Pilot bruikbaarheid onderwatervideocamera voor de signalering van randeffecten op de onderzoeksvakken van PRODUS dp 3

Doel van dit pilot-project was het inventariseren van effectiviteit en bruikbaarheid van de onderwatervideocamera voor het signaleren, bestuderen en analyseren van randeffecten. Hiervoor werd gekeken naar mogelijkheden om mosseldichtheid en bedekking van mosselen met slib of sediment te analyseren vanaf de onderwatervideobeelden. Er werd ook onderzocht of er een statistische techniek ingezet kan worden voor het aantonen van het wel of niet voorkomen van randeffecten

Development of analysis techniques for the use of aerial photography in the monitoring of intertidal mussel beds and oyster beds

This project aimed at improving the analysis techniques of aerial photography for mussel bed recognition and mapping. In this project two techniques were tested; recognition and mapping by human eye and recognition and mapping by automatic detection software. The detection with the human eye was tested in two ways. The first test considered recognition of mussel beds in an area were contours of the previous year were available. The second test concerned a blind recognition test without any knowledge on previous locations of mussel beds

The influence of air in mortar on the results of the RCM test

Chloride penetration into concrete structures reduces their service life. When chloride reaches the steel rebar, it may corrode which eventually leads to concrete deterioration. Hence, it is important to test concrete on chloride penetration resistance. Such testing often takes a long time, because of the slow process of chloride penetration. Therefore, using an accelerated test is an obvious choice. The RCM test is one of the most commonly used techniques to measure the chloride diffusion coefficient in concrete. One of the disadvantages of the RCM test is that it requires a saturated sample, while structures in practical conditions are mostly unsaturated. In this paper, the RCM test is performed for unsaturated mortar. Standard mortar samples with various air content of 0%, 2%, 4%, 6%, 8% and 10% are investigated. The air content in the sample is obtained by first water-saturating the sample under vacuum and than by placing the sample in a climate chamber with a relative humidity of 10% and a temperature of 50°C to induce drying, until the desired air content of the sample is reached. After the RCM test, the chloride penetration depth is measured with colorimetric and titration methods. The results show that the more air content in the samples is, the deeper chloride penetration in the samples will be

The influence of air in mortar on the results of the RCM test

Chloride penetration into concrete structures reduces their service life. When chloride reaches the steel rebar, it may corrode which eventually leads to concrete deterioration. Hence, it is important to test concrete on chloride penetration resistance. Such testing often takes a long time, because of the slow process of chloride penetration. Therefore, using an accelerated test is an obvious choice. The RCM test is one of the most commonly used techniques to measure the chloride diffusion coefficient in concrete. One of the disadvantages of the RCM test is that it requires a saturated sample, while structures in practical conditions are mostly unsaturated. In this paper, the RCM test is performed for unsaturated mortar. Standard mortar samples with various air content of 0%, 2%, 4%, 6%, 8% and 10% are investigated. The air content in the sample is obtained by first water-saturating the sample under vacuum and than by placing the sample in a climate chamber with a relative humidity of 10% and a temperature of 50°C to induce drying, until the desired air content of the sample is reached. After the RCM test, the chloride penetration depth is measured with colorimetric and titration methods. The results show that the more air content in the samples is, the deeper chloride penetration in the samples will be

An explorative study of interface support for image searching

In this paper we study interfaces for image retrieval systems. Current image retrieval interfaces are limited to providing query facilities and result presentation. The user can inspect the results and possibly provide feedback on their relevance for the current query. Our approach, in contrast, encourages the user to group and organise their search results and thus provide more fine-grained feedback for the system. It combines the search and management process, which - according to our hypothesis - helps the user to onceptualise their search tasks and to overcome the query formulation problem. An evaluation, involving young design-professionals and di®erent types of information seeking scenarios, shows that the proposed approach succeeds in encouraging the user to conceptualise their tasks and that it leads to increased user satisfaction. However, it could not be shown to increase performance. We identify the problems in the current setup, which when eliminated should lead to more effective searching overall

Unravelling variation in feeding, social interaction and growth patterns among pigs using an agent-based model

Domesticated pigs, Sus scrofa, vary considerably in feeding, social interaction and growth patterns. This variation originates partly from genetic variation that affects physiological factors and partly from behavioural strategies (avoid or approach) in competitive food resource situations. Currently, it is unknown how variation in physiological factors and in behavioural strategies among animals contributes to variation in feeding, social interaction and growth patterns in animals. The aim of this study was to unravel causation of variation in these patterns among pigs. We used an agent-based model to explore the effects of physiological factors and behavioural strategies in pigs on variation in feeding, social interaction and growth patterns. Model results show that variation in feeding, social interaction and growth patterns are caused partly by chance, such as time effects and coincidence of conflicts. Furthermore, results show that seemingly contradictory empirical findings in literature can be explained by variation in pig characteristics (i.e. growth potential, positive feedback, dominance, and coping style). Growth potential mainly affected feeding and growth patterns, whereas positive feedback, dominance and coping style affected feeding patterns, social interaction patterns, as well as growth patterns. Variation in behavioural strategies among pigs can reduce aggression at group level, but also make some pigs more susceptible to social constraints inhibiting them from feeding when they want to, especially low-ranking pigs and pigs with a passive coping style. Variation in feeding patterns, such as feeding rate or meal frequency, can indicate social constraints. Feeding patterns, however, can say something different about social constraints at group versus individual level. A combination of feeding patterns, such as a decreased feed intake, an increased feeding rate, and an increased meal frequency might, therefore, be needed to measure social constraints at individual level

Impact of mussel seed fishery on subtidal macrozoobenthos in the western Wadden Sea

Within the framework of PRODUS, the effect of mussel fishery on the macrofauna species sampled with a box-corer was investigated following a so-called split-plot design. Within areas where mussel seed fishery was allowed, 40 plots/locations were chosen within which one part was open for commercial fisheries and one part was closed of fisheries. Box-corers were taken in 21 of these locations, sampled one to several times

Automatic support for product based workflow design : generation of process models from a product data model

Product Based Workflow Design (PBWD) is one of the few scientific methodologies for the (re)design of workflow processes. It is based on an analysis of the product that is produced in the workflow process and derives a process model from the product structure. Until now this derivation has been a manual task and is therefore a time-consuming and error-prone exercise. Automatic support would enhance the use of the PBWD methodology. In this paper we propose several algorithms to automatically generate process models from a product structure and we present a software tool (implemented in ProM) to support this. Finally, the properties of the resulting process models are analysed and discussed