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  • 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.
41

“They don't know that we know they know we know” : Ett filosofiskt perspektiv på komplexa informationsbeteenden och digitala gränser / “They don't know that we know they know we know” : A philosophical approach to complex information behaviors and digital limits

Lyckblad, Camilla January 2022 (has links)
The human being and her behavior is complex. Research has shown serendipity and chance to play a great part in the scientific research praxis, still the complexity of human information retrieval is not fully acknowledged in modern libraries. This master thesis compares two different worldviews; the mechanistic and the organic. This in order to understand why information seeking today is increasingly linear when human information behavior is not. The way people believe the world to work reflects on how libraries and information seeking work. The mechanistic worldview, comparing the world to a machine, is rooted in humanity since the seventeenth century and is still shaping our world and institutions. Today databases and linear searches are pushing physical books off shelves to make room for computers and searching on limiting linear mechanical terms instead of complex human ones. This pattern often occurs without adequate questioning and online information is argued to be even more available to patrons than the physical library.  This thesis uses complexity theory and philosophical method to broaden perspectives and question linear searches in scientific information retrieval. It aims to highlight the importance of complex information retrieval and physical browsing for scientific innovation and creativity. Erdelez's original information encountering method was used to obtain source material for philosophical analysis. Philosophical method and complexity theory is used throughout the text to analyze the linear worldview leading up to a joint argumentative summary at the end of every chapter bringing the text forward.  The thesis contains a field study with semi-structured interviews with librarians at the Picture Collection, New York Public Library. This highlights the value of physical browsing through the strong criticism that arose from patrons when the library wanted to archive the unique and browsable research collection.  The result of the thesis argues that the linear technological development in libraries with less physical collections, librarian encounters, passive information gathering and random information paths without underlying commercial drivers create more like-mindedness instead of innovation. This significantly reducing the possibility of interdisciplinary discoveries. A technical development that at an alarming rate shifts information from being sought by people, to people being sought by information.  This is a two years master’s thesis in Library and Information Science.
42

Interactions between climate and land use which drive dynamics in treeline ecotone scrub in Scotland

Gilbert, Diana January 2011 (has links)
Treeline ecotone scrub, the suite of tall woody plant communities that bridge the boundary between tall forest and higher altitude open summit heaths, is a rare and little studied transition habitat in the UK. Individual species have recently attracted emergency measures to secure their future, but little is known about the current dynamics of the habitats. This thesis increases knowledge of treeline scrub dynamics, particularly in relation to young plants, and develops an understanding of the management required for future conservation. Climate and land use are the main drivers of treeline scrub dynamics, while land use policy will shape the future land use. This study focussed on three species: Betula nana, Salix myrsinites and Juniperus communis, as representatives of the main scrub communities. Firstly, the range of environmental conditions and the current land uses the species tolerate were surveyed for a large number of sites. This enabled the existing sites to be characterised to inform the selection of potential new sites for restoration. Secondly, experiments tested the response of young plants to the interaction between wind exposure and simulated browsing, and, separately, to over-wintering under snow. No evidence was found to suggest that declining snow cover will adversely affect the species, but while the response of the species to increasing exposure and browsing was complex heavy browsing is likely to limit expansion in the absence of specific management. Finally, a review of current land use policy identified that treeline ecotone scrub was included in existing implementation strategies. However, a survey of the understanding of and attitudes to these habitats by key individuals involved in creating, implementing and influencing policy demonstrated that restoration is unlikely to happen within the current structure, except through the interests of non-governmental organisations with a nature conservation focus.
43

Graphical and non-speech sound metaphors in email browsing : an empirical approach : a usability based study investigating the role of incorporating visual and non-speech sound metaphors to communicate email data and threads

Alharbi, Saad Talal January 2009 (has links)
This thesis investigates the effect of incorporating various information visualisation techniques and non-speech sounds (i.e. auditory icons and earcons) in email browsing. This empirical work consisted of three experimental phases. The first experimental phase aimed at finding out the most usable visualisation techniques for presenting email information. This experiment involved the development of two experimental email visualisation approaches which were called LinearVis and MatrixVis. These approaches visualised email messages based on a dateline together with various types of email information such as the time and the senders. The findings of this experiment were used as a basis for the development of a further email visualisation approach which was called LinearVis II. This novel approach presented email data based on multi-coordinated views. The usability of messages retrieval in this approach was investigated and compared to a typical email client in the second experimental phase. Users were required to retrieve email messages in the two experiments with the provided relevant information such as the subject, status and priority. The third experimental phase aimed at exploring the usability of retrieving email messages by using other type of email data, particularly email threads. This experiment investigated the synergic use of graphical representations with non-speech sounds (Multimodal Metaphors), graphical representations and textual display to present email threads and to communicate contextual information about email threads. The findings of this empirical study demonstrated that there is a high potential for using information visualisation techniques and non-speech sounds (i.e. auditory icons and earcons) to improve the usability of email message retrieval. Furthermore, the thesis concludes with a set of empirically derived guidelines for the use of information visualisation techniques and non-speech sound to improve email browsing.
44

Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra

Zamin, Tara 07 June 2013 (has links)
Arctic tundra vegetation communities are rapidly responding to climate warming with increases in aboveground biomass, particularly in deciduous shrubs. This increased shrub density has the potential to dramatically alter the functioning of tundra ecosystems through its effects on permafrost degradation and nutrient cycling, and to cause positive feedbacks to global climate change through its impacts on carbon balance and albedo. Experimental evidence indicates that tundra plant growth is most strongly limited by soil nutrient availability, which is projected to increase with warming. Therefore research to date into the mechanisms driving tundra 'shrub expansion' has taken a 'bottom-up' perspective, overlooking the potential role of herbivory in mediating plant-soil interactions. In this thesis, I integrate the impacts of climate warming and caribou browsing on tundra vegetation community structure, and specifically investigate if increases in soil fertility with warming might lead to changes in vegetation biomass and chemistry that could fundamentally alter herbivore-nutrient cycling feedbacks, shifting the role of caribou browsing from restricting shrub growth to facilitating it. Using experimental greenhouses, nutrient addition plots, and caribou exclosures at Daring Lake Research Station in the central Canadian low Arctic, I showed that warming increased soil nutrient availability and plant biomass, and that caribou browsing restricted tundra shrub growth under present conditions. Plant and soil nutrient pool responses to warming demonstrated that increased growing season temperatures enhanced tundra plant growth both by increasing soil nutrient availability and by inferred increases in the rate of photosynthesis, however that the former process was comparatively more limiting. Species- and plant part-specific changes in biomass and chemistry with warming and fertilization clearly indicated the rate and magnitude of change in soil fertility substantially alters plant community structure. Nonetheless, since plant nutrient concentrations decreased with warming and plant responses to browsing were independent of soil fertility, I did not find evidence for a shift from caribou decelerating to accelerating nutrient cycling with warming. Altogether this research indicates effective conservation and management of Rangifer populations is critical to understanding how climate change will affect tundra vegetation trajectories and ultimately tundra ecosystem carbon balances. / Thesis (Ph.D, Biology) -- Queen's University, 2013-06-07 15:13:21.698
45

Modeling Faceted Browsing with Category Theory for Reuse and Interoperability

Harris, Daniel R. 01 January 2017 (has links)
Faceted browsing (also called faceted search or faceted navigation) is an exploratory search model where facets assist in the interactive navigation of search results. Facets are attributes that have been assigned to describe resources being explored; a faceted taxonomy is a collection of facets provided by the interface and is often organized as sets, hierarchies, or graphs. Faceted browsing has become ubiquitous with modern digital libraries and online search engines, yet the process is still difficult to abstractly model in a manner that supports the development of interoperable and reusable interfaces. We propose category theory as a theoretical foundation for faceted browsing and demonstrate how the interactive process can be mathematically abstracted in order to support the development of reusable and interoperable faceted systems. Existing efforts in facet modeling are based upon set theory, formal concept analysis, and light-weight ontologies, but in many regards they are implementations of faceted browsing rather than a specification of the basic, underlying structures and interactions. We will demonstrate that category theory allows us to specify faceted objects and study the relationships and interactions within a faceted browsing system. Resulting implementations can then be constructed through a category-theoretic lens using these models, allowing abstract comparison and communication that naturally support interoperability and reuse. In this context, reuse and interoperability are at two levels: between discrete systems and within a single system. Our model works at both levels by leveraging category theory as a common language for representation and computation. We will establish facets and faceted taxonomies as categories and will demonstrate how the computational elements of category theory, including products, merges, pushouts, and pullbacks, extend the usefulness of our model. More specifically, we demonstrate that categorical constructions such as the pullback and pushout operations can help organize and reorganize facets; these operations in particular can produce faceted views containing relationships not found in the original source taxonomy. We show how our category-theoretic model of facets relates to database schemas and discuss how this relationship assists in implementing the abstractions presented. We give examples of interactive interfaces from the biomedical domain to help illustrate how our abstractions relate to real-world requirements while enabling systematic reuse and interoperability. We introduce DELVE (Document ExpLoration and Visualization Engine), our framework for developing interactive visualizations as modular Web-applications in order to assist researchers with exploratory literature search. We show how facets relate to and control visualizations; we give three examples of text visualizations that either contain or interact with facets. We show how each of these visualizations can be represented with our model and demonstrate how our model directly informs implementation. With our general framework for communicating consistently about facets at a high level of abstraction, we enable the construction of interoperable interfaces and enable the intelligent reuse of both existing and future efforts.
46

Att välja bok i biblioteksmiljön : En studie av hur bibliotekens exponering av litteratur påverkar biblioteksanvändarnas val / Choosing a book in the library environment : A study of how literature exposure in the library affects library users’ choice

Lidén, Rebecca January 2014 (has links)
The aim of this bachelor thesis is to describe in part the public library users’process when deciding which books to borrow. Focus is on the library users’experience of the process and how literature exposure can support them intheir choice of book. This study seeks to find out to what extent choices arespontaneously made at the library, which elements of exposure that the userfinds helpful in the process and which factors usually influence the user infinding new things to read.The data was gathered through 100 structured interviews with public libraryusers. To analyze the result a modified marketing research theory was used,providing a comprehensive view. The decision-making process can beunderstood as a combination of the orientation or attitude of the libraryuser, the behavior or tactics of the library user and the library environment.The results of the study show four examples of behavior patterns related tolibrary user orientations. The patterns are then linked to different aspects ofmediation of literature in the library environment. The study also presentsstatistics on spontaneous loans and divides these loans into three types. Byexamining the variety of library users’ behavior patterns and searchstrategies, this study contributes to further developing the literatureexposure of public library collections. / Program: Bibliotekarie
47

Vad styr älgars betesmönster? : Hur älgbetesskador på tall påverkas av tallungskogars rumsliga fördelning och areal / Browsing damage by moose in relation to stand size and degree of stand isolation

Berglund, Mattias January 2019 (has links)
One of the largest challenges humanity faces today is reducing CO₂-emissions to mitigate climate change. Part of the solution might be to increase the use of wood products. To do this, the efficiency of forestry has to be improved. In Sweden, a large obstacle for improving the efficiency of forestry is moose, or rather the damages its browsing causes on Scots pine. The aim of this study was to investigate how stand size and stand isolation affects the intensity of moose browsing damage on Scots pine. In addition, effects from tree density, stand age, and interactions between the different factors were investigated. This was done by using data from forest companies and field data collected from 29 Scots pine stands in central Sweden. The data were analysed in a multiple regression analysis, selecting the model that best explained variation in browsing damage. Results show that browsing damage was lower in more isolated stands. Stand size, however, did not have an effect on browsing damage. The factors stand age and Scots pine density had positive effects on the amount of browsing damage, but effects from stand age decreased with increasing pine density. In total, 77% of the variance in browsing damage was explained by the best model. In order to decrease browsing damage on Scots pine, I suggest that land owners take coordinated action to avoid creating large areas of young pine stands within the same area.
48

Understanding mobile network quality and infrastructure with user-side measurements

Fida, Mah-Rukh January 2019 (has links)
Measurement collection is a primary step towards analyzing and optimizing performance of a telecommunication service. With an Mobile Broadband (MBB) network, the measurement process has not only to track the network's Quality of Service (QoS) features but also to asses a user's perspective about its service performance. The later requirement leads to "user-side measurements" which assist in discovery of performance issues that makes a user of a service unsatisfied and finally switch to another network. User-side measurements also serve as first-hand survey of the problem domain. In this thesis, we exhibit the potential in the measurements collected at network edge by considering two well-known approaches namely crowdsourced and distributed testbed-based measurements. Primary focus is on exploiting crowdsourced measurements while dealing with the challenges associated with it. These challenges consist of differences in sampling densities at different parts of the region, skewed and non-uniform measurement layouts, inaccuracy in sampling locations, differences in RSS readings due to device-diversity and other non-ideal measurement sampling characteristics. In presence of heterogeneous characteristics of the user-side measurements we propose how to accurately detect mobile coverage holes, to devise sample selection process so to generate a reliable radio map with reduced sample cost, and to identify cellular infrastructure at places where the information is not public. Finally, the thesis unveils potential of a distributed measurement test-bed in retrieving performance features from domains including user's context, service content and network features, and understanding impact from these features upon the MBB service at the application layer. By taking web-browsing as a case study, it further presents an objective web-browsing Quality of Experience (QoE) model.
49

Control and Evaluation of Big Game Browsing Damage to Commercial Fruit Orchards

Stone, William E. 01 May 1988 (has links)
Diversionary feeding, artificial feeding designed to divert animals away from areas where they might cause property damage, was tested for efficacy in reducing fruit orchard browsing by big game animals during two consecutive winters in Utah. Strategically placed attractive feedstuffs lured deer to feed stations and reduced fruit-bud browsing (1st year, P< 0.07; 2nd year, P < 0.01). Blossom and apple numbers were greater (P < O. 05) on trees in the feed (treatment) orchard than in the no feed (control) orchard in each year. However, higher (P < 0.05) apple production on trees where browsing was excluded in the treatment orchards compared to the control orchards indicated that intercept feeding did not increase crop production. Tree periodicity and other factors affecting apple production masked the effect of diversionary feeding on crop yield. Two independent browsing damage assessment methods, a paired-tree technique and a harvest-inflation technique, predicted that the ratio of apples lost per browsed bud was 0.158 and 0.082, respectively. However, the values of the ratio varied widely with each method of estimation. Browsing damage differed (P < o. 001) according to branch position (below 1 m and distal, above 1 m and distal, and above 1 m and proximal to the tree trunk). A less intensive count of buds and browsed buds reliably predicted average browsing damage in the orchard (determined by counting all browsing zone buds on 5% of the orchard trees), when these branch classes were used. An economic analysis of this feeding program indicated that, at current prices, the value of the increased crop in the study orchards did warrant the cost of feeding associated with them (benefit/cost= 9.20 and 32.89). Deer-proof fencing, although expensive to install, is a more cost-efficient (benefit/cost= 129.28 and 121.11) method of preventing browsing damage in the orchards I studied.
50

Encroachment of sandplain heathland (kwongan) by Allocasuarina huegeliana in the Western Australian wheatbelt: the role of herbivores, fire and other factors

k.maher@murdoch.edu.au, Kellie Maher January 2008 (has links)
Kwongan, also known as sandplain heathland, occurs in remnant vegetation throughout the fragmented landscape of the Western Australian wheatbelt. This vegetation community has high levels of species richness and endemism, and is of high conservation value. In many vegetation remnants in the wheatbelt the native tree species Allocasuarina huegeliana (rock sheoak) is expanding out from its normal range and encroaching into kwongan. A. huegeliana may ultimately dominate the kwongan, causing a decline in floristic diversity. Altered disturbance regimes, particularly the absence of fire and reduced or absent browsing mammal herbivores, are likely to be responsible for causing A. huegeliana encroachment. This study used experimental and observational data from patches of kwongan in three Nature Reserves in the central and southern wheatbelt to investigate the role of fire, native mammal activities and interactions between these two factors in shaping A. huegeliana woodland–kwongan community boundaries. Investigations were carried out into the characteristics of encroaching A. huegeliana populations; the environmental factors affecting the extent of encroachment, naturally recruited juveniles, and seedling emergence and establishment; historical and current abundances of native mammals; and the effects of mammal herbivores on seedling establishment during inter-fire and post-fire periods. Results from this study confirm that A. huegeliana has encroached into kwongan throughout the wheatbelt region and recruitment appears likely to continue in most areas. Few of the environmental factors measured in this study affected the extent of encroachment, the locations of naturally recruited A. huegeliana juveniles, and seedling germination and establishment. Western grey kangaroos (Macropus fuliginosus) browsed extensively on seedlings, which largely prevented them from establishing in open areas of kwongan. However, numerous A. huegeliana seedlings escaped browsing herbivores by establishing in perennial shrubs, where they appeared to be tolerant of increased levels of inter-specific competition. There was no native mammal common to all three Reserves that declined around the time that A. huegeliana encroachment most likely began in the 1970s. In addition, tammar wallabies (Macropus eugenii) had little effect even where their densities were high. It is therefore unlikely that the decline of an individual mammal species initiated encroachment. A. huegeliana encroachment appears to be driven by increased propagule pressure, which is in turn caused by increased inter-fire intervals. Long periods of time without fire have enabled fire-sensitive A. huegeliana trees to produce increasing quantities of seed that are continuously released into kwongan. A range of other factors may interact synergistically with this process to affect encroachment and these are also discussed. This study considered the implications of these findings for management of remnant vegetation in fragmented landscapes, particularly kwongan in the Western Australian wheatbelt, and areas for further research are suggested.

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