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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

A Comparison of Second Grade Children's Learning Curves on School Tasks with Their Respective Performances on the "Black Box Test of Learning Ability"

Knox, Robert Stephen 01 May 1975 (has links)
This study investigated the usefulness of the Black Box Test of Learning Ability as an indicator of children's performance on math and writing tasks. Twelve second grade students, seven to eight years of age, demonstrated naivete on both tasks and were subsequently individually administered the learning test. The subjects were divided into two groups, and each group received a different task presentation order. Composite scores were derived for all subjects and tasks, and individual learning curves were compared. The combined Black Test score produced a significantly high correlate to math (rho = .733) and writing (rho = .841) than either the paired associate or sequential learning tasks alone. Although the length of the learning curve of the BBT was indicative of the learning curve lengths for each school task, trial by trial learning curve comparisons were less reliable. Analysis of these data suggested that the method of instruction (i.e., the amount of attempted practice and appropriate feedback) was the major factor correlating the Black Box Test to each school task. It was suggested that the most useful assessment of "learning ability" would employ a behavioral sample of the task itself, rather than utilize a correlated activity.
32

Towards a Quantitative Framework for Detecting Transfer ofLearning

Galdo, Brendan Matthew January 2020 (has links)
No description available.
33

A decade with robot-assisted surgery : How far have we come? A study comparing surgical outcomes in rectal cancer

Bala, Mikael Valentin January 2023 (has links)
Introduction: In recent years, robot-assisted surgery has taken over as a first option in rectal cancer treatment. The overall perception is that robot-assisted surgery is a method with good surgical outcomes. Many current studies have focused on comparing robot-assisted surgery to conventional laparoscopy. To our knowledge, few studies have been conducted to compare surgical outcomes in rectal cancer over time in robot-assisted surgery as training and knowledge increases in the field. Aim: To examine the two most commonly used robot-assisted surgical procedures in rectal cancer, to compare surgical outcomes of each procedure over a ten-year period. Method: A retrospective comparative study design was used. The national Swedish Colorectal Cancer Registry (SCRCR) was used to identify patients who underwent robot-assisted rectal cancer surgery at Örebro University Hospital between 2013 and 2022. Two surgical procedures were assessed: anterior resection and abdomino-perineal resection. Studied outcomes included: console-time, operation time, blood loss, hospital stay and conversion rate. Group comparisons were performed. Results: In total 202 patients were included and grouped into two periods (2013-2017; 2018-2022). A statistically significant reduction was observed in both procedures regarding blood loss in the later period. No other statistically significant differences were identified. Patients operated with APR in the later period were less fit. Conclusion: The surgical procedures showed comparable clinical outcomes in both periods. Our study showed that more complex cases in the group operated with APR were selected in the second period, which could imply that a higher degree of surgical proficiency was obtained over time.
34

THE DEVELOPMENT OF A PREDICTIVE PROBABILITY MODEL FOR EFFECTIVE CONTINUOUS LEARNING AND IMPROVEMENT

Maginnis, Michael Abbot 01 January 2012 (has links)
It is important for organizations to understand the factors responsible for establishing sustainable continuous improvement (CI) capabilities. This study uses learning curves as the basis to examine learning obtained by team members doing work with and without the application of fundamental aspects of the Toyota Production System. The results are used to develop an effective model to guide organizational activities towards achieving the ability to continuous improve in a sustainable fashion. This research examines the effect of standardization and waste elimination activities supported by systematic problem solving on team member learning at the work interface and system performance. The results indicate the application of Standard Work principles and elimination of formally defined waste using the systematic 8-step problem solving process positively impacts team member learning and performance, providing the foundation for continuous improvement Compared to their untreated counterparts, treated teams exhibited increased, more uniformly distributed, and more sustained learning rates as well as improved productivity as defined by decreased total throughput time and wait time. This was accompanied by reduced defect rates and a significant decrease in mental and physical team member burden. A major outcome of this research has been the creation of a predictive probability model to guide sustainable CI development using a simplified assessment tool aimed at identifying essential organizational states required to support sustainable CI development.
35

Clinical and Educational Efficacy of a University-Based Biofeedback Therapy Clinic.

Shiau, Shwu-Huey 12 1900 (has links)
This study is a qualitative analysis and a quantitative analysis of all peripheral biofeedback client data files of the University of North Texas Biofeedback Research and Training Laboratory since its establishment in 1991 and through the year of 2002. The purpose of this study is to evaluate the clinical and educational efficacy of the BRTL. Clients' electromyography and temperature measures, self-report of homework relaxation exercises and progress, and the pre- and post-Stress Signal Checklist were reviewed and analyzed. In regard to clinical efficacy, results indicate statistically significant changes in both temperature training and muscle tension training as a whole group. When divided into subtypes based on the clients' primary presenting problem, findings indicate statistical significance in chronic pain, tension headache, and temporomandibular jaw pain on temperature training, and show statistical significance in chronic pain, tension headache, hypertension, migraine headache, stress, and temporomandibular jaw pain on muscle tension training. When analyzing the Stress Signal Checklist, only 25% of clients had complete information on both pre- and post-Stress Signal Checklist. For these 25%, 87.5% reported symptoms decreased. When reviewing the clients' self-reported progress in therapist's session notes, there is no procedure for computing a treatment success to failure ratio due to the inconsistency of therapists in recording clients' statements. This study also identifies three basic biofeedback learning curves that show how people learn self-regulation skills in biofeedback therapy: 1) steady state and trainable (low variability), 2) phasic state and trainable (high variability), and 3) phasic state and low trainable (high variability).
36

Avaliação prospectiva de curva de aprendizado da prostatectomia radical laparoscópica assistida por robótica / Prospective evaluation of the learning curve for robotic assisted laparoscopic radical prostatectomy

Okano, Marcelo Takeo Rufato 10 October 2014 (has links)
INTRODUÇÃO: O câncer de próstata é responsável por 15% dos casos novos de câncer que acometem os homens e pela 5ª causa de morte. As técnicas minimamente invasivas, sobretudo a cirurgia robótica tornou-se a técnica comumente empregada nos Estados Unidos. Muitos artigos tentam demonstrar a curva de aprendizado necessária para a estabilização dos resultados, mas a implementação de novas tecnologias passa por diversos desafios, além da avaliação de seus resultados e dos custos, o que em países em desenvolvimento pode ter um importante impacto no sistema de saúde. OBJETIVO: Avaliar a curva de aprendizado da prostatectomia radical laparoscópica robótica assistida (PRRA) para o tratamento do câncer de próstata, de acordo com a continência urinária, a potência sexual, o tempo cirúrgico e o controle oncológico. MÉTODOS: Duzentos pacientes com neoplasia de próstata localizada submetidos à PRRA por um único cirurgião foram divididos em quatro grupos de acordo com a sequência das cirurgias. Foram avaliados os dados intra-operatórios, como: tempo cirúrgico, perda sanguínea estimada e as margens cirúrgicas. Também durante o pósoperatório foram avaliadas a potência (IIEF) e a continência (ICIQ). RESULTADOS: Os pacientes apresentaram idade média de 60,6 anos (59,72-61,61), volume prostático ao toque retal de 40 gramas e valor do PSA 6,95 ng/ml (5,79-8,10) semelhantes em todos os grupos (p > 0,05). A biópsia prostática pré-operatória mostrou diferença no escore de Gleason e no tamanho da próstata, sendo que o escore 6 foi menos frequente no grupo 4, representado por 23 pacientes (46%) e no grupo 1, com 39 pacientes (78%) (p < 0,01). Já o tamanho prostático avaliado pelo USTR foi de 39,6 gramas (29,75-48,7) no grupo 4 e 30,5 gramas (23,0-38,15) no grupo 2. A curva de aprendizado estabelecida demonstrou uma diminuição no tempo cirúrgico de 157 minutos (145-170) no grupo 1, para 132 minutos (119-140) no grupo 2 (p < 0,01). A perda sanguínea estimada também se reduziu aproximadamente pela metade: de 395 ml (250-500) no grupo 1, para 200 ml (150-250) no grupo 3 (p < 0,01). As margens positivas reduziram de 16% para apenas 8%, mas se mostraram estatisticamente semelhantes (p=0,236). A capacidade de penetração com doze meses praticamente dobrou de 38% (19 pacientes) no grupo 1 para 80% (40 pacientes) no grupo 4 (p=0,003). A continência avaliada com um ano mostrou-se melhor no grupo 4 (98%) quando comparado aos pacientes do grupo 1 (94%) (p=0,001). As complicações foram estatisticamente semelhantes entre os quatro grupos (p = 0,668). A análise da recidiva bioquímica não demonstrou diferença (p > 0,05). CONCLUSÕES: A curva de aprendizado da PRRA é variável de acordo com o parâmetro a ser avaliado, e apesar do equipamento e da tecnologia, à medida que se aumenta a experiência do cirurgião, melhores resultados são obtidos. O tempo de cirurgia e o sangramento estabilizaram-se, respectivamente, após 50 e 100 PRRA. A potência e a continência, por sua vez, estabilizaram-se após 150 PRRA. É importante ressaltar que o controle oncológico necessita de um período de acompanhamento mais longo para ser avaliado / BACKGROUND: Prostate cancer is responsible for 15% of new cases of male cancer and is the fifth leading cause of death. Minimally invasive and mainly, robotic surgery technique became the technique most widely utilized in the United States. Many articles have tried to demonstrate the required learning curve to achieve the plateau. Although, new techniques implementation go through many challenges besides the evaluation of its results, costs also became an issue, which may impact in developing countries health system. OBJECTIVE: We aim to evaluate the learning curve of robot-assisted radical prostatectomy (RARP) for the treatment of prostate cancer, according to continence, potency, surgical time and oncologic control. METHODS: Two hundred patients with localized prostate cancer that underwent RARP by a single surgeon were divided into four groups according to its surgical sequence. Intraoperative data, such as surgical time, estimated blood loss and margins were recorded. Also postoperative functional parameters as continence and potency were gathered using validated questionnaires (ICIQ and IIEF). RESULTS: Patients mean age were 60.6 years (59.72- 61.61), mean prostate volume at digital rectal examination was 40 grams and PSA value 6.95 ng/ml (5.79-8.10) were similar in all groups (p > 0.05). Pre-operative prostate biopsy showed difference in Gleason score and prostate size. Gleason score 6 was less frequent in group 4, 23 patients (46%), than group 1, 39 patients (78%)(p <0.01) and prostate size at TRUS was 39.6 grams (29.75- 48.7) in group 4 and 30.5 grams (23.0- 38.15) in group 2. The established learning curve showed a reduction on surgical time from 157 minutes (145-170) in group 1 to 132 minutes (119-140 min) in group 2 (p < 0.01). The estimated blood loss also decreased almost to half, from 395 ml (250-500) in group 1 to 200 ml (150-250) in group 3 (p < 0.01). Positive margins decreased from 16% to only 8 %, but were statistically similar (p=0.236). Nineteen patients (38%) could have sexual intercourse at an year after the surgery, in the first group but latest, in the fouth group, it doubled to 40 patients (80%) (p=0.003). Also continence improved in group 4(98%) when compared with group 1 (94%) (p=0.001). Complications were similar between groups (p=0.668). Biochemical recurrence also showed no difference (p > 0.05). CONCLUSIONS: Therefore, the learning curve of the RARP is variable according to the evaluated parameter and obviously, despite the equipment and technology, the increase of surgical experience the best the outcome. Surgery time plateau were achieved at 50 RARP, estimated blood loss stabilized after 100 surgeries, sexual function and urinary continence after 150 RARP. Cancer control requires a longer follow-up period for review
37

Multi-fidelity Gaussian process regression for computer experiments

Le Gratiet, Loic 04 October 2013 (has links) (PDF)
This work is on Gaussian-process based approximation of a code which can be run at different levels of accuracy. The goal is to improve the predictions of a surrogate model of a complex computer code using fast approximations of it. A new formulation of a co-kriging based method has been proposed. In particular this formulation allows for fast implementation and for closed-form expressions for the predictive mean and variance for universal co-kriging in the multi-fidelity framework, which is a breakthrough as it really allows for the practical application of such a method in real cases. Furthermore, fast cross validation, sequential experimental design and sensitivity analysis methods have been extended to the multi-fidelity co-kriging framework. This thesis also deals with a conjecture about the dependence of the learning curve (ie the decay rate of the mean square error) with respect to the smoothness of the underlying function. A proof in a fairly general situation (which includes the classical models of Gaussian-process based metamodels with stationary covariance functions) has been obtained while the previous proofs hold only for degenerate kernels (ie when the process is in fact finite-dimensional). This result allows for addressing rigorously practical questions such as the optimal allocation of the budget between different levels of codes in the multi-fidelity framework.
38

Technology adoption and inequality

Faissol, Daniel Mello 01 April 2008 (has links)
The prices of technological equipment have seen significant declines in recent decades. In Chapter 2 of this thesis, we examine the evidence and causes of these price declines. Among several factors, we focus on the learning curve effect where the cost of producing technological equipment declines as the cumulative number of produced units increases. In Chapter 3 we review the literature on technology adoption and the timing decisions of such adoptions. We aim to contribute to the literature by examining the timing of technology adoption under price declines. Furthermore, we consider the effect of human capital on such adoption decisions. We begin in Chapter 4 by developing a model of the timing of technology adoption under an exogenous price decline. Section 1 considers a single price drop in followed by multiple price drops in section 2. From the analytical results developed in these sections, we examine the effect of human capital on the adoption decision. Chapter 5 considers the price of the technological equipment to be endogenous to the model. We run computational experiments to demonstrate the declining price as a function of time. We examine the effect of the distribution of human capital on the price decline and adoption decision of the individuals of the population. We conclude with insights on the relationship between human capital inequality and technology adoption decisions.
39

Avaliação prospectiva de curva de aprendizado da prostatectomia radical laparoscópica assistida por robótica / Prospective evaluation of the learning curve for robotic assisted laparoscopic radical prostatectomy

Marcelo Takeo Rufato Okano 10 October 2014 (has links)
INTRODUÇÃO: O câncer de próstata é responsável por 15% dos casos novos de câncer que acometem os homens e pela 5ª causa de morte. As técnicas minimamente invasivas, sobretudo a cirurgia robótica tornou-se a técnica comumente empregada nos Estados Unidos. Muitos artigos tentam demonstrar a curva de aprendizado necessária para a estabilização dos resultados, mas a implementação de novas tecnologias passa por diversos desafios, além da avaliação de seus resultados e dos custos, o que em países em desenvolvimento pode ter um importante impacto no sistema de saúde. OBJETIVO: Avaliar a curva de aprendizado da prostatectomia radical laparoscópica robótica assistida (PRRA) para o tratamento do câncer de próstata, de acordo com a continência urinária, a potência sexual, o tempo cirúrgico e o controle oncológico. MÉTODOS: Duzentos pacientes com neoplasia de próstata localizada submetidos à PRRA por um único cirurgião foram divididos em quatro grupos de acordo com a sequência das cirurgias. Foram avaliados os dados intra-operatórios, como: tempo cirúrgico, perda sanguínea estimada e as margens cirúrgicas. Também durante o pósoperatório foram avaliadas a potência (IIEF) e a continência (ICIQ). RESULTADOS: Os pacientes apresentaram idade média de 60,6 anos (59,72-61,61), volume prostático ao toque retal de 40 gramas e valor do PSA 6,95 ng/ml (5,79-8,10) semelhantes em todos os grupos (p > 0,05). A biópsia prostática pré-operatória mostrou diferença no escore de Gleason e no tamanho da próstata, sendo que o escore 6 foi menos frequente no grupo 4, representado por 23 pacientes (46%) e no grupo 1, com 39 pacientes (78%) (p < 0,01). Já o tamanho prostático avaliado pelo USTR foi de 39,6 gramas (29,75-48,7) no grupo 4 e 30,5 gramas (23,0-38,15) no grupo 2. A curva de aprendizado estabelecida demonstrou uma diminuição no tempo cirúrgico de 157 minutos (145-170) no grupo 1, para 132 minutos (119-140) no grupo 2 (p < 0,01). A perda sanguínea estimada também se reduziu aproximadamente pela metade: de 395 ml (250-500) no grupo 1, para 200 ml (150-250) no grupo 3 (p < 0,01). As margens positivas reduziram de 16% para apenas 8%, mas se mostraram estatisticamente semelhantes (p=0,236). A capacidade de penetração com doze meses praticamente dobrou de 38% (19 pacientes) no grupo 1 para 80% (40 pacientes) no grupo 4 (p=0,003). A continência avaliada com um ano mostrou-se melhor no grupo 4 (98%) quando comparado aos pacientes do grupo 1 (94%) (p=0,001). As complicações foram estatisticamente semelhantes entre os quatro grupos (p = 0,668). A análise da recidiva bioquímica não demonstrou diferença (p > 0,05). CONCLUSÕES: A curva de aprendizado da PRRA é variável de acordo com o parâmetro a ser avaliado, e apesar do equipamento e da tecnologia, à medida que se aumenta a experiência do cirurgião, melhores resultados são obtidos. O tempo de cirurgia e o sangramento estabilizaram-se, respectivamente, após 50 e 100 PRRA. A potência e a continência, por sua vez, estabilizaram-se após 150 PRRA. É importante ressaltar que o controle oncológico necessita de um período de acompanhamento mais longo para ser avaliado / BACKGROUND: Prostate cancer is responsible for 15% of new cases of male cancer and is the fifth leading cause of death. Minimally invasive and mainly, robotic surgery technique became the technique most widely utilized in the United States. Many articles have tried to demonstrate the required learning curve to achieve the plateau. Although, new techniques implementation go through many challenges besides the evaluation of its results, costs also became an issue, which may impact in developing countries health system. OBJECTIVE: We aim to evaluate the learning curve of robot-assisted radical prostatectomy (RARP) for the treatment of prostate cancer, according to continence, potency, surgical time and oncologic control. METHODS: Two hundred patients with localized prostate cancer that underwent RARP by a single surgeon were divided into four groups according to its surgical sequence. Intraoperative data, such as surgical time, estimated blood loss and margins were recorded. Also postoperative functional parameters as continence and potency were gathered using validated questionnaires (ICIQ and IIEF). RESULTS: Patients mean age were 60.6 years (59.72- 61.61), mean prostate volume at digital rectal examination was 40 grams and PSA value 6.95 ng/ml (5.79-8.10) were similar in all groups (p > 0.05). Pre-operative prostate biopsy showed difference in Gleason score and prostate size. Gleason score 6 was less frequent in group 4, 23 patients (46%), than group 1, 39 patients (78%)(p <0.01) and prostate size at TRUS was 39.6 grams (29.75- 48.7) in group 4 and 30.5 grams (23.0- 38.15) in group 2. The established learning curve showed a reduction on surgical time from 157 minutes (145-170) in group 1 to 132 minutes (119-140 min) in group 2 (p < 0.01). The estimated blood loss also decreased almost to half, from 395 ml (250-500) in group 1 to 200 ml (150-250) in group 3 (p < 0.01). Positive margins decreased from 16% to only 8 %, but were statistically similar (p=0.236). Nineteen patients (38%) could have sexual intercourse at an year after the surgery, in the first group but latest, in the fouth group, it doubled to 40 patients (80%) (p=0.003). Also continence improved in group 4(98%) when compared with group 1 (94%) (p=0.001). Complications were similar between groups (p=0.668). Biochemical recurrence also showed no difference (p > 0.05). CONCLUSIONS: Therefore, the learning curve of the RARP is variable according to the evaluated parameter and obviously, despite the equipment and technology, the increase of surgical experience the best the outcome. Surgery time plateau were achieved at 50 RARP, estimated blood loss stabilized after 100 surgeries, sexual function and urinary continence after 150 RARP. Cancer control requires a longer follow-up period for review
40

Analyse économique de l’industrie photovoltaïque : mondialisation, dynamique des coûts, et politiques publiques / Economic analysis of the photovoltaic industry : globalisation, price dynamics, and incentive policies

Du Fayet de la Tour, Arnaud 14 December 2012 (has links)
Au cours de la dernière décennie, le marché photovoltaïque a été multiplié par 10, le prix des panneaux solaires réduit de 60%, et la Chine est devenue le premier producteur mondial. L'objectif de cette thèse est d'identifier les mécanismes à l'origine de ces fortes mutations. Grâce à des entretiens auprès d'acteurs de l'industrie photovoltaïque chinoise, et l'analyse de données de brevets, nous expliquons comment la Chine a réussi à acquérir la technologie et le savoir-faire nécessaires à ce succès. Le transfert de technologie a eu lieu grâce au déploiement du marché d'équipement de production et au recrutement de cadres formés dans les pays industrialisés. En revanche, la propriété intellectuelle n'a joué aucun rôle. L'analyse de l'évolution du coût des modules grâce au modèle de courbe d'apprentissage nous permet de prédire une réduction du coût de deux tiers d'ici à 2020. Elle donne des indications quant à la future compétitivité de l'électricité photovoltaïque. Enfin, une attention particulière est portée aux tarifs de rachat de l'électricité, qui ont largement contribué au développement du marché photovoltaïque. Nous analysons leur influence sur le marché et leur capacité à s'adapter à la volatilité du prix des modules, en analysant des séries temporelles. Nous construisons aussi un modèle théorique pour analyser l'influence du comportement stratégique des entreprises sur l'efficacité d'un tarif de rachat. Cela permet de suggérer des recommandations quant à la conception de ces instruments incitatifs. / In the last decade, the photovoltaic market was multiplied by 10, module price was reduced by 60%, and China increased its share in cell and module production from almost nothing to more than half. The purpose of this thesis is to shed light on the mechanisms driving these transformations. We analyse how China managed to acquire the photovoltaic technology, relying on interviews with actors of the Chinese photovoltaic industry, and data gathered on patents related to the photovoltaic technology. We show that intellectual property rights did not play a significant role, Chinese firms getting access to the technology by buying manufacturing equipment from industrialised countries, and from labour mobility. The cost decrease is analysed with experience curves models, allowing us to forecast a further cost decrease of two thirds by 2020, provided that the market follows the high predicted expansion. It gives some insight regarding when photovoltaic technology will become competitive. An important attention is dedicated to feed-in tariffs which largely participated in driving the demand so far. Their influence on the photovoltaic market, and their ability to adapt to module price volatility to avoid too attractive profits, is analysed using weekly data. A theoretical model analysing the influence of firms' strategies on the incentive effect of feed-in tariffs allows us to give further recommendations concerning an optimal feed-in tariff scheme.

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