Social Media allows people to post widely and share the posted online-items. Such items gain thei... more Social Media allows people to post widely and share the posted online-items. Such items gain their popularity by the amount of attention received. Thus, studies on modeling the arrival process of attention to an individual item have recently attracted a great deal of interest. In this paper, we propose, by combining a Dirichlet process with a Hawkes process in a novel way, a probabilistic model, called cooperative Hawkes process (CHP) model, to discover the cooperative structure among all the items involved. The proposed model takes into account all the arrival processes of shares for those items. We develop an efficient method of inferring the CHP model from the observed sequences of share events, and present an effective framework for predicting the future popularity of each of these items. Using synthetic data and real data from a cooking-recipe sharing site, we demonstrate the effectiveness of the CHP model, and uncover the cooperative structure among cooking-recipes in view of attention dynamics.
2017 IEEE International Conference on Data Mining Workshops (ICDMW), 2017
Social Media allows people to post widely and share the posted online-items. Such items gain thei... more Social Media allows people to post widely and share the posted online-items. Such items gain their popularity by the amount of attention received. Thus, studies on modeling the arrival process of attention to an individual item have recently attracted a great deal of interest. In this paper, we propose, by combining a Dirichlet process with a Hawkes process in a novel way, a probabilistic model, called cooperative Hawkes process (CHP) model, to discover the cooperative structure among all the items involved. The proposed model takes into account all the arrival processes of shares for those items. We develop an efficient method of inferring the CHP model from the observed sequences of share events, and present an effective framework for predicting the future popularity of each of these items. Using synthetic data and real data from a cooking-recipe sharing site, we demonstrate the effectiveness of the CHP model, and uncover the cooperative structure among cooking-recipes in view of ...
IEIC Technical Report (Institute of Electronics, Information and Communication Engineers), 2001
Video grammars are utilized in broadcasting videos as universal rules to convey the video content... more Video grammars are utilized in broadcasting videos as universal rules to convey the video contents uniquely. The minimum unit in the video grammar is a shot. The shot size is classified into relative three types; loose shot shooting objects from a long distance, middle shot shooting in a short distance, and tight shot shooting near by. This paper proposes a method to automatically discriminate the shot size using an active search method. Key words Active Search, Video Grammar, Shot Size
Aiming at knowledge discovery for temporal sequences of cooking recipes published in social media... more Aiming at knowledge discovery for temporal sequences of cooking recipes published in social media platforms from the viewpoint of network science, we consider an analysis of temporal higher-order networks of ingredients derived from such recipe streams by focusing on the framework of simplicial complex. Previous work found interesting properties of temporal simplicial complexes for the human proximity interactions in five different social settings by examining the configuration transitions before and after triplet interaction events corresponding to 2-simplices. In this paper, as an effective extension of the previous work to the case of higher dimensional n-simplices corresponding to newly published recipes, we propose a novel method of configuration transition analysis by incorporating the following two features. First, to focus on changes in the topological structure of temporal simplicial complex, we incorporate analyzing the transitions of boundary-based configurations. Next, t...
2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012
ABSTRACT One of the most well studied issues in genetic programming is how to make building block... more ABSTRACT One of the most well studied issues in genetic programming is how to make building blocks efficiently. To make building blocks, it is important to find the substructures that appear in the individuals with higher fitness. Recently, a method based on frequent substructures has been proposed, and it has shown good performance; however, the depth of trees is not considered in the method. In this paper, we propose a hybrid crossover that involves the consideration of a combination of frequent trees and the depth of trees and apply the proposed method to symbolic regression problems. We experimentally demonstrate the effectiveness of the proposed method.
Discovering good photo-spots in the real world is an important problem from the point of view of ... more Discovering good photo-spots in the real world is an important problem from the point of view of sightseeing industry. While a popular photo-spot in general means a spatially localized region, it should have its own hot-period, a period of time during which it can provide more interesting photographs than other photo-spots. In this paper, we address the problem of extracting a pair of a major photo-spot and its hot-period, which is called a hot photo-spot, from a large number of geotagged photographs with timestamps that many people have taken. We propose a mathematical model for hot photo-spots, and present a method of efficiently identifying them. Using synthetic and real Flickr data, we experimentally demonstrate the effectiveness of the proposed method.
We address the problem of modeling the occurrence process of events for visiting attractive place... more We address the problem of modeling the occurrence process of events for visiting attractive places, called points-of-interest (POIs), in a sightseeing city in the setting of a continuous time-axis and a continuous spatial domain, which is referred to as modeling geographical attention dynamics. By combining a Hawkes process with a time-varying Gaussian mixture model in a novel way and incorporating the influence structure depending on time slots as well, we propose a probabilistic model for discovering the spatio-temporal influence structure among major sightseeing areas from the viewpoint of geographical attention dynamics, and aim to accurately predict POI visit events in the near future. We develop an efficient method of inferring the parameters in the proposed model from the observed sequence of POI visit events, and present an analysis method for the geographical attention dynamics. Using real data of POI visit events in a Japanese sightseeing city, we demonstrate that the prop...
Social Media allows people to post widely and share the posted online-items. Such items gain thei... more Social Media allows people to post widely and share the posted online-items. Such items gain their popularity by the amount of attention received. Thus, studies on modeling the arrival process of attention to an individual item have recently attracted a great deal of interest. In this paper, we propose, by combining a Dirichlet process with a Hawkes process in a novel way, a probabilistic model, called cooperative Hawkes process (CHP) model, to discover the cooperative structure among all the items involved. The proposed model takes into account all the arrival processes of shares for those items. We develop an efficient method of inferring the CHP model from the observed sequences of share events, and present an effective framework for predicting the future popularity of each of these items. Using synthetic data and real data from a cooking-recipe sharing site, we demonstrate the effectiveness of the CHP model, and uncover the cooperative structure among cooking-recipes in view of attention dynamics.
2017 IEEE International Conference on Data Mining Workshops (ICDMW), 2017
Social Media allows people to post widely and share the posted online-items. Such items gain thei... more Social Media allows people to post widely and share the posted online-items. Such items gain their popularity by the amount of attention received. Thus, studies on modeling the arrival process of attention to an individual item have recently attracted a great deal of interest. In this paper, we propose, by combining a Dirichlet process with a Hawkes process in a novel way, a probabilistic model, called cooperative Hawkes process (CHP) model, to discover the cooperative structure among all the items involved. The proposed model takes into account all the arrival processes of shares for those items. We develop an efficient method of inferring the CHP model from the observed sequences of share events, and present an effective framework for predicting the future popularity of each of these items. Using synthetic data and real data from a cooking-recipe sharing site, we demonstrate the effectiveness of the CHP model, and uncover the cooperative structure among cooking-recipes in view of ...
IEIC Technical Report (Institute of Electronics, Information and Communication Engineers), 2001
Video grammars are utilized in broadcasting videos as universal rules to convey the video content... more Video grammars are utilized in broadcasting videos as universal rules to convey the video contents uniquely. The minimum unit in the video grammar is a shot. The shot size is classified into relative three types; loose shot shooting objects from a long distance, middle shot shooting in a short distance, and tight shot shooting near by. This paper proposes a method to automatically discriminate the shot size using an active search method. Key words Active Search, Video Grammar, Shot Size
Aiming at knowledge discovery for temporal sequences of cooking recipes published in social media... more Aiming at knowledge discovery for temporal sequences of cooking recipes published in social media platforms from the viewpoint of network science, we consider an analysis of temporal higher-order networks of ingredients derived from such recipe streams by focusing on the framework of simplicial complex. Previous work found interesting properties of temporal simplicial complexes for the human proximity interactions in five different social settings by examining the configuration transitions before and after triplet interaction events corresponding to 2-simplices. In this paper, as an effective extension of the previous work to the case of higher dimensional n-simplices corresponding to newly published recipes, we propose a novel method of configuration transition analysis by incorporating the following two features. First, to focus on changes in the topological structure of temporal simplicial complex, we incorporate analyzing the transitions of boundary-based configurations. Next, t...
2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012
ABSTRACT One of the most well studied issues in genetic programming is how to make building block... more ABSTRACT One of the most well studied issues in genetic programming is how to make building blocks efficiently. To make building blocks, it is important to find the substructures that appear in the individuals with higher fitness. Recently, a method based on frequent substructures has been proposed, and it has shown good performance; however, the depth of trees is not considered in the method. In this paper, we propose a hybrid crossover that involves the consideration of a combination of frequent trees and the depth of trees and apply the proposed method to symbolic regression problems. We experimentally demonstrate the effectiveness of the proposed method.
Discovering good photo-spots in the real world is an important problem from the point of view of ... more Discovering good photo-spots in the real world is an important problem from the point of view of sightseeing industry. While a popular photo-spot in general means a spatially localized region, it should have its own hot-period, a period of time during which it can provide more interesting photographs than other photo-spots. In this paper, we address the problem of extracting a pair of a major photo-spot and its hot-period, which is called a hot photo-spot, from a large number of geotagged photographs with timestamps that many people have taken. We propose a mathematical model for hot photo-spots, and present a method of efficiently identifying them. Using synthetic and real Flickr data, we experimentally demonstrate the effectiveness of the proposed method.
We address the problem of modeling the occurrence process of events for visiting attractive place... more We address the problem of modeling the occurrence process of events for visiting attractive places, called points-of-interest (POIs), in a sightseeing city in the setting of a continuous time-axis and a continuous spatial domain, which is referred to as modeling geographical attention dynamics. By combining a Hawkes process with a time-varying Gaussian mixture model in a novel way and incorporating the influence structure depending on time slots as well, we propose a probabilistic model for discovering the spatio-temporal influence structure among major sightseeing areas from the viewpoint of geographical attention dynamics, and aim to accurately predict POI visit events in the near future. We develop an efficient method of inferring the parameters in the proposed model from the observed sequence of POI visit events, and present an analysis method for the geographical attention dynamics. Using real data of POI visit events in a Japanese sightseeing city, we demonstrate that the prop...
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