531 research outputs found
Sets of probability distributions, independence, and convexity
No full textThis paper analyzes concepts of independence and assumptions of convexity in the theory of sets of probability distributions. The starting point is Kyburg and Pittarelli's discussion of "convex Bayesianism" (in particular their proposals concerning E-admissibility, independence, and convexity). The paper offers an organized review of the literature on independence for sets of probability distributions; new results on graphoid properties and on the justification of "strong independence" (using exchangeability) are presented. Finally, the connection between Kyburg and Pittarelli's results and recent developments on the axiomatization of non-binary preferences, and its impact on "complete" independence, are described.CNPqCNPqFAPESPFAPESP [04/09568-0, 08/03995-5
On the Imprecision of Full Conditional Probabilities
Get PDFThe purpose of this paper is to show that if one adopts conditional probabilities as the primitive concept of probability, one must deal with the fact that even in very ordinary circumstances at least some probability values may be imprecise, and that some probability questions may fail to have numerically precise answers
Towards a Virtual Museum of Ephemeral Architecture: Methods, Techniques and Semantic Models for a Post-digital Metaverse / Verso un museo virtuale dell’architettura effimera: metodi, tecniche e modelli semantici per un metaverso post-digitale
No full textPresentiamo gli ultimi esiti di una sperimentazione, fra ricerca e didattica, sul tema del Virtual Museum (VM), riflettendo sul flusso di lavoro e sui modelli semantici utilizzati per la realizzazione del suo Metaverso, nella consapevolezza delle potenzialità oggi offerte dalle tecnoculture post-digitali.
Sin dagli esordi negli anni 80’, l’idea interdisciplinare di VM, seguendo le conquiste tecnologiche dei tempi, esplora molteplici dimensioni confor-mative dello spazio digitale, sperimentando vari sistemi di visualizzazione e diverse forme di interazione, sia online, sia offline. Dall’ormai storico Virtual Museum commissionato dalla Guggenheim Foundation nel ‘99 al-lo studio Asymptote Architecture (Hani Rashid & Lise Anne Couture), al grande tema della conservazione ed esposizione del patrimonio digitale (cfr. la Carta per la conservazione del patrimonio digitale dell'UNESCO del 2003) – ricordiamo, ad es., la mostra Archaeology of the Digital, curata da Greg Lynn nel 2013 per il Canadian Centre for Architecture di Montréal –, fino all’odierna proposta del Virtual Museum NFTism dello studio Zaha Hadid Architects, emerge un’affascinante avventura delle idee che soprat-tutto nella rappresentazione trova le ragioni del suo essere spazio abitabile.
The essay summarises the latest results of an experiment, between research and didactics, on the general theme of the Virtual Museum (VM) in architecture and design (Fig. 1), explaining the workflow used and the semantic models elaborated for the realisation of a prototype (called VM5), conceived as a thematic metaverse of ephemeral architecture. In order to summarise the main outcomes of the carried out research, the contribution has been articulated with respect to three main thematic areas addressed in the study, each treated individually by one author. The first theme— Sect. 2. The State of the Art Survey: Conceptual Map, Timeline—was elaborated by Giovanni Caffio, and summarises the project and the contents of the conceptual map and timeline realised, where the most significant works were classified, also attempting to highlight the different types of application and use of the VM. In the third part of the experimentation.
The second topic—Sect. 3. The VM Project of Ephemeral Architecture, Between Research and Teaching—was elaborated by Maurizio Unali, and introduces some of the foundational aspects inherent to the structure of the entire research, summarising the design contents that nourished the realisation of the VM5 prototype, both in compositional terms and with respect to the type of fruition experience. The main results achieved are also analysed and some possible developments are highlighted— Sect. 4. The Processing of the Workflow to Realise the VM5 Prototype, here written by Fabio Zollo, the methods and techniques (workflow) used to realise the VM5 project were defined, a graduation theme of the same author, elaborated within the five-year degree thesis workshop in Architecture (a. a. 2021/22), coordinated by Professors G. Caffio and M. Unali, of the Department of Architecture of the University G. d’Annunzio of Chieti-Pescara (Figs. 2, 3, 4, 5, 6, and 7)
Imprecise probability models for inference in exponential families
Get PDFWhen considering sampling models described by a distribution from an exponential family, it is possible to create two types of imprecise probability models. One is based on the corresponding conjugate distribution and the other on the corresponding predictive distribution. In this paper, we show how these types of models can be constructed for any (regular, linear, canonical) exponential family, such as the centered normal distribution.
To illustrate the possible use of such models, we take a look at credal classification. We show that they are very natural and potentially promising candidates for describing the attributes of a credal classifier, also in the case of continuous attributes
Automatic knee flexion in lower limb orthoses
Get PDFLower limb orthoses are often plagued by a high rejection rate, due both to the excessive effort demanded from their users and to the lack of aesthetics of the resulting gait. These factors are caused, to a great extent, by the fact that orthoses force the whole gait to be performed with the knee articulation in full extension. This work presents a light and compact device, with a low energy consumption, that can improve the performance and the gait aesthetics of knee-ankle-foot orthoses (known as KAFO). To do so, we explore the natural dynamics of the lower limb through a spring that is attached to a standard orthosis system. We also add control circuitry, a small electric motor, sensors and microprocessors to the standard orthosis, so that we can control the whole gait in a relatively natural manner. We have designed the system through a large set of simulations and have shown that the passive dynamics of the lower limb, driven by a burst of energy from a spring at the beginning of the swing phase, is sufficient to reduce the compensation mechanisms required during the gait with orthosis. Thus, this strategy is an alternative to existing solutions relying on functional electrical stimulation (FES), which suffers from limitations such as rapid muscle fatigue and difficult motion control. We describe the design of the device, the model adopted for the swing phase of the gait, the numerical simulations performed and the tests we have conducted
Kuznetsov independence for interval-valued expectations and sets of probability distributions: Properties and algorithms
No full textKuznetsov independence of variables X and Y means that, for any pair of bounded functions f(X) and g(Y), E[f(X)g(Y)]=E[f(X)] *times* E[g(Y)], where E[.] denotes interval-valued expectation and *times* denotes interval multiplication. We present properties of Kuznetsov independence for several variables, and connect it with other concepts of independence in the literature; in particular we show that strong extensions are always included in sets of probability distributions whose lower and upper expectations satisfy Kuznetsov independence. We introduce an algorithm that computes lower expectations subject to judgments of Kuznetsov independence by mixing column generation techniques with nonlinear programming. Finally, we define a concept of conditional Kuznetsov independence, and study its graphoid properties
O futuro da (pesquisa em) inteligência artificial: algumas direções
No full textA área de inteligência artificial, ocupada com a criação de dispositivos que apresentem comportamento identificado como inteligente, teve explosivo crescimento nos últimos anos. Este artigo procura classificar as várias subáreas da inteligência artificial e sugerir algumas linhas de pesquisa que devem levar a resultados promissores nos próximos anos.The field of artificial intelligence, occupied with the creation of devices that are considered intelligent, has had explosive growth in recent years. This article seeks to classify the various subareas of artificial intelligence and suggest some lines of research that should lead t
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