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1
Decker, Joan 1977. "Synergism of radio-frequency current drive with the bootstrap current." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87209.
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Guyton, Matthew C. (Matthew Christopher). "Bandgap current source." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87308.
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Fulk, Rebecca Beacham. "The effects of current brain research in the science classroom." Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/fulk/FulkR0812.pdf.
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In this investigation brain breaks were implemented with the goal of improving student focus and learning in an afternoon science class. Different styles of breaks were offered each afternoon and quality of learning was monitored. Though students felt certain breaks were ineffective, on task behavior and grades improved after treatment.
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Hyanes, A. D. "Classroom based research on some current issues in science education." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376355.
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Lundberg, Karin. "Citizens and Contemporary Science Ways to dialogue in science centre contexts." Thesis, Högskolan Dalarna, Vetenskapskommunikation, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:du-2536.
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The current paper presents a study conducted at At-Bristol Science Centre, UK. It is a front-end evaluation for the “Live Science Zone” at At-Bristol, which will be built during the autumn of 2004. It will provide a facility for programmed events and shows, non-programmed investigative activities and the choice of passive or active exploration of current scientific topics. The main aim of the study is to determine characteristics of what kind of techniques to use in the Live Science Zone. The objectives are to explore what has already been done at At-Bristol, and what has been done at other science centres, and to identify successful devices. The secondary aim is mapping what sorts of topics that visitors are actually interested in debating. The methods used in the study are deep qualitative interviews with professionals working within the field of science communication in Europe and North America, and questionnaires answered by visitors to At-Bristol. The results show that there are some gaps between the intentions of the professionals and the opinions of the visitors, in terms of opportunities and willingness for dialogue in science centre activities. The most popular issue was Future and the most popular device was Film.
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Mayer, Peter (Peter Matthew) 1978. "Current fluctuations in semiconductor devices." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87247.
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Boulter, Stephen Jordan. "Aquinas and the realist dispute in science an Aristotelio-Thomistic contribution to current discussions in language, logic and science." Thesis, Connect to e-thesis, 1996. http://theses.gla.ac.uk/722/.
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Bernards, Jake R., Kimitake Sato, G. Gregory Haff, and Caleb D. Bazyler. "Current Research and Statistical Practices in Sport Science and a Need for Change." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/3789.
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Current research ideologies in sport science allow for the possibility of investigators producing statistically significant results to help fit the outcome into a predetermined theory. Additionally, under the current Neyman-Pearson statistical structure, some argue that null hypothesis significant testing (NHST) under the frequentist approach is flawed, regardless. For example, a p-value is unable to measure the probability that the studied hypothesis is true, unable to measure the size of an effect or the importance of a result, and unable to provide a good measure of evidence regarding a model or hypothesis. Many of these downfalls are key questions researchers strive to answer following an investigation. Therefore, a shift towards a magnitude-based inference model, and eventually a fully Bayesian framework, is thought to be a better fit from a statistical standpoint and may be an improved way to address biases within the literature. The goal of this article is to shed light on the current research and statistical shortcomings the field of sport science faces today, and offer potential solutions to help guide future research practices.
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Hodges, Clifford H. (Clifford Hill) 1979. "Modeling diffusion in the Antarctic circumpolar current." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28395.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.<br>Includes bibliographical references (leaf 29).<br>In order to understand the role of eddies in lateral mixing in a rotating fluid, a small scale laboratory model is constructed. An experiment is carried out in a rotating, differentially heated annulus and the evolution of a dye tracer mixed by turbulent motions is studied. Images are analyzed to extract the concentration mappings of tracer throughout the tank at each time instance and a diffusion coefficient K(r) is inferred.<br>by Clifford H. Hodges.<br>M.Eng.
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Lee, Janice C. (Janice Cheng-Yee) 1978. "Resonant readout of a superconducting persistent current qubit." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37845.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Includes bibliographical references (p. 211-218).<br>Superconducting Josephson junction devices rank among the best candidates for realizing a quantum computer. While the coherent control of quantum dynamics has been demonstrated in these solid-state, macroscopic quantum systems, a major challenge has been to increase the coherence times for these qubits. With an objective to reduce the level of readout-induced decoherence, this thesis work focuses on a resonant readout scheme developed for a niobium persistent-current (PC) qubit. This non-dissipative readout approach detects the flux state of the qubit by sensing a change in the Josephson inductance of a SQUID magnetometer. By incorporating the SQUID inductor in a high-Q resonant circuit, we distinguished the flux states of the qubit as a shift in the resonant frequency at 300 mK. The nonlinearity due to the Josephson inductance has characteristic effects on the resonant behavior of the readout circuit. We observed novel manifestation of this nonlinearity given the high quality factor of the resonance. The readout circuit was characterized in the linear as well as the nonlinear regime for its potential use as a bifurcation amplifier. Numerical simulations based on Josephson-junction circuits were also performed to understand the observed nonlinearity in the resonant behavior.<br>by Janice C. Lee.<br>Ph.D.
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Wang, Margaret Hsin-Yi 1978. "Study of current measurement in magnetic force microscopy." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87296.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.<br>Includes bibliographical references (p. 137-140).<br>by Margaret Hsin-Yi Wang.<br>M.Eng.
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Ferri, Matthew A. (Matthew Anthony). "Current distribution in cable-in conduit superconductors." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/28111.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.<br>Includes bibliographical references (p. 101-103).<br>by Matthew A. Ferri.<br>M.S.
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Ko, Jin-Seok. "Current profile measurements using MSE on Alcator C-Mod." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53273.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 319-325).<br>A Motional Stark Effect (MSE) diagnostic system has been installed on the Alcator C-Mod tokamak to measure the plasma internal magnetic pitch angle profile. The diagnostic utilizes polarization patterns from Doppler-shifted Balmer-alpha decay emission from an energetic neutral beam injected into a magnetically confined plasma. This dissertation consists of three parts: (1) the current status of the C-Mod MSE diagnostic which includes major upgrades in the hardware and calibration techniques; (2) the elimination of the spurious drift in the polarization measurements due to thermal-stress induced birefringence; and (3) the measurement of current density profiles in Lower Hybrid Current Drive (LHCD) experiments. The major hardware upgrades include replacement of photomultiplier tubes (PMT's) with avalanche photodiodes (APD's) which enhanced the quantum efficiency; installation of a wire-grid polarizer to verify small Faraday rotation in the diagnostic; installation of steep edge filters to minimize pollution by the thermal Balmer-alpha signals; rotation of the Diagnostic Neutral Beam (DNB) which significantly reduced the anomalous effect from the secondary beam neutrals during the beam-into-gas calibrations. The new calibration techniques include two plasma calibrations: plasma current sweeping and the plasma size sweeping whose feasibility was experimentally proven; and an absolute intensity calibration which measured the real optical throughput of the system. A large database study indicates the signal-to-background ratio larger than 100 is required to have the measurement uncertainty under 0.1 degrees.<br>(cont.) The spurious drift in the measurement has been identified as the thermals tress induced birefringence imposed on the in-vessel lenses. By modeling this effect as a single wave plate, an in-situ calibration method has been proposed and its feasibility was experimentally verified. Based on the experiments that characterized the thermal response of the system, a single-layer heat shield with gold plating and a lens holder which reduces the thermal conduction path to the lens have been designed and fabricated. A more rigorous model that includes an intrinsic phase shift by mirrors reveals the thermal phase shift can be greatly magnified by the intrinsic phase shift. The current density profiles from LHCD experiments have been obtained from the MSE data corrected by a baseline magnetic equilibrium whose internal profile is constrained by the sawtooth inversion radius. The resultant profiles successfully demonstrate several standard predictions of LHCD theory such as the dependence of efficiency on the parallel refractive index and the off-axis current drive.<br>by Jin-Seok Ko.<br>Ph.D.
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Seo, Hae-Ae Kennedy Larry DeWitt. "An analysis of the perceptions of science teacher educators and secondary school science teachers as to the current status of science teacher education programs in Korean universities." Normal, Ill. Illinois State University, 1993. http://wwwlib.umi.com/cr/ilstu/fullcit?p9416863.
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Thesis (Ed. D.)--Illinois State University, 1993.<br>Title from title page screen, viewed March 8, 2006. Dissertation Committee: Larry D. Kennedy (chair), Robert L. Fisher, George Padavil, Kenneth H. Strand. Includes bibliographical references (leaves 117-123) and abstract. Also available in print.
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White, Robyn C. "Heroes from the past : their beliefs and practices, and influence on current science education practice." Curtin University of Technology, Science and Mathematics Education Centre, 1998. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=9449.
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This study reflects my own search to clarify the process of cultural change in an educational setting. In particular it clarifies for me the process through which State-wide science curriculum reform was enacted in the late 1950s and into the 1970s. This period is interesting because of a continuing perception amongst science teachers that the system-wide changes of the time were widely supported by teachers and influenced classroom practice. My aim in this study was to explore how the characteristics of this cultural change process may be applied in the current climate of school reform.The members of the local science teacher community of the 1950s, 1960s and 1970s engaged in similar activities and conversations as they attended the same University then continued to enter into similar school-based activities. As a group of people with shared experiences and values, who made decisions based on similar understandings and priorities, this group may be regarded as an identifiable culture.The day to day activities of this community of science teachers were underpinned by each teacher's beliefs about scientific knowledge and processes and school science, as well as understandings about the teaching and learning process. Many of these beliefs were so fundamental as to be unquestioned, and may be referred to as referents, or myths. For the members of a culture to change their practice then, new referents must be introduced, or existing referents modified.In searching for the process by which this culture was able to access new understandings, this study examined the comparative influence of two highly visible science educators who promoted science curriculum change in the State. As a result of data collection involving interviews with twenty-five key informants and the examination of private and public archival records; the crucial role of these unique personalities emerged ++<br>consistently: Each of these men have been characterised as a Hero because each brought new understandings to their existing culture (Campbell, 1949).In reviewing the extended career of each Hero it was possible to draw strong parallels with mythical Greek heroes, Perseus and Theseus. This metaphorical representation not only effectively mirrored the life history of the modern-day heroes but also served to reconnect the logic of science along with that of the emotion of art - a balance well understood by the Greeks.The study found that the successful Heroes promoted significant long term change by instituting new rituals, ceremonies and artefacts throughout the science education community. Over time, these activities effectively modified older referents and created new ones, leading to new practice in the curriculum enacted by science teachers.In drawing together the stories of Perseus and Theseus, it was possible to recognise common elements in the processes by which these influential individuals were able to effect new practice in their community. Thus the study provides a template for the cultural change process in the future.In the final discussion, focus shifts to the relevance of this research to the everyday enterprise of schools and school systems. As a school practitioner z always read scholarly papers with the underpinning question; "See What?" The final chapter then, is largely hypothetical as it poses possibilities, makes predications and offers advice for readers seeking to improve the change process in their own context.
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McFerrin, D., and Marc A. Fagelson. "Staying Current with Tinnitus Research." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/1680.
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Penn, Alexander A. "On-chip current sensing for monolithic buck LED driver." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/85465.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2013.<br>"June 2013." Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 81-82).<br>This thesis explores and analyzes two different options for on-chip sensing and regulating current for a buck LED driver, as compared to a common external solution. With the rise of LED use in common lighting applications, it becomes increasingly necessary to develop solutions that are simple to use and accurate. In this paper, much of the focus is on reducing the external pin and component count while maintaining output current accuracy and power efficiency.<br>by Alexander A. Penn.<br>M. Eng.
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Chen, Christine M. Eng Massachusetts Institute of Technology. "Integrated DC-DC converter with ultra-low quiescent current." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/84879.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2013.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 93-94).<br>Based on the LTC3588, the design of a bandgap reference and a comparator for use in the control circuitry of DC-DC converter with an ultra-low quiescent current of 150nA is presented here. Not only will this thesis discuss the challenges encountered over the course of designing circuits to operate at such low current levels, but it will also provide proof of concept silicon evaluation data of modified LTC3588 chips demonstrating that such low current operation is viable.<br>by Christine Chen.<br>M.Eng.
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Selders, Robert L. (Robert Lee). "A current-balancing control system for cellular power converters." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11296.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.<br>Includes bibliographical references (p. 85-87).<br>by Robert L. Selders, Jr.<br>M.S.
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Coffing, Danielle. "Design and modeling of a high current switching regulator." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42714.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.<br>Includes bibliographical references (leaves 228-231).<br>by Danielle Coffing.<br>M.Eng.
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Pop, Eric 1975. "CMOS inverse doping profile extraction and substrate current modeling." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80565.
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Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.<br>Includes bibliographical references (p. 95-101).<br>by Eric Pop.<br>S.B.and M.Eng.
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Parisot, Alexandre 1979. "Mode conversion current drive experiments on Alcator C-Mod." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40505.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.<br>Includes bibliographical references (p. 189-197).<br>In tokamak plasmas with multiple ion species, fast magnetosonic waves (FW) in the Ion Cyclotron Range of Frequency can mode convert to shorter wavelength modes at the Ion-Ion hybrid layer, leading to localized electron heating and current drive. Due to k1l upshifts associated with the poloidal magnetic field, only small net driven currents were predicted from mode converted Ion Bernstein Waves (IBW). As studied first by Perkins, and later confirmed experimentally with Phase Contrast Imaging measurements on Alcator C-Mod, poloidal field effects can also lead to mode conversion to Ion Cyclotron Waves (MCICW), on the low field side of the mode conversion layer. In this thesis, mode conversion current drive in the ICW-dominated regime is studied numerically and through experiments on Alcator C-Mod. Solving a dispersion relation for the mode converted waves in a slab geometry relevant to tokamak equilibria and in the finite Larmor radius limit, we find that mode conversion to Ion Cyclotron Waves is ubiquitous to high temperature conventional tokamaks, as a result of the central value for the safety factor qo 1. MCICWs are identified as kinetically modified Ion Cyclotron Waves in the regime w/kllVthe < 1. Full wave simulations with the TORIC code predict net currents can be driven by MCICW as a result of up-down asymmetries in the mode conversion process. Initial estimates with the Ehst-Karney parametrization indicated up to -- 100 kA could be driven for 3 MW input power in C-Mod plasmas. More accurate calculations, consistent with the polarization of MCICWs, were carried out by importing a quasilinear diffusion operator build from the TORIC fields in the Fokker-Planck code DKE, and predicted lower current drive efficiencies by a factor of 2.<br>(cont.) The TFTR discharges in 1996 where net MCCD currents were inferred experimentally from loop voltage differences were simulated with TORIC, which indicates mode conversion to ICW can account for the driven currents. Similar loop voltage experiments in D(3He) plasmas were attempted on Alcator C-Mod, but did not yield conclusive current drive measurements. The lack of control over Zeff in C-Mod, which is illustrative of ICRF operation in tokamaks with metallic walls, makes reaching optimal plasma conditions for MCCD difficult, and limits the range of parameters in which MCCD can be useful as a net current drive tool in C-Mod. Solving the current diffusion equation in the cylindrical limit and with sawtooth reconnection models, the large sawtooth oscillations in C-Mod plasmas were also found to complicate current relaxation and hinder the loop voltage analysis for small central driven currents inside the q = 1 surface. In separate experiments on Alcator C-Mod, sawtooth period changes were used to infer localized MCCD near the q = 1 surface. The mode conversion layer was swept outward through the q = 1 surface in D(3He) plasmas, and the sawtooth period was found to vary from 3 to 12 ms, which is consistent wih localized current drive and TORIC predictions. A similar evolution was found in heating and co-current drive phasing, which suggests net currents are driven with a symmetric antenna spectrum, as predicted by TORIC as a result of asymmetries in the mode conversion process. Simulations of the sawtooth cycle with the Porcelli trigger model indicate that TORIC currents can account for the sawtooth period evolution in heating phasing.<br>(cont.) Based on simulations of the saw-tooth cycle with the Porcelli trigger model, localized electron heating, which could also explain the experimental results, was found not to be dominant compared to the current drive effect. The experimental results demonstrate that, while not optimal, MCCD can be used for sawtooth control.<br>by Alexandre Parisot.<br>Ph.D.
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Gardner, John Underhill. "Designing an ultra low quiescent current buck switching regulator." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/46105.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.<br>Includes bibliographical references (p. 119-120).<br>The new buck regulator proposed in this thesis was designed to operate with only a few micro-amps of supply current during no load output conditions, while maintaining low output voltage ripple. The regulator also has high efficiency for current loads above an amp to make the converter useful in a variety of applications. The specifications will be achieved by implementing a control scheme similar to the one used in the LT3481 buck regulator. The converter will use burst mode, pulse frequency modulation, and pulse width modulation to achieve control over the entire load range. The capabilities of a full BiCMOS process technology will be taken advantage of to enable implementation of good control dynamics at low currents. This micropower buck regulator was designed, fabricated, and tested in silicon to measure its characteristics as compared to simulation and desired specifications.<br>by John Underhill Gardner.<br>M.Eng.
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Lim, Sejoon. "Traffic prediction and navigation using historical and current information." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43072.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.<br>Includes bibliographical references (p. 101-104).<br>We developed a traffic prediction and navigation system that deals with uncertainty of road traffic conditions by stochastic modeling of road networks. Our system consists of a data collecting system, a data management system, and a path planning system. First, the data collecting system gathers real-time travel time data using a mobile sensor network system, CarTel. GPS sensor units having wireless connectivity were deployed on taxis running around the Boston area, and report their position and time information to the networked database system. Second, the raw GPS data collected from this CarTel system is processed to generate a database storing the statistical information of road travel time. We organize a large amount of data in a form in which they can be accessed efficiently and can capture important aspects of road traffic conditions. Third, we developed efficient stochastic shortest path algorithms that find best paths depending on drivers' goals. We evaluate our algorithms using both simulations and real-world drives. Finally, we implemented a path planning system using historical and current information organized by our data management system. Our system provides a Web-based interface that is publicly usable. The interface provides traffic information, including optimal paths and visualized traffic conditions. Our system also offers analysis tools of users' own driving routes with user track-log uploading interface. We evaluate the system using taxi trajectories and human driving experiments.<br>by Sejoon Lim.<br>S.M.
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Nakada, Daniel Yuki 1975. "Fabrication and measurement of a niobium persistent current qubit." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/18049.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.<br>Includes bibliographical references (p. 192-201).<br>Recent successes with superconducting Josephson junction qubits make them prime candidates for the implementation of quantum computing. This doctoral thesis details the study of a niobium Josephson junction circuit for quantum computing applications. The thesis covers two main areas: 1) the fabrication of sub-micron niobium Josephson junction devices using a Nb/Al/A1Ox/Nb trilayer process and 2) measurements of unique quantum properties of a superconducting device proposed as a quantum bit--the Persistent Current (PC) qubit. The thesis discusses the fabrication of niobium Josephson junction devices which is integral to the design and measurement of the circuit. The devices were fabricated at MIT Lincoln Laboratory using optical projection lithography to define features. A technique to produce more uniform critical-current densities across a wafer is developed within the scope of the thesis. We also introduce experimental work on the PC qubit performed at dilution refrigerator temperatures (T [approximately] 12mK). Microwave spectroscopy was used to map the energy level separation between macroscopic quantum states of the qubit system. We measured the intrawell energy relaxation time [tau]d between quantum levels in this particular device. The intrawell relaxation measurements are important in determining whether a promising decoherence time can be achieved in Nb-based Josephson devices, which has a more mature fabrication process compared to other superconducting fabrication processes.<br>by Daniel Yuki Nakada.<br>Ph.D.
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Fernandez, Maria del Mar, and Ignacio Porres. "An Evaluation of current IDS." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11635.
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<p>With the possibility of connecting several computers and networks the necessity of protecting the whole data and machines from attackers (hackers) that try to get some confident information to use for their own benefit or just destroy or modify valuable information was born. At this point IDS appears to help users, companies or institutions to detect when they are getting compromised. This thesis will cover two main parts: the first one consists of an intense research study about the world of IDS and its environment. Subsequently, we will conclude this part with some points where IDS still needs to be questioned and show up desirable requirements for “the perfect” intrusion detection system. This “perfect” adjective can of course be discussed variously. The second part of the thesis approaches the implementation of the most used open source IDS: Snort. Some basic attacks on the machine where Snort is installed will be performed in order to make the future user see what kind of protection it ensures and the usability of this. There is a brief discussion about two of the main challenges in IDS will follow: analyzing big amounts of packets and encrypted traffic. Finally there are conclusions for a safe computer environment as well as the suggestion that some skilled programmer should give Snort a more friendly interface for every kind of users and a built in programme package which includes webserver, database and other libraries that are needed to run it properly with all its features.</p>
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Garritson, Emily M. "DDT: Historical Framework, Current Uses, & Future Implications." Miami University Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1209157311.
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Irianto, Bambang. "An investigation of current problems facing the Science Teachers' Development and Training Centre in Indonesia." Curtin University of Technology, Science and Mathematics Education Centre, 2001. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=13035.
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The Science Teachers' Development and Training Centre or STDTC (Pusat Pengembangan dan Penataran Guru Ilmu Pengetahuan Alam or PPPG IPA) is an official in-service science teacher training, which is in Bandung, West Java, Indonesia. Between 1978 and 1997, an in-service science-teacher training project, which is known as the PKG IPA Project, was developed by the Directorate of General Secondary Education. The successful PKG IPA project implemented its own in-service science teacher training system within its own training network across Indonesia, without the involvement of the PPPG IPA as the existing official teacher-training agent. The existence of the project was discontinued when the World Bank loan ended. Unfortunately, the expensive infrastructures developed by the PKG IPA project could no longer be utilized because the PKG IPA project was excluded from the official structure of organization of the Ministry of Education and Culture (MOEC) which is now known as Ministry of National education (MNE). In addition, the ignorance of the staff of the PPPG IPA about the PKG IPA project is one indicator why that the PPPG IPA is facing some problems, which affect the implementation of its duties and functions.Based on this indicator, this study was implemented with two objectives, namely, to investigate and analyze current problems facing the PPPG IPA, and to make recommendations for formulating appropriate policies and strategies in order to rationalize the future roles of the PPPG IPA. The study involved seven research questions, which were grouped into three concerns, namely, the quality of the environment, a needs analysis, and analysis of the Directorate's policies. The seven research questions required different instruments to collect the data. Existing instruments, SLEQ (School Level Environment Questionnaire) and SLEI (Science Laboratory Environment Inventory), ++<br>were translated into Indonesian. The researcher developed other instruments. The study involved both qualitative and quantitative research methods and types of data, included various sampling strategy classifications, such as purposeful sampling and opportunistic sampling. The data collecting strategy involved surveys, observations, interviews, and mining documents.The study concluded that the PPPG IPA is facing some current problems related to the aspects of working environment, science laboratory environment, human resources, facilities, policies, and in-service training networking. The study recommended that the Ministry of National Education (MNE) formulate appropriate policies and strategies in order to rationalize the roles of the PPPG IPA in order to strengthen the implementation, and improve the quality, effectiveness, and efficiency of the in-service training programs. A new ministerial regulation also is recommended to be released to replace the previous relevant regulations in order to accommodate the above concerns.
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Stone, Katherine M. "Effects of an electric current applied to metals during solidification." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122446.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2019<br>"June 2019." Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 31-34).<br>Solidification is an important, yet not fully understood, materials process. One way to better understand solidification, or at least to better control it, is through applying outside effects onto the solidifying material. Private industrial experiments performed by Dr. Eric Dahlgren suggested that there might be a trend of increased undercooling in a metallic sample as more current was applied. An expansion of those experiments was commenced to A) confirm this trend and B) explore its potential causes, with the ultimate goal of being able to reliably change undercooling in a metallic material to affect its final properties. An experiment was designed where gallium could be subjected to between o and 20 amps of applied direct current. The gallium sample could then be cooled, while its thermal history over time could be recorded. The cooling curves of the gallium between melting and recalescence points were then used to try and quantify the effect of the applied current. It was shown that increasing the applied current did increase the undercooling time, specifically the time to homogenous nucleation. Although no mechanism to explain this phenomenon has been conclusively proved, this project was able to help reduce the likelihood of several theories. Simple calculations showed that joule heating does not create enough heat flux to change the temperature and effect the formation of nuclei in the melt. Experimental results showed that the observed phenomenon was due to the effects on a nucleation-based process, not a growth process, disproving several growth-based theories for this phenomenon. Additionally, certain common assumptions in previous experiments about the effects of a magnetic field, or of joule heating, were disproven. These advances, and some of the setbacks experienced in this project, lay a path for improvements in future work that may find the precise cause of this effect.<br>by Katherine M. Stone.<br>S.M.<br>S.M. Massachusetts Institute of Technology, Department of Materials Science and Engineering
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Saunders, Theo Graves. "Effect of electric current on ceramic processing." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/25943.
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This work was on the effect of electric current on the processing of ceramics. The focus was on electromigration/electrochemistry and plasma effects. While there is no solid evidence that there is plasma in Spark Plasma Sintering, (SPS), newer techniques e.g. flash, use different conditions so there is an interest in understanding the conditions under which a plasma forms. The minimum arcing voltage was found from literature to be from 10-15V for materials of interest. This is above that found in SPS (10V). However, due to the many contact points in a powder compact much higher voltages (50V) were required in practical experiments. Optical spectroscopy was used to verify the formation of a plasma, and emission peaks from the powder compact material were visible implying they were vaporised and formed the plasma. Electromigration was exploited to alter the oxidation of zirconium diboride, by passing current through the oxide layer (120μm zirconia base grown at 1200°C) oxygen could be pumped either away or toward the diboride bulk. Small cubes (3mm) of diboride had platinum foil electrodes applied on both sides and oxidation was performed at 1400°C for 5hr. Without a field the oxide grew to 360μm, by applying 10V and 100mA the oxide grew to 150μm under the +ve electrode but 1400μm under the -ve electrode. Electrochemical reduction was believed to have occurred due to the electrical properties of the material changing during oxidation and visible blackening of the oxide. Combining the techniques from both earlier works, a contactless flash sintering setup was developed. This used two plasma arcs as electrodes to heat and pass current through the sample. Various materials, currents and times were used, but the best result was with SiC:B4C which was sintered in 3s with 6A, the microstructure showed sharp grains, no segregation and limited grain growth ( initially 0.7μm SiC and 0.5μm B4C, this grew to 1.1μm and 1.4μm). This was the first recorded case of contactless flash sintering and the technique has the potential to sinter ceramics in a continuous manner.
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Decker, Joan 1977. "Electron Bernstein wave current drive modeling in toroidal plasma confinement." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33937.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.<br>Includes bibliographical references (p. 333-340).<br>The steady-state confinement of tokamak plasmas in a fusion reactor requires non-inductively driven toroidal currents. Radio frequency waves in the electron cyclotron (EC) range of frequencies can drive localized currents and are thus particularly attractive for control of the current profile. In the high-[beta] regimes of spherical tokamaks (ST) such as NSTX and MAST, heating and current drive (CD) by conventional electron cyclotron waves is not possible. However, electron Bernstein waves (EBW) have been proposed as an alternative for CD in these overdense devices. Given the important role predicted for CD by EBWs in high-[beta] STs, a detailed study of EBWCD must be undertaken. In this thesis a systematic analysis of EBWCD is provided. In particular, the characteristics of EBWs, the physics of resonant wave-particle interaction, and the CD mechanisms are investigated in detail. The CD efficiency and the current deposition profile are calculated using the numerical code DKE, which solve the drift-kinetic equation. Two scenarios for EBWCD are identified. The first scenario consists of approaching a harmonic of the EC resonance from a lower B-field region and drives current in the plasma core using the Fisch-Boozer mechanism.<br>(cont.) The other scenario consists of approaching a harmonic of the EC resonance from a higher B-field region and drives current off-axis on the outboard side using the Ohkawa mechanism. Both schemes drive current in the toroidal direction opposite to the parallel wave vector. The EBWCI) efficiency is found to be higher than ECCD efficiency because the EBW power is deposited in the tail of the electron distribution function. The results of this thesis confirm the important role of EBWs for driving currents in high-[beta] plasmas. The analytical and numerical tools developed as part of this thesis can be used to design, predict, and analyze future EBWCD experiments. Among these tools is the kinetic solver DKE, which can be used for electron current drive calculations in toroidal plasmas for different types of radio-frequency waves, such as lower hybrid and electron cyclotron waves.<br>by Joan Decker.<br>Ph.D.
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Lnu, Shimon. "Magnetoresistive Random Access Memory (MRAM) technology : current advancement and future development." Thesis, Massachusetts Institute of Technology, 2010. https://hdl.handle.net/1721.1/122861.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2010<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 80-85).<br>Ability to store data is one of the key utilities in modern computer. The memory industry grows as demand for denser, smaller, cheaper and faster memory device increases. The term memory has been used widely in computing jargon to refer to random access memory (RAM). RAMs are built with steady improvement over the years owing to semiconductor integrated circuit (IC) technology. However, RAMs are still struggling to achieve all aspect of the paramount design intended for memory device: non-volatile (including radiation hardness and materials stability), dense, fast, low power consumption, low cost, IC technology compatible and read/write (R/W) endurance. Magnetoresistive RAM (MRAM) offers such possibility. MRAM has just entered in 2002 with 128kbit product, but it has improved to reach 16 Mbit density in the year 2009, that makes a 128 density multiplication in 7 years. The prototyping has gone through an even higher density at 64 Mbit in 2010, along with optimistic view of reaching Gbit density in the near future by the introduction of spin-torque-transfer MRAM. A close look at the presented MRAM cost model, the cost of 64 and 128Mbit module can go as low as 4.4-4.9 cents/Mbit and 2.8-3.0 cents/Mbit respectively. Comparing to similar density (64 or 128 Mbit) DRAM product - around 1993-1996, DRAM pricing is revolving around $1/Mbit, which makes MRAM a cost competitive product with respect to DRAM or other memories. Evidently, MRAM cost looks promising to compete with superior memory products such as DRAM and Flash, while on its way, it will replace the first few market penetration areas such as embedded memory and SOC circuit for mobile/automotive application.<br>by Shimon.<br>M. Eng.<br>M.Eng. Massachusetts Institute of Technology, Department of Materials Science and Engineering
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Dagiene, Valentina, Tatjana Jevsikova, Carsten Schule, Sue Sentance, and Neena Thota. "A comparison of current trends within computer science teaching in school in Germany and the UK." Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6450/.
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In the last two years, CS as a school subject has gained a lot of attention worldwide, although different countries have differing approaches to and experiences of introducing CS in schools. This paper reports on a study comparing current trends in CS at school, with a major focus on two countries, Germany and UK. A survey was carried out of a number of teaching professionals and experts from the UK and Germany with regard to the content and delivery of CS in school. An analysis of the quantitative data reveals a difference in foci in the two countries; putting this into the context of curricular developments we are able to offer interpretations of these trends and suggest ways in which curricula in CS at school should be moving forward.
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SatÅ, Kenji. "A switching ripple based current sharing control system for celluar converters." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10464.
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Crankshaw, Donald S. (Donald Shane) 1974. "Measurement and on-chip control of a niobium persistent current qubit." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/28278.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.<br>Includes bibliographical references (p. 203-208).<br>The persistent current qubit is a superconducting ring interrupted by three Josephson junctions. Its two quantum states have circulating currents in opposite directions which can be measured by a dc SQUID magnetometer. This work examines a persistent current qubit fabricated in niobium, using Lincoln Laboratory's DPARTS process. Measurements of the niobium qubit show a promisingly high subgap resistance, demonstrate discrete energy levels, and give good estimates of the qubit parameters as fabricated. Although the variances on the qubit parameters are large, it is possible to design a qubit whose parameters are in the quantum regime. Additionally, we show how the qubit can be integrated with on-chip electronics while taking into account decoherence. A dc SQUID oscillator has been designed which can deliver an oscillating field at 10 GHz without reducing the decoherence time below 1 microsecond. The oscillator is shown to deliver power to the measurement device, although the qubit rotation has not yet been observed.<br>by Donald S. Crankshaw.<br>Ph.D.
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Wu, Michael A. M. Eng Massachusetts Institute of Technology. "A common platform for current sensor evaluation in industrial automation applications." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106391.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 57-58).<br>This thesis describes the design and implementation of an evaluation system for Silicon Labs' current sensor products. The system provides significant advantages over existing evaluation systems by reducing hazardous voltages and currents through increased sense resistance and improving simplicity through a modular motherboard, daughtercard, and software system. The system is versatile and supports modifications for additional customization. All existing Silicon Labs' current sensor products are implemented in the system. The performance of the constructed evaluation system is shown to exceed existing work. The constructed system uses lower currents, requires fewer specialized components, improves portability, and provides access to advanced product functionality.<br>by Michael A. Wu.<br>M. Eng.
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Palomera-Arias, Rogelio 1972. "PIN diode switch circuit for short time high current pulse signal." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47505.
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Pan, Menghsuan Sam. "Ionic conductivity and exchange current density of non-aqueous lithium polysulfide electrolyte." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/98665.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, June 2015.<br>Cataloged from PDF version of thesis. "May 2015."<br>Includes bibliographical references (pages 32-33).<br>Lithium-polysulfide flow batteries, which utilize the high solubility of lithium polysulfide in non-aqueous electrolytes to enable flowable electrodes, have high theoretical energy density and low raw materials cost. To achieve greater electrode-level energy density, higher sulfur concentrations are needed. In a given electrolyte system, sulfur charge storage capacity (e.g. mAh/g sulfur) decreases dramatically with increasing sulfur concentration at a fixed C-rate, which corresponds to higher current output in higher concentration system. Understanding the limiting factors that undercut the rate capacity is crucial to enhancing the performance of high energy density systems. In particular, we systematically investigate the ionic conductivity and exchange current density at the electrode surface with lithium polysulfide solutions of varying concentration and in differing solvents which solvent molecules of different sizes. Ionic conductivities are measured using a commercially available conductivity probe, while exchange current densities are measured using both impedance spectroscopy and galvanostatic polarization using glassy carbon working electrodes. The electrolyte solvent is found to dramatically affect the solution ionic conductivity and exchange current density. In the concentration range of interest (1-8 M [S]), the ionic conductivity monotonically decreases with increasing sulfur concentration while exchange current density shows a more complicated response in a given solvent system. Between solvent systems, we observed a five-fold increase in ionic conductivity, and a more than 15-fold enhancement in exchange current density. The conductivity and current density results are used to interpret the rate capability of suspension-based cells using lithium-polysulfide electrolyte and carbon black as the cathode with different solvents. With the improvement in kinetics parameters, we also observed better rate capability in solvent. We also study non-carbonaceous electrode materials to understand how the electrode material can affect exchange current density and thus cell capacity. Indium tin oxide electrode shows lower exchange current density then glassy carbon electrode in preliminary results.<br>by Menghsuan Sam Pan.<br>S.B.
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Colin, Irénée A. (Irénée Anthelme). "Field and current induced magnetization reversal in patterned Pseudo Spin Valve devices." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39546.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.<br>Includes bibliographical references.<br>The field and current induced magnetization switchings of Pseudo-Spin-Valve (PSV) devices are described in this dissertation. An aligned sequence of three (one optical and two electron-beam) lithographies was used to define the devices and their electrical contacts. The PSV stack comprised a layer of soft ferromagnetic material Ni80oFe20 (NiFe or Py), a non-magnetic spacer layer of Cu, a hard ferromagnetic layer of Co and a capping layer of Au. The current flowed in plane (CIP) and the devices displayed giant magnetoresistance (GMR). Three different shapes were investigated: notched bars, elliptical rings and rhomboidal rings. In the bars, the notches provided strong pinning potential wells for transverse domain walls in the NiFe layer, which, upon cycling an external field, reversed in a step-like fashion, with domain walls nucleating from both ends of the bars, due to strong magnetostatic coupling between both magnetic layers. Additional important magnetostatic coupling effects were measured and micromagnetic simulations confirmed the ubiquity of such coupling. Current induced magnetic switching (CIMS) experiments were conducted, and threshold densities of the order of 1011 A/m2 were used to switch the magnetization under an external bias field, and the critical current decreased with increasing bias.<br>(cont.) Simulations showed that the Oersted field generated by the current was sufficiently strong to switch the magnetization in the soft NiFe layer, without taking into account spin-transfer torque effects. Ring shaped devices allowed for a diversity of responses depending on the contact configurations used which may be divided into two categories: the classical configurations and the Wheatstone bridge configurations. The latter allowed for large effective GMR ratios up to 200 %, with low switching fields down to a few Oersted. Both types of contact configuration along with micromagnetic simulations enabled a deep understanding of the field-induced reversal of both elliptical and rhomboidal rings. Magnetostatic coupling effects were also found to play a key role. CIMS experiments were conducted, and the rhomboidal ring device successfully switched, in the Wheatstone bridge configuration, under zero bias with a threshold current density of the order of 1011 A/m2. The density and length of current pulses was found to change the critical current density, which suggested that the spin structure of the domain walls in the NiFe layer was modified by the current.<br>by Irénée A. Colin.<br>S.M.
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Mallon, Charlotte Marie. "Managing behaviours that challenge within English care homes : an exploration of current practices." Thesis, University of Kent, 2015. https://kar.kent.ac.uk/54752/.
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Behaviour that challenges in people with dementia is complex and multifactorial; there is no single solution for its management. In 2009 the Department of Health in England called for a reduction in the use of antipsychotics for people with dementia. Instead, individualised non-pharmacological interventions were recommended first-line. The aim of this study was to explore how behaviour that challenges in people with dementia is managed by care homes in England, and how they are managed in practice. The study used a mixed methods approach, incorporating five phases. Interviews were conducted with 41 care staff and managers from 11 care homes in South-East England, alongside observations of the care environment. Pilot interviews from this phase informed the design of a cross-sectional survey, distributed nationally (25.1% response rate). Three care homes participated in an ethnographic study of 12 residents and 17 care staff, involving 204 hours of participant observation. Exploring the use of medicines in each of the three homes sought to investigate the appropriateness of the medicines prescribed and the mechanisms of recording medicines administration. Finally, interviews with residents’ relatives provided an alternative perspective of managing behaviour that challenges in dementia. The findings from this study suggest that there is no one way to manage behaviour that challenges in dementia. Care staff did not believe that one size fits all, and the management of these behaviours changes from day to day and from person to person. Varying strategies were used; however these were not those advocated by practice guidelines, instead involving predominantly distraction and emotional reassurance. The level of antipsychotic use was lower than anticipated, however there was extensive use of other medications which were found to be questionable, indicating that perhaps the problems of managing behaviour that challenges are still present. Finally, relatives of people with dementia have valuable experience and opinion which must not be overlooked by researchers, or care home managers and staff. This thesis provides an important examination of the ways in which behaviours that challenge in people with dementia are managed by care homes in England. It provides a picture of how care is delivered to people with dementia in care homes, particularly during incidents of behaviour that challenges. It has established the ways in which people with dementia are cared for during these incidents, and has exposed that, rather than following current guidelines, knowing the resident, understanding causes of the behaviour, use of the care team and the use of the care environment play a vital role in enabling staff to manage these behaviours.
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McCullough, Cameron. "Application of numerical stochastic differential equations to air and stormwater quality models with comparisons to current modeling methods." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1591607.
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<p>Well known dynamic models for air and stormwater quality typically involve the application of deterministic differential equations (DDEs) or random differential equations (RDEs) that apply Monte Carlo simulation. An alternative to RDEs are stochastic differential equations (SDEs), which are DDEs that incorporate random noise. In this thesis, we develop air and stormwater quality models that employ DDEs, RDEs and SDEs numerically solved by finite difference methods. The numerical results of the model variants are compared to each other and empirical data. The outcome demonstrates the utility of the SDE approach. The stormwater model is based on a one-dimensional advection-diffusion partial differential equation (PDE) that simulates the stream transport of copper in a small area within Los Angeles. Two air models are implemented, an ordinary differential equation model based on the continuity equation and a two-dimensional advection-diffusion PDE. The models approximate carbon monoxide levels in Costa Mesa and the Coachella Valley in California. The numerical PDEs are solved with the Strang splitting method, where the Lax-Wendroff and Crank-Nicolson methods are employed for the advection and diffusion subproblems respectively. For the SDE case the Euler-Maruyama method is applied to the source term subproblem. </p>
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Hunter, Christopher L., Jennifer S. Funderburk, Jodi Polaha, David Bauman, Jeffrey L. Goodie, and Christine M. Hunter. "Primary Care Behavioral Health Model (PCBH) Research: Current State of the Science and a Call to Action." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/6739.
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The Primary Care Behavioral Health (PCBH) model of service delivery is being used increasingly as an effective way to integrate behavioral health services into primary care. Despite its growing popularity, scientifically robust research on the model is lacking. In this article, we provide a qualitative review of published PCBH model research on patient and implementation outcomes. We review common barriers and potential solutions for improving the quantity and quality of PCBH model research, the vital data that need to be collected over the next 10 years, and how to collect those data.
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Poitzsch, Alec Julius. "A high voltage, high current, low error operational amplifier with novel features." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91698.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 173-174).<br>This project details the design and evaluation of an operational amplifier designed in XF40, a 40 Volt bipolar process. Initially the signal path circuitry of the amplifier is outlined. Design decisions are chiefly formed around high voltage and high current drive functionality. A novel topology is introduced which compensates base current errors introduced by the individual stages, resulting in a very low (first-order canceled) overall input-referred voltage offset. Novel features are introduced which expand the functionality of the amplifier. Input stage gm is configurable, allowing for the tuning of amplifier bandwidth for a given gain configuration. A robust current-limiting architecture is implemented which allows for a user-configurable output current limit. When this current limit is reached, the amplifier latches into an alternate mode of operation, protecting the amplifier and the load. We utilize disjoint voltage supply rails at the input and output of the amplifier, substantially minimizing overall power dissipation. The chosen topology permits this feature without the introduction of additional errors. We introduce a "boosting" circuit which extends the large signal bandwidth and slew rate of the amplifier. Amplifier performance is evaluated through simulation in Cadence and ADICE (SPICE). The amplifier is capable of driving 1 Ampere through capacitive and resistive loads. The result is a low distortion amplifier with microvolt-order input-referred offset (VOS), 65 MHz large signal bandwidth, and 3000 V/[mu]s slew rate, powered at 20 mA quiescent current.<br>by Alec Julius Poitzsch.<br>M. Eng.
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Musah, Arthur. "An automated bench testing system for direct current parameters of instrumentation amplifiers." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33328.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.<br>Includes bibliographical references (p. 92-93).<br>Electrical testing is performed at multiple stages in the production of analog integrated circuits (ICs). An efficient system for low-volume IC testing is one that automates bench tests and provides good measurement precision and accuracy, while costing far less than the standard automated test equipment (ATE) used for high-volume manufacturing purposes. This thesis describes the design and implementation of an automated bench system for measuring the important direct current parameters associated with analog instrumentation amplifiers: voltage offset, input bias currents, input offset current, output swing, common mode rejection, power supply rejection, quiescent current and gain error. The system is developed on the PXI platform and consists of measurement and signal generating hardware modules, a Windows-based computer, a resource printed circuit board (PCB), a test-configuration PCB and LabVIEW-based software. The system is versatile and supports the testing of different instrumentation amplifier types and pin- outs. The performance of the system is characterized with respect to ATE results for the Texas Instruments instrumentation amplifier INA 126.<br>by Arthur Musah.<br>M.Eng.
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Martin, Henrik. "Control and current sensing systems for the parallel resonant pole inverter architecture." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/37516.
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Guerrera, Stephen A. (Stephen Angelo). "Highly scaled silicon field emitter arrays with integrated silicon nanowire current limiters." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103725.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 231-241).<br>Field emitter arrays (FEAs) are a promising class of cold electron sources with applications in RF amplifiers, terahertz sources, lithography, imaging, and displays. FEAs are yet to achieve widely implemented because of serious challenges which have limited their viability in systems that require advanced electron sources. We identified four major challenges that posed significant barriers to the application of field emitter arrays in systems. These challenges are (1) charge injection and breakdown of the insulator between the emitter and the extraction gate, (2) thermal runaway due to Joule heating or micro-plasma discharge, (3) back-ion bombardment resulting in emitter tip damage (4) large capacitance between the gate and the substate that limits switching performance. In this thesis, we address these challenges with a new device architecture that consists of a sharp silicon emitter atop a silicon nanowire embedded in a dielectric matrix of SiO₂ and SiNx. The 10-[mu]m tall, 200-nm diameter silicon nanowire limits current and improves reliability through velocity saturation and the pinch-off of majority carriers. The 2-[mu]m thick SiO₂ insulator between the gate and the substrate and the conformal dielectric matrix that embeds the nanowire current limiters prevents charge injection and minimizes the capacitance between the gate and the substrate. Since the nanowire current limiter is fabricated directly underneath each field emitter, we maintain an emitter density of 10⁸ emitters/cm², enabling high current density. The design of the anode prevents tip erosion from back-streaming ions. These arrays demonstrate consistent current scaling of array sizes from a single emitter to 25,000 emitters, low voltage (VGE < 60V), high current density (J > 100 A/cm² ), and long lifetime (t > 100 hours at 100 A/cm² , > 100 hours at 10 A/cm² , and > 300 hours at 100 mA/cm²). The current density enabled by our device structure is an improvement of > 10x over state-of-the art (~~ 1 - 10 A/cm²) for Si field emission cathodes operated in a direct current mode. Our devices demonstrated a turn-on voltage as low as 8.5 V. This low-voltage enabled operation in a 500 Torr He ambient with an anode-emitter voltage below the first ionization potential of He (~ 19 V). These high current, high current density, long lifetime cold cathodes could enable new approaches to x-ray imagers, RF amplifiers, THz sources, and deep UV sources.<br>by Stephen Angelo Guerrera.<br>Ph. D.
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Joung, Sandra K. (Sandra Kyongmee). "Qualification of a medium current ion implantation system in a semiconductor production environment." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40220.
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St, Clair Douglas Milton. "Current streamlining strategies: Restructuring vocational rehabilitation's vision into the twenty-first century." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280009.
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Streamlining is an attempt to make an organizational process increase its efficiency. The 1992 Amendments to the Rehabilitation Act of 1973 defined changes within the service delivery system of the Public State/Federal Vocational Rehabilitation (PS/FVR) Program, that appeared to suggest that streamlining was a new requirement from Congress. However, Congress, Rehabilitation Services Administration (RSA) and/or Council of State Administrators for Vocational Rehabilitation (CSAVR) did not mandate streamlining for the Public State/Federal Vocational Rehabilitation (PS/FVR) Program. Training on streamlining was designated to the Regional Rehabilitation Continuing Education Programs (RRCEP). The RRCEP programs exist in the Rehabilitation Act of 1973 to provide continuing education to employees of the PS/FVR Program, This studies literature review revealed Streamlining has resulted in inconsistent implementation approaches across state agencies and/or federal regions. Currently there is no data and/or consistent approaches to streamlining in the PS/FVR Program. Because of inconsistency in implementing streamlining, the RRCEP's ability to develop appropriate in-service training curriculum that is sensitive to the new needs and issues is jeopardized. The lack of a consistent methodology for streamlining implementation creates problems in planning pre-service academic rehabilitation counseling programs. The study utilized a Chi-Square analysis design due to the small sample size. However, while the sample size was small, the data were global in nature because each number analyzed represents thousands of individual Vocational Rehabilitation (VR) cases. Streamlining was developed to impact the success markers in a positive direction, i.e, clients with severe disabilities would obtain successful employment with higher wages after their employment, an increased number of individuals with severe disabilities would be served, and the VR counselor would spend less money to accomplish the employment goals. Each of the results examining these variables in this study was statistically significant in the states that had implemented streamlining. The study gave support to the premise that streamlining has a positive impact on the vocational rehabilitation process in increased wages for PS/FVR clients, reduced time in service, and decreased case service dollars spent.
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Cabrales, Eusebio Jose. "Assessment of the Current Status of Informatics in Colombia's Universities and Society." Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc278429/.
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This study tries to delineate the paradigms of opinion among Colombian Computer Industrialists with respect to the role of informatics in national development especially (1) their estimation of the performance of the informatics in the modernization process, (2) the perceptions on which this attitude was based, (3) their ability to integrate the informatics instruction into the development process, (4) their ability to establish the need of doctoral programs in informatics into the development process, and (5) their ability to recognize the importance of the network communication as a medium of knowledge exchange among higher education institutions.
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Price, Richard Michael. "Using current uptime to improve failure detection in peer-to-peer networks." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1101/.
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Peer-to-Peer (P2P) networks share computer resources or services through the exchange of information between participating nodes. These nodes form a virtual network overlay by creating a number of connections with one another. Due to the transient nature of nodes within these systems any connection formed should be monitored and maintained to ensure the routing table is kept up-to-date. Typically P2P networks predefine a fixed keep-alive period, a maximum interval in which connected nodes must exchange messages. If no other message has been sent within this interval then keep-alive messages are exchanged to ensure the corresponding node has not left the system. A fixed periodic interval can be viewed as a centralised, static and deterministic mechanism; maintaining overlays in an predictable, reliable and non-adaptive fashion. Several studies have shown that older peers are more likely to remain in the network longer than their short-lived counterparts. Therefore using the distribution of peer session times and the current age of peers as key attributes, we propose three algorithms which allow connections to extend the interval between successive keep-alive messages based upon the likelihood that a corresponding node will remain in the system. By prioritising keep-alive messages to nodes that are more likely to fail, our algorithms reduce the expected delay between failures occurring and their subsequent detection. Using extensively empirical analysis, we analyse the properties of these algorithms and compare them to the standard periodic approach in unstructured and structured network topologies, using tracedriven simulations based upon measured network data. Furthermore we also investigate the effect of nodes that misreport their age upon our adaptive algorithms and detail an efficient keep-alive algorithm that can adapt to the limitations network address translation devices.