Evaluation of Incentive-compatible Differentiated Scheduling for Packet-switched Networks

Communication applications have diverse network service requirements. For instance, Voice over IP (VoIP) demands short end-to-end delay, whereas File Transfer Protocol (FTP) benefits more from high throughput than short delay. However, the Internet delivers a uniform best-effort service. As a result, much research has been conducted to enhance the Internet to provide service differentiation. Most of the existing proposals require additional access-control mechanisms, such as admission control and pricing, which are complicated to implement and render these proposals not incrementally deployable. Incentive-compatible Differentiated Scheduling (ICDS) provides incentives for applications to choose a service class according to their burst characteristics without additional access-control mechanisms. This thesis investigates the behaviour of ICDS with different types of traffic by analysis and extensive simulations. The results show some evidences that ICDS can achieve its design goal. In addition, this thesis revises the initial ICDS algorithm to provide fast convergence for TCP traffic

Desarrollo y validación de una escala PLEs desde la perspectiva del alumno y el aprendizaje en la educación terciaria

The study's goal is to create and validate a Personal Learning Environment Scale (PLEs) from the learner and learning perspective (named PLEsS-LL) to ensure effective learning in Chinese tertiary education. 657 undergraduates participated in the study after completing scale development steps. Six factors were extracted from the PLEsS-LL using Exploratory Factor Analysis (EFA). Confirmatory Factor Analysis (CFA) supported the six-factor scale with 22 items. Furthermore, the PLEsS-LL was redesigned as a questionnaire to assess learners' readiness for PLE learning. The findings indicated that participants were comfortable learning in PLEs in general. They were mostly positive in terms of learning motivation and problem-solving abilities. They did, however, report less confidence in self-directed learning. Meanwhile, male participants outperformed female participants in all categories except learning motivation. The reasons were explained, and suggestions for future PLE design were made. The PLEsS-LL could be used as a resource or guide for learner preparation in the PLE context in higher education around the world.El objetivo del estudio es crear y validar una Escala de Entornos Personales de Aprendizaje (PLEsS) desde la perspectiva del alumno y el aprendizaje (llamada PLEsS-LL) para garantizar un aprendizaje efectivo en la educación terciaria china. 657 estudiantes universitarios participaron en el estudio después de completar los pasos de desarrollo de escala. Se extrajeron seis factores del PLEsS-LL mediante Análisis Factorial Exploratorio (EFA). El Análisis Factorial Confirmatorio (AFC) apoyó la escala de seis factores con 22 ítems.  Además, el PLEsS-LL fue rediseñado como un cuestionario para evaluar la preparación de los alumnos para el aprendizaje PLE. Los hallazgos indicaron que los participantes se sentían cómodos al aprender en PLE en general. En su mayoría fueron positivos en términos de motivación de aprendizaje y habilidades para resolver problemas. Sin embargo, informaron menos confianza en el aprendizaje autodirigido. Mientras tanto, los participantes masculinos superaron a las participantes femeninas en todas las categorías, excepto en la motivación de aprendizaje. Se explicaron las razones y se hicieron sugerencias para el diseño futuro de PLE. El PLEsS-LL podría utilizarse como un recurso o guía para la preparación del alumno en el contexto de los PLEs en la educación superior de todo el mundo

Effect of berbamine hydrochloride on the absorption of berberine hydrochloride in an in situ single-pass intestinal perfusion system in rats

Purpose: To investigate the intestinal absorption characteristics of berberine hydrochloride (BBH) under different perfusion conditions in rats.Methods: Based on the in situ single-pass intestinal perfusion model of rats, HPLC was used to determine the content of berberine hydrochloride in solution after perfusion under different conditions. The absorption rate constant (Ka), effective permeability coefficient (Papp) and cumulative absorption per unit area (Q) under different perfusion conditions were analyzed by one-way ANOVA.Results: The Papp and Ka of BBH in perfusion solution at pH 7.4 were greater than those in perfusion solution at pH 6 and 8. There was no significant difference (p > 0.05) in Papp and Ka of duodenum, jejunum and ileum at high, medium and low concentrations of berberine hydrochloride perfusion solution. The Q increased linearly with increase of mass concentration of perfusion solution. The Ka and Papp of BBH in duodenum, jejunum, and ileum of BBH and berbamine hydrochloride (BAH) combined at different ratios were higher than those of BBH control group at the same BBH concentration, but absorption of BBH in the ratio B40:A50 and B30:A20 groups was highest. In the ratio of B40:A50 ratio, B30:A20 ratio group or the same concentration's BBH group, Ka and Papp of BBH decreased in the order of jejunum > duodenum > ileum.Conclusion: Berberine hydrochloride is absorbed in neutral environment of pH 7.4. The intestinal absorption mechanism of BBH is passive diffusion, and jejunum is the best intestinal segment for absorption. BAH promotes the absorption of BBH