Random time series analysis for linear systems based on the Laplace transform using a real and positive variable

An analysis method using a particular Laplace transform has been developed for continuous-time and discrete-time linear systems energized by random or non periodic signais which can be either causal or non causal. This Laplace transform is particular in the sense that its variable.Une méthode d'analyse utilisant une transformée de Laplace particulière a été développée pour les systèmes linéaires continus ou discrets soumis à une excitation aléatoire ou non périodique, de nature causale ou non causale . Cette transformée de Laplace est particulière en ce sens que sa variable « s » est définie comme réelle et positive . Afin d'éviter toute ambiguïté, cette variable est appelée « a » . En pratique, dans le « domaine de sigma », a est utilisé d'une manière analogue à celle dont est utilisée la fréquence f dans le domaine des fréquences . Cette méthode convient soit aux systèmes et phénomènes continus régis par des équations différentielles ou aux dérivées partielles à coefficients constants, soit aux systèmes et phénomènes discrets régis par des équations aux différences à coefficients constants . Cet article fournit les éléments pour traiter un cas très fréquent en pratique. C'est celui d'un système linéaire continu ne comportant qu'une entrée et qu'une sortie, et régi par une équation différentielle de forme générale connue, mais dont les coefficients constants sont indéterminés . Les signaux représentant l'excitation et la réponse sont toutefois numérisés en vue d'un traitement de données . La comparaison de la fonction de transfert expérimentale discrète G*(a) avec la fonction de transfert théorique continue G(a), donne la possibilité de déterminer les valeurs spécifiques des coefficients constants, sans une seule incursion dans le domaine des fréquences . Pour que cette détermination devienne réalisable, deux tâches essentielles, dont la définition constitue l'objectif principal de cet article, doivent être accomplies : 1) À partir de l'équation représentant le système, G(a) théorique est calculé sans nécessiter de déphasage entre les fonctions représentant l'excitation et la réponse du système . Cela rend ce calcul bien plus simple et plus rapide que le calcul correspondant dans le domaine des fréquences . 2) G*(a) est calculé à partir de signaux discrets qui doivent satisfaire certaines conditions initiales . Pour ce faire, un algorithme est défini, qui peut être aisément généralisé si le système est plus compliqué . Cet algorithme, en combinant linéairement des tranches de séries temporelles originelles, construit des paires de signaux synthétiques qui, tout en satisfaisant les conditions initiales, ont l'avantage de ne comprendre qu'un nombre fini d'échantillons . Le rapport des transformées de Laplace des signaux synthétiques appartenant à la même paire donne G* (a) . Ces transformées offrent l'avantage de ne pas être affectées par l'effet de troncation lié à l'utilisation de la transformée de Fourier et peuvent, sans inconvénient, être appliquées à des signaux courts . 3) Deux appendices complètent cet exposé . Dans le premier appendice est abordée la question de la correspondance entre le spectre de fréquence de ces signaux synthétiques et leur transformée de Laplace dans le domaine de sigma . Le deuxième appendice, en partant de la relation existant entre transformée de Laplace discrète et transformée de Laplace continue, est consacré à examiner dans quelles conditions G*(a) tend vers G(a)

Engaging the next generation in Appalachian studies: building community and expanding outreach through technology and diversity of programming

https://scholarworks.moreheadstate.edu/student_scholarship_posters/1089/thumbnail.jp

Seasonal movements and habitat use of African buffalo in Ruaha National Park, Tanzania.

BACKGROUND:Assessing wildlife movements and habitat use is important for species conservation and management and can be informative for understanding population dynamics. The African buffalo (Syncerus caffer) population of Ruaha National Park, Tanzania has been declining, and little was known about the movement, habitat selection, and space use of the population, which is important for understanding possible reasons behind the decline. A total of 12 African buffalo cows from four different herds were collared with satellite transmitters. Movements were assessed over 2 years from 11 animals. RESULTS:The space use of the individual collared buffaloes as an approximation of the 95% home range size estimated using Brownian bridge models, ranged from 73 to 601 km2. The estimated home ranges were larger in the wet season than in the dry season. With the exception of one buffalo all collared animals completed a wet season migration of varying distances. A consistent pattern of seasonal movement was observed with one herd, whereas the other herds did not behave the same way in the two wet seasons that they were tracked. Herd splitting and herd switching occurred on multiple occasions. Buffaloes strongly associated with habitats near the Great Ruaha River in the dry season and had little association to permanent water sources in the wet season. Daily movements averaged 4.6 km (standard deviation, SD = 2.6 km), with the longest distances traveled during November (mean 6.9 km, SD = 3.6 km) at the end of the dry season and beginning of the wet season. The shortest daily distances traveled occurred in the wet season in April-June (mean 3.6 km, SD = 1.6-1.8 km). CONCLUSION:The Great Ruaha River has experienced significant drying in the last decades due to water diversions upstream, which likely has reduced the suitable range for buffaloes. The loss of dry season habitat due to water scarcity has likely contributed to the population decline of the Ruaha buffaloes

Next Generation Practitioner-Scholars Navigating Community Engagement Professional Development: A Collaborative Autoethnography

This collaborative autoethnographic research study examines the motivations, experiences, and professional outcomes of seven community engagement practitioner-scholars who served in a high-level elected position in a community engagement research association and its affiliated graduate student network. The findings highlight the role of professional associations and graduate student networks in facilitating professional development for next generation community engagement practitioner-scholars, such as supporting them in creating connections, expanding networks, developing professional identities, and cultivating cultural capital

Strengthening Competence of Therapists-in-Training in the Treatment of Health Anxiety (Hypochondriasis): Validation of the Assessment of Core CBT Skills (ACCS)

Although the observation and assessment of psychotherapeutic competences is central to training, supervision, patient care, quality control, and life‐long practice, structured instruments are used only occasionally. In the current study, an observation‐based tool for the Assessment of Core CBT Skills (ACCS) was translated into German and adapted, and its psychometric properties were pilot evaluated. Competence of therapists‐in‐training was assessed in a random sample of n = 30 videos on cognitive‐behavioral therapy including patients diagnosed with hypochondriasis. Two of three raters independently assessed the competences demonstrated in the entire, active treatment sessions (n = 60). In our sample, internal consistency was excellent, and interrater reliability was good. Convergent validity (Cognitive Therapy Scale) and discriminant validity (Helping Alliance Questionnaire) were within the expected ranges. The ACCS total score did not significantly predict the reduction of symptoms of hypochondriasis, and a one‐factorial structure of the instrument was found. By providing multiple opportunities for feedback, self‐reflection and supervision, the ACCS may complement current tools for the assessment of psychotherapeutic competences and importantly, support competence‐based training and supervision

A Feeling of Otherness: A Qualitative Research Synthesis Exploring the Lived Experiences of Stigma in Individuals with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) consists of Crohn's disease and ulcerative colitis, chronic conditions involving inflammation and ulceration of the gastrointestinal tract. Individuals with IBD may be susceptible to experiencing health-related stigma: experienced, perceived, or internalised social exclusion, rejection, blame, or devaluation resulting from negative social judgements based on the disease. This qualitative research synthesis draws together findings from 38 studies describing lived experiences to develop a unified interpretative account of the experience of stigma in IBD. Analysis developed two categories: 'The IBD journey' explores the dynamic ways in which having IBD impacted on individuals' self-identity and 'a need to be understood' examines the tension between wanting to be understood whilst feeling their true experiences needed to be hidden from or were misjudged by the social sphere. The overarching concept 'feeling of otherness' highlights that, rather than a static, binary experience, individuals moved across a continuum ranging from the excluding experience of feeling stigmatised and othered, to the inclusive experience of integration. Individuals fluctuated along this continuum across different physical, social, and health contexts. Psychological adjustment to IBD, drawing on experience of adaptive coping, and reconnecting with valued others through illness disclosure strengthened stigma resistance during more challenging time

Assessment of Functional Movement Screening by Assessors of Three Different Skill Levels

In Volume 3, Issue 1 of the JSMAHS you will find Professional abstracts, as well Under Graduate student research abstracts, case reports, and critically appraised topics. Thank you for viewing this 3rd Annual OATA Special Edition