Mémoire de bachelor : Haute école de gestion de Genève, 2015 ; TDEE 278.
Since China’s economic reforms in the late 1970s, foreign investments have initially flooded the so-called “first-tier cities” including Shanghai, Beijing, or even Shenzhen or Guangzhou. Due to rising labour costs, growing constraints over natural resources, long-term inflation and environmental issues among others (Zhuang et al. 2012; Zuojun, 2012), they have been undertaking structural...
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In: Scientific Reports, 2015, vol. 5, p. 17459
Controlling complex networks is of paramount importance in science and engineering. Despite recent efforts to improve controllability and synchronous strength, little attention has been paid to the speed of pinning synchronizability (rate of convergence in pinning control) and the corresponding pinning node selection. To address this issue, we propose a hypothesis to restrict the control cost,...
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In: Physica A: Statistical Mechanics and its Applications, 2014, vol. 408, p. 10–18
We investigate the problem of dynamic optimal capital growth of a portfolio. A general framework that one strives to maximize the expected logarithm utility of long term growth rate was developed. Exact optimization algorithms run into difficulties in this framework and this motivates the investigation of applying simulated annealing optimized algorithm to optimize the capital growth of a given...
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In: Physica A: Statistical Mechanics and its Applications, 2012, vol. 391, no. 3, p. 647–655
Recently, supply networks have attracted increasing attention from the scientific community. However, it lacks serious consideration of social preference in Supply Chain Management. In this paper, we develop an evolutionary decision-making model to characterize the effects of suppliers’ altruism in supply networks, and find that the performances of both suppliers and supply chains are improved...
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In: EPL - Europhysics Letters, 2011, vol. 95, no. 5, p. 58003
Based on a hybrid algorithm incorporating the heat conduction and probability spreading processes (Proc. Natl. Acad. Sci. U.S.A., 107 (2010) 4511), in this letter, we propose an improved method by introducing an item-oriented function, focusing on solving the dilemma of the recommendation accuracy between the cold and popular items. Differently from previous works, the present algorithm does not...
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In: The European Physical Journal B - Condensed Matter and Complex Systems, 2011, vol. 80, no. 2, p. 201-208
Recommender systems help people cope with the problem of information overload. A recently proposed adaptive news recommender model [M. Medo, Y.-C. Zhang, T. Zhou, Europhys. Lett. 88, 38005 (2009)] is based on epidemic-like spreading of news in a social network. By means of agent-based simulations we study a “good get richer” feature of the model and determine which attributes are...
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In: PLoS ONE, 2011, vol. 6, no. 7, p. e20648
The study of the organization of social networks is important for the understanding of opinion formation, rumor spreading, and the emergence of trends and fashion. This paper reports empirical analysis of networks extracted from four leading sites with social functionality (Delicious, Flickr, Twitter and YouTube) and shows that they all display a scale-free leadership structure. To reproduce this...
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In: Physica A: Statistical Mechanics and its Applications, 2011, vol. 390, no. 11, p. 2117-2126
Recommender systems represent an important tool for news distribution on the Internet. In this work we modify a recently proposed social recommendation model in order to deal with no explicit ratings of users on news. The model consists of a network of users which continually adapts in order to achieve an efficient news traffic. To optimize the network’s topology we propose different stochastic...
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In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 2011, vol. 83, no. 4, p. 045101
We propose a method called the residual edge-betweenness gradient (REBG) to enhance the synchronizability of networks by assigning the link direction while keeping the topology and link weights unchanged. Direction assignment has been shown to improve the synchronizability of undirected networks in general, but we find that in some cases incommunicable components emerge and networks fail to...
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In: Physica A: Statistical Mechanics and its Applications, 2011, vol. 390, no. 23-24, p. 4486-4493
The explosive growth of information asks for advanced information filtering techniques to solve the so-called information overload problem. A promising way is the recommender system which analyzes the historical records of users’ activities and accordingly provides personalized recommendations. Most recommender systems can be represented by user-object bipartite networks where users can...
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