Browsing by Author "Hartati, Sri"

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    Computer reasoning about nuclear physics processes
    (1996) Hartati, Sri
    Nuclear Process Theory (NPT) is a new process theory which models nuclear physics processes using a formal grammar. This, in turn, allows one to write computer programs which simulate nuclear process interactions. Knowledge of the nuclear physics process is expressed in terms of a basic nuclear physics model and an aggregate effects model. The basic nuclear physics model has the capability of expressing knowledge of nuclear physics processes for different types of reactions. The products of reactions are expressed in either deterministic or probabilistic values. The aggregate effects model coordinates basic nuclear physics processes expressed in the basic nuclear physics model. NPT has been tested by using it to represent several nuclear physics processes, including fission, radioactive capture, beta negative and positive decay, that occur in a homogeneous reactor core. A simulator called NPTsim was written in C to demonstrate the principles of NPT representation. Three examples of running 20 second simulations have been carried out using NPTsim. The three experiments used differing amounts of 235U and 238U corresponding to pure, natural and enriched Uranium. The experimental results are very closed to expected theoretical results. Unique approaches to symbolically representing the state space and probabilistic space equations required for nuclear physics processes are presented. In addition, a unique explanation mechanism for how products of nuclear physics processes arise is enabled by the NPT approach. This mechanism is illustrated in the thesis.
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    Nuclear process theory: a symbolic model for representing nuclear physics processes
    (1994) Hartati, Sri
    Nuclear Process Theory (NPT) models nuclear physics processes using a formal grammar. This, in turn, allows one to write computer programs which simulate nuclear process interactions. Knowledge of the nuclear physics process is expressed in terms of a basic nuclear physics model and an aggregate effects model. The basic nuclear physics model has the capability of expressing knowledge of nuclear physics process for different types of reactions. The products of reactions can be expressed in terms of either deterministic or probabilistic values. The aggregate effects model is used to simulate nuclear physics processes.
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    Orientation adaptive quadtrees
    (1990) Hartati, Sri
    This thesis addresses the area of spatial data structures. There are numerous hierarchical data structuring techniques in use for representing raster data. One commonly used method that is based on recursive decomposition is the quadtree. Its development has been motivated to a large extent by a desire to reduce the amount of space required to store raster data representations of objects. The Orientation Adaptive Quadtree (OAQ) representation is a new quadtree representation which positions the quadtree axes centered at the object's centroid and aligned with the object's principal axis of inertia. This approach is explained along with a quick method for computing the orientation of the object. Boolean operations on two OAQs representing two objects which differ in position, orientation, and resolution are also presented. The method maintains the quadtree structure, and it consists of two major operations : extracting polygons produced by intersecting every two blocks representing two specified nodes from different OAQs, and merging those polygons which results in an object to be represented as another OAQ. The result of Boolean OAQ opereation has its own orientation. O A Q representations for 17 different geographical objects are compared to their standard quadtree representations, with an average reduction of 9.5% in the number of nodes required for their representation. Two objects were also used to test the Boolean intersection and union operations on OAQs. OAQ representation of rectangular objects gives a reduction in the number of nodes of more than 80%.
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    Reasoning about physical systems in artificial intelligence
    (1993) Hartati, Sri
    This report, Reasoning About Physical Systems in Artificial-Intelligence, consists of several files: 1. master.doc is a file to print the whole documents. 2. list_not.doc is a list of notations used in this report. 3. list_fig.doc is a list of figures. 4. acknow.doc is acknowledgments of the author. 5. toc.doc is a list of table of contents. 6. intro.doc is an introduction chapter. 7. dynamics.doc is a discussion on dynamics systems. 8. rigid.doc is a discussion on solid systems. 9. liquid.doc is a discussion on liquid systems. 10. nuclear.doc is discussion on nuclear reactions. 11. qsim_env .doc is discussions on Qualitative Simulation and Envision physics reasoning systems. 12. dy-analy .doc is a discussion on reasoning about physical systems using dimensional analysis. 13. qpt.doc is a discussion on a physics reasoning system, Qualitative Process Theory. 14. hpt.doc is a discussion on a physics reasoning system, Hybrid Phenomena Theory. 15. property.doc is a comparison of physics reasoning systems. 16. conclusi.doc is conclusions of the discussions along with a brief discussion on commercial tool G2, and also open problems. 17. biblio.doc is a list of bibliographies. These files are written using the Microsoft Word version 2.0c and they are stored in Vermis under /home/grads/hartati/cstr directory. They are also stored in CORPUSC under /CORPUSC/HARTATVCSTR directory.