Designing a Self-reversing Track Layout with TrackMaster Tracks

This research project sought to find general track formations that allowed battery operated locomotives to traverse the entire train track in both directions infinitely. These formations allowed for any number of track pieces from TrackMaster Thomas and Friends sets by Fisher Price. The research looked at start position of the train and presetting of the switches as well as what is necessary to have a complete track with no dead ends. Surprisingly, there was found to be only one track formation that allowed for entire traversal of the track in both directions. This layout was termed a dog bone and consisted of two switch pieces connected at the ends with the tips of both switches connecting to themselves on the same switch. A proof that this layout is the only layout that satisfies the conditions is given

Foundations and applications of qualitative reasoning and model-based diagnosis

In this paper we summarize the foundation for a model-based approach to diagnosis of technical systems ud discuss the import&Dce of qualitative reasoning within this framework. Based on this, we propose to apply these diagnostic techniques to model building. Thus, theories about physical systems are checked for consistency ud against empirical observations. Thu leads to a tool that supports the conatruction ud maintena.nce of modellibra.ries as well as the process of theory formation in research

Models of Behavior Deviations in Model-based Systems. In:

Abstract. Tasks like diagnosis, failure-modes-and-effects analysis (FMEA), and therapy proposal involve reasoning about variables and parameters deviating from some reference state. In model-based systems, one tries to capture this kind of inferences by models that describe how such deviations are emerging and propagated through a system. Several techniques and systems have been developed that address this issue, in particular in the area of qualitative modeling. However, to our knowledge, a rigorous mathematical foundation and a "recipe" for how to construct such compositional deviation models has not been presented in the literature, despite the widespread use of the idea and the techniques. In this paper, we present a general mathematical formalization of deviation models. Based on this, aspects of constructing libraries of deviation models, their properties, and their application in consistency-based diagnosis and prediction-based FMEA in a componentoriented framework are analyzed

A Uniform Model Library and Knowledge-based Decision Support for Water-Energy-Food NEXUS Projects

In preparation of a planned Indo-European Project on water-energy-food-NEXUS we are an integrated modeling and knowledge-based decision support tool. The foundation is provided by a uniform modeling paradigm named process-oriented modeling. A process is a generic, elementary phenomenon that contributes to the dynamics of a complex system and is represented as an association between preconditions for its activity and the resulting effect. The goal is generating a library of the relevant processes in the domain, covering not only natural (rain, evaporation, etc.) and technological ones (oxidation, flocculation, …), but also construction and agricultural activities, social, economic, and governance processes. This library is the input to two steps in the decision support: situation assessment (semi-)automatically constructs a causal account for given observations as a configuration of instantiated processes, while solution/remedy proposal extends the situation with interventions that produce intended effects and given objectives. The intention is supporting research on and deployment of NEXUS solutions in several ways: the library is meant to establish a growing repository of domain knowledge that can be shared by different projects and researchers. Fed with information about the local conditions, objectives, available resources etc., a decision support system supports the choice of appropriate technologies. For an established solution, the decision support is provided to those operating the plant, esp. in the case of abnormalities, which appears important to non-expert operators in distributed solutions. We illustrate the approach with a principled structuring of the knowledge base and examples of processes and the configuration of governance structures

An investigation of the sequence of utilizing a simulation in an introductory programming course

The purpose of this study is to investigate the placement of a simulation in an instructional sequence and its effect on students of differing experience level. To conduct this investigation a pure simulation entitled SUBOPS was developed. This simulation incorporated a model of the communication process between program segments and was designed to help students visualize subroutines. SUBOPS uses a graphic model of a calling program and its subprogram(s) which must be used to perform one of nine assigned tasks. Each subroutine display shows the number and type of parameters required and the action performed. The student enters SUBOPS statements (much like a subroutine call) into the main program which first graphically displays the subroutine requested and then matches the variable(s) in the subroutine call with those in the subroutine itself. If the variables are compatible, the simulation then graphically executes the call (drawing lines to show program execution) displaying the communication between the main program and the subroutine and any activity that also occurs within the subroutine. When students complete a problem, they may ask the computer to evaluate their result. The computer evaluation indicates whether the solution is correct or incorrect. An incorrect computer evaluation does not reveal an appropriate answer but it does continue to show graphically where the glitch occurred in the program. SUBOPS covers as its content area the basic concepts inherent in invoking, executing and returning from subroutines. This knowledge is basic to success in computer programming. Since SUBOPS could either be used before formal instruction on subroutines as an experiencing simulation or after formal instruction as an integrating simulation, it offers an excellent opportunity to study the position of a simulation model in an instructional sequence

Factors related to adolescents' expectations of marital roles

Call number: LD2668 .T4 1969 S72Master of Scienc