Dissertations / Theses on the topic 'High integration'
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1
Ragnarsson, David. "Sensor Integration for High Temperature Measurements." Thesis, Luleå tekniska universitet, EISLAB, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-64544.
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In today's mining industry, most of the sensor measurements in high temperature environments are expensive and the sensors are not well integrated with the materials treated in the hot temperatures. The conditions can vary much between the sensors location and where the materials are located. It is crucial to have high performance measurements to reach a more optimized control over the oven. A more optimized process gives a better combustion which decreases the fuel consumption and is more energy efficient. To increase the performance of these measurements, it is necessary to have wireless sensor systems, which can be well integrated with the materials and have a low cost. This so there is no need to use same system several times and it shouldn't matter if it gets destroyed in the oven. In this thesis, the focus lies on building the electronics and software for controlling a wide band oxygen sensor. The electronics are built by components with an upper temperature limit of 125 ◦C or above. The sensor itself is supposed to be heated up by an internal heating element. However, in these experiments, it is heated up by the surroundings in the oven. A major challenge in the work was the design of the control loop to keep the sensor in a correct and stable operating point. When initial oxygen measurements were compared with reference measurement done simultaneously in the oven, it didn't match well. These differences were shown to be caused by different locations of the sensor and the reference measurements. Further measurements in a live industrial setting confirmed the functionality of the system.
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Söderberg, Fredrik. "High frequency Verlet integration physics on iPhone." Thesis, Umeå University, Department of Computing Science, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34669.
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When Apple first introduced the iPhone it was thought by many to be groundbraking. The main visible difference was that the phone had no keypad, just a touch screen. Another interesting feature in this phone was the addition of accelerometers. With this the device knows the forces applied to it and therefore knows how it is tilted. In april 2010 Steve Jobs announced 85 million iPhone OS devices sold. This makes it a very interesting OS from a developers point of view.This project aims to explore those two new key features and the iPhone OS by implementing a simplified version of the game Mad Skills Motocross by Turborilla. This is a fast paced sideways scrolling motocross game with demanding physics simulation. The physics is modeled via high frequency (1000 Hz) Verlet integration. Important aspects of the project are therefore also if the iPhone can handle the game and if it still will be a fun game considering the changes going from desktop to iPhone.The results were a game playable on one track with accurate physics, running with a visible frame rate of 30 frames per second and some interesting insights in what you need to think about when developing for iPhone OS.
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Krishnamurthy, Nicole Andrea. "Mixed material integration for high speed applications." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14684.
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Strandberg, Rickard, and Johan Låås. "Uncertainty quantification using high-dimensional numerical integration." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195701.
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We consider quantities that are uncertain because they depend on one or many uncertain parameters. If the uncertain parameters are stochastic the expected value of the quantity can be obtained by integrating the quantity over all the possible values these parameters can take and dividing the result by the volume of the parameter-space. Each additional uncertain parameter has to be integrated over; if the parameters are many, this give rise to high-dimensional integrals. This report offers an overview of the theory underpinning four numerical methods used to compute high-dimensional integrals: Newton-Cotes, Monte Carlo, Quasi-Monte Carlo, and sparse grid. The theory is then applied to the problem of computing the impact coordinates of a thrown ball by introducing uncertain parameters such as wind velocities into Newton’s equations of motion.
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Thompson, Jeremy Stewart. "High speed numerical integration of Fermi Dirac integrals." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA311805.
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Abdullah, Yousef. "GaN Integration For High Temperature Motor Drive Applications." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1598047797819895.
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Puttaswamy, Kiran. "Designing high-performance microprocessors in 3-dimensional integration technology." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19759.
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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Loh, Gabriel H.; Committee Co-Chair: Lee, Hsien-Hsin S.; Committee Member: Lim, Sung Kyu; Committee Member: Prvulovic, Milos; Committee Member: Yalamanchili, Sudhakar; Committee Member: Yoder, Douglas.
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Cao, Zhengwen [Verfasser]. "Membrane reactors for separation and catalysis : high integration and high efficiency / Zhengwen Cao." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2014. http://d-nb.info/1051036240/34.
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Gradin, Henrik. "Heterogeneous Integration of Shape Memory Alloysfor High-Performance Microvalves." Doctoral thesis, KTH, Mikrosystemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-94088.
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This thesis presents methods for fabricating MicroElectroMechanical System (MEMS) actuators and high-flow gas microvalves using wafer-level integration of Shape Memory Alloys (SMAs) in the form of wires and sheets. The work output per volume of SMA actuators exceeds that of other microactuation mechanisms, such as electrostatic, magnetic and piezoelectric actuation, by more than an order of magnitude, making SMA actuators highly promising for applications requiring high forces and large displacements. The use of SMAs in MEMS has so far been limited, partially due to a lack of cost efficient and reliable wafer-level integration approaches. This thesis presents new methods for wafer-level integration of nickel-titanium SMA sheets and wires. For SMA sheets, a technique for the integration of patterned SMA sheets to silicon wafers using gold-silicon eutectic bonding is demonstrated. A method for selective release of gold-silicon eutectically bonded microstructures by localized electrochemical etching, is also presented. For SMA wires, alignment and placement of NiTi wires is demonstrated forboth a manual approach, using specially built wire frame tools, and a semiautomatic approach, using a commercially available wire bonder. Methods for fixing wires to wafers using either polymers, nickel electroplating or mechanical silicon clamps are also shown. Nickel electroplating offers the most promising permanent fixing technique, since both a strong mechanical and good electrical connection to the wire is achieved during the same process step. Resistively heated microactuators are also fabricated by integrating prestrained SMA wires onto silicon cantilevers. These microactuators exhibit displacements that are among the highest yet reported. The actuators also feature a relatively low power consumption and high reliability during longterm cycling. New designs for gas microvalves are presented and valves using both SMA sheets and SMA wires for actuation are fabricated. The SMA-sheet microvalve exhibits a pneumatic performance per footprint area, three times higher than that of previous microvalves. The SMA-wire-actuated microvalve also allows control of high gas flows and in addition, offers benefits of lowvoltage actuation and low overall power consumption.QC 20120514
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Yusuf, Yazid. "Integration of high-Q filters with highly efficient antennas." Doctoral diss., University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4727.
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The integration of high-quality (Q)-factor 3-D filters with highly efficient antennas is addressed in this dissertation. Integration of filters and antennas into inseparable units eliminates the transitions between the otherwise separate structures resulting in more compact and efficient systems. The compact, highly efficient integrated 3-D filter/antenna systems, enabled by the techniques developed herein, allow for the realization of integrated RF front ends with significantly-reduced form factors. Integration of cavity filters with slot antennas in a single planar substrate is first demonstrated. Due to the high Q factor of cavity resonators, the efficiency of the integrated filter/antenna system is found to be the same as that of a reference filter with the same filtering characteristics. This means a near 100% efficient slot antenna is achieved within this integrated filter/antenna system. To further reduce the footprint of the integrated systems, vertically integrated filter/antenna systems are developed. We then demonstrate the integration of cavity filters with aperture antenna structures which enable larger bandwidths compared with slot antennas. The enhanced bandwidths are made possible through the excitation and radiation of surface waves. To obtain omnidirectional radiation patterns, we integrate cavity filters with monopole antennas. Finally, the integration of filters with patch antennas is addressed. Unlike the other filter/antenna integration examples presented, in which the antenna is utilized as an equivalent load, the patch antenna provides an additional pole in the filtering function. The presented techniques in this dissertation can be applied for filter/antenna integration in all microwave, and millimeter-wave frequency regions.ID: 030646198; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2011.; Includes bibliographical references (p. 147-149).
Ph.D.
Doctorate
Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
11
Lambert, Ben. "Integration of high and low-resolution aircraft vision systems." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437517.
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Ohse, Sebastian [Verfasser], and Rolf [Akademischer Betreuer] Backofen. "Integration of public high-throughput databases in quantitative biology." Freiburg : Universität, 2020. http://d-nb.info/1226657206/34.
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Cheah, Marc. "Offshore wind integration through high voltage direct current systems." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/101463/.
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Offshore wind generation has an important role in the transition to renewable energy. In particular, HVDC-connected Offshore Wind Power Plants (OWPPs) are emerging as an economical solution for long distances from the shore. This thesis was focused on three key areas related to planning, operation and stability issues, which are present technical challenges in the integration of OWPPs through VSC-HVDC transmission systems. In relation to planning, the installation of interlink cables between OWPPs was analysed to increase the wind power transfer. Different interlink options were compared based on a power loss reduction and an increase of availability. In general, it was recommended to have interlinks close to the wind generation point to provide more flexible active power sharing between OWPPs. Also, a cost-benefit analysis was used to quantify savings from the operation with interlinks and a design procedure was developed to determine the interlink cable capacity. In terms of operation, inertia emulation was analysed as a potential fast frequency response service from OWPPs. Synthetic inertia and temporary overproduction have been presented as main control strategies to implement inertia emulation and they were compared using MATLAB Simulink. Results showed similar frequency response performance from both strategies, however temporary overproduction was more appropriate in order to comply with system operator’s requirements. Emulation of inertia was also demonstrated in a HVDC-connected OWPP employing a hardware-in-the-loop set-up. The converter control interaction with electrical resonances of the offshore ac grid was analysed. An impedance-based representation of the system was used to identify resonant frequencies and to assess stability. A reformulation of the positive-net-damping criterion was used to evaluate the effect that the offshore HVDC converter control and OWPP configuration have on the stability. As a result, risk of resonance interaction was identified in no-load operation and when a limited number of wind turbines were connected.
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Do, Manh Cuong. "Piezoelectric Transformer Integration Possibility in High Power Density Applications." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A23676.
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The contents of this work investigate the capability of integrating the PT in applications by invoking the ratio of the throughput power to volume represented by the term: power density. The fundamentals of the PT are introduced in chapter two. In chapter three, the fundamental limitations of the PT's capability of transferring power to the load are studied. There are three major limitations: temperature rise due to losses during operation, electromechanical limits of material, and interactions with output rectifier. The analysis and estimation are then verified by experiments and calculations implemented on three different PT samples fabricated from three different manufacturers. The subject of chapter four is the behavior of the PT's power amplifier. This chapter concentrates on two main amplifier topologies, optimized based on the simplicity of structure and minimization of components (passive and active): class D and class E amplifiers. The operational characteristics of these amplifiers with the PT are then comparison. Methods to track the optimum frequency and discontinuous working mode of the PT are proposed as the approaches to improve the energy transfer of the PT. In chapter five, prototypes of four devices using a PT are developed and introduced as illustrations of the integration of PTs into practical applications: an igniter for high intensity discharge (HID) lamps, high DC voltage power supplies, and electronic ballasts for LEDs, and stand-alone ionizers for food sterilizers. Some concluding statements and ideas for future works are located in the last chapter - chapter six.
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Lin, Shih-Yung. "Integration and processing of high-resolution moiré-interferometry data." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/40181.
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A new hybrid method combining moire interferometry, high resolution data-reduction technique, two-dimensional datasmoothing method, and Finite Element Method (FEM) has been successfully developed. This hybrid method has been applied to residual strain analyses of composite panels, strain concentrations around optical fibers embedded in composites, and cruciform composite shear test.
This hybrid method allows moire data to be collected with higher precision and accuracy by digitizing overexposed moire patterns (U & V fields) with appropriate carrier fringes. The resolution of the data is ± 20 nm. The data extracted from the moire patterns are interfaced to an FEM package through an automatic mesh generator. This mesh generator produces a nonuniform FEM mesh by connecting the digitized data points into triangles. The mesh, which uses digitized displacement data as boundary conditions, is then fed to and processed by a commercial FEM package.
Due to the natural scatter of the displacement data digitized from moire patterns, the accuracy of strain values is significantly affected. A modified finite-element model with linear spring elements is introduced so data-smoothing can be done easily in two dimensional space. The results of the data smoothing are controlled by limiting the stretch of those springs to be less than the resolution of the experimental method.
With the full-field hybrid method, the strain contours from moire interferometry can be easily obtained with good accuracy. If the properties of the material are known, the stress patterns can also be obtained. In addition, this method can be used to analyze any two-dimensional displacement data, including the grid method and holography.Ph. D.
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Do, Manh Cuong. "Piezoelectric transformer integration possibility in high power density applications." Doctoral thesis, Dresden : TUDpress Verl. der Wiss, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1214984646187-55994.
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Hedrick, James E. "A Case Study in the Desegregation of George Washington High School and Langston High School in Danville, Virginia during the 1970-1971 School Year." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/26624.
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This paper provides a historical analysis of the desegregation of George Washington High School and Langston High School in Danville, Virginia in 1970. The author focuses on the related desegregation litigation on a national, state, and local level as well as the historical context for desegregation in the Commonwealth of Virginia.
In August of 1970, Danville, Virginia embarked on a new era in education as its schools would be totally desegregated. It would no longer operate under the freedom of choice plan that had been in effect since 1965 and permitted African-American parents to send their children to the all-white schools. The school system was to be fully integrated and operating as a unitary system.
Using newspaper accounts, correspondence from key figures, and interviews with key people in Danville in 1970, the author addresses four areas of research: (a) What led to the desegregation of schools in Danville, Virginia? (b) Who were the key players in the desegregation movement? (c) How were the community, the students, and the staff prepared for desegregation? and (d) What were the attitudes and the concerns about desegregation? The data was collected and analyzed using qualitative methodology. The constant-comparative method espoused by Maykut and Morehouse was used to analyze the data and Bronfenbrennerâ s concept of the â nested environmentâ was the theoetical model used to organize the data.Ed. D.
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Cappellani, Annalisa. "Metal gate integration in CMOS logic for RF applications." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366569.
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Chen, Zheng. "Electrical Integration of SiC Power Devices for High-Power-Density Applications." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23923.
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The trend of electrification in transportation applications has led to the fast development of high-power-density power electronics converters. High-switching-frequency and high-temperature operations are the two key factors towards this target. Both requirements, however, are challenging the fundamental limit of silicon (Si) based devices. The emerging wide-bandgap, silicon carbide (SiC) power devices have become the promising solution to meet these requirements. With these advanced devices, the technology barrier has now moved to the compatible integration technology that can make the best of device capabilities in high-power-density converters. Many challenges are present, and some of the most important issues are explored in this dissertation.
First of all, the high-temperature performances of the commercial SiC MOSFET are evaluated extensively up to 200 degree C. The static and switching characterizations show that the device has superior electrical performances under elevated temperatures. Meanwhile, the gate oxide stability of the device - a known issue to SiC MOSFETs in general - is also evaluated through both high-temperature gate biasing and gate switching tests. Device degradations are observed from these tests, and a design trade-off between the performance and reliability of the SiC MOSFET is concluded.
To understand the interactions between devices and circuit parasitics, an experimental parametric study is performed to investigate the influences of stray inductances on the MOSFETs switching waveforms. A small-signal model is then developed to explain the parasitic ringing in the frequency domain. From this angle, the ringing mechanism can be understood more easily and deeply. With the use of this model, the effects of DC decoupling capacitors in suppressing the ringing can be further explained in a more straightforward way than the traditional time-domain analysis. A rule of thumb regarding the capacitance selection is also derived.
A Power Electronics Building Block (PEBB) module is then developed with discrete SiC MOSFETs. Integrating the power stage together with the peripheral functions such as gate drive and protection, the PEBB concept allows the converter to be built quickly and reliably by simply connecting several PEBB modules. The high-speed gate drive and power stage layout designs are presented to enable fast and safe switching of the SiC MOSFET. Based on the PEBB platform, the state-of-the-art Si and SiC power MOSFETs are also compared in the device characteristics, temperature influences, and loss distributions in a high-frequency converter, so that special design considerations can be concluded for the SiC MOSFET.
Towards high-temperature, high-frequency and high-power operations, integrated wire-bond phase-leg modules are also developed with SiC MOSFET bare dice. High-temperature packaging materials are carefully selected based on an extensive literature survey. The design considerations of improved substrate layout, laminated bus bars, and embedded decoupling capacitors are all discussed in detail, and are verified through a modeling and simulation approach in the design stage. The 200 degree C, 100 kHz continuous operation is demonstrated on the fabricated module. Through the comparison with a commercial SiC phase-leg module designed in the traditional way, it is also shown that the design considerations proposed in this work allow the SiC devices in the wire-bond structure to be switched twice as fast with only one-third of the parasitic ringing.
To further push the performance of SiC power modules, a novel hybrid packaging technology is developed which combines the small parasitics and footprint of a planar module with the easy fabrication of a wire-bond module. The original concept is demonstrated on a high-temperature rectifier module with SiC JFET. A modified structure is then proposed to further improve design flexibility and simplify module fabrication. The SiC MOSFET phase-leg module built in this structure successfully reaches the switching speed limit of the device almost without any parasitic ringing.
Finally, a new switching loop snubber circuit is proposed to damp the parasitic ringing through magnetic coupling without affecting either conduction or switching losses of the device. The concept is analyzed theoretically and verified experimentally. The initial integration of such a circuit into the power module is presented, and possible improvements are proposed.Ph. D.
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Khumsat, Phanumas. "Transition frequency integration : technique for high frequency continuous-time filters." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398200.
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vaissie, laurent. "MONOLITHIC INTEGRATION OF DUAL OPTICAL ELEMENTS ON HIGH POWER SEMICOND." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3885.
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This dissertation investigates the monolithic integration of dual optical elements on high power semiconductor lasers for emission around 980nm wavelength. In the proposed configuration, light is coupled out of the AlGaAs/GaAs waveguide by a low reflectivity grating coupler towards the substrate where a second monolithic optical element is integrated to improve the device performance or functionality. A fabrication process based on electron beam lithography and plasma etching was developed to control the grating coupler duty cycle and shape. The near-field intensity profile outcoupled by the grating is modeled using a combination of finite-difference time domain (FDTD) analysis of the nonuniform grating and a self-consistent model of the broad area active region. Improvement of the near-field intensity profile in good agreement with the FDTD model is demonstrated by varying the duty cycle from 20% to 55% and including the aspect ratio dependent etching (ARDE) for sub-micron features. The grating diffraction efficiency is estimated to be higher than 95% using a detailed analysis of the losses mechanisms of the device. The grating reflectivity is estimated to be as low as 2.10-4. The low reflectivity of the light extraction process is shown to increase the device efficiency and efficiently suppress lasing oscillations if both cleaved facets are replaced by grating couplers to produce 1.5W QCW with 11nm bandwidth into a single spot a few mm above the device. Peak power in excess of 30W without visible COMD is achieved in this case. Having optimized, the light extraction process, we demonstrate the integration of three different optical functions on the substrate of the surface-emitting laser. First, a 40 level refractive microlens milled using focused ion beam shows a twofold reduction of the full-width half maximum 1mm above the device, showing potential for monolithic integration of coupling optics on the wafer. We then show that differential quantum efficiency of 65%, the highest reported for a grating-coupled device, can be achieved by lowering the substrate reflectivity using a 200nm period tapered subwavelength grating that has a grating wavevector oriented parallel to the electric field polarization. The low reflectivity structure shows trapezoidal sidewall profiles obtained using a soft mask erosion technique in a single etching step. Finally, we demonstrate that, unlike typical methods reported so far for in-plane beam-shaping of laser diodes, the integration of a beam-splitting element on the device substrate does not affect the device efficiency. The proposed device configuration can be tailored to satisfy a wide range of applications including high power pump lasers, superluminescent diodes, or optical amplifiers applications.Ph.D.
Other
Optics and Photonics
Optics
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Shen, Tzung-Sz. "Multiple-sensor integration for rapid and high-precision coordinate metrology /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488203857249915.
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Johnson, David Allen. "The Relationship Between School Integration and Student Attitude Toward Residential Racial Integration." PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/1180.
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This study examined factors related to the teaching effectiveness of adjunct faculty in higher education. Specifically, it explored the relationship between personality, as defined by the Five-Factor Model, occupation, and student ratings of teaching effectiveness. Results indicate that personality is correlated to an instructor's classroom behavior and education goals, which in turn are related to teaching effectiveness. In addition, instructors with occupations in social services and education had significantly higher mean teaching effectiveness scores than those from other occupations. Finally, there was an inverse relationship between age and teaching effectiveness in this study, and a positive relationship between teaching experience and teaching effectiveness. Although instructors may not be able to change their personality, they can modify their behavior and teaching practices to increase their effectiveness as educators.
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Li, Qiang. "Low-Profile Magnetic Integration for High-Frequency Point-of-Load Converter." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/28637.
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Today, every microprocessor is powered with a Voltage Regulator (VR), which is also known as a high current Point-of-Load converter (POL). These circuits are mostly constructed using discrete components, and populated on the motherboard. With this solution, the passive components such as inductors and capacitors are bulky. They occupy a considerable footprint on the motherboard. The problem is exacerbated with the current trend of reducing the size of all forms of portable computing equipment from laptop to netbook, increasing functionalities of PDA and smart phones. In order to solve this problem, a high power density POL needs to be developed. An integration solution was recently proposed to incorporate passive components, especially magnetic components, with active components in order to realize the needed power density for the POL. Todayâ s discrete VR only has around 100W/in3 power density. The 3D integration concept is widely used for low current integrated POL. With this solution, a very low profile planar inductor is built as a substrate for the active components of the POL. By doing so, the POL footprint can be dramatically saved, and the available space is also fully utilized. This 3D integrated POL can achieve 300-1000W/in3 power density, however, with considerably less current. This might address the needs of small hand-held equipment such as PDA and Smart phone type of applications. It does not, however, meet the needs for such applications as netbook, laptop, desk-top and server applications where tens and hundreds of amperes are needed. So, although the high density integrated POL has been demonstrated at low current level, magnetic integration is still one of the toughest barriers for integration, especially for high current POL.
In order to alleviate the intense thirst from the computing and telecom industry for high power density POL, the 3D integration concept needs be extended from low current applications to high current applications. The key technology for 3D integration is the low profile planar inductor design. Before this research, there was no general methodology to analyze and design a low profile planar inductor due to its non-uniform flux distribution, which is totally different as a conventional bulky inductor. A Low Temperature Co-fired Ceramic (LTCC) inductor is one of the most promising candidates for 3D integration for high current applications. For the LTCC inductor, besides the non-uniform flux, it also has non-linear permeability, which makes this problem even more complicated. This research focuses on penetrating modeling and design barriers for planar magnetic to develop high current 3D integrated POL with a power density dramatically higher than todayâ s industry products in the same current level.
In the beginning, a general analysis method is proposed to classify different low profile inductor structures into two types according to their flux path pattern. One is a vertical flux type; another one is a lateral flux type. The vertical flux type means that the magnetic flux path plane is perpendicular with the substrate. The lateral flux type means that the magnetic flux path plane is parallel with the substrate. This analysis method allows us to compare different inductor structures in a more general way to reveal the essential difference between them. After a very thorough study, it shows that a lateral flux structure is superior to a vertical flux structure for low profile high current inductor design from an inductance density point of view, which contradicts conventional thinking. This conclusion is not only valid for the LTCC planar inductor, which has very non-linear permeability, but is also valid for the planar inductor with other core material, which has constant permeability.
Next, some inductance and loss models for a planar lateral flux inductor with a non-uniform flux are also developed. With the help of these models, different LTCC lateral flux inductor structures (single-turn structure and multi-turn structures) are compared systematically. In this comparison, the inductance density, winding loss and core loss are all considered. The proposed modeling methodology is a valuable extension of previous uniform flux inductor modeling, and can be used to solve other modeling problems, such as non-uniform flux transformer modeling.
After that, a design method is proposed for the LTCC lateral flux inductor with non-uniform flux distribution. In this design method, inductor volume, core thickness, winding loss, core loss are all considered, which has not been achieved in previous conventional inductor design methods. With the help of this design method, the LTCC lateral flux inductor can be optimized to achieve small volume, small loss and low profile at the same time. Several LTCC inductor substrates are also designed and fabricated for the 3D integrated POL. Comparing the vertical flux inductor substrate with the lateral flux inductor substrate, we can see a savings of 30% on the footprint, and a much simpler fabrication process. A 1.5MHz, 5V to 1.2V, 15A 3D integrated POL converter with LTCC lateral flux inductor substrate is demonstrated with 300W/in3 power density, which has a factor of 3 improvements when compared to todayâ s industry products.
Furthermore, the LTCC lateral flux coupled inductor is proposed to further increase power density of the 3D integrated POL converter. Due to the DC flux cancelling effect, the size of LTCC planar coupled inductor can be dramatically reduced to only 50% of the LTCC planar non-coupled inductor. Compared to previous vertical flux coupled inductor prototypes, a lateral flux coupled inductor prototype is demonstrated to have a 50% core thickness reduction. A 1.5MHz, 5V to 1.2V, 40A 3D integrated POL converter with LTCC lateral flux coupled inductor substrate is demonstrated with 700W/in3 power density, which has a factor of 7 improvements when compared to today's industry POL products in the same current level.
In conclusion, this research not only overcame some major academia problems about analysis and design for planar magnetic components, but also made significant contributions to the industry by successfully scaling the integrated POL from today's 1W-5W case to a 40W case. This level of integration would significantly save the cost, and valuable motherboard real estate for other critical functions, which may enable the next technological innovation for the whole computing and telecom industry.Ph. D.
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Chaimov, Nicholas. "Insightful Performance Analysis of Many-Task Runtimes through Tool-Runtime Integration." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22731.
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Future supercomputers will require application developers to expose much more parallelism than current applications expose. In order to assist application developers in structuring their applications such that this is possible, new programming models and libraries are emerging, the many-task runtimes, to allow for the expression of orders of magnitude more parallelism than currently existing models.
This dissertation describes the challenges that these emerging many-task runtimes will place on performance analysis, and proposes deep integration between runtimes and performance tools as a means of producing correct, insightful, and actionable performance results. I show how tool-runtime integration can be used to aid programmer understanding of performance characteristics and to provide online performance feedback to the runtime for Unified Parallel C (UPC), High Performance ParalleX (HPX), Apache Spark, the Open Community Runtime, and the OpenMP runtime.
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Fowler, Lee V. "School Integration: A Case Study of the 1971-1972 School Year at Indian River High School." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/29817.
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This dissertation is a case study of the initial year of
integration at a predominantly white southern high school. The
school's racial configuration changed from approximately 10%
black to approximately 35% black in the course of a single
year. The study includes a background of desegration in
Virginia, a discussion of the closing of the black high school
in the local area, and a detailed, thematic study of the events
of the school year. The information is gleaned from newspapers,
historical works by original sources, school records, papers and
memos, and primarily, from sixty-six interviews with former students,
teachers, administrators, parents and community members.
Important sections deal with racial issues on a personal level
for the students and teachers involved. Organizations such as the
football team are dealt with in detail. Particular attention
is paid to clubs and organizations, especially those where the
students could choose the members. A substantial portion of
the paper provides first hand accounts of violence that occurred
during the school year, in particular an incident of riot
proportions. The objective of the study is to provide a
detailed account of school integration through first hand
accounts of day to day events at a school in the process of
desegregation.Ed. D.
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Huo, Xiao. "High performance passive components modeling and integration in RF/microwave systems /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20HUO.
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Shi, Jianlin. "Model and tool integration in high level design of embedded systems." Licentiate thesis, KTH, Machine Design (Div.), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4589.
Full textAbstract:
The development of advanced embedded systems requires a systematic approach as well as advanced tool support in dealing with their increasing complexity. This complexity is due to the increasing functionality that is implemented in embedded systems and stringent (and conflicting) requirements placed upon such systems from various stakeholders. The corresponding system development involves several specialists employing different modeling languages and tools. Integrating their work and the results thereof then becomes a challenge. In order to facilitate system architecting and design integration of different models, an approach that provides dedicated workspaces/views supported by structured information management and information exchange between domain models and tools is required.
This work is delimited to the context of embedded systems design and taking a model based approach. The goal of the work is to study possible technical solutions for integrating different models and tools, and to develop knowledge, support methods and a prototype tool platform.
To this end, this thesis examines a number of approaches that focus on the integration of multiple models and tools. Selected approaches are compared and characterized, and the basic mechanisms for integration are identified. Several scenarios are identified and further investigated in case studies. Two case studies have been performed with model transformations as focus. In the first one, integration of Matlab/Simulink® and UML2 are discussed with respect to the motivations, technical possibilities, and challenges. A preliminary mapping strategy, connecting a subset of concepts and constructs of Matlab/Simulink® and UML2, is presented together with a prototype implementation in the Eclipse environment. The second case study aims to enable safety analysis based on system design models in a UML description. A safety analysis tool, HiP-HOPS (Hierarchically Performed Hazard Origin and Propagation Studies), is partially integrated with a UML tool where an EAST-ADL2 based architecture model is developed. The experience and lessons learned from the experiments are reported in this thesis.
Multiple specific views are involved in the development of embedded systems. This thesis has studied the integration between system architecture design, function development and safety analysis through using UML tools, Matlab/Simulink, and HiP-HOPS. The results indicate that model transformations provide a feasible and promising solution for integrating multiple models and tools. The contributions are believed to be valid for a large class of advanced embedded systems. However, the developed transformations so far are not really scalable. A systematic approach for efficient development of model transformations is desired to standardize the design process and reuse developed transformations. To this end, future studies will be carried out to develop guidelines for model and tool integration and to provide support for structured information at both meta level and instance level.
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Shi, Jianlin. "Model and tool integration in high level design of embedded system /." Stockholm : Maskinkontruktion, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4589.
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Junesand, Carl. "High-quality InP on Si and concepts for monolithic photonic integration." Doctoral thesis, KTH, Halvledarmaterial, HMA, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127837.
Full textAbstract:
As the age of Moore’s law is drawing to a close, continuing increase in computing performance is becoming increasingly hard‐earned, while demand for bandwidth is insatiable. One way of dealing with this challenge is the integration of active photonic material with Si, allowing high‐speed optical inter‐ and intra‐chip connects on one hand, and the economies of scale of the CMOS industry in optical communications on the other. One of the most essential active photonic materials is InP, stemming from its capability in combination with its related materials to produce lasers, emitting at wavelengths of 1300 and 1550 nm, the two most important wavelengths in data‐ and telecom. However, integrating InP with Si remains a challenging subject. Defects arise due to differences in lattice constants, differences in thermal expansion coefficients, polarity and island‐like growth behavior. Approaches to counter these problems include epitaxial lateral overgrowth (ELOG), which involves growing InP laterally from openings in a mask deposited on a defective InP/Si substrate. This approach solves some of these problems by filtering out the previously mentioned defects. However, filtering may not be complete and the ELOG and mask themselves may introduce new sources for formation of defects such as dislocations and stacking faults. In this work, the various kinds of defects present in InP ELOG layers grown by hydride vapor phase epitaxy on Si, and the reason for their presence, as well as strategies for counteracting them, are investigated. The findings reveal that whereas dislocations appear in coalesced ELOG layers both on InP and InP/Si, albeit to varying extents, uncoalesced ELOG layers on both substrate types are completely free of threading dislocations. Thus, coalescence is a critical aspect in the formation of dislocations. It is shown that a rough surface of the InP/Si substrate is detrimental to defect‐free coalescence. Chemical‐mechanical polishing of this surface improves the coalescence in subsequent ELOG leading to fewer defects. Furthermore, ELOG on InP substrate is consistently free of stacking faults. This is not the case for ELOG on InP/Si, where stacking faults are to some extent propagating from the defective substrate, and are possibly also forming during ELOG. A model describing the conditions for their propagation is devised; it shows that under certain conditions, a mask height to opening width aspect ratio of 3.9 should result in their complete blocking. As to the potential formation of new stacking faults, the formation mechanism is not entirely clear, but neither coalescence nor random deposition errors on low energy facets are the main reasons for their formation. It is hypothesized that the stacking faults can be removed by thermal annealing of the seed and ELOG layers. Furthermore, concepts for integrating an active photonic device with passive Si components are elucidated by combining Si/SiO2 waveguides used as the mask in ELOG and multi‐quantum well (MQW) lasers grown on ELOG InP. Such a device is found to have favorable thermal dissipation, which is an added advantage in an integrated photonic CMOS device.QC 20130909
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Poolamai, Nipapan. "Integration of high-K gate dielectrics in silicon based semiconductor technology." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490153.
Full textAbstract:
To integrate high-K gate dielectrics into metal-oxide-semiconductor field-effect transistors (MOSFETs), challenges arise due to properties of high-K gate dielectrics themselves. High temperature processes after the formation of high- K gate dielectrics have been a major concern. Investigations on process sequences of MOSFETs with high-K gate dielectrics have been carried out and a MOSFET process flow with reduced thermal budget has been proposed. Furthermore, the application of high-K gate dielectrics to silicon carbide (SiC) tech.,.'1ology has been proposed recently due to the inferior Si02/SiC interface quality and reliability problems of SiC MOS power devices. Therefore, a high-Kgate stack structure on SiC has also been investigated. The effects of process sequences in conventional and replacement gate process on device characteristics of 70-nm MOSFETs with different high-K gate dielectric constant were studied by using process and device simulation, SILVACO TCAD software. It was found that high-K MOSFETs created by replacement gate process have a degradation in short channel performance whilst less short-chi:mnel effects are found in high-K MOSFETs created by conventional process. In addition, the use of high-K dielectrics in MOSFETs affects DC characteristics and gate delay of circuit performfu''1ce. However, with different process sequences, the device and circuit performance exhibited differing effects. This may be due to the changes of the doping and profile in the silicon substrate implicit in the fabrication sequences, and optimised retrograde channel doping profile may help to improve device performance of high-K devices. The PMOS process flow with reduced thermal budget was proposed to fabricate Ti02/Si02 Si MOSFETs with the gate lengths of 1, 3, 5, 10, 100 and 200 /lm. The capacitance-voltage characteristics were well behaved. The capacitive effective thickness (CET) of Ti02/SiOz gate stacked film was about 30-35 nm and its dielectric constant was ~ 14. Negative fixed oxide charges of 1.2x 1all cm-z, the frequency dispersion, and hysteresis were observed. The interface trap density (Dit) was about 1.1xl011 cm-2eV-! near midgap. The breakdown field. was 8 MV/cm. For the transistor performance, the short-channel effects were found. Since PMOS process flow with reduced thermal budget was introduced, the oxide quality found in TiOzlSiOz PMOS tra.l.'1sistors have approximately the same quality as that in TiOz/SiOz capacitors. The TiOz/Si02 gate stack structure was also proposed in 4H-SiC MOS capacitors. L11 this study, the oxidation temperature of evaporated titanium films was varied. From the experiment, the oxidation temperature of 800 °C provided good electrical characteristics. It gave CET of 17 TIm. The negative oxide trap charges were 2.87xl012 q(C/cmz) ai1.d interface trapped densities were 2-3x 012 cm-2 eyl at Ec-ET = 0-0.32 eV. The current density at gate voltage of 1 V was 2.4 X10-6 Ncmz. The use of SiOz films as an interfacial layer helps to improve leakage current of devices.
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Davey, William Mark. "High-k dielectric stacks for integration into an advanced CMOS process." Thesis, University of Liverpool, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526811.
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Clampitt, Norman Cornelius 1975. "Integration of the design and manufacture of high-precision cast components." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/89440.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Sloan School of Management; in conjunction with the Leaders for Manufacturing Program at MIT, 2000.Includes bibliographical references (p. 53).
by Norman Cornelius Clampitt, III.
S.M.
M.B.A.
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Manolatou, Christina. "Passive components for dense optical integration based on high index-contrast." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/28259.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (p. 181-185).
This work presents a theoretical and numerical investigation of high index-contrast passive components that can serve as building blocks at the end-pointsand nodes of WDM communications systems. The main characteristic of these structures is their miniature size (on the order of the optical wavelength), and their low radiation loss due to the strong light confinement in high index-contrast systems. Thus large scale, high density optical integration may be possible with the associated advantages of increased functionality, compactness and low-cost. Novel devices for filtering, optical interconnections and coupling to fibers are presented, specifically: a class of resonant add/drop filters that rely on symmetry and degeneracy of modes, low-loss right-angle bends, splitters, crossings based on transmission cavities, and fiber-chip couplers based on cascades of resonators or lensing mechanisms. Their operating principles are explained and an approximate analysis is obtained by analytical methods such as coupled-mode theory and gaussian/ray optics. For accurate analysis and optimized design, extensive numerical simulations are performed using the Finite Difference Time Domain method. The numerical results are in good agreement with the experimental data obtained for bends that were farbricated and tested at MIT. Issues that remain to be addressed for this technology to be viable and possible future directions are also discussed.
by Christina Manolatou.
Ph.D.
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Livermore, Luke. "Integration of offshore wind farms through High Voltage Direct Current networks." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/42892/.
Full textAbstract:
The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) to damp Subsynchronous Resonance (SSR) and ride through onshore AC faults was studied. Due to increased levels of wind generation in Scotland, substantial onshore and offshore reinforcements to the GB transmission network are proposed. Possible inland reinforcements include the use of series compensation through fixed capacitors. This potentially can lead to SSR. Offshore reinforcements are proposed by two HVDC links. In addition to its primary functions of bulk power transmission, a HVDC link can be used to provide damping against SSR, and this function has been modelled. Simulation studies have been carried out in PSCAD. In addition, a real-time hardware-in-the-loop HVDC test rig has been used to implement and validate the proposed damping scheme on an experimental platform. When faults occur within AC onshore networks, offshore MTDC networks are vulnerable to DC overvoltages, potentially damaging the DC plant and cables. Power reduction and power dissipation control systems were investigated to ride through onshore AC faults. These methods do not require dedicated fast communication systems. Simulations and laboratory experiments are carried out to evaluate the control systems, with the results from the two platforms compared.
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Webster, Eric Alexander Garner. "Single-Photon Avalanche Diode theory, simulation, and high performance CMOS integration." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/17987.
Full textAbstract:
This thesis explores Single-Photon Avalanche Diodes (SPADs), which are solid-state devices for photon timing and counting, and concentrates on SPADs integrated in nano-scale CMOS. The thesis focuses on: the search for new theory regarding Geiger-mode operation; proving the utility of calibrated Technology Computer- Aided Design (TCAD) tools for accurately simulating SPADs for the first time; the investigation of how manufacture influences device operation; and the integration of high performance SPADs into CMOS which rival discrete devices. The accepted theories of SPAD operation are revisited and it is discovered that previously neglected minority carriers have many significant roles such as determining: after-pulsing, Dark Count Rate (DCR), bipolar “SPAD latch-up,” nonequilibrium DCR, and “quenching”. The “quenching” process is revisited and it is concluded that it is the “probability time” of ≈100-200ps, and not the previously thought latching current that is important. SPADs are also found to have transient negative differential resistance. The new theories of SPADs are also supported by steady-state 1D, 2D and 3D TCAD simulations as well as novel transient simulations and videos. It is demonstrated as possible to simulate DCR, Photon Detection Efficiency (PDE), guard ring performance, breakdown voltage, breakdown voltage variation, “quenching,” and transient operation of SPADs with great accuracy. The manufacture of SPADs is studied focusing on the operation and optimisation of guard rings and it is found that ion implantation induced asymmetry from the tilt and rotation/twist is critical. Where symmetric, guard rings fail first along the <100> directions due to enhanced mobility. Process integration rules are outlined for obtaining high performance SPADs in CMOS while maintaining compatibility with transistors. The minimisation of tunnelling with lightly-doped junctions and the reduction of ion implantation induced defects by additional annealing are found essential for achieving low DCR. The thesis demonstrates that it is possible to realise high performance SPADs in CMOS through the innovation of a “Deep SPAD” which achieves record PDE of ≈72% at 560nm with >40% PDE from 410-760nm, combined with 18Hz DCR, <60ps FWHM timing resolution, and <4% after-pulsing which is demonstrated to have potential for significant further improvement. The findings suggest that CMOS SPAD-based micro-systems could outperform existing photon timing and counting solutions in the future.
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Terwin, Stephanie. "To reimagine the integration of public transport with high-density neighbourhoods." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22945.
Full textAbstract:
Transport is the network that moves people between places. It provides a means of access and opportunity. Transport routes in Cape Town have become expansive due to urban sprawl. There is an unjust spatial economy due to modern and apartheid planning. Poorer urban residents live far away from places of opportunity and are forced to travel long distances and spend a high percentage of their income on transport. Minibus taxis are the mode of transport best able to provide a flexible and on-demand service within this sprawling urban form. Public transport interchanges remain largely undeveloped and undesirable places. The concept of transit-oriented development (TOD) has the ability to transform these undesirable places into neighbourhoods of intensified mixed-use development, offering convenience, access and amenities to people who use the transport interchange or live nearby. The project involves the analysis of the transportation network in Delft, a rapidly transforming settlement 21 km from the inner city of Cape Town. Although the settlement is located far away from the historic city core, its main road follows an important desire line connecting Khayelitsha, a dense working-class neighbourhood and Belville, an important economic node. This has led to significant densification along Delft Main Road and people turning their homes into shops. Some 600 minibus taxis service the area because there is no high capacity train line or bus rapid transit (BRT) route. The project is sited within an important civic node in Delft and is well located to the R300, N2 and Symphony Way (regional roads). Taxis currently hover on the side of the street due to the people count in the area. The design is a public transport interchange and mixed-use - retail, residential and commercial - hub, which adopts transit-oriented development principles. The design proposal suggests an urban design framework that responds to the existing context, and a predicted idea of what the neighbourhood could become. lt aims to link the existing civic node to the new shopping mall development in a series of streets and active building edges. It responds to the life of the taxi by providing loading, holding, parking, servicing and washing areas. The taxi world evolves around the existing Caltex petrol station and Delft Main Road. The architecture responds to the current socio-economic context of Delft and how people currently inhabit space. The live-work unit provides flexibility for tenant and occupation mix, whilst contributing to the necessary density of the project. The dissertation explores how transportation can contribute to city building, economic activity and resi dential densification in an existing underserviced low-income suburb.
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Brown, Barbara, Toby Bennett, and Jose Betancourt. "High Performance CCSDS Processing Systems for EOS-AM Spacecraft Integration and Test." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/611597.
Full textAbstract:
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, NevadaThe Earth Observing System-AM (EOS-AM) spacecraft, the first in a series of spacecraft for the EOS, is scheduled for launch in June of 1998. This spacecraft will carry high resolution instruments capable of generating large volumes of earth science data at rates up to 150 Mbps. Data will be transmitted in a packet format based upon the Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations. The Data Systems Technology Division (DSTD) at NASA's Goddard Space Flight Center (GSFC) has developed a set of high performance CCSDS return-link processing systems to support testing and verification of the EOS-AM spacecraft. These CCSDS processing systems use Versa Module Eurocard bus (VMEBus) Very Large Scale Integration (VLSI)-based processing modules developed for the EOS ground segment to acquire and handle the high rate EOS data. Functions performed by these systems include frame synchronization, Reed-Solomon error correction, fill frame removal, virtual channel sorting, packet service processing, and data quality accounting. The first of the systems was delivered in October 1994 to support testing of the onboard formatting equipment. The second and third systems, delivered in April 1995, support spacecraft checkout and verification. This paper will describe the function and implementation of these systems.
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Yeung, Chi-keung. "Factors affecting teacher's attitude and integration of ICT in education /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B24700708.
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Sibilli, Thierry. "Modelling the aerodynamics of propulsive system integration at cruise and high-lift conditions." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7945.
Full textAbstract:
Due to a trend towards Ultra High Bypass Ratio engines the corresponding engine/airframe interference is becoming a key aspect in aircraft design. The present economic situation increases the pressure on commercial aviation companies to reduce the Direct Operating Cost, and the environmental situation requires a new generation of aircraft with a lower environmental impact. Therefore detailed aerodynamic investigations are required to evaluate the real benefits of new technologies.
The presented research activity is part of a long-term project with the main objective of generating a reliable and accurate tool to predict the performance of an aircraft over the whole flight domain. In particular the aim of this research was to perform advanced CFD in order to establish a tool able to evaluate engine installation effects for different configurations and attitudes. The developed tool can be provided with correlations of the Net Propulsive Force (NPF), the force exerted by the power-plant to the aircraft, as a function of position. This can be done in principle at cruise, hold, climb, descent, take-off and landing, to model the different integration effects at different phases.
Due to the complexity of the problem it was only possible at an initial stage to determine these correlations at cruise condition. Two parametric test cases were evaluated, showing that the engine horizontal positioning can influence the mission fuel burn by up to 6.4%. According to the extensive literature review that has been done, this study can be regarded as the first open literature engine position-NPF parametric study using CFD.
Even though no correlations were extracted for other conditions; a deployed high-lift wing configuration was also studied in detail, defining the main aerodynamics effects of the engine integration at high angle of attack. A topological study of the high-lift installation vortices is presented in this work and it can be considered the first in the open literature. It should be pointed out that extensive research is currently underway to correctly evaluate the high-lift aerodynamic using CFD. The Propulsive System Integration (PSI) in high-lift conditions is adding flow features to an already demanding problem, making it a real challenge for the numerical methods.
Nevertheless the additional effects of a nacelle chine on the maximum lift were also evaluated.
The main outcomes of this PhD research were: a coupled performance modelling tool able to handle the effects of engine-airframe integration as a function of geometry and attitude, and a topological study of the high-lift installation vortices.
During the course of the work, this research was successfully suggested as an extra activity for the European NEWAC project (New Aero Engine Core Concepts), and resulted in a new deliverable for that project.
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Su, Yipeng. "High Frequency, High Current 3D Integrated Point-of-Load Module." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51248.
Full textAbstract:
Point-of-load (POL) converters have been used extensively in IT products. Today, almost every microprocessor is powered by a multi-phase POL converter with high output current, which is also known as voltage regulator (VR). In the state-of-the-art VRs, the circuits are mostly constructed with discrete components and situated on the motherboard, where it can occupy more than 1/3 of the footprint of the motherboard. A compact POL is desirable to save precious space on motherboards to be used for some other critical functionalities. Recently, industry has released many modularized POL converters, in which the bulky inductor is integrated with the active components to increase the power density. This concept has been demonstrated at current levels less than 5A and power density around 600-1000W/in3. This might address the needs of small hand-held equipment such as smart phones, but it is far from meeting the needs for the applications such as laptops, desktops and servers, where tens and hundreds of amperes are needed.
A 3D integrated POL module with an output current of tens of ampere has been successfully demonstrated at the Center for Power Electronic Systems (CPES), Virginia Tech. In this structure, the inductor is elaborated with low temperature co-fire ceramic (LTCC) ferrite, as a substrate where the active components are placed. The lateral flux inductor is proposed to
achieve both a low profile and high power density. Generally, the size of the inductor can be continuously shrunk by raising the switching frequency. The emerging gallium-nitride (GaN) power devices enable the creation and use of a multi-MHz, high efficiency POL converter. This dissertation firstly explores the LTCC inductor substrate design in the multi-MHz range for a high-current POL module with GaN devices. The impacts of different frequencies and different LTCC ferrite materials on the inductor are also discussed. Thanks to the DC flux cancellation effect, the inverse coupled inductor further improves the power density of a 20A, 5MHz two-phase POL module to more than 1kW/in3. An FEA simulation model is developed to study the core loss of the lateral flux coupled inductor, which shows the inverse coupling is also beneficial for core loss reduction.
The ceramic-based 3D integrated POL module, however, is not widely adopted in industrial products because of the relatively high cost of the LTCC ferrite material and complicated manufacturing process. To solve that problem, a printed circuit board (PCB) inductor substrate with embedded alloy flake composite core is proposed. The layerwise magnetic core is laminated into a multi-layer PCB, and the winding of the inductor then is formed by the copper layers and conventional PCB vias. As a demonstration of system integration, a 20A, 1.5MHz integrated POL module is designed and fabricated based on a 4-layer PCB with embedded flake core, which realizes more than 85% efficiency and 600W/in3 power density. The application of standardized PCB processes reduces the cost for manufacturing the integrated modules due to the easy automation and the low temperature manufacturing process. Combining the PCB-embedded coupled inductor substrate and advanced control strategy, the two-phase 40A POL modules are elaborated as a complete integrated laptop VR solution. The coupled inductor structure is slightly modified to improve its transient performance. The nonlinearity of the inductance is controlled by adding either air slots or low permeability magnetic slots into the leakage flux path of the coupled inductor. Then the leakage flux, which determines the transient response of the coupled inductor, can be well controlled. If we directly replace the discrete VR solution with the proposed integrated modules, more than 50% of the footprint on the motherboard can be saved.
Although the benefits of the lateral flux inductor have been validated in terms of its high power density and low profile, the planar core is excited under very non-uniform flux. Some parts of the core are even pushed into the saturation region, which totally goes against the conventional sense of magnetic design. The final part of this dissertation focuses on evaluating the performance of the planar core with variable flux. The counterbalance between DC flux and AC flux is revealed, with which the AC flux and the core loss density are automatically limited in the saturated core. The saturation is essentially no longer detrimental in this special structure. Compared with the conventional uniform flux design, the variable flux structure extends the operating point into the saturation region, which gives better utilization of the core. In addition, the planar core with variable flux also provides better thermal management and more core loss reduction under light load.
As conclusions, this research first challenges the conventional magnetic design rules, which always assumes uniform flux. The unique characteristics and benefits of the variable flux core are proved. As an example of taking advantages of the lateral flux inductor, the PCB integrated POL modules are proposed and demonstrated as a high-density VR solution. The integrated modules are cost-effective and ready to be commercialized, which could enable the next technological innovation for the whole computing and telecom industry.Ph. D.
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Ji, Shu. "High Frequency, High Power Density GaN-Based 3D Integrated POL Modules." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19286.
Full textAbstract:
The non-isolated POL converters are widely used in computers, telecommunication systems, portable electronics, and many other applications. These converters are usually constructed using discrete components, and operated at a lower frequency around 200 ~ 600 kHz to achieve a decent efficiency at the middle of 80\'s%. The passive components, such as inductors and capacitors, are bulky, and they occupy a considerable foot-print. As the power demands increase for POL converters and the limited real estate of the mother board, the POL converters must be made significantly smaller than what they have demonstrated to date. To achieve these goals, two things have to happen simultaneously. The first is a significant increase in the switching frequency to reduce the size and weight of the inductors and capacitors. The second is to integrate passive components, especially magnetics, with active components to realize the needed power density.Today, this concept has been demonstrated at a level less than 5A and a power density around 300-700W/in3 by using silicon-based power semiconductors. This might address the need of small hand-held equipment such as PDAs and smart phones. However, it is far from meeting the needs for applications, such as netbook, notebook, desk-top and server applications where tens and hundreds of amperes are needed.
After 30 years of silicon MOSFET development, the silicon has approached its theoretical limits. The recently emerged GaN transistors as a possible candidate to replace silicon devices in various power conversion applications. GaN devices are high electron mobility transistors (HEMT) and have higher band-gap, higher electron mobility, and higher electron velocity than silicon devices, and offer the potential benefits for high frequency power conversions. By implementing the GaN device, it is possible to build the POL converter that can achieve high frequency, high power density, and high efficiency at the same time. GaN technology is in its early stage; however, its significant gains are projected in the future. The first generation GaN devices can outperform the state-of-the-art silicon devices with superior FOM and packaging.
The objective of this work is to explore the design of high frequency, high power density 12 V input POL modules with GaN devices and the 3D integration technique. This work discusses the fundamental differences between the enhancement mode and depletion mode GaN transistors, the effect of parasitics on the performance of the high frequency GaN POL, the 3D technique to integrate the active layer with LTCC magnetic substrate, and the thermal design of a high density module using advanced substrates with improved thermal conductivity.
The hardware demonstrators are two 12 V to 1.2 V highly integrated 3D POL modules, the single phase 10 A module and two phase 20 A module, all built with depletion mode GaN transistors and low profile LTCC inductors.
Master of Science
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Richard, Ron J. "An exploration of integrative dramatheatre in a regular Canadian high school." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28523.
Full textAbstract:
Integrative drama/theatre is a process founded upon the principles and practices of educational drama/theatre, and incorporates approaches and techniques intended to facilitate the integration of students with disabilities into regular classrooms. This educational approach is open-ended, creative and child-centred.This study explores the integrative drama/theatre process in two projects implemented in a regular high school in Montreal. Subjects for the study were 30 students from the school. The 17 students in the integrative drama project were from grade seven, and the 13 students in the integrative theatre project were from grade eleven. Three of the students in each project had disabilities and had had a significant portion of their previous education in segregated schools.
A variety of qualitative and quantitative data gathering instruments were incorporated into the design of each project in order to observe and record what happened. Data analyses suggest that both projects were effective in promoting the acceptance of students with disabilities by their non-disabled peers, and in providing students with disabilities experience and confidence working in integrated environments. The integrative theatre project seemed more successful than the integrative drama project. Student age, program content, teacher style and experience, the level of student social interaction skills and time management were found to be significant factors in influencing the relative effectiveness of the integrative drama/theatre process in these projects. The implication of these results, the study's limitations and suggestions for future research are discussed.
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Chow, Simon Ka Ming. "Integration of High Efficiency Solar Cells on Carriers for Concentrating System Applications." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19932.
Full textAbstract:
High efficiency multi-junction (MJ) solar cells were packaged onto receiver systems. The efficiency change of concentrator cells under continuous high intensity illumination was done. Also, assessment of the receiver design on the overall performance of a Fresnel-type concentration system was investigated.
We present on receiver designs including simulation results of their three-dimensional thermal operation and experimental results of tested packaged receivers to understand their efficiency in real world operation. Thermal measurements from solar simulators were obtained and used to calibrate the model in simulations. The best tested efficiency of 36.5% is obtained on a sample A receiver under 260 suns concentration by the XT-30 solar simulator and the corresponding cell operating temperature is ~30.5°C. The optimum copper thickness of a 5 cm by 5 cm simulated alumina receiver design was determined to be 6 mm and the corresponding cell temperature under 1000 suns concentration is ~36°C during operation.
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Lee, Hung Kyu Surveying & Spatial Information Systems Faculty of Engineering UNSW. "Integration of GPS/Pseudolite/INS for high precision kinematic positioning and navigation." Awarded by:University of New South Wales, 2004. http://handle.unsw.edu.au/1959.4/39971.
Full textAbstract:
The integrated GPS/INS system has become an indispensable tool for providing precise and continuous position, velocity, and attitude information for many positioning and navigation applications. Although the integrated GPS/INS system provides augmented solutions that make use of the complementary features of each component system, its performance is still limited by the quality of GPS measurements, and the geometric strength of the satellite constellation. To address such a problem this research has focussed on the integration of GPS, Pseudolite and INS technologies. The main research contributions are summarised below: (a)A cost effective GPS/INS integration approach has been developed and tested, consisting of a single-frequency L1 GPS receiver and a tactical-grade strapdown INS. Results of field experiments demonstrate that this approach is capable of delivering position accuracies of the order of a few centimetres under a benign operational environment and provides continuously positioning at sub-decimetre accuracy during GPS signal blockage lasting up to about five seconds. (b) A novel kinematic positioning and navigation system based on GPS/Pseudolite/INS integration has been proposed as an alternative to existing GPS/INS systems. With this integration approach, the continuity, integrity, and precision of the GPS/INS system can be significantly improved as the inclusion of pseudolite signals enhances the GPS signal availability and the geometry strength. (c)The impact of pseudolite location errors in such pseudolite-augmented systems has been investigated. Theoretical and numerical analyses reveal that the error effects on measurement models, and on final positioning solutions, can be minimised by selecting optimal pseudolite location(s). (d)A new ambiguity resolution procedure has been developed for use in the proposed GPS/Pseudolite/INS system. It is designed to rapidly and reliably resolve the single-frequency ambiguities due not only to the aiding by pseudolites and INS, but also by adopting a realistic stochastic model and a statistically rigorous ambiguity validation test. The proposed procedure can indeed improve the performance of the single-frequency ambiguity resolution algorithm in terms of both reliability and time-to-fix-ambiguity. (e)An effective cycle slip detection and identification algorithm has been developed, which is suitable for the integrated GPS/Pseudolite/INS system. Test results indicate that induced cycle slips can be reliably detected and instantaneously identified, even if the slips occur at successive epochs. (f)Flight trials have been conducted to evaluate the overall performance for aircraft approach and landing using the GPS/Pseudolite/INS system. Results from these trials show that an enhancement in the accuracy and reliability of the vehicle navigation solution can be achieved with the employment of one or more pseudolite.
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Cai, Rainbow Yuhong. "High level support for performance engineering, and model integration and model transformation." Thesis, University of Auckland, 2010. http://hdl.handle.net/2292/5798.
Full textAbstract:
This thesis provides high level support for Performance Engineering in software architecture design via two research projects - Argo/MTE and MaramaMTE+. The Argo/MTE project extends the well established ArgoUML tool to support software architecture modelling and performance evaluation. The Argo/MTE research shows how commonly used Components Off The Shelf (COTS) tools can improve the usability and maintainability of an in-house technology, and how the use of standard model representations can improve tool integration. The MaramaMTE+ research integrates the traditional software architecture modelling with the web user behaviour modelling using the Marama meta-tool. The MaramaMTE+ research shows how model integration can extend the applicable domain of a software model; how a meta-tool can support efficient tool extension; and how to support automatic generation of web load testing plans. This thesis provides high level support for Model Integration and Transformation via the research project MaramaCRelation. The MaramaCRelation research provides a structured approach to interconnect domain-specific models. It maintains the rational of an interconnection of domain-specific models; records semantics maintained and lost across the interconnected models; tracks the evolvement of modeling elements through the traceability across the interconnected models; and maintains behavior synchronization across the interconnected models. The thesis has made contributions in software architecture design, software architecture performance evaluation, web load testing, and model integration and transformation. More specifically, the research of the thesis is aimed for improving the automatic support, analysis and design support, and systematic and structured support for Performance Engineering and Model Driven Engineering.Whole document restricted until September 2012, but available by request, use the feedback form to request access.
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[Verfasser], Đ~ô-mạnh-Cuong. "Piezoelectric transformer integration possibility in high power density applications / Do Manh Cuong." Dresden : TUDpress, 2008. http://d-nb.info/1000793125/34.
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Roth, John D. "Integration of a high sensitivity MEMS directional sound sensor with readout electronics." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/27897.
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The miniaturization of a sound detection system is of great interest to applications such as sniper location. Current systems in use are larger and do not provide for the unencumbered movement of the warfighter. Inspiration for a smaller MEMS based sensor is therefore taken from the aural system of the fly Ormia ochracea. The focus of this thesis is the design of an integrated and miniaturized device utilizing commercial-off-the-shelf readout electronics with the biologically inspired sensor. An analysis of previously used techniques is presented along with a novel fully-integrated miniaturized design. Specific investigations include integration with external readout electronics, a hybrid discrete component design, and the fully-integrated single package design. Results include successful operation at all levels of integration and a more thorough analysis of the performance of the fully-integrated design.
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McCaughan, Adam Nykoruk. "High-Q superconducting coplanar waveguide resonators for integration into molecule ion traps." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61317.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 94-96).
Over the last decade, quantum information experiments with trapped ions have demonstrated essential steps towards quantum computing and quantum simulation. Large fields are required to achieve strong coupling to the ions via dipolar interactions, and so we fabricated transmission line microresonators-capable of producing large fields in a standing wave at resonance-for eventual integration into 2D ion trap structures. The resonators were superconducting to minimize loss and maximize quality factor. We fabricated the resonators as two dimensional coplanar waveguides in niobium on R-plane sapphire using optical lithography. Resist was patterned on the niobium using optical lithography, developed, then reactive-ion etched to transfer the pattern into the niobium. The resonators were cooled and tested in a cryogenic probe station and characterized with a network analyzer. Additionally, the resonator geometry was reproduced in commercial microwave simulation software. Results from our fabricated resonators showed first-resonance quality factors of 1.2x 104 at 3.23 GHz at device temperatures of 3-4 K.
by Adam Nykoruk McCaughan.
M.Eng.
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Papageorgiou, Vasileios. "Integration of planar Gunn diodes and HEMTs for high-power MMIC oscillators." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5701/.
Full textAbstract:
This work has as main objective the integration of planar Gunn diodes and high electron mobility transistors (HEMTs) on the same chip for the realisation of high-power oscillators in the millimeter-wave regime. By integrating the two devices, we can reinforce the high frequency oscillations generated by the diode using a transistor-based amplifier. The integration of the planar Gunn diode and the pseudomorphic HEMT was initially attempted on a combined gallium arsenide (GaAs) wafer. In this approach, the active layers of the two devices were separated by a thick buffer layer. A second technique was examined afterwards where both devices were fabricated on the same wafer that included AlGaAs/InGaAs/GaAs heterostructures optimised for the fabrication of pHEMTs. The second approach demonstrated the successful implementation of both devices on the same substrate. Planar Gunn diodes with 1.3 μm anode-to-cathode separation (Lac) presented oscillations up to 87.6 GHz with a maximum power equal to -40 dBm. A new technique was developed for the fabrication of 70 nm long T-gates, improving the gain and the high frequency performance of the transistor. The pHEMT presented cut-off frequency (fT) equal to 90 GHz and 200 GHz maximum frequency of oscillation (fmax). The same side-by-side approach was applied afterwards for the implementation of both devices on an indium phosphide (InP) HEMT wafer for the first time. Planar Gunn diodes with Lac equal to 1 μm generated oscillations up to 204 GHz with -7.1 dBm maximum power. The developed 70 nm T-gate technology was applied for the fabrication of HEMTs with fT equal to 220 GHz and fmax equal to 330 GHz. In the end of this work, the two devices were combined in the same monolithic microwave integrated circuit (MMIC), where the diode was connected to the transistor based amplifier. The amplifier demonstrated a very promising performance with 10 dB of stable gain at 43 GHz. However, imperfections of the material caused large variations at the current density of the devices. As a consequence, no signals were detected at the output of the complete MMIC oscillators.