scholarly journals An Information System for a Bauxite Mine

10.28945/3062 ◽  
2007 ◽  
Author(s):  
Jim Everett
Keyword(s):  
Information System ◽  
Sodium Carbonate ◽  
Random Error ◽  
Processing Plant ◽  
Exploration Drilling ◽  
Systematic And Random Error ◽  
Bauxite Mine

Bauxite is mined and transported by conveyor to a processing plant, screened and washed, then placed into blended stockpiles to feed the alumina refinery. While being stacked to the stockpile, the ore is sampled. Completed stockpiles must be acceptably close to target grade (composition), not only in alumina, but also in residual silica, carbon and sodium carbonate. The mine is an open-cut pit. Each day the choice of ore to mine, from multiple locations in the pit, is based upon estimates of grade. Estimated grade, from exploration drilling of the area before mining, has both systematic and random error. This paper describes an information system to guide the daily choice of ore to mine. Continually updating the comparison between forecasts and sampled product, the system provides adjusted forecasts. Ore is selected to bring the exponentially smoothed grade to target, in each of the control minerals.

scholarly journals VACUUM AND THERMOPLASTIC MOULD-BASED IMMOBILIZATION SYSTEMS USED IN PATIENT UNDERGOING PELVIC RADIATION THERAPY: A COMPARATIVE STUDY

2020 ◽  
pp. 8-10
Author(s):  
Mayuresh Virkar ◽  
N Arul Kumar ◽  
Pranav Chadha ◽  
Reuben Jake Rodrigues ◽  
Anup Kharde
Keyword(s):  
Random Error ◽  
Target Lesion ◽  
Treatment Session ◽  
Cone Beam ◽  
Pelvic Radiotherapy ◽  
Setup Errors ◽  
Lesion Location ◽  
Significant Difference ◽  
Added Benefit ◽  
Systematic And Random Error

Introduction: The aim of the present study was to compare two immobilization systems for comparison of setup errors in targeted radiotherapy. Methods: Retrospective analysis was done for the patients undergoing radiotherapy from May 2012 to December 2018 at our institution. Immobilization was performed on 30 patients sessions (Vacuum cushion i.e., Vac-Lok™ = 15; Thermoplastic mould i.e., Pelvicast pelvic masks = 15). A total of 763 cone-beams were analysed. The target lesion location was verified by cone-beam computed tomography (CBCT) prior to each session, with displacements assessed by CBCT simulation prior to each treatment session. Systematic setup errors, random setup errors, isocenter deviations in the Medio-lateral (ML), Supero-inferior (SI), Antero-posterior (AP), Rotation (yaw) directions of the patient position was calculated. Results: On comparing the Vac-Lok™ and Pelvicast pelvic masks group with respect to Systematic and random error in the lateral, longitudinal, vertical and YAW direction, no statistically significant difference was seen except the random error in YAW direction (P=0.037, Unpaired t-test). There was no difference observed in comparing the isocentric deviation. Conclusion: It was inferred and concluded that using a vacuum cushion for pelvic radiotherapy provides no added benefit compared to using a thermoplastic mould. Thermoplastic mould is recommended for patients receiving pelvic radiotherapy to improve overall reproducibility.Keywords: Rotational therapy; Radiotherapy; Systematic, random error; Thermoplastic mould; Vacuum cushion.

TARDIS: A COMPUTER MODEL TO PREDICT FUTURE GAS SUPPLY

1989 ◽  
Vol 29 (1) ◽  
pp. 41
Author(s):  
I.W. Northcott ◽  
R.C.M. McDonough
Keyword(s):  
Production Scheduling ◽  
South Australia ◽  
Field Size ◽  
Processing Plant ◽  
Mandatory Requirement ◽  
Liquid Products ◽  
On Line ◽  
Exploration Drilling ◽  
Gas Market ◽  
Gas Supply

Because much of South Australia's electricity is gas- generated the future supply of gas from the Cooper Basin is the central issue in the state's energy planning. Available proven reserves of gas are only sufficient to meet the state's demand until the early 1990s.The TARDIS computer program has therefore been written to enable production scheduling of proved and probable gas reserves and, by using historically derived discovery- rate algorithms, to calculate the exploration- drilling effort necessary to meet future gas supply requirements.The mandatory requirement was that the program should complete a simulation within several minutes. This necessitated the decomposition of complex engineering procedures to a simple level without unacceptable loss of accuracy.TARDIS simulates a network of discovered and undiscovered fields which may be allocated to four zones. The fields supply a defined gas market via a processing plant. Appraisal drilling in zones one and three converts estimates of possible gas- in- place into the proved and probable category after allowance for risk. Exploration drilling in zones two and four predicts the discovery of additional reserves using an algorithm, calibrated by historical data, based on the observation that field size decreases as cumulative drilling effort increases.Fields are scheduled in development priority and sufficient fields are brought on line to satisfy a defined gas market. The required number of on- line fields is determined by the cumulative field deliverability and the peak day gas demand. As each field comes on line development wells are drilled until the field is fully developed.A processing plant is simulated to produce sales gas which is within the required specification for chemical composition. The quantity of each of the ancillary gaseous and liquid products is also computed.Data entry and graphical display of results is processed with a spreadsheet and the program runs on a personal computer.TARDIS enables an assessment of whether the current and forecast drilling effort is likely to discover sufficient reserves to satisfy the market. It has proved an invaluable tool in investigating future gas- supply options for South Australia.

scholarly journals Systematic and random error components in satellite precipitation data sets

2012 ◽  
Vol 39 (9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Amir AghaKouchak ◽  
Ali Mehran ◽  
Hamidreza Norouzi ◽  
Ali Behrangi
Keyword(s):  
Random Error ◽  
Data Sets ◽  
Precipitation Data ◽  
Satellite Precipitation ◽  
Error Components ◽  
Systematic And Random Error
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