No description available.

No description available.

Properly accounting for the uncertainties in predicting ground motion parameters is critical for Probabilistic Seismic Hazard Analyses (PSHA). This is particularly important for critical facilities that are designed for long return period motions. Non-ergodic PSHA is a framework that allows for this proper accounting of uncertainties. This, in turn, allows for more informed decisions by designers, owners and regulating agencies. The ergodic assumption implies that the standard deviation applicable to a specific source-path-site combination is equal to the standard deviation estimated using a database with multiple source-path-site combinations. The removal of the ergodic assumption requires dense instrumental networks operating in seismically active zones so that a sufficient number of recordings are made. Only recently, with the advent of networks such as the Japanese KiK-net network has this become possible. This study contributes to the state of the art in earthquake engineering and engineering seismology in general and in non-ergodic seismic hazard analysis in particular. The study is divided in for parts. First, an automated protocol was developed and implemented to process a large database of strong ground motions for GMPE development. A comparison was conducted between the common records in the database processed within this study and other studies. The comparison showed the viability of using the automated algorithm to process strong ground motions. On the other hand, the automated algorithm resulted in narrower usable frequency bandwidths because of the strict criteria adopted for processing the data. Second, an approach to include path-specific attenuation rates in GMPEs was proposed. This approach was applied to a subset of the KiK-net database. The attenuation rates across regions that contains volcanoes was found to be higher than other regions which is in line with the observations of other researchers. Moreover, accounting for the path-specific attenuation rates reduced the aleatoric variability associated with predicting pseudo-spectral accelerations. Third, two GMPEs were developed for active crustal earthquakes in Japan. The two GMPEs followed the ergodic and site-specific formulations, respectively. Finally, a comprehensive residual analysis was conducted to find potential biases in the residuals and propose models to predict some components of variability as a function of some input parameters. / Ph. D.

The thesis presents a two pronged approach for predicting aerodynamics of air- foils/wings in the vicinity of the ground. The first approach is effectively a model for ground effect studies, employing an inexpensive Discrete Vortex Method for the 2D pre- dictions and the well known Numerical lifting line theory for the 3D predictions. The second one pertains to the dynamic ground effect analysis which employs the state of the art moving mesh methodology based time accurate CFD. In that sense, the thesis deals with two ends of spectrum in the ground effect analysis; one, a model to be used in the concept design phase and the other an advanced CFD tool for analysis. The proposed model for ground effect studies is based on the well known Discrete Vortex Method (DVM). An important aspect of this method is that it employs what is referred to as the Generalized Kutta Joukowski Theorem (GKJ), meant for interaction problems with multiple vortices, for predicting the lift (and drag) within a potential flow framework. After ascertaining the correctness of using the GKJ theorem for lift prediction for airfoils in ground effect, a modified DVM is presented as a model for ground effect predictions. As per this model, knowing the free stream lift and drag (either from an ex- periment or from a RANS computation) the aerodynamics of the section in ground effect can be predicted. The model is effectively built by constraining the DVM to produce the reference lift/drag in the free stream. The accuracy of the model, particularly for the more relevant high lift sections used during take-off and landing, is systematically estab- lished for a number of test cases. Knowing the sectional ground effect, the extension to 3D analysis is very simple and this is achieved through the well known Numerical Lifting Line theory. The efficacy of the proposed method for the 3D applications is demonstrated using a high lift wing in ground effect. It is worth noting that the proposed model predicts the lift and drag very accurately, practically at no computational cost as compared to modern RANS based CFD tools requiring over 40 or 50 million volumes at a high computational cost and intense human intervention for generating the grids for every ground clearance. The other aspect of the thesis pertains to what is referred to as the Dynamic Ground Effect. Normally the CFD computations mimic the ground effect experiments in simulat- ing the ground effect. These simulations do not maintain geometric similarity with the actual landing or take-off sequence of the aircrafts and this can only be achieved when the simulations are dynamic. Dynamics is also important in case of combat aircrafts (particularly their naval versions) with an aggressive landing and take-off. The dynamic ground effect simulations also provides a framework for simulating varied gust conditions. This dynamic simulation of the ground effect is accomplished using a novel sinking grid methodology, which allows the grids to sink in the ground as the aircraft approaches the ground along the glide path. These simulations make use of the state of the art, time accurate moving grid methods and therefore can be computationally expensive. Never- theless, the utility of such computations in terms of their ability to produce continuous data has been highlighted in the thesis. In that sense, these dynamic computations will be cheaper as compared to the static simulations to produce data at the same level of resolution.

The objective of this study is to evaluate the regional differences between the worldwide based NGA-W1 ground motion models and available Turkish strong ground motion dataset and make the required adjustments in the NGA-W1 models. A strong motion dataset using parameters consistent with the NGA ground motion models is developed by including strong motion data from Turkey. Average horizontal component ground motion is computed for response spectral values at all available periods using the GMRotI50 definition consistent with the NGA-W1 models. A random-effects regression with a constant term only is used to evaluate the systematic differences in the average level of shaking. Plots of residuals are used to evaluate the differences in the magnitude, distance, and site amplification scaling between the Turkish dataset and the NGA-W1 models. Model residuals indicated that the ground motions are overestimated by all 5 NGA-W1 models significantly, especially for small-to-moderate magnitude earthquakes. Model residuals relative to distance measures plots suggest that NGA-W1 models slightly underestimates the ground motions for rupture distances within 100-200 km range. Models including the aftershocks over-predict the ground motions at stiff soil/engineering rock sites. The misfit between the actual data and model predictions are corrected with adjustments functions for each scaling term. Turkey-Adjusted NGA-W1 models proposed in this study are compatible with the Turkish strong ground motion characteristics and preserve the well-constrained features of the global models. Therefore these models are suitable candidates for ground motion characterization and PSHA studies conducted in Turkey.

No description available.

The objective of this study is to provide an experimental performance assessment of cement borehole plugs subjected to dynamic loadings. This includes the study of dried-out plugs as well as of plugs that have remained wet throughout the testing period. Literature review indicates lack of quantitative data on plug performance under dynamic loading. Nevertheless, it shows that deep underground structures in competent rocks are safer than surface structures, openings at shallow depth, and openings in fractured rocks, when subjected to earthquakes and subsurface blasts. Flow test results indicate that wet cement seals are less permeable than Charcoal granite. Sealing performance is severely degraded when cement seals are allowed to dry. Dye injection tests show that the flow penetrates uniformly through the wet plugs, but occurs only along the plug/rock interface of the dried-out plugs. The permeability of wet and dried-out cement seals does not change significantly after the application of dynamic loads.

“Contributory intent” refers to the situation where, besides the defendant being at fault and causing harm to the plaintiff, the plaintiff also intentionally causes harm to him- or herself. “Contributory intent” can have the effect of either excluding the defendant’s liability (on the ground that the plaintiff's voluntary assumption of risk or intent completely cancels the defendant's negligence and therefore liability), or limiting the defendant’s liability (where both parties intentionally cause the plaintiff's loss thereby resulting in the reduction of the defendant’s liability). Under our law the "contributory intent" of the plaintiff, can either serve as a complete defence in terms of common law or it can serve to limit the defendant's liability in terms of the Apportionment of Damages Act 34 of 1956. The “Apportionment of Loss Bill 2003” which has been prepared to replace the current Act provides for the applicability of “contributory intent” as a defence limiting liability, but it is yet to be promulgated. / Criminal and Procedural Law

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper presents an approach to development of generic ground systems to be used for spacecraft testing and operations. This method makes use of a standard modeling method, which enables virtualization of spacecraft. By virtualizing spacecraft, development of generic systems that are applicable to different spacecraft becomes possible even if spacecraft themselves are not standardized. This is because systems can utilize (1) a standard database that can store information on any virtual spacecraft and (2) standard software tools that can be used for any virtual spacecraft. This paper explains the concept of virtualization of spacecraft, introduces the standard model used for virtualization of spacecraft, shows how to manipulate virtual spacecraft with software tools, and presents the core elements of generic ground systems.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Western Aeronautical Test Range (WATR) Integrated Next Generation System (WINGS) Mission Segment provides data acquisition, processing, display and storage in support of each project’s mission at NASA Dryden Flight Research Center (DFRC). The network architecture for WINGS Mission Segment is responsible for distributing a variety of information from the Telemetry and Radar Acquisition and Processing System (TRAPS), which is responsible for data acquisition and processing, to the Mission Control Centers (MCCs) for display of data to the user. WINGS consists of three TRAPS and four MCCs, where any TRAPS can drive any one or multiple MCCs. This paper will address the requirements for the TRAPS/MCC network and the design solution.