Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 70 for “"Ground Control"”.
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Applications of Surface and Subsurface Subsidence Theories to Solve Ground Control Problems
The stability of the underground mine openings largely depends on the surrounding ground conditions, such as stress concentrations, geological conditions and support intensities etc. In particular, the ground control stability associated with large movements and deformations of the strata is much …
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Experimental evaluation of polyester grout as a ground control measure in underground mines
… has been used to insure the stability of underground mine openings for more than twenty years. The polyurethane grout, which is currently being used, has a limited range of mechanical properties that restrict its utilization. Polyurethane also poses serious threats to miners' health due to its …
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The Effects of Backfilling on Ground Control and Recovery in Thin-Seam Coal Mining
… deposits are exhausted, methods of underground thin-seam extraction will have to be developed. These methods must be capable of removing coal efficiently and economically. Past experience with highwall mining of thin-seam coal has indicated that recovery rates tend to be lower than in …
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Design and Implementation of a “Ground Control Station” for Autonomous UAV Landing on Moving Targets
… μιας εφαρμογής ενός «Σταθμού Ελέγχου Εδάφους» (Ground Control Station – GCS), η οποία επιτρέπει τόσο τον χειροκίνητο έλεγχο ενός Parrot Anafi drone, όσο και την αυτόνομη προσγείωσή του σε κινούμενο στόχο. Το σύστημα που αναπτύχθηκε χρησιμοποιεί ένα «standard» Parrot Anafi drone, καθώς και ένα …
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Ground control ramifications and economic impact of retreat mining on room and pillar coal mines
… during pillar extraction and hence the cost of ground control also increases. Nevertheless, pillar extraction where possible has many potential advantages such as decreased operating cost, increased utilization of reserves, and extended life of the mine. There are several variables such as …
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A Study of Ground Penetrating Radar Methods in an Underground Stone Mine to Improve Ground Control
… with karst voids in large opening underground mines. Issues include water inrush, structural instability, and engineering uncertainty in these environments. Coupled with the fracturing prevalent in folded sedimentary rocks, karsts are complex and challenging ground control risks. …
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Assessment of geotechnical considerations for ground control and stability at Nkana Synclinorium copper mine Mopani Plc, Zambia.
… license area in Kitwe. The mine has been an underground operation since 1930 when the first shaft was sunk at Central Shaft. Vertical Crater Retreat (CVR) and Sub-Level Curving (SLC) are the main copper ore mining methods used at the mine. Due to increase in mine depth by 137m, from 3510ft to …
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Assessment of geotechnical considerations for ground control and stability at Nkana Synclinorium copper mine Mopani Plc, Zambia.
… license area in Kitwe. The mine has been an underground operation since 1930 when the first shaft was sunk at Central Shaft. Vertical Crater Retreat (CVR) and Sub-Level Curving (SLC) are the main copper ore mining methods used at the mine. Due to increase in mine depth by 137m, from 3510ft to …
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Single digital-photo correction for a GIS application and error analysis
… for a GIS application was investigated by control and test data from digital photos and USGS 1:24,000 topographic maps and by USGS 7.5-minute DEMs of two study areas, Prentiss, North Carolina and Blacksburg, Virginia. The collinearity equations were used to remove geometric errors caused by …
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Effect of in-situ stresses on the stability of coal mine development workings
Among the different types of ground control problems associated with underground coal mining, those related to in-situ stresses are the most common ones affecting the safety of a mining operation. As a result, this has been the focus of many ground control research works done in the recent years. …
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LOW-COST PHOTOGRAMMETRY SYSTEM FOR GEOREFERENCED STRUCTURE FROM MOTION
… UAV-based SFM relies on having a large number of ground control points that were surveyed ahead of time as the main source of geo-referenced data. The deployment and survey of ground control points are time consuming, and sometimes infeasible due to environmental constraints. A better solution is …
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Layout design for interactive zones in longwall multiple seam mining
… developed. The thesis examines the occurrence of ground control problems, and possibilities for improvements in strata control, in a variety of undermining situations. The effects of upper seam loading on undermining operations are invest~gated using physical modelling. Photoelastic stress …
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Model-based guidelines for user-centric satellite control software development
Three persistent common problems in satellite ground control software used by satellite controllers are obsolescence, lack of desired features and flexibilities, and endless software bug fixing. The obsolescence problem occurs when computer and ground equipment hardware become obsolete usually …
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The effects of the pressure arch upon multiple seam mining
… seam and the general economic situation, net on ground control considerations. One of the major ground control mechanisms that must be considered in the design of a mine is the arching of stresses around a previously mined lower seam. This investigation deals with the extent and magnitude of the …
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Interaction effects due to subsidence in multiple seam mining
… ownership, availability and economics, not on ground control considerations. One of the major ground control mechanisms that must be considered in mine design, when contiguous seams have not been extracted in descending order, is subsidence. This investigation examines the affects of subsidence …
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Applications of Close-Range Terrestrial 3D Photogrammetry to Improve Safety in Underground Stone Mines
The underground limestone mining industry is a small, but growing segment of the U.S. crushed stone industry. However, its fatality rate has been amongst the highest of the mining sector in recent years due to ground control issues related to ground collapses. It is therefore important to improve …
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Securing a UAV Using Features from an EEG Signal
… the UAVs (Unmanned aerial vehicles) and the ground control station. UAVs have attracted both commercial and military organizations in recent years. The progress in this field has reached significant popularity, and the research has incorporated different areas from the scientific domain. UAV …
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Pillar design for St. Peter sandstone formation
… is to: (1) elucidate factors contributing to ground control problems in St. Peter Sandstone mines; (2) derive a pillar design method for St. Peter Sandstone using numerical modeling; and (3) investigate the mechanics of “pinch out” failure in St. Peter Sandstone. The study found that the …
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Design of the control systems operations for the Iridium satellite system
… links. These satellites are monitored and controlled by ground control facilities for approximately 6 years ( the estimated life of the vehicles) and are then replaced. The ground control facilities are required to provide software upgrades, monitor the health of the vehicles, remove a …
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Validation of a Commercial Ultrasonic Real-Time Location System for Providing Position Constraints in Low-Cost Indoor Photogrammetric Reconstruction
… digital models without relying on extensive ground control point (GCP) networks or specialized surveying expertise. This research investigates whether commercial ultrasonic real-time location systems (RTLS) can provide sufficiently accurate camera position constraints to eliminate GCPs in …
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