23 October 2019

First monograph out !!!

FIRST monographs OUT !!

Recently published by The OR Society @tandfSTEM Taylor & Francis in the "Journal of Simulation" :

Highlighting the archetypes of sustainability management by means of simple dynamics models: (2019). Perissi Ilaria

In recent months, we are witnessing a global demonstration of people, predominantly young, spreading a clear message: “we must do something against climate change and do it immediately, the way we live is no longer sustainable”. Despite the urgency of the actions most of the people are not expert in sustainability, thus it is not always trivial to identify the effectiveness of any action, promoted by the collective or individuals, in changing our lifestyle. In the present work, a set of simple system dynamics models are proposed with the aim of helping help the understanding and the teaching of Sustainability and sustainable dynamics to young people and non-specialist. In particular, the study, inspired by the “World Dynamics” work of Jay Forrester, will focus on modelling the dynamics of energy transition from fossil fuels to renewables energy, which is recognised as a priority in fighting climate change and in granting the future society with a clean and long-lasting energy supply.
KEYWORDS: Sustainability, system dynamics, carrying capacity, energy transition, education

24 November 2018

Which is the impact of EU on climate change?

The purpose of this work I conducted in the frame of the Project MEDEAS H2020 (also @ProjectMEDEAS, MEDEAS on Facebook) in collaboration with the Global Sustainability Institute of the Anglia Ruskin University (Cambridge, UK) and Consejo Superior the Investigation Cientifica (Barcelona, SP) is to highlight the discrepancy that currently exists between the package of measures to mitigate the climate change promoted by COP21 and those actually adopted by the European Union in the Roadmap 2050 package. 

The COP 21 goal concerns the staying within 2°C of warming by 2100. This target temperature depends on the carbon dioxide concentration that will be present in the atmosphere in 2100, from which originated the idea of “carbon budget”, namely the amount of carbon dioxide gasses we can still emit, from present to 2100, to not overtake that limit. EU measures, instead, only pledge to cut the value of 1990 greenhouse gases emissions flow rates of -80% by 2050, but without giving an estimation or a maximum ceiling of the amount of carbon dioxide will be present in the atmosphere by 2050 (and later on to 2100) thanks to those measures. This is why the impact of the ongoing EU regulations on global warming is still unestimated. 

The aim and the novelty of this study are to propose, for the first time, a carbon budget estimation for the European Union, which represents the most significant physical characteristic to assess the feasibility of current EU-28 greenhouse gas reduction objectives under the goal of 2°C of global warming promoted by 2015 Paris treaty.

Enjoy the full article reading at:
Perissi, I.; Falsini, S.; Bardi, U.; Natalini, D.; Green, M.; Jones, A.; Solé, J.

Potential European Emissions Trajectories within the Global Carbon Budget. 
Sustainability 2018, 10, 4225.

EU emissions potential Pathways by sectors  applying decarbonisation policy from 2020 and from 2030

25 October 2018

Mechanisms of meme propagation in the mediasphere: a system dynamics model

Now published Ilaria Perissi, Sara Falsini and Ugo Bardi paper on how to discover if a Meme propagates thanks to own viral power or ....to commercial advertising/propaganda operation! 

The two peaks look like to be very simila....but they are not! 

@EmeraldGlobal-Kybernetes Mechanisms of meme propagation in the mediasphere: a system dynamics model

Mechanisms of meme propagation in the mediasphere: a system dynamics model | Kybernetes | Ahead of Print

20 September 2018

"Brains ....not in drain" - The decline of Fisheries

Discussing the plague of overfishing in the magazine "Sapere" (Dedalo Ed.)

Last August, I had the opportunity to write a column for the magazine "Sapere" (Edizioni Dedalo) in the section "CERVELLI NON IN FUGA" ( translatable in "Brains.... not in drain..."). "Sapere" is the oldest Italian magazine pledged to disseminate Science at a general public; further information on the magazine aims and topics are reported in the footnotes. 

Thus, here is the translation of the piece, which starts with the following sentences: 

"Give a man a fish and he will eat for a day, teach him how to fish and he will empty the ocean. "

This said may sound familiar, but the conclusion, in fact, was something like: 

"teach him to fish and eat for all life" 

You will ask why I transformed this wise statement, which invites the individual to be lively and far-sighted, in a sentence used to qualify a man who, instead, is anything but wise, that grabs beyond what is necessary for the subsistence, leaving behind an empty ocean. The answer is that the new version of the statement describes perfectly the phenomenon of overfishing (fishing over the limit), a term that qualifies modern fishing as a process no longer sustainable for the fish species and for the fisheries’ economy; to understand why we just need doing a small investigation. 

The first case of well-documented overfishing dates back to the nineteenth century when sperm and right whaling in the United States collapsed within a few years after almost one century of activity. The sperm whale is a precious whale, which provided the society with many primary goods, like the oil for illumination, stored in the front part of the whale’s skull; in addition, meat and even the bones were transformed into various types of tools.

At the end of the 50s, it has been the round of Californian sardines: they were so perfect in cans that at the end few remained in the sea. I also mention the case of the Peruvian anchovy (the 80s), of Canadian cod (1992) and the recent decline of the entire Japanese fishing industry: even after a long time, the values of landing in these areas never returned as abundant as before.

What's common in these episodes? 

Thanks to the work done during my post-doc at the Department of Chemistry of the University of Florence, when I began to develop mathematical models inherent to the dynamics of environmental sustainability, I could see that the landing trend, comparing the various historical data, had, in all the aforementioned cases, designed a bell shape curve. This trend is similar to the one described by a famous model of ecosystem dynamics, the prey-predator model. This model describes the dynamics of two populations, of which one is nourishment of the other: when there is an abundance of prey, predators increase, they catch the prey and then starving when the prey is too scarce, a condition that let the prey to reproduce and to return in abundance, closing the cycle. 

The problem today is that when the fish goes into deficit, the fishing industry activity, instead of slowing down, becomes more intense to satisfy the unvaried market requests, extracting the fish at a greater speed of that it is able to reproduce, creating a condition of over-exploitation. This causes damage unrecoverable, as in the case of the right whale, now in endangered, or recoverable only partially and with very long time. 

We need, therefore, to learn from the prey-predator dynamic to respect the rhythms of reproduction of species, avoiding in this way that the environment and the activity of the fishing sector being damaged irretrievably.

You can find the complete study at:

Dynamic Patterns of overexploitation in Fisheries - Ecological Modelling Journal
Perissi, I., Bardi, U., Lavacchi A., & El Asmar, T. Dynamic patterns of overexploitation in fisheries. Ecol. Modell. 359, (2017).

Founded in 1935, Sapere is the oldest Italian magazine pledged to make Science accessible at the most variate general public. Since its birth, it has replied in an exemplary way to the question of a rigorous scientific knowledge but at the same time clear, comprehensible and pleasantly usable. The rigour and the passion for science, the aversion to forced simplification, the refusal to follow the passing fashions, the big names and the authoritativeness of the contents, guaranteed by an editorial and scientific committee, remain of the tradition and the history of Sapere. The new Sapere magazine focuses its attention on scientific topicality and the history of ideas, giving rise to questions in readers useful to develop the critical sense, without ever forgetting the inseparable link between science and its discoveries on the one hand, and society and its members on the other.

1 January 2018

Vincent Van Gogh, the modeller

There is no blue without yellow and without orange. 

Vincent Van Gogh

Van Gogh was a genius, he invented a really new way of painting, and as you probably know, he has been an almost self-taught artist, and, as I'm going to show you, he has been also a very smart modeller.  But,  how I can affirm that 'to model' is relevant to Vincent Van Gogh operas?

Let me step back, before to go to the question point, and make me stress you a bit on the concept of modelling commonly intended in scientific areas. In fact, modelling has been and is an essential and inseparable part of many scientific disciplines evidencing the high frequency with which our mind struggles to scheme a complex reality to understand it better. Just think about the importance of the use of 'modelling', for instance,  in chemistry, where atoms and molecules are represented with graphical models by which we can solve the structure of almost all the known substance. Or, let's think to mathematical modelling, which is the most ancient and efficient tool to universally capture the patterns for the changes we observe around us. Moreover, thanks to the birth of computational science, we passed, in few decades, to scheme a model using pencils, papers and solving equations with hours of manual calculations, to realize it using a computer, with which we can sketch the same equations, now solved, very fast, by an appropriate software.
I used the word ‘sketch’ because, with some of these programs (i.e. google for the terms ‘Vensim’, ‘Stella’, and you will see), even math operators and variables can be represented by graphical objects. It is worth to highlight that those graphical objects often recall the shape of subjects that already have a meaning in our mind (arrows = flows, valves = regulators, boxes =stocks) so that, this new language permits 'to write mathematically' in a more intuitive way, allowing a huge saving of time in understanding if a model is catching the system under investigation or not, especially for those are not expert of math stuff.
The development of this kind of 'drawn-mathematical modelling' is mainly due to an idea of Jay Forrester, by which he revolutionised, during the 60s, the study of the 'dynamic of complex systems', better known as Systems DynamicYou can find all the information about Jay Forrester, his brilliant mind and his revolution searching in the web, anyway let's keep its name in mind, I will recall him again below.

In the view of the above, we can now reasonably affirm that modelling is an attitude of a rational mind, characterized by th
e use of reason or logic in thinking out a problem. An attitude, getting now to the point, that also the famous artist Vincent Van Gogh surely had, as I discovered visiting the Van Gogh Museum in Amsterdam, precisely during an 'off work' moment of the System Dynamic School, I was attended in Delft in summer 2016.

Van Gogh is famous for having lived an agitated existence, alternating moments of happiness and equilibrium to other blue and irascible moments. Fortunately, he left us proofs about his feelings and his life thanks to a lot of letters he wrote to his brother, Theo. By means these manuscripts we can know him better, anyway in the common imaginations, Van Gogh still remains an icon of one of the most irrational artists in the history of painting. And he seems to think so of himself too:
I put my heart and my soul into my work, and have lost my mind in the process (Vincent Van Gogh)
Anyway, if you go in depth in the history of his life and his art, you will find that the previous affirmation describes a feeling that is the result of all, except that an irrational process. And I realised this when I found in the Vang Gogh Museum, his famous ‘box of yarn’, a small Chinese, red lacquer wooden box, that held 16 balls of wool.

I knew some episodes of Van Gogh life from the night classes of the Art school 'L.B. Alberti' (website only in Italian) I attended between 2002 to 2004 in Florence, but I didn’t know the existence of this box before to go to the Museum. But when I saw it, I immediately realised he used this box ‘to model’ the colours’ contrast and combinations for his paintings.

A tool to paint...Vincent has been..in certain sense, a modeller!

Probably I went too fast to this conclusion, as sometimes intuition make you do, but, could I be confident with this affirmation?

This fact induced me to investigate more the importance that box could have had in Van Gogh art. Was that box, that modelling tool, really useful for him in understanding a system?

The available information about Van Gogh life report he studied the colour theory of Charles Blanc in 1884, when he lived in Neunen, dispelling the myth that his talent came out of some automatic unconscious well of genius and/or madness.

Van Gogh is also very famous because of the huge production of paintings in a relatively short time: first paintings are dated in 1881 and the latest in 1890, before he died on 29th July of the same year. Take a look at the following graph, which reports the number of Vincent’s paintings as a ‘function’ of time (figure 1):

Figure 1. Van Gogh numbers of paintings as a function of time. The first peak corresponds to the period in which the painter approached the colour theory, and used models of others. The second peak corresponds to the period in which he used the own modelling tool, the box of yarn, and his canvases started to look like textile.Data from Wikipedia, graph by Ilaria.

During those 9 years, he realised around 1000 canvases, culminating in two production ‘peaks’ in 1885 and in 1888. Could it be reasonable to suppose these higher 'production rates' were related to the use of modelling that helped the artist to catch the 'systems' he wanted to represent? Let's see what the facts tell us.

The first peak is in the year 1885, shortly after that Vincent approached the theory of colour using the models of others. Van Gogh quite certainly resorted also the ‘colour wheel’ devised by the chemist Michel Eugène Chevreul, with which he could preview the effect of mix determines tonalities. Probably, this modelling tool gave him a more in-depth understanding of how he could translate what he had in mind on the canvass, culminating in a production of around 150 paintings in the year 1885. We can also note, that from his first paintings of the period 1881-1883, he changed the style, introducing more colours and more contrasts (see the previous wikipedia source and scroll down the images of the paintings).

The second peak in 1888, could be connected with the use of the tool, ‘box of yarn’ (figure 2): Vincent invented is own modelling tool to model the colour combinations, inspired by the work of the weavers he painted in Neunen few years before.
It is Van Gogh’s friend, Bernard, who reported about the existence of this box, shortly after the painter death, and he said it was in Paris he saw the box for the first time, from 1886 to 1888 when Bernard met and worked with Van Gogh before Vincent left to Arles. In the paintings of these years it
 is clearly visibile the Vincent's famous brushstroke reminding the consistency of a textile. Moreover, with the help of the yarns, he was able to test the combination of colours without waste tempera. 

Figure 2. Van Gogh box of yarn. Van Gogh Museum, Amsterdam 

Thus, we can now reasonably conclude the maximum production of Vincent paintings corresponds at the moment in which he approached the colours’ modelling tools. But again, what system did he want to represent?

Analysing the historical changes in Van Gogh, let’s say, ‘styles of painting’, it is in evidence that Vincent mind wanted to go beyond the appearance of the colours, he ran after the colours' potential up to invented an own modelling tool, the ‘box of yarn, to represent the beauty of Nature and of life, let's say very successfully. In a certain sense, the box and the yarns could represent one of the precursors of the RGB colour model now implemented in the representation and display of images in electronic systems, such as televisions and computers.

Van Gogh approach in modelling is not so far from the one from Forrester. Let’s take a look at the following words from Jay Forrester, with which he defines what is a model:

The image of the world around us, which we carry in our head, is just a model. Nobody in his head imagines all the world, government or country. He has only selected concepts, and relationships between them, and uses those to represent the real system (Jay Forrester,1971).
Could these sentences represent also a painting process? Is a painter a sort of modeller? Following the rational of previous words, most of the painters are interested in reporting an image of the world and the paintings are just models of that images, including both the material world as well as the rapresentation of feelings and situations; they are not models of the whole world, but of a set of selected concepts and relationships used to represent a real material system, which could be a landscape, a still life, a portrait, a situation or event, as wars, battles, a sunset or a ‘starry night’, ‘potatoes eaters’ and representation of feelings as in the painting 'Sorrowing Old Man' or 'Two lovers'.

Then we could conclude saying that this is not only the case of Vincent …all what a painter paints can be seen as a model of a real system (material or intangible) and Van Gogh has had the added merit to invent a new modelling tool to do it.

So…is this concept reversible and is a scientist, an economist, and any other of the more 'common' intended modellers.. a sort of painters when modelling an image of the real world?

No easy to answer, I just can say I like to think so...

I wish a good work to all my friends and to have a new year full of inspirations

Information, Energy and Human development

In the MEDEAS  project ( the acronym states for Modelling Energy system Development under Environmental And Socioeconomic constraints) mor...