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1

Noise effect on parameters of quiet sonar with code modulation

Salamon Roman, Marszal Jacek, Jedel Andrzej

Vibrations in Physical Systems

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2023

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Vol. 34, nr 1

art. no. 2023109

EN

Earlier publications of the paper authors have shown that the use of code keying mixed with the CW FM sound signal allows the significant reduction in the distance measurement error, compared to classic silent CW FM sonar. In addition to the code modulation parameters, the magnitude of this error is influenced by the received input acoustic noise. The article shows the dependence of the input signal-to-noise ratio and the sound signal parameters on the target distance measurement error and the detection conditions, such as the output signal-to-noise ratio and the side lobe level. The results of the analysis were compared to the same parameters of the CW FM silent sonar without code modulation.

2

Wear Analysis of Iron Slag Reinforced Polyester Composites with Taguchi Optimization

Vijaya Kumar Nimmagadda, Basha Shaik Ahammad, Kishore Chitikena Chaitanya, Aswarthanarayana Potli, Kumar Prathipati Pradeep, Maruthi Rao Marthati, Ravi Babu Sajja

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 6

221--229

EN

In this paper, the dry sliding wear behaviour of the polyester composite reinforced with iron slag as filler was studied experimentally. The Taguchi method-based experiments were carried on pin-on-disk wear test set-up. The control factors considered for studying wear rate were sliding velocity, slag percentage and normal load applied on the member with constant sliding distance. The output performance parameters considered were coefficient of friction and weight loss. From the analysis of variance (ANOVA), it was observed that coefficient of friction is significantly affected by normal load then followed by slag content and sliding velocity. Sliding velocity plays a vital role on the weight loss, then followed by slag content and normal load. The optimal factor combination obtained was sliding velocity = 50 cm/s, slag percentage = 30 % and normal load = 4 kg. The model was validated using the set of optimal factor combinations to conduct a confirmation experiment.

3

ARL-Wavelet-BPF optimization using PSO algorithm for bearing fault diagnosis

Ahsan Muhammad, Bismor Dariusz, Manzoor Muhammad Arslan

Archives of Control Sciences

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2023

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Vol. 33, No. 3

589--606

EN

Rotating element bearings are the backbone of every rotating machine. Vibration signals measured from these bearings are used to diagnose the health of the machine, but when the signal-to-noise ratio is low, it is challenging to diagnose the fault frequency. In this paper, a new method is proposed to enhance the signal-to-noise ratio by applying the Asymmetric Real Laplace wavelet Bandpass Filter (ARL-wavelet-BPF). The Gaussian function of the ARL-wavelet represents an excellent BPF with smooth edges which helps to minimize the ripple effects. The bandwidth and center frequency of the ARL-wavelet-BPF are optimized using the Particle Swarm Optimization (PSO) algorithm. Spectral kurtosis (SK) of the envelope spectrum is employed as a fitness function for the PSO algorithm which helps to track the periodic spikes generated by the fault frequency in the vibration signal. To validate the performance of the ARL-wavelet-BPF, different vibration signals with low signal-to-noise ratio are used and faults are diagnosed.

4

Surface Hardness Prediction Model of Turning Duplex Stainless Steel under Different Cutting Variables

Abdulateef Osamah Fadhil, Ali Abduljabar H., Al Kareem Salah Sabeeh Abed

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 1

1--7

EN

The quality of machine components surfaces plays an important impact on their functional performance. Product performance may be restricted by changes to surface integrity, which includes changes to roughness, hardness, and microstructure. In this research, the impact of cutting variables in CNC turning under the conventional cooling condition on surface hardness of Duplex Stainless Steel. Cutting variables under conventional cooling, including cutting speed, feed, and depth of cut, have been optimized utilizing Taguchi’s L9 orthogonal array designed with three stages of turning variables. The optimal variable stages and the degree of significance of the cutting variables, respectively, were determined utilizing the analysis of means (ANOM) and analysis of variance (ANOVA). Effectiveness tests with optimum stages of variables were done to prove the viability of optimization by utilizing Taguchi. It has been found that the maximum surface hardness is most strongly affected by the feed 71.29%, followed by the depth of cut 12.1%, and finally the cutting speed 11.61%.

5

Processing for near-source potential resistivity based on the parallel electrical method

Hu Zean, Wu Rongxin, Cao Jianfu, Wang Xiaoyu

Acta Geophysica

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2022

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Vol. 70, no 6

2705--2714

EN

The parallel electrical method (PEM), which enhances the field-work efficiency by offering flexible data acquisition and processing a large amount of geoelectric field data, is mainly used to extract the high-density resistivity data. However, the method is unable to process nearly 75% of the data and hampered by noise interference. We proposed a novel method to calculate the apparent resistivity based on the near-source potential in the PEM system using the following algorithms: (1) selecting the measurement electrode nearest to the power source as the reference and keeping the AM interval as an invariant electrode distance, (2) calculating the potential difference between the measurement electrode and the first near-source electrode, (3) stepwise calculating the potential differences between other measurement electrodes and their corresponding near-source electrodes, and (4) calculating all the apparent resistivities at different positions. We further verified the effectiveness of near-source potential method to calculate resistivity based on the theoretical calculation and identified that it has higher calculation accuracy and stability. Compared to the maximum Pole-dipole deviation of 59.4%, the maximum deviation of the near-source potential resistivity is only 2.2%. The field experimental results showed that the near-source potential resistivity method performs well in the stratified geoelectric model and effectively improves the longitudinal resolution and the signal-to-noise ratio of deep apparent resistivity of the parallel direct-current resistivity method.

6

Using stealth technologies in mobile robotic complexes and methods of detection of low-sighted objects

Rudyk Andrii, Semenov Andriy, Semenova Olena, Kakovkin Sergey

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2021

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T. 11, nr 3

4--8

EN

The paper outlines the latest technologies used by the world's leading manufacturers in the development of mobile low-observable robotic systems and promising measures to improve the quality of components and design of such objects. Methods of detecting objects using stealth technologies are considered, and it is shown that only due to a system approach it is possible to compensate for the reduction of the effective scattering surface of low-observable objects by technical means of radar stations. It is shown that the main method of increasing the range to the radio horizont is the use of an air-based radar. Methods of detecting objects on the traces of their interaction with the environment are promising for organization of cooperation of several radars in the detection of low-observable objects.

PL

W artykule przedstawiono najnowsze technologie stosowane przez wiodących światowych producentów w rozwoju mobilnych systemów robotycznych o niskiej obserwowalności oraz obiecujące działania mające na celu poprawę jakości komponentów i konstrukcji takich obiektów. Rozważono metody wykrywania obiektów wykorzystujące technologie stealth i wykazano, że tylko dzięki podejściu systemowemu możliwa jest kompensacja zmniejszenia efektywnej powierzchni rozpraszania obiektów słabo obserwowalnych przez stacje radarowe. Wykazano, że główną metodą zwiększenia zasięgu do poziomu radiowego jest użycie radaru lotniczego. Metody wykrywania obiektów na podstawie śladów ich interakcji z otoczeniem są obiecujące w wykrywaniu obiektów słabo obserwowalnych przy współpracy kilku radarów.

7

Relationship Between Chinese Speech Intelligibility of Elderly and Speech Transmission Index

Peng Jianxin, Zeng Jiazhong, Zhao Yuezhe

Archives of Acoustics

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2021

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Vol. 46, No. 2

229--235

EN

In this paper, the relationship between Chinese speech intelligibility (CSI) scores of the elderly aged 60-69 and over 70 years old, and speech transmission index (STI) were investigated through the auralization method under different reverberation time and background noise levels (BNL, 40 dBA and 55 dBA). The results show that the CSI scores of the elderly are significantly worse than those of young adults. For the elderly over 70, the CSI scores become much lower than those of young adults. To be able to achieve the same CSI, the elderly, especially those over 70, need much higher STI and greater SNR than the young. The elderly aged 60-69 and over 70 need to improve their STI by 0.419 and 0.058 respectively under BNL 40 dBA, as well as 0.282 and 0.072 respectively under BNL 55 dBA, so as to obtain the same CSI scores as the young adults.

8

Design of a dedicated circular coil for Magnetic Resonance Spectroscopy studies in small phantoms and animal acquisition with a 3 Tesla Magnetic Resonance clinical scanner

Giovannetti Giulio, Flori Alessandra, Marchi De Daniele, Montanaro Domenico, Frijia Francesca

Polish Journal of Medical Physics and Engineering

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2020

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Vol. 26, Iss. 4

269--276

EN

Introduction: Magnetic Resonance Spectroscopy (MRS) is a very powerful tool to explore the tissue components, by allowing a selective identification of molecules and molecular distribution mapping. Due to intrinsic Signal-to-Noise Ratio limitations (SNR), MRS in small phantoms and animals with a clinical scanner requires the design and development of dedicated radiofrequency (RF) coils, a task of fundamental importance. In this article, the authors describe the simulation, design, and application of a 1H transmit/receive circular coil suitable for MRS studies in small phantoms and small animal models with a clinical 3T scanner. In particular, the circular coil could be an improvement in animal experiments for tumor studies in which the lesions are localized in specific areas. Material and methods: The magnetic field pattern was calculated using the Biot–Savart law and the inductance was evaluated with analytical calculations. Finally, the coil sensitivity was measured with the perturbing sphere method. Successively, a prototype of the coil was built and tested on the workbench and by the acquisition of MRS data. Results: In this work, we demonstrate the design trade-offs for successfully developing a dedicated coil for MRS experiments in small phantoms and animals with a clinical scanner. The coil designed in the study offers the potential for obtaining MRS data with a high SNR and good spectral resolution. Conclusions: The paper provides details of the design, modelling, and construction of a dedicated circular coil, which represents a low cost and easy to build answer for MRS experiments in small samples with a clinical scanner.

9

An evaluation of the impact of shot and receiver lines spacing on seismic data quality – the Wierzbica 3D AGH seismic experiment

Barmuta Jan, Korbecka Monika, Hadro Piotr, Pieniądz Krzysztof, Stefaniuk Michał, Dzwinel Krzysztof, Buniak Arkadiusz

Geology, Geophysics and Environment

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2020

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Vol. 46, no. 2

93--108

EN

An attempt was made to describe the quality of the stacked seismic data semi-quantitatively with respect to the spacing of shot and receiver lines. The methods used included: signal-to-noise ratio calculation, seismic-to-well tie accuracy, wavelet extraction effectiveness and reliability of semi-automated interpretation of seismic attributes. This study was focused on the Ordovician-Silurian interval of the Lublin Basin, Poland, as it was considered as a main target for the exploration of unconventional hydrocarbon deposits. Our results reconfirm the obvious dependency between the density of the acquisition parameters and data quality. However, we also discovered that the seismic data quality is less affected by the shot line spacing than by comparable receiver line spacing. We attributed this issue to the fact of the higher irregularity of the shot points than receiver points, imposed by the terrain accessibility. We have also proven that the regularity of receiver and shot point distribution is crucial for the reliable interpretation of structural seismic attributes, since these were found to be highly sensitive to the acquisition geometry.

10

Comparative Analysis of the Efficiency of Detecting Some Amplitude-Phase Modulated Signals in Wireless Communication Systems

Bondariev Andriy P., Horbatyi Ivan V., Maksymiv Ivan P., Altunin Sergiy I.

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 3

449--453

EN

This article presents the results of the research of noiseimmunity of wireless communication systems using signals that are formed on the basis of eight-position quadrature-amplitude modulation (8-QAM) and eight-position amplitude modulation of many components (8-AMMC). The research was conducted using simulation of a wireless communication system, built using a detector, implemented on the basis of a phase locked loop. The influence of phase locked loop parameters on the detection quality of these signals in the condition of the interference in the communication channel was researched, and a comparative analysis of the noise immunity of wireless communication systems using these signals was carried out.

11

Optical fiber marine seismic exploration system feasibility study

Wang Xiangchun, Li Xueliang, Zhang Haibing, Hao Xiaozhu, Yu Kaiben

Acta Geophysica

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2019

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Vol. 67, no. 5

1403--1411

EN

The signal-to-noise ratio (SNR), vertical resolution and fdelity of marine seismic data are closely related to the characteristics of hydrophones, namely the sensitivity and the frequency band range. In this article, we analyzed and processed seismic data collected in 2017 from a towed marine streamer equipped with optical fiber cable and hydrophones. Results from a pre-stack time migration section revealed that the optical fiber seismic data yielded high SNR, vertical resolution and fdelity. For validation purpose, a comparison of these data with those acquired by classic piezoelectric hydrophones along a migration section located in a very close location was carried out. This comparison showed that the SNR, fdelity and vertical resolution from the two means of measurements were comparable.

12

The Development of Iteration Method for Optimization of Pair "Signal-filter"

Koshevyy V.M., Gorishna I.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2018

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Vol. 12, no. 3

541--544

EN

This paper is devoted to the improvement of the working methods of the "signal-filter" pair using an iterative procedure to maximize the signal-to-noise ratio, namely, to highlight the useful signals to provide information about the environment during the adaptive radar sensing in the conditions of obstacles. An algorithm for determining the optimal filter for suppressing undesired side lobes is proposed, which allows improving the process of detection and identification the target objects. Qualitative characteristics and the stages of space-time signal processing in the radar were justified under correlation conditions (ССF) between the received and expected signals. The using of probing radar signals, shortened in their duration were proposed in order to reduce the power of reflections from the underlying surface and increase the contrast of the radar image. A simulation test of the developed methodology was carried out in order to confirm the reliability of the proposed algebraic expressions using a mathematical model implemented in the Matlab programming environment, and a conclusion is drawn about the practical quality of the technical solutions developed on the basis of the iteration method.

13

The Effects of the Noise and Reverberation on the Working Memory Span of Children

Jianxin P., Peng J.

Archives of Acoustics

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2018

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Vol. 43, No. 1

123--128

EN

Three different reverberation time (RT) conditions were obtained by room acoustical simulation. The working memory span of grades 3 (8 to 9 years old) and 6 children (11 to 12 years old) was tested under these reverberation conditions with different signal-to-noise ratio (SNR) by headphone reproduction in a quiet classroom. The working memory span scores (WMSSs) were obtained under the different RTs and SNRs conditions. The results demonstrated that children’s age, RT and SNR had significant effect on children’s WMSSs. With the increase of SNR and the decrease of RT, the WMSSs increased gradually. Under the same SNR and RT condition, the children’s WMSSs were increased with the increase of their age. Multiple linear regression analysis shows that children’s WMSSs are related to age, RT and SNR, and the correlation coefficient is 0.99.

14

The Use of Deep Learning in Speech Enhancement

Ram R., Mohanty M. N.

Annals of Computer Science and Information Systems

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2018

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Vol. 14

107--111

EN

Deep learning is an emerging area in current scenario. Mostly, Convolutional Neural Network (CNN) and Deep Belief Network (DBN) are used as the model in deep learning. It is termed as Deep Neural Network (DNN). The use of DNN is widely spread in many applications, exclusively for detection and classification purpose. In this paper, authors have used the same network for signal enhancement purpose. Speech is considered for the input signal with noise. The model of DNN is used with two layers. It has been compared with the ADALINE model to prove its efficacy.

15

Sensor Hop-based Energy Efficient Networking Approach for Routing in Underwater Acoustic Communication

Kohli S., Bhattacharya P. P.

Journal of Telecommunications and Information Technology

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2017

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nr 1

44--49

EN

Underwater Wireless Sensor Networks are deployed to explore the world under the water, measure different parameters and communicate the data to the surface, in the widespread applications. The main operating technology of these networks is the acoustic communication. The communication among the sensors and finally to the surface station requires a routing protocol. The sensors being battery limited and unfeasible to be replaced under the water requires an energy efficient routing protocol. Clustering imparted in routing is an energy saving technique in sensor networks. The routing may involve single or multi hop communication in the sensor networks. The paper gives a comparative study of the benchmark protocol multi-hop LEACH with the proposed Sensor Hop-based Energy Efficient Networking Approach (SHEENA) for the shallow as well as deep water in three dimensional Underwater Wireless Sensor Networks. The network energy model for the Underwater Wireless Sensor Networks is based among the different acoustic channel characteristics. The proposed approach is found to give better response.

16

Chinese Word Identification and Sentence Intelligibility in Primary School Classrooms

Peng J., Peng J.

Archives of Acoustics

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2016

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Vol. 41, No. 2

213--219

EN

The Chinese word identification and sentence intelligibility are evaluated by grades 3 and 5 students in the classrooms with different reverberation times (RTs) from three primary school under different signal-to-noise ratios (SNRs). The relationships between subjective word identification and sentence intelligibility scores and speech transmission index (STI) are analyzed. The results show that both Chinese word identification and sentence intelligibility scores for grades 3 and 5 students in the classroom increased with the increase of SNR (and STI), increased with the increase of the age of students, and decreased with the increase of RT. To achieve a 99% sentence intelligibility score, the STIs required for grades 3, grade 5 students, and adults are 0.71, 0.61, and 0.51, respectively. The required objective acoustical index determined by a certain threshold of the word identification test might be underestimated for younger children (grade 3 students) in classroom but overestimated for adults. A method based on the sentence test is more useful for speech intelligibility evaluation in classrooms than that based on the word test for different age groups. Younger children need more favorable classroom acoustical environment with a higher STI than older children and adults to achieve the optimum speech communication in the classroom.

17

3D Segmentation of Funnel Flow Boundary During Silo Emptying

Waktola S., Babout L., Grudzien K.

Image Processing & Communications

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2014

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Vol. 19, no. 2-3

141--149

EN

The paper presents an automatic method for segmenting 3D tomography images of a funnel flow area, during silo emptying process. For generating 3D images the silo model was scanned using X-ray Computed Tomography (CT) system. The method has been applied for a chosen single slice from 3D image. The image segmentation is based on the variance of pixels calculation in defined interrogation window (or kernel). The analysis of Signalto- Noise-Ratio (SNR) of the given image allows to improve the contrast in the image and facilitate the detection the boundary between funnel area and stagnant zone. The obtained results of image segmentation show a high potential in the silo flow investigation using in-situ experiment using X-ray visualization. Additionally, the study indicates that, the separation of the silo area into the funnel and stagnant zone parts is a very challenging task especially for the top and bottom area of silo where the contrast is the smallest.

18

The calculation of received optical power during airborne laser scanning of water object

Babushka A., Burshtynska K., Babiy L.

Geomatics, Landmanagement and Landscape

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2014

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no. 3

7--15

EN

In this paper calculation of some physical parameters of the receiver of laser scanning system is presented. Basic physical principles of laser scanning of water objects are considered. Ranging standard deviation for typical parameters of laser scanning system are calculated. Formula for calculation of reflected optical power for specular reflective objects is proposed.

19

Chinese Syllable and Phoneme Identification in Noise and Reverberation

Peng J.

Archives of Acoustics

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2014

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Vol. 39, No. 4

483--488

EN

Chinese is a tonal language, which differentiates it from non-tonal languages in the Western countries. A Chinese character consists of an initial, a final, and a tone. In the present study, the effects of noise and reverberation on the Chinese syllable, initial, final, and tone identification in rooms were investigated by using simulated binaural impulse responses through auralization method. The results show that the syllable identification score is the lowest, the tone identification score is the highest, and the initial iden- tification scores are lower than those of the final identification under the same reverberation time and signal-to-noise ratio condition. The Chinese syllable, initial, and final identification scores increase with the increase of signal-to-noise ratio and decrease of the reverberation time. The noise and reverberation have insignificant effects on the Chinese tone identification scores under most room acoustical environ- ments. The statistical relationship between the Chinese syllable articulation and phoneme articulation had been experimentally proved under different noise and reverberation conditions in simulated rooms.

20

The optimal power control method in multiuser cellular networks

Yaremko O., Stryhalyuk B., Maksymyuk T., Lavriv O., Kozhurov D.

ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes

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2013

|

Vol. 2, No 1

63--67

EN

In this paper a method of power control policies optimization in radiointerface of mobile network with code-division multiplexing is proposed. It allows reducing the interference level in downlink and uplink channels. The optimum SNR is provided in the cell based on this power control method. The SNR is enough to ensure capacity requirements and service quality parameters.