4,832 research outputs found
S.R. Lewis letter to Z. Eastman, March 5, 1874
No full textBrief letter from S.R. Lewis to Z. Eastman, marking the announcement of an abolitionists' reunion to be held in Chicago in June of 1875. Lewis requests that Eastman, given his close acquaintance with Benjamin Lundy, prepare a public statement of remembrance on Lundy and his contributions to the anti-slavery movement. Benjamin Lundy (1789-1839) was a prominent Quaker abolitionist best known for his development of abolitionist periodicals. His Genius of Universal Emancipation was first published in 1821 from his home in Mt. Pleasant, Ohio, and enjoyed a wide circulation across the antebellum United States. In the 1820s, the young William Lloyd Garrison came to work for The Genius. Benjamin Lundy traveled widely seeking subscriptions to The Genius, giving talks about the anti-slavery movement, and observing and documenting the conditions of enslaved people across the Americas. He was also involved in the establishment of freed slave colonies in Mexico
Floodplain connectivity, disturbance and change: a palaeoentomological investigation of floodplain ecology from south-west England
No full text1. Floodplain environments are increasingly subject to enhancement and restoration, with the purpose of increasing their biodiversity and returning them to a more 'natural' state. Defining such a state based solely upon neoecological data is problematic and has led several authors to suggest the use of a palaeoecological approach.2. Fossil Coleopteran assemblages recovered from multiple palaeochannel fills in south-west England were used to investigate past floodplain and channel characteristics during the mid- to late-Holocene. Ordination of coleopteran data was performed using Detrended Correspondence Analysis (DCA) and produced clear and discrete clustering. This clustering pattern is related to the nature of the environment in which assemblages were deposited and hence channel configuration and dynamics.3. The DCA clustering pattern is strongly related to measures of ecological evenness, and a strong relationship between these indices and the composition of the water beetle assemblage within samples was revealed. Repeating the ordination with presence–absence data results in a similar pattern of clustering, implying that assemblage composition is crucial in determining cluster placement.4. As assemblage composition is primarily a function of floodplain topography and hence disturbance regime, we attempt to relate these data to the Intermediate Disturbance Hypothesis (IDH). A significant positive correlation was found between ecological diversity (Shannon's H') and Axis 1 of all ordinations in predominantly aquatic assemblages
Modelling and optimization of a permanent-magnet machine in a flywheel
No full textThis thesis describes the derivation of an analytical model for the design and optimization of a permanent-magnet machine for use in an energy storage flywheel. A prototype of this flywheel is to be used as the peak-power unit in a hybrid electric city bus. The thesis starts by showing the feasibility of using a flywheel energy storage system for this application, as opposed to other energy storage technologies. It then continues by describing a prototype flywheel system and the required electrical machine: a radial-flux external-rotor permanent-magnet synchronous machine without slots in the stator iron and with a shielding cylinder. An analytical model for the machine is derived, based on 2D electromagnetic field calculations, including the reaction field of the eddy currents in the shielding cylinder. Torque and losses are calculated by means of the Theorem of Poynting and the Lorentz force. Such a machine was built and the analytical model has been validated by experimental measurements. Lastly, the thesis suggests and implements a machine optimization algorithm.Information Technology and System
Design metrics for evaluating the propulsive efficiency of future ships
No full textThere is an increasing need for the ship design process to take account of environmental issues such as the emission of greenhouse gases and the likely extension of a carbon dioxide charging mechanism to international shipping. These issues, together with the need for economic viability, provide further incentives to improve the efficiency of propulsion of ships. The main components of powering are firstly reviewed. Individual components and other power saving devices are identified which should contribute to improvements in the overall efficiency of propulsion. Suitable design metrics and procedures, taking into account economic and environmental factors, are recommended for the design of future ships
Description of S.R. Krom's system and machinery for dry crushing and concentrating ores.
No full textCover title.Mode of access: Internet.MAIN; TN500.K7 1876: Introduction signed by author, S.R. Krom
Data Integrity Problems in an Open Hypermedia Link Service
No full textA hypermedia link service is system which stores the information describing hypertext links in a database which is separate from the data content over which the links are intended to operate. One of the first open hypermedia link services was Microcosm, which takes this philosophy to the extreme, storing not only the links in a separate database, but also the information about the endpoints of the links. The most important advantage of such an organisation is that the system remains open so that hypertext functionality may be extended to third party applications. The first part of this thesis describes the background to open hypermedia link services and describes the Microcosm system, which was developed by the Multimedia Research Group at the University of Southampton. The major problem with storing all the information about links separately from the content is that such a scheme introduces many opportunities for the introduction of inconsistencies and the loss of integrity of the hypermedia data model. The second part of this thesis examines these problems, and proposes a number of solutions. It concludes that no one solution can resolve all the problems, and that in order to ensure integrity it is necessary to impose some conditions which limit the degree of openness
Refinement of solutions to the linear complimentarity problem
No full textNash equilibrium;game theaory;matrices
Coffea semsei A.P.Davis 2010, comb. nov.
No full textCoffea semsei (Bridson) A.P.Davis, comb. nov. Psilanthus semsei Bridson (1882: 36). Type: TANZANIA. Ulanga District: Magombera Forest Reserve, 8 November 1961, S.R. Semsei 3400 (holotype K!). Distribution: — Tanzania (Ulanga). TDWG: 25 TAN. Characteristics:— Coffea semsei can be set apart from all other species of Coffea formerly placed in Psilanthus due to the following combination of characters: habit deciduous; leaves membranous; leaf apex acuminate; stipules deltate to triangular, shortly apiculate (apiculum 1–2 mm long), stipular lobes of the calyculi narrowly triangular and glume-like; calyx with shortly triangular lobes, and each lobe bearing several colletes; and corolla lobes distinctly acuminate.Published as part of Davis, Aaron P., 2010, Six species of Psilanthus transferred to Coffea (Coffeeae, Rubiaceae), pp. 41-45 in Phytotaxa 10 on page 43, DOI: 10.11646/phytotaxa.10.1.6, http://zenodo.org/record/489978
Toward more efficient heuristic construction of Boolean functions
No full textBoolean functions have numerous applications in domains as diverse as coding theory, cryptography,and telecommunications. Heuristics play an important role in the construction of Boolean functions with the desired properties for a specific purpose. However, there are only sparse results trying to understand the problem’s difficulty. With this work, we aim to address this issue. We conduct a fitness landscape analysis based on Local Optima Networks (LONs) and investigate the influence of different optimization criteria and variation operators. We observe that the naive fitness formulation results in the largest networks of local optima with disconnected components. Also, the combination of variation operators can both increase or decrease the network size. Most importantly, we observe correlations of local optima’s fitness, their degrees of interconnection, and the sizes of the respective basins of attraction. This can be exploited to restart algorithms dynamically and influence the degree of perturbation of the current best solution when restarting.Domagoj Jakobovic, Stjepan Picek, Marcella S.R. Martins, Markus Wagne
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