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41.
Yeon S. Chang Jong Dae Do Weon Mu Jeong Sang Kwon Hyun Won-Dae Baek Jae Ho Choi Jae-Youll Jin 《Ocean Science Journal》2020,55(1):1-16
Beach erosion is a serious problem that can be aggravated by human-made structures, and the modeling of breaking waves near the coast and around coastal st 相似文献
42.
Lee Jong-Seok Baek Ji-Yeon Jung Dawoon Shim Jae-Seol Lim Hak-Soo Jo Young-Heon 《Ocean Science Journal》2019,54(3):349-362
Ocean Science Journal - Observing coastal water depths is very important to understand physical processes of the coastal environment and manage coastal resources. In this study, a low-altitude... 相似文献
43.
Shin Gyu-Beom Jo Bum-Hee Kim Sung-Ryul Baek Sung-Ha Chung Choong-Ki 《Acta Geotechnica》2022,17(9):4173-4190
Acta Geotechnica - This paper presents a finite element model for a load distributive compression anchor (LDCA). In an LDCA, the load applied to the strands is transmitted to the grout and ground... 相似文献
44.
The Government of Botswana has pledged a nationally determined contribution (NDC) as a commitment to the Paris Agreement. For the power sector, the NDC states that the government expects renewable energy (RE) to meet 25% of peak electricity demand by 2030. However, due to high initial cost of RE technologies, the government plans to maintain a coal-based power system in the future. Therefore, the purpose of this paper is to examine Botswana’s national plan from an economic perspective, using scenario and cost analysis, to explore the possibility of the power sector’s low carbon transition in the light of Botswana’s NDC. Five scenarios are designed to reflect a range of investment cost changes of RE technologies. While most scenarios only achieve 19% (P3, P4 and P5) and 54% (P6) of the NDC’s power sector target, the P7 scenario far exceeds the goal by achieving 188% of the NDC target. Furthermore, as the difference of levelized cost of electricity among the scenarios is minimal, the P7 scenario is the most attractive pathway for the government. Even for other scenarios, the government should still deploy the suggested capacity of solar photovoltaic (PV) as it is both economically and socially beneficial in the long term. However, in these cases, the government’s political will to meet the NDC’s power sector target and to promote the solar PV industry will be critical in designing future power sector policies.
Key policy insights
Model results show coal as the cheapest resource for electricity generation in Botswana up to 2030, but the cost competitiveness of solar photovoltaic (PV) against coal will continue to increase over time.
It is economically and socially beneficial to adjust the current national plan and substitute some share of coal with solar PV in the future energy mix.
Government support is critical in achieving the power sector’s NDC target, as cost reduction of solar PV alone does not guarantee success.
Encouraging independent power producers (IPP) with financial support mechanisms would be a suitable business model for developing the renewable energy industry.
45.
Myung-Seo Koo Sunghye Baek Kyung-Hee Seol Kyoungmi Cho 《Asia-Pacific Journal of Atmospheric Sciences》2017,53(3):361-373
As of 2013, the Noah Land Surface Model (LSM) version 2.7.1 was implemented in a new global model being developed at the Korea Institute of Atmospheric Prediction Systems (KIAPS). This land surface scheme is further refined in two aspects, by adding new physical processes and by updating surface input parameters. Thus, the treatment of glacier land, sea ice, and snow cover are addressed more realistically. Inconsistencies in the amount of absorbed solar flux at ground level by the land surface and radiative processes are rectified. In addition, new parameters are available by using 1-km land cover data, which had usually not been possible at a global scale. Land surface albedo/emissivity climatology is newly created using Moderate-Resolution Imaging Spectroradiometer (MODIS) satellitebased data and adjusted parameterization. These updates have been applied to the KIAPS-developed model and generally provide a positive impact on near-surface weather forecasting. 相似文献
46.
Jeong?Hwan?LeeEmail author Young?Soon?Baek Byong?Jae?Ryu Michael?Riedel Roy?D.?Hyndman 《Marine Geophysical Researches》2005,26(1):51-59
Recently, several countries have conducted projects to explore and develop natural gas hydrate, which is one of the new alternative
energy resources for the future. In Korea, a five-year national research project was initiated in 2000. As part of this project,
a seismic survey was performed in the East Sea of Korea to quantify the potential magnitude and distribution of natural gas
hydrates. Multi-channel seismic data and core samples have been acquired and recovered in the survey area. Analysis of seismic
data show clear bottom simulating reflectors (BSRs), seismic blank zones (or wipe-out zones) with velocity pull-up structure,
and pock-marks. In this study, we present the results of seismic surveys which indicate the existence of natural gas hydrates
in Korean offshore areas. These results will be applied to select areas for coring (or drilling) and detailed exploration
such as 2D seismic survey with long offset or 3D seismic in the future. 相似文献
47.
Using 8-10-m class telescopes and their Adaptive Optics (AO) systems, we conducted a long-term adaptive optics campaign initiated in 2003 focusing on four binary asteroid systems: (130) Elektra, (283) Emma, (379) Huenna, and (3749) Balam. The analysis of these data confirms the presence of their asteroidal satellite. We did not detect any additional satellite around these systems even though we have the capability of detecting a loosely-bound fragment (located at 1/4×RHill) ∼40 times smaller in diameter than the primary. The orbits derived for their satellites display significant eccentricity, ranging from 0.1 to 0.9, suggesting a different origin. Based on AO size estimate, we show that (130) Elektra and (283) Emma, G-type and P-type asteroids, respectively, have a significant porosity (30-60% considering CI-CO meteorites as analogs) and their satellite's eccentricities (e∼0.1) are possibly due to excitation by tidal effects. (379) Huenna and (3749) Balam, two loosely bound binary systems, are most likely formed by mutual capture. (3749) Balam's possible high bulk density is similar to (433) Eros, another S-type asteroid, and should be poorly fractured as well. (379) Huenna seems to display both characteristics: the moonlet orbits far away from the primary in term of stability (20%×RHill), but the primary's porosity is significant (30-60%). 相似文献
48.
Ji-Yeon Park Sang-Joon Kim You-Jin Lee Kitae Baek Ji-Won Yang 《Engineering Geology》2005,77(3-4):217-224
Feasibility of electrokinetic (EK) process combined with Fenton-like reaction was investigated for the removal of phenanthrene in a two-dimensional cell. Sandy soil and bentonite were selected as a model soil and a filling material to inhibit the leak of electrolyte solution within the electrode reservoirs into the soil by hydraulic pressure difference, respectively. The effects of parameters including current, electroosmotic flow (EOF), electrolyte pH, and moisture content on the removal efficiency were examined under constant voltage.
At the end of operation for 21 days, the concentration of phenanthrene near the anode was lower than the other positions of soil specimen and increased gradually towards the cathode because hydrogen peroxide solution was supplied from anode to cathode region following the direction of EOF. The concentration of phenanthrene at the bottom soil was lower than that at the top soil. Because capillary attraction in the sandy soil with high porosity was too low to maintain appropriate moisture at the top of the cell, EOF moved through the bottom soil with higher moisture content. Overall removal efficiency at 140 V was 81.6%, which was higher than 68.9% at 100 V because total EOF increased by a factor of 1.5 upon increase of the voltage from 100 to 140 V. In addition, power consumptions at 100 and 140 V were 7.2 and 19.4 kWh, respectively. 相似文献
49.
Sangho Baek Oh-Ig Kwoun Braun A. Zhong Lu Shum C.K. 《Geoscience and Remote Sensing Letters, IEEE》2005,2(4):413-417
We present a digital elevation model (DEM) of King Edward VII Peninsula, Sulzberger Bay, West Antarctica, developed using 12 European Remote Sensing (ERS) synthetic aperture radar (SAR) scenes and 24 Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles. We employ differential interferograms from the ERS tandem mission SAR scenes acquired in the austral fall of 1996, and four selected ICESat laser altimetry profiles acquired in the austral fall of 2004, as ground control points (GCPs) to construct an improved geocentric 60-m resolution DEM over the grounded ice region. We then extend the DEM to include two ice shelves using ICESat profiles via Kriging. Twenty additional ICESat profiles acquired in 2003-2004 are used to assess the accuracy of the DEM. After accounting for radar penetration depth and predicted surface changes, including effects due to ice mass balance, solid Earth tides, and glacial isostatic adjustment, in part to account for the eight-year data acquisition discrepancy, the resulting difference between the DEM and ICESat profiles is -0.57/spl plusmn/5.88 m. After removing the discrepancy between the DEM and ICESat profiles for a final combined DEM using a bicubic spline, the overall difference is 0.05/spl plusmn/1.35 m. 相似文献
50.
Dongseon Kim Eun-Jin Yang Seung Ho Baek Kyung-Hee Kim Jin-Hyun Jeong Young-Ok Kim 《Ocean Science Journal》2014,49(3):223-230
Dissolved inorganic carbon (DIC) and alkalinity were precisely measured for surface and bottom waters in Gwangyang Bay, Korea, during the four seasons to assess seasonal variations of aragonite saturation state (Ωarag). Both the surface and bottom waters were undersaturated with respect to aragonite during summer but were supersaturated during the other seasons. The summertime undersaturation of the surface waters with respect to aragonite may have been a result of the dilution effect caused by higher seasonal river runoff. In the bottom waters, the average DIC concentration increased by 40.6 μmol kg?1 from spring to summer, while the average alkalinity decreased by 74.7 μeq kg?1. As a result, the alkalinity/DIC ratio decreased from 1.07 in spring to 1.01 in summer and pH also decreased from 7.91 to 7.48, which resulted in the summertime undersaturation of the bottom waters. 相似文献