Age Replacement and Service Rate Control of Stochastically Degrading Queues

This thesis considers the problem of optimally selecting a periodic replacement time for a multiserver queueing system in which each server is subject to degradation as a function of the mean service rate and a stochastic and dynamic environment. Also considered is the problem of optimal service rate selection for such a system. In both cases, the performance metric is the long-run average cost rate. Analytical expressions are obtained, in terms of Laplace transforms, for the nonlinear objective functions, necessitating the use of numerical Laplace transform inversion to evaluate candidate solutions in conjunction with standard numerical algorithms. Due to the convexity of the objective function, the optimal replacement time is computed using a hybrid bisection-secant method which yields globally optimal solutions. The optimal service rates are obtained via gradient search methods but are only guaranteed to provide locally optimal solutions. The analytical results are implemented on three notional examples that demonstrate the benefits of dynamically adjusting service rates under the described maintenance policy

Keys to Profitable Grain Sorghum Production in the Blackland Prairie and the Grand Prairie.

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Hydrogel microparticles from lithographic processes: Novel materials for fundamental and applied colloid science

In recent years, there has been a surge in methods to synthesize geometrically and chemically complex microparticles. Analogous to atoms, the concept of a “periodic table” of particles has emerged and continues to be expanded upon. Complementing the natural intellectual curiosity that drives the creation of increasingly intricate particles is the pull from applications that take advantage of such high-value materials. Complex particles are now being used in fields ranging from diagnostics and catalysis, to self-assembly and rheology, where material composition and microstructure are closely linked with particle function. This is especially true of polymer hydrogels, which offer an attractive and broad class of base materials for synthesis. Lithography affords the ability to engineer particle properties a priori and leads to the production of homogenous ensembles of particles. This review summarizes recent advances in synthesizing hydrogel microparticles using lithographic processes and highlights a number of emerging applications. We discuss advantages and limitations of current strategies, and conclude with an outlook on future trends in the field.National Science Foundation (U.S.) (Grant DMR-1006147)Novartis-MIT Center for Continuous ManufacturingNational Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant R21EB008814

Geologic analysis of ERTS-1 imagery for the State of New Mexico

There are no author-identified significant results in this report

The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A

Thermal emission from cold dust grains in giant molecular clouds can be used to probe the physical properties, such as density, temperature and emissivity in star-forming regions. We present the SCUBA-2 shared-risk observations at 450 $\mu$m and 850 $\mu$m of the Orion A molecular cloud complex taken at the James Clerk Maxwell Telescope (JCMT). Previous studies showed that molecular emission lines can contribute significantly to the measured fluxes in those continuum bands. We use the HARP $^{12}$CO J=3-2 integrated intensity map for Orion A in order to evaluate the molecular line contamination and its effects on the SCUBA-2 maps. With the corrected fluxes, we have obtained a new spectral index $\alpha$ map for the thermal emission of dust in the well-known integral-shaped filament. Furthermore, we compare a sample of 33 sources, selected over the Orion A molecular cloud complex for their high $^{12}$CO J=3-2 line contamination, to 27 previously identified clumps in OMC-4. This allows us to quantify the effect of line contamination on the ratio of 850 $\mu$m to 450 $\mu$m flux densities and how it modifies the deduced spectral index of emissivity $\beta$ for the dust grains. We also show that at least one Spitzer-identified protostellar core in OMC-5 has a $^{12}$CO J=3-2 contamination level of 16 %. Furthermore, we find the strongest contamination level (44 %) towards a young star with disk near OMC-2. This work is part of the JCMT Gould Belt Legacy Survey.Comment: 13 pages, 6 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS

Overview of the Intern Position at SexGenLab and the Importance of Public Scholarship

This paper represents a culmination of my time interning with SexGenLab and addresses the work I did from September 2022 to July 2023. This paper discusses the work that was completed, and why it is important, indicating how it contributes to the world at large outside of academia. I discuss my motivations and intentions relating to the internship, and how I was able to carry out my goals through the work I completed. In addition, this paper discusses the nature and importance of public scholarship, and how this internship contributed to that mission