Aiming at the problem of on-line damage diagnosis in structural health monitoring （SHM）, an algorithm of feature extraction and damage alarming based on auto-regressive moving-average （ARMA） time series analysis i...Aiming at the problem of on-line damage diagnosis in structural health monitoring （SHM）, an algorithm of feature extraction and damage alarming based on auto-regressive moving-average （ARMA） time series analysis is presented. The monitoring data were first modeled as ARMA models, while a principalcomponent matrix derived from the AR coefficients of these models was utilized to establish the Mahalanobisdistance criterion functions. Then, a new damage-sensitive feature index DDSF is proposed. A hypothesis test involving the t-test method is further applied to obtain a decision of damage alarming as the mean value of DDSF had significantly changed after damage. The numerical results of a three-span-girder model shows that the defined index is sensitive to subtle structural damage, and the proposed algorithm can be applied to the on-line damage alarming in SHM.展开更多
The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response un...The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response under various scales are further formulated. The theoretical analysis results reveal that the wavelet packet energy spectrum （WPES） obtained from wavelet packet decomposition of structural dynamic response will detect the presence of structural damage. The sensitivity analysis of the WPES to structural damage and measurement noise is also performed. The transfer properties of the structural system matrix and the observation noise under various analysis scales are formulated, which verify the damage alarming reliability using the proposed WPES with preferable damage sensitivity and noise robusticity.展开更多
Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for...Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for bridge expansion joints based on long-term monitoring data was developed. The effects of environmental factors on the expansion joint displacement were analyzed. Multiple linear regression models were obtained to describe the correlation between displacements and the dominant environmental factors. The damage alarming index was defined based on the multiple regression models. At last, the X-bar control chart was utilized to detect the abnormal change of the displacements. Analysis results reveal that temperature and traffic condition are the dominant environmental factors to influence the displacement. When the confidence level of X-bar control chart is set to be 0.003, the false-positive indications of damage can be avoided. The damage sensitivity analysis shows that the proper X-bar control chart can detect 0.1 cm damage-induced change of the expansion joint displacement. It is reasonably believed that the proposed technique is robust against false-positive indication of damage and suitable to alarm the possible future damage of the expansion joints.展开更多
Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.Firs...Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions.展开更多
Deep analysis of call detail log of the alarming information indicates that reasons except user equipment(UE)issue are usually ignored.To effectively reduce call drop rate in wideband code division multiple access(WCD...Deep analysis of call detail log of the alarming information indicates that reasons except user equipment(UE)issue are usually ignored.To effectively reduce call drop rate in wideband code division multiple access(WCDMA)mobile communication system,a novel method is presented.First,the reliable trace information is extracted to observe the distribution of all the exceptions from radio network controller(RNC)daily report.Then,the antenna angle of generalized clustering network in 024 base station’s c sector(GCN024C)for environmental test(ET)which is obtained from the radio frequency(RF)engineer is manually changed from 4° to 6°.Experimental results show that the proposed method can guarantee the key performance indicators(KPI)of WCDMA and have obvious effect on reducing call drop rate.展开更多
ECG monitoring in daily life is an important means of treating heart disease. To make it easier for the medical to monitor the ECG of their patients outside the hospital, we designed and developed an ECG monitoring an...ECG monitoring in daily life is an important means of treating heart disease. To make it easier for the medical to monitor the ECG of their patients outside the hospital, we designed and developed an ECG monitoring and alarming system based on Android smart phone. In our system, an ECG device collects the ECG signal and transmits it to an Android phone. The Android phone detects alarms which come from the ECG devices. When alarms occur, Android phone will capture the ECG images and the details about the alarms, and sends them to the cloud Alarm Server (AS). Once received, AS push the messages to doctors’ phone, so the doctors could see the ECG images and alarm details on their mobile phone. In our system, high resolution ECG pictures are transmitted to doctors’ phone in a user-friendly way, which can help doctors keep track of their patient’s condition easily.展开更多
As weather radar stations require headroom environment to operate,they were mostly built on highlands which are usually unattended.The mains supply is relatively poor,and the risk of radar stoppages due to power outag...As weather radar stations require headroom environment to operate,they were mostly built on highlands which are usually unattended.The mains supply is relatively poor,and the risk of radar stoppages due to power outage is therefore ever-present.As such,the radar construction program is used to build a complementary security video monitoring system.By collecting monitoring images of the regulated power supply in real-time from power supply auto transfer systems in distribution rooms and radar transceiver rooms,using Spearman’s rank correlation coefficient to analyse pixel variation trends,and supplementing statistical analysis of pixel characteristics difference to eliminate misjudgments resulting from low image contrast in special scenarios,a software can be developed through C#.It has the function of automatically monitoring mains supply and alerting staff on duty to handle the power outage in a timely manner via text message so that any potential risk is neutralised before it can cause damage.This monitoring and auto-alerting approach is generally applicable to unattended rooms with large amounts of electronical equipment.展开更多
The EU has imposed a provisional anti-dumping duty on high tenacity yarn of polyesters from China on Jun. 2. Overseas crisis-fighting measures such as anti-dumping action, are up sharply in recent years. Chinese suppl...The EU has imposed a provisional anti-dumping duty on high tenacity yarn of polyesters from China on Jun. 2. Overseas crisis-fighting measures such as anti-dumping action, are up sharply in recent years. Chinese suppliers have to live with a challenging production environment展开更多
This article explores the design of a wireless fire alarm system supported by advanced data fusion technology.It includes discussions on the basic design ideas of the wireless fire alarm system,hardware design analysi...This article explores the design of a wireless fire alarm system supported by advanced data fusion technology.It includes discussions on the basic design ideas of the wireless fire alarm system,hardware design analysis,software design analysis,and simulation analysis,all supported by data fusion technology.Hopefully,this analysis can provide some reference for the rational application of data fusion technology to meet the actual design and application requirements of the system.展开更多
Apps can help you in your daily life.For example,the app Kiwake helps you wake up.Its special alarm won't turn off until you do three things.You must take a picture of something far from your bed.Then play a short...Apps can help you in your daily life.For example,the app Kiwake helps you wake up.Its special alarm won't turn off until you do three things.You must take a picture of something far from your bed.Then play a short game to wake up your mind.After that,you must review your goals for the day.展开更多
Avian alarm calls mediate defenses against brood parasites and predators. These calls facilitate communication among adults and alert nestlings to potential danger. While heterospecific call recognition has been exten...Avian alarm calls mediate defenses against brood parasites and predators. These calls facilitate communication among adults and alert nestlings to potential danger. While heterospecific call recognition has been extensively studied in adult birds, nestlings—lacking direct predation experience and heterospecific alarm exposure—represent an ideal system to investigate the response to interspecific warning cues. This study explored the recognition capabilities of 5–6-day-old nestlings in Oriental Reed Warbler (Acrocephalus orientalis), a common host of the Common Cuckoo (Cuculus canorus). We exposed the nestlings to playbacks of alarm calls directed at parasites and raptors from conspecific, Vinous-throated Parrotbill (Sinosuthora webbiana, sympatric species), Isabelline Shrike (Lanius isabellinus, allopatric species) and Common Tailorbird (Orthotomus sutorius, allopatric species) adults. Results indicated that there was no significant difference in the responses of nestlings to the alarm calls of conspecific and allopatric adults directed at cuckoos and sparrowhawks. In addition, interestingly, nestlings significantly reduced their begging in response to conspecific and unfamiliar allopatric Isabelline Shrike and Common Tailorbird alarm calls but exhibited a weak response to the sympatric Vinous-throated Parrotbill. Whether older warbler nestlings with more social experience exhibit stronger responses to the alarm calls of Vinous-throated Parrotbill adults requires further investigation.展开更多
Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,mal...Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,males and females are expected to differ in the perceived costs and/orbenefts associated with predator avoidance decisions.Recent studies suggest that male Trinidadian guppies(Poecilia reticulata)show reducedor absent responses to acute personal information cues,placing them at greater risk of predation relative to females.Our goal here was totest the hypothesis that adult(reproductively active)male guppies rely on social information to limit potential costs associated with their lack ofresponse to risky personal cues.Adult male guppies were exposed to personal chemosensory cues(either conspecifc alarm cues(AC),a novelodor,or a water control)in the presence of a shoal of three females inside a holding container that allowed the transmission of visual but notchemical cues.At the same time,we exposed females to either risk from AC or no risk,resulting in the display of a range of female behavior,from calm to alarmed,available as social information for males.Alarmed females caused male fright activity to increase and male interest infemales to decrease,regardless of the personal cue treatment.These results indicate that male guppies rely more on female information regarding predation risk than their own personal information,probably to balance trade-offs between reproduction and predator avoidance.展开更多
Emitting alarm calls may be costly,but few studies have asked whether calling increases a caller’s risk of predation and survival.Since observing animals calling and being killed is relatively rare,we capitalized on ...Emitting alarm calls may be costly,but few studies have asked whether calling increases a caller’s risk of predation and survival.Since observing animals calling and being killed is relatively rare,we capitalized on over 24,000 h of observations of marmot colonies and asked whether variation in the rate that yellow-bellied marmots(Marmota faviventer)alarm called was associated with the probability of summer mortality,a proxy for predation.Using a generalized mixed model that controlled for factors that infuenced the likelihood of survival,we found that marmots who called at higher rates were substantially more likely to die over the summer.Because virtually all summer mortality is due to predation,these results suggest that calling is indeed costly for marmots.Additionally,the results from a Cox survival analysis showed that marmots that called more lived signifcantly shorter lives.Prior studies have shown that marmots reduce the risk by emitting calls only when close to their burrows,but this newly quantifed survival cost suggests a constraint on eliminating risks.Quantifying the cost of alarm calling using a similar approach in other systems will help us better understand its true costs,which is an essential value for theoretical models of calling and social behavior.展开更多
Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of ot...Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.展开更多
There are multiple types of risks involved in the service of long-span railway bridges.Classical methods are difficult to provide targeted alarm information according to different situations of load anomalies and stru...There are multiple types of risks involved in the service of long-span railway bridges.Classical methods are difficult to provide targeted alarm information according to different situations of load anomalies and structural anomalies.To accurately alarm different risks of long-span railway bridges by structural health monitoring systems,this paper proposes a cross-cooperative alarm method using principal and secondary indicators during high-wind periods.It provides the prior criterion for monitoring systems under special conditions,defining the principal and secondary indicators,alarm levels,and thresholds based on the relationship between dynamic equilibrium equations and multiple linear regression analysis.Analysis of one-year monitoring data from a longspan railway cable-stayed bridge shows that the 10-min average cross-bridge wind speed(excitation indicator)can be selected as the principal indicator,while lateral displacement(response indicator)can serve as the secondary indicator.The threshold levels of the secondary indicator prioritize the safety of bridge operation(mainly aiming at the safety of trains traversing bridges),with values significantly lower than structural safety thresholds.This approach enhances alarm timeliness and effectively distinguishes between load anomalies,structural anomalies,and equipment failures.Consequently,it improves alarm accuracy and provides timely decision support for bridge maintenance,train traversing,and emergency treatment.展开更多
As oil and gas exploration continues to progress into deeper and unconventional reservoirs,the likelihood of kick risk increases,making kick warning a critical factor in ensuring drilling safety and efficiency.Due to ...As oil and gas exploration continues to progress into deeper and unconventional reservoirs,the likelihood of kick risk increases,making kick warning a critical factor in ensuring drilling safety and efficiency.Due to the scarcity of kick samples,traditional supervised models perform poorly,and significant fluctuations in field data lead to high false alarm rates.This study proposes an unsupervised graph autoencoder(GAE)-based kick warning method,which effectively reduces false alarms by eliminating the influence of field engineer operations and incorporating real-time model updates.The method utilizes the GAE model to process time-series data during drilling,accurately identifying kick risk while overcoming challenges related to small sample sizes and missing features.To further reduce false alarms,the weighted dynamic time warping(WDTW)algorithm is introduced to identify fluctuations in logging data caused by field engineer operations during drilling,with real-time updates applied to prevent normal conditions from being misclassified as kick risk.Experimental results show that the GAE-based kick warning method achieves an accuracy of 92.7%and significantly reduces the false alarm rate.The GAE model continues to operate effectively even under conditions of missing features and issues kick warnings 4 min earlier than field engineers,demonstrating its high sensitivity and robustness.After integrating the WDTW algorithm and real-time updates,the false alarm rate is reduced from 17.3%to 5.6%,further improving the accuracy of kick warnings.The proposed method provides an efficient and reliable approach for kick warning in drilling operations,offering strong practical value and technical support for the intelligent management of future drilling operations.展开更多
The intrusion of obstacles onto railway tracks presents a significant threat to train safety,characterized by sudden and unpredictable occurrences.With China leading the world in high-speed rail mileage,ensuring railw...The intrusion of obstacles onto railway tracks presents a significant threat to train safety,characterized by sudden and unpredictable occurrences.With China leading the world in high-speed rail mileage,ensuring railway security is paramount.The current laser monitoring technologies suffer from high false alarm rates and unreliable intrusion identification.This study addresses these issues by investigating high-resolution laser monitoring technology for railway obstacles,focusing on key parameters such as monitoring range and resolution.We propose an enhanced non-uniform laser scanning method,developing a laser monitoring system that reduces the obstacle false alarm rate to 2.00%,significantly lower than the 20%standard(TJ/GW135-2015).This rate is the best record for laser monitoring systems on China Railway.Our system operates seamlessly in all weather conditions,providing superior accuracy,resolution,and identification efficiency.It is the only 3D LiDAR system certified by the China State Railway Group Co.,Ltd.(Certificate No.[2023]008).Over three years,our system has been deployed at numerous points along various lines managed by the China State Railway Group,accumulating a dataset of 300,000 observations.This extensive deployment has significantly enhanced railway safety.The development and implementation of our railway laser monitoring system represent a substantial advancement in railway safety technology.Its low false alarm rate(2.00%),high accuracy(20 cm×20 cm×20 cm),and robust performance in diverse conditions underscore its potential for widespread adoption,promising to enhance railway safety in China and internationally.展开更多
A novel spectrum hole detection mechanism is proposed to improve the detection probability in cognitive radio networks for several typical scenarios. By removing the influence of the spatial false alarm （SFA）, the s...A novel spectrum hole detection mechanism is proposed to improve the detection probability in cognitive radio networks for several typical scenarios. By removing the influence of the spatial false alarm （SFA）, the spectrum hole detection probability of the secondary user under path loss and multi-path fading is derived. Meanwhile, the spectrum hole detection probability of multi-users cooperative sensing and that of single-user sensing in multi-bands are derived for comparison. Theoretical analyses and simulation results show that the spectrum hole detection probability of the proposed mechanism is inversely proportional to the sampling times and the area of the sensing region. The detection performance of the multi-users sensing is better than that of single-user sensing when with the AND ~ogic fusion rule but worse when with the OR logic fusion rule. The detection probability is further decreased in the Rayleigh fading channel but it is greatly increased in multi-bands.展开更多
基金The National High Technology Research and Devel-opment Program of China (863Program) (No2006AA04Z416)the National Natural Science Foundation of China (No50538020)
文摘Aiming at the problem of on-line damage diagnosis in structural health monitoring （SHM）, an algorithm of feature extraction and damage alarming based on auto-regressive moving-average （ARMA） time series analysis is presented. The monitoring data were first modeled as ARMA models, while a principalcomponent matrix derived from the AR coefficients of these models was utilized to establish the Mahalanobisdistance criterion functions. Then, a new damage-sensitive feature index DDSF is proposed. A hypothesis test involving the t-test method is further applied to obtain a decision of damage alarming as the mean value of DDSF had significantly changed after damage. The numerical results of a three-span-girder model shows that the defined index is sensitive to subtle structural damage, and the proposed algorithm can be applied to the on-line damage alarming in SHM.
文摘The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response under various scales are further formulated. The theoretical analysis results reveal that the wavelet packet energy spectrum （WPES） obtained from wavelet packet decomposition of structural dynamic response will detect the presence of structural damage. The sensitivity analysis of the WPES to structural damage and measurement noise is also performed. The transfer properties of the structural system matrix and the observation noise under various analysis scales are formulated, which verify the damage alarming reliability using the proposed WPES with preferable damage sensitivity and noise robusticity.
基金Project(2009BAG15B03) supported by the National Science and Technology Ministry of ChinaProjects(51178100, 51078080) supported by the National Natural Science Foundation of China+1 种基金Project(BK2011141) supported by the Natural Science Foundation of Jiangsu Province, ChinaProject(12KB02) supported by the Open Fund of the Key Laboratory for Safety Control of Bridge Engineering(Changsha University of Science and Technology), Ministry of Education, China
文摘Damage alarming and safety evaluation using long-term monitoring data is an area of significant research activity for long-span bridges. In order to extend the research in this field, the damage alarming technique for bridge expansion joints based on long-term monitoring data was developed. The effects of environmental factors on the expansion joint displacement were analyzed. Multiple linear regression models were obtained to describe the correlation between displacements and the dominant environmental factors. The damage alarming index was defined based on the multiple regression models. At last, the X-bar control chart was utilized to detect the abnormal change of the displacements. Analysis results reveal that temperature and traffic condition are the dominant environmental factors to influence the displacement. When the confidence level of X-bar control chart is set to be 0.003, the false-positive indications of damage can be avoided. The damage sensitivity analysis shows that the proper X-bar control chart can detect 0.1 cm damage-induced change of the expansion joint displacement. It is reasonably believed that the proposed technique is robust against false-positive indication of damage and suitable to alarm the possible future damage of the expansion joints.
基金Project(51078080)supported by the National Natural Science Foundation of ChinaProject(20130969010)supported by Aeronautical Science Foundation of China+1 种基金Project(2011Y03-6)supported by Traffic Transportation Technology Project of Jiangsu Province,ChinaProject(BK2012562)supported by the Natural Science Foundation of Jiangsu Province,China
文摘Structure damage identification and alarming of long-span bridge were conducted with three-dimensional dynamic displacement data collected by GPS subsystem of health monitoring system on Runyang Suspension Bridge.First,the effects of temperature on the main girder spatial position coordinates were analyzed from the transverse,longitudinal and vertical directions of bridge,and the correlation regression models were built between temperature and the position coordinates of main girder in the longitudinal and vertical directions;then the alarming indices of coordinate residuals were conducted,and the mean-value control chart was applied to making statistical pattern identification for abnormal changes of girder dynamic coordinates;and finally,the structural damage alarming method of main girder was established.Analysis results show that temperature has remarkable correlation with position coordinates in the longitudinal and vertical directions of bridge,and has weak correlation with the transverse coordinates.The 3%abnormal change of the longitudinal coordinates and 5%abnormal change of the vertical ones caused by structural damage are respectively identified by the mean-value control chart method based on GPS dynamic monitoring data and hence the structural abnormalities state identification and damage alarming for main girder of long-span suspension bridge can be realized in multiple directions.
文摘Deep analysis of call detail log of the alarming information indicates that reasons except user equipment(UE)issue are usually ignored.To effectively reduce call drop rate in wideband code division multiple access(WCDMA)mobile communication system,a novel method is presented.First,the reliable trace information is extracted to observe the distribution of all the exceptions from radio network controller(RNC)daily report.Then,the antenna angle of generalized clustering network in 024 base station’s c sector(GCN024C)for environmental test(ET)which is obtained from the radio frequency(RF)engineer is manually changed from 4° to 6°.Experimental results show that the proposed method can guarantee the key performance indicators(KPI)of WCDMA and have obvious effect on reducing call drop rate.
文摘ECG monitoring in daily life is an important means of treating heart disease. To make it easier for the medical to monitor the ECG of their patients outside the hospital, we designed and developed an ECG monitoring and alarming system based on Android smart phone. In our system, an ECG device collects the ECG signal and transmits it to an Android phone. The Android phone detects alarms which come from the ECG devices. When alarms occur, Android phone will capture the ECG images and the details about the alarms, and sends them to the cloud Alarm Server (AS). Once received, AS push the messages to doctors’ phone, so the doctors could see the ECG images and alarm details on their mobile phone. In our system, high resolution ECG pictures are transmitted to doctors’ phone in a user-friendly way, which can help doctors keep track of their patient’s condition easily.
基金Supported by Science and Technology Open Research Fund Project of Guizhou Meteorological Bureau(KF[2009]08)。
文摘As weather radar stations require headroom environment to operate,they were mostly built on highlands which are usually unattended.The mains supply is relatively poor,and the risk of radar stoppages due to power outage is therefore ever-present.As such,the radar construction program is used to build a complementary security video monitoring system.By collecting monitoring images of the regulated power supply in real-time from power supply auto transfer systems in distribution rooms and radar transceiver rooms,using Spearman’s rank correlation coefficient to analyse pixel variation trends,and supplementing statistical analysis of pixel characteristics difference to eliminate misjudgments resulting from low image contrast in special scenarios,a software can be developed through C#.It has the function of automatically monitoring mains supply and alerting staff on duty to handle the power outage in a timely manner via text message so that any potential risk is neutralised before it can cause damage.This monitoring and auto-alerting approach is generally applicable to unattended rooms with large amounts of electronical equipment.
文摘The EU has imposed a provisional anti-dumping duty on high tenacity yarn of polyesters from China on Jun. 2. Overseas crisis-fighting measures such as anti-dumping action, are up sharply in recent years. Chinese suppliers have to live with a challenging production environment
基金Chongqing Engineering University Undergraduate Innovation and Entrepreneurship Training Program Project:Wireless Fire Automatic Alarm System(Project No.:CXCY2024017)Chongqing Municipal Education Commission Science and Technology Research Project:Development and Research of Chongqing Wireless Fire Automatic Alarm System(Project No.:KJQN202401906)。
文摘This article explores the design of a wireless fire alarm system supported by advanced data fusion technology.It includes discussions on the basic design ideas of the wireless fire alarm system,hardware design analysis,software design analysis,and simulation analysis,all supported by data fusion technology.Hopefully,this analysis can provide some reference for the rational application of data fusion technology to meet the actual design and application requirements of the system.
文摘Apps can help you in your daily life.For example,the app Kiwake helps you wake up.Its special alarm won't turn off until you do three things.You must take a picture of something far from your bed.Then play a short game to wake up your mind.After that,you must review your goals for the day.
基金funded by the National Natural Science Foundation of China (No. 32301295 to JW, 32101242 to LM, and 32260253 to LW)High-Level Talents Research Start-Up Project of Hebei University (No. 521100222044 to JW)
文摘Avian alarm calls mediate defenses against brood parasites and predators. These calls facilitate communication among adults and alert nestlings to potential danger. While heterospecific call recognition has been extensively studied in adult birds, nestlings—lacking direct predation experience and heterospecific alarm exposure—represent an ideal system to investigate the response to interspecific warning cues. This study explored the recognition capabilities of 5–6-day-old nestlings in Oriental Reed Warbler (Acrocephalus orientalis), a common host of the Common Cuckoo (Cuculus canorus). We exposed the nestlings to playbacks of alarm calls directed at parasites and raptors from conspecific, Vinous-throated Parrotbill (Sinosuthora webbiana, sympatric species), Isabelline Shrike (Lanius isabellinus, allopatric species) and Common Tailorbird (Orthotomus sutorius, allopatric species) adults. Results indicated that there was no significant difference in the responses of nestlings to the alarm calls of conspecific and allopatric adults directed at cuckoos and sparrowhawks. In addition, interestingly, nestlings significantly reduced their begging in response to conspecific and unfamiliar allopatric Isabelline Shrike and Common Tailorbird alarm calls but exhibited a weak response to the sympatric Vinous-throated Parrotbill. Whether older warbler nestlings with more social experience exhibit stronger responses to the alarm calls of Vinous-throated Parrotbill adults requires further investigation.
基金supported by Concordia University and funded by the Natural Sciences and Engineering Research Council of Canada(Discovery Grant to G.E.B.,and an E.W.R.SteacieMemorial Fellowship to M.C.O.F.).
文摘Many prey species rely on publicly available personal and social information regarding local predation threats to assess risks and make contextappropriate behavioral decisions.However,in sexually dimorphic species,males and females are expected to differ in the perceived costs and/orbenefts associated with predator avoidance decisions.Recent studies suggest that male Trinidadian guppies(Poecilia reticulata)show reducedor absent responses to acute personal information cues,placing them at greater risk of predation relative to females.Our goal here was totest the hypothesis that adult(reproductively active)male guppies rely on social information to limit potential costs associated with their lack ofresponse to risky personal cues.Adult male guppies were exposed to personal chemosensory cues(either conspecifc alarm cues(AC),a novelodor,or a water control)in the presence of a shoal of three females inside a holding container that allowed the transmission of visual but notchemical cues.At the same time,we exposed females to either risk from AC or no risk,resulting in the display of a range of female behavior,from calm to alarmed,available as social information for males.Alarmed females caused male fright activity to increase and male interest infemales to decrease,regardless of the personal cue treatment.These results indicate that male guppies rely more on female information regarding predation risk than their own personal information,probably to balance trade-offs between reproduction and predator avoidance.
基金National Geographic Society,UCLA(Faculty Senate and the Division of Life Sciences),a Rocky Mountain Biological Laboratory research fellowship,NSF IDBR-0754247,and DEB-1119660 and 1557130 all to D.T.B.DBI-0242960,0731346,1226713,and 1755522 to the RMBL.K.A.was a NSF GRFP fellow during the fnal preparation of this MS。
文摘Emitting alarm calls may be costly,but few studies have asked whether calling increases a caller’s risk of predation and survival.Since observing animals calling and being killed is relatively rare,we capitalized on over 24,000 h of observations of marmot colonies and asked whether variation in the rate that yellow-bellied marmots(Marmota faviventer)alarm called was associated with the probability of summer mortality,a proxy for predation.Using a generalized mixed model that controlled for factors that infuenced the likelihood of survival,we found that marmots who called at higher rates were substantially more likely to die over the summer.Because virtually all summer mortality is due to predation,these results suggest that calling is indeed costly for marmots.Additionally,the results from a Cox survival analysis showed that marmots that called more lived signifcantly shorter lives.Prior studies have shown that marmots reduce the risk by emitting calls only when close to their burrows,but this newly quantifed survival cost suggests a constraint on eliminating risks.Quantifying the cost of alarm calling using a similar approach in other systems will help us better understand its true costs,which is an essential value for theoretical models of calling and social behavior.
基金funded by the Education Department of Hainan Province(no.HnjgY 2022-12)the National Natural Science Foundation of China(no.32260127).
文摘Alarm calls in bird vocalizations serve as acoustic signals announcing danger.Owing to the convergent evolution of alarm calls,some bird species can beneft from eavesdropping on certain parameters of alarm calls of other species.Vocal mimicry,displayed by many bird species,aids defense against predators and may help brood parasites during parasitism.In the coevolutionary dynamics between brood parasites,such as the common cuckoo(Cuculus canorus),and their hosts,female cuckoo vocalizations can induce hosts to leave the nest,increasing the probability of successful parasitism and reducing the risk of host attacks.Such cuckoo calls were thought to mimic those of the sparrowhawk.However,owing to their similarity to alarm calls,we propose a new hypothesis:Female cuckoos cheat their hosts by mimicking the parameters of the host alarm call.In this study,we tested this new hypothesis and the sparrowhawk mimicry hypothesis simultaneously by manipulating the syllable rate in male and female common cuckoo vocalizations and playing them in front of the host Oriental reed warbler(Acrocephalus orientalis)for examination.The results indicate that similar to a normal female cuckoo call,a female call with a reduced syllable rate prompted the hosts to leave their nests more frequently and rapidly than male cuckoo calls.Additionally,the male cuckoo calls with increased syllable rate did not prompt the host to leave their nests more frequently or quickly compared with the male cuckoo calls with a normal syllable rate.Our results further confrm that female common cuckoos mimic the vocalizations of Eurasian sparrowhawks(Accipiter nisus),reveal the function mechanisms underlying such mimicry,and support the theory of imperfect mimicry.
基金supported by the National Natural Science Foundation of China(Grants U23A20660,52008099,and 52378288)the Major Science and Technology Project of Yunnan Province,China(Grant 202502AD080007)the China Railway Engineering Corporation Science and Technology Research and Development Project(Grant 2022-Key-44).
文摘There are multiple types of risks involved in the service of long-span railway bridges.Classical methods are difficult to provide targeted alarm information according to different situations of load anomalies and structural anomalies.To accurately alarm different risks of long-span railway bridges by structural health monitoring systems,this paper proposes a cross-cooperative alarm method using principal and secondary indicators during high-wind periods.It provides the prior criterion for monitoring systems under special conditions,defining the principal and secondary indicators,alarm levels,and thresholds based on the relationship between dynamic equilibrium equations and multiple linear regression analysis.Analysis of one-year monitoring data from a longspan railway cable-stayed bridge shows that the 10-min average cross-bridge wind speed(excitation indicator)can be selected as the principal indicator,while lateral displacement(response indicator)can serve as the secondary indicator.The threshold levels of the secondary indicator prioritize the safety of bridge operation(mainly aiming at the safety of trains traversing bridges),with values significantly lower than structural safety thresholds.This approach enhances alarm timeliness and effectively distinguishes between load anomalies,structural anomalies,and equipment failures.Consequently,it improves alarm accuracy and provides timely decision support for bridge maintenance,train traversing,and emergency treatment.
基金Youth Foundation of National Natural Science Foundation of China (No. 52204020)Distinguished Young Foundation of National Natural Science Foundation of China (No. 52125401).
文摘As oil and gas exploration continues to progress into deeper and unconventional reservoirs,the likelihood of kick risk increases,making kick warning a critical factor in ensuring drilling safety and efficiency.Due to the scarcity of kick samples,traditional supervised models perform poorly,and significant fluctuations in field data lead to high false alarm rates.This study proposes an unsupervised graph autoencoder(GAE)-based kick warning method,which effectively reduces false alarms by eliminating the influence of field engineer operations and incorporating real-time model updates.The method utilizes the GAE model to process time-series data during drilling,accurately identifying kick risk while overcoming challenges related to small sample sizes and missing features.To further reduce false alarms,the weighted dynamic time warping(WDTW)algorithm is introduced to identify fluctuations in logging data caused by field engineer operations during drilling,with real-time updates applied to prevent normal conditions from being misclassified as kick risk.Experimental results show that the GAE-based kick warning method achieves an accuracy of 92.7%and significantly reduces the false alarm rate.The GAE model continues to operate effectively even under conditions of missing features and issues kick warnings 4 min earlier than field engineers,demonstrating its high sensitivity and robustness.After integrating the WDTW algorithm and real-time updates,the false alarm rate is reduced from 17.3%to 5.6%,further improving the accuracy of kick warnings.The proposed method provides an efficient and reliable approach for kick warning in drilling operations,offering strong practical value and technical support for the intelligent management of future drilling operations.
基金financially supported by the National Natural Science Foundation of China(Nos.62275244,62375258,62225507,U2033211,62175230,and 62175232)the CAS Project for Young Scientists in Basic Research(No.YSBR-065)+2 种基金Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20200001)National Key R&D Program of China(No.2022YFB3607800,No.2022YFB3605800,and No.2022YFB4601501)Key Program of the Chinese Academy of Sciences(ZDBS-ZRKJZ-TLC018)。
文摘The intrusion of obstacles onto railway tracks presents a significant threat to train safety,characterized by sudden and unpredictable occurrences.With China leading the world in high-speed rail mileage,ensuring railway security is paramount.The current laser monitoring technologies suffer from high false alarm rates and unreliable intrusion identification.This study addresses these issues by investigating high-resolution laser monitoring technology for railway obstacles,focusing on key parameters such as monitoring range and resolution.We propose an enhanced non-uniform laser scanning method,developing a laser monitoring system that reduces the obstacle false alarm rate to 2.00%,significantly lower than the 20%standard(TJ/GW135-2015).This rate is the best record for laser monitoring systems on China Railway.Our system operates seamlessly in all weather conditions,providing superior accuracy,resolution,and identification efficiency.It is the only 3D LiDAR system certified by the China State Railway Group Co.,Ltd.(Certificate No.[2023]008).Over three years,our system has been deployed at numerous points along various lines managed by the China State Railway Group,accumulating a dataset of 300,000 observations.This extensive deployment has significantly enhanced railway safety.The development and implementation of our railway laser monitoring system represent a substantial advancement in railway safety technology.Its low false alarm rate(2.00%),high accuracy(20 cm×20 cm×20 cm),and robust performance in diverse conditions underscore its potential for widespread adoption,promising to enhance railway safety in China and internationally.
基金The National Science and Technology Major Project( No. 2011ZX03005-004-03)the National Natural Science Foundation of China ( No. 61171081, 60872004 )the Natural Science Foundation of Guangxi Province ( No. 2011GXNSFB018075)
文摘A novel spectrum hole detection mechanism is proposed to improve the detection probability in cognitive radio networks for several typical scenarios. By removing the influence of the spatial false alarm （SFA）, the spectrum hole detection probability of the secondary user under path loss and multi-path fading is derived. Meanwhile, the spectrum hole detection probability of multi-users cooperative sensing and that of single-user sensing in multi-bands are derived for comparison. Theoretical analyses and simulation results show that the spectrum hole detection probability of the proposed mechanism is inversely proportional to the sampling times and the area of the sensing region. The detection performance of the multi-users sensing is better than that of single-user sensing when with the AND ~ogic fusion rule but worse when with the OR logic fusion rule. The detection probability is further decreased in the Rayleigh fading channel but it is greatly increased in multi-bands.
