An optimal guidance law for a missile flight is one which determines appropriate controls to produce a flight path such that some mission objective will be achieved in the most efficient manner. Optimal Control Theory is often used to accomplish this task. One must bear in mind, however, that the usefulness of optimal control is sharply divided between two distinct classes of dynamical systems, namely, linear systems and nonlinear systems. For linear systems, the theory is complete in the sense that given a quadratic cost, a closed-loop feedback guidance law may be determined. For nonlinear systems, generally the best one can do is to determine an open-loop guidance law numerically using a software package such as MISER (1). (Some notable exceptions exist where a complete analytical synthesis of the closed-loop control may be obtained for nonlinear systems, e.g., in (2).) Although open-loop optimal guidance laws for nonlinear systems can now be computed quite efficiently with the advances of sophisticated numerical techniques along with high-speed digital computers, the highly-nonlinear and complex dynamics of missiles precludes the possibility of on-line implementation of open-loop optimal control. It has always been realized that if optimal closed-loop solutions could be obtained for comprehensive nonlinear systems such as missiles, then guidance laws based on such results would be superior to any other guidance laws available today. This superiority is due to, among other things, the elimination of some of the restrictive, and in many cases unrealistic assumptions made in the derivation of most current guidance laws in use such as, for instance, "tail-chase", unbounded control, simplified dynamics and/or aerodynamics, and non-maneuvering target, to name a few. In this study, an optimal closed-loop control law is obtained off-line by means of a Neural Network which is then used as an on-line controller for a generic missile. In the nonlinear case, the missile/target scenario is set up as a mathematical model using realistic dynamics. Then, given a Performance Index, the open-loop control is obtained by solving the problem using the optimal control software MISER for a number of different initial configurations. These open-loop solutions are then used to "teach" a neural network via backpropagation. Through simulation, it is then demonstrated how well the neural network performs as a feedback controller. The miss distance as well as the value of the Performance Index are used as measures of performance to be compared under the original open-loop control and the neural network closed-loop control. This problem is further extended to include a time lag in the missile dynamics. The effect of this time delay in the overall performance of the optimal controller is then examined.

With today's rapidly changing business environment, more and more businesses are using competitive intelligence to improve planning efforts, identify threats and opportunities and help avoid unpleasant surprises. However, to be effective, this intelligence must be gathered and communicated between managers. Two research questions will address these issues: (1) can a representation of competitive knowledge be developed that reflects managerial thought and (2) will a graphical computer tool based on this representation elicit a more complete representation of competitive intelligence knowledge in a more efficient manner relative to traditional methods? Various studies have shown managerial thought to be represented in several ways, e.g., conceptual groupings, hierarchically, and causally. However, by proposing that managers represent information about competitors in a story structure and integrating this proposal with the literature from competitive intelligence and strategic planning, a more complete conceptual model results. To validate the proposed conceptual model, an archival case study of three competitors in the computer workstation market was conducted. Following that, interviews were conducted with six MBA students with experience in competitive intelligence and with six managers. The transcripts from these interviews have been analyzed and the conceptual model has been modified based on input from this content analysis. A prototype was developed using the ConceptBase platform, an X-windows tool that provides both graphical and textual access to concepts and their relationships. The prototype will allow managers to create a graphical representation of their competitive knowledge. This representation will allow managers to locate gaps in their knowledge and to communicate their information to others. The prototype was validated by two different groups of MBA students by asking them to represent a given competitive situation. One group used pencil and paper while the second group used the prototype. Both the number of uncategorized concepts and the number of relationships differed significantly. This indicates that a more complete representation was created using the prototype. The two main contributions of this research are: (1) a model of competitive intelligence knowledge based on managerial cognition, and (2) a prototype that will facilitate the elicitation of competitive intelligence knowledge in a graphical and understandable manner.

This study addressed the free recall and recognition memory processes of elementary school children. It has been discovered that when children recall items from episodically related collections, a non-monotonic relationship is found between the memory strengths of those items and the order in which they are recalled. This relationship is known as cognitive triage, and it is not understood if the same phenomena would occur with recall involving semantic memory. Regarding recognition memory, experiments have tapped children's tendency to falsely remember words whose gist is the same as the gist of newly learned items. These past studies have focused primarily on a reversal of the standard false-recognition effect, where related distractors were easier to reject than unrelated distractors under some conditions. No research to date has ignored reversals and clearly examined the false-recognition effect itself. This study examined kindergarten, third, and sixth grade children's free recall organization and false-recognition of related distractors. The cognitive triage experiment examined semantic memory through having children recall exemplars from categories in Battig and Montague's (1969) lists. The recognition experiment examined developmentally the differential rate of false-recognition for related and unrelated distractors. Fuzzy Trace Theory (FTT) contends that the ability to inhibit interference increases with age. Hence, younger children were hypothesized to show a weaker cognitive triage effect and more false-recognition than older children. The latter result was found, whereas the former result was not. False-recognition did decrease with age but although a triage effect was observed for category exemplar production, the effect did not vary developmentally. The principle difference between this triage study and previous research is that lists offering preexperimental measures of memory strength were employed. These lists were normed on adults and therefore cognitive triage may have been different for children. Thus, this study indicates that developmental effects are found for false-recognition of related distractors but not for category exemplar production when using Battig and Montague's (1969) lists.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.