Dongmin Seo

Data Correlation-Based Clustering Algorithm in Wireless Sensor Networks

Many types of sensor data exhibit strong correlation in both space and time. Both temporal and spatial suppressions provide opportunities for reducing the energy cost of sensor data collection. Unfortunately, existing clustering algorithms are difficult to utilize the spatial or temporal opportunities, because they just organize clusters based on the distribution of sensor nodes or the network topology but not on the correlation of sensor data. In this paper, we propose a novel clustering algorithm based on the correlation of sensor data. We modify the advertisement sub-phase and TDMA schedule scheme to organize clusters by adjacent sensor nodes which have similar readings. Also, we propose a spatio-temporal suppression scheme for our clustering algorithm. In order to show the superiority of our clustering algorithm, we compare it with the existing suppression algorithms in terms of the lifetime of the sensor network and the size of data which have been collected in the base station. As a result, our experimental results show that the size of data is reduced and the whole network lifetime is prolonged.

An Index Structure for Efficient k-NN Query Processing in Location Based Services

Many studies on index structures for k-NN query processing have been done in Location Based Services(LBS). However, they are not suitable for the moving objects because their update costs are so expensive due to the frequent location updates of the moving objects. In this paper, we propose Incremental Search R-tree(ISR-tree) that processes k-NN queries efficiently in the environment with static objects and moving clients. In ISR-tree, the leaf-nodes maintain the entries pointing to their relevant neighbor nodes and the entries help to find the neighbor leaf-nodes without visiting internal nodes when k-NN queries are processed. We prove the superiority of ISR-tree through the comparison with previous works. As a result, since ISR-tree saves the costs to visit internal nodes, it significantly improves the performance over the existing index structure.

Semantic Web based Multi-Dimensional Information Analysis System on the National Defense Weapons

As defense science and technology are developing, smart weapons are being developed continually. The collection and analysis of the future strategic weapon information from all over the world have become a greater priority because information sharing became active. So, a system to manage and analyze heterogeneous defense intelligence is required. Semantic Web is the next generation knowledge information management technology for integrating, searching and navigating heterogeneous knowledge resource. Recently, Semantic Web is wildly being used in intelligent information management system. Semantic Web supports the analysis with the high reliability because it supports the simple keyword search as well as the semantic based information retrieval. In this paper, we propose the semantic web based multi-dimensional information analysis system on the national defense weapons that constructs ontology for various weapons information such as weapon specifications, nations, manufacturers and technologies and searches and analyses the specific weapon based on ontology. The proposed system supports the semantic search and multi-dimensional information analysis based on the relations between weapon specifications. Also, our system improves the efficiency on acquiring smart weapon information because it is developed with ontology based on military experts` knowledge and various web documents related with various weapons and intelligent search service.

Implementation of Information Retrieval Service for Korean Spine Database with Degenerative Spinal Disease

Many people are interested in medical information because they want to take care of their health by themselves. Thus, some institutions provide medical term search services to help their understanding about difficult medical terms. However, those services are suffered from the low quality of search results because simple keyword search technologies are applied to medical term databases and Web sites. To prevent unnecessary spinal surgery and to support scientific diagnosis of spinal diseases and systematic prediction of treatment effects, we have been developing e-spine, which is a computerized simulation model of human spines. In this paper, as a background data for realizing e-spine, we have collected spine data from 77 cadavers and 298 patients with normal spine or degenerative spinal diseases. The spine data consists of 2D images such as CT, MRI, or X-ray, 3D shapes, geometry data and property data. Especially, we propose our database and the bioinformatics linked data based spine information retrieval service that provides more user-friendly services and very precise results. To provide abundant medical knowledge, our service provides search results of MeSH, OMIM, UniProt, GeneOntology and DBpedia. Also, the search results of PubMed are displayed to provide the related papers and books. As a result, our database will offer great value and utility in the diagnosis, treatment, and rehabilitation of patients suffering from spinal diseases.

Development of the Korean Spine Database and Automatic Surface Mesh Intersection Algorithm for Constructing e-Spine Simulator

By 2026, Korea is expected to surpass the UN’s definition of an aged society and reach the level of a superaged society. With an aging population come increased disorders involving the spine. To prevent unnecessary spinal surgery and support scientific diagnosis of spinal disease and systematic prediction of treatment outcomes, we have been developing e-Spine, which is a computer simulation model of the human spine. In this paper, we present the Korean spine database and automatic surface mesh intersection algorithm to construct e-Spine. To date, the Korean spine database has collected spine data from 77 cadavers and 298 patients. The spine data consists of 2D images from CT, MRI, or X-ray, 3D shapes, geometry data, and property data. The volume and quality of the Korean spine database are now the world’s highest ones. In addition, our triangular surface mesh intersection algorithm automatically remeshes the spine-implant intersection model to make it valid for finite element analysis (FEA). This makes it possible to run the FEA using the spine-implant mesh model without any manual effort. Our database and surface mesh intersection algorithm will offer great value and utility in the diagnosis, treatment, and rehabilitation of patients suffering from spinal diseases.

Implementing an Integrated System for R&D Results Management

In case that RD insert meta data of R&D results to the system, upload files of R&D results to the database of the system, inquire, and use meta data of R&D results. Based on the process, we design a system architecture for managing R&D results. In addition, it should be mainly considered to design a global schema for integrating R&D results into one database. The system shows detailed information on R&D results and provides R&D results conveniently to users. We expect that we may reduce the cost of reusing R&D results and improve the quality of R&D results with designing efficiently a process and a global schema of R&D result management system.

An Efficient Log Buffer Management Scheme of Flash Memory Through Delay of Merging Hot Data Blocks

In this paper, we propose a new log buffer management scheme considering the accessibility of the data. Our proposed scheme evaluates the worth of the merge of log blocks. It conducts the merge operations between infrequently updated data and the data blocks and postpones as much as possible the merge operations between frequently updated data and the data blocks. As a result, the proposed method prevents the unnecessary merge operations, reduces the number of the erase operations, and improves the utilization of the flash memory storage. In order to show the superiority of the proposed scheme, we compare it with BAST and FAST. It is shown through performance evaluation that the proposed method achieves about 25% and 65% performance improvements over BAST and FAST on average in terms of the number of the erase operations.

Design and Implementation of a Power-Saving Management System using Intelligent Scheduler based on RFID/USN Technology

Recently, the ubiquitous environment and the practical technology associated with it become more popular topic along with the rapid development of wireless technologies. The necessity of the automated system based on the ubiquitous environment has been increasing when the concept of the ubiquitous is integrated into the fields of existing IT. Also, the necessity of formulating a power-saving plan on large buildings and public institutions is gathering strength because of a raise in exchange rates and high oil prices. In this paper, to efficiently manage the power consumption of the electronic machine such as electric lights, electric heaters, and air conditioners in a building, power-saving manage- ment system using RFID/USN technologies is proposed. Proposed system controls the electric machine and monitor it`s condition by RFID and collects the real time information about the surrounding and the power consumption of the electric machine by USN. Especially, proposed system analyzes the real time information and supports the intelligent scheduler with the best power-saving. Finally, this paper shows the difference between proposed system and existing system and establishes thereality of our system through experiments in variety environments.

A Minimum Sequence Matching Scheme for Efficient XPath Processing

Index structures that are based on sequence matching for XPath processing such as ViST, PRIX and LCS-TRIM have recently been proposed to reduce the search time of XML documents. However, ViST can cause a lot of unnecessary computation and I/O when processing structural joint queries because its numbering scheme is not optimized. PRIX and LCS-TRIM require much processing time for matching XML data trees and queries. In this paper, we propose a novel index structure that solves the problems of ViST and improves the performance of PRIX and LCS-TRIM. Our index structure provides the minimum sequence matching scheme to efficiently process structural queries. Finally, to verify the superiority of the proposed index structure with the minimum sequence matching scheme, we compare our index structure with ViST, PRIX and LCS-TRIM in terms of query processing of a single path or of a branching path including wild-cards (‘*’ and ‘//’).

Design and Implementation of an Integrated Property Management System on Web using RFID

As ubiquitous computing technologies become the important paradigm for replacing internet based IT paradigm and developing the next generation IT, the research and development on the ubiquitous technologies are progressed actively. One of the core technologies for ubiquitous computing is RFID. In this paper, we design and implement the property management system as a new business item using the RFID since the demands for the u-business model that considers the ubiquitous environment are being grown. There are many properties in the organizations such as companies, schools and so on. Many users share these properties. Thus, these fields require efficient management systems for monitoring a variety of information such as the locations and the detailed information of the properties for the monitoring and lending services. We attach RFID tags to every property and monitor their information with our web-based management system. Our management system provides the monitoring service and the lending service for properties and users.