Age and tectonic evolution of the northwest corner of the West Philippine Basin     

Wen-Bin Doo  Shu-Kun Hsu  Yi-Ching Yeh  Ching-Hui Tsai  Ching-Ming Chang 《Marine Geophysical Researches》2015,36(2-3):113-125

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Comparison of low-carbon pathways for California     

Geoffrey M. Morrison  Sonia Yeh  Anthony R. Eggert  Christopher Yang  James H. Nelson  Jeffery B. Greenblatt  Raphael Isaac  Mark Z. Jacobson  Josiah Johnston  Daniel M. Kammen  Ana Mileva  Jack Moore  David Roland-Holst  Max Wei  John P. Weyant  James H. Williams  Ray Williams  Christina B. Zapata 《Climatic change》2015,131(4):545-557

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An improved genetic programming to SSM/I estimation typhoon precipitation over ocean     

Li Chen  Keh‐Chia Yeh  Hsiao‐Ping Wei  Gin‐Rong Liu 《水文研究》2011,25(16):2573-2583

This article proposes an improved multi‐run genetic programming (GP) and applies it to estimate the typhoon rainfall over ocean using multi‐variable meteorological satellite data. GP is a well‐known evolutionary programming and data mining method used to automatically discover the complex relationships among nonlinear systems. The main advantage of GP is to optimize appropriate types of function and their associated coefficients simultaneously. However, the searching efficiency of traditional GP can be decreased by the complex structure of parse tree to represent the multiple input variables. This study processed an improvement to enhance escape ability from local optimums during the optimization procedure. We continuously run GP several times by replacing the terminal nodes at the next run with the best solution at the current run. The current method improves GP, obtaining a highly nonlinear meaningful equation to estimate the rainfall. In the case study, this improved GP (IGP) described above combined with special sensor microwave imager (SSM/I) seven channels was employed. These results are then verified with the data from four offshore rainfall stations located on islands around Taiwan. The results show that the IGP generates sophisticated and accurate multi‐variable equation through two runs. The performance of IGP outperforms the traditional multiple linear regression, back‐propagated network (BPN) and three empirical equations. Because the extremely high values of precipitation rate are quite few and the number of zero values (no rain) is very large, the underestimations of heavy rainfall are obvious. A simple genetic algorithm was therefore used to search for the optimal threshold value of SSM/I channels, detecting the data of no rain. The IGP with two runs, used to construct an appropriate mathematical function to estimate the precipitation, can obtain more favourable results from estimating extremely high values. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Depth zonation and bathymetric trends of deep-sea megafaunal scavengers of the Hawaiian Islands     

John Yeh  Jeffrey C. Drazen 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(2):251-266

The deep sea has been shown to exhibit strong depth zonation in species composition and abundance. Examination of these patterns can offer ecological insight into how organisms adapt and respond to changing environmental parameters that co-occur with depth. Here we provide the first tropical study on bathymetric zonation and other depth-related trends (size, abundance, and species richness) spanning shelf to abyssal depths of scavenging megafauna. Baited time-lapse free-vehicle cameras were used to examine the deep-sea benthic and demersal scavenging communities of the Hawaiian Islands, an area for which the biology and ecology have remained poorly studied below 2000 m. Twenty-two deployments ranging in depth from 250 to 4783 m yielded 37 taxa attracted to bait, including the first known occurrence of the family Zoarcidae in the Hawaiian Islands. Cluster analysis of Bray–Curtis similarity of species peak abundance (n_max) revealed four main faunal zones (250–500, 1000, 1500–3000, and ?4000 m) with significant separation (ANOSIM, global R=0.907, p=0.001) between designated depth groups. A major faunal break was identified at the 500–1000 m transition where species turnover was greatest, coinciding with the location of the local oxygen minimum zone. Dominance in species assemblage shifted from decapod crustaceans to teleosts moving from shallow to deeper faunal zones. Significant size differences in total length with depth were found for two of the four fish species examined. A logarithmic decline was observed in scavenger relative abundance with depth. Evidence of interaction between scavenging species was also noted between Synaphobranchus affinis and Neolithodes sp. (competition) and Histiobranchus sp. and aristeid shrimp (predation), suggesting that interactions between scavengers could influence indices of abundance generated from baited camera data.  相似文献   

Gas seepage, pockmarks and mud volcanoes in the near shore of SW Taiwan   总被引：2，自引：0，他引：2  

Song-Chuen Chen  Shu-Kun Hsu  Ching-Hui Tsai  Chia-Yen Ku  Yi-Ching Yeh  Yunshuen Wang 《Marine Geophysical Researches》2010,31(1-2):133-147

In order to understand gas hydrate related seafloor features in the near shore area off SW Taiwan, a deep-towed sidescan sonar and sub-bottom profiler survey was conducted in 2007. Three profiles of high-resolution sub-bottom profiler reveal the existence of five gas seeps (G96, GS1, GS2, GS3 and GS4) and one pockmark (PM) in the study area. Gas seeps and pockmark PM are shown in lines A and C, while no gas venting feature is observed along line B. This is the first time that a gas-hydrate related pockmark structure has been imaged off SW Taiwan. The relatively high backscatter intensity in our sidescan sonar images indicates the existence of authigenic carbonates or chemosynthetic communities on the seafloor. More than 2,000 seafloor photos obtained by a deep-towed camera (TowCam) system confirm the relatively high backscatter intensity of sidescan sonar images related to bacteria mats and authigenic carbonates formation at gas seep G96 and pockmark PM areas. Water column gas flares are observed in sidescan sonar images along lines A and C. Likewise, EK500 echo sounder images display the gas plumes above gas seep G96, pockmark PM and gas seep GS1; the gas plumes heights reach about 150, 100 and 20 m from seafloor, respectively. Based on multichannel seismic reflection (MCS) profiles, an anticline structure trending NNE-SSW is found beneath gas seep G96, pockmark PM and gas seep GS2. It implies that the gas venting features are related to the anticline structure. A thermal fluid may migrate from the anticline structure to the ridge crest, then rises up to the seafloor along faults or fissures. The seafloor characteristics indicate that the gas seep G96 area may be in a transitional stage from the first to second stage of a gas seep self-sealing process, while the pockmark PM area is from the second to final stage. In the pockmark PM area, gas venting is observed at eastern flank but not at the bottom while authigenic carbonates are present underneath the pockmark. It implies that the fluid migration pathways could have been clogged by carbonates at the bottom and the current pathway has shifted to the eastern flank of the pockmark during the gas seep self-sealing process.  相似文献   

Considering the effect of body force for regional land displacements     

Ruey-Hsing Lu  Hund-Der Yeh 《国际地质力学数值与分析法杂志》1994,18(3):145-160

In this study, a general mathematical model was developed for land displacements that occur as a result of the pressure decline in confined and/or phreatic aquifers. Two equations were developed by employing the equilibrium (force balance) equation and the flow equation in a deforming aquifer system. Both of these equations were integrated over the thickness of the aquifer system once a regional model had been formulated. The change of the body force in saturated and unsaturated zones of aquifers was considered in the derivation of the equilibrium equation. It was assumed that no external loading or force acting on the aquifer system was present. Two coupled equations expressed in terms of the averaged dilation and pressure were then obtained. The pumping data sets given in the papers of Bear and Corapcioglu^1,2 in 1981 and 1983 were analysed. Drawdown and displacements in a confined aquifer were demonstrated to be identical to those estimated by Bear and Corapcioglu.¹ In the case of a phreatic aquifer, however, the results estimated by the present approach were slightly different from those obtained by Corapcioglu and Bear.² The discrepancies in the results are possibly due to errors in the equations presented by Corapcioglu and Bear.² The present approach was able to avoid several assumptions and complex procedures used by Bear and Corapcioglu,^1,2 especially in the case of a phreatic aquifer, by taking into account the change in the body force.  相似文献   

Seismic hazard and uncertainty analysis of the Taiwan area     

Chin-Hsiung Loh  Fwu-Shing Baw

Yeong-Tein Yeh 《Soil Dynamics and Earthquake Engineering》1992,11(8):497-508

The objectives of this paper are (1) to obtain estimates on the effect of uncertainties of the hazard model, and (2) to evaluate the seismic hazard in Taiwan for structural analysis and design purposes. The seismic hazard in the Taiwan area is presented in terms of an iso-acceleration map. Such a map is developed for return periods of peak ground acceleration of 225 years and 475 years. The contour map of b-values and mean occurence rates for this region is also presented. Uncertainty analyses of model parameters in hazard analysis are concentrated on the analysis of dispersion of PGA values and the probabilistic modeling of stationary and nonstationary Poisson models of occurrences. Th e overall results are considered to be conservative since for most uncertainty analyses the more conservative values are used.  相似文献   

Geochemistry of hydrothermal deposits from Loihi submarine volcano,Hawaii     

Eric H. De Carlo  Gary M. McMurtry  Hsueh-Wen Yeh 《Earth and Planetary Science Letters》1983

Dredging across the northeast rim of the summit crater of Loihi Seamount recovered several morphologically similar but chemically and mineralogically distinct hydrothermal deposits encrusting the surface of fresh pillow lava talus. The multicolored deposits suggest a precipitation sequence that may be controlled by an oxidation-reduction gradient in which smectite ranging in composition from Fe-montmorillonite to nontronite has precipitated along with iron oxide under slightly reducing conditions. This deposition was apparently followed by amorphous iron oxide and silica precipitation, possibly under more oxic conditions. Oxygen isotope geothermometry indicates formation temperatures in the range of 31–57°C for the Loihi smectites. Trace element enrichments appear to be positively correlated with the isotopic formation temperature of the smectite, suggesting either increased trace element solubility within the higher-temperature vent fluids or increased smectite and iron oxide scavenging with increased precipitation rates. The trace element abundances further suggest the presence of polymetallic sulfides that either are directly associated with the smectites as amorphous phases or occur beneath these deposits in the volcanic pile of the seamount.  相似文献   

Inexpensive Access Tube Installation of Tensiometers Below a Flowing Stream     

Laurel J. Lacher  Thomas Maddock III  T.-C. Jim Yeh 《Ground Water Monitoring & Remediation》1997,17(3):76-77

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Regionalization of unit hydrograph parameters: 1. Comparison of regression analysis techniques     

Y. -K. Tung  K. -C. Yeh  J. -C. Yang 《Stochastic Hydrology and Hydraulics》1997,11(2):145-171

Hydrologic regionalization is a useful tool that allows for the transfer of hydrological information from gaged sites to ungaged sites. This study developed regional regression equations that relate the two parameters in Nash's IUH model to the basin characteristics for 42 major watersheds in Taiwan. In the process of developing the regional equations, different regression procedures including the conventional univariate regression, multivariate regression, and seemingly unrelated regression were used. Multivariate regression and seeming unrelated regression were applied because there exists a rather strong correlation between the Nash's IUH parameters. Furthermore, a validation study was conducted to examine the predictability of regional equations derived by different regression procedures. The study indicates that hydrologic regionalization involving several dependent variables should consider their correlations in the process of establishing the regional equations. The consideration of such correlation will enhance the predictability of resulting regional equations as compared with the ones from the conventional univariate regression procedure.  相似文献