Progetti

Many decisions in modern societies have a very complex scientific basis. Clinicians have to choose between different drugs for treating a patient. Central bankers have to forecast the evolution of financial markets, and to control the amount of money that circulates in a society. Physicists have to evaluate the impact of continued CO2 emissions for life on the planet. All these decisions are based on the forecasts of scientific models, and sometimes, their predictions reach a great degree of exactness (e.g., in identifying high-risk hospital patients and allocating resources efficiently).

In short, how does science based on uncertain models contribute to good decisions?

Our project investigates the interface between modeling and decision-making. We develop an understanding of how scientific models function, how they advance our knowledge despite their intrinsic uncertainty, and how they are interpreted in a decision context. More specifically, we focus on the following three questions, which correspond to our main targets:

1. How can highly idealized and intrinsically uncertain scientific models be successful in prediction?

2. Why can we trust and accept scientific models in spite of their intrinsic uncertainty and how should we factor in this uncertainty?

3. How should we synthesize actuarial, model-based judgment with human expertise in making practical decisions?

In answering these three questions, our projects integrates foundational philosophical analysis (e.g., rational criteria for theory acceptance), formal and conceptual analysis, and case studies about construction and use of models in a number of relevant scientific disciplines like financial economics and evidence-based medicine.

This project brings together a variety of competences and methods to address an issue that has recently gained attention by scholars working at the intersection of different disciplines: economics, psychology, sociology, cognitive sciences. The issue under debate concerns the interaction between cognitive modes and prosocial behavior, i.e., the extent to which individual behavior is beneficial to the society as a whole. The basic question is: which cognitive mode is more likely to foster prosocial behavior? Up to now, such a debate is lively and far from being set. Indeed, the literature provides both conflicting theoretical arguments and inconclusive empirical evidence (see the state of the art in B.1.2).

Our hypothesis is that the different definitions of intuition used in the literature can, to some extent, explain opposing results in the analysis of intuitive behavior and prosociality.

The project investigates four research lines:

(1) from a theoretical perspective, we aim at providing an evolutionary explanation of the linkage between social motives and prosocial behavior in each cognitive mode;

(2) from a methodological perspective, we aim at identifying effective methods to manipulate the cognitive mode of subjects in an experimental setting (the aim is to be able to promote reliance on automatic intuition, conscious intuition and deliberation);

(3) from a behavioral perspective, we aim at understanding how cognitive modes and social motives interact to determine actual prosocial behavior;

(4) again from a behavioral perspective, we aim at understanding how cognitive modes affect the degree of discrimination of prosocial behavior (i.e., to what extent prosocial behavior is limited to interactions with individuals similar to the decision-maker).

By developing these research lines, we can obtain a rationalization of apparently conflicting evidence provided by the literature and, more in general, we can foster the understanding of the relationship between cognitive modes and prosocial behavior, as mediated by social motives.

Both deforestation and pollution are key factors in global climate change. This is because forests are natural pollution sinks able to capture carbon dioxide emissions from the atmosphere and convert them into oxygen, which both humans and animals can breathe safely. Unless proper countermeasures are taken, deforestation represents a big problem for climate: by cutting down forests without replacing the trees that are removed, the absorption efficiency of such carbon sinks is reduced, with possible catastrophic consequences. To counteract these effects, suitable policies are needed, such as reductions in the emission levels, and reforestation.

This project complements the few available attempts in the literature to unify deforestation and pollution issues.

These systems are, and will be more and more, pervasive and ubiquitous, also in safety-critical situations. Examples range from robots and drones delivering goods to self-driving vehicles and smart buildings. These systems must satisfy safety requirements, and meet performance goals. It is fundamental to keep all such requirements into account from the design phase, to reduce the cost of development and avoid dangerous situations coming from unexpected requirement violation.

Model-based engineering (MBE) of CPS is challenging due to some specific features of these systems: they act in an open physical space environment, which is subject to unpredictable changes. Hence, approaches to MBE of CPS have to explicitly take into account the uncertainty and the spatial structure of the environment in which they act. In this project, we will propose a framework in this direction, dealing with spatially distributed CPS in an uncertain environment. The framework will allow engineers to describe the system and the requirements with a high-level, UML like specification language, which will be automatically converted in a domain specific language from which a formal executable model of the system and a formalization of requirements will be extracted

Il corso organizzato all’interno del progetto Tuscan Start Up Academy è motivato dall’attivazione di centri di competenza regionale e nazionale su temi di Impresa 4.0 in cui la Scuola IMT è attivamente coinvolta sui temi della automazione, cybersecurity, big data e advanced manufacturing solutions, sia a livello di ricerca dottorale, che di trasferimento tecnologico. Il corso Imprendi 4.0 consentirà di analizzare nel dettaglio i possibili risvolti imprenditoriali associati a tali temi e ricerche, al fine di arricchire la formazione dei dottorandi della Scuola o provenienti dalle altre università su tematiche di trasferimento tecnologico e nello specifico di imprenditorialità accademica nell’ambito di Impresa 4.0.

The aim of this project is to develop an efficient two-scale numerical scheme integrating implicit finite element computations at the macro-scale and the boundary element method at the micro-scale for the accurate solution of frictional contact problems with microscopic interface roughness.

The project will enable the setup of a new cooperation between the Italian and German research teams which is envisaged to have impact on: (i) strengthening of the internationalization of their respective PhD programmes; (ii) strengthening of technology transfer capabilities of their computational methods for virtual testing of materials and structures; (iii) establishment of a network to be exploited for EU FP9 funding applications in the area of excellence science.

Le principali finalità del programma di intervento sono: favorire lo sviluppo del capitale umano e la sua occupabilità attraverso il finanziamento di percorsi di alta formazione tramite la ricerca; sostenere l’occupabilità degli assegnisti promuovendo lo sviluppo di percorsi di esperienza che ne assicurino la crescita professionale; creazione di un laboratorio sperimentale condiviso tra la Scuola IMT e l’azienda CROMOLOGY ITALIA SpA, a partire dal laboratorio MUSAM-Lab precedentemente finanziato dall’European Research Council e dal laboratorio di R&D di CROMOLOGY, per supportare e incrementare le attività di trasferimento tecnologico della Scuola IMT sul terrirorio nell’ambito dei materiali polimerici; accrescimento delle attività di ricerca e trasferimento tecnologico della Scuola IMT in ambito informatico in cooperazione con le aziende del territorio interessate a sviluppare metodi di cyber-security e con Fondazioni e associazioni interessate all’applicazione di metodi per l’analisi di big data scaturiti da eventi culturali e sociali, archivi museali, o applicazioni mediche.

Research Unit:

• LYNX
• SYSMA
• MUSAM

The capacity to have an aesthetic experience is a characteristic human trait and it is the result of a complex interplay between sensation, emotions and cognition. Although the concept of “beauty” has been the object of centuries of philosophical and psychological debate, only in recent decades has it been the object of an organized cognitive neuroscience research program. Although recent developments are very promising, more work is needed to uncover the functional and neural mechanisms mediating the aesthetic experience.

Our project aims to use neuroimaging (IMT Unit) and brain stimulation (Milano-Bicocca Unit) techniques to shed light on the neural network underpinning aesthetic experience for different categories of visual stimuli. Furthermore, consistent research points to the existence of several multisensory brain regions that process information regardless the sensory modality in which the input is acquired. Focusing here on touch, whether aesthetic appreciation of the same artworks in the visual and haptic modality lead to similar neural activations is not known. We will investigate this aspect, also considering a related fascinating question, i.e., whether the mechanisms mediating aesthetic experience in the blind brain are the same as in case of a normally sighted brain. What is “beauty” for a blind person’s brain? (Milano-Bicocca and Pisa Unit have a long experience in studying blindness).

Moreover, experience of and sensitivity to aesthetics has received little attention in the clinical setting. We know that aesthetical appreciation of paintings is spared in dementia and schizophrenia affects art perception, but very little is known for instance about major depression disorder, of which a core symptom is anhedonia. Can exposure to beautiful artistic images reduce non-physical pain? This hypothesis is grounded in neuroimaging and brain stimulation evidence showing that aesthetic viewing increases activity in the left dorsolateral prefrontal cortex that is usually hypo-activated in depressed patients.

Finally, although a certain simplification is inherent to experimental neuroscience (that necessarily tend to look at “average” experiences), an interdisciplinary approach in which knowledge from art history and experimental methods converge is needed (against reductionism). The project strongly aims to open a constructive dialogue between disciplines, such as art history and neuroscience, that have been often considered as having far (or even incompatible) approaches. The IMT-Lucca unit will have a fundamental role in assisting the other units in the selection of stimuli and paradigms and in critically contextualizing the findings about neural correlates of aesthetic appreciation in a broader perspective in which art history and philosophy are considered.

Research Unit:

• LYNX
• MOMILAB

Long-living software systems are typically available in a rich set of variants to deal with differing customer requirements and application contexts. Furthermore, users are often given the possibility to change to a different configuration online to dynamically adapt to varying environmental conditions. In addition to satisfying functional requirements, such changes are to preserve existing service-level agreements. The focus of this project is to define a methodology for expressing system variability and its impact on performance.

One of the most pressing and fascinating challenges scientists face today, is understanding the complexity of our globally interconnected society. The big data arising from the digital breadcrumbs of human activities promise to let us scrutinize the ground truth of individual and collective behaviour at an unprecedented detail and scale. There is an urgent need to harness these opportunities for scientific advancement and for the social good. The main obstacle to this accomplishment, besides the scarcity of data scientists, is the lack of a large-scale open infrastructure, where big data and social mining research canbe carried out.  To this end, SoBigData proposes to create the Social Mining & Big Data Ecosystem: a research infrastructure (RI) providing an integrated ecosystem for ethic-sensitive scientific discoveries and advanced applications of social data mining on the various dimensions of social life, as recorded by “big data”. Building on several established national infrastructures, SoBigData will open up new research avenues in multiple research fields, including mathematics, ICT, and human, social and economic sciences, by enabling easy comparison, re-use and integration of state-of-the-art big social data, methods, and services, into new research. It will not only strengthen the existing clusters of excellence in social data mining research, but also create a pan-European, inter-disciplinary community of social data scientists, fostered by extensive training, networking, and innovation activities. In addition, as an open research infrastucture, SoBigData will promote repeatable and open science. Although SoBigData is primarily aimed at serving the needs of researchers, the openly available datasets and open source methods and services provided by the new research infrastructure will also impact industrial and other stakeholders (e.g. government bodies, non-profit organisations, funders, policy makers).

The present project pursues three main objectives.

(1) A complete inventory of the manuscripts preserving Avicenna’s Ilāhiyyāt, through the systematic inspection of the catalogues of Arabic collections in libraries worldwide; the obtainment of copies of the censed manuscripts; and their description.

(2) To prepare an on-line critical edition of the Arabic text of the Ilāhiyyāt, divided in ten parts corresponding to the ten treatises of the work, with apparatus of variants, apparatus of sources, and apparatus of loci paralleli; to connect the edition with an English translation, based on the wording of the new critical edition, and with the Latin Medieval translation, according to its already existing critical edition; to provide a general introduction to the work and specific doctrinal introductions to the single treatises, with detailed overviews of their main doctrines and their function in the overall work, and a running commentary, with all the relevant explanatory information; to append complete indexes and lexica. Techniques of digital humanities will consent the creation and interplay of the different elements envisaged.

(3) A web platform, consisting of four main elements: i) a codicological database, containing all the relevant information and the key images of the manuscripts brought to light and used in the project; ii) the edition of the text and its complements (translations, commentary, lexica etc.); iii) a bibliographical archive of editions, translations, and studies of Avicenna’s philosophy, with particular regard to his metaphysics; iv) a newsletter for the sharing of information among scholars of Avicenna’s thought worldwide. Technology will provide instruments to store information on and images of manuscripts into the database; to record the collation of the testimonia of the work, and to convert the results of the collation into the critical apparatus; to link the Arabic text with its various complements (apparatuses, translations, commentary, indices, lexica); and to compile indices and lexica.

The BRIGHT project aims at enhancing the visibility and perception of researchers among the general population in the Tuscany Region, simultaneously with all the European Researchers’ Night (ERN) initiatives. BRIGHT acronym means “Brilliant Researchers Impact on Growth Health and Trust in research”, wishing to underline the positive aspect of the research activity in order to convey a positive message to the general public. BRIGHT focuses on creating awareness on the important role played by researchers in addressing the great challenges ahead, such as health and wellbeing, new technologies, sustainable development, physical and biological challenges, cultural heritage. BRIGHT will be successful if it will be able to convince the population of the IMPACT of the researchers and the research's products for the development of the society, and to make people TRUST the researchers instead of being driven away by hoaxes with no scientific basis.

The OpenMaker project aims to create a transformational and collaborative ecosystem that fosters collective innovations within the European manufacturing sector and drives it towards more sustainable business models, production processes, products, and governance systems.

Building on the paradigm of Open Manufacturing, the project will achieve this goal by bringing together traditional manufacturers and digital-savvy makers and engaging in the process also universities, local authorities, civil society organisations and policy-makers.

Lucca, con il suo patrimonio culturale, è sede di una grande varietà di eventi culturali che offrono un ampio potenziale per lo sviluppo locale della città in termini economici e sociali. Questi festival non solo attraggono turisti italiani e stranieri, e quindi flussi economici, ma contribuiscono anche a dar forma ad un’immagine specifica della città e dell’identità lucchese, in aggiunta ad altri benefici di natura non economica. Esplorare quindi gli impatti di questi grandi eventi culturali rappresenta un’operazione di cruciale importanza, in modo particolare per quanto riguarda il city-branding, lo sviluppo locale e il turismo.

Il progetto andrà ad affinare la conoscenza della scena culturale lucchese e internazionale e al tempo stesso a individuare priorità e interessi dei vari attori coinvolti, attraverso un approccio interdisciplinare che mobilita metodi e approcci tipici delle scienze umani, delle scienze sociali e dell'informatica. Nel suo ruolo di intermediario fra la politica e gli organizzatori da un lato, i residenti e il pubblico dall’altro, l’iniziativa mira ad analizzare la situazione attuale e proporre suggerimenti per concorrere alla crescita culturale ed economica della città.

Il progetto WiLIFE ha lo scopo di proporre e sviluppare un sistema innovativo per la gestione delle emergenze che sia in grado di coniugare efficacemente le nuove richieste operative con gli sviluppi tecnologi del settore. L’elemento principale di WiLIFE sarà un sistema per comunicazioni professionali in grado di combinare l’affidabilità e la sicurezza dei servizi offerti da reti professionali con i vantaggi prestazionali e di servizio di reti broadband di nuova concezione.

The research unit will develop three lines of research related to political institutions, social conflicts and economic policies. At a general level, the aim of this unit is to analyze the endogenous formation of political institutions and beliefs. We want to build dynamic general equilibrium models where institutions and different kind of beliefs affect each other and change endogenously over time in order to better understand the formation of institutions and beliefs in the society. The three directions of our research are the following. A first line focus on the study of the co-evolution of political institutions (such as democracies and dictatorships) and political ideology in terms of democratic culture. A second direction concerns the analysis of the interactions between religion and technology adoption with special attention on their effects on economic growth and fiscal policy outcomes. A third direction of this research focus on the effects of different political ideologies on the behavior of politicians, with special attention on their choices about reforms affecting their constituencies.

 Affiancamento del personale di Fabio Perini S.p.A. nell’individuazione e nella valutazione di progetti di innovazione per i propri prodotti.

 The MOBY-DIC project will research and develop a unique paradigm and supporting tool chain for the design of embedded control systems, based on modelling of the physical process and integrated design of both control algorithms and embedded circuits.

Il presente progetto si colloca nell’ambito delle attività del polo di innovazione Innopaper, che si pone tra le sue finalità la promozione di azioni di scouting e marketing nelle imprese per sostenere l’innovazione, lo sviluppo ed il trasferimento di competenze, il consolidamento dei rapporti tra università ed imprese, l’acquisizione di servizi avanzati e qualificati e la realizzazione — da parte delle imprese — di progetti innovativi di ricerca e sviluppo. In questo contesto, IMT ha il ruolo di identificare e validare una metodologia per il benchmarking dei processi aziendali, con un focus particolare per i processi che incidono maggiormente sul livello di integrazione della filiera produttiva.

 ICT developments both enable and also enforce large-scale, highly-connected systems in society and industry. Knowledge to cope with these emerging systems is lacking. HYCON2 will stimulate and establish the long-term integration of the European research community, leading institutions and industry in the strategic field of control of complex, large-scale, and networked dynamical systems. It will interconnect scattered groups to create critical mass and complementarity, and will provide the necessary visibility and communication with the European industries. HYCON2 will assess and coordinate basic and applied research, from fundamental analytical properties of complex systems to control design methodologies with networking, self-organizing and system-wide coordination. HYCON2 has identified several applications domains to motivate, integrate, and evaluate research in networked control. These domains are ground and aerospace transportation, electrical power networks, process industries, and biological and medical systems.

Analisi dell'impatto economico della ricerca scientifica e tecnologica nel settore delle scienze della vita applicate alla salute.

 The EU electric power system experiences a fundamental change in the quasi-monopolistic, top-down oriented, stable, and reasonable predictable arrangements of the past. It now spans continents, has hundreds of millions consumers and hundreds of thousand producers, from nuclear power plants to privately-owned and operated badly predictable renewables such as solar cells, wind and microturbines and operates in an increasingly liberalized market. These developments pose huge challenges for its reliable and economic operation. This proposal focuses on the real-time power imbalance in the power net, which arises as a consequence of errors in the prediction of both production and demand. As this power imbalance will increase both in size and in frequency, presents arrangements to cope with this imbalance are no longer valid. They are neither reliable nor economic anymore. This project proposes an advanced ICT and control framework for ancillary services (reserve capacity) which allows a more intelligent solution by giving consumers and producers clear, real-time financial incentives to adapt their consumption/production according to the actual needs of the power system. This design is based on a distributed control structure, enabled by a fast ICT infrastructure and advanced control theory to reliably and economically deal with the necessary ancillary services. Decisions by consumers, producers, power exchanges and TSOs can be taken locally, based on local or national preferences and regulation. Still, the embedded incentives of the proposed framework can guarantee that all these local decisions together contribute to the global objectives of the EE power net: a reliable electric energy supply at the lowest costs. Instead of investing in additional expensive and environment-unfriendly reserve production or storage facilities with a low utilization rate, the reliability and e4conomy are enforced by intelligent ICT and control.

There is a limited understanding of how virtual water trade affects food security. The benefits of such indirect trade of water, for instance, could be negatively affected by the lack of a single system of shared rules defining the economic value of water resources and preventing the consequent over-exploitation of these resources in fragile socio-economical and environmental contexts.
The ViWaN project addresses these issues with an innovative and interdisciplinary approach aimed at studying the main drivers and consequences of international virtual water flows. The main objectives are two: a better understanding of the global dynamics in virtual water flows and the evaluation of the impact of such flows on food safety. We will investigate the complex relationships between climatic, agronomic and socio-economic factors that shape the evolution of the worldwide trade of virtual water. The project will deliver quantitative modeling tools that enable an explicit representation of the relationships between virtual water flows and a set of explanatory variables; these models will be applied to a comprehensive database specifically built for the purpose. In addition, to improve the future management of the virtual water trade, the project will provide with a series of operational guidelines and proposals which are based on quantitative data.

 This project proceeds from the vision that fundamental advances of policy modelling in finance and climate finance can only stem from a genuinely interdisciplinary approach where network science, big data and ICT’s meet economics and financial regulation. Accordingly, on the one hand we will develop new methods to assess the systemic importance of market players in (climate) financial networks and we will evaluate the effect of regulations in close collaborations with representatives of various regulatory bodies. The results will contribute to the discussion on how financial innovations could ignite a transition towards a greener economy and a more sustainable financial system. On the other hand, we will leverage on open data initiatives and semantic web to empower citizens with a more active role in relation to EU policies, by crowd-sourcing the mapping of the networks of influence involved in the policy making process.

The problem: The design of collective adaptive systems (CAS) must be supported by a powerful well-founded framework for modelling and analysis. CAS consist of a large number of heterogeneous entities with decentralised control and varying degrees of complex autonomous behaviour. These entities may be competing for shared resources even when collaborating to reach common goals. The pervasive but transparent nature of CAS, together with the importance of the societal goals they address, mean that it is imperative that thorough a priori analysis and verification of their design is carried out to investigate all aspects of their behaviour before they are put into operation.

The overall objective of the project is to improve the competitiveness of the tissue converting sector, with particular reference to the Tuscany paper industry. The objective will be achieved through the planning and implementation of innovative energy-efficient solutions to ensure significant reduction of energy consumption and increase of both converting line productivity and processing line safety.

Theoretically, the utilization of short-term contracts could help increase labor force participation, employment, efficiency and labour market opportunities. However, if not regulated in integration with the specific institutional framework, short-term contracts might generate undesired effects. By promoting adverse selection, driving the better workers away from the mother country as the less productive workers take up short-term contracts, short-term contracts might actually increase the brain drain. The purpose of EXODUS is to investigate the validity of these concerns and to analyze the way short-term contracts affect the brain drain phenomenon. In particular, EXODUS will focus on investigating the employment condition and behavioral choices of a specific category of workers: young individuals with a high level of education.

The project addresses three main management problems in urban water system: optimal operational control, real-time monitoring and demand forecasting/management. Real-time optimal control deals with operating the main flow and pressure actuators to meet demands using the most sustainable sources and minimizing electricity costs and is tackled using stochastic model predictive control techniques. Real-time monitoring of water quantity and quality refers to the continuous detection and location of leakage and or water quality problems. It uses fault detection and diagnosis techniques. Demand forecasting and management is based on smart metering techniques and includes detailed modelling of consumption patterns as well as a service of communication to consumers. The project will provide an integrated software platform and two real-life pilot demonstrations in Barcelona (Spain) and Lemesos (Cyprus), respectively.

The DISIRE project has been inspired by the real existing needs of multiple industrial sectors, including the world leading industrial partners in the non-ferrous, ferrous, chemical and steel industries that are highly connected and already affiliated with the SPIRE PPP and its objectives. The overall clear and measurable objective of the DISIRE project is to evolve the existing industrial processes by advancing the 
Sustainable Process Industry through an overall Resource and Energy efficiency by the technological breakthroughs and concepts of the DISIRE technological platform in the field of Industrial Process Control (IPC). Specific DISIRE Process Analyzer Technology (PAT) will be able to define quality and performance requirements, that for the first time in the process industry will be able to be directly applied on the physical properties of the developed products and thus enabling the overall online and product specific reconfiguration of the control system.

 (PV) based on Silicon (Si) semiconductors is one the most growing technology in the World for renewable, sustainable, non-polluting, widely available clean energy sources. Theoretical and applied research aims at increasing the conversion efficiency of PV modules and their lifetime. The Si crystalline microstructure has an important role on both issues. Grain boundaries introduce additional resistance and reduce the conversion efficiency. Moreover, they are prone to micro-cracking, thus influencing the lifetime. At present, the existing standard qualification tests are not sufficient to provide a quantitative definition of lifetime, since all the possible failure mechanisms are not accounted for. In this project, an innovative computational approach to design and durability assessment of PV modules is put forward. The aim is to complement real tests by virtual (numerical) simulations. To achieve a predictive stage, a challenging multi-field (multi-physics) computational approach is proposed, coupling the nonlinear elastic field, the thermal field and the electric field. To model real PV modules, an adaptive multi-scale and multi-field strategy will be proposed by introducing error indicators based on the gradients of the involved fields. This numerical approach will be applied to determine the upper bound to the probability of failure of the system. This statistical assessment will involve an optimization analysis that will be efficiently handled by a Mathematica-based hybrid symbolic-numerical framework. Standard and non-standard experimental testing on Si cells and PV modules will also be performed to complement and validate the numerical approach. The new methodology based on the challenging integration of advanced physical and mathematical modelling, innovative computational methods and non-standard experimental techniques is expected to have a significant impact on the design, qualification and lifetime assessment of complex PV systems.

L’obiettivo di WB@Lucca è la realizzazione di una piattaforma mobile di servizi personali e personalizzati basati sull’uso di tecnologie ICT innovative e non invasive al fine di migliorare la qualità della vita e la condizione di benessere degli abitanti di Lucca e stimolarne la solidarietà sociale. WB@Lucca si rivolge ad una specifica categoria di utenti: persone anziane che tendono ad assumere comportamenti sedentari, spesso con problemi di riabilitazione motoria, non si curano di seguire un’alimentazione corretta e tendono ad isolarsi dal punto di vista sociale. WB@Lucca propone una serie di servizi ed applicazioni per dispositivi mobili mirati a migliorare le condizioni di vita di tali soggetti, aumentandone l’autonomia e fornendo un supporto anche per i loro familiari. WB@Lucca sarà sviluppata come piattaforma software in versione prototipale, estendibile con ulteriori servizi ed applicazioni sempre in ambito salute e benessere.