Evaluating unsupervised thesaurus-based labeling of audiovisual content in an archive production environment

In this paper we report on a two-stage evaluation of unsupervised labeling of audiovisual content using collateral text data sources to investigate how such an approach can provide acceptable results for given requirements with respect to archival quality, authority and service levels to external users. We conclude that with parameter settings that are optimized using a rigorous evaluation of precision and accuracy, the quality of automatic term-suggestion is sufficiently high. We furthermore provide an analysis of the term extraction after being taken into production, where we focus on performance variation with respect to term types and television programs. Having implemented the procedure in our production work-flow allows us to gradually develop the system further and to also assess the effect of the transformation from manual to automatic annotation from an end-user perspective. Additional future work will be on deploying different information sources including annotations based on multimodal video analysis such as speaker recognition and computer vision.     

Triacylglycerol Analysis of Fats and Oils by Evaporative Light Scattering Detection

A high performance liquid chromatography method with evaporative light scattering detection was developed for the analysis of oils and fats, which enabled excellent separation of major and minor triacylglycerol (TAG) species in 33 min, including regeneration of the column. The influence of the mobile phase and temperature on separation and analysis time were evaluated with a cocoa butter standard. The influence of the drift tube temperature and flow of the nebulising gas on the evaporative light scattering detector output signal was investigated by means of a response surface experimental design. Especially the flow of the nebulising gas had a profound effect on the detector signal. An optimal separation was obtained when using a 150 × 3.0 mm C18 column with 3 μm particle diameter at 20 °C and an acetonitrile/dichloromethane gradient at 0.72 mL/min. The maximum response was attained when the ELSD detector was set at the minimum temperature (45 °C) and a gas flow of 1.2 L/min. Finally, the linearity of the detector was investigated. It was found that at very low concentrations, the signal tends to flatten towards zero, giving an underestimation for minor TAG species, especially for oils or fats with a mixed fatty acid composition.     

Controller tuning freedom under plant identification uncertainty: double Youla beats gap in robust stability

In iterative schemes of identification and control one of the particular and important choices to make is the choice for a model uncertainty structure, capturing the uncertainty concerning the estimated plant model. Structures that are used in the recent literature encompass e.g. gap metric uncertainty, coprime factor uncertainty, and the Vinnicombe gap metric uncertainty. In this paper, we study the effect of these choices by comparing the sets of controllers that guarantee robust stability for the different model uncertainty bounds. In general these controller sets intersect. However in particular cases the controller sets are embedded, leading to uncertainty structures that are favourable over others. In particular, when restricting the controller set to be constructed as metric-bounded perturbations around the present controller, the so-called double Youla parametrization provides a set of robustly stabilizing controllers that is larger than corresponding sets that are achieved by using any of the other uncertainty structures. This is particularly of interest in controller tuning problems.     

A virus-based biocatalyst

Virus particles are probably the most precisely defined nanometre-sized objects that can be formed by protein self-assembly. Although their natural function is the storage and transport of genetic material, they have more recently been applied as scaffolds for mineralization and as containers for the encapsulation of inorganic compounds. The reproductive power of viruses has been used to develop versatile analytical methods, such as phage display, for the selection and identification of (bio)active compounds. To date, the combined use of self-assembly and reproduction has not been used for the construction of catalytic systems. Here we describe a self-assembled system based on a plant virus that has its coat protein genetically modified to provide it with a lipase enzyme. Using single-object and bulk catalytic studies, we prove that the virus-anchored lipase molecules are catalytically active. This anchored biocatalyst, unlike man-made supported catalysts, has the capability to reproduce itself in vivo, generating many independent catalytically active copies.     

Exposure to physical movement in low back pain patients: Restricted effects of generalization.

Whether the effects of exposure to 1 movement generalize to another dissimilar movement was investigated in 37 patients with low back pain (15 men, 22 women). Two movements were executed twice: bending forward while standing and lifting 1 leg while lying down. During each trial, baseline pain, expected pain, and experienced pain were recorded. Similar ratings for perceived harm were obtained. Analyses revealed an initial overprediction of pain, but after exposure the overprediction was readily corrected. This exposure effect did not generalize toward another dissimilar movement. These results were only characteristic for patients with catastrophic thinking about pain. Low pain catastrophizers did not overpredict pain. There were no effects of exposure on perceived harm. Exposure may profitably be conceived of as the learning of exceptions to a general rule. (PsycINFO Database Record (c) 2010 APA, all rights reserved)