Trisections of a 3-rotationally symmetric planar convex body minimizing the maximum relative diameter

In this work we study the fencing problem consisting of finnding a trisection of a 3-rotationally symmetric planar convex body which minimizes the maximum relative diameter. We prove that an optimal solution is given by the so-called standard trisection. We also determine the optimal set giving the minimum value for this functional and study the corresponding universal lower bound.Comment: Preliminary version, 20 pages, 15 figure

Clustering Uniswap v3 traders from their activity on multiple liquidity pools, via novel graph embeddings

Uniswap is a Constant Product Market Maker built around liquidity pools, where pairs of tokens are exchanged subject to a fee that is proportional to the size of transactions. At the time of writing, there exist more than 6000 pools associated with Uniswap v3, implying that empirical investigations on the full ecosystem can easily become computationally expensive. We propose a systematic workflow to extract a tractable sub-universe of liquidity pools, where the interconnection among such pools is maximised to capture broader dynamics within the ecosystem. The resultant set of 34 pools is then used to cluster market participants according to their liquidity consumption behaviour over such environments, for the time window January–June 2022. Introducing a novel approach, we proceed to represent each liquidity taker by a suitably constructed transaction graph. The graph is a fully connected network where nodes are the liquidity taker’s executed transactions on the 34 pools of reference, and edges contain weights encoding the time elapsed between any two transactions. We then extend the NLP-inspired graph2vec algorithm to the weighted undirected setting, and employ it to obtain an embedding of the set of graphs representing market participants. This embedding allows us to extract seven clusters of liquidity takers, with equivalent behavioural patterns that can be interpreted in terms of trading attributes, i.e. preference for exotic assets over stablecoins, frequency of activity, tolerance for higher trading fees

Returns-Driven Macro Regimes and Characteristic Lead-Lag Behaviour between Asset Classes

We define data-driven macroeconomic regimes by clustering the relative performance in time of indices belonging to different asset classes. We then investigate lead-lag relationships within the regimes identified. Our study unravels market features characteristic of different windows in time and leverages on this knowledge to highlight market trends or risks that can be informative with respect to recurrent market developments. The framework developed also lays the foundations for multiple possible extensions.Comment: 9 pages, 8 figure

SEC Form 13F-HR: Statistical investigation of trading imbalances and profitability analysis

US Institutions with more than $100 million assets under management must disclose part of their long positions into the SEC Form 13F-HR on a quarterly basis. We consider the number of variations in holdings between consecutive reporting periods, and compute imbalances in buying versus selling behaviour for the assets under consideration. A significant opportunity for profit arises if an external investor is willing to trade contrarian to the 13F filings imbalances. Indeed, imbalances capture the amount of information already consumed in the market and the related trades tend to be inflated by crowding and herding. Betting on a relatively short-term movement of prices against the sign of imbalances results in a profitable strategy especially when using a time horizon between 21 and 42 trading days (corresponding to 1-2 calendar months) after each financial quarter ends.Comment: 23 pages, 18 figure

Study of the root dentin permeability of primary teeth. Cleansers and irrigation method evaluation

Orientador: Regina Maria Puppin-RontaniDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Um dos principais objetivos do tratamento endodôntico é o debridamento do sistema de canais radiculares através da remoção dos restos pulpares, da smear layer e smear plugs, para eliminar a contaminação bacteriana e subprodutos da mesma, os quais podem se tornar reservatórios de irritantes no canal tratado. Além disso, as substâncias irrigadoras e os métodos de irrigação utilizados durante o preparo químico-mecânico, podem também contribuir para a remoção da smear layer e consequentemente alterar a permeabilidade dentinária. Dessa forma, os objetivos desta Dissertação foram: (1) discutir através da revisão da literatura, a eficácia de substâncias irrigadoras, bem como a influência de dois métodos de irrigação (irrigação manual ou ativação ultrasônica) utilizados durante o preparo químico-mecânico de dentes decíduos e permanentes, considerando a permeabilidade da dentina radicular; (2) correlacionar o índice de permeabilidade da dentina radicular de dentes decíduos sob a influência de substâncias irrigadoras associadas ou não a auxiliares de instrumentação (líquido de Dakin, líquido de Dakin associado ao peróxido de hidrogênio, solução salina associada à clorexidina gel e solução salina) e diferentes métodos de irrigação (irrigação manual ou ativação ultrasônica) aos seus aspectos morfológicos (presença ou ausência de smear layer). Baseando-se na revisão de literatura pôde-se concluir que as substâncias irrigadoras e associações utilizadas durante o tratamento endodôntico promoveram aumento da permeabilidade dentinária radicular de dentes permanentes e que não houve diferenças quanto à permeabilidade dentinária, quando comparada a irrigação realizada manualmente ou através de vibração ultrasônica. Não há estudos relacionados à permeabilidade radicular de dentes decíduos, quando estes são submetidos a substâncias irrigadoras e diferentes métodos de irrigação. A técnica de irrigação manual foi considerada mais efetiva do que a técnica de irrigação através de sistema de vibração ultrasônica, quanto à permeabilidade dentinária radicular de dentes decíduos. A presença da smear layer nas paredes radiculares foi um fator limitante à penetração do corante (índice de permeabilidade) para o terço médio quando dentes decíduos foram irrigados manualmente. O líquido de Dakin apresentou os maiores valores de índice de permeabilidade, nos três terços radiculares, sugerindo que essa solução irrigadora seja indicada para o tratamento endodôntico de dentes decíduos.Abstract: One of the main goals of root canal treatment is the cleaning of the entire root canal system, through removal of pulpal debris, smear layer and smear plugs in order to avoid harbor bacteria or bacterial by-products, providing a reservoir of potential irritants in treated root canal. In addition, the cleansers and irrigation methods used in the endodontic treatment, can also contribute with the smear layer removal and with permeability alterations. Thus, the aims of this Thesis was: (1) to discuss the efficacy of some cleansers, as well as the influence of two irrigation systems used during endodontic preparation of primary and permanent teeth (manual or ultrasonic vibration) with regard to root dentin permeability, based on a literature reviewing; (2) to correlate the dye permeability to morphological aspect (presence or absence of smear layer) of the primary root dentin wall, using scanning electron microscopy (SEM), regarding the endodontic preparation and irrigation methods. Based on literature review (1) it can be concluded that among the solutions used for permanent teeth, all solutions and associations studied increased the dentin permeability. There was no difference in the dentin permeability when comparing manual and ultrasonic irrigation. There are not enough papers focusing primary teeth on this subject to definitely establish the patterns of increased dentin permeability in tooth root canal treatment regarding the irrigating solutions and irrigation systems. The results of the second study showed that manual irrigation technique was better than ultrasonic one and that Dakin's liquid, Dakin's liquid associated with hydrogen peroxide, and saline solution showed the highest permeability index averages values. Regarding the correlation study, it could be concluded that the smear layer presence on the root dentin walls was a limiting factor to dye penetration (Permeability Index), in middle third for manual irrigation.MestradoOdontopediatriaMestre em Odontologi

Supporting active aging through a home automation infrastructure for social internet of things

The number of smart devices inside the living environments grows more and more every day, and with it the need to interface them in order to share data and activate functions. Each day, new scenarios and new applications emerge to make our lives easier in many different contexts. The AAL SOCIALIZE project aims to create a new reference platform for active ageing by applying technological solutions to care for the health of the elderly, facilitate their daily activities, simplify their access to dedicated services. The work presented herein describes the "Elderly Monitoring service" ‒ an IoT module of the SOCIALIZE platform, whose aim is to monitor elderly people's activities and physiological parameters and to combine smart device functions. This modeling process can actively contribute to anticipating, and thereby preventing, emergency situations, increasing elderly autonomy and making them feel "protected" and "safe". In this regard, the system implements a practicable, scalable solution that allows heterogeneous devices belonging to different domotic systems using diverse protocols to interact with each other, share data and services and bind together through ‘friendship’, thereby creating an infrastructure suitable for the creation of a true Social IoT (SIoT)

What’s going on in my city? Recommender systems and electronic participatory budgeting

In this paper, we present electronic participatory budgeting (ePB) as a novel application domain for recommender systems. On public data from the ePB platforms of three major US cities – Cambridge, Miami and New York City–, we evaluate various methods that exploit heterogeneous sources and models of user preferences to provide personalized recommendations of citizen proposals. We show that depending on characteristics of the cities and their participatory processes, particular methods are more effective than others for each city. This result, together with open issues identified in the paper, call for further research in the area

Emotional factors and mathematics: the role of maths anxiety and math-self perceptions in primary school children

openLa ricerca ha l'obiettivo di indagare l'apprendimento matematico e gli aspetti emotivi legati alla materia. Si analizza la relazione esistente tra ansia per la matematica, percezione di autoefficacia matematica, percezione di competenza e prestazione matematica

On relative isodiametric inequalities

We consider subdivisions of convex bodies G in two subsets E and G\E. We obtain several inequalities comparing the relative volume 1) with the minimum relative diameter and 2) with the maximum relative diameter. In the second case we obtain the best upper estimate only for subdivisions determined by straight lines in planar sets