The individual ‘working-to-rules’: reducing determinism in Taylor-made expert systems

Holden (1989) suggested that Taylorist scientific management principles, based upon machine-like models of man, may influence the development and application of expert systems. While Holden's work is a major contribution to the debate on the effects of technology on employment, it is argued that a similar deterministic and mechanistic image of the users of expert systems is implicit in his paper. In addition, this commentary also addresses some of the related issues concerning autonomous expert systems.     

Beyond ‘mobility’: A new understanding of moving with technology

We report a surprising experience with mobile technology: the lead author found herself seeing and acting differently while running over part of her usual running track with the exercise‐tracking application ‘Strava’ on her phone, even without focal attention to the app. We apply the method of problematization to a detailed empirical account of this experience, in conjunction with a literature analysis of taken‐for‐granted assumptions underpinning research on ‘mobile technology use’. This reveals that, while the relationship of attention, perception, movement and technology was a key element of the surprise, these themes are not well accounted for in current IS literature. In response, we employ William Gibson's ecological theory of visual perception to reinterpret the empirical account and thereby build a new understanding of the human plus mobile technology that we term moving‐with‐technology. We introduce to IS: moving‐with‐technology as a new analytical perspective; the new phenomena of digital sub‐species, digital‐niches and asynchronous co‐location; and stimulus for new ecologically oriented ‘mobile methods’. Moving‐with‐technology also has practical implications for urban planners who are using data from digital trace‐making tools such as Strava in their decision‐making, thereby generating what we call ecological feedback loops.     

A new tracking controller for discrete‐time SISO non minimum phase systems

A new tracking controller for discrete‐time Single Input Single Output (SISO) non‐minimum phase (NMP) systems is presented. In the proposed method, after cancelation of poles and cancelable zeros of the system, the controller adds some NMP zeros to compensate the effect of NMP zero (zeros) of the system. As a result, the phase of the overall transfer function will be almost linear and its magnitude approaches unity for all frequencies. The method can be applied even to the systems with complex conjugate NMP zeros. As well, it is applicable to the systems for which the conventional methods cannot properly be used. Furthermore, a generalization of method to continuous‐time systems is another given result. Several examples are provided to illustrate the effectiveness of the method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

A PDMS microfluidic impedance immunosensor for E. coli O157:H7 and Staphylococcus aureus detection via antibody-immobilized nanoporous membrane

In this article, a PDMS microfluidic immunosensor integrated with specific antibody immobilized alumina nanoporous membrane was developed for rapid detection of foodborne pathogens Escherichia coli O157:H7 and Staphylococcus aureus with electrochemical impedance spectrum. Firstly, antibodies to the targeted bacteria were covalently immobilized on the nanoporous alumina membranes via self assembled (3-glycidoxypropyl)trimethoxysilane (GPMS) silane. Then, the impedance spectrum was recorded for bacteria detection ranging from 1 Hz to 100 kHz. The maximum impedance amplitude change for these two food pathogens was around 100 Hz. This microfluidic immunosensor based on nanoporous membrane impedance spectrum could achieve rapid bacteria detection within 2 h with a high sensitivity of 10² CFU/ml. Cross-bacteria experiments for E. coli O157:H7 and S. aureus were also explored to testify the specificity. The results showed that impedance amplitude at 100 Hz had a significant reduction in binding of bacteria when the membrane was exposed to non-specific bacteria.     

A new approach to robust and non-fragile H∞ control for uncertain fuzzy systems

This paper investigates the robust H_∞ control and non-fragile control problems for Takagi-Sugeno (T-S) fuzzy systems with linear fractional parametric uncertainties. The robust H_∞ control problem is to design a state feedback controller such that the robust stability and a prescribed H_∞ performance of the resulting closed-loop system is ensured. And the non-fragile H_∞ control problem is to design a state feedback controller with parameter uncertainties. Based on the linear matrix inequality (LMI) approach, new sufficient conditions for the solvability of the two problems are obtained. It is shown that the desired state feedback fuzzy controller can be constructed by solving a set of LMIs. Numerical examples are also provided to demonstrate the effectiveness of the proposed design method.     

A new algebraic model for implementing expert systems represented under the ‘Concept-Attribute-Value’ paradigm

This paper is concerned with expounding a new representation paradigm for modeling expert systems based on computing Groebner Bases. Previous research on Groebner Bases expert systems has so far been connected to modeling expert systems based on propositional logics. Our approach instead is based on the well-known Artificial Intelligence ‘Concept-Attribute-Value’ paradigm for representing knowledge. More precisely, our research is based on translating an already existent expert system described in terms of the ‘Concept-Attribute-Value’ paradigm to a new algebraic model which represents knowledge by means of polynomials. In this way, issues about consistence and inference within this expert system will be, through this new model, transformed into algebraic problems involving calculating Groebner Bases. By using this new model of ours, some interesting advantages ensue: on the one hand, knowledge representation may be performed in a more straightforward and intuitive way; on the other, calculating the Groebner Bases associated to our algebraic model is usually faster adopting this new ‘Concept-Attribute-Value’-based paradigm than it was in previous propositional logic-based expert systems.     

A new continuous high‐gain controller scheme for a class of uncertain nonlinear systems

In this study, we present a new robust continuous controller mechanism for the tracking problem of uncertain nonlinear systems. The proposed strategy is based on a Lyapunov‐type stability argument and only requires the uncertainties of the dynamical system to be the first‐order differentiable to achieve asymptotic practical tracking. For the ease of presentation, the controller formulation is presented on a general, second‐order dynamical system, extension to higher order versions are also possible with a considerably small effort. Simulation studies comparing the performance of the proposed method with the classical Sliding mode and robust integral of the sign of the error controller are presented to illustrate the performance and the feasibility of the proposed strategy. Experimental validation on a two link direct drive robot manipulator are also included to illustrate the implementability of the proposed method. Copyright © 2013 John Wiley & Sons, Ltd.     

‘Long return’: A technique for improving the efficiency of inter-module communication

This paper describes a concept called ‘long return’ for use in inter-module communication systems. First an implementation which implies a simplification of—rather than an extension of—traditional inter-module communication systems is outlined. This implementation allows long returns to be used as an optimization technique without violating the commonly accepted principles of system structuring. Thereafter an experiment that provides an estimate of the improvements in efficiency of a particular operating system is described. In the SIMOS operating systems (based on the Cambridge CAP operating system) about 20 per cent of all inter-process communication operations can be avoided by using long returns, and as a consequence the amount of useful work done in the system is typically increased by about 2.0 per cent.     

Response to ‘Comments on: A cohesion measure for object‐oriented classes’

Indicating that CBMC does not satisfy the monotonic property in terms of the number of interactions, Xu and Zhou proposed an augmented definition of CBMC by adopting cut set instead of glue methods. The augmented CBMC clearly satisfies the monotonic property. However, CBMC is designed to overcome the problem with respect to the number of interactions and, therefore, focuses on the interaction pattern, especially, member connectivity. Consequently, it does not make sense to mention the monotonic property of CBMC with respect to interaction number. Moreover, the notion of glue methods allows several interpretations on the design quality of a class. However, that meaningful interpretation is not possible for the augmented definition due to the removal of the notion of glue methods. Copyright © 2001 John Wiley & Sons, Ltd.     

LyraNET: A zero-copy TCP/IP protocol stack for embedded systems

Embedded systems are usually resource limited in terms of processing power, memory, and power consumption, thus embedded TCP/IP should be designed to make the best use of limited resources. Applying zero-copy mechanism can reduce memory usage and CPU processing time for data transmission. Power consumption can be reduced as well. In this paper, we present the design and implementation of zero-copy mechanism in the target embedded TCP/IP component, LyraNET, which is derived from Linux TCP/IP codes and remodeled as a reusable software component that is independent from operating systems and hardware. Performance evaluation shows that TCP/IP protocol processing overhead can be significantly decreased by 23–63%. Besides, object code size of this network component is only 77.64% of the size of the original Linux TCP/IP stack. The experience of this study can serve as the reference for embedding Linux TCP/IP stack into a target system that requires network connectivity and improving the transmission efficiency of Linux TCP/IP by zero-copy implementation. This paper is an extended version of the paper “LyraNET: A Zero-Copy TCP/IP Protocol Stack for Embedded Operating Systems” that appeared in the 11th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications. Mei-Ling Chiang received the B.S. degree in Management Information Science from National Chengchi University, Taipei, Taiwan, in 1989. She received the M.S. degree in 1993 and her Ph.D degree in 1999 in Computer and Information Science from National Chiao Tung University, Hsinchu, Taiwan. Now she is an Assistant Professor in the Department of Information Management at National Chi-Nan University, Puli, Taiwan. Her current research interests include operating systems, embedded systems, and clustered systems. Yun-Chen Lee received the B.S degree in 2002 and the M.S. degree in 2005 in Information Management from National Chi-Nan University, Puli, Taiwan. He is currently a software engineer in InterVideo Digital Tech., responsible for software development of multimedia-related products.     

A new view of anti‐windup design for uncertain linear systems in the frequency domain

This paper presents a new perspective on the stability problem for uncertain LTI feedback systems with actuator input amplitude saturation. The solution is obtained using the quantitative feedback theory and a 3 DoF non‐interfering control structure. Describing function (DF) analysis is used as a criterion for closed loop stability and limit cycle avoidance, but the circle or Popov criteria could also be employed. The novelty is the combination of a controller parameterization from the literature and describing function‐based limit cycle avoidance with margins for uncertain plants. Two examples are given. The first is a benchmark problem and a comparison is made with other proposed solutions. The second is an example that was implemented and tested on an X‐Y linear stage used for nano‐positioning applications. Design and implementation considerations are given. An example is given on how the method can be extended to amplitude and rate saturation with the help of the generalized describing function, and a novel anti‐windup compensation structure inspired by previous contributions. Copyright © 2015 John Wiley & Sons, Ltd.     

A decision support system for the automatic management of keep-clear signs based on support vector machines and geographic information systems

This paper presents a decision support system for automatic keep-clear signs management. The system consists of several modules. First of all, an acquisition module obtains images using a vehicle equipped with two recording cameras. A recognition module, which is based on Support Vector Machines (SVMs), analyzes each image and decides if there is a keep-clear sign in it. The images with keep-clear signs are included into a Geographical Information System (GIS) database. Finally in the management module, the data in the GIS are compared with the council database in order to decide actions such as repairing or reposition of signs, detection of possible frauds etc. We present the first tests of the system in a Spanish city (Meco, Madrid), where the systems is being tested for its application in the near future.     

A new unified input‐to‐state stability criterion for impulsive stochastic delay systems with Markovian switching

In this paper, the problems of the input‐to‐state stability (ISS), the integral input‐to‐state stability (iISS), the stochastic input‐to‐state stability (SISS) and the e^λt(λ>0)‐weighted input‐to‐state stability (e^λt‐ISS) are investigated for nonlinear time‐varying impulsive stochastic delay systems with Markovian switching. We propose one unified criterion for the stabilizing impulse and the destabilizing impulse to guarantee the ISS, iISS, SISS and e^λt‐ISS for such systems. We verify that when the upper bound of the average impulsive interval is given, the stabilizing impulsive effect can stabilize the systems without ISS. We also show that the destabilizing impulsive signal with a given lower bound of the average impulsive interval can preserve the ISS of the systems. In addition, one criterion for guaranteeing the ISS of nonlinear time‐varying stochastic hybrid systems under no impulsive effect is derived. Two examples including one coupled dynamic systems model subject to external random perturbation of the continuous input and impulsive input disturbances are provided to illustrate the effectiveness of the theoretic results developed.     

Global output‐feedback stabilization for stochastic nonlinear systems: A double‐domination approach

This paper is concerned with global stabilization via output feedback for a class of stochastic nonlinear systems with time‐varying continuous output function. Under linear growth conditions, a new double‐domination method is proposed for the first time to construct an output‐feedback stabilizing controller. Different from the related results, the design of the observer is performed without using the information on the output function and nonlinearities. This paper also provides a viewpoint at the feedback stabilization to eliminate the continuous measurement error originating from inaccurate detection of system state. A simulation example is presented to demonstrate the effectiveness of control strategy.     

A specified‐time control framework for control‐affine systems and rigid bodies: A time‐rescaling approach

This paper addresses the specified‐time control problem for control‐affine systems and rigid bodies, wherein the specified‐time duration can be designed in advance according to the task requirements. By using the time‐rescaling approach, a novel framework to solve the specified‐time control problem is proposed, and the original systems are converted to the transformation systems based on which the specified‐time control laws for both control‐affine systems and rigid bodies are studied. Compared with the existing approaches, our proposed specified‐time control laws can be derived from the known stabilization control laws. To our best knowledge, it is the first time that transformation system–based specified‐time control framework for control‐affine system and rigid body dynamics is proposed. To further improve the convergence performance of specified‐time control, a finite‐time attitude synchronization control law for rigid bodies on rotation matrices is proposed, and thereby, the finite‐time–based specified‐time control law is designed eventually. In the end, numerical simulations and SimMechanics experiments are provided to illustrate effectiveness of the theoretical results.     

A robustness study of a finite‐time/exponential tracking continuous control scheme for constrained‐input mechanical systems: Analysis and experiments

The closed‐loop analysis of a recently proposed continuous scheme for the finite‐time or exponential tracking control of constrained‐input mechanical systems is reformulated under the consideration of an input‐matching bounded perturbation term. This is motivated by the poor number of works devoted to support the so‐cited argument claiming that continuous finite‐time controllers are more robust than asymptotical (infinite‐time) ones under uncertainties and the limitations of their results. We achieve to analytically prove that, for a perturbation term with sufficiently small bound, the considered tracking continuous control scheme leads the closed‐loop error variable trajectories to get into an origin‐centered ball whose radius becomes smaller in the finite‐time convergence case, entailing smaller posttransient variations than in the exponential case. Moreover, this is shown to be achieved for any initial condition, avoiding to restrain any of the parameters involved in the control design, and under the suitable consideration of the nonautonomous nature of the closed loop. The study is further corroborated through experimental tests on a multi‐degree‐of‐freedom robotic manipulator, which do not only confirm the analytical result but also explore the scope or limitations of its conclusions under adverse perturbation conditions.     

Dynamic predictor for systems with state and input delay: A time‐domain robust stability analysis

The robust stability of linear systems with both state and input delay in closed loop with dynamic predictor‐based controller is analyzed. The problem of time‐varying matrix uncertainty is studied in the Lyapunov‐Krasovskii framework. The complete type functional with prescribed derivative expressed in terms of the delay Lyapunov matrix associated with the nominal system is a key piece of our analysis. The robust stability conditions depend on the delay Lyapunov matrix whose computation is carried out. An illustrative example is presented.     

A new iterative algorithm for solving H∞ control problem of continuous‐time Markovian jumping linear systems based on online implementation

A new online iterative algorithm for solving the H_∞ control problem of continuous‐time Markovian jumping linear systems is developed. For comparison, an available offline iterative algorithm for converging to the solution of the H_∞ control problem is firstly proposed. Based on the offline iterative algorithm and a new online decoupling technique named subsystems transformation method, a set of linear subsystems, which implementation in parallel, are obtained. By means of the adaptive dynamic programming technique, the two‐player zero‐sum game with the coupled game algebraic Riccati equation is solved online thereafter. The convergence of the novel policy iteration algorithm is also established. At last, simulation results have illustrated the effectiveness and applicability of these two methods. Copyright © 2016 John Wiley & Sons, Ltd.     

Finite‐time H∞ bumpless transfer control for switched systems: A state‐dependent switching approach

This paper addresses the finite‐time H_∞ bumpless transfer control problem for switched systems. The main idea lies in designing a state‐feedback controller with amplitude limitation and a state‐dependent switching law to reduce control bumps caused by switching. First, a local bumpless transfer condition is proposed to limit the amplitude of switching controllers at switching points. Second, by introducing a state‐dependent switching law, a prescribed finite‐time H_∞ bumpless transfer control performance is attained even if it does not hold for each subsystem or system state remaining on a switching surface. Third, a sufficient condition verifying the solvability of finite‐time H_∞ bumpless transfer control problem is established by resorting to multiple Lyapunov function method. Finally, the effectiveness of developed method is illustrated by a numerical example.