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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Characterization of Motor Unit Discharge Rate in Patients with Amyotrophic Lateral Sclerosis

Kasi, Patrick K 04 May 2009 (has links)
In this study, we used a custom made quadrifilar needle electrode and multichannel electromyography (EMG) software tool to decompose EMG signals and investigate the behavior of motor unit discharge rate (MUDR) of concurrently active motor units in patients with amyotrophic lateral sclerosis (ALS). Decomposition is a technique used to break down the complex EMG signal into its constituent motor units. A motor unit is a single alpha motor neuron and all the muscle fibers it innervates. ALS is a progressive degenerative disorder of both the upper and lower motor neurons. We recorded four differentially amplified EMG signals from the first dorsal interosseous (FDI) muscle of six ALS patients (four with predominant lower motor neuron pathology and two with predominant upper motor neuron pathology) and seven control subjects. Recordings were made from force contractions of 20 and 50% of maximum voluntary contraction (MVC). All control subjects were between the ages of 40 and 70 years and were examined by a practicing physiatrist for exclusion criteria including neuromuscular disorders or any medications that might affect muscle activity. We observed differences in initial firing rates and variability of active motor units between control subjects and ALS patients. Furthermore we observed differences in firing rates and variability of active motor units between ALS patients with predominant upper motor neuron pathology and ALS patients with predominant lower motor neuron pathology. Initial motor unit firing rates for control subjects were 16.22 +/- 2.06 Hz at 20% MVC and 19.79 +/- 1.66 Hz at 50% MVC. As expected, initial motor unit firing rates from patients with predominant lower motor neuron pathology were higher than those of control subjects; 18.87 +/- 4.73 Hz at 20% MVC and 24.28 +/- 5.01 Hz at 50% MVC. ALS patients with predominant upper motor neuron pathology, as expected, had initial motor unit firing rates that were lower than those observed in control subjects; 9.22 +/- 1.68 Hz at 20% MVC and 12.83 +/- 2.26 Hz at 50% MVC. Motor unit firing rate time series in ALS patients with predominant upper motor neuron pathology showed decreased variability, 0.99 +/- 0.17 Hz at 20% MVC and 1.70 +/- 0.52 Hz at 50% MVC, when compared to control subjects, 2.37 +/- 0.67 at 20% MVC and 4.20 +/- 1.00 at 50% MVC. Variability of motor unit firing rate time series in ALS patients with predominant lower motor neuron were high, 3.38 +/- 1.2 Hz at 20% MVC and 4.07 +/- 1.56 Hz at 50% MVC, compared to control subjects. At 50% MVC, motor unit substitution was observed in ALS patients with predominant upper motor neuron pathology despite the contractions lasting just a few seconds. Motor unit action potentials (MUAPs) recorded from patients were polyphasic when compared to those from control subjects, as is characteristically found in practice.
132

Effects of decomposition on the recoverability of biological fluid evidence

Bemelmans, Elena A. 08 April 2016 (has links)
Several factors that influence the rate of human decomposition have been described in the literature, including temperature, access by insects, humidity and rainfall1. These environmental factors, as well as purge fluid released during decomposition2, can interact with evidence deposited on the clothing of a deceased individual. The present research assessed how these combined factors affect the detection and identification of blood and semen evidence, as well as subsequent DNA analysis. A 35-45 pound (lb) feeder pig (post-mortem interval (PMI) < 3 hours) was placed on a grassy area within the Boston University Outdoor Research Facility for a period of 22 days or 364.3 accumulated degree days (ADD) during late spring, with the temperature averaging 16.5 oC. Aliquots of 30 μl of either human blood or semen were pipetted onto 1 inch by 1 inch sections of a 95% cotton t-shirt. Twenty-two samples of each type were placed on top of and underneath the pig, as well as a similarly weighted bag of sand (control). One bloodstain and one semen stain were collected each day for a period of 22 days from each location, yielding 8 samples per day. Each sample was analyzed within 30 hours of collection. The blood samples beneath the control showed that environmental factors influenced the results of testing. Rain caused dilution and diffusion of the bloodstains and the color of the stains changed from red-brown to green-yellow. Kastle-Meyer (KM) testing was positive for all samples and ABAcard® HemaTrace® testing was positive for 14 of 22 samples, with the negative results occurring during days 12 - 21. Two stains that were negative at 10 minutes turned positive shortly thereafter, suggesting that a longer development time may be required for compromised samples. The blood samples placed beneath the pig yielded positive KM results on all 22 days and positive HemaTrace® results through day 10. All bloodstains placed on top of the pig and control yielded positive KM and HemaTrace® results. The blood samples from on top of the pig and control yielded full short tandem repeat (STR) profiles for each of the four days of testing (days 1, 8, 13 and 20). The blood samples from beneath the pig and control yielded full profiles on day 1 only. The three subsequent days of testing yielded a maximum of three alleles per sample, with the majority of samples failing to provide any profile at all. Semen samples from beneath the control began to show a decrease in fluorescence using an alternate light source (ALS) by day 3, and some areas of fluorescence occurred in a different location, indicating that the soluble components had diffused outward from the original region of deposition (ORD). Results for acid phosphatase (AP) and ABAcard® p-30 were mostly positive through day 16. By day 17, the ORD no longer fluoresced or yielded positive AP or p-30 results. With the exception of day 10, sperm were identified on all samples. Semen results from beneath the pig showed that even on day 1, the ORD was only weakly fluorescent and by day 4, fluorescent regions began appearing outside of the ORD. These outlying regions of fluorescence yielded positive results with AP Spot and p-30 testing, but showed few or no spermatozoa when examined microscopically. As the days passed, the ORD were no longer fluorescent and AP mapping and p-30 testing yielded negative results; however, spermatozoa could still be identified in almost all of the ORD through day 22. Semen samples collected from on top of the control showed that semen stains retained fluorescence and tested positive for AP, spermatozoa and p-30 through 22 days of testing. Semen samples collected from on top of the pig yielded similar results until day 16, when the fluorescence began to fade and AP testing did not yield traditional color changes associated with a positive result. By day 18, fluorescence was no longer visible with an ALS at 450 nm or 495 nm, however, UV light yielded positive fluorescence when used during days 19-21. Spermatozoa and p-30 were identified on samples saturated with products of decomposition, even when presumptive screening techniques were negative (450-495 nm) or showed an altered appearance (AP). Semen samples from within the ORD yielded full 16 loci profiles from beneath the pig and both on top of and beneath the control on each of the four days of testing. The samples collected from on top of the pig yielded full profiles on days 1, 6 and 14 and partial profiles on day 20. Samples from beneath the pig on days 6 and 14, which had positive presumptive results outside of the ORD, were also amplified, but failed to yield a profile.
133

Filtering tools in financial market trading: from moving average to empirical mode decomposition.

January 2012 (has links)
技術分析包括圖表分析和技術指標分析。比較兩者,前者偏於主觀,並且解讀方式不一,而後者卻能用科學方法來考量。本研究論文先分析市場上流行的技術指標,移動平均線。交易員觀測兩條不同日數的移動平均線,從兩線相交處尋找進出市場的時機。從領域來看,兩條不同日數的移動平均線之差屬於一種帶通濾波器。本文將解釋帶通濾波器與市場進出規則之間的關係。除了移動平均線這種線性方法,我們同時考慮非線性的訊號處理工具。特別地,本研究採用近代提出的經驗模態分解法,得出類似移動平均線相交法的一種新交易策略。我們將文中提及的方法應用在香港及中國過去五年的股票市場,並給出數值結果以顯其效。 / Technical analysis includes chart pattern reading and stock market indicators. While the former is subjective and open to different interpretations, the latter is quantied in a more scientic way. The moving average, a popular market indicator, will be analyzed in this thesis. Traders monitor the crossovers of two moving averages with different durations to nd market entry timings. From the viewpoint of frequency domain, the difference of two such moving averages is found to be a band-pass filter. The relation between band-pass filter and market entry strategy is explained. Apartfrom linear methods such as the moving average,non linear signal processing tool is also studied. In particular,the modern empirical mode decomposition is applied to derive a new trading strategy similar to the moving average crossover rule. The introduced methods are put to the test in the Hong Kong and Chinese stock markets for the last five years. Numerical results are presented to show the performance of the methods. / Detailed summary in vernacular field only. / Lee, Tsz Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 64-66). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.7 / Chapter 2 --- Linear Filters --- p.11 / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.2 --- Frequency response --- p.13 / Chapter 2.3 --- Recursive filters --- p.16 / Chapter 2.4 --- Convolution theorem --- p.20 / Chapter 3 --- Momentum Indicators --- p.23 / Chapter 3.1 --- Introduction --- p.23 / Chapter 3.2 --- Momentum indicators --- p.24 / Chapter 3.3 --- Crossover of two moving averages --- p.25 / Chapter 3.4 --- MACD and acceleration indicators --- p.27 / Chapter 4 --- Profitability of Momentum Indicators --- p.33 / Chapter 4.1 --- Introduction --- p.33 / Chapter 4.2 --- Trading methodology --- p.34 / Chapter 4.3 --- Evaluating the performance --- p.36 / Chapter 4.4 --- Results of evaluation --- p.39 / Chapter 5 --- Empirical Mode Decomposition --- p.45 / Chapter 5.1 --- Introduction --- p.45 / Chapter 5.2 --- Instantaneous frequency --- p.46 / Chapter 5.3 --- Empirical mode decomposition --- p.47 / Chapter 5.4 --- Trading methodology --- p.50 / Chapter 5.5 --- Results of evaluation --- p.52 / Chapter 6 --- Discussions --- p.57 / Chapter A Descriptive Statistics and Additional Numerical Results --- p.60 / Bibliography --- p.64
134

Product decomposition effects in coal pyrolysis

Lewellen, Philip Charles January 1975 (has links)
Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / Bibliography: leaves 194-198. / by Philip C. Lewellen. / M.S.
135

A domain decomposition method for some partial differential equations with singularities

Cheung, Charissa Chui-yee 01 January 1997 (has links)
No description available.
136

Suitcase concealment: an interdisciplinary analysis of the taphonomic processes and their effect on PMI estimation

Joseph, Amberlee Skylar 12 July 2017 (has links)
In homicide cases, suitcases provide concealment and ease of transport of a body and reduce the likelihood of detection. When estimating a minimum postmortem interval (mPMI), it is necessary to understand the taphonomic processes that occur when a body is concealed within a suitcase. In this study, the experimental carcasses consisted of pig (Sus scrofa Linnaeus) heads concealed within either hard shell or fabric suitcases whereas control pig heads were decomposed naturally. All control pigs heads attracted blowflies (Calliphoridae) immediately and mummified within days, whereas the experimental pigs heads had an oviposition delay of approximately 72 hours and decomposed resulting in skeletonization. Differences in the arthropod species present varied between the experimental and control pigs heads. Temperature comparisons revealed significant (p <0.001) differences between the experimental and control pigs heads. How a corpse decomposes when a suitcase is used for body disposal must be considered when estimating the mPMI.
137

Representation Theoretical Approach to n-Candidate Voting

Clifford, Grant 01 May 2004 (has links)
Voting theory as been explored mathematically since the 1780’s. Many people have tackled parts of it using various tools, and now we shall look at it through the eyes of a representation theorist. Each vote can be thought of as a permutation of the symmetric group, Sn, and a poll is similar to a linear combination of these elements. Specifically, we will focus on translating and generalizing the works of Donald Saari into more algebraic terms to discover not just one space, but a whole isotypic component essential to positional voting.
138

The Hilbert-Huang Transform: theory, applications, development

Barnhart, Bradley Lee 01 December 2011 (has links)
Hilbert-Huang Transform (HHT) is a data analysis tool, first developed in 1998, which can be used to extract the periodic components embedded within oscillatory data. This thesis is dedicated to the understanding, application, and development of this tool. First, the background theory of HHT will be described and compared with other spectral analysis tools. Then, a number of applications will be presented, which demonstrate the capability for HHT to dissect and analyze the periodic components of different oscillatory data. Finally, a new algorithm is presented which expands HHT ability to analyze discontinuous data. The sum result is the creation of a number of useful tools developed from the application of HHT, as well as an improvement of the HHT tool itself.
139

Convex decomposition techniques applied to handlebodies

Ortiz, Marcos A 01 May 2015 (has links)
Contact structures on 3-manifolds are 2-plane fields satisfying a set of conditions. The study of contact structures can be traced back for over two-hundred years, and has been of interest to mathematicians such as Hamilton, Jacobi, Cartan, and Darboux. In the late 1900's, the study of these structures gained momentum as the work of Eliashberg and Bennequin described subtleties in these structures that could be used to find new invariants. In particular, it was discovered that contact structures fell into two classes: tight and overtwisted. While overtwisted contact structures are relatively well understood, tight contact structures remain an area of active research. One area of active study, in particular, is the classification of tight contact structures on 3-manifolds. This began with Eliashberg, who showed that the standard contact structure in real three-dimensional space is unique, and it has been expanded on since. Some major advancements and new techniques were introduced by Kanda, Honda, Etnyre, Kazez, Matić, and others. Convex decomposition theory was one product of these explorations. This technique involves cutting a manifold along convex surfaces (i.e. surfaces arranged in a particular way in relation to the contact structure) and investigating a particular set on these cutting surfaces to say something about the original contact structure. In the cases where the cutting surfaces are fairly nice, in some sense, Honda established a correspondence between information on the cutting surfaces and the tight contact structures supported by the original manifold. In this thesis, convex surface theory is applied to the case of handlebodies with a restricted class of dividing sets. For some cases, classification is achieved, and for others, some interesting patterns arise and are investigated.
140

Expert vs. Novice: Problem Decomposition/Recomposition in Engineering Design

Ting, Song 01 May 2014 (has links)
The purpose of this research was to investigate the differences of using problem decomposition and problem recomposition among dyads of engineering experts, dyads of engineering seniors, and dyads of engineering freshmen. Fifty participants took part in this study. Ten were engineering design experts, 20 were engineering seniors, and 20 were engineering freshmen. Participants worked in dyads to complete an engineering design challenge within an hour. The entire design process was video and audio recorded. After the design session, members participated in a group interview. This study used protocol analysis as the methodology. Video and audio data were transcribed, segmented, and coded. Two coding systems including the FBS ontology and “levels of the problem” were used in this study. A series of statistical techniques were used to analyze data. Interview data and participants’ design sketches also worked as supplemental data to help answer the research questions. By analyzing the quantitative and qualitative data, it was found that students used less problem decomposition and problem recomposoition than engineer experts in engineering design. This result implies that engineering education should place more importance on teaching problem decomposition and problem recomposition. Students were found to spend less cognitive effort when considering the problem as a whole and interactions between subsystems than engineer experts. In addition, students were also found to spend more cognitive effort when considering details of subsystems. These results showed that students tended to use dept-first decomposition and experts tended to use breadth-first decomposition in engineering design. The use of Function (F), Behavior (B), and Structure (S) among engineering experts, engineering seniors, and engineering freshmen was compared on three levels. Level 1 represents designers consider the problem as an integral whole, Level 2 represents designers consider interactions between subsystems, and Level 3 represents designers consider details of subsystems. The results showed that students used more S on Level 1 and 3 but they used less F on Level 1 than engineering experts. The results imply that engineering curriculum should improve the teaching of problem definition in engineering design because students need to understand the problem before solving it.

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