Quasi-Stationary Asymptotics for Perturbed Semi-Markov Processes in Discrete Time

We consider a discrete time semi-Markov process where the characteristics defining the process depend on a small perturbation parameter. It is assumed that the state space consists of one finite communicating class of states and, in addition, one absorbing state. Our main object of interest is the asymptotic behaviour of the joint probabilities of the position of the semi-Markov process and the event of non-absorption as time tends to infinity and the perturbation parameter tends to zero. The main result gives exponential expansions of these probabilities together with an recursive algorithm for computing the coefficients in the expansions.Comment: 36 page

A theoretical study of ultrafast phenomena in complex atoms

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química. Fecha de lectura: 15-11-2019Esta tesis tiene embargado el acceso al texto completo hasta el 15-05-2021The ultrafast movement of electrons is a driving force of chemical reactions, making it a highly desirable avenue for study. This thesis studies such movements, making use of pump-probe methods such as attosecond transient absorption spectroscopy (ATAS) and reconstruction of attosecond beatings by interference of two-photon transitions (RABITT), in complex atomic systems. The main approach used to solve the time-dependent Schr¨odinger equation (TDSE) was exact, attosecond, full-electron, ab-initio calculations. Firstly, helium was probed above the second ionisation threshold, where severalionisationchannelsareopen, usingaccurateab-initiocalculations. Here, the ATAS method was employed to predict beatings between the autoionising 3snp1Po resonances and nearby 1Se and 1De states. More surprisingly, twophoton beatings between the doubly-excited 3s3p state and the 1Po continuum werealsoobserved,demonstratingcontrolofthecorrelated,two-electron,multichannel wave packet. Secondly, two studies of neon were carried out below the second ionisation threshold. The first makes use of ATAS calculations to probe beatings between the autoionising neon states. Using a two-colour, mixed extreme-ultraviolet (XUV) near-infrared (NIR) pump, one-photon beatings between the 2s−13p1Po and the nearby 2s−13s1Se and 2s−13d1De resonances are observed. Further, oneand two-photonbeatings between the autoionising 2s−13`, `∈{0,1}and the 1Po continuum are predicted. The second uses the RABITT method to probe the atomic phase in the vicinity of multiple resonances. This is far from trivial, and interferometric methods have until now been restricted to simpler energy-regions, due to the difficulty of accurately describing the electron correlation associated with the more complex case, making accurate ab-initio calculations needed to guide experiments unavailable. Despite the complex energy-dependence of the phase when several resonances are present, presented results from experiment and abinitiotheoryareinexcellentagreement. Further,usingasimpleextensionofthe Fano model for resonant continua, the contributions of the different involved resonances are disentangled. Such simple models are highly desirable in more advanced systems, where accurate ab-initio calculations are inaccessible. The ab-initio results of both neon studies were carried out using the newly developed XCHEM methodology, which is thus further validated by the excellent agreement with presented experiments and previous studies. Finally,aRABITTstudyofargoninthevicinityofthe3s−1n` resonanceswas performed. Angularly resolved, experimental results are presented, showing the anisotropy of the atomic phase in smooth continua as well as the vicinity of resonances. Due to the complexity of the system,no ab-initio results a represent. Instead, simpler interferometric models are used to successfully explain the anisotropic behaviour of the phaseEl movimiento ultrarrápido de electrones es la fuerza motriz de las reacciones químicas, por lo cual su estudio resulta muy atractivo. Esta tesis se dedica al estudio de ese tipo de movimientos, utilizando métodos de bombeo y sonda, como espectroscopia de absorción transitoria de attosegundos (ATAS) y reconstrucción de ”beatings” de attosegundo por interferencia de transiciones de dos fotones (RABITT), en átomos complejos. El método principal utilizado para resolver de la ecuación de Schrödinger dependiente del tiempo fue la propagación exacta (ab-initio) considerando todos los electrones. En primer lugar, se investigó el átomo de helio por encima del segundo umbral de ionización, donde existen varios canales de ionización. Aquí, el método de ATAS se empleó para predecir beatings entre las resonancias 3snp1Po y estados 1Se y 1De cercanos. Sorprendentemente, también se observaron beatings de dos fotones, lo cual muestra control del paquete de ondas correlacionado multicanal de dos electrones. En segundo lugar, dos estudios por debajo del segundo umbral de ionización del neón se llevaron a cabo. El primero utiliza cálculos de ATAS para investigar los beatings entre estados auto ionizantes de neón. Utilizando un bombeo de dos colores, radiación ultravioleta extrema (XUV) mezclada con radiación infrarrojo cercano (NIR), es posible observar beatings entre la resonancia del 2s−13p1Po y las 2s−13s1Se y 2s−13d1De. Además, se predicen beatings de uno y dos fotones entre las resonancias auto ionizantes 2s−13`, `∈{0,1}y el continuo 1Po. El segundo usa el método de RABITT para estudiar la fase atómica en las cercanías de las resonancias múltiples. Hasta ahora, los métodos interferométricos han estado restringidos a regiones de energía de hasta una resonancia, a causa de las dificultades en llevar a cabo propagaciones exactas (ab-initio), las cuales dependen de la correlación electrónica para describir bien los experimentos. A pesar de la complejidad de la dependencia de la energíac con la fase, debido a la presencia de varias resonancias, los resultados teóricos obtenidos comparan muy bien con los resultados experimentales presentados. Además, usando una extensión del modelo de Fano para continuos resonantes, las contribuciones de las distintas resonancias se han podido resolver. Modelos más simples son necesarios en sistemas más avanzados, donde cálculos ab-initio son inaccesibles. Los resultados ab-initio presentados en ambos estudios se realizaron con el método XCHEM recientemente propuesto, dando así validez al método. Finalmente, se realizó un estudio RABITT cerca de las resonancias 3s−1n` del argón. Se presentan experimentos mostrando la dependencia angular de la fase atómica, tanto en continuos suaves como en las cercanías de resonancias. Debido a la complejidad del sistema, no se presentan resultados ab-initio. En cambio, mediante modelos interferométricos se ha podido explicar el comportamiento anisótropo de la fas

Assessing Measurements for Feed-Forward Control

A method is presented for assessing disturbances in SISO loops.The method indicates if the SISO loop under consideration will benefit from an addition of feed forward control from a measured disturbance. The method uses minimal process knowledge and is based on measurement from normal operation

Control Structure Assessment in an Industrial Control System

This paper describes the implementation of a structure assessmentmethod in an industrial control system. The method uses available signals to evaluate if a given signal can be used for additional feed forward control action to improve the performance of a control loop

The nature stroke study; NASTRU: A randomized controlled trial of nature-based post-stroke fatigue rehabilitation

Objective: To determine whether nature-based rehabilitation, as an add-on to standard care, has a long-term influence on post-stroke fatigue, perceived value of everyday occupations, disability, health-related quality of life, anxiety, and depression at follow-up 8 and 14 months after randomization. Design: Single-blinded, 2-armed, randomized controlled trial. Methods: Stroke survivors, identified through routine 3-month follow-up visit (sub-acute) or medical records (chronic stroke >1 year previously), were randomized to standard care + nature-based rehabilitation (intervention group) or standard care alone (control group). Blinded evaluations were conducted at follow-up 8 and 14 months after randomization, for the following outcomes: post-stroke fatigue (Mental Fatigue Scale; MFS), perceived value of everyday occupations (Occupational value instrument with predefined items), disability (modified Rankin Scale; mRS), health-related quality of life (Euro-QoL-5 Demension Questionnaire), anxiety (Hospital Anxiety and Depression Scale; HAD) and depression (HAD). Results: Approximately one-quarter of the screened patients were eligible for inclusion in the study; of these, half agreed to participate; a final total of 101 patients were randomized (mean age 67 years, 60% female). The patients with sub-acute stroke were highly compliant with the intervention. The participants in both the intervention and control groups improved, However, no statistically significant differences in improvement were found between the intervention and control groups for any of the outcome measures. Fatigue decreased to a value below the suggested cut-off for mental fatigue (<10.5) in the intervention group, but not in the control group. Conclusion: Nature-based rehabilitation is feasible and well tolerated. A larger randomized controlled trial is warranted

Naturunderstödd rehabilitering på landsbygden i Region Skåne

Projektet Naturunderstödd rehabilitering på landsbygden består av en intervention där Region Skåne, Försäkringskassan, Arbetsförmedlingen, Lantbrukarnas Riksförbund (LRF) samt Sveriges Lantbruksuniversitet (SLU) samarbetat för att utveckla en ny rehabiliteringsmodell, där medicinska och ickemedicinska kompetenser samverkat. Målgruppen för projektet har varit personer som sökt primärvården på grund av utmattningssyndrom, mild till måttlig depression samt ångest. Projektet har bedrivits på gårdar på landsbygden i Skåne där natur och djur används som komplement i rehabiliteringen. Elva gårdar har deltagit i projektet och varit anslutna till vårdcentralerna. Vårdcentralen har ansvarat för den medicinska kompetensen medan landsbygdsföretaget ansvarat för naturbaserade aktiviteter. Deltagare har remitterats under 2012-2013 och har sedan fritt fått välja någon av de anslutna gårdarna. Under åtta veckor, tre gånger per vecka och ungefär fyra timmar per tillfälle, har deltagarna fått vistas på gården och efter egen förmåga tagit del av olika aktiviteter. På varje gård har det funnits flera deltagare och samtliga deltagare har deltagit i olika aktiviteter efter egen förmåga. I denna rapport har vi gjort en sammanställning av självrapporterad data som samlats in i samband med att deltagarna påbörjat Naturunderstödd rehabilitering på landsbygden, när de slutat samt vid sex respektive 12-månaders uppföljning. Resultaten baserar sig på 127 deltagare. Underlaget har, efter studiens slut, kompletterats med data från det patientadministrativa systemet (PASIS) på 67 deltagare som fått Naturunderstödd rehabilitering på landsbygden under perioden 2014-2016.Studien är genomförd utan kontrollgrupp. Därför kan vi inte uttala oss om huruvida den genomförda interventionen har haft effekt överstigande den effekt som hade upplevts utan interventionen. Vi har kunnat se att deltagarna i genomsnitt förbättras över tid avseende hälsorelaterad livskvalitet, arbetsförmåga, sömn, ångest och depression samt aktivitet. 28 % av deltagarna hade en kliniskt relevant förbättring avseende hälsorelaterad livskvalitet och/eller självskattad arbetsförmåga vid 12- månaders uppföljning av interventionen. Det är dock viktigt att notera att det är ett stort bortfall i uppföljningarna, vilket innebär att vi saknar information om ett stort antal deltagar

D7.3 Report on simulator test results and driver acceptance of PROSPECT functions

The process of developing new automotive systems includes various testing cycles to assure a save operation in traffic. Physical system testing on test tracks is very important for this purpose, but rather expensive and might only become possible in later stages of the development process. Using a virtual simulation environment offers a safe possibility of testing new systems in early stages of development. Aditionally, driver-in-the-loop tests at test track and in a virtual simulator make it possible to evaluate driver reaction and potential acceptance by the future users of those systems. Within PROSPECT the new functions are investigated under various aspects in several simulator studies and test track studies. This deliverable D7.3 gives detailed information of conduction and results of the each study. Three studies focus exclusively on the for Vulnerable Road Users (VRUs) specifically dangerous urban intersection scenarios. The first of those studies examines the driver behaviour in a turning situation when a byciclist might be crossing. The described phenomena are looked-but-failed-to-see and failed-to-look. The second study, which provides an initial step in this line of research, analyzed the acceptance of issued forward collision warning times. The positioning of the potential accident opponent and the subjective feeling towards the criticality of the situation by the driver were key parameters taken into account. Last, but not least the acceptance of an intersection assist autonomous emergency braking systems was tested regarding the acceptance of potential buyers. The study was run for five days in a row for each participant to be able to judge the behaviour in a comuting situation. Two studies focused on longitudinal scenarios. Both studies followed the same design, but one was conducted on a test track and the other one in a simulator. The main objective was to investigate drivers reactions to FCW warnings and Active Steering interventions in critical VRU scenarios in case of a distraction of the driver. Additionally, the test track study was used to validate the results from the simulator study. The results of those studies are the basis for a wide acceptance evaluation of the systems. No system is an asset in increasing road safety if it is not accepted by the user and therefore turned off, if it is not required the system to be default on in consumer tests. Complemented by an additional acceptance study where the participants had to give their opinion of those systems after they watched videos of dangerous situations, the acceptance was analyzed based on questionnaires developed in PROSPECT and reported in Deliverable 7.2. This wholistic approach allows an expert discussion on the potentials of the PROSPECT functions in the future