389 research outputs found
NMESys: An expert system for network fault detection
The problem of network management is becoming an increasingly difficult and challenging task. It is very common today to find heterogeneous networks consisting of many different types of computers, operating systems, and protocols. The complexity of implementing a network with this many components is difficult enough, while the maintenance of such a network is an even larger problem. A prototype network management expert system, NMESys, implemented in the C Language Integrated Production System (CLIPS). NMESys concentrates on solving some of the critical problems encountered in managing a large network. The major goal of NMESys is to provide a network operator with an expert system tool to quickly and accurately detect hard failures, potential failures, and to minimize or eliminate user down time in a large network
Viscid-inviscid interaction associated with incompressible flow past wedges at high Reynolds number
An analytical method is suggested for the study of the viscid inviscid interaction associated with incompressible flow past wedges with arbitrary angles. It is shown that the determination of the nearly constant pressure (base pressure) prevailing within the near wake is really the heart of the problem, and the pressure can only be established from these interactive considerations. The basic free streamline flow field is established through two discrete parameters which adequately describe the inviscid flow around the body and the wake. The viscous flow processes such as the boundary layer buildup, turbulent jet mixing, and recompression are individually analyzed and attached to the inviscid flow in the sense of the boundary layer concept. The interaction between the viscous and inviscid streams is properly displayed by the fact that the aforementioned discrete parameters needed for the inviscid flow are determined by the viscous flow condition at the point of reattachment. It is found that the reattachment point behaves as a saddle point singularity for the system of equations describing the recompressive viscous flow processes, and this behavior is exploited for the establishment of the overall flow field. Detailed results such as the base pressure, pressure distributions on the wedge, and the geometry of the wake are determined as functions of the wedge angle
Sablefish after the individual fishing quota program: an international economic market model
Thesis (M.S.) University of Alaska Fairbanks, 2015Sablefish (Anoplopoma fimbria) are distributed from Baja California to western Japan. Alaska is the world's principal supplier of sablefish with the majority of commercial landings occurring in the Gulf of Alaska and the Aleutian Islands. This demersal, long-lived fish is harvested in one of Alaska's highest valued commercial fisheries, primarily with fixed gear. The total value of the sablefish fishery is comparable to that of the Pacific halibut fishery, which is managed under the similar programs such as the federal IFQ program and various state programs. Although sablefish came to be managed under IFQs at the same time as halibut, the outcomes of IFQ implementation in this fishery have not received as much as attention as in the halibut fishery. Even twenty years after IFQ implementation, there is little published research on the impacts of IFQs on prices and revenues for sablefish. In this thesis project, I have described the various sablefish fisheries within Alaska and the international market conditions. A simultaneous equation market model for sablefish is developed to examine linkages between harvests, prices and revenues. The model is then used to examine the Alaska exvessel price and revenue effects that result from changes in landings, changes resulting from the implementation of the IFQs and changes to the Japanese economy
Know Your Victim: A Key to Prosecuting Human Trafficking Offenses
Article published in the Michigan State University School of Law Student Scholarship Collection
Understanding Hydraulic Fracture Growth, Effectiveness, and Safety Through Microseismic Monitoring
Protecting Women and Girls from Human Trafficking in the Democratic Republic of Congo: Toward Justice for Victims of Gender-Based Violence
Article published in the Michigan State International Law Review
The effect of base connection geometry on the fatigue performance of welded socket connections in multi-sided highmast lighting towers
Seismic imaging of hydraulically-stimulated fractures: A numerical study of the effect of the source mechanism
We present a numerical study of seismic imaging of hydraulically stimulated fractures using a single source from an adjacent fracturing-process. The source is either a point force generated from the perforation of the casing of the well or a double-couple as is typically observed from the induced microseismicity. We assume that the fracture is sufficiently stimulated to be imaged by reflected seismic energy. We show for a specific monitoring geometry of hydrofracturing that not only different waves (P and S) but also different source mechanisms from the same region form an image of different parts of the target fracture and thus add complementary information. The strategy presented here might be used as an additional monitoring tool of the hydrofracturing process
Full-waveform Based Microseismic Source Mechanism Studies in the Barnett Shale: Linking Microseismicity to Reservoir Geomechanics
Microseismic moment tensor (MT) contains important information on the reservoir and fracturing mechanisms. Difficulties arise when attempting to retrieve complete MT with conventional amplitude inversion methods if only one well is available. With the full-waveform approach, near-field information and non-direct waves (i.e. refracted/reflected waves) help stabilize the inversion and retrieve complete MT from the single-well dataset. However, for events which are at far field from the monitoring well, a multiple-well dataset is required. In this study, we perform the inversion with a dual-array dataset from a hydrofracture stimulation in the Barnett shale. Determining source mechanisms from the inverted MTs requires the use of a source model, which in this paper is the tensile earthquake model. The tensile model could describe the source more adequately and predict non-DC components. The source information derived includes the fault plane solution (FPS), slip direction, Vp/Vs ratio in the focal area and seismic moment. The primary challenge of extracting source parameters from MT is to distinguish the fracture plane from auxiliary plane. We analyze the microseismicity using geomechanics and use the insights gained from geomechanical analysis to determine the fracture plane. Furthermore, we investigate the significance of non-DC components by F-test. We also study the influence of velocity model errors, event mislocations and data noise using synthetic data. The results of source mechanism analysis are presented for the events with good signal-to-noise ratios (SNRs). Some events have fracture planes with similar orientations to natural fractures delineated by core analysis, suggesting reactivation of natural fractures. Other events occur as predominantly tensile events along the unperturbed maximum horizontal principal stress (SHmax) direction, indicating an opening mode failure on hydraulic fractures. Microseismic source mechanisms not only reveal important information about fracturing mechanisms, but also allow fracture characterization away from the wellbore, providing critical constraints for understanding fractured reservoirs.Halliburton Compan
Protecting Women and Girls from Human Trafficking in the Democratic Republic of Congo: Toward Justice for Victims of Gender-Based Violence
Article published in the Michigan State International Law Review
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