Search results

Confessions of a 'guilty' couch potato understanding and using context to optimize binge-watching behavior

Confessions of a 'guilty' couch potato understanding and using context to optimize binge-watching behavior

Viewers more frequently watch television content whenever they want, using devices they prefer, which stimulated 'Binge-watching' (consecutive viewing of television programs). Although binge-watching and health concerns have been studied before, the context in which binge-watching takes place and possibilities to use context to optimize binge-watching behavior have not. An in-situ, smartphone monitoring survey among Dutch binge-watchers was used to reveal context factors related to binge-watching and wellbeing. Results indicate that binge-watching is a solitary activity that occurs in an online socially active context. The amount of time spent binge-watching (number of episodes) correlates with the amount of free time and plays an important role in the effect of binge-watching on emotional wellbeing. Considering the difficulty viewers have to create an optimal viewing experience, these context factors are used as a framework to be able to design and promote a recommendation tool for TV streaming services to create a more optimal binge-watching experience.

The potential of permaculture principles in the agrifood transition

The current western agrifood system is highly successful in providing for human needs. However, the dominant agricultural approach of up-scaling and specialisation is put under pressure by a number of developments in the global landscape. Global developments such as population growth, pollution, soil degradation and climate change, in which agriculture plays a crucial role, make the need for a transition towards a paradigm with a broader range of values evident. Niche initiatives often develop as a reaction to needs not fulfilled by the regime. Therefore, certain niches may have the potential of driving a necessary transition. This research aims to determine if permaculture, being a niche, has this potential. The main question for this research was formulated as follows: How can a production system based on permaculture principles contribute to the agrifood transition? To answer this question, relevant current trends and global developments were used as a basis for developing a future scenario. Empirical qualitative data on permaculture businesses in the Netherlands was gathered as well, of which the results were used for a determination of permaculture’s performance in this future scenario. This was done by comparing a standardised permaculture system with a conventional potato system. As a result of this comparison, the Unique Selling Points of permaculture were identified, which determine the future potential of permaculture.

Hyper-spectral frequency selection for the classification of vegetation diseases

Reducing the use of pesticides by early visual detection of diseases in precision agriculture is important. Because of the color similarity between potato-plant diseases, narrow band hyper-spectral imaging is required. Payload constraints on unmanned aerial vehicles require reduc- tion of spectral bands. Therefore, we present a methodology for per-patch classification combined with hyper-spectral band selection. In controlled experiments performed on a set of individual leaves, we measure the performance of five classifiers and three dimensionality-reduction methods with three patch sizes. With the best-performing classifier an error rate of 1.5% is achieved for distinguishing two important potato-plant diseases.

Kinetic modelling

Three empirical models were used to fit the formation of acrylamide in crisps of three different cold-sweetened potato genotypes, fried under the same experimental conditions. Statistical methods were used to compare the performance of the models, with the "Logistic-Exponential" model performing the best. The obtained model parameters for the formation of acrylamide showed improvement in precision compared to an earlier study, the precision of the parameter estimates for the degradation of acrylamide was still problematic. Nevertheless, the predictive capacity of the "Logistic-Exponential" model was tested, as this model showed a strong correlation between parameter a and the reducing sugar content of the raw potato. The predictions from this model for the formation of acrylamide in potato crisps were close to earlier reported experimental values. Therefore, the use of the "Logistic-Exponential" model as a tool to predict acrylamide in potato crisps seems promising and should be developed further.

A study on the use of empirical models to predict the formation of acrylamide in potato crisps

The formation of acrylamide in potato crisps was fitted by empirical mathematical models. Potato slices were fried under the same experimental conditions for different times. Besides the content of precursors in the raw potato slices, acrylamide and water content in the potato crisps were quantified after predetermined times (2-6 min). The temperature developments in the surrounding oil and outer cell layer of the potato slices were monitored, giving more insight in the frying process and making future comparisons between studies possible. The pattern found for the formation of acrylamide, which was similar to earlier studies, was fitted to three empirical models. Statistical methods were used to compare the performance of the models, with the "Logistic-Exponential" and "Empirical" model performing equally well. The obtained model parameters were in the range of earlier reported studies, although this comparison is not unequivocal as the experimental conditions differed between studies. The precision of parameter estimates was problematic; this should be improved by better experimental design. Nevertheless, the approach of this study will make it possible to truly compare acrylamide formation patterns and model parameters in the future, with the ability to develop a tool to predict acrylamide formation in potato crisps.