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We discuss the unitary equivalence of generators G associated with abstract damped wave equations of the type $${\ddot{u} + R \dot{u} + A^*A u = 0}$$ in some Hilbert space $${\mathcal{H}_1}$$ and certain non-self-adjoint Dirac-type operators Q (away from the nullspace of the latter) in $${\mathcal{H}_1 \oplus \mathcal{H}_2}$$ . The operator Q represents a non-self-adjoint perturbation of a supersymmetric self-adjoint Dirac-type operator. Special emphasis is devoted to the case where 0 belongs to the continuous spectrum of A* A. In addition to the unitary equivalence results concerning G and Q, we provide a detailed study of the domain of the generator G, consider spectral properties of the underlying quadratic operator pencil $${M(z) = |A|^2 - iz R - z^2 I_{\mathcal{H}_1}, z\in\mathbb{C}}$$ , derive a family of conserved quantities for abstract wave equations in the absence of damping, and prove equipartition of energy for supersymmetric self-adjoint Dirac-type operators. The special example where R represents an appropriate function of | A| is treated in depth, and the semigroup growth bound for this example is explicitly computed and shown to coincide with the corresponding spectral bound for the underlying generator and also with that of the corresponding Dirac-type operator. The cases of undamped ( R = 0) and damped ( R ≠ 0) abstract wave equations as well as the cases $${A^* A \geq \varepsilon I_{\mathcal{H}_1}}$$ for some $${\varepsilon > 0}$$ and $${0 \in \sigma (A^* A)}$$ (but 0 not an eigenvalue of A* A) are separately studied in detail. [ABSTRACT FROM AUTHOR]

Abstract  Paper–pencil teacher tests of professional knowledge typically are organized around the conventional dimensions that define state teaching standards, such as classroom management and assessment. We examined if such tests could be partitioned into three other dimensions (general knowledge, academic or textbook knowledge, and functional teaching knowledge), and if these dimensions (1) identified between those who did and did not receive teacher preparation, and (2) predicted teaching competence. A teacher test was given to advanced and beginning education majors, and non-majors. We found that advanced education majors and non-majors differed mostly on academic knowledge, but that functional knowledge predicted competence to the greatest extent. A variety of useful information can be gleaned from teacher tests if subscores of these dimensions are generated. [ABSTRACT FROM AUTHOR]

We consider the discrete-time system x ( n )= βx ( n -1)+ f ( y ( n - k )), y ( n )= βy ( n -1)+ f ( x ( n - k )), n ∈ N describing the dynamic interaction of two identical neurons, where β ∈(0,1) is the internal decay rate, f is the signal transmission function and k is the signal transmission delay. We construct explicitly an attractive 2 k -periodic orbit in the case where f is a step function (McCulloch-Pitts Model). For the general nonlinear signal transmission functions, we use a perturbation argument and sharp estimates and apply the contractive map principle to obtain the existence and attractivity of a 2 k -periodic orbit. This is contrast to the continuous case (a delay differential system) where no stable periodic orbit can occur due to the monotonicity of the associated semiflow. [ABSTRACT FROM AUTHOR]

Examines the inflationary effects of high nominal interest rates. Slowing down of inflation; Depression of stocks of commodities throughout the economy; Analysis of real interest rates; Evaluation of the process used for cost-price adjustments when all working capital is financed by credit; Possibility for high nominal interest rates to generate steady inflation.

Discusses the future of teacher training and research on teaching. Perceptions about the professional development of teachers; Importance of performing preservice training programs for teachers; Research directions at the National Institute of Education.

This Research Report draws the attention of control engineers to some of the results obtained from the application of chaos theory to modelling complex behaviour, The example chosen is a typical management accounting system in a manufacturing firm, and the model includes not only the formal control devices, but also the responses af the human operators, the managers, to the variance signals from that system.Management accounting has become an eclectic discipline and so over time it has called upon a wide variety of methodologies to help to address its problems. It has, perhaps reluctantly, accepted the notion that statistical analysis and the assessment of probabilities can overcome, in part at least, the ambiguity of many managerial situations. It would be expected to be very eager to consider ways and means of reducing reliance on such methods and of increasing the explanaiory power of some of the tools already at its disposal within its own core discipline; for example, the setting of standards for budgetary control.This paper reports recent research into the application of 'Dynamical Systems Theory'as a means of explaining apparently random cost behaviour in a standard cost context. It suggests that attention should be directed to the effects of different standard setting policies on the stability of the behaviour of managerial control systems. [ABSTRACT FROM PUBLISHER]