#143 Tracking Protests Using Geotagged Flickr Photographs
Authors: Merve Alanyali, Tobias Preis and Suzy Moat
Recent years have witnessed waves of protests sweeping across countries and continents, which in some cases resulting in political and governmental change. Much media attention has been focused on the increasing usage of social media to coordinate and provide instantly available reports on these protests. In this talk, I will describe recent research in which we explore whether the data created through such widespread usage of online services may offer a valuable new source for measurements of behaviour during protests.
We analyse a large corpus of 25 million geotagged photographs taken and uploaded to Flickr in 2013. For each week and 244 countries and regions we used in our analyses, we determine how many photographs were uploaded with the word “protest” in 34 different languages in the photograph title, description or tag. In order to determine whether there is a link between the number of protest tagged photos and the number of protest outbreaks, we use data from newspaper reports as a proxy for ground truth. For each of the 244 countries and regions, we determine the weekly number of protest related online articles in The Guardian from 2013.
We find that higher proportions of protest tagged photos in a given area and week correspond to greater numbers of protest related articles about that area in The Guardian. Our results are in line with the hypothesis that data on photographs uploaded to Flickr may contain signs of protest outbreaks. These findings illustrate the potential value of photographs uploaded to the Internet as a source of global, cheap and rapidly available measurements of human behaviour in the real world.
#151 Differences of Epileptic Focal and Extra-focal Regions in Interictal and Ictal States
Authors: Mojtaba Khodadadi and Farhad Shahbazi
The EEG database that we have contains invasive EEG recordings of 3 patients suffering from medically intractable focal (partial) epilepsy. For each of the patients, there are datasets called "ictal" and "interictal", the former containing files with epileptic seizures and the latter containing approximately 24 hours of EEG-recordings without seizure activity. In this work we try to make a classification between interictal and ictal states or focal and extra-focal areas. We use rolling statistics in order to find correlation matrix of data increments as a matrix that evolves with time then compute eigenvalues of the matrix and consider each eigenvalue as a time series. After that we obtain distributions of these time series. Finally we estimate Markov-Einstein time scale and then compute drift and diffusion coefficients of eigenvalue of the matrix for different states and areas.
#152 Criticality in the emergence of event cascades in complex networks
Authors: Tomokatsu Onaga and Shigeru Shinomoto
Our life is full of cause-and-effect relationships, such that past events influence the future occurrence of events. The proliferation process has been studied using both macroscopic models, such as the epidemic model, and microscopic models, such as the self-exciting point process proposed by Hawkes. These models have been applied to analyze not only the communication of diseases but also urban crime, human activity, economics, genome sequences, and neuronal firing. A key quantity representing the interaction in these various phenomena is the basic reproduction ratio, which is defined as the average number of additional events induced by a single event. In epidemics, a disease becomes a pandemic in a homogeneous network if the reproduction ratio is greater than unity, as in a nuclear chain reaction, and vanishes otherwise.
Nevertheless, the event-occurrence does not cease if individuals are stimulated in external communities or exhibit spontaneous activity. In such situations, the system may still exhibit cascades of event-occurrences intermittently, even if the reproduction ratio is smaller than the epidemic threshold, as in tweets and neuronal firings in vivo. The nonstationary fluctuations may be terminated by reducing the reproduction ratio further. Event cascades can be a nuisance in some contexts, such as when the peak-demand causes vaccine shortages or heavy traffic on communication lines, but may be beneficial in other contexts; for example, spontaneous activity in neural networks may be used to generate motion or store memory. Thus, it is important to comprehend the mechanism by which such cascades appear. We demonstrate that we can predict whether cascades may emerge in a network, given information about the interactions between individuals. Furthermore, we suggest a systematic method for controlling systems to oppress or promote the event cascades. Accordingly we found that reciprocal connections and clustering tends to facilitate event cascades.
#155 A complexity science approach for generating health awareness tools
Authors: Herman van Wietmarschen, Shaji Krishnan, Heleen Wortelboer and Jan van der Greef
Background: It is well known that most chronic diseases are the result of an unhealthy life-style. Nevertheless, it appears to be very difficult to motivate people to adopt more healthy habits. The occurrence and development of such patterns of behavior can be very well described and explored by using complexity science. TNO recently developed several tools to generate awareness about interactions between biological, psychological and social mechanisms. Awareness of and simulations of scenario’s can be used by patients and consumers to improve their health and prevent chronic diseases from occurring. Furthermore, the relational models are used to develop methods for detecting critical transitions in datasets from type 2 diabetes patients.
Methods and results: an enriched causal loop diagram was developed related to health and overweight using a TNO tool called MARVEL. Group model building sessions were organized with a group of scientists from various disciplines (nutrition, systems biology, mathematical modelling, social psychology, cognitive psychology, physiology, movement sciences) to construct a biopsychosocial model which was used to explore the cross-domain interactions, feedback and feed forward loops related to health. Then the a mathematical formulation was designed for capturing complexity in cross domain data related to type 2 diabetes. The model was then used to simulate critical transitions in a biological system. Finally this model was tested using a data set of type 2 diabetes patients disease development.
Conclusions: the TNO owned systems dynamics software tool MARVEL can be used in group model building sessions to generate a shared understanding of multi-domain health problems among stakeholders. A mathematical model for type 2 diabetes has been designed as a demonstrator for capturing complexity in health.
#159 Pathways in Atmospheric Chemistry Reaction Networks
Authors: Jakob Fischer, Axel Kleidon, Eugenio Simoncini and Peter Dittrich
In the context of atmospheric life detection, we compare two photochemical models by decomposing the networks' steady states in (minimal) reaction pathways. This constitutes an analysis that combines topological features of the reaction network with the specific steady state of a typical simulation. One of the models describes the composition of Earth's current atmosphere and the other one the atmosphere of an early Earth without life. For simplicity we integrate these column models to a box model representation and focus on the steady state of the gas phase chemistry. We calculate the most relevant reaction pathways and find clear topological differences between the atmospheric reaction pathways of a dead and a living planet Earth. In a second step, we calculate approximate values for most of the species' chemical potentials. This approximation is used to characterize the reaction pathway's thermodynamic efficiency for transforming light into chemical energy and also the thermodynamic efficiency of the atmospheric chemistry itself. It also enables to associate the different state of the respective planets with the different structural and thermodynamical properties of the important pathways. In terms of how radiation is transformed to chemical energy by the system, we notice that the current atmosphere is a lot more efficient than that of the Earth without biological life on it. The most significant reaction pathways are simpler and tighter coupled to the system's environment. We attribute that to self organization like processes in the Earth system as a whole enhancing global cycling processes and linking of its subsystems.
Authors: Merve Alanyali, Tobias Preis and Suzy Moat
Recent years have witnessed waves of protests sweeping across countries and continents, which in some cases resulting in political and governmental change. Much media attention has been focused on the increasing usage of social media to coordinate and provide instantly available reports on these protests. In this talk, I will describe recent research in which we explore whether the data created through such widespread usage of online services may offer a valuable new source for measurements of behaviour during protests.
We analyse a large corpus of 25 million geotagged photographs taken and uploaded to Flickr in 2013. For each week and 244 countries and regions we used in our analyses, we determine how many photographs were uploaded with the word “protest” in 34 different languages in the photograph title, description or tag. In order to determine whether there is a link between the number of protest tagged photos and the number of protest outbreaks, we use data from newspaper reports as a proxy for ground truth. For each of the 244 countries and regions, we determine the weekly number of protest related online articles in The Guardian from 2013.
We find that higher proportions of protest tagged photos in a given area and week correspond to greater numbers of protest related articles about that area in The Guardian. Our results are in line with the hypothesis that data on photographs uploaded to Flickr may contain signs of protest outbreaks. These findings illustrate the potential value of photographs uploaded to the Internet as a source of global, cheap and rapidly available measurements of human behaviour in the real world.
#151 Differences of Epileptic Focal and Extra-focal Regions in Interictal and Ictal States
Authors: Mojtaba Khodadadi and Farhad Shahbazi
The EEG database that we have contains invasive EEG recordings of 3 patients suffering from medically intractable focal (partial) epilepsy. For each of the patients, there are datasets called "ictal" and "interictal", the former containing files with epileptic seizures and the latter containing approximately 24 hours of EEG-recordings without seizure activity. In this work we try to make a classification between interictal and ictal states or focal and extra-focal areas. We use rolling statistics in order to find correlation matrix of data increments as a matrix that evolves with time then compute eigenvalues of the matrix and consider each eigenvalue as a time series. After that we obtain distributions of these time series. Finally we estimate Markov-Einstein time scale and then compute drift and diffusion coefficients of eigenvalue of the matrix for different states and areas.
#152 Criticality in the emergence of event cascades in complex networks
Authors: Tomokatsu Onaga and Shigeru Shinomoto
Our life is full of cause-and-effect relationships, such that past events influence the future occurrence of events. The proliferation process has been studied using both macroscopic models, such as the epidemic model, and microscopic models, such as the self-exciting point process proposed by Hawkes. These models have been applied to analyze not only the communication of diseases but also urban crime, human activity, economics, genome sequences, and neuronal firing. A key quantity representing the interaction in these various phenomena is the basic reproduction ratio, which is defined as the average number of additional events induced by a single event. In epidemics, a disease becomes a pandemic in a homogeneous network if the reproduction ratio is greater than unity, as in a nuclear chain reaction, and vanishes otherwise.
Nevertheless, the event-occurrence does not cease if individuals are stimulated in external communities or exhibit spontaneous activity. In such situations, the system may still exhibit cascades of event-occurrences intermittently, even if the reproduction ratio is smaller than the epidemic threshold, as in tweets and neuronal firings in vivo. The nonstationary fluctuations may be terminated by reducing the reproduction ratio further. Event cascades can be a nuisance in some contexts, such as when the peak-demand causes vaccine shortages or heavy traffic on communication lines, but may be beneficial in other contexts; for example, spontaneous activity in neural networks may be used to generate motion or store memory. Thus, it is important to comprehend the mechanism by which such cascades appear. We demonstrate that we can predict whether cascades may emerge in a network, given information about the interactions between individuals. Furthermore, we suggest a systematic method for controlling systems to oppress or promote the event cascades. Accordingly we found that reciprocal connections and clustering tends to facilitate event cascades.
#155 A complexity science approach for generating health awareness tools
Authors: Herman van Wietmarschen, Shaji Krishnan, Heleen Wortelboer and Jan van der Greef
Background: It is well known that most chronic diseases are the result of an unhealthy life-style. Nevertheless, it appears to be very difficult to motivate people to adopt more healthy habits. The occurrence and development of such patterns of behavior can be very well described and explored by using complexity science. TNO recently developed several tools to generate awareness about interactions between biological, psychological and social mechanisms. Awareness of and simulations of scenario’s can be used by patients and consumers to improve their health and prevent chronic diseases from occurring. Furthermore, the relational models are used to develop methods for detecting critical transitions in datasets from type 2 diabetes patients.
Methods and results: an enriched causal loop diagram was developed related to health and overweight using a TNO tool called MARVEL. Group model building sessions were organized with a group of scientists from various disciplines (nutrition, systems biology, mathematical modelling, social psychology, cognitive psychology, physiology, movement sciences) to construct a biopsychosocial model which was used to explore the cross-domain interactions, feedback and feed forward loops related to health. Then the a mathematical formulation was designed for capturing complexity in cross domain data related to type 2 diabetes. The model was then used to simulate critical transitions in a biological system. Finally this model was tested using a data set of type 2 diabetes patients disease development.
Conclusions: the TNO owned systems dynamics software tool MARVEL can be used in group model building sessions to generate a shared understanding of multi-domain health problems among stakeholders. A mathematical model for type 2 diabetes has been designed as a demonstrator for capturing complexity in health.
#159 Pathways in Atmospheric Chemistry Reaction Networks
Authors: Jakob Fischer, Axel Kleidon, Eugenio Simoncini and Peter Dittrich
In the context of atmospheric life detection, we compare two photochemical models by decomposing the networks' steady states in (minimal) reaction pathways. This constitutes an analysis that combines topological features of the reaction network with the specific steady state of a typical simulation. One of the models describes the composition of Earth's current atmosphere and the other one the atmosphere of an early Earth without life. For simplicity we integrate these column models to a box model representation and focus on the steady state of the gas phase chemistry. We calculate the most relevant reaction pathways and find clear topological differences between the atmospheric reaction pathways of a dead and a living planet Earth. In a second step, we calculate approximate values for most of the species' chemical potentials. This approximation is used to characterize the reaction pathway's thermodynamic efficiency for transforming light into chemical energy and also the thermodynamic efficiency of the atmospheric chemistry itself. It also enables to associate the different state of the respective planets with the different structural and thermodynamical properties of the important pathways. In terms of how radiation is transformed to chemical energy by the system, we notice that the current atmosphere is a lot more efficient than that of the Earth without biological life on it. The most significant reaction pathways are simpler and tighter coupled to the system's environment. We attribute that to self organization like processes in the Earth system as a whole enhancing global cycling processes and linking of its subsystems.
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