Comments on “Timed Petri Nets in Modeling and Analysis of Cluster Tools”

In the above paper by Zuberek, conflict-free Petri nets with deterministic timing are used for modeling cluster tools. Performance analysis of the models is based on P-invariants. This comment tries to clarify some statements in the paper and points out a more efficient performance-analysis approach based on linear programming, which is of polynomial time complexity.     

Comments on “The Extreme Learning Machine”

This comment letter points out that the essence of the “extreme learning machine (ELM)” recently appeared has been proposed earlier by Broomhead and Lowe and Pao , and discussed by other authors. Hence, it is not necessary to introduce a new name “ELM.”      

Comments on “direct bilinear routh stability criteria for discrete systems”

The above paper¹ discusses useful Routh-like stability criteria for discrete systems. Unfortunately, however, previous work on the subject escaped the attention of the author. This note co-ordinates previous work with results obtained in the above paper. It also points out some of the more recent developments on the subject.     

Comments on “Controller Synthesis of Fuzzy-Dynamic Systems Based on Piecewise Lyapunov Functions”

This comment tries to describe a theoretical mistake made in the aforementioned paper [G. Feng, IEEE Trans. Fuzzy Syst., vol. 11, no. 5, pp. 605–612, Oct. 2003] to formulate the inverse of matrices used to construct the piecewise-quadratic Lyapunov functions. Derivation of these inverse matrices is the most critical step toward transforming the design constraints into linear matrix inequalities (LMIs). Therefore, the erroneous formulation essentially affects the validity of the approach and final results. Unfortunately, it seems that there is no simple correction for this problem. However, some close alternative approaches are suggested by the same authors in their other works.      

Author's reply: “A comment on optimal control of SISO continuous-time systems”

In the above-mentioned comment, the author points out a technical problem with the paper (Wang, Z. Q., & Sznaier, M. (1997). Automatica, 33(1), 85–90). As we show here, this technical problem can be easily solved. Moreover, it affects neither the main formulation nor the results, which remain valid.     

Correction to "Quadratic stability and stabilization of dynamic interval Systems"

It is pointed out that the counterexample in a previous comment is not a counterexample. A new counterexample is presented to show that the necessity part of Theorem 1 of the above paper is not valid in some cases. Furthermore, based on the M-matrix theory, a new quadratic stability condition for dynamic interval systems is proposed to correct the corresponding result in the above paper.     

Comments on “FuzzyShell: a large-scale expert system shellusing fuzzy logic for uncertainty reasoning” [and reply]

The above paper by Pan et al. (ibid. vol.6 (1998)) presents a rather complicated mechanism allowing fuzzy evidence to be aggregated when fuzzy inferences are made about the same fuzzy variable by different rules. The purpose of this comment is to present a simpler way to address this FuzzyCLIPS problem. In reply, the authors point out that the commenter's main conclusions about their work are ill founded. They believe that his erroneous conclusions were caused by his misunderstanding the difference between rule firing and evidence aggregation in their work     

Comments regarding “On stability of interval matrices”[with reply]

We note that several of the results on Schur-stability of interval matrices in the above paper by Sezer-Siljak (ibid. vol.39) can be viewed as special cases of results obtained in a more general framework, and some of the latter were previously reported in the literature. In reply, Sezer-Siljak response to the issues raised in the comment     

Comments and improvement on “Robust control of state delayed systems with polytopic type uncertainties via parameter-dependent Lyapunov functionals”

The errors are pointed out in the above paper. And then, a new delay-dependent condition is presented for the robust stability of uncertain time-delay systems, which is an improvement on the corresponding results in the above paper.     

Comments on “Approximate output regulation of a class of nonlinear systems”

In the above-mentioned paper [Journal of Process Control 11 (2001) 69–80], the problem of approximate output regulation of a class of nonlinear systems was considered. By a step-by-step systematic design procedure, a nonlinear controller is designed which is a dynamic and state feedback. However, we find that there exist some mistakes in the proof of the main theorem of this paper. This note points out the flaw of the commented paper.     

Comments on “A class of proportional-integral sliding mode control with application to active suspension system”

In this note, we first show that Theorem 2 in the above paper is incorrect. Then, we also show that Theorem 1 is not enough to support the claim in the above paper that the proportional-integral sliding mode control method is more robust than the linear quadratic regulator method when applying on the active suspension system with mismatched uncertainties.     

Notes on “Reducing Algorithm Complexity for Computing an Aggregate Uncertainty Measure”

In a recent paper, Liu have proposed the so-called F -algorithm which conditionally reduces the computational complexity of the Meyerowitz-Richman-Walker algorithm for the computation of the aggregate-uncertainty measure in the Dempster-Shafer theory of evidence, along with an illustration of its application in a practical scenario of target identification. In this correspondence, we will point out several technical mistakes, which some of them lead to some inexact or incomplete statements in the paper of Liu The corrections of these mistakes will be made, and some further improvement and results will be derived.     

Aspects of inspection in a knitwear company

The paper presents some of the results of a preliminary study on inspection performance in industry. Four data-gathering exercises were carried out; two concerned with measuring the accuracy of the examiners, one attempted to elucidate some of the differences between 'good' and 'bad' examiners in terms of their perceptions and knowledge of the task, and one presented some of the results to management representatives for comment. The results are discussed briefly, and a number of general conclusions drawn. Examiners' detection performance for faults is of the order of 50%, in a production process where the fault rate is of the order of 50%. It is believed that part of the cause for the above performance is due to organisational aspects of the job design. Communication of relevant information regarding the above is virtually non-existent, which has allowed the situation to continue as it is, and has allowed the organisation to believe that a much better state of affair exists. This company is not unusual in the industry in the above respects.     

“Graphical” Jogthrough: expert based methodology for user interface evaluation, applied in the case of an educational simulation interface

“Walkthrough” and “Jogthrough” techniques are well known expert based methodologies for the evaluation of user interface design. In this paper we describe the use of “Graphical” Jogthrough method for evaluating the interface design of the Network Simulator, an educational simulation program that enables users to virtually build a computer network, install hardware and software components, make the necessary settings and test the functionality of the network. Graphical Jogthrough is a further modification of a typical Jogthrough method, where evaluators' ratings produce evidence in the form of a graph, presenting estimated proportion of users who effectively use the interface versus the time they had to work with it in order to succeed effectiveness. We comment on the question: “What are the possible benefits and limitations of the Graphical Jogthrough method when applied in the case of educational software interface design?” We present the results of the evaluation session, and concluding from our experience we argue that the method could offer designers quantitative and qualitative data for formulating a useful (though rough in some aspects) estimation about the novice–becoming–expert pace that end users might follow when working with the evaluated interface.     

Comment on the paper “Microsystem Technologies: (2018) 24:2919–2928”

The present comment concerns some doubtful results included in the above paper.

     

Comments on ``An Automated Approach to the Design of Decision Tree Classifiers'

The above paper1 provides an automated technique for decision tree design which relies only on a priori statistics. The technique is basically to find a partition of the class set which maximizes the probability of correct classification at a given decision node. To do so, in the above paper1 all the possible partitions are searched exhaustively. In the present comment it is pointed out that the search for the partitions with a size of two is sufficient, and the higher order of partitions need not be searched.     

Further Comment on “Optimal Fuzzy Controller Design: Local Concept Approach”

Stability analysis and optimality are important in any systems. In the paper, "optimal fuzzy controller design: local concept approach," optimal fuzzy controller is design for Takagi-Sugeno fuzzy model. Unfortunately, it seems that some errors are happen and no simple correction can be done. In this paper, we show that some errors exit in the aforementioned paper with simple and clear examples.     

Comment and Further Result on “Fault Detection and Isolation Method Based on H−/H∞ Unknown Input Observer Design in Finite Frequency Domain”

This paper considers the work entitled “Fault detection and isolation method based on H_?/H_∞ unknown input observer design in finite frequency domain”, published previously in the Asian Journal of Control. We point out that some design matrices in the above mentioned article have no effect on the design result. Furthermore, we show that the conditions proposed therein for H_∞ design are conservative and propose an improved design method.     

Erratum to “On the Synthesis of Haptic Textures” [Jun 08 527-536]

In the above titled paper (ibid., vol. 24, no. 3, pp. 527-536, Jun 08), it is stated in Sec. IV-D3 that the characteristic number of the first variant of the "god object" method applied to texture synthesis is 1. This statement is not always true, and clarification of this issue is presented here.     

Comments on “Generalized Lyapunov Equation Approach to State-Dependent Stochastic Stabilization/ Detectability Criterion”

This note gives a correct proof for the first part of Theorem 3.2 in the above paper, which is an important theorem of the above paper.