In 2018, the number of mobile phone users will reach about 4.9 billion. Assuming an average of 5 photos taken per day using the built-in cameras would result in about 9 trillion photos annually... Show moreIn 2018, the number of mobile phone users will reach about 4.9 billion. Assuming an average of 5 photos taken per day using the built-in cameras would result in about 9 trillion photos annually. Thus, it becomes challenging to mine semantic information from such a huge amount of visual data. To solve this challenge, deep learning, an important sub-field in machine learning, has achieved impressive developments in recent years. Inspired by its success, this thesis aims to develop new approaches in deep learning to explore and analyze image data from three research themes: classification, retrieval and synthesis. In summary, the research of this thesis contributes at three levels: models and algorithms, practical scenarios and empirical analysis. First, this work presents new approaches based on deep learning to address eight research questions regarding the three themes. In addition, it aims towards adapting the approaches to practical scenarios in real world. Furthermore, this thesis provides numerous experiments and in-depth analysis, which can help motivate further research on the three research themes. Computer Vision Multimedia Applications Deep Learning Show less
Our study emphasizes the importance of two toxicity-modifying factors (the composition of the surrounding exposure media and mixture effects) in the assessment of toxic effects of metals and... Show more Our study emphasizes the importance of two toxicity-modifying factors (the composition of the surrounding exposure media and mixture effects) in the assessment of toxic effects of metals and metal-based NPs on higher plants. Based on the affinity of metals for binding sites on the biotic ligand at the water-organism interface, the mechanistic models we developed provide better links with the toxicity of metal mixtures. We also recommend that finding a statistically significant deviation from additivity can be the starting point for further mechanistic research concerning toxicologically relevant interactions between substances, instead of the endpoint of research used so far. As an extension of the research discussed in the third chapter of this thesis, the commonly known model for the toxicity of mixtures was proven to be suitable for preliminarily assessing the effects of metal-based NPs on terrestrial organisms. The experimental design of nested combinations helps establish a more realistic exposure scenario for the environment and makes it possible to identify where and how chemical-chemical interactions occur with metal-based NPs. Consequently, our findings enrich the rapidly evolving field of toxicology regarding metals and metal-based NPs. Show less
Although the influence of magnetic fields on the rates and product yields of a host of chemical reactions are well documented and can be understood in the framework of the Radical Pair Mechanism ... Show moreAlthough the influence of magnetic fields on the rates and product yields of a host of chemical reactions are well documented and can be understood in the framework of the Radical Pair Mechanism (RPM), it has so far proved impossible to demonstrate convincingly a biological RPM effect. In this work we present proof that biological systems, i.e. photosynthetic bacteria, for which it is known that the RPM is operative, can generate toxic products in amounts that depend on the presence of an applied magnetic field. This work, in turn, illustrates that magnetic fields influence the extent of photoinhibition in such a biological system. We show, to our knowledge, the first observation of magnetic field dependent singlet oxygen production in biological system. These measurements could in principle explain beneficial and adverse effects for low and high magnetic fields, respectively. Show less
This case study of the tea trade of the Dutch East India Company with China deals with its most profitable phase, when a direct shipping link was established between Canton and the Dutch Republic... Show moreThis case study of the tea trade of the Dutch East India Company with China deals with its most profitable phase, when a direct shipping link was established between Canton and the Dutch Republic in the second half of the eighteenth century. It focuses on the questions why and how the tea trade was taken out of the hands of the High Government in Batavia in 1757 and put under the supervision of the newly established China Committee in Amsterdam, and explains in detail what factors contributed to the phenomenal rise of this trade and its sudden decline in the 1780s. Show less
