Search results for " indicator"
showing 10 items of 613 documents
An efficient diagnostic technique for distribution systems based on under fault voltages and currents
2010
Service continuity is one of the major aspects 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. Moreover the increasing interest around modern distribution systems automation for management purposes gives faults diagnostics more tools to detect outages precisely and in short times. In this paper, the applicability of an efficient fault location and characterization methodology within a centralized monitoring system is discussed. The methodology, appropriate for any kind of fault, is based on the use of the analytical model of the network lines and uses the fundamental co…
A Geometrical Simple Approach for Power Silicon Devices Fault Detection and Fault-Tolerant Operation of a Voltage Source Inverter
2012
Fault-tolerant converters have been widely investigated for years and nowadays an extensive technical literature on this field exists. This paper presents a novel fault detection algorithm based on a simple geometrical approach. In the algorithm analysis both the case of faults in single device and the lose of an entire inverter leg have been considered. False positive detections are avoided by considering a proper number of current samples. The proposed fault detection algorithm is characterized by simplicity, low computational and implementation effort with a consequent enough fast execution, easy control integration with the possibility to use it both in hardware in the loop systems and …
Ground fault distribution on overhead transmission lines
2006
When a ground fault occurs on an overhead transmission line in a power network with grounded neutral, the fault current returns to the grounded neutral through the tower structures, ground return paths and ground wires. This paper presents an analytical method in order to evaluate the ground fault current distribution in an effectively grounded power network. The effect of soil resistivity, ground resistance of towers and power line configuration, on the magnitude of return currents, has been examined.
Control of solid-state fault current limiter for DG-integrated distribution systems
2017
Fault current limier (FCL) is a device that limits the system current under fault conditions without disconnecting the system and affecting the power system protection components such as circuit breakers. Many types of FCLs have been proposed to limit the magnitude of the fault current. Solid-state fault current limiters (SSFCLs) can limit the peak value of the fault current by applying several methods, such as controlling the system impedance or controlling the voltage that appears across the fault. In this paper, a new control scheme for the SSFCL circuit is presented. The control method is based on controlling the duty cycle of solid state switches to control the rms value of the system …
Risk Indicators and Road Accident Analysis for the Period 2012–2016
2017
Road accidents are a major societal issue for every country. The purpose of this paper is to assess the number of traffic and road accidents depending on a series of variables (collision mode, road configuration, conditions of occurrence, road category, type of vehicle involved, personal factors, and length of time of the driving license) in Romania from 2012–2016. The analysis of the road accident trend identifies the causes of accidents, road safety performance indicators, and risk indicators. Having these identified data, a framework is proposed for improving the road safety system and reducing accidents. The Romanian Police, the National Institute of Statistics (NIS) in Romania, and the…
Keys to success in investment rounds by immigrant entrepreneurs in Silicon Valley
2019
[EN] This study presents an updated diagnosis of the SV ecosystem itself and offers an insight into the entrepreneurial mobility trends prospects and expectations of the growing number of start-ups launched by immigrant entrepreneurs arriving in SV. The purpose is to determine and rank the attributes most valued by investors when assessing projects and start-ups founded by immigrant entrepreneurs. The model of analysis composed by three hypotheses leads to a series of findings about the profile and expectations of the immigrant entrepreneurs, and reveals remarkable hints and key targets to be met by immigrant entrepreneurs in SV in order to successfully close investment rounds in a hypercom…
Geostatistical Microscale Study of Magnetic Susceptibility in Soil Profile and Magnetic Indicators of Potential Soil Pollution
2015
Directional variograms, along the soil profile, can be useful and precise tool that can be used to increase the precision of the assessment of soil pollution. The detail analysis of spatial variability in the soil profile can be also an important part of the standardization of soil magnetometry as a screening method for an assessment of soil pollution related to the dust deposition. The goal of this study was to investigate the correlation between basic parameters of spatial correlations of magnetic susceptibility in the soil profile, such as a range of correlation and a sill, and selected magnetometric indicators of soil pollution. Magnetic indicators were an area under the curve of magnet…
INDICADORES PARA O GERENCIAMENTO DE FACULDADES: UM ESTUDO DE DOIS CASOS NA ESPANHA
2015
O objetivo deste artigo é explorar os indicadores para fazer o gerenciamento de duas faculdades privadas na Espanha. Fez-se a coleta de dados através de entrevista, observação direta por parte dos pesquisadores e análises de documentos internos das instituições de ensino. Ao final foi possível identificar os indicadores de gerenciamento, financeiros e não financeiros, de acordo com as quatro perspectivas do Quadro de Comando Integral (CMI, por sua sigla em espanhol). Conclui-se que o caso 01 utiliza 34 indicadores, sendo 12 financeiros, 10 relacionados com os clientes, 10 da perspectiva interna e somente 2 vinculados ao desenvolvimento pessoal; no caso 02, utilizam-se 41 indicadores, sendo …
Trattamento dell'incertezza epistemica nell'analisi affidabilistica
COMPLEX ANALYSIS OF COMPANY BANKRUPTCY FORECASTING: THEORETICAL INSIGHT
2018
In modern conditions for dynamic and competitive businesses, more and more companies face financial problems and eventually go bankrupt. A noteworthy trend: not only new companies that have not yet managed to establish themselves in the market go bankrupt but also large companies operating for years and maintaining good traditions. Bankruptcies of companies cause many problems not only for the companies themselves but also for the state and many members of society. Thus, it is crucial to evaluate the financial state of a company and its activity results as accurately and early as possible when forecasting the possibility of a bankruptcy. The paper recommends a complex analysis methodology f…