3. Asymptotics at Characteristic Points

2018 ◽  
pp. 103-213
Keyword(s):  
Characteristic Points

FACTOR ANALYSIS OF GEOGRAPHIC COORDINATES AT POINTS OF THE CHANNEL OF A SMALL RIVER ON SPACE IMAGES

2020 ◽  
Author(s):  
Peter Matveevich Mazurkin ◽  
Yana Oltgovna Georgieva
Keyword(s):  
Correlation Coefficient ◽  
Geographical Location ◽  
Small River ◽  
Binary Relations ◽  
Catchment Basin ◽  
Space Images ◽  
The North ◽  
Inverse Effect ◽  
Characteristic Points ◽  
Fractal Representation

The purpose of the article is the analysis of asymmetric wavelets in binary relations between three coordinates at 290 characteristic points from the source to the mouth of the small river Irovka. The hypsometric characteristic is the most important property of the relief. The Irovka River belongs to a low level, at the mouth it is 89 m high, and at the source it is 148 m above sea level. Modeling of binary relations with latitude, longitude, and height has shown that local latitude receives the greatest quantum certainty. In this case, all paired regularities received a correlation coefficient of more than 0.95. Such a high adequacy of wave patterns shows that geomorphology can go over to the wave multiple fractal representation of the relief. The Irovka River is characterized by a small anthropogenic impact, therefore, the relief over a length of 69 km has the natural character of the oscillatory adaptation of a small river to the surface of the Vyatka Uval from its eastern side. This allows us to proceed to the analysis of the four tributaries of the small river Irovka, as well as to model the relief of the entire catchment basin of 917 km2. The greatest adequacy with a correlation coefficient of 0.9976 was obtained by the influence of latitude on longitude, that is, the geographical location of the relief of the river channel with respect to the geomorphology of the Vyatka Uval. In second place with a correlation of 0.9967 was the influence of the height of the points of the channel of the small river on local longitude and it is also mainly determined by the relief of the Vyatka Uval. In third place was the effect of latitude on height with a correlation coefficient of 0.9859. And in last sixth place is the inverse effect of altitude on local latitude in the North-South direction.

scholarly journals The Effect of Subgrade Coefficient on Static Work of a Pontoon Made as a Monolithic Closed Tank

2021 ◽  
Vol 11 (9) ◽  
pp. 4259
Author(s):  
Anna Szymczak-Graczyk
Keyword(s):  
Minimum Energy ◽  
Floating Platform ◽  
Static Work ◽  
One Stage ◽  
Single Piece ◽  
Characteristic Points ◽  
Internal Partition ◽  
Conducting Research ◽  
Metacentric Height ◽  
Made In

This article presents the effect of taking into account the subgrade coefficient on static work of a pontoon with an internal partition, made in one stage and treated computationally as a monolithic closed rectangular tank. An exemplary pontoon is a single, ready-made shipping element that can be used as a float for a building. By assembling several floats together, the structure can form a floating platform. Due to the increasingly violent weather phenomena and the necessity to ensure safe habitation for people in countries at risk of inundation or flooding, amphibious construction could provide new solutions. This article presents calculations for a real pontoon made in one stage for the purpose of conducting research. Since it is a closed structure without any joint or contact, it can be concluded that it is impossible for water to get inside. However, in order to exclude the possibility of the pontoon filling with water, its interior was filled with Styrofoam. For static calculations, the variational approach to the finite difference method was used, assuming the condition for the minimum energy of elastic deflection during bending, taking into account the cooperation of the tank walls with the Styrofoam filling treated as a Winkler elastic substrate and assuming that Poisson’s ratio ν = 0. Based on the results, charts were made illustrating the change in bending moments at the characteristic points of the analysed tank depending on acting loads. The calculations included hydrostatic loads on the upper plate and ice floe pressure as well as buoyancy, stability and metacentric height of the pontoon. The aim of the study is to show a finished product—a single-piece pontoon that can be a prefabricated element designed for use as a float for “houses on water”.

scholarly journals Error Characteristic Analysis of Fluid Momentum Law Test Apparatus

2020 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
Song Yang ◽  
Xianyong Zhu ◽  
Hui Wang
Keyword(s):  
Measurement Error ◽  
Control Method ◽  
Theoretical Research ◽  
Structural Deformation ◽  
Error Characteristic ◽  
Characteristic Analysis ◽  
Jet Impact ◽  
Effect Theory ◽  
Characteristic Points ◽  
Periodic Error

The flat-plate momentum test bench is a widely used experimental device in the verification of the momentum law of fluid mechanics, and its error characteristics are of positive significance for theoretical research and engineering innovation and expansion. The SPH-FEM coupling algorithm and spectrum analysis method are used to calculate and analyze the displacement response and spectrum characteristics of the characteristic points of the sensor under different jet loads. Based on them, the cause, classification, law, scope, influence and control method of the measurement error of the system are discussed and analyzed with the application of the error theory and the lateral effect theory of strain gauges; combined with physical experiments, the relevant analysis methods and conclusions are verified. The results show that the measurement error of the system includes linear error and periodic error. Structural deformation in the direction of jet impact is the main source of linear error; linear error increases with the increase of jet loads. Meanwhile, periodic vibration in non-jet direction is the main cause of periodic error, and the periodic error decreases with the increase of jet loads.

scholarly journals Blue as an Underrated Alternative to Green: Photoplethysmographic Heartbeat Intervals Estimation under Two Temperature Conditions

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4241
Author(s):  
Evgeniia Shchelkanova ◽  
Liia Shchapova ◽  
Alexander Shchelkanov ◽  
Tomohiro Shibata
Keyword(s):  
Blue Light ◽  
Characteristic Point ◽  
Biological Effects ◽  
Green Light ◽  
Estimation Accuracy ◽  
Lower Sensitivity ◽  
Light Spectrum ◽  
Cardiovascular Parameter ◽  
Temperature Conditions ◽  
Characteristic Points

Since photoplethysmography (PPG) sensors are usually placed on open skin areas, temperature interference can be an issue. Currently, green light is the most widely used in the reflectance PPG for its relatively low artifact susceptibility. However, it has been known that hemoglobin absorption peaks at the blue part of the spectrum. Despite this fact, blue light has received little attention in the PPG field. Blue wavelengths are commonly used in phototherapy. Combining blue light-based treatments with simultaneous blue PPG acquisition could be potentially used in patients monitoring and studying the biological effects of light. Previous studies examining the PPG in blue light compared to other wavelengths employed photodetectors with inherently lower sensitivity to blue, thereby biasing the results. The present study assessed the accuracy of heartbeat intervals (HBIs) estimation from blue and green PPG signals, acquired under baseline and cold temperature conditions. Our PPG system is based on TCS3472 Color Sensor with equal sensitivity to both parts of the light spectrum to ensure unbiased comparison. The accuracy of the HBIs estimates, calculated with five characteristic points (PPG systolic peak, maximum of the first PPG derivative, maximum of the second PPG derivative, minimum of the second PPG derivative, and intersecting tangents) on both PPG signal types, was evaluated based on the electrocardiographic values. The statistical analyses demonstrated that in all cases, the HBIs estimation accuracy of blue PPG was nearly equivalent to the G PPG irrespective of the characteristic point and measurement condition. Therefore, blue PPG can be used for cardiovascular parameter acquisition. This paper is an extension of work originally presented at the 42nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

Camera Calibration Method Based on Circle Plane Board

2013 ◽  
Vol 475-476 ◽  
pp. 184-187
Author(s):  
Wen Guo Li ◽  
Shao Jun Duan
Keyword(s):  
Camera Calibration ◽  
Calibration Method ◽  
Lens Distortion ◽  
Edge Extraction ◽  
Circle Plane ◽  
Circle Centre ◽  
Extraction Algorithm ◽  
Calibration Algorithm ◽  
Characteristic Points ◽  
Distortion Parameters

We present a camera calibration method based on circle plane board. The centres of circles on plane are regarded as the characteristic points, which are used to implement camera calibration. The proposed calibration is more accurate than many previous calibration algorithm because of the merit of the coordinate of circle centre being obtained from thousand of of edge pionts of ellipse, which is very reliable to image noise caused by edge extraction algorithm. Experiments shows the proposed algorithm can obtain high precise inner parameters, and lens distortion parameters.

Analysis of Heat Transfer through PVC Window Profile Reinforced with Ti6Al4V Alloy

2016 ◽  
Vol 687 ◽  
pp. 236-242 ◽  
Author(s):  
Piotr Lacki ◽  
Judyta Różycka ◽  
Marcin Rogoziński
Keyword(s):  
Heat Transfer ◽  
Titanium Alloy ◽  
Thermal Insulation ◽  
Numerical Models ◽  
Characteristic Temperature ◽  
Permanent Deformation ◽  
Transfer Coefficients ◽  
Element Analysis ◽  
Ti6al4v Titanium Alloy ◽  
Characteristic Points

This requires the use of additional reinforcement in order to prevent excessive or permanent deformation of PVC windows. In the paper particular attention was devoted to space located in a corrosive environment exposed to chemical agents. For this purpose, proposed to change the previously used steel profiles reinforcements made of Ti6Al4V titanium alloy corrosion-resistant in the air, at sea and many types of industrial atmosphere. Analysis of the thermal insulation properties of PVC windows with additional reinforcement of profile Ti6Al4V titanium alloy was performed. PVC window set in a layer of thermal insulation was analyzed. Research was conducted using Finite Element Analysis. Numerical models and thermal calculations were made in the program ADINA, assuming appropriate material parameters. The constant internal temperature of 20 ̊ and an outer-20 ̊ was assumed. The course of temperature distribution in baffle in time 24 hours and graphs of characteristic points was obtained. The time of in which followed the steady flow of heat, as well as the course of isotherm of characteristic temperature in the baffle was determined. On the basis of numerical analysis obtained vector distribution of heat flux q [W/m2] and was determined heat transfer coefficients U [W/m2K] for the whole window with titanium reinforcement . All results were compared with the model of PVC windows reinforced with steel profile.

Parallel Improvement for a Classical Template Serial Thinning Algorithm

2011 ◽  
Vol 271-273 ◽  
pp. 1509-1513 ◽  
Author(s):  
Mei Xiu Lu ◽  
Fu Rong Wang ◽  
Feng Li
Keyword(s):  
Mathematical Morphology ◽  
Fingerprint Recognition ◽  
Thinning Algorithm ◽  
Recognition Algorithms ◽  
Characteristic Points ◽  
Image Thinning ◽  
Ideal Algorithm ◽  
Improved Algorithm

Image thinning is one of important steps of fingerprint preprocessing. Most of fingerprint recognition algorithms checked the characteristic points on thinning image. In this paper, we discover some shortages in OPTA and mathematical morphology thinning algorithm and find out the reasons for some shortages such as many glitches and snags, defective thinning, and so on. A new improved algorithm is proposed in the paper, which is an ideal algorithm because it is faster, produces less glitch, and thins completely.

A Palmprint Recognition Approach Based on Image Segmentation of Region of Interest

2016 ◽  
Vol 30 (02) ◽  
pp. 1656002 ◽  
Author(s):  
Qing E Wu ◽  
Zhiwu Chen ◽  
Ruijie Han ◽  
Cunxiang Yang ◽  
Yuhao Du ◽  
...  
Keyword(s):  
Image Segmentation ◽  
Wavelet Transform ◽  
Recognition Rate ◽  
Region Of Interest ◽  
Palmprint Recognition ◽  
Characteristic Points ◽  
Positioning Method ◽  
Roi Extraction ◽  
Energy Feature

To carry out an effective recognition for palmprint, this paper presents an algorithm of image segmentation of region of interest (ROI), extracts the ROI of a palmprint image and studies the composing features of palmprint. This paper constructs a coordinate by making use of characteristic points in the palm geometric contour, improves the algorithm of ROI extraction and provides a positioning method of ROI. Moreover, this paper uses the wavelet transform to divide up ROI, extracts the energy feature of wavelet, gives an approach of matching and recognition to improve the correctness and efficiency of existing main recognition approaches, and compares it with existing main approaches of palmprint recognition by experiments. The experiment results show that the approach in this paper has the better recognition effect, the faster matching speed, and the higher recognition rate which is improved averagely by 2.69% than those of the main recognition approaches.

Simulation of English text recognition model based on ant colony algorithm and genetic algorithm

2021 ◽  
pp. 1-12
Author(s):  
Fei Long
Keyword(s):  
Machine Learning ◽  
Genetic Algorithm ◽  
Ant Colony Algorithm ◽  
Ant Colony ◽  
Text Recognition ◽  
English Text ◽  
Recognition Model ◽  
Central Node ◽  
Model Based ◽  
Characteristic Points

The difficulty of English text recognition lies in fuzzy image text classification and part-of-speech classification. Traditional models have a high error rate in English text recognition. In order to improve the effect of English text recognition, guided by machine learning ideas, this paper combines ant colony algorithm and genetic algorithm to construct an English text recognition model based on machine learning. Moreover, based on the characteristics of ant colony intelligent algorithm optimization, a method of using ant colony algorithm to solve the central node is proposed. In addition, this paper uses the ant colony algorithm to obtain the characteristic points in the study area and determine a reasonable number, and then combine the uniform grid to select some non-characteristic points as the central node of the core function, and finally use the central node with a reasonable distribution for modeling. Finally, this paper designs experiments to verify the performance of the model constructed in this paper and combines mathematical statistics to visually display the experimental results using tables and graphs. The research results show that the performance of the model constructed in this paper is good.

Denoising of river surface photogrammetric DEMs using deep learning

2021 ◽  
Author(s):  
Radosław Szostak ◽  
Przemysław Wachniew ◽  
Mirosław Zimnoch ◽  
Paweł Ćwiąkała ◽  
Edyta Puniach ◽  
...  
Keyword(s):  
Higher Education ◽  
Deep Learning ◽  
Water Level ◽  
Water Surface ◽  
Research University ◽  
Static Characteristic ◽  
Water Levels ◽  
Training Dataset ◽  
Observation Data ◽  
Characteristic Points

<p>Unmanned Aerial Vehicles (UAVs) can be an excellent tool for environmental measurements due to their ability to reach inaccessible places and fast data acquisition over large areas. In particular drones may have a potential application in hydrology, as they can be used to create photogrammetric digital elevation models (DEM) of the terrain allowing to obtain high resolution spatial distribution of water level in the river to be fed into hydrological models. Nevertheless, photogrammetric algorithms generate distortions on the DEM at the water bodies. This is due to light penetration below the water surface and the lack of static characteristic points on water surface that can be distinguished by the photogrammetric algorithm. The correction of these disturbances could be achieved by applying deep learning methods. For this purpose, it is necessary to build a training dataset containing DEMs before and after water surfaces denoising. A method has been developed to prepare such a dataset. It is divided into several stages. In the first step a photogrammetric surveys and geodetic water level measurements are performed. The second one includes generation of DEMs and orthomosaics using photogrammetric software. Finally in the last one the interpolation of the measured water levels is done to obtain a plane of the water surface and apply it to the DEMs to correct the distortion. The resulting dataset was used to train deep learning model based on convolutional neural networks. The proposed method has been validated on observation data representing part of Kocinka river catchment located in the central Poland.</p><p>This research has been partly supported by the Ministry of Science and Higher Education Project “Initiative for Excellence – Research University” and Ministry of Science and Higher Education subsidy, project no. 16.16.220.842-B02 / 16.16.150.545.</p>

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