Research on the Summarization of the Gear Parameters

2013 ◽  
Vol 765-767 ◽  
pp. 2074-2077
Author(s):  
Chun Xiang Wang ◽  
Hong Min Shi
Keyword(s):  
Reverse Engineering ◽  
Measurement Technique ◽  
Point Cloud ◽  
Parameter Extraction ◽  
Extraction Methods ◽  
Measurement Technology ◽  
Image Measurement ◽  
Parameters Extraction ◽  
Research Situation ◽  
At Home

In this paper, combining with research situation at home and abroad,the gear parameters extraction methods were compared,including point cloud extraction in reverse engineering, image measurement technology and traditional measurement technique, etc. Analyzes the various technical method,At last,gear parameter extraction of the prospects for development are put forward.

A New Simplification Method within Deviation Parameters and Allowed Angles

2012 ◽  
Vol 566 ◽  
pp. 239-243
Author(s):  
Na Meng ◽  
Xin Li Chen ◽  
Yi Qi Zhou ◽  
Bao Qing Dai
Keyword(s):  
Surface Reconstruction ◽  
Point Cloud ◽  
Practical Method ◽  
Point Cloud Data ◽  
Memory Space ◽  
Cloud Data ◽  
Advantages And Disadvantages ◽  
Research Situation ◽  
Improved Algorithm ◽  
At Home

Research situation at home and abroad is described in detail about simplification methods of point cloud data. After analyzing the advantages and disadvantages of existing algorithms, an improved algorithm, a method combining with deviation parameters and allowed angles to simply mass cloud data, is proposed from several aspects of complexity, required time and memory space. The experiments show that the simplified point cloud have a great relationship with the selected tolerance value. And the point cloud after simplification has advantages of high reservation of curve and surface reconstruction perfectly, which is reserved enough data. The proposed simplification algorithm is an effective and practical method.

Open quantum system parameters for light harvesting complexes from molecular dynamics

2015 ◽  
Vol 17 (38) ◽  
pp. 25629-25641 ◽  
Author(s):  
Xiaoqing Wang ◽  
Gerhard Ritschel ◽  
Sebastian Wüster ◽  
Alexander Eisfeld
Keyword(s):  
Molecular Dynamics ◽  
Quantum System ◽  
Open Quantum System ◽  
Light Harvesting ◽  
Parameter Extraction ◽  
Extraction Methods ◽  
Light Harvesting Complexes ◽  
System Parameters ◽  
Open Quantum ◽  
The Difference

We elucidate the difference between various parameter extraction methods and demonstrate sensitivity to molecular dynamics equilibration.

User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

2021 ◽  
pp. 1-16
Author(s):  
Ghazanfar Ali Shah ◽  
Jean-Philippe Pernot ◽  
Arnaud Polette ◽  
Franca Giannini ◽  
Marina Monti
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Point Clouds ◽  
Geometric Constraints ◽  
Computer Assisted ◽  
Reconstruction Process ◽  
Mechanical Parts ◽  
Starting Point ◽  
Cad Models ◽  
Incomplete Datasets

Abstract This paper introduces a novel reverse engineering technique for the reconstruction of editable CAD models of mechanical parts' assemblies. The input is a point cloud of a mechanical parts' assembly that has been acquired as a whole, i.e. without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized geometries (i.e 2D sketches, 3D parts or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the reconstructed geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the updates and satisfies the geometric constraints as the fitting process goes on. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow for local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

scholarly journals Lateral Trochlear Inclination Angle: Measurement via a 2-Image Technique to Reliably Characterize and Quantify Trochlear Dysplasia

2020 ◽  
Vol 8 (10) ◽  
pp. 232596712095841
Author(s):  
Sheeba M. Joseph ◽  
Chris Cheng ◽  
Matthew J. Solomito ◽  
J. Lee Pace
Keyword(s):  
Measurement Technique ◽  
Trochlear Dysplasia ◽  
Intraclass Correlation ◽  
Single Image ◽  
Image Measurement ◽  
Mri Scan ◽  
Morphologic Characteristics ◽  
Mri Scans ◽  
Image Technique ◽  
Dejour Classification

Background: Trochlear dysplasia (TD) is a risk factor for patellar instability (PI). The Dejour classification categorizes TD but has suboptimal reliability. Lateral trochlear inclination (LTI) is a quantitative measurement of trochlear dysplasia on a single axial magnetic resonance imaging (MRI) scan. Hypothesis: A modified LTI measurement technique using 2 different axial MRI scans that reference the most proximal aspect of the trochlear cartilage on 1 image and the fully formed posterior condyles on the second image would be as reliable as and significantly different from the single-image measurement technique for LTI. Further, the 2-image LTI would adequately represent overall proximal trochlear morphologic characteristics. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients aged 9 to 18 years treated for PI between 2014 and 2017 were identified. The Dejour classification was radiographically determined. Single-image LTI was measured on a single axial MRI scan at the most proximal aspect of visible trochlear cartilage. A 2-image LTI was measured from 2 separate MRI scans: 1 at the most proximal aspect of trochlear cartilage and the second at the fully formed posterior condyles. This 2-image LTI was repeated at 3 subsequent levels (the first measurement is referred to as LTI-1; repeated measurements are LTI-2, LTI-3, and LTI-4, moving distally). In total, 65 patients met the inclusion criteria, and 30 were randomly selected for reliability analysis. Results: Inter- and intrarater reliability trended toward more variability for single-image LTI (intraclass correlation coefficient [ICC], 0.86 and 0.88, respectively) than for 2-image LTI (ICC, 0.97 and 0.96, respectively). The Dejour classification had lower intra- and interrater reliability (ICC, 0.31 and 0.73, respectively). Average single-image LTI (9.2° ± 12.6°) was greater than average 2-image LTI-1 (4.2° SD ± 11.9°) ( P = .0125). Single-image LTI classified 60% of patients with PI as having TD, whereas the 2-image LTI classified 71% as having TD. The 2-image LTI was able to capture 91% of overall proximal trochlear morphologic characteristics. Conclusion: LTI has higher reliability when performed using a 2-image measurement technique compared with single-image LTI and Dejour classification. The strong correlation between 2-image LTI and average LTI shows that 91% of TD is represented on the most proximal axial image. Because the single-image measurement appears to underestimate dysplasia, previously described thresholds should be reexamined using this 2-image technique to appropriately characterize TD.

scholarly journals A R-SHINY BASED PHENOLOGY ANALYSIS SYSTEM AND CASE STUDY USING DIGITAL CAMERA DATASET

2018 ◽  
Vol XLII-3 ◽  
pp. 2571-2574
Author(s):  
Y. K. Zhou
Keyword(s):  
Data Processing ◽  
Web Application ◽  
Vegetation Index ◽  
Digital Camera ◽  
Parameter Extraction ◽  
Growth Trajectory ◽  
Phenological Data ◽  
Combination Methods ◽  
Parameters Extraction ◽  
R Shiny

Accurate extracting of the vegetation phenology information play an important role in exploring the effects of climate changes on vegetation. Repeated photos from digital camera is a useful and huge data source in phonological analysis. Data processing and mining on phenological data is still a big challenge. There is no single tool or a universal solution for big data processing and visualization in the field of phenology extraction. In this paper, we proposed a R-shiny based web application for vegetation phenological parameters extraction and analysis. Its main functions include phenological site distribution visualization, ROI (Region of Interest) selection, vegetation index calculation and visualization, data filtering, growth trajectory fitting, phenology parameters extraction, etc. the long-term observation photography data from Freemanwood site in 2013 is processed by this system as an example. The results show that: (1) this system is capable of analyzing large data using a distributed framework; (2) The combination of multiple parameter extraction and growth curve fitting methods could effectively extract the key phenology parameters. Moreover, there are discrepancies between different combination methods in unique study areas. Vegetation with single-growth peak is suitable for using the double logistic module to fit the growth trajectory, while vegetation with multi-growth peaks should better use spline method.

scholarly journals A HYBRID MODEL FOR THE REVERSE ENGINEERING OF THE MILAN CATHEDRAL. CHALLENGES AND LESSON LEARNT

2021 ◽  
Author(s):  
Franco Spettu ◽  
Simone Teruggi ◽  
Francesco Canali ◽  
Cristiana Achille ◽  
Francesco Fassi
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Learning Algorithm ◽  
A Priori ◽  
Point Clouds ◽  
Logical Structure ◽  
Cloud Data ◽  
Survey Techniques ◽  
Periodic Maintenance ◽  
Maintenance And Inspection

Cultural Heritage (CH) 3D digitisation is getting increasing attention and importance. Advanced survey techniques provide as output a 3D point cloud, wholly and accurately describing even the most complex architectural geometry with a priori established accuracy. These 3D point models are generally used as the base for the realisation of 2D technical drawings and 3D advanced representations. During the last 12 years, the 3DSurveyGroup (3DSG, Politecnico di Milano) conduced an omni-comprehensive, multi-technique survey, obtaining the full point cloud of Milan Cathedral, from which were produced the 2D technical drawings and the 3D model of the Main Spire used by the Veneranda Fabbrica del Duomo di Milano (VF) to plan its periodic maintenance and inspection activities on the Cathedral. Using the survey product directly to plan VF activities would help to skip a long-lasting, uneconomical and manual process of 2D and 3D technical elaboration extraction. In order to do so, the unstructured point cloud data must be enriched with semantics, providing a hierarchical structure that can communicate with a powerful, flexible information system able to effectively manage both point clouds and 3D geometries as hybrid models. For this purpose, the point cloud was segmented using a machine-learning algorithm with multi-level multi-resolution (MLMR) approach in order to obtain a manageable, reliable and repeatable dataset. This reverse engineering process allowed to identify directly on the point cloud the main architectonic elements that are then re-organised in a logical structure inserted inside the informative system built inside the 3DExperience environment, developed by Dassault Systémes.

Evaluation of volatile behaviour and the volatilization volume of molten salt in DIR-MCFC by using the image measurement technique

2005 ◽  
Vol 145 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Kimihiko Sugiura ◽  
Makoto Yamauchi ◽  
Kazumi Tanimoto ◽  
Yasumasa Yoshitani
Keyword(s):  
Molten Salt ◽  
Measurement Technique ◽  
Image Measurement

scholarly journals Modified FOA Applied to Parameter Extraction of Flux-Gate Core

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Wenjuan Jiang ◽  
Yunbo Shi ◽  
Wenjie Zhao
Keyword(s):  
Optimization Algorithm ◽  
Fruit Fly ◽  
Parameter Extraction ◽  
Magnetic Core ◽  
Fruit Fly Optimization Algorithm ◽  
Fruit Fly Optimization ◽  
Analysis And Design ◽  
Parameters Extraction ◽  
Flux Gate ◽  
The Impact

The accuracy of the magnetic core model is important to the analysis and design of the flux-gate sensor. The Jiles-Atherton model (J-A model) is the mostly used model to describe the hysteresis characteristics of the flux-gate core. But the parameters of J-A model are difficult to identify. In this paper, Fruit Fly Optimization Algorithm (FOA) is proposed to identify the parameters of the J-A model. In order to enhance the performance of the identification, a Modified Fruit Fly Optimization Algorithm (MFOA) is applied to extract the parameters of the flux-gate core. The effectiveness of MFOA is verified through five typical test functions. The influence of variation factor h on the performance of MFOA is discussed. The impact of variation factor h on parameters extraction of hysteresis loop is studied. It is shown that MFOA with appropriate selection of variation factor h will get better performance in the accuracy, stability, and simulation time compared to those of PSO and FOA.

Analysis of Electrocardiogram Data Compression Techniques

2020 ◽  
pp. 930-970
Author(s):  
Anukul Pandey ◽  
Barjinder Singh Saini ◽  
Butta Singh ◽  
Neetu Sood
Keyword(s):  
Performance Evaluation ◽  
Performance Measures ◽  
Parameter Extraction ◽  
Extraction Methods ◽  
Walsh Transform ◽  
Ecg Compression ◽  
And Performance ◽  
Electrocardiogram Ecg ◽  
Ecg Database ◽  
Ecg Data

In this Chapter, a MATLAB-based approach is presented for compression of Electrocardiogram (ECG) data. The methodology employs in three different domains namely direct, transformed and parameter extraction methods. The selected techniques from direct ECG compression methods are TP, AZTEC, Fan, and Cortes. Moreover selected techniques from transformed ECG compression methods are Walsh Transform, DCT, and Wavelet transform. For each of the technique, the basic implementation of the algorithm was explored, and performance measures were calculated. All 48 records of MIT-BIH arrhythmia ECG database were employed for performance evaluation of various implemented techniques. Moreover, based on requirements, any basic techniques can be selected for further innovative processing that may include the lossless encoding.

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