Laser mode control with variable reflectivity mirrors

1988 ◽  
Vol 66 (10) ◽  
pp. 888-895 ◽  
Author(s):  
Pierre Lavigne ◽  
Nathalie McCarthy ◽  
André Parent ◽  
Kevin J. Snell

Global efficiency, transverse mode discrimination, and the near- and far-field optical quality of unstable laser resonators are improved with variable reflectivity mirrors (VRMs). Analytical and numerical results are given for Gaussian and parabolic reflectivity mirrors. The VRM design is described, and experimental results obtained using different lasers with Cassegrain cavities are presented.

2014 ◽  
Vol 611-612 ◽  
pp. 1062-1070 ◽  
Author(s):  
Reimund Neugebauer ◽  
Welf Guntram Drossel ◽  
Markus Rössinger ◽  
Alexander Eckert ◽  
Benjamin Hecht

The presented study applied the state of the art in roller hemming simulation on a car body assembly. Corner areas with changing flange lengths are always challenging in case of reaching the quality demands. Thus, the numerical results like e.g. springback, hem thickness, roll-in and hemming geometry are compared to experimental results. It is shown that the quality of prediction depends on the system stiffness of the roller hemming device, the geometrical contour of the car body assembly and the consideration of steps in the process chain like stamping and flanging. Finally, the gained cognitions point out challenges for future research in this topic.


2011 ◽  
Vol 19 (2) ◽  
pp. 407-413
Author(s):  
郭汝海 GUO Ru-hai ◽  
张合勇 ZHANG He-yong ◽  
王挺峰 WANG Ting-feng

Author(s):  
В. М. Жихарєв ◽  
В. Ю. Лоя ◽  
А. М. Соломон ◽  
Я. В. Грицище

2021 ◽  
Vol 40 (5) ◽  
pp. 9361-9382 ◽  
Author(s):  
Naeem Iqbal ◽  
Rashid Ahmad ◽  
Faisal Jamil ◽  
Do-Hyeun Kim

Quality prediction plays an essential role in the business outcome of the product. Due to the business interest of the concept, it has extensively been studied in the last few years. Advancement in machine learning (ML) techniques and with the advent of robust and sophisticated ML algorithms, it is required to analyze the factors influencing the success of the movies. This paper presents a hybrid features prediction model based on pre-released and social media data features using multiple ML techniques to predict the quality of the pre-released movies for effective business resource planning. This study aims to integrate pre-released and social media data features to form a hybrid features-based movie quality prediction (MQP) model. The proposed model comprises of two different experimental models; (i) predict movies quality using the original set of features and (ii) develop a subset of features based on principle component analysis technique to predict movies success class. This work employ and implement different ML-based classification models, such as Decision Tree (DT), Support Vector Machines with the linear and quadratic kernel (L-SVM and Q-SVM), Logistic Regression (LR), Bagged Tree (BT) and Boosted Tree (BOT), to predict the quality of the movies. Different performance measures are utilized to evaluate the performance of the proposed ML-based classification models, such as Accuracy (AC), Precision (PR), Recall (RE), and F-Measure (FM). The experimental results reveal that BT and BOT classifiers performed accurately and produced high accuracy compared to other classifiers, such as DT, LR, LSVM, and Q-SVM. The BT and BOT classifiers achieved an accuracy of 90.1% and 89.7%, which shows an efficiency of the proposed MQP model compared to other state-of-art- techniques. The proposed work is also compared with existing prediction models, and experimental results indicate that the proposed MQP model performed slightly better compared to other models. The experimental results will help the movies industry to formulate business resources effectively, such as investment, number of screens, and release date planning, etc.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 215
Author(s):  
Rajeev R. Kosireddy ◽  
Stephen T. Schaefer ◽  
Marko S. Milosavljevic ◽  
Shane R. Johnson

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.


2021 ◽  
pp. 112067212110021
Author(s):  
Javier Ruiz-Alcocer ◽  
Irene Martínez-Alberquilla ◽  
Amalia Lorente-Velázquez ◽  
José F Alfonso ◽  
David Madrid-Costa

Purpose: To objectively analyze the optical quality of the FineVision Toric intraocular lens (IOL) with two cylinder powers when different combinations of rotations and residual refractive errors are induced. Methods: This study assessed the FineVision Toric IOL with two different cylinder powers: 1.5 and 3.0 diopters (D). Three different rotation positions were considered: centered, 5° and 10° rotated. An optical bench (PMTF) was used for optical analysis. The optical quality of the IOLs was calculated by the modulation transfer function (MTF) at five different focal points (0.0, 0.25, 0.50, 0.75, and 1.00 D). Results: The MTF averaged value of the reference situation was 38.58 and 37.74 for 1.5 and 3.0 D of cylinder, respectively. For the 1.5 D cylinder, the combination of 5° of rotation with a defocus of 0.25, 0.50, 0.75, and 1.0 D induced a decrease on the MTF of 12.39, 19.94, 23.43, 24.23 units, respectively. When induced rotation was 10°, the MTF decrease was 17.26, 23.40, 24.33, 24.48 units, respectively. For the 3.0 D cylinder, the combination of 5° with 0.25, 0.50, 0.75, and 1.0 D of defocus, induced a decrease on the MTF of 12.51, 18.97, 22.36, 22.48 units, respectively. When induced rotation was 10°, the MTF decrease was: 18.42, 21.57, 23.08, and 23.61 units, respectively. Conclusion: For both FineVision Toric IOLs there is a certain optical tolerance to rotations up to 5° or residual refractive errors up to 0.25 D. Situations over these limits and their combination would affect the visual quality of patients implanted with these trifocal toric IOLs.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 673
Author(s):  
Augustyn Wójcik ◽  
Piotr Bilski ◽  
Robert Łukaszewski ◽  
Krzysztof Dowalla ◽  
Ryszard Kowalik

The paper presents the novel HF-GEN method for determining the characteristics of Electrical Appliance (EA) operating in the end-user environment. The method includes a measurement system that uses a pulse signal generator to improve the quality of EA identification. Its structure and the principles of operation are presented. A method for determining the characteristics of the current signals’ transients using the cross-correlation is described. Its result is the appliance signature with a set of features characterizing its state of operation. The quality of the obtained signature is evaluated in the standard classification task with the aim of identifying the particular appliance’s state based on the analysis of features by three independent algorithms. Experimental results for 15 EAs categories show the usefulness of the proposed approach.


2019 ◽  
Vol 9 (13) ◽  
pp. 2684 ◽  
Author(s):  
Hongyang Li ◽  
Lizhuang Liu ◽  
Zhenqi Han ◽  
Dan Zhao

Peeling fibre is an indispensable process in the production of preserved Szechuan pickle, the accuracy of which can significantly influence the quality of the products, and thus the contour method of fibre detection, as a core algorithm of the automatic peeling device, is studied. The fibre contour is a kind of non-salient contour, characterized by big intra-class differences and small inter-class differences, meaning that the feature of the contour is not discriminative. The method called dilated-holistically-nested edge detection (Dilated-HED) is proposed to detect the fibre contour, which is built based on the HED network and dilated convolution. The experimental results for our dataset show that the Pixel Accuracy (PA) is 99.52% and the Mean Intersection over Union (MIoU) is 49.99%, achieving state-of-the-art performance.


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