• Title/Summary/Keyword: time-spatial distribution

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Grid-Based Soil-Water Erosion and Deposition Modeling sing GIS and RS

  • Kim, Seong-Joon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2001.05a
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    • pp.25-34
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    • 2001
  • A grid-based KIneMatic wave soil-water EROsion and deposition Model (KIMEROM) that predicts temporal variation and spatial distribution of sediment transport in a watershed was developed. This model uses ASCII-formatted map data supported from the regular gridded map of GRASS (U.S. Army CERL, 1993)-GIS (Geographic Information Systems), and generates the distributed results by ASCIIl-formatted map data. For hydrologic process, the kinematic wave equation and Darcy equation were used to simulate surface and subsurface flow, respectively (Kim, 1798; Kim et al., 1993). For soil erosion process, the physically-based soil erosion concept by Rose and Hairsine (1988) was used to simulate soil-water erosion and deposition. The model adopts sing1e overland flowpath algorithm and simulates surface and subsurface water depth, and sediment concentration at each grid element (or a given time increment. The model was tested to a 162.3 km$^2$ watershed located in the tideland reclaimed area of South Korea. After the hydrologic calibration for two storm events in 1999, the results of sediment transport were presented for the same storm events. The results of temporal variation and spatial distribution of overland flow and sediment areas are shown using GRASS.

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The Spatial Distribution of the Ancient Liaoze in the Lower Reach of Liao River and Shoreline Change Since the Middle Holocene in China (중국 요하 하류부 고대 요택의 공간 분포와 Holocene 중기 이후 해안선 변화)

  • Yoon, Soon-Ock;Kim, Hyoseon;Jia, Jienqing;Bok, Gi-dae;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.1
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    • pp.51-62
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    • 2017
  • Liao River with the largest basin area in the northeastern part of China has constructed huge floodplain along the lower reach. Especially a vast marsh was developed around estuaries and coastline near Liaodong Bay. The marsh was called as Yotaek(or Liaoze) before the modern time, which is meaningful for understanding human life since prehistorian times. By the analysis of historical documents and geomorphic data, it can be assumed that the height of Yotaek of landward boundary reached 20~30m from Heishan to Liaoyang during Han dynasty. The shoreline of 7,000 yr BP is estimated to coincide with the contour line between 20m and 30m at present. And the ancient shoreline during Christ era indicates 10m.a.s.l., which is corresponding to the seaside boundary of the Yotaek. The shoreline of Liaodong Bay was progressed seaward 30km/ka during 1000~1100 AD, while 10~40km/ka during late 19 century ~ early 20 century.

A Numerical Study on Characteristics of Solute Transport in a Rough Single Fracture with Spatial Correlation Length and Effect of Effective Normal Stress (공간적 상관길이와 유효수직응력의 효과에 따른 거친 단일 균열내의 용질이동특성에 관한 수치적 연구)

  • Jeong, Woochang
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.1
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    • pp.5-14
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    • 2009
  • This study is to analyze numerically the spatial behaviors of the solute transport in a spatially correlated variable-aperture fracture under the effective normal stress conditions. Numerical results show that the solute transport in a fracture is strongly affected by the spatial correlation length of apertures and applied effective normal stress. According to increasing spatial correlation length, the mean residence time of solute is decreased and the tortuosity and Peclet number (is a dimensionless number relating the rate of advection of a flow to its rate of diffusion) is also decreased. These results mean that the geometry of the aperture distribution is favorable to the solute transport as the spatial correlation length is increased. However, according to the applied effective normal stress is increased, the mean residence time and tortuosity have a tendency to increase but the Peclet number is decreased. The main reason that the Peclet number is decreased, is that the solute is displaced by one or two channels with relatively higher local flow rate due to the increment of contact areas by increasing effective normal stress. Moreover, based on numerical results of the solute transport in this study, the exponential-type correlation formulae between the mean residence time and the effective normal stress are proposed.

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A Study on the Spatial Allocation Planning of Dental Care Departments in Dental Hospital in Korea (한국 치과병원내 진료과목의 공간배분계획에 관한 연구)

  • Jeong, Taejong;Choi, Jaepil
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.4
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    • pp.27-36
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    • 2017
  • Purpose: The characteristics of spatial allocation planning in dentistry through examining the dental hospitals in Korea and comparison between them are necessary for the development of planning of the dental healthcare system. This study has been started to provide basic informations such as zoning, allocation distribution, and space configuration for the planning of dental hospital architecture. Methods: Literature review of dental care departments and investigation on current status of dental hospital in Korea have been conducted. The spatial allocation and space configuration of eleven dental hospitals have been analyzed. Results: The result of this study can be summarized in three points. The first one is that dental hospitals in Korea are consisted with eight to eleven dental care departments and they are divided with the horizontal allocation type with three to four departments in a floor for the spatial communication or the vertical allocation type with a department in each floor for the independent space. The second one is that oral medicine and oral maxillofacial radiology are located near the main entrance, orthodontics and pedodontic dentistry in lower level, prosthodontics in upper level, and conservative dentistry and periodontics have no specific spatial consideration. The third one is that the factors to consider the allocation planning are zoning for examination & diagnosis, basic practice, adolescence, surgery, circulations for patient, dentist, staff, different access for department like as easy access for reception and pedodontic dentistry, enclosure space for prosthodontics and surgery, frequency of visit and treatment care time, and change of treatment concept from treatment department to disease control corporative practice. Implications: This study is the starting point for the research of spatial configuration in dentistry and it is necessary to analyze the architectural planning to develop the dental healthcare system.

Knowledge Structures to Simulate the Spatial Behavior of Intelligent Virtual Humans (지능형 가상인간의 공간적 행동을 모사하기 위한 지식구조)

  • Hong, Seung-Wan;Park, Jong-Hee
    • The Journal of the Korea Contents Association
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    • v.20 no.12
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    • pp.230-240
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    • 2020
  • To develop a virtual world-based immersive tutoring system, we would like to develop a simulation in the spatial aspect to maximize the diversity and realism of the situation. This implementation requires the modeling of virtual space as well as the knowledge and intelligent thinking functions of virtual humans. First, information structures are needed to simulate the hierarchical and multifaceted composition of space and the corresponding knowledge of virtual humans. Specifically, four structures for 2.5D spatial distribution expression, complex spatial relationship expression, object expression, and temporal and spatial representation of events are developed respectively. It then uses these expressed knowledge to develop the spatial thinking function of virtual humans needed to make spatial movement. In general, events have a chain effect on adjacent or connected objects through force, resulting in a variety of situations and reflected in the planning of the next action by the virtual humans involved. For this purpose, the development of events according to historical trends is recorded on the representation structure of time and space. It embodies typical events to demonstrate the feasibility of independent behavior in complex spaces among virtual people.

Spacial and Time Distribution Feature of Temperature Data in USN Based Fire Detectors (USN기반의 화재 온도 데이터의 시.공간 분포특성 분석)

  • Choi, Kap-Yong;Um, Jung-Sup
    • Fire Science and Engineering
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    • v.23 no.2
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    • pp.41-48
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    • 2009
  • In this paper, to overcome the limitation of the existing wired fire sensors and alert facilities, the real-time temperature data collected from the fire detectors applied USN is analyzed the time series and spacial features of temperature inside building using the GIS spatial modeling method. Resulting from the analysis of the distribution features by the spacial location and time series, the temperature sensors applied USN is installed by the consideration of the spacial structures features. This paper will suggest the objective and practical guideline of installation of fire sensors applied USN.

A Study on the Real-Time Temperature and Concentration Measurement of Combustion Pipe Flow Field (연소 배관 유동장의 실시간 온도, 농도 측정에 관한 연구)

  • Hong, Jeong Woong;Yoon, Sung Hwan;Jeon, Min Gyu
    • Journal of the Korean Society of Visualization
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    • v.20 no.2
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    • pp.86-92
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    • 2022
  • Pipe failure due to thermal fatigue and environmental regulations are increasing the importance of pipe monitoring systems in industrial plants. Since most pipe monitoring systems are focus on external crack inspected, it is necessary to temperature and concentration measuring monitoring system inside the pipe. These systems have spatial uncertainty due to sample inspection by one-point measurement. In addition, real-time measurement is not possible due to the limitation of time delay due to contact measurement. In this study, CT-TDLAS (Computed tomography-Tunable diode laser absorption spectroscopy) apply to overcome the limitations of existing methods. Lasers exhibiting an absorption response at a wavelength of 1395 nm were arranged in a lattice pattern on measuring cell. It showed that the inside of the pipe changed to an unstable combustion state over time.

Spatial View Materialization Technique by using R-Tree Reconstruction (R-tree 재구성 방법을 이용한 공간 뷰 실체화 기법)

  • Jeong, Bo-Heung;Bae, Hae-Yeong
    • The KIPS Transactions:PartD
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    • v.8D no.4
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    • pp.377-386
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    • 2001
  • In spatial database system, spatial view is supported for efficient access method to spatial database and is managed by materialization and non-materialization technique. In non-materialization technique, repeated execution on the same query makes problems such as the bottle-neck effect of server-side and overloads on a network. In materialization technique, view maintenance technique is very difficult and maintenance cost is too high when the base table has been changed. In this paper, the SVMT (Spatial View Materialization Technique) is proposed by using R-tree re-construction. The SVMT is a technique which constructs a spatial index according to the distribution ratio of objects in spatial view. This ratio is computed by using a SVHR (Spatial View Height in R-tree) and SVOC (Spatial View Object Count). If the ratio is higher than the average, a spatial view is materialized and the R-tree index is re-used. In this case, the root node of this index is exchanged a node which has a MBR (Minimum Boundary Rectangle) value that can contains the whole region of spatial view at a minimum size. Otherwise, a spatial view is materialized and the R-tree is re-constructed. In this technique, the information of spatial view is managed by using a SVIT (Spatial View Information Table) and is stored on the record of this table. The proposed technique increases the speed of response time through fast query processing on a materialized view and eliminates additional costs occurred from repeatable query modification on the same query. With these advantages, it can greatly minimize the network overloads and the bottle-neck effect on the server.

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Numerical analysis of local exhaust effectiveness using reverse-flow calculation method (역유동계산법을 이용한 국소배기효율의 수치해석)

  • 한화택
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.658-665
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    • 1998
  • This paper investigates local exhaust effectiveness in a room with a supply and an exhaust slots on the ceiling. The mean age of air is an indicator of supply effectiveness, while the mean residual life time can be used as an indicator of exhaust effectiveness. The distribution of local mean residual life time in a space is calculated by four different numerical procedures. The reverse-flow calculation method has been proved to show quite accurate results while it can save considerable amount of computation time and efforts, compared to the method by its original definition. It is concluded that the diffusion term in the equation of mean residual life time can be neglected. The spatial and temporal diffusion characteristics of the contaminant are also discussed.

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Changes Over Time in the Community Structure and Spatial Distribution of Forest Vegetation on Mt. Yeompo, Ulsan City, South Korea (염포산 산림식생의 군락 구조 및 공간 분포의 경시적 변화)

  • Oh, Jeong-Hak;Kim, Jun-Soo;Cho, Hyun-Je
    • Journal of Korean Society of Forest Science
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    • v.109 no.2
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    • pp.145-156
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    • 2020
  • In 2000 and 2018, phytosociological surveys were carried out in the forest vegetation of Mt. Yeompo, a representative isolated urban forest in Ulsan city. The trends of change in forest structure, composition, and spatial distribution were compared between years. Total percent coverage per 100 squaremeters of forest vegetation was similar, but natural vegetation showed a 9% increase. The importance of constituent species changed slightly. Specifically, Lindera erythrocarpa and Styrax japonicus showed very high growth rates of 835% and 269%, respectively. Species richness (S) and diversity (H') decreased by about 22% and 8%, respectively. Both S and H' showed slightly higher rates of decrease in artificial compared with natural vegetation. The constituent species life form spectrums were the same in 2000 and 2018 as 'MM-R5-D4-e'. The similarity (Jaccard coefficient) in the species composition of the forest vegetation was almost homogeneous at approximately 75%. The number of indicator species decreased from 16 species in 2000 to 7 species in 2018. This decrease was mostly due to a decline in herbaceous plants, such as Hemicryptophytes, Geophytes, and Therophytes, which are sensitive to disturbances. The spatial distribution of forest vegetation did not change significantly. The number of forest landscape elements (patches) increased by approximately 25% from 537 in 2000 to 721 in 2018, while the average size decreased by about 20% from 1.28 ha in 2000 to 1.03 ha in 2018.