Masakazu Ikezaki

Event handling mechanism for retrieving spatio-temporal changes at various detailed level

We propose an event handling mechanism for dealing with spatio-temporal changes. By using this mechanism, we can observe changes of features at diverse viewpoints. We formalize an event that changes a set of features. The relation between events has a hierarchical structure. This structure provides observations of spatial changes at various detailed level.

Event-Centralized Management of Geographic Information Collected from Blog

In this paper, we propose a method for automatically extracting events from information networks. Personal experiences can be handled by associating them with time and space information from a viewpoint of managing personal media data. We define an event as an occurrence experienced in the real world, and design a geographic information system that can handle them. We assume that when an event occurs in the real world, blog entries about it are directly registered in the Web. We collect these blog entries and extract appropriate events from them. Useful events are described with time and place. However, problems are caused by two factors. One, identical names are observed in different regions. The other is nonassociated place names are extracted with the event. In order to handle the former problem, a place name dictionary is prepared based on geographic inclusive relationships. In order to handle the latter problem, events are identified by type, time and place.

Geographical information structure for managing a set of objects as an event

This paper addresses a geographic information management to model various kinds of geographic objects with respect to the space and time features. In this model, an event represents the geographic situation in which geographic objects change, and represented as a set of geographic objects which are concerned to the event. It is possible to easily divide an event into sub-events along space and time criteria. Using this model, our geographic information system can provide users with a capability to manipulate an event from various viewpoints.

Event-based Specification for Controlling Spatio-temporal Changes of Geographic situation

In this paper, we propose a data model to manage dynamic aspects of geographic information. In our model, a geographic change is represented as an event. Three relations are defined on events: they are is-a relation, partof relation, and event-driven relation. We implemented a prototype system, and confirmed that our model is adaptable to searching dynamic aspects of geographic information based on real world phenomena.

Three-layered structure for sharing event information in distributed environment

We propose a three-layered structure model for handling broadly spreading geographic events successfully in the distributed environment. In our model, event data and geographic objects are represented independently in the 1st layer, and they are associated dynamically according to a query in the 2nd layer by using regular expression for attribute changes and spatio-temporal relation. In the 3rd layer, data propagated from the 2nd layer are aggregated to be used in application systems. Based on this framework, event data and geographic objects could be represented independently, and event data computed in the 2nd layer would be shared and re-used.

Sharing Event Information in Distributed Environment Based on Three-Layered Structure

Recently, geographic information models for handling events have been proposed. However, the models are not always suitable to handle broadly spreading events, specifically in a distributed environment. This is because event data should be synchronized between geographic objects. In this paper, we propose a three-layered structure model with a view to handling events successfully in the distributed environment. In our model, event data and geographic objects are represented independently in the 1st layer, and they are associated dynamically according to a query in the 2nd layer. In the 3rd layer, data propagated from the 2nd layer are aggregated so as to be used in application systems. Based on this framework, event data and geographic objects could be represented independently, and event data computed in the 2nd layer would be shared and re-used.

CAD system for quantitative evaluation of chronic obstructive pulmonary disease based on 3-D CT images

Abstract This paper presents a CAD system for quantitative evaluation of chronic obstructive pulmonary disease (COPD) based on 3-D chest X-ray CT images. In the system, distribution pattern of COPD is automatically analyzed and its result is presented to medical doctors. The system analyzes COPD by using true 3-D image processing techniques based on precise 3-D chest X-ray CT images. In the proposed CAD system, low attenuation areas (LAAs), which are clearly observed in the case of COPD, are automatically extracted by intensity threshold and intensity variance. The extracted regions are analyzed by using 3-D distance transformation. The analyzed results are also visualized by volume rendering and digital radiography reconstruction. The experimental results show that the proposed system is very useful of quantification of COPD diagnosis.