An Analysis of Conjunctive Goal Planning

This thesis develops a formal theory of planning, using a simple paradigm of planning that has been previously explored in work such as GPS, HACKER, STRIPS and NOAH. This thesis analyzes the goal interactions that occur when the goal is stated as a conjunction of subgoals. In this analysis we assume that the problem has a finite state space, and that operators are reversible. Graph theory can be used to characterize these subgoal interactions. The entire state space is treated as a graph, and each subgoal or conjunction of subgoals defines a subgraph. Each subgraph is composed of one or more connected components. Solving each subgoal by choosing a connected component that contains a final goal state is a necessary and sufficient condition for solving any planning problem. In the worst case, analyzing goal interactions is shown to be no more effective than enumerating the state space and searching. This complexity proves that no complete algorithm can solve all planning problems in linear time. The technique of goal ordering is analyzed, along with several extensions to that technique. While a generalization of goal ordering is possible, in the worst case generating the goal order requires as much computation as solving the problem by a brute-force search. A technique called capability analysis, derived from the connect component results, uses first-order logic to find the constraints that must apply as subgoals are achieved. A partial implementation uses counterfactual logic to identify the components of a world state that prevent the remaining subgoals from being achieved

Coca: The History and Medical Significance of an Ancient Andean Tradition

Coca leaf products are an integral part of the lives of the Andean peoples from both a cultural and traditional medicine perspective. Coca is also the whole plant from which cocaine is derived. Coca products are thought to be a panacea for health troubles in regions of South America. This review will examine the toxicology of whole coca and will also look at medicinal applications of this plant, past, present, and future

Avaliação de políticas públicas no Brasil e nos Estados Unidos : análise da pesquisa nos últimos 10 anos

Este estudo compara a pesquisa sobre avaliação de políticas públicas no Brasil e nos Estados Unidos. No intuito de examinar o grau em que a pesquisa em avaliação está estabelecida nesses países, este artigo usa os métodos bibliométrico e de análise de rede social para comparar as publicações recentes da pesquisa em avaliação em ambos os países. Os resultados mostram que o Brasil e os Estados Unidos têm pesquisado e publicado nas mesmas áreas, em especial, nas áreas de saúde, de educação e de bem-estar social. Observou-se também que os pesquisadores dos dois países utilizam métodos de investigação similares, embora os americanos façam maior uso de métodos quanti-quali e suas redes de pesquisa apresentem características semelhantes, apesar de as redes americanas serem de tamanho e densidade maiores. A partir das evidências encontradas, conclui-se que a pesquisa em avaliação no Brasil evoluiu durante o período investigado e que está em vias de consolidação como um campo de estudo e prática.This study compares research on evaluation of public policies in Brazil and the United States. To examine the extent to which evaluation research has been established in these countries, this article uses the methods of bibliometric and social network analysis to compare recent use of evaluation research in these countries. The results show that Brazil and the United States have focused on the same areas of research, especially the areas of health, education and social welfare. It was also observed that researchers from both countries use research methods, although American researchers make more use of quanti-quali methods, and that research networks on policy evaluation in the two country have similar characteristics, although the average size and density of networks in Brazil is less than that in the United States. On the basis of the evidence, it is concluded that evaluation research in Brazil evolved during the period investigated and is becoming consolidated as a field of study and practice.Este estudio hace una comparación entre la investigación sobre la evaluación de políticas públicas en Brasil y en Estados Unidos. Con el objetivo de examinar el grado en que la investigación en evaluación se establece en los ya citados países, este artículo utiliza los métodos bibliométricos y de análisis de red social para comparar las publicaciones recientes de la investigación en evaluación en ambos países. Los resultados muestran que Brasil y Estados Unidos han investigado y publicado en las mismas áreas, en especial en las áreas de salud, educación y el bienestar social. También se observó que los investigadores de los dos países utilizan métodos de investigación similares, aunque los estadounidenses hacen un mayor uso de métodos cuanti-cuali, y que sus redes de investigación tienen características similares, aunque las redes americanas son de un tamaño y una mayor densidad maiores. A partir de las evidencias encontradas, se concluye que la evaluación de la investigación en Brasil ha evolucionado durante el período de investigación y está en el proceso de consolidación como un campo de estudio y práctica

Children\u27s Law Center Site Redevelopment

Soda City Engineering and Consulting was contracted by the USC School of Law to redevelop the Children’s Law Center site in Columbia, SC. Currently, the site does not comply with current standards and specifications. The objective of this project is to completely redevelop the site with a new annex building and ensuring everything is up to code, while still allowing the historic structure to maintain its use throughout construction

Embodied conversations: Performance and the design of a robotic dancing partner

This paper reports insights gained from an exploration of performance-based techniques to improve the design of relationships between people and responsive machines. It draws on the Emergent Objects project and specifically addresses notions of embodiment as employed in the field of performance as a means to prototype and develop a robotic agent, SpiderCrab, designed to promote expressive interaction of device and human dancer, in order to achieve ‘performative merging’. The significance of the work is to bring further knowledge of embodiment to bear on the development of human-technological interaction in general. In doing so, it draws on discursive and interpretive methods of research widely used in the field of performance but not yet obviously aligned with some orthodox paradigms and practices within design research. It also posits the design outcome as an ‘objectile’ in the sense that a continuous and potentially divergent iteration of prototypes is envisaged, rather than a singular final product. The focus on performative merging draws in notions of complexity and user experience. Keywords: Embodiment; Performance; Tacit Knowledge; Practice-As-Research; Habitus.</p

Simulation of the Mars Surface Solar Spectra for Optimized Performance of Triple-Junction Solar Cells

The unparalleled success of the Mars Exploration Rovers (MER) powered by GaInP/GaAs/Ge triple-junction solar cells has demonstrated a lifetime for the rovers that exceeded the baseline mission duration by more than a factor of five. This provides confidence in future longer-term solar powered missions on the surface of Mars. However, the solar cells used on the rovers are not optimized for the Mars surface solar spectrum, which is attenuated at shorter wavelengths due to scattering by the dusty atmosphere. The difference between the Mars surface spectrum and the AM0 spectrum increases with solar zenith angle and optical depth. The recent results of a program between JPL and Spectrolab to optimize GaInP/GaAs/Ge solar cells for Mars are presented. Initial characterization focuses on the solar spectrum at 60-degrees zenith angle at an optical depth of 0.5. The 60-degree spectrum is reduced to ~1/6 of the AM0 intensity and is further reduced in the blue portion of the spectrum. JPL has modeled the Mars surface solar spectra, modified an X-25 solar simulator, and completed testing of Mars-optimized solar cells previously developed by Spectrolab with the modified X-25 solar simulator. Spectrolab has focused on the optimization of the higher efficiency Ultra Triple-Junction (UTJ) solar cell for Mars. The attenuated blue portion of the spectrum requires the modification of the top sub-cell in the GaInP/GaAs/Ge solar cell for improved current balancing in the triple-junction cell. Initial characterization confirms the predicted increase in power and current matched operation for the Mars surface 60-degree zenith angle solar spectrum

Factors Associated With Ocular Health Care Utilization Among Hispanics/Latinos: Results From an Ancillary Study to the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Regular ocular care is critical to early detection and prevention of eye disease and associated morbidity and mortality; however, there have been relatively few studies of ocular health care utilization among Hispanics/Latinos of diverse backgrounds

Genetic diversity in Campylobacter jejuni is associated with differential colonization of broiler chickens and C57BL/6J IL10-deficient mice

Previous studies have demonstrated that Campylobacter jejuni, the leading causative agent of bacterial food-borne disease in the USA, exhibits high-frequency genetic variation that is associated with changes in cell-surface antigens and ability to colonize chickens. To expand our understanding of the role of genetic diversity in the disease process, we analysed the ability of three C. jejuni human disease isolates (strains 11168, 33292 and 81-176) and genetically marked derivatives to colonize Ross 308 broilers and C57BL/6J IL10-deficient mice. C. jejuni colonized broilers at much higher efficiency (all three strains, 23 of 24 broilers) than mice (11168 only, 8 of 24 mice). C. jejuni 11168 genetically marked strains colonized mice at very low efficiency (2 of 42 mice); however, C. jejuni reisolated from mice colonized both mice and broilers at high efficiency, suggesting that this pathogen can adapt genetically in the mouse. We compared the genome composition in the three wild-type C. jejuni strains and derivatives by microarray DNA/DNA hybridization analysis; the data demonstrated a high degree of genetic diversity in three gene clusters associated with synthesis and modification of the cell-surface structures capsule, flagella and lipo-oligosaccharide. Finally, we analysed the frequency of mutation in homopolymeric tracts associated with the contingency genes wlaN (GC tract) and flgR (AT tracts) in culture and after passage through broilers and mice. C. jejuni adapted genetically in culture at high frequency and the degree of genetic diversity was increased by passage through broilers but was nearly eliminated in the gastrointestinal tract of mice. The data suggest that the broiler gastrointestinal tract provides an environment which promotes outgrowth and genetic variation in C. jejuni; the enhancement of genetic diversity at this location may contribute to its importance as a human disease reservoir

Grassland productivity limited by multiple nutrients

Terrestrial ecosystem productivity is widely accepted to be nutrient limited1. Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)2,3, the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized4,​5,​6,​7,​8. However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment