No description available.

No description available.

No description available.

No description available.

Oppgavens formål var å studere hvordan mentorer i ENT3Rprosjektet opplever at tilbakemeldinger virker på deres mestring. Gjennom kvalitativ metode ble fem mentorer, fra tre ENT3Rprosjekter, intervjuet. Det teoretiske grunnlag for oppgaven er basert på tidligere undersøkelser om tilbakemelding gitt i en arbeidslivskontekst og teoretiske perspektiver innen mestring, selvforståelse og motivasjon. Ut i fra problemstillingen som er valgt har jeg identifisert en god del elementer i hvordan tilbakemeldinger oppfattes av mentoren og hvilke reaksjoner det fører til, og hvordan det virker på selvfølelsen og mestring. Noen av disse elementene var forventet i forhold til tidligere forskning og teori, men også ut i fra mine egne erfaringer. Andre funn var mer overraskende og er nyttig som innspill til videre ledelse og drift av ENT3Rprosjektet. Mentorene i undersøkelsen har belyst både positive og negative sider av det å motta tilbakemeldinger. Resultatene viser at tilbakemeldinger gitt som ros er svært viktig for mentorenes selvtillit og for å føle seg trygg i jobben. Negative tilbakemeldinger skaper usikkerhet om egne valg og faglig kompetanse hvis de oppfattes som urimelige eller ubegrunnet. Mentorene rangerer viktigheten av tilbakemeldinger ut i fra hvem som er avsender, og det er særlig elevenes spontane positive tilbakemeldinger som verdsettes høyt. Studien viser at leders tilbakemelding er mindre viktig for mentorenes mestring. Elevene i ENT3R og med-mentor er virkningsfulle kilder for tilbakemelding og er sterkt forbundet med mentorenes opplevelse av mestring. Dette er diskutert i forhold til Banduras (1992; 1994) teori om subjektiv mestringsforventning. Resultatene viser også at mentorene i denne studien er høyt motivert for jobben, og at det er en nær sammenheng mellom motivasjon, selvtillit og forventning om mestring. Resultatene indikerer at positiv og konstruktiv feedback virker forsterkende på disse områdene hos mentorene. Ros og positiv feedback er gjennomgående tilbakemeldingsformer i ENT3Rprosjektet. Resultatene sier også at det eksisterer enkelte utfordringer i det å ta i bruk konstruktiv korrigerende tilbakemelding som et ledelsesverktøy.

No description available.

L'objectif de cette thèse est d'étudier la formation et le contrôle de structures spatiales apparaissant dans un cristal photoréfractif soumis à une simple boucle de rétro-action optique (simple feedback). Suite au mécanisme d'instabilité de modulation, un faisceau laser entrant dans un milieu non linéaire peut subir une structuration spatiale transverse,connue sous le nom de filamentation. Dans la configuration dite simple feedback, l'interaction de deux faisceaux laser contra-propageants peut donner naissance à des structures transverses auto-organisées (dites patterns) plus régulières que les filaments : par exemple une structure de type hexagonal. Dans ce document, nous étudions, à la fois théoriquement et expérimentalement le phénomène de formation de patterns photoréfractifs. Notre but est d'aller au-delà de la simple observation de patterns. En effet, nous focalisons notre étude sur l'adressage et la sélection de patterns, en utilisant les propriétés de contrôle de la lumière que fournissent les structures périodiques telles que les cristaux photoniques. L'insertion de telles structures au sein même du milieunon linéaire photoréfractif permet la création, la sélection et l'orientation de différents patterns. La géométrie, la vélocité et la dynamique de ces structures spatiales sont également fortement influencées lorsqu'un décalage transverse, induit par un désalignement du miroir de rétro-action, est imposé au système. Ainsi, pour la première fois dans un système photoréfractif, il devient possible d'observer des dynamiques dites convectives, c'est-à-dire entretenues par le bruit. Pour finir, une partie de cette thèse est dédiée à l'obtention de structures dites localisées. Trouvant leur originalité dans des applications comme les mémoires optiques adressables, ces structures ont été intensément étudiées ces dernière années. Nous proposons de les observer dans notre système photoréfractif, peu voire pas étudié dans cette configuration / The aim of the present manuscript is to study the formation and the controlof transverse structures in nonlinear optical systems by using photorefractivematerials as the optical nonlinear medium. A single laser beam entering insuch a nonlinear medium can experience transverse structuring due to themechanisms of modulation instability, which may lead to beam filamentation.In another case, the interaction of two beams may lead to spatially regularpatterns, as in the case of the single-feedback configuration.In this study, we focus on the conditions for the appearance of ordered patternedstructures and describe the theoretical and experimental background forthe observation of these effects. Our challenge is to go beyond the observation,classification and understanding of the nonlinear phenomena encountered. Weare especially interested in the properties of the free-running nonlinear system,combined with different control mechanisms. Principally, on one hand, we focuson the active addressing, selection and orientation of a desired pattern bysuitably using a periodic photonic structures as the control mechanisms.On the other hand, the dynamics, the geometry, and the velocity of thedifferent patterns are strongly influenced by an imposed misalignment of themirror producing the optical feedback. Consequently, convective dynamics, sustainedby noise, are expected in the system and will be observed for the firsttime in a photorefractive experiment.Finally, a part of the manuscript is devoted to the observation of localizedstructures. Potentially useful for optical memories, these structures have beenintensively studied in different configurations, but experiments in photorefractivematerials remain scarce. Thus, we will focus

Feedback On Nanosecond Timescales (FONT) is a feedback system being developed to correct the beam position jitter in the extraction line and final focus system at the Accelerator Test Facility (ATF2), Tsukuba, Japan. FONT5 is currently being tested and is used to correct the intra-train jitter for a 3-bunch train; the bunch spacing is 154ns. This system measures the position of an electron bunch, using beam position monitors (BPMs). From this measurement, digital feedback electronics calculate the required correction, and sends a pulse to a feedback kicker. The feedback kicker then deflects the next bunch in the train in order to correct its position. Stripline BPMs are used at ATF2, and analogue processors manipulate the BPM signals before they are interpreted by the feedback electronics. The BPM system has been modelled and tested so that it can be parameterised and optimised. The BPMs are calibrated regularly, and the resolution of the system measured. Both of these properties have been analysed and modelled. This has allowed the resolution to be minimised. The resolution is an important factor which limits the achievable feedback correction. Several other factors have also been investigated; these include the feedback gain and the bunch-bunch correlation. To allow the feedback electronics to be controlled remotely, several data acquisition systems (DAQs) have been developed to allow data flow both to and from the digital board. The DAQs have been designed specically for the firmware on the FONT digital board.

The work, of which this thesis is a record, is concerned with the development of a microprocessor-based signal analyser for machine condition monitoring. Until recently, the technology did not exist to produce such an instrument in a 'semi-portable' form. The work proceeds with a revision of condition monitoring and digital techniques which may be implemented on such an instrument. These techniques can be used to detect such faults as: bearing wear; out of balance; shaft misalignment; damaged gears and electrically induced vibration. The greater part of this work involves: firstly, establishing a suitable hardware architecture for the instrument and, secondly, implementing the digital signal processing algorithms required. Such a system, capable of implementing both time and spectral techniques, has been developed to laboratory prototype level. The system consists of a high-speed, multi-channel data acquisition unit and both 8-bit and 16-bit microprocessor systems. The microprocessors execute the operating system and signal processing software. The aim, to produce a simple to use and flexible instrument, was sustained throughout the design phase. The result is an instrument which should offer multi-functional protection of plant.

Feedback is consistently shown to be a key influence upon both achievement and performance. Feedback in medical education is not only important for the performance and progression of medical trainees but also for patient safety. However, despite recognition of the power of successful feedback, medical students within the United Kingdom and beyond consistently report dissatisfaction with the feedback they receive. Whilst the literature has begun to explore what students feel about feedback there is limited understanding of why they feel this way. Within this thesis are two distinct but related studies which combine to provide a synergistic picture of feedback at medical school. The first, a multi-school focus group study at three UK medical schools, explores students’ narratives of their lived experiences of positive and negative feedback. In exploring how students make sense of these experiences an in depth exploration is presented of not only what they think but also why. The second study presented in this thesis is a video-reflexive ethnography (VRE) study of feedback in two sites at medical school. This study comprises two phases: (1) an observational phase of data collection utilising video to capture feedback as it occurred in two sites at medical school (the simulated clinical skills setting and the medical workplace); and (2) the (reflexivity) phase of the study involving showing this footage back to student and tutor participants (separately) to explore their recognition and perception of feedback seen within the footage. In its totality, this VRE study allows for a comparison of student and tutor perspectives, as well as of feedback practices and perspectives in these two different sites. ii In summary, through listening to, and observing the lived experiences of feedback for medical students and their educators, the research presented within this thesis provides an in depth (and novel) understanding of both feedback practices and perceptions at medical school.