• Title/Summary/Keyword: long-term change

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Analysis of Gangwon-do Coastline Changes Using Aerial Photograph Immediately after the Liberation (해방 직후 항공사진을 이용한 강원도 해안선 변화 분석)

  • Ahn, Seunghyo;Choi, Hyun;Kim, Gihong
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.5
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    • pp.717-726
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    • 2020
  • Social costs are increasing in Gangwon-do east coast due to coastal erosion. Long-term coastline change information is essential for analyzing this phenomenon. In this study, aerial photographs immediately after liberation are used for 1950's coastline extraction. The study area is from Sokcho Cheongho beach to Yangyang Seorak beach. The aerial photograph is geometrically corrected using DLT(Direct Linear Transformation) method to extract past coastline and compare it with present data. Coastal erosion and deposition areas are calculated in study area. Artificial structures such as harbors and breakwaters have caused changes in ocean currents and sediments from river estuaries. In most cases, the deposition occurred at the southern area of artificial structures and the erosion occurred on surrounding beaches. Coastline information extracted from past aerial photographs can be useful to provide information on long-term changes.

A Study of Long-term Change in Carbon Dioxide Concentrations within and Across the Korean Peninsula between 1996 and 1997 (국내외 관측점간의 비교분석을 통한 이산화탄소의 장주기적 농도변화 특성에 관한)

  • 김기현;윤용훈;송기범
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.1
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    • pp.105-115
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    • 2001
  • This study was conducted to analyzed the pattern of $CO_2$ concentration changes in various time scale within and across the Korean Peninsula. We compared that data sets obtained from Moo-Ahn(NAN) station in Korea with those determined from major background observatory stations around the world from the periods of Aug. 1995 to Dec. 1997. The mean $CO_2$concentrations of the MAN area, if computed using the total of 884 daily mean values, were computed to by 374.5$\pm$6.6 ppm. When the background data for MAN were compared with those of other background site, the concentration of MAN was systematically higher than any other comparable sites. Results of correlation analysis between MAN and other background sites generally showed up the existence of strong correlations, indicating that the relative effect of $CO_2$ concentration change can proceed similarly over the globe. However, notable differences in annual growth rate of $CO_2$ between MAN and all the comparative sites suggested that its concentration in th MAN area be regulated in more complicated manners than those in the other areas. It is thus suspected that the data collected form MAN area be not effective enough to represent areal distribution characteristics of $CO_2$in the Korean Peninsula.

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Determination of the Optimal Sediment Discharge Formula for Hyeongsan River Using GSTARS (GSTARS모형을 이용한 형산강의 최적 유사량공식 결정)

  • Ahn, Jung Min;Lyu, Siwan;Lee, Nam Joo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1B
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    • pp.1-7
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    • 2012
  • Quasi-two dimensional numerical model (GSTARS) was applied to determine the optimal sediment discharge formula for simulating the sedimentologic characteristics of Hyeongsan river. The field measurements have been conducted to obtain the data, such as sediment discharge, bed material, and channel geometry, for model calibration and verification. The sediment discharge formulas, which have been generally used, have been assessed according to the average error, relative error, RMSE, RRMSE, discrepancy ratio and Nash-Sutcliffe efficiency coefficient for bed changes along the thalweg. From the results, Laursen formula(1958) shows the best performance to simulate the long-term bed change of Hyeongsan river.

이상파랑하에서의 해빈변화특성 해석

  • Kim, Hui-Jae;An, Hyo-Jae;Kim, Gang-Min;Lee, Jung-U
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.06a
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    • pp.241-243
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    • 2014
  • Recently, as the coastal erosion impacts greats to both social and economical aspects, each local government is trying to setup its countermeasures. However, it is necessary to survey the change of sediment movement characteristics and investigate the continuous environment change by long-term monitoring after building prevention constructions. In this study, predictions on wave deformation and sediment movement deduced through the numerical modeling are made, based on the ordinary and extraordinary wave through seasonal superiority wave direction, height, period and long-term wave characteristics on the eroded beach of central West sea.

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Sea-level Change and Coastal Erosion (해수면 변화와 해안 침식)

  • Jeon, Dong-Chull
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.289-304
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    • 1995
  • Time series of the relative sea levels at the selected tide-gauge stations in the North Pacific and historical aerial photographs in the Hawaiian Islands are analyzed. Long-term rising trend of sea level ranges from +1 to +5 mm/yr at most of the stations, which is primarily due to global warming and tectonic motion of the plates. The annual and interannual fluctuations of sea level result from the thermal expansion/contraction of sea-surface layer due to the annual change of the solar radiation and possibly from a coupled ocean-atmosphere phenomenon associated with an ENSO event, respectively. Sea-level changes in three different time-scales (linear trend. annual oscillation, and interannual fluctuation) and their quantitative contribution to the shoreline changes as a result of long-term cross-shore sediment transport arc hypothesized.

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Succinylated Pullulan Acetate Microspheres for Protein Delivery

  • Woo, Young-Rong;Seo, Seog-Jin;Na, Kun
    • Journal of Pharmaceutical Investigation
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    • v.41 no.6
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    • pp.323-329
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    • 2011
  • In order to develop new protein carrier replacing poly(DL-lactic acid-co-glycolic acid) (PLGA) microspheres, succinylated pullulan acetate (SPA) was investigated to fabricate a long term protein delivery carrier. SPA microspheres loaded with lysozyme (Lys) as a model protein drug were prepared by a water/oil/water (W/O/W) double emulsion method. An acidity test of SPA copolymers after hydrolysis was performed to estimate the change of protein stability during releasing proteins from the microspheres. There was no pH change of SPA copolymers, but pH of PLGA polymers after hydrolysis was significantly decreased to around pH 2, indicating that the long-term stability of proteins released from SPA microspheres can be guaranteed. Loading efficiency of proteins into SPA microspheres was three times higher than those into conventional PLGA microspheres, indication of inducing stronger charge interaction between proteins and succinyl groups in SPA microspheres. Although initial burst behaviors were monitored in Lys-loaded SPA microspheres due to relatively strong hydrophilic succinyl segments in SPA microspheres, initial burst issues would be circumvented if the ratio of charge density of succinyl moieties and hydrophobic acetate groups is harmonically controlled. Therefore, in this study, a new attempt of protein delivery system was made and functional SPA was successfully confirmed as a new protein carrier.

Analysis of Performance Characteristic for Small Scale Hydro Power Plant with Long Term Inflow Condition Change (장기유입량 변화에 의한 소수력발전소 성능특성분석)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • New & Renewable Energy
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    • v.5 no.4
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    • pp.39-43
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    • 2009
  • The variation of inflow at stream and hydrologic performance for small scale hydro power(SSHP) plants due to climate change have been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the variation of inflow caused from rainfall condition. And another model to predict hydrologic performance for SSHP plants is established. Monthly inflow data measured at Andong dam for 32 years were analyzed. The existing SSHP plant located in upstream of Andong dam was selected and analyzed hydrologic performance characteristics. The predicted results from the developed models show that the data were in good agreement with measured results of long term inflow at Andong dam and the existing SSHP plant. Inflow and ideal hydro power potential had increased greatly in recent years, however, these did not lead annual energy production increment of existing SSHP plant. As a results, it was found that the models represented in this study can be used to predict the primary design specifications and inflow of SSHP plants effectively.

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Longitudinal Relationships between Cigarette Smoking and Increases Risk for Incident Metabolic Syndrome: 16-year Follow-up of the Korean Genome and Epidemiology Study (KOGES)

  • Sang Shin Pyo
    • Biomedical Science Letters
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    • v.29 no.4
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    • pp.355-362
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    • 2023
  • This study aimed to determine whether smoking affects the metabolic syndrome and its components through long-term follow-up. Of the 10,030 cohort subjects in the community-based Korean Genome and Epidemiology Study (KoGES) from 2001 to 2018, 2,848 people with metabolic syndrome and 4,854 people with insufficient data for analysis were excluded for this study. The study population comprised 2,328 individuals (1,123 men, 1,205 women) who were eligible for inclusion. The mean age of the participants was 49.2±7.5 years, and 21.9% were current smoker. In log rank test, current smoker had a significantly higher cumulative incidence of metabolic syndrome compared with non smoker (P<0.001). In the Cox proportional hazards model adjusted for key variables, metabolic syndrome (hazard ratio [HR] 1.57, P<0.001), high fasting glucose (HR 1.40, P<0.01), hypertriglyceridemia (HR 1.60, P<0.001), low HDL-cholesterol (HR, 1.30, P<0.01), and abdominal obesity (HR 1.32, P<0.01) in current smoker compared with non smoker were statistically significant, respectively, but not hypertension (HR 1.00, P>0.05). After adjustment for confounders, the time (P-time<0.001) and group (P-group<0.001) effects on metabolic syndrome score change were statistically significant. Furthermore, the interaction analysis of time and smoking group on the change in metabolic syndrome score was statistically significant (P-interaction<0.001). In long-term follow-up, smoking worsens metabolic syndrome.

Manual Reduction of Temporomandibular Joint Long-standing Dislocation under General Anesthesia (전신마취하에 도수정복된 측두하악관절 장기탈구)

  • Son, Jeong-Seog;Oh, Ji-Hyeon;Choi, Byung-Ho;Yoo, Jae-Ha
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.13 no.3
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    • pp.121-126
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    • 2013
  • Temporomandibular joint (TMJ) dislocation is an acute paintful condition that causes severe functional limitation. So, manual reduction is the treatment of choice and should be performed as early as possible. Long-term dislocation of the TMJ that has persisted for more than 1 month is comparatively rare. This may include severe illness, neurological diseases and prolonged intensive care hospitalization with oral intubation and sedation. A joint that remains prolonged dislocated undergoes morphological change which is also true for periarticular tissue, especially in ligaments and muscles. Treatment of long-term TMJ dislocation should be different from acute TMJ dislocation, as simple reduction is difficult to achieve and it's likely to redislocate. The prevention of redislocation after reduction should be considered. This is a case report of about manual reduction of temporomandibular joint long-standing dislocation under general anesthesia.