Fast and Optimized Methodology to Generate Road Traffic Emission Inventories and Their Uncertainties          下载免费PDF全文

Bang Quoc Ho  Alain Clappier  Nadege Blond 《洁净——土壤、空气、水》2014,42(10):1344-1350

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2D acoustic‐elastic coupled waveform inversion in the Laplace domain     

Ho Seuk Bae  Changsoo Shin  Young Ho Cha  Yunseok Choi  Dong‐Joo Min 《Geophysical Prospecting》2010,58(6):997-1010

Although waveform inversion has been intensively studied in an effort to properly delineate the Earth's structures since the early 1980s, most of the time‐ and frequency‐domain waveform inversion algorithms still have critical limitations in their applications to field data. This may be attributed to the highly non‐linear objective function and the unreliable low‐frequency components. To overcome the weaknesses of conventional waveform inversion algorithms, the acoustic Laplace‐domain waveform inversion has been proposed. The Laplace‐domain waveform inversion has been known to provide a long‐wavelength velocity model even for field data, which may be because it employs the zero‐frequency component of the damped wavefield and a well‐behaved logarithmic objective function. However, its applications have been confined to 2D acoustic media. We extend the Laplace‐domain waveform inversion algorithm to a 2D acoustic‐elastic coupled medium, which is encountered in marine exploration environments. In 2D acoustic‐elastic coupled media, the Laplace‐domain pressures behave differently from those of 2D acoustic media, although the overall features are similar to each other. The main differences are that the pressure wavefields for acoustic‐elastic coupled media show negative values even for simple geological structures unlike in acoustic media, when the Laplace damping constant is small and the water depth is shallow. The negative values may result from more complicated wave propagation in elastic media and at fluid‐solid interfaces. Our Laplace‐domain waveform inversion algorithm is also based on the finite‐element method and logarithmic wavefields. To compute gradient direction, we apply the back‐propagation technique. Under the assumption that density is fixed, P‐ and S‐wave velocity models are inverted from the pressure data. We applied our inversion algorithm to the SEG/EAGE salt model and the numerical results showed that the Laplace‐domain waveform inversion successfully recovers the long‐wavelength structures of the P‐ and S‐wave velocity models from the noise‐free data. The models inverted by the Laplace‐domain waveform inversion were able to be successfully used as initial models in the subsequent frequency‐domain waveform inversion, which is performed to describe the short‐wavelength structures of the true models.  相似文献   

Does use of tropical beaches by tourists and island residents result in damage to fringing coral reefs? A case study in Moorea French Polynesia     

Allison Juhasz  Ellen Ho  Erika Bender  Peggy Fong 《Marine pollution bulletin》2010,60(12):2251-2256

Although coral reefs worldwide are subject to increasing global threats, humans also impact coral reefs directly through localized activities such as snorkeling, kayaking and fishing. We investigated five sites on the northern shore of Moorea, French Polynesia, and quantified the number of visitors on the beach and in shallow water. In field surveys, we measured total coral cover and colony sizes of two common genera, Porites and Acropora, a massive and branching morphology, respectively. One site, which hosted over an order of magnitude more people than the other four, had significantly less total coral cover and supported very little branching Acropora. In addition, size frequency distributions of both the branching and massive genera were skewed toward smaller colony sizes at the high use site. Our results demonstrated that the use of tropical beaches may result in less coral cover, with branching colonies rare and small.  相似文献   

Effects of <Emphasis Type="Italic">Urechis unicinctus</Emphasis> juveniles on chemical characteristics of organically contaminated coastal sediment     

Kyoung Ho Kang  Zhifeng Zhang  Jae Min Kim  Seung Chun Seon  Mingyu Shao 《中国海洋大学学报(英文版)》2010,9(1):48-52

Biological activities of marine benthos such as burrowing and feeding may change sediment characteristics. We conducted three experiments to examine the potential of using juveniles of a spoon worm Urechis unicinctus to improve the quality of organically contaminated coastal sediment. Sediment samples were collected from a site that was heavily contaminated with organic matter (Seonso) and two sites that were clean (Myo-do, Dolsan-do). Urechis juveniles, obtained by artificial fertilization and cultured in the laboratory, were introduced to the sediment (weight 3 kg, depth 10 cm) at a density of 500 individuals per aquarium (length 50 cm, width 35 cm, height 30 cm) (Experiment 1), or at densities ranging from 100 to 900 individuals per beaker (Experiment 2). To examine how sediment contamination can be modified by the effects of Urechis, 500 individuals (per aquarium) were exposed to the Seonso contaminated sediment that had been mixed with 0–100% clean sand (Experiment 3). Each experiment lasted two months and sediment samples were collected every 15 d to determine the several indexes of sediment quality, which included acid volatile sulfide (AVS), chemical oxygen demand (COD) and total ignition loss (TIL). In Experiment 1, the existence of Urechis did not result in significant changes in quality indexes in the sediments collected from Myo-do, Dolsan-do. However, AVS, COD and TIL of the Seonso sediment all decreased significantly after co-incubation with Urechis juveniles for 30 to 45 d. Experiment 2 showed that a density of at least 300 juveniles per beaker was necessary to significantly reduce all three quality indexes, and the magnitude of reduction was positively correlated with juvenile density. Experiment 3 revealed that Urechis juveniles were effective in reducing the AVS, COD and TIL of the Seonso sediment that had been mixed with 60%, 80%, and 80% of clean sand, respectively. The results of the present study therefore indicated that juveniles of this spoon worm have the potential to be used to improve the quality of organically contaminated sediment in coastal waters.  相似文献   

Cloning,characterization,and expression analysis of the DEAD-box family genes,Fc-vasa and Fc-PL10a,in Chinese shrimp (Fenneropenaeus chinensis)     

周倩如  邵明瑜  秦贞奎  康庆浩  张志峰 《中国海洋湖沼学报》2010,(1)

RNA helicases of the DEAD-box and related families are involved in various cellular processes including DNA replication,DNA repair,and RNA processing.However,the function of DEAD-box proteins in aquaculture species is poorly understood at molecular level.We obtained the full-length cDNA sequences of two genes encoding helicase-related proteins,Fc-vasa and Fc-PL10a,from the testes of Chinese shrimp,Fenneropenaeus chinensis.The two predicted amino acid sequences contain all the conserved motifs characterized ...  相似文献   

Effect of model error representation in the Yellow and East China Sea modeling system based on the ensemble Kalman filter   总被引：1，自引：1，他引：0  

Kyung Man Kwon  Byoung-Ju Choi  Sang-Ho Lee  Young Ho Kim  Gwang-Ho Seo  Yang-Ki Cho 《Ocean Dynamics》2016,66(2):263-283

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Seismic response estimation method for earthquake‐damaged RC buildings          下载免费PDF全文

Ho Choi  Yasushi Sanada  Hisatoshi Kashiwa  Yasuhiro Watanabe  Jafril Tanjung  Huanjun Jiang 《地震工程与结构动力学》2016,45(6):999-1018

This study proposes a procedure for identifying spectral response curves for earthquake‐damaged areas in developing countries without seismic records. An earthquake‐damaged reinforced concrete building located in Padang, Indonesia was selected to illustrate the identification of the maximum seismic response during the 2009 West Sumatra earthquake. This paper summarizes the damage incurred by the building; the majority of the damage was observed in the third story in the span direction. The damage was quantitatively evaluated using the damage index R according to the Japanese guidelines for post‐earthquake damage evaluation. The damage index was also applied to the proposed spectral response identification method. The seismic performance of the building was evaluated by a nonlinear static analysis. The analytical results reproduced a drift concentration in the third story. The R‐index decreased with an increase in the story drift, which provided an estimation of the maximum response of the building during the earthquake. The estimation was verified via an earthquake response analysis of the building using ground acceleration data, which were simulated based on acceleration records of engineering bedrock that considered site amplification. The maximum response estimated by the R‐index was consistent with the maximum response obtained from the earthquake response analysis. Therefore, the proposed method enables the construction of spectral response curves by integrating the identification results for the maximum responses in a number of earthquake‐damaged buildings despite a lack of seismic records. Copyright © 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.  相似文献   

Semiautomatic and Automatic Cooperative Inversion of Seismic and Magnetotelluric Data   总被引：1，自引：1，他引：0  

Cuong V. A. Le  Brett D. Harris  Andrew M. Pethick  Eric M. Takam Takougang  Brendan Howe 《Surveys in Geophysics》2016,37(5):845-896

Natural source electromagnetic methods have the potential to recover rock property distributions from the surface to great depths. Unfortunately, results in complex 3D geo-electrical settings can be disappointing, especially where significant near-surface conductivity variations exist. In such settings, unconstrained inversion of magnetotelluric data is inexorably non-unique. We believe that: (1) correctly introduced information from seismic reflection can substantially improve MT inversion, (2) a cooperative inversion approach can be automated, and (3) massively parallel computing can make such a process viable. Nine inversion strategies including baseline unconstrained inversion and new automated/semiautomated cooperative inversion approaches are applied to industry-scale co-located 3D seismic and magnetotelluric data sets. These data sets were acquired in one of the Carlin gold deposit districts in north-central Nevada, USA. In our approach, seismic information feeds directly into the creation of sets of prior conductivity model and covariance coefficient distributions. We demonstrate how statistical analysis of the distribution of selected seismic attributes can be used to automatically extract subvolumes that form the framework for prior model 3D conductivity distribution. Our cooperative inversion strategies result in detailed subsurface conductivity distributions that are consistent with seismic, electrical logs and geochemical analysis of cores. Such 3D conductivity distributions would be expected to provide clues to 3D velocity structures that could feed back into full seismic inversion for an iterative practical and truly cooperative inversion process. We anticipate that, with the aid of parallel computing, cooperative inversion of seismic and magnetotelluric data can be fully automated, and we hold confidence that significant and practical advances in this direction have been accomplished.  相似文献   

Isotherm Study of Phosphorus Uptake from Aqueous Solution Using Aluminum Oxide     

Liang Zhang  Song Hong  Jing He  Fuxing Gan  Yuh‐Shan Ho 《洁净——土壤、空气、水》2010,38(9):831-836

Aluminum oxide, which could be an alternative filter media for phosphorus uptake from aqueous solution, was selected as an adsorbent for the isotherm study of phosphorus uptake from aqueous solution. Batch method was adopted to investigate the adsorption behavior of phosphorus onto aluminum oxide. The Langmuir, Freundlich, and Redlich–Peterson isotherms were used to analyze the experimental data by both the linear and nonlinear regression methods. The adsorption experiment was conducted at various temperatures, to choose the appropriate method and obtain the creditable adsorption parameters for phosphorus uptake studies. The results indicated that the nonlinear regression method might be a better way to compare the best‐fitting isotherm and obtain the parameters for the adsorption of phosphorus onto aluminum oxide. Both the Redlich–Peterson and the Freundlich isotherms have high coefficients of determination for the adsorption of phosphorus onto aluminum oxide at various temperatures. In addition, a new relationship between the Redlich–Peterson and the Freundlich isotherm parameters was presented.  相似文献   

Semi‐active tuned mass damper building systems: Design     

Min‐Ho Chey  J. Geoffrey Chase  John B. Mander  Athol J. Carr 《地震工程与结构动力学》2010,39(2):119-139

Passive and semi‐active tuned mass damper (PTMD and SATMD) building systems are proposed to mitigate structural response due to seismic loads. The structure's upper portion self plays a role either as a tuned mass passive damper or a semi‐active resetable device is adopted as a control feature for the PTMD, creating a SATMD system. Two‐degree‐of‐freedom analytical studies are employed to design the prototype structural system, specify its element characteristics and effectiveness for seismic responses, including defining the resetable device dynamics. The optimal parameters are derived for the large mass ratio by numerical analysis. For the SATMD building system the stiffness of the resetable device design is combined with rubber bearing stiffness. From parametric studies, effective practical control schemes can be derived for the SATMD system. To verify the principal efficacy of the conceptual system, the controlled system response is compared with the response spectrum of the earthquake suites used. The control ability of the SATMD scheme is compared with that of an uncontrolled (No TMD) and an ideal PTMD building systems for multi‐level seismic intensity. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献