• Title/Summary/Keyword: temporal-spatial distribution

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Estimation of Effective Range of HFR Data and Analysis of M2 Tidal Current Characteristics in the Jeju Strait (제주해협 HFR 자료의 유효 범위 산정과 M2 조류 특성 분석)

  • Oh, Kyung-Hee;Lee, Seok;Park, Joonseong;Song, Kyu-Min;Jung, Dawoon
    • Ocean and Polar Research
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    • v.42 no.2
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    • pp.115-131
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    • 2020
  • The effective range of surface current data observed by high-frequency radar (HFR) operated in the northern coastal area of Jeju Island by Korea Institute of Ocean Science and Technology was estimated and the distribution and variability of the M2 tidal current of the Jeju Strait was analyzed. To evaluate the HFR data, the M2 tidal current corrected from 25 hours current data observed by the Korea Hydrographic and Oceanographic Agency (KHOA) was compared with the M2 tidal current in the Jeju Strait analyzed from the surface currents of HFR. The reliability of HFR data was confirmed by analyzing the characteristics of the tide components of these two data sets, and the effective range of HFR data was estimated through temporal and spatial analysis. The observation periods of HFR used in the analysis were from 2012 to 2014, and it was confirmed that there is a difference in the effective range of HFR data according to the observation time. During the analysis periods, the difference between the M2 current ellipses from the data of KHOA and the HFR was greater in the eastern than in the western part of the Jeju Strait, and represented a high reliability in the western and central parts of the Jeju Strait. The tidal current of the Jeju Strait analyzed using the HFR data revealed a seasonal variability a relatively weak in summer and a strong in winter, about a 17% fluctuations between the summer and winter based on the length of the semi-major axis of tidal ellipse. Appraisals and results of regarding the characteristics and seasonal variability of the M2 tidal current in the Jeju Strait using HFR data have not been previously reported, so the results of this study are considered meaningful.

Urban alienation and the just city (도시적 소외와 정의로운 도시)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.576-598
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    • 2016
  • This paper is to reconsider some characteristics of philosophical discussion on alienation, especially focusing on Lefebvre's concept of alienation, and then to conceptualize a number of features of alienation in both industrial and postindustrial capitalist cities. The construction and development of modern city in industrial capitalism has brought about alienation from nature and from land(i.e. means of production), and in these contexts, has generated alienated labour of urban labourers, which has been deepened through development of modern technologies and divisions of labour. The transformation from industrial to postindustrial society can be seen not as alleviating but as further intensifying and expanding process of alienation. Urban alienation in postindustrial society has been spatially and temporally extended through processes of glocalization and of financialization with the development of credit system. It also has been widened to fields of consumption and leisure and to spheres of non-material production, and has get more deeply involved in capital circulation through built environment and landscape(or spectacles) of cities. Finally this paper is to re-examine briefly theoretical discussions on dealienation in order to conceptualize the just city for dealienation of labour and of urban space, in particular considering the concept of 'the right to the city' as practical strategy of urban dealienation, and to suggest further three kinds of justice for the just city, that is, justice for distribution, for production and for recognition.

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Nutrient Balance and Application Efficiency of Nitrogen and Potassium in Salt-Accumulated Greenhouse Soil (염류(鹽類)가 축적(蓄積)된 시설재배(施設栽培) 토양(土壤)에서 질소(窒素)와 가리(加里)의 시비효과(施肥效果) 및 양분수지(養分收支))

  • Lee, Sang-Eun;Lee, Choon-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.27 no.2
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    • pp.78-84
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    • 1994
  • Yield response of tomato to nitrogen and potassium fertilizer and the balance of the two elements were determined in salt-accumulated greenhouse soil to improve the efficiency of fertilizer appiication. The response of tomato yield to nitrogen and potassium fertilizer application was not significant. The current parameters such as OM and $K/{\sqrt{Ca+Mg}}$ that were used to determine the level of nitrogen and potassium fertilizer in open field were not suitable in salt-accumulated greenhouse soil condition. The temporal and spatial distribution of $NO_3{^-}-N$showed the same pattern to those of $Cl^-$ ion that is non-reactive with soil, while the content of Ex. K was extraordinarily high in soil after harvesting of tomato, which had experienced relatively dry condition during harvesting time. The loss of $NO_3{^-}-N$ and Ex. K out of 28cm below the soil surface was 2~5 and 1.5~3.5 times greater than the amount of nitrogen and potassium uptake by the plant.

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Benthic Algal Flora in a Man-made Artificial Beach in the Hwawon Resort Complex, Southwestern Coast of Korea (화원관광단지 인공 해빈의 해조상)

  • Park, Chan Sun;Park, Kyung Yang;Hwang, Eun Kyoung
    • Korean Journal of Environmental Biology
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    • v.31 no.2
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    • pp.78-86
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    • 2013
  • Qualitative and quantitative algal survey was conducted from March 2010 to December 2010 on a man-made artificial beach in the Hwawon Resort Complex in order to understand seasonal changes of algal flora. The seasonal change of algal vegetation was compared with intact natural habitat near from the experimental sites. Total 15 algal species were found at the artificial beach; 8 Chlorophyta, 3 Phaeophyta and 4 Rhodophyta. And 38 algal species were found at the natural habitat; 7 Chlorophyta, 9 Phaeophyta and 22 Rhodophyta. Dominant algal species at the artificial beach were Ulva compressa, U. intestinalis, U. prolifera, U. pertusa in winter and Urospora penicilliformis, U. intestinalis, U. compress in summer. In natural habitat, dominant algal species were U. pertusa, U. compressa in winter and Sargassum thunbergii, Ishige okamurae in summer. (R+C)/P explaining spatial distribution of seaweeds was 3.7~4.0 (warm-temperature) in the artificial beach and 2.6~3.4 (polar-temperate) in the natural habitat, respectively. The flora of artificial beach could be classified into the filamentous form (64.4%), the sheet form (21.9%), and the coarsely branched form (13.7%). There was significant difference from the two habitats representing dominant species, distributions and ratio of functional-form groups.

Thermal Conductivity Effect of Heat Storage Layer using Porous Feldspar Powder (다공질 장석으로 제조한 축열층의 열전도 특성)

  • Kim, Sung-Wook;Go, Daehong;Choi, Eun-Kyeong;Kim, Sung-Hwan;Kim, Tae-Hyoung;Lee, Kyu-Hwan;Cho, Jinwoo
    • Economic and Environmental Geology
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    • v.50 no.2
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    • pp.159-170
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    • 2017
  • The temporal and spatial temperature distribution of the heat storage mortar made of porous feldspar was measured and the thermal properties and electricity consumption were analyzed. For the experiment, two real size chambers (control model and test model) with hot water pipes were constructed. Two large scale models with hot water pipes were constructed. The surface temperature change of the heat storage layer was remotely monitored during the heating and cooling process using infrared thermal imaging camera and temperature sensor. The temperature increased from $20^{\circ}C$ to $30^{\circ}C$ under the heating condition. The temperature of the heat storage layer of the test model was $2.0-3.5^{\circ}C$ higher than the control model and the time to reach the target temperature was shortened. As the distance from the hot water pipe increased, the temperature gap increased from $4.0^{\circ}C$ to $4.8^{\circ}C$. The power consumed until the surface temperature of the heat storage layer reached $30^{\circ}C$ was 2.2 times that of the control model. From the heating experiment, the stepwise temperature and electricity consumption were calculated, and the electricity consumption of the heat storage layer of the test model was reduced by 66%. In the cooling experiment, the surface temperature of the heat storage layer of the test model was maintained $2^{\circ}C$ higher than that of the control model. The heat storage effect of the porous feldspar mortar was confirmed by the temperature experiment. With considering that the time to reheat the heat storage layer is extended, the energy efficiency will be increased.

Spatial and Temporal Occurrence of Edwardsiella tarda at Flounder Farms in Jeju (제주도 넙치 양어장의 Edwardsiella tarda균의 분포에 관한 연구)

  • Kim, Jong-Su;Rho, Sum;Heo, Moon-Soo
    • Korean Journal of Environmental Biology
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    • v.19 no.2
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    • pp.173-181
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    • 2001
  • To find the appearance period and distribution of Edwardsiella tarda which causes severe damage to flounder (Paralichthys olivaceus) farms in Jeju-do, the rearing seawater (inflow, rearing water, outflow) and internal organs of flounders from 5 flounder farms were examined from June, 1997 to May, 1998. The number of bacteria in seawater was counted by plating the seawater on DSSS (Double Strength Salmonella-Shigella) agar plates or by plating after cultivation of bacteria. Bacteria in internal organs were counted by plating series of dilution of homogenized organ. The results are summarized as follows. E. tarda was detected in inflow seawater of five flounder farms in July, September and November, 1997 and February, March, April of 1998. In the rearing water and outflow water, the bacterium was detected throughout the year and the number of bacteria was much higher in summer than any other seasons. A large number of E. tarda in the internal organs were detected at farm B where a track-shaped tank was used, which has the characteristics of low circulation rate and bad discharge of excrement and residuals. In contast, none of E. tarda was detected at farm A where high circulation rate and good discharge of organic materials were applied. A few number of E. tarda at farm E were detected at the same condition as the farm A. A large number of E. tarda was observed in liver and intestines among the internal organs, and the number was higher from June to September in summer.

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Temporal and Spatial Fluctuations of Coastal Water Quality and Effect of Small Tide Embankment in the Muan Peninsula of Korea (무안반도 연안수질의 시ㆍ공간적 변동과 소규모 방조제의 영향)

  • Lee Dae-In;Cho Hyeon-Seo;Lee Gyu-Hyung;Lee Moon-Ok
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.6 no.4
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    • pp.24-36
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    • 2003
  • In this study, we estimated the seasonal fluctuations of water quality and effect of small tide embankment in coastal water around the Muan Peninsula, which is located in the northern part of Mokpo city, and layer farming ground is spread around there. Some physical and chemical factors were analyzed to characterize water quality from Jan. to Oct. in 1994. The results were as follows: Dissolved oxygen was slightly under saturation in the almost areas of July, and in some bottom layer at ebb tide of October. Distribution of COD showed high values that over 2㎎/L in October and flood tide of April by the discharge of freshwater and resuspension of benthic sediment, which exceeded water quality criteria II. Maximum values of dissolved inorganic nitrogen ware appeared in surface layer during the flood tide of October, while minimum of that showed in surface layer in April. Concentration of dissolved inorganic phosphorus was higher at July than the others, which ranged from 0.24 to 2.08㎍-at/L. Mostly mean values of N/P ratio were lower than 16, it mean that nitrogen is more limiting nutrient than phosphorus for the growth of phytoplankton. The values of eutrophication index were in the range of 0.07~0.81. However, very high values due to increase of COD were estimated near the tide embankment and southern part in relation to tidal current in October. Water quality around tide embankment was suddenly changed worse within a short period after opening the water gate during the rainfall.

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The Vegetational History of korea During the Holocene Period (홀로세 중 한국의 식생사)

  • 강우석
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.9-22
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    • 1994
  • The vegetational and environmental history of Korea during the Holocene period has reconstructed by the use of folral, palaeoclimatogical, archaeological data and written records. From 10,000 to 6,700 yeat B.P. in mid-eastern Korea, deciduous broadieaved trees gradually increased trees, notably at c.8,000 years B.P. From 6,700 to 4,500 years B.P., the vegetation remained dominated by Quercus and pinus(Diploxylon). Vegetational informations suggest the postglacial hypsithermal from c.8,000 to 4,500 years b.p. After 4,500 until 1,400 years B.P., the admixture of cryophilous trees in midland and thermophilous trees in south seems to imply the latitudinal divisions of vegetation and climate. The presence of cultivated rice pollen as well as non-arboreal pollen and spores indicates an increased rate of deforestation. From 1,400 years B.P., there was a sharp decrease in the representation of temperate trees, but the presence of the cryophilous genera Abies and pinus (Haploxylon) is noticea-ble and might be related to the occurrence of Little Ice Age. Fossil pollen diagram from western Korea and eastern Korea since 6,250 and 10,000 yeats B.P., respectively have enabled to compare vegetational dis-tribution patterns and changes in the Holocene period. In western Korea, Alnus- dominated vegetation continued from 6,250 to 1,500 years B.P., but pinus took over Alnus from 1,500 years B.P. In eastern Korea, however, Quercus and pinus dominated from 10,000 to 2,000 years B.P., but pinus be-came predominant from 2,000 years B.P. On a time- spatial basis, different vegetational distribution pattern can be recognised between western and east-ern Korea. The use of seven historical records which is unique to Korea also enabled to reconstruct the distributional pattern and temporal change of vegetation from 1425 to 1928.

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Flood Runoff Analysis using Radar Rainfall and Vflo Model for Namgang Dam Watershed (레이더강우와 Vflo모형을 이용한 남강댐유역 홍수유출해석)

  • Park, Jin-Hyeog;Kang, Boo-Sik;Lee, Geun-Sang;Lee, Eul-Rae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.13-21
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    • 2007
  • Recently, very short-term rainfall forecast using radar is required for regional flash flood according to climate change. This research is to evaluate the feasibility of GIS based distributed model using radar rainfall which can express temporal and spatial distribution in actual dam watershed during flood runoff period. Vflo model which was developed Oklahoma university was used as physical based distributed model, and Namgang dam watershed ($2,293km^2$) was applied as study site. Distributed rainfall according to grid resolution was generated by using K-RainVieux, preprocess program of radar rainfall, from JIN radar. Also, GIS hydrological parameters were extracted from basic GIS data such as DEM, land cover and soil map, and used as input data of distributed model(Vflo). Results of this research can provide a base for building of real-time short-term rainfall runoff forecast system according to flash flood in near future.

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Assessment of PM-10 Monitoring Stations in Daegu using GIS Interpolation (공간 보간법을 이용한 도시지역 미세먼지 측정소의 배치 적절성 평가)

  • Kim, Hyo-Jeong;Jo, Wan-Kuen
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.2
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    • pp.3-13
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    • 2012
  • This study evaluated the feasibility of the location for PM-10 Monitoring Stations utilizing through GIS analysis. In addition, optimal sites were investigated to properly manage PM-10 which are closely related with public health. There are 11 PM-10 monitoring stations in Daegu area and the PM-10 data monitored at these stations are utilized to understand the overall status of PM-10 pollution. However, there are contrastive issues on the locations of current monitoring stations. Thus, this study prepared the map of PM-10 concentrations in Daegu area using IDW and Kriging techniques. Furthermore, average PM-10 concentrations were calculated using zonal statistical methods according to legal divisions and then, the current monitoring stations were evaluated whether their location is appropriate or not for PM-10 pollution distribution. It was found that, on the basis of yearly, seasonal and daily concentration analysis, the location of current PM-10 monitoring stations were not appropriate, particularly as they could not represent regional PM-10 pollution characteristics. In order to supplement this deficiency, seven sites(Namsandong, Namildong, Dongildong, Buksungro 1, Jongro 1, Hyangchondong and Haejeondong) commonly selected from each analytical step are suggested as additional PM-10 monitoring sites. It is further suggested that this kind of scientific evaluation for the location of PM-10 monitoring stations are needed in order to properly manage public heath in other cities as well as Daegu area.