旋转加速度计重力梯度仪误差分析

安装误差和加速度计标度系数的不匹配对旋转加速度计重力梯度仪的分辨率影响很大。为此,用线性微扰方法对旋转加速度计重力梯度仪的测量方程求取变分,得到重力梯度仪的误差方程;对误差方程进行分析,得到安装误差各项对重力梯度仪输出的影响;同时,给出含有加速度计性能参数的重力梯度仪的误差方程。以澳大利亚FALCON旋转加速度计重力梯度仪为例,具体给出径向距离误差、切向误差角等大小值。

三分量磁通门传感器校正的循环优化算法

由于制造工艺的原因,三分量磁通门传感器存在固有的零位误差、标度误差和正交误差。介绍了三分量磁通门传感器固有误差的特点,及其数学描述方法。提出了一种循环优化算法,将优化算法引入全部固有误差的校正,采用循环计算的思想提高了解算误差校正参数的准确度。解决了由于测量数据中三种固有误差的同时存在,难于准确求算每种校正参数的问题。应用表明,循环优化算法大大提高了三分量磁通门传感器的校正效果。

角加速度对闭环光纤陀螺输出的影响

通过对闭环干涉式光纤陀螺 ( IFOG)原理的分析 ,修正了以往闭环 IFOG输入、输出的表达式。指出在角加速度存在的情况下 ,光功率的波动产生 IFOG输出误差 ,通过仿真验证了所提出的观点。最后得出结论 ,研制高精度并能适用于剧烈运动状态的 IFOG时 ,必须考虑到角加速度这个因素 。

病毒传播与级联故障相互作用过程的研究

为研究聚类系数对病毒传播与级联故障相互作用的影响,提出一种改进的病毒传播与级联故障相互作用模型。通过改变平均度和三角连接概率调节网络聚类系数,以此观察病毒传播与级联故障相互作用过程。当不考虑三角连接概率时,平均度越小,网络抵制相互作用的能力越强,且区分度越明显,但也会增强级联故障子过程的破坏力。当平均度较小时,三角连接概率越大,网络抵制相互作用的能力越弱。当平均度较大时,不同三角连接概率对应的网络抵制相互作用的效果相似。仿真结果表明,对比单一病毒传播模型,相互作用模型在同一时刻的破坏力更大。

工业配料中的自控

本文介绍了微机在工业配料过程中的应用情况，对上料-计量-下料的全过程即“动态运行-静态计量-动态运行”进行控制．

硅微角振动陀螺仪温度特性补偿方法研究

在研究硅微角振动陀螺结构和温度特性的基础上,创建了二元高阶多项式补偿模型,并设计了基于STM32F405的硬件补偿电路,实现该陀螺仪实时温度补偿。实验结果表明:温度补偿后的标度因数温度系数和全温零偏稳定性分别由344×10-6/℃和441°/h减小为12.6×10-6/℃和40.6°/h,使得该陀螺仪的温度特性有明显改善,验证了该补偿方法的有效性和可行性。

A Robust Method for Ordering Performances of Multi-assets, Based Purely on Their Return Series

This study propose a new robust method to rank the performances of multi-assets （portfolios）, based purely on their return time series. This method makes no assumption on the distributions. Topsoe distance is symmetrized Kullback-Leibler divergence by average of the probabilities. The square root of Topsoe distance is a metric. We extend this metric from probability density functions to real number series on （0, 1 ]. We call it ST-metric. We show the consistency of ST-metric with mean-variance theory and stochastic dominance method of order one and two. We demonstrate the advantages of ST-metric over mean-variance rule and stochastic dominance method of order one and two.

Evaluating the Algorithm for Correction of the Bright Band Effects in QPEs with S-, C-and X-Band Dual-Polarized Radars

The bright band, a layer of enhanced radar reflectivity associated with melting ice particles, is a major source of signifi- cant overestimation in quantitative precipitation estimation （QPE） based on the Z-R （reflectivity factor-rain rate） relationship. The effects of the bright band on radar-based QPE can be eliminated by vertical profile of reflectivity （VPR） correction. In this study, we applied bright-band correction algorithms to evaluate three different bands （S-, C- and X-band） of dual-polarized radars and to reduce overestimation errors in Z-R relationship-based QPEs. After the reflectivity was corrected by the algo- rithms using average VPR （AVPR） alone and a combination of average VPR and the vertical profile of the copolar correlation coefficient （AVPR＋CC）, the QPEs were derived. The bright-band correction and resulting QPEs were evaluated in eight precipitation events by comparing to the uncorrected reflectivity and rain-gange observations, separately. The overestimation of Z-R relationship-based QPEs associated with the bright band was reduced after correction by the two schemes for which hourly rainfall was less than 5 mm. For the verification metrics of RMSE （root-mean-square error）, RMAE （relative mean absolute error） and RMB （relative mean bias） of QPEs, averaged over all eight cases, the AVPR method improved from 2.28, 0.94 and 0.78 to 1.55, 0.60 and 0.40, respectively, while the AVPR＋CC method improved to 1.44, 0.55 and 0.30, respectively. The QPEs after AVPR＋CC correction had less overestimation than those after AVPR correction, and similar conclusions were drawn for all three different bands of dual-polarized radars.

Thin Film Chip Resistors with High Resistance and Low Temperature Coefficient of Resistance

High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 ty...

New Change of Technical Indicators System of Watt-Hour Meters

There is an imperfection in the accuracy indicators system and the technical parameters system in IEC standards 62053-21 implemented for watt-hour meters currently. This article quoted some parts of OIML MI-003 and R46 contents to provide a reference of the integrity comparison between the accuracy system and technical parameter system. The comparison result shows that the watt-hour meter accuracy technical indicators system of OIML R46 is more integrated. First reason is that it determines all the accuracy （basic error） defining rules just by using the technical parameter I efficiently; secondly, it can solve the contradiction that no error regulation of the range from starting current to minimum current in the process of providing, handing over and checking watt-hour meter products＇ qualities efficiently. Please pay close attention to the R46 official version which will be released soon, as it is still in the Committee Draft （CD6） stage currently.

An Extended Bailey-welch Rule with No-show and Walk-in For Outpatient Appointment Scheduling

In clinic＇s appointment scheduling system no-shows have been a significant and confirmed issue with a bad influence on patient accessibility and clinic efficiency. The problem of walk-in has often been seen as the opposite of no-show problem. In this work we revisit a walk-in admitting based approach to mitigate the bad influence of no-show without overbooking. First we establish a model which utilizes marginal benefit objective function to balance the interests of the clinic, the patient and the doctor, we prove that no-show and walk-in cancels out each other straightly has a bad property. Then we propose a new rule which is an extension of the well-known Bailey - Welch rule, the simulation results show that our rule has an improvement comparing with the common rule that cancels them out straightly.

层次分析法的标度研究

近年来，由美国著名的运筹学家Ｔ．Ｌ．Ｓａａｔｙ所提出的一种实用的决策方法——层次分析法在我国得到了广泛的应用。但是，在实际应用中，根据Ｓａａｔｙ给出的判断标度进行两两比较、构造判断矩阵，有可能导致排序上的错误的结论。

Global Smooth Solutions to the 2-D Inhomogeneous Navier-Stokes Equations with Variable Viscosity

Under the assumptions that the initial density ρ0 is close enough to 1 and ρ0-1∈Hs+1(R2);u0∈Hs(R2)∩H_∈(R2) for s>2 and 0<ε<1;the authors prove the global existence and uniqueness of smooth solutions to the 2-D inhomogeneous Navier-Stokes equations with the viscous coefficient depending on the density of the fluid.Furthermore,the L2 decay rate of the velocity field is obtained.

An intuitive general rank-based correlation coefficient

Correlation analysis is an effective mechanism for studying patterns in data and making predictions.Many interesting discoveries have been made by formulating correlations in seemingly unrelated data. We propose an algorithm to quantify the theory of correlations and to give an intuitive, more accurate correlation coefficient.We propose a predictive metric to calculate correlations between paired values, known as the general rank-based correlation coefficient. It fulfills the five basic criteria of a predictive metric： independence from sample size,value between-1 and 1, measuring the degree of monotonicity, insensitivity to outliers, and intuitive demonstration.Furthermore, the metric has been validated by performing experiments using a real-time dataset and random number simulations. Mathematical derivations of the proposed equations have also been provided. We have compared it to Spearman＇s rank correlation coefficient. The comparison results show that the proposed metric fares better than the existing metric on all the predictive metric criteria.

Effects of Some Topological Ingredients on the Evolutionary Ultimatum Game

This study aims at figuring out the crucial topological ingredients which affect the outcomes of the ultimatum game located on different networks, encompassing the regular network, the random network, the smallworld network, and the scale-free network. With the aid of random interchanging algorithm, we investigate the relations between the outcomes of the ultimatum game and some topological ingredients, including the average range, the clustering coefficient and the heterogeneity, and so forth. It is found that for the regular, random and small-work networks, the average range and the clustering coefficient have evident impacts on the ultimatum game, while for the scale-free network, the original degree heterogeneity and the underlying rich-club characterizations are the mainly important topological ingredients that influence the outcomes of ultimatum game substantially.

The scaling behavior of the second virial coefficient of linear and ring polymer

The scaling behavior of the second virial coefficient of ring polymers at the theta temperature of the corresponding linear polymer(θ_L) is investigated by off-lattice Monte Carlo simulations. The effects of the solvents are modeled by pairwise interaction between polymer monomers in this approach. Using the umbrella sampling, we calculate the effective potential U(r) between two ring polymers as well as the second virial coefficient A_2 of ring polymers at θ_L, which results from a combination of 3-body interactions and topological constraints. The trend in the strength of the effective potential with respect to chain length shows a non-monotonic behavior, differently from that caused only by topological constraints. Our simulation suggests that there are three regimes about the scaling behavior of A_2 of ring polymers at θ_L: 3-body interactions dominating regime, the crossover regime, and the topological constraints dominating regime.

Non-Markovianity and Indivisible Quantum dynamics of a Apin-S System

Using a measure for the divisibility of a dynamical map, we study the non-Markovian character of a quantum evolution of a spin-S system, which is in an external field and weakly coupled to a bosonic bath with a certain temperature. The finite-temperature dynamics of the open system is obtained by the time-convolutionless master equation in the secular approximation. Besides the influence of the environmental spectral density function, the external field and low temperatures can affect the quantum non-Markovianity. It is found out that the non-Markovian feature of a dynamical map of a high-dimensional spin system is noticeable in contrast to that of a low-dimension spin system.

Isotopic Effects on Stereodynamics of the C^+ + H_2→CH^+ + H Reaction

The effects of isotope substitution on stereodynamic properties for the reactions C^+ + H_2/HD/HT →CH^+ + H/D/T have been studied applying a quasi classical trajectory method occurring on the new ground state CH_2^+ potential energy surface [J. Chem. Phys. 142(2015) 124302]. In the center of mass coordinates applying the quasi classical trajectory method to investigate the orientation and the alignment of the product molecule. Differential cross section and three angle distribution functions P(θ_r), P(ф_r), P(θ_r, ф_r) on the potential energy surface that fixed the collision energy with a value is 40 kcal/mol have been studied. The isotope effect becomes more and more important with the reagent molecules H_2 changing into HD and HT. P(θ_r, ф_r) as the joint probability density function of both polar angles θ_r and ф_r, which can illustrate more detailed dynamics information. The isotope effect is obvious influence on the properties of stereodynamics in the reactions of C^+ + H_2/HD/HT → CH^+ + H/D/T.

Scaling laws of aquatic locomotion

In recent years studies of aquatic locomotion have provided some remarkable insights into the many features of fish swimming performances. This paper derives a scaling relation of aquatic locomotion CD(Re)~2 =(Sw)~2 and its corresponding log law and power law. For power scaling law,(Sw)~2 = β_nRe^((2-1)/n), which is valid within the full spectrum of the Reynolds number Re=UL/v from low up to high, can simply be expressed as the power law of the Reynolds number Re and the swimming number Sw=ωAL/v as Re ∝ (Sw)~σ,with σ=2 for creeping flows,σ=4/3 for laminar flows, σ=10/9 and σ=14/13 for turbulent flows. For log law this paper has derived the scaling law as Sw ∝ Re=(lnRe+1.287), which is even valid for a much wider range of the Reynolds number Re. Both power and log scaling relationships link the locomotory input variables that describe the swimmer's gait A;ω via the swimming number Sw to the locomotory output velocity U via the longitudinal Reynolds number Re, and reveal the secret input-output relationship of aquatic locomotion at different scales of the Reynolds number.