Simulation of a Three-Stage Process for Forming a Closed Cone From a Plate

2008 ◽  
Author(s):  
Zhengkun Feng ◽  
Henri Champliaud ◽  
Thien-My Dao
Keyword(s):  
Numerical Simulations ◽  
Explicit Scheme ◽  
Implicit Scheme ◽  
Commercial Software ◽  
Geometrical Quality ◽  
Trailing Edges ◽  
Stage Process ◽  
Closed Cone

High geometrical quality of bent cones is required in assembling several cone segments into a crown of Francis turbines. Although closed cones were successfully obtained using pyramidal three-roll conical bending machines with cylindrical rolls which is more adaptive and less expensive, the zones close to the leading and trailing edges of the plate never pass under the inner roll and remain planar. For the purpose of obtaining high geometrical quality, a three-stage process is proposed to obtain a jointed cone with no planar zones. The planar zones resulted from the first stage of the conical bending is eliminated after the repassing of the bent cone in the bending machine with the leading and trailing edges jointed together by forces. Numerical simulations with commercial software ANSYS/LS-DYNA in explicit scheme and ANSYS in implicit scheme are performed and bent cones with improved qualities are obtained.

scholarly journals Development of the Telehealth Usability Questionnaire (TUQ)

2016 ◽  
Vol 8 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Bambang Parmanto ◽  
Allen Nelson Lewis, Jr. ◽  
Kristin M. Graham ◽  
Marnie H. Bertolet
Keyword(s):  
User Interface ◽  
Service Delivery ◽  
Computer Interface ◽  
Commercial Software ◽  
Telehealth Service ◽  
Computer Based

Current telehealth usability questionnaires are designed primarily for older technologies, where telehealth interaction is conducted over dedicated videoconferencing applications. However, telehealth services are increasingly conducted over computer-based systems that rely on commercial software and a user supplied computer interface. Therefore, a usability questionnaire that addresses the changes in telehealth service delivery and technology is needed.  The Telehealth Usability Questionnaire (TUQ) was developed to evaluate the usability of telehealth implementation and services.  This paper addresses: 1) the need for a new measure of telehealth usability, 2) the development of the TUQ, 3) intended uses for the TUQ, and 4) the reliability of the TUQ. Analyses indicate that the TUQ is a solid, robust, and versatile measure that can be used to measure the quality of the computer-based user interface and the quality of the telehealth interaction and services.    

scholarly journals IMPROVING UAV TELEMETRY POSITIONING FOR DIRECT PHOTOGRAMMETRY

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 61-68
Author(s):  
L. Rossi ◽  
F. Ioli ◽  
E. Capizzi ◽  
L. Pinto ◽  
M. Reguzzoni
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Control Points ◽  
Three Dimensional Model ◽  
Commercial Software ◽  
Ground Control Points ◽  
Lower Accuracy ◽  
Least Squares Adjustment ◽  
Gnss Receivers

Abstract. A fundamental step of UAV photogrammetric processes is to collect Ground Control Points (GCPs) by means of geodetic-quality GNSS receivers or total stations, thus obtaining an absolutely oriented model with a centimetric accuracy. This procedure is usually time-consuming, expensive and potentially dangerous for operators who sometimes need to reach inaccessible areas. UAVs equipped with low-cost GNSS/IMU sensors can provide information about position and attitude of the images. This telemetry information is not enough for a photogrammetric restitution with a centimetric accuracy, but it can be usefully exploited when a lower accuracy is required. The algorithm proposed in this paper aims at improving the quality of this information, in order to introduce it into a direct-photogrammetric process, without collecting GCPs. In particular, the estimation of an optimal trajectory is obtained by combining the camera positions derived from UAV telemetry and from the relative orientation of the acquired images, by means of a least squares adjustment. Then, the resulting trajectory is used as a direct observation of the camera positions into a commercial software, thus replacing the information of GCPs. The algorithm has been tested on different datasets, comparing the classical photogrammetric solution (with GCPs) with the proposed one. These case-studies showed that using the improved trajectory as input to the commercial software (without GCPs) the reconstruction of the three-dimensional model can be improved with respect to the solution computed by using the UAV raw telemetry only.

scholarly journals Towards Managing Visual Pollution: A 3D Isovist and Voxel Approach to Advertisement Billboard Visual Impact Assessment

2021 ◽  
Vol 10 (10) ◽  
pp. 656
Author(s):  
Szymon Chmielewski
Keyword(s):  
Cultural Context ◽  
Policy Makers ◽  
Quality Issue ◽  
Geometrical Quality ◽  
Visual Landscape ◽  
Landscape Quality ◽  
Visual Impact ◽  
The Impact ◽  
Visible Volume

Visual pollution (VP) is a visual landscape quality issue, and its most consistently recognized symptom is an excess of out of home advertising billboards (OOHb). However, the VP related research concerns landscape aesthetic and advertisement cultural context, leaving the impact of outdoor billboard infrastructure on landscape openness unanswered to date. This research aims to assess the visual impact of outdoor billboard infrastructure on landscape openness, precisely the visual volume—a key geometrical quality of a landscape. The method uses 3D isovists and voxels to calculate the visible and obstructed subsets of visible volume. Using two case studies (Lublin City, Poland) and 26 measurement points, it was found that OOHb decreased landscape openness by at least 4% of visible volume; however, the severe impact may concern up to 35% of visual volume. GIS scientists develop the proposed method for policy-makers, and urban planners end users. It is also the very first example of compiling 3D isovists and voxels in ArcGIS Pro software in an easy-to-replicate framework. The research results, accompanied by statistically significant proofs, explain the visual landscape’s fragility and contribute to understanding the VP phenomenon.

Nature’s Mathematics

2019 ◽  
pp. 17-36
Author(s):  
Thomas Owens
Keyword(s):  
Material World ◽  
Geometrical Quality ◽  
Mathematical Expressions ◽  
The World ◽  
The Mind ◽  
Theological Vision

Chapter 1 explores the geometrical quality of Wordsworth’s and Coleridge’s imaginative commitments. Focusing principally on The Pedlar, the Guide to the Lakes, and Coleridge’s Notebooks, the chapter locates the origins of Wordsworth’s and Coleridge’s geometric visions in a divinely relational language of shapes which they intuited as children to describe the world about them and which moulded their shared Pedlar consciousness in the 1790s. It proposes that Wordsworth and Coleridge sustained the mathematical expressions of the Pedlar’s ethico-theological vision in their dealings with nature and the mind, perceiving in the material world a language of geometric forms which held it together.

Effect of connection on transport between scale free networks

2017 ◽  
Vol 28 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Ould Baba ◽  
O. Bamaarouf ◽  
A. Rachadi ◽  
H. Ez-Zahraouy
Keyword(s):  
Numerical Simulations ◽  
Power Law ◽  
Preferential Attachment ◽  
Electrical Conductance ◽  
Global Network ◽  
Scale Free ◽  
Scale Free Networks ◽  
Conductance Distribution

Using numerical simulations, we investigate the effects of the connectivity and topologies of network on the quality of transport between connected scale free networks. Hence, the flow as the electrical conductance between connected networks is calculated. It is found that the conductance distribution between networks follow a power law [Formula: see text] where [Formula: see text] is the exponent of the global Network of network, we show that the transport in the symmetric growing preferential attachment connection is more efficient than the symmetric static preferential attachment connection. Furthermore, the differences of transport and networks communications properties in the different cases are discussed.

Doubly modifiable synapses: a model of short and long term auto-associative memory

1989 ◽  
Vol 238 (1291) ◽  
pp. 137-154 ◽  
Keyword(s):  
Long Term Memory ◽  
Short Term ◽  
High Quality ◽  
Stage Process ◽  
Short And Long Term ◽  
Associative Recall ◽  
Term Performance ◽  
Long Term Experience

Synapses that can be strengthened in temporary and persistent manners by two separate mechanisms are shown to have powerful advantages in neural networks that perform auto-associative recall and recognition. A multiplicative relation between the two weights allows the same set of connections to be used in a closely interactive way for short-term and long-term memory. Algorithms and simulations are described for the storage, consolidation and recall of patterns that have been presented only once to a network. With double modifiability, the short-term performance is dramatically improved, becoming almost independent of the amount of long-term experience. The high quality of short-term recall allows consolidation to take place, with benefits from the selection and optimization of long term engram s to take account of relations between stored patterns. Long-term capacity is greater than short-term capacity, with little or no deficit compared with that, obtained with singly modifiable synapses. Long-term recall requires special, simply implemented, procedures for increasing the temporary weights of the synapses being used to initiate recall. A consolidation algorithm is described for improving long-term recall when there is overlap between patterns. Confusional errors are reduced by strengthening the associations between non-overlapping elements in the patterns, in a two-stage process that has several of the characteristics of sleep.

scholarly journals Solutions for increasing the quality of hydro-technical building elements obtained by numerical simulation

2019 ◽  
Vol 85 ◽  
pp. 02011
Author(s):  
Alexandru Fodorean ◽  
Adrian Cureu ◽  
Oana Giurgiu ◽  
Dan Opruţa
Keyword(s):  
Waste Water ◽  
Numerical Simulation ◽  
Wastewater Treatment ◽  
Numerical Simulations ◽  
Numerical Models ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Design Phase

Sewage treatment remains a delicate subject and requires technical improvements to increase the efficiency of the systems responsible for the treatment. Numerical simulations are also a very useful tool, especially if they are used during the design phase. Thus, the paper aims to present the results obtained by CFD numerical simulations in the case of an important element within an existing wastewater treatment plant, namely the waste water treatment well, thus obtaining constructive solutions of a better functionally to the designed version. Through these, the work demonstrates the necessity of analyzes with CFD methods during design of the main elements of hydrotechnical constructions, but also the necessity of adjusting the numerical models with results obtained from experiments, measurements. The results show that the modifications described in the paper would bring significant improvements in waste disposal.

scholarly journals Biomedical Photoacoustic Imaging Optimization with Deconvolution and EMD Reconstruction

2018 ◽  
Vol 8 (11) ◽  
pp. 2113 ◽  
Author(s):  
Chengwen Guo ◽  
Yingna Chen ◽  
Jie Yuan ◽  
Yunhao Zhu ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Empirical Mode Decomposition ◽  
Photoacoustic Imaging ◽  
Optimization Method ◽  
Positive Polarity ◽  
Image Optimization ◽  
Mode Decomposition ◽  
Phantom Studies ◽  
Micro Structures

A photoacoustic (PA) signal of an ideal optical absorbing particle is a single N-shape wave. PA signals are a combination of several individual N-shape waves. However, the N-shape wave basis leads to aliasing between adjacent micro-structures, which deteriorates the quality of final PA images. In this paper, we propose an image optimization method by processing raw PA signals with deconvolution and empirical mode decomposition (EMD). During the deconvolution procedure, the raw PA signals are de-convolved with a system dependent deconvolution kernel, which is measured in advance. EMD is subsequently adopted to further process the PA signals adaptively with two restrictive conditions: positive polarity and spectrum consistency. With this method, signal aliasing is alleviated, and the micro-structures and detail information, previously buried in the reconstructing images, can now be revealed. To validate our proposed method, numerical simulations and phantom studies are implemented, and reconstructed images are used for illustration.

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