• Title/Summary/Keyword: Temporal characteristics

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A Theoretical Study on the Landscape Development by Different Erosion Resistance Using a 2d Numerical Landscape Evolution Model (침식저항도 차이에 따른 지형발달 및 지형인자에 대한 연구 - 2차원 수치지형발달모형을 이용하여 -)

  • Kim, Dong-Eun
    • Economic and Environmental Geology
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    • v.55 no.5
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    • pp.541-550
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    • 2022
  • A pre-existing landform is created by weathering and erosion along the bedrock fault and the weak zone. A neotectonic landform is formed by neotectonic movements such as earthquakes, volcanoes, and Quaternary faults. It is difficult to clearly distinguish the landform in the actual field because the influence of the tectonic activity in the Korean Peninsula is relatively small, and the magnitude of surface processes (e.g., erosion and weathering) is intense. Thus, to better understand the impact of tectonic activity and distinguish between pre-existing landforms and neotectonic landforms, it is necessary to understand the development process of pre-existing landforms depending on the bedrock characteristics. This study used a two-dimensional numerical landscape evolution model (LEM) to study the spatio-temporal development of landscape according to the different erodibility under the same factors of climate and the uplift rate. We used hill-slope indices (i.e., relief, mean elevation, and slope) and channels (i.e., longitudinal profile, normalized channel steepness index, and stream order) to distinguish the difference according to different bedrocks. As a result of the analysis, the terrain with high erosion potential shows low mean elevation, gentle slope, low stream order, and channel steepness index. However, the value of the landscape with low erosion potential differs from that with high erodibility. In addition, a knickpoint came out at the boundary of the bedrock. When researching the actual topography, the location around the border of difference in bedrock has only been considered a pre-existing factor. This study suggested that differences in bedrock and various topographic indices should be comprehensively considered to classify pre-existing and active tectonic topography.

Ordinary Kriging of Daily Mean SST (Sea Surface Temperature) around South Korea and the Analysis of Interpolation Accuracy (정규크리깅을 이용한 우리나라 주변해역 일평균 해수면온도 격자지도화 및 내삽정확도 분석)

  • Ahn, Jihye;Lee, Yangwon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.1
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    • pp.51-66
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    • 2022
  • SST (Sea Surface Temperature) is based on the atmosphere-ocean interaction, one of the most important mechanisms for the Earth system. Because it is a crucial oceanic and meteorological factor for understanding climate change, gap-free grid data at a specific spatial and temporal resolution is beneficial in SST studies. This paper examined the production of daily SST grid maps from 137 stations in 2020 through the ordinary kriging with variogram optimization and their accuracy assessment. The variogram optimization was achieved by WLS (Weighted Least Squares) method, and the blind tests for the interpolation accuracy assessment were conducted by an objective and spatially unbiased sampling scheme. The four-round blind tests showed a pretty high accuracy: a root mean square error between 0.995 and 1.035℃ and a correlation coefficient between 0.981 and 0.982. In terms of season, the accuracy in summer was a bit lower, presumably because of the abrupt change in SST affected by the typhoon. The accuracy was better in the far seas than in the near seas. West Sea showed better accuracy than East or South Sea. It is because the semi-enclosed sea in the near seas can have different physical characteristics. The seasonal and regional factors should be considered for accuracy improvement in future work, and the improved SST can be a member of the SST ensemble around South Korea.

The effect of similarity, time of release, and message type on the evaluation of extended brand in the era of consumption polarization (소비 양극화 시대에 확장 유사성, 출시 시기, 메시지 유형이 확장 브랜드 평가에 미치는 영향)

  • Kwak, Junsik
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.9
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    • pp.141-149
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    • 2017
  • Numerous products are on the market every day and consumption is becoming increasingly polarized. Some products have been introduced to the market for the first time and others are the existing products that have upgraded performance. For companies, new products must be released constantly to prevent losing existing customers and to increase loyalty. However, when companies released new product, they communicate consumer brand name and core benefits of the new product. Moreover, if a new product fails, the amount that the company has to pay is bound to grow. So companies often use brand extension strategies that use the names of famous brands that are already loved by their customers for new products. In this study, the effect of extension similarity, time of release, and message type on brand extension was investigated. Result shows that using abstract messages rather than specific messages is more effective when similarities with existing brands are poor. In particular, the closer the release period is, the more effective these effects are. However, in case of extending the brand with high similarity products, it is effective to focus on concrete messages when the release time is near, and to communicate abstract messages when the release time is long. This result suggests that companies should take into consideration not only the similarity of extension but also the timing and characteristics of messages when extending the brand.

Extraction of Snowmelt Parameters using NOAA AVHRR and GIS Technique for 7 Major Dam Watersheds in South Korea (NOAA AVHRR 영상 및 GIS 기법을 이용한 국내 주요 7개 댐 유역의 융설 매개변수 추출)

  • Shin, Hyung Jin;Kim, Seong Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2B
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    • pp.177-185
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    • 2008
  • Accurate monitoring of snow cover is a key component for studying climate and global as well as for daily weather forecasting and snowmelt runoff modelling. The few observed data related to snowmelt was the major cause of difficulty in extracting snowmelt factors such as snow cover area, snow depth and depletion curve. Remote sensing technology is very effective to observe a wide area. Although many researchers have used remote sensing for snow observation, there were a few discussions on the characteristics of spatial and temporal variation. Snow cover maps were derived from NOAA AVHRR images for the winter seasons from 1997 to 2006. Distributed snow depth was mapped by overlapping between snow cover maps and interpolated snowfall maps from 69 meteorological observation stations. Model parameters (Snow Cover Area: SCA, snow depth, Snow cover Depletion Curve: SDC) were built for 7 major watersheds in South Korea. The decrease pattern of SCA for time (day) was expressed as exponentially decay function, and the determination coefficient was ranged from 0.46 to 0.88. The SCA decreased 70% to 100% from the maximum SCA when 10 days passed.

Spatio-Temporal Characteristics of Droughts in Korea: Construction of Drought Severity-Area-Duration Curves (가뭄의 시공간적 분포 특성 연구: 가뭄심도-가뭄면적-가뭄지속기간 곡선의 작성)

  • Kim, Bo Kyung;Kim, Sang Dan;Lee, Jae Soo;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1B
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    • pp.69-78
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    • 2006
  • The rainfall depth-area-duration analysis which is used to characterize precipitation extremes for specification of so-called design storms, provides a basis for evaluation of drought severity when storm depth is replaced by an appropriate measure of drought severity. So we propose a method for constructing drought severity-area-duration curves in this study. Monthly precipitation data over the whole Korea are used to compute SPI. Such SPIs are abstracted to several independent spatial components from EOF analysis. Using Kriging method, these spatial components are used to constitute grid-based SPI data set over the whole Korea including Jeju island with $6km{\times}6km$ resolution. After identifying main drought events, the drought severity-area-duration curves for these events over 32-year period of record are finally constructed. As a result, such curves show the similar shape with storm-based curves in the sense that the drought severity (or rainfall depth) is inversely proportional to drought area from the curves, but drought-based curves are different from storm-based curves in the sense that the drought severity decreasing rate with respect to drought area is much less than depth decreasing rate.

Aesthetic Consciousness and Literary Logic in the Jamesian Transatlantic Perspective: Towards a Dialectic of "a big Anglo Saxon total"

  • Kim, Choon-hee
    • Journal of English Language & Literature
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    • v.57 no.3
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    • pp.367-389
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    • 2011
  • The aesthetic attitude, in general or in particular, represented in matters of taste through aesthetic ideas and value judgments postulates a certain literary logic. And this literary logic reveals itself a sense of morality, philosophy, or moral aesthetic consciousness through the moments of act and thought demonstrated in the characters invented in literary works. Henry James, among many others, offers a very special cultural paradigm for transnational argument because of his diverse ways of shaping transatlantic relations in terms of aesthetic consciousness. And this international paradigm produced varied expressions referring to Henry James as "an American expatriate," "an Anglicized American artist," "a Europeanized aesthete," "a cosmopolitan intelligence," "a bohemian cosmopolitan" to designate his literary career and its characteristics shaped in Europe. Such expressions resonate with Transatlantic Sketches, James's first collection on travel and cultures in 1875 which heralded his long "expatriation" in terms of self-distantiation. James's temperament of mind, far from being always identified with shared values within an ideological framework, never avoided friction with fixed ideas but rather absorbed it fully for another friction which intervenes in his house of fiction. My question arises here regarding his cultural belonging or dislocation: where is the place of his mind or what could be his ultimate destination? In this essay, I'd like to define a place or rather the place of James's literary mind by proving a certain "sympathetic justice" for his literary logic. For this purpose, I'll try to examine: how James used transatlantic perspective, a spatio-temporal assessment to formulate his moral aesthetic consciousness; and how the aesthetic framework functions in assessing his literary logic of aesthetic consciousness. To start with the first argument, I'll analyze some essential aspects of aesthetic attitude of his characters to postulate a persona capable of theorizing James's aestheticism conditioned by the transatlantic context. And for the second argument, I'll examine how the persona functions in formulating a proper cultural stance of James's aesthetic consciousness in transatlantic perspective to illuminate the way of how Jamesian individuality reflects the American mind. This process of theorizing a place of James's own will lead, I hope, to our discovering James's ultimate destination on the assumption that it'll prove or create a certain "sympathetic justice" for his humanist aestheticism, a Jamesian absolute morality.

Geomorphology and Spatio-Temporal Land Cover Changes in Sincheon Wetland, Mangyeong River (만경강 신천습지의 지형과 시공간적 토지 피복 변화)

  • Jangsoo Kim;Jeong-Sik Oh
    • The Korean Journal of Quaternary Research
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    • v.34 no.1
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    • pp.41-51
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    • 2024
  • The Sincheon wetland shows a remarkable diversity of fluvial landforms, such as river islands, anastomosing channels, braided channels, and sand-gravel bars, which contribute to its rich ecological habitat. The wetland area is characterized by a ecological diversity of herbaceous and woody plants. Significant changes in land cover within the wetlands were observed from 2008 to 2020. Notably, there was a rapid decrease in agricultural area from 18% to 0.04%, while the vegetation area expanded from 45% to 54%. Concurrently, the water area also experienced a notable increase from 34% to 41%. The surface sediment composition in the studied area displays sandy loam characteristics and exhibits acidic soil properties. Sediment acidity tends to increase downstream and in the central part of channels. Variations in acidity are also observed at nearby collection sites due to the tributaries and local discharge. The presence of dense vegetation in river islands and bars has led to a significant transformation of sediments into soil, with this change being more pronounced downstream, particularly near the weirs. The installation of a weir in Sincheon wetland is believed to have a significant impact on altering flow velocities between upstream and downstream sections, as well as influencing erosion and sediment deposition patterns. However, given the formation of landforms in response to weirs, effective administration and management are essential to address potential risks of catastrophic environmental disruptions, such as the removal of weirs and/or the maintenance of river channels.

Development of Inquiry Activity Materials for Visualizing Typhoon Track using GK-2A Satellite Images (천리안 위성 2A호 영상을 활용한 태풍 경로 시각화 탐구활동 수업자료 개발)

  • Chae-Young Lim;Kyung-Ae Park
    • Journal of the Korean earth science society
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    • v.45 no.1
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    • pp.48-71
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    • 2024
  • Typhoons are representative oceanic and atmospheric phenomena that cause interactions within the Earth's system with diverse influences. In recent decades, the typhoons have tended to strengthen due to rapidly changing climate. The 2022 revised science curriculum emphasizes the importance of teaching-learning activities using advanced science and technology to cultivate digital literacy as a citizen of the future society. Therefore, it is necessary to solve the temporal and spatial limitations of textbook illustrations and to develop effective instructional materials using global-scale big data covered in the field of earth science. In this study, according to the procedure of the PDIE (Preparation, Development, Implementation, Evaluation) model, the inquiry activity data was developed to visualize the track of the typhoon using the image data of GK-2A. In the preparatory stage, the 2015 and 2022 revised curriculum and the contents of the inquiry activities of the current textbooks were analyzed. In the development stage, inquiry activities were organized into a series of processes that can collect, process, visualize, and analyze observational data, and a GUI (Graphic User Interface)-based visualization program that can derive results with a simple operation was created. In the implementation and evaluation stage, classes were conducted with students, and classes using code and GUI programs were conducted respectively to compare the characteristics of each activity and confirm its applicability in the school field. The class materials presented in this study enable exploratory activities using actual observation data without professional programming knowledge which is expected to contribute to students' understanding and digital literacy in the field of earth science.

Spatial Characteristics of Fish Assemblage in Seomjin River Estuary and Gwangyang Bay (광양만 및 섬진강 하구에서 채집된 어류의 공간적 군집 특성)

  • Yong Jun Kim;Tae-Sik Yu;Chang Woo Ji;Ihn-Sil Kwak
    • Korean Journal of Ichthyology
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    • v.35 no.4
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    • pp.285-293
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    • 2023
  • This study conducted to investigate the temporal and spatial variations in the fish community structure in the Seomjin River estuary (ES1~ES3) and Gwangyang Bay (ES4~ES8). Surveys were conducted at eight points between May and September from 2020 to 2021. A total of 5,111 fish were collected, representing 42 families, 68 genera, and 78 species. The dominant species collected during the survey period were Pennahia argentata, with 2,370 individuals and a relative abundance of 46.4%. Also, as a subdominant species, Nuchequula nuchalis, 1643 individuals were caught, accounting for 32.1% relative abundance. According to Bray-Curtis similarities, observations were divided into three groups based on the fish community composition, and they were further categorized into brackish water areas, coastal areas, inner areas, and outer areas. Group 1 mainly consisted of fish inhabiting freshwater and brackish water areas, while group 3 exclusively contained fish living in marine waters. ANOSIM (Analysis of Similarity) analysis revealed a significant difference (ANOSIM R=0.783, p=0.001) between Group 2 and Group 3, and the species contributing to these clusters were P. argentata and Muraenesox cinereus. The study demonstrated spatial changes in the fish community structure from the Seomjin River estuary to the outer coast. The findings highlight the importance of long-term monitoring of major species that exhibit spatial variations, serving as essential foundational data for the conservation and management of economically significant fish species.

Spatial and Temporal Variation of Surface Sediments by Tidal Environment Changes: Muan Bay, West Coast of Korea (조석환경 변화에 의한 표층퇴적물의 시.공간적 분포 변화: 한국 서해안의 무안만)

  • Ryu, Sang-Ock;Chang, Jin-Ho;Lee, Hee-Jun;Jo, Yeong-Jo;Choi, Ok-In
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.14 no.1
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    • pp.10-21
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    • 2009
  • Muan Bay has extensively undertaken artificial influences through a series of construction of dams and dykes nearby resulting in a substantial increase in highest high water level. To unravel sedimentary responses to the water level rise, we collected a number of surface sediment samples and hydrodynamic data from in-situ observations of tidal currents in Muan Bay in 1998 and 2007. Comparison of the data between 1998 and 2007 shows that the relative content of coarse fractions, sand and gravel, in the sediment samples has increased with a decreased mean size, on average, from 6.2 to 5.8${\phi}$ at the expense of silt contents. Such a coarsening trend, which is more evident around high water level, particularly on the tidal flats of Dongam-ri, Guro-ri and Aphae-do, is most likely attributable to rising water level. On the other hand, an increase of fine fractions locally in the western entrance of the bay can be explained with changes in characteristics of tidal currents imposed by construction of bridges therein, such as decreased velocities and varied direction and phase of the tidal currents.