Active identification for discrete-time nonlinear control. II.Strict-feedback systems

For Part I, see ibid., vol. 47, no. 2, pp. 210-24 (2002). Presents a novel adaptive control design procedure for discrete-time nonlinear systems that can be transformed into the parametric-strict feedback form. This procedure utilizes the tools that were introduced in Part I, namely temporal separation of the parameter estimation task from the control task, the implementation of an active identification procedure through a recursive orthogonalized projection estimator and an input selection algorithm that guarantees complete identification in finite time. However, compared to the output-feedback case presented in Part I, the active identification task is now further complicated by the fact that the nonlinearities are allowed to depend on all states, not just the output. This requires a significant modification of the input selection procedure, which utilizes all the measured states to guarantee that the identification task will be completed in less time than in the output-feedback case     

Comments on "Adaptive fuzzy decentralized control for a class of large-scale nonlinear systems"

In a previous paper (see ibid., vol.34, no.1, p.770-5, 2004), direct and indirect adaptive output-feedback fuzzy decentralized controllers for a class of uncertain large-scale nonlinear systems were presented. A comment is made here to show that the proposed control schemes of the previous paper are not realizable.     

Authors' reply to comment on "stability of fuzzy control systems with bounded uncertain delays"

For comment see ibid., p.285-6 (2004). The authors reply to a comment on their paper (Z. Yi and P.A. Heng, see ibid., vol.10, p.92-7, 2002) by agreeing with the comment.     

The formal specification of a small bookshop information system

A specification, and its development, for a small bookshop information system are discussed. the specification is presented using mathematics and the scheme calculus of C. Morgan and B. Sufrin (see ibid., vol.SE-10, no.2, p.128-142, 1984). An insight is given into how the specification was developed and why a formal specification is appropriate     

Correction to `Allocating programs containing branches and loopswithin a multiple processor system'

A number of typographical errors in the above-mentioned paper (see ibid., vol.12, no.10, p.1018-24 (1986)) are corrected     

Comments on “Robust adaptive regulation with minimal priorknowledge”

The author comments on the paper by F. Giri et al. (see ibid., vol.37, no.3, p.305-15, 1992). The author argues that there is a circularity in the argument of the paper and that therefore, the correctness of the results of the paper is ambiguous     

Correction to `A practical view of software measurement andimplementation experiences within Motorola'

A corrected reference list for the above-titled paper (see ibid., vol.18, no.11, p.998-1010, (1992)) is presented     

A menagerie of rational B-spline circles

The article was motivated by J. Blinn's column on the many ways to draw a circle (see ibid., vol.7, no.8, p.39-44, 1987). The authors have found several other ways to represent the circle as a nonuniform rational B-spline curve, which they present. Square-based methods, infinite control points, triangle-based methods, general circular arcs and rational cubic circles are some of the methods and types of circle discussed     

Comments, with reply, on `On the projection method for protocolverification' by T.-Y. Cheung

A counterexample to a theorem given in a paper by T.-Y. Cheung (see ibid., vol.12, no.11, p.1088-9, 1986) is given. In a reply, the author of the original paper argues that the counterexample is not correct     

Comments, with reply, on `The standardization line' by A. Winder

The commenter maintains that the author of the above-titled article (see ibid., vol.7, no.3, p.84-85, 1990) failed to consider psychological, sociological and design aspects of the subject of naming conventions, and he discusses some research that has been done on these issues. The author responds that the commenter's points are valid if naming standards is viewed as an isolated exercise. She points out, however, that the naming scheme she described assumes a context, which is to normalize an organization's data and business practices     

Correction to `Ontological versus knowledge engineering'

The author previously cited an incorrect publisher (see ibid., vol.1, p.84-8, 1989). The correct publisher information is: Reading, MA: Addison Wesley     

How to Solve a Cubic Equation, Part 3: General Depression and a New Covariant

For pt.2 see ibid., vol. 26, no. 4, p. 90-100 (2006). Our ultimate goal here is twofold. We want to get insight into how cubic polynomials work, what are the invariants/covariants and their geometric interpretations. This article also describes how a transformation in parameter space relates to the transformation in coefficient space     

Correction to `The case for electric design of real-time software'

The title of this paper (see ibid., vol.15, p.360-2 (1989)) was printed incorrectly. It should have read: the case for the eclectic design of real-time software     

Comments on `A comparison of RISC architectures' by R.S. Piepho andW.S. Wu

For original article see ibid., vol.9, no.4, p.51-62, (Aug. 1989). The author points out that the relative addressing capability of a given architecture allows one to create position-independent code, that is, code (and data) that can be mapped anywhere in memory. The author notes that this capability is required to create shareable libraries, a feature that is available in the SunOS 4 and Unix System 5.4     

Comments on `Internal stabilization and decoupling in linearmultivariable systems by unity output feedback compensation'

A straightforward and neat proof is presented for the main result of the above mentioned technical note by A.I.G Vardulakis (see ibid., vol.AC-32, no.8, p.735-39, Aug. 1987)     

Comments on “An SVD-Based Watermarking Scheme for Protecting Rightful Ownership”

For original paper see ibid., vol. 4, no. 1, p. 121-8 (2002). It is shown that the watermarking algorithm presented in the above paper (R. Liu et al., 2002) can be easily discredited and ipso facto cannot be used for protecting rightful ownership     

Comments, with reply, on `Extensions to SQL for historicaldatabases' by N.L. Sarda

The commenters point out that the author of the above-titled paper (see ibid., vol.2, p.220-30, 1990) failed to acknowledge their contemporary publications of almost identical results and the subsequent, comprehensive refinement of this work. The author replies that he did not have access to their publications. He indicates some differences between their work and his     

Comments, with reply, on `Using function abstraction to understandprogram behavior' by P.A. Hausler et al

The commenter shows that an example given in the above-titled article (see ibid., vol.7, no.1, p.55-63 (1990)), namely a program for swapping the values of two variables, is incorrect, even though its correctness is proved by the author. Three of the authors respond, agreeing that the commenter's point is valid and explaining the discrepancy     

Comments, with reply, on `On criteria for module interfaces' by D.Hoffman

The commenter acknowledges that the practical criteria provided in the above-titled paper (see ibid., vol.16, no.5, p.537-42, 1990), offer substantive guidelines for designing module interfaces. He points out that the results obtained can be further improved and certain remaining conflicts resolved through consideration of established principles of structured design and software engineering. He illustrates his point with an example involving the specification of a stack interface that requires two or three separate references to replace one. He presents two designs and argues that the first is better. The author refutes the commenter's arguments and argues that the second design is better     

Putting the "Web" into Web services. Web services interaction models.2

For pt.1 see ibid., vol.6, no.3, p. 89-91 (2002). As I discussed in my previous column, each different style of middleware promotes one or more interaction models that determine how applications based on that middleware communicate and work with each other. It is difficult to say what the best interaction models would be for Web services, mainly because the World Wide Web Consortium (W3C) is still developing the architecture. The author considers the use of remote procedure calls, Web services and messaging and interface complexity.