Delimitation of the warm and cold period of the year based on the variation of the Aegean sea surface temperature

Knowledge of the warm and cold season onset is important for the living conditions and the occupational activities of the inhabitants of a given area, and especially for agriculture and tourism. This paper presents a way to estimate the onset/end of the cold and warm period of the year, based on the sinusoidal annual variation of the Sea Surface Temperature. The method was applied on data from 8 stations of the Hellenic Navy Hydrographic Service, covering the period from 1965-1995. The results showed that the warm period starts sometime between April 28th and May 21st while it ends between October 27th and November 19th in accordance with the findings of other studies. Characteristic of the nature of the parameter used is the very low variance per station – 15 days at maximum. The average date of warm period onset is statistically the same for the largest part of the Aegean, with only one differentiation, that between Kavala and the southern stations ( Thira and Heraklion)

Model-driven Enterprise Systems Configuration

Enterprise Systems potentially lead to significant efficiency gains but require a well-conducted configuration process. A promising idea to manage and simplify the configuration process is based on the premise of using reference models for this task. Our paper continues along this idea and delivers a two-fold contribution: first, we present a generic process for the task of model-driven Enterprise Systems configuration including the steps of (a) Specification of configurable reference models, (b) Configuration of configurable reference models, (c) Transformation of configured reference models to regular build time models, (d) Deployment of the generated build time models, (e) Controlling of implementation models to provide input to the configuration, and (f) Consolidation of implementation models to provide input to reference model specification. We discuss inputs and outputs as well as the involvement of different roles and validation mechanisms. Second, we present an instantiation case of this generic process for Enterprise Systems configuration based on Configurable EPCs

Distribution of trace metals in the sediments of Elefsis Gulf

The present work examines the temporal evolution of industrial contamination in sediments caused by trace metals in the Elefsis Gulf, Greece. The current state of contamination as well as the related sources can be obtained from the study of the sediments. Trace metals, namely Ni, Cu, Fe, and Mn, were collected during 1984-2003 by the local monitoring network. The statistical analysis of the data and the contaminants isopleths patterns support the following conclusions: There is a strong correlation between the nearby coastal industrial activities and the distribution of the trace metals’ concentration in sediments. There is no seasonal or annual variation of the distribution. The sediments’ concentration of Mn in all sampling points and Cu in the center of the Gulf has decreased during the last years

COMPRESSED DOMAIN IMAGE INDEXING AND RETRIEVAL BASED ON THE MINIMAL SPANNING TREE

ABSTRACT In this paper, a method for content-based retrieval of JPEG images is presented, utilizing features directly from the discrete cosine transform (DCT) domain. Image indexing is achieved by extracting color and texture feature vectors, using an efficient technique applied on the DCT coefficients. Similarity between the query-and database-images is provided based on a statistical graph matching approach. The proposed measure makes use of the Wald-Wolfowitz test, a nonparametric test that assesses the commonality between two different sets of multivariate observations. Experimental results demonstrate the enhanced performance of our approach, compared to previously reported methods

Spectral Evidence of Ice on Aircrafts – The SEI Project

The general objective of the SEI project (reference call: MANUNET III 2018) is to experiment spectral sensor fusion techniques of data acquired by UAVs (Unmanned Aerial Vehicles) during aircraft preflight inspection. In General Aviation, an important safety issue regards the presence of ice on the aircraft's fuselage and wings. Ice on the wings can cause loss of lift and stalling, which in most cases would result, during take-off phase, in airplane’s fatal crash. Another important aspect to consider is the high amount of de-icing liquid usually involved in the process incurring in high costs and considerable damage to the environment. This is not a typical industrial scenario, but the project addresses important aspects related to the manufacturing sector: it has to accomplish specific tasks following a design process; it involves human operators (labour) collaborating with machines and tools; it includes the usage of semi-raw materials (glycol fluids) to accomplish a service; it sees serialization of the process that could be invoked at any needed time. Moreover, it targets safety issues both for operators and machines regarding reliability of results at the end of the process, it is order-based and comparable to a discrete manufacturing process

The temperature of the sea-surface in the region of the Aegean and its relation to air temperature

In this study the annual course of the air and sea-surface temperature in the Aegean sea is examined and a possibly existing relation between these two meteorological parameters is sought. To do this the monthly values of both elements for the period 1971-1975 were cross-correlated. It was found that in general the observed delay of the maximum and minimum values of the temperature of the sea was of the order of one month. © 1990 Springer-Verlag