An executive guide to ADP contingency planning

This paper provides, in the form of questions and answers, the background and basic essential information required to understand the developmental process for Automatic Data Processing (ADP) contingency plans. The primary intended audience consists of executives and managers who depend on ADP resources and services, yet may not be directly responsible for the daily management of supervision of data processing activities or facilities.     

Direct heuristic dynamic programming based on an improved PID neural network

In this paper,an improved PID-neural network(IPIDNN) structure is proposed and applied to the critic and action networks of direct heuristic dynamic programming(DHDP).As one of online learning algorithm of approximate dynamic programming(ADP),DHDP has demonstrated its applicability to large state and control problems.Theoretically, the DHDP algorithm requires access to full state feedback in order to obtain solutions to the Bellman optimality equation. Unfortunately,it is not always possible to access all the states in a real system.This paper proposes a solution by suggesting an IPIDNN configuration to construct the critic and action networks to achieve an output feedback control.Since this structure can estimate the integrals and derivatives of measurable outputs,more system states are utilized and thus better control performance are expected.Compared with traditional PIDNN,this configuration is flexible and easy to expand. Based on this structure,a gradient decent algorithm for this IPIDNN-based DHDP is presented.Convergence issues are addressed within a single learning time step and for the entire learning process.Some important insights are provided to guide the implementation of the algorithm.The proposed learning controller has been applied to a cart-pole system to validate the effectiveness of the structure and the algorithm.     

基于梯度估计的非线性系统最优控制及仿真

基于自适应动态规划（ADP）执行-评价结构,应用神经网络（NN）对非线性系统进行最优控制求解.首先提出所求解非线性系统的一般形式;其次给定二次正定性能指标,求其哈密尔顿函（HJB）函数;分别应用神经网络对执行-评价结构中的性能指标和最优控制进行逼近,神经网络权重参数应用梯度法求得,从而可以求得其最有控制策略.而且对执行机构和评价机构神经网络权重参数的收敛性以及系统总体的稳定性进行了详细的分析,证明所求控制策略可以使系统稳定;最后,用仿真结果来验证所提出的方法的可行性.     

Adaptive dynamic surface-based differential games for a class of pure-feedback nonlinear systems with output constraints

ABSTRACT

This paper investigates the zero-sum differential game problem for a class of uncertain nonlinear pure-feedback systems with output constraints and unknown external disturbances. A barrier Lyapunov function is introduced to tackle the output constraints. By constructing an affine variable at each dynamic surface control design step rather than utilising the mean-value theorem, the tracking control problem for pure-feedback systems can be transformed into an equivalent zero-sum differential game problem for affine systems. Then, the solution of associated Hamilton–Jacobi–Isaacs equation can be obtained online by using the adaptive dynamic programming technique. Finally, the whole control scheme that is composed of a feedforward dynamic surface controller and a feedback differential game control strategy guarantees the stability of the closed-loop system, and the tracking error is remained in a bounded compact set. The simulation results demonstrate the effectiveness of the proposed control scheme.     

Combined 1H and 31P MR spectroscopic imaging: impaired energy metabolism in severe carotid stenosis and changes upon treatment

OBJECT: To evaluate if combined (1)H and (31)P MR spectroscopic imaging (MRSI) before and after treatment of severe internal carotid artery (ICA) stenosis detects significant changes in energy metabolism in the basal ganglia of both hemispheres. MATERIALS AND METHODS: A group of 14 patients with high-grade ICA stenosis and 11 healthy control subjects were examined with 2D (1)H MRSI and 3D (31)P MRSI at 3 T before and after treatment of severe ICA stenosis. Spectroscopic data were processed with LCModel and jMRUI software. Changes of the phosphorylated metabolites, pH, N-acetyl-acetate, creatine and choline-containing compounds prior/post intervention were analyzed and patients' data were compared with that of control subjects. RESULTS: Untreated patients had significantly higher Adenosindiphosphate (ADP) in basal ganglia ipsi- and contralateral to the side of ACI stenosis compared to controls. After treatment, ADP of both hemispheres significantly decreased by approximately 20% compared to the pre-treatment values. Further, significant decreases of phosphorylated metabolites prior/post intervention were found for patients compared to controls. CONCLUSION: This spectroscopic study reveals that unilateral high-grade ICA stenosis has an effect on cerebral high-energy metabolism of both hemispheres, which is at least partially reversible after treatment. Therefore the restoration of blood flow in high-grade ICA stenosis recovers the impaired energy balance of the brain.     

The Local Environment of Loop Switch 1 Modulates the Rate of ATP-Induced Dissociation of Human Cardiac Actomyosin

Two isoforms of human cardiac myosin, alpha and beta, share significant sequence similarities but show different kinetics. The alpha isoform is a faster motor; it spends less time being strongly bound to actin during the actomyosin cycle. With alpha isoform, actomyosin dissociates faster upon ATP binding, and the affinity of ADP to actomyosin is weaker. One can suggest that the isoform-specific actomyosin kinetics is regulated at the nucleotide binding site of human cardiac myosin. Myosin is a P-loop ATPase; the nucleotide-binding site consists of P-loop and loops switch 1 and 2. All three loops position MgATP for successful hydrolysis. Loops sequence is conserved in both myosin isoforms, and we hypothesize that the isoform-specific structural element near the active site regulates the rate of nucleotide binding and release. Previously we ran molecular dynamics simulations and found that loop S291-E317 near loop switch 1 is more compact and exhibits larger fluctuations of the position of amino acid residues in beta isoform than in alpha. In alpha isoform, the loop forms a salt bridge with loop switch 1, the bridge is not present in beta isoform. Two isoleucines I303 and I313 of loop S291-E317 are replaced with valines in alpha isoform. We introduced a double mutation I303V:I313V in beta isoform background and studied how the mutation affects the rate of ATP binding and ADP dissociation from actomyosin. We found that ATP-induced actomyosin dissociation occurs faster in the mutant, but the rate of ADP release remains the same as in the wild-type beta isoform. Due to the proximity of loop S291-E317 and loop switch 1, a faster rate of ATP-induced actomyosin dissociation indicates that loop S291-E317 affects structural dynamics of loop switch 1, and that loop switch 1 controls ATP binding to the active site. A similar rate of ADP dissociation from actomyosin in the mutant and wild-type myosin constructs indicates that loop switch 1 does not control ADP release from actomyosin.     

丹酚酸对ADP诱导的血小板聚集的影响

目的 研究丹酚酸(salvianolic acid,SA)及其代谢物对腺苷-5'二磷酸(adenosine-5-diphosphate,ADP)诱导的血小板聚集的影响,为寻找到高效低毒的抗血栓药物提供依据.方法 取健康雄性SD大鼠动脉血浆,以药物替格瑞洛为阳性对照,ADP为诱导剂,考察SA对血小板聚集的体外作用,用比浊...     

基于ADP3806的高功率LED驱动电路设计

设计了一种基于ADP3806的高功率发光二极管(LED)的高效驱动电路。ADP3806是一款开关模式电源控制器,拥有双环路恒定电压和恒定电流控制、远程精确电流检测以及关断和可编程可同步开关频率,能提供恒定电流。同时在设计中利用单端原边电感转换器(SEPIC),其可以提供一种可以高于或低于输入电压的输出电压,在适当的占空比下工作,使连续传导模式(CCM)和脉冲宽度调制(PWM)控制变得简单,提高了效率,并且避免由变压器泄漏电感带来的电压尖峰和振铃。从而在需要进行升压和降压转换来同时驱动多个高功率LED的场合,这个设计是非常适合的。     

基于数据的自学习优化控制:研究进展与展望

自适应动态规划(Adaptive dynamic programming, ADP)方法可以解决传统动态规划中的"维数灾"问题, 已经成为控制理论和计算智能领域最新的研究热点. ADP方法采用函数近似结构来估计系统性能指标函数, 然后依据最优性原理来获得近优的控制策略. ADP是一种具有学习和优化能力的智能控制方法, 在求解复杂非线性系统的最优控制问题中具有极大的潜力. 本文对ADP的理论研究、算法实现、相关应用等方面进行了全面的梳理, 涵盖了最新的研究进展, 并对ADP的未来发展趋势进行了分析和展望.     

中小企业信息系统解决方案之实践研究

根据中小企业信息系统的特点和实际需求,提出了一种适合中小企业信息系统的解决方案——ADP。以中小医院管理信息系统开发为研究对象,引人ADP方案,遵循结构化的程序设计方法和面向对象的程序设计方法,深入探讨了中小企业信息系统的设计与实现过程,从而为中小企业信息系统开发的技术选型和解决方案提供了一种实用、快捷的思路和途径。