Weonil Chung

Spatial Operation Allocation Scheme over Common Query Regions for Distributed Spatial Data Stream Processing

According to increasing of various location-based services, distributed data stream processing techniques have been widely studied to provide high scalability and availability. In previous researches, in order to balance the load of distributed nodes, the geographic characteristics of spatial data stream are not considered. For this reason, distributed operations for adjacent spatial regions increases the overall system load. We propose a operation allocation scheme considering the characteristics of spatial operations to effectively processing spatial data stream in distributed computing environments. The proposed method presents the efficient share maximizing approach that preferentially distributes spatial operations sharing the common query regions to the same node in order to separate the adjacent spatial operations on overlapped regions.

A Study on Road Network Modeling over POI for Pedestrian Navigation Services in Smart Phones

Abstract Recently, the wide spread popularity of smart phones causes the advent of various mobile applications base on the location information. Since previous pedestrian navigations are applied by extending car navigations, these are not only difficult to provide the appropriate route information, but also raise limitations in the efficient query processing by data structures of car road networks. In addition, these increase the power consumption caused by the growth of I/O frequency. In this paper, we propose a pedestrian road network model for the accurate route information and a storage structure for the pedestrian road network based on POI to reduce the I/O frequency. The proposed method enables efficient route searches over POI reflecting the characteristics and requirements of pedestrian roads. Also, a reduction of query processing costs for the route searching by a data structure considered with POI can save the power consumption more than previous approaches.Key Words : Pedestrian Navigation, Road Network Model, Smart Phone

A Case Study on Program Outcomes Assessment of Information Security Program for Engineering Education Accreditation

Engineering education accreditation addresses evaluation for program outcomes according to educational objectives and assessment process, which students are expected to obtain by the time of graduation in order to train international competitive engineers with continuous quality improvement in engineering programs. This paper shows a case study of a program outcomes assessment system including performance criteria, evaluation process, document system and continuous quality improvement process and an achievement evaluation by the assessment system for program outcomes in Information Security Program of Hoseo university.

A novel outlier detection method for spatio-tempral trajectory data

The development of mobile device technology and localization technology makes the collection of spatio-temporal information from moving objects much easier than before, and outlier detection for spatio-temporal trajectory is becoming increasingly attractive to data mining community. However, there is a lack of serious studies in this area. Several existing trajectory outlier methods such as the partition-and-detect framework can only deal with the trajectory data which only includes spatial attributes. It cannot be applied to the spatio-temporal trajectory data which includes both spatial and temporal attributes. In this paper, we propose an enhanced partition-and-detect framework to detect the outliers of spatio-temporal trajectory data. In this framework, we mainly introduce an outlier detection method which uses trajectory MBBs(Minimum Boundary Boxs). Based on this enhanced framework, we propose a congestion outlier detection method. Finally, the efficiency and accuracy are evaluated through experiments which use a real traffic dataset called US Highway 101 Dataset.

Spatial Data Stream Processing Platform for Ubiquitous Application Services

Sensors related to the geographic information are gathering strength as core technologies for various ubiquitous services like u-City project for the new town of the future to provide total information services by the high IT infrastructure. These sensors generate the very large real-time streaming data because these are set up and controlled with wide areas of the geographical distribution. On this, we propose an efficient spatial data stream processing system to support various u-GIS services based on geographic sensors.

Partition-based Operator Sharing Scheme for Spatio-temporal Data Stream Processing

In ubiquitous environments, many continuous query processing techniques make use of operator network and sharing methods on continuous data stream generated from various sensors. Since similar continuous queries with the location information intensively occur in specific regions, we suggest a new operator sharing method based on grid partition for the spatial continuous query processing for location-based applications. Due to the proposed method shares moving objects by the given grid cell without sharing spatial operators individually, our approach can not only share spatial operators including similar conditions, but also increase the query processing performance and the utilization of memory by reducing the frequency of use of spatial operators.

An Efficient Storing Scheme of Real-time Large Data to improve Semiconductor Process Productivities

Automatic semiconductor manufacturing systems are demanded to improve the efficiency of the semiconductor production process. These systems include the functionalities such as the analysis and management schemes for very large real-time data in order to enhance the productivities. So, it requires the efficient storage management system to store very large real-time data. Traditional database management systems(e.g. Oracle, MY-SQL, MS-SQL) are based on disk. However, previous DBMS`s have the limitation on the low storing performance. In this paper, we propose a compress-merge storing method of very large real-time data using insert transaction of a block unit. The proposed method shows better processing performances compare to conventional DBMS`s. Also compress-merge method makes it possible that it can store large real-time data on low storage cost. Therefore, the proposed method can be applied to an efficient storage management system in the semiconductor production process.