A Lyapunov–Krasovskii methodology for ISS and iISS of time-delay systems

This paper presents a Lyapunov–Krasovskii methodology for studying the input-to-state stability and the integral input-to-state stability of nonlinear time-delay systems. An integral input-state estimate which takes into account non-zero initial conditions is also proposed.     

I,Chatbot: Modeling the determinants of users’ satisfaction and continuance intention of AI-powered service agents

Chatbots are mainly text-based conversational agents that simulate conversations with users. This study aims to investigate drivers of users’ satisfaction and continuance intention toward chatbot-based customer service. We propose an analytical framework combining the expectation-confirmation model (ECM), information system success (ISS) model, TAM, and the need for interaction with a service employee (NFI-SE). Analysis of data collected from 370 actual chatbot users reveals that information quality (IQ) and service quality (SQ) positively influence consumers’ satisfaction, and that perceived enjoyment (PE), perceived usefulness (PU), and perceived ease of use (PEOU) are significant predictors of continuance intention (CI). The need for interaction with an employee moderates the effects of PEOU and PU on satisfaction. The findings also revealed that satisfaction with chatbot e-service is a strong determinant and predictor of users’ CI toward chatbots. Thus, chatbots should enhance their information and service quality to increase users’ satisfaction. The findings imply that digital technologies services, such as chatbots, could be combined with human service employees to satisfy digital users.     

Input-to-state stability of time-varying nonlinear discrete-time systems via indefinite difference Lyapunov functions

In this paper, we propose new sufficient criteria for input-to-state stability (ISS) of time-varying nonlinear discrete-time systems via indefinite difference Lyapunov functions. The proposed sufficient conditions for ISS of system are more relaxed than for ISS with respect to Lyapunov functions with negative definite difference. We prove system is ISS by two methods. The first way is to prove system is ISS by indefinite difference ISS Lyapunov functions. The second method is to prove system is ISS via introducing an auxiliary system and indefinite difference robust Lyapunov functions. The comparison of the sufficient conditions for ISS obtained via the two methods is discussed. The effectiveness of our results is illustrated by three numerical examples.     

面向对象和设计模式在ISS管理系统中的应用

提出了利用面向对象和设计模式方法作为ISMS的设计新方法,并使用UML语言描述了面向对象和设计模式在综合传感器管理系统(ISMS)中的具体应用,在系统的设计和开发中取得了较好的效果。最后进一步指出了面向体系结构(SOA)模式为以后ISMS的设计新方向。     

Coke Deposition on Automotive Three-Way Catalysts Studied with LEIS

LEIS measurements have been performed on fresh and used commercial three-way catalysts (Pt/Rh/CeO₂/-Al₂O₃). The catalysts showed a significant decrease in the platinum surface concentration of approximately 50% after use in hydrocarbon oxidation at cold-start conditions, and could be completely regenerated. The selectivity towards the outermost atomic layer of LEIS allowed a one to one correlation between the surface Pt concentration as detected with LEIS and that obtained by kinetic modelling. This supports recent assumptions on selective deactivation. Conventional surface science techniques such as XPS, SIMS or AES would have yielded ambiguous results since their probing depths are not limited to the outermost atomic layer.     

嵌入式系统软硬件协调设计环境构造与实现方法

文章研究嵌入式系统协调设计方法,重点讨论一个完整的嵌入式系统协调设计环境———BitCoDesign构造,把嵌入式系统设计分解为系统功能描述和划分阶段、软硬件设计阶段、协同模拟阶段和软硬件综合阶段。具体阐述各设计阶段功能的实现方法,使嵌入式系统在设计初期,通过协同模拟手段验证系统的设计正确性,避免设计反复,降低开发成本,缩短开发周期     

Robustness of network flow control against disturbances and time-delay

This paper studies robustness of Kelly's source and link control laws in (J. Oper. Res. Soc. 49 (1998) 237) with respect to disturbances and time-delays. This problem is of practical importance because of unmodelled flows, and propagation and queueing delays, which are ubiquitous in networks. We first show L_p-stability, for p[1,∞], with respect to additive disturbances. We pursue L_∞-stability within the input-to-state stability (ISS) framework of Sontag (IEEE Trans. Automat. Control 34 (1989) 435), which makes explicit the vanishing effect of initial conditions. Next, using this ISS property and a loop transformation, we prove that global asymptotic stability is preserved for sufficiently small time-delays in forward and return channels. For larger delays, we achieve global asymptotic stability by scaling down the control gains as in Paganini et al. (Proceedings of 2001 Conference on Decision and Control, Orlando, FL, December 2001, pp. 185–190)     

软硬件协同模拟的通信同步算法设计与实现

协同模拟技术是嵌入式系统软硬件协调设计的关键技术之一,它在整个设计过程中对系统起着功能验证和性能预测的作用。采用指令集模拟和硬件事件驱动模拟器相结合的协同模拟技术是一种高效的、低代价的嵌入式系统协同验证方案,但解决指令集模拟器和硬件模拟器之间的同步问题是保证协同模拟正确性和提高模拟效率的关键。文章介绍了一种基于Windowssockets和Lock-step的协同模拟通信同步算法,最后介绍了几种降低通信开销,提高协同模拟效率的方法。     

基于参数自适应的ISS盲水印算法

提出了一种基于改进的扩频(improved spread spectrum,ISS)技术的盲水印算法,针对ISS技术局部嵌入失真不可控制的缺点,结合人类视觉系统模型(HVS模型)建立一个限失真的数学模型实现水印自适应最优嵌入。实验结果表明,提出的算法克服了ISS算法中局部失真大的问题,并且有比ISS算法更好的鲁棒性。水印图像在JPEG压缩、各种噪声、常见滤波的攻击下能够提取出水印信息,表现较强的鲁棒性。     

一种多核指令集仿真器构建技术

为了提高指令集仿真器的速度并降低多核构造的复杂度, 提出了一种多核指令集仿真器的快速搭建技术。该技术结合了解释型、编译型以及混合仿真策略的优点, 通过预解码技术、可扩展单核结构、单核结构中的cache和TLB模拟机制以及多核调度机制的相互配合, 以实现多核的快速搭建。该技术已经成功应用于基于中国科学院微电子所自主研发的IME-Diamond多核DSP的四核仿真器ISD的搭建。复杂度分析与实验结果表明, 该技术复杂度低且能够提高仿真速度。