Comparison of statistical linear interpolation models for monthly precipitation in South Korea     

Sanghoo Yoon  Maeng-Ki Kim  Jeong-Soo Park 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(5):1371-1382

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Comparative study between N-body and Fokker–Planck simulations for rotating star clusters – I. Equal-mass system     

Eunhyeuk Kim  Ilsang Yoon  Hyung Mok Lee  Rainer Spurzem 《Monthly notices of the Royal Astronomical Society》2008,383(1):2-10

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Assessment of the volcanic hazard of Mt. Paektu explosion to international air traffic using South Korean airspace     

Kim  Seyun  Lee  Jiseon  Oh  Soohwan  Yoon  Yoonjin 《Natural Hazards》2019,96(2):647-667

Natural Hazards - A volcanic eruption is one of the most critical natural hazards in air transportation. In the European region, the Eyjafjallajökull eruption in 2010 triggered extensive...  相似文献   

Sampling error of areal average rainfall due to radar partial coverage     

Chulsang Yoo  Jungsoo Yoon  Eunho Ha 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(8):1097-1111

Areal average rainfall is important as it is used as an input for most rainfall-runoff analysis in Hydrology and Water Resources. Different from traditional methods of using rain gauge data, the use of radar rainfall for the estimation of areal average rainfall is very straightforward. However, in some cases with severe terrain blockages, the value of the incomplete radar information is of serious concern. This study investigated this problem and derived an equation for estimating the error involved in the areal average rainfall due to partial radar coverage of a basin or sub-basin. When only partial radar information is available, the sampling error decreases with increasing radar coverage and the number of radar bin clusters. As an application example, this study considered the Han River Basin with its rainfall observations using the Ganghwa rain radar. Among a total of 24 mid-sized sub-basins in the Han River Basin evaluated, only five sub-basins were fully covered by the radar and three were totally uncovered. The remaining 16 sub-basins were covered partially by radar leading to incomplete radar information. The results show that the sampling error ranged from several % to tens % of standard deviation of the areal average rainfall depending on the relative areal radar coverage.  相似文献   

Morphological identification of <Emphasis Type="Italic">Alexandrium</Emphasis> species (Dinophyceae) from Jinhae-Masan Bay,Korea     

Eun Song Kim  Zhun Li  Seok Jin Oh  Yang Ho Yoon  Hyeon Ho Shin 《Ocean Science Journal》2017,52(3):427-437

Outbreaks of paralytic shellfish poisoning (PSP) and dense blooms caused by Alexandrium species in Jinhae-Masan Bay, Korea have been nearly annual events for many years. However, excluding some Alexandrium species responsible for PSP, there are no critical reports on the morphology of Alexandrium species in this bay. To identify the Alexandrium species based on detailed morphological features, vegetative cells collected water samples and established by the incubation of resting cysts isolated from sediment trap samples were analyzed. Four species of Alexandrium were identified: Alexandrium affine, A. fundyense, A. catenella, and A. insuetum. Morphological features of these species were basically consistent with those outlined in previous studies. However, the ventral pore and the connecting pore on the sulcal plate, which have been accepted as diagnostic characteristics for the identification of A. fundyense and A. catenella, need to be reevaluated, indicating that useful morphological features for identifying these two species should be recommended to avoid confusion in the classification of species in genus Alexandrium.  相似文献   

Effects of temperature and salinity on the asexual reproduction of <Emphasis Type="Italic">Nemopilema nomurai</Emphasis> (Scyphozoa: Rhizostomeae)     

Hye Eun Lee  Chang Hoon Han  ByeongHo Kim  Won Duk Yoon 《Ocean Science Journal》2017,52(4):573-579

Asexual reproduction of polyps of Nemopilema nomurai, of which massive blooms have occurred in Korean waters every summer since 2003, were tested under 20 combinations of temperature (10, 15, 20, and 25°C) and salinity (12, 17, 22, 27, and 32 psu). Production of podocysts increased with increasing temperature (20 and 25°C), while strobilaton and ephyral liberation occurred at low temperatures (10 and 15°C). Temperature also affected the initiation of ephyral liberation (approximately 25 days at 15°C, and 50 days at 10 and 20°C, respectively). The number of podocysts was only significantly different between 27 and 32 psu, and salinity had no significant effect on the excystment of podocysts, ephyral liberlation, showing N. nomurai is euryhaline. These results demonstrated that temperature is an important factor on both the podocysts production and ephyrae liberation, possibly explaining early spring liberation of ephyrae and continuous introduction of medusae into Korean coastal waters through summer to fall.  相似文献   

Response of Pile Groups Driven in Sand Subjected to Combined Loads     

Yoon Seok Choi  Jintae Lee  Monica Prezzi  Rodrigo Salgado 《Geotechnical and Geological Engineering》2017,35(4):1587-1604

Although the loads applied on piles are usually a combination of both vertical and lateral loads, very limited experimental research has been done on the response of pile groups subjected to combined loads. Due to pile–soil–pile interaction in pile groups, the response of a pile group may differ substantially from that of a single pile. This difference depends on soil state and pile spacing. This paper presents results of experiments designed to investigate pile interaction effects on the response of pile groups subjected to both axial and lateral loads. The experiments were load tests performed on model pile groups (2 × 2 pile groups) in calibration chamber sand samples. The model piles were driven into the sand samples prepared with different relative densities using a sand pluviator. The combined load tests were performed on the model pile groups subjected to different axial load levels, i.e., 0 (pure lateral loading), 25, 50, and 75% of the ultimate axial load capacity of the pile groups, defined as the load corresponding to a settlement of 10% of the model pile diameter. The combined load test results showed that the bending moment and lateral deflection at the head of the piles increased substantially for tests performed in the presence of axial loads, suggesting that the presence of axial loads on groups of piles driven in sand is detrimental to their lateral capacity.  相似文献   

Wintertime suspended sediment simulation in the Huanghai and East China Seas   总被引：1，自引：0，他引：1  

CHOI Byung Ho  MUN Jong Yoon  KO Jin Seok 《海洋学报(英文版)》2005,24(1):46-59

A simulation of suspended sediment movement relating to tidal and wave forcing during a winter monsoon in November 1983 in the Huanghai and East China Seas continental shelf is attempted by using the model describing the cohesive/non-cohesive sediment resuspension generated by interactions between currents and waves.model simulation showed that sediment concentration was increased by resuspension at shallow depths during the strong storm conditions due to high bottom stress interacted between currents and waves. This result is in general agreement with observations in horizontal distribution of suspended sediment distribution.At three current meter mooring positions off the southern Shandong Peninsula resuspension occurred only at a depth of 22m,nearest coastal position and at deeper parts at depths of 51 and 80m wave-current interaction effects were not significant. It has shown that the present model simulation demonstrated the capability of reproduction of suspended sediment movement under wintertime extreme event reasonably well.  相似文献   

Hydraulic and Thermal Conductivities of Kaolin–Silica Mixtures under Different Consolidation Stresses     

Keunbo Park  Junhwan Lee  Hyung-Koo Yoon 《Marine Georesources & Geotechnology》2016,34(6):532-541

Stable backfill materials for the heat sensitive structures of buried power cables, hot water pipes, and gas pipelines are suggested to have low permeability and high heat transfer characteristics. The hydraulic and thermal conductivities of backfill materials or clay liners are important parameters in proper design and construction of geotechnical structures involved with heat transfers. In this study, to investigate the optimal natural backfill or liner materials, thermal and hydraulic conductivities of kaolin–silica mixtures examined based on the results from laboratory tests under different consolidation conditions. From the experiment results, the thermal conductivity increases while hydraulic conductivity decreases with increasing density during consolidation process. As a result, back-fill materials with high kaolin content under low consolidation stress were desirable materials for burial of heat sensitive structures.  相似文献   

Stress-Strain Behavior of Light-Weighted Soils     

Gil-Lim Yoon  Byung-Tak Kim 《Marine Georesources & Geotechnology》2013,31(3):248-266

Unconfined and triaxial compression tests were carried out to examine the behavior of light-weighted soils (LWS) consisting of expanded polystyrene (EPS), dredged soils, and cement with respect to initial water content. The stress-strain behavior of LWS are analyzed with varying initial water content and silt contents of dredged soils, cement ratio, and confined stress. As initial water contents increase, the compressibility index increases and the preconsolidation pressure was vice versa. As initial water contents increase, the slope of stress-strain curve in elastic zone increases and strain rate at failure decreases and the strain rate at failure was not changed by the being of foams. As initial water contents increase, a compressive strength of LWS decreases. The decrement ratio of compressive strength of LWS with foams increases as cement content increases and initial water contents decreases. The compressive strength increases as silt contents increases.  相似文献