ISEE: Internet‐based Simulation for Earthquake Engineering—Part I: Database approach     

Yuan‐Sen Yang  Shang‐Hsien Hsieh  Keh‐Chyuan Tsai  Shiang‐Jung Wang  Kung‐Juin Wang  Wei‐Choung Cheng  Chuan‐Wen Hsu 《地震工程与结构动力学》2007,36(15):2291-2306

An Internet‐based framework, named Internet‐based Simulation for Earthquake Engineering (ISEE) was developed to facilitate collaborative earthquake engineering experiments performed by multiple laboratories in a network environment. One of the approaches in the ISEE framework, named Database Approach, offers an easy way to perform multi‐site networked collaborative pseudo‐dynamic experiments. The Database Approach uses the Structured Query Language (SQL), a common and standardized computer language used in database management systems, for inter‐laboratory communications. Using the SQL protocol, it is easy to monitor the experiments' progress, access the data, as well as develop additional programs to expand the functions for a networked experiment. This approach offers consistency and durability of selected experimental data both during and after experiments. Two networked pseudo‐dynamic experiments were conducted to demonstrate the feasibility and expansibility of the Database Approach in ISEE. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Toxicity identification evaluation (TIE) of pore water of contaminated marine sediments collected from Hong Kong waters   总被引：2，自引：0，他引：2  

Kwok YC  Hsieh DP  Wong PK 《Marine pollution bulletin》2005,51(8-12):1085-1091

Marine sediment can function both as a source and as a sink of marine chemical contaminants. The toxicity of contaminated marine sediment can be assessed by toxic evaluation of its pore water, the inter-particle water of sediment, because toxicants in the pore water may be bioavailable to marine organisms. In this study, the toxicity identification evaluation (TIE) was performed to identify the major toxicants in the pore water of marine sediment collected in Hong Kong waters. In Phase 1 TIE, the suspected toxicants were characterized as anions or organic compounds that are either oxidizable or filterable in alkaline medium. In Phase 2 TIE, the suspected toxicants were identified as sulfide (S²⁻) based on the reduction of toxicity due to lowering of sulfide concentrations by experimental manipulations. The mass balance and spiking analyses in Phase 3 confirmed that S²⁻ was one of the major toxicants and that some non-toxic unknown compounds measured by LC–MS, which was removed by C18 solid phase extraction, enhanced the toxicity of S²⁻ in the pore water samples.  相似文献   

Evaluation of Linear and Non-Linear Downscaling Methods in Terms of Daily Variability and Climate Indices: Surface Temperature in Southern Ontario and Quebec,Canada   总被引：1，自引：0，他引：1  

C.F. Gaitan  W.W. Hsieh  A.J. Cannon  P. Gachon 《大气与海洋》2014,52(3):211-221

We downscaled atmospheric reanalysis data using linear regression and Bayesian neural network (BNN) ensembles to obtain daily maximum and minimum temperatures at ten weather stations in southern Quebec and Ontario, Canada. Performance of the linear and non-linear downscaling models was evaluated using four different sets of predictors, not only in terms of their ability to reproduce the magnitude of day-to-day variability (i.e., “weather,” mean absolute error between the daily values of the predictand(s) and the downscaled data) but also in terms of their ability to reproduce longer time scale variability (i.e., “climate,” indices of agreement between the predictand's observed annual climate indices and the corresponding downscaled values). The climate indices used were the 90th percentile of the daily maximum temperature, 10th percentile of the daily minimum temperature, number of frost days, heat wave duration, growing season length, and intra-annual temperature range.

Our results show that the non-linear models usually outperform their linear counterparts in the magnitude of daily variability and, to a greater extent, in annual climate variability. In particular, the best model simulating weather and climate was a BNN ensemble using stepwise selection from 20 reanalysis predictors, followed by a BNN ensemble using the three leading principal components from the aforementioned predictors. Finally, we showed that, on average, the first three indices presented higher skills than the growing season length, number of frost days, and the heat wave duration.  相似文献   

Impact of climate change on stream discharge and sediment yield in Northern Viet Nam   总被引：3，自引：0，他引：3  

D. B. Phan  C. C. Wu  S. C. Hsieh 《Water Resources》2011,38(6):827-836

The purpose of this paper is to apply “Soil and Water Assessment Tool (SWAT)” model to assess the impacts of climate change on stream discharge and sediment yield from Song Cau watershed in Northern Viet Nam. Three climate change scenarios B1, B2, and A2; representing low, medium, and high levels of greenhouse gas emission, respectively, were considered in this study. The highest changes in stream discharge (up to 11.4%) and sediment load (15.3%) can be expected in wet season in 2050s according to the high emission scenario (A2), while for the low emission scenario the corresponding changes equal to 8.8% and 12.6%. The results show that the stream discharge is likely to increase in the future during the wet season with increasing threats of sedimentation.  相似文献   

Using differential SAR interferometry to map land subsidence: a case study in the Pingtung Plain of SW Taiwan   总被引：3，自引：2，他引：1  

Hsieh  Chia-Sheng  Shih  Tian-Yuan  Hu  Jyr-Ching  Tung  Hsin  Huang  Mong-Han  Angelier  Jacques 《Natural Hazards》2011,58(3):1311-1332

Synthetic aperture radar (SAR) interferometry (InSAR) is a geodetic tool widely applied in the studies of earth-surface deformation. This technique has the benefits of high spatial resolution and centimetre-scale accuracy. Differential SAR interferometry (DInSAR) is used to measure ground deformation with repeat-pass SAR images. This study applied DInSAR and persistent scatterers InSAR (PSInSAR) for detecting land subsidence in the Pingtung Plain, southern Taiwan, between 1995 and 2000. In recent years, serious land subsidence occurred along coastal regions of Taiwan as a consequence of over-pumping of underground water. Results of this study revealed that the critical subsidence region is located on the coast near the estuary of Linpien River. It is also found that subsidence was significantly higher during the dry season than the wet season. The maximum annual subsidence rate of the dry season is up to −11.51 cm/year in critical subsidence region and the vertical land movement rate is much slower during the wet season. The average subsidence rates in wet and dry seasons are −0.31 and −3.37 cm/year, respectively. As a result, the subsidence rate in dry seasons is about 3 cm larger than in wet seasons.  相似文献   

Solar wind plasma protrusion into the martian magnetosphere: ASPERA-3 observations     

E. Dubinin  D. Winningham  J. Woch  S. Barabash  R. Frahm  A.J. Coates  J.-A. Sauvaud  H. Andersson  A. Grigoriev  K. Asamura  K.S. Hsieh  H. Koskinen  P. Riihelä  T. Säles  J. Luhmann  R. Cerulli-Irelli  M. Maggi  D. Williams  P. Wurz  C. Dierker  M. Carter 《Icarus》2006,182(2):343-349

The ASPERA-3 experiment onboard the Mars Express spacecraft revealed, near the wake boundary of Mars, a spatially narrow, strip-like plasma structure composed of magnetosheath-like electrons and planetary ions. The peak electron energy often exceeds the peak energy at the bow shock that indicates a significant heating (acceleration) during the structure formation. It is shown that this structure is formed during efficient plasma penetration into the martian magnetosphere in the region near the terminator. The penetration of sheath electrons and their gradual heating (acceleration) is accompanied by a change of the ion composition from a solar wind plasma to a planetary plasma dominated by oxygen ions. A possible mechanism of plasma inflow to the magnetosphere is discussed.  相似文献   

PAPPA: Primordial anisotropy polarization pathfinder array     

A. Kogut  D.T. Chuss  D. Fixsen  G.F. Hinshaw  M. Limon  S.H. Moseley  N. Phillips  E. Sharp  E.J. Wollack  K. U-Yen  N. Cao  T. Stevenson  W. Hsieh  M. Devlin  S. Dicker  C. Semisch  K. Irwin 《New Astronomy Reviews》2006,50(11-12):1009

The primordial anisotropy polarization pathfinder array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20° × 20° patch at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212, and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip transmission line to combine the phase modulation techniques used in radio astronomy with the sensitivity of transition-edge superconducting bolometers. Each switched circuit modulates the incident polarization on a single detector, allowing nearly instantaneous characterization of the Stokes I, Q, and U parameters. We describe the instrument design and status.  相似文献   

A Borehole Test for Chlorinated Solvent Diffusion and Degradation Rates in Sedimentary Rock     

Richelle M. Allen-King  Rebecca L. Kiekhaefer  Daniel J. Goode  Paul A. Hsieh  Michelle M. Lorah  Thomas E. Imbrigiotta 《Ground Water Monitoring & Remediation》2022,42(2):23-34

We present a new field measurement and numerical interpretation method (combined termed “test”) to parameterize the diffusion of trichloroethene (TCE) and its biodegradation products (DPs) from the matrix of sedimentary rock. The method uses a dual-packer system to interrogate a low-permeability section of the rock matrix adjacent to a previously contaminated borehole and uses the borehole monitoring history to establish the pretest condition. TCE and its DPs are removed from the groundwater between the packers at the onset of the testing. The parameters estimated by fitting a radial diffusion model to the concentration history and borehole concentration data, also termed back diffusion, are the tortuosity factor and sorption coefficients of TCE and DPs in the rock matrix and the TCE and DP biodegradation rate coefficients in the borehole. We demonstrate the equipment design and the interpretive method using a borehole accessing the gray mudstone at a TCE contaminated site in the Newark Basin. In this test, both nonreactive (bromide) and reactive (trichlorofluoroethene) tracers are used to constrain the estimated parameters; however, the bromide tracer was not needed to estimate the parameters in this test. The parameters estimated from the field test are consistent with values measured independently in laboratory experiments using field samples of similar lithology. From the interpretation, we compute the TCE and DP concentration distributions in the rock matrix prior to the test to illustrate how the results can be used to enhance understanding of contaminant distribution in the rock matrix.  相似文献   

Modeling Groundwater Inflow to the New Crater Lake at Kīlauea Volcano,Hawai'i     

S. E. Ingebritsen  A. F. Flinders  J. P. Kauahikaua  P. A. Hsieh 《Ground water》2021,59(1):7-15

During the 2018 eruption of Kīlauea Volcano, Hawai'i, scientists relied heavily on a conceptual model of explosive eruptions triggered when lava-lake levels drop below the water table. Numerical modeling of multiphase groundwater flow and heat transport revealed that, contrary to expectations, liquid water inflow to the drained magma conduit would likely be delayed by months to years, owing to the inability of liquid water to transit a zone of very hot rock. The summit of Kīlauea subsequently experienced an ∼2-month period of consistent repeated collapses, and the crater now extends below the equilibrium position of the water table. Liquid water first emerged into the deepened crater in late July 2019. The timing of first appearance of liquid water (about 14 months postcollapse) and the rate of crater lake filling (currently ∼27 kg/s) were well-predicted by the numerical modeling done in late spring 2018, which forecast liquid inflow after 3 to 24 months at rates of 10 to 100 kg/s. A second-generation groundwater model, reflecting the current crater geometry, forecasts lake filling over the next several years. The successful 2018 to present forecasts with both models are based on unadjusted in situ permeability estimates (1 to 6 × 10⁻¹⁴ m²) and water-table elevations (600 to 800 m) from a nearby research drillhole and geophysical surveys. Important unknowns that affect the reliability of longer-term forecasts include the equilibrium water-table geometry, the rate of evaporation from the hot and growing crater lake (currently ∼29,000 m² at 70-80 °C), and heterogenous permeability changes caused by the 2018 collapse.  相似文献   

64层锥束CT扫描的优化系统     

谢强  Eugene Williams  唐向阳  Brian Grekowicz  Roy Nilsen  Sandeep Dutta  Robert Senzig 《CT理论与应用研究》2005,14(4):59-67

近年来X射线断层成像(CT)技术获得了突飞猛进的发展,自1998年推出4层螺旋CT后,CT扫描设备在容积覆盖,空间分辨率,扫描速度,切片数方面取得了长足进展.这不仅给医学应用带来了深远的影响,同时也给CT系统设计提出了巨大的挑战.容积CT(VCT)的设计过程引入了各种策略来战胜其复杂性.这些方法学包括:理论分析,系统性能预测的图像分析工具,各种基于专家背对背评价的参数优化.本文论述了64层CT系统设计中的一些考虑因素及优化过程.这些设计过程保证了锥束CT的优化性能.首批客户的应用反馈显示了我们设计实践的有效率性.  相似文献