• Title/Summary/Keyword: real-time databases

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Design of Framework for Implementation of the New Paradigm Map (신 패러다임 맵 구현을 위한 프레임워크 설계)

  • Kim, Sun-Woo;Yang, Kwang-Ho;Park, Ki-Shik;Park, Ju-Young;Ra, In-Ho
    • The Journal of the Korea Contents Association
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    • v.15 no.3
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    • pp.32-39
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    • 2015
  • In this paper, We propose the futuristic map using variety technology of advanced ICT-based. The futuristic maps are expected to developed into a new format of user participation to express the results in various formats through the understanding and interpretation of the facts and phenomena of tangible and intangible that exist in the real world. In the future, the map is expected to be developed into form of a new paradigm map made in real time that economy, industry, the collection of information necessary for everyday life, processing, usage, analysis, distribution and sharing. In this paper, we provide a real-time personalized contents to digitize the information of the real space based on the concept of map, databases, spatial analysis and describes the key technologies that characterized by the representation of time-series data by analyzing and prediction every field macro phenomena of society, economy, culture and etc. And we establish the concepts of the 'New Paradigm Map' for future creative economy.

Similarity Search in Time Series Databases based on the Normalized Distance (정규 거리에 기반한 시계열 데이터베이스의 유사 검색 기법)

  • 이상준;이석호
    • Journal of KIISE:Databases
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    • v.31 no.1
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    • pp.23-29
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    • 2004
  • In this paper, we propose a search method for time sequences which supports the normalized distance as a similarity measure. In many applications where the shape of the time sequence is a major consideration, the normalized distance is a more suitable similarity measure than the simple Lp distance. To support normalized distance queries, most of the previous work has the preprocessing step for vertical shifting which normalizes each sequence by its mean. The proposed method is motivated by the property of sequence for feature extraction. That is, the variation between two adjacent elements of a time sequence is invariant under vertical shifting. The extracted feature is indexed by the spatial access method such as R-tree. The proposed method can match time series of similar shape without vertical shifting and guarantees no false dismissals. The experiments are performed on real data(stock price movement) to verify the performance of the proposed method.

A Distributed Real-Time Concurrency Control Scheme using Transaction the Rise of Priority (트랜잭션 우선 순위 상승을 이용한 분산 실시간 병행수행제어 기법)

  • Lee, Jong-Sul;Shin, Jae-Ryong;Cho, Ki-Hyung;Yoo, Jae-Soo
    • Journal of KIISE:Databases
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    • v.28 no.3
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    • pp.484-493
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    • 2001
  • As real-time database systems are extended to the distributed computing environment, the need to apply the existing real-time concurrency control schemes to the distributed computing environment has been made. In this paper we propose an efficient concurrency control scheme for distributed real-time database system. Our proposed scheme guarantees a transaction to commit at its maximum, reduces the restart of a transaction that is on the prepared commit phase, and minimizes the time of the lock holding. This is because it raises the priority of the transaction that is on the prepared commit phase in the distributed real-time computing environment. In addition, it reduces the waiting time of a transaction that owns borrowed data and improves the performance of the system, as a result of lending the data that the transaction with the raised priority holds. We compare the proposed scheme with DO2PL_PA(Distributed Optimistic Two-Phase Locking) and MIRROR(Managing Isolation in Replicated Real-time Object Repositories) protocol in terms of the arrival rate of transactions, the size of transactions, the write probability of transactions, and the replication degree of data in a firm-deadline real-time database system based on two-phase commit protocol. It is shown through the performance evaluation that our scheme outperforms the existing schemes.

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Real-Time Face Detection by Estimating the Eye Region Using Neural Network (신경망 기반 눈 영역 추정에 의한 실시간 얼굴 검출 기법)

  • 김주섭;김재희
    • Proceedings of the IEEK Conference
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    • 2001.06d
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    • pp.21-24
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    • 2001
  • In this paper, we present a fast face detection algorithm by estimating the eye region using neural network. To implement a real time face detection system, it is necessary to reduce search space. We limit the search space just to a few pairs of eye candidates. For the selection of them, we first isolate possible eye regions in the fast and robust way by modified histogram equalization. The eye candidates are paired to form an eye pair and each of the eye pair is estimated how close it is to a true eye pair in two aspects : One is how similar the two eye candidates are in shape and the other is how close each of them is to a true eye image A multi-layer perceptron neural network is used to find the eye candidate region's closeness to the true eye image. Just a few best candidates are then verified by eigenfaces. The experimental results show that this approach is fast and reliable. We achieved 94% detection rate with average 0.1 sec Processing time in Pentium III PC in the experiment on 424 gray scale images from MIT, Yale, and Yonsei databases.

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Hippocratic XML Databases: A Model and Access Control Mechanism (히포크라테스 XML 데이터베이스: 모델 및 액세스 통제 방법)

  • Lee Jae-Gil;Han Wook-Shin;Whang Kyu-Young
    • Journal of KIISE:Databases
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    • v.31 no.6
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    • pp.684-698
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    • 2004
  • The Hippocratic database model recently proposed by Agrawal et al. incorporates privacy protection capabilities into relational databases. Since the Hippocratic database is based on the relational database, it needs extensions to be adapted for XML databases. In this paper, we propose the Hippocratic XML database model, an extension of the Hippocratic database model for XML databases and present an efficient access control mechanism under this model. In contrast to relational data, XML data have tree-like hierarchies. Thus, in order to manage these hierarchies of XML data, we extend and formally define such concepts presented in the Hippocratic database model as privacy preferences, privacy policies, privacy authorizations, and usage purposes of data records. Next, we present a new mechanism, which we call the authorization index, that is used in the access control mechanism. This authorization index, which is Implemented using a multi-dimensional index, allows us to efficiently search authorizations implied by the authorization granted on the nearest ancestor using the nearest neighbor search technique. Using synthetic and real data, we have performed extensive experiments comparing query processing time with those of existing access control mechanisms. The results show that the proposed access control mechanism improves the wall clock time by up to 13.6 times over the top-down access control strategy and by up to 20.3 times over the bottom-up access control strategy The major contributions of our paper are 1) extending the Hippocratic database model into the Hippocratic XML database model and 2) proposing an efficient across control mechanism that uses the authorization index and nearest neighbor search technique under this model.

Optimal Construction of Multiple Indexes for Time-Series Subsequence Matching (시계열 서브시퀀스 매칭을 위한 최적의 다중 인덱스 구성 방안)

  • Lim, Seung-Hwan;Kim, Sang-Wook;Park, Hee-Jin
    • Journal of KIISE:Databases
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    • v.33 no.2
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    • pp.201-213
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    • 2006
  • A time-series database is a set of time-series data sequences, each of which is a list of changing values of the object in a given period of time. Subsequence matching is an operation that searches for such data subsequences whose changing patterns are similar to a query sequence from a time-series database. This paper addresses a performance issue of time-series subsequence matching. First, we quantitatively examine the performance degradation caused by the window size effect, and then show that the performance of subsequence matching with a single index is not satisfactory in real applications. We argue that index interpolation is fairly useful to resolve this problem. The index interpolation performs subsequence matching by selecting the most appropriate one from multiple indexes built on windows of their inherent sizes. For index interpolation, we first decide the sites of windows for multiple indexes to be built. In this paper, we solve the problem of selecting optimal window sizes in the perspective of physical database design. For this, given a set of query sequences to be peformed in a target time-series database and a set of window sizes for building multiple indexes, we devise a formula that estimates the cost of all the subsequence matchings. Based on this formula, we propose an algorithm that determines the optimal window sizes for maximizing the performance of entire subsequence matchings. We formally Prove the optimality as well as the effectiveness of the algorithm. Finally, we perform a series of extensive experiments with a real-life stock data set and a large volume of a synthetic data set. The results reveal that the proposed approach improves the previous one by 1.5 to 7.8 times.

An Index-Based Approach for Subsequence Matching Under Time Warping in Sequence Databases (시퀀스 데이터베이스에서 타임 워핑을 지원하는 효과적인 인덱스 기반 서브시퀀스 매칭)

  • Park, Sang-Hyeon;Kim, Sang-Uk;Jo, Jun-Seo;Lee, Heon-Gil
    • The KIPS Transactions:PartD
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    • v.9D no.2
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    • pp.173-184
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    • 2002
  • This paper discuss an index-based subsequence matching that supports time warping in large sequence databases. Time warping enables finding sequences with similar patterns even when they are of different lengths. In earlier work, Kim et al. suggested an efficient method for whole matching under time warping. This method constructs a multidimensional index on a set of feature vectors, which are invariant to time warping, from data sequences. For filtering at feature space, it also applies a lower-bound function, which consistently underestimates the time warping distance as well as satisfies the triangular inequality. In this paper, we incorporate the prefix-querying approach based on sliding windows into the earlier approach. For indexing, we extract a feature vector from every subsequence inside a sliding window and construct a multidimensional index using a feature vector as indexing attributes. For query processing, we perform a series of index searches using the feature vectors of qualifying query prefixes. Our approach provides effective and scalable subsequence matching even with a large volume of a database. We also prove that our approach does not incur false dismissal. To verify the superiority of our approach, we perform extensive experiments. The results reveal that our approach achieves significant speedup with real-world S&P 500 stock data and with very large synthetic data.

An Efficient Dynamic Path Query Processing Method for Digital Road Map Databases (디지털 로드맵 데이터베이스에서 효율적인 동적 경로 질의어 처리 방안)

  • Jung, Sung-Won
    • Journal of KIISE:Databases
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    • v.28 no.3
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    • pp.430-448
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    • 2001
  • In navigation system, a primary task is to compute the minimum cost route from the current location to the destination. One of major problems for navigation systems is that a significant amount of computation time is required when the digital road map is large. Since navigation systems are real time systems, it is critical that the path be computed while satisfying a time constraint. In this paper, we have developed a HiTi(Hierarchical MulTi) graph model for hierarchically structuring large digital road maps to speedup the minimum cost path computation. We propose a new shortest path algorithm named SPAH, which utilizes HiTi graph model of a digital road map for its computation. We prove that the shortest path computed by SPAH is the optimal. Our performance analysis of SPAH also showed that it significantly reduces the computation time over exiting methods. We present an in-depth experimental analysis of HiTi graph method by comparing it with other similar works.

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An Ontology-based Knowledge Management System - Integrated System of Web Information Extraction and Structuring Knowledge -

  • Mima, Hideki;Matsushima, Katsumori
    • Proceedings of the CALSEC Conference
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    • 2005.03a
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    • pp.55-61
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    • 2005
  • We will introduce a new web-based knowledge management system in progress, in which XML-based web information extraction and our structuring knowledge technologies are combined using ontology-based natural language processing. Our aim is to provide efficient access to heterogeneous information on the web, enabling users to use a wide range of textual and non textual resources, such as newspapers and databases, effortlessly to accelerate knowledge acquisition from such knowledge sources. In order to achieve the efficient knowledge management, we propose at first an XML-based Web information extraction which contains a sophisticated control language to extract data from Web pages. With using standard XML Technologies in the system, our approach can make extracting information easy because of a) detaching rules from processing, b) restricting target for processing, c) Interactive operations for developing extracting rules. Then we propose a structuring knowledge system which includes, 1) automatic term recognition, 2) domain oriented automatic term clustering, 3) similarity-based document retrieval, 4) real-time document clustering, and 5) visualization. The system supports integrating different types of databases (textual and non textual) and retrieving different types of information simultaneously. Through further explanation to the specification and the implementation technique of the system, we will demonstrate how the system can accelerate knowledge acquisition on the Web even for novice users of the field.

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Establishment of advancement and usage-enhancement method of water service GIS system (수도GIS 시스템 고도화 및 활용성 증대 방안)

  • Hwang, Eui-Ho;Koh, Deuk-Koo;Lee, Geun-Sang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.366-372
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    • 2007
  • In this research, a ubiquitous-based strategy for managing waterworks facilities is proposed to increase the usability of the existing related databases and to ensure the systematic way of distributing information. The current status of the existing waterworks GIS and GIS database were analyzed to achieve the goal. By studying the state-of-the-art technology, we found that importing the LBS(Location Based Service) technology to the databases is necessary. The results of these efforts are exclusive waterworks-mobile-terminals and LBS system supporting them. Furthermore, the applicability of the ubiquitous technology to waterworks has been examined to realize the real-time waterworks management.

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