• 대한지리학회지
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• 제37권2호
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• pp.191-202
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• 2002

지리 사상과 인간의 활동은 공간적 차원(spatiality)과 시간적 차원(temporality)으로 구분되는데, 공간에서의 지리 사상과 인간 활동의 변화는 시간의 흐름 속에 기록된다. 이를 체계적으로 연구하기 위해서는 공간적 특성과 시간적 특성을 통합적으로 분석하고 표현할 수 있는 방법이 필요하다 이 연구에서는 지가 변동과 같은 지리적 현상의 시 .공간적 차원을 통합적으로 분석할 수 있도록 GIS 기법을 이용하여 시간 지도를 구현하는 것을 목적으로 하여, 안양시의 지가 변동 분석을 사례로 모델을 설계하고 구현하며 지가의 시 .공간적인 통합 분석을 시도하였다. 이를 위하여 이 연구에서는 문헌 연구를 통하여 지가 변동 분석과 Temporal GIS의 연계 가능성에 대해 탐색하였고, 실험적 차원에서 구체적인 지역을 대상으로 시.공간적으로 통합 분석이 가능한 지가 변동 분석 모델을 설계하고 구현하였다. 토지는 공간 자료, 속성 자료, 시간 자료의 변화가 지속적이기 때문에 시간 지도의 필요성이 매우 높은 분야이다. 본 연구에서 구현한 시간 지도를 통해 지가 정보를 비롯한 다양한 지리 사상의 시간 자료. 속성 자료. 공간 자료의 변화과정을 통합적으로 분석할 수 있다.

• Ocean and Polar Research
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• 제44권2호
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• pp.179-190
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• 2022

Data missing in optical satellite images caused by natural variations have been a crucial barrier in observing the status of marine surfaces. Although there have been many attempts to fill the gaps of non-observation, there is little research to analyze the ratio of missing grids to overall sea grids and their seasonal patterns. This report introduces the method of quantifying the distribution of missing points and then shows how the missing points have spatial correlation and seasonal trends. Both temporal and spatial integration methods are compared to assess the effectiveness of reducing missing data. The temporal integration shows more outstanding performance than the spatial integration. Moran's I and K-function with statistical hypothesis testing show that missing grids are clustered and there is a non-random distribution from daily integration. The result of the seasonality test for Moran's I through a periodogram shows dependency on full-year, half-year, and quarter-year periods respectively. These analysis results can be used to deduce appropriate integration periods with permissible estimation errors.

• 농촌계획
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• 제2권2호
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• pp.91-102
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• 1996

Monitoring techniques for afro-ecological environments were studied, Hydrologic and ecological components in conjunction with water quality were monitored in the Balkan watershed. The hydrologic monitoring program consists of four water level gauging stations along creeks and stream at the watershed having 26.5 km2. Stage - storage relationship of reservoir, rainfall amount of the watershed, and rating curve of the stream gauging stations were established. Soil type, land use, hydrologic soil group, population and economic activities within the watershed were surveyed. Water quality data from the streams were sampled weekly and chemical analysis was conducted. Temporal variations of water quality were investigated and water quality map of each reach of stream was made to identify spatial variations. Seasonal and spatial variations of vegetation densities along stream in the watershed were investigated using grid, Density variations of insect species such as arthropod, flying insect, spider spices, rice insects were also monitored to determine seansonal surveying density. These monitored data will be used to develop monitoring techi%ues and afro - ecological environment models.

• 천문학논총
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• 제15권spc2호
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• pp.1-13
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• 2000

Through the coupling between the near-earth space environment and the polar ionosphere via geomagnetic field lines, the variations occurred in the magnetosphere are transferred to the polar region. According to recent studies, however, the polar ionosphere reacts not only passively to such variations, but also plays active roles in modifying the near-earth space environment. So the study of the polar ionosphere in terms of geomagnetic disturbance becomes one of the major elements in space weather research. Although it is an indirect method, ground magnetic disturbance data can be used in estimating the ionospheric current distribution. By employing a realistic ionospheric conductivity model, it is further possible to obtain the distributions of electric potential, field-aligned current, Joule heating rate and energy injection rate associated with precipitating auroral particles and their energy spectra in a global scale with a high time resolution. Considering that the ground magnetic disturbances are recorded simultaneously over the entire polar region wherever magnetic station is located, we are able to separate temporal disturbances from spatial ones. On the other hand, satellite measurements are indispensible in the space weather research, since they provide us with in situ measurements. Unfortunately it is not easy to separate temporal variations from spatial ones specifically measured by a single satellite. To demonstrate the usefulness of ground magnetic disturbance data in space weather research, various ionospheric quantities are calculated through the KRM method, one of the magneto gram inversion methods. In particular, we attempt to show how these quantities depend on the ionospheric conductivity model employed.

• The Journal of the Acoustical Society of Korea
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• 제22권2E호
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• pp.78-86
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• 2003

We analyzed the measured acoustic field to explore the characteristics of a horizontal coherence in shallow water. Signal spatial coherence data were obtained in the continental shelf off the east coast of Korea using a horizontal line array. The array was deployed on the bottom of 130 m water depth and a sound source was towed at 26 m depth in the source-receiver ranges of 1-13 ㎞. The source transmitted 200 ㎐ pure tone. Topography and temperature profiles along the source track were measured to investigate the relationship between the horizontal coherence and environment variations. The beam bearing disturbance and array signal gain degradation is examined as parameters of horizontal coherence. The results show that the bearing disturbance is about ± 8° and seems to be affected by temporal variations of temperature caused by internal waves. The array signal gains show degradation more than 5㏈ by the temporal and spatial variations of temperature and by the down-sloped topography.

• 지질공학
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• 제21권4호
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• pp.305-312
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• 2011

지하수 함양량은 기후조건, 토지이용, 수리지질학적 비균질성에 의해 시공간적인 변동성을 나타내는 수문량이므로 통합지표수-지하수 모델 기반의 시공간변동성을 갖는 일단위 함양량의 추정이 필요하다. 진천지역을 대상으로 SWAT-MODFLOW 통합모형이 일단위 함양량 추정에 사용되었으며 추정된 함양량의 시변성은 국가 지하수 관측망과 기초조사 기간(2009-2010)중에 설치된 자동관측망 자료와 잘 부합하는 것을 확인하였다. 진천지역을 포함한 미호천 유역 평균 지하수 함양률은 강수대비 20.8%로 나타났는데 이는 해석적 방법인 기저유출 분리법의 결과와도 잘 일치하였다. 통합모델링 기반의 함양량 산정은 국가 지하수 관리를 위해 유용하게 활용될 수 있을 것으로 판단된다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.450-453
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• 2006

Hydrographic data including particulate organic carbon (POC) from the Northeastern Gulf of Mexico (NEGOM) study were used along with remotely sensed data obtained from NASA's Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to develop POC algorithms to estimate POC concentration based on empirical and model-based principal component analysis (PCA) methods. In Case I and II waters empirical maximized simple ratio (MSR) and model-based PCA algorithms using full wavebands (blue, green and red wavelengths) provide more robust estimates of POC. The predicted POC concentrations matched well the spatial and seasonal distributions of POC measured in situ in the Gulf of Mexico. The ease in calculating the MSR algorithm compared to PCA analysis makes MSR the preferred algorithm for routine use. In order to determine the inter-annual variations of POC, MSR algorithms applied to calculate 100 monthly mean values of POC concentrations (September 1997-December 2005). The spatial and temporal variations of POC and sea surface temperature (SST) were analyzed with the empirical orthogonal function (EOF) method. POC estimates showed inter-annual variation in three different locations and may be affected by El $Ni{\tilde{n}}o/Southern$ Oscillation (ENSO) events.

• ALGAE
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• 제19권1호
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• pp.15-22
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• 2004

This study investigated the temporal and spatial dynamics of an epilithic algal community in the Hantan River in November 2001, February, May and August 2002. It was identified a total of an epiphlithic 301 taxa which were composed of 275 species, 16 varieties and 10 unidentified species. The standing crops ranged between 598,600-16,525,200 cells $\cdot$ $cm^2$ and showed the temporal and spatial variations, A higher value was found at the lower station than the upper station in winter, but a higher value was found at the upper station than the lower station in summer due to the effects of typhoons. Chlorophyll concentrations ranged between 13.4-304.2 ${\mu}g$ $\cdot$ $cm^2$. Standing crops and chlorophyll showed similar trends in autumn and winter, but temporal dynamics were not apparent in the overgrowth of Lyngbya, Schizothrix and so others in Cyanophyceae in spring and summer. They were composed of species in Chlorophyceae-Bascillariophyceae-Cyanophyceae and no seasonal effect was detected. Low diversity index values probably indicated the effects of environmental stresses (water temperature, flow and current velocity) other than organic pollution. An assessment of organic pollution using epilithic diatoms (DAIpo) showed $\alpha$-oligosaprobic states at the upper- and mid- stations, and $\alpha$-mesosaprobic states at the lower- stations.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.118-121
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• 2006

Variations in the extent and dispersal of river plume are important in the study of coastal environment. The objectives of this study are to examine relationship between satellite detected plume area and river discharge and to clarify the temporal and spatial dynamic of plume from Tokachi River, Hokaido, Japan. We used 1.1 km spatial resolution of SeaWiFS normalized water-leaving radiance (nLw) images from 1998 to 2002. Supervised maximum likelihood classification was implemented to define classes of surface water optical properties. Satellite observed plume area was correlated to the amount of river discharge from April to October. First mode (44% of variance) of EOF analysis shows the turbid plume distribution resulting from re-suspension by strong wind mixing along the coast during winter. This mode also shows plume distribution along-shelf direction in spring and late summer. Second mode (17% of variance) shows spring pattern across-shelf direction due to strong discharge of snow melting water.

• 한국물환경학회지
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• 제29권1호
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• pp.97-106
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• 2013

The temporal and spatial variations of water quality in a stratified reservoir are fully dependent on the characteristics of inflow loading from its watershed and the transport regimes of pollutants after entering the reservoir. Because of the meteorological and hydrological conditions in Korea, the pollutants loading to reservoirs are mostly occur during rainfall events. Therefore it is important to understand the characteristics of pollutants loading from upstream rivers and their spatial propagation through the stratified reservoir during the rainfall events. The objectives of this study were to characterize the water quality variations in upstream rivers of Imha Reservoir during a rainfall event, and the transport and spatial variations of pollutants in the reservoir through extensive field monitoring and laboratory analysis. The results showed that the event mean concentration (EMC) of SS, BOD, $COD_{Mn}$, T-N, T-P, $PO_4-P$ are 8.6 ~ 362.1, 2.5 ~ 5.1, 1.5 ~ 5.1, 1.1 ~ 1.9, 8.3 ~ 57.1, 5.6 ~ 25.7 times greater than the mean concentrations of these parameters during non-rainfall period. The turbidity and SS data showed good linear correlations, but the relationships between flow and SS showed large variations because of hysteresis effect during rising and falling periods of the flood. The ratio of POC to TOC were 12.6 ~ 14.7% during the non-rainfall periods, but increased up to 28.2 ~ 41.7% during the flood event. The turbid flood flow formed underflow and interflow after entering the reservoir, and delivered a great amount of non-point pollutants such as labile and refractory organic matters and nutrients to the metalimnion layer of reservoir, which is just above the thermocline. Spatially, the lateral variations of most water quality parameters were marginal but the vertical variations were significant.