• The Transactions of the Korea Information Processing Society
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• v.6 no.9
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• pp.2294-2304
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• 1999

Our research purpose in this paper is to improve the performance of query processing in GIS(Geographic Information System) by enhancing the I/O performance exploiting parallel I/O and efficient disk access. By packing adjacent spatial data, which are very likely to be referenced concurrently, into one block or continuous disk blocks, the number of disk accesses and the disk access overhead for query processing can be decreased, and this eventually leads to the I/O time decrease. So, in this paper, we proposes EPR(Enhanced Parallel R-tree) indexing method which integrates the parallel I/O method of the previous Parallel R-tree method and a packing-based clustering method. The major characteristics of EPR method are as follows. First, EPR method arranges spatial data in the increasing order of proximity by using Hilbert space filling curve, and builds a packed R-tree by bottom-up manner. Second, with packing-based clustering in which arranged spatial data are clustered into continuous disk blocks, EPR method generates spatial data clusters. Third, EPR method distributes EPR index nodes and spatial data clusters on multiple disks through round-robin striping. Experimental results show that EPR method achieves up to 30% or more gains over PR method in query processing speed. In particular, the larger the size of disk blocks is and the smaller the size of spatial data objects is, the better the performance of query processing by EPR method is.

• The KIPS Transactions:PartD
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• v.16D no.4
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• pp.507-516
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• 2009

In stream data processing system, generally the interval queries are in advance registered in the system. When a data is input to the system continuously, for realtime processing, a query indexing method is used to quickly search queries. Thus, a main memory-based query index with a small storage cost and a fast search time is needed for searching queries. In this paper, we propose a LVC-based(Limited Virtual Construct-based) query index method using a hashing to meet the both needs. In LVC-based query index, we divide the range of a stream into limited virtual construct, or LVC. We map each interval query to its corresponding LVC and the query ID is stored on each LVC. We have compared with the CEI-based query indexing method through the simulation experiment. When the range of values of input stream is broad and there are many short interval queries, the LVC-based indexing method have shown the performance enhancement for the storage cost and search time.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.229-232
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• 2008

웹 정보량이 급속히 늘어나면서 원하는 정보를 효율적으로 찾는 검색 기술의 중요성이 커지고 있다. 검색의 정확성을 높이기 위해서는 검색 질의어와 함께 사용자의 환경, 검색 만족도와 같은 다양한 정보가 필요하다. 사용자의 명시적 피드백을 요구하는 것은 거부감을 줄 수 있으므로 사용자의 잠재적 피드백과 연관 검색어 분석을 통해 검색 질의어를 확장하는 연구가 이뤄지고 있다. 그러나 이러한 검색어 확장과 검색 정확성 사이의 상관관계에 대한 분석이 없어 연관 검색어를 정량적으로 평가할 수 없었다. 본 논문에서는 사용자가 검색 질의어를 변경하면서 검색을 반복하는 과정을 사용자의 잠재적 피드백의 하나로 보고 사용자 만족도를 반영하는 페이지 방문 시간과 함께 분석하여 연속적으로 입력된 검색어가 검색 결과 순위와 사용자 만족도에 미치는 영향을 분석하는 방법을 제안하였다. 마우스 클릭 정보 분석을 통하여 사용자의 검색 만족도를 정량화하였고 특정 주제어에서 관련 검색어가 확장되어 가는 과정은 트리 구조로 표현하였다. 이를 통해 하나의 주제어와 관련해 연속적으로 입력된 검색어 집합으로부터 연관검색어를 추출하고 검색 결과의 정확성을 높일 수 있으며 제안된 트리 구조를 다양한 방향으로 분석하여 검색어, 검색 결과, 사용자 만족도, 배경 지식 등 단순 검색어 분석에서는 나타나지 않는 다양한 정보를 얻을 수 있다.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.321-325
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• 1986

A laboratory experiment was conducted to investigate silica solubility in soil with specific reference to the characteristics of iron refinery slag and wollastonite. The results are as follows; 1. The slilia concentrations successively extracted by distilled water and N-NaOAc (pH 4.0) in soil treated with the two silicate fertilizers, is higher in iron refinery slag than in wollastonite, while the pH values of soil-fertilizer suspensions successively extracted by distilled water were the opposite. 2. Silica concentrations due to increasing of fertilizer application were decreased in iron refinery slag-soil suspensions but the concentrations were increased in wollastonite-soil suspensions. 3. The amounts of silica adsorbed in different pH of soil suspension were maximized under the condition maintained pH of near to 9.4.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.183-186
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• 2012

To process continuous queries on a sensor network, it is required to transfer query predicates and build a query index on each sensor node. However, if we transfer query predicates to all sensor nodes, it makes the number of messages for query predicates increase. In this paper, we propose the scheme to construct the tree based relationship structure using data region of the sensor node and select the target nodes to transfer query predicates. we also implement the tree based relationship structure and measure the number of messages for sending predicates.

• The KIPS Transactions:PartD
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• v.15D no.1
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• pp.23-30
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• 2008

The basic research of context aware in ubiquitous environment is an internet technique and XML. The XML data of continuous stream type are popular in network application through the internet. And also there are researches related to query processing for streaming XML data. As a basic research to efficiently query, we propose not only a labeled ordered tree model representing the XML but also a mining method to extract frequent structures from streaming XML data. That is, XML data to continuously be input are modeled by a stream tree which is called by XFP_tree and we exactly extract the frequent structures from the XFP_tree of current window to mine recent data. The proposed method can be applied to the basis of the query processing and index method for XML stream data.

• Journal of Korea Spatial Information System Society
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• v.8 no.2 s.17
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• pp.75-89
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• 2006

LBS (Location-Based Service) systems have become a serious subject for research and development since recent rapid advances in wireless communication technologies and position measurement technologies such as global positioning system. The architecture named the GALIS (Gracefully Aging Location Information System) has been suggested which is a cluster-based distributed computing system architecture to overcome performance losses and to efficiently handle a large volume of data, at least millions. The GALIS consists of SLDS and LLDS. The SLDS manages current location information of moving objects and the LLDS manages past location information of moving objects. In this thesis, we implement a monitoring technique for the GALIS prototype, to allow dynamic load balancing among multiple computing nodes by keeping track of the load of each node in real-time during the location data management and spatio-temporal query processing. We also propose a buffering technique which efficiently manages the query results having overlapped query regions to improve query processing performance of the GALIS. The proposed scheme reduces query processing time by eliminating unnecessary query execution on the overlapped regions with the previous queries.

• Journal of Conservation Science
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• v.19
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• pp.19-30
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• 2006

Alteration of physical and chemical characteristics and the effect of removal of mineral substances in waterlogged archaeological woods by different cleaning processes were examined using oak wood(Quercus spp.) that was excavated from wetland near Gwangju, Korea. Cleaning methods employed in the present work were (1) tools, (2) deaeration, (3) EDTA and (4) ultrasonic cleaning, which are being currently applied in the field of preservation treatment. Cleaning process were performed independently or continuously. Composition of mineral substances in the waterlogged archaeological wood was almost same as the that of soil in which waterlogged archaeological woods were buried. In case of independent cleaning, tools cleaning efficiently removed the mineral substances on surface. Surface color become brighter after cleaning with EDTA. In contrast, deaeration and ultrasonic cleaning did not show any significant removal of mineral substances. In continuous cleaning process, tool cleaning as the first step treatment showed the same effect as shown in independent cleaning. Although deaeration as the second step cleaning did not remove the mineral substances, it could be assumed to contribute the infiltration of dimensional agents by homogenization of wood. EDTA treatment (the third step cleaning) removed the iron(Fe) and increased the whiteness of wood color. The ultrasonic treatment (the fourth step cleaning) removed the sodium(Na) remained after EDTA treatment and the fine mineral substances.

• Journal of KIISE:Databases
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• v.35 no.1
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• pp.1-16
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• 2008

Join queries having heavy cost are necessary to Data Stream Management System in Sensor Network where plural short information is generated. It is reasonable that each join operator has a sliding-window constraint for preventing DISK I/O because the data stream represents the infinite size of data. In addition, the join operator should be able to take multiple inputs for overall results. It is possible for the MJoin operator with sliding-windows to do so. In this paper, we consider the data stream environment where multiple MJoin operators are registered and propose MMJoin which deals with issues of building and processing a globally shared query considering characteristics of the MJoin operator with sliding-windows. First, we propose a solution of building the global shared query execution plan. Second, we solved the problems of updating a window size and routing for a join result. Our study can be utilized as a fundamental research for an optimization technique for multiple continuous joins in the data stream environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.145-152
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• 2010

With the recent development of the ubiquitous computing technology, there are increasing interest and research in technologies such as sensors and RFID related to information recognition and location positioning in various ubiquitous fields. Especially, RTLS(Real-Time Locating Services) dealing with spatio-temporal data is emerging as a promising technology. For these reasons, the ISO/IEC published the RTLS standard specification for compatibility and interoperability in RTLS. Therefore, in this paper, we designed and implemented Spatio-temporal Query Processing Systems for efficiently managing and searching the incoming Spatio-temporal data stream of moving objects. Spatio-temporal Query Processing Systems's spatio-temporal middleware maintains interoperability among heterogeneous devices and guarantees data integrity in query processing through real time processing of unceasing spatio-temporal data streams and two way synchronization of spatio-temporal DBMSs. Web Server uses the SOAP(Simple Object Access Protocol) message between client and server for interoperability and translates client's SOAP message into CQL(Continuous Query Language) of the spatio-temporal middleware. Finally, this thesis proved the utility of the system by applying the spatio-temporal Query Processing Systems to a real-time Locating Services.