Hiroyuki Nakagawa

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During the massive Tohoku earthquake, while landlines and mobile phone lines got stuck, Twitter were used to exchange information about evacuation. On 11 March, the number of tweets from Japan dramatically increased to about 33 million, 1.8 times higher than the average figure. However, since texts on Twitter are unstructured data, are more complex than(More)
Self-adaptive systems have recently attracted attention because of their ability to cope with changing environments, including system intrusions or faults. Such software must modify itself to better fit its environment, and one of the approaches by which we expect this capability to be achieved is the introduction of multiple control loops to assess the(More)
Formal methods and requirements analysis are techniques for developing complex systems. However, there is little research on reconciling the requirements phase with the formal specification phase. To bridge this gap, we propose a formal specification generator based on model transformation techniques. This tool transforms KAOS models (requirements(More)
Fusarium graminearum is responsible for Fusarium head blight (FHB), which is a destructive disease of wheat that makes its quality unsuitable for end use. To understand the temporal molecular response against this pathogen, microarray gene expression analysis was carried out at two time points on three wheat genotypes, the spikes of which were infected by(More)
A goal for the creation and improvement of music recommendation is to retrieve users' preferences and select the music adapting to the preferences. Although the existing researches achieved a certain degree of success and inspired future researches to get more progress, problem of the cold start recommendation and the limitation to the similar music have(More)
Using a simple model for the trail formation of ants, the relation between i)the schedule of feeding which represents the unsteady natural environment, ii)emerging patterns of trails connecting a nest with food resources, and iii)the foraging efficiency is studied. Simulations and a simple analysis show that the emergent trail pattern flexibly varies(More)
It is important to make sure that software satisfies stakeholders' requirements. However, as software has been getting more large-scale and complicated in recent years, it has certainly become more difficult to satisfy requirements. Even if there are goal-oriented requirements analysis approaches as techniques to systematically satisfy stakeholders'(More)