Estimation of Seasonal Representation of the Sea Water Temperature Profile Using Machine Learning and Its Effect on the Prediction of Underwater Acoustic Detection Performance     

Park  Nayoung  Kim  Young-Gyu  Kim  Kyeong Ok  Son  Su-Uk  Park  JongJin  Kim  Young Ho 《Ocean Science Journal》2022,57(3):528-540

Ocean Science Journal - Seawater temperature and salinity profiles are important physical properties that represent oceanic environments and affect underwater acoustic detection prediction...  相似文献   

Debris flow in metropolitan area — 2011 Seoul debris flow   总被引：4，自引：2，他引：2  

Chan-Young Yune  Yun-Ki Chae  Joongcheol Paik  Gihong Kim  Seung-Woo Lee  Heung-Seok Seo 《山地科学学报》2013,10(2):199-206

A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m. on July 27, 2011, at the center of Seoul, Korea. This area is located in the southern part of Seoul and is a densely populated district. As a result of the debris flow event, 16 people were killed, 30 houses were buried, and 116 houses were damaged around Umyeon Mountain, a relatively small mountain with a height of 312.6 m. Since the debris flow event, field investigations on the initiation and transportation zones of debris flows have been carried out. Rainfall data were collected from the automatic weather stations (AWSs) which are operated by the Korea Meteorological Administration (KMA). Video files recorded by residents were also acquired and used to analyze the flow characteristics of the debris flow. Field investigation shows that about 40 debris flows occurred around Umyeon Mountain and most of the debris flows were initiated by small slope failures. The effects of the precipitation that triggered the debris flows were analyzed as well. A landslide hazard map which considers slope gradient and aspect, strength of soil, hazard record, rainfall conditions, and vegetation, was constructed and compared with the initiation zones of debris flows.  相似文献   

Surface current response to wind and plumes in a bay-shape estuary of the eastern Yellow Sea: Ocean radar observation     

Sang-Ho Lee  Chan-Young Kang  Byoung-Ju Choi  Chang-Shik Kim 《Ocean Science Journal》2013,48(1):117-139

Response of surface subtidal current to wind and outflow plume in the bay-shape estuary, which had been artificially made by the Samangeum reclamation dike with two sluices in the west coast of Korea, was examined using the ocean radar-derived current data obtained in the summer 2010. The southerly wind was dominant due to Asian summer monsoon and the outflow plume water was discharged by the gate operation of the Shinsi and Garyeok sluices separated by 11 km into the study area that are opened in a southwestward direction. The monthly-mean flow pattern consisted of the westward outflow currents around the two sluices, the along-dike currents between the two sluices and the northward currents in the outer bay. Based upon the complex correlations of subtidal current to wind and outflow jets we explained that the northward mean current in the outer bay be formed by both the southerly wind-driven current and the geostrophic current by mean pressure setup due to the Ekman transport and plume water accumulation in the inner bay, and the along-dike mean current may be induced by the southerly wind that generates on-dike currents in the central region of study area and leads to pressure setup toward the dike between the two sluices. Combination of outflow jets, wind and coastline configuration affects variations of subtidal surface current in the inner bay. Variability of subtidal current in the outer bay is dominated by wind variation. The southerly wind produced the northward current in the outer bay though the outflow plumes from the two sluices turned clockwise from the inner to the outer bay due to the geostrophic balance when the wind was calm. The wind factor was from 2% to 7% depending on the amount of freshwater outflow and wind speed. Occasionally, when plume water discharges were large and the southerly wind was stronger than 5 m/s, a large eddy with a closed loop current was produced off the Shinsi sluice.  相似文献   

A multiphase approach to the stability analysis of reinforced earth structures accounting for a soil–strip failure condition     

Thai Son Quang  Hassen GhaziBuhan de Patrick 《Computers and Geotechnics》2009

A multiphase model, developed in the context of elastoplasticity, is applied to the simulation and design of reinforced earth retaining structures. The main feature of this model is to combine the advantage of a homogenization approach, as regards its computational efficiency, with the ability to account for a specific failure condition at the interface between the soil and the reinforcing strips, which may have a decisive influence on the behavior of the structure. A particular emphasis is put on the stability analysis of this kind of reinforced soil structures, formulated within the framework of the yield design theory. Making use of a generalized rigid block failure mechanism, the stability of a reinforced earth retaining wall is investigated by means of the kinematic approach, leading to upper bound estimates for the stability factor of the structure, which are then favorably compared with the results of an elastoplastic analysis. Special attention is paid to assessing in a quantitative way how a specific soil–strip failure condition affects the stability of the reinforced earth structure as a whole.  相似文献   

International Association for Gondwana Research 2009 Annual Convention and Gondwana to Asia Symposium,Hanoi, Vietnam     

Trinh Hai Son 《Gondwana Research》2009,15(2):223

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<国际地震动态>创刊30周年的回顾   总被引：1，自引：0，他引：1  

宋守全 《国际地震动态》2001,(5):3

在新世纪第一年的 5月迎来了《国际地震动态》创刊 30周年纪念。“30而立”一般泛指人到 30岁左右日臻成熟或在事业上取得初步成就 ,而对于一个已创办了 30年的刊物来说似也具有较为特殊的意义。作为本刊的创刊主编 ,此刻抚今追昔 ,不胜感慨 ,略作些许回顾 ,愿与本刊新老读者共飨。 1　本刊的历史沿革首先在此赘述几句 ,本人在文革前一直在外事单位工作 ,其中工作之一是先后主持编辑出版过英文周刊《北京动态》 (What's on inPeking)和参加编辑过中文周刊《国际文化动态“参考资料版”》;文革后调至地球物理研究所直至 1 987年 8月退休。来…  相似文献   

An Image Analysis Technique for Exploration of Manganese Nodules     

Chan-Young Park  Seung-Ho Park  Choon-Woo Kim  Jung-Keuk Kang  Ki-Hyune Kim 《Marine Georesources & Geotechnology》1999,17(4):371-386

In order to develop the mineral resources contained in manganese nodules of the deep sea, the Korea Ocean Research & Development Institute (KORDI) has explored the area allocated by the United Nations in the Clarion-Clipperton Fracture Zone in the northeastern Pacific. During research cruises, the seabed surface was photographed every 30 s by the KORDI Deep Tow Imaging System (DTIS). Features such as the coverage and size distribution of manganese nodules on the photographs serve as the essential information to determine the potential mining areas. This article presents (semi)automatic procedures to extract the useful features from the photographs of the seabed surface using digital image processing techniques. The 35-mm films are first digitized by the film scanner. The depth information written on the film is then recognized to compensate for distortions due to nonuniform illumination. The nodule areas on the digitized image are recognized and separated from the background based on the characteristics of the nodules. The nodule coverage and distribution of nodule diameters are then calculated from the processed image. The proposed technique has been applied to sample photographs of the seabed surface. Experimental results indicate that the technique could be utilized as an efficient tool to process the massive collection of photographs of the seabed surface.  相似文献   

Sedimentary Basin Analysis and Petroleum Potential of the Cretaceous Yuchon Group in Haenam Depression, SW Korea     

Son Jin - Dam 《东北亚地学研究》2000,(2)

IntroductionThe Haenam Depression filled with the LateCretaceous sediments and volcanics lies to the southwestern coast of Korea peninsula. The Cretaceousstrata (Yucheon Group) cover an area of ca. 200km2in the Haenam and Mokpo area. Regional geologicalsu…  相似文献   

Improved Chlorophyll-a Algorithm for the Satellite Ocean Color Data in the Northern Bering Sea and Southern Chukchi Sea     

Sang Heon Lee  Jongseong Ryu  Jung-woo Park  Dabin Lee  Jae-Il Kwon  Jingping Zhao  SeungHyun Son 《Ocean Science Journal》2018,53(3):475-485

The Bering and Chukchi seas are an important conduit to the Arctic Ocean and are reported to be one of the most productive regions in the world’s oceans in terms of high primary productivity that sustains large numbers of fishes, marine mammals, and sea birds as well as benthic animals. Climate-induced changes in primary production and production at higher trophic levels also have been observed in the northern Bering and Chukchi seas. Satellite ocean color observations could enable the monitoring of relatively long term patterns in chlorophyll-a (Chl-a) concentrations that would serve as an indicator of phytoplankton biomass. The performance of existing global and regional Chl-a algorithms for satellite ocean color data was investigated in the northeastern Bering Sea and southern Chukchi Sea using in situ optical measurements from the Healy 2007 cruise. The model-derived Chl-a data using the previous Chl-a algorithms present striking uncertainties regarding Chl-a concentrations – for example, overestimation in lower Chl-a concentrations or systematic overestimation in the northeastern Bering Sea and southern Chukchi Sea. Accordingly, a simple two band ratio (R_rs(443)/R_rs(555)) algorithm of Chl-a for the satellite ocean color data was devised for the northeastern Bering Sea and southern Chukchi Sea. The MODIS-derived Chl-a data from July 2002 to December 2014 were produced using the new Chl-a algorithm to investigate the seasonal and interannual variations of Chl-a in the northern Bering Sea and the southern Chukchi Sea. The seasonal distribution of Chl-a shows that the highest (spring bloom) Chl-a concentrations are in May and the lowest are in July in the overall area. Chl-a concentrations relatively decreased in June, particularly in the open ocean waters of the Bering Sea. The Chl-a concentrations start to increase again in August and become quite high in September. In October, Chl-a concentrations decreased in the western area of the Study area and the Alaskan coastal waters. Strong interannual variations are shown in Chl-a concentrations in all areas. There is a slightly increasing trend in Chl-a concentrations in the northern Bering Strait (SECS). This increasing trend may be related to recent increases in the extent and duration of open waters due to the early break up of sea ice and the late formation of sea ice in the Chukchi Sea.  相似文献   

A case study on the influence of THM coupling on the near field safety of a spent fuel repository in sparsely fractured granite     

Thanh Son Nguyen  Lennart Börgesson  Masakazu Chijimatsu  Jan Hernelind  Lanru Jing  Akira Kobayashi  Jonny Rutqvist 《Environmental Geology》2009,57(6):1239-1254

In order to demonstrate the feasibility of geological disposal of spent CANDU fuel in Canada, a safety assessment was performed for a hypothetical repository in the Canadian Shield. The assessment shows that the maximum long term radionuclide release from such repository would meet international criteria for dose rate; however, uncertainties in the assumed evolution of the repository were identified. Such uncertainties could be resolved by the consideration of coupled Thermal-Hydro-Mechanical-Chemical (THMC) processes. In Task A of the DECOVALEX-THMC project, THM models were developed within the framework of the theory of poroelasticity. Such model development was performed in an iterative manner, using experimental data from laboratory and field tests. The models were used to perform near-field simulations of the evolution of the repository in order to address the above-mentioned uncertainties. This paper presents the definition and rationale of task A and the results of the simulations. From a repository safety point of view, the simulations predict that the maximum temperature would be well below the design target of 100°C; however, the stress on the container can marginally exceed the design value of 15 MPa. However, the most important finding from the simulations is that a rock damage zone could form around the emplacement borehole. Such damage zone can extend a few metres from the walls of the emplacement holes, with permeability values that are orders of magnitude higher than the initial values. The damage zone has the potential to increase the radionuclide transport flux from the geosphere; the effect of such an increase should be taken into account in the safety assessment and mitigated if necessary by the provision of sealing systems. Prepared for publication in Environmental Geology. DECOVALEX-THMC Special Issue.  相似文献