• Title/Summary/Keyword: Spatial Pattern

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Comparative Evaluation of UAV NIR Imagery versusin-situ Point Photo in Surveying Urban Tributary Vegetation (도심소하천 식생조사에서 현장사진과 UAV 근적외선 영상의 비교평가)

  • Lee, Jung-Joo;Hwang, Young-Seok;Park, Seong-Il;Um, Jung-Sup
    • Journal of Environmental Impact Assessment
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    • v.27 no.5
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    • pp.475-488
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    • 2018
  • Surveying urban tributary vegetation is based mainly on field sampling at present. The tributary vegetation survey integrating UAV NIR(Unmanned Aerial Vehicle Near Infrared Radiance) imagery and in-situ point photo has received only limited attentions from the field ecologist. The reason for this could be the largely undemonstrated applicability of UAV NIR imagery by the field ecologist as a monitoring tool for urban tributary vegetation. The principal advantage of UAV NIR imagery as a remote sensor is to provide, in a cost-effective manner, information required for a very narrow swath target such as urban tributary (10m width or so), utilizing very low altitude flight, real-time geo-referencing and stereo imaging. An exhaustive and realistic comparison of the two techniques was conducted, based on operational customer requirement of urban tributary vegetation survey: synoptic information, ground detail and quantitative data collection. UAV NIR imagery made it possible to identify area-wide patterns of the major plant communities subject to many different influences (e.g. artificial land use pattern), which cannot be acquired by traditional field sampling. Although field survey has already gained worldwide recognition by plant ecologists as a typical method of urban tributary vegetation monitoring, this approach did not provide a level of information that is either scientifically reliable or economically feasible in terms of urban tributary vegetation (e.g. remedial field works). It is anticipated that this research output could be used as a valuable reference for area-wide information obtained by UAV NIR imagery in urban tributary vegetation survey.

Interactions between Soil Moisture and Weather Prediction in Rainfall-Runoff Application : Korea Land Data Assimilation System(KLDAS) (수리 모형을 이용한 Korea Land Data Assimilation System (KLDAS) 자료의 수문자료에 대한 영향력 분석)

  • Jung, Yong;Choi, Minha
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.172-172
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    • 2011
  • The interaction between land surface and atmosphere is essentially affected by hydrometeorological variables including soil moisture. Accurate estimation of soil moisture at spatial and temporal scales is crucial to better understand its roles to the weather systems. The KLDAS(Korea Land Data Assimilation System) is a regional, specifically Korea peninsula land surface information systems. As other prior land data assimilation systems, this can provide initial soil field information which can be used in atmospheric simulations. For this study, as an enabling high-resolution tool, weather research and forecasting(WRF-ARW) model is applied to produce precipitation data using GFS(Global Forecast System) with GFS embedded and KLDAS soil moisture information as initialization data. WRF-ARW generates precipitation data for a specific region using different parameters in physics options. The produced precipitation data will be employed for simulations of Hydrological Models such as HEC(Hydrologic Engineering Center) - HMS(Hydrologic Modeling System) as predefined input data for selected regional water responses. The purpose of this study is to show the impact of a hydrometeorological variable such as soil moisture in KLDAS on hydrological consequences in Korea peninsula. The study region, Chongmi River Basin, is located in the center of Korea Peninsular. This has 60.8Km river length and 17.01% slope. This region mostly consists of farming field however the chosen study area placed in mountainous area. The length of river basin perimeter is 185Km and the average width of river is 9.53 meter with 676 meter highest elevation in this region. We have four different observation locations : Sulsung, Taepyung, Samjook, and Sangkeug observatoriesn, This watershed is selected as a tentative research location and continuously studied for getting hydrological effects from land surface information. Simulations for a real regional storm case(June 17~ June 25, 2006) are executed. WRF-ARW for this case study used WSM6 as a micro physics, Kain-Fritcsch Scheme for cumulus scheme, and YSU scheme for planetary boundary layer. The results of WRF simulations generate excellent precipitation data in terms of peak precipitation and date, and the pattern of daily precipitation for four locations. For Sankeug observatory, WRF overestimated precipitation approximately 100 mm/day on July 17, 2006. Taepyung and Samjook display that WRF produced either with KLDAS or with GFS embedded initial soil moisture data higher precipitation amounts compared to observation. Results and discussions in detail on accuracy of prediction using formerly mentioned manners are going to be presented in 2011 Annual Conference of the Korean Society of Hazard Mitigation.

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Relationship between Squid (Todarodes pacificus) Catch by Sea Block and Marine Environment in the East Sea during 1980s and 1990s (1980-1990년대 동해에서 해구별 오징어(Todarodes pacificus) 어획량과 해양환경의 관계)

  • Kim, Yoon-Ha;Moon, Chang-Ho;Choi, Kwang-Ho;Lee, Chung-Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.3
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    • pp.259-268
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    • 2010
  • Data on squid catches by the Korean jig fishery in sea blocks ($30'{\times}30'$), water temperatures at depth(30m, 50m and 100m) and zooplankton biomass in the East Sea from 1980 to 1999 were analyzed to examine the mechanism of formation of the high density stock area. Japanese common squid (Todarodes pacificus) catch in the East Sea was low in 1980s, while the catch was high in 1990s. The five sea blocks (No. 76, 82, 83, 87, 88) of the southern part in the eastern coastal waters of Korea showed high levels of percentage of total catch (35.1%), whereas the four sea blocks (No. 65, 71, 72, 78) of the coastal waters of Uleung Island showed high levels of percentage of CPUE (61.2%) for 20 years. Squid catches showed monthly fluctuations according to the vertical distribution of optimum water temperature for fishing ($14^{\circ}C{\sim}19^{\circ}C$). High total catch and high CPUE area matched well with $10^{\circ}C$ isothermal lines at 100m depth indicating northern limiting of Tsushima Warm Current, and temporal and spatial change in $10^{\circ}C$ isothermal line caused the change in total catch and CPUE. Horizontal distribution of zooplankton biomass by sea block was not matched well with those of total catch and CPUE, however pattern of time-series change in total zooplankton biomass was similar to that in total squid catch.

$N_2O$ Emissions with Different Land-Use Patterns in a Basin (유역 내 토지이용도에 따른 $N_2O$ 배출양상)

  • Seo, Ju-Young;Kang, Ho-Jeong
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.2
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    • pp.86-90
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    • 2012
  • The gaseous product of nitrogen cycle, nitrous oxide ($N_2O$) is a potent greenhouse gas whose Global Warming Potential (GWP) is about 300 times greater than $CO_2$. The dynamics of $N_2O$ emission are controlled by such environments and soil conditions. The main aim of this study is to investigate variations of $N_2O$ emission and its controlling factors with different land-use patterns in Haean basin. A forest, a radish field and a rice paddy were selected as three different land-use patterns. Their $N_2O$ emissions were measured every month during a growing season. We also collected soil samples with seasons and analyzed soil characteristics including inorganic nitrogen content. $N_2O$ emission was greatest at the radish field likely due to anthropogenic nitrogen addition by fertilization. Soils of forest and rice paddy also contained inorganic nitrogen originated from organic matter. However, the spatial variation was great and it looks that nitrogen cycle and $N_2O$ production were slower than that of radish field. Intensive observation and control of fertilization would be requiredto adjust $N_2O$ emission from agriculture soils.

The Influence of Information Commons on User Traffic Patterns and Perceptions of the Library (정보공유공간이 이용자 유동패턴과 도서관인식에 미치는 영향)

  • Park, Ji-Hong;Park, Jinhee;Nam, Eunkyung;Lee, Seoha
    • Journal of the Korean Society for information Management
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    • v.30 no.4
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    • pp.93-110
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    • 2013
  • During the last decade, increasing use of technology that facilitates information access has changed academic library services. The emergence of information commons is one of the key changes. Most previous studies on information commons have focused on its conception and role. Whereas, considering information commons as a spatial service, this study aims to examine the influence of information commons on user traffic patterns within the library and perception of the library. As the information commons grew into main library service space and facility, it is necessary to explore what influences information commons have on the behavior and recognition of users. Two methods were used. First, observation method was used to record traffic pattern and user behavior. Second, twenty undergraduates and twelve graduates were interviewed regarding the use and recognition of the information commons and the library. The results of the study show that the traffic patterns were different between undergraduate students and graduate students; the location and structure of facilities influences their movement and behaviors; and the recognition of information commons tends to affect the perception of the entire library. The findings may help librarians improve and plan for library spaces to meet user demands.

Sea, wind, or bird: Origin of Fagus multinervis (Fagaceae) inferred from chloroplast DNA sequences (엽록체 염기서열을 통한 너도밤나무(너도밤나무과)의 기원 추론)

  • Oh, Sang-Hun
    • Korean Journal of Plant Taxonomy
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    • v.45 no.3
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    • pp.213-220
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    • 2015
  • To elucidate the origin and patterns of establishment of insular plants on Ulleungdo Island, maternally inherited chloroplast DNA, which is useful for tracing seed movements, was used. Fagus multinervis, an endemic species that dominated broadleaf deciduous forests on Ulleungdo Island, is an excellent model for such a study. To understand the diversity and spatial distribution of the chloroplast haplotypes of F. multinervis, nucleotide sequences of the psbA-trnH region were determined from 144 individuals sampled throughout the island. Results of a phylogenetic analysis of the region with close relatives of F. multinervis suggest that F. multinervis is sister to a clade of F. japonica and F. engleriana. No haplotype variation was found within F. multinervis. This remarkably low cpDNA haplotype diversity is in contrast to the findings of previous allozyme studies of F. multinervis populations that showed high genetic diversity on Ulleungdo Island. Repeated colonization during the early stage of establishment via birds that migrated from a source area where the F. multinervis cpDNA haplotype was geographically structured may have resulted in the observed pattern of haplotype diversity. Alternatively, long-distance dispersal of seeds of the progenitor of F. multinervis via birds or typhoons to Ulleungdo may have been a single event, whereas the immigration of pollen from the mainland likely occurred frequently. Comparative phylogeographic studies of other species endemic to Ulleungdo Island and their close relatives on the neighboring mainland are necessary for a more complete understanding of the evolution of the island's native species.

Classification of Sedimentary Facies Using IKONOS Image in Hwangdo Tidal Flat, Cheonsu Bay (IKONOS 영상을 이용한 천수만 황도 갯벌 표층 퇴적상 분류)

  • Ryu, Joo-Hyung;Woo, Han Jun;Park, Chan-Hong;Yoo, Hong-Rhyong
    • Journal of Wetlands Research
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    • v.7 no.2
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    • pp.121-132
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    • 2005
  • To classify the surface sedimentary facies using IKONOS image collected over Hwangdo tidal flat in Cheonsu Bay, the optical reflectance was compared for characterizing various sedimentary environments such as grain size, tidal channel pattern and area ratio of surface remnant water. The intertidal DEM (Digital Elevation Model) was generated by echo-sounder for analyzing the relationship between IKONOS image and sedimentary environments including topography. The boundary of the optical reflectance between mud-mixed facies and sand facies was distinct, and discrimination of the associated sandbar feature was also possible. The mud-mixed facies coupled with intricate tidal channels is confined to the relatively hi호 topography of Hwangdo tidal flat. The boundary between mud and mixed flat was indistinct in IKONOS optical reflectance but it would have a difference in the area ratio of surface remnant water. The dark area in the image represented the well developed sand facies having a lot of surface remnant water due to the relatively low surface topography. The overall accuracy of characterizing the surface sediment facies by maximum likelihood classification method was 86.2 %. These results demonstrate that high spatial resolution satellite imagery such as IKONOS coupled with knowledge of grain size, surface remnant water and tidal channel network can be effectively used to characterize the surface sedimentary facies (mud, mixed and sand) network of the tidal flat environments.

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A Study on the Change of Urban Land Use According to the Change of Transportation Accessibility (교통 접근성 변동에 따른 도시 토지이용 변화에 관한 연구)

  • Won, Seok Hwan;Hwang, Chul-sue
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.1
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    • pp.127-142
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    • 2017
  • The purpose of this study is to examine the status of urbanization of Namyangju-Si from 2001 till 2008, analyze the correlation of the change of surrounding land use according to the change of accessibility and analyze the correlation of the change of land use. Based on the result from correlation analysis, I simulated from the view point of interactions between agents of land use and transportation accessibility by using MAS. I tried to forecast, based on space, the change of surrounding land use caused by the change of accessibility. I conducted landscape analysis by using a land registration map. Also, I conducted GIS analysis statistical analysis simulation analysis of traffic data, land use data in order to analyze the correlation of the change of surrounding land use according to the change of accessibility. I could find out a certain pattern that new roads and railroads causes the within 500m adjacent land to change into urban land use, which led me to construct a system through which land use changing phenomenon can be expected according to the change of accessibility. It is expected that it can make the best use of selecting the location where new transportation facilities are constructed.

The Comparison Research on Walking Pattern of Rehabilitation Training Program Participants in Stroke Patients (재활운동에 참가한 뇌졸중 환자들의 걷기형태 비교 연구)

  • Jin, Young-Wan
    • Journal of Life Science
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    • v.19 no.9
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    • pp.1299-1303
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    • 2009
  • The purpose of this study was to analyse the gait characteristics of stroke patients walking on a Zebris system, through quantitative three-dimensional biomechanical analysis. They underwent a continuous rehabilitation training program (RTP). A comparison was made between 3 month and 6 month RTP participants. Their ages were between 60 and 65. The data were analyzed by t-test. The result of comparative analysis of the two groups can be summarized as below. Temporal-spatial data, sagittal plane angular kinematics data, and peak ground reaction force and max pressure data showed that there were no significant differences between the 3 month RTP group and the 6month RTP group (Table 2, Table3, Table 4). It can be suggested that patients with hemiplegia after stroke can improve their walking function through continuous RTP participation.

3 Dimensional Changes of Bedrock Surface with Physical Modelling of Abrasion (마식에 의한 기반암면의 표면 변화에 대한 실험 연구)

  • Kim, Jong-Yeon
    • Journal of the Korean Geographical Society
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    • v.42 no.4
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    • pp.506-525
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    • 2007
  • Incision into bedrock channel is the primary control of landform evolution, but research into bedrock incision process stagnated for long time. Due to the scaling problem of the application of results from flume studies to bedrock channel, there is a strong need to simulate the bedrock incision process with more realistic models. As a part of investigation into controls of bedrock channel incision, three-dimensional changes of rock surface with abrasion was investigated with physical modelling. 18 rock plates were abraded with various sediment particle size and sediment load and abraded surfaces of the plates were scanned with high resolution 3-D scanner. To identify the spatial pattern of erosion of the rock plates, various methods were used. There was no synthetic or holistic method that showed all features of bedrock plate produced by abrasion, so each plate was analyzed using some available methods. Contour maps, shaded relief maps and profiles show that abrasion concentrated on the centre of plate (cross profile) and upstream and downstream edges (longitudinal profile) and eroded area extended inwards. It also found that the cracks and boundaries of forming materials easily eroded than other parts. Changing patterns of surface roughness were investigated with profiles, regression analysis and spectral analysis. Majority of plates showed decrease in small-scale roughness, but it depends on microstructures of the plates rather than general hardness or other factors. SEM inspection results supported this idea.