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Tagarakis A.,University of Thessaly | Tagarakis A.,Center For Research And Technology Thessaly Cereteth | Liakos V.,University of Thessaly | Fountas S.,University of Thessaly | And 2 more authors.
Precision Agriculture | Year: 2013

Precision viticulture aims at managing vineyards at a sub-field scale according to the real needs of each part of the field. The current study focused on delineating management zones using fuzzy clustering techniques and developing a simplified approach for the comparison of zone maps. The study was carried out in a 1. 0 ha commercial vineyard in Central Greece during 2009 and 2010. Variation of soil properties across the field was initially measured by means of electrical conductivity, soil depth and topography. To estimate grapevine canopy properties, NDVI was measured at different stages during the vine growth cycle. Yield and grape composition (must sugar content and total acidity) mapping was carried out at harvest. Soil properties, yield and grape composition parameters showed high spatial variability. All measured data were transformed on a 48-cell grid (10 × 20 m) and maps of two management zones were produced using the MZA software. Pixel-by-pixel comparison between maps of electrical conductivity, elevation, slope, soil depth and NDVI with yield and grape composition maps, set as reference parameters, allowed for the calculation of the degree of agreement, i. e. the percentage of pixels belonging to the same zone. The degree of agreement was used to select the best-suited parameters for final management zones delineation. For the year 2009 soil depth, early and mid season NDVI were used for yield-based management zones while for quality-based management zones ECa, early and mid season NDVI were utilized. For the year 2010 ECa, elevation and NDVI acquired during flowering and veraison were used for the delineation of yield-based management zones while for quality-based management zones ECa and NDVI acquired during flowering and harvest were utilized. Results presented here could be the basis for simple management zone delineation and subsequent improved vineyard management. © 2012 Springer Science+Business Media, LLC. Source

Budimir M.,INETEC Institute for Nuclear Technology Ltd. | Mohimi A.,Brunel University | Moustakidis S.,Center For Research And Technology Thessaly Cereteth | Gan T.-H.,Brunel University
12th International Conference of the Slovenian Society for Non-Destructive Testing: Application of Contemporary Non-Destructive Testing in Engineering, ICNDT 2013 - Conference Proceedings | Year: 2013

Majority of the current nuclear plants reactors are either close to the end of their 40-years operating license, or already entering a granted extension period. Operators perform expensive refurbishments to address the security and economical soundness of keeping the plants running until they reach 80 or more years. It will most probably be essential to have preventive in-situ continuous structural health monitoring techniques for aging plants. A powerful such tool is high temperature ultrasonic guided waves (UGW) for monitoring the plants pipework. A high temperature lithium niobate piezoelectric shear mode UGW transducer operating at 600C has been developed and tested in this work. The electromechanical parameters of the transducer have been experimentally investigated as functions of temperature. The flaws detection capability of UGW in steel pipes at elevated temperatures has been studied using finite element analysis. The decreased transducers signals at elevated temperatures have been tackled by advanced signal analysis that has been done through pre-processing techniques, such as pattern recognition, along with signal focusing algorithms. Source

Albakour M.-D.,University of Essex | Kruschwitz U.,University of Essex | Nanas N.,Center For Research And Technology Thessaly Cereteth | Neville B.,University of Essex | And 2 more authors.
NIST Special Publication | Year: 2011

This paper provides an overview of the experiments we car- ried out at the TREC 2011 Session Track. We propose two different approaches to tackle the task introduced this year. The first one relies on a biologically inspired adaptive model for information filtering to build a user profile of multiple topics of interests throughout the session. The learnt pro- file is then exploited in the retrieval process. The second approach is an extension of our anchor log technique we proposed in the previous year. We use the anchor logs to simulate queries in order to derive query expansions that are relevant to user information needs throughout the session. Source

Fevgas A.,University of Thessaly | Tsompanopoulou P.,University of Thessaly | Tsompanopoulou P.,Center For Research And Technology Thessaly Cereteth | Lalis S.,University of Thessaly | Lalis S.,Center For Research And Technology Thessaly Cereteth
IFMBE Proceedings | Year: 2010

Recent years there is an extremely growing interest in the study of human motion. A large amount of scientific research projects deal with problems like monitoring human motion, gesture and posture recognition, fall detection etc. Wearable computers and electronic textiles have been successfully used for the study of human physiology, rehabilitation and ergonomics. We present a platform and a methodology for rapid prototype development of e-textile applications for human activity monitoring. © 2010 International Federation for Medical and Biological Engineering. Source

Nanas N.,Center For Research And Technology Thessaly Cereteth | Vavalis M.,Center For Research And Technology Thessaly Cereteth | Vavalis M.,University of Thessaly | Houstis E.,Center For Research And Technology Thessaly Cereteth | Houstis E.,University of Thessaly
Information Processing and Management | Year: 2010

Content-based filtering can be deployed for personalised information dissemination on the web, but this is a possibility that has been largely ignored. Nowadays, there are no successful content-based filtering applications available online. Nootropia is an immune-inspired user profiling model for content-based filtering. It has the advantageous property to be able to represent a user's multiple interests and adapt to a variety of changes in them. In this paper we describe our early efforts to develop real world personalisation services based on Nootropia. We present, the architecture, implementation, usage and evaluation of the personalised news and paper aggregator, which aggregates news and papers that are relevant to an individual's interests. Our user study shows that Nootropia can effectively learn a user's interests and identify relevant information. It also indicates that information filtering is a complicated task with many factors affecting its successful application in a real situation. © 2009 Elsevier Ltd. All rights reserved. Source

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