Human reliability increasing approach in aircraft maintenance technician’s training process

This article presents an approach for increasing the maintenance technician’s reliability by considering the human fault rate as utility function’s maximization problem in the technician’s training process. Adequately trained technicians are capable to perform a maintenance and manage the reliability of their assigned assets within the complex aircraft systems. In general, a degradation of aircraft reliability, due to maintenance tecnician’s competency, typically leads to significant, undesirable safety and economic consequences. In this article, an optimal control theory is applied on the purpose of finding of a fault rate reduction series in the training process which leads to highest technician’s reliability in the maintenance process of the complex aircraft systems.

A reduction series of neodymium supported by pyridine(diimine) ligands

A series of reduced PDI neodymium complexes by the PDI ligand acting as an electron sink.

Continuous-time methods in the study of discretely sampled functionals of Lévy processes. I. The positive process case

In this paper we develop a constructive approach to studying continuously and discretely sampled functionals of Lévy processes. Estimates for the rate of convergence of the discretely sampled functionals to the continuously sampled functionals are derived, reducing the study of the latter to that of the former. Laguerre reduction series for the discretely sampled functionals are developed, reducing their study to that of the moment generating function of the pertinent Lévy processes and to that of the moments of these processes in particular. The results are applied to questions of contingent claim valuation, such as the explicit valuation of Asian options, and illustrated in the case of generalized inverse Gaussian Lévy processes.

Continuous-time methods in the study of discretely sampled functionals of Lévy processes. I. The positive process case

In this paper we develop a constructive approach to studying continuously and discretely sampled functionals of Lévy processes. Estimates for the rate of convergence of the discretely sampled functionals to the continuously sampled functionals are derived, reducing the study of the latter to that of the former. Laguerre reduction series for the discretely sampled functionals are developed, reducing their study to that of the moment generating function of the pertinent Lévy processes and to that of the moments of these processes in particular. The results are applied to questions of contingent claim valuation, such as the explicit valuation of Asian options, and illustrated in the case of generalized inverse Gaussian Lévy processes.

On ladder height densities and Laguerre series in the study of stochastic functionals. II. Exponential functionals of brownian motion and asian option values

In this paper we develop a constructive structure theory for a class of exponential functionals of Brownian motion which includes Asian option values. This is done in two stages of differing natures. As a first step, the functionals are represented as Laguerre reduction series obtained from main results of Schröder (2006), this paper's companion paper. These reduction series are new and given in terms of the negative moments of the integral of geometric Brownian motion, whose structure theory is developed in a second step. Providing a new angle on these processes, this is done by establishing connections with theta functions. Integral representations and computable formulae for the negative moments are thus derived and then shown to furnish highly efficient ways for computing the negative moments. Application of this paper's Laguerre reduction series in numerical examples suggests that one of the most efficient methods for the explicit valuation of Asian options is obtained. The paper also provides mathematical background results referred to in Schröder (2005c).

Mastication in the rabbit: a description of movement and muscle activity

1. Mastication was studied in awake rabbits that had previously been prepared for chronic recording of jaw movement and jaw muscle electromyography (EMG) under general anesthesia. Data were stored on tape and replayed for computer-assisted analysis. Most data was taken from the mastication of rabbit chow, but the basic features described in the paper also apply to eating of other foods. The series of movements was divided into cycles, and the phases that compose them, using peaks in the vertical movement, velocity, and acceleration. 2. The whole series of movements from ingestion to swallowing was termed the masticatory sequence. We found, as have others, that the sequence can be divided into three consecutive periods, based on the form of the movements. These were named the preparatory, reduction, and preswallowing series of cycles. 3. The results of earlier studies suggest that the food is transported back to the molar teeth during the preparatory series, ground up during the reduction series, and that the bolus is formed for swallowing during the preswallowing series. 4. The typical cycle of the preparatory series was called type I; it had two phases: opening (O) and fast closing (FC). The jaw-opening muscles were very active during O, but EMG bursts from the closer muscles were small or undefinable during FC. There was not much movement away from the midline in either phase, and the cycles were the shortest in the sequence. 5. The reduction series was predominantly composed of type II cycles. These were of intermediate duration and had three phases [O, a short FC, and a slow closing phase (SC)], during which the pellets were crushed between the molar teeth. The jaw moved toward the working side during FC. At or soon after the start of SC, the closer muscles became very active and continued to contract as the teeth were drawn toward the midline and slightly backwards. 6. The preswallowing series was made up of five-phase cycles that we called type III. These were the longest of the sequence. Jaw opening now occurred in three stages: O1 was the fall from tooth contact to approximately the postural position, O2 was a pause, and O3 was defined as the final movement to maximum opening. The digastric burst occurred during O3. There were again two closing phases, FC and SC, but closer bursts were smaller than in type II, and SC was shorter.(ABSTRACT TRUNCATED AT 400 WORDS)