• Title/Summary/Keyword: spatiotemporal changes

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Design of a spatiotemporal object model for 2D geographic objects (2차원 지리 객체를 위한 시공간 객체 모델 설계)

  • Lee, Hyeon-Ah;Nam, Kwang-Woo;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.9D no.1
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    • pp.43-56
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    • 2002
  • Most of works have been performed on representation of spatiotemporal objects from various points of view. Most of them represent spatiotemporal objects using approaches from GIS, temporal databases, object-oriented databases or data type. Spatiotemporal objects can be classified as objects whose position and shape changes discretely over time, objects whose position changes continuously and objects whose shape changes continuously as well as position. Previous works on spatiotemporal model have focused on only one of them. In this paper, we propose a spatiotemporal model that can represent three types of objects in Euclidean plan. For this purpose, we represent both discrete and continuous moving objects by defining temporal model extended from valid time and by defining relationship between two consecutive versions of objects. The proposed spatiotemporal object model is based on open GIS specification so that it has compatibility with existing spatial data model.

Multidimensional Model for Spatiotemporal Data Analysis and Its Visual Representation (시공간데이터 분석을 위한 다차원 모델과 시각적 표현에 관한 연구)

  • Cho Jae-Hee;Seo Il-Jung
    • Journal of Information Technology Applications and Management
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    • v.13 no.1
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    • pp.137-147
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    • 2006
  • Spatiotemporal data are records of the spatial changes of moving objects over time. Most data in corporate databases have a spatiotemporal nature, but they are typically treated as merely descriptive semantic data without considering their potential visual (or cartographic) representation. Businesses such as geographical CRM, location-based services, and technologies like GPS and RFID depend on the storage and analysis of spatiotemporal data. Effectively handling the data analysis process may be accomplished through spatiotemporal data warehouse and spatial OLAP. This paper proposes a multidimensional model for spatiotemporal data analysis, and cartographically represents the results of the analysis.

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Spatiotemporal characteristics of stroke patients gait (뇌졸중 환자에서 보행의 시공간적 특징)

  • Lee, Sangkwan;Choi, Sanho;Oh, Jaegun;Lee, Ilsuk;Park, Kee-eon;Hong, Haejin;Sung, Kang-keyng
    • The Journal of the Society of Stroke on Korean Medicine
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    • v.14 no.1
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    • pp.1-7
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    • 2013
  • The following study reviewed the walking patterns of stroke patients with hemiplegia, which is called hemiplegic gait of stroke patients. Focusing is given to the changes in the distance and temporal factors of walking, which is called spatiotemporal characteristics, throughout the walking cycle. First, we introduced the definitions of essential terms related to gait and its measure. Second, we reviewed the spatiotemporal characteristics of hemiplegic gait. A main issue was that hemiplegic gait showed significant deviations from normal healthy gait. Although hemiplegia is primarily associated with unilateral motor disorder, changes in almost all spatiotemporal parameters used to assess walking were evident on both the involved and uninvolved sides of the body. Last, we reviewed the changes of spatiotemporal parameters of hemiplegic gait according to the prognosis or status of stroke patients, which may help to give a specific intervention for rehabilitation of stroke.

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Spatiotemporal Changes of the Sand Barrier using Marine Charts Analysis in the Nakdong River Estuarine (해도분석을 통한 낙동강 하구 사주 면적의 시.공간 변화)

  • Yoo, Chang-Ill;Yoon, Han-Sam;Ryu, Cheong-Ro;Lee, In-Cheol
    • Journal of Ocean Engineering and Technology
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    • v.20 no.6 s.73
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    • pp.54-60
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    • 2006
  • This study discusses characteristic of spatiotemporal changes of the sand barrier in the Nakdong estuarine for the last century, focusing on geomarphologic evolution and mobility of sand barriers in the view of coastal engineering. The Nakdong estuarine, the research subject, has a complexly changing natural environment by interaction between ground and marine elements such as ocean wave, tidal current, sediment, etc. Moreover, recently, unnatural geomorphologic changes (e.g., seaside reclamation, new harbor construction, etc.) has been radically increased in this area with increasing desire for coastal development. Because of this, its sand barrier has developed quite unstable condition. Therefore, to identify the development process of geomorphologic changes in this area, required is a close examination on historical characteristics of spatiotemporal changes of the sand barrier in relation to surrounding seaside reclamation and physical environmental changes. This study, based on the marine charts published in between 1927 and 1995 year, analyzes the length and area of the sand barrier for the last hundred years, and investigates the cause of the changes by looking into the change of water depth for the last two years and doing ocean-physical site observations. In conclusion, the sand barrier of the Nakdong estuarine expands toward the open sea by $7.4{\sim}26m$ in annual average, maintaining a fixed distance of $1,241{\sim}1.279m$, and its area is expected to increase about $2.8km^2$ annually. This is characterized by the wocean wave from the open sea and the discharge of Nakdong River.

Algorithm for Topological Relationship On an Indeterminate Spatiotemporal Object (불확실한 시공간 객체에 관한 위상 관계 알고리즘)

  • Ji, Jeong-Hui;Kim, Dae-Jung;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.10D no.6
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    • pp.873-884
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    • 2003
  • So far, significant achievements have been studied on the development of models for spatial and spatiotemporal objects with indeterminate boundaries which are found in many applications for geographic analysis and image understanding. Therefore, in this paper we propose the spatiotemporal data model which is applicable for spatial and spatiotemporal objects with uncertainty. Based on this model, we defined topological relationships among the indeterminate spatiotemporal objects and designed the algorithm for the operations. For compatibility with existing spatial models, the proposed model has been designed by extending the spatiotemporal object model which is based on the open GIS specification. We defined indeterminate spatial objects, such as the objects whose position and the shape change discretely over time, and the objects whose shape changes continuously as well as the position. We defined topological relationships among these objects using the extended 9-IM. The proposed model can be efficiently applied to the management systems of natural resource data, westher information, geographic information. and so on.

Monitoring of the Changes of Tidal Land at Simpo Coast with Sea Surface inside Saemangeum Embankment Using Multi-temporal Satellite Image (다중시기 위성영상을 이용한 새만금 방조제 내측 해수면에 의한 심포항 연안의 간석지 지형 변화 탐지)

  • Lee, Hong-Ro;Lee, Jae-Bong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.1
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    • pp.13-22
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    • 2005
  • This paper classifies the topography of the Saemangeum Tidal flats based on Landsat TM satellite images by unsupervised ISODATA method, and analysis of the spatiotemporal changes of the classified shapes. The sedimental topography represents various properties according to the Saemangeum Tidal Embankment progress. We well proceed this study of the sedimental changes and distributions. By specifying the topographic characteristics of inner sea areas respectively, the investigation on the case study area according to the changes of the tidal will be useful in the establishment of land reclamation plan and the land use of the reclaimed area. In addition, the estuary image can be divided into tidal flats and sea surfaces using the band 4, also the detailed topography using the band 5, respectively among Landsat TM 7 bands. This paper contributes to the efficient image processing of the spatiotemporal sedimental changes.

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A Study on Surrealistic Design by Apporaches to Spatiotemporal Idealism (시간과 공간의 관념론적 접근을 통한 초현실주의적 디자인에 관한 연구)

  • 김정아
    • Korean Institute of Interior Design Journal
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    • v.13 no.1
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    • pp.46-53
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    • 2004
  • This study has importance of that it verifies applicability of a new interpretation of surrealism to spatial design. Transcendental cognitive form of idealism, concept of time and space are premise of reality and surreality is finally condensed to the matter of time and space. Surrealistic techniques are automatic description, double association, montage and etc, and all of them are trials to approach to essence of images expressing unconsciousness through spatiotemporal changes of object. The purpose of this study is to find the surrealistic methods that can be applied to spatial design.

A Space-Time Model with Application to Annual Temperature Anomalies;

  • Lee, Eui-Kyoo;Moon, Myung-Sang;Gunst, Richard F.
    • Communications for Statistical Applications and Methods
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    • v.10 no.1
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    • pp.19-30
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    • 2003
  • Spatiotemporal statistical models are used for analyzing space-time data in many fields, such as environmental sciences, meteorology, geology, epidemiology, forestry, hydrology, fishery, and so on. It is well known that classical spatiotemporal process modeling requires the estimation of space-time variogram or covariance functions. In practice, the estimation of such variogram or covariance functions are computationally difficult and highly sensitive to data structures. We investigate a Bayesian hierarchical model which allows the specification of a more realistic series of conditional distributions instead of computationally difficult and less realistic joint covariance functions. The spatiotemporal model investigated in this study allows both spatial component and autoregressive temporal component. These two features overcome the inability of pure time series models to adequately predict changes in trends in individual sites.

A Study on Improved Split Algorithms for Moving Object Trajectories in Limited Storage Space (한정된 저장 공간상에서 이동 객체 궤적들에 대한 개선된 분할 알고리즘에 관한 연구)

  • Park, Ju-Hyun;Cho, Woo-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.9
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    • pp.2057-2064
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    • 2010
  • With the development of wireless network technology, the location information of a spatiotemporal object which changes their location is used in various application. Each spatiotemporal object has many location information, hence it is inefficient to search all trajectory information of spatiotemporal objects for a range query. In this paper, we propose an efficient method which divides a trajectory and stores its division data on restricted storage space. Using suboptimal split algorithm, an extended split algorithm that minimizes the volume of EMBRs(Extended Minimum Bounding Box) is designed and simulated. Our experimental evaluation confirms the effectiveness and efficiency of our proposed splitting policy

Changes in Gait Patterns after Physical Therapy in Patients with Non-specific Chronic Low Back Pain: a Pilot Study

  • Song, Seonghyeok;Cho, Namjeong;Kim, Hyun-Joong
    • Physical Therapy Rehabilitation Science
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    • v.11 no.1
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    • pp.105-112
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    • 2022
  • Objective: Nonspecific low back pain (NS-LBP) causes pain and disability, affecting the neuromuscular system and altering gait patterns. The purpose of this study is to investigate the effect of improvement of low back pain symptoms through physical therapy on foot pressure and spatiotemporal gait parameters. Design: A pilot study. Methods: Participants received manual therapy and supervised therapeutic exercise, which consisted of 12 sessions for 6 weeks. Participants were assessed for pain intensity (a numeric pain rating scale), disability index (oswestry disability index), and spatiotemporal gait parameters before and after intervention. Wilcoxon signed rank test was used to analyze the before-and-after differences in a single group. Results: All seven NS-LBP patients completed the study without dropout. After six weeks of physical therapy, the numeric pain rating scale and oswestry disability index showed significant improvement (Z= -2.388, P=0.017). There was no significant improvement in both static and dynamic conditions in foot pressure (P>0.05). However, in the spatiotemporal gait parameters, there were significant differences in all variables except the right stance phase and left mid stance (P<0.05). Conclusions: In our pilot study, 12 sessions of physical therapy in NS-LBP patients improved gait quilty in spatiotemporal gait parameters. Similarly, it has resulted in clinically positive improvements in pain and disability.