The Role of Responsive Pricing in the Internet

The Internet continues to evolve as it reaches out to a wider user population. The recent introduction of user-friendly navigation and retrieval tools for the World Wide Web has triggered an unprecedented level of interest in the Internet among the media and the general public, as well as in the technical community. It seems inevitable that some changes or additions are needed in the control mechanisms used to allocate usage of Internet resources. In this paper, we argue that a feedback signal in the form of a variable price for network service is a workable tool to aid network operators in controlling Internet traffic. We suggest that these prices should vary dynamically based on the current utilization of network resources. We show how this responsive pricing puts control of network service back where it belongs: with the users.Internet, pricing, feedback, networks

Cost-based burst dropping strategy in optical burst switching networks

Optical burst switching (OBS) is a new paradigm for future all-optical networks. Intentional burst dropping is one of techniques used to achieve desired quality of service. In this paper we note that some bursts are more likely to cause contention. We propose a cost function that can be used to predict the likelihood that a given burst will interfere with other traffic, then we explain how, by using this information a new burst dropping strategy can be designed. We compare our method with a random burst dropping technique and show that the cost-based approach offers a significant performance improvement

Ontology-Based Quality Evaluation of Value Generalization Hierarchies for Data Anonymization

In privacy-preserving data publishing, approaches using Value Generalization Hierarchies (VGHs) form an important class of anonymization algorithms. VGHs play a key role in the utility of published datasets as they dictate how the anonymization of the data occurs. For categorical attributes, it is imperative to preserve the semantics of the original data in order to achieve a higher utility. Despite this, semantics have not being formally considered in the specification of VGHs. Moreover, there are no methods that allow the users to assess the quality of their VGH. In this paper, we propose a measurement scheme, based on ontologies, to quantitatively evaluate the quality of VGHs, in terms of semantic consistency and taxonomic organization, with the aim of producing higher-quality anonymizations. We demonstrate, through a case study, how our evaluation scheme can be used to compare the quality of multiple VGHs and can help to identify faulty VGHs.Comment: 18 pages, 7 figures, presented in the Privacy in Statistical Databases Conference 2014 (Ibiza, Spain

Synthetic Data Generation using Benerator Tool

Datasets of different characteristics are needed by the research community for experimental purposes. However, real data may be difficult to obtain due to privacy concerns. Moreover, real data may not meet specific characteristics which are needed to verify new approaches under certain conditions. Given these limitations, the use of synthetic data is a viable alternative to complement the real data. In this report, we describe the process followed to generate synthetic data using Benerator, a publicly available tool. The results show that the synthetic data preserves a high level of accuracy compared to the original data. The generated datasets correspond to microdata containing records with social, economic and demographic data which mimics the distribution of aggregated statistics from the 2011 Irish Census data.Comment: 12 pages, 5 figures, 10 reference

A survey of fertilizer use from 2001-2003 for grassland and arable crops

End of project reportFarm management data for the years 2001-2003 from the Teagasc National Farm Survey (NFS) were used as the basis for this fertilizer use survey. The farms which took part in the survey were randomly selected to represent the major farm systems and sizes using information from the CSO Census of Agriculture 2000. Farms were classified into 6 main farm systems namely: dairying, dairying with other enterprises, cattle rearing, cattle with other systems, mainly sheep and tillage systems. These systems refer to the dominant enterprise in each group

A bridging-based solution for efficient multicast support in wireless mesh networks

Proceedings of: The 34th Annual IEEE Conference on Local Computer Networks (LCN 2009), October 20-23, 2009, Zurich, SwitzerlandWireless mesh networking is a promising, cost effective and efficient technology for realizing backhaul networks supporting high quality services. In such networks, multicast data are transmitted blindly without any mechanism protecting data from loss, ensuring data reception, and optimizing channel allocation. The multicast services may undergo, then, very high data loss ratio which is exacerbated with the number of hops. In this paper, we propose a Reliable Multicast Distribution System (RMDS) to optimize multicast packets transmission in bridged networks. Relying on a modification of the IGMP snooping protocol, RMDS enables reliable services provisioning support in common wireless mesh networks. In particular, RMDS only exploits the local knowledge of a particular node to compute the multicast tree, which significantly reduces the signalling overhead in comparison with network layer and overlay solutions. Simulation results elucidate that RMDS optimizes resources’ allocation by reducing significantly the network load, the media access delay and the data drop rate compared to the classical approach, which is based on the combination of spanning tree algorithm and IGMP snooping protocol.European Community's Seventh Framework ProgramPublicad

Corporate expenditure on environmental protection

We examine the determinants of firm's current environmental expenditure and firm's capital investment in equipment for pollution control using a Heckman selection model. As regards current environmental expenditure, we find that larger, exporting firms and firms subject to the Integrated Pollution Prevention and Control directive are more likely to spend resources at all. Once the decision to commit resources has been taken, larger firms, firms that are foreign-owned, and firms that report low shares of water and refuse charges in turnover have higher absolute levels of environmental expenditure. With respect to investment in equipment for pollution control, we find that energy intensive and exporting firms are more likely to invest at all. Once the decision to invest has been taken, larger firms and firms that report high water and refuse charges invest more in equipment for pollution control. This suggests that the firms for whom environmental concerns are most costly in terms of production and image do most to address them

Behind-the-scenes of IEEE 802.11a based multi-radio mesh networks: a measurement driven evaluation of inter-channel interference

To successfully develop IEEE 802.11a based wireless mesh network solutions that can achieve the reliability and capacities required to offer high quality triple play services the use of multiple radios in each mesh node is essential. Unfortunately, the co-location of multiple antennas in a single device leads to a number of interference problems. In this paper the impact of non-overlapping channel interference in IEEE 802.11a based multi-radio nodes is investigated. A detailed explanation of the performance decreases and their relation to radio settings is presented. The primary contribution of this paper is the discovery of a channel interference effect which is present over the entire 802.11a frequency space. This interference appears if two radios are located less than 50 cm from each other and both are attempting to operate as usual. The results were obtained by conducting experiments in a well planned testbed to produce reliable and reproducible results. The presented results incorporate multiple parameters including transmission power, modulation coding scheme, channel separation and physical layer effects such as adjacent channel interference, carrier sensing, retransmissions and packet distortion.European Community's Seventh Framework ProgramPublicad

Corporate Expenditure on Environmental Protection. ESRI WP347. June 2010

We examine the determinants of firm’s current environmental expenditure and firm’s capital investment in equipment for pollution control using a Heckman selection model. As regards current environmental expenditure, we find that larger, exporting firms and firms subject to the Integrated Pollution Prevention and Control directive are more likely to spend resources at all. Once the decision to commit resources has been taken, larger firms, firms that are foreign-owned, and firms that report low shares of water and refuse charges in turnover have higher absolute levels of environmental expenditure. With respect to investment in equipment for pollution control, we find that energy intensive and exporting firms are more likely to invest at all. Once the decision to invest has been taken, larger firms and firms that report high water and refuse charges invest more in equipment for pollution control. This suggests that the firms for whom environmental concerns are most costly in terms of production and image do most to address them