R. De Sutter

Enhancing RSS feeds: eliminating overhead through binary encoding

While RSS feeds increase in popularity as a mean to stay up to date with the most recent changes on a Web site, its XML representation is causing bandwidth related problems. These issues relate to the verbosity and the indivisible nature of the XML language. As such, bandwidth is wasted twofold as: (1) an RSS feed has no compact representation due to the plain text XML representation; and (2) previously received information about the RSS feed is discarded every time the RSS viewer retrieves the feed. Compression (binary encoding) of the XML data becomes relevant to eliminate the overhead. In this paper, we demonstrate the usefulness of the MPEG-7 binary format for metadata to address both overhead issues. We validate its usability in a typical RSS scenario by calculating the byte size reduction and by comparing the processing speed of creating and parsing binary encoded RSS feeds to traditional RSS feeds.

Evaluation of models for parsing binary encoded XML-based metadata

In multimedia applications, XML is being increasingly used to represent metadata. As with the media data, the size of, or the overhead induced by, the XML metadata is important, particularly when used on constrained mobile devices. Therefore, compression (binary encoding) of the XML data becomes relevant to reduce this overhead. Within the MPEG-7 standardization effort, a binary format for metadata (BiM) was developed, providing good compression efficiency and facilitating random access into, and manipulation of, the binary encoded bit stream. In order to support processing of metadata streams in the binary domain and making this task for client applications as simple as possible, we are developing a universal parser for handling both plain text and binary encoded XML-based metadata. The parser exposes a single interface making it transparent for the application whether a plain text or a binary XML document is being processed. As part of this effort, this paper provides a detailed study of five existing XML parser models and evaluates their applicability to serve as a model for parsing binary XML data.

The erosion of cohesive mixed deposits: implications for sewer flow quality modelling.

Abstract The movement of sediments in sewers has been widely recognised as being strongly linked with poor sewer flow quality. Currently, empirically calibrated transport capacity relationships are used to estimate the movement of in-sewer sediments. The majority of these relationships were developed and calibrated with laboratory data sets that used uniformly sized granular sediment. In many combined sewers, there are both organic and inorganic sediments. The fine-grained organic sediments are thought to be able to develop considerable cohesive strength under certain conditions. This paper describes the results from laboratory experiments in which the erosion of non-homogeneous in-pipe sediment deposits was investigated. The types of sediment mixtures used ensured that a range of cohesive deposit strengths was developed. The measured bed load and suspended load were compared with transport capacity relationships currently used for sewer design. Significant divergence between the transport capacity predictions and experimental observations was discovered. It was seen that it is unwise to model in-sewer deposits as homogeneous and granular and that it is important to take into account the impact of deposit cohesion.

Personalizing Quality Aspects in Scalable Video Coding

In video coding, certain limitations imposed by the environment, most typically the bit rate, need to be fulfilled. This is achieved by allowing the encoder to reduce the quality in one or several ways, such as the distortion, the resolution and the frame rate. The upcoming scalable video coding mechanisms allow this reduction to take place not exclusively during the encoding step, but at any time. This allows us to reduce the quality in a more personalized way, taking into consideration the preferences of the end user. This paper presents a framework that enables such user dependent quality reductions. We validated this framework by means of a test involving 19 test persons. The results of this mechanism are good, but up to now not sufficiently reliable to use it in commercial applications. At the same time, we still see some room for improvement

Climate change: Threat or opportunity for Belgian sea fisheries?

Sea fisheries are an important activity for the coastal community of Flanders from a socio-cultural-economic point of view. It’s apparent that the Belgian fishing fleet operates in a complex, changing and uncertain environment. The strong specialization of the Belgian fleet with regard to fishing method (93% beam trawlers) and target species (mainly flatfish) makes the Belgian fisheries sector rather vulnerable to these continuously changing circumstances. Recently the sector is faced with yet another factor which contributes to the growing uncertainty: climate change. Climate change will most probably impose additional pressure on the sea fishery, but may also offer opportunities.

Simulation Of Sediment Transport In A SmallBasin With Artificial Flood Events

The purpose of creating artificial storm events in a small brook is to perform an isolated examination of in-channel sediment transport processes without the interference of soil erosion and runoff. The interaction is investigated between the kinematic flood wave and the sediment . A compatible experimental setup makes it possible to correct and to validate the field measurements. It is shows how the variation of the characteristics of the suspended and the dissolved load exerts an influence. This paper shows some interesting links between the chemical aspects and physical properties of the sediments as a result of a interdisciplinary cooperation between engineers and hydroiogists.