Competing Explanations of U.S. Defense Industry Consolidation in the 1990s and Their Policy Implications

Was the consolidation of defense industry in the 1990s driven by U.S. Department of Defense (DOD) directives, or was it driven instead by the same forces that drove consolidation in many other sectors of the U.S. economy in the 1990s? To better understand the roles of DOD policy and economy-wide forces in shaping the U.S. defense industry, we test for structural breaks in defense industry and spending data and compare our findings to those relating to other sectors and the general economy. We identify structural breaks in the defense-related data in the early 1980s and throughout the 1990s, roughly consistent with changes in the U.S. economy, including broader merger trends. Overall, our results are more consistent with the view that economy-wide factors drove defense industry consolidation, largely independent of the DOD policy changes that occurred early in the 1990s.

Societal Change and Values in Arab Communities in Israel: Intergenerational and Rural–Urban Comparisons

This study tested and extended Greenfield’s theory of social change and human development to adolescent development in Arab communities in Israel undergoing rapid social change. The theory views sociodemographic changes—such as contact with an ethnically diverse urban setting and spread of technology—as driving changes in cultural values. In one research design, we compared three generations, high school girls, their mothers, and their grandmothers, in their responses to value-assessment scenarios. In a second research design, we compared girls going to high school in an ethnically diverse city with girls going to school in a village. As predicted by the theory, a t test and ANOVA revealed that both urban life and membership in the youngest generation were significantly related to more individualistic and gender-egalitarian values. Regression analysis and a bootstrapping mediation analysis showed that the mechanism of change in both cases was possession of mobile technologies

An Algorithmic Palette Tool

Our algorithmic tool follows the model of RGB percentage curves, but now the control of these curves is though algorithms that indirectly, and more abstractly, create, evolve, and modify such curves. To fully explain our methods we must first introduce the topic mutating expressions. This is done in Section Two. In Section Three we document the user-interface problems we dealt with, and finally in Section Four discuss conclusions and suggest ideas for future exploration. Before commencing with the technical details however, we wish to emphasize the nature of the colorization problem that led to the conception and development of our methods

On Agent Communication in Large Groups

The problem is fundamental and natural, yet deep - to simulate the simplest possible form of communication that can occur within a large multi-agent system. It would be prohibitive to try and survey all of the research on communication in general so we must restrict our focus. We will devote our efforts to synthetic communication occurring within large groups. In particular, we would like to discover a model for communication that will serve as an abstract model, a prototype, for simulating communication within large groups of biological organisms

Merlin\u27s Magic Square Enhanced

This paper first considers questions about games related to Merlin\u27s Magic Square from the point of view of group actions. At this juncture, little beyond the formal model is new, but the exposition sets the stage for considering certain enhanced versions of these games. The analysis of enhanced games, with the aid of semigroup actions, is carried out in complete detail for an ostensibly simpler (k = 3) game before turning to a Merlin ( k = 4) game. Concluding sections discuss various ways to generalize our games. To review the solution to Merlin\u27s Magic Square, we begin by introducing our formal model. As usual, we use 1 to represent an ON light and 0 to represent an OFF light. When light and button are one unit as in Merlin we shall also speak of the button itself as being ON or OFF

Graphical Evolution Experiments in Artificial Life

Larry Yaeger\u27s alife simulation running on a Silicon Graphics Iris Workstation is called Poly World. Our description of PolyWorld is based on notes taken during an oral presentation and video demonstration given in the Artificial Life Panel Session of SIGGRAPH \u2792: In PolyWorld the visual organisms roam on a bounded two dimensional grid. The organisms brains are small neural nets enabling the organisms to control their external visual appearance and to perceive the external world by processing pixmaps. The simulation controls for total energy while striving to explore competition and self-organization. Genes present are for size, strength, maximum speed, mutation rate, number of crossover points in the neural net, lifespan, energy to offspring, and ID (a parameter used to enable mimicry). The neural net can make decisions about whether the organism should eat, fight, mate, move, turn, light (effecting the external appearance of the light sensor panel it emits), or focus (gaze at the appearance of others). To see the organisms evolve to different species adopting distinct and atypical strategies and behaviors for survival is most impressive. Words do not do justice to the video animation sequences

On Uniform and Relative Distribution in the Brauer Group

In this progress/technical report our objective is twofold. First, to formalize and expand upon remarks appearing in [7] concerning the relativization of the fundamental identity in the setting of the Brauer group of a ring, and second to exhibit a construction which shows how to interpret uniform distribution as a homological phenomenon

On Quaternionic Pseudo-Random Number Generators

There is no dearth of published literature on the design, implementation, analysis, or use of pseudo-random number generators or PRNGs. For example, [6] [7] [14] and the references therein, provide a broad overview and firm grounding for the subject. This report complements and elaborates upon the work of McKeever [9], who investigated PRNGs constructed in a non-commutative setting with the target application being so-called cryptographically secure PRNGs as discussed in [12] or [13]. Novel solutions to the problem of designing cryptographically secure PRNGS continue to be proposed [1] [2] [10] [15], so despite the caution and skepticism required, the area remains active. The concept elaborated upon here is computation in a finite non-commutative object which is more than a matrix ring over a finite field. Specifically, we consider computation in a homomorphic image of a maximal order of an ordinary quaternion algebra. In Section Two we develop the necessary algebraic machinery. In Section Three we consider PRNG design in this computational setting. In Section Four we attempt some preliminary analysis of the PRNGs described. In Section Five we offer some final remarks and conclusions

Simulated Annealing and Optimal Codes

Following standard notation, an (n, m, d) code C denotes a binary code C which has length n, size m, and Hamming distance d. According to Hill [6] the “main coding theory problem” is to optimize one of these three parameters when the other two are held fixed. The usual version of this optimization problem is to find the largest code for a given length and given minimum distance. This is the problem we shall consider, thus making it clear what we mean by an “optimal code.