Prediction of Rock Burst, Squeezing and Support Design using Three-Dimensional and Conventional Methods Along Headrace Tunnel in Balephi, Nepal

Abstract Background Accurate total body surface area burned (TBSAB) estimation is a crucial aspect of early burn management. It helps guide resuscitation and is essential in the calculation of fluid requirements. Conventional methods of estimation can often lead to large discrepancies in burn percentage estimation. We aim to compare a new method of TBSAB estimation using a three-dimensional smart-phone application named 3D Burn Resuscitation (3D Burn) against conventional methods of estimation—Rule of Palm, Rule of Nines and the Lund and Browder chart. Methods Three volunteer subjects were moulaged with simulated burn injuries of 25%, 30% and 35% total body surface area (TBSA), respectively. Various healthcare workers were invited to use both the 3D Burn application as well as the conventional methods stated above to estimate the volunteer subjects’ burn percentages. Results Collective relative estimations across the groups showed that when used, the Rule of Palm, Rule of Nines and the Lund and Browder chart all over-estimated burns area by an average of 10.6%, 19.7%, and 8.3% TBSA, respectively, while the 3D Burn application under-estimated burns by an average of 1.9%. There was a statistically significant difference between the 3D Burn application estimations versus all three other modalities (p < 0.05). Time of using the application was found to be significantly longer than traditional methods of estimation. Conclusions The 3D Burn application, although slower, allowed more accurate TBSAB measurements when compared to conventional methods. The validation study has shown that the 3D Burn application is useful in improving the accuracy of TBSAB measurement. Further studies are warranted, and there are plans to repeat the above study in a different centre overseas as part of a multi-centre study, with a view of progressing to a prospective study that compares the accuracy of the 3D Burn application against conventional methods on actual burn patients.

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Charuco Board-Based Omnidirectional Camera Calibration Method

Electronics ◽

10.3390/electronics7120421 ◽

2018 ◽

Vol 7 (12) ◽

pp. 421 ◽

Cited By ~ 11

Author(s):

Gwon An ◽

Siyeong Lee ◽

Min-Woo Seo ◽

Kugjin Yun ◽

Won-Sik Cheong ◽

...

Keyword(s):

Camera Calibration ◽

Mean Absolute Error ◽

Three Dimensional ◽

Absolute Error ◽

Calibration Method ◽

Feature Points ◽

Omnidirectional Camera ◽

Reprojection Error ◽

Conventional Methods ◽

Better Than

In this paper, we propose a Charuco board-based omnidirectional camera calibration method to solve the problem of conventional methods requiring overly complicated calibration procedures. Specifically, the proposed method can easily and precisely provide two-dimensional and three-dimensional coordinates of patterned feature points by arranging the omnidirectional camera in the Charuco board-based cube structure. Then, using the coordinate information of the feature points, an intrinsic calibration of each camera constituting the omnidirectional camera can be performed by estimating the perspective projection matrix. Furthermore, without an additional calibration structure, an extrinsic calibration of each camera can be performed, even though only part of the calibration structure is included in the captured image. Compared to conventional methods, the proposed method exhibits increased reliability, because it does not require additional adjustments to the mirror angle or the positions of several pattern boards. Moreover, the proposed method calibrates independently, regardless of the number of cameras comprising the omnidirectional camera or the camera rig structure. In the experimental results, for the intrinsic parameters, the proposed method yielded an average reprojection error of 0.37 pixels, which was better than that of conventional methods. For the extrinsic parameters, the proposed method had a mean absolute error of 0.90° for rotation displacement and a mean absolute error of 1.32 mm for translation displacement.

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Cryo-EM with sub–1 Å specimen movement

Science ◽

10.1126/science.abb7927 ◽

2020 ◽

Vol 370 (6513) ◽

pp. 223-226 ◽

Cited By ~ 4

Author(s):

Katerina Naydenova ◽

Peipei Jia ◽

Christopher J. Russo

Keyword(s):

Electron Microscopy ◽

Electron Beam ◽

High Speed ◽

Three Dimensional ◽

Water Layer ◽

Information Loss ◽

Particle Movement ◽

Support Design ◽

Quality Movement ◽

Subsequent Deformation

Most information loss in cryogenic electron microscopy (cryo-EM) stems from particle movement during imaging, which remains poorly understood. We show that this movement is caused by buckling and subsequent deformation of the suspended ice, with a threshold that depends directly on the shape of the frozen water layer set by the support foil. We describe a specimen support design that eliminates buckling and reduces electron beam–induced particle movement to less than 1 angstrom. The design allows precise foil tracking during imaging with high-speed detectors, thereby lessening demands on cryostage precision and stability. It includes a maximal density of holes, which increases throughput in automated cryo-EM without degrading data quality. Movement-free imaging allows extrapolation to a three-dimensional map of the specimen at zero electron exposure, before the onset of radiation damage.

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Geo-Stress Measurement and its Application in the Yangchangwan Coal Mine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.353-356.398 ◽

2013 ◽

Vol 353-356 ◽

pp. 398-402

Author(s):

Xiao Yu Zhang ◽

Feng Ming Liu ◽

Gang Chen

Keyword(s):

Stability Analysis ◽

Coal Mine ◽

Basic Parameter ◽

Stress Measurement ◽

Three Dimensional ◽

Stress Relief ◽

Tectonic Stress ◽

Surrounding Rock ◽

Support Design ◽

Rock Stability

The initial stress of rock is a basic parameter, which can be used for surrounding rock stability analysis, exploitation and support design. By utilizing stress relief method of hollow inclusion with its characters of high precision and obtaining three dimensional stress at one time, we have measured three dimensional stress magnitude and direction in north wing roadway (-850m) and 710 open-off cut (-1000m), respectively. The results show that the horizontal tectonic stress is obvious in this coal area.

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Inverse Analysis of Forming Processes Based on FORGE Environment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.611-612.1494 ◽

2014 ◽

Vol 611-612 ◽

pp. 1494-1502 ◽

Cited By ~ 6

Author(s):

Stephane Marie ◽

Richard Ducloux ◽

Patrice Lasne ◽

Julien Barlier ◽

Lionel Fourment

Keyword(s):

Inverse Analysis ◽

Optimization Problems ◽

Three Dimensional ◽

Optimization Method ◽

Transfer Coefficients ◽

Support Design ◽

Finite Element Software ◽

Automatic Optimization ◽

Dimensional Simulation ◽

Constitutive Parameters

In the field of materials forming processes, the use of simulation coupled with optimization is a powerful numerical tool to support design in industry and research. The finite element software Forge®, a reference in the field of the two-dimensional and three-dimensional simulation of forging processes, has been coupled to an automatic optimization engine. The optimization method is based on meta-model assisted evolutionary algorithm. It allows solving complex optimization problems quickly. This paper is dedicated to a specific application of optimization, inverse analysis. In a first stage, a range of reverse analysis applications are considered such as material rheological and tribological characterization, identification of heat transfer coefficients and, finally, the estimation of Time Temperature Transformation curves based on existing Continuous Cooling Transformation diagrams for steel quenching simulation. In a second part, a novel inverse analysis application is presented in the field of cold sheet forming, the identification of the material anisotropic constitutive parameters that allow matching with the final shape of the component after stamping. The advanced numerical methods used in this kind of complex simulations are described along with the obtained optimization results. This article shows that automatic optimization coupled with Forge® can solve many inverse analysis problems and is a valuable tool for supporting development and design of metals forming processes.

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A toolbox for volumetric visualization of light properties

Lighting Research and Technology ◽

10.1177/1477153518822159 ◽

2019 ◽

Vol 51 (6) ◽

pp. 838-857

Author(s):

T Kartashova ◽

H de Ridder ◽

SF te Pas ◽

SC Pont

Keyword(s):

Light Field ◽

Three Dimensional ◽

Complex Problem ◽

Easy Access ◽

Two Dimensional ◽

Web Based ◽

Primary Qualities ◽

Third Stage ◽

Primary Direction ◽

Conventional Methods

In this paper, we introduce a toolbox for the perceptually based visualization of light in a volume, focusing on the visual effects of illumination. First, our visualizations extend the conventional methods from a two-dimensional representation on surfaces to the whole volume of a scene. Second, we extend the conventional methods from showing only light intensity to visualizing three light properties (mean illuminance, primary direction and diffuseness). To make our methods generally available and easily accessible, we provide a web-based tool, to which everybody can upload data, measured by a cubic or simple illuminance meter or even a smartphone-app, and generate a variety of three-dimensional visualizations of the light field. The importance of considering the light field in its full complexity (and thus as a three-dimensional vector field instead of its two-dimensional sections) is widely acknowledged. Our toolbox allows easy access to sophisticated methods for analysing the spatial distribution of light and its primary qualities as well as how they vary throughout space. It is our hope that our results raise interest in ‘third stage’ approaches to lighting research and design, and the toolbox offers a practical solution to this complex problem.

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Virtual Manufacturing Tools in the Product Design Environment

10.1115/imece1999-0172 ◽

1999 ◽

Author(s):

Ronald C. Braun ◽

Warren G. Marx

Keyword(s):

Product Development ◽

Product Design ◽

Three Dimensional ◽

Virtual Manufacturing ◽

Assembly Planning ◽

Shop Floor ◽

Design Environment ◽

Support Design ◽

Simulation Tools ◽

Lean Product Development

Abstract Design and manufacturing modeling and simulation have been identified as important to the principles of lean product development. Early in the product development cycle, the use of three-dimensional (3-D) engineering models allows us to electronically (or virtually) prototype physical products, and conduct product feasibility and producibility studies. Manufacturing issues can be identified early and used to drive the product design toward the lowest cost. This paper describes the Northrop Grumman Corporation (NGC) approach to extending classic prototype simulation to virtual manufacturing (VM) tools that accommodate the visualization of interacting production processes, process planning, scheduling, and assembly planning. Previous simulation tools were limited to the design environment. Our tools not only support design; they also provide functionality by bringing the results to the assembly floor. The use of these tools has resulted in “first-time quality” both above and on the shop floor, with significant reductions in product cost and cycle time.

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Creating Polytope Representations of Design Spaces for Visual Exploration Using Consistency Techniques

Journal of Mechanical Design ◽

10.1115/1.4001528 ◽

2010 ◽

Vol 132 (8) ◽

Cited By ~ 8

Author(s):

Srikanth Devanathan ◽

Karthik Ramani

Keyword(s):

Design Process ◽

Design Space ◽

Parametric Design ◽

Three Dimensional ◽

Visual Exploration ◽

Support Design ◽

Design Exploration ◽

Design Variables ◽

Finite Set ◽

Geometry Problem

Understanding the limits of a design is an important aspect of the design process. When mathematical models are constructed to describe a design concept, the limits are typically expressed as constraints involving the variables of that concept. The set of values for the design variables that do not violate constraints constitute the design space of that concept. In this work, we transform a parametric design problem into a geometry problem thereby enabling computational geometry algorithms to support design exploration. A polytope-based representation is presented to geometrically approximate the design space. The design space is represented as a finite set of (at most) three-dimensional (possibly nonconvex) polytopes, i.e., points, intervals, polygons, and polyhedra. The algorithm for constructing the design space is developed by interpreting constraint-consistency algorithms as computational-geometric operations and consequently extending (3,2)-consistency algorithm for polytope representations. A simple example of a fingernail clipper design is used to illustrate the approach.

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Numerical Simulation of Mining-Induced Stress Evolution and Fault Slip Behavior in Deep Mining

Advances in Materials Science and Engineering ◽

10.1155/2021/8276408 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Zhenhua Jiao ◽

Lei Wang ◽

Ming Zhang ◽

Jiong Wang

Keyword(s):

Rock Burst ◽

Underground Mining ◽

High Stress ◽

Three Dimensional ◽

Elastic Strain Energy ◽

Fault Reactivation ◽

Reverse Fault ◽

Geological Model ◽

Stress Evolution ◽

3D Geological Model

The ground pressure distributes significant variation in underground mining near fault. Fault reactivation is an important factor to induce the rock burst. Therefore, characterizing geological settings in mining areas by the geological information can improve the accuracy of simulation. To investigate the characteristic of mining stress evolution and reactivation of the F16 reverse fault during the retreat Mining-Induced s in Yima coalfield, a three-dimensional digital elevation model based on GIS platform was applied. The 3D geological model includes three working faces, and F16 fault was constructed by AutoCAD software. Then, the 3D geological model was imported into the FLAC3D code to simulate the potential of mining-induced fault reactivation. The simulation results illustrate that the footwall of F16 fault is a high stress concentration area. Affected by F16 fault and the huge thick gravel rock in the roof, the coal seam near the fault accumulates a large amount of elastic strain energy, which increases the potential of rock burst hazards in the process of mining.

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