scholarly journals C1 and C2 interpolation of orientation data along spatial Pythagorean-hodograph curves using rational adapted spline frames

2018 ◽  
Vol 66 ◽  
pp. 1-15 ◽  
Author(s):  
Hwan Pyo Moon ◽  
Rida T. Farouki
Keyword(s):  
Orientation Data ◽  
Pythagorean Hodograph

scholarly journals Rheological Contrast between Quartz and Coesite Generates Strain Localization in Deeply Subducted Continental Crust

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Kouhei Asano ◽  
Katsuyoshi Michibayashi ◽  
Tomohiro Takebayashi
Keyword(s):  
Rheological Behavior ◽  
Strain Localization ◽  
Shear Zones ◽  
Ultrahigh Pressure ◽  
Ultramafic Rocks ◽  
Crustal Material ◽  
Orientation Data ◽  
Crystallographic Preferred Orientation ◽  
Dabie Shan ◽  
Felsic Rocks

Deformation microstructures of peak metamorphic conditions in ultrahigh-pressure (UHP) metamorphic rocks constrain the rheological behavior of deeply subducted crustal material within a subduction channel. However, studies of such rocks are limited by the overprinting effects of retrograde metamorphism during exhumation. Here, we present the deformation microstructures and crystallographic-preferred orientation data of minerals in UHP rocks from the Dabie–Shan to study the rheological behavior of deeply subducted continental material under UHP conditions. The studied samples preserve deformation microstructures that formed under UHP conditions and can be distinguished into two types: high-strain mafic–ultramafic samples (eclogite and garnet-clinopyroxenite) and low-strain felsic samples (jadeite quartzite). This distinction suggests that felsic rocks are less strained than mafic–ultramafic rocks under UHP conditions. We argue that the phase transition from quartz to coesite in the felsic rocks may explain the microstructural differences between the studied mafic–ultramafic and felsic rock samples. The presence of coesite, which has a higher strength than quartz, may result in an increase in the bulk strength of felsic rocks, leading to strain localization in nearby mafic–ultramafic rocks. The formation of shear zones associated with strain localization under HP/UHP conditions can induce the detachment of subducted crustal material from subducting lithosphere, which is a prerequisite for the exhumation of UHP rocks. These findings suggest that coesite has an important influence on the rheological behavior of crustal material that is subducted to coesite-stable depths.

scholarly journals Dandelion Diagram: Aggregating Positioning and Orientation Data in the Visualization of Classroom Proxemics

2020 ◽  
Author(s):  
Pengcheng An ◽  
Saskia Bakker ◽  
Sara Ordanovski ◽  
Chris L.E. Paffen ◽  
Ruurd Taconis ◽  
...  
Keyword(s):  
Orientation Data

A Simple Algorithm to Eliminate Ambiguities in EBSD Orientation Map Visualization and Analyses: Application to Fatigue Crack-Tips/Wakes in Aluminum Alloys

2010 ◽  
Vol 16 (6) ◽  
pp. 831-841 ◽  
Author(s):  
Vipul K. Gupta ◽  
Sean R. Agnew
Keyword(s):  
Fatigue Crack ◽  
Aluminum Alloys ◽  
Direct Determination ◽  
Simple Algorithm ◽  
Electron Backscattered Diffraction ◽  
Lattice Curvature ◽  
Orientation Data ◽  
Orientation Map ◽  
Crack Tips ◽  
Map Visualization

AbstractA simple algorithm is developed and implemented to eliminate ambiguities, in both statistical analyses of orientation data (e.g., orientation averaging) and electron backscattered diffraction (EBSD) orientation map visualization, caused by symmetrically equivalent orientations and the wrap-around or umklapp effect. Using crystal symmetry operators and the lowest Euclidian-distance criterion, the orientation of each pixel within a grain is redefined. An advantage of this approach is demonstrated for direct determination of the representative orientation of a grain within an EBSD map by mean, median, or quaternion-based averaging methods that can be further used within analyses or visualization of misorientation or geometrically necessary dislocation (GND) density. If one also considers the lattice curvature tensor, five components of the dislocation density tensor—corresponding to a part of the GND content—may be inferred. The methodology developed is illustrated using EBSD orientation data obtained from the fatigue crack-tips/wakes in aerospace aluminum alloys 2024-T351 and 7050-T7451.

DATACON: A quickbasic program to reformat orientation data from faults

1998 ◽  
Vol 24 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Christopher Shorrock ◽  
Richard J. Lisle
Keyword(s):  
Orientation Data

scholarly journals Measurement of motion corrected wind velocity using an aerostat lofted sonic anemometer

2013 ◽  
Vol 6 (1) ◽  
pp. 703-720 ◽  
Author(s):  
W. R. Stevens ◽  
W. Squier ◽  
W. Mitchell ◽  
B. K. Gullett ◽  
C. Pressley
Keyword(s):  
Reference System ◽  
Meteorological Data ◽  
Translational Motion ◽  
Sonic Anemometer ◽  
Wind Data ◽  
Measurement Unit ◽  
Dispersion Modeling ◽  
Plume Dispersion ◽  
Fire Plume ◽  
Orientation Data

Abstract. An aerostat-lofted, sonic anemometer was used to determine instantaneous 3 dimensional wind velocities at altitudes relevant to fire plume dispersion modeling. An integrated GPS, inertial measurement unit, and attitude heading and reference system corrected the wind data for the rotational and translational motion of the anemometer and rotated wind vectors to a global North, West, Up coordinate system. Data were taken at rates of 10 and 20 Hz to adequately correct for motion of the aerostat. The method was applied during a prescribed forest burn. These data were averaged over 15 min intervals and used as inputs for subsequent dispersion modeling. The anemometer's orientation data are demonstrated to be robust for converting the wind vector from the internal anemometer reference system to the global reference system with an average bias between 5 and 7°. Lofted wind data are compared with sonic anemometer data acquired at 10 m on a mast located near the tether point of the aerostat and with local meteorological data.

Geometric Hermite interpolation by spatial Pythagorean-hodograph cubics

2005 ◽  
Vol 22 (4) ◽  
pp. 325-352 ◽  
Author(s):  
Francesca Pelosi ◽  
Rida T. Farouki ◽  
Carla Manni ◽  
Alessandra Sestini
Keyword(s):  
Hermite Interpolation ◽  
Pythagorean Hodograph ◽  
Geometric Hermite Interpolation

scholarly journals Obstacle Avoidance in Groping Locomotion of a Humanoid Robot

10.5772/5783 ◽  
2005 ◽  
Vol 2 (3) ◽  
pp. 26 ◽  
Author(s):  
Hanafiah Yussof ◽  
Mitsuhiro Yamano ◽  
Yasuo Nasu ◽  
Kazuhisa Mitobe ◽  
Masahiro Ohka
Keyword(s):  
Control System ◽  
Obstacle Avoidance ◽  
Force Control ◽  
Humanoid Robot ◽  
Flat Surface ◽  
Rotation Angle ◽  
Basic Research ◽  
Orientation Data ◽  
Robotic Arms ◽  
End Effectors

This paper describes the development of an autonomous obstacle-avoidance method that operates in conjunction with groping locomotion on the humanoid robot Bonten-Maru II. Present studies on groping locomotion consist of basic research in which humanoid robot recognizes its surroundings by touching and groping with its arm on the flat surface of a wall. The robot responds to the surroundings by performing corrections to its orientation and locomotion direction. During groping locomotion, however, the existence of obstacles within the correction area creates the possibility of collisions. The objective of this paper is to develop an autonomous method to avoid obstacles in the correction area by applying suitable algorithms to the humanoid robot's control system. In order to recognize its surroundings, six-axis force sensors were attached to both robotic arms as end effectors for force control. The proposed algorithm refers to the rotation angle of the humanoid robot's leg joints due to trajectory generation. The algorithm relates to the groping locomotion via the measured groping angle and motions of arms. Using Bonten-Maru II, groping experiments were conducted on a wall's surface to obtain wall orientation data. By employing these data, the humanoid robot performed the proposed method autonomously to avoid an obstacle present in the correction area. Results indicate that the humanoid robot can recognize the existence of an obstacle and avoid it by generating suitable trajectories in its legs.

scholarly journals Usability in 4D AR: Visualising Multi-temporal Real-time Geo-data in Augmented Reality Environments

2015 ◽  
Vol 9 (4) ◽  
pp. 23 ◽  
Author(s):  
Bernd Resch ◽  
Andreas Wichmann ◽  
Nicolas Göll
Keyword(s):  
Augmented Reality ◽  
Real Time ◽  
Temporal Variations ◽  
Time Base ◽  
Future Research ◽  
Time Data ◽  
Orientation Data ◽  
Information Density ◽  
Real Time Data ◽  
Multi Temporal

Even though advantages of 3D visualisation of multi-temporal geo-data versus 2D approaches have been widely proven, the particular pertaining challenge of real-time visualisation of geo-data in mobile Digital Earth applications has not been thoroughly tackled so far. In the emerging field of Augmented Reality (AR), research needs comprise finding the optimal information density, the interplay between orientation data in the background and other information layers, using the appropriate graphical variables for display, or selecting real-time base data with adequate quality and suitable spatial accuracy. In this paper we present a concept for integrating real-time data into 4D (three spatial dimensions plus time) AR environments, i.e., data with “high” spatial and temporal variations. We focus on three research challenges: 1.) high-performance integration of real-time data into AR; 2.) usability design in terms of displaying spatio-temporal developments and the interaction with the application; and 3.) design considerations regarding reality vs. virtuality, visualisation complexity and information density. We validated our approach in a prototypical application and extracted several limitations and future research areas including natural feature recognition, the cross-connection of (oftentimes monolithic) AR interface developments and well-established cartographic principles, or fostering the understanding of the temporal context in dynamic 4D Augmented Reality environments.

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