Yong-Ik Yoon

Learn More
We propose query optimization techniques that fully utilize the advantages of path indexes in object-oriented database systems. Although path indexes provide an eecient access to complex objects, little research has been done on query optimization that fully utilize path indexes. We rst devise a generalized index intersection technique, adapted to the(More)
Although various types of path indexes – indexes on path expressions – have been proposed for efficient processing of object-oriented queries, conventional join algorithms do not effectively utilize them. We propose a new join algorithm called OID join algorithm that effectively utilizes (multiple) path indexes in object-oriented databases. When (multiple)(More)
On behalf of all the ICACT2016 international conference committees, we would like to welcome all of you to ICACT2016. It is a great pleasure for us to host The ICACT is annual international conference in the communications field, where all experts from home and abroad come together to present their work, and share new ideas and visions for achieving the(More)
Context information can be an important factor of user behavior modeling and various context recognition recommendations. However, state-of-the-art context modeling methods cannot deal with contexts of other dimensions such as those of users and items and cannot extract special semantics. On the other hand, some tasks for predicting multidimensional(More)
In the recently, the Closed Circuit Television (CCTV) has been used to ensure the security and evidence for the crimes. However, the video captured from CCTV has being used in the postprocessing to apply to the evidence. The using pattern of CCTV shows a slight effect on the purpose of prevention a crime rather than prevention a pre-crime that occurs in(More)
People have multiple smart devices these days, such as smart phones, tablet computers and smart TVs among others. So now it is possible to offer advertisements everywhere. There is also an emerging technology with public Smart Digital Displays, which can be interacted with by smart mobile devices, by using the displays' touchscreen and other ways. Those(More)
In recent, service providers would like to support actual feeling services for internet users to give a satisfaction. Since web environments are changed more newly, internet users want to satisfy their needs. For offering the satisfaction to users, we suggest a middleware to give impressive media that is named Harmonized Media Service Middleware (HMSM).(More)
Applying the chunge impact unalysis to the distributed environment is not straightforward since it is based on the centralized system environment. In this paper, we investigate the change impact analysis of object-oriented, software in the distributed environment. We, fmt, categorize the types of change elements in object-oriented software into thret(More)