• Title/Summary/Keyword: Construction Periods

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Compatibility of MODIS Vegetation Indices and Their Sensitivity to Sensor Geometry (MODIS 식생지수에 미치는 센서 geometry의 영향과 센서 간 자료 호환성 검토)

  • Park, Sunyurp
    • Journal of the Korean Geographical Society
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    • v.49 no.1
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    • pp.45-56
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    • 2014
  • Data composite methods have been typically applied to satellite-based vegetation index(VI) data to continuously acquire vegetation greenness over the land surface. Data composites are useful for construction of long-term archives of vegetation indices by minimizing missing data or contamination from noise. In addition, if multi-sensor vegetation indices that are acquired during the same composite periods are used interchangeably, data stability and continuity may be significantly enhanced. This study evaluated the influences of sensor geometry on MODIS vegetation indices and investigated data compatibility of two difference vegetation indices, the Normalized Difference Vegetation Index(NDVI) and the Enhanced Vegetation Index(EVI), for potential improvement of long-term data construction. Relationships between NDVI and EVI turned out statistically significant with variations among vegetation covers. Due to their curvilinear relationships, NDVI became saturated and leveled off as EVI reached high ranges. Correlation coefficients between Terra- and Aqua-based vegetation indices ranged from 0.747 to 0.963 for EVI, and from 0.641 to 0.880 for NDVI, showing better compatibility for EVI compared to NDVI. In-depth analyses of VI outliers that deviated from regression equations constructed from the two different sensors remain as a future study to improve their compatibility.

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An Analysis on the Influence of the Financial Market Fluctuations on the Housing Market before and after the Global Financial Crisis (글로벌 금융위기 전후 금융시장 변동이 주택시장에 미치는 영향 분석)

  • Kim, Sang-Hyeon;Kim, Jae-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.480-488
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    • 2016
  • As the subprime mortgage crisis spread globally, it depressed not only the financial market, but also the construction business in Korea. In fact, according to CERIK, the BSI of the construction businesses plunged from 80 points in December 2006 to 14.6 points in November 2008, and the extent of the depression in the housing sector was particularly serious. In this respect, this paper analyzes the influence of the financial market fluctuation on the housing market before and after the Global Financial Crisis using VECM. The periods from January 2000 to December 2007 and January 2008 to October 2015, before and after the financial crisis, were set as Models 1 and 2, respectively. The results are as follows. First, when the economy is good, the Gangnam housing market is an attractive one for investment. However, when it is depressed, the Gangnam housing market changes in response to the macroeconomic fluctuations. Second, the Gangbuk and Gangnam housing markets showed different responses to fluctuations in the financial market. Third, when the economy is bad, the effect of low interest rates is limited, due to the housing market risk.

Changes in Land Use and Ownership of Kumnamno in Kwangju Under the Rule of Japanese Colonialism (일제(日帝) 강점기(强占期) 광주(光州) 금남로(錦南路) 지역(池域)의 토지이용(土地利用)과 소유(所有)의 변화(變化))

  • Jo, Jung-Kyu
    • Journal of the Korean association of regional geographers
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    • v.7 no.1
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    • pp.1-20
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    • 2001
  • This study explored the changes of the patterns of land use and the social patterns of ownership of Kumnamno in Kwangju under the rule of Japanese colonialism by analyzing the townscape of Kumnamno in terms of the form and function of it. The research was done considering three periods: the year of 1912, 1930 and 1945. Kumnamno is the name of the street as well as the legal district name, and includes Kumnamno 1-ga, 2-ga, 3-ga, 4-ga and 5-ga. In the year 1912, Kumnamno was utilized as land, farmland and road. With the increase in population and the urbanization of the Kwangju area, it gradually began to be changed into land. By 1941, it was completely turned into land. Before and after the year 1910, the streets intersecting the Kumnamno area came into being as the roads of the Kwangju town, and were built with a lattice pattern. The road building of the Kumnamno began in accordance with the building of Kwangju station in 1922. The road building linking Kwangju Station to Chonnam Provincial Hall marked the first appearance of Kumnamno. The block from Ku-sung-no to Kumnamno 3-ga was built in 1925, the block from Kumnamno 3-ga to 2-ga in 1921, and Kumnamno 1-ga in 1930. It was not until the year 1933 that the construction of streets ranging from Ku-sung-no through Kumnamno 5-ga was finished. Examining the land ownership of the Kumnamno area in 1912, the Japanese possessed the land of Kumnamno 1-ga, 2-ga and 3-ga on the one hand and the Koreans possessed the land of 4-ga and 5-ga on the other hand. In 1930, the Japanese enlarged their sphere of influence and controlled the land located in all the areas of Kumnamno, and the Koreans reduced their ownership of Kumnamno 4-ga and 5-ga. There was a tendency for companies to occupy the land rapidly. In 1945, while the land owned by the Japanese decreased and the land owned by the Koreans did not change in quantity, the possessions of companies increased. To summarize, the Kumnamno area had some changes in the use of land during the above mentioned period. This was in part due to the construction of a street linking Kwangju Station to Chonnam Provincial Hall in order to strengthen the authority of the Japanese Government-General of Korea, as well as the expansion of the residential zone with the increase of the population of Kwangju.

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Change in Species Composition of Shallow Water Fish at the Namdang Beach after Dike Construction in Cheonsu Bay (천수만 방조제 건설 후 남당 천해 어류 종조성의 중장기 변화)

  • Kwon, Soon Yeol;Lee, Jeong Hoon;Hong, Ji Min;Hwang, Hak Bin;Lee, Tae Won
    • Korean Journal of Ichthyology
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    • v.25 no.2
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    • pp.106-118
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    • 2013
  • Monthly variation in species composition of shallow water fish in Cheonsu Bay were determined using samples collected by a beach seine in the shallow water at Namdang beach from April 2010 to March 2011. The species composition were compared to the data obtained in 1885~86 and in 1993, and factors affecting the long-term change in species composition were analyzed. Fish collected during the study were 25 species, 2,194 individuals and 16,762 g. Chelon haematocheilus were predominated in abundance, accounting 68.5% in the number of individuals. A few number of fish were collected during the cold months from November to April. Abundance was high from July to September by a large catch of juveniles of pelagic fish. Species composition in 1993 did not differ significantly from that in 1985~86 although Fabonigobius gymnauchen living in the fine sediments were increased in abundance. Abundance increase of this gobiid fish was considered to be related to the sedimentation of fine particles due to weakened water circulation after dike construction. The number of species and catch amount in 2010~11 were significantly decreased comparing to those of the former periods; especially in pelagic fish and benthic fish, but C. haematocheilus were greatly increased in abundance. C. haematocheilus is an estuarine fish being able to survive in relatively poor quality of water. This increase seems to be related to fish larvae from the culture net cages recently installed in the inner bay. Recent decrease in abundance of shallow water fish suggested that water quality has been gradually getting poor and recently attained over a critical level for the nursery function of fish.

The Study on the Statistical Characteristics of Road Traffic Noise in Apartment Complex (국내 단지도로에서 도로교통소음에 대한 통계학적 특성연구 -도로교통 소음원이 수음점에 미치는 수평.수직 음원 분포특성 중심으로-)

  • Cho, Il-Hyoung;Chang, Soon-Woong;Kang, Sung-Won;Kim, Seog-Ku;Ko, Jung-Young
    • Journal of Environmental Science International
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    • v.16 no.10
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    • pp.1179-1187
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    • 2007
  • This paper represents the statistical characteristics of sources and receptors for road traffic noise in apartment complex. Also we suggested that the site-specific characteristics of vertical and horizontal distributions in the complex apartment have been derived using a different analysis for evaluating levels of Leq1h by the apartment floor at a given distance from a road in terms of the flow rate, the mean speed of the traffic, and the percentage of the type vehicles in the day and night periods. As a result, the contribution orders of traffic quantity by the type of vehicles showed as followed: light vehicle>medium vehicle>heavy vehicle>motorcycle. Especially, the mixing ratio of entering the road on the heavy vehicle in the daytime was two times higher than that of in the night. The speed in all types of vehicle is in the range of 41 and 81 km/hr and noise level was not significantly different in day and night-time. The sources of road traffic noise had different variations and uncertainties using a random variable and probability distribution. The sound distribution to receptors by the apartment floor showed S curve between 1st floor and $15^{th}$ floor With the normality test, the normal distributions using Anderson-Darling Test followed $1^{st},\;3^{th},\;13^{th}$ and $15^{th}$, floor in the daytime and all floors except $7^{th}$ floor in the night (p>0.05). And also, the value of the pearson correlation coefficient (r) obtained in this study have significantly different at the range of floor. In conclusion, the results suggested that the distribution characteristics of levels of $Leq_{1h}$ on the sources and receptors of road traffic noise in apartment complex must be improved and developed on the guideline of regulation of road traffic noise.

Technology Trends of Oil-sands Plant Modularization using Patent Analysis (특허분석을 통한 오일샌드 플랜트 모듈화 기술 동향 연구)

  • Park, Gwon Woo;Hwang, In-Ju
    • Economic and Environmental Geology
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    • v.49 no.3
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    • pp.213-224
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    • 2016
  • Non-conventional resource and alternative energy were researched for predicting oil peak. In this study, one of many non-conventional resources, specifically oil-sands, was investigated due to the increasing interest of oil-sands plant modularization in permaforst areas for reducing the construction periods through modular transportation while limiting local construction workers. Hence, tehcnological trends were analyzed for oil-sand plant modularization. Data used were between 1994 and 2015 for patent analysis while targets included Korea, US, Japan, Europe and Canada. Technology classification system consisted of mining, steam assisted gravity drainage(SAGD), separation/upgrading/tailors ponds, module design/packaging, module transportation and material/maintenance. Result of patent analysis, patent application accounts 89% in US and Canada. The main competitive companies were Shell, Suncor and Exxon-mobil. Unlike other oil developments, oil-sands have a long-term stable production characteristic, hence, it is important to ensure the competitiveness of oil-sands for obtaining a patent in the long run.

Temporal changes in river channel habitat diversity by large weirs in the Geum River using satellite imagery analysis (위성영상 분석을 통한 금강수계 대형보에 따른 수변서식처 다양성 변화 연구)

  • Ock, Giyoung;Choi, Mikyoung;Kim, Jeong-Cheol;Park, Hyung-Geun
    • Korean Journal of Environmental Biology
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    • v.38 no.4
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    • pp.705-713
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    • 2020
  • The present study investigated the temporal changes of river habitats caused by construction and operation of the three large weirs (Sejong, Gongju, and Baekje) in the Geum River. High resolution satellite imagery taken during three periods (preconstruction, before and after gate operation) were used for habitat analysis. We divided bar area into eight habitat types in addition to water area. Then, we identified the nine habitat types from the satellite imagery and estimated each habitat area. Our results show that after weir construction, large bar areas were dramatically decreased and bareland was nearly absent post gate-operation in all three weirs. However, total bar area and bareland were again increased distinctively soon after weir opening events, especially in the uppermost weir, the Sejongbo. These results suggest that weir opening operations provide a relatively simple channel of more diverse through the process of increasing bar area in a river channel.

Dynamic Numerical Modeling of Subsea Railway Tunnel Based on Geotechnical Conditions and Seismic Waves (지반조건과 지진파를 고려한 해저철도 터널의 동적 수치 모델링)

  • Kwak, Chang-Won;Yoo, Mintaek
    • Journal of the Korean Geotechnical Society
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    • v.38 no.11
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    • pp.69-86
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    • 2022
  • The railway is widely used to transport passengers and freight due to its punctuality and large transport capacity. The recent remarkable development in construction technology enables various subsea railway tunnels for continent-continent or continent-island connectivity. In Korea, design and construction experience is primarily based on the successful completion of the Boryeong subsea tunnel (2021) and the Gadeok subsea tunnel (2010). However, frequent earthquakes with diverse magnitudes, globally induced and continuously increased the awareness of seismic risks and the frequency of domestic earthquakes. The effect of an earthquake on the subsea tunnel is very complicated. However, ground conditions and seismic waves are considered the main factors. This study simulated four ground types of 3-dimensional numerical models, such as soil, rock, composite, and fractured zone, to analyze the effect of ground type and seismic wave. A virtual subsea railway shield tunnel considering external water pressure was modeled. Further, three different seismic waves with long-term, short-term, and both periods were studied. The dynamic analyses by finite difference method were performed to investigate the displacement and stress characteristics. Consequently, the long-term period wave exhibited a predominant lateral displacement response in soil and the short-term period wave in rock. The artificial wave, which had both periodic characteristics, demonstrated predominant in the fractured zone. The effect of an earthquake is more noticeable in the stress of the tunnel segment than in displacement because of confining effect of ground and structural elements in the shield tunnel. 

A study on changes in water cycle characteristics of university campus catchment: focusing on potential evapotranspiration improvement in Mt. Gwanak catchment (대학 캠퍼스 유역의 물순환 특성 변화에 관한 연구: 관악산 유역 잠재증발산량 개선을 중심으로)

  • Kim, Hyeonju;Kim, Young-Oh
    • Journal of Korea Water Resources Association
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    • v.55 no.12
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    • pp.1077-1089
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    • 2022
  • With the construction of Seoul National University (SNU), the Mt. Gwanak watershed has undergone some urbanization. As with other campus catchments, data related to the water cycle is extremely limited. Therefore, this study began by collecting hydrological and meteorological data using Atmos-41, a complex meteorological observation instrument. The observation results of Atmos-41 were validated by analyzing the statistical characteristics and confidence intervals based on the monthly variability of data from the Korea Meteorological Administration. Results of the previous research were used to validate the simulated surface runoff and infiltration using the Storm Water Management Model (SWMM). The potential evapotranspiration (PET) simulated by the SWMM was rectified by comparing it to the Atmos-41 observation data. Multiple regression analysis was employed to adjust for the fluctuations in precipitation, relative humidity, and wind speed because the calculated SWMM PET tends to be underestimated during periods of low temperatures. R2 increased from 0.54 to 0.80 when compared to the Atmos-41 PET. The rate of change in the water cycle as a consequence of the SNU's construction resulted in a 15.7% increase in surface runoff, a 14.2% decrease in infiltration rate, and a 1.6% decrease in evaporation.

A Study on the Service Status of Public Domain Works in Digital Library: Focusing on the Case of the National Library of Korea's Expired Works Service (디지털도서관의 퍼블릭도메인 저작물 서비스 현황에 관한 연구: 국립중앙도서관의 보호기간 만료 저작물 서비스 사례를 중심으로)

  • Hosin Lee
    • Journal of the Korean Society for information Management
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    • v.40 no.3
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    • pp.119-142
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    • 2023
  • Copyright is a legal criterion for determining the scope and method of digital library service. Works with expired protection periods correspond to the public domain and can be freely used by anyone. For this reason, it is a priority consideration in digital library construction and services. The purpose of this study is to examine how actively libraries are using expired protected works for digital library services. To this end, the relevant provisions of the Copyright Act applied to the construction and service of digital libraries were first summarized, and the meaning of the copyright protection period was theoretically examined. The current status of online services for expired works by the National Library of Korea was examined, focusing on the works of three Japanese colonial era writers, Kim Yoo-jung, Lee Hyo-seok, and Chae Man-sik, to check the specific service status of expired works. It reveals that the National Library of Korea is not fully utilizing the scope of the law, and that this situation is linked to the rights of other authors included in the book. Based on these results, it suggests that there is a need to change the service unit to focus on copyrighted works and to use authority records to systematize the management of authors' death years.