高通量药物筛选中靶分子固定化数学物理模型的建立

通过对高能量药物筛选基本过程的分析 ,探索了靶分子固定化可能对筛选质量构成的影响 .从分子相互作用看 ,实际的过程远较理想的情况复杂 .分子间存在的静电力、疏水作用力及氢键力能对固定化的机理构成较大影响 ,甚至可能诱发多层吸附的固定化模式 .基于固定化过程中可能存在的靶分子与靶分子、靶分子与微球、体相与表面相之间的相互作用 ,构筑了相应的数学物理模型 ,为实际的筛选工作提供了可参考的理论依据 .     

Bayesian and frequentist estimation of the performance of free space optical channels under weak turbulence conditions

Approximate mathematical form expressions were derived for the estimation of the average (ergodic) capacity and the average bit error rate of a log-normal free space optical channel in the cases of weak to moderate atmospheric turbulence conditions. We investigate the average capacity, the average bit error rate and the outage probability of free space optical communication channels using the frequentist and the Bayesian approach. Emphasis is given on the cases of weak to moderate atmospheric turbulence leading to channels modeled by log-normal distributed intensity fading. Furthermore, accurate approximate closed-form expressions and estimation procedures for their achievable capacity as well as their bit error rate and the important parameters of interest are derived. The derived approximate analytical expressions are verified by various numerical examples and simulations. Moreover, each methodology is reviewed in terms of their analytic convenience and their accuracy is also discussed.     

A new method to estimate a first-order plus time delay model from step response

In this paper an identification method to estimate the parameters of a first-order plus time delay model is proposed. Such a method directly obtains these parameters using a new linear regression equation. No iterations in calculation are needed. Moreover, a simple true/false criterion to establish if the hypothesis on the process type is correct can be easily derived. The proposed method shows an acceptable robustness to disturbances and measurement noise as it is confirmed by several simulated experiments.     

Spectral efficiency for selection combining RAKE receivers over Weibull fading channels

Novel closed-form expressions for the probability density function and the average output signal-to-noise ratio at the output of a selection combiner in Weibull fading are derived. Using these expressions, the spectral efficiency of a direct sequence code division multiple access system is analytically obtained and performance evaluation results are presented.     

Bivariate Densities with Diagonal Expansions in Gegenbauer Polynomials

Closed-form expressions and diagonal series expansions in Gegenbauer polynomials are derived for two bivariate density functions.     

Truncation error analysis in computing of SEP and SEP floor for partially coherent receiver of MPSK signals over composite fading channels

In this paper, we analyze detection of multilevel phase-shift keying (MPSK) signals transmitted over a Gamma shadowed Nakagami-m fading channel. We derive novel analytical expression, in terms of Meijer’s G function, for Fourier coefficients of the probability density function of the received signal composite phase. Under the assumption of the imperfect reference signal extraction in the receiver, which is performed from the pilot signal, the analytical expression is derived for the symbol error probability (SEP) in the form of convergent series. The existence of the error floor is identified, and expression for its computation is provided. Mathematical proofs for convergence of Fourier series are provided for both SEP and SEP floor, and novel expressions of upper bounds for truncation errors are derived in terms of elementary mathematical functions. The convergence rate of the derived expressions is examined. Numerical results are confirmed independently by Monte-Carlo simulations.     

非协调轴对称杂交应力元单元刚度矩阵的准确建立

给出新型三类用理性杂交模式、根据一种修正的Ｈｅｌｌｉｎｇｅｒ－Ｒｅｉｓｓｎｅｒ原理、建立高精度非协调轴对称实体旋转有限元时，其单元刚度矩阵的准确计算式。     

Augmented complex-valued normalized subband adaptive filter: Algorithm derivation and analysis

In this paper, a novel augmented complex-valued normalized subband adaptive filter (ACNSAF) algorithm is proposed for processing the noncircular complex-valued signals. Based on the augmented statistics, the proposed algorithm is derived by computing a constraint cost function. Due to contain all second-order statistical properties, the ACNSAF algorithm can process the circular and noncircular complex-valued signals simultaneously. Moreover, the stability and mean square steady-state analysis of the proposed algorithm is derived by using the energy conservation principle. Computer simulation experiments on complex-valued system identification, prediction and noise cancelling show that the proposed algorithm achieves the improved mean square deviation and prediction gain compared to the ACNLMS algorithm. And the simulation results are consistent with the analysis results.     

黑龙江流域MODIS和AMSR-E 雪盖产品精度分析

以黑龙江流域气象站数据作为"真值",检验了2002~2007年黑龙江流域MODIS积雪产品和AMSR-E数据识别积雪的精度,分析了云以及海拔高度对积雪识别的影响.结果表明,MOD10A2、MOD10C2、AMSR-E识别积雪的平均精度分别为75.4%、88.7%和88.9%,云仍然是影响积雪识别精度的主要原因,MOD10C2的积雪识别结果接近于气象站的真实值,AMSR-E高估积雪覆盖面积.此外通过软分类方法得出的MOD10A2和MOD10C2的积雪覆盖面积要低于硬分类得出的积雪覆盖面积,软分类法得到的结果更接近真实值.     

Data filtering-based multi-innovation forgetting gradient algorithms for input nonlinear FIR-MA systems with piecewise-linear characteristics

The piecewise-linear characteristics often appear in the nonlinear systems that operate in different ways in different input regions. This paper studies the identification issue of a class of block-oriented systems with piecewise-linear characteristics. The asymmetric piecewise-linear nonlinearity is expressed as a linear parametric representation through introducing an appropriate switching function, then the identification model of the system is derived by using the key term separation technique. On this model basis, a multi-innovation forgetting gradient algorithm is presented to estimate the unknown parameters. To further enhance the identification accuracy, the filtering identification model of the system is derived by changing the structure of the system without changing the relationship between the input and output. Further, a data filtering-based multi-innovation forgetting gradient algorithm is proposed through the use of the data filtering technique. A simulation example is employed to illustrate that the proposed approaches are effective for parameter estimation and the data filtering-based multi-innovation forgetting gradient algorithm has better estimation performance.     

Modelling and analysis of display terminal at a finite user resource sharing node in distributed computer systems

An intelligent display terminal system at a finite user resource sharing node in distributed computer systems is modelled as a queueing model with finite microcomputer memory, burst Erlang arrivals from the display terminal cathode-ray-tube, constant service-time, synchronous transmission and single server interrupted through a first-order Markov process. A new generalized method differs from the usual stage and summing method used by the previous research-workers is presented to calculate burst Erlang arrival probabilities. The display terminal microcomputer memory performance is studied for finite and infinite cases and the expressions for overflow probabilities and average queueing delays are derived using the recursive method developed for calculating steady state probabilities of the microcomputer memory states. An integrated voice-data system is presented as a probable application of the model at remote areas and some of its computed values are portrayed on graphs to be useful in calculating response times of remote display terminals sharing voice channels for transmission purpose.     

Stochastic error simulation method of fiber optic gyros based on performance indicators

Gyro simulation is an important process of inertial navigation theory research, with the major difficulty being the stochastic error modeling. One commonly used stochastic model for a fiber optic gyro (FOG) is a Gaussian white (GW) noise plus a first order Markov process. The model parameters are usually obtained by using time series analysis methods or the Allan variance method through FOG static experiment. However, in a real life situation, a FOG may not be used. In this paper, a simulation method is proposed for estimating the stochastic errors of FOG. When using this method, the model parameters are set based on performance indicators, which are chosen as the angle random walk (ARW) and bias stability. During the research, the ARW and bias stability indicators of the GW noise and the first order Markov process are analyzed separately. Their analytical expressions are derived to reveal the relation between the model parameters and performance indicators. In order to verify the theory, a large number of simulations were carried out. The results show that the statistical performance indicators of the simulated signals are consistent with the theory. Furthermore, a simulation of a VG951 FOG is designed in this research. The Allan variance curve of the simulated signal is in agreement with the real one.     

关系认同研究进展和展望

从关系认同的概念、测量方法、前因变量和结果变量、研究视角等方面系统地回顾与分析了国内外关系认同的研究现状与成果。对关系认同的研究进行了梳理和评价。总体来看,研究者主要从状态观和过程观两大视角界定关系认同,已有标准化的测量工具,关系认同会受个体因素和情境因素的影响,对个体的状态和产出有强大的预测力。目前,已经出现了社会交换理论、社会学习理论、社会支持理论和性别、文化等四大研究视角。未来研究应深入讨论其发生过程、前因、结果,并尝试进行本土化研究。     

新兴技术视域下潜在竞争对手识别研究——以智能驾驶领域为例

【目的/意义】诸多知名企业由于没有意识到新兴技术的发展趋势,忽略了未来可能对自身造成威胁的潜在 竞争对手,最终陷入破产境地。目前缺乏从新兴技术视角开展的潜在竞争对手识别研究。【方法/过程】在文献调研 的基础上,对潜在竞争对手识别的内涵进行分析,并构建新兴技术视域下潜在竞争对手识别流程。识别流程涵盖 预处理专利数据、新兴技术识别和潜在竞争对手识别三个步骤,涉及LDA主题模型构建、新兴技术指标体系建立和 技术知识存量计算等关键问题。【结果/结论】以智能驾驶领域为例,证明了基于新兴技术开展潜在竞争对手识别具 有一定的可行性,期望本方法能够为领先企业识别潜在竞争对手提供决策支持。【创新/局限】创新性地将新兴技术 识别与潜在竞争对手识别相结合,丰富潜在竞争对手识别理论与方法。     

State space model identification of multirate processes with time-delay using the expectation maximization

This paper presents the problems of state space model identification of multirate processes with unknown time delay. The aim is to identify a multirate state space model to approximate the parameter-varying time-delay system. The identification problems are formulated under the framework of the expectation maximization algorithm. Through introducing two hidden variables, a new expectation maximization algorithm is derived to estimate the unknown model parameters and the time-delays simultaneously. The effectiveness of the proposed algorithm is validated by a simulation example.     

Transient responses of m-derived filters

The analytic expressions of the unit-impulse and the unit-step responses ofthe classical m-derived and the composite filters are derived. The equations have been computed by means of an IBM 360 Model 44 digital computer. Normalized curves of the unit-step response are presented. They are completely universal and can be applied to specific situations by rescaling the axes.     

Analysis and tracer identification of multiphase transport systems with recycling

We consider the identification of the exchange coefficients of a multiphase spacially inhomogeneous transport system with absorbing-reflecting boundaries (i.e. recycling) by means of the tracer technique. A probabilistic approach is used. The model is described and equations are derived for functionals of the tracer distributions at the outputs. Previous results on identifiability and identification for the case without recycling are extended to the case of a recycling system.     

基于信息过程模型的创业机会识别研究

基于创业机会识别与信息/知识之间的重要关联性,本文运用经典信息过程模型剖析了创业机会的内涵,以此为基础阐述了基于创业信息过程模型的创业机会识别机理,并针对创业信息过程的3个环节分析了创业机会识别的关键影响因素。     

创新链视角下高新技术企业认定效应与机制研究

    基于创新链视角,探究高新技术企业认定对企业创新的影响及其作用机制。以沪深A股上市公司为样本,研究发现：高新技术企业认定对企业创新绩效的影响存在多重路径,创新投入和成果产出在其过程中分别发挥中介作用,且创新投入与成果产出的链式中介效应显著。进一步,从信号机制、杠杆机制和触发机制三方面,揭示高新技术企业认定影响企业创新过程的内在机制。结果显示：在创新投入阶段,高新技术企业认定的信号机制激励外源融资进入创新链,提升企业研发投入;在成果产出阶段,高新技术企业认定发挥杠杆作用,撬动企业寻求产学研合作,促进企业科技成果产出;而高新技术企业认定是否能触发企业创新绩效提升,认定质量是关键情境变量。根据研究结论,提出了相应政策建议。     

粒子群算法优化BP神经网络的指纹识别技术

指纹识别技术是当今应用最广泛的生物识别技术之一。在指纹识别过程中,图像处理、特征提取、匹配等过程数据量庞大,计算比较烦琐。BP神经网络具有良好的自学习能力、强大的分类能力和容错能力,将其应用到指纹识别中是可行的。为改进BP神经网络计算速度较慢,梯度下降法不能处理一些不可微传递函数的问题,采用粒子群算法对BP算法进行优化,提高了指纹识别的速度和准确度。