Naoki Yoshinaga

Symbiotic Service Guidance and its application to transport services

This paper describes the development of a Symbiotic Service Guidance (SSG) system, and its application to a multi-modal transport system. The basic idea of symbiotic service guidance is to provide guidance to both service users and service providers in a way which supports the adaptation of supply and demand toward mutually satisfactory states. In this paper, we present a model scenario which can be used for testing symbiotic guidance methods in public transport systems. As a specific example, we implement a simulation of a local public transport system in Nara, Japan. The simulation results show that SSG can achieve a large improvement of satisfaction for both service users and service providers.

First-use analysis of communication in a social network

The study of communication activity in social networks is aimed at understanding and promoting communications in groups, organizations and communities. In this paper, we propose a method for the analysis of communication records to extract content-based network activity, with a focus on first-use. Links between people in a social network are defined based on content and temporal relation of messages sent and received. We introduce the notion of first-use, first-use paths, and classes of users based on first-usage. First-use is defined with respect to a specific time period and specific communication content. It refers to the sending of messages containing the specified contents for the first time before being receiving them from any other user in the specified time period. First-use paths are defined as sequences of first-use events in communication networks, and m-ary classes of users are defined recursively as users who receive for the first time from (m-1)-ary users. We present an example of application of the analysis to the email records of a large company.

Multi-user-type travel simulator based on open travel data

We have developed a simulator for evaluating changes in travel quality experienced during travel in multi-modal transit systems. The simulator has a new behavior model for users of multimodal systems that includes changes of user satisfaction, route and mode choices during travel, and interaction with on-line route guidance. This paper proposes a method for implementing user behavior models based on travel survey data, and describes an application example using open data for the city of Sydney.

Proposal of ride-sharing system using harmonic aggregation of user demands

In this paper, we propose a ride-sharing system with harmonic aggregation of user demands to support both human satisfaction and resource efficiency, and report results of the simulation of our proposed system showing the efficiency of our method. Our proposed ride-sharing system alters user action time and harmonically aggregates user transfer by using flexible parts of users demands toward their actions. We built a demonstration system visualizing our future vision in which the proposed ride-sharing method was represented as one scenario. In this system, the ride-sharing will be implemented as the joining of several small personal vehicles. We performed our simulations with basic scenarios including part of the proposed method and obtained results showing that the ride-sharing system with our proposed method has four-times higher efficiency than that without the method.

Proposal of user-collaborative mobile object assignment system

Recently, mobile object sharing systems including car-sharing systems have been gathering more attention as an ecological activity. In this paper, we propose a user-collaborative mobile object assignment system using location information of users. The optimal mobile object assignment is to minimize travel distances of mobile objects in the existing mobile object assignment system, and the system controls allocation of mobile objects. The system recommends the two users to hand over the mobile object to each other if it is the optimal way for users, for example, one user gets off the car and another user rides on the same car continuously. Our proposed system uses the location information of both current and next users to find the optimal way for both users, and informs them the information. Then, the system can trigger the independent collaboration of users by leaving a final decision up to them. Firstly our system calculates optimal mobile object assignment for both current and next users. Secondly, if it is efficient for both current and next users to change the destination of the current user, the system recommends the current user to change the current destination to the calculated one. Thereafter, the system gets an extra fee from the next user, and gives a part of that to the current user as incentive for change of destination when it is needed. Our system can achieve a more friendly system for both user and environment than the current system and solve the distribution problem of mobile objects. Also, we did multi-agent simulations with basic scenarios including a part of proposed method, and got results showing that the system was effective at increasing the number of people who were collaborate with each other.