Assessment of Capillary Rise from Shallow Groundwater by the Simulation Model SIMWASER Using Either Estimated Pedotransfer Functions or Measured Hydraulic Parameters

The performance of the water balance and crop growth model SIMWASER to estimate the water supply of a lawn by capillary rise from shallow ground water was investigated by using lysimeter measurements with a sandy and a clayey soil. Moreover the robustness of the model was evaluated by running it either with measured hydraulic soil parameters or with estimated pedotransfer functions (PTFs) derived from texture and bulk density. Simulations were performed for the years 1996–1998 with input data from the lysimeter station Berlin-Dahlem (Germany) for lysimeters containing undisturbed sandy or clayey soil monoliths, with groundwater at 135 cm depth. Simulated evapotranspiration and percolation/capillary rise were in good agreement with the measured data for all variants, while simulated soil water storage was acceptable only for the variants using hydraulic soil data based on laboratory measurements or using PTFs derived from known soil class and bulk density. PTFs based on mean total pore volume of the respective soil classes yielded soil water storages which were evidently too high; therefore they should be used with care and must be avoided at all in simulating the soil water balance of arid sites with shallow groundwater.     

On‐Line Detection Of State‐Of‐Charge In Lead Acid Battery Using Radial Basis Function Neural Network

To realize a stable supply of electric power in an automobile, an accurate and reliable detection method of SOC (state‐of‐charge) in a lead acid battery is required. However the dynamics of the battery is very complicated. The characteristics of the battery greatly change due to its degradation. Moreover a automobile has many driving patterns, which are unknown beforehand. Thus it is not easy to detect the SOC analytically. In this paper, to overcome this problem, a new on‐line SOC detection method with a radial basis function neural network is proposed. In order to increase the detection accuracy of degraded batteries, physical values related to the degradation degree are used as input signal in the neural network. The detection accuracies for different sized batteries and various degradation states are investigated.     

CARS光谱测温及仪器狭缝函数对测量的影响

设计了一种利用光参量振荡器(OPO)来代替染料激光器的宽带相干反斯托克斯喇曼散射(CARS)光谱测温实验装置。为了提高CARS测量温度的精度,测量和分析了检测系统中狭缝函数对测量结果的影响,确定了狭缝函数的具体形式。将测量结果与热电偶读数比较,发现在温度范围300K～1200K内,温度测量的不确定度小于2%。     

用改进的逐次逼近解法计算二维井间电磁场

提出了一种计算积分方程的新方法——改进的逐次逼近解法 (MSAM) ,并用该方法计算了轴对称二维井间电磁场。与传统的逐次逼近解法 (SAM)相比 ,该方法收敛性强 ,应用范围广 ,可适用于高电导率对比地层。由于不必进行直接的大型矩阵求逆运算 ,因此与积分方程的直接解法 (IE)相比 ,该方法计算速度更快 ,所需内存更少。采用矩阵求逆方法计算了成层介质中的二维 Green函数 ,并对含 Green函数的积分进行了简化 ,从而加快了计算速度。数值计算结果显示 ,在地层电导率对比度达到 2个数量级时 MSAM仍收敛 ,且计算结果与直接求解积分方程的结果一致 ,因此 MSAM是一种有效的计算轴对称二维井间电磁场的方法     

变异函数在进间砂体预测中的应用

应用变异函数探讨了砂体的定量预测问题。通过对北二东密井网试验区不同类型砂体，不同井网密和岩厚度的预测，检验了此方法的精度（为70％左右），在原方法的基础上，通过对预报精度的分析并结合精度地质研究进一步完善了该方法，提出二次建模法并应用于北二东西块聚驱井的砂岩厚度预测中，预测精度可提高5％以上，从而说明应用变异函数研究砂体的定量预测问题具有可借鉴性，可以为今后新井调整厚度的预测及砂体描述提供依据。     

TRANSFER FUNCTION MODEL ORDER AND PARAMETER ESTIMATION

Abstract. A distributed lag model with a rational transfer function is considered. We have demonstrated that the C -table can be used to determine the orders of the rational transfer function and the Padé table can be used to estimate the parameters of an identifiable transfer function. In case the model is not uniquely identified, the C -table reduces possible competing models to only a few for further examination. Padé approximant gives consistent initial values for possibly more efficient iterative procedures to estimate the coefficients of the identified model. Some asymptotic results on the estimation of the C -table and the Padé table are given. A few examples are presented to demonstrate the effectiveness of the method.     

Linear interpolation in a fuzzy information space

An approach to solving a linear interpolation problem in a fuzzy information space is proposed. Two different schemes of interpolation are outlined: a heuristic one, based on the geometrical interpretation of operations, and an optimization one, based on the expansion principle. The results obtained allow performing fuzzy linear prediction. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 55–68, March–April 2006.     

不规则I型和L型横截面形状薄壁杆件的横向弯曲稳定分析

根据势能驻值原理,采用转换B3样条函数模拟杆件横截面的翘曲位移场,文[8]提出了用于分析在横向荷载作用下薄壁杆件稳定问题的样条有限杆元法。方法适用于任意横截面形状和任意边界条件的薄壁杆件,考虑了杆壁中面上剪切变形的影响,能很好地描述剪力滞后现象。本文讨论了不规则I型截面简支梁和L型截面简支梁的屈曲分析,数值算例的结果表明了方法的灵活性、精确性和有效性。     

密码学函数迭代原理信息论分析

在密码编码学中,经常利用密码学函数迭代技术来实现密码算法,其所依赖的理论基础包括相关免疫理论,扩散准则,雪崩原理等.本文利用信息论原理以及随机过程理论给出了密码学函数迭代原理分析,得到了经过密码学函数迭代之后,输出为均匀分布时,输入输出互信息极限为零的充分必要条件,以及在一定条件下输入输出互信息收敛速度的一个上界.