• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1391
  • 468
  • 131
  • 129
  • 86
  • 29
  • 26
  • 19
  • 14
  • 12
  • 10
  • 7
  • 7
  • 7
  • 6
  • Tagged with
  • 3583
  • 1529
  • 1328
  • 499
  • 419
  • 380
  • 327
  • 325
  • 279
  • 271
  • 259
  • 247
  • 242
  • 220
  • 217
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The beginnings of Darwinian ethics: 1859-1871

Gantz, Kenneth Franklin, January 1900 (has links)
Part of Thesis (Ph. D.)--University of Chicago, 1937. / "Reprinted from the University of Texas Studies in English, 1939." "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois.
2

Local adaptation (mostly) remains local: reassessing environmental associations of climate-related candidate SNPs in Arabidopsis halleri

Rellstab, C., Fischer, M.C., Zoller, S., Tedder, Andrew, Shimizu, K.K., Widmer, A., Holderegger, R., Gugerli, F. 13 September 2019 (has links)
No / Numerous landscape genomic studies have identified single-nucleotide polymorphisms (SNPs) and genes potentially involved in local adaptation. Rarely, it has been explicitly evaluated whether these environmental associations also hold true beyond the populations studied. We tested whether putatively adaptive SNPs in Arabidopsis halleri (Brassicaceae), characterized in a previous study investigating local adaptation to a highly heterogeneous environment, show the same environmental associations in an independent, geographically enlarged set of 18 populations. We analysed new SNP data of 444 plants with the same methodology (partial Mantel tests, PMTs) as in the original study and additionally with a latent factor mixed model (LFMM) approach. Of the 74 candidate SNPs, 41% (PMTs) and 51% (LFMM) were associated with environmental factors in the independent data set. However, only 5% (PMTs) and 15% (LFMM) of the associations showed the same environment-allele relationships as in the original study. In total, we found 11 genes (31%) containing the same association in the original and independent data set. These can be considered prime candidate genes for environmental adaptation at a broader geographical scale. Our results suggest that selection pressures in highly heterogeneous alpine environments vary locally and signatures of selection are likely to be population-specific. Thus, genotype-by-environment interactions underlying adaptation are more heterogeneous and complex than is often assumed, which might represent a problem when testing for adaptation at specific loci.
3

Automatic design of analogue circuits

Sapargaliyev, Yerbol January 2011 (has links)
Evolvable Hardware (EHW) is a promising area in electronics today. Evolutionary Algorithms (EA), together with a circuit simulation tool or real hardware, automatically designs a circuit for a given problem. The circuits evolved may have unconventional designs and be less dependent on the personal knowledge of a designer. Nowadays, EA are represented by Genetic Algorithms (GA), Genetic Programming (GP) and Evolutionary Strategy (ES). While GA is definitely the most popular tool, GP has rapidly developed in recent years and is notable by its outstanding results. However, to date the use of ES for analogue circuit synthesis has been limited to a few applications. This work is devoted to exploring the potential of ES to create novel analogue designs. The narrative of the thesis starts with a framework of an ES-based system generating simple circuits, such as low pass filters. Then it continues with a step-by-step progression to increasingly sophisticated designs that require additional strength from the system. Finally, it describes the modernization of the system using novel techniques that enable the synthesis of complex multi-pin circuits that are newly evolved. It has been discovered that ES has strong power to synthesize analogue circuits. The circuits evolved in the first part of the thesis exceed similar results made previously using other techniques in a component economy, in the better functioning of the evolved circuits and in the computing power spent to reach the results. The target circuits for evolution in the second half are chosen by the author to challenge the capability of the developed system. By functioning, they do not belong to the conventional analogue domain but to applications that are usually adopted by digital circuits. To solve the design tasks, the system has been gradually developed to support the ability of evolving increasingly complex circuits. As a final result, a state-of-the-art ES-based system has been developed that possesses a novel mutation paradigm, with an ability to create, store and reuse substructures, to adapt the mutation, selection parameters and population size, utilize automatic incremental evolution and use the power of parallel computing. It has been discovered that with the ability to synthesis the most up-to-date multi-pin complex analogue circuits that have ever been automatically synthesized before, the system is capable of synthesizing circuits that are problematic for conventional design with application domains that lay beyond the conventional application domain for analogue circuits.
4

The Ecophysiology of Surface Cryptogams from Alpine Tundra and Semi-Arid Grassland of Southwestern Alberta

Coxson, Stanley Darwyn 05 1900 (has links)
<p>The seasonal response patterns of net photosynthesis and respiration (and nitrogenase activity in Nostoc) are described within a multivariate framework of temperature, moisture and light for the alpine and grassland crustaceous lichens Rhizocarpon superficiale and Caloplaca trachyphylla respectively and for the grassland surface cyanophyte Nostoc commune. These physiological responses are discussed in context of each species' boundary layer environment, with particular emphasis placed on interactions between environmental constancy and adoption of acclimation strategies.</p> <p>For R. superficiale the high frequency of thermal fluctuations experienced by hydrated thalli, sometimes on an hourly basis, precluded any strategy of seasonal acclimation. Instead, photosynthetic rates exhibited a broad temperature response, remaining near 1 mg CO₂ h⁻¹g⁻¹ from 1 up to 21°C, with no changes evident between seasonal responses. In marked contrast C. trachyphylla shows a distinct winter/summer pattern of photosynthetic acclimation. In winter months rates are optimal near 7°C, while in summer the temperature optima of net photosynthesis shift to 21°C. These changes correlate well with predictable seasonal microclimate events, particularly those associated with winter Chinook snowmelt periods. A third pattern of response was seen in N. commune, where no seasonal changes in response patterns were evident and both nitrogenase activity and net photosynthesis were maximal near 35°C. This response pattern allows maximum carbon gain and nitrogen fixation during spring and summer periods following precipitation events, while its more sheltered aspect reduces the importance of winter snowmelt periods.</p> / Doctor of Philosophy (PhD)
5

An evolutionary psycholinguistic approach to the pragmatics of reference

Bailes, Rachael Louise January 2017 (has links)
Pragmatics concerns the material function of language use in the world, and thus touches on profound questions about the relationship between our cognition and the environments in which we operate. Both psycholinguistics and evolutionary linguistics have afforded greater attention to pragmatics in recent years. Though the potential of evolutionary psycholinguistics has been noted for over twenty-five years (e.g. Tooby & Cosmides, 1990; Scott-Phillips, 2010a), there has arguably been little dialogue between these two fields of study. This thesis explicitly acknowledges and investigates the adaptationist nature of functional claims in psycholinguistics, and attempts to demonstrate that psycholinguistic inquiry can provide evidence that is relevant to theories of how the cognitive architecture of linguistic communication evolved. Chapter two reviews a broad polarisation in the pragmatic and psycholinguistic literature concerning the relative roles of linguistic convention and contextual information in comprehension. It makes explicit the theoretical approaches that reliably give rise to these polar positions across scholarly domains. It goes on to map each model of comprehension to the adaptationist particulars it may entail, and in doing so illustrates two different pictures of how linguistic cognition has developed over phylogeny. The Social Adaptation Hypothesis (SAH) holds that linguistic comprehension is performed by relevance-oriented inferential mechanisms that have been selected for by a social environment (i.e. inference-using conspecifics). In particular, the SAH holds that linguistic conventions are attended to in the same way as other ostensive stimuli and contextual information, and because of their relevance to communicative interactions. The Linguistic Adaptation Hypothesis (LAH) holds that linguistic comprehension is performed by specialised cognition that has been selected for by a linguistic environment (i.e. language-using conspecifics) that was established subsequent to, and as a consequence of, the emergence of inferential communication. In particular, the LAH holds that linguistic conventions are a privileged domain of input for the comprehension system. The plausibility and congruence of both accounts with the current state of knowledge about the evolutionary picture necessitates empirical psycholinguistic evidence. The remainder of the thesis presents a series of experiments investigating referential expressions relevant to the contrastive predictions of these two adaptationist accounts. The broad question that covers all of these experiments is: how sensitive is the comprehension process to linguistic input qua linguistic input, relative to various other grades of relevant contextual information? Chapter three presents a reaction time experiment that uses speaker-specific facts about referents as referring expressions, in a conversational precedent paradigm. The experiment measures the relative sensitivity of comprehension processing to the knowledge states of speakers and the consistent use of linguistic labels, and finds greater sensitivity to linguistic labels. Chapter four introduces a further contextual variable into this paradigm, in the form of culturally copresent associations between labels and referents. The experiment presented in this chapter compares the relative sensitivity of processing to culturally copresent common ground, the privileged knowledge state of speakers, and the consistent use of linguistic labels. The results indicated greater sensitivity to linguistic labels overall, and were consistent with the LAH. Chapter five turns to visual context as a constraint on reference, and presents two pairs of experiments. Experiments 3 and 4 investigate the comprehension of referring expressions across congruous, incongruous, and abstract visual contexts. The experiments measured reaction time as subjects were prompted to identify constituent parts of tangram pictures. The results indicated a sensitivity to the visual context and the linguistic labels, and are broadly consistent with the SAH. If comprehension is characterised by particular sensitivities, we may expect speakers to produce utterances that lend themselves well to how hearers process them. Experiments 5 and 6 use a similar tangram paradigm to elicit referring expressions from speakers for component parts of tangrams. The experiments measure the consistency of produced labels for the same referents across visual contexts of varied congruity. The results indicated some methodological limitations of the tangram paradigm for the study of repeated reference across contexts. Lastly, the thesis concludes by considering the SAH and LAH in light of the empirical evidence presented and its accompanying limitations, and argues that the evidence is generally consistent with the assumptions of the LAH.
6

An analysis of island models in evolutionary computation

Skolicki, Zbigniew Maciej, January 2007 (has links)
Thesis (Ph. D.)--George Mason University, 2007. / Title from PDF t.p. (viewed Jan. 22, 2008). Thesis director: Kenneth A. De Jong. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Science. Vita: p. 422. Includes bibliographical references (p. 413-421). Also available in print.
7

Evolution to the xtreme evolving evolutionary strategies using a meta-level approach /

Ferguson, Darrell January 1900 (has links)
Thesis (M.C.S.) - Carleton University, 2002. / Includes bibliographical references (p. 144-147). Also available in electronic format on the Internet.
8

Co-evolutionary automated software correction: a proof of concept

Wilkerson, Joshua Lee, January 2008 (has links) (PDF)
Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed June 18, 2009) Includes bibliographical references (p. 62-64).
9

Evolutionary Scheduling

Dahal, Keshav P., Tan, K.C., Cowling, Peter I. January 2007 (has links)
No
10

Foraging and life history strategies in multi-trophic communities

Weisser, W. W. January 1994 (has links)
No description available.

Page generated in 0.0914 seconds