Yabo Xu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 57-60). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Frequent Pattern Mining --- p.1 / Chapter 1.2 --- Biosequence Pattern Mining --- p.2 / Chapter 1.3 --- Organization of the Thesis --- p.4 / Chapter 2 --- PP-Mine: Fast Mining Frequent Patterns In-Memory --- p.5 / Chapter 2.1 --- Background --- p.5 / Chapter 2.2 --- The Overview --- p.6 / Chapter 2.3 --- PP-tree Representations and Its Construction --- p.7 / Chapter 2.4 --- PP-Mine --- p.8 / Chapter 2.5 --- Discussions --- p.14 / Chapter 2.6 --- Performance Study --- p.15 / Chapter 3 --- Fast Biosequence Patterns Mining --- p.20 / Chapter 3.1 --- Background --- p.21 / Chapter 3.1.1 --- Differences in Biosequences --- p.21 / Chapter 3.1.2 --- Mining Sequential Patterns --- p.22 / Chapter 3.1.3 --- Mining Long Patterns --- p.23 / Chapter 3.1.4 --- Related Works in Bioinformatics --- p.23 / Chapter 3.2 --- The Overview --- p.24 / Chapter 3.2.1 --- The Problem --- p.24 / Chapter 3.2.2 --- The Overview of Our Approach --- p.25 / Chapter 3.3 --- The Segment Phase --- p.26 / Chapter 3.3.1 --- Finding Frequent Segments --- p.26 / Chapter 3.3.2 --- The Index-based Querying --- p.27 / Chapter 3.3.3 --- The Compression-based Querying --- p.30 / Chapter 3.4 --- The Pattern Phase --- p.32 / Chapter 3.4.1 --- The Pruning Strategies --- p.34 / Chapter 3.4.2 --- The Querying Strategies --- p.37 / Chapter 3.5 --- Experiment --- p.40 / Chapter 3.5.1 --- Synthetic Data Sets --- p.40 / Chapter 3.5.2 --- Biological Data Sets --- p.46 / Chapter 4 --- Conclusion --- p.55 / Bibliography --- p.60

No description available.

We contribute a quantitative and systematic model to capture etch non-uniformity in deep reactive ion etch of microelectromechanical systems (MEMS) devices. Deep reactive ion etch is commonly used in MEMS fabrication where high-aspect ratio features are to be produced in silicon. It is typical for many supposedly identical devices, perhaps of diameter 10 mm, to be etched simultaneously into one silicon wafer of diameter 150 mm. Etch non-uniformity depends on uneven distributions of ion and neutral species at the wafer level, and on local consumption of those species at the device, or die, level. An ion–neutral synergism model is constructed from data obtained from etching several layouts of differing pattern opening densities. Such a model is used to predict wafer-level variation with an r.m.s. error below 3%. This model is combined with a die-level model, which we have reported previously, on a MEMS layout. The two-level model is shown to enable prediction of both within-die and wafer-scale etch rate variation for arbitrary wafer loadings. / Singapore-MIT Alliance (SMA)

Thesis (Ph.D)--Stanford University, 1999. / Title from pdf t.p. (viewed May 9, 2002). "May 1999." "Adminitrivia V1/Prg/19990528"--Metadata.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 147-155).

This thesis documents the results of high pressure testing of hole-pattern annular gas seals conducted at the Texas A&M University's Turbomachinery Laboratory. The testing conditions were aimed at determining the test seals sensitivity to pressure ratio, inlet fluid preswirl, rotor speed, and rotor to seal clearance. The rotordynamic coefficients showed only small changes resulting from the different pressure ratios tested. Only the damping terms at the lower frequencies showed some influence. One other notable result from the testing of different pressure ratios is that the seals were tested in a choked flow condition, and there was not a significant change in the seal behavior when the seals transitioned to the choked condition. The inlet fluid preswirl only had a notable effect on the cross-coupled stiffness in the larger clearance tests. These results lead to the conclusion that a swirl brake could have some rotordynamic value, but only if the seals have sufficiently large clearance. Conversely this also means that if hole-pattern seals are being implemented with a small clearance, then a swirl brake would not be an effective way to improve the rotordynamic stability of the system. The only significant effect that the rotor speeds had on the rotordynamic coefficients were that the cross-coupled coefficients increased as the rotor speed increased. This is the expected result because as the rotor speed increases there is a greater shear force on the gas as it passes through the seal resulting in more fluid circumferential velocity, which results in stronger cross-coupled coefficients. The changes in clearance resulted in drastic changes in the magnitude of the coefficients. The smaller clearance yielded much higher coefficients than the larger clearance. All of the rotordynamic coefficients were predicted well by ISOTSEAL. The code was found to do a good job predicting the seal leakage as well. This gives more credence to the coefficients and leakage that ISOTSEAL predicts.

Predictions are presented for a selected compressor using longer hole-pattern seals with L/D ratios from 0.5 to 2.5. Results were obtained for back-to-back and in-line compressors with the seal located at mid-span and at 82% of rotor span respectively, considering different seal lengths, radial seal clearances, as well as constant clearance and convergent-tapered seal geometries. Predictions of the synchronous rotordynamic coefficients and leakage were estimated using a code developed by Kleynhans and Childs with zero preswirl and constant pressure ratio of 0.5. This code does not include moment coefficients; which can affect the results. Results of all configurations show an increase of stiffness and damping coefficients with increasing seal length. In addition, a significant reduction in leakage (approximately 47 percent) as L/D increases is exhibited for constant clearance and convergent-tapered hole-pattern seals. For the back-to-back compressor, the stability analysis predicts that the system is stable for all speeds and L/D ratios. In fact, the rotor cylindrical-bending mode becomes more stable with lengthening the seals, for both constant clearance and convergent-tapered hole-pattern seals. For constant clearance seals (Case A), the synchronous response at mid-span show a critical speed at 8,000 rpm (cylindrical-bending mode) for all L/D ratios, while a reduction of 85 percent in the peak response is exhibited as L/D increases. Case B, in which the radial clearance is increased as L/D increases to have the same leakage as case A, slightly increases the synchronous response of the model compared to case A. For convergent-tapered seals (Case C), the synchronous response at mid-span shows a higher critical speed (9,000 rpm) for all L/D ratios, and a larger reduction (89 percent) in peak response with increasing L/D, compared to Case A. However, the magnitude of the peak response is larger for convergent-tapered seals than that for constant clearance seals, for all L/D ratios. For in-line compressor, the stability analysis predicts two critical speeds at 6,000 (conical mode) and 18,000 rpm (first bending mode) respectively. Both modes are predicted to be stable for all speed and L/D ratios. Synchronous response at the mid-span for Case A shows the peak response at the first critical speed is slightly reduced as L/D increases while the response at the second critical speed is increased for most of the cases. In addition, the second critical speed is reduced from 18,000 to 13,000 rpm, which is not a concern because it remains above the running speed. This was also the trend for convergent-tapered hole-pattern seal. In addition, the increase of radial clearance in Case B slightly increases the amplitude of vibration, compared to Case A.

Pecan [Carya illinoinensis (Wangenh.) C. Koch] is a species distributed over an area of varied geographic and climatic variation in the Unites States and Mexico providing a potential for anatomical and physiological adaptation within the cultivars and provenances (i.e., the area of origin of seed). An assessment of leaf anatomical traits of pecan cultivars (Pawnee, Mohawk and Starking Hardy Giant) collected from three locations (Tifton, GA., Chetopa, KS., and Stillwater, OK.) was conducted to provide an understanding of patterns of ecogeographic variation within the natural range. The stomatal density 'Pawnee’ (404 stomata/mm2) was intermediate between that of ‘Mohawk’ (363 stomata/mm2) and ‘Starking Hardy Giant’ (463 stomata/mm2). There were differences among the three pecan cultivars at the same location but there were no differences in stomatal density within the same cultivar grown at three distinct locations. The study suggested that differences in stomatal density in pecans are cultivar-specific rather than being determined by environmental factors. The stability of certain leaf anatomical characteristics, such as stomatal density, for pecan cultivars grown at different locations confirms that these traits can be used for screening provenances with desirable leaf anatomical characteristics for breeding and cultivar development. To achieve the objective of studying anatomical, morphological and physiological traits, Mexican and U.S. provenances grown at the Pecan Genetics and Breeding Program facility in Somerville, Texas were used. The prominent results from the provenance study indicate the presence of intra-specific variation in pecan provenances for the morphological and anatomical traits along the east-west gradient. It is also interesting to note that western provenances displayed the least stomatal density (350 stomata/mm2) while an eastern provenance showed the greatest stomatal density (728 stomata/mm2). This trend may be explained with the gradient in moisture availability from the wetter conditions in the east to the arid conditions in the west in North America. Most of the physiological traits measured did not show any distinct differences between the provenances. There is a great possibility that anatomical traits like stomatal density are genetically controlled to a great extent in pecan in comparison to the physiological traits.

Computer algorithms are routinely used to aid in the identification of biological patterns not easily detected with standard statistics. Currently, observed changes in normal patterns of feeding behavior (FB) are used to identify morbid feedlot cattle. The objective of this study was to use pattern classification techniques to develop algorithms capable of identifying morbid (M) cattle earlier than traditional pen checking methods. In two separate studies, individual feeding behaviour was obtained from 384 feedlot steers (228 ± 22.7 kg, initial BW) in a 226 d trial (model dataset), and 384 feedlot heifers (322 ± 34.7 kg, initial BW) in a 142 d trial (naive dataset). Data was collected using an automated feed bunk monitoring system. FB variables calculated included feeding duration, inter-meal interval (min., max., avg., SD and total; min/d) and feeding frequency (visits/d). Animal health records including the number of times treated, d in the hospital and d on feed were also collected. Ninety-three and 53 morbid (M) animals were identified in each trial respectively, and were categorized into low, moderate and high groups, based on severity of sickness. FB data for 68 cattle from the model dataset (45 classified as Moderate and 25 classified as High) was analyzed to develop an algorithm which would aid in identifying morbid FB. This algorithm was later tested on 18 M animals (12 classified as Moderate and 6 as High) in the naive dataset. The pattern recognition procedure involved reducing data dimensionality via Principal Component Analysis, followed by K-means clustering and finally the development of a binary string to aid in the classification of M feeding behaviour. The developed procedure resulted in an overall classification accuracy of 84 % (82.5 and 85 % accuracy for H and M, respectively) for the model dataset, and 75 % overall (100 and 50 % accuracy for H and M, respectively) for the naive dataset. The model predicted morbidity on average 3.3 and 1.2 d earlier than pen checkers could for each trial respectively. The application of pattern recognition algorithms to FB shows value as a method of identifying morbid cattle in advance of overt physical signs of morbidity.

Computer algorithms are routinely used to aid in the identification of biological patterns not easily detected with standard statistics. Currently, observed changes in normal patterns of feeding behavior (FB) are used to identify morbid feedlot cattle. The objective of this study was to use pattern classification techniques to develop algorithms capable of identifying morbid (M) cattle earlier than traditional pen checking methods. In two separate studies, individual feeding behaviour was obtained from 384 feedlot steers (228 ± 22.7 kg, initial BW) in a 226 d trial (model dataset), and 384 feedlot heifers (322 ± 34.7 kg, initial BW) in a 142 d trial (naive dataset). Data was collected using an automated feed bunk monitoring system. FB variables calculated included feeding duration, inter-meal interval (min., max., avg., SD and total; min/d) and feeding frequency (visits/d). Animal health records including the number of times treated, d in the hospital and d on feed were also collected. Ninety-three and 53 morbid (M) animals were identified in each trial respectively, and were categorized into low, moderate and high groups, based on severity of sickness. FB data for 68 cattle from the model dataset (45 classified as Moderate and 25 classified as High) was analyzed to develop an algorithm which would aid in identifying morbid FB. This algorithm was later tested on 18 M animals (12 classified as Moderate and 6 as High) in the naive dataset. The pattern recognition procedure involved reducing data dimensionality via Principal Component Analysis, followed by K-means clustering and finally the development of a binary string to aid in the classification of M feeding behaviour. The developed procedure resulted in an overall classification accuracy of 84 % (82.5 and 85 % accuracy for H and M, respectively) for the model dataset, and 75 % overall (100 and 50 % accuracy for H and M, respectively) for the naive dataset. The model predicted morbidity on average 3.3 and 1.2 d earlier than pen checkers could for each trial respectively. The application of pattern recognition algorithms to FB shows value as a method of identifying morbid cattle in advance of overt physical signs of morbidity.