Algorithms are presented for the computationally efficient manipulation of graphs. These are subsequently used as the basis of a Monte Carlo method for sampling from the microcanonical ensemble of lattice configurations of a percolation model within a neighbourhood of the critical point. This new method arbitrarily increments and decrements the number of occupied lattice sites, and is shown to be a generalisation of several earlier, purely incremental, methods. As demonstrations of capability, the method was used to construct a phase diagram for exciton transport on a disordered surface, and to study finite size effects upon the incipient spanning cluster. Application of the method to the classical site percolation model on the two-dimensional square lattice resulted in an exceptionally precise estimate of the critical threshold. Although this estimate is not in agreement with earlier results, its accuracy was established through an application specific test of randomness, which is also introduced here. The same test suggests that many earlier results have been systematically biased due to the use of deficient pseudorandom number generators. The estimate made here has since been independently confirmed.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 204-212). Also available via the Internet.

Thesis (Ph. D.)--Columbia University, 1937. / Vita. "Reprinted from Osiris (vol. III, part I), November 1937." Cover title. "Annotated bibliography": p. 374-394.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 91-92).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 154-158).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis submitted in fulfilment of the requirements for the degree Magister Technologiae: Mechanical Engineering in the Faculty of Engineering at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2009 / Finite element analysis modelling of sheet metal stamping is an important step in the design of tooling and process parameters. One of the critical measurements to determine the effectiveness of a numerical model is its capability of accurately predicting failure modes. To be able to make accurate predictions of deformation, tool force, blank design, etc computer simulation is almost necessary. In the automotive industry the tooling design can now be made by computer and analysed with FEA, and the amount of prototypes required for qualifying a design before manufacturing commences is greatly reduced. Tool design is a specialized phase of tool engineering. While there are many diecutting operation, some of which are very complex, they can all be reduce to plain blanking , piercing, lancing, cutting off and parting, notching, shaving and trimming. The cutting action that occurs in the piercing is quite similar to that of the chip formation ahead of a cutting tool. The punch contact the material supported by the die and a pressure builds up occurs, When the elastic limit of the work material is the exceeded the material begins to flow plastically (plastic deformation). It is often impractical to pierce holes while forming, or before forming because they would become distorted in the forming operation. The aim of the research is to develop techniques that would reduce the amount time spent during the tool qualifying stage. By accurately setting a finite element simulation that closely matches the experimental or real-life situation we can great understand the material behaviour and properties before tool designing phase commences. In this analysis, during the piercing process of the drainage hole for a shock absorber seat, there is visible material tearing (on the neck) which as a result the component is rejected. This results in material wastage, and prolonged cycle time since the operation has to be now done separately at a different workstation.

The problem treated in this thesis is to create a system to monitor multiple interacting simulators. The problem is encountered in an attempt to simulate urban growth. The resulting system has a supervisor which controls all of the components of the system, namely the I/O routines, the graphics routine, the command routines, and the simulators. The main task of the supervisor is to display whichever data values the user desires. This involves executing some simulators, and extracting the data values from the data base. The extraction process first finds an association path between the files in the data base in order to relate the variables being displayed. Then using the association path the physical values are extracted from the data base. The data values are then passed to the graphics routine to be displayed for the user. / Science, Faculty of / Computer Science, Department of / Graduate

Few theorems are known about planar graphs. For, example, Kuratowski proved that a graph is planar if and only if it has no subgraph homeomorphic to K₅ or K₃,₃. It has remained as a direct criterion for determining whether a graph is planar or not. Powerful as the theorem is, it is not always easy to apply. This leads us to try some practical methods to test a planar graph. In this thesis, we have an algorithm for finding an outer circuit for a simple connected planar graph. Then, we use this outer circuit to draw a straight line graph in the plane. The programme for this algorithm is written in FORTRAN for an IBM 360/67 Computer. / Science, Faculty of / Computer Science, Department of / Graduate