Dynamic and emergent information systems strategy formulation and implementation

Early attempts to formulate information systems (IS) strategies concentrated on the analytical task of deriving IS strategies from business plans. The limitations of the static plans that often resulted from these formal studies were, however, soon discovered. The critics suggested informal and incremental planning to ensure flexibility, creativity and strategic thinking to comprise emergent strategies as well as planned strategies.In previous IS planning research, there appears to be a contradiction between the published planning methods and the generally held views about effective implementation of IS planning process. The explicit methods described in IS literature predominantly assume a comprehensive IS planning process. Despite the fact that many researchers consider incremental approaches to be more effective, methods that can be used to facilitate incremental IS planning are few, not detailed enough and not comprehensive.The four cycles method introduced in this paper attempts to combine the strengths of both the comprehensive and incremental planning to be able to recognise emerging trends and to make an e-business strategy. The method provides a basic schedule for organising planning activities. IS planning is seen as a continuous process that is periodically adjusted to the expectations of the participating managers. Practising managers can use the method to facilitate implementation of an incremental and continuous IS planning process. For e-business strategy research, the paper provides a theoretically based method that can be tested in future action research projects.The first results of conducted action research show that the method should not be used as a checklist but as a choice list. Each period had a constant focus on external developments and the fit with internal possibilities. The method provided a flexible and dynamic basis for actions. The emergent nature of the changes and the difficulty of formalising creativity and innovation placed restrictions on the planning process. We learned that a thematic approach where each cycle is given a creative subject helped to “open up” the users in the organisation. Future research should focus on the inter-organisational nature of e-business strategy. If it is difficult to get top management participation, it will be even more difficult with more organisations involved.     

协作多点通信系统中的资源分配算法及仿真

为了进一步提高协作多点通信系统的系统性能,文章将小区中的用户分为小区边缘用户和小区中心用户,小区中心用户采用单小区服务的方式,而小区边缘用户采用多小区服务的方式,并为小区边缘用户选择路径增益最大的两个小区为其提供服务。仿真结果表明,所提出的算法有效地提高了小区边缘用户的吞吐量,明显降低了用户掉话率。     

基于知识转移的组织间创新响应建模与仿真

作为一种系统中的激励反应,创新响应是创新策源行为的必经之路。为明确细化以社会互动理论为基础的创新响应机理,以促进区域创新策源能力提升,提出包括创新发起者、创新响应者、创新综合属性和响应媒介的创新响应四要素,建立基于知识转移视角的创新响应模型,以灵敏度分析为切入点构建系统动力学模型并进行仿真实验,结果发现创新的综合属性是前提,增强创新发起者的发送能力是关键,提高创新响应者对知识的敏感度是核心,响应媒介在创新发起者与创新响应者之间起到桥梁作用。因此,要激起创新行为者对创新的响应,增强创新发起者知识发送能力和提高创新响应者的需求参数、降低创新响应者知识失效率较为重要。     

磨削强化过程的温度场计算机动态仿真与实验验证

对磨削强化技术进行了计算机仿真与实验分析,并将结果进行对比验证,温度场的有限元计算表明仿真结果与实验结果基本相符,提示磨削强化过程的计算机仿真可以基本代替成本高昂的实际磨削强化试验,不仅大大节省了研究成本,而且有望对磨削强化结果进行预测。     

Dynamic event-triggered control of networked control systems with uncertainty and transmission delay

This paper presents a method for designing dynamic event-triggered controller of networked control systems (NCSs) with uncertainty and time delays. Under the condition that the Lyapunov function of the system is allowed to increase at each jump point, the globally exponentially stable (GES) of the system can be achieved by using the Riccati differential equation and the principle of average dwell time (ADT). The minimum allowable inter-event interval is obtained by limiting the increment of the Lyapunov function within the transmission interval. Both the static event triggering and no transmission delay are included in the designed dynamic event triggering mechanism as special cases. A numerical example is given to verify the correctness and validity of the proposed method.     

Human lung-on-chips: Advanced systems for respiratory virus models and assessment of immune response

Respiratory viral infections are leading causes of death worldwide. A number of human respiratory viruses circulate in all age groups and adapt to person-to-person transmission. It is vital to understand how these viruses infect the host and how the host responds to prevent infection and onset of disease. Although animal models have been widely used to study disease states, incisive arguments related to poor prediction of patient responses have led to the development of microfluidic organ-on-chip models, which aim to recapitulate organ-level physiology. Over the past decade, human lung chips have been shown to mimic many aspects of the lung function and its complex microenvironment. In this review, we address immunological responses to viral infections and elaborate on human lung airway and alveolus chips reported to model respiratory viral infections and therapeutic interventions. Advances in the field will expedite the development of therapeutics and vaccines for human welfare.     

Fractional-order partial pole assignment for time-delay systems based on resonance and time response criteria analysis

In this paper, a novel fractional-order partial pole assignment (FPPA) control algorithm is proposed for systems with time-delay. The FPPA control algorithm is essentially an extension of the original pole assignment, which could change undesired pole locations into desired pole locations. The presented control scheme can be used on open loop poorly damped or unstable systems, which is superior to most other time-delay compensation schemes. The discussion on choosing desirable pole locations is presented based on stability and resonance conditions in the frequency domain. The controlled system is also studied in the time domain based on different transient performance indicators, namely overshoot, settling time, and rising time. In addition, the parameters of the proposed FPPA control algorithm are tunable, thus the control scheme can be used to satisfy different control requirements. Simulation results of stable and unstable fractional-order plants with time-delay are shown to verify the effectiveness and practicability of the FPPA control algorithm.     

Social absorption capability, systems of innovation and manufactured export response to preferential trade incentives

In many extant analyses of the impact of non-reciprocal system of trade preferences it is typical to focus on the details of market access value of tariff concessions as explanation for why export of beneficiaries may or may not respond to incentives. Very often, the role that supply related factors can, and do play in the process is relegated to the background. This paper argues that the social absorption capability of a beneficiary's economy as expressed in her incumbent systems of innovation is a crucial determinant of export performance response. The experience of sub-Sahara African countries under the US African Growth and Opportunity Act apparel trade incentive is used as a classical illustration of this proposition. It is shown that the comparative efficiency of Lesotho, despite emerging from a relatively weak trade performance potential background, in recording the highest level of export success among beneficiaries of the scheme is a function of the relative efficiency of her systems of innovation.     

Dynamic event-triggered adaptive semi-global bipartite consensus of linear multi-agent systems with input saturation under fixed and switching topologies

This paper investigates dynamic event-triggered adaptive leader-following semi-global bipartite consensus (SGBC) of multi-agent systems (MASs) with input saturation. A dynamic event-triggered adaptive control (DETAC) protocol is presented, where the triggering function can regulate its threshold value dynamically. It’s turned out that the SGBC can be achieved via the DETAC protocol under some inequalities. Then, the proposed DETAC protocol is extended to solve bipartite consensus under jointly connected topology. Furthermore, the Zeno behaviors will be avoided. Finally, the rationality of proposed DETAC protocols are tested by simulation results.     

Dynamic output-feedback control for nonlinear continuous-time systems based on parametric uncertain subsystem and interval type-2 fuzzy model

This paper addresses the interval type-2 fuzzy robust dynamic output-feedback control problem for a class of nonlinear continuous-time systems with parametric uncertainties and immeasurable premise variables. First, the parametric uncertainties are assumed to be a subsystem based on the control input matrix and output matrix, and described as a linear fractional. Secondly, the nonlinear continuous-time systems are described by the interval type-2 fuzzy model. Thirdly, the new dynamic output feedback controller is designed based on the interval type-2 fuzzy model and the linear fractional (parametric uncertainties), the sufficient conditions for robust stabilization are given in the form of linear matrix inequalities (LMIs). Compared with previous work, the developed methods not only have abilities to handle the fuzzy system with immeasurable premise variables but also can deal with the parametric uncertainties effectively. The results are further extended to a mobile robot case and a chemical process case. Finally, two simulation examples are performed to show the effectiveness of the propose methods.     

The response of liver lipid peroxidative and antioxidant defense systems of protein undernourished rats to liver regeneration

The response of liver lipid peroxidative and antioxidant defense system of protein undernourished rats to liver regeneration induced by partial hepatectomy was examined in rats. Animals were divided into four groups; A,B,C and D of four animals each. Animals in group A were maintained on 16% casein diet while those in groups B, C and D were placed on low-protein diet (5% casein) for fourteen weeks and fed ad libitum. 72 hours before sacrifice, partial hepatectomy was carried out on animals in group D while animals in group C were sham-operated. The results show that protein undernutrition induced an increase in lipid peroxidation but reduced catalase activity, glutathione level and superoxide dismutase activity when compared with well-nourished rats. Liver regeneration however, resulted in significant increases in lipid peroxidation and catalase activity but significant reductions in glutathione level and superoxide dismutase activity in protein undernutrition rats when compared with their sham-operated counterparts. These results suggest that liver regeneration induced by partial hepatectomy exacerbates lipid peroxidation in protein undernutrition rats and that Catalase plays a major role in the mopping up of reactive oxygen species generated following liver regeneration in partially hepatectomised protein undernutrition rats.     

基于模糊决策与变分法的易逝品动态定价

建立了当消费者呈现价值判断异性时的动态定价模型,利用模糊函数引入购买可能性的概念来刻划消费者的消费模式,定义了博弈的理性期望均衡,并在线性购买可能性的假设下利用变分法求出恰当的价格函数.     

Pole-placement in discrete systems by using single and multirate sampling

This paper deals with closed-loop pole-placement in discrete, linear systems under single and multirate sampling. The technique is extendable to hybrid systems, i.e. those involving both continuous and discrete substates. The sampling rates for the state, input and output components are used as a controller design technique to achieve closed-loop pole-placement since the controller, which is also discrete or hybrid in the general case, can be periodically reparametrized, the main useful effect of which being the availability of multiple design gains whose number and value are under the designer's choice. The key design factor in the multirate sampling design is that once the closed-loop running sampling period (i.e. that defining the closed-loop dynamics and thus the controller reparametrization periodicity) has been chosen, one can use freedom in the choice of smaller sampling periods for the various plant input and output components as well as for those of the controller state. All these sampling periods are chosen as submultiples of the closed-loop running sampling period.     

Optimization-based adaptive neural sliding mode control for nonlinear systems with fast and accurate response under state and input constraints

The high-performance control requires the system to be stable, fast and accurate simultaneously. However, various systems (e.g., motors, industrial robots) generally face technical challenges such as nonlinearities, uncertainties, external disturbances and physical constraints, which make it difficult to reach the hardware potential of the systems to track the desired trajectories when satisfying the high-performance control requirements. Therefore, take a two-order nonlinear system for example, an optimization-based adaptive neural sliding mode control based on a two-loop control structure is proposed in this paper, where the outer and inner loops are designed separately to achieve different control requirements. Namely, the outer loop is designed as a model predictive control (MPC)-based optimization problem, which can optimize the desired trajectories to meet the state and input constraints, and maximize the converging speed of transient response as fast as possible, and the inner loop is designed with a recurrent neural network (RNN)-based adaptive neural sliding mode controller, which can guarantee the tracking of the replanned desired trajectories from outer loop as accurate as possible. The stability of the system is guaranteed by Lyapunov theorem, the optimal tracking performance is achieved under nonlinearities, uncertainties, external disturbances and physical constraints, and comparative simulation with a motor system is carried out to verify the effectiveness and superiority of the proposed approach.     

Microprocessor-based simulation of sampled data systems with/without a hold device using a set of sample-and-hold functions and Dirac delta functions

In the present work, Dirac delta function (DF) set and sample-and-hold functions (SHF) set are used for microprocessor-based simulation of discrete time as well as sample-and-hold systems. Such simulations are useful for identification of control systems with known input and output sequence. The presented method utilizes operational matrices of different orders in the DF and SHF domain to develop different operational transfer functions. A few open-loop as well as closed-loop systems have been studied and the simulation results obtained are compared with exact solutions derived with the help of z-transform analysis. Experiments have also been carried out to establish the validity of the proposal.