103,130 research outputs found
Knowledge sharing for improving damage identification across a population of heterogeneous laboratory-scale aircraft models
No full textAdvances in machine learning and pattern recognition have led to the development of data-driven approaches for Structural Health Monitoring (SHM).
However, their application in real case studies is often limited by the lack or incompleteness of experimental data.
Thus, Population-Based Structural Health Monitoring (PBSHM) addresses these issues by promoting knowledge-sharing between similar structures.
The PBSHM theory distinguishes between homogeneous and heterogeneous populations.
Structures in a heterogeneous population include different sources of variability, which affect their dynamic response and could reduce the effectiveness of knowledge-sharing performance, leading to so-called negative transfer.
This study investigates how attribute variations influence knowledge transfer in a population of heterogeneous laboratory-scale aircraft. The transfer-learning problem is solved via a domain-adaptation algorithm, i.e., the Joint Distribution Adaptation (JDA), considering damage-detection and localisation tasks
Three-dimensional structure of a low-Reynolds-number turbulent boundary layer
No full textA low-Reynolds-number zero-pressure-gradient incompressible turbulent boundary layer was investigated using a volumetric imaging technique. The Reynolds number based on momentum thickness was 700. The flow was tagged with a passive scalar from two spanwise dye slots to distinguish between fluid motions originating in the inner and outer portions of the boundary layer. The resulting volumetric scalar field was interrogated using a laser sheet scanner developed for this study. Two- and three-dimensional time-dependent visualizations of a 50 volume time series are presented (equivalent to 17δ in length). In the outer portion of the boundary layer, scalar structures were observed to lie along lines in the (x, z)-plane, inclined to the streamwise (x-)direction in the range ±50°. The ejection of brightly dyed fluid packets from the near-wall region was observed to be spatially organized, and related to the passage of the large-scale scalar structures.Carl J Delo, Richard M Kelson and Alexander J Smit
Using the inverse finite‐element method to harmonise classical modal analysis with fibre‐optic strain data for robust population‐based structural health monitoring
No full textVibration-based approaches to structural health monitoring (SHM) gained increasing significance for assessing the behaviour of existing structures because of their non-intrusive nature and high sensitivity to damage. However, data availability often limits the application of SHM approaches. The population-based structural health monitoring (PBSHM) theory addresses this challenge, enhancing diagnostic inferences by sharing knowledge across a population of similar structures. In real-life scenarios, sharing data from distinct structures requires dealing with results obtained with different experimental setups, multiple sensors, input choices and acquisition systems. Therefore, it is crucial to harmonise various features to achieve accurate and reliable results. The present study presents the results of a classic experimental modal analysis (EMA) using scanning laser Doppler vibrometer (SLDV) measurements and a strain-based EMA conducted using high-definition distributed fibre-optic strain sensors. The experimental case study of a laboratory-scale steel aircraft subjected to specific operating and damage conditions is introduced, allowing for a comprehensive discussion of the features extracted from the two EMA techniques, which can also be generalised to structures within different domains. This research highlights the advantages and limitations of fibre-optic-based EMA compared to classic methods, as fibre-optic strain sensors offer a cost-effective alternative to accelerometers or SLDV for dynamic testing. Furthermore, the feasibility of employing the inverse finite-element method (iFEM) in the dynamic domain is investigated. This method can estimate the whole displacement field of a structure from a limited number of strain values, thus harmonising strain measurements with the SLDV measurements. By analysing the features extracted from different EMA techniques within the PBSHM framework, this study contributes to advancing the understanding and application of the PBSHM approach in diverse experimental scenarios, laying the foundation for further investigation of features and adequate methods for sharing damage-state knowledge across a population of structures
Novelty detection across a small population of real structures: A negative selection approach
No full textVibration-based Structural Health Monitoring (SHM), exploits a variety of approaches for novelty detection. In particular, many data-based methods try to recognise patterns by exploiting analogies with the human body's natural defences at a cellular level. These algorithms fall within the Artificial Immune System (AIS) class and can be chosen, according to their peculiarities, to solve specific problems in diverse application areas. This study investigates the damage-detection process in different operational conditions, obtained by applying structural modifications to a laboratory-scale aeroplane, which follows the geometric features of the GARTEUR benchmark project. Damage identification is performed by exploiting the Negative Selection Algorithm (NSA), already applied by some of the authors on numerically-simulated case studies, and chosen for its capability of self/non-self discrimination under varying operational or environmental conditions. The research is expanded by using sparse autoencoders for feature dimensionality reduction. The method is applied to an experimental dataset acquired via Scanning Laser Doppler Vibrometer (SLDV) measurements, to identify consistent damage-sensitive features from the frequency response functions, and to obtain a reliable fault-detection performance
Tradicionalna romska poroka : diplomsko delo visokošolskega strokovnega študija Varnost in policijsko delo
No full textDelo govori o tradicionalni romski poroki, muslimanske romske skupnosti na Slovenskem iz perpektive Policije. Značilnosti, primer in način obravnave opisane tematik
Policijsko delo v skupnosti v Republiki Sloveniji
No full textMagistrsko delo kronološko prikazuje razvoj policijskega dela v skupnosti od osamosvojitve Slovenije leta 1991 dalje. Osnova za raziskovalno delo so bili strateški dokumenti in normativni akti, ki dajejo pravno podlago, da policija lahko izvaja svoje delo v skupnosti, dokumenti, s katerimi je preventivno delo implementirano v delo policije, in dokumenti, ki opredeljujejo organizacijsko strukturo, ki se v policiji ukvarja s to dejavnostjo.
V raziskovalno publicističnem delu so bili poiskani in pregledani strokovni in znanstveni članki ter druga zaključna dela, ki obravnavajo tematiko policijskega dela v skupnosti. Prav tako so bili v reviji Varnost, ki jo izdaja Ministrstvo za notranje zadeve - Policija, na to temo poiskani članki. Naloge in članki so bili analitično pregledani, iz njih pa je bilo kritično povzeto bistvo preučevanega problema. V magistrskem delu sta bili postavljeni dve hipotezi, ki sta bili preučeni s pomočjo analize strateško usmerjevalnih dokumentov na eni strani ter analiza strokovnih in znanstvenih člankov, zaključnih del in člankov v reviji Varnost na temo policijskega dela v skupnosti na drugi strani. Glede postavljenih hipotez je bilo ugotovljeno, da je policijsko delo v skupnosti sprva obravnavano v člankih revije Varnost. Šele leta 1995 je bilo policijsko delo v skupnosti na nivoju Ministrstva za notranje zadeve tudi normativno urejeno, in sicer v dveh delih - Usmeritve za delo na področju javne varnosti v letu 1995 (1995) in v priročniku Policijska preventiva (Mikulan, 1995). Istega leta so se na temo policijske preventive pričeli objavljati še strokovni in znanstven članki ter razna zaključna dela na temo policijskega dela v skupnosti.
Ugotovljeno je bilo, da je bilo področje policijskega dela v skupnosti analizirano najprej v člankih objavljenih v reviji Varnost, šele kasneje v strokovnih in znanstvenih člankih ter zaključnih delih Fakultete za varnostne vede. Je pa bilo policijsko delo v skupnosti bolj podrobno analizirano v strokovnih in znanstvenih člankih ter zaključnih delih Fakultete za varnostne vede, kot v člankih, izdanih v reviji Varnost.Master thesis shows the chronological development of police work in community since Slovenia became independent in 1991. The basis for the research work were strategic documents and normative acts, which provide the legal basis for the police to carry out its work in the community, the documents with which preventive work is implemented in the work of the police and the documents that define the organizational structure, which deals with this activity in the police. In the research journalist part the technical and scientific articles and different finishing papers, which examine the topic of police work in the community were searched and examined. Also in journal Varnost, issued by the Ministry of the Interior-Police articles on this topics were searched. Papers and articles were analytically examined and from them the essence of the studied problem was critically summarized. In Master thesis two hypotheses were defined and they were studied with the help of the analysis of strategic guidance documents on one hand, and an analysis of technical and scientific articles, finishing papers and articles in journal Varnost on subject police work in the community on the other hand. Regarding given hypotheses it was found that the police work in the community is first addressed in only a few articles in the journal Varnost. From 1995 the police work in the community was also normatively regulated in two parts at the level of the Ministry of the Interior, Guidelines for work in the field of public safety in 1995 (1995) and handbook Police Prevention (Mikulan, 1995). In the same year technical and scientific articles on police prevention and different finishing papers on police work in community were being published. It is established that the area of police work in community was first analyzed in the articles published in the journal Varnost and only later in the technical and scientific articles and other finishing papers. However, police work in the community was analyzed in detail in technical and scientific articles, and various finishing papers as the articles published in the journal Varnost
Il giuramento di Cidippe nell'Artemision di Delo
No full textIndagine linguistica, letteraria e giuridica del giuramento di Cidippe, inserito nell'ambiente dell'Artemision di Delo e del culto di Artemis in quell'isola
IL LAGO DEI CIGNI DI DELO: DAL «THRENOS» AL PEANA
No full textDalla tragedia di Euripide alla filosofia platonica fino alla dotta poesia callimachea, si riscontra una interessante associazione tra la menzione di Delo e dei suoi cigni e il passaggio dall’espressione trenodica del dolore a quella liberatoria e guaritrice del peana. L’articolo, partendo da una breve incursione nell’epica omerica per rilevare le più antiche attestazioni di una presenza congiunta del threnos e del peana, e nella lirica e innografia arcaiche per recuperare le origini della connotazione del cigno come uccello apollineo della poesia, si concentra su alcuni passi euripidei (Eracle, Ione e Ifigenia in Tauride), platonici (Fedone) e callimachei (Inno a Delo e Inno ad Apollo) in cui il lago dei cigni di Delo viene menzionato, cercando di comprenderne il valore e metterne in luce gli elementi di continuità.</p
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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