Life in the late Intermediate Period at Armatambo, Peru

Title from PDF of title page (University of Missouri--Columbia, viewed on October 18, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisors: Dr. Robert A. Benfer and Dr. Deborah M. PearsallVita.Ph.D. University of Missouri--Columbia 2011."May 2011"This study examines the ability of the ruling class to provide for the health of their subjects through labor in the Late Intermediate Period site of Armatambo. The thesis of this dissertation is that the development of complex urban states in the central Andean coast was made possible by depleting the health and increasing the physical activity of the adult laborers while using the fruits of their labor to support the health of the subadults. Bioarchaeological indicators will be used to evaluate both chronic stress and acute stress episodes. Arthritic changes, signs of trauma, and age at death will measure adult responses to state demands. Comparisons between Armatambo and earlier sites found evidence supporting the main hypothesis. Results found that subadult health at Armatambo reversed a trend of worsening health seen in less complex sites through time. In contrast, adults from Armatambo showed more indicators of high activity levels. However, health at Armatambo compares less favorably to health at a Huari empire site: subadult health at Armatambo was generally worse, and adult physical activity was higher.Includes bibliographical reference

Essays on Bargaining and Markets

Chapter 1: Inefficiency in a Frictionless Market Gale and Sabourian (2006) discuss the existence of inefficient Markov-perfect equilibrium (MPE) in a heterogeneous market. This paper shows that the example they provide cannot be supported as a MPE. Indeed, with two buyers and two sellers, the dispersion of bargaining positions is not sufficiently wide to support any inefficient trades in their setup. I then prove that their conjecture is correct by constructing a continuum of inefficient MPE with three buyers and three sellers, where the dynamics of continuation payoffs is rich enough to support wide dispersion of bargaining positions at the first stage, which in turn renders inefficient trades individually rational. This suggests that the number of players in a market could be essential for allocative inefficiency. Chapter 2: Re-trading and Efficient Allocation Inefficient Markov-perfect equilibria (MPE) are prevalent in dynamic matching and bargaining games (DMBG). I observe this inefficiency is caused by a substantial friction commonly assumed in the literature: players must exit the market after trading once. In response, this paper studies a simple heterogeneous market with a finite number of players, where re-trading is allowed and each player can choose to exit the market at any period. I show that, for sufficiently small search cost, all MPE are allocative efficient. The reasoning is conceptually distinct from the existing literature, and indispensable to models where players are allowed to exit the market amidst the game. Chapter 3: Redistributive Effects of Search Frictions van den Berg and van Vuuren (2010) recorded the empirical puzzle that search frictions have a positive impact on the wages of managers, as against the prediction of the canonical model of Pissarides (2000). I argue the discrepancy is caused by the assumption of perfectly elastic vacancy supply in the latter, which is inappropriate for managerial labour markets. In response, I construct a search and matching model with perfectly inelastic vacancy supply, and show that the comparative statics with respect to search frictions are totally different. The results explain the divergent welfare impacts of search frictions on workers at different levels of the corporate hierarchy. They also show that lowering search frictions is not necessarily Pareto-improving even in a homogeneous setting

Process planning by recognizing and learning machining features

We present two methods for process planning of 2.5D machined parts. The first method is based on feature recognition from a 3D model. We embedded the shape and the machining method of two generic classes of machining features in a set of OPS5 rules to form a machining feature recognizer. When successfully recognizing a machining feature, machining instructions, in terms of the tool entrance face, drive face and part face, for cutting the machining feature will be generated and further processed to produce NC codes. The second method is based on learning the shape and the machining method of the machining feature. When a machining feature cannot be recognized by the former feature recognizer, the user can use the machining feature as a positive training example to instruct the system about the tool entrance face, drive face and part face of the machining feature. The system then builds a new rule, using the boundary shape of the unrecognized machining feature as the rule's matching condition and the acquired machining instruction as the rule's action. The new rule can be used subsequently for process planning of machining features that have shapes similar to the memorized one

Monte Carlo modeling of multiply scattered laser ceilometer returns

February 1994.Also issued as Chan W. Keith's thesis (M.S.) -- Colorado State University, 1994.Includes bibliographical references.Initial analysis of the data from the laser ceilometer used during the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment (FIRE) and Atlantic Stratocumulus Transition Experiment (ASTEX) programs indicated that clouds were sometimes not reported even though clouds were visible over the ceilometer. In order to understand this inconsistency, a model using Monte Carlo techniques has been refined to study the effect that multiple scattering and other physical processes have on near infrared laser ceilometer returns. The model traces photon paths through three orders of scattering within various scattering media and determines the photon's probability of returning to the receiver at each scattering point. The Monte Carlo model allows for a limited number of horizontal and vertical inhomogeneities in the extinction coefficient and scattering phase function within the scattering media. Clear air and background aerosol scattering, based on published standards are also introduced within the model. Results from the current model are compared with previously published results. Specific atmospheric media and laser ceilometer parameters are modeled, and a factor, a, is defined to measure the effects of each. Results from the model indicate that precipitation and extinction by the subcloud layer have the most significant impact upon the return signal. For clouds with the same optical depth, those with an increasing extinction with depth exhibited a flatter, smaller magnitude return signal than those with a constant or decreasing extinction. Rayleigh scattering and background aerosols in the subcloud layer decrease the return signal from the cloud and introduce a background level of return from below the cloud. Rain in the subcloud layer lowers the return signal from the cloud, but increases the signal from the subcloud layer due to its relatively large extinction, while realistic levels of absorption have no significant impact. Lastly, a quantitative assessment of detectability for clouds is made, based on amin as a threshold. Model results indicate that conditions can exist where a cloud may not be identified by the laser ceilometer.Sponsored by the National Oceanic and Atmospheric Administration grant NAG 1-1146, and the Office of Naval Research contract N00014-91-J-1422, P0004

Periodic chiral magnetic domains in single-crystal nickel nanowires

We report on experimental and computational investigations of the domain structure of ~0.2 x 0.2 x 8 {\mu}m single-crystal Ni nanowires (NWs). The Ni NWs were grown by a thermal chemical vapor deposition technique that results in highly-oriented single-crystal structures on amorphous SiOx coated Si substrates. Magnetoresistance measurements of the Ni NWs suggest the average magnetization points largely off the NW long axis at zero field. X-ray photoemission electron microscopy images show a well-defined periodic magnetization pattern along the surface of the nanowires with a period of {\lambda} = 250 nm. Finite element micromagnetic simulations reveal that an oscillatory magnetization configuration with a period closely matching experimental observation ({\lambda} = 240 nm) is obtainable at remanence. This magnetization configuration involves a periodic array of alternating chirality vortex domains distributed along the length of the NW. Vortex formation is attributable to the cubic anisotropy of the single crystal Ni NW system and its reduced structural dimensions. The periodic alternating chirality vortex state is a topologically protected metastable state, analogous to an array of 360{\deg} domain walls in a thin strip. Simulations show that other remanent states are also possible, depending on the field history. Effects of material properties and strain on the vortex pattern are investigated. It is shown that at reduced cubic anisotropy vortices are no longer stable, while negative uniaxial anisotropy and magnetoelastic effects in the presence of compressive biaxial strain contribute to vortex formation.Comment: 15 pages, 11 figure

Life expectancy of persons receiving combination antiretroviral therapy in low-income countries: a cohort analysis from Uganda

Little is known about the effect of combination antiretroviral therapy (cART) on life expectancy in sub-Saharan Africa