Studies on the "Tools" for Positive Behavior Change were originally conducted with people involved in the foster care system. Few studies have conducted the trainings in classroom environments to increase the positive interactions between teachers and their students. Numerous studies have demonstrated the usefulness of behavioral skills training in teaching a wide variety of behavioral skills; however, relatively few of them have shown generalization to their natural environment and maintenance of appropriate responding following the training. Methods of prompting following the initial trainings that have been utilized are often quite intrusive especially when it interrupts the flow of the participants' natural environment. For this study, a multiple-baseline ABC across participants design was utilized to assess the combination of behavioral skills training to teach "Tools" for responding to child behavior with a less intrusive method of prompting in the form of visual prompts that are embedded into the training to maintain the skills acquired following the training.

Reflection is one of the most important factors that affects learning. A good learning strategy is supposed to improve a learner's reflection level. In addition, the past studies has proved u-learning can enhance learning performance, motivation and efficiency of learners. This study integrates these into learning activity of distinguishing vegetation, let learner reflect in u-learning environment. Almost of past researches promoted learners¡¦ reflection was by text-based. However, the limit of learning activity's character and mobile device¡¦s screen, the design of text-based promotes is confined. Therefore, this study proposes a video-based reflection prompts strategies in high media richness, and the Context-Aware Reflection Prompt System (CRPS) can detect learner¡¦s location by QR Code to provide appropriate guidance, facilitating learner to observe and reflect. Further to explore effects of reflection level and satisfaction between video-based and text-based reflection prompt strategies. This study recruited 70 college students to participate in this experiment, and divide into two groups of video-based and text- based reflection prompts. The results showed that the reflection level of the video-based reflection prompt group is significantly improved than of the text-based reflection prompt group; however, there was no differences found on the satisfaction. In addition, this study further investigated the learners¡¦ opinions and perspectives toward a video-based and a text-based reflection prompt strategy, and interviewed some learners to obtain the potential factors which may affect satisfaction.

Le spectre des neutrons prompts de fission (PFNS) est une donnée très importante pour diverses applications de la physique nucléaire. Cependant, en dehors du spectre de la fission spontanée du 252Cf, qui est reconnu comme un standard international et est utilisé pour la métrologie, le PFNS reste mal connu pour la plupart des noyaux fissionnants. En particulier, pour la fission rapide (induite par un neutron de plus de 100 keV environ), il existe peu de mesures, et les évaluations internationales présentent de fortes contradictions. De plus, il existe très peu de données sur les covariances associées aux diverses évaluations du spectre. Dans cette thèse, trois aspects de l'évaluation du PFNS sont abordés. Le premier aspect est la modélisation du spectre via le code FIFRELIN, développé au CEA Cadarache, qui simule la chaine de désexcitation des fragments de fission par émissions successives de neutrons et gammas prompts par la méthode de Monte-Carlo. Ce code a pour vocation de calculer les observables de fission dans un même calcul cohérent, à partir des distributions en masse, en énergie cinétique et en spin des fragments de fission. FIFRELIN a donc un caractère prédictif que n'ont pas les modèles analytiques utilisés pour décrire le PFNS. Une étude des paramètres de modèle influents, notamment le paramètre de densité de niveaux, est mené afin de tenter de mieux reproduire le spectre. Le deuxième aspect de la thèse concerne l'évaluation du PFNS et de sa matrice de covariance. On propose une méthodologie pour évaluer le spectre et sa matrice de covariance de manière rigoureuse, à travers l'outil CONRAD du CEA Cadarache. Ceci implique la modélisation du spectre à travers des modèles simples, notamment celui de Madland-Nix qui est le plus utilisé dans les évaluations, en ajustant les paramètres de ces modèles afin de reproduire les données expérimentales. La matrice de covariance provient de la propagation rigoureuse des sources d'incertitude qui interviennent dans le calcul. En particulier, les incertitudes systématiques liées au dispositif expérimental sont propagées par des techniques de marginalisation. La marginalisation permet de propager ces incertitudes sur le spectre calculé, en obtenant des incertitudes réalistes sans besoin d'être artificiellement rehaussées comme c'est souvent le cas dans le cadre d'ajustements bayésiens. La propagation de ces incertitudes expérimentales impacte aussi la matrice de corrélation du spectre calculé. On présente les résultats pour la fission induite par neutron thermique de l'235U et du 239Pu. Pour le modèle de Madland-Nix avec section inverse constante, l'énergie moyenne des neutrons prompts obtenue est de 1.979 MeV pour l'235U, et de 2.087 MeV pour le 239Pu. Le dernier aspect de la thèse est l'étude de l'impact du PFNS et de ses covariances sur le calcul du flux neutronique sur la cuve d'un réacteur. L'enjeu est de taille, car l'estimation de la fluence au niveau de la cuve d'un réacteur détermine l'intégrité de celle-ci, et donc la durée de vie du réacteur. On observe l'importance des termes de corrélations du spectre pour calculer notamment l'incertitude sur le flux intégré au-dessus de 1 MeV, de l'ordre de 6% (incertitude due seulement au spectre). / The prompt fission neutron spectrum (PFNS) is very important for various nuclear physics applications. Yet, except for the 252Cf spontaneous fission spectrum which is an international standard and is used for metrology purposes, the PFNS is still poorly known for most of the fissionning nuclides. In particular, few measurements exist for the fast fission spectrum (induced by a neutron whose energy exceeds about 100 keV), and the international evaluations show strong discrepancies. There are also very few data about covariances associated to the various PFNS evaluations. In this work we present three aspects of the PFNS evaluation. The first aspect is about the spectrum modeling with the FIFRELIN code, developed at CEA Cadarache, which simulates the fission fragment de-excitation by successive emissions of prompt neutrons and gammas, via the Monte-Carlo method. This code aims at calculating all fission observables in a single consistent calculation, starting from fission fragment distributions (mass, kinetic energy and spin). FIFRELIN is therefore more predictive than the analytical models used to describe the spectrum. A study of model parameters which impact the spectrum, like the fragment level density parameter, is presented in order to better reproduce the spectrum. The second aspect of this work is about the evaluation of the PFNS and its covariance matrix. We present a methodology to produce this evaluation in a rigorous way, with the CONRAD code, developed at CEA Cadarache. This implies modeling the spectrum through simple models, like the Madland-Nix model which is the most commonly used in the evaluations, by adjusting the model parameters to reproduce experimental data. The covariance matrix arises from the rigorous propagation of the sources of uncertainty involved in the calculation. In particular, the systematic uncertainties arising from the experimental set-up are propagated via a marginalization technique. The marginalization allows propagating these uncertainties on the calculated spectrum, and obtaining realistic uncertainties without having to artificially raise them, as it is sometimes necessary in Bayesian adjustments. The experimental uncertainty propagation also impacts the spectrum correlation matrix. We present the result for thermal neutron-induced fission of 235U and 239Pu. For the Madland-Nix model with constant inverse cross-section, the prompt neutron mean energy is 1.979 MeV for 235U and 2.087 MeV for 239Pu. The last aspect of this work is the calculation of the impact of the PFNS and its covariance matrix on a reactor vessel flux. This calculation is of major importance, since the vessel fluence estimation determines the vessel integrity, and therefore determines the reactor lifetime. We observe the importance of the PFNS correlation terms, to compute in particular the vessel flux uncertainty above 1 MeV, which is of the order of 6% (uncertainty only due to PFNS).

The prompt gamma-ray timing (PGT) method offers a relatively simple approach for range verification in proton therapy. Starting from the findings of previous experiments, several steps toward a clinical application of PGT have been performed in this work. First of all, several scintillation materials have been investigated in the context of PGT. The time resolution was determined at high photon energies in the MeV-region. In conclusion, the fast and bright scintillator CeBr3 is the material of choice in combination with a timing photomultiplier tube as light detector. A second study was conducted at Universitäts Protonen Therapie Dresden (UPTD) to characterize the proton bunch structure of a clinical beam concerning its time width and relative arrival time. The data is mandatory as input for simulation studies and to correct for phase drifts. The obtained data could furthermore be used for the first 2D imaging of a heterogeneous phantom based on prompt gamma-rays. In a last step, a PGT prototype system was designed using the findings from the first two studies. The prototype system is based on a newly developed digital spectrometer and a CeBr3 detector. The device is characterized at the ELBE bremsstrahlung beam. It was verified that the prototype operates within the specifications concerning time and resolution as well as throughput rate. Finally, for the first time the PGT system was used under clinical conditions in the treatment room of UPTD. Here, PGT data was obtained from the delivery of a three-dimensional treatment plan onto PMMA phantoms. The spot-by-spot analysis helped to investigate the performance of the prototype device under clinical conditions. As a result, range variations of 5 mm could be detected for the first time with an uncollimated system at clinically relevant doses. To summarize, the obtained results help to bring PGT closer to a clinical application.

In this project, different fission models in the nuclear reaction code TALYS have been compared to GEF version 2020/1.2. The data included in the comparison are mass yield distributions, average prompt neutron energies per fragment mass, and average multiplicities of both neutrons and γ-rays per fragment mass. The reaction studied in the first part of the project is 1 keV neutron-induced fission of 235U. In the second part of the study, a variety of different nuclei and different incident energies were included in comparisons, but a limitation was set to only include neutron-induced fission. The results from the comparison suggested that TALYS fymodel 2 and 3 were less consistent with GEF than fymodel 4. For the comparisons with experimental data, fymodel 4 also performed better overall. TALYS fymodel 2 and 3 make use of implemented partial versions of GEF to produce fission fragment distributions, while fymodel 4 takes fission fragment distribution data from separate yieldfiles. A database of these yieldfiles with 737 different nuclei and 10 energy levels was produced, to be implemented in future versions of TALYS. The energy levels were chosen to get a range of energies that can be accurately interpolated between. This method of using TALYS fymodel 4 with a yieldfile from GEF consistently showed a strong agreement with GEF version 2020/1.2 for the mass yield distributions and the neutron multiplicities. The γ-ray multiplicities and the neutron energies show a slightly weaker agreement, and TALYS gives consistently smaller values than GEF for these quantities.

Automated Program Repair (APR) is gaining popularity in the field of software engineering. APR reduces the time and effort needed to find and fix software bugs, with a goal of completely automating bug fixing without any human input. The first part of this study focuses on replicating ChatRepair, an advanced APR tool, and benchmarking it on 6 projects of the Defects4J 2.0. The evaluation revealed three enhancement options: Data Augmentation, Prompt Engineering, and Response Parsing. The second part of the study entails the design and implementation of a new tool, called RapidCapr, based on the newly found features and the structure of ChatRepair. Subsequently, RapidCapr was benchmarked on the same data set as ChatRepair. RapidCapr outperformed ChatRepair in terms of efficiency by producing comparable amount of plausible patches using 7 times fewer tokens. Regarding performance RapidCapr exceeded ChatRepair by generating 15% more plausible and 10% more fixed patches while using 63% fewer tokens. Importantly, the novel approach introduced in this study offers a dual advantage: it significantly reduces the cost associated with conversational-based Automated Program Repair (APR) while concurrently enhancing repair performance. / Automatisk programreparation (APR) ökar i popularitet inom mjukvaruutvecklingsområdet. APR minskar den tid och ansträngning som krävs för att hitta och åtgärda mjukvarubuggar, med målet att helt automatisera buggfixering utan något mänskligt ingripande. Den första delen av denna studie fokuserar på att replikera ChatRepair, ett avancerat APR-verktyg, och att utvärdera det på 6 projekt från Defects4J 2.0. Utvärderingen avslöjade tre förbättringsalternativ: Dataaugmentering, Prompt Engineering och Responsanalys. Den andra delen av studien innefattar design och implementation av ett nytt verktyg, kallat RapidCapr, baserat på de nyligen funna funktionerna och strukturen hos ChatRepair. Därefter utvärderades RapidCapr på samma datamängd som ChatRepair. RapidCapr presterade bättre än ChatRepair i fråga om effektivitet genom att producera en jämförbar mängd möjliga patchar och åtgärdade patchar med 3 till 7 gånger färre ”tokens” och 11 till 16 gånger färre anrop, beroende på stoppvillkor. När det gäller prestanda överträffade RapidCapr ChatRepair genom att generera 15% fler möjliga patchar och 10% fler åtgärdade patchar samtidigt som det använde 7% till 63% färre ”tokens”, beroende på stoppvillkor. Viktigt att notera är att det nya tillvägagångssättet som introduceras i denna studie erbjuder en dubbel fördel: det minskar betydligt kostnaderna för konversationsbaserad automatisk programreparation (APR) samtidigt som det förbättrar reparationsprestandan.

samples were irradiated for approximately 45 minutes to allow for the saturation of fission products. The first method used the beam port shutter and allowed for longer counting and irradiation times, but was unsuitable for examining fission products with half-lives below 10 seconds. The on/off method used a cycle of equal irradiation and counting times of one minute. The second method is able to measure track the production of fission products with half-lives of less than 10 seconds. This method used a borated aluminum wheel beam chopper to stop the irradiation of the sample during counting. The beam chopper was set to cycle for approximately one second of counting following half a second of irradiation. The spectra from both methods were analyzed and the peaks were assigned to the appropriate fission products. The majority of the peaks were composed of gamma-rays from multiple nuclides. The peaks created by gamma-rays from decays of a single nuclide were used to calculate the detection limits of the system. Using the beam chopper system, 21 peaks would be above the detection limits of our system 95% of the time for uranium samples of less than one kilogram. / text

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 112-118). Also available on the Internet.

Accurate estimates for the molecular transport coefficients are critical to predicting the movement of gases in geological media. Here I present a novel methodology for using prompt gamma activation analysis to measure the effective diffusivity of noble gases in a porous medium. I also present a model to estimate the connectivity parameter of a soil from measurements of its saturated conductivity, macro porosity, and pore volume and pore surface fractal dimensions. Experiments with argon or xenon diffusing through a nitrogen saturated geological media were conducted. The noble gas concentration variations at its source were measured using prompt gamma activation analysis and later compared to a numerical diffusion model to estimate the effective diffusion coefficient. Numerical simulations using the estimated diffusivity and the experimental argon data produced results with a correlation parameter R² = 0.98. However, neglecting transport mechanisms other than diffusion largely under-predicted the xenon depletion rates observed during the first hours of experiment. To explain these results, a second model was developed which included the effect of pressure gradients and bulk convection that might arise from the faster molecular migration of the light species in a non-equimolar system and gravitational currents. Finally, the fractal model developed for this dissertation was used to estimate the connectivity parameters and walking fractal dimension of a group of geological samples that were previously characterized. This model successfully predicted positive connectivity factors and walking fractal dimensions between two and three for every sample analyzed. / text

Gamma-ray Bursts (GRBs) are powerful explosions that emit most of their energy, as their name suggests, in gamma-rays of typical energies of about 1 MeV. This emission lasts for about two minutes or less and it is called the prompt emission. The isotropic energy radiated in GRBs is equivalent to the energy that the Sun will radiate in its entire lifetime. After decades of studying this cosmological phenomenon, we have come to learn that it involves a collimated and relativistic jet. Also, we know that they radiate energy in the X-ray, optical and radio bands for days, weeks and years, respectively, which is called the afterglow. Recently, NASA's Fermi Satellite was launched and, in addition to MeV photons, it detected GeV photons from these astrophysical sources. We show that these GeV photons are produced when the GRB jet interacts with the medium that surrounds it: the external forward shock model. We arrive at this conclusion not only by studying the GeV emission, but also by studying the afterglow observations (Chapter 2). We corroborate this model by studying the electron acceleration in the external forward shock model and find that electrons can radiate at the maximum observed energy of ~ 10 GeV (Chapter 3). We also provide an extensive analysis of the most recent afterglow observations of GRB 090902B within the same framework of an external forward shock origin. We find that the data for this burst requires a small deviation from the traditionally used power-law electron energy distribution, however, our previous results remain unchanged (Chapter 4). To conclude, we use the end of the prompt emission phase, which exhibits a steep X-ray temporal decay, to constrain the behavior of the central engine responsible for launching the relativistic jet (Chapter 5). / text