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.     

Tracer identifiability of multiphase transport systems

Using the two-component Markov process of Ref. (3) to describe tracer flow in a multiphase spacially inhomogeneous transport (plug-flow) system a mathematical framework is established for the conduction of tracer experiments for system identification.Transport velocities are assumed known. The problem of unique identification of the exchange coefficients between various phases using boundary measurements is studied. Cases of different output-boundary configurations are considered (accessible and inaccessible outputs). Sufficient conditions for identifiability are given.     

Linear stochastic system identification using correlation techniques

The identification of linear, discrete time, scalar output systems which are driven exclusively by white, zero mean, inaccessible noise sequences is discussed. Two principal results are presented. First, two methods (least squares and an autocorrelation technique) for identifying the system characteristic equation coefficients are compared. The least squares approach is shown to be biased except for special cases. In general, the bias cannot be removed. If the state transition matrix is of the phase variable form, bias removal requires a knowledge of the measurement noise variance and all but one of the state driving noise variances. The autocorrelation technique is not biased asymptotically and does not require a knowledge of the noise variances.Secondly, it is shown that the m² elements of the state transition matrix cannot be identified uniquely from the scalar output sequence autocorrelation coefficients if the system order is higher than one. The implication of this uncertainty in the state transition matrix on optimal filtering of the output sequence is briefly discussed.     

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。     

Optimal trajectory exploration large-scale deep reinforcement learning tuned optimal controller for proton exchange membrane fuel cell

To accurately regulate hydrogen flow and guarantee satisfactory output voltage control performance, taking advantage of the high adaptability and robustness of large-scale deep reinforcement learning, an optimal fractional-order proportion integral differential (FOPID) controller for controlling proton exchange membrane fuel cell (PEMFC) output voltage is proposed in this paper. In addition, an optimal trajectory exploration large-scale multi-delay deep deterministic policy gradient (OTEL-MD3PG) algorithm, which naturally considers the baseline FOPID coefficients in the design objective and provides the online coefficient adjusting ability through learning, is designed as the tuner of the controller to improve adaptability and robustness. This algorithm adopts the optimal trajectory exploration policy, whereby a new agent (demonstrator) generates demonstration samples that instruct the agent to learn, and another agent (tracker) adds noise to the action of the demonstrator to explore the limits of its control trajectory, thereby obtaining a more robust control strategy. The simulation results show that this proposed algorithm offers a rapid response, strong anti-interference, and excellent control performance.     

高新技术企业认定政策的创新增量效应及作用机制

以湖北2015-2017年新三板年报披露的463家公司数据,从信号传递与股权集中度的调节角度,运用“倾向得分匹配”方法,评估了高新技术企业认定政策的创新增量效应及其作用机制。实证发现：①高新技术企业认定政策能有效激励产出增量,策略性创新激励效应大于实质性创新激励效应;②信号传递的调节作用存在异质性。金融支撑体系对认定政策的投入增量和产出增量效应具有负向调节作用,股权流通性对认定政策的产出增量效应具有正向调节作用;③股权集中度对认定政策的产出增量效应具有负向调节作用。研究结果从投入与产出增量视角丰富了创新激励影响因素研究的文献,并为高新技术企业认证的政策完善提供了实证指导。     

基于随机前沿分析方法的学术期刊知识交流效率研究

[目的/意义]评价期刊知识交流效率对正确评价期刊在学术交流中的地位以及作用具有重要的参考价值。[方法/过程]选取29种CSSCI管理学期刊为对象,构建学术期刊知识交流效率评价指标体系。采用信息熵方法计算学术期刊知识产出指标权重,并合并成一个综合产出指标。采用随机前沿分析方法SFA测算学术期刊知识交流效率。[结果/结论]期刊知识交流效率是评价期刊影响力的重要指标,CSSCI管理学期刊知识交流效率整体较低,期刊之间效率差距较大。     

VBA技术在医院门诊收费管理系统中的应用

介绍了医院门诊管理系统软件中医院门诊计算过程采用数据交换和自动输出功能实现的技术原理及编程方法:应用VBA技术对Excel文件分别进行后台操作,然后实现两者文件的合并,统一以Word文件的形式输出。这对其他具有报表输出功能的软件系统开发有一定的参考价值。     

财政科技投入产出效应研究

本文揭示了财政科技投入效应与财政科技产出效应的关联性,对于财政科技投入效应的潜变量及观察变量、财政科技产出效应的潜变量及观察变量分别进行了设置,建立了财政科技投入产出效应的结构方程模型,得出了财政科技投入的触发效应、波及效应、风险效应与财政科技产出的滞后效应、乘数效应与挤出效应之间的路径系数。     

管理科学部重要期刊知识交流效率评价——基于Super-SBM与SFA模型的实证研究

[目的/意义]知识交流效率衡量学术期刊投入与产出的比较,对于考察学术期刊在知识交流中的地位和作用具有重要参考价值,为跨学科学术期刊评价提供了一种新的研究思路。[方法/过程]采用非参数形式Super-SBM与参数形式SFA方法,测算国家自然科学基金委员会管理科学部认定的30种重要期刊知识交流效率。[结果/结论]两种方法计算结果均发现2009-2013年间30种重要期刊知识交流效率整体水平较低。两种方法计算得到的知识交流效率不具有显著差异,二者在比较期刊知识交流效率值高低和依据效率得分进行期刊排序上具有通用性。     

Hierarchical recursive least squares parameter estimation of non-uniformly sampled Hammerstein nonlinear systems based on Kalman filter

This paper focuses on parameter estimation problems for non-uniformly sampled Hammerstein nonlinear systems. By combining the lifting technique and state space transformation, we derive a nonlinear regression identification model with different input and output updating rates. Furthermore, the unmeasurable state vector is estimated by Kalman filter, and by using the hierarchical identification principle, we develop a hierarchical recursive least squares algorithm for estimating the unknown parameters of the identification model. Finally, illustrative examples are given to indicate that the proposed algorithm is effective.     

Exact analysis for the identification of non-minimum phase processes

Analytical expressions are derived from a single symmetrical relay feedback test for the identification of open loop stable and unstable non-minimum phase processes. The second derivative of the limit cycle output helps in finding the time delay of the process. The derived expressions can be used to identify the process models with up to five unknowns. The effectiveness of the proposed identification method is verified through different simulation results.     

面向空间通信不平等差错保护的联合信源信道编解码方法

提出了一种面向空间通信不平等差错保护的联合信源信道编解码方法. 该方法采用一种可逆编解码方法对直流系数进行重点保护,即对直流系数编码输出码流进行二进制游程编码,并采用可逆变长码对游程长度进行编码. 对重要性较低的交流(AC)系数采用可变长编解码. 仿真实验结果和分析表明,该方法有效地解决了错误扩散,提高了直流系数的抗差错性能,改善了图像传输质量.     

基于月度数据对中国出口贸易的实证分析

本文选取1994年1月到2008年8月的月度数据,在考虑了中国加入WTO和2005年7月汇改的结构性影响之后,运用Johansen协整检验以及误差修正模型,对我国出口与外国实际收入、中国相对出口价格、汇率的波动性之间的关系进行了实证分析.Johansen协整检验的结果表明:我国出口与外国实际收入、中国相对出口价格具有长期的均衡关系而且中国出口对主要贸易伙伴国实际收入的弹性(为正数)很高,中国出口的价格弹性(为负数)也较高;误差修正模型的结果显示:较大的汇率波动性能够导致出口减少.这都突出反映了我国经济一直以来过度依赖外需推动,内需严重不足的问题以及我国出口产业本身的深层次问题.     

A new excitation scheme for closed-loop subspace identification using additional sampling outputs and its extension to instrumental variable method

It is known that feedback from outputs to inputs causes non-identifiability in many subspace identification algorithms. In this paper, a new excitation method is proposed for closed-loop subspace identification. By adding an output sampling point within two adjacent control times, a difficult closed loop identification issue is recast into an open loop identification. Uncorrelation between the process inputs and the noises in closed loop is obtained, and the persistently exciting condition is proven to be satisfied based on spectral analysis and innovation state space models so that the consistent estimates with no demand for external exciting signals can be guaranteed. Simultaneously, the additional sampling scheme offers different selections of instrumental variables for the non-error-in-variable case and the error-in-variable case in some instrumental variables-based identification algorithms. A simulation is performed to test the identification efficiency of the new scheme.     

银行间债券市场与交易所债券市场之间的国债价格差异研究

引入虚拟变量建构计量模型研究了我国银行间债券市场与交易所债券市场之间的国债价格差异。主要发现:在其他情况不变的条件下,在不同的债券市场交易对国债的无风险收益率有显著影响;流动性变量对到期收益率具有很好的解释能力,两类市场对流动性风险的补偿系数存在显著差异。     

基于RFID/物联网的校车安全监管系统的架构

射频识别（RFID）技术以其穿透性能好、安全性能强、可同时识别多个电子标签等特点,可以实现多目标、非接触式的唯一性识别,是构建“物联网”的支撑技术之一。以RFID 技术为基础,结合电子传感、信息处理以及无线通信等技术,实现监管系统与校车间的主动辨识以及信息交互在校车安全领域中的应用具有重要意义。     

The impact of static output nonlinearities on the control strategies that humans use in command-following tasks

The results of a human-in-the-loop experiment are used to investigate the control strategies that humans use to interact with nonlinear dynamic systems. Two groups of human subjects interact with a dynamic system and perform a command-following task. The first group interacts with a linear time-invariant (LTI) dynamic system. The second group interacts with a Wiener system, which consists of the same LTI dynamics cascaded with a static output nonlinearity. Both groups exhibit improved performance over the trials, but the average of the linear group’s performance is better on more than three-fourths of the trials. A new nonlinear subsystem identification algorithm is presented and used to identify the feedback and feedforward control strategies used by the subjects in both groups. The identification results for the linear group agree with prior studies suggesting that adaptive feedforward inversion is a primary control strategy used by humans for command-following tasks. The main results of this paper address an open question of whether a similar control strategy is used for nonlinear systems. The identification results for the nonlinear group suggest that those subjects also use adaptive feedforward inversion. However, the static output nonlinearity inhibits the human’s ability to approximate the inverse.     

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。