scholarly journals Simulation of fragmental rockfalls detected using terrestrial laser scans from rock slopes in south-central British Columbia, Canada

2019 ◽  
Vol 19 (11) ◽  
pp. 2385-2404 ◽  
Author(s):  
Zac Sala ◽  
D. Jean Hutchinson ◽  
Rob Harrap

Abstract. Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Rockfall risk assessment frameworks often involve the determination of rockfall runout in an attempt to understand the likelihood that rockfall debris will reach an element at risk. Rockfall modelling programs which simulate the trajectory of rockfall material are one method commonly used to assess potential runout. This study aims to demonstrate the effectiveness of a rockfall simulation prototype which uses the Unity 3D game engine. The technique is capable of simulating rockfall events comprised of many mobile fragments, a limitation of many industry standard rockfall modelling programs. Five fragmental rockfalls were simulated using the technique, with slope and rockfall geometries constructed from high-resolution terrestrial laser scans. Simulated change detection was produced for each of the events and compared to the actual change detection results for each rockfall as a basis for testing model performance. In each case the simulated change detection results aligned well with the actual observed change in terms of location and magnitude. An example of how the technique could be used to support the design of rockfall catchment ditches is shown. Suggestions are made for future development of the simulation technique with a focus on better informing simulated rockfall fragment size and the timing of fragmentation.

2019 ◽  
Author(s):  
Zac Sala ◽  
D. Jean Hutchinson ◽  
Rob Harrap

Abstract. Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Rockfall risk assessment frameworks often involve the determination of rockfall runout in an attempt to understand the likelihood that rockfall debris will reach an element at risk. Rockfall modelling programs which simulate the trajectory of rockfall material are one method commonly used to assess potential runout. This study aims to demonstrate the effectiveness of a rockfall simulation prototype which uses the Unity3D game engine. The technique is capable of simulating rockfall events comprised of many mobile fragments, a common limitation of available rockfall modelling programs. Five fragmental rockfalls were simulated using the technique, with slope and rockfall geometries constructed from high-resolution terrestrial laser scans. Simulated change detection was produced for each of the events and compared to the actual change detection results for each rockfall as a basis for testing model performance. In each case the simulated change detection results aligned well with the actual observed change in terms of location and magnitude. An example of how the technique could be used to support the design of rockfall catchment ditches is shown. Suggestions are made for future development of the simulation technique with a focus on better informing simulated rockfall fragment size and the timing of fragmentation.


2021 ◽  
Vol 46 (3) ◽  
pp. 40-48
Author(s):  
Magó László ◽  
Kosta Gligorević ◽  
Milan Dražić ◽  
Mićo Oljača

ISO organization (https://www.iso.org) in early 90s defined an industry standard for the communication protocol among electronic devices of different manufacturers of agricultural machines. After that, all of the market actors recognised that this technology would be very important for agricultural electronics. The appearance of ISOBUS products in the market was in the mid-2000s. ISOBUS description could be found in ISO-11783 (https://www.iso.org). Through the standards and the related technical background, the production processes and the operations could be followed and monitored by the extensive Data Management. Farmers' and users legitimate needs and developing goal is to elaborate a decision support systems that follow-up the utilisation of the machines and ensure the quality of operations. For this purpose, it is essential to determine which technical, economical, technological parameters detection, measurement, transmission, processing, and evaluation becomes necessary. In our work, we reviewed which mechanical characteristic, settings are monitored within the ISOBUS system by the major machine manufacturers. We developed the system of parameters and derived features that provide effective farm-, and land-management in case of attached equipment for spreading of input materials, plant protection and tillage implements.


2011 ◽  
Vol 187 ◽  
pp. 411-415
Author(s):  
Lu Yue Xia ◽  
Hai Tian Pan ◽  
Meng Fei Zhou ◽  
Yi Jun Cai ◽  
Xiao Fang Sun

Melt index is the most important parameter in determining the polypropylene grade. Since the lack of proper on-line instruments, its measurement interval and delay are both very long. This makes the quality control quite difficult. A modeling approach based on stacked neural networks is proposed to estimation the polypropylene melt index. Single neural network model generalization capability can be significantly improved by using stacked neural networks model. Proper determination of the stacking weights is essential for good stacked neural networks model performance, so determination of appropriate weights for combining individual networks using the criteria about minimization of sum of absolute prediction error is proposed. Application to real industrial data demonstrates that the polypropylene melt index can be successfully estimated using stacked neural networks. The results obtained demonstrate significant improvements in model accuracy, as a result of using stacked neural networks model, compared to using single neural network model.


2016 ◽  
Vol 73 (8) ◽  
pp. 1202-1212 ◽  
Author(s):  
Jill Crossman ◽  
M. Catherine Eimers ◽  
Shaun A. Watmough ◽  
Martyn N. Futter ◽  
Jason Kerr ◽  
...  

The plausibility of land disturbance as a cause of declining phosphorus (P) concentrations in oligotrophic lakes within south-central Ontario, Canada, is evaluated using the process-based model INCA-P. The model was calibrated upon three catchments in the Muskoka–Haliburton region (MHR): Harp (HP), Dickie (DE), and Plastic (PC), which have varying degrees of declining P export and different forms of historic disturbances (timber harvesting, tree death, and soil acidification, respectively). Hindcasts (1978–2007) were run with and without simulated disturbances. Model performance of both DE and HP was greatly improved when effects of wetland tree deaths (DE) and harvesting (HP) were included. In PC, with no record of timber harvesting and relatively minor declines in P, initial hindcasts successfully accounted for the majority of interannual P fluxes, and performance was only marginally improved through the simulation of soil acidification. Vegetation decay, harvesting, and catchment acidification accounted for 63%, 24%, and 0.6%, respectively, of P export over the past 30 years. Of all disturbances, wetland vegetation death had the highest impact on areal P exports, indicating that riparian stability is particularly important.


1997 ◽  
Vol 64 (1) ◽  
pp. 111-117 ◽  
Author(s):  
M. F. Thomas ◽  
M. H. Oliver ◽  
S. C. Hodgkinson

AbstractThe influence of pre-slaughter nutrition on the potency of foetal serum in cell culture was studied. Ewes carrying late-gestation foetuses (120-day gestation) were either fasted for 66 h (F), fasted for 66 h but drenched with Ketol, a propylene glycol preparation, (5 × 120 ml doses; FK), given food ad libitum (A), or given food ad libitum and drenched with Ketol (5 × 120 ml doses; AK). Following slaughter foetal blood was collected for the determination of potency in cell culture using industry-standard cell culture bioassays: cloning efficiency, plating efficiency and a 96 h cell proliferation assay. Foetal serum insulin-like growth factor (IGF) concentrations were also measured. Pre-slaughter fasting or drenching with Ketol had no effect on the potency of foetal serum in any of the cell culture bioassays. Fasting significantly lowered foetal plasma IGF-1 levels (F < 0·01). Foetal IGF-2 levels were unaffected by fasting or drenching with Ketol.


Author(s):  
Milos Nemcek ◽  
Zdenek Dejl

Nowadays special modified tools are mostly used for rough or semi-finishing milling in the mass production of ground or shaved gears today. These modifications ensure the desired chamfer at the head or the undercut at the bottom of the gear tooth. Diameters of the beginning and the end of the operational involute (exact knowledge of them is necessary for the calculation of important meshing parameters) are found by using several techniques. The first one is the simulation of the generating action of a hob tooth using suitable graphic software with the subsequent measuring of these diameters from the envelope of hob tooth positions which was created. The second one is measuring directly on the gear manufactured using a measuring device. These simulations or measuring are often not performed and the tool with recommended parameters of the protuberance or the ramp is simply chosen by an educated guess [1]. But it is not an acceptable technique in a mass production (car industry). Standard DIN 3960 [2] gives a certain manual for the determination of these diameters. It suggests the iterative method for the calculation of the chamfer beginning circle diameter but without a reliable guideline. And as regards the protuberance, it refers to the correct calculation only in theory. This paper deals with the computing method to determine diameters of the beginning and the end of the function part of a tooth flank involute. It is designed for a specified tool with modifications for creating the chamfer or the protuberance undercut. The paper also takes into account the necessary shaving (grinding) stock or the backlash. Furthermore it refers to possible problems when the basic profile of the generating tool with the protuberance is designed from the basic rack tooth profile.


2013 ◽  
Vol 56 (5) ◽  
pp. 1248-1256 ◽  
Author(s):  
Wen Zhang ◽  
JianPing Chen ◽  
Wu Zhang ◽  
Yan Lü ◽  
YuFei Ma ◽  
...  

2006 ◽  
Vol 131 (6) ◽  
pp. 738-743 ◽  
Author(s):  
Attila Hegedüs ◽  
Zoltán Szabó ◽  
József Nyéki ◽  
Júlia Halász ◽  
Andrzej Pedryc

The most commercially grown peach [Prunus persica (L.) Batsch.] cultivars do not require cross-pollination for reasonable fruit set; however, self-incompatibility is a well-known feature within the Prunoideae subfamily. Isoelectric focusing and native polyacrylamide gel electrophoresis of S-ribonucleases; PCR analyses of S-RNase and S-haplotype-specific F-box genes as well as DNA sequencing were carried out to survey the self-(in)compatibility allele pool and to uncover the nature of self-compatibility in peach. From 25 cultivars and hybrids with considerable diversity in phenotype and origin, only two S-haplotypes were detected. Allele identity could be checked by exact length determination of the PCR-amplified fragments and/or partial sequencing of the peach S1-, S2-, and Prunus davidiana (Carr.) Franch. S1-RNases. S-RNases of peach were detected to possess ribonuclease activity, and a single nucleotide polymorphism in the S1-RNase was shown, which represents a synonymous substitution and does not change the amino acid present at the position in the protein. A 700-bp fragment of the peach SFB gene was PCR-amplified, which is similar to the fragment size of functional Prunus L. SFBs. All data obtained in this study may support the contribution of genes outside the S-locus to the self-compatible phenotype of peaches.


2021 ◽  
Vol 66 (4) ◽  
pp. 217-222
Author(s):  
E. V. Grigorova ◽  
L. V. Rychkova ◽  
N. L. Belkova ◽  
U. M. Nemchenko ◽  
M. V. Savelkaeva ◽  
...  

The level of sensitivity of Klebsiella pneumoniae strains isolated from children of the first half of life with functional gastrointestinal disorders (FGID) to commercial bacteriophage preparations was assessed. The material was the feces of 67 children of the first half of life with FGID who are breastfed. Culture of K. pneumoniae isolated from faeces of children, amounted to two comparison groups, depending on the age of the patients. The first group included 43 K. pneumoniae strains isolated from the colon of children aged from birth to three months, in the second group - 24 strains, from children aged three to six months. The composition of the colon microbiota was studied using standard methods, and the results were evaluated in accordance with Industry Standard 91500.11.0004-2003. Identification of K. pneumoniae was performed by bacteriological methods. Determination of the level of lytic activity of K. pneumoniae, Klebsiella polyvalent and sextaphage bacteriophages to K. pneumoniae strains was conducted by the drip method (spot-test) according to clinical recommendations. It is shown that the formation of FGID symptoms in children correlates with age - the frequency of regurgitation decreased in children up to six months (from 23.3% to 4.2%) against the background of the formation of a symptom complex associated with defecation disorder. Bacteriological analysis showed that in General, phages show a low level of lytic activity, sensitivity to them Klebsiella also correlated with age and was higher in children of three to six months. Thus, in the first comparison group, the absence of Klebsiella lysis in relation to the Klebsiella pneumoniae bacteriophage was registered three times more often (30.2%, p<0.05) and twice less often (30.2%, p<0.05), the low level of lysis of K. pneumoniae strains to the Klebsiella polyvalent phage compared to the second group. The sensitivity of K. pneumoniae strains to sextaphage was comparable in comparison groups and varied from 2 to 10%. Thus, among the studied K. pneumoniae observed a low level of sensitivity to specific drugs - bacteriophage Klebsiella pneumoniae, Klebsiella polyvalent and sextaphage. This fact reflects the insufficient activity of phages and predicts low effectiveness of empirical phage therapy without elimination from the intestinal biocenosis of K. pneumoniae in children with FGID who are breastfed.


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