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You searched for subject:(log position). Showing records 1 – 3 of 3 total matches.

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University of Canterbury

1. Satchell, Stuart Dean. Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury.

Degree: Master of Forestry Science, Forestry, 2015, University of Canterbury

This case study investigated profitability of a small stand of fast-grown Eucalyptus nitens in Canterbury for sawn timber production. This stand was pruned and thinned and then harvested at 15 years old. An estimate of per-hectare log yields and diameters was made from the stand. Sample logs were sawn, dried and profiled, then products quantified. Log prices were estimated using the residual value method. Prices were summed for sawn products from each log, from which processing expenses and sawmill profit were deducted for an estimate of log value. In the absence of market prices for sawn E. nitens products empirical estimates of price were derived from market survey data. Predictive models were produced from estimated stand log yields along with predicted product revenues and processing costs from sample logs. These were used for estimating per-hectare log residual values from the case study stand trees. Financial returns to the grower were then calculated as discounted cash flows from the estimated log residual values per hectare, taking into account grower costs along with harvesting and transport costs. Best-practice processing methods were identified from the literature and applied as a productivity benchmark. Methods were developed with the view to standardising data across research efforts that seek to improve grade recoveries for E. nitens. A range of factors were investigated that potentially influenced E. nitens log residual value in this case study, including log diameter and log position. Outcomes included a reasonably favourable return on investment for the grower. However, this depended on a number of factors such as land price, distance from processor, product prices, grading methods, drying methods and level of sawmill profit. The application of contemporary best practice small-scale processing methods indicates that E. nitens has potential as a profitable plantation species for solid timber production.

Subjects/Keywords: Eucalytus; nitens; solid timber; sawn; products; profitability; degrade; residual value; return on investment; economics; case study; flooring; processing; checking; collapse; log position; prices; grading; value; solid timber production

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Satchell, S. D. (2015). Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury. (Masters Thesis). University of Canterbury. Retrieved from http://dx.doi.org/10.26021/1396

Chicago Manual of Style (16th Edition):

Satchell, Stuart Dean. “Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury.” 2015. Masters Thesis, University of Canterbury. Accessed January 15, 2021. http://dx.doi.org/10.26021/1396.

MLA Handbook (7th Edition):

Satchell, Stuart Dean. “Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury.” 2015. Web. 15 Jan 2021.

Vancouver:

Satchell SD. Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury. [Internet] [Masters thesis]. University of Canterbury; 2015. [cited 2021 Jan 15]. Available from: http://dx.doi.org/10.26021/1396.

Council of Science Editors:

Satchell SD. Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury. [Masters Thesis]. University of Canterbury; 2015. Available from: http://dx.doi.org/10.26021/1396

2. Albayrak, Aras. Automatic Pose and Position Estimation by Using Spiral Codes.

Degree: Halmstad Embedded and Intelligent Systems Research (EIS), 2014, Halmstad University

This master thesis is about providing the implementation of synthesis, detection of spiral symbols and estimating the pan/tilt angle and position by using camera calibration. The focus is however on the latter, the estimation of parameters of localization. Spiral symbols are used to be able to give an object an identity as well as to locate it. Due to the spiral symbol´s characteristic shape, we can use the generalized structure tensor (GST) algorithm which is particularly efficient to detect different members of the spiral family. Once we detect spirals, we know the position and identity parameters of the spirals within an apriori known geometric configuration (on a sheet of paper). In turn, this information can be used to estimate the 3D-position and orientation of the object on which spirals are attached using a camera calibration method.   This thesis provides an insight into how automatic detection of spirals attached on a sheet of paper, and from this, automatic deduction of position and pose parameters of the sheet, can be achieved by using a network camera. GST algorithm has an advantage of running the processes of detection of spirals efficiently w.r.t detection performance and computational resources because it uses a spiral image model well adapted to spiral spatial frequency characteristic. We report results on how detection is affected by zoom parameters of the network camera, as well as by the GST parameters; such as filter size. After all spirals centers are located and identified w.r.t. their twist/bending parameter, a flexible technique for camera calibration, proposed by Zhengyou Zhang implemented in Matlab within the present study, is performed. The performance of the position and pose estimation in 3D is reported. The main conclusion is, we have reasonable surface angle estimations for images which were taken by a WLAN network camera in different conditions such as different illumination and different distances. 

Subjects/Keywords: Position Estimation; Pose Estimation; Automatic Pose; Spiral Code; Log-spiral detection

…object that we want to find its pose and position. After detecting image points of log-spiral… …hand. Pose and position estimation of the log-spiral pattern is focused on this flexible… …21 Detection of Log Spiral Codes and Their Synthesis… …24 3.1 3.2 Detection of Log Spiral Codes… …2 1.2 Image of printed nine log-spiral symbols… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Albayrak, A. (2014). Automatic Pose and Position Estimation by Using Spiral Codes. (Thesis). Halmstad University. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-27175

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Albayrak, Aras. “Automatic Pose and Position Estimation by Using Spiral Codes.” 2014. Thesis, Halmstad University. Accessed January 15, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-27175.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Albayrak, Aras. “Automatic Pose and Position Estimation by Using Spiral Codes.” 2014. Web. 15 Jan 2021.

Vancouver:

Albayrak A. Automatic Pose and Position Estimation by Using Spiral Codes. [Internet] [Thesis]. Halmstad University; 2014. [cited 2021 Jan 15]. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-27175.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Albayrak A. Automatic Pose and Position Estimation by Using Spiral Codes. [Thesis]. Halmstad University; 2014. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-27175

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Brigham Young University

3. Hakala, Tim. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.

Degree: PhD, 2006, Brigham Young University

A new method of adaptive impulse control is developed to precisely and quickly control the position of machine components subject to friction. Friction dominates the forces affecting fine positioning dynamics. Friction can depend on payload, velocity, step size, path, initial position, temperature, and other variables. Control problems such as steady-state error and limit cycles often arise when applying conventional control techniques to the position control problem. Studies in the last few decades have shown that impulsive control can produce repeatable displacements as small as ten nanometers without limit cycles or steady-state error in machines subject to dry sliding friction. These displacements are achieved through the application of short duration, high intensity pulses. The relationship between pulse duration and displacement is seldom a simple function. The most dependable practical methods for control are self-tuning; they learn from online experience by adapting an internal control parameter until precise position control is achieved. To date, the best known adaptive pulse control methods adapt a single control parameter. While effective, the single parameter methods suffer from sub-optimal settling times and poor parameter convergence. To improve performance while maintaining the capacity for ultimate precision, a new control method referred to as Adaptive Impulse Control (AIC) has been developed. To better fit the nonlinear relationship between pulses and displacements, AIC adaptively tunes a set of parameters. Each parameter affects a different range of displacements. Online updates depend on the residual control error following each pulse, an estimate of pulse sensitivity, and a learning gain. After an update is calculated, it is distributed among the parameters that were used to calculate the most recent pulse. As the stored relationship converges to the actual relationship of the machine, pulses become more accurate and fewer pulses are needed to reach each desired destination. When fewer pulses are needed, settling time improves and efficiency increases. AIC is experimentally compared to conventional PID control and other adaptive pulse control methods on a rotary system with a position measurement resolution of 16000 encoder counts per revolution of the load wheel. The friction in the test system is nonlinear and irregular with a position dependent break-away torque that varies by a factor of more than 1.8 to 1. AIC is shown to improve settling times by as much as a factor of two when compared to other adaptive pulse control methods while maintaining precise control tolerances.

Subjects/Keywords: control; position; adaptive; impulsive; settling-time; nonlinear friction; pulses; displacements; precise; tolerances; log-spaced; update; distributed; learning; Coulomb; Stribeck; Tomizuka; Yang; AIC; PID; MRAC; STR; RTAI; Linux; FreeBSD; kernel modules; microcontroller; convergence; practical; self-tuning; methods; techniques; limit-cycles; steady-state; error; zero; stable; stability; bound; envelope; partitioned; scheme; lookup-table; multi-point; adaptation; repeatable; mean; servo; motor; exponential; square-law; rise-time; real-time; log-log interpolation; pro-forma; curve-fit; sensitivity; compliance; variable; static; dynamic response; torque; acceleration; velocity; optical encoder; parameters; evolution; fixed-law; enhanced split; weighting; initialization; trajectory; layered processes; Mechanical Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Hakala, T. (2006). Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. (Doctoral Dissertation). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd

Chicago Manual of Style (16th Edition):

Hakala, Tim. “Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.” 2006. Doctoral Dissertation, Brigham Young University. Accessed January 15, 2021. https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd.

MLA Handbook (7th Edition):

Hakala, Tim. “Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control.” 2006. Web. 15 Jan 2021.

Vancouver:

Hakala T. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. [Internet] [Doctoral dissertation]. Brigham Young University; 2006. [cited 2021 Jan 15]. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd.

Council of Science Editors:

Hakala T. Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control. [Doctoral Dissertation]. Brigham Young University; 2006. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2060&context=etd

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