Journal articles: 'Study signals'

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Cheng, Xiu Zhi, Zhen Yu, and Guang Zhu. "Experimental Study of Mine AE Signal Based on Wavelet Analysis." Applied Mechanics and Materials 148-149 (December 2011): 1127–30. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.1127.

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Because the wavelet transform can characterize the local signals in time and frequency domain, in the coal mine’s sound signals’ process, an audio signal processing based on wavelet analysis is proposed, the audio signal P wave is isolated and determined by wavelet transform, at the same time, the earthquake source can be located. Through the research of the mine AE signal’s activity patterns, the sound monitoring technology to forecast the mine power disaster is achieved.

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Mace, Douglas, Mark Finkle, and Sara Pennak. "Daytime Photometric Requirements for Pedestrian Signals." Transportation Research Record: Journal of the Transportation Research Board 1605, no. 1 (January 1997): 41–48. http://dx.doi.org/10.3141/1605-06.

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Forty-eight senior citizens participated in a field study of the visibility of letters and symbols in pedestrian traffic signals. Subjects were asked to identify signal messages from distances of 18.3 m and 29.3 m, with signal voltage set at 100 percent, 75 percent, and 50 percent of full power. Incandescent, fiber-optic, and light-emitting diode commercially available pedestrian signals were tested, including 22.9-cm and 30.5-cm rectangular signal housings and two round red-amber-green signals with symbol masks. Each subject was asked to identify the signal’s location in the test stimuli array, to name the signal’s display configuration (Walk, Don’t Walk, walking person, or hand), and to assess the signal’s brightness on a five-point scale. Analyses also were conducted on the percentage of responses about “too bright” signals and subject uncertainty about the signal message. Testing was conducted only on bright sunny days but did not include the worst-case condition of direct sunlight on the signal face. The analysis of recognition, uncertainty, and “too bright” responses suggested that a signal intensity of 25 cd minimizes the frequency of both “too bright” and uncertain responses regardless of size, distance, or technology, or whether the message is symbol or text. The data further suggest that 22.9-cm incandescent signals provide sufficient visibility with less phantom effect than 30.5-cm signals.

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Wang, Er Lie, Hui Yan Chen, Gang Tao, and Yu Hui Hu. "Study on Data Acquisition for Heavy Off-Road Vehicle AT Testing." Applied Mechanics and Materials 155-156 (February 2012): 765–69. http://dx.doi.org/10.4028/www.scientific.net/amm.155-156.765.

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Based on the analysis of the testing automatic transmission (AT), the AT’s solenoid valve control signals conditioning circuits and revolving speed F/V converter conditioning circuits are designed, and the data acquisition system is designed based on virtual instrument. The system is composed of the PCI-6024E data acquisition card, signal conditioning circuits and computer, and the acquisition procedure is programmed in graphical language LabVIEW. Finally, the data acquisition system has been verified on vehicle test bench which loads ZF-Ecomat 6HP500 AT. Controlling signals of switching solenoid valves, duty cycle signal of proportional solenoid valve, accelerator aperture signal, oil pressure signals and speed signals are collected, it turns out that the data acquisition system has good feasibility.

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Li, Dang, Jun Lu Wang, Yong Li, Jian Hua Li, and Pin Rong Lin. "A Preliminary Study on CSAMT Anti-Jamming Transmitter System." Advanced Materials Research 962-965 (June 2014): 317–21. http://dx.doi.org/10.4028/www.scientific.net/amr.962-965.317.

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On the basis of the relevant identification theory of pseudo-random code signal, the signals of CSAMT are divided into three parts according to the frequency of the signal. The signals which are susceptible to 50Hz interference signal and its harmonic components should be set by pseudo-random code way. Others are set by single square waveform way. The Control and signal generation software of the transmitter system is built on the advanced virtual instrument platform, LabVIEW. The hardware of the transmitter system is mainly composed of host computer, data acquisition card, high-speed optocoupler, IGBT driver module and four IGBT switches. The data acquisition card generate PWM signals, the high-speed optocoupler isolates low-voltage part and high-voltage part. IGBT drive module and four IGBT switches constitute high-voltage part. Entire transmitter system is suitable for different environments and research tasks, the transmit frequency are adjustable, and the pseudo-random code signal has strong capability to suppress the interference signals. The control software on host computer is simple and clear. There is good prospect for the use.

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Blum, T., and I. Inasaki. "A Study on Acoustic Emission from the Orthogonal Cutting Process." Journal of Engineering for Industry 112, no. 3 (August 1, 1990): 203–11. http://dx.doi.org/10.1115/1.2899576.

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Comprehensive experiments have been conducted to determine the influence of cutting conditions on the generation of Acoustic Emission (AE) signals while machining S45C steel. The simultaneous observation of AE-sensor signals and tool dynamometer signals provides extensive data on the orthogonal cutting process. Theoretical relationships drawn between the energy content of the AE-signal and the plastic work of deformation in the primary and secondary cutting zone will be discussed with these data. In addition, shortcomings of the established theory will be highlighted. A relationship between the AE-signals generated and the strain rate will be estimated. The influence of flank wear on the generation of AE signals will be emphasized. Finally, the feasibility of utilizing AE in tool wear sensing will be pointed out while comparing AE-signal generation and machining force measurements for the orthogonal cutting process.

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Wang, Da Long, Zheng Bin Wu, and Jian Wang. "Study of Effects of Differential via on Signal Integrity." Advanced Materials Research 805-806 (September 2013): 1011–16. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.1011.

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If characteristic impedance along a transmission line mismatch on a printed circuit board, high-speed signal has serious signal integrity problems. When signal path of a differential pair jumps layers, mismatched impedance between differential via and differential line will affect the signal integrity. The models of a coupled transmission line and via are presented in this paper. Impedance matching of the coupled transmission line and differential via for differential signals is studied. The effects of differential via dimensions on differential signals is simulated and analyzed.

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Dou, Zheng, Weidong Song, and Wenxu Zhang. "Study on the Characteristics of LFM Signals, BC Signals and Their Mixed Modulation Signals." International Journal of Communications, Network and System Sciences 10, no. 08 (2017): 196–205. http://dx.doi.org/10.4236/ijcns.2017.108b021.

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Zhou, Hui. "Study of Combining DVB-SH Signals from Satellite and Terrestrial Repeater." International Journal of Future Computer and Communication 3, no. 4 (2014): 287–90. http://dx.doi.org/10.7763/ijfcc.2014.v3.313.

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Gao, Guang Chun, Kai Xiong, Li Na Shang, Sheng Ying Zhao, and Cui Zhang. "Study on Over-Complete Dictionaries for Sparse Representations of Signals." Applied Mechanics and Materials 157-158 (February 2012): 796–99. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.796.

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In recent years there has been a growing interest in the study of sparse representation of signals. The redundancy of over-complete dictionary can make it effectively capture the characteristics of the signals. Using an over-complete dictionary that contains prototype signal-atoms, signals are described as linear combinations of a few of these atoms. Applications that use sparse representation are many and include compression, regularization in inverse problems, Compressed Sensing (CS), and more. Recent activities in this field concentrate mainly on the study of sparse decomposition algorithm and dictionary design algorithm. In this paper, we discuss the advantages of sparse dictionaries, and present the implicit dictionaries for signal sparse presents. The overcomplete dictionaries which combined the different orthonormal transform bases can be used for the compressed sensing. Experimental results demonstrate the effectivity for sparse presents of signals.

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Mursaev, A. N., S. V. Zinkin, and D. A. Novichkov. "Theoretical study of methods of finding signals and synchronization of the earth stations of satellite communications." Informatization and communication, no. 2 (February 16, 2021): 7–14. http://dx.doi.org/10.34219/2078-8320-2021-12-2-7-14.

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When using spread-spectrum signals, the problem of searching by frequency and delay must be solved before the signal is processed. For demodulation of simple signals with AM, CHM and FM, it is fundamentally necessary to provide only a frequency search, and clock synchronization can be carried out after the first decision circuit, i.e. in the signal conversion equipment, usually placed in the interface equipment or channel-forming equipment. The paper presents a theoretical analysis of the methods of the search of signals and synchronization in earth stations - search and tracking of singaporemetro signals with an expanded range and features auto scan and auto-tracking frequency when receiving simple signals.

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Wang, Yan, Ji Fei Cai, Yang Zhang, Guang Li, and Rui Ming Fang. "Study on Acoustic Emission Detective Signal Restoration under Multifactor Interference." Applied Mechanics and Materials 329 (June 2013): 274–77. http://dx.doi.org/10.4028/www.scientific.net/amm.329.274.

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For solving signal restoration distortion affected by the signal spectrum composition changes and tested baseline drift, this papers methods mainly involve time-frequency energy analysis, wavelet soft threshold de-noising algorithm and baseline drift cancellation method. The result shows that these methods can effectively eliminate the interference of different micro-variable fault signals. The restored high-fidelity signals provide base for subsequent identification of fault reasons.

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Gyun, Na Eui, Kim Hoon, and Kanji Ono. "Study on Evaluation of AE Signals at Weld Region of SA 516 Steel." Key Engineering Materials 321-323 (October 2006): 1729–32. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1729.

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The purpose of this study is to find out the method to detect AE signals at around the notch tip and to evaluate the AE signal characteristics for the basemetal, PWHT(post weld heat treatment) and weldment specimens of SA-516 steel during bend test. AE signals were produced in the process of plastic deformation. AE signal strength and amplitude of the weldment was the strongest, followed by PWHT specimen and basemetal. More AE signals were produced from the weldment because of the oxides, and discontinuous mechanical properties. The stronger AE signal strength, amplitude and more AE event counts for the weldment were shown.

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Lima, Miguel F. M., J. A. Tenreiro Machado, and Manuel Crisóstomo. "Experimental backlash study in mechanical manipulators." Robotica 29, no. 2 (March 4, 2010): 211–19. http://dx.doi.org/10.1017/s0263574710000056.

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SUMMARYThe behavior of mechanical manipulators with backlash is analyzed. In order to acquire and study the signals an experimental setup is implemented. The signal processing capabilities of the wavelets are used for de-noising the experimental signals and the energy of the obtained components is analyzed. To evaluate the backlash effect upon the robotic system, it is proposed an index based on the pseudo phase plane representation. Several tests are developed that demonstrate the coherence of the results.

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Din, Zia Ud, and Leonhard E. Bernold. "Experimental study of signal behavior for wireless communication in construction." Construction Innovation 17, no. 4 (October 20, 2017): 475–91. http://dx.doi.org/10.1108/ci-11-2016-0061.

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Purpose The purpose of this study is to understand the effects of building components of a growing concrete structure and different building materials such as glass and steel on Wi-Fi signals propagation in a construction site. Wireless local area networks are considered effective tools to link the islands-of-communication in construction. Still, designing a Wi-Fi network that can grow with a new construction requires that one understands the performance of propagation of electromagnetic signals transmitted at 2.4 GHz. Design/methodology/approach This paper reviews the theoretical behavior of electromagnetic signals when signal attenuation is caused by various construction materials changing their strengths, directions and possibly leading to total absorption. The authors used a typical building layout to conduct experimental work to measure the effect of common building features and communication technologies on signal strengths. Findings The measured data not only confirmed the theory-based predictions but also demonstrated the complexity of predicting signal propagation when obstructions inhibit the line-of-sight “travel” of electromagnetic signals. Originality/value Different to other papers, the experiments were conducted outside a concrete building mimicking the situation where the transmitter is set up at the site office.

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Desai, Raghavendra Reddy, Thomas A. Krouskop, and Raffaella Righetti. "Elastography Using Harmonic Ultrasonic Imaging: A Feasibility Study." Ultrasonic Imaging 32, no. 2 (April 2010): 103–17. http://dx.doi.org/10.1177/016173461003200204.

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Tissue Harmonic Imaging (THI) is a relatively new modality that has had a significant impact in the ultrasound field. In the recent past, imaging the mechanical properties of tissues using elastography has also gained great interest. In this paper, we investigate the feasibility of combining these two state-of-the-art ultrasound-imaging modalities. The performance of elastograms obtained using harmonic ultrasonic signals is studied with simulations and compared to the performance of conventional elastograms using standard statistical methods. Experiments are used as a proof of the technical feasibility of generating tissue-harmonic elastograms using experimental harmonic signals. The results of our simulation study indicate that all image quality factors considered in this study (elastographic signal-to-noise ratio, elastographic contrast-to-noise ratio and spatial resolution) may be improved when using harmonic ultrasonic signals, provided that the ultrasound system is characterized by high bandwidth, high sampling frequency and large lateral sampling. Preliminary experimental results suggest that it is technically feasible to generate experimental elastograms using harmonic signals, provided that the sonographic signal-to-noise ratio of the pre- and postcompression harmonic frames is sufficiently high to guarantee reliable values of correlation.

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Lu, Zhenyu, Tingya Yang, and Min Zhu. "Study of the Method of Multi-Frequency Signal Detection Based on the Adaptive Stochastic Resonance." Abstract and Applied Analysis 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/420605.

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Recently, the stochastic resonance effect has been widely used by the method of discovering and extracting weak periodic signals from strong noise through the stochastic resonance effect. The detection of the single-frequency weak signals by using stochastic resonance effect is widely used. However, the detection methods of the multifrequency weak signals need to be researched. According to the different frequency input signals of a given system, this paper puts forward a detection method of multifrequency signal by using adaptive stochastic resonance, which analyzed the frequency characteristics and the parallel number of the input signals, adjusted system parameters automatically to the low frequency signals in the fixed step size, and then measured the stochastic resonance phenomenon based on the frequency of the periodic signals to select the most appropriate indicators in the middle or high frequency. Finally, the optimized system parameters are founded and the frequency of the given signals is extracted in the frequency domain of the stochastic resonance output signals. Compared with the traditional detection methods, the method in this paper not only improves the work efficiency but also makes it more accurate by using the color noise, the frequency is more accurate being extracted from the measured signal. The consistency between the simulation results and analysis shows that this method is effective and feasible.

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Chen, Hua, and Xue Ting Zhang. "The Comparison Study of Targeting Observation for Extratropical Transition of Hurricane Fabian." Advanced Materials Research 518-523 (May 2012): 5840–45. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.5840.

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This study compares the propagation methods of the impact of targeted observations during the extratropical transition (ET) of Hurricane Fabian in three denial experiments. In sensitive experiment, the signal (forecast difference between denial experiments and control) propagates from the tropical cyclone (TC) to the midlatitude jet through the interaction between the TC and the jet itself. Thereafter, signals propagate eastward along the jet by way of Rossby wave packets. Some differences exist between random/Atlantic and sensitive experiment although many of their signal propagation characteristics are similar. The signal in random experiment is the weakest, and that in Atlantic experiment is the strongest. In Atlantic experiment, initial signals appear not only in Fabian, but also in other regions. In some cases, signals even do not appear in Fabian. Its propagation method is similar to that in sensitive and random experiment except some signals exist at ridges occasionally. From the discussion above, we conclude that targeted observations have more positive impact than random observations, but can not replace observations taken in the whole Atlantic.

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Malekjafarian, Abdollah, Eugene OBrien, Paraic Quirke, and Cathal Bowe. "Railway Track Monitoring Using Train Measurements: An Experimental Case Study." Applied Sciences 9, no. 22 (November 13, 2019): 4859. http://dx.doi.org/10.3390/app9224859.

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This paper investigates the use of drive-by train measurements for railway track monitoring. An in-service Irish Rail train was instrumented while using accelerometers and a global positioning system. The measurements were taken over two months and the train bogie accelerations from 60 passes on the Dublin-Belfast line were used for this study. A 6 km section of the line is the particular focus, where the maintenance measurements from a Track Recording Vehicle (TRV) were available. The Hilbert transform is used to obtain the instantaneous amplitudes of the acceleration signals. A new representation of the signal is proposed to show the signal energy level as a function of train location. It is shown that the forward speed of the train has a significant influence on the energy level of the signals. Therefore, a two-step speed correction is applied to the data. First, data from passes with forward speed below a certain limit are removed from the data set. Subsequently, a scaling factor is defined for the remaining signals and the energy levels of those signals are scaled while using online speed measurements. The scaled amplitudes are compared with the TRV data. It is shown that the energy levels of the signals match the TRV measurements very well.

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Thammasan, Nattapong, Ivo V. Stuldreher, Elisabeth Schreuders, Matteo Giletta, and Anne-Marie Brouwer. "A Usability Study of Physiological Measurement in School Using Wearable Sensors." Sensors 20, no. 18 (September 20, 2020): 5380. http://dx.doi.org/10.3390/s20185380.

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Measuring psychophysiological signals of adolescents using unobtrusive wearable sensors may contribute to understanding the development of emotional disorders. This study investigated the feasibility of measuring high quality physiological data and examined the validity of signal processing in a school setting. Among 86 adolescents, a total of more than 410 h of electrodermal activity (EDA) data were recorded using a wrist-worn sensor with gelled electrodes and over 370 h of heart rate data were recorded using a chest-strap sensor. The results support the feasibility of monitoring physiological signals at school. We describe specific challenges and provide recommendations for signal analysis, including dealing with invalid signals due to loose sensors, and quantization noise that can be caused by limitations in analog-to-digital conversion in wearable devices and be mistaken as physiological responses. Importantly, our results show that using toolboxes for automatic signal preprocessing, decomposition, and artifact detection with default parameters while neglecting differences between devices and measurement contexts yield misleading results. Time courses of students’ physiological signals throughout the course of a class were found to be clearer after applying our proposed preprocessing steps.

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Liu, Gui Jie, Qiang Wang, and Ren Ke Kang. "Study on the Wavelet Transform Based Monitor Signal Processing Method for Grinding Wheel Dull." Key Engineering Materials 375-376 (March 2008): 598–602. http://dx.doi.org/10.4028/www.scientific.net/kem.375-376.598.

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A processing method based on wavelet transform for the monitoring signals of grinding wheel dull is presented. The noise-falling method based on wavelet transform is used to process AE signals, grinding force signals and the electric current signals of main axis motor produced in grinding process, and the processing results can be used to identify grinding wheel state. Test result indicates that the grinding wheel state can be identified exactly by these three kinds of signal characteristics, and have higher identified precision.

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Jia, Huilin, Yue Niu, Xiaofei Liu, and Enyuan Wang. "Study on Electric-Magnetic-Acoustic Signal Regularity and Its Correlation during Rock Shear Failure." Advances in Materials Science and Engineering 2019 (July 18, 2019): 1–12. http://dx.doi.org/10.1155/2019/4687607.

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http://mts.hindawi.com/update/) in our Manuscript Tracking System and after you have logged in click on the ORCID link at the top of the page. This link will take you to the ORCID website where you will be able to create an account for yourself. Once you have done so, your new ORCID will be saved in our Manuscript Tracking System automatically."?>During mining activities, the deformation and damage of coal rock materials might result in coal rock dynamic disasters, such as rock burst. It leads to serious casualties and property losses. Generally, the occurrence of dynamic failure of coal and rock are caused by shear failure of coal seam. Geophysics signals are generated and related to damage evolution in this loading process. In this paper, sandstone samples were subjected to shear failure laboratory experiments, and the electric-magnetic-acoustic signal regularity was measured and analyzed comparatively. The results indicated magnetic signals were more correlated with stress and acoustic emission (AE) signals, while the amplitude of electric signal fluctuation was larger when main failure occurred. With the increase of sample size and shear strength, the strength of electric-magnetic-acoustic signals increased. The correlation coefficients between the magnetic signal and stress as well as AE energy were superior to those of electric signals. The coupling model between AE and electric signals was established, which shows good statistical correlation. This study lays the foundations for further interpreting the generation mechanism of the electric signal. It provides a new method to indicate the damage evolution of coal rock materials.

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Yu, Ke, and Huapu Lu. "Effects of Countdown Signals in Red Phase on Drivers: A Comparative Study between Japan and Turkey." Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/671589.

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Countdown signals can be found in many countries; however, there are only a few researches that study the impact of the signals on driver behavior. In this study, we focus particularly on the behavior of drivers reacting to countdown signals when the signal shifted from red to green. Although the countdown signal can reduce startup delay, it also causes drivers premature start. This paper determines the factors influencing the behaviors of drivers on startup delay, premature start, and headway due to countdown signals. The analysis results are compared between Japan and Turkey. From our findings, we propose countermeasures to reduce the problems caused by the countdown signals which can be a guideline for implementation or modification of countdown-signalized intersections in many countries in order to increase safety of both drivers and pedestrians as well as drivers’ satisfactions.

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Huang, Xiu Xiang, Qing Tan, Yi Min Xia, and Wen Hua Liu. "Study on Profibus-Based Control System of the Experimental Device for Cutter Head in Shield Tunneling Machine." Advanced Materials Research 317-319 (August 2011): 604–7. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.604.

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The structure and characteristics of test signals of the experimental device for cutter head in shield machine are analyzed. Based upon this analysis, Profibus-based control system is designed. With the use of a distributed I / O station on-site analog signal, the problems of anti-interference for long-distance transmission of signals are resolved, and high-speed transmission for sensor signals and control signals are realized.

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Zhou, You Hang, Sai Yuan Xie, and Hou Ming Zhou. "The AE Signals Bi-Spectrum Features Study in Batch Drilling." Materials Science Forum 800-801 (July 2014): 745–48. http://dx.doi.org/10.4028/www.scientific.net/msf.800-801.745.

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Based on the coupling phenomena between the batch drilling process quality fluctuation and monitoring signal features changes, the acoustic emission signals of batch drilling are taken as research objects to solve the quality consistency control and detection problem of the high-precision batch drilling step. The average bi-spectrum amplitude of each signal is taken as an eigenvalue for the quantitative analysis of the deviation degree from Gaussian distribution under different conditions. The calculation and analysis results show that there are organic connections between the bi-spectrum feature of monitoring signals and drilling step quality, and the consistency quality testing of batch drilling step is realized by bi-spectrum features.

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Chen, Yu Cai, Xi Wang, Li Bing Liu, Dong Ting Liao, and Fei Wu. "An Experimental Study on Electric Hot Milling for T10A Tool Steel." Applied Mechanics and Materials 117-119 (October 2011): 1843–46. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.1843.

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This paper introduces a kind of electric hot milling method for T10A tool steel and analyses its feasibility. Collect temperature signals and vibration signals in the machining process by a set of signal acquisition system. Afterwards, process these signals by using wavelet transform and wavelet packet transform, compare and analyze them in different working conditions. The results of the study indicate that through comparison between dry milling and electric hot milling, the latter can be more effectively milling tool steel, and improve the cutting tool durability.

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You, Xun, Bin Gong, Xin Lv, and Longfei Hu. "Study on the Mathematical Model and Propagation Characteristics of AE Waveform Signals during Rock Fracture." Advances in Civil Engineering 2021 (February 9, 2021): 1–13. http://dx.doi.org/10.1155/2021/6685357.

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Rock deformation or fracture is accompanied by the phenomenon of acoustic emission (AE). Due to the heterogeneity and anisotropy of rock materials as well as the complexity of their fracture, AE signals recorded by sensors at different positions have different characteristics. To explore factors influencing these differences, this study examines the effects of the physical properties of rocks, such as heterogeneity, anisotropy, and viscosity, on AE waveform signals from the perspective of the rock material and its fracture characteristics as well as the characteristics of the propagation of different AE waveform signals. The results show that the frequency (f) of the AE signals generated by rock fracture is inversely proportional to crack length (c) and directly proportional to the rate of crack growth ( v ). During signal propagation, the comprehensive effects of such factors as the heterogeneity, anisotropy, and viscosity of rocks as well as environmental noise weaken the energy of the signals and enhance the distribution of signal frequency. Each factor differently influences the time frequency of AE. A model for the propagation of AE signals was built and verified. Finally, as for on-site rock mass engineering, the low-frequency signals should be analysed prior to analysis in rock mass disaster monitoring.

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Ji, Xiao Dong, Zi Xian Yang, Xu Li, Guang Hui Xue, and Miao Wu. "Study on Method for Real-Time Vibration Signal of Shearer Acquisition." Applied Mechanics and Materials 373-375 (August 2013): 865–69. http://dx.doi.org/10.4028/www.scientific.net/amm.373-375.865.

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In order to acquire and analyze the real-time vibration signals of shearer in the process of coal mining. This experiment used the portable vibration measurement data recorder, which developed by ourselves. We design a comprehensive set of solutions for data acquisition according to underground mining machines working in real time. Through the data collection package, obtained a shearer vibration signal sample on real-time working. Meanwhile, analyze the vibration signal using signal analysis method. Through the experiment we acquire vibration signals of shearer's ranging-arms on real-time working, and the analysis results indicate that data collection solution is reasonably practicable.

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URIBE, R., J. ALMARAZ BARRERA MA DE, M. ROBLES-FLORES, G. MENDOZA HERNÁNDEZ, A. GONZÁLEZ-ROBLES, R. HERNÁNDEZ-RIVAS, N. GUILLEN, and M. VARGAS. "A functional study of nucleocytoplasmic transport signals of the EhNCABP166 protein from Entamoeba histolytica." Parasitology 139, no. 13 (August 23, 2012): 1697–710. http://dx.doi.org/10.1017/s0031182012001199.

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SUMMARYEhNCABP166 is an Entamoeba histolytica actin-binding protein that localizes to the nucleus and cytoplasm. Bioinformatic analysis of the EhNCABP166 amino acid sequence shows the presence of 3 bipartite nuclear localization signals (NLS) and a nuclear export signal (NES). The present study aimed to investigate the functionality of these signals in 3 ways. First, we fused each potential NLS to a cytoplasmic domain of ehFLN to determine whether the localization of this domain could be altered by the presence of the NLSs. Furthermore, the localization of each domain of EhNCABP166 was determined. Similarly, we generated mutations in the first block of bipartite signals from the domains that contained these signals. Additionally, we added an NES to 2 constructs that were then evaluated. We confirmed the intranuclear localization of EhNCABP166 using transmission electron microscopy. Fusion of each NLS resulted in shuttling of the cytoplasmic domain to the nucleus. With the exception of 2 domains, all of the evaluated domains localized within the nucleus. A mutation in the first block of bipartite signals affected the localization of the domains containing an NLS. The addition of an NES shifted the localization of these domains to the cytoplasm. The results presented here establish EhNCABP166 as a protein containing functional nuclear localization signals and a nuclear export signal.

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Kim, Min-Gu, and Sung Bum Pan. "A Study on User Recognition Using the Generated Synthetic Electrocardiogram Signal." Sensors 21, no. 5 (March 8, 2021): 1887. http://dx.doi.org/10.3390/s21051887.

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Electrocardiogram (ECG) signals are time series data that are acquired by time change. A problem with these signals is that comparison data that have the same size as the registration data must be acquired every time. A network model of an auxiliary classifier based generative adversarial neural network that is capable of generating synthetic ECG signals is proposed to resolve the data size inconsistency problem. After constructing comparison data with various combinations of the real and generated synthetic ECG signal cycles, a user recognition experiment was performed by applying them to an ensemble network of parallel structure. Recognition performance of 98.5% was demonstrated when five cycles of real ECG signals were used. Moreover, 98.7% and 97% accuracies were provided when the first cycle of synthetic ECG signals and the fourth cycle of real ECG signals were repetitively used as the last cycle, respectively, in addition to the four cycles of real ECG. When two cycles of synthetic ECG signals were used with three cycles of real ECG signals, 97.2% accuracy was shown. When the last third cycle was repeatedly used with the three cycles of real ECG signals, the accuracy was 96%, which was 1.2% lower than the performance obtained while using the synthetic ECG. Therefore, even if the size of the registration data and that of the comparison data are not consistent, the generated synthetic ECG signals can be applied to a real life environment, because a high recognition performance is demonstrated when they are applied to an ensemble network of parallel structure.

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Lacerda, Vinícius A., Pedro I. N. Barbalho, RenatoM Monaro, and Denis V. Coury. "Signal processing techniques for synchrophasors considering short-circuit signals: a comparative study." IET Generation, Transmission & Distribution 14, no. 19 (October 2, 2020): 3962–71. http://dx.doi.org/10.1049/iet-gtd.2020.0208.

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Setlak, Lucjan, and Rafał Kowalik. "Study and Analysis of Interference Signals of the LTE System of the GNSS Receiver." Sensors 21, no. 14 (July 19, 2021): 4901. http://dx.doi.org/10.3390/s21144901.

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Sometimes, it is impossible to conduct tests with the use of the GNSS system, or the obtained results of the measurements made differ significantly from the predicted accuracy. The most common cause of the problems (external factors, faulty results) are interference disturbances from other radio telecommunication systems. The subject of this paper is to conduct research, the essence of which is an in-depth analysis in the field of elimination of LTE interference signals of the GNSS receiver, that is based on the developed effective methods on counteracting the phenomenon of interference signals coming from this system and transmitted on the same frequency. Interference signals are signals transmitted in the GNSS operating band, and unwanted signals may cause incorrect processing of the information provided to the end-user about his position, speed, and current time. This article presents methods of identifying and detecting interference signals, with particular emphasis on methods based on spatial processing of signals transmitted by the LTE system. A comparative analysis of the methods of detecting an unwanted signal was made in terms of their effectiveness and complexity of their implementation. Moreover, the concept of a new comprehensive anti-interference solution was proposed. It includes, among others, information on the various stages of GNSS signal processing in the proposed system, in relation to the algorithms used in traditional GNSS receivers. The final part of the article presents the obtained research results and the resulting significant observations and practical conclusions.

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Bhatta, Gopal. "Study of Periodic Signals from Blazars." Proceedings 17, no. 1 (December 10, 2019): 15. http://dx.doi.org/10.3390/proceedings2019017015.

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The search for periodic signals from blazars has become an actively pursued field of research in recent years. This is because periodic signals bring us information about the processes occurring near the innermost regions of blazars, which are mostly inaccessible to our direct view. Such signals provide insights into some of the extreme conditions that take place in the vicinity of supermassive black holes that lead to the launch of the relativistic jets. In addition, studies of characteristic timescales in blazar light curves shed light on some of the challenging issues in blazar physics that include disk-jet connection, strong gravity near fast-rotating supermassive black holes and release of gravitational waves from binary supermassive black hole systems. However, a number of issues associated with the search for quasi-periodic oscillations (QPOs) in blazars e.g., red-noise dominance, modest significance of the detection, periodic modulation lasting for only a couple of cycles and their transient nature, make it difficult to estimate the true significance of the detection. Consequently, it also becomes difficult to make meaningful inferences about the nature of the on-going processes. In this proceedings, results of study focused on searching for QPOs in a number of blazar multi-frequency light curves are summarized. The time series analyses of long term observations of the blazars revealed the presence of year-timescale QPOs in the sources including OJ 287 (optical), Mrk 501 (gamma-ray), J1043+2408 (radio) and PKS 0219-164 (radio). A likely explanations, we discuss a number of scenarios including binary supermassive black hole systems, lense-thirring precession, and jet precession.

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Cai, Weiming, and Qingke Qi. "Study on Electrophysiological Signal Monitoring of Plant under Stress Based on Integrated Op-Amps and Patch Electrode." Journal of Electrical and Computer Engineering 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/4182546.

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Electrophysiological signal in plant is a weak electrical signal, which can fluctuate with the change of environment. An amplification detection system was designed for plant electrical signal acquisition by using integrated op-amps (CA3140, AD620, and INA118), patch electrode, data acquisition card (NI USB-6008), computer, and shielded box. Plant electrical signals were also studied under pressure and flooding stress. The amplification detection system can make nondestructive acquisition for Aquatic Scindapsus and Guaibcn with high precision, high sensitivity, low power consumption, high common mode rejection ratio, and working frequency bandwidth. Stress experiments were conducted through the system; results show that electrical signals were produced in the leaf of Aquatic Scindapsus under the stress of pressure. Electrical signals in the up-leaf surface of Aquatic Scindapsus were stronger than the down-leaf surface. Electrical signals produced in the leaf of Guaibcn were getting stronger when suffering flooding stress. The more the flooding stress was severe, the faster the electrical signal changed, the longer the time required for returning to a stable state was, and the greater the electrical signal got at the stable state was.

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Kahl, Lorenz, and Ulrich Hofmann. "Removal of ECG Artifacts Affects Respiratory Muscle Fatigue Detection—A Simulation Study." Sensors 21, no. 16 (August 23, 2021): 5663. http://dx.doi.org/10.3390/s21165663.

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This work investigates elimination methods for cardiogenic artifacts in respiratory surface electromyographic (sEMG) signals and compares their performance with respect to subsequent fatigue detection with different fatigue algorithms. The analysis is based on artificially constructed test signals featuring a clearly defined expected fatigue level. Test signals are additively constructed with different proportions from sEMG and electrocardiographic (ECG) signals. Cardiogenic artifacts are eliminated by high-pass filtering (HP), template subtraction (TS), a newly introduced two-step approach (TSWD) consisting of template subtraction and a wavelet-based damping step and a pure wavelet-based damping (DSO). Each method is additionally combined with the exclusion of QRS segments (gating). Fatigue is subsequently quantified with mean frequency (MNF), spectral moments ratio of order five (SMR5) and fuzzy approximate entropy (fApEn). Different combinations of artifact elimination methods and fatigue detection algorithms are tested with respect to their ability to deliver invariant results despite increasing ECG contamination. Both DSO and TSWD artifact elimination methods displayed promising results regarding the intermediate, “cleaned” EMG signal. However, only the TSWD method enabled superior results in the subsequent fatigue detection across different levels of artifact contamination and evaluation criteria. SMR5 could be determined as the best fatigue detection algorithm. This study proposes a signal processing chain to determine neuromuscular fatigue despite the presence of cardiogenic artifacts. The results furthermore underline the importance of selecting a combination of algorithms that play well together to remove cardiogenic artifacts and to detect fatigue. This investigation provides guidance for clinical studies to select optimal signal processing to detect fatigue from respiratory sEMG signals.

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LIN, ROBERT, REN-GUEY LEE, CHWAN-LU TSENG, YAN-FA WU, and JOE-AIR JIANG. "DESIGN AND IMPLEMENTATION OF WIRELESS MULTI-CHANNEL EEG RECORDING SYSTEM AND STUDY OF EEG CLUSTERING METHOD." Biomedical Engineering: Applications, Basis and Communications 18, no. 06 (December 25, 2006): 276–83. http://dx.doi.org/10.4015/s1016237206000427.

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A multi-channel wireless EEG (electroencephalogram) acquisition and recording system is developed in this work. The system includes an EEG sensing and transmission unit and a digital processing circuit. The former is composed of pre-amplifiers, filters, and gain amplifiers. The kernel of the later digital processing circuit is a micro-controller unit (MCU, TI-MSP430), which is utilized to convert the EEG signals into digital signals and fulfill the digital filtering. By means of Bluetooth communication module, the digitized signals are sent to the back-end such as PC or PDA. Thus, the patient's EEG signal can be observed and stored without any long cables such that the analogue distortion caused by long distance transmission can be reduced significantly. Furthermore, an integrated classification method, consisting of non-linear energy operator (NLEO), autoregressive (AR) model, and bisecting k-means algorithm, is also proposed to perform EEG off-line clustering at the back-end. First, the NLEO algorithm is utilized to divide the EEG signals into many small signal segments according to the features of the amplitude and frequency of EEG signals. The AR model is then applied to extract two characteristic values, i.e., frequency and amplitude (peak to peak value), of each segment and to form characteristic matrix for each segment of EEG signal. Finally, the improved modified k-means algorithm is utilized to assort similar EEG segments into better data classification, which allows accessing the long-term EEG signals more quickly.

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Sun, Ying Juan, Ying Hui Sun, and Dong Bing Pu. "Study of Rough Set-Based Taste Signals Identification." Advanced Materials Research 354-355 (October 2011): 1170–73. http://dx.doi.org/10.4028/www.scientific.net/amr.354-355.1170.

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This paper gives a new method of rough set-based on taste signals identification. Further improve the identification accuracy by dividing regions more appropriate. The simulation data and the latest UCI machine learning taste signal data (Wine Quality) are used to verify the new method, and the new method is compared with other identification algorithms. The results fully show the correctness and effectiveness of the proposed identification method based on rough set.

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Babińska, Joanna, Krystyna Dyrek, and Piotr Wyszomirski. "EPR Study of Paramagnetic Defects in Clay Minerals." Mineralogia 38, no. 2 (January 1, 2007): 125–38. http://dx.doi.org/10.2478/v10002-007-0021-x.

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EPR Study of Paramagnetic Defects in Clay MineralsRadiation induced defects (RID-s) and transition metal ion impurities were revealed by EPR (Electron Paramagnetic Resonance) spectroscopy in kaolinites from a number of Polish deposits. Arelationship between the intensity of the EPR signals of the RID-s and quantity of radioactive elements was defined in these minerals. In one of the deposits of kaolinites (Wyszonowice) the EPR signal intensity depends on grain size. Other clay minerals studied (illites, montmorillonites) only show weak signals of the RID type.

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Fang, Liang, and Hongchun Sun. "Study on EEMD-Based KICA and Its Application in Fault-Feature Extraction of Rotating Machinery." Applied Sciences 8, no. 9 (August 23, 2018): 1441. http://dx.doi.org/10.3390/app8091441.

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A method is proposed to improve the feature extraction of vibration signals of rotating machinery. Firstly, the single-channel vibration signal is decomposed with ensemble empirical mode decomposition (EEMD). Then, the number of fault signals can be estimated with singular-value decomposition (SVD). Finally, the fault signals can be extracted with kernel-independent component analysis (KICA). The advantage of this method is that it can estimate the number of fault signals of single-channel vibration signals and can extract the fault features clearly. Compared with wavelets, empirical mode decomposition (EMD), variational mode decomposition (VMD) and EEMD, the better performance of this method is proven with three experimental analyses of faulty gear, a faulty rolling bearing and a faulty shaft. The results demonstrate that the proposed method is efficient to extract the fault features of single-channel vibration signals of rotating machinery.

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Zhang, Wei Min, Shu Xuan Liu, Yong Qiu, and Cheng Feng Chen. "Study of the Metal Crack Propagation by Acoustic Emission Testing." Applied Mechanics and Materials 105-107 (September 2011): 2179–82. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.2179.

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Crack propagation is the main reason which leads to the invalidity of the metal components. A set of detecting equipment based on the acoustic emission method was designed, and it was mainly composed of acoustic emission sensor, signal operating circuits and signal acquisition system. Specimens of 16MnR material were manufactured and the static axial tension test of them was carried on. Acoustic emission signals from the specimen were detected by acoustic emission equipment by using piezoelectric ceramic sensor. Signal datum were acquired and operated by the acquisition system, as well as the acquisition program written for it. The final results has demonstrated that acoustic emission equipment designed for the test performed well in acquiring the signals induced by the metal crack propagation.

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Salmelin, R., and J. Mäkelä. "Magnetic Signals in the Study of Human Brain Dynamics." Rivista di Neuroradiologia 8, no. 3 (June 1995): 329–44. http://dx.doi.org/10.1177/197140099500800302.

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Magnetoencephalography provides a totally noninvasive method to study brain function with a millisecond time resolution. The measured signal alone gives an approximate site, intensity, and orientation of the current flow in the cortex. More accurate information is obtained by applying standard source models with physiological constraints. The MEG signals are readily combined with the images obtained by other techniques, such as MRI or PET. To increase our understanding of the human brain, an obvious approach is to characterize and quantify the sequences of cortical events related to repeated stimuli or tasks with good combined temporal and spatial resolution. Magnetic signals thus open one important window for assessing brain function.

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Liu, Yan, Yue Min Wang, Chuan Jun Shen, and Feng Rui Sun. "Study on Recognize for Lamb Wave Test Signals Based on Finite Element Modeling." Applied Mechanics and Materials 288 (February 2013): 25–29. http://dx.doi.org/10.4028/www.scientific.net/amm.288.25.

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In the defect test of plate-like structure, acousto-ultrasonic technique can stimulate a multi-mode Lamb wave. This paper used an FEM method to investigate the Lamb wave propagation, the simulating signals are decomposed and reconstructed by MP and compared with the theoretical parameter curve of the frequency dispersed curves. It was proved that matching pursuit based on tEP can accurately search the characteristic parameters of the signal, realize the rapid signal decomposition and reconstruction, and identify the defect signals.

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Belkić, Dževad, and Karen Belkić. "Feasibility study for applying the lower-order derivative fast Padé transform to measured time signals." Journal of Mathematical Chemistry 58, no. 1 (November 27, 2019): 146–77. http://dx.doi.org/10.1007/s10910-019-01077-2.

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AbstractMagnetic resonance spectroscopy (MRS), as a powerful and versatile diagnostic modality in physics, chemistry, medicine and other basic and applied sciences, depends critically upon reliable signal processing. It provides time signals by encoding, but cannot quantify on its own. Mathematical methods do so. The signal processor of choice for MRS is the fast Padé transform (FPT). The spectrum in the FPT is the unique polynomial quotient for the given Maclaurin expansion. The parametric FPT (parameter estimator) performs quantification of time signals encoded with MRS by explicitly solving the spectral analysis problem. Thus far, the non-parametric FPT (shape estimator) could not quantify. However, the non-parametric derivative fast Padé transform (dFPT) can quantify despite performing shape estimation alone. The dFPT was successfully benchmarked on synthesized MRS time signals for derivative orders ranging from 1 to 50. It simultaneously improved resolution (by splitting apart tightly overlapped peaks) and enhanced signal-to-noise ratio (by suppressing the background baseline). The same advantageous features of improving both resolution and signal-to-noise ratio are presently found to be upheld with encoded MRS time signals. Moreover, it is demonstrated that the dFPT hugely outperforms the derivative fast Fourier transform even for derivatives of orders as low as four. The clinical implications are discussed.

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Zhu, Ying, Yong Xing Jia, and Yuan Wang. "Study and Discussion on the Theory of Compressive Sensing." Applied Mechanics and Materials 239-240 (December 2012): 1462–65. http://dx.doi.org/10.4028/www.scientific.net/amm.239-240.1462.

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Compressive sensing(CS)is a novel information theory proposed recently.It broke through the restrictions of the traditional Nyquist sampling theorem on the sampling frequency,which can only use fewer sampling signals to describe the original signals. This article introduces the theory of CS including three main process like sparse representation, mesurement matric design and signal reconstruction.Then it also discusses the issures requiring improvement about the algorithm,the hardware implementation ,finds the reasons and gives some advices in follow-up studies.

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Fu, Jian Ting, Yi Zhi Shi, Lei Ma, and Yao Li. "Study of Forearm Surface EMG Using a Continuous Force Profile Generator." Advanced Materials Research 765-767 (September 2013): 2742–45. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.2742.

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This project designs a novel musculoskeletal force evaluation system, which could generate continuous varying force, acquire wireless signals and measure surface EMG signals simultaneously. Experiments have been developed to validate the functionality and effectiveness of this design. This system could be used to analyze the relationship between surface EMG signal and forearm musculoskeletal force, which will build the theoretical basis for smoother gesture and force detection in humanmachine interaction control.

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Delgado-Arredondo, Paulo Antonio, Arturo Garcia-Perez, Daniel Morinigo-Sotelo, Roque Alfredo Osornio-Rios, Juan Gabriel Avina-Cervantes, Horacio Rostro-Gonzalez, and Rene de Jesus Romero-Troncoso. "Comparative Study of Time-Frequency Decomposition Techniques for Fault Detection in Induction Motors Using Vibration Analysis during Startup Transient." Shock and Vibration 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/708034.

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Induction motors are critical components for most industries and the condition monitoring has become necessary to detect faults. There are several techniques for fault diagnosis of induction motors and analyzing the startup transient vibration signals is not as widely used as other techniques like motor current signature analysis. Vibration analysis gives a fault diagnosis focused on the location of spectral components associated with faults. Therefore, this paper presents a comparative study of different time-frequency analysis methodologies that can be used for detecting faults in induction motors analyzing vibration signals during the startup transient. The studied methodologies are the time-frequency distribution of Gabor (TFDG), the time-frequency Morlet scalogram (TFMS), multiple signal classification (MUSIC), and fast Fourier transform (FFT). The analyzed vibration signals are one broken rotor bar, two broken bars, unbalance, and bearing defects. The obtained results have shown the feasibility of detecting faults in induction motors using the time-frequency spectral analysis applied to vibration signals, and the proposed methodology is applicable when it does not have current signals and only has vibration signals. Also, the methodology has applications in motors that are not fed directly to the supply line, in such cases the analysis of current signals is not recommended due to poor current signal quality.

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Zhou, Hao. "Study on Improvement of MUSIC Estimation Method." Applied Mechanics and Materials 543-547 (March 2014): 2750–54. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.2750.

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MUSIC algorithm is a subspace decomposition method whose high resolution capability and other aspects of its performance have been investigated widely. Application of MUSIC algorithm to DOA (direction-of-arrival) estimation is of massive computation and requires that the number of signals must be known to partition the space into signal subspace and noise subspace. Moreover, the algorithm does not make use of information on the intensity of signals. This paper deeply investigates the theory of MUSIC algorithm and proposes a modification method which overcomes the disadvantages above. Finally, simulation tests have been undertaken to compare the original algorithm and its modification, which verifies the validity of the theory.

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Jin, Zhi Hao, Xue Ting Zheng, and Li Ming Tang. "Study on Spectral Characteristics of Acoustic Emission from Pressure Pipe Leakage." Applied Mechanics and Materials 48-49 (February 2011): 1182–85. http://dx.doi.org/10.4028/www.scientific.net/amm.48-49.1182.

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Detecting leakage liquid-filled pipe by acoustic emission instrument and researching the acoustic signal that measured with water by experimental medium. Gathering the acoustic signals in different pressures or different diameters of leakage aperture and analyzing the spectrum characteristics by wavelet packets and db5 wavelet basis. The result show that major frequency components contained at about 232KHz-239KHz. The acoustic emission signals’ amplitude and energy enhance as pressure and leakage aperture diameters’ increase.

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Paskas, Milorad. "Two approaches for log-compression parameter estimation: Comparative study." Serbian Journal of Electrical Engineering 6, no. 3 (2009): 419–25. http://dx.doi.org/10.2298/sjee0903419p.

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Standard ultrasound devices perform nonlinear compression reducing dynamic range of the signal. In order to reconstruct original signal it is necessary to find out statistics of the signal before and signal after compression. There are two techniques for compression parameter estimation or, that is equivalent, compressed signal reconstruction advised in literature. In the paper we perform comparison of these techniques both for computer generated signals and ultrasound images. .

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Ilyakhinskii, A. V., V. M. Rodyushkin, D. A. Ryabov, A. A. Khlybov, and V. I. Erofeev. "STUDY ACOUSTIC EMISSION SIGNALS AT TENSION STEEL 20." Problems of strenght and plasticity 83, no. 2 (2021): 188–97. http://dx.doi.org/10.32326/1814-9146-2021-83-2-188-197.

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An investigation was made of acoustic emission signals during uniaxial tensile testing of flat specimens of steel 20 used for parts of welded structures with a large volume of welding, as well as pipelines, collectors and other parts operating at temperatures from –40 to 450 °C under pressure. Tensile testing with simultaneous registration of acoustic emission was carried out on a universal testing machine manufactured by Tinius OIlsen Ltd, model H100KU, at a movement speed of the active gripper of 0.05 meters per minute. Registration of AE signals was carried out using wideband GT350 sensors from GlobalTest and an analog-to-digital converter NationalInstruments 6363X with subsequent storage of the registration results in the form of a time series in the computer memory. A comparative analysis of the amplitude distribution of the AE signal for the area of the yield area and the area of destruction was carried out according to the value of information entropy, fractal dimension, and self-organization parameter. It was found that the parameter of self-organization of the amplitude distribution of the signal is the most informative in describing the processes associated with acoustic emission. As additional information, it is advisable to use data on the structure of the self-organization parameter. The results obtained indicate the possibility of using the statistical model of the Dirichlet distribution as a model of processes associated with the appearance of acoustic emission signals from sources of incipient and developing defects during routine tests of products made of structural carbon high-quality steels with a pearlite-ferrite structure. The paper presents a version of the model and modeling algorithms for FE-modeling corrosion cracking processes in structural elements loaded by pressure and exposed to aggressive corrosion media. To assess the effectiveness of the present models and algorithms, the failure process of a thin-walled tubular specimen partly submerged into a chlorine-containing liquid and loaded by axial tension is numerically modeled.

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Sriyanto, Sesar Prabu Dwi. "Adaptive seismic noise reduction using Wiener filter." Jurnal Teknologi dan Sistem Komputer 8, no. 1 (October 17, 2019): 12–20. http://dx.doi.org/10.14710/jtsiskom.8.1.2020.12-20.

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Seismic noise disrupts the earthquake observation system due to the frequency and amplitude of seismic noise similar to the earthquake signal. The filter process is one of the methods that can be used to reduce seismic noise. In this study, the Wiener filter algorithm was designed with the Decision-Directed method for Apriori SNR estimation. This filter was chosen because it is adaptive, so it can adjust to environmental conditions without requiring manual parameter settings. The data used are earthquake signals that occur in the Palu area, Central Sulawesi, which are recorded on PKA29 temporary seismic station from February 3 to April 28, 2015. After each signal data has been filtered, then it is evaluated by calculating SNR differences before and after filtering, the signal's dominant frequency, and the cross-correlation of the signal before and after filtering. As a result, the Wiener filter is able to reduce the noise content in earthquake signals according to noisy frequencies before earthquake signals. The impact is that SNR has increased with an average of 8.056 dB. In addition, this filter is also able to maintain the shape of earthquake signals. This is indicated by the normalization value of the cross-correlation between signals before and after the filter which ranges from 0.703 to 1.00.

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Journal articles on the topic 'Study signals'

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