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1071 research outputs found
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Study on Preparation of Functional Polymer-Grafted Natural Rubber
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Machine Learning-based Protein Name Identification among Biomedical Entities
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Electrochemical and Thermal Investigation of Li-ion Secondary Cells Using Electrochemical Impedance Spectroscopy and Accelerating Rate Calorimetry
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Model Spin-Up Behavior for Wet and Dry Basins: A Case Study Using the Xinanjiang Model
No full textArticleModel spin-up is an adjustment process where its internal stores move from an initial state of unusual conditions to one of equilibrium. Model outputs during this spin-up process are often unrealistic and misleading. This study investigates some primary factors affecting spin-up time using the Xinanjiang model for 22 river basins throughout the United States. A 10-year recursive simulation with three data sets indicates that time required for model equilibrium is not only a function of initial conditions, but also is affected by input data sets (precipitation and evaporation). The model requires less time to be equilibrated under wetter initial conditions (lowest under saturated initial condition). Moreover, model spin-up time shows distinct variations with the dryness of the input data sets. Analysis suggests that wet basins (ratio of evaporation over precipitation <0.9) require less time (55 days) for model equilibrium in comparison to that of dry basins (298 days). The spin-up time displayed an exponential relationship with the basin aridity index (r2 = 0.85). This relationship could provide a way to predict the maximum model spin-up time using the precipitation and evaporation information only. Predicting maximum model spin-up time based on this relationship could be valuable to reduce uncertainty, particularly under data scarce situations.journal articl
A data-driven method to remove temperature effects in TDR-measured soil water content at a Mongolian site
No full textArticleAs a convenient, easy-to-use tool, time-domain reflectometry (TDR) is becoming extensively used to measure soil water content. Used not only in hydrological applications, the measurements are also used as ground truth for satellite remote sensing of soil moisture. However, TDR measurements usually include diurnal fluctuation caused by diurnal change of temperature. Though this is an old problem, there is not a general solution. The purpose of this study is to develop an algorithm to remove temperature effects of TDR measurements by analyzing its relationship with meteorological variables. From data observed at a Mongolian site, it is found that impact of soil temperature on soil water content is nearly proportional to soil temperature itself and soil water content. An algorithm is developed and applied to the Mongolian data set. The temperature effects can be effectively removed under dry and wet conditions.journal articl
APPLICATION OF ARIDITY INDEX IN ESTIMATION OF DATA ADJUSTMENT PARAMETERS IN THE XINANJIANG MODEL
No full textArticleBased on the sensitivity analysis at annual, monthly and daily scales, parameters of the Xinanjiang model could be divided into three groups and optimized independly without considering the effects from other groups. This paper focuses on the optimization of data adjustment parameters, Cp and Cep, which are sensitive at annual scale. The concept of aridity index is introduced into the optimization process, and proposed a relationship describing Cp and Cep as a function of annual runoff coefficient and pan aridity index. Three different methods are developed to estimate the value of Cp and Cep in ideal condition and actual practice respectively. The results show that, compared with optimizing Cp and Cep independly, the method considering the relationship of runoff coefficient and pan aridity index will narrow the parameter space, and keep the same accuracy. The effectivity of method using the simple linear relationship will depend on the length of data series and correlation between annual runoff coefficient and pan aridity index.journal articl
