• 제목/요약/키워드: spatial domain

검색결과 881건 처리시간 0.024초

An Efficient Algorithm for Mining Frequent Sequences In Spatiotemporal Data

  • ;지정희;류근호
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2005년도 추계학술대회
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    • pp.61-66
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    • 2005
  • Spatiotemporal data mining represents the confluence of several fields including spatiotemporal databases, machine loaming, statistics, geographic visualization, and information theory. Exploration of spatial data mining and temporal data mining has received much attention independently in knowledge discovery in databases and data mining research community. In this paper, we introduce an algorithm Max_MOP for discovering moving sequences in mobile environment. Max_MOP mines only maximal frequent moving patterns. We exploit the characteristic of the problem domain, which is the spatiotemporal proximity between activities, to partition the spatiotemporal space. The task of finding moving sequences is to consider all temporally ordered combination of associations, which requires an intensive computation. However, exploiting the spatiotemporal proximity characteristic makes this task more cornputationally feasible. Our proposed technique is applicable to location-based services such as traffic service, tourist service, and location-aware advertising service.

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입자 속도 및 인텐시티를 공간 영역에서 이산화할 때 발생하는 오차 (Particle Velocity and Intensity Estimation Error in Spatial Discrete Domain)

  • 김양한;최영철
    • 한국소음진동공학회논문집
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    • 제14권4호
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    • pp.352-357
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    • 2004
  • This paper studies the errors that associated with particle velocity and intensity in a space. We theoretically derived their bias error and random error. The analysis shows that the more samples do not always guarantee the better results. The random error of the velocity and intensity are increased when we have many samples. The characteristics of the amplification of the random error are analyzed in terms of the sample spacing. The amplification was found to be related to the spatial differential of random noise. The numerical simulations are performed to verify theoretical results.

Innovation Policies and Locational Competitiveness : Lessons from Singapore

  • Ebner, Alexander
    • 기술혁신연구
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    • 제12권2호
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    • pp.47-66
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    • 2004
  • The relationship between innovation policies and locational competitiveness has emerged as an important area in the analysis of economic development, reflecting both the centralisation and decentralisation of globalising economic activities. The underlying spatial and institutional components are subject to a pattern of cumulative causation in which strategic interventions of policy actors exercise a decisive role in shaping competitive advantages, while promoting interactions with local and foreign partners both from the private and public sectors. The Singaporean development experience illustrated these strategic interdependencies of innovation policies and locational competitiveness. Based on her role as a manufacturing and service hub, Singapore is viewed as an infrastructural nodal point which is interconnected to global production networks. Paralleling efforts in the domain of technological innovation, Singapore's policies for locational competitiveness aim at an adaptive harmonisation of the needs of international investors with local developmental objectives. This orientation characterises also current efforts in promoting Singapore as a knowledge agglomeration with a distinct science base, expanding R&D operations and an innovation-driven pattern of economic development. In conclusion, the locational rationale of Singapore's innovation policies provides lessons for dealing with the spatial and institutional implications of technological globalisation.

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색상정보를 이용하는 공간영역에서의 워커마킹기법 (Watermarking in Spatial-Domain using Image Color)

  • 이만석;최진구
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (C)
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    • pp.548-551
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    • 2006
  • 본 논문에서는 최근 많은 연구가 진행되고 있는 디지털 워터마크의 삽입 기법이 영상의 공간영역에서 효과적으로 이루어질 수 있는 방법을 제안한다. 제안하는 워터마킹 방법은 각 색상정보의 히스토그램을 구하여 영상에 가장 밀접한 관계를 가지는 색상별로 워터마크를 색상화소의 최하위 비트에 워터마크를 합성한다. 본 논문에서 제안하는 워터마킹은 공간영역의 합성방법에서 지적되었던 워터마크의 다양한 정보를 저장할 수 없던 문제점을 극복하였다. 또한 잡음이나 신호의 변화 에도 강인하면서도 속도는 주파수영역의 워터마킹에 비해 매우 빠르다. 본 논문에서는 주파수 영역과 공간영역에서의 합성방법과 비교하는 실험을 통해 다른 방법에 비해 높은 강인성과 주파수 영역의 연산에 비해 60% 정도의 연산속도를 가짐을 검증하여 분석하였다.

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기상자료 3차원 가시화 기술개발 연구 (Development of 3D Visualization Technology for Meteorological Data)

  • 서인범;조민수;윤자영
    • 한국가시화정보학회지
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    • 제1권2호
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    • pp.58-70
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    • 2003
  • Meteorological data contains observation and numerical weather prediction model output data. The computerized analysis and visualization of meteorological data often requires very high computing capability due to the large size and complex structure of the data. Because the meteorological data is frequently formed in multi-variables, 3-dimensional and time-series form, it is very important to visualize and analyze the data in 3D spatial domain in order to get more understanding about the meteorological phenomena. In this research, we developed interactive 3-dimensional visualization techniques for visualizing meteorological data on a PC environment such as volume rendering, iso-surface rendering or stream line. The visualization techniques developed in this research are expected to be effectively used as basic technologies not only for deeper understanding and more exact prediction about meteorological environments but also for scientific and spatial data visualization research in any field from which three dimensional data comes out such as oceanography, earth science, and aeronautical engineering.

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북경 '사합원' 주택의 공간적 특성에 관한 연구 (A Study on spatial qualities of Beijing 'Sanapwon' dwelling Houses in Indoor Space)

  • 김정;김문덕
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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    • pp.145-149
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    • 2006
  • China which has 960km of domain area is one of the biggest countries in the world. Also China has a large population of 1,300,000,000 which are 25% of total world population and consist of 56 ethnic groups. In addition, History of China is immemorial and Confucianism of feudalistic and Taoism idea have effect on Chinese for a long time and architecture is influenced by them. Thus a large degree of variety, abundance, and uniqueness can be found in Chinese traditional dwelling. This research will be focusing on Sanapwon, a traditional housing in Beijing, which represents China's original and distinctive dwelling features. By looking at Sanapwon, we can learn the distinguishable characteristics of Chinese residential area and understand the concept of space. By looking closely at the worldly outlook, historical view, originality, and the spatial notion centered around human beings, many types of Sanapwon and its formation process have been examined Likewise indoor plane construction, and basic element of composition of space will help to study the whole of residing space.

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버스와 지하철 진동에 대한 중층건물의 진동특성 (Vibration Characteristic of Medium-rise Building by Bus and Subway-induced Vibration)

  • 윤성원
    • 한국공간구조학회논문집
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    • 제7권4호
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    • pp.97-104
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    • 2007
  • 교통진동의 영향을 받는 중층건물의 진동특성에 관한 논문이다. 현장진동계측은 진동원과 진동감소대책을 위하여 실시되었다. 시간영역 진동데이터는 버스와 지하철로 인한 건물에 전달된 진동 영향 등의 진동특성을 위하여 이용되었다. 진동대책을 통한 진동감소의 효과 역시 입증할 수 있었다.

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개방형 자기공명영상시스템용 경사자계코일의 새로운 설계기법 (A new gradient coil design technique for open magnetic resonance imaging systems)

  • 이수열;박부식;이정한;이완
    • 전자공학회논문지S
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    • 제34S권1호
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    • pp.72-79
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    • 1997
  • Most open magnetic resonance imaging systems have used the planar gradient coils whose inductances were minimized through the magnetic energy minimization procedure in the spatial frequency domain. Though the planar gradient coils have smaller inductance than conventional gradient coils, the planar gradient coils often suffer from their poor magnetic field linearity. Scaling the spatial frequencies of the current density function designed by the magnetic energy minimization, magnetic field linearity of the planar gradient coils can be greatly improved with small sacrifice of gradient coil inductance. We have found that the figure of merit of the planar gradient coils, defined by the gradient strength divided by the linearity error and the inductance, can be improved by proposed technique.

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Lifting Scheme을 이용한 이미지 잡음 제거 (Image Be-noising Using Lifting Scheme)

  • Park, Young-Seok;Kwak, Hoon-Sung
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.1731-1734
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    • 2003
  • In this paper, we describe an approach for image denoising using the lifting construction, with the spatial adaptive wavelet transform. The adaptive lifting scheme is implemented in spatial domain to be adjusted thresholds to reduce noise. In this approach we represent adaptive characteristics of biorthogonal wavelets for choosing predictors effectively. Predict filter is changed from sample to sample according to local signal features with their vanishing moments. We in this approach have implemented and applied to image denoising by finding a relevant minimax threshold. Experimental results show that the adaptive method of denoising process is compared with existing ones, such as non-adaptive wavelet, CRF(13, 7) and SWE(13, 7) wavelets used by JPEG2000.

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일차원 웨이브렛 변환을 이용한 광학기기의 자동 초점 조절에 관한 연구 (Development of a Wavelet Based Optical Instrument Autofocusing algorithm)

  • 박봉길;김세훈;김윤수;박상희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.603-605
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    • 1997
  • A new algorithm using 1-dimensional wavelet transform for autofocusing of optical instrument has been developed. Previous studies based on the conventional frequency analysis have shown that as the lens-object distance approaches the optimum value, the high frequency energy in the corresponding image shows a consistent increase. However, as conventional frequency analysis techniques hide spatial distribution of each band energy, shape information in the original signal cannot be easily utilized. In this paper, a newly devised wavelet based focus measuring scheme is presented. Unlike other frequency domain analysis techniques that simply produce "frequency-only" spectra, wavelet analysis provides a "time-frequency" localized view of a given signal. As a result, both frequency band filtering and spatial distribution filtering can easily be realized. Depending on the proposed focus quality measuring algorithm, a fast and reliable automatic focus adjustment of optical devices could be implemented.

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