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Sounding the alarm:Functionally referential signaling in Azure-winged Magpie
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作者 Xingyi Jiang Yanyun Zhang 《Avian Research》 SCIE CSCD 2024年第1期35-41,共7页
Functionally referential signals are a complex form of communication that conveys information about the external environment.Such signals have been found in a range of mammal and bird species and have helped us unders... Functionally referential signals are a complex form of communication that conveys information about the external environment.Such signals have been found in a range of mammal and bird species and have helped us understand the complexities of animal communication.Corvids are well known for their extraordinary cognitive abilities,but relatively little attention has been paid to their vocal function.Here,we investigated the functionally referential signals of a cooperatively breeding corvid species,Azure-winged Magpie(Cyanopica cyanus).Through field observations,we suggest that Azure-winged Magpie uses referential alarm calls to distinguish two types of threats:’rasp’ calls for terrestrial threats and ’chatter’ calls for aerial threats.A playback experiment revealed that Azure-winged Magpies responded to the two call types with qualitatively different behaviors.They sought cover by flying into the bushes in response to the ’chatter’ calls,and flew to or stayed at higher positions in response to ’rasp’ calls,displaying a shorter response time to ’chatter’ calls.Significant differences in acoustic structure were found between the two types of calls.Given the extensive cognitive abilities of corvids and the fact that referential signals were once thought to be unique to primates,these findings are important for expanding our understanding of social communication and language evolution. 展开更多
关键词 alarm call Animal communication Azure-winged Magpie Referential signal
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Design of AI-Enhanced and Hardware-Supported Multimodal E-Skin for Environmental Object Recognition and Wireless Toxic Gas Alarm
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作者 Jianye Li Hao Wang +8 位作者 Yibing Luo Zijing Zhou He Zhang Huizhi Chen Kai Tao Chuan Liu Lingxing Zeng Fengwei Huo Jin Wu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第12期1-22,共22页
Post-earthquake rescue missions are full of challenges due to the unstable structure of ruins and successive aftershocks.Most of the current rescue robots lack the ability to interact with environments,leading to low ... Post-earthquake rescue missions are full of challenges due to the unstable structure of ruins and successive aftershocks.Most of the current rescue robots lack the ability to interact with environments,leading to low rescue efficiency.The multimodal electronic skin(e-skin)proposed not only reproduces the pressure,temperature,and humidity sensing capabilities of natural skin but also develops sensing functions beyond it—perceiving object proximity and NO2 gas.Its multilayer stacked structure based on Ecoflex and organohydrogel endows the e-skin with mechanical properties similar to natural skin.Rescue robots integrated with multimodal e-skin and artificial intelligence(AI)algorithms show strong environmental perception capabilities and can accurately distinguish objects and identify human limbs through grasping,laying the foundation for automated post-earthquake rescue.Besides,the combination of e-skin and NO2 wireless alarm circuits allows robots to sense toxic gases in the environment in real time,thereby adopting appropriate measures to protect trapped people from the toxic environment.Multimodal e-skin powered by AI algorithms and hardware circuits exhibits powerful environmental perception and information processing capabilities,which,as an interface for interaction with the physical world,dramatically expands intelligent robots’application scenarios. 展开更多
关键词 Stretchable hydrogel sensors Multimodal e-skin Artificial intelligence Post-earthquake rescue Wireless toxic gas alarm
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A lightweight false alarm suppression method in heterogeneous change detection
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作者 XU Cong HE Zishu LIU Haicheng 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期899-905,共7页
Overlooking the issue of false alarm suppression in heterogeneous change detection leads to inferior detection per-formance.This paper proposes a method to handle false alarms in heterogeneous change detection.A light... Overlooking the issue of false alarm suppression in heterogeneous change detection leads to inferior detection per-formance.This paper proposes a method to handle false alarms in heterogeneous change detection.A lightweight network of two channels is bulit based on the combination of convolutional neural network(CNN)and graph convolutional network(GCN).CNNs learn feature difference maps of multitemporal images,and attention modules adaptively fuse CNN-based and graph-based features for different scales.GCNs with a new kernel filter adaptively distinguish between nodes with the same and those with different labels,generating change maps.Experimental evaluation on two datasets validates the efficacy of the pro-posed method in addressing false alarms. 展开更多
关键词 convolutional neural network(CNN) graph convolu-tional network(GCN) heterogeneous change detection LIGHTWEIGHT false alarm suppression
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Design of Signal Lamp Filament Monitoring Alarm Instrument
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作者 Haifeng Zhu 《Journal of Electronic Research and Application》 2024年第5期38-45,共8页
To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based ... To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot. 展开更多
关键词 Signal lamp Monitoring alarm instrument Precision rectifier signal conditioning circuit
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Pattern Matching of Industrial Alarm Floods Using Word Embedding and Dynamic Time Warping
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作者 Wenkai Hu Xiangxiang Zhang +2 位作者 Jiandong Wang Guang Yang Yuxin Cai 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第4期1096-1098,共3页
Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values t... Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values that represent alarms and also reflect the relationships between alarm occurrences.Then,similarities between numerically encoded alarm flood sequences are calculated by DTW and groups of similar floods are identified via clustering.The effectiveness of the proposed method is demonstrated by a case study with alarm&event data obtained from a public industrial simulation model. 展开更多
关键词 WORD alarm DTW
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Enhancing Feature Discretization in Alarm and Fire Detection Systems Using Probabilistic Inference Models
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作者 Joe Essien 《Journal of Computer and Communications》 2023年第7期140-155,共16页
Sensors for fire alarms require a high level of predictive variables to ensure accurate detection, injury prevention, and loss prevention. Bayesian networks can aid in enhancing early fire detection capabilities and r... Sensors for fire alarms require a high level of predictive variables to ensure accurate detection, injury prevention, and loss prevention. Bayesian networks can aid in enhancing early fire detection capabilities and reducing the frequency of erroneous fire alerts, thereby enhancing the effectiveness of numerous safety monitoring systems. This research explores the development of optimized probabilistic graphic models for the discretization thresholds of alarm system predictor variables. The study presents a statistical model framework that increases the efficacy of fire detection by predicting the discretization thresholds of alarm system predictor variable fluctuations used to detect the onset of fire. The work applies the Bayesian networks and probabilistic visual models to reveal the specific characteristics required to cope with fire detection strategies and patterns. The adopted methodology utilizes a combination of prior knowledge and statistical data to draw conclusions from observations. Utilizing domain knowledge to compute conditional dependencies between network variables enabled predictions to be made through the application of specialized analytical and simulation techniques. 展开更多
关键词 Neural Network DISCRETIZATION alarm Systems Graphical Models Machine Learning
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Machine Learning-Based Alarms Classification and Correlation in an SDH/WDM Optical Network to Improve Network Maintenance
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作者 Deussom Djomadji Eric Michel Takembo Ntahkie Clovis +2 位作者 Tchapga Tchito Christian Arabo Mamadou Michael Ekonde Sone 《Journal of Computer and Communications》 2023年第2期122-141,共20页
The evolution of telecommunications has allowed the development of broadband services based mainly on fiber optic backbone networks. The operation and maintenance of these optical networks is made possible by using su... The evolution of telecommunications has allowed the development of broadband services based mainly on fiber optic backbone networks. The operation and maintenance of these optical networks is made possible by using supervision platforms that generate alarms that can be archived in the form of log files. But analyzing the alarms in the log files is a laborious and difficult task for the engineers who need a degree of expertise. Identifying failures and their root cause can be time consuming and impact the quality of service, network availability and service level agreements signed between the operator and its customers. Therefore, it is more than important to study the different possibilities of alarms classification and to use machine learning algorithms for alarms correlation in order to quickly determine the root causes of problems faster. We conducted a research case study on one of the operators in Cameroon who held an optical backbone based on SDH and WDM technologies with data collected from 2016-03-28 to “2022-09-01” with 7201 rows and 18. In this paper, we will classify alarms according to different criteria and use 02 unsupervised learning algorithms namely the K-Means algorithm and the DBSCAN to establish correlations between alarms in order to identify root causes of problems and reduce the time to troubleshoot. To achieve this objective, log files were exploited in order to obtain the root causes of the alarms, and then K-Means algorithm and the DBSCAN were used firstly to evaluate their performance and their capability to identify the root cause of alarms in optical network. 展开更多
关键词 Optical Network alarmS Log Files Root Cause Analysis Machine Learning
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SCADA Data-Based Support Vector Machine for False Alarm Identification for Wind Turbine Management
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作者 Ana María Peco Chacón Isaac Segovia Ramírez Fausto Pedro García Márquez 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期2595-2608,共14页
Maintenance operations have a critical influence on power gen-eration by wind turbines(WT).Advanced algorithms must analyze large volume of data from condition monitoring systems(CMS)to determine the actual working co... Maintenance operations have a critical influence on power gen-eration by wind turbines(WT).Advanced algorithms must analyze large volume of data from condition monitoring systems(CMS)to determine the actual working conditions and avoid false alarms.This paper proposes different support vector machine(SVM)algorithms for the prediction and detection of false alarms.K-Fold cross-validation(CV)is applied to evaluate the classification reliability of these algorithms.Supervisory Control and Data Acquisition(SCADA)data from an operating WT are applied to test the proposed approach.The results from the quadratic SVM showed an accuracy rate of 98.6%.Misclassifications from the confusion matrix,alarm log and maintenance records are analyzed to obtain quantitative information and determine if it is a false alarm.The classifier reduces the number of false alarms called misclassifications by 25%.These results demonstrate that the proposed approach presents high reliability and accuracy in false alarm identification. 展开更多
关键词 Machine learning classification support vector machine false alarm wind turbine cross-validation
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Glass-compatible and self-powered temperature alarm system by temperature-responsive organic manganese halides via backward energy transfer process
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作者 Pengfei Xia Fan Liu +4 位作者 Yuru Duan Xuefang Hu Changgui Lu Shuhong Xu Chunlei Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期188-194,I0006,共8页
A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which h... A pioneering glass-compatible transparent temperature alarm system self-powered by luminescent solar concentrators(LSCs) is reported.Single green-emitted organic manganese halides(OMHs) of PEA_(2)MnBr_(2)I_(2),which has a unique temperature-dependent backward energy transfer process from selftrapped state to^(4)T_(1)energy level of Mn,is used for triggering the temperature alarm.The LSC with redemitted CsPbI_(3)perovskite-polymer composite films on the glass substrate is used for power supply.The spectrally separated nature between the green-emitted OMHs for temperature alarm and red-emitted CsPbI3in LSC for power supply allows for probing the signal light of temperature-responsive OMHs without the interference of LSCs,making it possible to calibrate the temperature visually just by a self-powered brightness detection circuit with LED indicators.Taking advantage of LSC without hot spot effects plaguing the solar cells,as-prepared temperature alarm system can operate well on both sunny and cloudy day. 展开更多
关键词 Luminescent solar concentrators Organic manganese halides Perovskite-polymer compositefilms Self-powered temperature alarm system Backward energy transfer process
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Predictive value of alarm features in diagnosing upper gastrointestinal malignancies among dyspeptic patients:A cross-sectional study in Ethiopia
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作者 Wudassie Melak Wassihun Asmare +1 位作者 Abate Bane Mengistu Erkie 《Gastroenterology & Hepatology Research》 2023年第3期29-39,共11页
Objective:The study aimed to determine the overall predictive value of alarm features in diagnosing upper Gastrointestinal(GI)malignancies and significant endoscopic findings among patients undergoing elective Esophag... Objective:The study aimed to determine the overall predictive value of alarm features in diagnosing upper Gastrointestinal(GI)malignancies and significant endoscopic findings among patients undergoing elective Esophagogastroduodenoscopy(EGD)at Tikur Anbessa Special Hospital(TASH)and Adera Medical Centre(AMC).Methods:It was an institution-based cross-sectional study conducted on patients undergoing elective endoscopy for an upper GI complaint from July to September 2022.Data was collected from patient charts,and biopsies were taken for histologic confirmation.The study assessed the association of alarm symptoms and signs with significant upper gastrointestinal(UGI)endoscopic findings and malignancies.Results:142 patients were selected,with an average age of 48.35 and 52.1% being male.Epigastric pain was the most common reason for an endoscopy.62% of patients had at least one alarm feature,the most common being unexplained weight loss and UGI bleeding.The study found a strong association between the presence of alarm features,significant endoscopic findings,and UGI malignancies.The pooled sensitivity and specificity of any alarm feature for any significant finding were 79% and 64.9%,respectively,and for malignancy,100% and 39.7%,respectively.The presence of the alarm feature was associated with an increase of 6.801 in the odds of developing SEF and an increase of 4.199 in the odds of developing malignancy.Conclusions:UGI alarm symptoms and signs like an abdominal mass,persistent vomiting,dysphagia,and UGI bleeding are predictive of significant endoscopic findings and malignancies.Hence,EGD should be done and suspicious lesions should be biopsied early,regardless of gender,age,or duration of symptoms. 展开更多
关键词 alarm symptoms DYSPEPSIA ENDOSCOPY gastric cancer PUD esophageal cancer
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基于STM32单片机的家庭安防系统设计 被引量:2
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作者 王克勇 杨清志 《河北北方学院学报(自然科学版)》 2024年第3期22-27,共6页
为了更好地对居家环境进行安全监测与防范,以STM32F103单片机为处理核心设计了一套家庭安防系统。系统采用各种传感器进行环境监测,并将监测信息传至单片机,进行存储、显示与报警等处理,同时通过ESP8266无线传输模块将监测信息传至互联... 为了更好地对居家环境进行安全监测与防范,以STM32F103单片机为处理核心设计了一套家庭安防系统。系统采用各种传感器进行环境监测,并将监测信息传至单片机,进行存储、显示与报警等处理,同时通过ESP8266无线传输模块将监测信息传至互联网,实现远程监测与报警。试验结果表明,传感器与报警系统工作正常,数据传输准确,验证了系统设计的可靠性。 展开更多
关键词 传感器 STM32F103 ESP8266 监测 报警
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4种血培养瓶4种临床常用抗菌药物吸附能力分析
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作者 杨会林 陈娟 +3 位作者 闫津津 欧嘉文 文明明 周丽娜 《检验医学》 CAS 2024年第6期578-582,共5页
目的分析4种血培养瓶对亚胺培南、哌拉西林-他唑巴坦、万古霉素和卡泊芬净4种临床常用抗菌药物的吸附能力,为提高血培养病原体检出率提供参考。方法选择亚胺培南、哌拉西林-他唑巴坦、万古霉素和卡泊芬净敏感标准菌株进行配对,将抗菌药... 目的分析4种血培养瓶对亚胺培南、哌拉西林-他唑巴坦、万古霉素和卡泊芬净4种临床常用抗菌药物的吸附能力,为提高血培养病原体检出率提供参考。方法选择亚胺培南、哌拉西林-他唑巴坦、万古霉素和卡泊芬净敏感标准菌株进行配对,将抗菌药物和配对菌株分别加入4种临床常用的血培养瓶(FA plus、FNplus、Aerobic、Anaerobic)进行培养,根据培养瓶报阳情况和阳性报警时长,评估不同血培养瓶对4种抗菌药物的吸附能力。结果对照瓶(无抗菌药物吸附措施)培养5 d均未报阳。FA plus、FN plus、Aerobic、Anaerobic阳性报警率分别为75.0%(15/20)、100.0%(10/10)、70.0%(14/20)、0.0%(0/10)。亚胺培南/大肠埃希菌组,FN plus均能报阳(5/5),阳性报警时长为(12.4±0.3)h,FA plus、Aerobic和Anaerobic5d均未报阳;哌拉西林-他唑巴坦/铜绿假单胞菌组,FAplus和Aerobic能报阳(5/5),阳性报警时长分别为(16.2±0.3)和(18.1±0.4)h,2种血培养瓶阳性报警时长差异有统计学意义(P<0.05);万古霉素/金黄色葡萄球菌组,FA plus、FN plus和Aerobic能报阳,阳性报警时长分别为(16.7±0.4)、(24.1±0.6)和(31.3±3.9)h,3种血培养瓶阳性报警时长差异有统计学意义(P<0.05),Anaerobic培养5 d未报阳。卡泊芬净/白念珠菌组,FA plus和Aerobic能报阳,阳性报警时长分别为(47.1±3.3)和(42.9±2.0)h,2种血培养瓶阳性报警时长差异有统计学意义(P<0.05)。结论FN plus具有吸附亚胺培南、万古霉素的能力,FA plus和Aerobic具有吸附万古霉素、哌拉西林-他唑巴坦和卡泊芬净的能力;对采集血液样本前使用了抗菌药物的患者,不建议使用无吸附抗菌药物措施的血培养瓶,应根据临床抗菌药物使用习惯选择合适的培养瓶。 展开更多
关键词 血培养 抗菌药物吸附 病原菌 阳性报警时长
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基于STM32的智能家居安防系统设计 被引量:2
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作者 冼进 冼允廷 《信息技术》 2024年第3期49-55,共7页
物联网应用技术快速发展,智能安防产品受到越来越多人的关注,尤其是智能家居安防产品。为了最大程度确保人身以及财产安全,满足人民群众对自身安全和家庭安防的要求,以STM32为主控芯片,结合各类智能传感器、控制器、报警器及智能手机小... 物联网应用技术快速发展,智能安防产品受到越来越多人的关注,尤其是智能家居安防产品。为了最大程度确保人身以及财产安全,满足人民群众对自身安全和家庭安防的要求,以STM32为主控芯片,结合各类智能传感器、控制器、报警器及智能手机小程序,设计并实现一套基于STM32的家居安防报警系统,该系统能实时、远程监测家居室内外环境状况,及时、有效防止家居安全事故发生,对保护家庭成员生命、财产安全具有重要的现实意义。 展开更多
关键词 STM32单片机 家居安防 家居监控 防火 防盗
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基于ML估计的高动态GNSS信号快速捕获检测方法
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作者 郝顺义 李建文 +1 位作者 卢航 黄国荣 《电子测量与仪器学报》 CSCD 北大核心 2024年第8期87-94,共8页
针对高动态环境下GNSS因频域带宽增加导致捕获难度增大的问题,分析了接收端数字中频采样信号的传输特性及复基带信号经FFT模块处理后的相关峰的检测,提出了基于极大似然(ML)估计的高动态GNSS信号快速捕获检测方法。首先,根据随机信号的... 针对高动态环境下GNSS因频域带宽增加导致捕获难度增大的问题,分析了接收端数字中频采样信号的传输特性及复基带信号经FFT模块处理后的相关峰的检测,提出了基于极大似然(ML)估计的高动态GNSS信号快速捕获检测方法。首先,根据随机信号的统计理论建立二元假设检验条件,构建了奈曼-皮尔逊准则下的GNSS信号捕获判决门限模型;其次,通过判决量的统计特性对等效高斯白噪声方差进行ML估计,根据其估计值计算捕获判决门限,其中通过虚警率的量化放大处理,解决了判决量样本值的增加带来的估计偏差问题;最后,对不同高动态条件下北斗B3I信号进行了捕获检测仿真实验。结果表明采用ML估计方法确定捕获判决门限从而提高高动态GNSS信号捕获的检测方法对高动态适应范围较宽,其频移捕获精度与SINS信息辅助捕获相当,比序贯检测算法提高约28%以上,相同条件下具有更快的平均捕获检测速度。 展开更多
关键词 GNSS 捕获 极大似然 判决门限 虚警率
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智能报警气管导管防滑脱装置的设计及应用
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作者 王宜庭 杨细虎 邵振莉 《护理研究》 北大核心 2024年第6期1117-1120,共4页
目的:设计智能报警气管导管防滑脱装置,并评价其临床应用效果。方法:选取2022年4月-5月镇江市某三级甲等医院恢复室收治的172例全身麻醉手术病人作为研究对象,将2022年4月的86例全身麻醉气管插管病人作为对照组,将2022年5月的86例全身... 目的:设计智能报警气管导管防滑脱装置,并评价其临床应用效果。方法:选取2022年4月-5月镇江市某三级甲等医院恢复室收治的172例全身麻醉手术病人作为研究对象,将2022年4月的86例全身麻醉气管插管病人作为对照组,将2022年5月的86例全身麻醉气管插管病人作为观察组。对照组按照常规的气管插管方法协助置管及护理,观察组应用智能报警气管导管防滑脱装置协助气管导管固定。对两组病人气管导管移位或脱出情况、病人面部皮肤情况、病人咽喉痛发生情况及护士满意度进行比较。结果:观察组病人气管导管移位或脱出风险小于对照组,面部皮肤并发症发生率、咽喉痛程度低于对照组,护士满意度高于对照组,差异均有统计学意义(均P<0.05)。结论:使用智能报警气管导管防滑脱装置可减少病人气管导管移位或脱出,降低病人皮肤并发症发生率、咽喉痛程度,提高护士满意度。 展开更多
关键词 智能报警 气管插管 非计划拔管 机械通气 护理
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基于模式物理量参数的云南雷暴大风概率预报技术研究
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作者 陈小华 李华宏 +2 位作者 何钰 马文倩 李耀孙 《高原山地气象研究》 2024年第2期112-119,共8页
利用2019—2021年云南125个国家站大风数据和云南省地闪资料,统计云南雷暴大风个例,并挑选对雷暴大风有重要意义的物理量参数,结合NCEP再分析资料确定云南雷暴大风个例的物理量阈值,再基于ECMWF数值模式预报产品及确定的阈值,采用二分... 利用2019—2021年云南125个国家站大风数据和云南省地闪资料,统计云南雷暴大风个例,并挑选对雷暴大风有重要意义的物理量参数,结合NCEP再分析资料确定云南雷暴大风个例的物理量阈值,再基于ECMWF数值模式预报产品及确定的阈值,采用二分法进行云南雷暴大风概率预报。结果表明:在云南三次雷暴大风过程预报检验中,8月4日云南中部及东北部雷暴大风均命中,但在云南西部及西南部出现大范围的虚警,导致此次过程虚警率较高和临界成功指数较低;8月5日云南中部、东北及西北部雷暴大风预报正确,且云南西部及南部虚警范围小,虚警率较8月4日明显降低;7月7日云南自东北向西南出现大范围的雷暴大风天气过程,雷暴大风预报落区与实况基本吻合,呈现命中率高、虚警率较低的特征;三次过程命中率、临界成功指数、虚警率平均为0.873、0.203、0.789。 展开更多
关键词 雷暴大风 概率预报 命中率 虚警率
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基于机器学习对呼吸机报警分析
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作者 刘强 郭瑞 +1 位作者 王勤 孙凯 《中国医疗设备》 2024年第3期53-57,79,共6页
目的 探讨应用机器学习方法对呼吸机在临床使用中的通气类报警进行研究,获得影响报警的重要参数及报警预测模型,识别无效报警并给予临床提示,使临床得以高效应对呼吸机报警,避免造成报警疲劳等消极影响。方法 建立符合标准数据流程的呼... 目的 探讨应用机器学习方法对呼吸机在临床使用中的通气类报警进行研究,获得影响报警的重要参数及报警预测模型,识别无效报警并给予临床提示,使临床得以高效应对呼吸机报警,避免造成报警疲劳等消极影响。方法 建立符合标准数据流程的呼吸机数据管理平台,根据单中心的呼吸机报警信息分析特征值,得出重要参数排序;利用超参数调优建模预测报警的真假;用混淆矩阵、受试者工作特征(Receiver Operating Characteristic,ROC)对机器学习模型进行多项指标验证。结果 对测试集5936次通气类报警进行评估,得出无效报警率为88%(召回率为0.88),模型准确度为0.94,精准度为0.78,ROC曲线下面积为0.92,F1得分为0.82。结论 采用机器学习便于临床单中心数据建模,能够及时分析获得呼吸机真实警报的重要参数及报警预测;通过呼吸机数据管理平台可有效提示临床无效报警,从而减少医护人员的压力,提高医疗质量。 展开更多
关键词 呼吸机 数据接口 报警项目 机器学习 重要特征变量
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计及源荷不确定性的电力系统静态电压稳定极限预警方法研究
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作者 任惠 王希 +3 位作者 田磊 赵明君 常喜强 甄钊 《太阳能学报》 EI CAS CSCD 北大核心 2024年第10期249-258,共10页
针对源荷双侧不确定性问题,对电力系统静态电压稳定极限进行预警研究。首先通过数学推导与理论分析证明快慢系统在分叉及噪声双重诱导发生临界转变的过程中,系统变量的方差系数趋势变化显著。由于存在噪声诱导失稳,电压变化趋势观测难... 针对源荷双侧不确定性问题,对电力系统静态电压稳定极限进行预警研究。首先通过数学推导与理论分析证明快慢系统在分叉及噪声双重诱导发生临界转变的过程中,系统变量的方差系数趋势变化显著。由于存在噪声诱导失稳,电压变化趋势观测难度增大,固定阈值趋势检测方法会失效。其次,对新能源电力系统节点电压的临界转变特点和扰动情况进行分析,提出基于临界转变电压崩溃预警方法。针对噪声导致的趋势预测困难问题,基于量测数据,利用贝叶斯变点检测,对节点电压的方差进行实时监测,并根据贝叶斯变点检测得到的概率在趋势发生显著变化之初预警节点电压崩溃,并通过仿真计算验证该方法的有效性。 展开更多
关键词 不确定性分析 可再生能源 电压测量 临界转变 电力系统稳定 预警系统
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基于杂波拖尾分布的雷达无人机检测性能分析
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作者 杨勇 王雪松 《系统工程与电子技术》 EI CSCD 北大核心 2024年第1期113-120,共8页
固定翼无人机(unmanned aerial vehicle,UAV)给雷达低空监视提出了严峻挑战。分析雷达对固定翼UAV的检测性能,可为雷达UAV检测能力评估和技术升级提供重要参考。本文结合雷达探测低空固定翼UAV外场实测数据,首先分析了低空固定翼UAV雷... 固定翼无人机(unmanned aerial vehicle,UAV)给雷达低空监视提出了严峻挑战。分析雷达对固定翼UAV的检测性能,可为雷达UAV检测能力评估和技术升级提供重要参考。本文结合雷达探测低空固定翼UAV外场实测数据,首先分析了低空固定翼UAV雷达接收信号幅度统计分布,采用多项式对杂波拖尾导致的虚警概率进行拟合建模;然后,根据虚警概率分布得到雷达检测门限;进而根据UAV回波+杂波幅度分布理论推导得到雷达检测概率;最后,将理论分析性能与传统性能分析结果、雷达实际检测性能进行对比。结果表明,采用多项式对杂波拖尾导致的虚警概率进行单独建模,由此获得的雷达检测门限精度更高,从而使雷达UAV检测性能分析结果较传统性能分析结果更准确。 展开更多
关键词 雷达检测 杂波拖尾 无人机 性能分析 虚警概率
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一起带有程序误判的液压系统故障分析
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作者 朱培显 丁正 张元 《液压气动与密封》 2024年第1期112-114,共3页
某热轧板生产线卸卷车的升降由液压缸驱动,升降高度的检测采用了间接测量方法,通过流量计先测量进出油缸无杆腔的油量,再由PLC进行计算得到位置数据。相对于常规采用的位移传感器直接测量方法,该方式很好地避免了现场高温和水淋对检测... 某热轧板生产线卸卷车的升降由液压缸驱动,升降高度的检测采用了间接测量方法,通过流量计先测量进出油缸无杆腔的油量,再由PLC进行计算得到位置数据。相对于常规采用的位移传感器直接测量方法,该方式很好地避免了现场高温和水淋对检测元件的损害,提高了元件的可靠度。经过对一起故障的排查、分析、处理,发现了该系统存在的不完善地方,提出了解决办法。 展开更多
关键词 卸卷车 液压缸 内泄 报警
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