111 |
Quantitative diffuse reflectance spectroscopy : myocardial oxygen transport from vessel to mitochondriaLindbergh, Tobias January 2009 (has links)
In the field of biomedical optics, diffuse reflectance spectroscopy (DRS) is a frequently used technique for obtaining information about the optical properties of the medium under investigation. The method utilizes spectral difference between incident and backscattered light intensity for quantifying the underlying absorption and scattering processes that affects the light-medium interaction. In this thesis, diffuse reflectance spectroscopy (DRS) measurements have been combined with an empirical photon migration model in order to quantify myocardial tissue chromophore content and status. The term qDRS (quantitative DRS) is introduced in the thesis to emphasize the ability of absolute quantification of tissue chromophore content. To enable this, the photon migration models have been calibrated using liquid optical phantoms. Methods for phantom characterization in terms of scattering coefficient, absorption coefficient, and phase function determination are also presented and evaluated. In-vivo qDRS measurements were performed on both human subjects undergoing routine coronary artery bypass grafting (CABG), and on bovine heart during open-chest surgery involving hemodynamic and respiratory provocations. The application of a hand-held fiber-optic surface probe (human subjects) proved the clinical applicability of the technique as the results were in agreement with other studies. However, problems with non-physiological variations in detected intensity due to intermittent probe-tissue discontact were observed. Also, systematic deviations between modeled and measured spectra were found. By model inclusion of additional chromophores revealing the mitochondrial oxygen uptake ability, an improved model fit to measured data was achieved. Measurements performed with an intramuscular probe (animal subjects) diminished the influence of probe-tissue discontact on the detected intensity. It was demonstrated that qDRS could quantify variations in myocardial oxygenation induced by physiological provocations, and that absolute quantification of tissue chromophore content could be obtained. The suggested qDRS method has the potential of becoming a valuable tool in clinical practice, as it has the unique ability of monitoring both the coronary vessel oxygen delivery and the myocardial mitochondrial oxygen uptake ability. This makes qDRS suitable for directly measuring the result of different therapies, which can lead to a paradigm shift in the monitoring during cardiac anesthesia.
|
112 |
Resource Allocation on the MISO Interference ChannelLindblom, Johannes January 2010 (has links)
The need for wireless communications has increased during the last decades. To increase the data rates of the communication links there is a need of allocating larger frequency bands. These bands are strictly regulated and the majority of the frequencies are allocated to licensed systems. The splitting of the bandwidth is orthogonal, which mean that the different systems are not interfering each other. But, orthogonal splitting is inefficient since it does not exploit all degrees of freedom in the wireless channels. There are also unlicensed bands where different systems co-exist and operate simultaneously in a non-orthogonal manner and interfere each other. This interference degrades the performance of each system. This motivates the use of so-called spectrum sharing techniques for interference management. The spectrum sharing can be modeled via the so-called interference channel (IFC). This consists of at least two transmitter (TX)-receiver (RX) pairs. These pairs can share resources such as frequency, time, power, code, or space. Here, the focus is on the sharing of spatial resources. By employing multiple antennas at the TXs, spatial diversity is obtained and it is possible to steer the power in any spatial direction. Assuming a single antenna at each RX we get the so-called multiple-input single-output (MISO) IFC. There is a conflict inherent in the IFC since the TX-RX pairs optimize conflicting objectives, e.g., the data rates. To analyze this conflict we use game-theoretic concepts. In general, the situation where the TXs transmit in the directions which are optimal for their objective is inefficient. That is, it is possible increase all rates of some (or all) TX-RX pairs without decreasing the rate of any of the pairs. To do so, the TXs change their strategies such that interference is decreased. We define several rate regions, which depend on the channel model and channelstate information at the transmitters. Also, some of the most important game-theoretic operating points are described.
|
113 |
An Examination of Pre-Service Mathematics Teachers’ Integration of Technology into Instructional Activities Using a Cognitive Demand Perspective and Levels of Technology ImplementationAkcay, Ahmet Oguz 17 May 2016 (has links)
Technology has changed every aspect of our lives such as communication, shopping, games, business, and education. Technology has been used for decades in the teaching and learning environment in K-12 education and higher education, especially in mathematics education where the use of instructional technology has great potential. Today’s students have grown up in the technology era, so our education system should consider this situation before developing curriculum and instructional strategies. Technology can increase the quality of mathematical investigations, portray meaningful mathematical ideas to students and teachers from multiple perspectives, and change traditional ways of doing mathematics (NCTM, 2000). According to NCTM’s Principles and Standards for School Mathematics (2000), technologies not only increase students’ understanding and learning of mathematics but also help teachers make instruction more effective and meaningful for students.
<br>The purpose of this study is to explore how pre-service teachers design mathematics lesson activities that integrate technology. Specifically, the level of cognitive demands of the mathematics tasks in the technology activities: 1) created by pre-service teachers (PST) for an assignment in their elementary, middle level, and/or secondary mathematics methods course, and 2) created and used by secondary mathematics PSTs during student teaching were examined.
<br>PSTs designed technology-based instructional activities with high-level cognitive demands, and the mean scores were increased for Described Implementation and Student Response. In these instances, elementary and secondary level PSTs were able to select technology-based tasks with high cognitive demands in greater percentages than middle level PSTs. The mean scores for Described Implementation and Expected Student Response were higher than the means for Potential of the Task for all grade levels. However the means scores for Expected Student Response were lower than the means for Described Implementation for the elementary and middle levels, and the means scores are same for the secondary level. The results also indicated that PSTs were doing very well with their own personal computer use, troubleshooting, identification of instructional practices that reflected a learner-based curriculum design, and effectively technology implementation. By the analyzing relationship between IQA rubrics scores (Potential of the Task, Describe Implementation, and Expected Student Response) and each LoTi-Digital Age levels (PCU, CIP, and LoTi), the researcher discovered that the LoTi Digital-Age scores did not correlate with the IQA scores. / School of Education; / Instructional Technology (EdDIT) / EdD; / Dissertation;
|
114 |
The effects of game-based technology on high school students' algebraic learning in an urban school classroomAbdelhafez, Amal 09 February 2017 (has links)
<p> In the last few years, educational computer games have gained attention as a tool for facilitating. Few empirical studies have investigated the effects of educational games in the context of formal K-12 settings.</p><p> The purpose of this study was to examine the effects of game-based technology on high school students’ algebraic lear ning on their motivation towards math, conceptual knowledge, and reasoning skills. The participants in this study were 15 girls and 25 boys in algebra II classes. The age of participants ranged from 15 to 17 years old. There were three algebra II classes; two of them would use the game-based learning on line twice a week for 41-minute every time (experimental group), and the last one would be the (control group). The teacher-researcher is a certified mathematics teacher for twelve years. </p><p> Students’ conceptual knowledge and reasoning skills were measured using assessments once every two weeks as well as pre and post assessment. SMS (Students Motivation Survey) was designed based on Keller’s (1987a) ARCS model of motivational to analyze the data. The overall analysis results revealed that using game-based learning in addition to traditional non-electronic role-playing and board games with algebra II high school students would increase their motivation. However, there was no effect on their conceptual knowledge or reasoning skills. </p><p> Effective mathematics games should be integrated with classroom activities if teachers want to increase mathematics class motivation, which would effect the students’ performance. Further study would be needed with larger sample size and carried through for a longer intervention period. Also, future research might use modifying games to investigate the influence of the implementation of the reasoning skills on individual differences. In addition, future research might examine contextual settings for effects upon game play, and conduct an experimental design that includes an introductory game play seminar as the treatment.</p>
|
115 |
An analysis of automated solutions for the Certification and Accreditation of navy medicine information assetsGonzales, Dominic V. 09 1900 (has links)
A process.
|
116 |
Modeling of Additive Manufacturing with Reduced Computational EffortMalmelöv, Andreas January 2016 (has links)
Simulation of laser metal deposition with Inconel 625 / <p>Validerat; 20160627 (global_studentproject_submitter)</p>
|
117 |
Polarization characteristics in polyelectrolyte thin film capacitors : Targeting field-effect transistors and sensorsLarsson, Oscar January 2009 (has links)
Polymers are very attractive materials that can be tailored for specific needs and functionality. They can for instance be made electrically insulating or (semi)conducting, with specific mechanical properties. Polymers are often processable from a solution, which enables the use of low-cost manufacturing techniques to fabricate polymer devices. Polymer-based electronic and electrochemical devices and sensors have been developed. This thesis is related to the polarization characteristics in polyelectrolyte thin film capacitor structures. The polarization characteristics have been analyzed at various humidity levels for polyelectrolyte capacitors alone and when incorporated as the gate-insulating material in polyelectrolyte-gated organic field-effect transistors. Both limitations and possibilities of this class of transistors have been identified. Also, a concept for wireless readout of a passively operated humidity sensor circuit is demonstrated. The sensing mechanism of this sensor is related to the polarization in a polyelectrolyte thin film capacitor. This sensor circuit can be manufactured entirely with common printing technologies of today and can be integrated into a low-cost passive sensor label.
|
118 |
Leading for educational equity in a context of accountability| Instructional technology methods and depth of knowledgeBaer, Erick R. 25 August 2016 (has links)
<p> As schools across the United States continue to earmark funds for instructional technology in the classroom we must consider how it is being used in the classroom. This qualitative research study was conducted to investigate instructional technology methods being used in sixth through eighth grade classrooms and to understand the Depth of Knowledge of those lessons. The study was grounded in Huberman’s Teacher Life Cycle Theory, Constructivism Theory, and Norman Webb’s Depth of Knowledge Theory. Interviews and observations were conducted to gather data about how teachers plan and deliver instructional technology methods to students in 6-8th grade classrooms. Findings from this study determined the instructional technology methods (ITMs) teachers utilize in the classroom, the perceptions teachers have about integrating technology, and instructional technology tools (ITTs) teachers used in the classroom. Discussion of the research findings revolved around how ITMs and methods teachers use in the classroom and teacher perceptions about how they integrate technology methods in the classroom to achieve depth of knowledge with their students. One implication of this study is that teachers would benefit from utilizing Puentendura’s (2009) SAMR Model as a guide for ITM planning to improve ITMs and to sustain ITM use in the classroom.</p>
|
119 |
Underhållsplanering & genomförande på ScandBookFerdeen, Erik January 2010 (has links)
Detta projekt gick ut på att utföra ett möjligt underhållsschema för ScandBook i Falun. Innan dess hade akuta reparationer skett då en del lager gått sönder utan föraning på transportlinan. Genom undersökningar som värmekamera, mätklocka, okulärbesiktning m.m. kunde ett beslut fattas om huruvida detta gick att genomföra. Det behövde inte innebära reparationer utan även utbyte av lager, bultar, upphägningar m.m. / <p>A-huset</p>
|
120 |
An examination of student satisfaction in blended learning environments| A mixed methods studyRoff, Kimberly 05 April 2017 (has links)
<p> Researchers have studied blended learning environments, but few focused-on student satisfaction in these environments. This mixed methods study addresses this gap in literature by focusing on how student satisfaction is viewed in blended learning environments. The conceptual framework is based upon research that discusses both face-to-face and online environments, which make a key argument for blended learning. This framework is community and inquiry. In conjunction with this, the study relied on the multimodal model that examines different learning environments. A mixed methods study design was conducted using surveys. A sample of 20-25 students from blended undergraduate courses were used. Data was analyzed using open and axial coding in order to identify emergent themes. The main findings indicated that students were satisfied with blended learning environments because they are flexible and convenient. Some of the areas that participants indicated there was dissatisfaction were: nothing, disconnection, and technology.</p>
|
Page generated in 0.0551 seconds