连云港口门防波堤建设对航道回淤影响数值研究

以连云港海区为例,建立潮流、波浪共同作用下的泥沙运动数学模型,应用年平均含沙量场作为依据对临界冲刷切应力和冲刷率进行率定,并利用实测资料对模型进行验证。在模型基础上研究了口门防波堤建设对年平均含沙量场及进港航道回淤的影响,分析了工程后平均含沙量场的分布形式和航道回淤强度的沿程变化规律。结果表明防波堤修建后,口门处含沙量较高,并向港内和外海逐渐降低,航道回淤强度分布形态与航槽内含沙量分布形态相似;航槽第二年回淤率低于第一年。     

Spherical approximation for multiple cameras in motion estimation: Its applicability and advantages

Estimating motions of a multi-camera system which may not have overlapping fields of view is generally complex and computationally expensive because of the non-zero offset between each camera’s center. It is conceivable that if we can assume that multiple cameras share a single optical center, and thus can be modeled as a spherical imaging system, motion estimation and calibration of this system would become simpler and more efficient.     

阵列信号处理中一种新的误差分析及其矫正技术

分析了空间谱估计中多信号源方向和频率估计中通道失配和阵元互耦导致系统性能下降的机制。克服了现有矫正方法只能针对单频信号补偿某个或某几个误差影响因素的局限性，提出通道失配和阵元互耦的综合补偿新技术，大大提高了误差矫正的精度。首次尝试在频率、方向同时估计中应用误差校正技术，并得出了一重要结论－这几种误差影响因素对频率估计没有影响，且此方法可推广应用于倍频程信号、窄带随机信号和单频信号的组合情况。消声室声学实验证明了该方法的正确性。     

Simulation experiments in parameter identification for robot calibration

This paper examines the factors to be considered for the identification of kinematic parameters during robot calibration. A generalised calibration experiment has been simulated using two different identification techniques. Details of the identitication techniques and considerations for implementing them using standard IMSL routines are presented. The factors considered during the simulations include initial estimates of parameters, effect of measurement noise, number of pose measurements, and accuracy of the measurement system used. Results are tabulated for the various cases and suggestions are made towards the efficient planning and execution of robot-calibration experiments.     

The quantification of remote sensing

Presently China has developed and launched more than 30 earth observing satellites. The primary series of FY, HY and resource satellites have been constructed. In China, earth observing techniques have been developed rapidly and the achievements are re- markable, but compared with the developed countries, there is still a long way to go. Besides, the quantitative application research of satellites data in China is not profound enough. Thus, it is urgent to consider how to systematically con…     

Standards for Waveform Metrology Based on Digital Techniques

Over the last decade the use of digital synthesis and sampling techniques for generating and measuring electrical waveforms has increased dramatically with the availability of improved digital-to-analog (D/A) and analog-to-digital (A/D) converters and related devices. With this evolution has come the need for physical laboratory standards and test methods to support the performance specifications of digital devices and the instruments in which they are used. This article describes the research and development at NIST of several laboratory standards and test systems that utilize “digital technology” for characterizing data converters and for implementing various waveform synthesis and sampling instruments.     

U.K. National Radiological Protection Board Radon Calibration Procedures

A procedure for the calibration of instruments for the detection of ²²²Rn in air is described. The method is based on the alpha-spectrometric determination of the concentration in air of ²¹⁸Po in the calibration chamber. The calibration chamber is described, together with the method of maintaining a high aerosol concentration. The ²¹⁸Po concentration at steady state in the chamber is found to be 98% of the ²²²Rn concentration typically. An assessment of the sources of uncertainty in the method presented indicate that the ²²²Rn concentration in the chamber can be determined with an overall uncertainty of about 7% at the 95% confidence level.     

Calibration of the automated z-axis of a microscope using focus functions

Applications in automated microscopy and three-dimensional microscopy require careful calibration of the microscope system. This paper presents methods for calibration of the motorized z -axis (focus or optical axis) of an automated microscope. Apart from the automated microscope the procedures require a CCD camera and a test slide containing a simple bar pattern. The calibration embraces the following characteristics of the z -axis: (a) measuring the motor step size in nanometres; (b) measuring the mechani-cal backlash in the focus mechanism of the microscope and (c) measuring the reproducibility and the stability of the focus position over time. The measurements employ focus functions to determine the z -position of the microscope stage.     

储层岩性高分辨率地震资料精细解释技术初步探讨

普遍采用基于不同算法的预测软件利用高分辨率地震资料进行储层预测，预测结果除受地震资料的频率和保真度影响外，主要受软件本身算法的影响。无论哪 种软件，其算法主要是数学原理，缺少地质信息，使其结果具有多解性，往往不符合地质规律。     

原油动态计量和标定

原油动态计量就是通过高精度的流量计,对流动状态下的原油进行连续的计量。用于贸易结算的流量计在使用前后,应分别进行在线实液标定,确定流量计系数及精度,使流量计满足贸易结算的使用要求。在原油中转码头及油库,对卸油和装油的计量通常由计量站完成,计量站一般包括计量系统、标定系统和辅助系统。介绍了原油动态计量和标定的原理、详细阐述了原油计量系统和标定系统的基本构成和主要设备及功能,给出了原油动态计量和标定的工程设计方法。