The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. Th...The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. The ability of the International Monitoring System (IMS) infrasound network to detect atmospheric nuclear explosions and other signals of interest is strongly dependent on station-specific ambient noise. This ambient noise, includes both incoherent wind noise and real coherent infrasonic waves. Infrasound analysis software detects tens to hundreds of events per day which consume a lot of time for the Infrasound analysts, to define and categorize events where around 90% of the detections are coherent noise. This study analyzed the importance of the synergy between infrasound and seismic data, and provided the infrasound data analyst with the most important local coherent infrasound sources in the region as recorded by the IMS station I48TN, in order to reduce the workload of the analysts and give them a clear view on the coherent noise affecting this station for better discrimination between events of interest like nuclear explosions and coherent sources. DTK_GPMCC and DIVA software were used to perform this study. Geotool software from the International Data Centre (IDC) was used in analysing seismic data from the Tunisian IMS station KEST. The result of this study allowed the characterization of the most important coherent local infrasound sources (Mines and Quarries) which are considered as coherent noise to I48TN station and correct parameters in some reference events in the Reference Event Database source of the International Data Centre.展开更多
Objective The objective was to observe damage of hippocampus in rats after exposure to infrasound, and to assess HSP70 expression in hippocampus. Methods SD rats in the experimental group were exposed to 140 d B（8 Hz...Objective The objective was to observe damage of hippocampus in rats after exposure to infrasound, and to assess HSP70 expression in hippocampus. Methods SD rats in the experimental group were exposed to 140 d B（8 Hz） infrasound for 2 h per day for 3 days. The morphology of the hippocampus was examined by transmission electronic microscopic（TEM）. Cell apoptosis was observed by TUNEL staining at 0 h, 24 h, 48 h, and 2 w after exposure. HSP70 expression was detected by immunohistochemistry（IHC） and Western blotting（WB）. Results TEM showed that hippocampus was significantly damaged by exposure, and exhibited recovery 1 week after exposure. The TUNEL data showed that neuronal apoptosis after exposure was significantly higher than in the control rats at 24 h and 48 h, and the apoptotic cells decreased one week after exposure. IHC and WB showed HSP70 expression was significantly higher in the exposed rats, peaked at 24 h. Conclusion Exposure to 140 d B（8 Hz） infrasound for 2 h per day for 3 days appeared to induce damage to the hippocampus of rats, based on changes in ultrastructure and increased cell apoptosis. However, recovery from the damage occurred overtime. HSP70 expression also increased after the exposure and decreased by 48 h.展开更多
As heavy trucks pass over highway bridges, bridge vibration occurs and generates infrasound. General trucks in Japan with rear leaf suspension have whole body vibration （suspension spring vibration） frequencies of a...As heavy trucks pass over highway bridges, bridge vibration occurs and generates infrasound. General trucks in Japan with rear leaf suspension have whole body vibration （suspension spring vibration） frequencies of about 3 Hz. Also, the frequencies of the wheel vibration （tire spring vibration） are about 10-20 Hz. The continuous steel highway bridges with middle span length have vibration modes with the same phase in each span at the frequencies of about 3 Hz and also have those with the secondary mode shape at the frequencies of about 10-20 Hz. Truck vibrations and bridge vibrations are closely related. In this work, vibration tests are conducted using a heavy test truck for two cases of infrasound complaints in order to investigate the relation between the continuous steel bridge vibration modes generated by the vibration of moving heavy trucks and its infrasound characteristics. As a result of the examination, two types of bridge vibration modes are caused by the vibrations of a moving heavy truck. Moreover, the bending vi- bration modes with the same phase in each span have the most powerful infrasound pressure, since each span vibrates with the same phase. Two countermeasures, including viscoelastic damper at the end of the girders and extended deck method, are proposed to reduce the amplitude of bridge vibration and its infrasound.展开更多
Determining the frequency range of derma nerve that responds to audio current is fundamental for the development of skin-hearing technology. Previous studies have shown that the range of derma nerve responding to audi...Determining the frequency range of derma nerve that responds to audio current is fundamental for the development of skin-hearing technology. Previous studies have shown that the range of derma nerve responding to audio current is 15-15 000 Hz, because audio amplification is not separated from the step-up transformer. Therefore, the present study used a signal generator which directly drives plane electrodes, simplified the original experimental environment for skin-hearing, measured lower limit voltage of frequency for derma nerve receiving pulse current signals, and revealed that the frequency range of human derma nerve response was as wide as 0.1-30 000 Hz. Results demonstrate that human derma nerve receives audio signals and infrasound within a wide frequency range.展开更多
The classification of infrasound events has considerable importance in improving the capability to identify the types of natural disasters.The traditional infrasound classification mainly relies on machine learning al...The classification of infrasound events has considerable importance in improving the capability to identify the types of natural disasters.The traditional infrasound classification mainly relies on machine learning algorithms after artificial feature extraction.However,guaranteeing the effectiveness of the extracted features is difficult.The current trend focuses on using a convolution neural network to automatically extract features for classification.This method can be used to extract signal spatial features automatically through a convolution kernel;however,infrasound signals contain not only spatial information but also temporal information when used as a time series.These extracted temporal features are also crucial.If only a convolution neural network is used,then the time dependence of the infrasound sequence will be missed.Using long short-term memory networks can compensate for the missing time-series features but induces spatial feature information loss of the infrasound signal.A multiscale squeeze excitation–convolution neural network–bidirectional long short-term memory network infrasound event classification fusion model is proposed in this study to address these problems.This model automatically extracted temporal and spatial features,adaptively selected features,and also realized the fusion of the two types of features.Experimental results showed that the classification accuracy of the model was more than 98%,thus verifying the effectiveness and superiority of the proposed model.展开更多
Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several ...Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.展开更多
We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station...We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station-level nuclear-event detection. Receiver Operating Characteristic (ROC) curve analysis is used with real ground truth data to determine the trade-off between the probability of detection (PD) and the false alarm rate (FAR) at various detection thresholds. Further, statistical detection theory via maximum a posteriori and Bayes cost approaches is used to determine station-level optimum “family” size thresholds before detections should be considered for network-level processing. These threshold-determining methods are extensible for family-characterizing statistics other than “size,” such as a family’s collective F-statistic or signal-to-noise ratio (SNR). Therefore, the reliability of analysts’ decisions as to whether families should be preserved for network-level processing can only benefit from access to multiple, independent, optimum decision thresholds based upon size, F-statistic, SNR, etc.展开更多
Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal functio...Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motiliW and gastric morphology and to assess the expression of nitric oxide synthase （NOS） in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology.展开更多
A statistical correlation study on the basis of published data has been performed in order to find whether an abnormal degree of human physiological ailments and a psychology of sustained violent reactions in highly p...A statistical correlation study on the basis of published data has been performed in order to find whether an abnormal degree of human physiological ailments and a psychology of sustained violent reactions in highly populated habitats are correlated with environmental infrasound emissions related to seismic activity and sustained by mountain air turbulence. The study focus is on Latitude 34° North coinciding with boundaries of colliding Tectonic Plates in three continents. Earthquakes, rock fractures and landslides in these regions are creating geoacoustic activity in the form of hotspots of infrasound emissions. Sources of infrasound have been located by global infrasound monitoring stations. One single earthquake can cause multiple infrasound sources in a region. Low frequency “infrasound” creates an environment of unseen and inaudible energies that are hazardous to the local population. In one region on 34°N latitude the percentage of population with hearing disabilities increases or decreases almost directly proportional to frequency of earthquakes. In this region, the casualties due to social disorder and violence increased as the frequency of earthquake events increased and decreased as this frequency decreased. Comprehensive public health studies bring out that a sizable percentage of the regional population remain in a constant state of irritation, annoyance and anger;and suffer many other psychosomatic ailments corresponding to exposure to infrasound in 5 - 16 Hz frequencies and 120 - 140 dB amplitude. A new natural hazard inimical to life on planet earth has thus been identified. The time has arrived for public health authorities to locally pinpoint infrasound hotspots by scientific measurements. Thereafter new technologies can be developed to actively, and passively, mitigate/cancel these hazardous environmental emissions of infrasound and a Public Health Security Systems put in place as sustainable solutions for a healthy, livable habitat.展开更多
The verification of nuclear test ban necessitates the classification and identification of infrasound events.The accurate and eff ective classification of seismic and chemical explosion infrasounds can promote the cla...The verification of nuclear test ban necessitates the classification and identification of infrasound events.The accurate and eff ective classification of seismic and chemical explosion infrasounds can promote the classification and identification of infrasound events.However,overfitting of the signals of seismic and chemical explosion infrasounds easily occurs during training due to the limited amount of data.Thus,to solve this problem,this paper proposes a classification method based on the mixed virtual infrasound data augmentation(MVIDA)algorithm and multiscale squeeze-and-excitation ResNet(MS-SE-ResNet).In this study,the eff ectiveness of the proposed method is verified through simulation and comparison experiments.The simulation results reveal that the MS-SE-ResNet network can eff ectively determine the separability of chemical explosion and seismic infrasounds in the frequency domain,and the average classification accuracy on the dataset enhanced by the MVIDA algorithm reaches 81.12%.This value is higher than those of the other four types of comparative classification methods.This work also demonstrates the eff ectiveness and stability of the augmentation algorithm and classification network in the classification of few-shot infrasound events.展开更多
Infrasound,known for its strong penetration and low attenuation,is extensively used in monitoring and warning systems for debris flows.Here,a debris-flow forecasting method was proposed by combining infrasound-based v...Infrasound,known for its strong penetration and low attenuation,is extensively used in monitoring and warning systems for debris flows.Here,a debris-flow forecasting method was proposed by combining infrasound-based variational mode decomposition and Autoregressive Integrated Moving Average(ARIMA)model.High-precision infrasound sensor was utilized in experiments to record signals under twelve varying conditions of debris flow volume and velocity.Variational mode decomposition was performed on the detected raw signals,and the optimal decomposition scale and penalty factor were obtained through the sparrow search algorithm.The Hilbert transform,rescaled range analysis,power spectrum analysis,and Pearson correlation coefficients judgment criteria were employed to separate and reconstruct the signals.Based on the reconstructed infrasound signals,an ARIMA model was constructed to forecast the trend of debris flow infrasound signal.Results reveal that the Hilbert transform effectively separated noise,and the predictive model’s results fell within a 95%confidence interval.The Mean Absolute Percentage Error(MAPE)across four experiments were 4.87%,5.23%,5.32%and 4.47%,respectively,showing a satisfactory accuracy and providing an alternative for predicting debris flow by infrasound signals.展开更多
Several complaints arose from houses near an object bridge about rattling sounds caused by infrasound, a low-frequency noise in the 0 - 20 Hz frequency range. In Japan, conventional trucks with a rear leaf suspension ...Several complaints arose from houses near an object bridge about rattling sounds caused by infrasound, a low-frequency noise in the 0 - 20 Hz frequency range. In Japan, conventional trucks with a rear leaf suspension have vibration frequencies of about 3.0 Hz;furthermore, their tire spring vibration frequency is 10 - 20 Hz. Infrasound is radiated from the bridge owing to the truck’s suspension spring vibration and/or tire spring vibration. In this study, the bridge vibrations were investigated using test trucks or conventional trucks to determine the cause of rattling sounds. It was found that the truck’s spring vibration caused excessive bending vibration in the object bridge;this in turn was transmitted to nearby houses as infrasound. Various preventive measures for infrasound were then considered, and their effectiveness was investigated through a simulation of the dynamic response using a running truck. The difference between each measure’s effectiveness as obtained by a comparison with each simulation’s result provided a clear picture about the infrasound reduction methods in consideration of both construction cost and working difficulty.展开更多
The microcirculation of mammals is an autoregulated and complex synchronised system according to the current demand for nutrients and oxygen. The undisturbed course of vital functions such as of growth, blood pressure...The microcirculation of mammals is an autoregulated and complex synchronised system according to the current demand for nutrients and oxygen. The undisturbed course of vital functions such as of growth, blood pressure regulation, inflammatory sequence and embryogenesis is bound to endothelial integrity. The sensible vasomotion is particularly dependent on it. Mechano-transduction signalling networks play a critical role in vital cellular processes and are the decisive physiological mechanism for an adequate NO-release, main responsible for the autoregulation of vessels. Disturbed endothelial integrity, originating, e.g., from chronic oxidative stress and/or mechanic (oscillatory) stress, leads to disturbance of vasomotion as well as a disequilibrium of redox systems, recognized as main cause for the development of chronic inflammation diseases such as atherosclerosis and corresponding secondary illnesses, possibly cancer. The endothelial cytoskeleton, which corresponds to a viscoelastic “tensegrity model”, offers the possibility for mechano-transduction via its special construction. The rapidly growing knowledge about mechanical forces in cellular sensing and regulation of the last years (that culminated in the Nobel Prize award for the decoding of pressure/vibration sensing ion channels), led us to the following hypothesis: The extern stressor “Noise” produces under certain conditions an oscillatory stress field in the physiologically laminar flow bed of capillaries, which is able to lead to irregular mechano-transductions. Findings provide a strict dependence on frequency in mechano-transduction with determination of thresholds for a 1:1 transmission. The knowledge, recently gained on endothelial mechano-transduction, sheds a new light on the importance of low frequencies. This could indicate the long-sought pathophysiological way in which infrasound can exert a stressor effect at the cellular level. Noise-exposed citizens, who live near infrastructures such as a biogas installation, heat pumps, block-type thermal power stations and bigger industrial wind turbines (IWT’s), show worldwide mainly a symptomatology associated with microcirculatory disorder. Conceivable are also effects on insects or fishes, since the piezo-channels are recognised as conserved structures of all multicellular organism. An experimental design is proposed to demonstrate the direct pathological influence of infrasound of defined strength, frequency, effect/time profile and duration on the sensitive vasomotion.展开更多
In earlier published studies it was shown that an anomalous degree of human physiological ailments and a psychology of sustained anger and violence exist in highly populated countries located on boundaries of collidin...In earlier published studies it was shown that an anomalous degree of human physiological ailments and a psychology of sustained anger and violence exist in highly populated countries located on boundaries of colliding Tectonic Plates in three continents at Latitude 34° north. The Valley of Kashmir in Northern India is also located exactly on this latitude, hence chosen for detailed experimental verification of this phenomenon. This region also suffers from chronic public health hazards. Infrasound is very low frequency acoustic wave with frequencies ranging from 0.01 Hz to 20 Hz. It emanates from earthquakes, geological Faults, colliding tectonic plates and atmospheric wind turbulence. Hearing protections like ear muffs and ear plugs offer little protection. One single earthquake can cause multiple infrasound sources in a region. It is shown how regional geomorphology in the Kashmir Valley enhances and sustains this phenomenon. Both the percentage of population with hearing disabilities;and casualties due to social violence increase or decrease in proportion to frequency of earthquakes. Infrasound is shown to be the causal linkage. Public health hazards due to environmental infrasound closely resemble public health hazards actually being suffered by the population in Kashmir as established by formal and extensive medical investigations. Hence a Field Study was carried out to locate and record infrasound emissions in ten locations near 34°N latitude in Kashmir Valley. An analytical technique was developed to integrate infrasound spectrum in specific locations with public health hazards. It was discovered that infrasound recorded in South Kashmir around 34°N latitude at the locations of highest amplitude lies in proximity of Active Faults from earthquake ruptures;and in proximity to a large field of past earthquakes that took place in 2006-2012. A comprehensive public health security system needs to be set up very urgently. Technological measures are identified and appropriate technologies suggested cordoning off and mitigating this natural environmental hazard in the Kashmir Valley.展开更多
Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200...Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200 Hz, combined with one broadband barometer was deployed at Jang Bogo Station, Terra Nova Bay, Antarctica. The two years of data by the broadband barometer contain characteristic signals that caused by surface environment nearby the station, mixing with local noises such as katabatic winds. Clear continuous signals by oceanic swells (microbaroms) were recorded with a predominant frequency of around 0.2 s. Variations of frequency context and amplitudes in the Power Spectral Density were considered as affected by sea-ice dynamics surrounding the Terra Nova Bay. Monitoring of microbaroms could contribute to understanding ocean wave climate, with other oceanographic, cryospheric and geophysical data in Antarctica. Infrasound data in Terra Nova Bay might be a new proxy for estimating environmental variations affected by global warming, cryosphere dynamics, together with volcanic eruptions in Victoria Land.展开更多
The split characteristics of the tropical Mesoscale Convective System (MCS) of April 9, 2018, in northern Ghana were studied using infrasound data measured by the mobile array (I68CI) which was deployed by C<span s...The split characteristics of the tropical Mesoscale Convective System (MCS) of April 9, 2018, in northern Ghana were studied using infrasound data measured by the mobile array (I68CI) which was deployed by C<span style="white-space:nowrap;">?</span>te d’Ivoire National Data Center (NDC) in collaboration with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These infrasound measurements were made during a measurement campaign from January 1st, 2018 to December 31, 2018, in northeast Cote d’Ivoire, precisely in Comoe National Park. Graphic Progressive Multi-Channel Correlation (GPMCC) method based on a progressive study of the correlation functions was used to analyze and visualize data. The infrasound detection from this MCS shows clearly a division of the MCS structure into 2 distinct subsystems under the effect of internal and external constraints not well known but related to convection;a smaller subsystem in the north, associated with an area of intense rainfall of about 30 mm/hour and located at 9.5<span style="white-space:nowrap;">°</span>N - 2<span style="white-space:nowrap;">°</span>E with an azimuth of 70<span style="white-space:nowrap;">°</span> and, a large subsystem in the south, associated with a zone of high rainfall of about 96 mm/hour and located at 8.8<span style="white-space:nowrap;">°</span>N - 1.4<span style="white-space:nowrap;">°</span>E with an azimuth of 90<span style="white-space:nowrap;">°</span>. These two subsystems were located 200 km and 260 km from the I68CI station with frequencies of 2.3 Hz and 1 Hz respectively. The mesoscale convective systems in this region are moving from East to West and including several storm cells.展开更多
Noise due to surface wind and temperature is a problem in infrasound. Efficiency of IMS network concerns scientists. It is obvious to find the causes of deficiencies of detection of infrasound station by studying back...Noise due to surface wind and temperature is a problem in infrasound. Efficiency of IMS network concerns scientists. It is obvious to find the causes of deficiencies of detection of infrasound station by studying background noise power with respect to the surface wind and the temperature. Data measured by MB2000 microbarometer of infrasound station I33MG are used for the study. Infrasound records are separated into 4 frequency bands centered respectively at: 1 Hz, 0.25 Hz, 0.0625 Hz and 0.0156 Hz. Effects of surface wind and temperature are studied by plotting the variations of the background noise power with respect to the temperature or wind speed in the four considered frequency bands and compared with the median of background noise power. The influence of temperature is manifested by a reduction in the number of low-frequency detection. The surface wind reduces the number of detection at a high frequency. An exponential function is proposed to predict the variations of the noise power in different observation frequencies and temperature and wind conditions. The views expressed herein are those of the authors and do not necessarily reflect the views of the CTBTO Preparatory Commission.展开更多
文摘The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO), characterized by its location in the heart of the IMS Infrasound network. The ability of the International Monitoring System (IMS) infrasound network to detect atmospheric nuclear explosions and other signals of interest is strongly dependent on station-specific ambient noise. This ambient noise, includes both incoherent wind noise and real coherent infrasonic waves. Infrasound analysis software detects tens to hundreds of events per day which consume a lot of time for the Infrasound analysts, to define and categorize events where around 90% of the detections are coherent noise. This study analyzed the importance of the synergy between infrasound and seismic data, and provided the infrasound data analyst with the most important local coherent infrasound sources in the region as recorded by the IMS station I48TN, in order to reduce the workload of the analysts and give them a clear view on the coherent noise affecting this station for better discrimination between events of interest like nuclear explosions and coherent sources. DTK_GPMCC and DIVA software were used to perform this study. Geotool software from the International Data Centre (IDC) was used in analysing seismic data from the Tunisian IMS station KEST. The result of this study allowed the characterization of the most important coherent local infrasound sources (Mines and Quarries) which are considered as coherent noise to I48TN station and correct parameters in some reference events in the Reference Event Database source of the International Data Centre.
文摘Objective The objective was to observe damage of hippocampus in rats after exposure to infrasound, and to assess HSP70 expression in hippocampus. Methods SD rats in the experimental group were exposed to 140 d B（8 Hz） infrasound for 2 h per day for 3 days. The morphology of the hippocampus was examined by transmission electronic microscopic（TEM）. Cell apoptosis was observed by TUNEL staining at 0 h, 24 h, 48 h, and 2 w after exposure. HSP70 expression was detected by immunohistochemistry（IHC） and Western blotting（WB）. Results TEM showed that hippocampus was significantly damaged by exposure, and exhibited recovery 1 week after exposure. The TUNEL data showed that neuronal apoptosis after exposure was significantly higher than in the control rats at 24 h and 48 h, and the apoptotic cells decreased one week after exposure. IHC and WB showed HSP70 expression was significantly higher in the exposed rats, peaked at 24 h. Conclusion Exposure to 140 d B（8 Hz） infrasound for 2 h per day for 3 days appeared to induce damage to the hippocampus of rats, based on changes in ultrastructure and increased cell apoptosis. However, recovery from the damage occurred overtime. HSP70 expression also increased after the exposure and decreased by 48 h.
文摘As heavy trucks pass over highway bridges, bridge vibration occurs and generates infrasound. General trucks in Japan with rear leaf suspension have whole body vibration （suspension spring vibration） frequencies of about 3 Hz. Also, the frequencies of the wheel vibration （tire spring vibration） are about 10-20 Hz. The continuous steel highway bridges with middle span length have vibration modes with the same phase in each span at the frequencies of about 3 Hz and also have those with the secondary mode shape at the frequencies of about 10-20 Hz. Truck vibrations and bridge vibrations are closely related. In this work, vibration tests are conducted using a heavy test truck for two cases of infrasound complaints in order to investigate the relation between the continuous steel bridge vibration modes generated by the vibration of moving heavy trucks and its infrasound characteristics. As a result of the examination, two types of bridge vibration modes are caused by the vibrations of a moving heavy truck. Moreover, the bending vi- bration modes with the same phase in each span have the most powerful infrasound pressure, since each span vibrates with the same phase. Two countermeasures, including viscoelastic damper at the end of the girders and extended deck method, are proposed to reduce the amplitude of bridge vibration and its infrasound.
基金the National Natural Science Foundation of China,No.60672001the Special Fund of Education Department of Shaanxi Province,No.05JC0
文摘Determining the frequency range of derma nerve that responds to audio current is fundamental for the development of skin-hearing technology. Previous studies have shown that the range of derma nerve responding to audio current is 15-15 000 Hz, because audio amplification is not separated from the step-up transformer. Therefore, the present study used a signal generator which directly drives plane electrodes, simplified the original experimental environment for skin-hearing, measured lower limit voltage of frequency for derma nerve receiving pulse current signals, and revealed that the frequency range of human derma nerve response was as wide as 0.1-30 000 Hz. Results demonstrate that human derma nerve receives audio signals and infrasound within a wide frequency range.
基金supported by the Shaanxi Province Natural Science Basic Research Plan Project(2023-JC-YB-244).
文摘The classification of infrasound events has considerable importance in improving the capability to identify the types of natural disasters.The traditional infrasound classification mainly relies on machine learning algorithms after artificial feature extraction.However,guaranteeing the effectiveness of the extracted features is difficult.The current trend focuses on using a convolution neural network to automatically extract features for classification.This method can be used to extract signal spatial features automatically through a convolution kernel;however,infrasound signals contain not only spatial information but also temporal information when used as a time series.These extracted temporal features are also crucial.If only a convolution neural network is used,then the time dependence of the infrasound sequence will be missed.Using long short-term memory networks can compensate for the missing time-series features but induces spatial feature information loss of the infrasound signal.A multiscale squeeze excitation–convolution neural network–bidirectional long short-term memory network infrasound event classification fusion model is proposed in this study to address these problems.This model automatically extracted temporal and spatial features,adaptively selected features,and also realized the fusion of the two types of features.Experimental results showed that the classification accuracy of the model was more than 98%,thus verifying the effectiveness and superiority of the proposed model.
文摘Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.
文摘We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station-level nuclear-event detection. Receiver Operating Characteristic (ROC) curve analysis is used with real ground truth data to determine the trade-off between the probability of detection (PD) and the false alarm rate (FAR) at various detection thresholds. Further, statistical detection theory via maximum a posteriori and Bayes cost approaches is used to determine station-level optimum “family” size thresholds before detections should be considered for network-level processing. These threshold-determining methods are extensible for family-characterizing statistics other than “size,” such as a family’s collective F-statistic or signal-to-noise ratio (SNR). Therefore, the reliability of analysts’ decisions as to whether families should be preserved for network-level processing can only benefit from access to multiple, independent, optimum decision thresholds based upon size, F-statistic, SNR, etc.
基金financially supported by the Shaanxi province science and technology project[grant number 2005k12-G1-3]
文摘Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motiliW and gastric morphology and to assess the expression of nitric oxide synthase （NOS） in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology.
文摘A statistical correlation study on the basis of published data has been performed in order to find whether an abnormal degree of human physiological ailments and a psychology of sustained violent reactions in highly populated habitats are correlated with environmental infrasound emissions related to seismic activity and sustained by mountain air turbulence. The study focus is on Latitude 34° North coinciding with boundaries of colliding Tectonic Plates in three continents. Earthquakes, rock fractures and landslides in these regions are creating geoacoustic activity in the form of hotspots of infrasound emissions. Sources of infrasound have been located by global infrasound monitoring stations. One single earthquake can cause multiple infrasound sources in a region. Low frequency “infrasound” creates an environment of unseen and inaudible energies that are hazardous to the local population. In one region on 34°N latitude the percentage of population with hearing disabilities increases or decreases almost directly proportional to frequency of earthquakes. In this region, the casualties due to social disorder and violence increased as the frequency of earthquake events increased and decreased as this frequency decreased. Comprehensive public health studies bring out that a sizable percentage of the regional population remain in a constant state of irritation, annoyance and anger;and suffer many other psychosomatic ailments corresponding to exposure to infrasound in 5 - 16 Hz frequencies and 120 - 140 dB amplitude. A new natural hazard inimical to life on planet earth has thus been identified. The time has arrived for public health authorities to locally pinpoint infrasound hotspots by scientific measurements. Thereafter new technologies can be developed to actively, and passively, mitigate/cancel these hazardous environmental emissions of infrasound and a Public Health Security Systems put in place as sustainable solutions for a healthy, livable habitat.
基金supported by the Natural Science Foundation of Shaanxi Province(2023-JC-YB-221).
文摘The verification of nuclear test ban necessitates the classification and identification of infrasound events.The accurate and eff ective classification of seismic and chemical explosion infrasounds can promote the classification and identification of infrasound events.However,overfitting of the signals of seismic and chemical explosion infrasounds easily occurs during training due to the limited amount of data.Thus,to solve this problem,this paper proposes a classification method based on the mixed virtual infrasound data augmentation(MVIDA)algorithm and multiscale squeeze-and-excitation ResNet(MS-SE-ResNet).In this study,the eff ectiveness of the proposed method is verified through simulation and comparison experiments.The simulation results reveal that the MS-SE-ResNet network can eff ectively determine the separability of chemical explosion and seismic infrasounds in the frequency domain,and the average classification accuracy on the dataset enhanced by the MVIDA algorithm reaches 81.12%.This value is higher than those of the other four types of comparative classification methods.This work also demonstrates the eff ectiveness and stability of the augmentation algorithm and classification network in the classification of few-shot infrasound events.
基金funded by National Key R&D Program of China(No.2022YFC3003403)Sichuan Science and Technology Program(No.2024NSFSC0072)+1 种基金Natural Science Foundation of Hebei Province(No.F2021201031)Geological Survey Project of China Geological Survey(No.DD20230442).
文摘Infrasound,known for its strong penetration and low attenuation,is extensively used in monitoring and warning systems for debris flows.Here,a debris-flow forecasting method was proposed by combining infrasound-based variational mode decomposition and Autoregressive Integrated Moving Average(ARIMA)model.High-precision infrasound sensor was utilized in experiments to record signals under twelve varying conditions of debris flow volume and velocity.Variational mode decomposition was performed on the detected raw signals,and the optimal decomposition scale and penalty factor were obtained through the sparrow search algorithm.The Hilbert transform,rescaled range analysis,power spectrum analysis,and Pearson correlation coefficients judgment criteria were employed to separate and reconstruct the signals.Based on the reconstructed infrasound signals,an ARIMA model was constructed to forecast the trend of debris flow infrasound signal.Results reveal that the Hilbert transform effectively separated noise,and the predictive model’s results fell within a 95%confidence interval.The Mean Absolute Percentage Error(MAPE)across four experiments were 4.87%,5.23%,5.32%and 4.47%,respectively,showing a satisfactory accuracy and providing an alternative for predicting debris flow by infrasound signals.
文摘Several complaints arose from houses near an object bridge about rattling sounds caused by infrasound, a low-frequency noise in the 0 - 20 Hz frequency range. In Japan, conventional trucks with a rear leaf suspension have vibration frequencies of about 3.0 Hz;furthermore, their tire spring vibration frequency is 10 - 20 Hz. Infrasound is radiated from the bridge owing to the truck’s suspension spring vibration and/or tire spring vibration. In this study, the bridge vibrations were investigated using test trucks or conventional trucks to determine the cause of rattling sounds. It was found that the truck’s spring vibration caused excessive bending vibration in the object bridge;this in turn was transmitted to nearby houses as infrasound. Various preventive measures for infrasound were then considered, and their effectiveness was investigated through a simulation of the dynamic response using a running truck. The difference between each measure’s effectiveness as obtained by a comparison with each simulation’s result provided a clear picture about the infrasound reduction methods in consideration of both construction cost and working difficulty.
文摘The microcirculation of mammals is an autoregulated and complex synchronised system according to the current demand for nutrients and oxygen. The undisturbed course of vital functions such as of growth, blood pressure regulation, inflammatory sequence and embryogenesis is bound to endothelial integrity. The sensible vasomotion is particularly dependent on it. Mechano-transduction signalling networks play a critical role in vital cellular processes and are the decisive physiological mechanism for an adequate NO-release, main responsible for the autoregulation of vessels. Disturbed endothelial integrity, originating, e.g., from chronic oxidative stress and/or mechanic (oscillatory) stress, leads to disturbance of vasomotion as well as a disequilibrium of redox systems, recognized as main cause for the development of chronic inflammation diseases such as atherosclerosis and corresponding secondary illnesses, possibly cancer. The endothelial cytoskeleton, which corresponds to a viscoelastic “tensegrity model”, offers the possibility for mechano-transduction via its special construction. The rapidly growing knowledge about mechanical forces in cellular sensing and regulation of the last years (that culminated in the Nobel Prize award for the decoding of pressure/vibration sensing ion channels), led us to the following hypothesis: The extern stressor “Noise” produces under certain conditions an oscillatory stress field in the physiologically laminar flow bed of capillaries, which is able to lead to irregular mechano-transductions. Findings provide a strict dependence on frequency in mechano-transduction with determination of thresholds for a 1:1 transmission. The knowledge, recently gained on endothelial mechano-transduction, sheds a new light on the importance of low frequencies. This could indicate the long-sought pathophysiological way in which infrasound can exert a stressor effect at the cellular level. Noise-exposed citizens, who live near infrastructures such as a biogas installation, heat pumps, block-type thermal power stations and bigger industrial wind turbines (IWT’s), show worldwide mainly a symptomatology associated with microcirculatory disorder. Conceivable are also effects on insects or fishes, since the piezo-channels are recognised as conserved structures of all multicellular organism. An experimental design is proposed to demonstrate the direct pathological influence of infrasound of defined strength, frequency, effect/time profile and duration on the sensitive vasomotion.
文摘In earlier published studies it was shown that an anomalous degree of human physiological ailments and a psychology of sustained anger and violence exist in highly populated countries located on boundaries of colliding Tectonic Plates in three continents at Latitude 34° north. The Valley of Kashmir in Northern India is also located exactly on this latitude, hence chosen for detailed experimental verification of this phenomenon. This region also suffers from chronic public health hazards. Infrasound is very low frequency acoustic wave with frequencies ranging from 0.01 Hz to 20 Hz. It emanates from earthquakes, geological Faults, colliding tectonic plates and atmospheric wind turbulence. Hearing protections like ear muffs and ear plugs offer little protection. One single earthquake can cause multiple infrasound sources in a region. It is shown how regional geomorphology in the Kashmir Valley enhances and sustains this phenomenon. Both the percentage of population with hearing disabilities;and casualties due to social violence increase or decrease in proportion to frequency of earthquakes. Infrasound is shown to be the causal linkage. Public health hazards due to environmental infrasound closely resemble public health hazards actually being suffered by the population in Kashmir as established by formal and extensive medical investigations. Hence a Field Study was carried out to locate and record infrasound emissions in ten locations near 34°N latitude in Kashmir Valley. An analytical technique was developed to integrate infrasound spectrum in specific locations with public health hazards. It was discovered that infrasound recorded in South Kashmir around 34°N latitude at the locations of highest amplitude lies in proximity of Active Faults from earthquake ruptures;and in proximity to a large field of past earthquakes that took place in 2006-2012. A comprehensive public health security system needs to be set up very urgently. Technological measures are identified and appropriate technologies suggested cordoning off and mitigating this natural environmental hazard in the Kashmir Valley.
文摘Infrasound signals in Antarctica reflect physical interaction in the surface environments around the recorded area. In December 2015, an infrasound array by three sensors in the detectable frequency range of 0.1 - 200 Hz, combined with one broadband barometer was deployed at Jang Bogo Station, Terra Nova Bay, Antarctica. The two years of data by the broadband barometer contain characteristic signals that caused by surface environment nearby the station, mixing with local noises such as katabatic winds. Clear continuous signals by oceanic swells (microbaroms) were recorded with a predominant frequency of around 0.2 s. Variations of frequency context and amplitudes in the Power Spectral Density were considered as affected by sea-ice dynamics surrounding the Terra Nova Bay. Monitoring of microbaroms could contribute to understanding ocean wave climate, with other oceanographic, cryospheric and geophysical data in Antarctica. Infrasound data in Terra Nova Bay might be a new proxy for estimating environmental variations affected by global warming, cryosphere dynamics, together with volcanic eruptions in Victoria Land.
文摘The split characteristics of the tropical Mesoscale Convective System (MCS) of April 9, 2018, in northern Ghana were studied using infrasound data measured by the mobile array (I68CI) which was deployed by C<span style="white-space:nowrap;">?</span>te d’Ivoire National Data Center (NDC) in collaboration with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These infrasound measurements were made during a measurement campaign from January 1st, 2018 to December 31, 2018, in northeast Cote d’Ivoire, precisely in Comoe National Park. Graphic Progressive Multi-Channel Correlation (GPMCC) method based on a progressive study of the correlation functions was used to analyze and visualize data. The infrasound detection from this MCS shows clearly a division of the MCS structure into 2 distinct subsystems under the effect of internal and external constraints not well known but related to convection;a smaller subsystem in the north, associated with an area of intense rainfall of about 30 mm/hour and located at 9.5<span style="white-space:nowrap;">°</span>N - 2<span style="white-space:nowrap;">°</span>E with an azimuth of 70<span style="white-space:nowrap;">°</span> and, a large subsystem in the south, associated with a zone of high rainfall of about 96 mm/hour and located at 8.8<span style="white-space:nowrap;">°</span>N - 1.4<span style="white-space:nowrap;">°</span>E with an azimuth of 90<span style="white-space:nowrap;">°</span>. These two subsystems were located 200 km and 260 km from the I68CI station with frequencies of 2.3 Hz and 1 Hz respectively. The mesoscale convective systems in this region are moving from East to West and including several storm cells.
文摘Noise due to surface wind and temperature is a problem in infrasound. Efficiency of IMS network concerns scientists. It is obvious to find the causes of deficiencies of detection of infrasound station by studying background noise power with respect to the surface wind and the temperature. Data measured by MB2000 microbarometer of infrasound station I33MG are used for the study. Infrasound records are separated into 4 frequency bands centered respectively at: 1 Hz, 0.25 Hz, 0.0625 Hz and 0.0156 Hz. Effects of surface wind and temperature are studied by plotting the variations of the background noise power with respect to the temperature or wind speed in the four considered frequency bands and compared with the median of background noise power. The influence of temperature is manifested by a reduction in the number of low-frequency detection. The surface wind reduces the number of detection at a high frequency. An exponential function is proposed to predict the variations of the noise power in different observation frequencies and temperature and wind conditions. The views expressed herein are those of the authors and do not necessarily reflect the views of the CTBTO Preparatory Commission.
