388 research outputs found

    Measuring Kruger visitors’ place attachment to specific camps

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    Tourists become emotionally, physically and socially attached to national parks as they become familiar with the park’s settings and endow it with value. Researchers have pointed out that place attachment leads to environmentally responsible behaviour and higher levels of visitor satisfaction. Therefore, increasing the level of attachment that visitors feel is vital for park and camp managers, and to do so a greater understanding of the various dimensions of it is needed. While attachment to parks has been evaluated previously, attachment to specific camps in parks has not been done. The main purpose of this research study was to measure the extent to which visitors to the Tamboti and Satara camps in the Kruger National Park feel attached to these camps. We also determined whether differences exist between visitors in terms of the level of attachment that they experience towards these camps. Finally, we established the variables that influence place attachment. A self-administered paper-based questionnaire was distributed to visitors to the Tamboti and Satara camps, with 201 questionnaires completed. The results show that visitors generally have a neutral feeling towards the camps. Furthermore, the differences in visitors’ levels of attachment could be attributed to their nationality, wild card membership and frequency of visits. Various managerial implications are drawn and recommendations made on how to increase place attachment to these camps. Conservation implications: This results indicate that visitors do not show particularly strong attachment towards Tamboti and Satara. Recommendations are given for camp managers to increase place attachment to the camps. If camp managers can succeed in fostering stronger levels of attachment to these camps, visitors are more likely to display environmentally responsible behaviour in the camps, with positive conservation implications

    Forecasting the probability of commercial wind power development in lagging countries

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    There is significant under-utilization of wind energy resources, particularly in countries that have high wind potential. From the 67 highest wind potential countries, 39 have installed less than 500 ​MW of wind power capacity, while the remaining countries have an average installed capacity of 20,596 ​MW. In the lagging countries, there is significant potential for sustainable value creation, however large investment gaps need to be closed. Entering a new market for wind power Original Equipment Manufacturers is complex and requires a prediction of the future market size. Quantitative research to promote wind power internationalization is scarce. The objective of this paper is therefore to estimate the market size by predicting the probability of commercial wind development in the lagging countries. The purpose is to help the Original Equipment Manufacturers in their market entry decisions. The second purpose is to provide an example how to reduce risk required to close the Sustainable Development Goals financing gap. Using a binary logistic regression model based on technological path creation theory, the probability for the 39 lagging countries to enter the wind power commercialization stage was predicted. Results show that 12 of the lagging countries have a high probability to commercialize wind energy. A new simulation-based approach was presented to stimulate wind power market entry. The prediction of adoption probability proves useful to reduce risk required to close the financing gap to achieve the Sustainable Development Goals

    Photometric Redshift Calibration with Self Organising Maps

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    Accurate photometric redshift calibration is central to the robustness of all cosmology constraints from cosmic shear surveys. Analyses of the KiDS re-weighted training samples from all overlapping spectroscopic surveys to provide a direct redshift calibration. Using self-organising maps (SOMs) we demonstrate that this spectroscopic compilation is sufficiently complete for KiDS, representing 99%99\% of the effective 2D cosmic shear sample. We use the SOM to define a 100%100\% represented `gold' cosmic shear sample, per tomographic bin. Using mock simulations of KiDS and the spectroscopic training set, we estimate the uncertainty on the SOM redshift calibration, and find that photometric noise, sample variance, and spectroscopic selection effects (including redshift and magnitude incompleteness) induce a combined maximal scatter on the bias of the redshift distribution reconstruction (Δ⟨z⟩=⟨z⟩est−⟨z⟩true\Delta \langle z \rangle=\langle z \rangle_{\rm est}-\langle z \rangle_{\rm true}) of σΔ⟨z⟩≤0.006\sigma_{\Delta \langle z \rangle} \leq 0.006 in all tomographic bins. We show that the SOM calibration is unbiased in the cases of noiseless photometry and perfectly representative spectroscopic datasets, as expected from theory. The inclusion of both photometric noise and spectroscopic selection effects in our mock data introduces a maximal bias of Δ⟨z⟩=0.013±0.006\Delta \langle z \rangle =0.013\pm0.006, or Δ⟨z⟩≤0.025\Delta \langle z \rangle \leq 0.025 at 97.5%97.5\% confidence, once quality flags have been applied to the SOM. The method presented here represents a significant improvement over the previously adopted direct redshift calibration implementation for KiDS, owing to its diagnostic and quality assurance capabilities. The implementation of this method in future cosmic shear studies will allow better diagnosis, examination, and mitigation of systematic biases in photometric redshift calibration.Comment: 22 pages, 10 figures, 4 appendices, accepted for publication in A&

    Understanding visitor expectations for responsible tourism in an iconic national park: Differences between local and international visitors

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    A survey on expectations for responsible tourism was administered to 201 visitors to the iconic Kruger National Park, comprising 55% South African nationals and 45% international tourists. Using Likert-scale questions, respondents were invited to indicate the level of importance they attached to 38 aspects of responsible tourism. Space was also provided for open comments. Conservation of biodiversity and geological features were rated very highly by both groups while aspects related to the local community, though considered important overall, were ranked lowest overall, with international tourists rating this category as more important than South Africans. Aspects related to traffic and access were rated to be more important by South Africans, probably because they mostly self-drive while international visitors rely more on organised game drives. Visual and aesthetic features of camps, as well as energy, water and waste management were all considered very important by all respondents, with members of both groups making further suggestions for improvement. This suggests that visitors are supportive of low environmental impact tourism in the Kruger National Park. In light of the strategic goal of South African National Parks to increase visitor numbers, it will be important that this goal is achieved without compromising sound environmental performance

    A resource efficient approach for quantum and classical simulations of gauge theories in particle physics

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    Gauge theories establish the standard model of particle physics, and lattice gauge theory (LGT) calculations employing Markov Chain Monte Carlo (MCMC) methods have been pivotal in our understanding of fundamental interactions. The present limitations of MCMC techniques may be overcome by Hamiltonian-based simulations on classical or quantum devices, which further provide the potential to address questions that lay beyond the capabilities of the current approaches. However, for continuous gauge groups, Hamiltonian-based formulations involve infinite-dimensional gauge degrees of freedom that can solely be handled by truncation. Current truncation schemes require dramatically increasing computational resources at small values of the bare couplings, where magnetic field effects become important. Such limitation precludes one from `taking the continuous limit' while working with finite resources. To overcome this limitation, we provide a resource-efficient protocol to simulate LGTs with continuous gauge groups in the Hamiltonian formulation. Our new method allows for calculations at arbitrary values of the bare coupling and lattice spacing. The approach consists of the combination of a Hilbert space truncation with a regularization of the gauge group, which permits an efficient description of the magnetically-dominated regime. We focus here on Abelian gauge theories and use 2+12+1 dimensional quantum electrodynamics as a benchmark example to demonstrate this efficient framework to achieve the continuum limit in LGTs. This possibility is a key requirement to make quantitative predictions at the field theory level and offers the long-term perspective to utilise quantum simulations to compute physically meaningful quantities in regimes that are precluded to quantum Monte Carlo.Comment: 25 pages, 9 figures, journal versio

    KiDS+VIKING-450:Improved cosmological parameter constraints from redshift calibration with self-organising maps

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    We present updated cosmological constraints for the KiDS+VIKING-450 cosmic shear data set (KV450), estimated using redshift distributions and photometric samples defined using self-organising maps (SOMs). Our fiducial analysis finds marginal posterior constraints of S8≡σ8Ωm/0.3=0.716−0.038+0.043S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}=0.716^{+0.043}_{-0.038}; smaller than, but otherwise consistent with, previous work using this data set (∣ΔS8∣=0.023|\Delta S_8| = 0.023). We analyse additional samples and redshift distributions constructed in three ways: excluding certain spectroscopic surveys during redshift calibration, excluding lower-confidence spectroscopic redshifts in redshift calibration, and considering only photometric sources which are jointly calibrated by at least three spectroscopic surveys. In all cases, the method utilised here proves robust: we find a maximal deviation from our fiducial analysis of ∣ΔS8∣≤0.011|\Delta S_8| \leq 0.011 for all samples defined and analysed using our SOM. To demonstrate the reduction in systematic biases found within our analysis, we highlight our results when performing redshift calibration without the DEEP2 spectroscopic data set. In this case we find marginal posterior constraints of S8=0.707−0.042+0.046S_8=0.707_{-0.042}^{+0.046}; a difference with respect to the fiducial that is both significantly smaller than, and in the opposite direction to, the equivalent shift from previous work. These results suggest that our improved cosmological parameter estimates are insensitive to pathological misrepresentation of photometric sources by the spectroscopy used for direct redshift calibration, and therefore that this systematic effect cannot be responsible for the observed difference between S8S_8 estimates made with KV450 and Planck CMB probes.Comment: 10 pages, 3 figures, 4 appendices, accepted for publication in A&A Letter

    Local-Oscillator Noise Coupling in Balanced Homodyne Readout for Advanced Gravitational Wave Detectors

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    The second generation of interferometric gravitational wave detectors are quickly approaching their design sensitivity. For the first time these detectors will become limited by quantum back-action noise. Several back-action evasion techniques have been proposed to further increase the detector sensitivity. Since most proposals rely on a flexible readout of the full amplitude- and phase-quadrature space of the output light field, balanced homodyne detection is generally expected to replace the currently used DC readout. Up to now, little investigation has been undertaken into how balanced homodyne detection can be successfully transferred from its ubiquitous application in table-top quantum optics experiments to large-scale interferometers with suspended optics. Here we derive implementation requirements with respect to local oscillator noise couplings and highlight potential issues with the example of the Glasgow Sagnac Speed Meter experiment, as well as for a future upgrade to the Advanced LIGO detectors.Comment: 7 pages, 5 figure

    Popular Conceptions of Nationhood in Old and New European Member States: Partial Support for the Ethnic-Civic Framework

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    One of the most influential theories in the study of nationalism has been the ethnic-East/civic-West framework developed by Hans Kohn. Using the 2002 Eurobarometer survey on national identity and building on earlier survey studies, this article examines whether the Kohn framework is valid at the level of popular understandings of nationhood. It scrutinizes the framework both conceptually - do people define nationhood in civic or ethnic terms? - and regionally - is the East indeed more ethnic than the West and the West more civic than the East? It will show that identity markers cluster in a political, a cultural and an ethnic dimension. Respondents do not see these dimensions as competing sources of nationhood, however. The article further lends some support for the regional component of the framework. Lastly, it argues that it is the intensity of national identifications rather than their qualitative nature (ethnic-civic) that correlates with xenophobia. © 2006 Taylor & Francis

    Effects of static and dynamic higher-order optical modes in balanced homodyne readout for future gravitational waves detectors

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    With the recent detection of Gravitational waves (GW), marking the start of the new field of GW astronomy, the push for building more sensitive laser-interferometric gravitational wave detectors (GWD) has never been stronger. Balanced homodyne detection (BHD) allows for a quantum noise (QN) limited readout of arbitrary light field quadratures, and has therefore been suggested as a vital building block for upgrades to Advanced LIGO and third generation observatories. In terms of the practical implementation of BHD, we develop a full framework for analyzing the static optical high order modes (HOMs) occurring in the BHD paths related to the misalignment or mode matching at the input and output ports of the laser interferometer. We find the effects of HOMs on the quantum noise limited sensitivity is independent of the actual interferometer configuration, e.g. Michelson and Sagnac interferometers are effected in the same way. We show that misalignment of the output ports of the interferometer (output misalignment) only effects the high frequency part of the quantum noise limited sensitivity (detection noise). However, at low frequencies, HOMs reduce the interferometer response and the radiation pressure noise (back action noise) by the same amount and hence the quantum noise limited sensitivity is not negatively effected in that frequency range. We show that the misalignment of laser into the interferometer (input misalignment) produces the same effect as output misalignment and additionally decreases the power inside the interferometer. We also analyze dynamic HOM effects, such as beam jitter created by the suspended mirrors of the BHD. Our analyses can be directly applied to any BHD implementation in a future GWD. Moreover, we apply our analytical techniques to the example of the speed meter proof of concept experiment under construction in Glasgow. We find that for our experimental parameters, the performance of our seismic isolation system in the BHD paths is compatible with the design sensitivity of the experiment
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