Search results for "Engineering"
showing 10 items of 44231 documents
Nanofilm Low Cost Oxygen Sensors
2009
Abstract The resitivity change of ultra thin metals under air exposure is used for vacuum or inert gas packaging control. In order to reach low cost, single use applications, few nm thin Aluminum layers were deposited on PET substrates and combined with wireless electronic readout circuitry. The sensor respose is characterized by resistance changes and explained in terms of multiphase diffusion mechanisms which are very sensitive to technological parameters.
Compensation of Nonlinearity of Voltage and Current Instrument Transformers
2019
This paper aims at characterizing and improving the metrological performances of current and voltage instrument transformers (CTs and VTs) in harmonic measurements in the power system. A theoretical analysis is carried out to demonstrate that, due to the iron core nonlinearity, CT and VT output signal is distorted even when the input signal is a pure sine wave. Starting from this analysis, a new method for CT and VT characterization and compensation is proposed. In a first step, they are characterized in sinusoidal conditions and the harmonic phasors of the distorted output are measured; in the second step, these phasors are used to compensate the harmonic phasors measured in normal operati…
Deconstruction and hermeneutical space as keys to understanding the rural
2020
The purpose of this article is to complement the existing literature on defining the rural by suggesting a novel approach that makes possible a holistic understanding of the rural. The proposed approach is based on deconstruction of the concept of the rural and on hermeneutical philosophy. The current approaches applied in rural studies are evaluated through the lens of holistic understanding, and solutions to the observed problems are discussed. The problems of current rural studies stem from inadequate conceptualization and biased social theory. The conceptual problems can be alleviated, firstly, by understanding the concept of space not only literally but also figuratively. Secondly, the…
A Computationally Efficient Online/Offline Signature Scheme for Underwater Wireless Sensor Networks
2022
Underwater wireless sensor networks (UWSNs) have emerged as the most widely used wireless network infrastructure in many applications. Sensing nodes are frequently deployed in hostile aquatic environments in order to collect data on resources that are severely limited in terms of transmission time and bandwidth. Since underwater information is very sensitive and unique, the authentication of users is very important to access the data and information. UWSNs have unique communication and computation needs that are not met by the existing digital signature techniques. As a result, a lightweight signature scheme is required to meet the communication and computation requirements. In this researc…
Rural Population in Romania. Development and Tendencies (2000 – 2010)
2013
Abstract Demography is among the top factors which exert an undeniable influence upon the economic environment. Therefore, the populace - through its dynamics and characteristics - leaves an imprint upon the social and economic landscape, being a keen barometer and contributing to economic progress. The relationship demography-economy is extremely tight, since the populace is perceived as being a true representation of what characterizes our economy. Romania originated as a country with an agriculture-based economy – a fact which translated in its major rural population; nowadays, due to a sum of various developments, the rural populace is undergoing a decreasing trend. The situation is all…
Influence of uniaxial pressure on dielectric properties of (1- x )Na 0.5 Bi 0.5 TiO 3– x SrTiO 3 for x = 0.01, 0.04, and 0.1 ceramics
2017
The publication costs of this article were covered by the Estonian Academy of Sciences and the University of Tartu.
Pedagogical practices predicting perceived learning of social skills among university students
2022
The aim of this study was to examine what kinds of pedagogical practices predict perceived learning of university students’ social skills in classes where these skills are not set as learning outcomes. Data were collected from students of various disciplines by means of a questionnaire and then analysed using regression analysis. Students’ learning of social skills was explained by pedagogical factors related to 1) the modes of teaching and learning, 2) the features of the constructivist learning environment, 3) the features of the integrative pedagogy, and 4) the circumstances pertaining to the atmosphere of the learning environments involved in their studies. Factors belonging to three of…
Application of the Information Bottleneck method to discover user profiles in a Web store
2018
The paper deals with the problem of discovering groups of Web users with similar behavioral patterns on an e-commerce site. We introduce a novel approach to the unsupervised classification of user sessions, based on session attributes related to the user click-stream behavior, to gain insight into characteristics of various user profiles. The approach uses the agglomerative Information Bottleneck (IB) algorithm. Based on log data for a real online store, efficiency of the approach in terms of its ability to differentiate between buying and non-buying sessions was validated, indicating some possible practical applications of the our method. Experiments performed for a number of session sampl…
A new forum for upconversion research: The UPCON conference
2019
International audience; The Conference and Spring School on Properties, Design and Applications of Upconversion Nanomaterials (UPCON) provides a new forum for all experts and newcomers in the field of upconversion research. On the occasion of the second UPCON 2018 in Valencia (Spain), we are pleased to present a collection of 12 reviews and research articles that reflect recent advances in upconversion materials, their unique luminescent properties and many applications spanning from nanoscale thermometry to biomedicine.
IEA EBC Annex83 Positive Energy Districts
2021
At a global level, the need for energy efficiency and an increased share of renewable energy sources is evident, as is the crucial role of cities due to the rapid urbanization rate. As a consequence of this, the research work related to Positive Energy Districts (PED) has accelerated in recent years. A common shared definition, as well as technological approaches or methodological issues related to PEDs are still unclear in this development and a global scientific discussion is needed. The International Energy Agency’s Energy in Buildings and Communities Programme (IEA EBC) Annex 83 is the main platform for this international scientific debate and research. This paper describes the challeng…