to premature failure [1,2]. The use of passive unsteady load mitigation technology, such as bend-twist coupling, is typically limited to low frequency fluctuations and is not suitable to large blades, due to structural rigidity requirements. Active control systems, such as actuated flaps, can respond to higher frequencies than whole-blade passive devices due to their smaller size [3]. However, active systems may reduce turbine reliability. Hence there is a need to develop reliable technology that mitigates unsteady loading in a varied range of frequencies, in order to prolong the fatigue life of tidal turbines. Analytically, it is possible to cancel the unsteady loading of a tidal turbine that rotates through the ocean shear layer with a fully chordwise highly flexible blade. Here, we demonstrate that under attached flow conditions, when a blade is rigid near the leading-edge and flexible near the trailing-edge, the unsteady load mitigation is proportional to the ratio of the flexible length to the full chord of the blade. We verify this relationship experimentally with a blade that has a passively morphing trailing-edge. The morphing trailing-edge extends 25% of the chord of the blade and it allows unsteady load mitigation of up to 25%, without any variation in the mean load -thus there is no penalty in terms of power extraction. In separated flow conditions, when the length-scale of vortical structures is similar to that of the flexible part of the blade, the load mitigation is about 15%. Hence, chordwise morphing blades alleviate loads in variable flow conditions and can contribute to tidal turbine survivability in a reliable way. [1] G.T.Scarlett, B.Sellar, T.van den Bremer,I.M.Viola, Unsteady hydrodynamics of a full-scale tidal turbine operating in large wave conditions, Renewable Energy, 143 (2019), 199-213. [2] G.T.Scarlett,I.M.Viola, Unsteady hydrodynamics of tidal turbineblades, Renewable Energy, 146 (2020), 843-855. [3] A. Young, J. Farman, R. Miller, Load alleviation technology for extending life in tidal turbines, Proceedings of 2nd International Conference on Renewable Energies Offshore, RENEW 2016, 521-530

Graduate Recital: Zhiyuan Gao, Horn; Grace Eom, Piano; Anna Woods, Violin; Nicholas McKee, Viola; Ulzhan Ydyryssova, Viola; April 8, 2023

Kemp Recital HallApril 8, 2023Saturday Afternoon3:00 p.m

Artists Residencies, Challenges and Opportunities for Communities’ Empowerment and Heritage Regeneration

The paper debates the results of a research carried out by the Department of Architecture of the University of Naples “Federico II” (DiARC), as part of the Creative Europe 2018 Artists in Architecture, Re-activating modern European houses program (entitled EACEA 32/2017 and EACEA 35/2017; scientific coordinator: Maria Rita Pinto; project manager: Serena Viola). The research investigates the relationships between creativity and sharing as tools of a new form of social sustainability. These elements can induce positive effects on the settlement qualities of the places, acting as engines of the custody of the settlement values and the collaborative regeneration of the built environment. The methodology is based on participatory approaches able to restore the levels of cohesion, care, and creativity that the experimentation typology of the Artists Residencies is able to trigger on the territory and on the communities who inhabit it. The results return in the form of the complex process of the artist exhibition reception a significant strategy of sustainable development, capable of influencing the community by entrusting it with the role of custodian of the existing heritage and of renewing local entrepreneurship with innovative productions