Representations for multi-document event clustering

We study several techniques for representing, fusing and comparing content representations of news documents. As underlying models we consider the vector space model (both in a term setting and in a latent semantic analysis setting) and probabilistic topic models based on latent Dirichlet allocation. Content terms can be classified as topical terms or named entities, yielding several models for content fusion and comparison. All used methods are completely unsupervised. We find that simple methods can still outperform the current state-of-the-art techniques.     

The effect of composition and driving force on the performance of packed distillation columns-I

In a series of experiments the performance of a small packed column has been determined as a function of composition of the liquid phase while distilling n-heptane/methylcyclohexane at total reflux. The overall number of vapor phase transfer units (N_og) showed a distinct maximum value near the middle of the concentration range. Further the number of transfer units at zero driving force, (N_og)₀, has been determine throughout the entire composition range from x = 0 to x = 1 by contacting countercurrently equilibrated vapour and liquid phases in a series of experiments, during which only tritiated methylcyclohexane was transferred. In that case (N_og)₀ appeared to vary virtually linearly with composition. It is shown that the relative change in N_og at total reflux compared to (N_og)₀ is most probably determined exclusively by surface tension influences defined by the stabilising-index, M = −(dγ/dx)(x−x*).     

Effect of culture conditions on the achievable taxonomic resolution of Raman spectroscopy disclosed by three Bacillus species

Confocal micro-Raman spectroscopy requires a minimum of sample handling and no reagents and allows fast identification of microorganisms. Since it reflects the overall molecular composition of the cells, it provides much more information than classical, microbial analyses. However, since the molecular makeup of a cell depends on culture conditions, it can be argued that this will affect the reproducibility and discrimination ability of Raman spectroscopy. We used Bacillus cereus, Bacillus pumilus, and Bacillus licheniformis, which are known to be clearly distinct from each other and each displaying important phenotypic heterogeneity, in a wide variety of culture conditions to analyze this. It is illustrated that the influence of culture conditions on the identification accuracy and taxonomic resolution of Raman spectroscopy is important though the effect on the final identification is limited within the set of stains studied. Furthermore, some conditions even allow for better discrimination than others. From a practical point of view, it is especially important that differences in culturing time (and culturing temperature) can be accommodated.     

Delivering scalable video with QoS to the home

User satisfaction is a key factor in the success of novel multimedia services. Yet, to enable service providers and network operators to control and maximize the quality (QoS, QoE) of delivered video streams, quite some challenges remain. In this paper, we particularly focus on three of them. First of all, objectively measuring video quality requires appropriate quality metrics and methods of assessing them in a real-time fashion. Secondly, the recent Scalable Video Coding (SVC) format opens opportunities for adapting video to the available (network) resources, yet the appropriate configuration of video encoding as well as real-time streaming adaptation are largely unaddressed research areas. Thirdly, while bandwidth reservation mechanisms in access/core networks do exist, service providers lack a means for guaranteeing QoS in the increasingly complex home networks (which they are not in full control of). In this paper we offer a broad view on these interrelated issues, by presenting the developments originating in a Flemish research project (including proof-of-concept demonstrations). From a developmental perspective, we propose an architecture combining a real-time video quality monitoring platform, on-the-fly adaptation (optimizing the video quality) and QoS reservation in a heterogeneous home network based on UPnP QoS?v3. From a research perspective, we propose a new subjective test procedure that revealed user preference for temporal scalability over quality scalability. In addition, an extensive study on optimizing HD SVC encoding in IPTV scenarios with fluctuating bandwidth showed that under certain bandwidth constraints (prohibiting sufficient fidelity) spatial scalability is a better option than quality scalability.     

Edible insects – defining knowledge gaps in biological and ethical considerations of entomophagy

ABSTRACT

While seeking novel food sources to feed the increasing population of the globe, several alternatives have been discussed, including algae, fungi or in vitro meat. The increasingly propagated usage of farmed insects for human nutrition raises issues regarding food safety, consumer information and animal protection. In line with law, insects like any other animals must not be reared or manipulated in a way that inflicts unnecessary pain, distress or harm on them. Currently, there is a great need for research in the area of insect welfare, especially regarding species-specific needs, health, farming systems and humane methods of killing. Recent results from neurophysiological, neuroanatomical and behavioral sciences prompt caution when denying consciousness and therefore the likelihood of presence of pain and suffering or something closely related to it to insects. From an animal protection point of view, these issues should be satisfyingly solved before propagating and establishing intensive husbandry systems for insects as a new type of mini-livestock factory farming.     

Qualitative and event-specific PCR real-time detection methods for StarLink maize

In this paper we present qualitative detection and identification methods for StarLink maize (event CBH-351). The methodology proposed envisages detection of an internal target site in the cry9c coding region, as well as two event-specific target sites at the junction between the CBH-351 insert DNA and the genomic plant DNA. The cry9c-specific primer pair, generating a 180 bp amplicon, has been tested and optimised for conventional end-point PCR amplification. The event-specific primer pairs, generating amplicons of 138 bp and 100 bp respectively, give good performance in a conventional end-point PCR and in a real-time PCR assay. Our results clearly demonstrate that the primer pairs proposed can be used in an unambiguous and specific PCR identification assay for StarLink maize.     

Ruggedness of Integrated VDMOS Transistors Under TLP Stress

The ruggedness of integrated vertical DMOS transistors under transmission line pulsing stress is experimentally investigated at current levels close to the thermal failure current. In addition to the parasitic vertical bipolar closest to the n-sinker contact, the lateral n-p-n transistor with the p-type junction termination as a base also goes into avalanche and supports the total current. As such, the total heat generation in the transistor is shared over a larger cross section, reducing the peak temperature. Along the device width, multiple traveling current filaments are observed; the speed of each individual filament is decreasing with the stress current. A model to predict the normalized thermal failure current I_tf as a function of the device width is proposed. It is shown that I_tf follows a ~W ^-0.5 dependence