Optical 3D Surface Vertical Measurement Based on 2D Generalized S-Transform

Force and vibration generated in apical direction by three endodontic files of different kinematics during simulated canal preparation: An in vitro analytical study.

This paper investigates the feasibility of measuring form error of all the optical surfaces on a lens in a single setup using a dual tipped diamond stylus. Two lenses were measured with a dual, 2 μm conisphere tipped, diamond stylus on a tactile profilometer having a phase grating interferometer (PGI) gauge. When the lens was mounted in a horizontal orientation, one of the stylus tips was used to measure the optical surface on top of the lens (hereafter referred to as measurement using normal bias), whereas the other stylus tip (180˚ opposite) was used to measure the optical surface on bottom of the lens (hereafter referred to as measurement using reverse bias). To validate the results from the measurement using reverse bias, a given optical surface was measured using both normal bias and reverse bias of the PGI gauge with a suitable fixture. Moreover, this surface was also measured on a LuphoScan instrument, a 3D non-contact profiler based on multiwavelength interferometry, and an average form error profile was extracted from the 3D surface form error map. Surface form was quantified by evaluating peak-to-valley (PV), and root mean square (RMS) parameters to compare the results obtained from measurements using normal bias, reverse bias, and multiwavelength interferometer. It is shown that there is a good agreement not only between normal bias and reverse bias measurements using PGI gauge but also with measurement performed on multiwavelength interferometer. With this additional capability of PGI gauge to measure form error of all the optical surfaces in a single setup, results from both surfaces can be correlated to determine wedge, commonly referred to as inner centration, decenter error between the two surfaces, and thickness of the lens under test.

Three-Dimensional Quantitative Comparative Analysis of Trapezial-Metacarpal Joint Surface Curvatures in Human Populations

The aim of the present research is to calculate the Relative Accuracy (R.A) and Root Mean Square Error (RMSE) for the location of Technical Institute, Mosul in Nineveh Governorate, Iraq. at the northern part of Mosul city by using surveying Instruments (GPS 1230 , Total Station 06 & Level NAK2), to calculate the coordinates and elevations of (16) Ground Control Points which covered the study area. The field data, remote sensing techniques and GIS software (Arc Map GIS10.3) are used to check the digital map of study area that helped the administrator to take the correct decision, determining positions of the future expansionist for buildings, roads, measuring lengths, areas and there coordinates, directions as well as the total costs estimation needed for any development from the final map. The gradient percentage between the highest and lowest points is calculated to be (9.954%). Relative accuracy for the based measured points (R.A) = 1:60000), and Root Mean Square error in Easting coordinates (RMSE) = ± 0.102m, in Northing coordinates (RMSN) = ± 0.096m, the Root Mean Square for the resultant (RMSR) = ± 0.099m, and Root Mean Square for Elevations ( RMSRL)= ± 0.005m. We Matched and correlated (10) measured points from study area with their graphic data positions on the aerial photo, determining the offsets for position and elevations as follows: (RMSE = ± 0.076m), (RMSN = ± 0.125m), (RMSR = ± 0.088m), and (Root Mean Square for Elevations = RMSRL= ± 0.045m). This research enable us after checking the results to produce new maps from Aerial photograph or Digital Image to use it for land uses and future extensions in whole study area.

Radar antennas in the open air are affected by dynamic wind loading during azimuthal scanning. In this state, the acquisition and prediction of the aerodynamic load is the focus of the structure design for the antenna. We performed wind tunnel force tests on flat plate antennas with different aspect ratios. The changes in mean, maximum, and root mean square values of the aerodynamic coefficients relative to the antenna aspect ratio and reduced frequency are given for the first time. The effects of the antenna aspect ratio and reduced frequency on aerodynamic characteristics are analyzed. The experimental results indicate that the magnitude of the azimuthal moment is related to the antenna aspect ratio and the reduced frequency. It is worth noting that the antenna aspect ratio has a significant impact on the mean, maximum, and root mean square values of dynamic aerodynamic coefficients. The mean, maximum, and root mean square values of the rolling moment coefficient, azimuth moment coefficient, and pitching moment coefficient monotonously decrease with the increase in aspect ratio. In addition, the influence of reduced frequency on the dynamic aerodynamic coefficient is closely related to the antenna aspect ratio. Under the same antenna aspect ratio, increasing the reduced frequency will increase the mean, maximum, and root mean square values of the aerodynamic coefficient. For flat plate antennas with different aspect ratios, at the condition of increasing the aspect ratios, the mean, maximum, and root mean square values of aerodynamic coefficients do not change significantly with the change of reduced frequency.

Due to its low complexity and acceptable accuracy, phase retrieval technique has been proposed as an alternative to solve the classic optical surface measurement task. However, to capture the overall wave field, phase retrieval based optical surface measurement (PROSM) system has to moderate the CCD position during the multiple-sampling procedure. The mechanical modules of CCD movement may bring about unexpectable deviation to the final results. To overcome this drawback, we propose a new PROSM method based on spatial light modulator (SLM). The mechanical CCD movement can be replaced by an electrical moderation of SLM patterns; thus the deviation can be significantly suppressed in the new PROSM method. In addition, to further improve the performance, we propose a new iterative threshold phase retrieval algorithm with sparsity-constraint to effectively reconstruct the phase of wave field. Experimental results show that the new method provides a more simple and robust solution for the optical surface measurement than the traditional techniques and achieves higher accuracy.

Soil Roughness Measuring System Combined With Image Processing

The control of surface errors as a function of spatial frequency is critical during the fabrication of modern optical systems. A large-scale surface figure error is controlled by a guided removal process, such as computer-controlled optical surfacing. Smaller-scale surface errors are controlled by polishing process parameters. Surface errors of only a few millimeters may degrade the performance of an optical system, causing background noise from scattered light and reducing imaging contrast for large optical systems. Conventionally, the microsurface roughness is often given by the root mean square at a high spatial frequency range, with errors within a 0.5×0.5 mm local surface map with 500×500 pixels. This surface specification is not adequate to fully describe the characteristics for advanced optical systems. The process for controlling and minimizing mid- to high-spatial frequency surface errors with periods of up to ∼2-3 mm was investigated for many optical fabrication conditions using the measured surface power spectral density (PSD) of a finished Zerodur optical surface. Then, the surface PSD was systematically related to various fabrication process parameters, such as the grinding methods, polishing interface materials, and polishing compounds. The retraceable experimental polishing conditions and processes used to produce an optimal optical surface PSD are presented.

Analysis of lard extracted from lipstick formulation containing castor oil has been performed using FTIR spectroscopic method combined with multivariate calibration. Three different extraction methods were compared, namely saponification method followed by liquid/liquid extraction with hexane/dichlorometane/ethanol/water, saponification method followed by liquid/liquid extraction with dichloromethane/ethanol/water, and Bligh & Dyer method using chloroform/methanol/water as extracting solvent. Qualitative and quantitative analysis of lard were performed using principle component (PCA) and partial least square (PLS) analysis, respectively. The results showed that, in all samples prepared by the three extraction methods, PCA was capable of identifying lard at wavelength region of 1200-800 cm-1 with the best result was obtained by Bligh & Dyer method. Furthermore, PLS analysis at the same wavelength region used for qualification showed that Bligh and Dyer was the most suitable extraction method with the highest determination coefficient (R2) and the lowest root mean square error of calibration (RMSEC) as well as root mean square error of prediction (RMSEP) values.

Refractive and Aberrometric Outcomes of Intracorneal Ring Segments for Keratoconus: Mechanical versus Femtosecond-assisted Procedures

Benchmarking Functional Status in Older Adults

Objectives. This study provides a quantitative assessment of the impact of latent variables on regional economic activity and examines the interactions among various economic sectors and their contributions to regional growth. The analysis focuses on identifying latent factors of socio-economic development across Belarusian regions during the period 2016-2024, using factor analysis techniques and structural equation modeling (SEM). Methods. To reduce data dimensionality and identify latent factors, exploratory factor analysis (EFA) was applied using the Principal Component Analysis (PCA) extraction method. A structural equation model was constructed using the SEMOPY library in Python to estimate relationships among the identified factors. To assess the quality of the model, standard fit indices were used: CFI – comparative fit index; TLI – Tucker-Lewis index; RMSEA – root mean square error of approximation. The values of these indices allow evaluating the degree of consistency between the model and the empirical data. The model is based on a system of 23 socio-economic indicators across 128 administrative districts and cities of regional subordination. Results. The resulting SEM demonstrates high internal consistency and statistical reliability (CFI = 0,98; TLI = 0,97; RMSEA = 0,04), revealing significant causal linkages between latent factors. It was established that the financial sector is a key driver of investment activity, while growth in the housing stock directly stimulates consumer demand. Negative relationships were identified between agricultural potential and financial stability, as well as between industrial development and financial sustainability. Conclusion. The developed model is an effective analytical tool for formulating evidence-based regional policy, optimizing resource allocation, and strategic planning. Promising directions for future research include incorporating time lags, adding indicators of innovation and human potential, and applying spatial econometrics methods.

Electrocardiogram (ECG) is easily submerged in noise of the complex environment during remote medical treatment, and this affects the intelligent diagnosis of cardiovascular diseases. Considering this situation, this paper proposes an echo state network (ESN) denoising algorithm based on recursive least square (RLS) for ECG signals. The algorithm trains the ESN through the RLS method, and can automatically learn the deep nonlinear and differentiated characteristics in the noisy ECG data, and then the network can use these characteristic to separate out clear ECG signals automatically. In the experiment, the proposed method is compared with the wavelet transform with subband dependent threshold and the S-transform method by evaluating the signal-to-noise ratio and root mean square error. Experimental results show that the denoising accuracy is better and the low frequency component of the signal is well preserved. This method can effectively filter out complex noise and effectively preserve the effective information of ECG signals, which lays a foundation for the recognition of ECG signal feature waveform and the intelligent diagnosis of cardiovascular disease.

Present a novel method of 3D shape measurement of optical free-from surface based on fringe projection. A virtual reference surface is proposed which can be used to improve the detection efficiency and realize the automation of measuring process. Sinusoidal fringe patterns are projected to the high reflected surface of the measured object. The deflection fringe patterns that modulated by the object surface are captured by the CCD camera. The slope information can be obtained by analyzing the relationship between the phase deflectometry and the slope of the object surface. The wave-front reconstruction method is used to reconstruct the surface. With the application of fringe projection technology the accuracy of optical free-form surfaces measurement could reach the level of tens of micrometer or even micrometer.

The preparation, structure, and mechanical stability of self-assembled monolayers formed by octadecyltriethoxysilane (OTE) on mica have been studied by atomic force microscopy. The nanometer scale morphology of the films (3-D clusters, pinholes, etc.) is compared for various preparation methods and correlated with their macroscopic wettability. High-resolution images of the atomically smooth monolayer (1.5 A root mean square roughness) reveal the existence of only short range order. By applying a load above 10 nN with sharp Si{sub 3}N{sub 4} tips (radius < 300 A), the film could be removed leaving 25 A deep holes. Using the same tip, thiol monolayers on gold could be displaced at loads 5 nN, although, in this case, the displacement was reversible. In contrast to the case of OTE, films formed by octadecyldimethylmethoxysilane (ODMS) showed the presence of only 3-D clusters with poor adhesion to the mica substrate. On the basis of these results, we conclude that the mechanical strength of the films formed by OTE is due to siloxane cross-linking between molecules rather than to chemical bonding to the mica substrate. 13 refs., 5 figs.