Fast Hierarchical Clustering and Other Applications of Dynamic Closest Pairs

We develop data structures for dynamic closest pair problems with arbitrary distance functions, that do not necessarily come from any geometric structure on the objects. Based on a technique previously used by the author for Euclidean closest pairs, we show how to insert and delete objects from an n-object set, maintaining the closest pair, in O(n log^2 n) time per update and O(n) space. With quadratic space, we can instead use a quadtree-like structure to achieve an optimal time bound, O(n) per update. We apply these data structures to hierarchical clustering, greedy matching, and TSP heuristics, and discuss other potential applications in machine learning, Groebner bases, and local improvement algorithms for partition and placement problems. Experiments show our new methods to be faster in practice than previously used heuristics.Comment: 20 pages, 9 figures. A preliminary version of this paper appeared at the 9th ACM-SIAM Symp. on Discrete Algorithms, San Francisco, 1998, pp. 619-628. For source code and experimental results, see http://www.ics.uci.edu/~eppstein/projects/pairs

Cultural Evolutionary Tipping Points in the Storage and Transmission of Information

Human culture has evolved through a series of major tipping points in information storage and communication. The first was the appearance of language, which enabled communication between brains and allowed humans to specialize in what they do and to participate in complex mating games. The second was information storage outside the brain, most obviously expressed in the Upper Paleolithic Revolution - the sudden proliferation of cave art, personal adornment, and ritual in Europe some 35,000-45,000 years ago. More recently, this storage has taken the form of writing, mass media, and now the Internet, which is arguably overwhelming humans\u27 ability to discern relevant information. The third tipping point was the appearance of technology capable of accumulating and manipulating vast amounts of information outside humans, thus removing them as bottlenecks to a seemingly self-perpetuating process of knowledge explosion. Important components of any discussion of cultural evolutionary tipping points are tempo and mode, given that the rate of change, as well as the kind of change, in information storage and transmission has not been constant over the previous million years

The Impact of Drone Technology on Precision Agriculture at The Morehead State University Farm

https://scholarworks.moreheadstate.edu/student_scholarship_posters/1227/thumbnail.jp

Testing the potential use of UK wetland plant species in paludiculture using examples from the Somerset Levels

The trade-off between economic benefits and environmental sustainability results in the unsustainable use of wetlands through conversion to agricultural land. As a result, causing peat degradation, reducing the ecosystem’s capacity to provide ecosystem services. Paludiculture, the concept of cultivating wetland plant species in rewetted conditions that can be converted and utilised commercially, presents an opportunity to harmonise economic stability and environmental protection. However, most research into paludiculture has been conducted in continental Europe; there is a knowledge gap regarding paludiculture in the UK. In this research, seven UK wetland plant species were harvested from the Somerset Levels, a low-lying wetland area with high agricultural presence and nutrient contamination. Samples were harvested as close to a monoculture as possible using a 0.25m2 quadrat, freeze-dried to enable the dry biomass production to be calculated, milled, and then passed through an X-ray Fluorescence (XRF) and Carbon, Hydrogen, and Nitrogen (CHN) analyser to determine the nutrient removal capacity of each plant species. Statistical analysis, including a one-way ANOVA test, identified a significant difference between the dry biomass production of the plant species; Typha latifolia produced the greatest dry biomass yield of 50.32 t ha-1-yr-1, followed by Phragmites australis; Glyceria maxima produced the smallest dry biomass yield of 3.35 t ha-1-yr-1. Furthermore, T.latifolia demonstrates a significantly greater nutrient removal capacity, potentially removing 21.8 t ha-1-yr-1 of carbon and 3.12 t ha-1-yr-1 of phosphorus per yield, followed by P.australis. These findings show that T.latifolia and P.australis have the greatest potential for paludiculture within the UK to remediate nutrient contamination and restore the wetlands whilst maintaining land productivity. Although this study has demonstrated the potential of paludiculture on the Somerset Levels and Moors (SLM) the individual conditions of alternative locations in the UK, such as soil pH and water table depth, should be revised to determine the suitability for paludiculture

Feasibility, acceptability and potential effectiveness of dignity therapy for family carers of people with motor neurone disease

BACKGROUND: Dignity therapy is a brief psychotherapy that has been shown to enhance the end of life experience. Dignity therapy often involves family carers to support patients weakened by illness and family carers are also the usual recipients of the legacy documents created. No research to date has examined the impact of dignity therapy on family carers at the time of the intervention. This study examined the effects of dignity therapy on family carers of people with motor neurone disease (MND). METHODS: This is a cross-sectional study utilizing a one-group pre-test post-test design with 18 family carers of people diagnosed with MND. Outcomes measured caregiver burden, anxiety, depression, and hopefulness. Acceptability was measured with a questionnaire. Feasibility was assessed by examining family carers’ involvement in the therapy sessions, time taken to conduct sessions, and any special accommodations or deviations from the dignity therapy protocol.RESULTS: There were no significant pre-test post-test changes on the group level, but there were decreases in anxiety and depression on the individual level. Baseline measures indicate that 50% of family carers had moderate to severe scores for anxiety prior to dignity therapy. MND family carers saw benefits to the person with MND and to themselves after bereavement, but acceptability of dignity therapy at the time of the intervention was mixed with some family carers indicating it was helpful, some indicating it was harmful, and many expressing ambivalence. Dignity therapy involving MND family carers is feasible and the involvement of family carers has minimal impact on the therapy. CONCLUSION: Dignity therapy is not likely to alleviate caregiver burden in MND family carers, but it may have the ability to decrease or moderate anxiety and depression in distressed MND family carers. Dignity therapy is feasible and generally acceptable to MND family carers. Dignity therapists may provide a better experience for family carers when they are aware of acceptance levels and the quality of partner relationships

Religiosity, trauma, and Posttraumatic Stress Disorder in a sample of East African refugees

Somali refugees have been found to experience more exposure to traumatic events than other refugees and asylum seekers (Gerritsen et al, 2006). Culturally, religious beliefs are key to Somali perceptions mental health and well-being (Abu-Raiya & Pargament, 2011; Mulatu, 1999). This study examined organizational religious activity (ORA), non-organizational religious activity (NORA), and intrinsic religiosity as potential moderators of PTSD symptom clusters among a sample of Somali refugees in the United States. Participants were 59 Somali refugees in the Pacific Northwest (Mage = 39 years, 66% male). Results indicated ORA and NORA moderated the relationship between trauma exposure and re-experiencing symptoms of PTSD

It takes a ballpark village : stadiums, coalitions, and growth in two cities

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2006.Includes bibliographical references (p. 81-85).The typical stadium development story features a City interested in investing in its future. The City looks to a new ballpark to spark revitalization, provide new jobs and industry, and increase civic pride. Yet, academic research suggests that the City is looking in the wrong place. Economic and even social benefits rarely materialize in quantities sufficient to compensate the City's investment of money, time, and opportunities forgone. Assuming that stadium proponents and local governments behave rationally in their choice to support these projects and that academic research is accurate, a different motive may cause the continued support and interest in new stadium projects. I suggest that what motivates the local governments, interest groups, and private individuals that actively support stadium construction is a central interest in growth. This belief in growth and general development as the desired outcome, rather than specific new jobs or civic pride, may guide the stadium process. Using case study data from San Diego and St. Louis, I examine the stadium planning process, groups involved; motives for participation, and outcomes produced.(cont.) I then compare the two cases, paying particular attention to evidence of a motivating growth agenda and a new element in these stadium projects - the 'ballpark village' development. My core analysis is prefaced by a review of relevant planning literature, including stadium costs and benefits, growth machine urban theory, equitable development, and community organizing; it is followed by a ruminative consideration of the ballpark village as a stadium development strategy.by Anna O. Bentley.M.C.P

Electron mobility in surface- and buried- channel flatband In_0.53Ga_0.47As MOSFETs with ALD Al₂O₃ gate dielectric.

In this paper, we investigate the scaling potential of flatband III-V MOSFETs by comparing the mobility of surface and buried In<sub>0.53</sub>Ga<sub>0.47</sub>As channel devices employing an Atomic Layer Deposited (ALD) Al<sub>2</sub>O<sub>3</sub> gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure. Peak electron mobilities of 4300 cm<sup>2</sup>/V·s and 6600 cm<sup>2</sup>/V·s at a carrier density of 3×1012 cm<sup>-2</sup> for the surface and buried channel structures respectively were determined. In contrast to similarly scaled inversion-channel devices, we find that mobility in surface channel flatband structures does not drop rapidly with electron density, but rather high mobility is maintained up to carrier concentrations around 4x10<sup>12</sup> cm<sup>-2</sup> before slowly dropping to around 2000 cm<sup>2</sup>/V·s at 1x10M<sup>13</sup> cm<sup>-2</sup>. We believe these to be world leading metrics for this material system and an important development in informing the III-V MOSFET device architecture selection process for future low power, highly scaled CM