An Analysis of Deviations of Cylindrical Surfaces with the Use of Wavelet Transform

2013 ◽  
Vol 20 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Krzysztof Stępień ◽  
Włodzimierz Makieła

Abstract Wavelet transform becomes a more and more common method of processing 3D signals. It is widely used to analyze data in various branches of science and technology (medicine, seismology, engineering, etc.). In the field of mechanical engineering wavelet transform is usually used to investigate surface micro- and nanotopography. Wavelet transform is commonly regarded as a very good tool to analyze non-stationary signals. However, to analyze periodical signals, most researchers prefer to use well-known methods such as Fourier analysis. In this paper authors make an attempt to prove that wavelet transform can be a useful method to analyze 3D signals that are approximately periodical. As an example of such signal, measurement data of cylindrical workpieces are investigated. The calculations were performed in the MATLAB environment using the Wavelet Toolbox.

Author(s):  
M. Liaghat ◽  
A. Abdollahi ◽  
F. Daneshmand ◽  
T. Liaghat

Non-stationary signals are frequently encountered in a variety of engineering fields. The inability of conventional Fourier analysis to preserve the time dependence and describe the evolutionary spectral characteristics of non-stationary processes requires tools which allow time and frequency localization beyond customary Fourier analysis. The spectral analysis of non-stationary signals cannot describe the local transient features due to averaging over the duration of the signal [1]. The Fourier Transform (FT) and the short time Fourier transform (STFT) have been often used to measure transient phenomena. These techniques yield good information on the frequency content of the transient, but the time at which a particular disturbance in the signal occurred is lost [2, 3]. Wavelets are relatively new analysis tools that are widely being used in signal analysis. In wavelet analysis, the transients are decomposed into a series of wavelet components, each of which is a time-domain signal that covers a specific octave band of frequency. Wavelets do a very good job in detecting the time of the signal, but they give the frequency information in terms of frequency band regions or scales [4]. The main objective of this paper is to use the wavelet transform for analysis of the pressure fluctuations occurred in the bottom-outlet of Kamal-Saleh Dam. The “Kamalsaleh Dam” is located on the “Tire River” in Iran, near the Arak city. The Bottom Outlet of the dam is equipped with service gate and emergency gate. A hydraulic model test is conducted to investigate the dynamic behavior of the service gate of the outlet. The results of the calculations based on the wavelet transform is then compared with those obtained using the traditional Fast Fourier Transform.


Author(s):  
Armando Martínez Ríos

ABSTRACTMexico lacks a scientific culture. Investigations and reports show that only has a record of 38 thousand scientific and 0.5% global of registered patents in the world. Communications and electronics engineering (ICE) is one of the three formations in the school of mechanical engineering and electrical (ESIME) unit Zacatenco from the Instituto Politécnico Nacional (IPN) Mexico. Among the objectives of this mentioned formation on its web site, is the form professionals with scientific and technological foundations; However, the curriculum includes only two subjects with these characteristics. Less than 1% of the graduates also choose to devote himself to scientific work. This paper shows the results obtained by means of a survey on the perception that students have about scientists in order to propose actions that foster a greater interest in them by the science and technology into their professional formation.RESUMENMéxico carece de una cultura científica ya que algunas encuestas muestran que solo se tiene un registro de 38 mil científicos y el 0.5% del total mundial de patentes registradas. Ingeniería en Comunicaciones y Electrónica (ICE) es una de las tres carreras de la Escuela Superior de Ingeniería Mecánica y Eléctrica (ESIME) unidad Zacatenco del Instituto Politécnico Nacional (IPN) México. Entre los objetivos de esta carrera mencionado en su sitio web, es el de formar profesionistas con fundamentos científicos y tecnológicos; sin embargo, el currículo, contempla solo dos asignaturas con estas características. Asimismo, menos del 1% de los egresados elige dedicarse a una labor científica. Este trabajo muestra los resultados obtenidos por medio de una encuesta sobre la percepción que los estudiantes tienen sobre los científicos con el fin de proponer acciones que fomenten un mayor interés en ellos por la ciencia y la tecnología dentro de su formación.


Author(s):  
Joanne Pransky

Purpose The following paper is a “Q&A interview” conducted by Joanne Pransky of Industrial Robot Journal as a method to impart the combined technological, business and personal experience of a prominent, robotic industry PhD-turned-entrepreneur regarding the commercialization and challenges of bringing a technological invention to market. This paper aims to discuss these issues. Design/methodology/approach The interviewee is Dr Jun Ho Oh, Professor of Mechanical Engineering at the Korea Advanced Institute of Science and Technology (KAIST) and Director of KAIST’s Hubolab. Determined to build a humanoid robot in the early 2000s to compete with Japan’s humanoids, Dr Oh and KAIST created the KHR1. This research led to seven more advanced versions of a biped humanoid robot and the founding of the Robot for Artificial Intelligence and Boundless Walking (Rainbow) Co., a professional technological mechatronics company. In this interview, Dr Oh shares the history and success of Korea’s humanoid robot research. Findings Dr Oh received his BSc in 1977 and MSc in Mechanical Engineering in 1979 from Yonsei University. Oh worked as a Researcher for the Korea Atomic Energy Research Institute before receiving his PhD from the University of California (UC) Berkeley in mechanical engineering in 1985. After his PhD, Oh remained at UC Berkeley to do Postdoctoral research. Since 1985, Oh has been a Professor of Mechanical Engineering at KAIST. He was a Visiting Professor from 1996 to 1997 at the University of Texas Austin. Oh served as the Vice President of KAIST from 2013-2014. In addition to teaching, Oh applied his expertise in robotics, mechatronics, automatic and real-time control to the commercial development of a series of humanoid robots. Originality/value Highly self-motivated and always determined, Dr Oh’s initial dream of building the first Korean humanoid bipedal robot has led him to become one of the world leaders of humanoid robots. He has contributed widely to the field over the nearly past two decades with the development of five versions of the HUBO robot. Oh led Team KAIST to win the 2015 DARPA Robotics Challenge (DRC) and a grand prize of US$2m with its humanoid robot DRC-HUBO+, beating 23 teams from six countries. Oh serves as a robotics policy consultant for the Korean Ministry of Commerce Industry and Energy. He was awarded the 2016 Changjo Medal for Science and Technology, the 2016 Ho-Am Prize for engineering, and the 2010 KAIST Distinguished Professor award. He is a member of the Korea Academy of Science and Technology.


2021 ◽  
Vol 2066 (1) ◽  
pp. 011001

2021 International Conference on Information Technology and Mechanical Engineering Youqiang Xing1, Shuanghua Yang2 1Department of Mechanical Engineering, Southeast University, China 2Engineering College, Southern University of Science and Technology, China E-mail: [email protected], [email protected] 2021 International Conference on Information Technology and Mechanical Engineering were successfully held online from 29th to 30th April 2021, Hangzhou, China. The conference was jointly organized and sponsored by Shaanxi Juxing Exhibition Co., Ltd and Juneng Electronic Technology Co., Ltd. Called by Dr. Youqiang Xing from Department of Mechanical Engineering, Southeast University and researcher Shuanghua Yang from the Engineering College, Southern University of Science and Technology, the conference invited scholars and experts in the fields of information technology and mechanical engineering from various universities to participate in the review and guidance of this conference. The conference focuses on the latest research fields such as “information technology” and “mechanical engineering”, and aims to provide an international cooperation and exchange platform for experts, scholars and business managers in the fields of information technology and mechanical engineering application to share their research achievements, discuss the key challenges and research directions of the development of this field, and jointly promote the industrialization cooperation and continuous innovation of international academic achievements. This collection of Proceedings compiles oral and paper presentations submitted by the authors and scrutinized by the Special Committee. The conference was scheduled to be held on April 29-30, 2021 at Marco Polo Holiday Hotel, Hangzhou, Zhejiang, China. In view of travel restrictions and indoor activities related to COVID-19, we were forced to move the conference online. Attendees were notified one month in advance that the on-site conference was changed to an online conference, and the time and order of the conference were determined. The online conference was held on the video conferencing software Tencent Meeting. The video conference was held on the original date, but due to the large number of attendees, we extended the Meeting for 2 days. Due to the wide coverage of this conference and the large number of attendees, we divided the conference into main venue and sub-venue. The opening ceremony was held in the main venue and a speech was delivered by the invited speaker. After the main venue, we divided the invited 154 authors into 3 groups. Each author spoke for about 10-15 minutes on detailed material in the slides, with the same amount of time set aside for questions and discussion. The format of questioning and discussion was that after each author’s introduction, the conference chairman and committee members asked and answered questions. At least one attendee could ask questions that will be answered by the speaker. This conference has brought together many excellent works and the latest ideas and concepts. New ideas have been provided in the fields of information technology and mechanical engineering applications. For this, we have set up three awards, which were won by six authors. Due to the large number of attendees and the instability of the video conference software, we edited and retained part of the conference speech pictures and videos after the video conference. We put some screenshots of the conference on the official website for display. Although most attendees expressed regret that we had not been able to have the informal face-to-face discussions that usually take place between conferences, the virtual conferences had been surprisingly successful. The organizing and editorial committee of the ITME2021 hopes you enjoy the reading of this volume of the JPCS. Besides, we wish to thank all authors and participants for providing their valuable contributions for this proceeding as well as the reviewers for their constructive recommendations and criticism aiding to improve the presented articles. Likewise, we are confident that this issue will serve as a reference for experts, scholars and enterprise managers in the fields of the information technology and mechanical engineering. List of Photos, Organizing Committee are available in this pdf.


Solar Physics ◽  
2015 ◽  
Vol 290 (9) ◽  
pp. 2507-2518 ◽  
Author(s):  
E. Aguilar-Rodriguez ◽  
J. C. Mejia-Ambriz ◽  
B. V. Jackson ◽  
A. Buffington ◽  
E. Romero-Hernandez ◽  
...  

1984 ◽  
Vol 3 (1) ◽  
pp. 29-33
Author(s):  
P. C. Haarhoff

The first technological revolution, in the fourth millennium BC, was followed by immense social progress. The second revolution, which is now taking place, could lead to an even greater development in the human sciences, by setting men free from their daily struggle for existence while simultaneously exacting high social standards. Natural law - the “marriage between the ways of heaven and the ways of earth” of the Chinese - represents a route to such progress. In natural science and technology, natural law demands that conclusions be based on observation rather than speculation. The social sciences would do well to follow this example.


2013 ◽  
Vol 303-306 ◽  
pp. 1043-1047
Author(s):  
Hai Long Li ◽  
Jun Xu ◽  
Wen Jia ◽  
Sheng Zhu ◽  
Sha Li ◽  
...  

Spectral measurement is a common method for color measurement. Spectral data of color samples gathered by spectrometers contains a series of noises. The traditional de-noising methods have their limitation in dealing with such signal. In this paper, a de-noising method is proposed for spectral signal based on Wavelet Transform. Compared the performance of our de-nosing method with the traditional method, the results show that our method a better effect.


2021 ◽  
Vol 11 (1) ◽  
pp. 216-222
Author(s):  
Guiping Zhang ◽  
Lili Zhou ◽  
Xiao Zhang ◽  
Xiaoli Gao ◽  
Lingling Li

In order to improve the treatment accuracy of patients with different subtypes of bladder prolapse (BP), the value of ultrasonic images based on fuzzy theory (FT) and wavelet transform (WT) algorithm for detection and classification of subtypes of BP was discussed. First, the effects of fuzzy enhancement (FE) algorithm, WT enhancement algorithm, and FT combined wavelet algorithm on medical ultrasonic images were compared. Then, 144 cases of BP patients admitted to our hospital from October 2017 to October 2019 were selected as study objects. Ultrasound technology was used to examine the patient's bottom information. Finally, the data of posterior urethra-vesical angle (PUVA), rotation angle (RA) of urethra, mobility of bladder neck, lowest point of bladder and lowest point of posterior wall of bladder were measured under resting and Vslsalva conditions. According to Green classification, different subtypes of bladder prolapse were distinguished by the measurement data of pelvic floor (PF) ultrasound image. The clinical characteristics of Stress Urinary Incontinence (SUI), dysuria, and frequent urination of subtypes of BP were compared. The results showed that the ultrasonic image quality was the best by combining FT with WT; BP type II PUVA was more than 140°, BP type III PUVA was less than 140°, and the difference between the two was statistically significant (P < 0.05); the lowest point of the bladder in patients with type III BP was significantly higher than that in patients with type II BP (P < 0.05), and the neck mobility of type III bladder and the lowest point of the posterior wall of the bladder were significantly lower than that in patients with type II BP (P < 0.05); the difference of urethral RA between type II and type III of BP was not statistically significant (P > 0.05); the incidence of SUI in patients with type II BP was higher than that of type III BP (P < 0.05), and the incidence of dysuria in patients with type III BP was higher than that of type II BP (P < 0.05); the incidence of urinary frequency in patients with type II and type III BP was not statistically significant (P > 0.05), which showed that PF ultrasound based on FT and WT algorithm could effectively detect and identify different subtypes of BP.


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