• Journal of Information Technology Applications and Management
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• v.9 no.1
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• pp.27-44
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• 2002

Performance evaluations of database algorithms are usually conducted on a set of queries for a given test database. For more detailed evaluation results, it is often necessary to use different query workloads several times. Each query workload should reflect the querying patterns of the application domain in real world, which are non-uniform in the usage frequencies of attributes in queries of the workload for a given database. It is not trivial to generate many different query workloads manually, while considering non-uniform distributions of attributes'usage frequencies. In this paper we propose a technique to generate non-uniform distributions, which will help construct query workloads more efficiently. The proposed algorithm generates a query-attribute usage distribution based on given constraints on usage frequencies of attributes and qreries. The algorithm first allocates as many attributes to queries as Possible. Then it corrects the distribution by considering attributes and queries which are not within the given frequency constraints. We have implemented and tested the performance of the proposed algorithm, and found that the algorithm works well for various input constraints. The result of this work could be extended to help automatically generate SQL queries for various database performance benchmarking.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.331-343
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• 2013

In RFID systems, the anti-collision algorithm is being improved to recognize Tag's ID within recognition area of the reader quickly and efficiently. This paper focuses on Tag collision. Many studies have been carried out to resolve Tag collision. This paper proposes a new N-ary Query Tree Algorithm to resolve more than Tag collision simultaneously, according to the value of m(2 ~ 6). This algorithm can identify more tags than existing methods by treating a maximum 6 bit collision, regardless of the continuation/non-continuation Tag's ID patterns. So, it extracts maximumly different $2^6$ bit patterns per single prefix in recognition process. The performance of N-ary Query Tree Algorithm is evaluated by theoretical analysis and simulation program.

• ETRI Journal
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• v.31 no.4
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• pp.463-465
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• 2009

In this letter, we present an event stream processing system that can evaluate a pattern query for a data sequence with predicates. We propose a pattern query language and develop a pattern query processing system. In our system, we propose novel techniques for run-time aggregation and negation processing and apply our system to stream data generated from vehicles to monitor unusual driving patterns.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.619-626
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• 2012

With the service suggesting additional extended or related query, search engines aim to provide their users more convenience. The extended or related query suggestion service based on popularity, or by how many people have searched on web using the query, has limitations to elevate users' satisfaction, because each user's preference and interests differ. This paper will demonstrate the design and realization of the system that suggests extended query appropriate for users' demands, and also an improvement in the computing process between entering the first search word and the subsequent extension to the related themes. According to the evaluation the proposed system suggested 41% more extended or related query than when searching on Google, and 48% more than on Yahoo. Also by improving the shortcomings of the extended or related query system based on general popularity rather than each user's preference, the new system enhanced users' convenience further.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.2
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• pp.147-160
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• 2005

This study examines trends of web query types and topics submitted to NAVER during one year period by analyzing query logs and click logs. There was a seasonal difference in the distribution of query types. Query type distribution was also different between weekdays and weekends, and between different days of the week. The log data show seasonal changes in terms of the topics of queries. Search topics seem to change between weekdays and weekends, and between different days of the week. However, there was little change in overall patterns of search behavior across one year. The implications for system designers and web content providers are discussed.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.1
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• pp.68-78
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• 2005

A new emotion-based image retrieval method is proposed in this paper. The research was motivated by Soen's evaluation of human emotion on color patterns. Thirteen pairs of adjective words expressing emotion pairs such as like-dislike, beautiful-ugly, natural-unnatural, dynamic-static, warm-cold, gay-sober, cheerful-dismal, unstablestable, light-dark, strong-weak, gaudy-plain, hard-soft, heavy-light are modeled by 19-dimensional color array and $4{\times}3$ gray matrix in off-line. Once the query is presented in text format, emotion model-based query formulation produces the associated color array and gray matrix. Then, images related to the query are retrieved from the database based on the multiplication of color array and gray matrix, each of which is extracted from query and database image. Experiments over 450 images showed an average retrieval rate of 0.61 for the use of color array alone and an average retrieval rate of 0.47 for the use of gray matrix alone.

• Journal of the Korea Society of Computer and Information
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• v.21 no.10
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• pp.1-10
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• 2016

In this paper, we propose an approach to generate machine readable context annotations for SPARQL Results. According to W3C Recommendations, the retrieved data from RDF or OWL data sources are represented in tabular form, in which each cell's data is described by only type and value. The simple query result form is generally useful, but it is not sufficient to explain the semantics of the data in query results. To explain the meaning of the data, appropriate annotations must be added to the query results. In this paper, we generate the annotations from the basic graph patterns in user's queries. We could also manipulate the original queries to complete the annotations. The generated annotations are represented using the RDFa syntax in our study. The RDFa expressions in HTML are machine-understandable. We believe that our work will improve the trustworthiness of query results and contribute to distribute the data to meet the vision of the Semantic Web.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.119-121
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• 2008

Pattern matching is increasingly being employed in various researches as health care service, RFID-based system, facility management, and surveillance. Geosensor filter correlates a data stream to match specific patterns in distribution environments. In this paper, we present a geosensor query language to represent efficiently declarative geosensor query. Geosensor operators are proposed to use for fast query processing in terms of spatial and temporal area in distribution environments. We also propose a geosensor filter to match new query predicates into incoming stream predicates. Our filter can reduce the volume of transmission data and save power consumption of sensors. It can be utilized the stream data mining system to process in real-time various data as location, time, and geosensor information in distribution environments.

• Journal of Communications and Networks
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• v.13 no.4
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• pp.400-407
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• 2011

Various air indexing and data scheduling schemes for wireless broadcast of spatial data have been developed for energy efficient query processing. The existing schemes are not effective when the clients' data access patterns are skewed to some items. It is because the schemes are based on flat broadcast that does not take the popularity of the data items into consideration. In this paper, thus, we propose a data scheduling scheme letting the popular items appear more frequently on the channel, and grid-based distributed index for non-flat broadcast (GDIN) for window query processing. The proposed GDIN allows quick and energy efficient processing of window query, matching the clients' linear channel access pattern and letting the clients access only the queried data items. The simulation results show that the proposed GDIN significantly outperforms the existing schemes in terms of access time, tuning time, and energy efficiency.

• Annual Conference on Human and Language Technology
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• 2010.10a
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• pp.15-21
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• 2010

본 논문은 검색 서비스 기능 중에 빼놓을 수 없는 기능인 한글 검색 질의어(query) 교정 시스템을 '야후!'에서 구축하며 분석한 한글 오타 패턴 그리고 사용자 로그를 기반으로 설계한 질의어 교정 서비스에 대한 설명을 하고 있다. 이 교정 서비스는 현재 '야후! 코리아'에 적용되어 있으며, 한글을 고려한 키스트 로크를 기반으로 한 설계 방식 그리고 동적으로 에러모델을 구축하는 방법을 소개하고 있으며 또한 구축된 모델의 성능을 다른 검색 서비스와 비교한 결과를 소개한다.