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Headphones are commonly used in various environments including at home, outside and on public transport. However, the perception and modelling of the interaction of headphone audio and noisy environments is relatively unresearched. This work investigates the headphone listening experience in noisy environments using the perceptual attributes of distraction and quality of listening experience. A virtual sound environment was created to simulate real-world headphone listening, with variations in foreground sounds, background contexts and busyness, headphone media content and simulated active noise control. Listening tests were performed, where 15 listeners rated both distraction and quality of listening experience across 144 stimuli using a multiple-stimulus presentation. Listener scores were analysed and compared to a computational model of listener distraction. The distraction model was found to be a good predictor of the perceptual distraction rating, with a correlation of 0.888 and an RMSE of 13.4%, despite being developed to predict distraction in the context of audio-on-audio interference in sound zones. In addition, perceived distraction and quality of listening experience had a strong negative correlation of − 0.953. Furthermore, the busyness and type of the environment, headphone media, loudness of the foreground sound and active noise control on/off were significant factors in determining the distraction and quality of listening experience scores.

Using spatially distributed loudspeakers and properly designed control filters, it is possible to generate sound zones that play dif- ferent audio contents in different regions of the same room. For low frequency content, the design of control filters relies on the room impulse responses (RIRs) between each loudspeaker and the desired listening positions. Estimates of the RIRs can be obtained by distributing wireless microphones within the sound zones and thereby systematically acquiring sufficient knowledge about the acoustical characteristics of the room and loudspeakers. Longer ac- quisition times would generally lead to better estimates of the RIRs but would also introduce processing delays, which is undesirable in cases where time-varying RIRs are to be compensated. In addition, shorter RIRs may imply lower computational complexity.In this work, control filters were calculated using truncated ver- sions of the RIRs in order to simulate the effect of a reduced acquisi- tion time. The performance was evaluated in terms of the acoustic contrast ratio (ACR) and it was seen that within a certain limit, doubling the acquisition time increases the ACR around 4 dB or more. Moreover, to keep the sound pressure low in the dark zone, only a limited part of the reverberation tail is required.

Understanding the concept of immersion and its influencing factors is critical for enabling engaging audiovisual experiences. However, a lack of definitional consensus and suitable methods for assessing immersion hinder research on the subject. This chapter discusses the idea of immersion based on a non-exhaustive literature review of the topic and presents an adaptable definition of immersion that is not limited to virtual reality applications. Additionally, an exploratory experimental paradigm for measuring immersion in audiovisual experiences is described. The description of immersion and the experimental framework presented in this chapter are a starting point for resolving the difference in opinion and developing novel methods to thoroughly explore the concept of immersion respectively.

This report introduces a new database of room impulse responses (RIRs) measured in an empty rectangular room using subwoofers as sound sources. The purpose of this database, publicly available for download, is to provide acoustic measurements within the frequency region of modal resonances. Performing acoustic measurements at low frequencies presents many difficulties, mainly related to ambient noise and to unavoidable nonlinearities of the subwoofer. In this report, it is shown that these issues can be addressed and partially solved by means of the exponential sine-sweep technique and a careful calibration of the measurement equipment. A procedure for estimating the reverberation time at very low frequencies is proposed, which uses a cosine-modulated filterbank and an approximation of the RIRs using parametric models in order to reduce problems related to low signal-to-noise ratio and to the length of typical band-pass filter responses.

Many of the semi-natural landscape elements found in rural areas, such as woodlots, hedgerows and grasslands, were originally maintained as part of the agricultural system. During the 20th century, they lost most of their functions and were often removed or transformed. Presently, production concerns are less dominant and many landscape and land use changes are undertaken to improve public goods or fulfil personal and family ambitions and values. This paper investigates the patterns of farm-level land use changes that occurred between 2002 and 2012 in three different landscape regions of Europe (peri-urban landscapes, areas with marginal potential for agriculture, post-socialist landscapes) and the drivers behind, based on a questionnaire survey in six study areas. A second objective is to analyse landowners’ decision-making and endogenous factors that are correlated with their engagement in land use changes. Common to all areas is that agricultural production is under pressure due to physical or socio-economic challenges. The results indicate that relatively more nature or landscape features have been added by landowners than removed by them in the six study areas. Furthermore, the analysis revealed that full-time landowners were responsible for the largest proportion of landscape change and that the areas involved differed greatly. The analysis also underlined the variety of European landscapes, as many landscape activities exhibited strong geographical patterns. A multivariate analysis of the relationship between ten farm and landowner characteristics confirmed the geographical diversity, as only a dummy variable representing the geographical location was statistically significant. When location was omitted from the analysis, two factors were significant: farm size and ownership of livestock. In addition, the results suggest that landowners in peri-urban locations were more engaged in landscape activities than landowners in other locations.

The perceptual differences between the sound reproductions of headphones were investigated in a pair-wise comparison study. Two musical excerpts were reproduced over 21 headphones positioned on a mannequin and recorded. The recordings were then processed and reproduced over one set of headphones to listeners, who were asked to evaluate their perceived degree of dissimilarity. The two musical excerpts were used in separate experiments. The processing of the recordings consisted of compensating for the influences of the playback headphones worn by the listeners as well as for the mannequin's ear canals. A multidimensional scaling analysis revealed two dominating perceptual dimensions used by the listeners to differentiate the reproductions of the headphones. These dimensions were similar for the two musical excerpts. Objective metrics are proposed to describe them, leading to correlations ranging from 0.89 to 0.97 between the dimensions and metrics. The first perceptual dimension was associated with the relative strength of bass, while the second dimension was related to the relative strength of the lower midrange.

Agricultural land use has a large impact on landscape diversity and the types and quality of the services landscapes provide to society. This editorial introduces four papers in a themed section of Land Use Policy which examines different themes related to agriculture and landscape interaction. The papers present new findings from research undertaken within the scope of the VOLANTE research project ( Kristensen et al., 2013 ). The main objective of the research was to increase our knowledge about landowners’ decision-making processes and drivers of land use change in rural Europe.

This paper investigates the personal and property characteristics of landowners who use EU Rural Development agri-environmental schemes (AES), as well as their motives for participation or non-participation in such schemes. The study is based on a questionnaire survey with landowners, in selected study areas in the Netherlands, Denmark, Austria, Italy and Greece. Our principal findings show that AES tend to attract more the owners of larger farms, who are frequently full-time, younger, post-primary school educated and agriculturally-trained farmers. The latter findings are contingent on local geographical particularities and on subjective factors, farmers' individualities, different rural cultures, landscape types, EU and national policies and special needs of the study areas—all areas where agricultural production is increasingly marginalized, for different reasons. Subsidy scheme participation motives did not seem to be strictly economic; they also regarded personal satisfaction. They are all together generally appeared to be place specific, since the respondents from peri-urban Northern European areas were more motivated to participate in AES than respondents from Central and Southern European areas with marginal potential for agriculture. Motives for non-participation were also found to be dependent on the level of farming engagement and on case-area landscape types.

We utilize the close link between Cohen’s d , the effect size in an ANOVA framework, and the Thurstonian (Signal detection) d -prime to suggest better visualizations and interpretations of standard sensory and consumer data mixed model ANOVA results. The basic and straightforward idea is to interpret effects relative to the residual error and to choose the proper effect size measure. For multi-attribute bar plots of F -statistics this amounts, in balanced settings, to a simple transformation of the bar heights to get them transformed into depicting what can be seen as approximately the average pairwise d -primes between products. For extensions of such multi-attribute bar plots into more complex models, similar transformations are suggested and become more important as the transformation depends on the number of observations within factor levels, and hence makes bar heights better comparable for factors with differences in number of levels. For mixed models, where in general the relevant error terms for the fixed effects are not the pure residual error, it is suggested to base the d -prime-like interpretation on the residual error. The methods are illustrated on a multifactorial sensory profile data set and compared to actual d -prime calculations based on Thurstonian regression modeling through the ordinal package. For more challenging cases we offer a generic “plug-in” implementation of a version of the method as part of the R -package SensMixed . We discuss and clarify the bias mechanisms inherently challenging effect size measure estimates in ANOVA settings.

Vocal clarity is one of the most important quality parameters of music mixes. The clarity of isolated sounds depends heavily on spectral factors and can therefore be manipulated with EQ. Spectrum is also an important factor in determining vocal timbral and quality parameters. An experiment where listeners rate the spectral clarity of equalized vocals within a noise backing track can provide insight into spectral predictors of vocal clarity. Overall, higher frequencies contribute to vocal clarity more positively than lower ones, but the relationship is program-item-dependent. Changes in harmonic centroid (or dimensionless spectral centroid) correlate well with changes in clarity and so does the vocal-to-backing track ratio.

This work concentrates on validating a real-time perceptual model predicting distraction caused by audio-on-audio interference. The real-time model was recently developed on the basis of another successfully validated, perceptual distraction model, which is not able to calculate predictions in real time. Both models are non-blind, i.e., their inputs take target and interferer signals separately. This paper describes a validation experiment for the real-time distraction model, which compares the model's predictions to subjective distraction ratings obtained from a listening experiment. The accuracy of the real-time model is also compared to that of the original distraction model. The calculated root-mean-squared errors for a speech zone and a music zone were 10.2% and 12.6% for the real-time model, respectively, compared to 11.3% and 11.5% for the original model. The results indicate that the real-time model is able to predict the distraction with similar accuracy as the original model, and thus, is a suitable tool for sound-zone evaluation. Furthermore, the real-time capability of the model is considered to be vital for certain applications, including the evaluation of adaptive sound zones.

This research proposes a spatial sound analysis and synthesis approach for automobile sound systems, where the acquisition of the measurement data is much faster than with the Binaural Car Scanning method. This approach avoids the problems that are typically found with binaural reproduction and dummy head measurements. In combination with a compact microphone array, the approach is based on the recently introduced parametric spatial sound analysis method, called the Spatial Decomposition Method (SDM). An objective analysis of the sound field with respect to direction and energy enables the synthesis of multichannel loudspeaker reproduction. Because of the extreme acoustics of an automobile cabin, the authors recommend several steps to improve both the objective and perceptual performance. Because SDM is a parametric approach to spatial impulse response analysis, this allows automobile audio systems to be tuned in a laboratory environment instead of in-situ.

The QESTRAL (Quality Evaluation of Spatial Transmission and Reproduction using an Artificial Listener) system is intended to be an artificial-listener-based evaluation system capable of predicting the perceived spatial quality degradations resulting from SAPs (Spatial Audio Processes) commonly encountered in consumer audio reproduction. A generalizable model employing just five metrics and two principal components performs well in its prediction of the quality over a range of program types. Commonly-encountered SAPs can have a large deleterious effect on several spatial attributes including source location, envelopment, coverage angle, ensemble width, and spaciousness. They can also impact timbre, and changes to timbre can then influence spatial perception. Previously obtained data was used to build a regression model of perceived spatial audio quality in terms of spatial and timbral metrics. In conjunction with two simple probe signals, the resulting model can form the core of an evaluation system.

The demand for biofuels has been rising, which has led developing countries to focus on production of feedstocks for biodiesel and bioethanol production. This has caused concerns for the impacts on food security, food prices and environmental sustainability. This paper examines a hypothetical case of cassava-based bioethanol production in southern Mali, assessing its environmental, economic and social sustainability. Results demonstrate that environmental sustainability of cassava-based bioethanol production depends on the ‘baseline’ chosen: Compared to the situation before the decline in cotton production 10 years ago, the carbon stocks will increase. However, if compared to the current situation, where considerable carbon stocks have accumulated in fallow fields, the loss of carbon will be substantial. Increased cassava production will create greater incomes and better temporal distribution of labour input. Analysis of the significance of current cassava production for food security shows that bioethano...

An experiment was conducted to determine the perceptual effects of car cabin acoustics on the reproduced sound field. In-car measurements were conducted whilst the cabin's interior was physically modified. The captured sound fields were recreated in the laboratory using a three-dimensional loudspeaker array. A panel of expert assessors followed a rapid sensory analysis protocol, the flash profile, to perceptually characterize and evaluate 12 acoustical conditions of the car cabin using individually elicited attributes. A multivariate analysis revealed the panel's consensus and the identified perceptual constructs. Six perceptual constructs characterize the differences between the acoustical conditions of the cabin, related to bass, ambience, transparency, width and envelopment, brightness, and image focus. The current results indicate the importance of several acoustical properties of a car's interior on the perceived sound qualities. Moreover, they signify the capacity of the applied methodology in assessing spectral and spatial properties of automotive environments in laboratory settings using a time-efficient and flexible protocol. ispartof: Journal of the Acoustical Society of America vol:141 issue:3 pages:1459-1469 ispartof: location:United States status: published

Cassava based bioethanol production is a promising alternative to conventional fossil fuels and commercial production is already well established in several countries. A production based on small holder production may involve a transformation of the existing production system and it is therefore imperative to investigate opportunities and barriers for expansion of cassava production. This paper investigates the potential for an expansion of cassava cultivation for bioethanol production in Southern Mali. It is based on a questionnaire survey with 65 households in 2 villages in Loulouni municipality, which represent two major agro-ecological environments in the Soudan-zone in Mali. The results reveal that farmers are experienced cassava producers and are interested in an expansion of cassava cultivation for bioethanol production and that suitable areas are available, especially for an expansion of the Attieke cassava variety. Little competition with food crops is likely, as cassava most likely would replace cotton as primary cash crop, following the decline of cotton production since 2005 and hence food security concerns appear not to be an issue. Stated price levels to motivate an expansion of cassava production are close to acceptable levels to make bioethanol production profitable and the advantages of a continuous demand at agreed prices may motivate farmers to accept prices which would make bioethanol production competitive.

Farm diversification presents important development opportunities and challenges in peri-urban landscapes. New economic activities in left over farm buildings have traditionally been seen as a way to broaden the income base in particular in more remote areas. The positive economic effects needs to be balanced with the negative effects of the hidden urbanization that may convert rural areas to de facto urban areas and an inefficient use of demarcated industrial zones. Nowhere is the range of interests and competition for land greater than in peri-urban areas, which therefore represent special planning challenges. We investigated the patterns and processes of On-farm Business Structure Diversification (OFBSD) in Greater Copenhagen, with a particular focus on the use of three resources: land, buildings and rural assets for OFBSD activities as well as the motives behind farm purchase. The results are based on a case study with 146 farm owners. They show that 60% of all land owners were involved in OFBSD activities. No significant relationship with particular farm or farmer characteristics was detected. An estimation of resource use indicates that buildings are essential for 95% of the OFBSD activities, while 47% and 31% of the activities rely on the use of outdoor space or nearby rural assets. The results indicate that most activities are “footloose” and might as well be located in an urban setting. Furthermore, the results indicate that many farm owners purchased their farm based on a range of motives, combining both private and business considerations. This result has important planning implications, as physical planning regulation traditionally has focused on separate domains of interest, which corresponds poorly with current dynamics of OFBSD activities in peri-urban areas.

In this article, we investigate drivers behind land use changes in a peri-urban landscape. The research focuses on the motives and factors behind landowners’ decision-making in relation to land use changes, with the objective of improving our knowledge of the dynamics of land use change processes on farmland. An actor-centred conceptual framework is developed on the basis of the concept of lenses of decision-making. Data on farm and farmer characteristics were collected through a survey conducted in Roskilde Municipality, Denmark, a peri-urban landscape with a high level of landscape dynamics. A logistic regression analysis was used to analyse the relationship between nine purposively selected farm and farmer characteristics and the landscape activities of 93 landowners in the municipality. The results indicate that small farms, farms without livestock and landowners with a basic level of education are less likely to engage in landscape activities. A cluster analysis was used to analyse patterns of motive...

This paper discusses the employment strategies of young people in selected rural areas of Zambia and Uganda, with a focus on the opportunities and constraints that they face. It investigates mobility patterns to determine what motivates some youth to stay, while others choose to migrate to urban areas. Quantitative and qualitative data are drawn on to analyse the role of exogenous and endogenous support for young entrepreneurs. The findings indicate that agriculture plays a major role as a source of livelihood for rural youth and, in combination with other economic activities, provides a more resilient livelihood than a single enterprise strategy. The importance of an enabling environment, personal skills and favourable market conditions are also highlighted. The question of whether young people remain in or leave rural areas is shown to vary between the Ugandan and Zambian contexts. In Uganda, a significant proportion of the youth, especially young men, migrate to urban areas, whereas in Zambia, almost a...

We consider a source coding problem with a network scenario in mind, and formulate it as a remote vector Gaussian Wyner-Ziv problem under covariance matrix distortions. We define a notion of minimum for two positive-definite matrices based on which we derive an explicit formula for the rate-distortion function (RDF). We then study the special cases and applications of this result. We show that two well-studied source coding problems, i.e. remote vector Gaussian Wyner- Ziv problems with mean-squared error and mutual information constraints are in fact special cases of our results. Finally, we apply our results to a joint source coding and denoising problem. We consider a network with a centralized topology and a given weighted sum-rate constraint, where the received signals at the center are to be fused to maximize the output SNR while enforcing no linear distortion. We show that one can design the distortion matrices at the nodes in order to maximize the output SNR at the fusion center. We thereby bridge between denoising and source coding within this setup.

Due to the distributed structure of many modern audio transmission setups, it is likely to have an observation at the receiver which is correlated with the desired source at the transmitter. This observation could be used as side information to reduce the transmission rate using distributed source coding. How to integrate distributed source coding into the perceptual audio compression procedure is thus a fundamental question. In this paper, we take a completely analytical approach to this problem, in particular to the rate-distortion trade-off and the corresponding coding schemes. We then interpret the results from an audio coding perspective. The main result is that, to upgrade a regular perceptual audio coder to a distributed coder, one needs to revise the perceptual masking curve. The revised masking curve models the availability of the side information as an extra masking effect, yielding lower rates. Interestingly, this means that at least conceptually, the distributed coding scenario could be integrated into the audio coder with minor changes, and without destructing the original coder.

Increasing energy use and the need to mitigate climate change make production of liquid biofuels ahigh priority. Farmers respond worldwide to this increasing demand by converting forests andgrassland into biofuel crops, but whether biofuels offer carbon savings depends on the carbonemissions that occur when land use is changed to biofuel crops. This paper reports the results of astudy on cassava-based bioethanol production undertaken in the Sikasso region in Southern Mali.The paper outlines the estimated impacts on above-ground carbon stocks when land use is changed toincrease cassava production. The results show that expansion of cassava production for bioethanol willmost likely lead to the conversion of fallow areas to cassava. A land use change from fallow to cassavacreates a reduction in the above-ground carbon stocks in the order of 4–13 Mg C ha 1 , depending on(a) the age of the fallow, (b) the allometric equation used and (c) whether all trees are removed or thelarger, useful trees are preserved. This ‘carbon debt’ associated with the above-ground biomass losswould take 8–25 years to repay if fossil fuels are replaced with cassava-based bioethanol.& 2011 Elsevier Ltd. All rights reserved.

This paper explores the changing nature of social institutions and organizations for resourcemanagement on Ontong Java and their central role in maintaining livelihoods. Using detailedfield data for three time periods, 1970–72, 1986 and 2006–07, and drawing on earlier secondarydata, a longitudinal analysis of changes in governance and livelihoods is undertaken. Increasedexploitation of marine resources has widened the resource base and increased people’s access togoods and services. Following the ban in 2005 on the beche-de-mer trade, however, livelihoodshave reverted to being more subsistence oriented. For almost two decades after 1978, a com-munal organization, the Area Council, succeeded in regulating exploitation of the atoll’s marineresources to ensure sustainable use, but in the 1990s it collapsed. In addition there was aparalysis of institutions that had once settled land disputes. This failure of atoll governance is agreater threat to future ‘sustainability’ than the usual processes that are invoked for atolls andsmall islands generally. As the Solomon Islands state is also failing, we argue that local institu-tions and organizations have a vital role to play in managing access to resources and the futureof livelihoods on Ontong Java atoll.Keywords: atoll, beche-de-mer, governance, livelihoods, Ontong Java, Solomon Islands

Geografisk Tidsskrift—Danish Journal of Geography 109(1):47–67, 2009 The intensification of agriculture was a key driver behind rural landscape changes in Europe during the 20th century, with severe environmental impacts. This paper investigates land use changes in a rural landscape with contrasting biophysical potential for agricultural production in western Denmark in a 136 year period (1870–2006). The purpose is to explore links between drivers of landscape change and observed changes during this period as well as to document the spatial variability of landscape changes. The analysis is based on a longitudinal case study of Gadbjerg and Givskud parishes. A heuristic framework, the coupled human-environmental timeline, is used to examine the environmental history of rural landscape in order to highlight the co-evolution of the land use dynamics and major socio-economic, technological and legislative events. Land use patterns are analysed by use of topographical maps from 1870, 1950 and 2006. Ad...

Many blueprints for urban development argue for the benefits of a sharp distinction between rural and urban space. While such planning designs have been quite successful in maintaining a physical distinction between rural and urban, major transformations of the socio-economic environment in peri-urban areas are creating a more diffuse and porous interface. This paper examines socio-economic consequences of the current transformation of peri-urban areas. Three themes are selected for analysis: changing economies, overall impact of urbanisation as perceived by the individual farm owner and the degree of their local orientation and engagement. Based on case studies in Greater Copenhagen, longitudinal trends and details of the current situation are analysed. In addition, by differentiating between newcomers and long-term residents, possible future changes are indicated. The analysis shows that the importance of agriculture has declined, whereas other gainful activities and residential use have increased. Thus, the functions of the local economy and community are changing. An increasing proportion of the farm owners appreciate the proximity to urban agglomerations (public services, shopping, public transport, social relationships and markets), but this location also has drawbacks, for example in terms of uncertainty concerning future urban development, inconveniences for agricultural production and problems related to public access to private properties. Differences between newcomers and long-time residents are identified. Newcomers without any agricultural background are frequent. They often work outside the municipality and are more frequently personally involved in other gainful activities on-farm. Newcomers perceive more problems related to people accessing the farm properties and are less involved in local activities. In combination, these trends indicate possible future increase in conflicts between farm owners and the public and that the local engagement may be declining. The analysis, however, also shows similarities between newcomers and long-time residents, and therefore does not indicate the development of two cultures or “two nations”. Rather, the urban fringe population is becoming more heterogeneous, ranging from full-time farmers to residents with their social and professional network outside the local area or people engaging in non-agricultural business on-farm.

In this paper the influence of ambient light and peak white (maximum brightness) of a display on the subjective quality of videos shown with local backlight dimming is examined. A subjective experiment investigating those factors is set-up using high contrast test sequences. The results are firstly analyzed with an ANalysis Of VAriance, which shows significant effect of the Sequence and Algorithms interactions and the Peak White and Ambient Light interactions. This latter allows us to define test cases for which the peak white and ambient light are adapted to one another. An objective model of the subjective grades is then computed using Partial Least Squares regression that achieves 0.68 correlation.

This paper investigates how different types of farmers manage the landscape with primary emphasis on farmland afforestation, planned landscape changes, and the extent to which EU agri-environmental schemes take farm type specific characteristics into account in information strategies. The empirical data concern landscape practices of more than 2,000 landowners in 16 European areas in eight countries who were surveyed using quantitative questionnaires. Supplementary in-depth interviews were conducted for two case areas in Denmark to further investigate the role of the policy information environment. The analysis is based on a categorization of the farmers into hobby, part-time, full-time and retired farmers. This study shows that hobby farmers constitute a high proportion of landowners and manage a large part of the rural landscape. At the same time, hobby farmers are relatively more interested in landscape changes and differ from other landowners by considering farmland afforestation more often than full-time landowners, for example. Yet, 40% of the hobby farmers who are considering farmland afforestation are not familiar with the agri-environmental scheme for farmland afforestation. One reason may be their low membership rate in traditional information networks such as farmers’ or foresters’ associations, as revealed by the in-depth analysis of the cases in Denmark. Thus, it is proposed that policy impact may be improved if farmer type specific differences are explicitly taken into account in the scheme logistics for EU agri-environmental schemes.

Peri-urban areas are characterised by great heterogeneity and rapid changes of land use. Furthermore, population composition changes as peri-urban areas offer attractive residential alternatives to city centres or more remote locations. The dynamic processes leave peri-urban areas in an in-between situation, neither city nor countryside and home to a range of functions, spanning from agricultural production to residential and recreational areas. The paper investigates the urbanisation of agricultural areas in the Greater Copenhagen region based on quantitative data collected on agricultural properties in nine study areas between 1984 and 2004. The overall conclusion is that agricultural land use has continued largely unaffected by the processes of urbanisation. However, most of the production is concentrated on a few very large full-time farms. In addition, the economic activities have been greatly diversified over the last three decades. The structural components of the areas (land use and lands...

Geografisk Tidsskrift, Danish Journal of Geography 105(2):23–37, 2005 As a reaction to the 'top-down 'approach to rural development during the 1970's and 1980's, and in line with the increased focu...

Recent landscape changes in a farmed landscape are analysed and related to farm and farmer characteristics. It is assumed that farm and farmer characteristics serve as mediators of large scale or macro driving forces of change-in the present case, a changing farming context including demands for a more environmentally friendly farming practise and a reduced output. The results are based on multivariate analyses of data collected from structured interviews of 160 farmers in a case study area, in central Jutland, measuring 5000 ha. The analysis shows that farmers are highly involved in landscape changes. The investigated landscape changes include creation and removal of landscape elements as well as certain management changes. The most common activity was creation of elements: hedgerows, small woodlands and conversion of rotational arable land to permanent grassland, whereas removal of elements, mainly hedgerows and semi-natural grasslands, were seen less frequently. Management changes like abandonment of permanent grassland were widespread. The results indicate a general extensification of the land use and the authors interpret the results partly as an indication of a change from productivism to a more multifunctional agricultural regime. The observed landscape changes at the farm level show a low, but structured relationship with the current farm and farmer characteristics, meaning that landscape changes were undertaken by various farmers and on various farms. On a general level, however, the age of the farmer and the duration of farm ownership seem to have a major influence on the landscape changes.

The industrialisation and intensification of agriculture over the last 50 years had a negative impact on landscape diversity and habitat values. During the last two decades, farmers have become increasingly engaged in landscape activities, to maintain or create habitats on their property. The purpose of this paper is to investigate the relationship between landscape changes in rural areas and farm characteristics. In addition, the results are used to determine if farms with certain farm characteristics or combinations of characteristics can be related to different patterns of landscape changes. The analysis is based on a case study of the landscape activities carried out by 104 farmers between 1990 and 1995 in two parishes in central Jutland, Denmark. A multivariate analysis, consisting of a multiple correspondence analysis (MCA) and cluster analysis, is used to identify groups of farmers with distinct farm characteristics and landscape activities. The results indicate that 57% of the farms in the study area had engaged in landscape activities. Hedgerow planting and removal, and water point digging and cleaning were the most popular activities in terms of number of farmers involved. The planting of Christmas trees and cultivation of permanent grassland covered the largest area. In total, the activities concerned 125 ha or 1.5% of the study area. A parameter to parameter relationship could be identified between some landscape activities and farm characteristics. In particular, forest removal was closely related to intensive arable production while a range of activities were correlated with “hobby” farm characteristics. The results indicate that a range of motives influence farmers’ landscape activities and that more information is needed to understand and model complex decision-making processes.

This paper focuses on the influence of ambient light on the perceived quality of videos displayed on Liquid Crystal Display (LCD) with local backlight dimming. A subjective test assessing the quality of videos with two backlight dimming methods and three lighting conditions, i.e. no light, low light level (5 lux) and higher light level (60 lux) was organized to collect subjective data. Results show that participants prefer the method exploiting local dimming possibilities to the conventional full backlight but that this preference varies depending on the ambient light level. The clear preference for one method at the low light conditions decreases at the high ambient light, confirming that the ambient light significantly attenuates the perception of the leakage defect (light leaking through dark pixels). Results are also highly dependent on the content of the sequence, which can modulate the effect of the ambient light from having an important influence on the quality grades to no influence at all.

This paper investigates the changes in a shelterbelt network between 1950 and 1997 in a study area in central Jutland, Denmark. The analysis consists of two parts. Firstly, the changes in key parameters which are of landscape ecological importance (shelterbelt density, connectivity, node type and landscape grain size) are examined. The results of this analysis show that shelterbelt density varied considerably during the period due to changes in biophysical and socio-economic factors. A GIS analysis shows that landscape grain size decreased in 45 percent of the area. A major change of shelterbelt type occurred in the area with landscape ecological and visual scenery implications. It appears that public-subsidised shelterbelt planting programmes were the most important factors influencing changes in the shelterbelt network in the study area while differences in soil type were less important. Secondly, data from a questionnaire survey were used to examine the driving forces behind shelterbelt activities over a 10 year period. Hobby farmers were the most active farmer group in shelterbelt planting and agronomic reasons were the most important motives for shelterbelt planting in the study area during this period. Furthermore, it appeared that microclimate effects and aesthetical considerations have become important reasons for shelterbelt planting.

This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli using a simple loudspeaker setup, consisting of only two loudspeakers, one for the target sound source and the other for the interfering sound source. Recently, the model was successfully validated in a complex personal sound-zone system with speech-on-music stimuli. Second round of validations were conducted by physically altering the sound-zone system and running a set of new listening experiments utilizing two sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. Preliminary results show that the model performance is equally good in both zones, i.e., with both speech-on-music and music-on-speech stimuli, and comparable to the previous validation round (RMSE approximately 10%). The results further confirm that the distraction model can be used as a valuable tool in evaluating and optimizing the performance of personal sound-zone systems.

Local backlight dimming is a technology aiming at both saving energy and improving visual quality on television sets. As the rendition of the image is specified locally, the numerical signal corresponding to the displayed image needs to be computed through a model of the display. This simulated signal can then be used as input to objective quality metrics. The focus of this paper is on determining which characteristics of locally backlit displays influence quality assessment. A subjective experiment assessing the quality of highly contrasted videos displayed with various local backlight-dimming algorithms is set up. Subjective results are then compared with both objective measures and objective quality metrics using different display models. The first analysis indicates that the most significant objective features are temporal variations, power consumption (probably representing leakage), and a contrast measure. The second analysis shows that modeling of leakage is necessary for objective quality assessment of sequences displayed with local backlight dimming.

This paper examines the dynamics of hedgerow planting and removal in a study area with marginal agricultural potential in central Jutland. The study is based on a questionnaire survey with farmers in two parishes supplemented by aerial photo interpretation. The first section examine changes in hedgerow network parameters between 1972 and 1995. The length of the hedgerow network declined by 9% during this period. The connectivity of the hedgerow network was very low in both years, indicating that options for species dispersal along hedgerows was poor. The second section analyses the net effect of planting activities between 1987 and 1997 and the motives behind them. Full-time farmers were the most active farm group concerning the proportion of farmers planting hedgerows. Hobby farmers planted more hedgerows than other farm groups. Most hedgerows have been planted in the parish with the greater agricultural potential and lesser need for shelter against wind erosion. This surprising result indicates...

This article examines some of the landscape changes which have accompanied agricultural developments in Denmark over the past 25 years. GIS is used to analyse the spatial aspects of the changes in Rostrup, Denmark, highlighting the polarisation of the farming community into small part-time or hobby farms and large full-time farms. The analysis of landscape changes between 1973 and 1995 indicates that both full-time and part-time farms are involved in extensification of land use. The classification of farms according to economic key factors alone is too coarse to estimate the potential improvement of ‘nature values’ in rural landscapes.

A general framework and first experimental results are presented for a computational model for achieving optimal colour appearance of natural images on television displays. The image quality framework includes: (a) analysis of relationships between overall image quality and quality-related attributes; (b) analysis of relationships between the quality-related attributes and their psychometric correlates; (c) analysis of relationships between the psychometric correlates and the physical parameters of a display; and (d) development of an adaptive algorithm for optimal image appearance by manipulation of the display's parameters. In the psychophysical experiments, observers viewed a series of colour images on high-end consumer television display, to investigate the relationships between overall image quality and four quality-related attributes: brightness rendering, chromatic rendering, visibility of details and overall naturalness. The results of the experiments suggest that these attributes are interrelated. Some subjects can more easily separate the quality-related attributes than other subjects. The overall image quality can be modelled as a linear combination of the brightness rendering and chromatic rendering judgements with different weights, which are subject dependent. The optimal value of the overall image quality judgements is slightly skewed towards the darker end of the lightness scale and towards the more colourful end of the chroma scale. The degree of skewedness depends on image content.

Geografisk Tidsskrift, Danish Journal of Geography 99: 69–80, 1999 The agricultural sector in Denmark has experienced drastic structural changes since World War 2 which have reduced the number of farms from 200.000 in 1960 to 63.000 in 1997. This article analyses the changes in agricultural structure at a local scale, comparing key farm parameters for farmers in Gadbjerg and Givskud parishes in central Jutland in 1973 and 1997. It was found that the proportion of full-time farmers has declined from 77% to 41%, and that the dominant farm type changed from farm with mixed animal production to farms without animals. It is concluded that the drive towards a bipolarization of the farming community into large full-time farms and small hobby farms which is a common development in Denmark for the period was more pronounced in Gadbjerg and Givskud parishes. Farmers have followed different pathways of development to adapt to the variable farming conditions, with the adoption of part-time farming being a ve...

In this paper, we consider a distributed remote source coding problem, where a sequence of observations of source vectors is available at the encoder. The problem is to specify the optimal rate for encoding the observations subject to a covariance matrix distortion constraint and in the presence of side information at the decoder. For this problem, we derive lower and upper bounds on the rate-distortion function (RDF) for the Gaussian case, which in general do not coincide. We then provide some cases, where the RDF can be derived exactly. We also show that previous results on specific instances of this problem can be generalized using our results. We finally show that if the distortion measure is the mean squared error, or if it is replaced by a certain mutual information constraint, the optimal rate can be derived from our main result., Comment: This is the final version accepted at ISIT'14

In the field of auditory masking threshold predictions an optimal method for buffering a continuous, ecologically valid programme combination into discrete temporal windows has yet to be determined. An investigation was carried out into the use of a variety of temporal window durations, shapes, and steps, in order to discern the resultant effect upon the accuracy of various masking threshold prediction models. Selection of inappropriate temporal windows can triple the prediction error in some cases. Overlapping windows were found to produce the lowest errors provided that the predictions were smoothed appropriately. The optimal window shape varied across the tested models. The most accurate variant of each model resulted in root mean squared errors of 2.3, 3.4, and 4.2 dB.

Auditory interference scenarios, where a listener wishes to attend to some target audio while being presented with interfering audio, are prevalent in daily life. The goal of developing an accurate computational model which can predict masking thresholds for such scenarios is still incomplete. While some sophisticated, physiologically inspired, masking prediction models exist, they are rarely tested with ecologically valid programs (such as music and speech). In order to test the accuracy of model predictions human listener data is required. To that end a masking threshold experiment was conducted for a variety of target and interferer programs. The results were analyzed alongside predictions made by the computational auditory signal processing and prediction model described by Jepsen et al. (2008). Masking thresholds were predicted to within 3 dB root mean squared error with the greatest prediction inaccuracies occurring in the presence of speech. These results are comparable to those of the model by Glasberg and Moore (2005) for predicting the audibility of time-varying sounds in the presence of background sounds, which otherwise represent the most accurate predictions of this type in the literature.