• 제목/요약/키워드: techniques: indexing and querying

검색결과 3건 처리시간 0.016초

NVST DATA ARCHIVING SYSTEM BASED ON FASTBIT NOSQL DATABASE

  • Liu, Ying-Bo;Wang, Feng;Ji, Kai-Fan;Deng, Hui;Dai, Wei;Liang, Bo
    • 천문학회지
    • /
    • 제47권3호
    • /
    • pp.115-122
    • /
    • 2014
  • The New Vacuum Solar Telescope (NVST) is a 1-meter vacuum solar telescope that aims to observe the fine structures of active regions on the Sun. The main tasks of the NVST are high resolution imaging and spectral observations, including the measurements of the solar magnetic field. The NVST has been collecting more than 20 million FITS files since it began routine observations in 2012 and produces maximum observational records of 120 thousand files in a day. Given the large amount of files, the effective archiving and retrieval of files becomes a critical and urgent problem. In this study, we implement a new data archiving system for the NVST based on the Fastbit Not Only Structured Query Language (NoSQL) database. Comparing to the relational database (i.e., MySQL; My Structured Query Language), the Fastbit database manifests distinctive advantages on indexing and querying performance. In a large scale database of 40 million records, the multi-field combined query response time of Fastbit database is about 15 times faster and fully meets the requirements of the NVST. Our slestudy brings a new idea for massive astronomical data archiving and would contribute to the design of data management systems for other astronomical telescopes.

A New Three-dimensional Integrated Multi-index Method for CBIR System

  • Zhang, Mingzhu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제15권3호
    • /
    • pp.993-1014
    • /
    • 2021
  • This paper proposes a new image retrieval method called the 3D integrated multi-index to fuse SIFT (Scale Invariant Feature Transform) visual words with other features at the indexing level. The advantage of the 3D integrated multi-index is that it can produce finer subdivisions in the search space. Compared with the inverted indices of medium-sized codebook, the proposed method increases time slightly in preprocessing and querying. Particularly, the SIFT, contour and colour features are fused into the integrated multi-index, and the joint cooperation of complementary features significantly reduces the impact of false positive matches, so that effective image retrieval can be achieved. Extensive experiments on five benchmark datasets show that the 3D integrated multi-index significantly improves the retrieval accuracy. While compared with other methods, it requires an acceptable memory usage and query time. Importantly, we show that the 3D integrated multi-index is well complementary to many prior techniques, which make our method compared favorably with the state-of-the-arts.

MapReduce 환경에서의 실시간 LBS를 위한 이동궤적 데이터 색인 및 검색 시스템 설계 (Design of Trajectory Data Indexing and Query Processing for Real-Time LBS in MapReduce Environments)

  • 정재화
    • 디지털콘텐츠학회 논문지
    • /
    • 제14권3호
    • /
    • pp.313-321
    • /
    • 2013
  • 최근 모바일 스마트 기기의 보급으로 스마트 기기에 탑재된 다양한 센서에서 수집되는 대량이 데이터를 분석하여 처리하는 빅 데이터의 시대는 위치기반 서비스(LBSs: Location-Based Services)에 까지 확대대고 있다. 이동궤적에 대한 데이터도 초 대용량으로 증가하고 있다. 초 대용량 이동궤적 데이터 처리를 위해서는 클라우드 컴퓨팅 기술 및 맵리듀스와 같은 병행처리 플랫폼에 대한 연구가 필요하다. 최근 대용량 데이터의 병렬처리를 위해 맵리듀스 기반의 연구는 진행되고 있으나, 일괄처리 및 키-값 데이터 구조에 적합한 맵리듀스는 실시간 LBS에 적용에 적합하지 않다. 따라서 본 연구는 맵리듀스 특성을 면밀히 분석하고 실시간적 서비스에 적합하도록 모듈 단위로 효율적인 색인 기법 및 검색에 대한 시스템 설계를 제시한다.