Extracting Straight Lines from Building Image Based on Edge Orientation Image

2010 ◽  
Vol 30 (10) ◽  
pp. 2904-2910 ◽  
Author(s):  
丁伟利 Ding Weili ◽  
王文锋 Wang Wenfeng ◽  
张旭光 Zhang Xuguang ◽  
苏连成 Su Liancheng
Author(s):  
Joseph J. Comer

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.


1979 ◽  
Vol 7 (1) ◽  
pp. 31-39
Author(s):  
G. S. Ludwig ◽  
F. C. Brenner

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.


2019 ◽  
Vol 2019 (12) ◽  
pp. 209-1-209-6
Author(s):  
Alfredo Restrepo ◽  
Julian Quiroga

2020 ◽  
Vol 634 ◽  
pp. A26 ◽  
Author(s):  
L. S. Pilyugin ◽  
E. K. Grebel ◽  
I. A. Zinchenko ◽  
J. M. Vílchez ◽  
F. Sakhibov ◽  
...  

We derive the photometric, kinematic, and abundance characteristics of 18 star-forming MaNGA galaxies with fairly regular velocity fields and surface brightness distributions and with a large offset between the measured position angles of the major kinematic and photometric axes, ΔPA ≳ 20°. The aim is to examine if there is any other distinctive characteristic common to these galaxies. We found morphological signs of interaction in some (in 11 out of 18) but not in all galaxies. The observed velocity fields show a large variety; the maps of the isovelocities vary from an hourglass-like appearance to a set of straight lines. The position angles of the major kinematic axes of the stellar and gas rotations are close to each other. The values of the central oxygen abundance, radial abundance gradient, and star formation rate are distributed within the intervals defined by galaxies with small (no) ΔPA of similar mass. Thus, we do not find any specific characteristic common to all galaxies with large ΔPA. Instead, the properties of these galaxies are similar to those of galaxies with small (no) ΔPA. This suggests that either the reason responsible for the large ΔPA does not influence other characteristics or the galaxies with large ΔPA do not share a common origin, they can, instead, originate through different channels.


2021 ◽  
Vol 11 (12) ◽  
pp. 5722
Author(s):  
Stefania Lucantonio ◽  
Andrea Di Giuliano ◽  
Katia Gallucci

The European research project CLARA (chemical looping gasification for sustainable production of biofuels, G.A. 817841) investigated chemical looping gasification of wheat straw pellets. This work focuses on pretreatments for this residual biomass, i.e., torrefaction and torrefaction-washing. Devolatilizations of individual pellets were performed in a laboratory-scale fluidized bed made of sand, at 700, 800, and 900 °C, to quantify and analyze the syngas released from differently pretreated biomasses; experimental data were assessed by integral-average parameters: gas yield, H2/CO molar ratio, and carbon conversion. A new analysis of devolatilization data was performed, based on information from instantaneous peaks of released syngas, by simple regressions with straight lines. For all biomasses, the increase of devolatilization temperature between 700 and 900 °C enhanced the thermochemical conversion in terms of gas yield, carbon conversion, and H2/CO ratio in the syngas. Regarding pretreatments, the main evidence is the general improvement of syngas quality (i.e., composition) and quantity, compared to those of untreated pellets; only slighter differentiations were observed concerning different pretreatments, mainly thanks to peak quantities, which highlighted an improvement of the H2/CO molar ratio in correlation with increased torrefaction temperature from 250 to 270 °C. The proposed methods emerged as suitable straightforward tools to investigate the behavior of biomasses and the effects of process parameters and biomass nature.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Gang Yu

In structural dynamic analysis, the blind source separation (BSS) technique has been accepted as one of the most effective ways for modal identification, in which how to extract the modal parameters using very limited sensors is a highly challenging task in this field. In this paper, we first review the drawbacks of the conventional BSS methods and then propose a novel underdetermined BSS method for addressing the modal identification with limited sensors. The proposed method is established on the clustering features of time-frequency (TF) transform of modal response signals. This study finds that the TF energy belonging to different monotone modals can cluster into distinct straight lines. Meanwhile, we provide the detailed theorem to explain the clustering features. Moreover, the TF coefficients of each modal are employed to reconstruct all monotone signals, which can benefit to individually identify the modal parameters. In experimental validations, two experimental validations demonstrate the effectiveness of the proposed method.


2004 ◽  
Author(s):  
Jeroen A. P. Tegenbosch ◽  
Paul M. Hofman ◽  
Marco K. Bosma

2014 ◽  
Vol 11 (97) ◽  
pp. 20140320 ◽  
Author(s):  
Gabriel Rosser ◽  
Ruth E. Baker ◽  
Judith P. Armitage ◽  
Alexander G. Fletcher

Most free-swimming bacteria move in approximately straight lines, interspersed with random reorientation phases. A key open question concerns varying mechanisms by which reorientation occurs. We combine mathematical modelling with analysis of a large tracking dataset to study the poorly understood reorientation mechanism in the monoflagellate species Rhodobacter sphaeroides . The flagellum on this species rotates counterclockwise to propel the bacterium, periodically ceasing rotation to enable reorientation. When rotation restarts the cell body usually points in a new direction. It has been assumed that the new direction is simply the result of Brownian rotation. We consider three variants of a self-propelled particle model of bacterial motility. The first considers rotational diffusion only, corresponding to a non-chemotactic mutant strain. Two further models incorporate stochastic reorientations, describing ‘run-and-tumble’ motility. We derive expressions for key summary statistics and simulate each model using a stochastic computational algorithm. We also discuss the effect of cell geometry on rotational diffusion. Working with a previously published tracking dataset, we compare predictions of the models with data on individual stopping events in R. sphaeroides . This provides strong evidence that this species undergoes some form of active reorientation rather than simple reorientation by Brownian rotation.


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