El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Each year there are more construction companies seeking for implementation of the Building Information Modeling (BIM) methodology in their projects since it provides different benefits related to project time, cost and quality. Besides, different countries currently demands its application. However, companies do not always achieve these benefits at its totality because BIM implementation must overcomes a series of difficulties related to interoperability and personnel, difficulties which are generated by a lack of collaboration and communication between the project stakeholders. The present investigation finds a new solution to this problem, reducing the waste generated at the design stage of the BIM projects by implementing the A360 collaboration tool, a platform which provides a virtual centralized space that allows storing BIM files, visualizing them and making comments in real time from any device. The results show a reduction of waste that finally reduce the time for the design stage in a BIM project

Philosophiae Doctor - PhD / The nature of naval member’s job demands is that they experience high levels of stress. Stress is introduced in military training to familiarize sailors with real life stressors. This study is located in piloting and validity theory. It focuses explicitly on validating an existing tool, the Therapeutic Recreation Stress Leisure Appraisal Tool, to measure stress in the South African Navy. This study aimed to pilot and evaluate the validity and reliability of the developed tool in an African context in the South African Navy. A multi-stage procedure of instrument development using the instrument development model will be used, consisting of the following steps: 1) preliminary phase, 2) questionnaire development, 3) pilot testing, and 4) evaluation. The scope of this study, is only focused on stages three and four. The current study followed an explanatory sequential mixed-method design. In this study, the qualitative phase was done first, followed by the quantitative phase. The mixed-method design is used to build upon the same research questions. PHASE 1, the pilot-testing phase (qualitative, n=50), explored if the developed appraisal tool is interpreted correctly and contains the necessary applicable questions. This population and sample were purposefully selected from the navy. Data were collected in focus groups taking place at a naval base. Five focus groups of ten members each were completed using interview schedules. Recorded data was transcribed verbatim. Data were analysed using thematic analysis with data coding to extract themes. This study is an extension of from a masters study linked to the current study, which contributed towards the finalisation of the questionnaire. Iterative exploratory factor analyses were used at the item and scale levels to select and reassign the items and scales. PHASE 2, the evaluation phase (quantitative, n=1000), determined the validity and reliability of the refined, developed appraisal tool. The population (N=7000) and sample (n=1000) consisted of senior and junior ranks from the officer core, conveniently selected from a naval base. PHASE 1 informed PHASE 2, the evaluation phase.

Since the cost of petroleum fluctuates widely, it is advisable to optimize extraction of oil and other hydrocarbon products form existing oil reserves. Because of the costs involved in recovering oil from a reservoir, predicting reservoir performance can be a useful tool for determining whether continued extraction might be profitable. This can be done using computer simulations of the physical processes involved such as pressure/head, fluid velocities, and so forth. Fluid flow within a reservoir occurs at a very small scale relative to the size of the reservoir. This size difference makes performing simulations at the physically appropriate scale unfeasible. Homogenization is a technique used in reservoir simulation to upscale small scale dependent behavior, such as a permeability tensor, to make simulation feasible. To calculate a homogenized permeability tensor, the solution to a system of uncoupled elliptic partial differential equations must be found repeatedly throughout the reservoir. Generally, the solution to the system of differential equations is approximated numerically using finite element or finite difference methods. We explore using wavelets as a means of characterizing homogenization in reservoir simulations in the search for fast algorithms for computing equivalent tensors. In addition to the analogy developed between homogenization and wavelets, proofs of convergence results from homogenization within the wavelet characterization are considered.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19236号 / 工博第4071号 / 新制||工||1628(附属図書館) / 32235 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 西脇 眞二, 教授 松原 厚, 准教授 小森 雅晴 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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The study examined students’ perceptions of Facebook, Twitter and blogs as tools for learning in a classroom environment. The population of the research was of 109 students from a 4-year college located in the southern region of the US. The results showed that most of the students were undecided in their perception of Facebook, Twitter and blogs as learning tools. The findings also showed that most of the participants were undecided in perception that Facebook, Twitter and blogs were viewed as sources of learning distraction. The findings equally indicated that significant number (about half of the population) of the participants disagreed that they felt intimidated using blogs to enhance learning while a third of the population was undecided. The results of the study did reveal that statistically significant differences existed among students in their perception of Twitter based on ethnicity. Hispanic and African American students perceived that using Twitter in the learning environment helped them to engage in collaborative learning. In addition, the findings showed African American respondents perceived that tweeting was also perceived as a distraction unlike other ethnic groups. The findings equally indicated that African American students perceived that Twitter was used as a tool to share life experiences unlike other ethnic groups represented in this study. The results equally revealed that female students actively participated in discussion forums more than their male counterparts did. The findings showed that Hispanic and African American students believed that using tweeting in the learning environment helped them to learn from one another. Whites and Native Americans did not share similar opinions. The results also revealed that African Americans and Hispanic Americans perceived that using Facebook during instruction enhanced collaboration among learners. In addition, the findings revealed that African American respondents perceived that tweets were helpful to them in sharing ideas as they complete assignments. However, White Americans, Hispanic Americans and Asian Americans did not have a similar view. The conclusion drawn from this study was that students enjoyed using social media tools for personal and entertainment purposes however; they did not enjoy using the tools for educational purposes. The general conclusion was that students were undecided in their perception of Facebook, Twitter and blogs as learning tools as well as perceived sources of distraction and intimidation.

To make computational thinking appealing to young learners, initial programming instruction looks very different now than a decade ago, with the increasing use of graphics and robots both real and virtual. After the first steps, children want to create interactive programs, and they need a model for this. State diagrams provide such a model, as observed previously by other researchers. This thesis documents the design and implementation of a Model-Driven Engineering tool, SD~Draw, that allows even primary-aged children to draw and understand state diagrams, and create modifiable app templates. We have tested this with grade 4 and 5 students. In our initial test, we discovered that children very quickly understand the motivation and use of state diagrams using this tool, and will independently discover abstract states even if they are only taught to model using concrete states. To determine whether this approach is appropriate for children of this age we asked three questions: do children understand state diagrams, do they understand the role of reachability, and are they engaged by them. We found that they are able to translate between different representations of the state diagrams, strongly indicating that they do understand them. We found with confidence p=0.001 that they do understand reachability by refuting the null hypothesis that they are creating diagrams randomly. And we found that they were engaged by the concept, with many students continuing to develop their diagrams on their own time after school and on the weekend. / Thesis / Master of Science (MSc)

This study explored the use of a dichotomous key as a scaffolding tool in the museum setting. The dichotomous key was designed as a scaffolding tool to help students make more detailed observations as they identified various species of birds on display. The dichotomous key was delivered to groups of fifth and seventh graders in two ways: on a mobile platform and by museum educators. Data was collected in the forms of pre- and post-testing and observations to compare the two methods. Findings suggest the Mobile Dichotomous Key (MDK), developed by educators at the Bean Life Science Museum at Brigham Young University, was equally as effective as a teacher (museum educator) in assisting students in a learning activity designed to improve or develop scientific observation skills. While both groups' outcomes were the same, data from observations made during the learning activity showed that there were significant differences in the experience for the students. Students using the MDK were more engaged, could work at their own pace, and were more likely to work with their peers than students working in groups led by a museum educator. In contrast, students in the educator-led group were able to receive immediate feedback during the learning activity, as museum educators were able to make assessments and answer questions or expand the learning experience. A feedback mechanism is suggested for a future version of the Mobile Dichotomous Key app.

In manufacturing, monitoring machine health is an important step when implementing Industry 4.0 and ensures effective machining operations and minimal downtime. Monitoring the health of cutting tools during a machining process helps contain the faults associated with gradual tool wear, because they can be tracked and responded to as wear worsens. Left unchecked, tool failures can lead to more severe problems, such as dimensional and surface issues with machined workpieces and lower overall productivity during the machining process. This research explores the use of a machine vision setup used internally by the McMaster Manufacturing Research Institute (MMRI) in their three lathe machines. This machine vision setup provides a direct indication of the tool's maximum flank wear (VBmax), which, according to ISO 3685:1993(E), is set to be 300 µm. Also investigated was the use of image processing and analysis methods to determine the flank wear without removing the tool from the machine. This new, in-machine vision setup is intended to replace the use of an external optical microscope, which requires extended downtime between cutting passes. As a result of this replacement, the experimentation downtime was decreased by around 98.6%, leading to the experiment time to decrease from 5 weeks or more to just a couple of days. In addition, the difference in measurement between a commonly used optical microscope and in-machine vision setup was found to be ±3µm. / Thesis / Master of Science (MSc)

Many types of devices based on power converters have been proposed and studied for utility applications. In recent years most of the control systems for these converters have been digital. Unfortunately, such digital controllers, which are often based on a digital signal processor (DSP), are difficult to model in simulation. Thus, hardware prototypes are usually required. This thesis presents a tool for fast prototyping that helps overcome these difficulties. Namely, a hardware-in-the-loop simulation is provided for the digital controller in order to evaluate control algorithms without the voltage source converter and power system. The controller in the loop design methodology is described and the division between the real-time power system model and the hardware controller with an interface is shown. Also, the modulation type, integration time step selection and synchronization between the controller and the real-time system simulation are discussed. The hardware configuration for the real-time simulator and the software implementation of the simulator is discussed. In this thesis an example application of a shunt active compensator following this formal procedure is presented. The active compensator prototyping was first developed in MATLAB/Simulink. Then, following a formal design procedure, the power system was modeled in a digital simulator and the controller was implemented in a digital controller board. Finally, a hardware-in-the-loop test was carried out to validate the performance of the hardware controller for the active compensator. Although the tools and methods presented here are aimed at shunt connected current controller application, they may be generalized for use in the development of any digitally controlled power electronic converter.