H2 and H∞-Feedback Control Design for Nonlinear Gene Networks via Successive Galerkin’s Approximation

This paper presents a design method of H2 and H∞-feedback control loop for nonlinear smooth gene networks that are in control affine form. Formulaic solution methodology for solving the nonlinear partial differential equations, namely the Hamilton-Jacobi-Bellman and Hamilton-Jacobi-Isaacs equations through successive Galerkin’s approximation is implemented and the results are compared. Throughout the implementation, there were several caveats that need to be further resolved for practical applications in general cases. Such issues and the clarification of causes are mathematically established and reviewed.

Parameterized design of nonlinear feedback controllers for servo positioning systems

To achieve fast, smooth and accurate set point tracking in servo positioning systems, a parameterized design of nonlinear feedback controllers is presented, based on a so-called composite nonlinear feedback （CNF） control technique. The controller designed here consists of a linear feedback part and a nonlinear part. The linear part is responsible for stability and fast response of the closed-loop system. The nonlinear part serves to increase the damping ratio of closed-loop poles as the controlled output approaches the target reference. The CNF control brings together the good points of both the small and the large damping ratio cases, by continuously scheduling the damping ratio of the dominant closed-loop poles and thus has the capability for superior transient performance, i.e. a fast output response with low overshoot. In the presence of constant disturbances, an integral action is included so as to remove the static bias. An explicitly parameterized controller is derived for servo positioning systems characterized by second-order model. Practical application in a micro hard disk drive servo system is then presented, together with some discussion of the rationale and characteristics of such design. Simulation and experimental results demonstrate the effectiveness of this control design methodology.

On the Design of Optimal Feedback Control for Systems of Second Order

A difficult but important problem in optimal control theory is the design of an optimal feedback control, i.e., the design of an optimal control as function of the phase (state) coordinates [1,2]. This problem can be solved not often. We study here the autonomous nonlinear system of second order in general form. The constraints imposed on the control input can depend on the phase (state) coordinates of the system. The goal of the control is to maximize or minimize one phase coordinate of the considered system while other takes a prescribed in advance value. In the literature, optimal control problems for the systems of second order are most frequently associated with driving both phase coordinates to a prescribed in advance state. In this statement of the problem, the optimal control feedback can be designed only for special kind of systems. In our statement of the problem, an optimal control can be designed as function of the state coordinates for more general kind of the systems. The problem of maximization or minimization of the swing amplitude is considered explicitly as an example. Simulation results are presented.

Model-Following Designs Using Direct State Derivative Measurement Feedback in Novel Reciprocal State Space Form

The paper introduces effective and straightforward algorithms of both explicit and implicit model-following designs with state derivative measurement feedback in novel reciprocal state space form (RSS) to handle state derivative related performance output and state related performance output design cases. Applying proposed algorithms, no integrators are required. Consequently, implementation is simple and low-cost. Simulation has also been carried out to verify the proposed algorithms. Since acceleration can only be modeled as state derivative in state space form and micro-accelerometer which is the state derivative sensor is getting more and more attentions in many microelectromechanical and nanoelectromechanical systems (MEMS/NEMS) applications, the proposed algorithms are suitable for MEMS/NEMS systems installed with micro-accelerometers.

Transformer for the Design of Automatic Control Systems with Prefilters

A machine learning model, using the transformer architecture, is used to design a feedback compensator and prefilter for various simulated plants. The output of the transformer is a sequence of compensator and prefilter parameters. The compensator and prefilter are linear models, preserving the ability to analyze the system with linear control theory. The input to the network is a window of recent reference and output samples. The goal of the transformer is to minimize tracking error at each time step. The plants under consideration range from simple to challenging. The more difficult plants contain closely spaced, lightly damped, complex conjugate pairs of poles and zeros. Results are compared to PID controllers tuned for a similar crossover frequency and optimal phase margin. For simple plants, the transformer converges to solutions which overly rely on the prefilter, neglecting the maximization of negative feedback. For more complex plants, the transformer designs a compensator and prefilter with more desirable qualities. In all cases, the transformer can start with random model parameters and modify them to minimize tracking error on the step reference.

H∞-Feedback Control of Heparin-Controlled Blood Clotting Network for Cardiac Surgeries

This paper presents a solution methodology for H∞-feedback control design problem of Heparin controlled blood clotting network under the presence of stochastic noise. The formulaic solution procedure to solve nonlinear partial differential equation, the Hamilton-Jacobi-Isaacs equation with Successive Galrkin’s Approximation is sketched and validity is proved. According to Lyapunov’s theory, with solutions of the nonlinear PDEs, robust feedback control is designed. To confirm the performance and robustness of the designed controller, numerical and Monte-Carlo simulation results by Simulink software on MATLAB are provided.

Ethernet Controller SoC Design and Its Low-Power DFT Considerations

In this paper, an Ethernet controller SoC solution and its low power design for testability （DFT） for information appliances are presented. On a single chip, an enhanced one-cycle 8-bit micro controller unit （MCU）, media access control （MAC） circuit and embedded memories such as static random access memory （SRAM）, read only memory （ROM） and flash are all integrated together. In order to achieve high fault coverage, at the same time with low test power, different DFT techniques are adopted for different circuits： the scan circuit that reduces switching activity is implemented for digital logic circuits; BIST-based method is employed for the on-chip SRAM and ROM. According to the fault-modeling of embedded flash, we resort to a March-like method for flash built in self test （BIST）. By all means above, the result shows that the fault coverage may reach 97%, and the SoC chip is implemented successfully by using 0.25 μm two-poly four-metal mixed signal complementary metal oxide semiconductor （CMOS） technology, the die area is 4.8×4.6 mm^2. Test results show that the maximum throughput of Ethemet packets may reach 7Mb·s^1.

State Feedback Stabilzation for a Class of Time-delay Nonlinear Systems

The problem of global stabilization by state feedback for a class of time-delay nonlinear system is considered. By constructing the appropriate Lyapunov-Krasovskii functionals (LKF) and using the backstepping design, a linear state feedback controller making the closed-loop system globally asymptotically stable is constructed.

Qualitative System Dynamics as a Tool in Accessible Design

A description of the Systems Dynamics paradigm is given and the reduced Qualitative System Dynamics (QSD) form explained. A simple example is given to illustrate the diagram construction. The principles of states (levels), rates and feedback loops are outlined. The QSD method is used to address the problem of accessibility by using human control of automation as an example, and applying the QSD method to evaluate the effects of the researcher and user in the de- sign of an accessible artefact. This simple automation model illustrates what can be found out from such a picture, in this indicating how the feedback from users has an influence on the time to deliver such designs.

在线协作会话中情绪设计支持的教学代理反馈模型构建及应用研究

教学代理的反馈有利于提升学习绩效,并且反馈的情绪设计可以有效激发学习者的积极情绪并增强他们的学习动机。然而,目前针对在线协作会话中学习者参与度低、协作知识建构抑制等问题,探讨情绪设计支持的教学代理反馈策略的研究依旧较少。文章通过梳理情绪反应理论等相关研究,构建了情绪设计支持的教学代理反馈模型,为面向在线协作会话的智能教学代理反馈设计提供参考。在此基础上,文章开展了准实验研究以验证模型的有效性。研究发现:(1)教学代理提供的学习情况反馈能够促进协作会话参与和协作知识建构;(2)且情绪设计支持的教学代理反馈更能促进在线协作会话参与和协作知识建构;(3)学习者对提供学习情况和积极情绪反馈的教学代理的技术接受程度显著高于只提供学习情况反馈的教学代理。这些发现为教学代理的设计和开发提供了有益的指导。

Robust output-feedback stabilization of a class of nonlinear systems with the nonlinearities of varied form

The back-stepping designs based on confine functions are suggested for the robust output-feedback global stabilization of a class of nonlinear continuous systems; the proposed stabilizer is efficient for the nonlinear continuous systems confined by a bound function, the nonlinearities of the systems may be of varied forms or uncertain; the designed stabilizer is robust means that a class of nonlinear continuous systems can be stabilized by the same output feedback stabilization schemes; numerical simulation examples are given.

智能技术赋能虚拟科学探究学习过程评价与适应性反馈研究

虚拟科学探究学习过程的自动评价和适应性反馈是提升探究学习效果的重要支撑手段。研究首先从虚拟科学探究学习过程要素表征和分析模型、自动分析与实时评价、适应性反馈三个方面概述了智能技术在虚拟科学探究学习中的应用现状,总结了当前技术应用面临的深层次探究要素表征难、不确定探究过程刻画难、适应性反馈生成难等现实挑战。其次,在此基础上,提出了基于活动流的底层计算模型构建、复杂探究过程动态监测与自动评价、可解释性归因的自适应反馈内容生成三个关键技术。再次,基于关键技术设计了虚拟科学实验自主探究学习平台的技术架构。最后,研究总结了当前研究的创新之处并提出未来建议,为智能技术赋能虚拟科学探究学习领域开展更深入的技术探索提供有益参考。

Miniature 6-axis force/torque sensor for force feedback in robot-assisted minimally invasive surgery

In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive sensing method,a flexural-hinged Stewart platform is designed as the flexible structure,and a straightforward optimization method considering the force and sensitivity isotropy of the sensor is proposed to determine geometric parameters which are best suited for the given external loads.The accuracy of this method is preliminarily discussed by finite element methods(FEMs).The sensor prototype is fabricated with the development of the electronic system.Calibration and dynamic loading tests for this sensor prototype are carried out.The working ranges of this sensor prototype are 30 N and 300 N·mm,and resolutions are 0.08 N in radial directions,0.25 N in axial direction,and 2.4 N·mm in rotational directions.It also exhibits a good capability for a typical dynamic force sensing at a frequency close to the normal heart rate of an adult.The sensor is compatible with surgical instruments for force feedback in RMIS.

Robust Control Design of Wheeled Inverted Pendulum Assistant Robot

This paper examines the design concept and mobile control strategy of the human assistant robot I-PENTAR(inverted pendulum type assistant robot). The motion equation is derived considering the non-holonomic constraint of the twowheeled mobile robot. Different optimal control approaches are applied to a linearized model of I-PENTAR. These include linear quadratic regulator(LQR), linear quadratic Gaussian control(LQG), H_2 control and H_∞ control. Simulation is performed for all the approaches yielding good performance results.

心理抗拒视角下打破“信息茧房”交互设计策略研究

大数据时代背景之下,为解决用户长时间接收个性化推荐信息而困于“信息茧房”的问题,优化用户个性化推荐平台使用体验,帮助平台延展功能领域。基于心理抗拒理论,采用问卷调查和数据分析的方法,分析“信息茧房”效应下影响用户心理抗拒的因素,构建个性化推荐服务平台用户持续获取信息行为影响因素模型。用户对个性化推送的心理抗拒明显阻碍了其对信息的持续获取行为,并且主要受到推送信息的质量、用户自身的认知程度以及平台的交互反馈设计三方面的影响。在模型基础上提出了3个打破“信息茧房”交互设计优化的策略:基于情境感知技术,实现信息分流;调整平台与用户之间的耦合关系,鼓励用户参与平台建设;以及提升平台交互质量,增加用户满意度。以此为个性化推荐平台打破“信息茧房”提供交互设计策略参考。

An Algorithm for the Feedback Vertex Set Problem on a Normal Helly Circular-Arc Graph

The feedback vertex set (FVS) problem is to find the set of vertices of minimum cardinality whose removal renders the graph acyclic. The FVS problem has applications in several areas such as combinatorial circuit design, synchronous systems, computer systems, and very-large-scale integration (VLSI) circuits. The FVS problem is known to be NP-hard for simple graphs, but polynomi-al-time algorithms have been found for special classes of graphs. The intersection graph of a collection of arcs on a circle is called a circular-arc graph. A normal Helly circular-arc graph is a proper subclass of the set of circular-arc graphs. In this paper, we present an algorithm that takes time to solve the FVS problem in a normal Helly circular-arc graph with n vertices and m edges.

基于SPOC的完全线上病例讨论的教学设计

基于当前多种教学方式争鸣的教学时代,通过临床教学实践总结提出基于小规模限制性在线课程(small private online courses,SPOC)的完全线上病例讨论教学模式,该模式以学生为主体,以典型病例分析讨论为导向,教师须做好课程教学的策划、设计、组织、监督,以充分激发学生的学习兴趣,增强临床诊疗思维的培养,提升在线教育质量,总结线上医学教育经验。该模式打破了传统教学的时间空间限制,在大规模开放式在线课程(massive open online courses,MOOC)教学模式的基础上增加监管反馈设计,线上实现1对1、多对多双面交流教学,进而充分利用教育资源,提高教学效率。为将来外地住院医师规范化培训学生、基层医生的线上职业培训提供参考。

西安市鄠邑区红色文化资源融入高校思政课教学现状研究——以西安某高校为例

为了解西安市鄠邑区红色文化资源融入高校思政课教学的现状,随机抽取西安某高校46名思政课教师进行问卷调查。结果显示,绝大部分教师对红色文化的内涵有一定了解,但一半的教师对此了解的还不充分。思政课教师主要通过实践活动和理论学习的途径了解鄠邑区红色文化资源。认为鄠邑区红色文化资源内涵丰富,应该继承和发扬的教师占97.83%。大部分思政课教师能将鄠邑区红色文化资源融入到思政课教学中,且教学效果良好,但其教学组织与设计维度的均值尚未达到理想水平。基于此,西安市高校思政教师应不断创新教学方法,灵活运用鄠邑区红色文化资源,丰富网络教学形式,有效利用鄠邑区红色文化资源,通过思政教育实现高校立德树人的目标。

利用CCtalk平台进行高校体育专项课程的个性化教学设计与实施

CCtalk平台是一种多功能的在线教育平台,为教师和学生提供了便捷的教学和学习环境。该文探讨了CCtalk平台在高校体育专项课程个性化教学设计与实施中的应用。具体包括确定教学目标与内容、设计个性化教学策略与方法、制定评估与反馈机制,以及加强与学生的互动与沟通等方面。应用CCtalk平台可以提高教学效果,满足学生的个性化需求,促进教学和学习的互动。

在线课程学习满意度影响机制研究——基于课程视角的实证研究

基于认知结构学习理论和生态系统理论,建立在线课程结构和课程设计影响学习满意度研究模型。通过对368份样本进行实证分析,结果表明:在线课程结构与课程设计显著正向影响学生在线学习满意度;学生的学习认知和学习行为在在线课程结构和课程设计影响学生学习满意度的关系中均起到部分中介作用;教师反馈分别正向调节在线课程结构和课程设计与学生学习认知和学习行为间关系。基于分析结果,结合具体教育实践提出以下建议:一是结合专业特点,优化在线课程结构与课程设计,完善在线课程体系;二是深入理解学生需求,培养学生发散思维,转变学生认知态度,强化学生在线学习行动;三是发挥教师反馈作用,注意反馈内容与形式。本研究为提升学生在线学习满意度和完善多时空培养高等专业人才模式提供理论依据和实践支持。