Interpolation error estimates on hermite rational “Wachspress type” third degree finite element

This paper is about the study of interpolation error for the Hermite rational “Wachspress type” third degree finite element that is constructed in[1]. We obtain results analogous with those of the “corresponding” ADINI (polynomial) finite element.     

A comment on “L∞ optimal control of SISO continuous-time systems”

The paper “L_∞ optimal control of SISO continuous-time systems” by Wang and Sznaier (Wang & Sznaier (1997). Automatica, 33 (1), 85–90) studies the problem of designing a controller that optimally minimizes the peak absolute value of system output, due to a fixed input signal. With a newly defined function space A_∞, it was claimed that the set of all L_∞-bounded outputs could be parameterized and that the problem could be transformed to a minimal distance problem on L_∞ space. We believe, however, their formulation has essential flaws.     

The role of coherence in eliciting and handling imprecise probabilities and its application to medical diagnosis

We refer to an arbitrary family of events (hypotheses), i.e., has neither any particular algebraic structure nor is a partition of the certain event Ω. We detect logical relations among the given events (the latter could represent some possible diseases), and some further information is carried by probability assessments, relative to an event E (e.g., a symptom) conditionally to some of the H_i's (“partial likelihood”). If we assess (prior) probabilities for the events H_i's, then the ensuing problems are: (i) is this assessment coherent? (ii) is the partial likelihood coherent “per se”? (iii) is the global assignment (the initial one together with the likelihood) coherent? If the relevant answers are all YES, then we may try to “update” (coherently) the priors P(H_i) into the posteriors P(H_i|E). This is an instance of a more general issue, the problem of coherent extensions: a very particular case is Bayes' updating for exhaustive and mutually exclusive hypotheses, in which this extension is unique. In the general case the lack of uniqueness gives rise to upper and lower updated probabilities, and we could now update again the latter, given a new event F and a corresponding (possibly partial) likelihood. In this paper, many relevant features of this problem are discussed, keeping an eye on the distinction between semantic and syntactic aspects.     

Boolean operations and inclusion test for attribute–element constraints

The history of schema languages for XML is (roughly) an increase of expressiveness. While early schema languages mainly focused on the element structure, Clark first paid an equal attention to attributes by allowing both element and attribute constraints in a single constraint expression (we call his mechanism “attribute–element constraints”). In this paper, we investigate intersection and difference operations and inclusion test for attribute–element constraints, in view of their importance in static typechecking for XML processing programs. The contributions here are (1) proofs of closure under intersection and difference as well as decidability of inclusion test and (2) algorithm formulations incorporating a “divide-and-conquer” strategy for avoiding an exponential blow-up for typical inputs.     

Rush Hour is PSPACE-complete, or “Why you should generously tip parking lot attendants”

Rush Hour is a children's game that consists of a grid board, several cars that are restricted to move either vertically or horizontally (but not both), a special target car, and a single exit on the perimeter of the grid. The goal of the game is to find a sequence of legal moves that allows the target car to exit the grid. We consider a slightly generalized version of the game that uses an n×n grid and assume that we can place the single exit and target car at any location we choose on initialization of the game.

In this work, we show that deciding if the target car can legally exit the grid is PSPACE-complete. Our constructive proof uses a lazy form of dual-rail reversible logic such that movement of “output” cars can only occur if logical combinations of “input” cars can also move. Emulating this logic only requires three types of devices (two switches and one crossover); thus, our proof technique can be easily generalized to other games and planning problems in which the same three primitive devices can be constructed.     

On two-sided infinite fixed points of morphisms

Let Σ be a finite alphabet, and let h:Σ^* → Σ^* be a morphism. Finite and infinite fixed points of morphisms—i.e., those words w such that h(w)=w—play an important role in formal language theory. Head characterized the finite fixed points of h, and later, Head and Lando characterized the one-sided infinite fixed points of h. Our paper has two main results. First, we complete the characterization of fixed points of morphisms by describing all two-sided infinite fixed points of h, for both the “pointed” and “unpointed” cases. Second, we completely characterize the solutions to the equation h(xy)=yx in finite words.     

Line patterning of graphite and the fabrication of cheap, inexpensive, “throw-away” sensors

A new simple method (“line patterning technique”) using only standard office equipment is described whereby clearly defined, electrically conducting patterns of graphite can be deposited on polymer (plastic) or paper substrates. The properties of the conductive patterns have been characterized by electrical conductivity and SEM measurements. Sensors were constructed by using interdigitated patterns of graphite deposited on plastic and paper, and coated with a thin film of conducting electronic polymer, e.g. polyaniline emeraldine salt.     

A general treatment of dynamic integrity constraints

This paper introduces a general, set-theoretic model for expressing dynamic integrity constraints, i.e., integrity constraints on the state changes that are allowed in a given state space. In a managerial context, such dynamic integrity constraints can be seen as representations of “real world” constraints and business rules. This topic has important practical applications in many business areas. The notions of (direct) transition, reversible and irreversible transition, transition relation, and consistency of a transition relation will be introduced. The expected link with Kripke models (for modal and temporal logics) is also made explicit. Several practical examples of dynamic integrity constraints will illustrate the applicability of the theory. Some important subclasses of dynamic integrity constraints in a database context will be identified, e.g., various forms of cumulativity (which can be regarded as “transitional” inclusion dependencies concerning two different “points in time”), non-decreasing values, integrity constraints on initial and final values, life cycles, changing life cycles, and transition and constant dependencies. Several formal properties of these dependencies will be derived. For instance, it turns out that functional dependencies can be considered as “degenerated” transition dependencies. Also, the distinction between primary keys and alternate keys is reexamined, from a dynamic point of view.     

Fuzzy independence and extended conditional probability

In many applications, the use of Bayesian probability theory is problematical. Information needed to feasibility calculate is unavailable. There are different methodologies for dealing with this problem, e.g., maximal entropy and Dempster-Shafer Theory. If one can make independence assumptions, many of the problems disappear, and in fact, this is often the method of choice even when it is obviously incorrect. The notion of independence is a 0–1 concept, which implies that human guesses about its validity will not lead to robust systems. In this paper, we propose a fuzzy formulation of this concept. It should lend itself to probabilistic updating formulas by allowing heuristic estimation of the “degree of independence.” We show how this can be applied to compute a new notion of conditional probability (we call this “extended conditional probability”). Given information, one typically has the choice of full conditioning (standard dependence) or ignoring the information (standard independence). We list some desiderata for the extension of this to allowing degree of conditioning. We then show how our formulation of degree of independence leads to a formula fulfilling these desiderata. After describing this formula, we show how this compares with other possible formulations of parameterized independence. In particular, we compare it to a linear interpolant, a higher power of a linear interpolant, and to a notion originally presented by Hummel and Manevitz [Tenth Int. Joint Conf. on Artificial Intelligence, 1987]. Interestingly, it turns out that a transformation of the Hummel-Manevitz method and our “fuzzy” method are close approximations of each other. Two examples illustrate how fuzzy independence and extended conditional probability might be applied. The first shows how linguistic probabilities result from treating fuzzy independence as a linguistic variable. The second is an industrial example of troubleshooting on the shop floor.     

Recognizing image “style” and activities in video using local features and naive Bayes

The goal of this paper is to offer a framework for classification of images and video according to their “type”, or “style”––a problem which is hard to define, but easy to illustrate; for example, identifying an artist by the style of his/her painting, or determining the activity in a video sequence. The paper offers a simple classification paradigm based on local properties of spatial or spatio-temporal blocks. The learning and classification are based on the naive Bayes classifier. A few experimental results are presented.     

Combined effects of in-plane boundary conditions and stiffening on buckling of eccentrically stringer-stiffened cylindrical panels

Donnel type stability equations for buckling of stringer stiffened cylindrical panels under combined axial compression and hydrostatic pressure are solved by the displacement approach of [6], The solution is employed for a parametric study over a wide range of panel and stringer geometries to evaluate the combined influence of panel configurations and boundary conditions along the straight edges on the buckling behavior of the panel relative to a complete “counter” cylinder (i.e. a cylinder with identical skin and stiffener parameters).

The parametric studies reveal a “sensitivity” to the “weak in shear”, N_x = N_xφ = 0, along the straight edges, SS1 boundary conditions type where the panel buckling loads are always smaller than those predicted for a complete “counter” cylinder. In the case of “classical”, SS3 B.Cs., there always exist values of panel width, 2φ₀, for which ρ = 1, i.e. the panel buckling load equals that of the complete “counter” cylinder. For SS2 and SS4 B.Cs. types, the nature by which the panel critical load approaches that of the complete cylinder appears to be panel configuration dependent.

Utilization of panels for the experimental determination of a complete cylinder buckling load is found to be satisfactory for relatively very lightly and heavily stiffened panels, as well as for short panels, (L/R) = 0.2 and 0.5. Panels of moderate length and stiffening have to be debarred, since they lead to nonconservative buckling load predictions.     

Maybe A “Knowledge Culture” Isn't Always so Important after All!

THE PREVAILING WISDOM, AND a common “best practice,” of knowledge management (KM) is that a primary determinant of success in getting people to submit their most valuable personal knowledge to a repository is the existence of a “knowledge culture” in the organization.     

Analysis of “Salary man” motivation and the will to work (YARUKI)

The Inner Graphic Formula Method (IGF) which was originally conceived by Professor Ishiketa and further developed by him and his associates was used to investigate the motivation of new company employees.

Japanese companies traditionally recruit new employees from senior classes and notify successful candidates of their intention to employ them around the first of January. Since graduation is in March, April first is, then, the first day of work for almost all of these graduates in their new companies.

The investigation period for this study covers the eleven months from January until the middle of November, and therefore includes the three month period after notification but prior to actual work, from January first until March thirty-first, and the first eight month of actual work, from April first to the middle of November. The subjects fell, naturally, into two groups; a “Blue Collar” group and a “White Collar” group.

This paper deals with the motivation of these newly employed workers in general and, specifically, with the difference in motivational tendencies between “Blue Collar” and “White Collar” workers. As expected analysis showed that clear motivational differences appeared.

Motivation in the white collar workers tended to raise after an initial downturn, while a general downward trend was detected for the blue collar workers. White collar worker's attitudes toward themselves and toward their work seemed to change for the better as a result of having the chance to become introspective while plotting the graph and writing the anecdotal responses needed to complete the investigative sheet for this study.     

“Chaotic relaxation” in concurrently asynchronous neural networks

In this paper we analyze a fundamental issue which directly impacts the scalability of current theoretical neural network models to applicative embodiments, in both software as well as hardware. This pertains to the inherent and unavoidable concurrent asynchronicity of emerging fine-grained computational ensembles and the consequent chaotic manifestations in the absence of proper conditioning. The latter concern is particularly significant since the computational inertia of neural networks in general and our dynamical learning formalisms manifests itself substantially, only in massively parallel hardward—optical, VLSI or opto-electronic. We introduce a mathematical framework for systematically reconditioning additive-type models and derive a neuro-operator, based on the chaotic relaxation paradigm whose resulting dynamics are neither “concurrently” synchronous nor “sequentially” asynchronous. Necessary and sufficient conditions guaranteeing concurrent asynchronous convergence are established in terms of contracting operators. Lyapunov exponents are also computed to characterize the network dynamics and to ensure that throughput-limiting “emergent computational chaos” behavior in models reconditioned with concurrently asynchronous algorithms was eliminated.     

Mach band optical ray illusion—Drawing with the second differential

Mach bands running along convex ramp edges in a computer graphics image produce the illusion of optical rays, and a concave ramp edge defines an interface for “reflection.” The positive and negative brightness enhancements (E) observed in the illusion are simulated by convolving the pattern of gradient increments (Δg) computed at the edges with a Gaussian kernel (G): E ∝ − Δg G.     

The “burning ship” and its quasi-Julia sets

By manipulating the imaginary part of the complex-analytic quadratic equation, we obtain, by iteration, a set that we call the “burning ship” because of its appearance. It is an analogue to the Mandelbrot set (M-set). Its nonanalytic “quasi”-Julia sets yield surprizing graphical shapes.     

The power of the “always” operator in first-order temporal logic

It is shown that in first-order linear-time temporal logic, validity questions can be translated into validity questions of formulas not containing “next” or “until” operators. The translation can be performed in linear time.     

The evolution of the gingerbread man

Two versions of the evolution of the Gingerbread Man for the iteration z → z^x + c are presented. A previously published version shows an asymmetric evolution as positive real x increases, while a new version shows a symmetric evolution, and several interesting features. Fractal “growth” is described that occurs along certain “shock” lines with this new evolution. A floating “object” appears while approaching certain positive even integer values of x. Finally, a few comments are made about images created from negative values of x.     

A new blue emitting TFEL phosphor: SrS : Cu

A highly efficient new blue emitting electroluminescent (EL) phosphor material, SrS : Cu, was developed. A wide range of EL characteristics of SrS : Cu can be achieved by varying co-dopant material. While the singly doped SrS : Cu thin film EL (TFEL) devices have a cyan color with “CIE y” varying between 0.27 and 0.32, the SrS : Cu devices co-doped with Ag exhibit a true blue color, e.g., CIE y = 0.13–0.22. The luminous efficiency of SrS : Cu, Ag, e.g. 0.15–0.24 lm/W is much higher than the existing blue EL phosphors, e.g. (SrCa)Ga₂S_4:Ce and blue filtered SrS : Ce, when the color is matched. It is expected that the color and brightness performance of the next generation of color TFEL displays will be greatly improved once SrS : Cu, Ag is implemented into production.     

Parallel algorithms for certain matrix computations

The complexity of performing matrix computations, such as solving a linear system, inverting a nonsingular matrix or computing its rank, has received a lot of attention by both the theory and the scientific computing communities. In this paper we address some “nonclassical” matrix problems that find extensive applications, notably in control theory. More precisely, we study the matrix equations AX + XA^T = C and AX − XB = C, the “inverse” of the eigenvalue problem (called pole assignment), and the problem of testing whether the matrix [B AB … Aⁿ⁻¹ B] has full row rank. For these problems we show two kinds of PRAM algorithms: on one side very fast, i.e. polylog time, algorithms and on the other side almost linear time and processor efficient algorithms. In the latter case, the algorithms rely on basic matrix computations that can be performed efficiently also on realistic machine models.