Dario Paschini, A Comparative Analysis between Litecoin and Bitcoin Cash Network and Price Dynamics, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Bachelor's Thesis)
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Weiner Fabian, Transforming Capital Markets through Blockchain Technology: Opportunities, Impact and Challenges, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Bachelor's Thesis)
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Oliver Jud, Self-sovereign Identity: BlockchainEnabled Identity Solutions as Gateway to Develop Finance, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Bachelor's Thesis)
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Valon Gjukaj, The impact of Blockchain Technology on the financial industry, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Bachelor's Thesis)
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Simon Niederberger, Effects of aggregation in temporal networks, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Bachelor's Thesis)
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Caspar Schwarz-Schilling, Agent-based modelling of strategic behaviour in blockchain-based consensus mechanisms, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Master's Thesis)
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Farbod Izadyar, From comparison to machine learning prediction of cryptocurrency transaction networks , University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Master's Thesis)
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Basil Rupper, Spreading dynamics and influencer identification in temporal networks, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Master's Thesis)
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Raphael Schnyder, The Application of Blockchain Technology in the Supply Chain Management for Real-time Tracking and Information Exchange, University of Zurich, Faculty of Business, Economics and Informatics, 2020. (Master's Thesis)
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Carlo Campajola, Fabrizio Lillo, Daniele Tantari, Unveiling the relation between herding and liquidity with trader lead-lag networks, Quantitative Finance, Vol. 20 (11), 2020. (Journal Article)
We propose a method to infer lead-lag networks of traders from the observation of their trade record as well as to reconstruct their state of supply and demand when they do not trade. The method relies on the Kinetic Ising model to describe how information propagates among traders, assigning a positive or negative ‘opinion’ to all agents about whether the traded asset price will go up or down. This opinion is reflected by their trading behavior, but whenever the trader is not active in a given time window, a missing value will arise. Using a recently developed inference algorithm, we are able to reconstruct a lead-lag network and to estimate the unobserved opinions, giving a clearer picture about the state of supply and demand in the market at all times. We apply our method to a dataset of clients of a major dealer in the Foreign Exchange market at the 5 minute time scale. We identify leading players in the market and define a herding measure based on the observed and inferred opinions. We show the causal link between herding and liquidity in the inter-dealer market used by dealers to rebalance their inventories. |
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Xia Cao, Chuanyun Li, Wei Chen, Jinqiu Li, Chaoran Lin, Research on the invulnerability and optimization of the technical cooperation innovation network based on the patent perspective—A case study of new energy vehicles, PLoS ONE, Vol. 15 (9), 2020. (Journal Article)
This paper takes new energy vehicles as the research object, building the technical cooperation innovation network of new energy vehicles based on the patent perspective by establishing the related technology patent search expression, and analyzing the processes of the invulnerability and optimization in the actual technology cooperation innovation network by using the simulation analysis method. The research results show that the harmfulness of the degree value priority attack in the technical cooperation innovation network of new energy vehicles is stronger than the weighted degree value priority attack and random attack, and the attacks of the State Grid and other hub nodes have an important impact on the network invulnerability. During the network optimization process of three types of connection preferences, the “weak”-“weak” connection is the best connection mode given the situation of an unweighted network without considering the weight of the connected edge. However, the “strong”-“weak” connection is the best mode given the situation of a weighted network considering the weight of the connected edge. In addition, compared with the weighted network situation, the “strong”-“weak” connection has better network optimization results given the situation of an unweighted network. Finally, we propose counter measures and suggestions to promote the innovation network invulnerability capabilities of technical cooperation in new energy vehicles. |
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Jian-Hong Lin, Kevin Primicerio, Tiziano Squartini, Christian Decker, Claudio Tessone, Lightning network: a second path towards centralisation of the Bitcoin economy, New Journal of Physics, Vol. 22 (8), 2020. (Journal Article)
The Bitcoin Lightning Network (BLN), a so-called "second layer" payment protocol, was launched in 2018 to scale up the number of transactions between Bitcoin owners. In this paper, we analyse the structure of the BLN over a period of 18 months, ranging from 12th January 2018 to 17th July 2019. Here, we consider three representations of the BLN: the daily snapshot one, the weekly snapshot one and the daily-block snapshot one. By studying the topological properties of the three representations above, we find that the total volume of transacted bitcoins approximately grows as the square of the network size; however, despite the huge activity characterising the BLN, the bitcoins distribution is very unequal: the average Gini coefficient of the node strengths (computed across the entire history of the Bitcoin Lightning Network) is, in fact, ~0.88 causing the 10% (50%) of the nodes to hold the 80% (99%) of the bitcoins at stake in the BLN (on average, across the entire period). This concentration brings up the question of which minimalist network model allows us to explain the network topological structure. Like for other economic systems, we hypothesise that local properties of nodes, like the degree, ultimately determine part of its characteristics. Therefore, we have tested the goodness of the Undirected Binary Configuration Model (UBCM) in reproducing the structural features of the BLN: the UBCM recovers the disassortative and the hierarchical character of the BLN but underestimates the centrality of nodes; this suggests that the BLN is becoming an increasingly centralised network, more and more compatible with a core-periphery structure. Further inspection of the resilience of the BLN shows that removing hubs leads to the collapse of the network into many components, an evidence suggesting that this network may be a target for the so-called split attacks. |
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Sheng-Nan Li, Zhao Yang, Claudio Tessone, Proof-of-Work cryptocurrency mining: a statistical approach to fairness, In: 2020 IEEE/CIC International Conference on Communications in China (ICCC Workshops), IEEE/CIC, 2020-08-09. (Conference or Workshop Paper published in Proceedings)
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Sheng-Nan Li, Zhao Yang, Claudio Tessone, Mining blocks in a row: a statistical study of fairness in Bitcoin mining, In: 2020 IEEE International Conference on Blockchain and Cryptocurrency (ICBC), IEEE, 2020-05-02. (Conference or Workshop Paper published in Proceedings)
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Xia Cao, Chuanyun Li, Evolutionary game simulation of knowledge transfer in industry-university-research cooperative innovation network under different network scales, Scientific Reports, Vol. 10 (4027), 2020. (Journal Article)
This paper takes the industry-university-research cooperation innovation network constructed by the weighted evolutionary BBV model as the research object, which is based on bipartite graph and evolutionary game theory, and constructing the game model of knowledge transfer in the industry-university-research cooperation innovation network, by using the simulation analysis method and analyzing the evolution law of knowledge transfer in the industry-university-research cooperation innovation network under different network scales, three scenarios, the knowledge transfer coefficient and the knowledge reorganization coefficient. The results show that the increase of network scale reduces the speed of knowledge transfer in the network, and the greater the average cooperation intensity of the nodes, the higher the evolution depth of knowledge transfer. Compared with university-research institutes, the evolution depth of knowledge transfer in enterprises is higher, and with the increase of network scale, the gap between the evolution depth of knowledge transfer between them is gradually increasing. Only when reward, punishment and synergistic innovation benefits are higher than the cost of knowledge transfer that can promote the benign evolution of industry-university-research cooperation innovation networks. Only when the knowledge transfer coefficient and the knowledge reorganization coefficient exceed a certain threshold will knowledge transfer behavior emerge in the network. With the increase of the knowledge transfer coefficient and the knowledge reorganization coefficient, the knowledge transfer evolutionary depth of the average cooperation intensity of all kinds of nodes is gradually deepening. |
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Chuanyun Li, Xia Cao, Ming Chi, Research on an evolutionary game model and simulation of a cluster innovation network based on fairness preference, PLoS ONE, Vol. 15 (1), 2020. (Journal Article)
The cluster innovation network is an important part of regional economic development. In addition, the fairness preference of internal innovators in the processes of investment and benefit distribution are particularly important for curbing "free riding" and other speculative behaviors and for creating a good cooperation environment. Therefore, taking a cluster innovation network constructed by the weighted evolutionary BBV model as the research subject, this paper constructs an evolutionary game model of a cluster innovation network based on a spatial public goods game and the theory of fairness preferences, which involves the processes of investment and payoff allocation. Using simulation analysis, this paper studies the evolution of innovators’ cooperative behaviors and benefits in cluster innovation network under the conditions of a fairness preference and a return intensity. The results show that an increase in the weight coefficient, gain coefficient and degree of differentiation between the previous income and current investment can effectively promote improvements in the level of enterprise cooperation. Indeed, the greater the weight coefficient, the gain coefficient and the degree of differentiation are, the more substantial the improvement in the level of enterprise cooperation will be. Moreover, an improvement in the differentiation of the breadth and depth of enterprise cooperation has an inhibitory effect on enterprise cooperation. Furthermore, whereas increases in regulation and gain coefficients can effectively promote enterprise cooperation. However, the increase in the weight coefficient has a different effect on enterprise benefit in terms of the breadth and depth of cooperation. Finally, we hope to improve the overall cooperation level and cooperation income of the network by deeply understanding the fair preferences of innovators in the processes of investment and benefit distribution, which is helpful for promoting the evolution and development of cluster innovation networks. |
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Albertine Weber, Flavio Iannelli, Sebastián Gonçalves, Trend analysis of the COVID-19 pandemic in China and the rest of the world, 2020. (Other Publication)
The recent epidemic of Coronavirus (COVID-19) that started in China has already been "ex-
ported" to more than 140 countries in all the continents, evolving in most of them by local spreading. In this contribution we analyze the trends of the cases reported in all the Chinese provinces, as well as in some countries that, until March 15th, 2020, have more than 500 cases reported. Notably and differently from other epidemics, the provinces did not show an exponential phase. The data available at the Johns Hopkins University site [1] seem to fit well an algebraic sub-exponential growing behavior as was pointed out recently [2]. All the provinces show a clear and consistent pattern of slowing down with growing exponent going nearly zero, so it can be said that the epidemic was contained in China. On the other side, the more recent spread in countries like, Italy, Iran, and Spain show a clear exponential growth, as well as other European countries. Even more recently, US - which was one of the first countries to have an individual infected outside China (Jan 21st, 2020)- seems to follow the same path. We calculate the exponential growth of the most affected countries, showing the evolution along time after the first local case. We identify clearly different patterns in the analyzed data and we give interpretations and possible explanations for them. The
analysis and conclusions of our study can help countries that, after importing some cases, are not yet in the local spreading phase, or have just started. |
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Carlo Campajola, Fabrizio Lillo, Piero Mazzarisi, Daniele Tantari, On the equivalence between the Kinetic Ising Model and discrete autoregressive processes, arXiv preprint arXiv:2008.10666, 2020. (Journal Article)
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Carlo Campajola, Domenico Di Gangi, Fabrizio Lillo, Daniele Tantari, Modelling time-varying interactions in complex systems: the Score Driven Kinetic Ising Model, arXiv preprint arXiv:2007.15545, 2020. (Journal Article)
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Maria J Palazzi, Javier Borge-Holthoefer, Claudio Tessone, Albert Solé-Ribalta, Macro- and mesoscale pattern interdependencies in complex networks, Journal of the Royal Society Interface, Vol. 16 (159), 2019. (Journal Article)
Identifying and explaining the structure of complex networks at different scales has become an important problem across disciplines. At the mesoscale, modular architecture has attracted most of the attention. At the macroscale, other arrangements—e.g. nestedness or core–periphery—have been studied in parallel, but to a much lesser extent. However, empirical evidence increasingly suggests that characterizing a network with a unique pattern typology may be too simplistic, since a system can integrate properties from distinct organizations at different scales. Here, we explore the relationship between some of these different organizational patterns: two at the mesoscale (modularity and in-block nestedness); and one at the macroscale (nestedness). We show experimentally and analytically that nestedness imposes bounds to modularity, with exact analytical results in idealized scenarios. Specifically, we show that nestedness and modularity are interdependent. Furthermore, we analytically evidence that in-block nestedness provides a natural combination between nested and modular networks, taking structural properties of both. Far from a mere theoretical exercise, understanding the boundaries that discriminate each architecture is fundamental, to the extent that modularity and nestedness are known to place heavy dynamical effects on processes, such as species abundances and stability in ecology. |
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