Flexible power converters for the fault tolerant operation of Micro-Grids

The progressive penetration level of Distributed Generation (DG) is destined to cause deep changes in the existing distribution networks no longer considered as passive terminations of the whole electrical system. A possible solution is the realization of small networks, namely the Micro-Grids, reproducing in themselves the structure of the main production and distribution of the electrical energy system. In order to gain an adequate reliability level of the microgrids the individuation and the management of the faults with the goal of maintaining the micro-grid operation (fault tolerant operation) is quite important. In the present paper flexible power converters and a companion control algorithm for the fault tolerant operation of microgrids are presented. The effectiveness of such an algorithm and of the fault tolerant power converters are verified through computer simulations

Forage mixture productivity and silage quality from a grass/legume intercrop in a semiarid Mediterranean environment

In semiarid environments of the Mediterranean region, intercropping is a sustainable agricultural system of long standing. In this area, the pea (Pisum sativum L.) is one of the most commonly grown legume crops. Little information is available on the quality of silages to be obtained from forage mixtures of pea intercropped with cereals or annual grasses. In this study, two experiments were conducted over the course of two growing seasons in Sicily (Italy) with the aim to determine the biomass production of forage crop mixtures and assess, only in the second experiment, the silage quality of grass and legumes. Four cereals and one annual grass species were grown in pure stand and in mixture with pea, and their main agronomic traits were determined. The land equivalent ratio (LER), competitive ratio, and aggressivity index were also calculated. A number of parameters were considered to assess the quality of silage obtained from fermented biomasses derived from pea–ryegrass (Lolium multiflorum Lam. var. Westerwoldicum) intercropping. In the first experiment, the best performance between the intercrops was recorded for the pea–wheat mixture. The total LER calculated for fodder yields was always greater than 1, indicating crop yield advantages ranging from 2.0% to 47.0%. In the second experiment, the pea–ryegrass mixture appeared to respond well, depending on plant arrangement and seeding ratio factors: the ratios 50:50 and 100:50 showed the greatest crop yield advantages, of 12.0% and 11.0%, respectively. All silages revealed a very good suitability of a pea–ryegrass intercropping system with high-quality silage production in the Southern Mediterranean region

Effects of harvesting methods on seed yield and quality of Scorpiurs muricatus L..

Scorpiurus muricatus L. is an annual legume, widely distributed in Mediterranean pastures, that is appreciated by farmers for its productivity, forage quality, and palatability. It is characterised by long flowering and ripening periods and by pod shedding. These characteristics cause high seed losses, which could reduce its seed harvest efficiency in terms of seed yield and quality. In this study, we investigated the effects on seed yield and quality of different harvesting methods (windrowing at different times with subsequent combining was compared with direct combining). Our results show that direct combining when the pods were fully ripened reduced pod losses compared with swathing methods, producing the highest yield of seed actually harvested. However, in this study, the unique climatic conditions during the pod development stage (extremely high temperatures) accelerated the ripening process, presumably limiting pod shedding

Extracting Touristic Information from Online Image Collections

In this paper, we present a Geographical Information Retrieval system, which aims to automatically extract and analyze touristic information from photos of online image collections (in our case of study Flickr). Our system collect all the photos, and the related information, that are associated to a specific city. We then use Google Maps service to geolocate the retrieved photos, and finally we analyze geo-referenced data to obtain our goals: 1) determining and locating the most interesting places of the city, i.e. the most visited locations, and 2) reconstructing touristic routes of the users visiting the city. Information is filtered by using a set of constraints, which we apply to select only the users that reasonably are tourists visiting the city. Tests were performed on an Italian city, Palermo, that is rich in artistic and touristic attractions, but preliminary tests showed that our technique could successfully be applied to any city in the world with a reasonable number of touristic landmarks

Fault Tolerant Ancillary Function of Power Converters in Distributed Generation Power System within a Microgrid Structure

Distributed generation (DG) is deeply changing the existing distribution networks which become very sophisticated and complex incorporating both active and passive equipment. The simplification of their management can be obtained assuming a structure with small networks, namely, microgrids, reproducing, in a smaller scale, the structure of large networks including production, transmission, and distribution of the electrical energy. Power converters in distributed generation systems carry on some different ancillary functions as, for example, grid synchronization, islanding detection, fault ride through, and so on. In view of an optimal utilization of the generated electrical power, fault tolerant operation is to be considered as a suitable ancillary function for the next future. This paper presents a complete modeling of fault tolerant inverters able to simulate the main fault type occurrence and a control algorithm for fault tolerant converters suitable for microgrids. After the model description, formulated in terms of healthy device and leg binary variables, and the illustration of the fault tolerant control strategy, the paper shows how the control preserves power quality when the converter works in the linear range. The effectiveness of the proposed approach and control is shown through computer simulations and experimental results

Non-projective Dependency-based Pre-Reordering with Recurrent Neural Network for Machine Translation

The quality of statistical machine translation performed with phrase based approaches can be increased by permuting the words in the source sentences in an order which resembles that of the target language. We propose a class of recurrent neural models which exploit source side dependency syntax features to reorder the words into a target-like order. We evaluate these models on the German-to-English language pair, showing significant improvements over a phrase-based Moses baseline, obtaining a quality similar or superior to that of hand-coded syntactical reordering rules

Digital transformation in the visual inspection of heritage railways tunnels: Technology, artificial intelligence and methodology

The knowledge, the preservation and the maintenance of heritage infrastructures is one of the most challenging matters facing modern civilization. It involves, in inextricable patterns, factors belonging to different fields (cultural, humanistic, social, technical, economical, administrative) coupled with the requirements of safety that can be in conflict with the integrity of part of the infrastructure. For these reasons, it is fundamental to carry out investigations and new planning strategies to know and predict the conditions of very old structures. The paper focused on heritage railway tunnels, one of the most crucial elements of the railway infrastructures in Europe. ETS Srl introduced a new method for diagnostic of existing tunnels through multi-dimensional mobile mapping systems, and a new approach for the Management and Identification of the Risk for Existing Tunnels. The approach belongs to the digital strategies for infrastructure maintenance that are very fast and minimally invasive. The integrated instrumentation allows to have almost all the information necessary for the diagnostics of a structure with non-destructive tests, preserving the integrity of very old structures in a phase of preliminary assessment. In such a way, the process of visual inspection is automatized and back-officed. The results, in terms of defects on the structures, are digitalized and manipulated in different IT environments. The results can be incorporated in the information modelling and virtual reality inspections. The use of artificial intelligence will be necessary to speed-up the back-office phase and introduce the technologies as a new inspection standard. A case study for the application is presented through the methodologies, including some preliminary applications of AI algorithms for the detection of water defects

Roller Speed Skating Kinematics and Electromyographic Analysis: A Methodological Approach

Roller speed skating is a discipline similar to hockey and ice skating from a biomechanical point of view, but there are no specific functional protocols for rehabilitation and performance improvement for these athletes. The aim of the study is to create a dedicated functional, kinematic and electromyographic protocol to be used as a tool for future studies on the subject. The protocol was created, starting from a correct and repeatable movement as a case study, on a world speed skating champion, using an inertial sensor positioned at the level of the first sacral vertebra, eight electromyographic probes positioned on one or the other lower limb, and a high-definition camera at 50 Hz. The results show the electromyographic activity of the muscles investigated, the degree of absolute muscle activation and compared to their maximum voluntary isometric contraction (MVIC), the level of co-activation of the agonist/antagonist muscles, and the accelerations of the body on the three axes of space. The results will represent the basis for physiotherapy and specific training use. Future developments will include the analysis of a sample of elite athletes to be able to build a normal range on the parameters investigated, and the possibility of treating in the most appropriate way possible muscle injuries (which mostly occur in the groin in such athletes) once they have occurred, even with oriented MVIC or co-activation oriented exercises