Transforming Education with Photogrammetry:Creating Realistic 3D Objects for Augmented Reality Applications

Augmented reality(AR)is an emerging dynamic technology that effectively supports education across different levels.The increased use of mobile devices has an even greater impact.As the demand for AR applications in education continues to increase,educators actively seek innovative and immersive methods to engage students in learning.However,exploring these possibilities also entails identifying and overcoming existing barriers to optimal educational integration.Concurrently,this surge in demand has prompted the identification of specific barriers,one of which is three-dimensional(3D)modeling.Creating 3D objects for augmented reality education applications can be challenging and time-consuming for the educators.To address this,we have developed a pipeline that creates realistic 3D objects from the two-dimensional(2D)photograph.Applications for augmented and virtual reality can then utilize these created 3D objects.We evaluated the proposed pipeline based on the usability of the 3D object and performance metrics.Quantitatively,with 117 respondents,the co-creation team was surveyed with openended questions to evaluate the precision of the 3D object created by the proposed photogrammetry pipeline.We analyzed the survey data using descriptive-analytical methods and found that the proposed pipeline produces 3D models that are positively accurate when compared to real-world objects,with an average mean score above 8.This study adds new knowledge in creating 3D objects for augmented reality applications by using the photogrammetry technique;finally,it discusses potential problems and future research directions for 3D objects in the education sector.

利用分数阶Fourier域滤波的机载SAR多运动目标检测

强度相差较大的多运动目标检测是机载合成孔径雷达 ( SAR)技术的一个重点和难点 ,传统的频域滤波和现代的时频分布方法都无法解决这个问题。首先分析了机载 SAR运动目标回波本质上为线性调频信号 ,据此提出一种基于分数阶 Fourier域滤波的运动目标检测新方法 ,并且应用逐次消去的思想有效地解决了强度相差较大的多目标检测问题。仿真的结果验证了算法的有效性。

广义SRLW方程的Fourier谱方法

考虑了一类广义的对称正则长波方程的周期初值问题．对所论问题构造了不同于已有文献的半离散和全离散的ＦｏｕｒｉｅｒＧａｌｅｒｋｉｎ 谱格式，采用更精细的估计不等式，给出了近似解的收敛性证明和最佳误差估计，改进了已有文献的结果．

快速Fourier变换的信号流图自动生成

快速 Fourier 变换信号流图对于快速 Fourier 变换的研究是很有意义的。本文系统地提出了快速 Fourier 变换信号流图自动生成的算法,包括一般快速 Fourier 变换和广义滑动快速 Fourier 变换的信号流图的自动生成算法。根据算法提出了面向对象的实现方法并开发了相应的应用程序。

一类广义Burgers－BBM方程的Fourier谱方法及误差估计

本文对［３－５］中提出的一类广义的Ｂｕｒｇｅｒｓ－ＢＢＭ方程的周期初值问题建立了不同于［５］的谱方法。构造了半离散和全离散的Ｆｏｕｒｉｅｒ－Ｇａｌｅｒｋｉｎ格式，从理论上给出了半离散和全离散格式近似解的收敛性证明及严格的误差估计。改进了［５］的结果。

理想导体目标重建的Fourier衍射定理

本文给出推广的物理光学近似下理想导体目标的Ｆｏｕｒｉｅｒ衍射定理，其形式与介质目标的相应关系式十分相似，利用这一关系式可以由测量直线上散射场分布重建二维理想导体目标Ｆｏｕｒｉｅｒ域的空间谱值。通过简单例子讨论了这一关系式的适用性。

EXISTENCE AND NONEXISTENCE OF GLOBAL SOLUTIONS FOR NONLINEAR EVOLUTION EQUATION OF FOURTH ORDER

The existence and uniqueness of classical global solutions and the nonexistence of global solutions to the first boundary value problem and the second boundary value problem for the equation u tt -a 1u xx -a 2u xxt -a 3u xxtt =φ(u x ) x are proved.

The estimations of four basic parameters for gamma-ray loud blazars

The method used in our previous papers is adopted to estimate four basic parameters （the central black hole mass （M）, the boosting factor （or Doppler factor） （6）, the propagation angle （Φ） and the distance along the axis to the site of the γ-ray production （d）） for 59 γ-ray loud blazars （20 BL Lacertae objects and 39 flat spectrum radio quasars）. The central black hole masses estimated for this sample are in a range of from 107 Me to 109 MG. In the case of black hole mass, there is no clear difference between BL Lacertae objects and flat spectrum radio quasars, which is consistent with the previous results suggesting that the central black hole masses do not play an important role in the evolutionary sequence of blazars.

Initial value problem for a class of fourth-order nonlinear wave equations

In this paper, existence and uniqueness of the generalized global solution and the classical global solution to the initial value problem for a class of fourth-order nonlinear wave equations are studied in the fractional order Sobolev space using the contraction mapping principle and the extension theorem. The sufficient conditions for the blow up of the solution to the initial value problem are given.

Study of Stability Analysis for a Class of Fourth Order Boundary Value Problems

Fourth order differential equations are considered to develop the class of methods for the numerical solution of boundary value problems. In this paper, we have discussed the regions of absolute stability of fourth order boundary value problems. Methods proposed and derived in this paper are applied to solve a fourth-order boundary value problem. Numerical results are given to illustrate the efficiency of our methods and compared with exact solution.

SYNTHESIS AND CHARACTERIZATION OF FOUR-ARMED BLOCK POLY(STYRENE-b-p-NITROPHENYL METHACRYLATE)PREPARED BY THE ATRP METHOD

A novel tetrafunctional initiator, C [CH_2O (CH_2)_3 OOCCH(Br)CH_3]_4 (1), was synthesized through the reaction oftetraol with α-bromopropionyl chloride, and then was used as initiator of atom transfer radical polymerization (ATRP) in thepreparation of 4-armed polystyrene (PSt) with narrow polydispersity. The structure, molecular weight and molecular weightdistribution (MWD) of each arm were studied by ~1H-NMR and GPC data of hydrolyzed products of the 4-armed PSt. TheATRP of St using 1/CuBr/bpy as initiator system is of 'living' character based on the following evidence: narrow MWD,constant concentration of chain radical during the polymerization, control of molecular weight by the molar ratio of monomerconsumed to 1. The 4-armed poly(St-b-p-nitrophenyl methacrylate) [poly(St-b-NPMA)] was prepared by the ATRP ofNPMA using 4-armed PSt with terminal bromine as the initiator, and characterized by FT-IR, ~1H-NMR spectra and GPCcurves. The micelles with PSt as core, and PNPMA as shell were formed by dropping DMSO into a solution of 4-armedpoly(St-b-NPMA) in DMF, as proved by laser light scatter (LLS) method.

Numerical Solution of the Coupled Viscous Burgers’ Equation Using Differential Quadrature Method Based on Fourier Expansion Basis

The differential quadrature method based on Fourier expansion basis is applied in this work to solve coupled viscous Burgers’ equation with appropriate initial and boundary conditions. In the first step for the given problem we have discretized the interval and replaced the differential equation by the Differential quadrature method based on Fourier expansion basis to obtain a system of ordinary differential equation (ODE) then we implement the numerical scheme by computer programing and perform numerical solution. Finally the validation of the present scheme is demonstrated by numerical example and compared with some existing numerical methods in literature. The method is analyzed for stability and convergence. It is found that the proposed numerical scheme produces a good result as compared to other researcher’s result and even generates a value at the nodes or mesh points that the results have not seen yet.

Image Analysis by Two Types of Franklin-Fourier Moments

In this paper,we first derive two types of transformed Franklin polynomial:substituted and weighted radial Franklin polynomials.Two radial orthogonal moments are proposed based on these two types of polynomials,namely substituted Franklin-Fourier moments and weighted Franklin-Fourier moments(SFFMs and WFFMs),which are orthogonal in polar coordinates.The radial kernel functions of SFFMs and WFFMs are transformed Franklin functions and Franklin functions are composed of a class of complete orthogonal splines function system of degree one.Therefore,it provides the possibility of avoiding calculating high order polynomials,and thus the accurate values of SFFMs and WFFMs can be obtained directly with little computational cost.Theoretical and experimental results show that Franklin functions are not well suited for constructing higher-order moments of SFFMs and WFFMs,but compared with traditional orthogonal moments(e.g.,BFMs,OFMs and ZMs)in polar coordinates,the proposed two types of Franklin-Fourier Moments have better performance respectively in lower-order moments.

THE GLOBAL SOLUTIONS FOR A FOURTH ORDER NONLINEAR SCHRaINGER EQUATION

Is this Paper, the global existence of smooth solutions to the Antial value problem for the fourth order nonlinear Schrodinger equation in the Lax hierarchy of the nonlinear fSchrodinger equation(NLS equation) is established by using the so-called continuation method and delicate a priori estimate. In addition, the asylnptotic properties of the solutions as|×|+∞ are discussed.

Estimation of Winds at Different Isobaric Levels Based on the Observed Winds at 850 hPa Level Using Double Fourier Series

A technique based on the double Fourier series is developed to estimate the winds at different isobaric levels forthe limited area domain, 35°E to 140°E and 30°S to 40°N, using the observed winds at 850 hPa lcvcl for the month ofJune. For this purpose the wind field at a level under consideration is taken in the ratio form with that of 850 hPa level and the coefficients of the double Fouricr series are computed. These coefficients are subsequently used to computethe winds which are compared with the actual winds. The results of the double Fourier series technique are comparedwith those of the polynomial surface fitting method developed by Bavadekar and Khaladkar (1 992). The technique isalso applied for the daily wind data of 11. June, 1979 and the validation of the technique is tested for a few radiosondestations of india. The computed winds for these radiosonde stations arc quite close to observed winds.

The Use of Fourier Descriptors for the Classification and Analysis of Peripheral Blood Smears Image

The article discusses the use of Fourier descriptors for the analysis and classification of blood cells. A model describing the contour boundaries in the form of two-dimensional numerical sequence Fourier descriptors. The influence of the shape and orientation of the figures on the parameters of the Fourier descriptors. Explore ways to ensure the invariance of the Fourier descriptors with respect to geometric transformations. A model of the graphical representation of the Fourier descriptors of computer graphics tools. A method of forming a space of informative features based on Fourier descriptors for the neural network, classifying the contours of borders image segments.

The Four Intersection-and-Difference Model for Line-Line Topological Relations

The description of line-line topological relations is still an unsolved issue although much effort has been done. The problem is involved in many practical applications such as spatial query, spatial analysis and cartographic generalization. To develop a sound and effective approach to describe line-line relations, it is first necessary to define the topology of an individual line, i.e., local topology. The concept of connective degree is used for the identification of topological differences in the geometric structure of a line. The general topological definition of a line is given, i.e., endpoints set and interior point set. This definition can be applied to the embedded spaces of different dimensions, whether co-dimension is equal to or larger than zero. On this basis, a generic model called the 4 intersection-and-difference is set up for the description of basic line-line topological relations, upon which a conceptual neighborhood graph is built with consideration of topological distance, it is concluded that the proposed model can represent the property of topological changes, and basic relations between line segments in IR^1 and IR^2.

ALMOST SURE GLOBAL WELL-POSEDNESS FOR THE FOURTH-ORDER NONLINEAR SCHR?DINGER EQUATION WITH LARGE INITIAL DATA

We consider the fourth-order nonlinear Schr?dinger equation(4NLS)(i?t+εΔ+Δ2)u=c1um+c2(?u)um-1+c3(?u)2um-2,and establish the conditional almost sure global well-posedness for random initial data in Hs(Rd)for s∈(sc-1/2,sc],when d≥3 and m≥5,where sc:=d/2-2/(m-1)is the scaling critical regularity of 4NLS with the second order derivative nonlinearities.Our proof relies on the nonlinear estimates in a new M-norm and the stability theory in the probabilistic setting.Similar supercritical global well-posedness results also hold for d=2,m≥4 and d≥3,3≤m<5.

A Simple and Effective Surface Defect Detection Method of Power Line Insulators for Difficult Small Objects

Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable scale,and fuzzy edge morphology of insulator defects,we construct an insulator dataset with 1600 samples containing flashovers and breakages.Then a simple and effective surface defect detection method of power line insulators for difficult small objects is proposed.Firstly,a high-resolution featuremap is introduced and a small object prediction layer is added so that the model can detect tiny objects.Secondly,a simplified adaptive spatial feature fusion(SASFF)module is introduced to perform cross-scale spatial fusion to improve adaptability to variable multi-scale features.Finally,we propose an enhanced deformable attention mechanism(EDAM)module.By integrating a gating activation function,the model is further inspired to learn a small number of critical sampling points near reference points.And the module can improve the perception of object morphology.The experimental results indicate that concerning the dataset of flashover and breakage defects,this method improves the performance of YOLOv5,YOLOv7,and YOLOv8.In practical application,it can simply and effectively improve the precision of power line insulator defect detection and reduce missing detection for difficult small objects.

一种基于Laplace-Fourier域衰减系数的初始模型获取策略

频率域全波形算法由于其高精度,高效计算性能,已逐步成为地震勘探中重要的反演手段。但其对低频信息和初始模型有较大依赖,在Laplace-Fourier域进行反演能产生一些伪低频信息,为实际反演提供较好的初始模型,与此同时,其反演的有效深度也会随之变浅,且衰减系数因子越大,反演有效深度越浅。针对这些不足,本文提出一种结合不同衰减系数因子的基于Laplace-Fourier域全波形反演策略,利用不同衰减系数因子反演时的不同的波数信息相结合的方式,获得与目标模型相接近的初始速度模型。