111 research outputs found

    Cognitive mapping of public space: Causal assumptions and core values among Nordic city planners

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    This paper is an attempt to show how planning logics, or worldviews with physical and theoretical components found locally in city planning, can be modelled through the creation of ‘cognitive maps’ depicting planners’ core values and causal assumptions as regards public space. Applying cognitive mapping (cf. Eden & Ackerman, 1998) as an approach to explicate the cognitive models at work in planning may have at least two benefits: Firstly, it may be of academic interest to explicate planners’ tacit theories of any subject, particularly since this partly implicit knowledge is itself derived from reading, observing and experimenting in the field. To paraphrase Kaplan’s original adage: there is no better source of theory than good practice. Secondly, one may argue that it is good planning practice to explicate the hidden assumptions behind one’s planning imperatives, so that these can be confronted with existing knowledge, tested and if necessary, revised. This paper will provide an inroad into this methodology from the point of view of public space planning. First, it will briefly and very selectively discuss a number of planning models for city spaces, mainly in order to provide exemplification. Second, cognitive mapping will be presented and put in a broader methodological and intellectual context. After this the empirical material will be presented, including the cognitive maps of public space derived from the planning documents of four Nordic cities. Finally, the issue of how cognitive maps reveal both a theoretical consistency across planning contexts as well as a number of internal contradictions, of academic as well as of practical interest, will be raised

    Autonomous Forest Vehicles: Historic, envisioned, and state-of-the-art

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    The feasibility of using autonomous forest vehicles (which can be regarded as logical developments in the ongoing automation of forest machines), the systems that could be applied in them, their potential advantages and limitations (in the foreseeable future) are considered in this paper. The goals were to analyze: 1) the factors influencing the degree of automation in logging; 2) the technical principles that can be applied to autonomous forest machines, and 3) the feasibility of developing an autonomous path-tracking forest vehicle. A type of vehicle that is believed to have considerable commercial potential is an autonomous forwarder. The degree of automation is influenced by increased productivity, the machine operator as a bottle-neck, cost reduction, and environmental aspects. Technical principles that can be applied to autonomous forest vehicles are satellite navigation, wheel odometry, laser scanner, and radar. A new path-tracking algorithm has been developed to reduce deviations from the desired path by utilizing the driver’s steering commands. The presented system has demonstrated both possibilities and difficulties associated with autonomous forest machines. A field study has shown that it is quite possible for them to learn and track a path previously demonstrated by an operator with an accuracy of 0.1 m on flat ground and also to detect and avoid unexpected obstacles. Although the forest machine safely avoids obstacles, the study shows that further research in the field of obstacle avoidance is needed to optimize performance and ensure safe operation in a real forest environment

    A Focus Group Study

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    This paper argues that knowledge mapping may provide a fruitful avenue for intellectual capital management in academic environments such as university departments. However, while some research has been conducted on knowledge mapping and intellectual capital management in the public sector, the university has so far not been directly considered for this type of management. The paper initially reviews the functions and techniques of knowledge mapping and assesses these in the light of academic demands. Secondly, the result of a focus group study is presented, where academic leaders were asked to reflect of the uses of knowledge mapping at their departments and institutes. Finally a number of suggestions are made as to the rationale and conduct of knowledge mapping in academe. Keywords: Knowledge mapping, academic, intellectual capital management, focus group, research managemen

    A Method to Measure Saw-Chain Lubrication

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    A saw-bar with a saw-chain is a common tool in both mechanized and motor-manual harvesting operations. The friction between the saw-bar and the saw-chain must be reduced by lubrication. A precise oil flow control can reduce the amount of oil needed. Traditionally, mineral oils have been used, but the use of biodegradable vegetable-based oils has increased. The goal of this study was to evaluate the lubrication characteristics at different oil flows of two vegetable-based and one mineral-based saw-chain oil. The study was done on an experimental rig with a saw-chain speed of 23 m/s and with pressure between the saw-chain and a rotating rubber roller. The temperature of the saw-bar was used as an indicator of the lubrication efficiency. The saw-chain tension was constant and independent of temperature. In general, increased oil flow resulted in a lower temperature. For rapeseed oil and pine oils, the results were consistently significant between oil flows of 2 and 6 ml/min. At an oil flow of 2 ml/min and 5 minute test time, pine oil resulted in the highest temperature (121°C, standard deviation [SD] 6.4) and at 6 ml/min the lowest temperature (99°C, SD 1.1) compared with the other oils. No difference in temperature was found between mineral oil and rapeseed oils at oil flows of 2 or 6 ml/min. An oil flow of 2 ml/min was found to be enough to prevent high temperatures for all oil types. The study method, with an adjustable experimental rig as the tool, was found to be suitable for studies on lubrication of the saw-bar and saw-chain

    Environmental DNA metabarcoding elucidates patterns of fish colonisation and co-occurrences with amphibians in temperate wetlands created for biodiversity

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    Wetlands are biodiversity hotspots that provide several essential ecosystem services. On a global scale, wetlands have greatly declined due to human activities. To counteract wetland loss, created wetlands are used as a conservation tool to facilitate biodiversity and provide habitats mainly for birds and amphibians. Fishes are likely to colonise the created wetlands and potentially affect the diversity and occurrence of amphibians. Still, species occurrence data for fish in created wetlands are largely lacking. Using eDNA metabarcoding, we investigated occurrence and co-occurrence patterns of fish and amphibian communities in 52 wetlands (some of which are ponds) created to benefit mainly bird and amphibian communities in south-central Sweden. Altogether, 17 fish and five amphibian species were detected in the created wetlands out of the 32 fish and six amphibian species found in the regional species pool. Amphibians were less common in wetlands physically connected to other wetlands. Connected wetlands were more fish-rich than isolated ones, suggesting potential fish avoidance. Additionally, the amphibian community occupied a narrower environmental niche compared to the fish community. Nevertheless, we observed only five statistically significant negative fish-amphibian species co-occurrences (out of 14 species considered). Even though our results suggest amphibian avoidance/exclusion from the created biodiversity wetlands, they also show that fish and amphibians frequently co-exist. Increased habitat heterogeneity in terms of water vegetation, size, shape, and structure of the wetland could be possible factors enabling the co-existence of these two taxa. With this study, we contribute to the general knowledge of fish occurrence patterns in created biodiversity wetlands. By comparing the frequencies of fish occurrence in natural and created wetlands, we have shown that there was some mismatch in what is common in natural compared to created wetlands. This mismatch probably comes from species-specific habitat requirements, stocking, and differences in detectability when using eDNA metabarcoding (small species detected) versus conventional multi-mesh gill-net methods (small species missed). Therefore, our results obtained using eDNA metabarcoding can complement the pre-existing knowledge of amphibian and fish associations and increase our understanding of how to create wetlands to facilitate biodiversity of several taxa

    Frontiers in quantifying wildlife behavioural responses to chemical pollution

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    Animal behaviour is remarkably sensitive to disruption by chemical pollution, with widespread implications for ecological and evolutionary processes in contaminated wildlife populations. However, conventional approaches applied to study the impacts of chemical pollutants on wildlife behaviour seldom address the complexity of natural environments in which contamination occurs. The aim of this review is to guide the rapidly developing field of behavioural ecotoxicology towards increased environmental realism, ecological complexity, and mechanistic understanding. We identify research areas in ecology that to date have been largely overlooked within behavioural ecotoxicology but which promise to yield valuable insights, including within- and among-individual variation, social networks and collective behaviour, and multi-stressor interactions. Further, we feature methodological and technological innovations that enable the collection of data on pollutant-induced behavioural changes at an unprecedented resolution and scale in the laboratory and the field. In an era of rapid environmental change, there is an urgent need to advance our understanding of the real-world impacts of chemical pollution on wildlife behaviour. This review therefore provides a roadmap of the major outstanding questions in behavioural ecotoxicology and highlights the need for increased cross-talk with other disciplines in order to find the answers
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