This research presents two switching techniques using SOT and SLACK, as complementary sequencing rules, to show that they are practical procedures to control a job shop. These two approaches are: - Static switching of the complementary rules. - Dynamic switching of the complementary rules. This study also presents questions which arise in creating different switching rules or procedures for an interactive scheduling system. It is also developed a normalized objective function to measure the balance of the best properties produced by SOT (low flow time) and SLACK (low tardiness). It should be noted that even though such a system could be viewed as complex and expensive,it is not. Computational requirement will be slightly increased, but no more data is required than is expected for a typical scheduling procedure. Finally, a procedure to calculate the upper and lower limits is presented for dynamic switching procedures. / Master of Science

Identification of the resonances and the local determination of the radius of curvature of an acoustically rigid sphere from simulated transient input-output data is presented. The scattering from the sphere is formulated using three techniques: the classic Mie-Lorenz series, the singularity expansion method (SEM), and the asymptotic series approximation. The Mie-Lorenz series is used to provide synthetic data. The SEM and the asymptotic series are used to develop two parametric inverse models. The scattered velocity potential is separated into three components: the reflection, the first creeping wave, and the second creeping wave. The effect of removing various components of the scattered potential on the resonance identification is shown, along with the effect of adding small amounts of noise. We find that the identification of a few resonances requires a relatively high order autoregressive, moving-average model. In addition, we show that removing the reflection from the synthetic output has only a small effect on the single or multiple output identified resonances. However, we find that changing the time origin, removing the second creeping wave, or adding small amounts of noise results in large errors in the identified resonances. We find that the radius of curvature can be accurately determined from synthetic data using the asymptotic series based identification. In addition, the identification is robust in the presence of noise, and requires only a low order asymptotic series model.

The sub-surface region of chemical vapour deposition (CVD) diamond was transformed by C+ ion implantation followed by isochronal annealing up to 1200 oC. Different implantation regimes and with different energies at different implantation temperatures would give different thicknesses were studied. This enabled a study in the evolution of the stiffness of the damaged layer as a function of annealing. The technique of choice for this study was the non-destructive Brillouin light scattering (BLS) utilizing two scattering geometries; indirectly scattered phonons (Kr¨uger-type geometry) for temperature anneals up to 600 oC, and the conventional surface ripple mechanism up to 1200 oC. It has been argued that surface acoustic waves (SAW) on a transparent medium are enhanced by applying a thin metallic reflective layer on the surface, this study has showed that opacity of the substrate is key. In fact, bulk modes with SAW-like characteristics emanating from indirect photon scattering off phonons after reflection at the smooth reflective back of the sample dominated down to transmission below 5% which was observed after annealing between 500-600 oC (low annealing temperatures). The other complementing techniques employed to understand the changing structure of the ion implanted diamond were Raman spectroscopy, electromagnetic transmission in the visible range, electron energy loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM) in addition to theoretical techniques: transport of ions in matter (TRIM), finite element modelling (FEM) and elastodynamic Green’s functions. Although the electronic techniques showed a structurally changing material at the low annealing temperatures, the optical ones did not show significant changes in the ion-damaged material possibly due to lack of distinct interface between the pristine diamond and the ion irradiated region at these lower annealing temperatures.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Includes bibliographical references. / by Michael Anthony Zuniga. / Ph.D.

Zhang, Hai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 106-109). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.5 / Chapter 2 --- Preliminaries --- p.13 / Chapter 2.1 --- Maxwell equations --- p.13 / Chapter 2.2 --- Reflection principle --- p.15 / Chapter 3 --- Scattering by General Polyhedral Obstacle --- p.19 / Chapter 3.1 --- Direct problem --- p.19 / Chapter 3.2 --- Inverse problem and statement of main results --- p.21 / Chapter 3.3 --- Proof of the main results --- p.22 / Chapter 3.3.1 --- Preliminaries --- p.23 / Chapter 3.3.2 --- Properties of perfect planes --- p.24 / Chapter 3.3.3 --- Proofs --- p.33 / Chapter 4 --- Scattering by Bi-periodic Polyhedral Grating (I) --- p.35 / Chapter 4.1 --- Direct problem --- p.36 / Chapter 4.2 --- Inverse problem and statement of main results --- p.38 / Chapter 4.3 --- Preliminaries --- p.39 / Chapter 4.4 --- Classification of unidentifiable periodic structures --- p.41 / Chapter 4.4.1 --- Observations and auxiliary tools --- p.41 / Chapter 4.4.2 --- First class of unidentifiable gratings --- p.45 / Chapter 4.4.3 --- Preparation for finding other classes of unidentifiable gratings --- p.47 / Chapter 4.4.4 --- A simple transformation --- p.52 / Chapter 4.4.5 --- Second class of unidentifiable gratings --- p.53 / Chapter 4.4.6 --- Third class of unidentifiable gratings --- p.58 / Chapter 4.4.7 --- Excluding the case with L --- p.61 / Chapter 4.4.8 --- Summary on all unidentifiable gratings --- p.65 / Chapter 4.5 --- Proof of Main results --- p.65 / Chapter 5 --- Scattering by Bi-periodic Polyhedral Grating (II) --- p.69 / Chapter 5.1 --- Preliminaries --- p.70 / Chapter 5.2 --- Classification of unidentifiable periodic structures --- p.72 / Chapter 5.2.1 --- First class of unidentifiable gratings --- p.72 / Chapter 5.2.2 --- Preparation for finding other classes of unidentifiable gratings --- p.73 / Chapter 5.2.3 --- Studying of the case L --- p.76 / Chapter 5.2.4 --- Study of the case with L --- p.89 / Chapter 5.2.5 --- Study of the case with L --- p.95 / Chapter 5.2.6 --- Summary on all unidentifiable gratings --- p.104 / Chapter 5.3 --- Unique determination of bi-periodic polyhedral grating --- p.104 / Bibliography --- p.106

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In today's rapidly expanding communications industry, there is an ever-increasing demand for greater bandwidth, higher data rates and better spectral efficiency. As a result current and future communication systems will need to employ advanced spatial, temporal and frequency diversity techniques in order to meet these demands. Even with the utilisation of such techniques, the congestion of the lower frequency bands, will inevitably lead to the increased usage of the millimetre-wave frequencies in terrestrial communication systems. Before such systems can be deployed, radio system designers require realistic and readily useable channel and propagation models at their disposal to predict the behaviour of such communication links and ensure that reliable and efficient data transmission is achieved The scattering and attenuation of electromagnetic waves by rain is a serious problem for microwave and millimetre-wave frequencies. The conversion of rain rate to specific attenuation is a crucial step in the analysis of the total path attenuation and hence radio-link availability. It is now common practice to relate the specific attenuation and the rain rate using the simple power law relationship. The power-law parameters are then used in the path attenuation model, where the spatial variations of rainfall are estimated by a path-integration of the rain rate. These power law parameters are strongly influenced by the drop-size-distribution (DSD). Thus an examination of the various DSDs and their influence on the specific attenuation and link availability is warranted. Several models for the DSD have been suggested in literature, from the traditional exponential, to the gamma, log normal and Weibull distributions. The type of DSD varies depending on the geographical location and rainfall type. An important requirement of the DSD is that it is consistent with rain rate (i.e. the DSD must satisfy the rain-rate integral equation). Thus before application in the specific attenuation calculations, normalisation needs to be performed to ensure the consistency, as done in this study. Once the specific attenuation has been evaluated for necessary frequency and rain-rate range, path averaging is performed to predict the rain attenuation over the communication link. The final step in this dissertation is the estimation of the percentage of time of such occurrences. For this, cumulative time statistics of surface point rain rates are needed. The resulting cumulative distribution model of the fade depth and duration due to rain is a valuable tool for system designers. With such models the system designer can then determine the appropriate fade margin for the communication system and resulting period of unavailability for the link / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2006.

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Thesis (Ph. D.)--University of Washington, 1989. / Vita. Includes bibliographical references (leaves [118]-122).