199 research outputs found

    Using digital watermarking to enhance security in wireless medical image transmission

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    This is the published version of the article. Copyright 2010 Mary Ann Liebert Inc.During the last few years, wireless networks have been increasingly used both inside hospitals and in patients’ homes to transmit medical information. In general, wireless networks suffer from decreased security. However, digital watermarking can be used to secure medical information. In this study, we focused on combining wireless transmission and digital watermarking technologies to better secure the transmission of medical images within and outside the hospital. Methods: We utilized an integrated system comprising the wireless network and the digital watermarking module to conduct a series of tests. Results: The test results were evaluated by medical consultants. They concluded that the images suffered no visible quality degradation and maintained their diagnostic integrity. Discussion: The proposed integrated system presented reasonable stability, and its performance was comparable to that of a fixed network. This system can enhance security during the transmission of medical images through a wireless channel.The General Secretariat for Research and Technology of the Hellenic Ministry of Development and the British Council

    Endocrine correlates of male breast cancer risk: a case-control study in Athens, Greece

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    We studied the relation of certain endocrine-related variables among 23 cases of male breast cancer and 76 apparently healthy male controls. There were significant inverse associations with smoking (P = 0.03), birth order (P = 0.02) and reported frequency of orgasms in later life (P = 0.0004). The study provides strong indirect evidence that endocrine factors are important in the aetiology of male breast cancer. © 2000 Cancer Research Campaig

    Efficiency and productivity changes in Greek airports during the crisis years 2010–2014

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    © 2016 Elsevier Ltd The aim of this study is to evaluate the operating efficiency and productivity changes of the Greek airports, during the first years of the severe economic crisis in Greece (2010–2014), by using two methods: Data Envelopment Analysis (DEA) and Malmquist Productivity index (MPI). Findings have shown that, despite the dramatic effects of the economic crisis on the socio-economic life of the country, overall airport efficiency and productivity improved, mainly due to exogenous factors such as international tourism growth. The MPI reveals that over the period of the study, airports have experienced an annual average increase in total factor productivity (TFP) of 0.9% (an increase of 3.6% over the examined period). On examining the components of this productivity change, it becomes evident that this is due to the combination of both positive (a slight progress) annual average technology change (0.5%) and technical efficiency change (0.4%). The results also indicate that 65.8% of airports have an increase in average TFP during the period 2010–2014, ranging between 0.4% and 20%. However, as Greek airports operate at poor levels of efficiency, there is still considerable space for improvements in most of the airports

    Improving the eco-efficiency of an agricultural water use system

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    During the last two decades, the concept of eco-efficiency has been recognized as a suitable measure of progress towards a greener and more sustainable economy. The prefix “eco-” refers to both economic and ecological (environmental) performance. The need for improving eco-efficiency leads to the challenge of identifying the most promising alternative solutions which improve both the economic and the environmental performance of a given system (“eco-innovations”). Therefore, it becomes critical to develop eco-efficiency metrics for measuring environmental and economic performance of a system. The current paper presents a methodological framework that attempts to explore the use of eco-efficiency indicators in meso-level water use systems and through them to assess the impact of innovative technologies in such systems. The assessment of the environmental performance follows a life-cycle oriented approach using the midpoint impact categories while the economic performance is measured using the Total Value Added to the product due to water use. The eco-efficiency is expressed as the ratio of the economic performance indicator to the environmental performance indicator. The proposed approach is applied to a water use system of the agricultural sector, and more specifically to the fresh form tomato crop production in Phthiotida. The analysis reveals that the most important environmental impacts of the system are (i) greenhouse gas emissions due to energy consumption, (ii) release of toxic substances, due to the use of fertilizers and pesticides and (iii) depletion of freshwater resources. Three alternative interventions are examined for upgrading the value chain: (i) installation of sub-surface drip irrigation system, (ii) replacement of diesel pumps with solar pumps and (iii) use of organic fertilizers. Based on the findings, all of the proposed interventions have a positive impact on the overall eco-efficiency of the system. Sub-surface drip irrigation is the least favorable mainly due to its high investment cost. The use of solar pumps strongly influences climate change and photochemical ozone formation while the use of organic fertilizers has a more balanced impact on all indicators, with an emphasis on eutrophication. Thus, for a more holistic approach, regarding the eco-efficiency performance, a combined application of these three scenarios may be proposed

    RAPP System Architecture

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    International audience— Robots are fast becoming a part of everyday life. This rise can be evidenced both through the public news and announcements, as well as in recent literature in the robotics scientific communities. This expanding development requires new paradigms in producing the necessary software to allow for the users' particular needs. In this paper we present a novel architectural design of the RAPP framework that attempts to address this issue, developed within the context of the EU funded project RAPP "Robotic Applications for Delivering Smart User Empowering Application". The proposed framework has been designed aiming towards a cloud-based approach to integrating robotic devices and their respective applications. This goal was defined going beyond the up-coming trends in infrastructures, and focusing on alternative approaches to conventional robotic controllers, while at the same time expanding the capabilities of the RAPP framework in a seamless and scaling manner

    The interplay of wind and uplift facilitates over-water flight in facultative soaring birds.

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    Flying over the open sea is energetically costly for terrestrial birds. Despite this, over-water journeys of many birds, sometimes hundreds of kilometres long, are uncovered by bio-logging technology. To understand how these birds afford their flights over the open sea, we investigated the role of atmospheric conditions, specifically wind and uplift, in subsidizing over-water flight at a global scale. We first established that ΔT, the temperature difference between sea surface and air, is a meaningful proxy for uplift over water. Using this proxy, we showed that the spatio-temporal patterns of sea-crossing in terrestrial migratory birds are associated with favourable uplift conditions. We then analysed route selection over the open sea for five facultative soaring species, representative of all major migratory flyways. The birds maximized wind support when selecting their sea-crossing routes and selected greater uplift when suitable wind support was available. They also preferred routes with low long-term uncertainty in wind conditions. Our findings suggest that, in addition to wind, uplift may play a key role in the energy seascape for bird migration that in turn determines strategies and associated costs for birds crossing ecological barriers such as the open sea

    Comparative efficiency analysis of Portuguese bank branches

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    The advent of Internet banking and phone banking is changing the role of bank branches from a predominantly transaction-based one to a sales-oriented role. This paper reports on an assessment of the branches of a Portuguese bank in terms of their performance in their new roles in three different areas: Their efficiency in fostering the use of new transaction channels, their efficiency in increasing sales and their customer base, and their efficiency in generating profits. Service quality is also a major issue in service organisations like bank branches, and therefore we analyse the way this dimension of performance has been accounted for in the literature and take it into account in our empirical application. We have used data envelopment analysis (DEA) for the different performance assessments, but we depart from traditional DEA models in some cases. Performance comparisons on each dimension allowed us to identify benchmark bank branches and also problematic bank branches. In addition, we found positive links between operational and profit efficiency and also between transactional and operational efficiency. Service quality is positively related with operational and profit efficiency. © 2006 Elsevier B.V. All rights reserved

    Data envelopment analysis in financial services: a citations network analysis of banks, insurance companies and money market funds

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    Development and application of the data envelopment analysis (DEA) method, have been the subject of numerous reviews. In this paper, we consider the papers that apply DEA methods specifically to financial services, or which use financial services data to experiment with a newly introduced DEA model. We examine 620 papers published in journals indexed in the Web of Science database, from 1985 to April 2016. We analyse the sample applying citations network analysis. This paper investigates the DEA method and its applications in financial services. We analyse the diffusion of DEA in three sub-samples: (1) banking groups, (2) money market funds, and (3) insurance groups by identifying the main paths, that is, the main flows of the ideas underlying each area of research. This allows us to highlight the main approaches, models and efficiency types used in each research areas. No unique methodological preference emerges within these areas. Innovations in the DEA methodologies (network models, slacks based models, directional distance models and Nash bargaining game) clearly dominate recent research. For each subsample, we describe the geographical distribution of these studies, and provide some basic statistics related to the most active journals and scholars

    Next-generation HLA typing of 382 International Histocompatibility Working Group reference B-lymphoblastoid cell lines: Report from the 17th International HLA and Immunogenetics Workshop

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    Extended molecular characterization of HLA genes in the IHWG reference B-lymphoblastoid cell lines (B-LCLs) was one of the major goals for the 17th International HLA and Immunogenetics Workshop (IHIW). Although reference B-LCLs have been examined extensively in previous workshops complete high-resolution typing was not completed for all the classical class I and class II HLA genes. To address this, we conducted a single-blind study where select panels of B-LCL genomic DNA samples were distributed to multiple laboratories for HLA genotyping by next-generation sequencing methods. Identical cell panels comprised of 24 and 346 samples were distributed and typed by at least four laboratories in order to derive accurate consensus HLA genotypes. Overall concordance rates calculated at both 2- and 4-field allele-level resolutions ranged from 90.4% to 100%. Concordance for the class I genes ranged from 91.7 to 100%, whereas concordance for class II genes was variable; the lowest observed at HLA-DRB3 (84.2%). At the maximum allele-resolution 78 B-LCLs were defined as homozygous for all 11 loci. We identified 11 novel exon polymorphisms in the entire cell panel. A comparison of the B-LCLs NGS HLA genotypes with the HLA genotypes catalogued in the IPD-IMGT/HLA Database Cell Repository, revealed an overall allele match at 68.4%. Typing discrepancies between the two datasets were mostly due to the lower-resolution historical typing methods resulting in incomplete HLA genotypes for some samples listed in the IPD-IMGT/HLA Database Cell Repository. Our approach of multiple-laboratory NGS HLA typing of the B-LCLs has provided accurate genotyping data. The data generated by the tremendous collaborative efforts of the 17th IHIW participants is useful for updating the current cell and sequence databases and will be a valuable resource for future studies
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