• Journal for History of Mathematics
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• v.22 no.3
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• pp.273-292
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• 2009

According to historical commentators such as Newton and Einstein, bodily behaviors are causally explained by the geometrical structure of space-time whose existence analogous to that of material substance. This essay challenges this conventional wisdom of interpreting space-time geometry within both Newtonian and Einsteinian physics. By tracing recent historical studies on the interpretation of space-time geometry, I defends that space-time structure is a by-product of a more fundamental fact, the laws of motion. From this perspective, I will argue that the causal properties of space-time cannot provide an adequate account of the theory-change from Newtoninan to Einsteinian physics.

• The KIPS Transactions:PartD
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• v.16D no.2
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• pp.237-248
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• 2009

Recently, based on dynamic location or mobility of moving object, many researches on pattern mining methods actively progress to extract more available patterns from various moving patterns for development of location based services. The performance of moving pattern mining depend on how analyze and process the huge set of spatio-temporal data. Some of traditional spatio-temporal pattern mining methods[1-6,8-11]have proposed to solve these problem, but they did not solve properly to reduce mining execution time and minimize required memory space. Therefore, in this paper, we propose new spatio-temporal pattern mining method which extract the sequential and periodic frequent moving patterns efficiently from the huge set of spatio-temporal moving data. The proposed method reduces mining execution time of $83%{\sim}93%$ rate on frequent moving patterns mining using the moving sequence tree which generated from historical data of moving objects based on hash tree. And also, for minimizing the required memory space, it generalize the detained historical data including spatio-temporal attributes into the real world scope of space and time using spatio-temporal concept hierarchy.

• Proceedings of the KGS Conference
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• 2003.11a
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• pp.144-148
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• 2003

1) 연구의 배경와 목적 정보통신기술의 비약적 발전은 공간이동에 있어서 '거리' 개념의 근본적인 변화를 가져오고 있다. 흔히 '시간에 의한 공간소멸' 또는 '시공간 압축'이라고 표현되는 그와 같은 변화는 일상적 생활공간에서뿐만 아니라 전지구적 범위에 이르기까지 장소와 장소, 지역과 지역 간에 발생하는 정보의 흐름을 실시간(real time)으로 연결한다. 그러나 정보통신기술의 발달이 장소와 장소, 지역과 지역 간에 발생하는 모든 통행을 대체하지는 못한다. (중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.2
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• pp.209-215
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• 2020

In order to understand the characteristics of natural droughts, it is very important to interpret the spatio-temporal relationship between different types of droughts. In this study, meteorological and hydrological drought events were defined to account for the overlap between drought duration and spatial extent in three dimensions (i.e., latitude, longitude, and timing). In other words, the spatio-temporal drought propagation characteristics were analyzed based on the drought characteristic factors (duration, area, depth, center). The drought map considering the characteristics of spatio-temporal drought propagation can be used to find the fundamental cause of the hydrological drought which is expected to frequently occur in the future. In addition, the drought map is expected to be useful in preparing an effective drought response plan.

• Journal of the Korean Geographical Society
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• v.40 no.3 s.108
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• pp.310-320
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• 2005

This study attempts at prototyping and evaluating a geovisualization tool that summarizes and explores human activity patterns using spatio-temporal trajectory data collected from GPS receiver. A set of core conceptualization developed in 'time geography' is successfully represented by our prototype based on the notion of 'space-time cube.' The notions of 'temporal dispersion cylinder' and 'parallel plane plot' are also implemented to allow funker analyses of human activity pattern on the space-time trajectory. The capabilities of the geovisualization environment we proposed include the interactive and dynamic functions that support a variety of explorations on the three components of spatio-temporal data : space(where), time(when), and object(what).

• Journal of Korea Spatial Information System Society
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• v.6 no.2 s.12
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• pp.51-62
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• 2004

Recently, the location-based service for moving customers is becoming one of the most important service in mobile communication area. For moving object applications, there are lots of update operations and such update loads are concentrated on some particular area unevenly. The primary processing of LBS application is spatio-temporal range queries. To improve the throughput of spatio-temporal range queries, the time of disk I/O in query processing should be reduced. In this paper, we adopt non-uniform two-level grid index structures of GALIS architecture,which are designed to minimize update operations. We propose query scheduling technique using spatial relationship and time relationship and a combined spatio-temporal query processing method using time zone concepts to improve the throughput of query processing. Some experimental results are shown for range queries with different query range to show the performance tradeoffs of the proposed methods.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.1
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• pp.35-40
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• 2005

Recently, the location based service for moving customers is becoming one of the most important service in mobile communication area and for moving object applications, there are lots of update operations and such update loads are concentrated on some particular area unevenly. The primary processing of LBS application is spatio-temporal range queries and to improve the throughput of spatio-temporal range queries, the time of disk I/O in query processing should be reduced. In this paper, we adopt non-uniform two-level grid index structure, which are designed to minimize update operations. We propose query scheduling technique using spatial relationship and time relationship and a combined spatio-temporal query processing method using time zone concepts to improve the throughput of query processing. Some experimental results are shown for range queries with different query range to show the performance tradeoffs of the proposed methods.

• Journal of Korea Water Resources Association
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• v.45 no.10
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• pp.1069-1079
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• 2012

In this study, to analyze travelling route and transition characteristics which is a spatial time interpretation method now actively progressed in domestic as well as abroad, it was intended to develop new drought interpretation technique which can decide the centroid and orbit of drought through assuming ellipse using Mass Moment concept. First of all, after estimating Standard Precipitation Index (SPI) per different precipitation observatory station to extract drought events, by selecting precipitation sites where drought starting and end point are same, these were categorized as CASE. As a results, with various CASE selections falling in specific duration for monthly drought analysis, it is possible to find out drought area that additionally occurred, and drought reliving process could be confirmed more definitely. Therefore, if the research methods adopted in this study for drought monitoring are utilized, not only accurate spatio-temporal drought analysis is possible, also pattern of drought centroid movement can be analyzed by establishing statistically significant spatial characteristics data after separating all the drought events that occurred sporadically in Korea Peninsula.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.434-434
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• 2011

가뭄은 홍수와는 달라서 정확한 발생시점, 지속시간, 피해반경 등을 정의하기 어렵다. 가뭄은 가뭄지수를 통해서 정의되며 정해진 지속시간에 따라서 가뭄의 특성을 평가하는 것이 일반적이다. 이러한 가뭄의 심도를 평가하기 위해서 많이 사용되는 지수로 표준강수지수(standardized precipitation index)가 있다. 본 연구에서는 6개월 지속시간에 SPI 지수를 대상으로 연구를 수행하였다. 최근 가뭄연구에서 시공간적 거동을 평가하는 연구가 중요한 연구주제로 자리 잡고 있다. 가뭄은 홍수와는 달리 공간적으로 전이되는 특성을 가지고 있어서 가뭄의 시작점과 영역반경을 평가하는 것은 가뭄을 예측하는데 있어서 기본적으로 선결되어야 한다. 그러나 상대적으로 가뭄의 시공간적 분석 연구는 많이 진행되지 않았다. 본 연구에서는 질량모멘트 개념을 도입하여 가뭄의 중심과 영역을 평가하는 기법을 개발하였다. 가뭄의 중심(centroid)은 1차모멘트를 통해서 추정되며 가뭄의 영역은 2차모멘트 즉, x방향의 공분산, y방향의 공분산, xy의 공분산을 통해서 타원(ellipse)형태로 수치적 접근이 가능하다. 다음 그림과 같이 가뭄의 중심을 1차모멘트로 추정하게 되면 +형태로 표시될 수 있으며 분산을 타원체로 표현하여 가뭄의 영역을 정의할 수 있다. 1, 2차모멘트를 추정하는데 있어서 Threshold 로 -2.0 이하의 값만을 이용하였으며 각 격자별 SPI 강도를 가중인자로 이용하였다. 그림과 같이 가뭄이 서해안에서 시작되어 시간에 따라 중동부로 퍼져나가는 것을 정량적으로 확인할 수 있다. 본 모형을 통해서 추출된 1, 2차 모멘트 정보를 활용하여 가뭄의 특성을 범주화하고 이를 기상학적 특성과 연결시키면 기상특성을 고려한 가뭄 예측모형으로의 개발도 가능할 것으로 판단된다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1083-1097
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• 1998

The conventional geographic information systems(GIS) is a software which handles spatial and aspatial information of objects in the real world. The system can not support users time-varying information because it manipulates their snapshot data in the spatial database. Also even though it supports time-varying information, it is very limited and hs many difficulties in presenting and processing queries. This paper therefore describes an integrated spatiotemporal data model using loosely-coupled approach which is extended a time dimension for the previous spatial database and which handles time-varying historical information of spatial objects. Conclusionally this paper not only designed a data structure for spatiotemporal database, but also implemented spatial comparison operations varying over time.