Applications of integrated design/analysis systems in aerospace structural design

Integrated structural analysis and design systems and structural optimization procedures are being used in a production environment. Successful use of these systems requires experienced personnel. Interactive computer graphics can and will play a significant role in the analysis, optimization, design and manufacturing areas. Practical structural optimization procedures are tools that must be made available to the team. Much work still needs to be done to tie finite-element modeling to actual design details which are being tracked on systems such as CADAM or CATIA. More work needs to be done to automate the detailed design and analysis process. More emphasis should be placed on the real design problems

Resistance of a compartmented surface-effect ship

A series of carefully controlled experiments on the resistance of a model of a compartmented surface-effect ship has been conducted in a towing tank. Configurations of the model included cases encompassing one subcushion and two subcushions, as well as differing values of the pressures in the subcushions. It was shown that a reduced total resistance in the appropriate range of Froude number could be achieved in this manner. Furthermore, the previously developed theory for the resistance of a surface-effect ship was verified for the model for a Froude number greater than 0.40

A validation study of a measure of dieting self-efficacy

Based on the potential clinical and research value of a measure of confidence in dieting, this study applied the principles of Self-Efficacy Theory to the validation of the previously developed Dieting Self-Efficacy Test (DSET). The DSET is a 30-item, paper and pencil measure of the ability to control dieting behaviors. In the current study, data were collected from two subject populations, a student group (N = 214) and an adult group (N = 237). Across a variety of sub-groups, DSET scores were related in a predictable manner to differences in subject\u27s perceptions of their ideal weights. Specifically, high DSET scores were associated with being near-normal weight, while low DSET scores were associated with being overweight. Data analyses showed no major differences between the two groups, suggesting that age is an irrelevant factor in determining dieting self-efficacy. In addition, DSET scores from a substance-abuse recovery group were similar to a non-abusing group. Thus, substance-abuse was also determined to be an irrelevant factor. Further, DSET scores were shown to be unrelated to factors that influenced scores on a general self-efficacy measure. These analyses supported the construct and discriminant validity of the instrument. Significant differences were found between scores of males and females, with males scoring consistently higher than females. These differences were attributed to a feminine desire for thinness as explained by feminist theories of weight satisfaction. Consistent with the DSM-III-R bulimia nervosa criterion of a feeling of lack of control in eating, bulimics were shown to score considerably lower on the measure than non-bulimics. Finally, as predicted by self-efficacy theory, repetitive dieters who failed to achieve or maintain their ideal weights scored lower on the DSET than their non-dieting counterparts. As in the initial development study, the DSET was found to have high internal consistency (0.96). This study supported the DSET as a reliable and valid instrument for quantifying dieting self-efficacy

Impacts And Implications Of Polytypism On The Evolution Of Aposematic Coloration

Aposematic signaling is a comdefensive strategy whereby prey species use conspicuous signals (i.e., bright coloration) to warn predators of the risks of predation due to a secondary defense. Theoretical, lab, and field experiments have demonstrated that individuals who project novel conspicuous signals should experience disproportionately high predation pressure as predators will not associate novel signals with a secondary defense. Thus, aposematic signaling should be subject to strong positive frequency-dependent selection (FDS). Numerous species show considerable intrapopulation variation (polymorphism) in direct conflict with the expectations of FDS. Interpopulation variation (polytypism) can adhere to expectations of FDS, but as its origins likely involve polymorphism, FDS likely plays a role in the establishment of such populations. Both the Dyeing Poison Frog (Dendrobates tinctorius) and the Australian Brood Frogs (Pseudophryne) exhibit considerable inter- and intrapopulation variation making them excellent candidates to investigate how aposematic signaling can evolve and under what circumstances of FDS can be relaxed. Consequently, I approach this question by systematically investigating how predators perceive conspicuous colors, how secondary defense influences predator response, how predators respond to known and novel colors, and the role that gene flow plays in promoting or limiting phenotypic divergence. By using model, naïve predators for learning experiments, I found that the hue color component influences predators’ abilities to learn to avoid an aposematic signal. I provide the first among-population characterization of alkaloid toxins in D. tinctorius and, when using a model avian predator to examine unpalatability of alkaloid toxins, found that a subset of these alkaloids is driving the predator response. In examining how predators respond to known and novel phenotypes, I elucidate the function of conspicuous signals in Pseudophryne and how predators may generalize to novel signals. Finally, I find that despite field and lab experiments that indicate a selective disadvantage of a weak aposematic signal, it can persist when isolated with limited gene flow. Together, these studies provide evidence for the evolution of aposematic signals and propose mechanisms that can allow the relaxation of FDS and thus allow for phenotypic polymorphism in aposematic species

Mutual Aid Housing for San Juan

A policy program for mutual aid construction is presented. In this approach, rural families organize teams to build their dwellings and buy construction materials through new savings organizations. The chief prerequisite for mutual aid in a specific situation is that the ratio of material to labor costs be high. Pride in home ownership, training in construction skills, and natural evolved neighborhoods prove the thesis that mutual aid is the most promising solution for housing the poor in developing societies. Financial burden on the public is minimized, and the government can control municipal expansion by retaining land ownership. In high density areas, a basic multi-story frame can be finished by inhabitants owning units in a condominium arrangement. A design of this type, La Puntillu, is presented as a prototype