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This study presents an upper bound plastic limit analysis for predicting drag anchor trajectory and load capacity. The shank and fluke of the anchor are idealized as simple plates. The failure mechanism involves the motion of the anchor about a center of rotation, the coordinates of which are systematically optimized to determine the minimum load at the shackle. For a given anchor orientation, the direction of the shackle force is varied to establish a relationship between the magnitude and direction of the shackle load. Coupling this relationship to the Neubecker-Randolph anchor line solution produces a unique solution for the magnitude and orientation of the shackle force. The anchor is then advanced a small increment about the optimum center of rotation and the process is repeated. The upper bound method (UBM) provides a practical means to determine the trajectory of the anchor and the anchor load capacity at any point in the trajectory. To better understand of the anchor behavior, extensive parameter studies were carried out varying the properties of the anchor, anchor line, and soil. The UBM show good agreement with six full-scale tests covering several different anchor types and centrifuge model tests.

In reduced speed zones, where no other cues indicate the need to slow down, drivers sometimes fail to notice the standard Speed Limit sign and may be speeding inadvertently. To help reduce inadvertent speeding, a red border was installed around the Speed Limit sign in seven reduced speed areas and the impacts of the increased conspicuity on speed limit compliance were measured. The general study approach was to collect and compare speed data for a standard sign (before condition) and a red border sign (after condition). The short-term effects of a modified red border sign, which was achieved by replacing the thin black border of the standard sign with a four inch wide red border, were evaluated at four sites. Results of this modified border study indicated that there was a statistically significant reduction in the mean speeds as well as in the 85th percentile speeds for the red border sign conditions, however the reductions were not practically significant. This study also evaluated the effect of using a higher conspicuity sheeting material at two sites. The results indicated that use of higher conspicuity sheeting has some benefits for the standard sign but no additional benefits for the red border sign. The added border study evaluated the long-term effects (approximately nine to eleven months after the treatment) of adding a three inch wide red border to the standard Speed Limit sign at three sites. The results of this study indicated that impacts of the red border treatment increase with passage of time. The mean speeds decreased by 8.1 percent and the percent of vehicles exceeding the speed limit (55 mph) decreased by 21.7 percent. The decreases in speeds were both statistically and practically significant. A comparison of the thesis study with other similar studies found in literature shows comparable benefits of the red border sign with other speed management measures. Based on the results for long-term effects, use of the red border Speed Limit sign is recommended in reduced speed zones where inadvertent speeding is common.

published_or_final_version / Statistics / Master / Master of Philosophy

No description available.

In this thesis, we study time-dependent empirical processes, which extend the classical empirical processes to have a time parameter; for example the empirical process for a sequence of independent stochastic processes {Yi : i ∈ N}: (1) ν_n(t, y) = n^(−1/2 )Sigma[1_(Y i(t)¬<=y) – P(Yi(t) <= y)] from i=1 to n, t ∈ E, y ∈ R. In the case of independent identically distributed samples (that is {Yi(t) : i ∈ N} are iid), Kuelbs et al. (2013) proved a Central Limit Theorem for ν_n(t, y) for a large class of stochastic processes. In Chapter 3, we give a sufficient condition for the weak convergence of the weighted empirical process for iid samples from a uniform process: (2) α_n(t, y) := n^(−1/2 )Sigma[w(y)(1_(X (t)<=y) – y)] from i=1 to n, t ∈ E, y ∈ [0, 1] where {X (t), X1(t), X2(t), • • • } are independent and identically distributed uniform processes (for each t ∈ E, X (t) is uniform on (0, 1)) and w(x) is a “weight” function satisfying some regularity properties. Then we give an example when X (t) := Ft(Bt) : t ∈ E = [1, 2], where Bt is a Brownian motion and Ft is the distribution function of Bt. In Chapter 4, we investigate the weak convergence of the empirical processes for non-iid samples. We consider the weak convergence of the empirical process: (3) β_n(t, y) := n^(−1/2 )Sigma[(1_(Y (t)<=y) – Fi(t,y))] from i=1 to n, t ∈ E ⊂ R, y ∈ R where {Yi(t) : i ∈ N} are independent processes and Fi(t, y) is the distribution function of Yi(t). We also prove that the covariance function of the empirical process for non-iid samples indexed by a uniformly bounded class of functions necessarily uniformly converges to the covariance function of the limiting Gaussian process for a CLT.

No description available.

A Smale space is a chaotic dynamical system with canonical coordinates of contracting and expanding directions. The basic sets for Smale’s Axiom A systems are a key class of examples. R.F. Williams considered the special case where the basic set had a totally disconnected contracting set and a Euclidean expanding one. He provided a construction using inverse limits of such examples and also proved that (under appropriate hyptotheses) all such basic sets arose from this construction. We will be working in the metric setting of Smale spaces, but the goal is to extend Williams’ results by removing all hypotheses on the unstable sets. We give criteria on a stationary inverse limit which ensures the result is a Smale space. We also prove that any irreducible Smale space with totally disconnected local stable sets is obtained through this construction. / Graduate

No description available.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 48-51). Also available in electronic version. Access restricted to campus users.