Mean and fluctuating velocity contours and acoustic characteristics of subsonic and supersonic jets

Shadowgraph photographs of subsonic and supersonic jet

The Role of Marketing in Corporate Competitiveness: Marketing Practice Analysis of Hungarian Companies

The objective of this article is to analyse the marketing practice of Hungarian companies. On the one hand, the role of marketing function in the company has been revealed, and on the other hand the relationship between marketing efforts and market performance has been investigated. In frame of the Hungarian Competitiveness Studies, 300 marketing executives were surveyed to rate the marketing practice of their companies, concentrating on branding, pricing policy, applied marketing channels and promotional activities. The results confirm that sophisticated marketing practice leads to higher business performance. Keywords: marketing tools, competitiveness, performanc

Movement-related potentials in Parkinson's disease

To date, many different approaches have been used to study the impairment of motor function in Parkinson's disease (PD). Event-related potentials (ERPs) are averaged amplitude fluctuations of the ongoing EEG activity that are time locked to specific sensory, motor or cognitive events, and as such can be used to study different brain processes with an excellent temporal resolution. Movement-related potentials (MRPs) are ERPs associated with processes of voluntary movement preparation and execution in different paradigms. In this review we concentrate on MRPs in PD. We review studies recording the Bereitschaftspotential, the Contingent Negative Variation, and the lateralized readiness potential in PD to highlight the contributions they have made to further understanding motor deficits in PD. Possible directions for future research are also discussed

Event-related potentials and cognition in Parkinson's disease: An integrative review

Cognitive impairment is a common non-motor symptom of Parkinson’s disease (PD), but the nature of cognitive changes varies considerably between individuals. According to the dual-syndrome hypothesis, one cluster of patients is characterized by deficits in executive function that may be related to fronto-striatal dysfunction. Other patients primarily show non-frontal cognitive impairments that progress rapidly to PD dementia (PDD). We provide a comprehensive review of event-related potential (ERP) studies to identify ERP measures substantiating the heterogeneity of cognitive impairment in PD. Our review revealed evidence for P3b and mismatch-negativity alterations in PDD, but not in non-demented PD, indicating that alterations of these ERPs constitute electrophysiological markers for PDD. In contrast, ERP correlates of executive functions, such as NoGo-P3, N2, and error(-related) negativity (Ne/ERN), appear to be attenuated in non-demented PD patients in a dopamine-dependent manner. Hence, ERP measures confirm and yield distinct electrophysiological markers for the heterogeneity of cognitive impairment in PD. We discuss limitations and open questions of the ERP approach and provide directions and predictions for future ERP research

Preliminary trade-off and design of a navigation method for collaborative rendezvous and proximity operations

LAUREA MAGISTRALEL’obiettivo di questa tesi è sviluppare e testare un avanzato sistema di navigazione relativa per le missioni di Rendezvous and Docking (RVD) di veicoli spaziali. La ricerca si concentra sull’implementazione di filtri di navigazione che consentano una precisa stima dello stato di posizione, velocità e assetto durante le diverse fasi della missione. Il sistema multi-sensore del veicolo chaser include una Narrow-Angle Camera e un GNSS/Inter-Satellite Link (ISL) per il lungo raggio, e una Wide-Angle Camera per il corto raggio. Il veicolo target collaborativo è dotato della controparte GNSS/ISL ed è equipaggiato con marcatori ottici per la guida a corto raggio. Filtri separati sono progettati per le diverse fasi dell’avvicinamento. Il filtro per il lungo raggio è basato su Relative Orbital Elements (ROE), che offrono una migliore descrizione analitica del moto relativo e una comprensione geometrica più chiara rispetto ai filtri Cartesiani. Sono stati sviluppati e confrontati un Extended Kalman Filter (EKF) ed un Unscented Kalman Filter (UKF) basati su ROE. Anche se l’UKF mostri vantaggi in casi di alta eccentricità o grandi errori iniziali, entrambi i filtri forniscono risultati soddisfacenti nella maggior parte degli scenari. Per la fase a corto raggio, viene simulata la rilevazione dei marcatori sul piano focale della camera, e gli angoli e le misurazioni della distanza vengono ricavati geometricamente. Mentre per la parte traslazionale viene utilizzato un EKF Cartesiano con tuning adattivo delle misure della distanza, per la parte rotazionale viene impiegato un Multiplicative Extended Kalman Filter (MEKF), poiché è in grado di gestire meglio le dinamiche rotazionali del veicolo spaziale rispetto a un filtro additivo. I filtri a corto raggio mostrano un’alta precisione e una rapida convergenza. Un punto di stazionamento a una distanza di 20 metri facilita una transizione fluida tra i filtri per il lungo raggio e il corto raggio. I risultati delle simulazioni dimostrano che l’algoritmo di navigazione proposto funziona efficacemente nel fornire stime accurate dello stato durante le varie fasi della missione, offrendo indicazioni utili per i sistemi di navigazione relativa nelle future missioni spaziali.The aim of this thesis is to develop and test an advanced relative navigation system for spacecraft rendezvous and docking (RVD). The research focuses on the implementation of navigation filters that enable precise state estimation of position, velocity, and attitude during various mission phases. The multi-sensor suite of the chaser spacecraft includes a Narrow-Angle Camera integrated with a GNSS/Inter-Satellite Link (ISL) for far-range and a Wide-Angle Camera for close-range. The collaborative target provides the counterpart of the GNSS/ISL and is equipped with optical markers for close-range guidance. Separate filters are designed for the different phases of the approach. The far-range filter is based on Relative Orbital Elements (ROE), which offer a better analytical description of the relative motion and a clearer geometrical insight compared to Cartesian filters. An ROE-based Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) are developed and compared. While the UKF shows advantages in cases of high eccentricity or large initial errors, both filters perform satisfactorily in most scenarios. For the close-range phase, marker detection on the camera’s focal plane is simulated, and angles and range measurements are derived geometrically. While for the translational part, a Cartesian EKF with adaptive range measurement tuning is utilized, the rotational part employs a Multiplicative Extended Kalman Filter (MEKF), since it can handle the rotational spacecraft dynamics better than an additive filter. The close-range filters show high accuracy and fast convergence. A hold point at a 20-meter separation facilitates a smooth transition between far-range and close-range filters. The simulation results demonstrate the effectiveness of the proposed navigation algorithm in obtaining accurate state estimates throughout various mission phases, offering useful insights for relative navigation systems in future space missions

Towards developing support tools for sustainable control of gastrointestinal nematodes in sheep : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, Manawatū, New Zealand

Gastrointestinal nematode (GIN) parasitism is a major animal health challenge for sheep. Parasitized animals typically display a number of clinical signs, including a reduction in voluntary feed intake, altered grazing behaviour and lethargy. The aim of this thesis was to use remote sensing technologies to advance the development of a methodology where early changes in animal behaviour can be used to help identify sheep suffering ill effects of GIN parasitism, especially in a pre-clinical situation. It was hypothesised that lambs with even modest worm burdens will be less active, graze for less time and spend more time resting than those herd mates that were less heavily parasitized. The movement and behavioural activity of young and mature, infected and uninfected sheep were monitored in a series of studies using global positioning system (GPS) and tri-axial accelerometer sensors. Key behaviours were identified using machine learning techniques. Also assessed was the influence of host genotype on movement activity. Accelerometry data accurately identified grazing, resting and walking activities of sheep. The sensors were able to identify the effects of GIN parasitism on movement and behaviour in sheep. Clear evidence was found that GIN were associated with reduced movement and overall activity in growing lambs, with reductions in time spent ‘grazing’ and ‘walking’ occurring concomitantly with increases in ‘resting’ activity, and before effects were recorded on growth rates. Host genotype also had an effect on movement activity of lambs in untreated sheep, but not in treated individuals. Adult sheep, however, showed no consistent changes in movement and behaviour associated with parasitism, as measured by faecal egg counts. Overall, the findings in this thesis have demonstrated the potential value in remote monitoring of sheep as a diagnostic marker to detect the generally subtle behavioural changes associated with changing GIN infection status. Such monitoring could therefore be used as the basis for deciding whether animals need to be treated with anthelmintic on the basis of individual need, and such decisions could be taken early, i.e. before animals have failed to grow adequately or started to manifest more overt signs of clinical illness such as weight loss

Complex Dynamics in Fed-Batch Systems: Modeling, Analysis and Control of Alcoholic Fermentations

Modeling and control of fed-batch fermentation processes has been a subject of great interest to realize high productivity and yields from the fermentation technique. The goal of this dissertation was to gain insights into how the complex dynamic behaviors exhibited in fed-batch fermentation systems affect the stability of standard single-loop as well as non-standard feedback control structures. Novel PID stability theorems were established to help construct the controller stabilizing regions

Hetkede killud : loov-praktiline lõputöö

Loov-praktiline lõputöö baseerub minu autorikontserdil “Hetkede killud”, kus Konguta Rahvamaja laulustuudio laululapsed, esitavad minu loodud laule. Repertuaar on stiililiselt varieeruv ning valikusse pääsesid lood, mis on esitajatele eakohased ning kõlaliselt lauljatele sobilikud. Töö kirjalikus osas annan ülevaate oma muusikalistest õpingutest ja tööst muusikaõpetajana, loov-praktilise lõputöö kontserdikava ülesehitusest, repertuaarist ja selle metoodilisest analüüsist, ettevalmistusprotsessist ja kontserdi ettekandmisest.https://www.ester.ee/record=b5238147*es

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