Resilient availability and bandwidth-aware multipath provisioning for media transfer over the internet (Best Paper Award)

Traditional routing in the Internet is best-effort. Path differentiation including multipath routing is a promising technique to be used for meeting QoS requirements of media intensive applications. Since different paths have different characteristics in terms of latency, availability and bandwidth, they offer flexibility in QoS and congestion control. Additionally protection techniques can be used to enhance the reliability of the network. This paper studies the problem of how to optimally find paths ensuring maximal bandwidth and resiliency of media transfer over the network. In particular, we propose two algorithms to reserve network paths with minimal new resources while increasing the availability of the paths and enabling congestion control. The first algorithm is based on Integer Linear Programming which minimizes the cost of the paths and the used resources. The second one is a heuristic-based algorithm which solves the scalability limitations of the ILP approach. The algorithms ensure resiliency against any single link failure in the network. The experimental results indicate that using the proposed schemes the connections availability improve significantly and a more balanced load is achieved in the network compared to the shortest path-based approaches

Nutrient recovery from digestates : techniques and end-products

In nitrate vulnerable zones application of animal manure to land is limited. Digestate from anaerobic digestion plants competes with manure for nutrient disposal on arable land, which forms a serious hinder for the biogas sector to develop in these regions. Hence, one of its biggest challenges is to find cost-effective and sustainable ways for digestate processing or disposal. Furthermore, primary phosphorus resources are becoming scarce and expensive and will be depleted within a certain time. This urges the need to recycle P from secondary sources, like digestate or manure. From a sustainability point of view, it seems therefore no more than logical that digestate processing techniques switched their focus to nutrient recovery rather than nutrient removal. This paper gives an overview of digestate processing techniques, with a special focus on nutrient recovery techniques. In this paper nutrient recovery techniques are delineated as techniques that (1) create an end-product with higher nutrient concentrations than the raw digestate or (2) separate the envisaged nutrients from organic compounds that are undesirable in the end-product, with the aim to produce an end-product that is fit for use in chemical or fertiliser industry or as a mineral fertiliser replacement. Various nutrient recovery techniques are described, with attention for some technical bottlenecks and the current state of development. Where possible, physicochemical characteristics of the endproducts are given

A contrast-sensitive reversible visible image watermarking technique

A reversible (also called lossless, distortion-free, or invertible) visible watermarking scheme is proposed to satisfy the applications, in which the visible watermark is expected to combat copyright piracy but can be removed to losslessly recover the original image. We transparently reveal the watermark image by overlapping it on a user-specified region of the host image through adaptively adjusting the pixel values beneath the watermark, depending on the human visual system-based scaling factors. In order to achieve reversibility, a reconstruction/ recovery packet, which is utilized to restore the watermarked area, is reversibly inserted into non-visibly-watermarked region. The packet is established according to the difference image between the original image and its approximate version instead of its visibly watermarked version so as to alleviate its overhead. For the generation of the approximation, we develop a simple prediction technique that makes use of the unaltered neighboring pixels as auxiliary information. The recovery packet is uniquely encoded before hiding so that the original watermark pattern can be reconstructed based on the encoded packet. In this way, the image recovery process is carried out without needing the availability of the watermark. In addition, our method adopts data compression for further reduction in the recovery packet size and improvement in embedding capacity. The experimental results demonstrate the superiority of the proposed scheme compared to the existing methods