Use of Taguchi design of experiments to optimize and increase robustness of preliminary designs

The research performed this summer includes the completion of work begun last summer in support of the Air Launched Personnel Launch System parametric study, providing support on the development of the test matrices for the plume experiments in the Plume Model Investigation Team Project, and aiding in the conceptual design of a lunar habitat. After the conclusion of last years Summer Program, the Systems Definition Branch continued with the Air Launched Personnel Launch System (ALPLS) study by running three experiments defined by L27 Orthogonal Arrays. Although the data was evaluated during the academic year, the analysis of variance and the final project review were completed this summer. The Plume Model Investigation Team (PLUMMIT) was formed by the Engineering Directorate to develop a consensus position on plume impingement loads and to validate plume flowfield models. In order to obtain a large number of individual correlated data sets for model validation, a series of plume experiments was planned. A preliminary 'full factorial' test matrix indicated that 73,024 jet firings would be necessary to obtain all of the information requested. As this was approximately 100 times more firings than the scheduled use of Vacuum Chamber A would permit, considerable effort was needed to reduce the test matrix and optimize it with respect to the specific objectives of the program. Part of the First Lunar Outpost Project deals with Lunar Habitat. Requirements for the habitat include radiation protection, a safe haven for occasional solar flare storms, an airlock module as well as consumables to support 34 extra vehicular activities during a 45 day mission. The objective for the proposed work was to collaborate with the Habitat Team on the development and reusability of the Logistics Modules

Some Computational Aspects of Essential Properties of Evolution and Life

While evolution has inspired algorithmic methods of heuristic optimisation, little has been done in the way of using concepts of computation to advance our understanding of salient aspects of biological evolution. We argue that under reasonable assumptions, interesting conclusions can be drawn that are of relevance to behavioural evolution. We will focus on two important features of life--robustness and fitness optimisation--which, we will argue, are related to algorithmic probability and to the thermodynamics of computation, subjects that may be capable of explaining and modelling key features of living organisms, and which can be used in understanding and formulating algorithms of evolutionary computation

Approximations of Algorithmic and Structural Complexity Validate Cognitive-behavioural Experimental Results

We apply methods for estimating the algorithmic complexity of sequences to behavioural sequences of three landmark studies of animal behavior each of increasing sophistication, including foraging communication by ants, flight patterns of fruit flies, and tactical deception and competition strategies in rodents. In each case, we demonstrate that approximations of Logical Depth and Kolmogorv-Chaitin complexity capture and validate previously reported results, in contrast to other measures such as Shannon Entropy, compression or ad hoc. Our method is practically useful when dealing with short sequences, such as those often encountered in cognitive-behavioural research. Our analysis supports and reveals non-random behavior (LD and K complexity) in flies even in the absence of external stimuli, and confirms the "stochastic" behaviour of transgenic rats when faced that they cannot defeat by counter prediction. The method constitutes a formal approach for testing hypotheses about the mechanisms underlying animal behaviour.Comment: 28 pages, 7 figures and 2 table

Study of the apsidal precession of the Physical Symmetrical Pendulum

We study the apsidal precession of a Physical Symmetrical Pendulum (Allais' precession) as a generalization of the precession corresponding to the Ideal Spherical Pendulum (Airy's Precession). Based on the Hamilton-Jacobi formalism and using the technics of variation of parameters along with the averaging method, we obtain approximate solutions, in terms of which the motion of both systems admits a simple geometrical description. The method developed in this paper is considerably simpler than the standard one in terms of elliptical functions and the numerical agreement with the exact solutions is excellent. In addition, the present procedure permits to show clearly the origin of the Airy's and Allais' precession, as well as the effect of the spin of the Physical Pendulum on the Allais' precession. Further, the method can be extended to the study of the asymmetrical pendulum in which an exact solution is not possible anymore.Comment: 20 pages, 8 figures, LaTeX2

Regional dairy production: short-term projections and expected demand for inputs

Over the period 1991-2003, New Zealand’s milk production more than doubled. At the same time, dairy farming expanded its boundaries into non-traditional dairy production regions. The distribution of regional production is of particular interest because of effects on supply and demand balances for key inputs and outputs. Changes in the geographical distribution of dairy production alter local economic output and, consequently, income distribution and community viability. The aim of this paper is to present regional short-term estimates of demand for selected key production inputs and milk output. Short-term estimates for milk production and land use were derived based on past growth rates in stocking rate, cow numbers and productivity per cow for each region. Input demand forecasts were, in turn, derived using regional milk production and land use forecasts and baseline estimates of input and energy use reported in Wells (2001). Results indicate that by season 2006/07, the effective area devoted to dairy production will be at 1.56 million hectares, a 7% increase with respect to the 2003 baseline. However, contrary to what happened prior to 2003, almost all the gain in dairy area is explained by increases in the South Island. Over the same period, national milk production is expected to increase by 20% to 1,431 million kgs. MS. Similarly, the South Island accounted for much of the gain, increasing its share in total milk production to 34% up from 28% in 2003. It is expected that the use of inputs such as nitrogen, potassium, phosphorous and sulphur per unit of area will intensify for all dairy regions. However, the increase in the use of inputs per unit of area relative to the baseline is lower in long-established dairy regions, Northland, South Auckland and Taranaki, than in non-traditional dairy regions like, North and South Canterbury, Otago and Southland.Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Land Economics/Use, Livestock Production/Industries,

Redox supercapacitor performance of nanocrystalline molybdenum nitrides obtained by ammonolysis of chloride- and amide-derived precursors

Reactions of MoCl5 or Mo(NMe2)4 with ammonia result in cubic ?-Mo2N or hexagonal ?1-MoN depending on reaction time and temperature. At moderate temperatures the cubic product from Mo(NMe2)4 exhibits lattice distortions. Fairly high surface areas are observed in the porous particles of the chloride-derived materials and high capacitances of up to 275 F g?1 are observed when electrodes made from them are cycled in aqueous H2SO4 or K2SO4 electrolytes. The cyclic voltammograms suggest charge is largely stored in the electrochemical double layer at the surface of these materials. Amide-derived molybdenum nitrides have relatively low surface areas and smaller capacitances, but do exhibit strong redox features in their cyclic voltammograms, suggesting that redox capacitance is responsible for a significant proportion of the charge stored

Performance of nanocrystalline Ni3N as a negative electrode for sodium-ion batteries

Nickel nitride is synthesised by high temperature ammonolysis of nickel(II) hexamine and tris(ethylenediamine) salts. Its electrochemical characteristics are examined in half-cells vs. lithium and sodium. Samples with high surface area are found to have significant reversible charge storage capacity in sodium cells and hence to be a promising negative electrode material for sodium-ion batteries

Middle Management Strategic Roles: Strategic Role Conflict and its Antecedents

The middle-management perspective has produced a great understanding of the connection of middle managers involvement in strategy and organizational outcomes (Floyd & Wooldridge, 1992, 1996; Floyd & Wooldridge, 2000; Wooldridge & Floyd, 1990). Strategic role conflict has been identified in the literature as a hindrance, even an impediment, to effective middle-management involvement in strategy (Floyd & Lane, 2000). Despite a growing body of theoretical work by scholars on the strategy process, there has been limited empirical research of the antecedents of strategic role conflict. Drawing from the literatures of role conflict, middle management perspective, and social exchange theory, this dissertation hypothesized that demographic characteristics of middle managers, the nature of their position within the organization, the quality of their relationships with top management, and the degree of dissimilarity of their environmental perceptions vis-à-vis top management are associated with middle managers’ strategic role conflict. A large, global manufacturing company based in the United States participated in the study. Survey data was collected from 249 middle managers at four organizational levels within two divisions. Two structural models were tested. Data showed that the more parsimonious model was not supported while the less parsimonious model was supported. Results indicated that key predictors of middle managers’ strategic role conflict were the amount of boundary spanning that middle managers engage in as part of their jobs, the degree of disparity in their perception of the products and factors markets vis-à-vis top management, the frequency of their direct communication with their top manager, the amount of mutual trust between the top manager and the middle manager, and the amount of disparity in the feelings of mutual affect between the top manager and the middle manager. This study contributes to the strategy literature by demonstrating the applicability of role conflict theory to the strategy process in explicating links between strategic role conflict and its antecedents. A better understanding of strategic role conflict is important to the strategy process literature because of its theorized interference with middle manager’s effective strategic performance and its possible negative consequences for the organization. An alternative model of strategic role conflict is presented