Abstract The tendency to manufacture of semiconductor is to minimize the size of device. With the size was minimized, the number of transistor on the chip was maximized at the same time .However, when the drift region of Power-MOSFET is shorter will result in the Breakdown Voltage is lower, so this do not conform our purpose for application, and therefore we should look for some alternative method to enhance efficiency. One of these method of efficiency promotion is adopting channel strain. We adopt bending silicon substrate to obtain strain. By using this method, we successfully enhance drain current and mobility 12.1% and 4.1% individually. Furthermore, regarding the reliability study, we realize the hot-carrier effect influence under strain silicon. The longer the size(Lg & DL) of Power- MOSFET , the reliability is better. When device were bent under Bending R=40mm and Lg=0.8(m conditions, we can obtain the better reliability of device than flat chip.

Analysis was performed to quantify and compare the reliability of several different notional shipboard DC distribution system topologies in serving their equipment loads. Further, the relationship between the relative placement of loads and generators within a distribution system and the system’s reliability was investigated, resulting in an algorithmically-derived optimal placement configuration in the system topology found to be the most reliable in the initial analysis. Using Markov models and fault-tree analysis, system reliability indices were derived from distribution system component reliability indices, and these values were compared between competing topologies and equipment configurations. A distribution system based on the breaker-and-a-half topology often used in terrestrial utility substations was found to be superior in terms of reliability to the currently-standard ring bus topology. Expected rates of service interruptions to equipment systems served by the breaker-and-a-half system were reduced overall, in some cases dropping dramatically to less than one expected interruption per 10,000 years. This improvement, however, came at the expense of requiring more circuit breakers in the distribution system’s construction. Within this breaker-and-a-half distribution system, an optimal placement of loads and generators was algorithmically derived, which further improved the reliability of the system. This improvement over the base case was marginal, but the optimized placement configuration was able to reduce the expected interruption rate of the ship’s radar system by over 40%. / text

abstract / Civil Engineering / Doctoral / Doctor of Philosophy

Jacket platforms are fixed base offshore structures used to produce oil and gas in relatively shallow waters worldwide. Their pile foundation systems seemed to perform better than what they were designed for during severe hurricanes. This observation has led to a common belief in the offshore oil and gas industry that foundation design is overly conservative. The objective of this research is to provide information to help improve the state of practice in designing and assessing jacket pile foundations to achieve a consistent level of performance and reliability. A platform database consisting of 31 structures was compiled and 13 foundation systems were analyzed using a simplified foundation collapse model, supplemented by a 3-D structural model. The predicted performance for most of the 13 platform foundations is consistent with their observed performance. These cases do not preclude potential conservatism in foundation design because only a small number of platform foundations were analyzed and only one of them actually failed. The potential failure mechanism of a foundation system is an important consideration for its performance in the post-hurricane assessment. Structural factors can be more important than geotechnical factors on foundation system capacity. Prominent structural factors include the presence of well conductors and jacket leg stubs, yield stress of piles and conductors, axial flexibility of piles, rigidity and strength of jackets, and robustness of foundation systems. These factors affect foundation system capacity in a synergistic manner. Sand layers play an important role in the performance of three platform foundations exhibiting the largest discrepancy between predicted and observed performance. Site-specific soil borings are not available in these cases. Higher spatial variability in pile capacity can be expected in alluvial or fluviatile geology with interbedded sands and clays. The uncertainties in base shear and overturning moment in the load are approximately the same and they are slightly higher than the uncertainty in the overturning capacity of a 3-pile foundation system. The uncertainty in the overturning capacity of this foundation system is higher than the uncertainty in shear capacity. These uncertainties affect the reliability of this foundation system. / text

No description available.

No description available.

To be effective, applications such as streaming multimedia require both a more stable and more reliable service than the default best effort service from the underlying computer network. To guarantee steady data transmission despite the unpredictability of the network, a single reserved path for each traffic flow is used. However, a single dedicated path suffers from single link failures. To allow for continuous service inexpensively, unreserved backup paths are used in this thesis. While there are no wasted resources using unreserved backup paths, recovery from a failure may not be perfect. Thus, a goal for this approach is to design algorithms that compute backup paths to mask the failure for all traffic, and failing that, to maximize the number of flows that can be unaffected by the failure. Although algorithms are carefully designed with the goal to provide perfect recovery, when using only unreserved backup paths, re-routing of all affected flows, at the same service quality as before the failure, may not be possible under some conditions, particularly when the network was already fully loaded prior to the failure. Alternate strategies that trade off service quality for continuous traffic flow to minimize the effects of the failure on traffic should be considered. In addition, the actual backup path calculation can be problematic because finding backup paths that can provide good service often requires a large amount of information regarding the traffic present in the network, so much that the overhead can be prohibitive. Thus, algorithms are developed with trade-offs between good performance and communication overhead. In this thesis, a family of algorithms is designed such that as a whole, inexpensive, scalable, and effective performance can be obtained after a failure. Simulations are done to study the trade-offs between performance and scalability and between soft and hard service guarantees. Simulation results show that some algorithms in this thesis yield competitive or better performance even at lower overhead. The more reliable service provided by unreserved backup paths allows for better performance by current applications inexpensively, and provides the groundwork to expand the computer network for future services and applications.

No description available.

The purpose of this study was to investigate the reliability of three different electromyography (EMG) detection systems commonly used to acquire EMG data from the pelvic floor muscles (PFM) at rest, during maximum voluntary contractions (MVCs) and during a coughing task. Twelve nulliparous women between the ages of 24 and 40 participated in the study. EMG data were recorded from each side of the pelvic floor using surface (Femiscan™ and Periform™ vaginal probes), and fine-wire electrodes while subjects performed three repetitions of each task in supine and in standing. RMS amplitudes of baseline and peak PFM activity were computed from the data acquired during the MVC and the coughing tasks. The peak RMS amplitudes from the cough data were also normalized to each subject’s MVC and report as a percent of their maximum voluntary electrical activation (% MVE). Signal to noise ratio (SNR) was calculated for each task. Comparisons were made between the RMS amplitudes and SNR recorded from each side of the PFM. Between-trial and between-day reliability was determined using a variety of measures including intraclass correlation coefficients (ICC), coefficients of variation (CV) and mean absolute difference (MAD). The reliability of the different devices was compared using the MAD normalized to average signal amplitude (nMAD). The results indicated that the EMG data recorded from the right and left sides of the PFM were different, therefore the EMG data acquired from each side of the pelvic floor were analyzed separately. Between-trial reliability assessed by ICC was good for all the devices (left and right average ICC(3,1) = 0.80 – 0.96); the CVs supported these findings (average CV = 12.4 – 17.1%) Between-day reliability was poor and inconsistent across all devices as tasks. When the cough data were normalized however, the between-day RMS amplitudes were very consistent (79.5 – 90.2% MVE). Each device recorded consistent activation amplitudes within a given day. Between-day reliability results indicate that EMG data recorded on separate days with these instruments should not be compared unless data can be normalized. Clinicians and researchers are cautioned to normalize their data if day-to-day comparisons in EMG amplitude are to be made using data recorded with these devices. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2007-12-14 17:31:34.552

No description available.