Search results for "Wide area"

The working partner in family enterprise : European and national issues

2021

The essay focuses on the discipline of the work done by one partner in the company of the other in cross-border couples and on the problems involved in this case. More specifically the focus is on the hermeneutical problems that arise both at the level of European legislation and at the level of Italian national discipline which is applicable according to European conflict criteria, showing the ambiguities and wide areas of shadow left uncovered by the latter.

Long-term changes in drought indices in eastern and central Europe

2021

This study analyses long-term changes in drought indices (Standardised Precipitation Index—SPI, Standardised Precipitation–Evapotranspiration Index—SPEI) at 1 and 3?months scales at 182 stations in 11 central and eastern European countries during 1949–2018. For comparative purposes, the necessary atmospheric evaporative demand (AED) to obtain SPEI was calculated using two methods, Hargreaves-Samani (SPEIH) and Penman-Monteith (SPEIP). The results show some relevant changes and tendencies in the drought indices. Statistically significant increase in SPI and SPEI during the cold season (November–March), reflecting precipitation increase, was found in the northern part of the study region, in …

Wide area monitoring of sustained oscillations using double-stage mode decomposition

2018

Virtual Environment for Implementation and Testing Private Wide Area Network Solutions

2013

In this paper the concept of virtual environment for implementation and testing private Wide Area Network (WAN) solutions is presented. The VMware vSphere virtualization platform is used. The paper presents the ability to reflect the structure of any given WAN topology using Vyatta software routers and VMware virtualization platform and verifies its reliability regarding data transfer. The paper includes a number of performance tests to verify the dependability of the proposed solution and provide a proof-of-concept for the network topology during the Design phase of the PPDIOO methodology, right before the Implementation phase.

The Two-Criteria Topological Design Problem in WAN with Delay Constraint: An Algorithm and Computational Results

2003

The problem is concerned with designing of wide area networks (WAN). The problem consists in selection of flow routes, channel capacities and wide area network topology in order to minimize the total average delay per packet and the leasing cost of channels subject to delay constraint. The problem is NP complete. Then, the branch and bound method is used to construct the exact algorithm. Lower bound of the criterion function is proposed. Computational results are reported. Based on computational experiments, several properties of the considered problem are formulated.

ETP/GDOP Behavior Study for N-Sensors Arrays ina Multilateration Radar System

2009

In this paper, we evaluated the ETP (Expected Theoretical Precision) and GDOP (Geometric Dilution Of Precision) enhancement related to the number of sensors in a Multilateration radar system. An introduction about the principles of the Multilateration radar system basis operation is described, then, the formulation for evaluation the ETP/GDOP of the 3D positioning is shown. We observed that the ETP and GDOP enhance with the increase of the number of sensors. A substantial improvement was obtained until nine sensors but, for more sensors that improvement is reduced. Results for a 75km×75km area are shown, including LAM (Local Area Multilateration) and WAM (Wide Area Multilateration) settings…

Drumming signals within the family Taeniopterygidae (Plecoptera)

2014

Drumming signals of the 11 species of Palaearctic Taeniopterygidae are described for the first time based on the study of populations from nine different European countries from Spain to Russia. In this way, a contribution is made to our knowledge of the constancy respectively the divergence of signals typical for the species distributed over a very wide area. Communication patterns of the family under varying temperatures were analysed. The dependence on temperature indicates that the adults of this family are cold stenothermic insects. Within the genus Brachyptera (Newport, 1851), the call signal of males is significantly different from their response signal (duration and drumming frequen…

Applicational Aspects of a New Diagnostic Methodology for Fault Location in MV Networks: Problems, Solutions and Improvements

2005

The electrical energy market liberalization has encouraged utilities to make new investments at distribution level so as to attain higher quality levels. Service continuity is one of the aspects of greater importance in the definition of the quality of the electrical energy, for this reason, the research in the field of faults diagnostic for distribution systems is spreading ever more. The Authors have just developed a new methodology for diagnostic management of automated distribution systems. The technique is based on the use of circuital models of the electrical system resulting from the composition of quadripoles. In this paper, after a brief description of the proposed approach, the is…

Review of IEEE 802.22 and IEC 61850 for real-time communication in Smart Grid

2015

Real time data communication in Smart Grid is a big challenge due to its vastness and complexities. Wireless Regional Area Network (WRAN) - IEEE 802.22 permits opportunistic use of television white space (TVWS) by secondary user, if it is not being utilized by primary user. This standard has the potential to transfer big data of smart grid in real time to control center. The IEC 61850 is the standard for electrical substation automation that uses TCP/IP for data transfer among different ‘intelligent electronic devices’ (IEDs). IEC 61850 consists of different message types which belong to different performance classes that are mapped to different communication protocols. The different perfor…

Performance of LoRa for Bike-Sharing Systems

2019

Today bike sharing systems are becoming popular in many cities as short-distance transit vehicles. More than 18 million bicycles are available worldwide for public use and one of the main problems that afflicts such sharing systems is the loss of bikes, which can be stolen or simply left in unknown locations. Thus, many bikes are docked or tracked using GPS and costly cellular connections. In this paper, we consider the emerging Long Range (LoRa) technology for use in bike sharing systems. LoRa exploits free ISM bands and has been conceived for low power and low data rate applications. Additionally, LoRa is characterized by large cells and heterogeneous application domains, which may lead t…