An identification of wave propagation based on a single-point measurement     

S.H. Kwon  C.H. Kim  T.S. Jang 《Ocean Engineering》2007,34(10):1405-1412

This study presents the identification of wave propagation using the information measured at a fixed point. The mathematical model used to carry out this research is an integral equation. The equation turned out to be a Fredholm integral equation of the first kind. The discretized matrix equation yielded an ill-conditioned system. To secure the stability of the system, Tikhonov regularization was applied to the ill-conditioned system. The analysis of the numerical computation proved that the regularization was able to retain the target spectrum.  相似文献   

A nonlinear wave profile correction of the diffraction of a wave by a long breakwater: Fixed point approach     

T.S. Jang  S.H. Kwon  Takeshi Kinoshita  B.J. Kim 《Ocean Engineering》2007,34(3-4):500-509

The authors of the present paper have suggested an iterative scheme to calculate the nonlinear wave profiles [Jang and Kwon, 2005. Application of nonlinear iteration scheme to the nonlinear water wave problem: Stokes wave. Ocean Engineering 32, 1862–1872]. The scheme was shown to be good for estimating nonlinear wave profiles. In the study, the iterative scheme is applied to the wave-diffraction problem by a long breakwater to calculate a diffracted wave by the breakwater. The iterative solution of diffraction was compared with the linear solution of Sommerfeld, 1896. [Mathematische Theoried der Diffraction. Mathematical Annals 47, 317–374]. For a small wave slope, the two solutions were in good agreement. However, the scheme enabled us to observe the nonlinear behaviors of a beating phenomenon and of wave profile such as Stokes’ wave for a relatively large wave slope: as the wave slope becomes larger, we can examine the nonlinear wave characteristics of the actual shapes of waves, i.e., the crests are steeper and the troughs are flatter.  相似文献   

M2 Tidal Current Estimation from One-day Observation Data off the Western and Southern Coasts of Korea     

Lee  Seok  Oh  Kyung-Hee  Jang  Sung-Tae  You  Hak Yoel  Park  Joonsung  Song  Kyu-Min 《Ocean Science Journal》2019,54(1):39-50

Ocean Science Journal - A practical method to estimate the M2 tidal current is proposed based on one-day current observations. In this method, the semi-diurnal constituent, composed of several...  相似文献   

Hydrologic impact of regional climate change for the snowfed and glacierfed river basins in the Republic of Tajikistan: hydrological response of flow to climate change     

S. Kure  S. Jang  N. Ohara  M. L. Kavvas  Z. Q. Chen 《水文研究》2013,27(26):4057-4070

The warming of the Earth's atmosphere system is likely to change temperature and precipitation, which may affect the climate, hydrology and water resources at the river basins over the world. The importance of temperature change becomes even greater in snow or glacier dominated basins where it controls the snowmelt processes during the late‐winter, spring and summer months. In this study hydrologic responses of streamflow in the Pyanj and Vaksh River basins to climate change are analysed with a watershed hydrology model, based on the downscaled atmospheric data as input, in order to assess the regional climate change impact for the snowfed and glacierfed river basins in the Republic of Tajikistan. As a result of this analysis, it was found that the annual mean river discharge is increasing in the future at snow and glacier dominated areas due to the air temperature increase and the consequent increase in snow/ice melt rates until about 2060. Then the annual mean flow discharge starts to decrease from about 2080 onward because the small glaciers start to disappear in the glacier areas. It was also found that there is a gradual change in the hydrologic flow regime throughout a year, with the high flows occuring earlier in the hydrologic year, due to the warmer climate in the future. Furthermore, significant increases in annual maximum daily flows, including the 100‐year return period flows, at the Pyanj and Vaksh River basins toward the end of the 21st century can be inferred from flood frequency analysis results. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

市级区域自动站信息处理系统的开发和应用   总被引：1，自引：1，他引：0  

蒋礼珍  符永兴  徐一晖 《气象研究与应用》2010,31(1):77-79

介绍了钦州市区域自动站信息处理系统的体系结构、主要功能、特点以及实施意义。通过建立区域自动站信息资料处理系统,对各市局乃至各区域站的历史资料进行剥离,实现各区域站历史资料的独立存档、统计,便于对区域气象站历史资料进行开发和应用。  相似文献   

Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan,Taiwan     

Kuang-Liang Lu  Chen-Wuing Liu  Sheng-Wei Wang  Cheng-Shin Jang  Kao-Hung Lin  Vivian Hsiu-Chuan Liao  Chung-Min Liao  Fi-John Chang 《Applied Geochemistry》2010

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Characterization of groundwater quality in Kinmen Island using multivariate analysis and geochemical modelling     

Chen‐Wuing Liu  Cheng‐Shin Jang  Chan‐Po Chen  Chun‐Nan Lin  Kuo‐Liang Lou 《水文研究》2008,22(3):376-383

Kinmen is located in the south‐west of Mainland China and mainly has two islands, Large Kinmen and Leiyu. Residents in Kinmen have drunk groundwater over several decades. This work characterized the quality of groundwater in Kinmen using factor analysis (FA), cluster analysis (CA) and geochemical simulation. The factor scores were plotted spatially to illustrate the groundwater quality and were used to discuss the grouped relationship using CA. Salinization, redox and organic matter factors are identified from 17 hydrochemical measurements in 18 wells. Acidic and oxidizing groundwater with nitrate‐N pollution is distributed mainly in the west of Large Kinmen. Saline groundwater is distributed to the north‐east of Large Kinmen and in the south of Leiyu. Groundwater with organic matter is present throughout Leiyu. Five groups of the groundwater quality divided by CA can be interpreted according to one to three factors. The grouped characteristics of the groundwater quality help the local government and industries to plan the use and protection of groundwater resources. Furthermore, a geochemical simulation was used to demonstrate the formation processes of the acidic and oxidizing groundwater properties in granitic sediments. A large amount of the precipitation of the kaolinite and magnetite releases concentrations of hydrogen ion and raises the redox potential in the aquifers. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Geotechnical and hydrogeological approaches towards conservation of the Muryong Royal Tomb in Korea   总被引：2，自引：0，他引：2  

Min-Ho Koo  Man-Cheol Suh 《Environmental Geology》2001,41(3-4):470-479

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Major and trace element composition of Skaergaard plagioclase; geochemical evidence for changes in magma dynamics during the final stage of crystallization of the Skaergaard intrusion     

Yun D. Jang  H. R. Naslund 《Contributions to Mineralogy and Petrology》2001,140(4):441-457

Plagioclase separates from the Layered Series (LS), Upper Border Series (UBS), and Marginal Border Series (MBS) of the Skaergaard intrusion were analyzed to examine major and trace element variations. In general, plagioclase from the LS, UBS, and MBS show similar trends in major elements vs. crystallization: SiO₂, Na₂O, and K₂O progressively increase, and CaO and MgO progressively decrease with fractionation. No abrupt changes in the trends of major components of Skaergaard plagioclase during the differentiation of the intrusion are observed. Trace elements in plagioclase reflect changes in the Skaergaard magma and changes in plagioclase distribution coefficients with differentiation. Sr, Ga, and probably Ba are included elements in Skaergaard plagioclase, but were excluded from the other cumulus phases, and as a result systematically increased in the magma and plagioclase during differentiation. Be, Cs, Hf, Rb, Ta, U, and Zr, and the transition metals Co, Cr, Cu, Ni, Sc, V, and Zn were excluded elements in Skaergaard plagioclase, and remained low in plagioclase during differentiation. Changes in the abundances of these elements in plagioclase during differentiation reflect changes in their abundance in the magma. With the exception of the lower zone, which is enriched in the light rare earth elements, rare earth elements in LS plagioclase, in general, increase with differentiation of the Skaergaard intrusion, but decrease dramatically at the UZa/UZb boundary where abundant apatite first appears. Rare earth elements in UBS plagioclase followed a similar trend to LS plagioclase, except during the initial and final stages of differentiation. UBS plagioclase is much more enriched in rare earth elements during the final 20% of crystallization, except for Eu, which is similar in plagioclase from the two series. The observed trends suggest that the floor and roof sequences became isolated from each other and that the floor sequence may have been more reducing and the roof sequence more oxidizing during the final 20% of crystallization. As the Skaergaard magma ceased convection, or convected as isolated cells, during the final stages of differentiation, volatile elements may have accumulated in the UBS magma, resulting in an increase in ƒO₂, and a decrease in Eu/Sm in UBS plagioclase. The observed trends of rare earth elements in plagioclase from the LS and UBS fit well with theoretical calculations that assume closed-system crystallization, and would be difficult to reconcile with any model requiring significant discharge of magma from the chamber during the final 20% of crystallization. The enrichment of light rare earth elements in plagioclase, suggests that the lower part of the intrusion re-equilibrated with a late, light rare earth element-rich fluid or melt. The recharge model proposed by earlier workers to explain anomalous Sr and Nd isotopes appears unlikely in light of the two to fourfold enrichment of light rare earth elements in these samples. Received: 1 October 1999 / Accepted: 14 May 2000  相似文献   

Instability of an underground ancient tomb due to excavation and its relationship to the temperature and ground water     

Mancheol Suh  Min-Ho Koo  Suck-Won Choi  Insun Song 《Geotechnical and Geological Engineering》2004,22(2):269-283

In order to consider a counterplan to preserve an ancient royal tomb in Kongju, Korea, the deformation of the wall structure, the atmospheric temperature in the tomb, and the groundwater level have been monitored. The long-term measurement of biaxial tilting of the tomb walls revealed that the brick-built subsurface opening had been subjected to severe structural instability. The measured deformation of the tomb was consistent with the displacement of soil around the tomb calculated using a numerical analysis. The instability of the tomb structure is closely related to the rainy season as the deformations measured are several times that in the dry season. A sudden change of temperature inside the tomb exerted an influence on the deformation of the tomb structure as well. It is suggested that the excavation be restored for tourists, the quicklime layer for preventing groundwater infiltration is reinforced, and a constant temperature is kept inside the tomb. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献