Patient characteristics associated with false arrhythmia alarms in intensive care.
Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao
2017-01-01
A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients' annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient characteristics were compared in relation to 1) the number and 2) the duration of false arrhythmia alarms per 24-hour period, using nonparametric statistics to minimize the influence of outliers. Among the significant associations were the following: age ≥60 years ( P =0.013; P =0.034), confused mental status ( P <0.001 for both comparisons), cardiovascular diagnoses ( P <0.001 for both comparisons), electrocardiographic (ECG) features, such as wide ECG waveforms that correspond to ventricular depolarization known as QRS complex due to bundle branch block (BBB) ( P =0.003; P =0.004) or ventricular paced rhythm ( P =0.002 for both comparisons), respiratory diagnoses ( P =0.004 for both comparisons), and support with mechanical ventilation, including those with primary diagnoses other than respiratory ones ( P <0.001 for both comparisons). Patients likely to trigger a higher number of false arrhythmia alarms may be those with older age, confusion, cardiovascular diagnoses, and ECG features that indicate BBB or ventricular pacing, respiratory diagnoses, and mechanical ventilatory support. Algorithm improvements could focus on better noise reduction (eg, motion artifact with confused state) and distinguishing BBB and paced rhythms from ventricular arrhythmias. Increasing awareness of patient conditions that apparently trigger a higher rate of false arrhythmia alarms may be useful for reducing unnecessary noise and improving alarm management.
Patient characteristics associated with false arrhythmia alarms in intensive care
Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao
2017-01-01
Introduction A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. Results A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients’ annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient characteristics were compared in relation to 1) the number and 2) the duration of false arrhythmia alarms per 24-hour period, using nonparametric statistics to minimize the influence of outliers. Among the significant associations were the following: age ≥60 years (P=0.013; P=0.034), confused mental status (P<0.001 for both comparisons), cardiovascular diagnoses (P<0.001 for both comparisons), electrocardiographic (ECG) features, such as wide ECG waveforms that correspond to ventricular depolarization known as QRS complex due to bundle branch block (BBB) (P=0.003; P=0.004) or ventricular paced rhythm (P=0.002 for both comparisons), respiratory diagnoses (P=0.004 for both comparisons), and support with mechanical ventilation, including those with primary diagnoses other than respiratory ones (P<0.001 for both comparisons). Conclusion Patients likely to trigger a higher number of false arrhythmia alarms may be those with older age, confusion, cardiovascular diagnoses, and ECG features that indicate BBB or ventricular pacing, respiratory diagnoses, and mechanical ventilatory support. Algorithm improvements could focus on better noise reduction (eg, motion artifact with confused state) and distinguishing BBB and paced rhythms from ventricular arrhythmias. Increasing awareness of patient conditions that apparently trigger a higher rate of false arrhythmia alarms may be useful for reducing unnecessary noise and improving alarm management. PMID:28458554
False Alarms and Overmonitoring: Major Factors in Alarm Fatigue Among Labor Nurses.
Simpson, Kathleen Rice; Lyndon, Audrey
2018-06-08
Nurses can be exposed to hundreds of alarms during their shift, contributing to alarm fatigue. The purposes were to explore similarities and differences in perceptions of clinical alarms by labor nurses caring for generally healthy women compared with perceptions of adult intensive care unit (ICU) and neonatal ICU nurses caring for critically ill patients and to seek nurses' suggestions for potential improvements. Nurses were asked via focus groups about the utility of clinical alarms from medical devices. There was consensus that false alarms and too many devices generating alarms contributed to alarm fatigue, and most alarms lacked clinical relevance. Nurses identified certain types of alarms that they responded to immediately, but the vast majority of the alarms did not contribute to their clinical assessment or planned nursing care. Monitoring only those patients who need it and only those physiologic values that are warranted, based on patient condition, may decrease alarm burden.
Multiple-Parameter, Low-False-Alarm Fire-Detection Systems
NASA Technical Reports Server (NTRS)
Hunter, Gary W.; Greensburg, Paul; McKnight, Robert; Xu, Jennifer C.; Liu, C. C.; Dutta, Prabir; Makel, Darby; Blake, D.; Sue-Antillio, Jill
2007-01-01
Fire-detection systems incorporating multiple sensors that measure multiple parameters are being developed for use in storage depots, cargo bays of ships and aircraft, and other locations not amenable to frequent, direct visual inspection. These systems are intended to improve upon conventional smoke detectors, now used in such locations, that reliably detect fires but also frequently generate false alarms: for example, conventional smoke detectors based on the blockage of light by smoke particles are also affected by dust particles and water droplets and, thus, are often susceptible to false alarms. In contrast, by utilizing multiple parameters associated with fires, i.e. not only obscuration by smoke particles but also concentrations of multiple chemical species that are commonly generated in combustion, false alarms can be significantly decreased while still detecting fires as reliably as older smoke-detector systems do. The present development includes fabrication of sensors that have, variously, micrometer- or nanometer-sized features so that such multiple sensors can be integrated into arrays that have sizes, weights, and power demands smaller than those of older macroscopic sensors. The sensors include resistors, electrochemical cells, and Schottky diodes that exhibit different sensitivities to the various airborne chemicals of interest. In a system of this type, the sensor readings are digitized and processed by advanced signal-processing hardware and software to extract such chemical indications of fires as abnormally high concentrations of CO and CO2, possibly in combination with H2 and/or hydrocarbons. The system also includes a microelectromechanical systems (MEMS)-based particle detector and classifier device to increase the reliability of measurements of chemical species and particulates. In parallel research, software for modeling the evolution of a fire within an aircraft cargo bay has been developed. The model implemented in the software can describe the concentrations of chemical species and of particulate matter as functions of time. A system of the present developmental type and a conventional fire detector were tested under both fire and false-alarm conditions in a Federal Aviation Administration cargo-compartment- testing facility. Both systems consistently detected fires. However, the conventional fire detector consistently generated false alarms, whereas the developmental system did not generate any false alarms.
Perceptual evaluation of visual alerts in surveillance videos
NASA Astrophysics Data System (ADS)
Rogowitz, Bernice E.; Topkara, Mercan; Pfeiffer, William; Hampapur, Arun
2015-03-01
Visual alerts are commonly used in video monitoring and surveillance systems to mark events, presumably making them more salient to human observers. Surprisingly, the effectiveness of computer-generated alerts in improving human performance has not been widely studied. To address this gap, we have developed a tool for simulating different alert parameters in a realistic visual monitoring situation, and have measured human detection performance under conditions that emulated different set-points in a surveillance algorithm. In the High-Sensitivity condition, the simulated alerts identified 100% of the events with many false alarms. In the Lower-Sensitivity condition, the simulated alerts correctly identified 70% of the targets, with fewer false alarms. In the control condition, no simulated alerts were provided. To explore the effects of learning, subjects performed these tasks in three sessions, on separate days, in a counterbalanced, within subject design. We explore these results within the context of cognitive models of human attention and learning. We found that human observers were more likely to respond to events when marked by a visual alert. Learning played a major role in the two alert conditions. In the first session, observers generated almost twice as many False Alarms as in the No-Alert condition, as the observers responded pre-attentively to the computer-generated false alarms. However, this rate dropped equally dramatically in later sessions, as observers learned to discount the false cues. Highest observer Precision, Hits/(Hits + False Alarms), was achieved in the High Sensitivity condition, but only after training. The successful evaluation of surveillance systems depends on understanding human attention and performance.
Daluwatte, Chathuri; Vicente, Jose; Galeotti, Loriano; Johannesen, Lars; Strauss, David G; Scully, Christopher G
Performance of ECG beat detectors is traditionally assessed on long intervals (e.g.: 30min), but only incorrect detections within a short interval (e.g.: 10s) may cause incorrect (i.e., missed+false) heart rate limit alarms (tachycardia and bradycardia). We propose a novel performance metric based on distribution of incorrect beat detection over a short interval and assess its relationship with incorrect heart rate limit alarm rates. Six ECG beat detectors were assessed using performance metrics over long interval (sensitivity and positive predictive value over 30min) and short interval (Area Under empirical cumulative distribution function (AUecdf) for short interval (i.e., 10s) sensitivity and positive predictive value) on two ECG databases. False heart rate limit and asystole alarm rates calculated using a third ECG database were then correlated (Spearman's rank correlation) with each calculated performance metric. False alarm rates correlated with sensitivity calculated on long interval (i.e., 30min) (ρ=-0.8 and p<0.05) and AUecdf for sensitivity (ρ=0.9 and p<0.05) in all assessed ECG databases. Sensitivity over 30min grouped the two detectors with lowest false alarm rates while AUecdf for sensitivity provided further information to identify the two beat detectors with highest false alarm rates as well, which was inseparable with sensitivity over 30min. Short interval performance metrics can provide insights on the potential of a beat detector to generate incorrect heart rate limit alarms. Published by Elsevier Inc.
Decision-level fusion of SAR and IR sensor information for automatic target detection
NASA Astrophysics Data System (ADS)
Cho, Young-Rae; Yim, Sung-Hyuk; Cho, Hyun-Woong; Won, Jin-Ju; Song, Woo-Jin; Kim, So-Hyeon
2017-05-01
We propose a decision-level architecture that combines synthetic aperture radar (SAR) and an infrared (IR) sensor for automatic target detection. We present a new size-based feature, called target-silhouette to reduce the number of false alarms produced by the conventional target-detection algorithm. Boolean Map Visual Theory is used to combine a pair of SAR and IR images to generate the target-enhanced map. Then basic belief assignment is used to transform this map into a belief map. The detection results of sensors are combined to build the target-silhouette map. We integrate the fusion mass and the target-silhouette map on the decision level to exclude false alarms. The proposed algorithm is evaluated using a SAR and IR synthetic database generated by SE-WORKBENCH simulator, and compared with conventional algorithms. The proposed fusion scheme achieves higher detection rate and lower false alarm rate than the conventional algorithms.
Designing and Implementing a Family of Intrusion Detection Systems
2004-11-01
configure (train), generates many false alarms – Misuse detection (signature analysis) (NFR, Emerald , Snort, STAT) • Generates few false alarms • Detects...to create .rhosts file in world-writable ftp home directory – rlogin using bogus .rhosts file S0 create_file read_rhosts S3S2 login S1 STAT KN-14...world-writable ftp home directory – rlogin using bogus .rhosts file S0 create_file read_rhosts S3S2 login S1 STAT KN-17 ftp-write in STATL use ustat
Detection of gas plumes in cluttered environments using long-wave infrared hyperspectral sensors
NASA Astrophysics Data System (ADS)
Broadwater, Joshua B.; Spisz, Thomas S.; Carr, Alison K.
2008-04-01
Long-wave infrared hyperspectral sensors provide the ability to detect gas plumes at stand-off distances. A number of detection algorithms have been developed for such applications, but in situations where the gas is released in a complex background and is at air temperature, these detectors can generate a considerable amount of false alarms. To make matters more difficult, the gas tends to have non-uniform concentrations throughout the plume making it spatially similar to the false alarms. Simple post-processing using median filters can remove a number of the false alarms, but at the cost of removing a significant amount of the gas plume as well. We approach the problem using an adaptive subpixel detector and morphological processing techniques. The adaptive subpixel detection algorithm is able to detect the gas plume against the complex background. We then use morphological processing techniques to isolate the gas plume while simultaneously rejecting nearly all false alarms. Results will be demonstrated on a set of ground-based long-wave infrared hyperspectral image sequences.
Application of the PageRank Algorithm to Alarm Graphs
NASA Astrophysics Data System (ADS)
Treinen, James J.; Thurimella, Ramakrishna
The task of separating genuine attacks from false alarms in large intrusion detection infrastructures is extremely difficult. The number of alarms received in such environments can easily enter into the millions of alerts per day. The overwhelming noise created by these alarms can cause genuine attacks to go unnoticed. As means of highlighting these attacks, we introduce a host ranking technique utilizing Alarm Graphs. Rather than enumerate all potential attack paths as in Attack Graphs, we build and analyze graphs based on the alarms generated by the intrusion detection sensors installed on a network. Given that the alarms are predominantly false positives, the challenge is to identify, separate, and ideally predict future attacks. In this paper, we propose a novel approach to tackle this problem based on the PageRank algorithm. By elevating the rank of known attackers and victims we are able to observe the effect that these hosts have on the other nodes in the Alarm Graph. Using this information we are able to discover previously overlooked attacks, as well as defend against future intrusions.
2011-09-01
Electromagnetic interference (EMI) may cause some Philips Healthcare IntelliVue MMS, MP2, MP5, and X2 patient monitoring products to incorrectly display a flat electrocardiogram (ECG) waveform and generate a false asystole alarm. This occurs while the devices' pace pulse rejection feature is enabled. Facilities that suspect such behavior in their inventories should contact Philips to discuss whether installation of firmware version D.02.05 will help address the problem.
Performance Evaluation of New-Generation Pulse Oximeters in the NICU: Observational Study.
Nizami, Shermeen; Greenwood, Kim; Barrowman, Nick; Harrold, JoAnn
2015-09-01
This crossover observational study compares the data characteristics and performance of new-generation Nellcor OXIMAX and Masimo SET SmartPod pulse oximeter technologies. The study was conducted independent of either original equipment manufacturer (OEM) across eleven preterm infants in a Neonatal Intensive Care Unit (NICU). The SmartPods were integrated with Dräger Infinity Delta monitors. The Delta monitor measured the heart rate (HR) using an independent electrocardiogram sensor, and the two SmartPods collected arterial oxygen saturation (SpO2) and pulse rate (PR). All patient data were non-Gaussian. Nellcor PR showed a higher correlation with the HR as compared to Masimo PR. The statistically significant difference found in their median values (1% for SpO2, 1 bpm for PR) was deemed clinically insignificant. SpO2 alarms generated by both SmartPods were observed and categorized for performance evaluation. Results for sensitivity, positive predictive value, accuracy and false alarm rates were Nellcor (80.3, 50, 44.5, 50%) and Masimo (72.2, 48.2, 40.6, 51.8%) respectively. These metrics were not statistically significantly different between the two pulse oximeters. Despite claims by OEMs, both pulse oximeters exhibited high false alarm rates, with no statistically or clinically significant difference in performance. These findings have a direct impact on alarm fatigue in the NICU. Performance evaluation studies can also impact medical device purchase decisions made by hospital administrators.
Siebig, Sylvia; Kuhls, Silvia; Imhoff, Michael; Langgartner, Julia; Reng, Michael; Schölmerich, Jürgen; Gather, Ursula; Wrede, Christian E
2010-03-01
Monitoring of physiologic parameters in critically ill patients is currently performed by threshold alarm systems with high sensitivity but low specificity. As a consequence, a multitude of alarms are generated, leading to an impaired clinical value of these alarms due to reduced alertness of the intensive care unit (ICU) staff. To evaluate a new alarm procedure, we currently generate a database of physiologic data and clinical alarm annotations. Data collection is taking place at a 12-bed medical ICU. Patients with monitoring of at least heart rate, invasive arterial blood pressure, and oxygen saturation are included in the study. Numerical physiologic data at 1-second intervals, monitor alarms, and alarm settings are extracted from the surveillance network. Bedside video recordings are performed with network surveillance cameras. Based on the extracted data and the video recordings, alarms are clinically annotated by an experienced physician. The alarms are categorized according to their technical validity and clinical relevance by a taxonomy system that can be broadly applicable. Preliminary results showed that only 17% of the alarms were classified as relevant, and 44% were technically false. The presented system for collecting real-time bedside monitoring data in conjunction with video-assisted annotations of clinically relevant events is the first allowing the assessment of 24-hour periods and reduces the bias usually created by bedside observers in comparable studies. It constitutes the basis for the development and evaluation of "smart" alarm algorithms, which may help to reduce the number of alarms at the ICU, thereby improving patient safety. Copyright 2010 Elsevier Inc. All rights reserved.
False Fire Alarms: A Deviant Pattern of Seeking Help.
ERIC Educational Resources Information Center
Camblin, Louise; Weinland, Laura
1987-01-01
Discusses the phenomenon of false fire alarms, the deliberate, intentional false reporting of fires, by mentally troubled persons as a primitive kind of help-seeking behavior. Several common themes found by reviewing false alarm cases are presented. Suggests that identifying the intrapsychic dynamics of false alarm reporters could be useful in…
Reducing false asystole alarms in intensive care.
Dekimpe, Remi; Heldt, Thomas
2017-07-01
High rates of false monitoring alarms in intensive care can desensitize staff and therefore pose a significant risk to patient safety. Like other critical arrhythmia alarms, asystole alarms require immediate attention by the care providers as a true asystole event can be acutely life threatening. Here, it is illustrated that most false asystole alarms can be attributed to poor signal quality, and we propose and evaluate an algorithm to identify data windows of poor signal quality and thereby help suppress false asystole alarms. The algorithm combines intuitive signal-quality features (degree of signal saturation and baseline wander) and information from other physiological signals that might be available. Algorithm training and testing was performed on the MIMIC II and 2015 PhysioNet/Computing in Cardiology Challenge databases, respectively. The algorithm achieved an alarm specificity of 81.0% and sensitivity of 95.4%, missing only one out of 22 true asystole alarms. On a separate neonatal data set, the algorithm was able to reject 89.7% (890 out of 992) of false asystole alarms while keeping all 22 true events. The results show that the false asystole alarm rate can be significantly reduced through basic signal quality evaluation.
The Threat Detection System that Cried Wolf: Reconciling Developers with Operators
2017-01-01
generating false alarms when true threats are not present. As a result, operators lose faith in the systems—ignoring them or even turning them off and...taking the chance that a true threat will not appear. This article reviews statistical concepts to reconcile the performance metrics that summarize a...the fraction of true threats for which the system correctly declares an alarm. Conversely, Pfa describes the fraction of true clutter ( true non
Burr, Tom; Hamada, Michael S.; Howell, John; ...
2013-01-01
Process monitoring (PM) for nuclear safeguards sometimes requires estimation of thresholds corresponding to small false alarm rates. Threshold estimation dates to the 1920s with the Shewhart control chart; however, because possible new roles for PM are being evaluated in nuclear safeguards, it is timely to consider modern model selection options in the context of threshold estimation. One of the possible new PM roles involves PM residuals, where a residual is defined as residual = data − prediction. This paper reviews alarm threshold estimation, introduces model selection options, and considers a range of assumptions regarding the data-generating mechanism for PM residuals.more » Two PM examples from nuclear safeguards are included to motivate the need for alarm threshold estimation. The first example involves mixtures of probability distributions that arise in solution monitoring, which is a common type of PM. The second example involves periodic partial cleanout of in-process inventory, leading to challenging structure in the time series of PM residuals.« less
NASA Technical Reports Server (NTRS)
Scalzo, F.
1983-01-01
Sensor redundancy management (SRM) requires a system which will detect failures and reconstruct avionics accordingly. A probability density function to determine false alarm rates, using an algorithmic approach was generated. Microcomputer software was developed which will print out tables of values for the cummulative probability of being in the domain of failure; system reliability; and false alarm probability, given a signal is in the domain of failure. The microcomputer software was applied to the sensor output data for various AFT1 F-16 flights and sensor parameters. Practical recommendations for further research were made.
Algorithm of reducing the false positives in IDS based on correlation Analysis
NASA Astrophysics Data System (ADS)
Liu, Jianyi; Li, Sida; Zhang, Ru
2018-03-01
This paper proposes an algorithm of reducing the false positives in IDS based on correlation Analysis. Firstly, the algorithm analyzes the distinguishing characteristics of false positives and real alarms, and preliminary screen the false positives; then use the method of attribute similarity clustering to the alarms and further reduces the amount of alarms; finally, according to the characteristics of multi-step attack, associated it by the causal relationship. The paper also proposed a reverse causation algorithm based on the attack association method proposed by the predecessors, turning alarm information into a complete attack path. Experiments show that the algorithm simplifies the number of alarms, improve the efficiency of alarm processing, and contribute to attack purposes identification and alarm accuracy improvement.
Deep belief networks for false alarm rejection in forward-looking ground-penetrating radar
NASA Astrophysics Data System (ADS)
Becker, John; Havens, Timothy C.; Pinar, Anthony; Schulz, Timothy J.
2015-05-01
Explosive hazards are one of the most deadly threats in modern conflicts. The U.S. Army is interested in a reliable way to detect these hazards at range. A promising way of accomplishing this task is using a forward-looking ground-penetrating radar (FLGPR) system. Recently, the Army has been testing a system that utilizes both L-band and X-band radar arrays on a vehicle mounted platform. Using data from this system, we sought to improve the performance of a constant false-alarm-rate (CFAR) prescreener through the use of a deep belief network (DBN). DBNs have also been shown to perform exceptionally well at generalized anomaly detection. They combine unsupervised pre-training with supervised fine-tuning to generate low-dimensional representations of high-dimensional input data. We seek to take advantage of these two properties by training a DBN on the features of the CFAR prescreener's false alarms (FAs) and then use that DBN to separate FAs from true positives. Our analysis shows that this method improves the detection statistics significantly. By training the DBN on a combination of image features, we were able to significantly increase the probability of detection while maintaining a nominal number of false alarms per square meter. Our research shows that DBNs are a good candidate for improving detection rates in FLGPR systems.
Comparison between pulse oximetry and transthoracic impedance alarm traces during home monitoring.
Nassi, N; Piumelli, R; Lombardi, E; Landini, L; Donzelli, G; de Martino, M
2008-02-01
To compare transthoracic impedance (TTI/ECG) and pulse oximetry alarm traces detected during home monitoring in infants at risk of apnoea, bradycardia and hypoxaemia. A retrospective evaluation of the monitor downloads of 67 infants who had undergone either TTI/ECG or pulse oximetry home monitoring using a device which can detect both parameters. The patients were categorised as: apparent life-threatening events (n = 39), preterm infants (n = 21) and miscellaneous (n = 7). TTI/ECG and pulse oximetry alarm traces were scored as either true or false alarms. Classification criteria were based on visual analysis of the impedance and plethysmographic waveforms captured by the memory monitor every time alarm thresholds were violated. 5242 alarms occurred over 3452 days of monitoring: 4562 (87%) were false and 680 (13%) true. The mean duration of monitoring was 51 days (range 5-220 days). There were 2982 TTI/ECG false alarms (65% of the total) and 1580 pulse oximetry false alarms (35%) (p = 0.0042). Of the 680 true alarms, 507 (74%) were desaturations not attributable to central apnoea and 173 (26%) were true TTI/ECG alarms (p = 0.0013). Comparison of pulse oximetry and TTI/ECG alarm traces shows that true events were mostly attributable to desaturations, while false alarms were mainly provoked by TTI/ECG. The total number of false alarms is lower than reported in other studies using TTI/ECG only, thus indicating that monitoring using both pulse oximetry and TTI/ECG is suitable for home use. When the combination of both techniques is not feasible or not required, we recommend the use of motion resistant pulse oximetry alone.
A random forest algorithm for nowcasting of intense precipitation events
NASA Astrophysics Data System (ADS)
Das, Saurabh; Chakraborty, Rohit; Maitra, Animesh
2017-09-01
Automatic nowcasting of convective initiation and thunderstorms has potential applications in several sectors including aviation planning and disaster management. In this paper, random forest based machine learning algorithm is tested for nowcasting of convective rain with a ground based radiometer. Brightness temperatures measured at 14 frequencies (7 frequencies in 22-31 GHz band and 7 frequencies in 51-58 GHz bands) are utilized as the inputs of the model. The lower frequency band is associated to the water vapor absorption whereas the upper frequency band relates to the oxygen absorption and hence, provide information on the temperature and humidity of the atmosphere. Synthetic minority over-sampling technique is used to balance the data set and 10-fold cross validation is used to assess the performance of the model. Results indicate that random forest algorithm with fixed alarm generation time of 30 min and 60 min performs quite well (probability of detection of all types of weather condition ∼90%) with low false alarms. It is, however, also observed that reducing the alarm generation time improves the threat score significantly and also decreases false alarms. The proposed model is found to be very sensitive to the boundary layer instability as indicated by the variable importance measure. The study shows the suitability of a random forest algorithm for nowcasting application utilizing a large number of input parameters from diverse sources and can be utilized in other forecasting problems.
NASA Astrophysics Data System (ADS)
Moradi, Saed; Moallem, Payman; Sabahi, Mohamad Farzan
2018-03-01
False alarm rate and detection rate are still two contradictory metrics for infrared small target detection in an infrared search and track system (IRST), despite the development of new detection algorithms. In certain circumstances, not detecting true targets is more tolerable than detecting false items as true targets. Hence, considering background clutter and detector noise as the sources of the false alarm in an IRST system, in this paper, a false alarm aware methodology is presented to reduce false alarm rate while the detection rate remains undegraded. To this end, advantages and disadvantages of each detection algorithm are investigated and the sources of the false alarms are determined. Two target detection algorithms having independent false alarm sources are chosen in a way that the disadvantages of the one algorithm can be compensated by the advantages of the other one. In this work, multi-scale average absolute gray difference (AAGD) and Laplacian of point spread function (LoPSF) are utilized as the cornerstones of the desired algorithm of the proposed methodology. After presenting a conceptual model for the desired algorithm, it is implemented through the most straightforward mechanism. The desired algorithm effectively suppresses background clutter and eliminates detector noise. Also, since the input images are processed through just four different scales, the desired algorithm has good capability for real-time implementation. Simulation results in term of signal to clutter ratio and background suppression factor on real and simulated images prove the effectiveness and the performance of the proposed methodology. Since the desired algorithm was developed based on independent false alarm sources, our proposed methodology is expandable to any pair of detection algorithms which have different false alarm sources.
NASA Technical Reports Server (NTRS)
Trudell, Bernard J.; Dreibelbis, Ryland R.
1990-01-01
An analysis was conducted of current ELT problems and potential improvements that could be made by employing the TSO-C91a ELTs to replace the current TSO-C91 ELTs. The scope of the study included the following: (1) validate the problems; (2) determine specific failure causes; (3) determine false alarm causes; (4) estimate improvements from TSO-C91a; (5) estimate benefits from replacement of the current ELTs; and (6) determine need and benefits for improved ELT inspection and maintenance. A detailed comparison between the two requirements documents (TSO-C91 and -91a) was made to assess improved performance of the ELT in each category of failure cause and each cause of false alarms. The comparison and analysis resulted in projecting a success of operation rate approximately 3 times the current rate and a reduction in false alarms to 0.25 of those generated by TSO-C91 ELTs. These improvements led to a projection of benefits of approximately 25 additional lives to be saved each year with TSO-C91a ELTs and an improved inspection and maintenance program.
NASA Astrophysics Data System (ADS)
Marble, Jay A.; Gorman, John D.
1999-08-01
A feature based approach is taken to reduce the occurrence of false alarms in foliage penetrating, ultra-wideband, synthetic aperture radar data. A set of 'generic' features is defined based on target size, shape, and pixel intensity. A second set of features is defined that contains generic features combined with features based on scattering phenomenology. Each set is combined using a quadratic polynomial discriminant (QPD), and performance is characterized by generating a receiver operating characteristic (ROC) curve. Results show that the feature set containing phenomenological features improves performance against both broadside and end-on targets. Performance against end-on targets, however, is especially pronounced.
Rice, Stephen; McCarley, Jason S
2011-12-01
Automated diagnostic aids prone to false alarms often produce poorer human performance in signal detection tasks than equally reliable miss-prone aids. However, it is not yet clear whether this is attributable to differences in the perceptual salience of the automated aids' misses and false alarms or is the result of inherent differences in operators' cognitive responses to different forms of automation error. The present experiments therefore examined the effects of automation false alarms and misses on human performance under conditions in which the different forms of error were matched in their perceptual characteristics. Young adult participants performed a simulated baggage x-ray screening task while assisted by an automated diagnostic aid. Judgments from the aid were rendered as text messages presented at the onset of each trial, and every trial was followed by a second text message providing response feedback. Thus, misses and false alarms from the aid were matched for their perceptual salience. Experiment 1 found that even under these conditions, false alarms from the aid produced poorer human performance and engendered lower automation use than misses from the aid. Experiment 2, however, found that the asymmetry between misses and false alarms was reduced when the aid's false alarms were framed as neutral messages rather than explicit misjudgments. Results suggest that automation false alarms and misses differ in their inherent cognitive salience and imply that changes in diagnosis framing may allow designers to encourage better use of imperfectly reliable automated aids.
A novel algorithm for reducing false arrhythmia alarms in intensive care units.
Srivastava, Chandan; Sharma, Sonal; Jalali, Ali
2016-08-01
Alarm fatigue in intensive care units (ICU) is one of the top healthcare issues in the US. False alarms in ICU will decrease the quality of care and staff response time over the alarms. Normally, false alarm will cause desensitization of the clinical staff which leads to warnings and misleading, if the triggered alarm is true. In this study, we have proposed a multi-model ensemble approach to reduce the false alarm rate in monitoring systems. We have used 750 patient records from PhysioNet database. At First arrhythmia based features from electrocardiogram (ECG), arterial blood pressure (ABP) and photoplethysmogram (PPG) features were extracted from the records. Next, the dataset has been separated into two subsets on the basis of available features information. The first dataset (DS1) is the combination of ECG physiological, ABP and PPG features. Their correlation coefficient and p-values criteria have been applied for relevant alarm-wise feature-set selection, and random forest classifier was used for model development and validation. The threshold based approach was used on second dataset (DS2) which is the combination of arrhythmia, ABP and PPG features. The developed ensemble model is able to achieve sensitivity 83.33-100 % (average 95.56 %) being true alarms and suppress false alarms rate 66.67-89% (average 77.25%). The predictability of classifier shows the advantage to deal with unbalanced set of information, therefore overall model performance has reached to 83.96% accuracy.
McCabe, David P.; Roediger, Henry L.; McDaniel, Mark A.; Balota, David A.
2011-01-01
In 1985 Tulving introduced the remember–know procedure, whereby subjects are asked to distinguish between memories that involve retrieval of contextual details (remembering) and memories that do not (knowing). Several studies have been reported showing age-related declines in remember hits, which has typically been interpreted as supporting dual-process theories of cognitive aging that align remembering with a recollection process and knowing with a familiarity process. Less attention has been paid to remember false alarms, or their relation to age. We reviewed the literature examining aging and remember/know judgments and show that age-related increases in remember false alarms, i.e., false remembering, are as reliable as age-related decreases in remember hits, i.e., veridical remembering. Moreover, a meta-analysis showed that the age effect size for remember hits and false alarms are similar, and larger than age effects on know hits and false alarms. We also show that the neuropsychological correlates of remember hits and false alarms differ. Neuropsychological tests of medial-temporal lobe functioning were related to remember hits, but tests of frontal-lobe functioning and age were not. By contrast, age and frontal-lobe functioning predicted unique variance in remember false alarms, but MTL functioning did not. We discuss various explanations for these findings and conclude that any comprehensive explanation of recollective experience will need to account for the processes underlying both remember hits and false alarms. PMID:19100756
Negative feedback from maternal signals reduces false alarms by collectively signalling offspring.
Hamel, Jennifer A; Cocroft, Reginald B
2012-09-22
Within animal groups, individuals can learn of a predator's approach by attending to the behaviour of others. This use of social information increases an individual's perceptual range, but can also lead to the propagation of false alarms. Error copying is especially likely in species that signal collectively, because the coordination required for collective displays relies heavily on social information. Recent evidence suggests that collective behaviour in animals is, in part, regulated by negative feedback. Negative feedback may reduce false alarms by collectively signalling animals, but this possibility has not yet been tested. We tested the hypothesis that negative feedback increases the accuracy of collective signalling by reducing the production of false alarms. In the treehopper Umbonia crassicornis, clustered offspring produce collective signals during predator attacks, advertising the predator's location to the defending mother. Mothers signal after evicting the predator, and we show that this maternal communication reduces false alarms by offspring. We suggest that maternal signals elevate offspring signalling thresholds. This is, to our knowledge, the first study to show that negative feedback can reduce false alarms by collectively behaving groups.
Fong, Allan; Mittu, Ranjeev; Ratwani, Raj; Reggia, James
2014-01-01
Alarm fatigue caused by false alarms and alerts is an extremely important issue for the medical staff in Intensive Care Units. The ability to predict electrocardiogram and arterial blood pressure waveforms can potentially help the staff and hospital systems better classify a patient's waveforms and subsequent alarms. This paper explores the use of Echo State Networks, a specific type of neural network for mining, understanding, and predicting electrocardiogram and arterial blood pressure waveforms. Several network architectures are designed and evaluated. The results show the utility of these echo state networks, particularly ones with larger integrated reservoirs, for predicting electrocardiogram waveforms and the adaptability of such models across individuals. The work presented here offers a unique approach for understanding and predicting a patient's waveforms in order to potentially improve alarm generation. We conclude with a brief discussion of future extensions of this research.
Harding, G; Fleckenstein, H; Kosciesza, D; Olesinski, S; Strecker, H; Theedt, T; Zienert, G
2012-07-01
The steadily increasing number of explosive threat classes, including home-made explosives (HMEs), liquids, amorphous and gels (LAGs), is forcing up the false-alarm rates of security screening equipment. This development can best be countered by increasing the number of features available for classification. X-ray diffraction intrinsically offers multiple features for both solid and LAGs explosive detection, and is thus becoming increasingly important for false-alarm and cost reduction in both carry-on and checked baggage security screening. Following a brief introduction to X-ray diffraction imaging (XDI), which synthesizes in a single modality the image-forming and material-analysis capabilities of X-rays, the Multiple Inverse Fan Beam (MIFB) XDI topology is described. Physical relationships obtaining in such MIFB XDI components as the radiation source, collimators and room-temperature detectors are presented with experimental performances that have been achieved. Representative X-ray diffraction profiles of threat substances measured with a laboratory MIFB XDI system are displayed. The performance of Next-Generation (MIFB) XDI relative to that of the 2nd Generation XRD 3500TM screener (Morpho Detection Germany GmbH) is assessed. The potential of MIFB XDI, both for reducing the exorbitant cost of false alarms in hold baggage screening (HBS), as well as for combining "in situ" liquid and solid explosive detection in carry-on luggage screening is outlined. Copyright © 2011 Elsevier Ltd. All rights reserved.
Data-based Considerations in Portal Radiation Monitoring of Cargo Vehicles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weier, Dennis R.; O'Brien, Robert F.; Ely, James H.
2004-07-01
Radiation portal monitoring of cargo vehicles often includes a configuration of four-panel monitors that record gamma and neutron counts from vehicles transporting cargo. As vehicles pass the portal monitors, they generate a count profile over time that can be compared to the average panel background counts obtained just prior to the time the vehicle entered the area of the monitors. Pacific Northwest National Laboratory has accumulated considerable data regarding such background radiation and vehicle profiles from portal installations, as well as in experimental settings using known sources and cargos. Several considerations have a bearing on how alarm thresholds are setmore » in order to maintain sensitivity to radioactive sources while also controlling to a manageable level the rate of false or nuisance alarms. False alarms are statistical anomalies while nuisance alarms occur due to the presence of naturally occurring radioactive material (NORM) in cargo, for example, kitty litter. Considerations to be discussed include: • Background radiation suppression due to the shadow shielding from the vehicle. • The impact of the relative placement of the four panels on alarm decision criteria. • Use of plastic scintillators to separate gamma counts into energy windows. • The utility of using ratio criteria for the energy window counts rather than simply using total window counts. • Detection likelihood for these various decision criteria based on computer simulated injections of sources into vehicle profiles.« less
Encountering bird alarms in full-stare IRSTs
NASA Astrophysics Data System (ADS)
de Jong, Arie N.; Winkel, Hans; Kemp, Rob A. W.
2000-12-01
Birds are a potential source of frequent false alarms in Infrared Search and Track (IRST) systems. One reason is that the signals, generated by birds at short ranges (1-2 km) in IR sensors may be of the same magnitude as the signals generated by real targets (missiles) at long ranges (10-20 km). Another reason is that new generations of IRSTs have more sensitivity which brings more birds within the detection range. Furthermore military operations tend to be held more and more in coastal zones, where the frequency of occurrence of birds is greater than in the open ocean. Finally, the variety in type of birds and their flight characteristics and signature is larger. In the paper attention is spent on the IR signatures of birds in various backgrounds, including rapid variations in signature due to wing motions. Basically, these fluctuations and the flight pattern of a bird provide opportunities to encounter bird alarms in next generation IRSTs, using multiple Focal Plan Array cameras with high frame rates. One has to take into account in this process the difference between signal variations due to wing motions and scintillation for long range targets above the horizon.
NASA Astrophysics Data System (ADS)
Ackley, Kendall; Eikenberry, Stephen; Klimenko, Sergey; LIGO Team
2017-01-01
We present a false-alarm rate for a joint detection of gravitational wave (GW) events and associated electromagnetic (EM) counterparts for Advanced LIGO and Virgo (LV) observations during the first years of operation. Using simulated GW events and their recostructed probability skymaps, we tile over the error regions using sets of archival wide-field telescope survey images and recover the number of astrophysical transients to be expected during LV-EM followup. With the known GW event injection coordinates we inject artificial electromagnetic (EM) sources at that site based on theoretical and observational models on a one-to-one basis. We calculate the EM false-alarm probability using an unsupervised machine learning algorithm based on shapelet analysis which has shown to be a strong discriminator between astrophysical transients and image artifacts while reducing the set of transients to be manually vetted by five orders of magnitude. We also show the performance of our method in context with other machine-learned transient classification and reduction algorithms, showing comparability without the need for a large set of training data opening the possibility for next-generation telescopes to take advantage of this pipeline for LV-EM followup missions.
Kim, Sungho; Lee, Joohyoung
2014-01-01
This paper presents a region-adaptive clutter rejection method for small target detection in sea-based infrared search and track. In the real world, clutter normally generates many false detections that impede the deployment of such detection systems. Incoming targets (missiles, boats, etc.) can be located in the sky, horizon and sea regions, which have different types of clutters, such as clouds, a horizontal line and sea-glint. The characteristics of regional clutter were analyzed after the geometrical analysis-based region segmentation. The false detections caused by cloud clutter were removed by the spatial attribute-based classification. Those by the horizontal line were removed using the heterogeneous background removal filter. False alarms by sun-glint were rejected using the temporal consistency filter, which is the most difficult part. The experimental results of the various cluttered background sequences show that the proposed region adaptive clutter rejection method produces fewer false alarms than that of the mean subtraction filter (MSF) with an acceptable degradation detection rate. PMID:25054633
Source monitoring and false memories in children: relation to certainty and executive functioning.
Ruffman, T; Rustin, C; Garnham, W; Parkin, A J
2001-10-01
We presented children aged 6, 8, and 10 years with a video and then an audio tape about a dog named Mick. Some information was repeated in the two sources and some was unique to one source. We examined: (a) children's hit rate for remembering whether events occurred and their tendency to make false alarms, (b) their memory for the context in which events occurred (source monitoring), (c) their certainty about hits, false alarms, and source, and (d) whether working memory and inhibition were related to hits, false alarms, and source monitoring. The certainty ratings revealed deficits in children's understanding of when they had erred on source questions and of when they had made false alarms. In addition, inhibitory ability accounted for unique variance in the ability to avoid false alarms and in some kinds of source monitoring but not hits. In contrast, working memory tended to correlate with all forms of memory including hits. Copyright 2001 Academic Press.
NASA Astrophysics Data System (ADS)
Cui, Yiqian; Shi, Junyou; Wang, Zili
2017-11-01
Built-in tests (BITs) are widely used in mechanical systems to perform state identification, whereas the BIT false and missed alarms cause trouble to the operators or beneficiaries to make correct judgments. Artificial neural networks (ANN) are previously used for false and missed alarms identification, which has the features such as self-organizing and self-study. However, these ANN models generally do not incorporate the temporal effect of the bottom-level threshold comparison outputs and the historical temporal features are not fully considered. To improve the situation, this paper proposes a new integrated BIT design methodology by incorporating a novel type of dynamic neural networks (DNN) model. The new DNN model is termed as Forward IIR & Recurrent FIR DNN (FIRF-DNN), where its component neurons, network structures, and input/output relationships are discussed. The condition monitoring false and missed alarms reduction implementation scheme based on FIRF-DNN model is also illustrated, which is composed of three stages including model training, false and missed alarms detection, and false and missed alarms suppression. Finally, the proposed methodology is demonstrated in the application study and the experimental results are analyzed.
An automatic fall detection framework using data fusion of Doppler radar and motion sensor network.
Liu, Liang; Popescu, Mihail; Skubic, Marjorie; Rantz, Marilyn
2014-01-01
This paper describes the ongoing work of detecting falls in independent living senior apartments. We have developed a fall detection system with Doppler radar sensor and implemented ceiling radar in real senior apartments. However, the detection accuracy on real world data is affected by false alarms inherent in the real living environment, such as motions from visitors. To solve this issue, this paper proposes an improved framework by fusing the Doppler radar sensor result with a motion sensor network. As a result, performance is significantly improved after the data fusion by discarding the false alarms generated by visitors. The improvement of this new method is tested on one week of continuous data from an actual elderly person who frequently falls while living in her senior home.
Method and apparatus for distinguishing actual sparse events from sparse event false alarms
Spalding, Richard E.; Grotbeck, Carter L.
2000-01-01
Remote sensing method and apparatus wherein sparse optical events are distinguished from false events. "Ghost" images of actual optical phenomena are generated using an optical beam splitter and optics configured to direct split beams to a single sensor or segmented sensor. True optical signals are distinguished from false signals or noise based on whether the ghost image is presence or absent. The invention obviates the need for dual sensor systems to effect a false target detection capability, thus significantly reducing system complexity and cost.
Counting the cost of false alarms.
2013-05-01
While fire and rescue service personnel, the Government, those responsible for fire safety in the healthcare sector, the Health and Safety Executive, fire and rescue services, and indeed fire alarm and detection equipment manufacturers, must be pleased that the number of false fire alarms continues to fall, fire services still attended just under 585,000 fires or false alarm incidents across Great Britain in 2011/12. Of this total, 272,000 were actual fires, of which around 24,000 were in premises classified by the Department for Communities and Local Government (DCLG) as 'other buildings', i.e. not 'dwellings', a category that includes healthcare facilities (representing a 4% fall on 2010-2011). HEJ looks behind the statistics, and at the possibility that some fire services could, in future, charge healthcare providers that persistently report incidents that turn out to be false alarms.
Verfaellie, Mieke; Rapcsak, Steven Z; Keane, Margaret M; Alexander, Michael P
2004-01-01
This study examined verbal recognition memory in amnesic patients with frontal lesions (AF), nonamnesic patients with frontal lesions (NAF), and amnesic patients with medial temporal lesions (MT). To examine susceptibility to false alarms, the number of studied words drawn from various categories was varied. The AF and MT groups demonstrated reduced hits and increased false alarms. False alarms were especially elevated when item-specific recollection was strongest in control participants. The NAF group performed indistinguishably from control participants, but several patients showed excessive false alarms in the context of normal hit rates. These patients exhibited impaired monitoring and verification processes. The findings demonstrate that elevated false recognition is not characteristic of all frontal patients and may result from more than 1 underlying mechanism. ((c) 2004 APA, all rights reserved)
Repetition increases false recollection in older people.
Pitarque, Alfonso; Sales, Alicia; Meléndez, Juan Carlos; Algarabel, Salvador
2015-02-01
Aging is accompanied by an increase in false alarms on recognition tasks, and these false alarms increase with repetition in older people (but not in young people). Traditionally, this increase was thought to be due to a greater use of familiarity in older people, but it was recently pointed out that false alarms also have a clear recollection component in these people. The main objective of our study is to analyze whether the expected increase in the rate of false alarms in older people due to stimulus repetition is produced by an inadequate use of familiarity, recollection, or both processes. To do so, we carried out an associative recognition experiment using pairs of words and pairs of images (faces associated with everyday contexts), in which we analyzed whether the repetition of some of the pairs increases the rate of false alarms in older people (compared to what was found in a sample of young people), and whether this increase is due to familiarity or recollection (using a remember-know paradigm). Our results show that the increase in false alarms in older people due to repetition is produced by false recollection, calling into question both dual and single-process models of recognition. Also, older people falsely recollect details of never studied stimuli, a clear case of perceptual illusions. These results are better explained in terms of source-monitoring errors, mediated by people's retrieval expectations. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.
Solar Energetic Particle Forecasting Algorithms and Associated False Alarms
NASA Astrophysics Data System (ADS)
Swalwell, B.; Dalla, S.; Walsh, R. W.
2017-11-01
Solar energetic particle (SEP) events are known to occur following solar flares and coronal mass ejections (CMEs). However, some high-energy solar events do not result in SEPs being detected at Earth, and it is these types of event which may be termed "false alarms". We define two simple SEP forecasting algorithms based upon the occurrence of a magnetically well-connected CME with a speed in excess of 1500 km s^{-1} (a "fast" CME) or a well-connected X-class flare and analyse them with respect to historical datasets. We compare the parameters of those solar events which produced an enhancement of {>} 40 MeV protons at Earth (an "SEP event") and the parameters of false alarms. We find that an SEP forecasting algorithm based solely upon the occurrence of a well-connected fast CME produces fewer false alarms (28.8%) than an algorithm which is based solely upon a well-connected X-class flare (50.6%). Both algorithms fail to forecast a relatively high percentage of SEP events (53.2% and 50.6%, respectively). Our analysis of the historical datasets shows that false-alarm X-class flares were either not associated with any CME, or were associated with a CME slower than 500 km s^{-1}; false-alarm fast CMEs tended to be associated with flare classes lower than M3. A better approach to forecasting would be an algorithm which takes as its base the occurrence of both CMEs and flares. We define a new forecasting algorithm which uses a combination of CME and flare parameters, and we show that the false-alarm ratio is similar to that for the algorithm based upon fast CMEs (29.6%), but the percentage of SEP events not forecast is reduced to 32.4%. Lists of the solar events which gave rise to {>} 40 MeV protons and the false alarms have been derived and are made available to aid further study.
Tanantong, Tanatorn; Nantajeewarawat, Ekawit; Thiemjarus, Surapa
2015-02-09
False alarms in cardiac monitoring affect the quality of medical care, impacting on both patients and healthcare providers. In continuous cardiac monitoring using wireless Body Sensor Networks (BSNs), the quality of ECG signals can be deteriorated owing to several factors, e.g., noises, low battery power, and network transmission problems, often resulting in high false alarm rates. In addition, body movements occurring from activities of daily living (ADLs) can also create false alarms. This paper presents a two-phase framework for false arrhythmia alarm reduction in continuous cardiac monitoring, using signals from an ECG sensor and a 3D accelerometer. In the first phase, classification models constructed using machine learning algorithms are used for labeling input signals. ECG signals are labeled with heartbeat types and signal quality levels, while 3D acceleration signals are labeled with ADL types. In the second phase, a rule-based expert system is used for combining classification results in order to determine whether arrhythmia alarms should be accepted or suppressed. The proposed framework was validated on datasets acquired using BSNs and the MIT-BIH arrhythmia database. For the BSN dataset, acceleration and ECG signals were collected from 10 young and 10 elderly subjects while they were performing ADLs. The framework reduced the false alarm rate from 9.58% to 1.43% in our experimental study, showing that it can potentially assist physicians in diagnosing a vast amount of data acquired from wireless sensors and enhance the performance of continuous cardiac monitoring.
Tamkus, Arvydas A; Rice, Kent S; McCaffrey, Michael T
2018-02-01
Although some authors have published case reports describing false negatives in intraoperative neurophysiological monitoring (IONM), a systematic review of causes of false-negative IONM results is lacking. The objective of this study was to analyze false-negative IONM findings in spine surgery. This is a retrospective cohort analysis. A cohort of 109 patients with new postoperative neurologic deficits was analyzed for possible false-negative IONM reporting. The causes of false-negative IONM reporting were determined. From a cohort of 62,038 monitored spine surgeries, 109 consecutive patients with new postoperative neurologic deficits were reviewed for IONM alarms. Intraoperative neurophysiological monitoring alarms occurred in 87 of 109 surgeries. Nineteen patients with new postoperative neurologic deficits did not have an IONM alarm and surgeons were not warned. In addition, three patients had no interpretable IONM baseline data and no alarms were possible for the duration of the surgery. Therefore, 22 patients were included in the study. The absence of IONM alarms during these 22 surgeries had different origins: "true" false negatives where no waveform changes meeting the alarm criteria occurred despite the appropriate IONM (7); a postoperative development of a deficit (6); failure to monitor the pathway, which became injured (5); the absence of interpretable IONM baseline data which precluded any alarm (3); and technical IONM application issues (1). Overall, the rate of IONM method failing to predict the patient's outcome was very low (0.04%, 22/62,038). Minimizing false negatives requires the application of a proper IONM technique with the limitations of each modality considered in their selection and interpretation. Multimodality IONM provides the most inclusive information, and although it might be impractical to monitor every neural structure that can be at risk, a thorough preoperative consideration of available IONM modalities is important. Delayed development of postoperative deficits cannot be predicted by IONM. Absent baseline IONM data should be treated as an alarm when inconsistent with the patient's preoperative neurologic status. Alarm criteria for IONM may need to be refined for specific procedures and deserves continued study. Copyright © 2017 Elsevier Inc. All rights reserved.
Goense, J B M; Ratnam, R
2003-10-01
An important problem in sensory processing is deciding whether fluctuating neural activity encodes a stimulus or is due to variability in baseline activity. Neurons that subserve detection must examine incoming spike trains continuously, and quickly and reliably differentiate signals from baseline activity. Here we demonstrate that a neural integrator can perform continuous signal detection, with performance exceeding that of trial-based procedures, where spike counts in signal- and baseline windows are compared. The procedure was applied to data from electrosensory afferents of weakly electric fish (Apteronotus leptorhynchus), where weak perturbations generated by small prey add approximately 1 spike to a baseline of approximately 300 spikes s(-1). The hypothetical postsynaptic neuron, modeling an electrosensory lateral line lobe cell, could detect an added spike within 10-15 ms, achieving near ideal detection performance (80-95%) at false alarm rates of 1-2 Hz, while trial-based testing resulted in only 30-35% correct detections at that false alarm rate. The performance improvement was due to anti-correlations in the afferent spike train, which reduced both the amplitude and duration of fluctuations in postsynaptic membrane activity, and so decreased the number of false alarms. Anti-correlations can be exploited to improve detection performance only if there is memory of prior decisions.
False recognition depends on depth of prior word processing: a magnetoencephalographic (MEG) study.
Walla, P; Hufnagl, B; Lindinger, G; Deecke, L; Imhof, H; Lang, W
2001-04-01
Brain activity was measured with a whole head magnetoencephalograph (MEG) during the test phases of word recognition experiments. Healthy young subjects had to discriminate between previously presented and new words. During prior study phases two different levels of word processing were provided according to two different kinds of instructions (shallow and deep encoding). Event-related fields (ERFs) associated with falsely recognized words (false alarms) were found to depend on the depth of processing during the prior study phase. False alarms elicited higher brain activity (as reflected by dipole strength) in case of prior deep encoding as compared to shallow encoding between 300 and 500 ms after stimulus onset at temporal brain areas. Between 500 and 700 ms we found evidence for differences in the involvement of neural structures related to both conditions of false alarms. Furthermore, the number of false alarms was found to depend on depth of processing. Shallow encoding led to a higher number of false alarms than deep encoding. All data are discussed as strong support for the ideas that a certain level of word processing is performed by a distinct set of neural systems and that the same neural systems which encode information are reactivated during the retrieval.
21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to produce...
21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to produce...
21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to produce...
Blauch, A J; Schiano, J L; Ginsberg, M D
2000-06-01
The performance of a nuclear resonance detection system can be quantified using binary detection theory. Within this framework, signal averaging increases the probability of a correct detection and decreases the probability of a false alarm by reducing the variance of the noise in the average signal. In conjunction with signal averaging, we propose another method based on feedback control concepts that further improves detection performance. By maximizing the nuclear resonance signal amplitude, feedback raises the probability of correct detection. Furthermore, information generated by the feedback algorithm can be used to reduce the probability of false alarm. We discuss the advantages afforded by feedback that cannot be obtained using signal averaging. As an example, we show how this method is applicable to the detection of explosives using nuclear quadrupole resonance. Copyright 2000 Academic Press.
30 CFR 57.4360 - Underground alarm systems.
Code of Federal Regulations, 2011 CFR
2011-07-01
... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire alarm... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Underground alarm systems. 57.4360 Section 57...
30 CFR 57.4360 - Underground alarm systems.
Code of Federal Regulations, 2012 CFR
2012-07-01
... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire alarm... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Underground alarm systems. 57.4360 Section 57...
30 CFR 57.4360 - Underground alarm systems.
Code of Federal Regulations, 2014 CFR
2014-07-01
... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire alarm... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Underground alarm systems. 57.4360 Section 57...
30 CFR 57.4360 - Underground alarm systems.
Code of Federal Regulations, 2013 CFR
2013-07-01
... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire alarm... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Underground alarm systems. 57.4360 Section 57...
46 CFR 113.43-3 - Alarm system.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Alarm system. 113.43-3 Section 113.43-3 Shipping COAST... SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-3 Alarm system. (a) Each vessel must have a steering failure alarm system that actuates an audible and visible alarm in the pilothouse when the actual...
46 CFR 113.43-3 - Alarm system.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Alarm system. 113.43-3 Section 113.43-3 Shipping COAST... SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-3 Alarm system. (a) Each vessel must have a steering failure alarm system that actuates an audible and visible alarm in the pilothouse when the actual...
46 CFR 113.43-3 - Alarm system.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Alarm system. 113.43-3 Section 113.43-3 Shipping COAST... SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-3 Alarm system. (a) Each vessel must have a steering failure alarm system that actuates an audible and visible alarm in the pilothouse when the actual...
Dixon, Stephen R; Wickens, Christopher D
2006-01-01
Two experiments were conducted in which participants navigated a simulated unmanned aerial vehicle (UAV) through a series of mission legs while searching for targets and monitoring system parameters. The goal of the study was to highlight the qualitatively different effects of automation false alarms and misses as they relate to operator compliance and reliance, respectively. Background data suggest that automation false alarms cause reduced compliance, whereas misses cause reduced reliance. In two studies, 32 and 24 participants, including some licensed pilots, performed in-lab UAV simulations that presented the visual world and collected dependent measures. Results indicated that with the low-reliability aids, false alarms correlated with poorer performance in the system failure task, whereas misses correlated with poorer performance in the concurrent tasks. Compliance and reliance do appear to be affected by false alarms and misses, respectively, and are relatively independent of each other. Practical implications are that automated aids must be fairly reliable to provide global benefits and that false alarms and misses have qualitatively different effects on performance.
46 CFR 108.627 - Carbon dioxide alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next to...
46 CFR 169.732 - Carbon dioxide alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...
46 CFR 169.732 - Carbon dioxide alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...
46 CFR 113.25-12 - Alarm signals.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...
46 CFR 113.25-12 - Alarm signals.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...
46 CFR 113.25-12 - Alarm signals.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...
46 CFR 113.25-12 - Alarm signals.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...
46 CFR 113.25-12 - Alarm signals.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Alarm signals. 113.25-12 Section 113.25-12 Shipping... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-12 Alarm signals. (a) Each general emergency alarm signal must be an electrically-operated bell, klaxon, or other warning device capable of...
Fusion of ultrasonic and infrared signatures for personnel detection by a mobile robot
NASA Astrophysics Data System (ADS)
Carroll, Matthew S.; Meng, Min; Cadwallender, William K.
1992-04-01
Passive Infrared sensors used for intrusion detection, especially those used on mobile robots, are vulnerable to false alarms caused by clutter objects such as radiators, steam pipes, windows, etc., as well as deliberately caused false alarms caused by decoy objects. To overcome these sources of false alarms, we are now combining thermal and ultrasonic signals, the results being a more robust system for detecting personnel. Our paper will discuss the fusion strategies used for combining sensor information. Our first strategy uses a statistical classifier using features such as the sonar cross-section, the received thermal energy, and ultrasonic range. Our second strategy uses s 3-layered neural classifier trained by backpropagation. The probability of correct classification and the false alarm rate for both strategies will be presented in the paper.
46 CFR 76.35-10 - Location and spacing of manual alarm boxes.
Code of Federal Regulations, 2014 CFR
2014-10-01
... PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-10 Location and spacing of manual alarm boxes. (a) There shall be at least one manual alarm box in each zone. (b) Manual alarms shall be located in main... 46 Shipping 3 2014-10-01 2014-10-01 false Location and spacing of manual alarm boxes. 76.35-10...
46 CFR 76.35-10 - Location and spacing of manual alarm boxes.
Code of Federal Regulations, 2013 CFR
2013-10-01
... PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-10 Location and spacing of manual alarm boxes. (a) There shall be at least one manual alarm box in each zone. (b) Manual alarms shall be located in main... 46 Shipping 3 2013-10-01 2013-10-01 false Location and spacing of manual alarm boxes. 76.35-10...
46 CFR 76.35-10 - Location and spacing of manual alarm boxes.
Code of Federal Regulations, 2011 CFR
2011-10-01
... PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-10 Location and spacing of manual alarm boxes. (a) There shall be at least one manual alarm box in each zone. (b) Manual alarms shall be located in main... 46 Shipping 3 2011-10-01 2011-10-01 false Location and spacing of manual alarm boxes. 76.35-10...
46 CFR 76.35-10 - Location and spacing of manual alarm boxes.
Code of Federal Regulations, 2012 CFR
2012-10-01
... PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-10 Location and spacing of manual alarm boxes. (a) There shall be at least one manual alarm box in each zone. (b) Manual alarms shall be located in main... 46 Shipping 3 2012-10-01 2012-10-01 false Location and spacing of manual alarm boxes. 76.35-10...
46 CFR 76.35-10 - Location and spacing of manual alarm boxes.
Code of Federal Regulations, 2010 CFR
2010-10-01
... PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-10 Location and spacing of manual alarm boxes. (a) There shall be at least one manual alarm box in each zone. (b) Manual alarms shall be located in main... 46 Shipping 3 2010-10-01 2010-10-01 false Location and spacing of manual alarm boxes. 76.35-10...
Jose, Bipin; Lodha, Rakesh; Kabra, S K
2014-12-01
To compare the performance of two new generation pulse oximeters, one with enhanced signal extraction technology (SET) and other without enhanced SET in detecting hypoxemia and to correlate it with arterial blood gas analysis. Forty-eight patients, admitted to pediatric intensive care unit (PICU) of a teritiary care teaching hospital in India for critical care and support during the study period, who had an arterial catheter in situ were included. Children with those disease conditions known to interfere with pulse oximetry and blood gas analysis were excluded.184 set of observations were made during the study period. Each set had oxygen saturation (SpO2) measured from both the pulse oximeters and the corresponding arterial oxygen saturation (SaO2). The values were compared for occurrence of true and false alarms during periods of normal BP, hypotension and varying degrees of hypoxia. The mean arterial SaO2 in the study was 94.4 % ± 4.9. The mean SpO2 recorded in conventional and enhanced signal extraction technology (SET) pulse oximeters were 94.9 % ± 4.5 and 97.2 % ± 4.7 respectively. Enhanced signal extraction technology pulse oximeter detected 4/27 (15 %) of true hypoxemic events and 1 event was a false alarm. Conventional pulse oximeter detected 11/27 (41 %) true hypoxemic events but recorded 6 false alarms. Both pulse oximeters were not found to be performing satisfactorily in picking up hypoxemia in the study. There was good correlation with mean SpO2 from pulse oximeters and arterial SaO2. The reliability of pulse oximetry decreases with worsening hypoxemia and hypotension, and the sensitivity for picking up hypoxemia can be as low as 15 %.
Autonomous long-range open area fire detection and reporting
NASA Astrophysics Data System (ADS)
Engelhaupt, Darell E.; Reardon, Patrick J.; Blackwell, Lisa; Warden, Lance; Ramsey, Brian D.
2005-03-01
Approximately 5 billion dollars in US revenue was lost in 2003 due to open area fires. In addition many lives are lost annually. Early detection of open area fires is typically performed by manned observatories, random reporting and aerial surveillance. Optical IR flame detectors have been developed previously. They typically have experienced high false alarms and low flame detection sensitivity due to interference from solar and other causes. Recently a combination of IR detectors has been used in a two or three color mode to reduce false alarms from solar, or background sources. A combination of ultra-violet C (UVC) and near infra-red (NIR) detectors has also been developed recently for flame discrimination. Relatively solar-blind basic detectors are now available but typically detect at only a few tens of meters at ~ 1 square meter fuel flame. We quantify the range and solar issues for IR and visible detectors and qualitatively define UV sensor requirements in terms of the mode of operation, collection area issues and flame signal output by combustion photochemistry. We describe innovative flame signal collection optics for multiple wavelengths using UV and IR as low false alarm detection of open area fires at long range (8-10 km/m2) in daylight (or darkness). A circular array detector and UV-IR reflective and refractive devices including cylindrical or toroidal lens elements for the IR are described. The dispersion in a refractive cylindrical IR lens characterizes the fire and allows a stationary line or circle generator to locate the direction and different flame IR "colors" from a wide FOV. The line generator will produce spots along the line corresponding to the fire which can be discriminated with a linear detector. We demonstrate prototype autonomous sensors with RF digital reporting from various sites.
Renzi, Cristina; Whitaker, Katriina L; Wardle, Jane
2015-02-04
This literature review examined research into the impact of a previous 'all-clear' or non-cancer diagnosis following symptomatic presentation ('false alarm') on symptom attribution and delays in help seeking for subsequent possible cancer symptoms. The comprehensive literature review included original research based on quantitative, qualitative and mixed data collection methods. We used a combination of search strategies, including in-depth searches of electronic databases (PubMed, EMBASE, PsychInfo), searching key authors and articles listed as 'related' in PubMed, and reference lists. We performed a narrative synthesis of key themes shared across studies. The review included studies published after 1990 and before February 2014 reporting information on adult patients having experienced a false alarm following symptomatic presentation. We excluded false alarms in the context of screening. We evaluated the effect of a 'false alarm' on symptom attribution and help seeking for new or recurrent possible cancer symptoms. Overall, 1442 papers were screened and 121 retrieved for full-text evaluation. Among them, 19 reported on false alarms and subsequent symptom attribution or help seeking. They used qualitative (n=14), quantitative (n=3) and mixed methods (n=2). Breast (n=7), gynaecological (n=3), colorectal (n=2), testicular (n=2), and head and neck cancers (n=2) were the most studied. Two broad themes emerged underlying delays in help seeking: (1) over-reassurance from the previous 'all-clear' diagnosis leading to subsequent symptoms being interpreted as benign, and (2) unsupportive healthcare experiences in which symptoms were dismissed, leaving patients concerned about appearing hypochondriacal or uncertain about the appropriate next actions. The evidence suggested that the effect of a false alarm can persist for months and even years. In conclusion, over-reassurance and undersupport of patients after a false alarm can undermine help seeking in the case of new or recurrent potential cancer symptoms, highlighting the need for appropriate patient information when investigations rule out cancer. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
46 CFR 78.47-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b) [Reserved] ...
46 CFR 196.37-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...
46 CFR 97.37-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...
46 CFR 196.37-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...
47 CFR 80.318 - Use of alarm signals.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...
47 CFR 80.318 - Use of alarm signals.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 5 2010-10-01 2010-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...
46 CFR 108.627 - Carbon dioxide alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM...
47 CFR 80.318 - Use of alarm signals.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 5 2012-10-01 2012-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...
47 CFR 80.318 - Use of alarm signals.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 5 2014-10-01 2014-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...
47 CFR 80.318 - Use of alarm signals.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 5 2013-10-01 2013-10-01 false Use of alarm signals. 80.318 Section 80.318... § 80.318 Use of alarm signals. (a) The radiotelegraph or radiotelephone alarm signal, as appropriate... transmission of an urgent cyclone warning. In this case the alarm signal may only be used by coast stations...
Small target pre-detection with an attention mechanism
NASA Astrophysics Data System (ADS)
Wang, Yuehuan; Zhang, Tianxu; Wang, Guoyou
2002-04-01
We introduce the concept of predetection based on an attention mechanism to improve the efficiency of small-target detection by limiting the image region of detection. According to the characteristics of small-target detection, local contrast is taken as the only feature in predetection and a nonlinear sampling model is adopted to make the predetection adaptive to detect small targets with different area sizes. To simplify the predetection itself and decrease the false alarm probability, neighboring nodes in the sampling grid are used to generate a saliency map, and a short-term memory is adopted to accelerate the `pop-out' of targets. We discuss the fact that the proposed approach is simple enough in computational complexity. In addition, even in a cluttered background, attention can be led to targets in a satisfying few iterations, which ensures that the detection efficiency will not be decreased due to false alarms. Experimental results are presented to demonstrate the applicability of the approach.
False alarm recognition in hyperspectral gas plume identification
Conger, James L [San Ramon, CA; Lawson, Janice K [Tracy, CA; Aimonetti, William D [Livermore, CA
2011-03-29
According to one embodiment, a method for analyzing hyperspectral data includes collecting first hyperspectral data of a scene using a hyperspectral imager during a no-gas period and analyzing the first hyperspectral data using one or more gas plume detection logics. The gas plume detection logic is executed using a low detection threshold, and detects each occurrence of an observed hyperspectral signature. The method also includes generating a histogram for all occurrences of each observed hyperspectral signature which is detected using the gas plume detection logic, and determining a probability of false alarm (PFA) for all occurrences of each observed hyperspectral signature based on the histogram. Possibly at some other time, the method includes collecting second hyperspectral data, and analyzing the second hyperspectral data using the one or more gas plume detection logics and the PFA to determine if any gas is present. Other systems and methods are also included.
Space debris detection in optical image sequences.
Xi, Jiangbo; Wen, Desheng; Ersoy, Okan K; Yi, Hongwei; Yao, Dalei; Song, Zongxi; Xi, Shaobo
2016-10-01
We present a high-accuracy, low false-alarm rate, and low computational-cost methodology for removing stars and noise and detecting space debris with low signal-to-noise ratio (SNR) in optical image sequences. First, time-index filtering and bright star intensity enhancement are implemented to remove stars and noise effectively. Then, a multistage quasi-hypothesis-testing method is proposed to detect the pieces of space debris with continuous and discontinuous trajectories. For this purpose, a time-index image is defined and generated. Experimental results show that the proposed method can detect space debris effectively without any false alarms. When the SNR is higher than or equal to 1.5, the detection probability can reach 100%, and when the SNR is as low as 1.3, 1.2, and 1, it can still achieve 99%, 97%, and 85% detection probabilities, respectively. Additionally, two large sets of image sequences are tested to show that the proposed method performs stably and effectively.
Entanglement-enhanced Neyman-Pearson target detection using quantum illumination
NASA Astrophysics Data System (ADS)
Zhuang, Quntao; Zhang, Zheshen; Shapiro, Jeffrey H.
2017-08-01
Quantum illumination (QI) provides entanglement-based target detection---in an entanglement-breaking environment---whose performance is significantly better than that of optimum classical-illumination target detection. QI's performance advantage was established in a Bayesian setting with the target presumed equally likely to be absent or present and error probability employed as the performance metric. Radar theory, however, eschews that Bayesian approach, preferring the Neyman-Pearson performance criterion to avoid the difficulties of accurately assigning prior probabilities to target absence and presence and appropriate costs to false-alarm and miss errors. We have recently reported an architecture---based on sum-frequency generation (SFG) and feedforward (FF) processing---for minimum error-probability QI target detection with arbitrary prior probabilities for target absence and presence. In this paper, we use our results for FF-SFG reception to determine the receiver operating characteristic---detection probability versus false-alarm probability---for optimum QI target detection under the Neyman-Pearson criterion.
Liu, Chengyu; Zhao, Lina; Tang, Hong; Li, Qiao; Wei, Shoushui; Li, Jianqing
2016-08-01
False alarm (FA) rates as high as 86% have been reported in intensive care unit monitors. High FA rates decrease quality of care by slowing staff response times while increasing patient burdens and stresses. In this study, we proposed a rule-based and multi-channel information fusion method for accurately classifying the true or false alarms for five life-threatening arrhythmias: asystole (ASY), extreme bradycardia (EBR), extreme tachycardia (ETC), ventricular tachycardia (VTA) and ventricular flutter/fibrillation (VFB). The proposed method consisted of five steps: (1) signal pre-processing, (2) feature detection and validation, (3) true/false alarm determination for each channel, (4) 'real-time' true/false alarm determination and (5) 'retrospective' true/false alarm determination (if needed). Up to four signal channels, that is, two electrocardiogram signals, one arterial blood pressure and/or one photoplethysmogram signal were included in the analysis. Two events were set for the method validation: event 1 for 'real-time' and event 2 for 'retrospective' alarm classification. The results showed that 100% true positive ratio (i.e. sensitivity) on the training set were obtained for ASY, EBR, ETC and VFB types, and 94% for VTA type, accompanied by the corresponding true negative ratio (i.e. specificity) results of 93%, 81%, 78%, 85% and 50% respectively, resulting in the score values of 96.50, 90.70, 88.89, 92.31 and 64.90, as well as with a final score of 80.57 for event 1 and 79.12 for event 2. For the test set, the proposed method obtained the score of 88.73 for ASY, 77.78 for EBR, 89.92 for ETC, 67.74 for VFB and 61.04 for VTA types, with the final score of 71.68 for event 1 and 75.91 for event 2.
Shadow Probability of Detection and False Alarm for Median-Filtered SAR Imagery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Raynal, Ann Marie; Doerry, Armin Walter; Miller, John A.
2014-06-01
Median filtering reduces speckle in synthetic aperture radar (SAR) imagery while preserving edges, at the expense of coarsening the resolution, by replacing the center pixel of a sliding window by the median value. For shadow detection, this approach helps distinguish shadows from clutter more easily, while preserving shadow shape delineations. However, the nonlinear operation alters the shadow and clutter distributions and statistics, which must be taken into consideration when computing probability of detection and false alarm metrics. Depending on system parameters, median filtering can improve probability of detection and false alarm by orders of magnitude. Herein, we examine shadow probabilitymore » of detection and false alarm in a homogeneous, ideal clutter background after median filter post-processing. Some comments on multi-look processing effects with and without median filtering are also made.« less
The Strategic Nature of False Recognition in the DRM Paradigm
ERIC Educational Resources Information Center
Miller, Michael B.; Guerin, Scott A.; Wolford, George L.
2011-01-01
The false memory effect produced by the Deese/Roediger & McDermott (DRM) paradigm is reportedly impervious to warnings to avoid false alarming to the critical lures (D. A. Gallo, H. L. Roediger III, & K. B. McDermott, 2001). This finding has been used as strong evidence against models that attribute the false alarms to a decision…
Kobayashi, Leo; Gosbee, John W; Merck, Derek L
2017-07-01
(1) To develop a clinical microsystem simulation methodology for alarm fatigue research with a human factors engineering (HFE) assessment framework and (2) to explore its application to the comparative examination of different approaches to patient monitoring and provider notification. Problems with the design, implementation, and real-world use of patient monitoring systems result in alarm fatigue. A multidisciplinary team is developing an open-source tool kit to promote bedside informatics research and mitigate alarm fatigue. Simulation, HFE, and computer science experts created a novel simulation methodology to study alarm fatigue. Featuring multiple interconnected simulated patient scenarios with scripted timeline, "distractor" patient care tasks, and triggered true and false alarms, the methodology incorporated objective metrics to assess provider and system performance. Developed materials were implemented during institutional review board-approved study sessions that assessed and compared an experimental multiparametric alerting system with a standard monitor telemetry system for subject response, use characteristics, and end-user feedback. A four-patient simulation setup featuring objective metrics for participant task-related performance and response to alarms was developed along with accompanying structured HFE assessment (questionnaire and interview) for monitor systems use testing. Two pilot and four study sessions with individual nurse subjects elicited true alarm and false alarm responses (including diversion from assigned tasks) as well as nonresponses to true alarms. In-simulation observation and subject questionnaires were used to test the experimental system's approach to suppressing false alarms and alerting providers. A novel investigative methodology applied simulation and HFE techniques to replicate and study alarm fatigue in controlled settings for systems assessment and experimental research purposes.
Data Filtering of Western Hemisphere GOES Wildfire ABBA Products
NASA Astrophysics Data System (ADS)
Theisen, M.; Prins, E.; Schmidt, C.; Reid, J. S.; Hunter, J.; Westphal, D.
2002-05-01
The Fire Locating and Modeling of Burning Emissions (FLAMBE') project was developed to model biomass burning emissions, transport, and radiative effects in real time. The model relies on data from the Geostationary Operational Environment Satellites (GOES-8, GOES-10), that is generated by the Wildfire Automated Biomass Burning Algorithm (WF ABBA). In an attempt to develop the most accurate modeling system the data set needs to be filtered to distinguish the true fire pixels from false alarms. False alarms occur due to reflection of solar radiation off of standing water, surface structure variances, and heat anomalies. The Reoccurring Fire Filtering algorithm (ReFF) was developed to address such false alarms by filtering data dependent on reoccurrence, location in relation to region and satellite, as well as heat intensity. WF ABBA data for the year 2000 during the peak of the burning season were analyzed using ReFF. The analysis resulted in a 45% decrease in North America and only a 15% decrease in South America, respectively, in total fire pixel occurrence. The lower percentage decrease in South America is a result of fires burning for longer periods of time, less surface variance, as well as an increase in heat intensity of fires for that region. Also fires are so prevalent in the region that multiple fires may coexist in the same 4-kilometer pixel.
46 CFR 78.47-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM...
Chelliah, Pandian; Murgesan, Kasinathan; Samvel, Sosamma; Chelamchala, Babu Rao; Tammana, Jayakumar; Nagarajan, Murali; Raj, Baldev
2010-07-10
Optical-fiber-based sensors have inherent advantages, such as immunity to electromagnetic interference, compared to the conventional sensors. Distributed optical fiber sensor (DOFS) systems, such as Raman and Brillouin distributed temperature sensors are used for leak detection. The inherent noise of fiber-based systems leads to occasional false alarms. In this paper, a methodology is proposed to overcome this. This uses a looped back fiber mode in DOFS and voting logic is employed to considerably reduce the false alarm rate.
Multi-level scanning method for defect inspection
Bokor, Jeffrey; Jeong, Seongtae
2002-01-01
A method for performing scanned defect inspection of a collection of contiguous areas using a specified false-alarm-rate and capture-rate within an inspection system that has characteristic seek times between inspection locations. The multi-stage method involves setting an increased false-alarm-rate for a first stage of scanning, wherein subsequent stages of scanning inspect only the detected areas of probable defects at lowered values for the false-alarm-rate. For scanning inspection operations wherein the seek time and area uncertainty is favorable, the method can substantially increase inspection throughput.
Tarriela, Albert Fajardo; Gomez, Tiffany Michelle; Reed, Charles Calhoun; Rapp, Kami Marie
2015-01-01
Background Intensive care units (ICUs) are complex work environments where false alarms occur more frequently than on non-critical care units. The Joint Commission National Patient Safety Goal .06.01.01 targeted improving the safety of clinical alarm systems and required health care facilities to establish alarm systems safety as a hospital priority by July 2014. An important initial step toward this requirement is identifying ICU nurses’ perceptions and common clinical practices toward clinical alarms, where little information is available. Objective Our aim was to determine perceptions and practices of transplant/cardiac ICU (TCICU) nurses toward clinical alarms and benchmark the results against the 2011 Healthcare Technology Foundation’s (HTF) Clinical Alarms Committee Survey. Methods A quality improvement project was conducted on a 20-bed TCICU with 39 full- and part-time nurses. Nurses were surveyed about their perceptions and attitudes toward and practices on clinical alarms using an adapted HTF clinical alarms survey. Results were compared to the 2011 HTF data. Correlations among variables were examined. Results All TCICU nurses provided usable responses (N=39, 100%). Almost all nurses (95%-98%) believed that false alarms are frequent, disrupt care, and reduce trust in alarm systems, causing nurses to inappropriately disable them. Unlike the 2011 HTF clinical alarms survey results, a significantly higher percentage of our TCICU nurses believed that existing devices are complex, questioned the ability and adequacy of the new monitoring systems to solve alarm management issues, pointed to the lack of prompt response to alarms, and indicated the lack of clinical policy on alarm management (P<.01). Major themes in the narrative data focused on nurses’ frustration related to the excessive number of alarms and poor usability of the cardiac monitors. A lack of standardized approaches exists in changing patients’ electrodes and individualizing parameters. Around 60% of nurses indicated they received insufficient training on bedside and central cardiac monitors. A correlation also showed the need for training on cardiac monitors, specifically for older nurses (P=.01). Conclusions False and non-actionable alarms continue to desensitize TCICU nurses, perhaps resulting in missing fatal alarms. Nurses’ attitudes and practices related to clinical alarms are key elements for designing contextually sensitive quality initiatives to fight alarm fatigue. Alarm management in ICUs is a multidimensional complex process involving usability of monitoring devices, and unit, clinicians, training, and policy-related factors. This indicates the need for a multi-method approach to decrease alarm fatigue and improve alarm systems safety. PMID:27025940
Mass detection with digitized screening mammograms by using Gabor features
NASA Astrophysics Data System (ADS)
Zheng, Yufeng; Agyepong, Kwabena
2007-03-01
Breast cancer is the leading cancer among American women. The current lifetime risk of developing breast cancer is 13.4% (one in seven). Mammography is the most effective technology presently available for breast cancer screening. With digital mammograms computer-aided detection (CAD) has proven to be a useful tool for radiologists. In this paper, we focus on mass detection that is a common category of breast cancers relative to calcification and architecture distortion. We propose a new mass detection algorithm utilizing Gabor filters, termed as "Gabor Mass Detection" (GMD). There are three steps in the GMD algorithm, (1) preprocessing, (2) generating alarms and (3) classification (reducing false alarms). Down-sampling, quantization, denoising and enhancement are done in the preprocessing step. Then a total of 30 Gabor filtered images (along 6 bands by 5 orientations) are produced. Alarm segments are generated by thresholding four Gabor images of full orientations (Stage-I classification) with image-dependent thresholds computed via histogram analysis. Next a set of edge histogram descriptors (EHD) are extracted from 24 Gabor images (6 by 4) that will be used for Stage-II classification. After clustering EHD features with fuzzy C-means clustering method, a k-nearest neighbor classifier is used to reduce the number of false alarms. We initially analyzed 431 digitized mammograms (159 normal images vs. 272 cancerous images, from the DDSM project, University of South Florida) with the proposed GMD algorithm. And a ten-fold cross validation was used for testing the GMD algorithm upon the available data. The GMD performance is as follows: sensitivity (true positive rate) = 0.88 at false positives per image (FPI) = 1.25, and the area under the ROC curve = 0.83. The overall performance of the GMD algorithm is satisfactory and the accuracy of locating masses (highlighting the boundaries of suspicious areas) is relatively high. Furthermore, the GMD algorithm can successfully detect early-stage (with small values of Assessment & low Subtlety) malignant masses. In addition, Gabor filtered images are used in both stages of classifications, which greatly simplifies the GMD algorithm.
47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 5 2014-10-01 2014-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...
47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 5 2013-10-01 2013-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...
47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...
47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 5 2012-10-01 2012-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...
46 CFR 113.27-1 - Engineers' assistance-needed alarm.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Engineers' assistance-needed alarm. 113.27-1 Section 113.27-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engineers' Assistance-Needed Alarm § 113.27-1 Engineers...
46 CFR 113.27-1 - Engineers' assistance-needed alarm.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Engineers' assistance-needed alarm. 113.27-1 Section 113.27-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engineers' Assistance-Needed Alarm § 113.27-1 Engineers...
46 CFR 113.27-1 - Engineers' assistance-needed alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Engineers' assistance-needed alarm. 113.27-1 Section 113.27-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engineers' Assistance-Needed Alarm § 113.27-1 Engineers...
46 CFR 113.27-1 - Engineers' assistance-needed alarm.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Engineers' assistance-needed alarm. 113.27-1 Section 113.27-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engineers' Assistance-Needed Alarm § 113.27-1 Engineers...
46 CFR 113.27-1 - Engineers' assistance-needed alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Engineers' assistance-needed alarm. 113.27-1 Section 113.27-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engineers' Assistance-Needed Alarm § 113.27-1 Engineers...
46 CFR 113.20-1 - Sprinkler alarm system.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Sprinkler alarm system. 113.20-1 Section 113.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND... sprinkler alarm system, including annunciator, power supply, alarm switches, and bells, must meet Subpart 76...
46 CFR 113.20-1 - Sprinkler alarm system.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Sprinkler alarm system. 113.20-1 Section 113.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND... sprinkler alarm system, including annunciator, power supply, alarm switches, and bells, must meet Subpart 76...
46 CFR 113.20-1 - Sprinkler alarm system.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Sprinkler alarm system. 113.20-1 Section 113.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND... sprinkler alarm system, including annunciator, power supply, alarm switches, and bells, must meet Subpart 76...
46 CFR 113.20-1 - Sprinkler alarm system.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Sprinkler alarm system. 113.20-1 Section 113.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND... sprinkler alarm system, including annunciator, power supply, alarm switches, and bells, must meet Subpart 76...
46 CFR 113.20-1 - Sprinkler alarm system.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Sprinkler alarm system. 113.20-1 Section 113.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND... sprinkler alarm system, including annunciator, power supply, alarm switches, and bells, must meet Subpart 76...
24 CFR 3285.703 - Smoke alarms.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Smoke alarms. 3285.703 Section 3285... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.703 Smoke alarms. Smoke alarms must be functionally tested in accordance with applicable requirements of the smoke...
24 CFR 3285.703 - Smoke alarms.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Smoke alarms. 3285.703 Section 3285... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.703 Smoke alarms. Smoke alarms must be functionally tested in accordance with applicable requirements of the smoke...
24 CFR 3285.703 - Smoke alarms.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Smoke alarms. 3285.703 Section 3285... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.703 Smoke alarms. Smoke alarms must be functionally tested in accordance with applicable requirements of the smoke...
24 CFR 3285.703 - Smoke alarms.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Smoke alarms. 3285.703 Section 3285... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.703 Smoke alarms. Smoke alarms must be functionally tested in accordance with applicable requirements of the smoke...
47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 5 2010-10-01 2010-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...
On the independence of compliance and reliance: are automation false alarms worse than misses?
Dixon, Stephen R; Wickens, Christopher D; McCarley, Jason S
2007-08-01
Participants performed a tracking task and system monitoring task while aided by diagnostic automation. The goal of the study was to examine operator compliance and reliance as affected by automation failures and to clarify claims regarding independence of these two constructs. Background data revealed a trend toward nonindependence of the compliance-reliance constructs. Thirty-two undergraduate students performed the simulation that presented the visual display while dependent measures were collected. False alarm-prone automation hurt overall performance more than miss-prone automation. False alarm-prone automation also clearly affected both operator compliance and reliance, whereas miss-prone automation appeared to affect only operator reliance. Compliance and reliance do not appear to be entirely independent of each other. False alarms appear to be more damaging to overall performance than misses, and designers must take the compliance-reliance constructs into consideration.
NASA Technical Reports Server (NTRS)
Edelson, R. E.
1977-01-01
Some aspects of signal extraction in a microwave search for evidence of extraterrestrial intelligence are examined. Parametric relations are summarized which are applicable to a microwave search of constrained duration that employs FFT spectrum-analyzer receivers, with sensitivity enhancement by spectrum accumulation and detection by a threshold criterion. Three types of natural and man-made false alarms are identified, the probability of false alarm in a single data channel is computed, and the implications of false alarms for a constant-beamwidth sky survey are considered. It is shown that the key to an efficient search is the prompt and unambiguous elimination of false alarms. An experimental protocol is suggested which eliminates spurious signals primarily through procedural techniques involving antenna repointing, delayed repeated observations, and storage of particular historical parameters for suspect signals.
User acceptance of intelligent avionics: A study of automatic-aided target recognition
NASA Technical Reports Server (NTRS)
Becker, Curtis A.; Hayes, Brian C.; Gorman, Patrick C.
1991-01-01
User acceptance of new support systems typically was evaluated after the systems were specified, designed, and built. The current study attempts to assess user acceptance of an Automatic-Aided Target Recognition (ATR) system using an emulation of such a proposed system. The detection accuracy and false alarm level of the ATR system were varied systematically, and subjects rated the tactical value of systems exhibiting different performance levels. Both detection accuracy and false alarm level affected the subjects' ratings. The data from two experiments suggest a cut-off point in ATR performance below which the subjects saw little tactical value in the system. An ATR system seems to have obvious tactical value only if it functions at a correct detection rate of 0.7 or better with a false alarm level of 0.167 false alarms per square degree or fewer.
Effects of amphetamine, morphine, and CP 55, 940 on Go/No-Go task performance in rhesus monkeys.
Koek, Wouter; Gerak, Lisa R; France, Charles P
2015-08-01
In humans, impulsivity measured as false alarms in a Go/No-Go task is reportedly decreased by amphetamine and is not affected by oxycodone and delta(9)-tetrahydrocannabinol. To model these findings in animals, three rhesus monkeys were trained to perform a food-reinforced Go/No-Go task. In this task, amphetamine was found to decrease false alarms (i.e. responding during No-Go trials), but only at doses that also decreased hits (i.e. responding during Go trials). Morphine generally decreased hits but not false alarms. The cannabinoid receptor agonist CP 55, 940 decreased both false alarms and hits, but only at doses that also decreased the number of trials completed. Additional studies in animals and humans are necessary to delineate the conditions under which amphetamine and other psychoactive drugs affect impulsivity in Go/No-Go tasks.
Differences in alarm events between disposable and reusable electrocardiography lead wires.
Albert, Nancy M; Murray, Terri; Bena, James F; Slifcak, Ellen; Roach, Joel D; Spence, Jackie; Burkle, Alicia
2015-01-01
Disposable electrocardiographic lead wires (ECG-LWs) may not be as durable as reusable ones. To examine differences in alarm events between disposable and reusable ECG-LWs. Two cardiac telemetry units were randomized to reusable ECG-LWs, and 2 units alternated between disposable and reusable ECG-LWs for 4 months. A remote monitoring team, blinded to ECG-LW type, assessed frequency and type of alarm events by using total counts and rates per 100 patient days. Event rates were compared by using generalized linear mixed-effect models for differences and noninferiority between wire types. In 1611 patients and 9385.5 patient days of ECG monitoring, patient characteristics were similar between groups. Rates of alarms for no telemetry, leads fail, or leads off were lower in disposable ECG-LWs (adjusted relative risk [95% CI], 0.71 [0.53-0.96]; noninferiority P < .001; superiority P = .03) and monitoring (artifact) alarms were significantly noninferior (adjusted relative risk [95% CI]: 0.88, [0.62-1.24], P = .02; superiority P = .44). No between-group differences existed in false or true crisis alarms. Disposable ECG-LWs were noninferior to reusable ECG-LWs for all false-alarm events (N [rate per 100 patient days], disposable 2029 [79.1] vs reusable 6673 [97.9]; adjusted relative risk [95% CI]: 0.81 [0.63-1.06], P = .002; superiority P = .12.) Disposable ECG-LWs with patented push-button design had superior performance in reducing alarms created by no telemetry, leads fail, or leads off and significant noninferiority in all false-alarm rates compared with reusable ECG-LWs. Fewer ECG alarms may save nurses time, decrease alarm fatigue, and improve patient safety. ©2015 American Association of Critical-Care Nurses.
46 CFR 62.25-20 - Instrumentation, alarms, and centralized stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 2 2012-10-01 2012-10-01 false Instrumentation, alarms, and centralized stations. 62.25... Instrumentation, alarms, and centralized stations. (a) General. Minimum instrumentation and alarms required for specific types of automated vital systems are listed in Table 62.35-50. (b) Instrumentation Location. (1...
46 CFR 62.25-20 - Instrumentation, alarms, and centralized stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 2 2011-10-01 2011-10-01 false Instrumentation, alarms, and centralized stations. 62.25... Instrumentation, alarms, and centralized stations. (a) General. Minimum instrumentation and alarms required for specific types of automated vital systems are listed in Table 62.35-50. (b) Instrumentation Location. (1...
46 CFR 62.25-20 - Instrumentation, alarms, and centralized stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 2 2014-10-01 2014-10-01 false Instrumentation, alarms, and centralized stations. 62.25... Instrumentation, alarms, and centralized stations. (a) General. Minimum instrumentation and alarms required for specific types of automated vital systems are listed in Table 62.35-50. (b) Instrumentation Location. (1...
46 CFR 62.25-20 - Instrumentation, alarms, and centralized stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 2 2013-10-01 2013-10-01 false Instrumentation, alarms, and centralized stations. 62.25... Instrumentation, alarms, and centralized stations. (a) General. Minimum instrumentation and alarms required for specific types of automated vital systems are listed in Table 62.35-50. (b) Instrumentation Location. (1...
24 CFR 3280.208 - Smoke alarm requirements.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Smoke alarm requirements. 3280.208... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Fire Safety § 3280.208 Smoke alarm requirements. (a) Labeling. Each smoke alarm required under paragraph (b) of this section must conform with the...
24 CFR 3280.208 - Smoke alarm requirements.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Smoke alarm requirements. 3280.208... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Fire Safety § 3280.208 Smoke alarm requirements. (a) Labeling. Each smoke alarm required under paragraph (b) of this section must conform with the...
24 CFR 3280.208 - Smoke alarm requirements.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Smoke alarm requirements. 3280.208... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Fire Safety § 3280.208 Smoke alarm requirements. (a) Labeling. Each smoke alarm required under paragraph (b) of this section must conform with the...
24 CFR 3280.208 - Smoke alarm requirements.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Smoke alarm requirements. 3280.208... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Fire Safety § 3280.208 Smoke alarm requirements. Link to an amendment published at 78 FR 73982, Dec. 9, 2013. (a) Labeling. Each smoke alarm...
21 CFR 870.1100 - Blood pressure alarm.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood pressure...
21 CFR 870.1100 - Blood pressure alarm.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood pressure...
21 CFR 870.1100 - Blood pressure alarm.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood pressure...
21 CFR 870.1100 - Blood pressure alarm.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood pressure...
46 CFR 131.815 - Alarm for fixed gaseous fire-extinguishing system.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Alarm for fixed gaseous fire-extinguishing system. 131... VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Alarm for fixed gaseous fire-extinguishing system. Each alarm for a fixed gaseous fire-extinguishing system must be...
46 CFR 131.815 - Alarm for fixed gaseous fire-extinguishing system.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Alarm for fixed gaseous fire-extinguishing system. 131... VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Alarm for fixed gaseous fire-extinguishing system. Each alarm for a fixed gaseous fire-extinguishing system must be...
46 CFR 108.623 - General alarm bell switch.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing. ...
46 CFR 108.623 - General alarm bell switch.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing. ...
46 CFR 108.623 - General alarm bell switch.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing. ...
46 CFR 108.623 - General alarm bell switch.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing. ...
46 CFR 108.623 - General alarm bell switch.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false General alarm bell switch. 108.623 Section 108.623... AND EQUIPMENT Equipment Markings and Instructions § 108.623 General alarm bell switch. Each general alarm bell switch must be marked “GENERAL ALARM” on a plate or other firm noncorrosive backing. ...
46 CFR 130.450 - Machinery alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST... MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms. (a... must provide battery power for the alarm required by § 130.460(a)(8) of this subpart. ...
46 CFR 130.460 - Placement of machinery alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to indicate...
46 CFR 130.460 - Placement of machinery alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to indicate...
46 CFR 130.460 - Placement of machinery alarms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to indicate...
46 CFR 130.450 - Machinery alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST... MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms. (a... must provide battery power for the alarm required by § 130.460(a)(8) of this subpart. ...
46 CFR 130.460 - Placement of machinery alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to indicate...
46 CFR 130.450 - Machinery alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST... MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms. (a... must provide battery power for the alarm required by § 130.460(a)(8) of this subpart. ...
46 CFR 130.450 - Machinery alarms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST... MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms. (a... must provide battery power for the alarm required by § 130.460(a)(8) of this subpart. ...
40 CFR 265.34 - Access to communications or alarm system.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm..., STORAGE, AND DISPOSAL FACILITIES Preparedness and Prevention § 265.34 Access to communications or alarm... involved in the operation must have immediate access to an internal alarm or emergency communication device...
40 CFR 264.34 - Access to communications or alarm system.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Access to communications or alarm... FACILITIES Preparedness and Prevention § 264.34 Access to communications or alarm system. (a) Whenever... operation must have immediate access to an internal alarm or emergency communication device, either directly...
DOE Office of Scientific and Technical Information (OSTI.GOV)
White, Karen S; Kasemir, Kay
2009-01-01
An effective alarm system consists of a mechanism to monitor control points and generate alarm notifications, tools for operators to view, hear, acknowledge and handle alarms and a good configuration. Despite the availability of numerous fully featured tools, accelerator alarm systems continue to be disappointing to operations, frequently to the point of alarms being permanently silenced or totally ignored. This is often due to configurations that produce an excessive number of alarms or fail to communicate the required operator response. Most accelerator controls systems do a good job of monitoring specified points and generating notifications when parameters exceed predefined limits.more » In some cases, improved tools can help, but more often, poor configuration is the root cause of ineffective alarm systems. A SNS, we have invested considerable effort in generating appropriate configurations using a rigorous set of rules based on best practices in the industrial process controls community. This paper will discuss our alarm configuration philosophy and operator response to our new system.« less
Using Bayesian Networks for Candidate Generation in Consistency-based Diagnosis
NASA Technical Reports Server (NTRS)
Narasimhan, Sriram; Mengshoel, Ole
2008-01-01
Consistency-based diagnosis relies heavily on the assumption that discrepancies between model predictions and sensor observations can be detected accurately. When sources of uncertainty like sensor noise and model abstraction exist robust schemes have to be designed to make a binary decision on whether predictions are consistent with observations. This risks the occurrence of false alarms and missed alarms when an erroneous decision is made. Moreover when multiple sensors (with differing sensing properties) are available the degree of match between predictions and observations can be used to guide the search for fault candidates. In this paper we propose a novel approach to handle this problem using Bayesian networks. In the consistency- based diagnosis formulation, automatically generated Bayesian networks are used to encode a probabilistic measure of fit between predictions and observations. A Bayesian network inference algorithm is used to compute most probable fault candidates.
Compensated intruder-detection systems
McNeilly, David R.; Miller, William R.
1984-01-01
Intruder-detection systems in which intruder-induced signals are transmitted through a medium also receive spurious signals induced by changes in a climatic condition affecting the medium. To combat this, signals received from the detection medium are converted to a first signal. The system also provides a reference signal proportional to climate-induced changes in the medium. The first signal and the reference signal are combined for generating therefrom an output signal which is insensitive to the climatic changes in the medium. An alarm is energized if the output signal exceeds a preselected value. In one embodiment, an acoustic cable is coupled to a fence to generate a first electrical signal proportional to movements thereof. False alarms resulting from wind-induced movements of the fence (detection medium) are eliminated by providing an anemometer-driven voltage generator to provide a reference voltage proportional to the velocity of wind incident on the fence. An analog divider receives the first electrical signal and the reference signal as its numerator and denominator inputs, respectively, and generates therefrom an output signal which is insensitive to the wind-induced movements in the fence.
Improved detection and false alarm rejection for chemical vapors using passive hyperspectral imaging
NASA Astrophysics Data System (ADS)
Marinelli, William J.; Miyashiro, Rex; Gittins, Christopher M.; Konno, Daisei; Chang, Shing; Farr, Matt; Perkins, Brad
2013-05-01
Two AIRIS sensors were tested at Dugway Proving Grounds against chemical agent vapor simulants. The primary objectives of the test were to: 1) assess performance of algorithm improvements designed to reduce false alarm rates with a special emphasis on solar effects, and 3) evaluate performance in target detection at 5 km. The tests included 66 total releases comprising alternating 120 kg glacial acetic acid (GAA) and 60 kg triethyl phosphate (TEP) events. The AIRIS sensors had common algorithms, detection thresholds, and sensor parameters. The sensors used the target set defined for the Joint Service Lightweight Chemical Agent Detector (JSLSCAD) with TEP substituted for GA and GAA substituted for VX. They were exercised at two sites located at either 3 km or 5 km from the release point. Data from the tests will be presented showing that: 1) excellent detection capability was obtained at both ranges with significantly shorter alarm times at 5 km, 2) inter-sensor comparison revealed very comparable performance, 3) false alarm rates < 1 incident per 10 hours running time over 143 hours of sensor operations were achieved, 4) algorithm improvements eliminated both solar and cloud false alarms. The algorithms enabling the improved false alarm rejection will be discussed. The sensor technology has recently been extended to address the problem of detection of liquid and solid chemical agents and toxic industrial chemical on surfaces. The phenomenology and applicability of passive infrared hyperspectral imaging to this problem will be discussed and demonstrated.
NASA Astrophysics Data System (ADS)
Czirjak, Daniel
2017-04-01
Remote sensing platforms have consistently demonstrated the ability to detect, and in some cases identify, specific targets of interest, and photovoltaic solar panels are shown to have a unique spectral signature that is consistent across multiple manufacturers and construction methods. Solar panels are proven to be detectable in hyperspectral imagery using common statistical target detection methods such as the adaptive cosine estimator, and false alarms can be mitigated through the use of a spectral verification process that eliminates pixels that do not have the key spectral features of photovoltaic solar panel reflectance spectrum. The normalized solar panel index is described and is a key component in the false-alarm mitigation process. After spectral verification, these solar panel arrays are confirmed on openly available literal imagery and can be measured using numerous open-source algorithms and tools. The measurements allow for the assessment of overall solar power generation capacity using an equation that accounts for solar insolation, the area of solar panels, and the efficiency of the solar panels conversion of solar energy to power. Using a known location with readily available information, the methods outlined in this paper estimate the power generation capabilities within 6% of the rated power.
Abbot, Ted A; Premus, Vincent E; Abbot, Philip A; Mayer, Owen A
2012-09-01
This paper presents recent experimental results and a discussion of system enhancements made to the real-time autonomous humpback whale detector-classifier algorithm first presented by Abbot et al. [J. Acoust. Soc. Am. 127, 2894-2903 (2010)]. In February 2010, a second-generation system was deployed in an experiment conducted off of leeward Kauai during which 26 h of humpback vocalizations were recorded via sonobuoy and processed in real time. These data have been analyzed along with 40 h of humpbacks-absent data collected from the same location during July-August 2009. The extensive whales-absent data set in particular has enabled the quantification of system false alarm rates and the measurement of receiver operating characteristic curves. The performance impact of three enhancements incorporated into the second-generation system are discussed, including (1) a method to eliminate redundancy in the kernel library, (2) increased use of contextual analysis, and (3) the augmentation of the training data with more recent humpback vocalizations. It will be shown that the performance of the real-time system was improved to yield a probability of correct classification of 0.93 and a probability of false alarm of 0.004 over the 66 h of independent test data.
NASA Astrophysics Data System (ADS)
Zhang, Shengfeng; Wu, Zhongliang; Jiang, Changsheng
2017-06-01
The annual consultation on the likelihood of earthquakes in the next year, the `Annual Consultation Meeting', has been one of the most important forward forecast experiments organized by the China Earthquake Administration (CEA) since the 1970s, in which annual alarm regions are identified by an expert panel considering multi-disciplinary `anomalies'. In such annual forecasts, one of the problems in need of further technical solution is its false alarms. To tackle this problem, the concept of `reverse tracing of precursors (RTP)' is used to the annual consultation, as a temporal continuation and spatial extension of the work of Z hao et al. (Pure Appl Geophys 167:783-800, 2010). The central China north-south seismic belt (in connection to the CSEP testing region) is selected as the testing region of such an approach. Applying the concept of RTP, for an annual alarm region delineated by the Annual Consultation Meeting, the distribution of `hotspots' of the pattern informatics (PI), which targets the 5-year-scale seismic hazard, is considered. The `hit', or successful forecast, of the annual seismic hazard is shown to be related to the sufficient coverage of the `hotspots' within the annual alarm region. The ratio of the areas of the `hotspots' over the whole area of the annual alarm region is thus used to identify the false alarms which have few `hotspots'. The results of the years 2004-2012 show that using a threshold of 17 % can reduce 34 % (13 among 38) of the false alarms without losing the successful hit (being 6 in that period).
46 CFR 169.730 - General alarm bell switch.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 7 2012-10-01 2012-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse, clearly...
46 CFR 169.730 - General alarm bell switch.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse, clearly...
46 CFR 169.730 - General alarm bell switch.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse, clearly...
46 CFR 169.730 - General alarm bell switch.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 7 2014-10-01 2014-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse, clearly...
46 CFR 169.730 - General alarm bell switch.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 7 2013-10-01 2013-10-01 false General alarm bell switch. 169.730 Section 169.730... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.730 General alarm bell switch. On vessels of 100 gross tons and over there must be a general alarm bell switch in the pilothouse, clearly...
33 CFR 127.207 - Warning alarms.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Warning alarms. 127.207 Section... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The marine... be located so that the warning alarm is not obstructed for a distance of 1.6 km (1 mile) in all...
33 CFR 127.207 - Warning alarms.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Warning alarms. 127.207 Section... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The marine... be located so that the warning alarm is not obstructed for a distance of 1.6 km (1 mile) in all...
33 CFR 127.207 - Warning alarms.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Warning alarms. 127.207 Section... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The marine... be located so that the warning alarm is not obstructed for a distance of 1.6 km (1 mile) in all...
33 CFR 127.207 - Warning alarms.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Warning alarms. 127.207 Section... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The marine... be located so that the warning alarm is not obstructed for a distance of 1.6 km (1 mile) in all...
33 CFR 127.207 - Warning alarms.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Warning alarms. 127.207 Section... Waterfront Facilities Handling Liquefied Natural Gas Equipment § 127.207 Warning alarms. (a) The marine... be located so that the warning alarm is not obstructed for a distance of 1.6 km (1 mile) in all...
46 CFR 78.47-75 - Ventilation alarm failure.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 3 2013-10-01 2013-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...
46 CFR 78.47-75 - Ventilation alarm failure.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 3 2014-10-01 2014-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...
46 CFR 78.47-75 - Ventilation alarm failure.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 3 2010-10-01 2010-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...
46 CFR 78.47-75 - Ventilation alarm failure.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 3 2012-10-01 2012-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...
46 CFR 78.47-75 - Ventilation alarm failure.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...
Stereotypes influence false memories for imagined events.
Kleider, Heather M; Goldinger, Stephen D; Knuycky, Leslie
2008-02-01
Two experiments tested the influences of vivid imagery and person schemata on eyewitness accuracy. Participants watched an event sequence including actors performing stereotype-consistent and inconsistent actions. Additionally, participants either read descriptions of actions (Experiment 1) or vividly imagined actions (Experiment 2). After either 30 minutes or 2 days, recognition memory, source memory, and remember/know judgements were made. After 2 days, false alarms to imagined events increased, relative to the 30-minute test; those false alarms were more often misattributed to stereotype-consistent actors, relative to the same actions in the reading condition. In addition, the accompanying remember judgements were higher for false alarms to imagined events, relative to read events, regardless of stereotype consistency. Overall the results suggest that, over time, vivid imagery reinforces schema activation, increasing stereotype-consistent false memories.
Use of the Cygnus GlucoWatch biographer at a diabetes camp.
Gandrud, Laura M; Paguntalan, Helen U; Van Wyhe, M Michelle; Kunselman, Betsy L; Leptien, Amy D; Wilson, Darrell M; Eastman, Richard C; Buckingham, Bruce A
2004-01-01
Detection and prevention of nocturnal hypoglycemia is a major medical concern at diabetes camps. We conducted an open-label trial of the Cygnus GlucoWatch biographer to detect nocturnal hypoglycemia in a diabetes camp, a nonclinical environment with multiple activities. Forty-five campers (7-17 years old) wore a biographer. The biographer was placed on the arm at 6:00 PM, with the low alarm set to 85 mg/dL (4.7 mmol/L). Overnight glucose monitoring occurred per usual camp protocol. Counselors were to check and record blood glucose values if the biographer alarmed. Biographers were worn for 154 nights by 45 campers. After a 3-hour warm-up period, 67% of biographers were calibrated, of which 28% were worn the entire night (12 hours). Thirty-four percent of readings were skipped because of: "data errors" (65%), sweat (20%), and temperature change (16%). Reported biographer values correlated with meter glucose values measured 11 to 20 minutes later (r = 0.90). Of 20 low-glucose alarms with corresponding meter values measured within 20 minutes, there were 10 true-positive alarms, 10 false-positive alarms, and no false-negative alarms. Campers reported sleep disruption 32% of the nights, and 74% found the biographer helpful. Campers reported they would wear the biographer 4 to 5 nights each week. Half of the biographer low-glucose alarms that had corresponding blood meter values were true-positive alarms, and the remaining were false-positive alarms. There was close correlation between the biographer and meter glucose values. The majority of campers found the biographer helpful and would use it at home.
Change-based threat detection in urban environments with a forward-looking camera
NASA Astrophysics Data System (ADS)
Morton, Kenneth, Jr.; Ratto, Christopher; Malof, Jordan; Gunter, Michael; Collins, Leslie; Torrione, Peter
2012-06-01
Roadside explosive threats continue to pose a significant risk to soldiers and civilians in conflict areas around the world. These objects are easy to manufacture and procure, but due to their ad hoc nature, they are difficult to reliably detect using standard sensing technologies. Although large roadside explosive hazards may be difficult to conceal in rural environments, urban settings provide a much more complicated background where seemingly innocuous objects (e.g., piles of trash, roadside debris) may be used to obscure threats. Since direct detection of all innocuous objects would flag too many objects to be of use, techniques must be employed to reduce the number of alarms generated and highlight only a limited subset of possibly threatening regions for the user. In this work, change detection techniques are used to reduce false alarm rates and increase detection capabilities for possible threat identification in urban environments. The proposed model leverages data from multiple video streams collected over the same regions by first applying video aligning and then using various distance metrics to detect changes based on image keypoints in the video streams. Data collected at an urban warfare simulation range at an Eastern US test site was used to evaluate the proposed approach, and significant reductions in false alarm rates compared to simpler techniques are illustrated.
Stein, Dan J
2006-01-01
There have been significant advances in our understanding of the anxiety disorders; a range of data is now available on their epidemiology, nosology, psychobiology, and management. An integrative framework is required in order to conceptualize this data and to apply it in the clinic. This is a nonsystematic review of literature on the psychobiology of some the major anxiety disorders, focused on the idea that each of these conditions can be conceptualized in terms of a different "false alarm," mediated by specific neurocircuitry and with a particular evolutionary origin. The "false alarm" concept is able to integrate a range of data on the proximal mechanisms of anxiety disorders (including their mediating neurochemistry and neurogenetics), as well as hypotheses about the distal or evolutionary underpinnings of these conditions. Fortunately, serotonergic antidepressants and cognitive-behavioral psychotherapy appear to be able to normalize the putative "false alarms" in anxiety disorders. A better understanding of the cognitive-affective neuroscience of anxiety disorders will hopefully lead to improved treatments.
46 CFR 108.627 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...
46 CFR 108.627 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...
46 CFR 97.37-9 - Carbon dioxide alarm.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN...
46 CFR 108.627 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 108.627 Section 108.627 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide and clean agent alarms. Each carbon dioxide alarm must be...
46 CFR 154.1330 - Liquid level alarm system: Independent tank type C.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 5 2012-10-01 2012-10-01 false Liquid level alarm system: Independent tank type C. 154..., Construction and Equipment Instrumentation § 154.1330 Liquid level alarm system: Independent tank type C. Independent tanks type C need not have the high liquid level alarm system under § 154.1325 if: (a) The tank...
46 CFR 154.1330 - Liquid level alarm system: Independent tank type C.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Liquid level alarm system: Independent tank type C. 154..., Construction and Equipment Instrumentation § 154.1330 Liquid level alarm system: Independent tank type C. Independent tanks type C need not have the high liquid level alarm system under § 154.1325 if: (a) The tank...
46 CFR 154.1330 - Liquid level alarm system: Independent tank type C.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 5 2013-10-01 2013-10-01 false Liquid level alarm system: Independent tank type C. 154..., Construction and Equipment Instrumentation § 154.1330 Liquid level alarm system: Independent tank type C. Independent tanks type C need not have the high liquid level alarm system under § 154.1325 if: (a) The tank...
46 CFR 154.1330 - Liquid level alarm system: Independent tank type C.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Liquid level alarm system: Independent tank type C. 154..., Construction and Equipment Instrumentation § 154.1330 Liquid level alarm system: Independent tank type C. Independent tanks type C need not have the high liquid level alarm system under § 154.1325 if: (a) The tank...
46 CFR 154.1330 - Liquid level alarm system: Independent tank type C.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 5 2014-10-01 2014-10-01 false Liquid level alarm system: Independent tank type C. 154..., Construction and Equipment Instrumentation § 154.1330 Liquid level alarm system: Independent tank type C. Independent tanks type C need not have the high liquid level alarm system under § 154.1325 if: (a) The tank...
46 CFR 153.409 - High level alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false High level alarms. 153.409 Section 153.409 Shipping... Systems § 153.409 High level alarms. When Table 1 refers to this section or requires a cargo to have a closed gauging system, the cargo's containment system must have a high level alarm: (a) That gives an...
46 CFR 119.530 - Bilge high level alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the following...
Optimal Sensor Location Design for Reliable Fault Detection in Presence of False Alarms
Yang, Fan; Xiao, Deyun; Shah, Sirish L.
2009-01-01
To improve fault detection reliability, sensor location should be designed according to an optimization criterion with constraints imposed by issues of detectability and identifiability. Reliability requires the minimization of undetectability and false alarm probability due to random factors on sensor readings, which is not only related with sensor readings but also affected by fault propagation. This paper introduces the reliability criteria expression based on the missed/false alarm probability of each sensor and system topology or connectivity derived from the directed graph. The algorithm for the optimization problem is presented as a heuristic procedure. Finally, a boiler system is illustrated using the proposed method. PMID:22291524
Glint-induced false alarm reduction in signature adaptive target detection
NASA Astrophysics Data System (ADS)
Crosby, Frank J.
2002-07-01
The signal adaptive target detection algorithm developed by Crosby and Riley uses target geometry to discern anomalies in local backgrounds. Detection is not restricted based on specific target signatures. The robustness of the algorithm is limited by an increased false alarm potential. The base algorithm is extended to eliminate one common source of false alarms in a littoral environment. This common source is glint reflected on the surface of water. The spectral and spatial transience of glint prevent straightforward characterization and complicate exclusion. However, the statistical basis of the detection algorithm and its inherent computations allow for glint discernment and the removal of its influence.
Winters, Bradford D; Cvach, Maria M; Bonafide, Christopher P; Hu, Xiao; Konkani, Avinash; O'Connor, Michael F; Rothschild, Jeffrey M; Selby, Nicholas M; Pelter, Michele M; McLean, Barbara; Kane-Gill, Sandra L
2018-01-01
Alarm fatigue is a widely recognized safety and quality problem where exposure to high rates of clinical alarms results in desensitization leading to dismissal of or slowed response to alarms. Nonactionable alarms are thought to be especially problematic. Despite these concerns, the number of clinical alarm signals has been increasing as an everincreasing number of medical technologies are added to the clinical care environment. PubMed, SCOPUS, Embase, and CINAHL. We performed a systematic review of the literature focused on clinical alarms. We asked a primary key question; "what interventions have been attempted and resulted in the success of reducing alarm fatigue?" and 3-secondary key questions; "what are the negative effects on patients/families; what are the balancing outcomes (unintended consequences of interventions); and what human factor approaches apply to making an effective alarm?" Articles relevant to the Key Questions were selected through an iterative review process and relevant data was extracted using a standardized tool. We found 62 articles that had relevant and usable data for at least one key question. We found that no study used/developed a clear definition of "alarm fatigue." For our primary key question 1, the relevant studies focused on three main areas: quality improvement/bundled activities; intervention comparisons; and analysis of algorithm-based false and total alarm suppression. All sought to reduce the number of total alarms and/or false alarms to improve the positive predictive value. Most studies were successful to varying degrees. None measured alarm fatigue directly. There is no agreed upon valid metric(s) for alarm fatigue, and the current methods are mostly indirect. Assuming that reducing the number of alarms and/or improving positive predictive value can reduce alarm fatigue, there are promising avenues to address patient safety and quality problem. Further investment is warranted not only in interventions that may reduce alarm fatigue but also in defining how to best measure it.
Next-Generation Undersea Warfare and Undersea Distributed Networked Systems
2007-01-31
Probability of false alarm R5 Redeployment, refueling, repositioning, replacement, and recovery ROE Rules of engagement RSTA Reconnaissance, surveillance...and decision aids) at a given point, considering mission, tasks, rules of engagement (ROE), objectives, and other appropriate factors. " Manning within...trajectories are important and must occur concurrently; they must, however, be governed by different rule sets.21 II Mission Capability Centric .•UDNS
Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong
2016-01-20
In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector's false alarms.
33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm, must...
33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm, must...
33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm, must...
33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm, must...
33 CFR 149.135 - What should be marked on the cargo transfer system alarm switch?
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false What should be marked on the cargo transfer system alarm switch? 149.135 Section 149.135 Navigation and Navigable Waters COAST GUARD... switch? Each switch for activating an alarm, and each audio or visual device for signaling an alarm, must...
NASA Technical Reports Server (NTRS)
Toth, S.; Gershkoff, I.
1979-01-01
The statistics of emergency locator transmitter (ELT) alarms are presented. The primary sources of data include ELT Incident Logs, Service Difficulty Reports, and Frequency Interference Reports. The number of reported and unreported alarms is discussed, as are seasonal variations, duration of ELT transmissions, and cost of silencing. Origin, causes, and possible strategies for reducing the impact of alarms on the aviation community are considered.
46 CFR 78.47-7 - General alarm bells.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 3 2010-10-01 2010-10-01 false General alarm bells. 78.47-7 Section 78.47-7 Shipping... and Emergency Equipment, Etc. § 78.47-7 General alarm bells. (a) All general alarm bells shall be identified by red lettering at least 1/2 inch high: “GENERAL ALARM—WHEN BELL RINGS GO TO YOUR STATION.” (b...
Christensen, Martin; Dodds, Andrew; Sauer, Josh; Watts, Nigel
2014-08-01
The aim of this survey was to assess registered nurse's perceptions of alarm setting and management in an Australian Regional Critical Care Unit. The setting and management of alarms within the critical care environment is one of the key responsibilities of the nurse in this area. However, with up to 99% of alarms potentially being false-positives it is easy for the nurse to become desensitised or fatigued by incessant alarms; in some cases up to 400 per patient per day. Inadvertently ignoring, silencing or disabling alarms can have deleterious implications for the patient and nurse. A total population sample of 48 nursing staff from a 13 bedded ICU/HDU/CCU within regional Australia were asked to participate. A 10 item open-ended and multiple choice questionnaire was distributed to determine their perceptions and attitudes of alarm setting and management within this clinical area. Two key themes were identified from the open-ended questions: attitudes towards inappropriate alarm settings and annoyance at delayed responses to alarms. A significant number of respondents (93%) agreed that alarm fatigue can result in alarm desensitisation and the disabling of alarms, whilst 81% suggested the key factors are those associated with false-positive alarms and inappropriately set alarms. This study contributes to what is known about alarm fatigue, setting and management within a critical care environment. In addition it gives an insight as to what nurses' within a regional context consider the key factors which contribute to alarm fatigue. Clearly nursing burnout and potential patient harm are important considerations for practice especially when confronted with alarm fatigue and desensitisation. Therefore, promoting and maintaining an environment of ongoing intra-professional communication and alarm surveillance are crucial in alleviating these potential problems. Copyright © 2014. Published by Elsevier Ltd.
What can be done to reduce false alarms?
Baillie, Jonathan
2013-05-01
Although (the Department for Communities and Local Government's 'Fire statistics' reveal) the number of such incidents has fallen every year since 2006/07, UK fire and rescue services still attended over 312,400 'false fire alarms,' i.e. instances where, on arriving at a site, they found no fire, in 2011/12. Such incidents have been a significant concern for healthcare facilities teams, and for the fire and rescue services serving them, for many years, and, although the past decade has seen determined efforts to substantially reduce the number bearing fruit, many believe far too many still occur. HEJ editor, Jonathan Baillie, reports on a recent London roundtable discussion staged by two leading fire detection and alarm equipment specialists, Apollo Fire Detectors, and Static Systems Group, with IHEEM, which brought together experts to discuss what more can be done to minimise false fire alarms.
46 CFR 130.450 - Machinery alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms. (a...
Real-time automatic inspection under adverse conditions
NASA Astrophysics Data System (ADS)
Carvalho, Fernando D.; Correia, Fernando C.; Freitas, Jose C. A.; Rodrigues, Fernando C.
1991-03-01
This paper presents the results of a R&D Program supported by a grant from the Ministry of Defense, devoted to the development of an inteffigent camera for surveillance in the open air. The effects of shadows, clouds and winds were problems to be solved without generating false alarm events. The system is based on a video CCD camera which generates a video CCIR signal. The signal is then processed in modular hardware which detects the changes in the scene and processes the image, in order to enhance the intruder image and path. Windows may be defined over the image in order to increase the information obtained about the intruder and a first approach to the classification of the type of intruder may be achieved. The paper describes the hardware used in the system, as well as the software, used for the installation of the camera and the software developed for the microprocessor which is responsible for the generation of the alarm signals. The paper also presents some results of surveillance tasks in the open air executed by the system with real time performance.
Hanczakowski, Maciej; Mazzoni, Giuliana
2011-04-01
A reduction in false alarms to critical lures is observed in the DRM paradigm (Roediger & McDermott, 1995) when distinctive information is presented at encoding. Two mechanisms have been proposed to account for this reduction. According to the monitoring theory (e.g., the distinctiveness heuristic), lack of diagnostic recollection serves as a basis for discarding non-presented lures. According to the encoding theory, presenting distinctive information at study leads to impoverished relational processing, which results in a reduction in memorial information elicited by critical lures. In the present study a condition was created in which the use of the distinctiveness heuristic was precluded by associating, within the same study, lures with distinctive information in a context different from the study session. Under that condition reduction in false alarms to distinctive critical lures was still observed. This result supports the predictions of the encoding theory. However, when in the same study the use of the distinctiveness heuristic was not precluded, reductions in false alarms to unrelated lures were also observed when distinctive information was presented at study, indicating that both mechanisms are likely to contribute to the rejection of false memories.
Long-term monitoring of cardiorespiratory patterns in drug-resistant epilepsy.
Goldenholz, Daniel M; Kuhn, Amanda; Austermuehle, Alison; Bachler, Martin; Mayer, Christopher; Wassertheurer, Siegfried; Inati, Sara K; Theodore, William H
2017-01-01
Sudden unexplained death in epilepsy (SUDEP) during inpatient electroencephalography (EEG) monitoring has been a rare but potentially preventable event, with associated cardiopulmonary markers. To date, no systematic evaluation of alarm settings for a continuous pulse oximeter (SpO 2 ) has been performed. In addition, evaluation of the interrelationship between the ictal and interictal states for cardiopulmonary measures has not been reported. Patients with epilepsy were monitored using video-EEG, SpO 2 , and electrocardiography (ECG). Alarm thresholds were tested systematically, balancing the number of false alarms with true seizure detections. Additional cardiopulmonary patterns were explored using automated ECG analysis software. One hundred ninety-three seizures (32 generalized) were evaluated from 45 patients (7,104 h recorded). Alarm thresholds of 80-86% SpO 2 detected 63-73% of all generalized convulsions and 20-28% of all focal seizures (81-94% of generalized and 25-36% of focal seizures when considering only evaluable data). These same thresholds resulted in 25-146 min between false alarms. The sequential probability of ictal SpO 2 revealed a potential common seizure termination pathway of desaturation. A statistical model of corrected QT intervals (QTc), heart rate (HR), and SpO 2 revealed close cardiopulmonary coupling ictally. Joint probability maps of QTc and SpO 2 demonstrated that many patients had baseline dysfunction in either cardiac, pulmonary, or both domains, and that ictally there was dissociation-some patients exhibited further dysfunction in one or both domains. Optimal selection of continuous pulse oximetry thresholds involves a tradeoff between seizure detection accuracy and false alarm frequency. Alarming at 86% for patients that tend to have fewer false alarms and at 80% for those who have more, would likely result in a reasonable tradeoff. The cardiopulmonary findings may lead to SUDEP biomarkers and early seizure termination therapies. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.
21 CFR 876.2040 - Enuresis alarm.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Enuresis alarm. 876.2040 Section 876.2040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Monitoring Devices § 876.2040 Enuresis alarm. (a) Identification. An enuresis...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Alarms. 193.15-30 Section 193.15-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon..., and the alarm shall depend on no source of power other than the carbon dioxide. ...
33 CFR 127.1207 - Warning alarms.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Warning alarms. 127.1207 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1207 Warning alarms. (a) Each marine... the local COTP additional or alternative warning devices that provide an equivalent level of safety...
33 CFR 127.1207 - Warning alarms.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Warning alarms. 127.1207 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1207 Warning alarms. (a) Each marine... the local COTP additional or alternative warning devices that provide an equivalent level of safety...
33 CFR 127.1207 - Warning alarms.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Warning alarms. 127.1207 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1207 Warning alarms. (a) Each marine... the local COTP additional or alternative warning devices that provide an equivalent level of safety...
33 CFR 127.1207 - Warning alarms.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Warning alarms. 127.1207 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1207 Warning alarms. (a) Each marine... the local COTP additional or alternative warning devices that provide an equivalent level of safety...
33 CFR 127.1207 - Warning alarms.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Warning alarms. 127.1207 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Equipment § 127.1207 Warning alarms. (a) Each marine... the local COTP additional or alternative warning devices that provide an equivalent level of safety...
21 CFR 870.1100 - Blood pressure alarm.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood pressure alarm. 870.1100 Section 870.1100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm...
False CAM alarms from radon fluctuations.
Hayes, Robert
2003-11-01
The root cause of many false continuous air monitor (CAM) alarms is revealed for CAMs that use constant spectral shape assumptions in transuranic (TRU) alpha activity determination algorithms. This paper shows that when atmospheric radon levels continually decrease and bottom out at a minimum level, reduced false TRU count rates are not only expected but measured. Similarly, when the radon levels continually increase to a maximum level, elevated false TRU count rates were measured as predicted. The basis for expecting this dependence on changes in radon levels is discussed.
NASA Astrophysics Data System (ADS)
Partsinevelos, Panagiotis; Kallimani, Christina; Tripolitsiotis, Achilleas
2015-06-01
Rockfall incidents affect civil security and hamper the sustainable growth of hard to access mountainous areas due to casualties, injuries and infrastructure loss. Rockfall occurrences cannot be easily prevented, whereas previous studies for rockfall multiple sensor early detection systems have focused on large scale incidents. However, even a single rock may cause the loss of a human life along transportation routes thus, it is highly important to establish methods for the early detection of small-scale rockfall incidents. Terrestrial photogrammetric techniques are prone to a series of errors leading to false alarm incidents, including vegetation, wind, and non relevant change in the scene under consideration. In this study, photogrammetric monitoring of rockfall prone slopes is established and the resulting multi-temporal change imagery is processed in order to minimize false alarm incidents. Integration of remote sensing imagery analysis techniques is hereby applied to enhance early detection of a rockfall. Experimental data demonstrated that an operational system able to identify a 10-cm rock movement within a 10% false alarm rate is technically feasible.
Comparison of human and algorithmic target detection in passive infrared imagery
NASA Astrophysics Data System (ADS)
Weber, Bruce A.; Hutchinson, Meredith
2003-09-01
We have designed an experiment that compares the performance of human observers and a scale-insensitive target detection algorithm that uses pixel level information for the detection of ground targets in passive infrared imagery. The test database contains targets near clutter whose detectability ranged from easy to very difficult. Results indicate that human observers detect more "easy-to-detect" targets, and with far fewer false alarms, than the algorithm. For "difficult-to-detect" targets, human and algorithm detection rates are considerably degraded, and algorithm false alarms excessive. Analysis of detections as a function of observer confidence shows that algorithm confidence attribution does not correspond to human attribution, and does not adequately correlate with correct detections. The best target detection score for any human observer was 84%, as compared to 55% for the algorithm for the same false alarm rate. At 81%, the maximum detection score for the algorithm, the same human observer had 6 false alarms per frame as compared to 29 for the algorithm. Detector ROC curves and observer-confidence analysis benchmarks the algorithm and provides insights into algorithm deficiencies and possible paths to improvement.
Sensor Anomaly Detection in Wireless Sensor Networks for Healthcare
Haque, Shah Ahsanul; Rahman, Mustafizur; Aziz, Syed Mahfuzul
2015-01-01
Wireless Sensor Networks (WSN) are vulnerable to various sensor faults and faulty measurements. This vulnerability hinders efficient and timely response in various WSN applications, such as healthcare. For example, faulty measurements can create false alarms which may require unnecessary intervention from healthcare personnel. Therefore, an approach to differentiate between real medical conditions and false alarms will improve remote patient monitoring systems and quality of healthcare service afforded by WSN. In this paper, a novel approach is proposed to detect sensor anomaly by analyzing collected physiological data from medical sensors. The objective of this method is to effectively distinguish false alarms from true alarms. It predicts a sensor value from historic values and compares it with the actual sensed value for a particular instance. The difference is compared against a threshold value, which is dynamically adjusted, to ascertain whether the sensor value is anomalous. The proposed approach has been applied to real healthcare datasets and compared with existing approaches. Experimental results demonstrate the effectiveness of the proposed system, providing high Detection Rate (DR) and low False Positive Rate (FPR). PMID:25884786
Biological aerosol background characterization
NASA Astrophysics Data System (ADS)
Blatny, Janet; Fountain, Augustus W., III
2011-05-01
To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.
Chancey, Eric T; Bliss, James P; Yamani, Yusuke; Handley, Holly A H
2017-05-01
This study provides a theoretical link between trust and the compliance-reliance paradigm. We propose that for trust mediation to occur, the operator must be presented with a salient choice, and there must be an element of risk for dependence. Research suggests that false alarms and misses affect dependence via two independent processes, hypothesized as trust in signals and trust in nonsignals. These two trust types manifest in categorically different behaviors: compliance and reliance. Eighty-eight participants completed a primary flight task and a secondary signaling system task. Participants evaluated their trust according to the informational bases of trust: performance, process, and purpose. Participants were in a high- or low-risk group. Signaling systems varied by reliability (90%, 60%) within subjects and error bias (false alarm prone, miss prone) between subjects. False-alarm rate affected compliance but not reliance. Miss rate affected reliance but not compliance. Mediation analyses indicated that trust mediated the relationship between false-alarm rate and compliance. Bayesian mediation analyses favored evidence indicating trust did not mediate miss rate and reliance. Conditional indirect effects indicated that factors of trust mediated the relationship between false-alarm rate and compliance (i.e., purpose) and reliance (i.e., process) but only in the high-risk group. The compliance-reliance paradigm is not the reflection of two types of trust. This research could be used to update training and design recommendations that are based upon the assumption that trust causes operator responses regardless of error bias.
Blankush, Joseph M; Freeman, Robbie; McIlvaine, Joy; Tran, Trung; Nassani, Stephen; Leitman, I Michael
2017-10-01
Modified Early Warning Scores (MEWS) provide real-time vital sign (VS) trending and reduce ICU admissions in post-operative patients. These early warning calculations classically incorporate oxygen saturation, heart rate, respiratory rate, systolic blood pressure, and temperature but have not previously included end-tidal CO2 (EtCO 2 ), more recently identified as an independent predictor of critical illness. These systems may be subject to failure when physiologic data is incorrectly measured, leading to false alarms and increased workload. This study investigates whether the implementation of automated devices that utilize ongoing vital signs monitoring and MEWS calculations, inclusive of a score for end-tidal CO 2 (EtCO 2 ), can be feasibly implemented on the general care hospital floor and effectively identify derangements in a post-operative patient's condition while limiting the amount of false alarms that would serve to increase provider workload. From July to November 2014, post-operative patients meeting the inclusion criteria (BMI > 30 kg/m 2 , history of obstructive sleep apnea, or the use of patient-controlled analgesia (PCA) or epidural narcotics) were monitored using automated devices that record minute-by-minute VS included in classic MEWS calculations as well as EtCO 2 . Automated messages via pagers were sent to providers for instances when the device measured elevated MEWS, abnormal EtCO 2 , and oxygen desaturations below 85 %. Data, including alarm and message details from the first 133 patients, were recorded and analyzed. Overall, 3.3 alarms and pages sounded per hour of monitoring. Device-only alarms sounded 2.7 times per hour-21 % were technical alarms. The remaining device-only alarms for concerning VS sounded 2.0/h, 70 % for falsely recorded VS. Pages for abnormal EtCO 2 sounded 0.4/h (82 % false recordings) while pages for low blood oxygen saturation sounded 0.1/h (55 % false alarms). 143 times (0.1 pages/h) the devices calculated a MEWS warranting a page (rise in MEWS by 2 or 5 or greater)-62 % were false scores inclusive of falsely recorded VS. An abnormal EtCO 2 value resulted in or added to an elevated MEWS score in 29 % of notifications, but 50 % of these included a falsely abnormal EtCO 2 value. To date, no adverse events have occurred. There were no statistically significant demographic, post-operative condition, or pre-existing comorbidity differences between patients who had a majority of true alarms from those who had mostly false-positive alarms. Although not statistically significant, the group of patients in whom automated MEWS suggested greater utility included those with a history of hypertension (p = 0.072) and renal disease (p = 0.084). EtCO 2 monitoring was more likely to be useful in patients with a history of type 2 diabetes, coronary artery disease, and obstructive sleep apnea (p < 0.05). These patients were also more likely to have been on a PCA post-operatively (p < 0.05). Overall, non-invasive physiologic monitoring incorporating an automated MEWS system, modified to include end-tidal CO2 can be feasibly implemented in a hospital ward. Further study is needed to evaluate its clinical utility, including an end-tidal CO 2 score, is feasibly implemented and can be useful in monitoring select post-operative patients for derangements in physiologic metrics. Like any other monitoring system, false alarms may occur at high rates. While further study is needed to determine the additive utility of EtCO 2 in MEWS calculations, this study suggests utility of EtCO 2 in select post-operative patients.
46 CFR 111.33-7 - Alarms and shutdowns.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power semiconductor...
46 CFR 111.33-7 - Alarms and shutdowns.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power semiconductor...
46 CFR 111.33-7 - Alarms and shutdowns.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power semiconductor...
46 CFR 111.33-7 - Alarms and shutdowns.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Alarms and shutdowns. 111.33-7 Section 111.33-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Semiconductor Rectifier Systems § 111.33-7 Alarms and shutdowns. Each power semiconductor...
46 CFR 113.43-5 - Power supply.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Power supply. 113.43-5 Section 113.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-5 Power supply. Each steering failure alarm...
46 CFR 113.43-5 - Power supply.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Power supply. 113.43-5 Section 113.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-5 Power supply. Each steering failure alarm...
46 CFR 113.43-5 - Power supply.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Power supply. 113.43-5 Section 113.43-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-5 Power supply. Each steering failure alarm...
46 CFR 113.10-1 - Approved equipment.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Approved equipment. 113.10-1 Section 113.10-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-1 Approved equipment. Each alarm...
46 CFR 113.10-1 - Approved equipment.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Approved equipment. 113.10-1 Section 113.10-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-1 Approved equipment. Each alarm...
46 CFR 113.10-1 - Approved equipment.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Approved equipment. 113.10-1 Section 113.10-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-1 Approved equipment. Each alarm...
46 CFR 113.10-1 - Approved equipment.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Approved equipment. 113.10-1 Section 113.10-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-1 Approved equipment. Each alarm...
46 CFR 113.10-1 - Approved equipment.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Approved equipment. 113.10-1 Section 113.10-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-1 Approved equipment. Each alarm...
46 CFR 193.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 7 2013-10-01 2013-10-01 false Fire detecting, manual alarm, and supervised patrol...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 193.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 193.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 7 2012-10-01 2012-10-01 false Fire detecting, manual alarm, and supervised patrol...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 193.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 193.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 7 2011-10-01 2011-10-01 false Fire detecting, manual alarm, and supervised patrol...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 193.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 193.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 7 2014-10-01 2014-10-01 false Fire detecting, manual alarm, and supervised patrol...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 193.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 95.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Fire detecting, manual alarm, and supervised patrol... AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 95.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 95.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Fire detecting, manual alarm, and supervised patrol... AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 95.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 193.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Fire detecting, manual alarm, and supervised patrol...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 193.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 95.05-1 - Fire detecting, manual alarm, and supervised patrol systems.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Fire detecting, manual alarm, and supervised patrol... AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Fire Detecting and Extinguishing Equipment, Where Required § 95.05-1 Fire detecting, manual alarm, and supervised patrol systems. (a) Fire detecting, manual...
46 CFR 131.805 - General alarm bell, switch.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in the...
46 CFR 131.805 - General alarm bell, switch.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in the...
46 CFR 131.805 - General alarm bell, switch.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in the...
46 CFR 131.805 - General alarm bell, switch.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in the...
46 CFR 131.805 - General alarm bell, switch.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false General alarm bell, switch. 131.805 Section 131.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.805 General alarm bell, switch. The switch in the...
46 CFR 153.438 - Cargo pressure or temperature alarms required.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 5 2013-10-01 2013-10-01 false Cargo pressure or temperature alarms required. 153.438... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a...
46 CFR 153.438 - Cargo pressure or temperature alarms required.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 5 2014-10-01 2014-10-01 false Cargo pressure or temperature alarms required. 153.438... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a...
46 CFR 153.438 - Cargo pressure or temperature alarms required.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo pressure or temperature alarms required. 153.438... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a...
46 CFR 153.438 - Cargo pressure or temperature alarms required.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pressure or temperature alarms required. 153.438... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a...
46 CFR 153.438 - Cargo pressure or temperature alarms required.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo pressure or temperature alarms required. 153.438... CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a...
33 CFR 146.105 - General alarm system.
Code of Federal Regulations, 2010 CFR
2010-07-01
... manned facility must have a general alarm system. When operated, this system shall be audible in all... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false General alarm system. 146.105 Section 146.105 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED...
33 CFR 157.440 - Autopilot alarm or indicator.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Autopilot alarm or indicator. 157.440 Section 157.440 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 157.440 Autopilot alarm or indicator. (a) A tankship owner or operator shall ensure that each...
33 CFR 157.440 - Autopilot alarm or indicator.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Autopilot alarm or indicator. 157.440 Section 157.440 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 157.440 Autopilot alarm or indicator. (a) A tankship owner or operator shall ensure that each...
Assessment of target detection limits in hyperspectral data
NASA Astrophysics Data System (ADS)
Gross, W.; Boehler, J.; Schilling, H.; Middelmann, W.; Weyermann, J.; Wellig, P.; Oechslin, R.; Kneubuehler, M.
2015-10-01
Hyperspectral remote sensing data can be used for civil and military applications to detect and classify target objects that cannot be reliably separated using broadband sensors. The comparably low spatial resolution is compensated by the fact that small targets, even below image resolution, can still be classified. The goal of this paper is to determine the target size to spatial resolution ratio for successful classification of different target and background materials. Airborne hyperspectral data is used to simulate data with known mixture ratios and to estimate the detection threshold for given false alarm rates. The data was collected in July 2014 over Greding, Germany, using airborne aisaEAGLE and aisaHAWK hyperspectral sensors. On the ground, various target materials were placed on natural background. The targets were four quadratic molton patches with an edge length of 7 meters in the colors black, white, grey and green. Also, two different types of polyethylene (camouflage nets) with an edge length of approximately 5.5 meters were deployed. Synthetic data is generated from the original data using spectral mixtures. Target signatures are linearly combined with different background materials in specific ratios. The simulated mixtures are appended to the original data and the target areas are removed for evaluation. Commonly used classification algorithms, e.g. Matched Filtering, Adaptive Cosine Estimator are used to determine the detection limit. Fixed false alarm rates are employed to find and analyze certain regions where false alarms usually occur first. A combination of 18 targets and 12 backgrounds is analyzed for three VNIR and two SWIR data sets of the same area.
Response-related fMRI of veridical and false recognition of words.
Heun, Reinhard; Jessen, Frank; Klose, Uwe; Erb, Michael; Granath, Dirk-Oliver; Grodd, Wolfgang
2004-02-01
Studies on the relation between local cerebral activation and retrieval success usually compared high and low performance conditions, and thus showed performance-related activation of different brain areas. Only a few studies directly compared signal intensities of different response categories during retrieval. During verbal recognition, we recently observed increased parieto-occipital activation related to false alarms. The present study intends to replicate and extend this observation by investigating common and differential activation by veridical and false recognition. Fifteen healthy volunteers performed a verbal recognition paradigm using 160 learned target and 160 new distractor words. The subjects had to indicate whether they had learned the word before or not. Echo-planar MRI of blood-oxygen-level-dependent signal changes was performed during this recognition task. Words were classified post hoc according to the subjects' responses, i.e. hits, false alarms, correct rejections and misses. Response-related fMRI-analysis was used to compare activation associated with the subjects' recognition success, i.e. signal intensities related to the presentation of words were compared by the above-mentioned four response types. During recognition, all word categories showed increased bilateral activation of the inferior frontal gyrus, the inferior temporal gyrus, the occipital lobe and the brainstem in comparison with the control condition. Hits and false alarms activated several areas including the left medial and lateral parieto-occipital cortex in comparison with subjectively unknown items, i.e. correct rejections and misses. Hits showed more pronounced activation in the medial, false alarms in the lateral parts of the left parieto-occipital cortex. Veridical and false recognition show common as well as different areas of cerebral activation in the left parieto-occipital lobe: increased activation of the medial parietal cortex by hits may correspond to true recognition, increased activation of the parieto-occipital cortex by false alarms may correspond to familiarity decisions. Further studies are needed to investigate the reasons for false decisions in healthy subjects and patients with memory problems.
ECG signal quality during arrhythmia and its application to false alarm reduction.
Behar, Joachim; Oster, Julien; Li, Qiao; Clifford, Gari D
2013-06-01
An automated algorithm to assess electrocardiogram (ECG) quality for both normal and abnormal rhythms is presented for false arrhythmia alarm suppression of intensive care unit (ICU) monitors. A particular focus is given to the quality assessment of a wide variety of arrhythmias. Data from three databases were used: the Physionet Challenge 2011 dataset, the MIT-BIH arrhythmia database, and the MIMIC II database. The quality of more than 33 000 single-lead 10 s ECG segments were manually assessed and another 12 000 bad-quality single-lead ECG segments were generated using the Physionet noise stress test database. Signal quality indices (SQIs) were derived from the ECGs segments and used as the inputs to a support vector machine classifier with a Gaussian kernel. This classifier was trained to estimate the quality of an ECG segment. Classification accuracies of up to 99% on the training and test set were obtained for normal sinus rhythm and up to 95% for arrhythmias, although performance varied greatly depending on the type of rhythm. Additionally, the association between 4050 ICU alarms from the MIMIC II database and the signal quality, as evaluated by the classifier, was studied. Results suggest that the SQIs should be rhythm specific and that the classifier should be trained for each rhythm call independently. This would require a substantially increased set of labeled data in order to train an accurate algorithm.
Simulation analysis of a wildfire suppression system
Abílio Pereira Pacheco; João Claro; Tiago Oliveira
2013-01-01
Rekindles and false alarms are unusually high in the Portuguese wildfire management system, representing a high burden on suppression resources in particular, and fire management resources in general. In 20,049 occurrences that the suppression system handled in the summer of 2010, 12.5% were false alarms and 15.0% were rekindles. We present a discreteevent simulation...
Optimal go/no-go ratios to maximize false alarms.
Young, Michael E; Sutherland, Steven C; McCoy, Anthony W
2018-06-01
Despite the ubiquity of go/no-go tasks in the study of behavioral inhibition, there is a lack of evidence regarding the impact of key design characteristics, including the go/no-go ratio, intertrial interval, and number of types of go stimuli, on the production of different response classes of central interest. In the present study we sought to empirically determine the optimal conditions to maximize the production of a rare outcome of considerable interest to researchers: false alarms. As predicted, the shortest intertrial intervals (450 ms), intermediate go/no-go ratios (2:1 to 4:1), and the use of multiple types of go stimuli produced the greatest numbers of false alarms. These results are placed within the context of behavioral changes during learning.
Anomaly metrics to differentiate threat sources from benign sources in primary vehicle screening.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cohen, Israel Dov; Mengesha, Wondwosen
2011-09-01
Discrimination of benign sources from threat sources at Port of Entries (POE) is of a great importance in efficient screening of cargo and vehicles using Radiation Portal Monitors (RPM). Currently RPM's ability to distinguish these radiological sources is seriously hampered by the energy resolution of the deployed RPMs. As naturally occurring radioactive materials (NORM) are ubiquitous in commerce, false alarms are problematic as they require additional resources in secondary inspection in addition to impacts on commerce. To increase the sensitivity of such detection systems without increasing false alarm rates, alarm metrics need to incorporate the ability to distinguish benign andmore » threat sources. Principal component analysis (PCA) and clustering technique were implemented in the present study. Such techniques were investigated for their potential to lower false alarm rates and/or increase sensitivity to weaker threat sources without loss of specificity. Results of the investigation demonstrated improved sensitivity and specificity in discriminating benign sources from threat sources.« less
Justus, Alan L
2015-05-01
This paper presents technically-based techniques to deal with nuisance personnel contamination monitor (PCM) alarms. The techniques derive from the fundamental physical characteristics of radon progeny. Some PCM alarms, although valid alarms and not actually "false," could be due to nuisance naturally-occurring radionuclides (i.e., radon progeny). Based on certain observed characteristics of the radon progeny, several prompt techniques are discussed that could either remediate or at least mitigate the problem of nuisance alarms. Examples are provided which demonstrate the effective use of the techniques.
46 CFR 154.1842 - Cargo system: Controls and alarms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo system: Controls and alarms. 154.1842 Section 154... SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1842 Cargo system: Controls and alarms. The master shall ensure that the cargo emergency shut-down system and the...
46 CFR 154.1842 - Cargo system: Controls and alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo system: Controls and alarms. 154.1842 Section 154... SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Operations § 154.1842 Cargo system: Controls and alarms. The master shall ensure that the cargo emergency shut-down system and the...
46 CFR 154.1325 - Liquid level alarm system: All cargo tanks.
Code of Federal Regulations, 2010 CFR
2010-10-01
... percent liquid full and without causing the pressure in the loading lines to exceed the design pressure... 46 Shipping 5 2010-10-01 2010-10-01 false Liquid level alarm system: All cargo tanks. 154.1325... Equipment Instrumentation § 154.1325 Liquid level alarm system: All cargo tanks. Except as allowed under...
46 CFR 154.1325 - Liquid level alarm system: All cargo tanks.
Code of Federal Regulations, 2013 CFR
2013-10-01
... percent liquid full and without causing the pressure in the loading lines to exceed the design pressure... 46 Shipping 5 2013-10-01 2013-10-01 false Liquid level alarm system: All cargo tanks. 154.1325... Equipment Instrumentation § 154.1325 Liquid level alarm system: All cargo tanks. Except as allowed under...
46 CFR 154.1325 - Liquid level alarm system: All cargo tanks.
Code of Federal Regulations, 2012 CFR
2012-10-01
... percent liquid full and without causing the pressure in the loading lines to exceed the design pressure... 46 Shipping 5 2012-10-01 2012-10-01 false Liquid level alarm system: All cargo tanks. 154.1325... Equipment Instrumentation § 154.1325 Liquid level alarm system: All cargo tanks. Except as allowed under...
46 CFR 154.1325 - Liquid level alarm system: All cargo tanks.
Code of Federal Regulations, 2011 CFR
2011-10-01
... percent liquid full and without causing the pressure in the loading lines to exceed the design pressure... 46 Shipping 5 2011-10-01 2011-10-01 false Liquid level alarm system: All cargo tanks. 154.1325... Equipment Instrumentation § 154.1325 Liquid level alarm system: All cargo tanks. Except as allowed under...
46 CFR 154.1325 - Liquid level alarm system: All cargo tanks.
Code of Federal Regulations, 2014 CFR
2014-10-01
... percent liquid full and without causing the pressure in the loading lines to exceed the design pressure... 46 Shipping 5 2014-10-01 2014-10-01 false Liquid level alarm system: All cargo tanks. 154.1325... Equipment Instrumentation § 154.1325 Liquid level alarm system: All cargo tanks. Except as allowed under...
46 CFR 182.530 - Bilge high level alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 7 2010-10-01 2010-10-01 false Bilge high level alarms. 182.530 Section 182.530... TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a... operating station to indicate a high water level in each of the following normally unmanned spaces: (1) A...
46 CFR 113.25-7 - Power supply overcurrent protection.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Power supply overcurrent protection. 113.25-7 Section... COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-7 Power supply overcurrent protection. (a) If the general emergency alarm system is the only load supplied by the general...
46 CFR 113.25-7 - Power supply overcurrent protection.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Power supply overcurrent protection. 113.25-7 Section... COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-7 Power supply overcurrent protection. (a) If the general emergency alarm system is the only load supplied by the general...
33 CFR 401.17 - Pitch indicators and alarms.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pitch indicators and alarms. 401... indicators and alarms. Every vessel of 1600 gross registered tons or integrated tug and barge or articulated... propeller shall be equipped with— (a) A pitch indicator in the wheelhouse and the engine room; and (b...
33 CFR 401.17 - Pitch indicators and alarms.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pitch indicators and alarms. 401... indicators and alarms. Every vessel of 1600 gross registered tons or integrated tug and barge or articulated... propeller shall be equipped with— (a) A pitch indicator in the wheelhouse and the engine room; and (b...
Investigating the mechanisms of visually-evoked tactile sensations.
McKenzie, Kirsten J; Lloyd, Donna M; Brown, Richard J; Plummer, Faye; Poliakoff, Ellen
2012-01-01
When attempting to detect a near-threshold signal, participants often incorrectly report the presence of a signal, particularly when a stimulus in a different modality is presented. Here we investigated the effect of prior experience of bimodal visuotactile stimuli on the rate of falsely reported touches in the presence of a light. In Experiment 1, participants made more false alarms in light-present than light-absent trials, despite having no experience of the experimental visuotactile pairing. This suggests that light-evoked false alarms are a consequence of an existing association, rather than one learned during the experiment. In Experiment 2, we sought to manipulate the strength of the association through prior training, using supra-threshold tactile stimuli that were given a high or low association with the light. Both groups still exhibited an increased number of false alarms during light-present trials, however, the low association group made significantly fewer false alarms across conditions, and there was no corresponding group difference in the number of tactile stimuli correctly identified. Thus, while training did not affect the boosting of the tactile signal by the visual stimulus, the low association training affected perceptual decision-making more generally, leading to a lower number of illusory touch reports, independent of the light. Copyright © 2011 Elsevier B.V. All rights reserved.
Cognitive mechanisms of false facial recognition in older adults.
Edmonds, Emily C; Glisky, Elizabeth L; Bartlett, James C; Rapcsak, Steven Z
2012-03-01
Older adults show elevated false alarm rates on recognition memory tests involving faces in comparison to younger adults. It has been proposed that this age-related increase in false facial recognition reflects a deficit in recollection and a corresponding increase in the use of familiarity when making memory decisions. To test this hypothesis, we examined the performance of 40 older adults and 40 younger adults on a face recognition memory paradigm involving three different types of lures with varying levels of familiarity. A robust age effect was found, with older adults demonstrating a markedly heightened false alarm rate in comparison to younger adults for "familiarized lures" that were exact repetitions of faces encountered earlier in the experiment, but outside the study list, and therefore required accurate recollection of contextual information to reject. By contrast, there were no age differences in false alarms to "conjunction lures" that recombined parts of study list faces, or to entirely new faces. Overall, the pattern of false recognition errors observed in older adults was consistent with excessive reliance on a familiarity-based response strategy. Specifically, in the absence of recollection older adults appeared to base their memory decisions on item familiarity, as evidenced by a linear increase in false alarm rates with increasing familiarity of the lures. These findings support the notion that automatic memory processes such as familiarity remain invariant with age, while more controlled memory processes such as recollection show age-related decline.
NASA Astrophysics Data System (ADS)
Hanson, Jeffrey A.; McLaughlin, Keith L.; Sereno, Thomas J.
2011-06-01
We have developed a flexible, target-driven, multi-modal, physics-based fusion architecture that efficiently searches sensor detections for targets and rejects clutter while controlling the combinatoric problems that commonly arise in datadriven fusion systems. The informational constraints imposed by long lifetime requirements make systems vulnerable to false alarms. We demonstrate that our data fusion system significantly reduces false alarms while maintaining high sensitivity to threats. In addition, mission goals can vary substantially in terms of targets-of-interest, required characterization, acceptable latency, and false alarm rates. Our fusion architecture provides the flexibility to match these trade-offs with mission requirements unlike many conventional systems that require significant modifications for each new mission. We illustrate our data fusion performance with case studies that span many of the potential mission scenarios including border surveillance, base security, and infrastructure protection. In these studies, we deployed multi-modal sensor nodes - including geophones, magnetometers, accelerometers and PIR sensors - with low-power processing algorithms and low-bandwidth wireless mesh networking to create networks capable of multi-year operation. The results show our data fusion architecture maintains high sensitivities while suppressing most false alarms for a variety of environments and targets.
Myocardial infarction false alarm: initial electrocardiogram and cardiac enzymes.
Gupta, Esha Das; Sakthiswary, Rajalingham
2014-05-01
The objectives of this study were to determine the incidence of a myocardial infarction "false alarm" and evaluate the efficacy of the initial electrocardiogram and cardiac enzymes in diagnosing myocardial infarction in Malaysia. We recruited patients who were admitted with suspected myocardial infarction from June to August 2008. The medical records of these patients were reviewed for the initial electrocardiogram, initial cardiac enzyme levels (creatinine kinase-MB and troponin T), and the final diagnosis upon discharge. The subjects were stratified into 2 groups: true myocardial infarction, and false alarm. 125 patients were enrolled in this study. Following admission and further evaluation, the diagnosis was revised from myocardial infarction to other medical conditions in 48 (38.4%) patients. The sensitivity and specificity of the initial ischemic electrocardiographic changes were 54.5% and 70.8%, respectively. Raised cardiac enzymes had a sensitivity of 44.3% and specificity of 95.8%. A significant proportion of patients in Malaysia are admitted with a false-alarm myocardial infarction. The efficacy of the electrocardiogram in diagnosing myocardial infarction in Malaysia was comparable to the findings of Western studies, but the cardiac enzymes had a much lower sensitivity.
Recent Results on "Approximations to Optimal Alarm Systems for Anomaly Detection"
NASA Technical Reports Server (NTRS)
Martin, Rodney Alexander
2009-01-01
An optimal alarm system and its approximations may use Kalman filtering for univariate linear dynamic systems driven by Gaussian noise to provide a layer of predictive capability. Predicted Kalman filter future process values and a fixed critical threshold can be used to construct a candidate level-crossing event over a predetermined prediction window. An optimal alarm system can be designed to elicit the fewest false alarms for a fixed detection probability in this particular scenario.
46 CFR 28.250 - High water alarms.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...
46 CFR 28.250 - High water alarms.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...
46 CFR 113.25-25 - General emergency alarm systems for manned ocean and coastwise barges.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false General emergency alarm systems for manned ocean and coastwise barges. 113.25-25 Section 113.25-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Systems § 113.25-25 General emergency alarm systems for manned ocean and coastwise barges. A manned ocean...
46 CFR 113.25-25 - General emergency alarm systems for manned ocean and coastwise barges.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false General emergency alarm systems for manned ocean and coastwise barges. 113.25-25 Section 113.25-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Systems § 113.25-25 General emergency alarm systems for manned ocean and coastwise barges. A manned ocean...
46 CFR 113.25-25 - General emergency alarm systems for manned ocean and coastwise barges.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false General emergency alarm systems for manned ocean and coastwise barges. 113.25-25 Section 113.25-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Systems § 113.25-25 General emergency alarm systems for manned ocean and coastwise barges. A manned ocean...
46 CFR 113.25-25 - General emergency alarm systems for manned ocean and coastwise barges.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false General emergency alarm systems for manned ocean and coastwise barges. 113.25-25 Section 113.25-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Systems § 113.25-25 General emergency alarm systems for manned ocean and coastwise barges. A manned ocean...
46 CFR 113.25-25 - General emergency alarm systems for manned ocean and coastwise barges.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false General emergency alarm systems for manned ocean and coastwise barges. 113.25-25 Section 113.25-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Systems § 113.25-25 General emergency alarm systems for manned ocean and coastwise barges. A manned ocean...
46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...
46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...
46 CFR 169.732 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...
46 CFR 169.732 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...
46 CFR 169.732 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 169.732 Section 169.732 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide and clean agent alarms. (a) Each carbon dioxide o...
46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...
46 CFR 131.815 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
46 CFR 131.815 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
46 CFR 131.815 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 131.815 Section 131.815 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.815 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
46 CFR 28.250 - High water alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 1 2014-10-01 2014-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...
46 CFR 28.250 - High water alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 1 2012-10-01 2012-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...
46 CFR 28.250 - High water alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 1 2013-10-01 2013-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...
46 CFR 97.37-50 - Ventilation alarm failure.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation alarm failure. 97.37-50 Section 97.37-50... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-50 Ventilation alarm failure. (a) The...-inch letters “VENTILATION FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15286, Dec. 6...
46 CFR 97.37-50 - Ventilation alarm failure.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation alarm failure. 97.37-50 Section 97.37-50... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-50 Ventilation alarm failure. (a) The...-inch letters “VENTILATION FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15286, Dec. 6...
46 CFR 97.37-50 - Ventilation alarm failure.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation alarm failure. 97.37-50 Section 97.37-50... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-50 Ventilation alarm failure. (a) The...-inch letters “VENTILATION FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15286, Dec. 6...
46 CFR 97.37-50 - Ventilation alarm failure.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation alarm failure. 97.37-50 Section 97.37-50... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-50 Ventilation alarm failure. (a) The...-inch letters “VENTILATION FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15286, Dec. 6...
A new approach to importance sampling for the simulation of false alarms. [in radar systems
NASA Technical Reports Server (NTRS)
Lu, D.; Yao, K.
1987-01-01
In this paper a modified importance sampling technique for improving the convergence of Importance Sampling is given. By using this approach to estimate low false alarm rates in radar simulations, the number of Monte Carlo runs can be reduced significantly. For one-dimensional exponential, Weibull, and Rayleigh distributions, a uniformly minimum variance unbiased estimator is obtained. For Gaussian distribution the estimator in this approach is uniformly better than that of previously known Importance Sampling approach. For a cell averaging system, by combining this technique and group sampling, the reduction of Monte Carlo runs for a reference cell of 20 and false alarm rate of lE-6 is on the order of 170 as compared to the previously known Importance Sampling approach.
2017-12-01
values designating each stimulus as a target ( true ) or nontarget (false). Both stim_time and stim_label should have length equal to the number of...position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an official endorsement or...depend strongly on the true values of hit rate and false-alarm rate. Based on its better estimation of hit rate and false-alarm rate, the regression
Sensor fusion methods for reducing false alarms in heart rate monitoring.
Borges, Gabriel; Brusamarello, Valner
2016-12-01
Automatic patient monitoring is an essential resource in hospitals for good health care management. While alarms caused by abnormal physiological conditions are important for the delivery of fast treatment, they can be also a source of unnecessary noise because of false alarms caused by electromagnetic interference or motion artifacts. One significant source of false alarms is related to heart rate, which is triggered when the heart rhythm of the patient is too fast or too slow. In this work, the fusion of different physiological sensors is explored in order to create a robust heart rate estimation. A set of algorithms using heart rate variability index, Bayesian inference, neural networks, fuzzy logic and majority voting is proposed to fuse the information from the electrocardiogram, arterial blood pressure and photoplethysmogram. Three kinds of information are extracted from each source, namely, heart rate variability, the heart rate difference between sensors and the spectral analysis of low and high noise of each sensor. This information is used as input to the algorithms. Twenty recordings selected from the MIMIC database were used to validate the system. The results showed that neural networks fusion had the best false alarm reduction of 92.5 %, while the Bayesian technique had a reduction of 84.3 %, fuzzy logic 80.6 %, majority voter 72.5 % and the heart rate variability index 67.5 %. Therefore, the proposed algorithms showed good performance and could be useful in bedside monitors.
Detection of Unexploded Ordnance Using Airborne LWIR Emissivity Signatures
2015-11-25
glass and wood, are spectrally distinct and would not appear as false alarms. Index Terms— Hyperspectral, Long Wave Infrared , Emissivity, Target...hyperspectral; radar). Because of previous successes using thermal infrared bands for UXO [3, 4] and landmine detection [5], this paper aims at...potential false alarms. They included materials made of rubber , cardboard, metal, wood, glass and plastic (Figure 1). 2.2. Laboratory LWIR signature
Time Course of Visual Extrapolation Accuracy
1995-09-01
The pond and duckweed problem: Three experiments on the misperception of exponential growth . Acta Psychologica 43, 239-251. Wiener, E.L., 1962...random variation in tracker velocity. Both models predicted changes in hit and false alarm rates well, except in a condition where response asymmetries...systematic velocity error in tracking, only random variation in tracker velocity. Both models predicted changes in hit and false alarm rates well
ERIC Educational Resources Information Center
Rice, Stephen; McCarley, Jason S.
2011-01-01
Automated diagnostic aids prone to false alarms often produce poorer human performance in signal detection tasks than equally reliable miss-prone aids. However, it is not yet clear whether this is attributable to differences in the perceptual salience of the automated aids' misses and false alarms or is the result of inherent differences in…
Experimental Comparison of High Duty Cycle and Pulsed Active Sonars in a Littoral Environment
2014-09-30
A series of metrics (eg. number of detections, matched-filter gain, false alarm rates, track purity, track latency, etc.) will be used to quantify...for QA. These data were used to generate spectrograms, ambient noise and reverberation decay plots, and clutter images, all of which helped...Perhaps the most useful of these for QA were the clutter images which provided a rapid visual assessment to estimate SNR, identify at what range the
33 CFR 149.414 - What are the requirements for a fire detection and alarm system?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the requirements for a fire detection and alarm system? 149.414 Section 149.414 Navigation and Navigable Waters COAST GUARD... national consensus standard, as that term is defined in 29 CFR 1910.2, for fire detection and fire alarm...
46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 1 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...
46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 1 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7... Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or...: “WHEN ALARM SOUNDS VACATE AT ONCE. [CARBON DIOXIDE/CLEAN AGENT—as appropriate] BEING RELEASED.” [USCG...
46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...
46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 3 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 3 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...
46 CFR 97.37-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 97.37-9 Section 97.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent...
46 CFR 78.47-9 - Carbon dioxide and clean agent alarms.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 3 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 78.47-9 Section 78.47-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide and clean agent alarms. Each carbon dioxide or clean agent fire...
An improved PCA method with application to boiler leak detection.
Sun, Xi; Marquez, Horacio J; Chen, Tongwen; Riaz, Muhammad
2005-07-01
Principal component analysis (PCA) is a popular fault detection technique. It has been widely used in process industries, especially in the chemical industry. In industrial applications, achieving a sensitive system capable of detecting incipient faults, which maintains the false alarm rate to a minimum, is a crucial issue. Although a lot of research has been focused on these issues for PCA-based fault detection and diagnosis methods, sensitivity of the fault detection scheme versus false alarm rate continues to be an important issue. In this paper, an improved PCA method is proposed to address this problem. In this method, a new data preprocessing scheme and a new fault detection scheme designed for Hotelling's T2 as well as the squared prediction error are developed. A dynamic PCA model is also developed for boiler leak detection. This new method is applied to boiler water/steam leak detection with real data from Syncrude Canada's utility plant in Fort McMurray, Canada. Our results demonstrate that the proposed method can effectively reduce false alarm rate, provide effective and correct leak alarms, and give early warning to operators.
Online anomaly detection in wireless body area networks for reliable healthcare monitoring.
Salem, Osman; Liu, Yaning; Mehaoua, Ahmed; Boutaba, Raouf
2014-09-01
In this paper, we propose a lightweight approach for online detection of faulty measurements by analyzing the data collected from medical wireless body area networks. The proposed framework performs sequential data analysis using a smart phone as a base station, and takes into account the constrained resources of the smart phone, such as processing power and storage capacity. The main objective is to raise alarms only when patients enter in an emergency situation, and to discard false alarms triggered by faulty measurements or ill-behaved sensors. The proposed approach is based on the Haar wavelet decomposition, nonseasonal Holt-Winters forecasting, and the Hampel filter for spatial analysis, and on for temporal analysis. Our objective is to reduce false alarms resulting from unreliable measurements and to reduce unnecessary healthcare intervention. We apply our proposed approach on real physiological dataset. Our experimental results prove the effectiveness of our approach in achieving good detection accuracy with a low false alarm rate. The simplicity and the processing speed of our proposed framework make it useful and efficient for real time diagnosis.
Forrin, Noah D; Groot, Brianna; MacLeod, Colin M
2016-07-01
It can be difficult to judge the effectiveness of encoding techniques in a within-subject design. Consider the production effect-the finding that words read aloud are better remembered than words read silently. In the absence of a baseline, a within-subject production effect in a mixed study list could reflect a benefit of reading aloud, a cost of reading silently, or both. To help interpret within-subject data, memory researchers have compared within-subject and between-subjects designs, with the between-subjects (i.e., pure list) conditions serving as baselines against which the within-subject (i.e., mixed-list) conditions are compared. In the present article, the authors highlight a shortcoming of using this comparison to assess costs and benefits in recognition. Unlike between-subjects experiments where separate false alarm rates are obtained for each condition, the typical within-subject experiment yields a collapsed false alarm rate, which, the authors argue, can potentially bias calculations of memory discrimination (d'). Across 3 experiments that used production as the encoding manipulation, they used a typical mixed-list versus pure-list design (Experiment 1) and then made modifications to this design (Experiments 2 and 3) that yielded separate mixed-list false alarm rates. The results of the latter 2 experiments demonstrated that words that are read aloud in a mixed list have an overall memorial benefit over words that are read aloud in a pure list-both in terms of increased hits and reduced false alarms. The authors frame these results in terms of the distinctiveness heuristic. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
McGarraugh, Geoffrey
2010-01-01
Continuous glucose monitoring (CGM) devices available in the United States are approved for use as adjuncts to self-monitoring of blood glucose (SMBG); all CGM alarms require SMBG confirmation before treatment. In this report, an analysis method is proposed to determine the CGM threshold alarm accuracy required to eliminate SMBG confirmation. The proposed method builds on the Clinical and Laboratory Standards Institute (CLSI) guideline for evaluating CGM threshold alarms using data from an in-clinic study of subjects with type 1 diabetes. The CLSI method proposes a maximum time limit of +/-30 minutes for the detection of hypo- and hyperglycemic events but does not include limits for glucose measurement accuracy. The International Standards Organization (ISO) standard for SMBG glucose measurement accuracy (ISO 15197) is +/-15 mg/dl for glucose <75 mg/dl and +/-20% for glucose > or = 75 mg/dl. This standard was combined with the CLSI method to more completely characterize the accuracy of CGM alarms. Incorporating the ISO 15197 accuracy margins, FreeStyle Navigator CGM system alarms detected 70 mg/dl hypoglycemia within 30 minutes at a rate of 70.3%, with a false alarm rate of 11.4%. The device detected high glucose in the range of 140-300 mg/dl within 30 minutes at an average rate of 99.2%, with a false alarm rate of 2.1%. Self-monitoring of blood glucose confirmation is necessary for detecting and treating hypoglycemia with the FreeStyle Navigator CGM system, but at high glucose levels, SMBG confirmation adds little incremental value to CGM alarms. 2010 Diabetes Technology Society.
Joshi, Rohan; Straaten, Henrica van; Mortel, Heidi van de; Long, Xi; Andriessen, Peter; Pul, Carola van
2018-06-30
To determine differences in alarm pressure between two otherwise comparable neonatal intensive care units (NICUs) differing in architectural layout-one of a single-family room (SFR) design and the other of an open bay area (OBA) design. Retrospective audit of more than 2000 patient days from each NICU cataloguing the differences in the number and duration of alarms for critical and alerting alarms, as well as the interaction of clinicians with the patient monitor. Two level 3 NICUs. A total of more than 150 000 critical and 1.2 million alerting alarms were acquired from the two NICUs. The number of audible alarms and the associated noise pollution varied considerably with the OBA NICU generating 44% more alarms per infant per day even though the SFR NICU generated 2.5 as many critical desaturation alarms per infant per day. Differences in the architectural layout of NICUs and the consequent differences in delays, thresholds and distribution systems for alarms are associated with differences in alarm pressure. © Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
2009-09-01
Forecasts ECS East China Sea ESRL Earth Systems Research Laboratory FA False alarm FARate False alarm rate xviii GDEM Generalized Digital...uses a LTM based, global ocean climatology database called Generalized Digital Environment Model ( GDEM ), in tactical decision aid (TDA) software, such...environment for USW planning. GDEM climatology is derived using temperature and salinity profiles from the Modular Ocean Data Assimilation System
A Viola-Jones based hybrid face detection framework
NASA Astrophysics Data System (ADS)
Murphy, Thomas M.; Broussard, Randy; Schultz, Robert; Rakvic, Ryan; Ngo, Hau
2013-12-01
Improvements in face detection performance would benefit many applications. The OpenCV library implements a standard solution, the Viola-Jones detector, with a statistically boosted rejection cascade of binary classifiers. Empirical evidence has shown that Viola-Jones underdetects in some instances. This research shows that a truncated cascade augmented by a neural network could recover these undetected faces. A hybrid framework is constructed, with a truncated Viola-Jones cascade followed by an artificial neural network, used to refine the face decision. Optimally, a truncation stage that captured all faces and allowed the neural network to remove the false alarms is selected. A feedforward backpropagation network with one hidden layer is trained to discriminate faces based upon the thresholding (detection) values of intermediate stages of the full rejection cascade. A clustering algorithm is used as a precursor to the neural network, to group significant overlappings. Evaluated on the CMU/VASC Image Database, comparison with an unmodified OpenCV approach shows: (1) a 37% increase in detection rates if constrained by the requirement of no increase in false alarms, (2) a 48% increase in detection rates if some additional false alarms are tolerated, and (3) an 82% reduction in false alarms with no reduction in detection rates. These results demonstrate improved face detection and could address the need for such improvement in various applications.
Memory for radio advertisements: the effect of program and typicality.
Martín-Luengo, Beatriz; Luna, Karlos; Migueles, Malen
2013-01-01
We examined the influence of the type of radio program on the memory for radio advertisements. We also investigated the role in memory of the typicality (high or low) of the elements of the products advertised. Participants listened to three types of programs (interesting, boring, enjoyable) with two advertisements embedded in each. After completing a filler task, the participants performed a true/false recognition test. Hits and false alarm rates were higher for the interesting and enjoyable programs than for the boring one. There were also more hits and false alarms for the high-typicality elements. The response criterion for the advertisements embedded in the boring program was stricter than for the advertisements in other types of programs. We conclude that the type of program in which an advertisement is inserted and the nature of the elements of the advertisement affect both the number of hits and false alarms and the response criterion, but not the accuracy of the memory.
46 CFR 35.40-7 - Carbon dioxide and clean agent alarms-T/ALL.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 1 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-7 Carbon dioxide and clean agent alarms—T/ALL. Each carbon dioxide or clean agent fire extinguishing alarm...
46 CFR 162.050-20 - Separator and bilge alarm test fluids.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 6 2010-10-01 2010-10-01 false Separator and bilge alarm test fluids. 162.050-20... § 162.050-20 Separator and bilge alarm test fluids. (a) Tests required in §§ 162.050-23 and 162.050-35 must be performed using the following three types of test fluids: (1) Test Fluid A, which is a marine...
NASA Astrophysics Data System (ADS)
Leahy, Kevin; Gallagher, Colm; Bruton, Ken; O'Donovan, Peter; O'Sullivan, Dominic T. J.
2017-11-01
Using 10-minute wind turbine SCADA data for fault prediction offers an attractive way of gaining additional prognostic capabilities without needing to invest in extra hardware. To use these data-driven methods effectively, the historical SCADA data must be labelled with the periods when the turbine was in faulty operation as well the sub-system the fault was attributed to. Manually identifying faults using maintenance logs can be effective, but is also highly time consuming and tedious due to the disparate nature of these logs across manufacturers, operators and even individual maintenance events. Turbine alarm systems can help to identify these periods, but the sheer volume of alarms and false positives generated makes analysing them on an individual basis ineffective. In this work, we present a new method for automatically identifying historical stoppages on the turbine using SCADA and alarms data. Each stoppage is associated with either a fault in one of the turbine’s sub-systems, a routine maintenance activity, a grid-related event or a number of other categories. This is then checked against maintenance logs for accuracy and the labelled data fed into a classifier for predicting when these stoppages will occur. Results show that the automated labelling process correctly identifies each type of stoppage, and can be effectively used for SCADA-based prediction of turbine faults.
Hundhausen, T; Müller, T H
2005-08-01
The microbial detection system BacT/ALERT (bioMérieux) is widely used to monitor bacterial contamination of platelet concentrates (PCs). Recently, the manufacturer introduced polycarbonate culture bottles and a modified pH-sensitive liquid emulsion sensor as microbial growth indicator. This reconfigured assay was investigated in a routine setting. In each of eight transfusion centers, samples from 500 consecutive PCs were monitored for 1 week. For all PCs with a positive BacT/ALERT signal, retained samples and, if available, original PC containers and concomitant red blood cell concentrates were analyzed independently. Initially BacT/ALERT-positive PCs without bacterial identification in any sample were defined as false-positive. BacT/ALERT-positive PCs with bacteria in the first sample only were called potentially positive. PCs with bacteria in the first sample and the same strain in at least one additional sample were accepted as positive. Five PCs (0.13%) were positive, 9 PCs (0.23%) were potentially positive, and 35 PCs (0.9%) were false-positive. The rate of false-positive BacT/ALERT results varied substantially between centers (<0.2%-3.2%). Tracings from false-positive cultures lacked an exponential increase of the signal during incubation. Most of these false-positives were due to malfunctioning cells in various BacT/ALERT incubation units. Careful assessment of individual tracings of samples with positive signals helps to identify malfunctioning incubation units. Their early shutdown or replacement minimizes the high rate of unrectifiable product rejects attributed to false-positive alarms and avoids unnecessary concern of doctors and patients after conversion to a reconfigured BacT/ALERT assay.
Object classification for obstacle avoidance
NASA Astrophysics Data System (ADS)
Regensburger, Uwe; Graefe, Volker
1991-03-01
Object recognition is necessary for any mobile robot operating autonomously in the real world. This paper discusses an object classifier based on a 2-D object model. Obstacle candidates are tracked and analyzed false alarms generated by the object detector are recognized and rejected. The methods have been implemented on a multi-processor system and tested in real-world experiments. They work reliably under favorable conditions but sometimes problems occur e. g. when objects contain many features (edges) or move in front of structured background.
Fürbass, F; Ossenblok, P; Hartmann, M; Perko, H; Skupch, A M; Lindinger, G; Elezi, L; Pataraia, E; Colon, A J; Baumgartner, C; Kluge, T
2015-06-01
A method for automatic detection of epileptic seizures in long-term scalp-EEG recordings called EpiScan will be presented. EpiScan is used as alarm device to notify medical staff of epilepsy monitoring units (EMUs) in case of a seizure. A prospective multi-center study was performed in three EMUs including 205 patients. A comparison between EpiScan and the Persyst seizure detector on the prospective data will be presented. In addition, the detection results of EpiScan on retrospective EEG data of 310 patients and the public available CHB-MIT dataset will be shown. A detection sensitivity of 81% was reached for unequivocal electrographic seizures with false alarm rate of only 7 per day. No statistical significant differences in the detection sensitivities could be found between the centers. The comparison to the Persyst seizure detector showed a lower false alarm rate of EpiScan but the difference was not of statistical significance. The automatic seizure detection method EpiScan showed high sensitivity and low false alarm rate in a prospective multi-center study on a large number of patients. The application as seizure alarm device in EMUs becomes feasible and will raise the efficiency of video-EEG monitoring and the safety levels of patients. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Expert system constant false alarm rate processor
NASA Astrophysics Data System (ADS)
Baldygo, William J., Jr.; Wicks, Michael C.
1993-10-01
The requirements for high detection probability and low false alarm probability in modern wide area surveillance radars are rarely met due to spatial variations in clutter characteristics. Many filtering and CFAR detection algorithms have been developed to effectively deal with these variations; however, any single algorithm is likely to exhibit excessive false alarms and intolerably low detection probabilities in a dynamically changing environment. A great deal of research has led to advances in the state of the art in Artificial Intelligence (AI) and numerous areas have been identified for application to radar signal processing. The approach suggested here, discussed in a patent application submitted by the authors, is to intelligently select the filtering and CFAR detection algorithms being executed at any given time, based upon the observed characteristics of the interference environment. This approach requires sensing the environment, employing the most suitable algorithms, and applying an appropriate multiple algorithm fusion scheme or consensus algorithm to produce a global detection decision.
Ethical dilemmas related to predictions and warnings of impending natural disaster.
Phua, Kai-Lit; Hue, J W
2013-01-01
Scientists and policy makers issuing predictions and warnings of impending natural disaster are faced with two major challenges, that is, failure to warn and issuing a false alarm. The consequences of failure to warn can be serious for society overall, for example, significant economic losses, heavy infrastructure and environmental damage, large number of human casualties, and social disruption. Failure to warn can also have serious for specific individuals, for example, legal proceedings against disaster research scientists, as in the L'Aquila earthquake affair. The consequences of false alarms may be less serious. Nevertheless, false alarms may violate the principle of nonmaleficence (do no harm), affect individual autonomy (eg, mandatory evacuations), and may result in the "cry wolf" effect. Other ethical issues associated with natural disasters include the promotion of global justice through international predisaster technical assistance and postdisaster aid. Social justice within a particular country is promoted through greater postdisaster aid allocation to the less privileged.
Mukherjee, Anadi; Dunayevskiy, Ilya; Prasanna, Manu; Go, Rowel; Tsekoun, Alexei; Wang, Xiaojun; Fan, Jenyu; Patel, C Kumar N
2008-04-01
The need for the detection of chemical warfare agents (CWAs) is no longer confined to battlefield environments because of at least one confirmed terrorist attack, the Tokyo Subway [Emerg. Infect. Dis. 5, 513 (1999)] in 1995, and a suspected, i.e., a false-alarm of a CWA in the Russell Senate Office Building [Washington Post, 9 February 2006, p. B01]. Therefore, detection of CWAs with high sensitivity and low false-alarm rates is considered an important priority for ensuring public safety. We report a minimum detection level for a CWA simulant, dimethyl methyl phosphonate (DMMP), of <0.5 ppb (parts in 10(9)) by use of a widely tunable external grating cavity quantum cascade laser and photoacoustic spectroscopy. With interferents present in Santa Monica, California street air, we demonstrate a false-alarm rate of 1:10(6) at a detection threshold of 1.6 ppb.
Dual sensitivity mode system for monitoring processes and sensors
Wilks, Alan D.; Wegerich, Stephan W.; Gross, Kenneth C.
2000-01-01
A method and system for analyzing a source of data. The system and method involves initially training a system using a selected data signal, calculating at least two levels of sensitivity using a pattern recognition methodology, activating a first mode of alarm sensitivity to monitor the data source, activating a second mode of alarm sensitivity to monitor the data source and generating a first alarm signal upon the first mode of sensitivity detecting an alarm condition and a second alarm signal upon the second mode of sensitivity detecting an associated alarm condition. The first alarm condition and second alarm condition can be acted upon by an operator and/or analyzed by a specialist or computer program.
1983-06-30
activating a separate transmitter, audible alarm, or contact closure. This sensor is compatible with any device that utilizes an input pulse or...transmitter, audible alarm, or contact closure. This sensor is compatible *i with any device that utilizes an output to produce an alarm. 110-4769-002. This...used to generate an alarm by activating a separate transmitter, audible alarm, or contact closure. This sensor is compatible with any device that
[Research on early fire detection with CO-CO2 FTIR-spectroscopy].
Du, Jian-hua; Zhang, Ren-cheng; Huang, Xiang-ying; Gong, Xue; Zhang, Xiao-hua
2007-05-01
A new fire detection method is put forward based on the theory of FTIR spectroscopy through analyzing all kinds of detection methods, in which CO and CO2 are chosen as early fire detection objects, and an early fire experiment system has been set up. The concentration characters of CO and CO2 were obtained through early fire experiments including real alarm sources and nuisance alarm sources. In real alarm sources there are abundant CO and CO2 which change regularly. In nuisance alarm sources there is almost no CO. So it's feasible to reduce the false alarms and increase the sensitivity of early fire detectors through analyzing the concentration characters of CO and CO2.
Rossum, Huub H van; Kemperman, Hans
2017-07-26
General application of a moving average (MA) as continuous analytical quality control (QC) for routine chemistry assays has failed due to lack of a simple method that allows optimization of MAs. A new method was applied to optimize the MA for routine chemistry and was evaluated in daily practice as continuous analytical QC instrument. MA procedures were optimized using an MA bias detection simulation procedure. Optimization was graphically supported by bias detection curves. Next, all optimal MA procedures that contributed to the quality assurance were run for 100 consecutive days and MA alarms generated during working hours were investigated. Optimized MA procedures were applied for 24 chemistry assays. During this evaluation, 303,871 MA values and 76 MA alarms were generated. Of all alarms, 54 (71%) were generated during office hours. Of these, 41 were further investigated and were caused by ion selective electrode (ISE) failure (1), calibration failure not detected by QC due to improper QC settings (1), possible bias (significant difference with the other analyzer) (10), non-human materials analyzed (2), extreme result(s) of a single patient (2), pre-analytical error (1), no cause identified (20), and no conclusion possible (4). MA was implemented in daily practice as a continuous QC instrument for 24 routine chemistry assays. In our setup when an MA alarm required follow-up, a manageable number of MA alarms was generated that resulted in valuable MA alarms. For the management of MA alarms, several applications/requirements in the MA management software will simplify the use of MA procedures.
Incorporation of operator knowledge for improved HMDS GPR classification
NASA Astrophysics Data System (ADS)
Kennedy, Levi; McClelland, Jessee R.; Walters, Joshua R.
2012-06-01
The Husky Mine Detection System (HMDS) detects and alerts operators to potential threats observed in groundpenetrating RADAR (GPR) data. In the current system architecture, the classifiers have been trained using available data from multiple training sites. Changes in target types, clutter types, and operational conditions may result in statistical differences between the training data and the testing data for the underlying features used by the classifier, potentially resulting in an increased false alarm rate or a lower probability of detection for the system. In the current mode of operation, the automated detection system alerts the human operator when a target-like object is detected. The operator then uses data visualization software, contextual information, and human intuition to decide whether the alarm presented is an actual target or a false alarm. When the statistics of the training data and the testing data are mismatched, the automated detection system can overwhelm the analyst with an excessive number of false alarms. This is evident in the performance of and the data collected from deployed systems. This work demonstrates that analyst feedback can be successfully used to re-train a classifier to account for variable testing data statistics not originally captured in the initial training data.
Fusion of thermal- and visible-band video for abandoned object detection
NASA Astrophysics Data System (ADS)
Beyan, Cigdem; Yigit, Ahmet; Temizel, Alptekin
2011-07-01
Timely detection of packages that are left unattended in public spaces is a security concern, and rapid detection is important for prevention of potential threats. Because constant surveillance of such places is challenging and labor intensive, automated abandoned-object-detection systems aiding operators have started to be widely used. In many studies, stationary objects, such as people sitting on a bench, are also detected as suspicious objects due to abandoned items being defined as items newly added to the scene and remained stationary for a predefined time. Therefore, any stationary object results in an alarm causing a high number of false alarms. These false alarms could be prevented by classifying suspicious items as living and nonliving objects. In this study, a system for abandoned object detection that aids operators surveilling indoor environments such as airports, railway or metro stations, is proposed. By analysis of information from a thermal- and visible-band camera, people and the objects left behind can be detected and discriminated as living and nonliving, reducing the false-alarm rate. Experiments demonstrate that using data obtained from a thermal camera in addition to a visible-band camera also increases the true detection rate of abandoned objects.
Multiratio fusion change detection with adaptive thresholding
NASA Astrophysics Data System (ADS)
Hytla, Patrick C.; Balster, Eric J.; Vasquez, Juan R.; Neuroth, Robert M.
2017-04-01
A ratio-based change detection method known as multiratio fusion (MRF) is proposed and tested. The MRF framework builds on other change detection components proposed in this work: dual ratio (DR) and multiratio (MR). The DR method involves two ratios coupled with adaptive thresholds to maximize detected changes and minimize false alarms. The use of two ratios is shown to outperform the single ratio case when the means of the image pairs are not equal. MR change detection builds on the DR method by including negative imagery to produce four total ratios with adaptive thresholds. Inclusion of negative imagery is shown to improve detection sensitivity and to boost detection performance in certain target and background cases. MRF further expands this concept by fusing together the ratio outputs using a routine in which detections must be verified by two or more ratios to be classified as a true changed pixel. The proposed method is tested with synthetically generated test imagery and real datasets with results compared to other methods found in the literature. DR is shown to significantly outperform the standard single ratio method. MRF produces excellent change detection results that exhibit up to a 22% performance improvement over other methods from the literature at low false-alarm rates.
Carpenter, Tim E; Chrièl, Mariann; Greiner, Matthias
2007-01-16
Emergency preparedness relies on the ability to detect patterns in rare incidents in an early stage of an outbreak in order to implement relevant actions. Early warning of an abortion storm as a result of infection with a notifiable disease, e.g. brucellosis, bovine viral diarrhea (BVD) or infectious bovine rhinotracheitis (IBR), is a significant surveillance tool. This study used data from 507 large Danish dairy herds. A modified two-stage method for detecting an unusual increase in the abortion incidence was applied to the data. An alarm was considered true if an abortion were detected in the month following the alarm month, otherwise false. The total number of abortions that could potentially be avoided if effective action were taken ranged from 769 (22.9%) to 10 (0.3%), as the number of abortions required to set the alarm increased from 1 to 6. The vast majority of abortions could, however, not be predicted, much less prevented, given this early-warning system. The false to true alarm ratio was reduced when the number of abortions that set the alarm increased. The financial scenarios evaluated demonstrated that the value of an abortion, the cost of responding to an alarm and the efficiency of the actions are important for decision making when reporting an alarm. The presented model can readily be extended to other disease problems and multiple-time periods.
Fractal analysis of seafloor textures for target detection in synthetic aperture sonar imagery
NASA Astrophysics Data System (ADS)
Nabelek, T.; Keller, J.; Galusha, A.; Zare, A.
2018-04-01
Fractal analysis of an image is a mathematical approach to generate surface related features from an image or image tile that can be applied to image segmentation and to object recognition. In undersea target countermeasures, the targets of interest can appear as anomalies in a variety of contexts, visually different textures on the seafloor. In this paper, we evaluate the use of fractal dimension as a primary feature and related characteristics as secondary features to be extracted from synthetic aperture sonar (SAS) imagery for the purpose of target detection. We develop three separate methods for computing fractal dimension. Tiles with targets are compared to others from the same background textures without targets. The different fractal dimension feature methods are tested with respect to how well they can be used to detect targets vs. false alarms within the same contexts. These features are evaluated for utility using a set of image tiles extracted from a SAS data set generated by the U.S. Navy in conjunction with the Office of Naval Research. We find that all three methods perform well in the classification task, with a fractional Brownian motion model performing the best among the individual methods. We also find that the secondary features are just as useful, if not more so, in classifying false alarms vs. targets. The best classification accuracy overall, in our experimentation, is found when the features from all three methods are combined into a single feature vector.
46 CFR 162.050-33 - Bilge alarm: Design specification.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 6 2010-10-01 2010-10-01 false Bilge alarm: Design specification. 162.050-33 Section 162.050-33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment § 162...
10 CFR 74.57 - Alarm resolution.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 2 2010-01-01 2010-01-01 false Alarm resolution. 74.57 Section 74.57 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) MATERIAL CONTROL AND ACCOUNTING OF SPECIAL NUCLEAR MATERIAL Formula... unresolved beyond the time period specified for its resolution in the licensee's fundamental nuclear material...
46 CFR 113.05-7 - Environmental tests.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Environmental tests. 113.05-7 Section 113.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Provisions § 113.05-7 Environmental tests. Communication, alarm system...
24 CFR 3285.703 - Smoke alarms.
Code of Federal Regulations, 2010 CFR
2010-04-01
... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Electrical Systems and Equipment § 3285.703 Smoke... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Smoke alarms. 3285.703 Section 3285.703 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued...
Brannon, Timothy S
2008-11-06
Resolution of apnea of prematurity is a criterion for hospital discharge of the preterm infant. False alarms recorded as true events can prolong hospitalization and increase cost of care. The UFuRT process was used to analyze neonatal apnea monitoring, using a typical monitor display. The goals were to determine 1) the data needed to recognize true events and reject false alarms, and 2) how the display layout could be modified to better support these tasks.
1997-01-01
isolated targets, significantly reduce false alarms ( PFA = 0.01/km2), and recognize force structure (e.g., maneuver battalions). During FY97, a laboratory...probability of false alarm ( Pfa ) of 0.3 at an altitude of 500-1,000 ft and at airspeeds of 60-100 kn is planned. Enhanced COBRA optics-including a...hibiting the desired properties and initiate agent sorption assessments. The FY00 goal is to com- plete performance evaluations of candidate
2006-05-15
alarm performance in a cost-effective manner is the use of track - before - detect strategies, in which multiple sensor detections must occur within the...corresponding to the traditional sensor coverage problem. Also, in the track - before - detect context, reference is made to the field-level functions of...detection and false alarm as successful search and false search, respectively, because the track - before - detect process serves as a searching function
Environmentally Adaptive UXO Detection and Classification Systems
2016-04-01
probability of false alarm ( Pfa ), as well as Receiver Op- erating Characteristic (ROC) curve and confusion matrix characteristics. The results of these...techniques at a false alarm probability of Pfa = 1× 10−3. X̃ = g(X). In this case, the problem remains invariant to the group of transformations G = { g : g(X...and observed target responses as well as the probability of detection versus SNR for both detection techniques at Pfa = 1× 10−3. with N = 128 and M = 50
Hypoglycemia early alarm systems based on recursive autoregressive partial least squares models.
Bayrak, Elif Seyma; Turksoy, Kamuran; Cinar, Ali; Quinn, Lauretta; Littlejohn, Elizabeth; Rollins, Derrick
2013-01-01
Hypoglycemia caused by intensive insulin therapy is a major challenge for artificial pancreas systems. Early detection and prevention of potential hypoglycemia are essential for the acceptance of fully automated artificial pancreas systems. Many of the proposed alarm systems are based on interpretation of recent values or trends in glucose values. In the present study, subject-specific linear models are introduced to capture glucose variations and predict future blood glucose concentrations. These models can be used in early alarm systems of potential hypoglycemia. A recursive autoregressive partial least squares (RARPLS) algorithm is used to model the continuous glucose monitoring sensor data and predict future glucose concentrations for use in hypoglycemia alarm systems. The partial least squares models constructed are updated recursively at each sampling step with a moving window. An early hypoglycemia alarm algorithm using these models is proposed and evaluated. Glucose prediction models based on real-time filtered data has a root mean squared error of 7.79 and a sum of squares of glucose prediction error of 7.35% for six-step-ahead (30 min) glucose predictions. The early alarm systems based on RARPLS shows good performance. A sensitivity of 86% and a false alarm rate of 0.42 false positive/day are obtained for the early alarm system based on six-step-ahead predicted glucose values with an average early detection time of 25.25 min. The RARPLS models developed provide satisfactory glucose prediction with relatively smaller error than other proposed algorithms and are good candidates to forecast and warn about potential hypoglycemia unless preventive action is taken far in advance. © 2012 Diabetes Technology Society.
Hypoglycemia Early Alarm Systems Based on Recursive Autoregressive Partial Least Squares Models
Bayrak, Elif Seyma; Turksoy, Kamuran; Cinar, Ali; Quinn, Lauretta; Littlejohn, Elizabeth; Rollins, Derrick
2013-01-01
Background Hypoglycemia caused by intensive insulin therapy is a major challenge for artificial pancreas systems. Early detection and prevention of potential hypoglycemia are essential for the acceptance of fully automated artificial pancreas systems. Many of the proposed alarm systems are based on interpretation of recent values or trends in glucose values. In the present study, subject-specific linear models are introduced to capture glucose variations and predict future blood glucose concentrations. These models can be used in early alarm systems of potential hypoglycemia. Methods A recursive autoregressive partial least squares (RARPLS) algorithm is used to model the continuous glucose monitoring sensor data and predict future glucose concentrations for use in hypoglycemia alarm systems. The partial least squares models constructed are updated recursively at each sampling step with a moving window. An early hypoglycemia alarm algorithm using these models is proposed and evaluated. Results Glucose prediction models based on real-time filtered data has a root mean squared error of 7.79 and a sum of squares of glucose prediction error of 7.35% for six-step-ahead (30 min) glucose predictions. The early alarm systems based on RARPLS shows good performance. A sensitivity of 86% and a false alarm rate of 0.42 false positive/day are obtained for the early alarm system based on six-step-ahead predicted glucose values with an average early detection time of 25.25 min. Conclusions The RARPLS models developed provide satisfactory glucose prediction with relatively smaller error than other proposed algorithms and are good candidates to forecast and warn about potential hypoglycemia unless preventive action is taken far in advance. PMID:23439179
46 CFR 113.25-3 - Requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Requirements. 113.25-3 Section 113.25-3 Shipping COAST... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-3 Requirements. Each vessel must have a general emergency alarm system that meets the requirements of this subpart. ...
46 CFR 113.25-3 - Requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Requirements. 113.25-3 Section 113.25-3 Shipping COAST... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-3 Requirements. Each vessel must have a general emergency alarm system that meets the requirements of this subpart. ...
46 CFR 113.25-3 - Requirements.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Requirements. 113.25-3 Section 113.25-3 Shipping COAST... SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-3 Requirements. Each vessel must have a general emergency alarm system that meets the requirements of this subpart. ...
46 CFR 162.050-35 - Bilge alarm: Approval tests.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 6 2010-10-01 2010-10-01 false Bilge alarm: Approval tests. 162.050-35 Section 162.050-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment § 162.050-35...
21 CFR 870.2640 - Portable leakage current alarm.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Portable leakage current alarm. 870.2640 Section 870.2640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 3 2014-10-01 2014-10-01 false Application. 76.35-1 Section 76.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-1 Application. (a) Where a manual alarm system is installed, the...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 3 2012-10-01 2012-10-01 false Application. 76.35-1 Section 76.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-1 Application. (a) Where a manual alarm system is installed, the...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false Application. 76.35-1 Section 76.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-1 Application. (a) Where a manual alarm system is installed, the...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 3 2013-10-01 2013-10-01 false Application. 76.35-1 Section 76.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-1 Application. (a) Where a manual alarm system is installed, the...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 3 2010-10-01 2010-10-01 false Application. 76.35-1 Section 76.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Alarm System, Details § 76.35-1 Application. (a) Where a manual alarm system is installed, the...
21 CFR 870.2640 - Portable leakage current alarm.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Portable leakage current alarm. 870.2640 Section 870.2640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable...
McGarraugh, Geoffrey
2010-01-01
Continuous glucose monitoring (CGM) devices available in the United States are approved for use as adjuncts to self-monitoring of blood glucose (SMBG). Alarm evaluation in the Clinical and Laboratory Standards Institute (CLSI) guideline for CGM does not specifically address devices that employ both CGM and SMBG. In this report, an alarm evaluation method is proposed for these devices. The proposed method builds on the CLSI method using data from an in-clinic study of subjects with type 1 diabetes. CGM was used to detect glycemic events, and SMBG was used to determine treatment. To optimize detection of a single glucose level, such as 70 mg/dl, a range of alarm threshold settings was evaluated. The alarm characterization provides a choice of alarm settings that trade off detection and false alarms. Detection of a range of high glucose levels was similarly evaluated. Using low glucose alarms, detection of 70 mg/dl within 30 minutes increased from 64 to 97% as alarm settings increased from 70 to 100 mg/dl, and alarms that did not require treatment (SMBG >85 mg/dl) increased from 18 to 52%. Using high glucose alarms, detection of 180 mg/dl within 30 minutes increased from 87 to 96% as alarm settings decreased from 180 to 165 mg/dl, and alarms that did not require treatment (SMBG <180 mg/dl) increased from 24 to 42%. The proposed alarm evaluation method provides information for choosing appropriate alarm thresholds and reflects the clinical utility of CGM alarms. 2010 Diabetes Technology Society.
Bayesian performance metrics of binary sensors in homeland security applications
NASA Astrophysics Data System (ADS)
Jannson, Tomasz P.; Forrester, Thomas C.
2008-04-01
Bayesian performance metrics, based on such parameters, as: prior probability, probability of detection (or, accuracy), false alarm rate, and positive predictive value, characterizes the performance of binary sensors; i.e., sensors that have only binary response: true target/false target. Such binary sensors, very common in Homeland Security, produce an alarm that can be true, or false. They include: X-ray airport inspection, IED inspections, product quality control, cancer medical diagnosis, part of ATR, and many others. In this paper, we analyze direct and inverse conditional probabilities in the context of Bayesian inference and binary sensors, using X-ray luggage inspection statistical results as a guideline.
NASA Technical Reports Server (NTRS)
Caglayan, A. K.; Godiwala, P. M.
1985-01-01
The performance analysis results of a fault inferring nonlinear detection system (FINDS) using sensor flight data for the NASA ATOPS B-737 aircraft in a Microwave Landing System (MLS) environment is presented. First, a statistical analysis of the flight recorded sensor data was made in order to determine the characteristics of sensor inaccuracies. Next, modifications were made to the detection and decision functions in the FINDS algorithm in order to improve false alarm and failure detection performance under real modelling errors present in the flight data. Finally, the failure detection and false alarm performance of the FINDS algorithm were analyzed by injecting bias failures into fourteen sensor outputs over six repetitive runs of the five minute flight data. In general, the detection speed, failure level estimation, and false alarm performance showed a marked improvement over the previously reported simulation runs. In agreement with earlier results, detection speed was faster for filter measurement sensors soon as MLS than for filter input sensors such as flight control accelerometers.
NASA Astrophysics Data System (ADS)
Ciany, Charles M.; Zurawski, William; Kerfoot, Ian
2001-10-01
The performance of Computer Aided Detection/Computer Aided Classification (CAD/CAC) Fusion algorithms on side-scan sonar images was evaluated using data taken at the Navy's's Fleet Battle Exercise-Hotel held in Panama City, Florida, in August 2000. A 2-of-3 binary fusion algorithm is shown to provide robust performance. The algorithm accepts the classification decisions and associated contact locations form three different CAD/CAC algorithms, clusters the contacts based on Euclidian distance, and then declares a valid target when a clustered contact is declared by at least 2 of the 3 individual algorithms. This simple binary fusion provided a 96 percent probability of correct classification at a false alarm rate of 0.14 false alarms per image per side. The performance represented a 3.8:1 reduction in false alarms over the best performing single CAD/CAC algorithm, with no loss in probability of correct classification.
Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients1
Bridi, Adriana Carla; Louro, Thiago Quinellato; da Silva, Roberto Carlos Lyra
2014-01-01
OBJECTIVES: to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue. METHOD: this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds. RESULTS: a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and 199 were triggered by other equipment (infusion pumps, dialysis pumps, mechanical ventilators, and intra-aortic balloons); that is an average of 10.6 alarms per hour. CONCLUSION: the results reinforce the importance of properly configuring physiological variables, the volume and parameters of alarms of multi-parametric monitors within the routine of intensive care units. The alarms of equipment intended to protect patients have increased noise within the unit, the level of distraction and interruptions in the workflow, leading to a false sense of security. PMID:25591100
46 CFR 113.10-5 - Common return.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Common return. 113.10-5 Section 113.10-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-5 Common return. A conductor...
46 CFR 153.408 - Tank overflow control.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 5 2012-10-01 2012-10-01 false Tank overflow control. 153.408 Section 153.408 Shipping... Systems § 153.408 Tank overflow control. (a) When table 1 references this section, a cargo containment... the tank (automatic shutdown system). (b) The high level alarm and the cargo overflow alarm or...
46 CFR 162.050-19 - Oil content meter and bilge alarm test rig.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 6 2010-10-01 2010-10-01 false Oil content meter and bilge alarm test rig. 162.050-19 Section 162.050-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL ENGINEERING EQUIPMENT Pollution Prevention Equipment...
46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7... Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing... AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...
46 CFR 108.445 - Alarm and means of escape.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Alarm and means of escape. 108.445 Section 108.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.445...
46 CFR 113.25-6 - Power supply.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Power supply. 113.25-6 Section 113.25-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-6 Power supply. The emergency power source...
46 CFR 113.25-6 - Power supply.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Power supply. 113.25-6 Section 113.25-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-6 Power supply. The emergency power source...
46 CFR 113.25-6 - Power supply.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Power supply. 113.25-6 Section 113.25-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-6 Power supply. The emergency power source...
46 CFR 108.445 - Alarm and means of escape.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Alarm and means of escape. 108.445 Section 108.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.445...
46 CFR 113.10-5 - Common return.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Common return. 113.10-5 Section 113.10-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-5 Common return. A conductor...
46 CFR 113.10-7 - Connection boxes.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Connection boxes. 113.10-7 Section 113.10-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-7 Connection boxes. Each...
46 CFR 113.10-7 - Connection boxes.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Connection boxes. 113.10-7 Section 113.10-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-7 Connection boxes. Each...
46 CFR 113.10-5 - Common return.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Common return. 113.10-5 Section 113.10-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-5 Common return. A conductor...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs between...
46 CFR 113.10-5 - Common return.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Common return. 113.10-5 Section 113.10-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-5 Common return. A conductor...
46 CFR 113.10-7 - Connection boxes.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Connection boxes. 113.10-7 Section 113.10-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-7 Connection boxes. Each...
46 CFR 113.10-7 - Connection boxes.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Connection boxes. 113.10-7 Section 113.10-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-7 Connection boxes. Each...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs between...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs between...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs between...
46 CFR 113.10-5 - Common return.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Common return. 113.10-5 Section 113.10-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-5 Common return. A conductor...
46 CFR 113.10-7 - Connection boxes.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Connection boxes. 113.10-7 Section 113.10-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-7 Connection boxes. Each...
29 CFR 1926.150 - Fire protection.
Code of Federal Regulations, 2014 CFR
2014-07-01
.... Modification of sprinkler systems to permit alterations or additional demolition should be expedited so that... each floor. (e) Fire alarm devices. (1) An alarm system, e.g., telephone system, siren, etc., shall be... 29 Labor 8 2014-07-01 2014-07-01 false Fire protection. 1926.150 Section 1926.150 Labor...
29 CFR 1926.150 - Fire protection.
Code of Federal Regulations, 2011 CFR
2011-07-01
.... Modification of sprinkler systems to permit alterations or additional demolition should be expedited so that... each floor. (e) Fire alarm devices. (1) An alarm system, e.g., telephone system, siren, etc., shall be... 29 Labor 8 2011-07-01 2011-07-01 false Fire protection. 1926.150 Section 1926.150 Labor...
29 CFR 1926.150 - Fire protection.
Code of Federal Regulations, 2013 CFR
2013-07-01
.... Modification of sprinkler systems to permit alterations or additional demolition should be expedited so that... each floor. (e) Fire alarm devices. (1) An alarm system, e.g., telephone system, siren, etc., shall be... 29 Labor 8 2013-07-01 2013-07-01 false Fire protection. 1926.150 Section 1926.150 Labor...
29 CFR 1926.150 - Fire protection.
Code of Federal Regulations, 2012 CFR
2012-07-01
.... Modification of sprinkler systems to permit alterations or additional demolition should be expedited so that... each floor. (e) Fire alarm devices. (1) An alarm system, e.g., telephone system, siren, etc., shall be... 29 Labor 8 2012-07-01 2012-07-01 false Fire protection. 1926.150 Section 1926.150 Labor...
33 CFR 401.16 - Propeller direction alarms.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...
33 CFR 401.16 - Propeller direction alarms.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...
33 CFR 401.16 - Propeller direction alarms.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...
33 CFR 401.16 - Propeller direction alarms.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...
33 CFR 401.16 - Propeller direction alarms.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Propeller direction alarms. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller... and barge unit of combined 1600 gross registered tons or more shall be equipped with— (a) Propeller...
46 CFR 113.25-6 - Power supply.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Power supply. 113.25-6 Section 113.25-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-6 Power supply. The emergency power source...
46 CFR 113.25-6 - Power supply.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Power supply. 113.25-6 Section 113.25-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT General Emergency Alarm Systems § 113.25-6 Power supply. The emergency power source...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Cable runs. 113.10-3 Section 113.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Fire and Smoke Detecting and Alarm Systems § 113.10-3 Cable runs. Cable runs between...
46 CFR 113.50-5 - General requirements.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false General requirements. 113.50-5 Section 113.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM... alarm contact maker on the navigating bridge. (c) There must be a means to silence all other audio...
46 CFR 113.50-5 - General requirements.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false General requirements. 113.50-5 Section 113.50-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM... alarm contact maker on the navigating bridge. (c) There must be a means to silence all other audio...
Wickens, Christopher; Colcombe, Angela
2007-10-01
Performance consequences related to integrating an imperfect alert within a complex task domain were examined in two experiments. Cockpit displays of traffic information (CDTIs) are being designed for use in airplane cockpits as responsibility for safe separation becomes shared between pilots and controllers. Of interest in this work is how characteristics of the alarm system such as threshold, modality, and number of alert levels impact concurrent task (flight control) performance and response to potential conflicts. Student pilots performed a tracking task analogous to flight control while simultaneously monitoring for air traffic conflicts with the aid of a CDTI alert as the threshold, modality, and level of alert was varied. As the alerting system became more prone to false alerts, pilot compliance decreased and concurrent performance improved. There was some evidence of auditory preemption with auditory alerts as the false alarm rate increased. Finally, there was no benefit to a three-level system over a two-level system. There is justification for increased false alarm rates, as miss-prone systems appear to be costly. The 4:1 false alarm to miss ratio employed here improved accuracy and concurrent task performance. More research needs to address the potential benefits of likelihood alerting. The issues addressed in this research can be applied to any imperfect alerting system such as in aviation, driving, or air traffic control. It is crucial to understand the performance consequences of new technology and the efficacy of potential mitigating design features within the specific context desired.
Huang, Charles Lung-Cheng; Hsiao, Sigmund; Hwu, Hai-Gwo; Howng, Shen-Long
2012-12-30
The Chinese Facial Emotion Recognition Database (CFERD), a computer-generated three-dimensional (3D) paradigm, was developed to measure the recognition of facial emotional expressions at different intensities. The stimuli consisted of 3D colour photographic images of six basic facial emotional expressions (happiness, sadness, disgust, fear, anger and surprise) and neutral faces of the Chinese. The purpose of the present study is to describe the development and validation of CFERD with nonclinical healthy participants (N=100; 50 men; age ranging between 18 and 50 years), and to generate normative data set. The results showed that the sensitivity index d' [d'=Z(hit rate)-Z(false alarm rate), where function Z(p), p∈[0,1
Görges, Matthias; West, Nicholas C; Christopher, Nancy A; Koch, Jennifer L; Brodie, Sonia M; Lowlaavar, Nasim; Lauder, Gillian R; Ansermino, J Mark
2016-04-01
Respiratory depression in children receiving postoperative opioid infusions is a significant risk because of the interindividual variability in analgesic requirement. Detection of respiratory depression (or apnea) in these children may be improved with the introduction of automated acoustic respiratory rate (RR) monitoring. However, early detection of adverse events must be balanced with the risk of alarm fatigue. Our objective was to evaluate the use of acoustic RR monitoring in children receiving opioid infusions on a postsurgical ward and identify the causes of false alarm and optimal alarm thresholds. A video ethnographic study was performed using an observational, mixed methods approach. After surgery, an acoustic RR sensor was placed on the participant's neck and attached to a Rad87 monitor. The monitor was networked with paging for alarms. Vital signs data and paging notification logs were obtained from the central monitoring system. Webcam videos of the participant, infusion pump, and Rad87 monitor were recorded, stored on a secure server, and subsequently analyzed by 2 research nurses to identify the cause of the alarm, response, and effectiveness. Alarms occurring within a 90-second window were grouped into a single-alarm response opportunity. Data from 49 patients (30 females) with median age 14 (range, 4.4-18.8) years were analyzed. The 896 bedside vital sign threshold alarms resulted in 160 alarm response opportunities (44 low RR, 74 high RR, and 42 low SpO2). In 141 periods (88% of total), for which video was available, 65% of alarms were deemed effective (followed by an alarm-related action within 10 minutes). Nurses were the sole responders in 55% of effective alarms and the patient or parent in 20%. Episodes of desaturation (SpO2 < 90%) were observed in 9 patients: At the time of the SpO2 paging trigger, the RR was >10 bpm in 6 of 9 patients. Based on all RR samples observed, the default alarm thresholds, to serve as a starting point for each patient, would be a low RR of 6 (>10 years of age) and 10 (4-9 years of age). In this study, the use of RR monitoring did not improve the detection of respiratory depression. An RR threshold, which would have been predictive of desaturations, would have resulted in an unacceptably high false alarm rate. Future research using a combination of variables (e.g., SpO2 and RR), or the measurement of tidal volumes, may be needed to improve patient safety in the postoperative ward.
46 CFR 154.906 - Inert gas generators.
Code of Federal Regulations, 2012 CFR
2012-10-01
...: (a) Produce an inert gas containing less than 5% oxygen by volume; (b) Have a device to continuously sample the discharge of the generator for oxygen content; and (c) Have an audible and visual alarm in the cargo control station that alarms when the inert gas contains 5% or more oxygen by volume. ...
46 CFR 154.906 - Inert gas generators.
Code of Federal Regulations, 2014 CFR
2014-10-01
...: (a) Produce an inert gas containing less than 5% oxygen by volume; (b) Have a device to continuously sample the discharge of the generator for oxygen content; and (c) Have an audible and visual alarm in the cargo control station that alarms when the inert gas contains 5% or more oxygen by volume. ...
46 CFR 154.906 - Inert gas generators.
Code of Federal Regulations, 2013 CFR
2013-10-01
...: (a) Produce an inert gas containing less than 5% oxygen by volume; (b) Have a device to continuously sample the discharge of the generator for oxygen content; and (c) Have an audible and visual alarm in the cargo control station that alarms when the inert gas contains 5% or more oxygen by volume. ...
46 CFR 154.906 - Inert gas generators.
Code of Federal Regulations, 2011 CFR
2011-10-01
...: (a) Produce an inert gas containing less than 5% oxygen by volume; (b) Have a device to continuously sample the discharge of the generator for oxygen content; and (c) Have an audible and visual alarm in the cargo control station that alarms when the inert gas contains 5% or more oxygen by volume. ...
46 CFR 154.906 - Inert gas generators.
Code of Federal Regulations, 2010 CFR
2010-10-01
...: (a) Produce an inert gas containing less than 5% oxygen by volume; (b) Have a device to continuously sample the discharge of the generator for oxygen content; and (c) Have an audible and visual alarm in the cargo control station that alarms when the inert gas contains 5% or more oxygen by volume. ...
Leandro, G; Rolando, N; Gallus, G; Rolles, K; Burroughs, A
2005-01-01
Background: Monitoring clinical interventions is an increasing requirement in current clinical practice. The standard CUSUM (cumulative sum) charts are used for this purpose. However, they are difficult to use in terms of identifying the point at which outcomes begin to be outside recommended limits. Objective: To assess the Bernoulli CUSUM chart that permits not only a 100% inspection rate, but also the setting of average expected outcomes, maximum deviations from these, and false positive rates for the alarm signal to trigger. Methods: As a working example this study used 674 consecutive first liver transplant recipients. The expected one year mortality set at 24% from the European Liver Transplant Registry average. A standard CUSUM was compared with Bernoulli CUSUM: the control value mortality was therefore 24%, maximum accepted mortality 30%, and average number of observations to signal was 500—that is, likelihood of false positive alarm was 1:500. Results: The standard CUSUM showed an initial descending curve (nadir at patient 215) then progressively ascended indicating better performance. The Bernoulli CUSUM gave three alarm signals initially, with easily recognised breaks in the curve. There were no alarms signals after patient 143 indicating satisfactory performance within the criteria set. Conclusions: The Bernoulli CUSUM is more easily interpretable graphically and is more suitable for monitoring outcomes than the standard CUSUM chart. It only requires three parameters to be set to monitor any clinical intervention: the average expected outcome, the maximum deviation from this, and the rate of false positive alarm triggers. PMID:16210461
IR gas cloud imaging in oil and gas applications: immunity to false stimuli
NASA Astrophysics Data System (ADS)
Naranjo, Edward; Baliga, Shakar; Park, John; Bernascolle, Philippe
2011-05-01
Fixed gas detection equipment for the petroleum industries is no ordinary equipment. It is designed for continued unattended surveillance in harsh environments. The equipment must be reliable and require limited field maintenance. An additional requirement is a high resistance to false alarms and interferences, which can potentially reduce the detector's efficacy and the level of protection provided. In recent years, several manufactures of IR imaging devices have launched commercial models that are applicable to a wide range of chemical species and suitable for industrial use. These cameras are rugged and sufficiently sensitive to detect low concentrations of combustible and toxic gases. Nonetheless, as users become acquainted with these imaging systems, questions of resilience to solar and flame radiation and other IR sources, interferences by fog or steam, have begun to emerge. These questions, in fact, reflect similar concerns as those raised with open path IR gas detectors when they first appeared in the market over 20 years ago. This paper examines an IR gas imager's performance when exposed to several false alarm sources. Gas detection sensitivity in the presence of false stimuli and response and recovery times under an uncontrolled outdoor environment were measured. The results show the specific model tested is reasonably immune to false alarms, while response times were unaffected by the presence of these sources.
A False Alarm Reduction Method for a Gas Sensor Based Electronic Nose
Rahman, Mohammad Mizanur; Suksompong, Prapun; Toochinda, Pisanu; Taparugssanagorn, Attaphongse
2017-01-01
Electronic noses (E-Noses) are becoming popular for food and fruit quality assessment due to their robustness and repeated usability without fatigue, unlike human experts. An E-Nose equipped with classification algorithms and having open ended classification boundaries such as the k-nearest neighbor (k-NN), support vector machine (SVM), and multilayer perceptron neural network (MLPNN), are found to suffer from false classification errors of irrelevant odor data. To reduce false classification and misclassification errors, and to improve correct rejection performance; algorithms with a hyperspheric boundary, such as a radial basis function neural network (RBFNN) and generalized regression neural network (GRNN) with a Gaussian activation function in the hidden layer should be used. The simulation results presented in this paper show that GRNN has more correct classification efficiency and false alarm reduction capability compared to RBFNN. As the design of a GRNN and RBFNN is complex and expensive due to large numbers of neuron requirements, a simple hyperspheric classification method based on minimum, maximum, and mean (MMM) values of each class of the training dataset was presented. The MMM algorithm was simple and found to be fast and efficient in correctly classifying data of training classes, and correctly rejecting data of extraneous odors, and thereby reduced false alarms. PMID:28895910
A False Alarm Reduction Method for a Gas Sensor Based Electronic Nose.
Rahman, Mohammad Mizanur; Charoenlarpnopparut, Chalie; Suksompong, Prapun; Toochinda, Pisanu; Taparugssanagorn, Attaphongse
2017-09-12
Electronic noses (E-Noses) are becoming popular for food and fruit quality assessment due to their robustness and repeated usability without fatigue, unlike human experts. An E-Nose equipped with classification algorithms and having open ended classification boundaries such as the k -nearest neighbor ( k -NN), support vector machine (SVM), and multilayer perceptron neural network (MLPNN), are found to suffer from false classification errors of irrelevant odor data. To reduce false classification and misclassification errors, and to improve correct rejection performance; algorithms with a hyperspheric boundary, such as a radial basis function neural network (RBFNN) and generalized regression neural network (GRNN) with a Gaussian activation function in the hidden layer should be used. The simulation results presented in this paper show that GRNN has more correct classification efficiency and false alarm reduction capability compared to RBFNN. As the design of a GRNN and RBFNN is complex and expensive due to large numbers of neuron requirements, a simple hyperspheric classification method based on minimum, maximum, and mean (MMM) values of each class of the training dataset was presented. The MMM algorithm was simple and found to be fast and efficient in correctly classifying data of training classes, and correctly rejecting data of extraneous odors, and thereby reduced false alarms.
Detection of explosive remnants of war by neutron thermalisation.
Brooks, F D; Drosg, M; Smit, F D; Wikner, C
2012-01-01
The HYDAD-D landmine detector (Brooks and Drosg, 2005) has been modified and field-tested for 17 months in a variety of soil conditions. Test objects containing about the same mass of hydrogen (20g) as small explosive remnants of war, such as antipersonnel landmines, were detected with efficiency 100% when buried at cover depths up to 10cm. The false alarm rate under the same conditions was 9%. Plots of detection efficiency versus false alarm rate are presented. Copyright © 2011 Elsevier Ltd. All rights reserved.
2008-04-04
Poisson process, the probabilities of false alarm PFA and detection PD are computed as PFA P k1 N yk 0 k 1 eNXeNXek k! 1...character- istics (ROC) (PD versus PFA ) curves for detecting opaque objects in heavy fog, considering a detector with Xe 20 and a laser power as in...objects in this scattering me- dium up to a distance of 30 MFPs. Figure 4(b) shows the system performance curves by fixing the false alarm rate PFA at
Recognition errors suggest fast familiarity and slow recollection in rhesus monkeys
Basile, Benjamin M.; Hampton, Robert R.
2013-01-01
One influential model of recognition posits two underlying memory processes: recollection, which is detailed but relatively slow, and familiarity, which is quick but lacks detail. Most of the evidence for this dual-process model in nonhumans has come from analyses of receiver operating characteristic (ROC) curves in rats, but whether ROC analyses can demonstrate dual processes has been repeatedly challenged. Here, we present independent converging evidence for the dual-process model from analyses of recognition errors made by rhesus monkeys. Recognition choices were made in three different ways depending on processing duration. Short-latency errors were disproportionately false alarms to familiar lures, suggesting control by familiarity. Medium-latency responses were less likely to be false alarms and were more accurate, suggesting onset of a recollective process that could correctly reject familiar lures. Long-latency responses were guesses. A response deadline increased false alarms, suggesting that limiting processing time weakened the contribution of recollection and strengthened the contribution of familiarity. Together, these findings suggest fast familiarity and slow recollection in monkeys, that monkeys use a “recollect to reject” strategy to countermand false familiarity, and that primate recognition performance is well-characterized by a dual-process model consisting of recollection and familiarity. PMID:23864646
Triantafyllou, Dinara; North, Carol S; Zartman, Andrea; Roediger, Henry L
2015-08-01
Posttraumatic stress disorder (PTSD) has been found to be associated with abnormalities in memory function. This relationship has not previously been studied using the Deese-Roediger-McDermott (DRM) false memory paradigm in disaster-exposed populations. Three years after the September 11, 2001 (9/11) attacks, 281 participants from a volunteer sample of 379, recruited from 8 companies directly affected by the attacks, completed an interview about their disaster experience, a structured diagnostic interview, and the DRM paradigm. It was hypothesized that participants with PTSD would demonstrate more associative errors, termed false alarms to critical lures, compared to those without PTSD. This hypothesis was not supported; the only predictor of false alarms to critical lures was direct 9/11 trauma exposure. The finding that 9/11 trauma-exposure was associated with false alarms to critical lures suggests that neural processing of trauma-exposure memory may involve associative elements of overgeneralization coupled with insufficient inhibition of responses to related but harmless stimuli. Future research will be needed to differentiate psychopathology, such as PTSD, from physiological fight-or-flight responses to trauma.
Smart container UWB sensor system for situational awareness of intrusion alarms
DOE Office of Scientific and Technical Information (OSTI.GOV)
Romero, Carlos E.; Haugen, Peter C.; Zumstein, James M.
An in-container monitoring sensor system is based on an UWB radar intrusion detector positioned in a container and having a range gate set to the farthest wall of the container from the detector. Multipath reflections within the container make every point on or in the container appear to be at the range gate, allowing intrusion detection anywhere in the container. The system also includes other sensors to provide false alarm discrimination, and may include other sensors to monitor other parameters, e.g. radiation. The sensor system also includes a control subsystem for controlling system operation. Communications and information extraction capability maymore » also be included. A method of detecting intrusion into a container uses UWB radar, and may also include false alarm discrimination. A secure container has an UWB based monitoring system« less
NASA Astrophysics Data System (ADS)
Simpson, R. A.; Davis, D. E.
1982-09-01
This paper describes techniques to detect submicron pattern defects on optical photomasks with an enhanced direct-write, electron-beam lithographic tool. EL-3 is a third generation, shaped spot, electron-beam lithography tool developed by IBM to fabricate semiconductor devices and masks. This tool is being upgraded to provide 100% inspection of optical photomasks for submicron pattern defects, which are subsequently repaired. Fixed-size overlapped spots are stepped over the mask patterns while a signal derived from the back-scattered electrons is monitored to detect pattern defects. Inspection does not require pattern recognition because the inspection scan patterns are derived from the original design data. The inspection spot is square and larger than the minimum defect to be detected, to improve throughput. A new registration technique provides the beam-to-pattern overlay required to locate submicron defects. The 'guard banding" of inspection shapes prevents mask and system tolerances from producing false alarms that would occur should the spots be mispositioned such that they only partially covered a shape being inspected. A rescanning technique eliminates noise-related false alarms and significantly improves throughput. Data is accumulated during inspection and processed offline, as required for defect repair. EL-3 will detect 0.5 um pattern defects at throughputs compatible with mask manufacturing.
46 CFR 109.201 - Steering gear, whistles, general alarm, and means of communication.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Steering gear, whistles, general alarm, and means of communication. 109.201 Section 109.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Tests, Drills, and Inspections § 109.201 Steering gear...
46 CFR 109.201 - Steering gear, whistles, general alarm, and means of communication.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 4 2014-10-01 2014-10-01 false Steering gear, whistles, general alarm, and means of communication. 109.201 Section 109.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Tests, Drills, and Inspections § 109.201 Steering gear...
46 CFR 109.201 - Steering gear, whistles, general alarm, and means of communication.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 4 2012-10-01 2012-10-01 false Steering gear, whistles, general alarm, and means of communication. 109.201 Section 109.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Tests, Drills, and Inspections § 109.201 Steering gear...
46 CFR 109.201 - Steering gear, whistles, general alarm, and means of communication.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 4 2013-10-01 2013-10-01 false Steering gear, whistles, general alarm, and means of communication. 109.201 Section 109.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Tests, Drills, and Inspections § 109.201 Steering gear...
46 CFR 109.201 - Steering gear, whistles, general alarm, and means of communication.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, whistles, general alarm, and means of communication. 109.201 Section 109.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Tests, Drills, and Inspections § 109.201 Steering gear...
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Physical security controls for non-practitioners..., DISTRIBUTORS, AND DISPENSERS OF CONTROLLED SUBSTANCES Security Requirements § 1301.73 Physical security... adequate security for the area or building. If such security requires an alarm, such alarm, upon...
46 CFR 113.43-5 - Power supply.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 4 2011-10-01 2011-10-01 false Power supply. 113.43-5 Section 113.43-5 Shipping COAST... SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-5 Power supply. Each steering failure alarm system must be supplied by a circuit that: (a) Is independent of other steering gear system and steering...
46 CFR 113.43-5 - Power supply.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 4 2010-10-01 2010-10-01 false Power supply. 113.43-5 Section 113.43-5 Shipping COAST... SYSTEMS AND EQUIPMENT Steering Failure Alarm Systems § 113.43-5 Power supply. Each steering failure alarm system must be supplied by a circuit that: (a) Is independent of other steering gear system and steering...
Code of Federal Regulations, 2012 CFR
2012-01-01
... 10 Energy 1 2012-01-01 2012-01-01 false Records of alarm system and entrance control checks at permanent radiographic installations. 34.75 Section 34.75 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 10 Energy 1 2014-01-01 2014-01-01 false Records of alarm system and entrance control checks at permanent radiographic installations. 34.75 Section 34.75 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping...
Code of Federal Regulations, 2011 CFR
2011-01-01
... 10 Energy 1 2011-01-01 2011-01-01 false Records of alarm system and entrance control checks at permanent radiographic installations. 34.75 Section 34.75 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping...
Code of Federal Regulations, 2010 CFR
2010-01-01
... 10 Energy 1 2010-01-01 2010-01-01 false Records of alarm system and entrance control checks at permanent radiographic installations. 34.75 Section 34.75 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping...
Code of Federal Regulations, 2013 CFR
2013-01-01
... 10 Energy 1 2013-01-01 2013-01-01 false Records of alarm system and entrance control checks at permanent radiographic installations. 34.75 Section 34.75 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping...
An entropy decision approach in flash flood warning: rainfall thresholds definition
NASA Astrophysics Data System (ADS)
Montesarchio, V.; Napolitano, F.; Ridolfi, E.
2009-09-01
Flash floods events are floods characterised by very rapid response of the basins to the storms, and often they involve loss of life and damage to common and private properties. Due to the specific space-time scale of this kind of flood, generally only a short lead time is available for triggering civil protection measures. Thresholds values specify the precipitation amount for a given duration that generates a critical discharge in a given cross section. The overcoming of these values could produce a critical situation in river sites exposed to alluvial risk, so it is possible to compare directly the observed or forecasted precipitation with critical reference values, without running on line real time forecasting systems. This study is focused on the Mignone River basin, located in Central Italy. The critical rainfall threshold values are evaluated minimising an utility function based on the informative entropy concept. The study concludes with a system performance analysis, in terms of correctly issued warning, false alarms and missed alarms.
Hypoglycemia prediction with subject-specific recursive time-series models.
Eren-Oruklu, Meriyan; Cinar, Ali; Quinn, Lauretta
2010-01-01
Avoiding hypoglycemia while keeping glucose within the narrow normoglycemic range (70-120 mg/dl) is a major challenge for patients with type 1 diabetes. Continuous glucose monitors can provide hypoglycemic alarms when the measured glucose decreases below a threshold. However, a better approach is to provide an early alarm that predicts a hypoglycemic episode before it occurs, allowing enough time for the patient to take the necessary precaution to avoid hypoglycemia. We have previously proposed subject-specific recursive models for the prediction of future glucose concentrations and evaluated their prediction performance. In this work, our objective was to evaluate this algorithm further to predict hypoglycemia and provide early hypoglycemic alarms. Three different methods were proposed for alarm decision, where (A) absolute predicted glucose values, (B) cumulative-sum (CUSUM) control chart, and (C) exponentially weighted moving-average (EWMA) control chart were used. Each method was validated using data from the Diabetes Research in Children Network, which consist of measurements from a continuous glucose sensor during an insulin-induced hypoglycemia. Reference serum glucose measurements were used to determine the sensitivity to predict hypoglycemia and the false alarm rate. With the hypoglycemic threshold set to 60 mg/dl, sensitivity of 89, 87.5, and 89% and specificity of 67, 74, and 78% were reported for methods A, B, and C, respectively. Mean values for time to detection were 30 +/- 5.51 (A), 25.8 +/- 6.46 (B), and 27.7 +/- 5.32 (C) minutes. Compared to the absolute value method, both CUSUM and EWMA methods behaved more conservatively before raising an alarm (reduced time to detection), which significantly decreased the false alarm rate and increased the specificity. 2010 Diabetes Technology Society.
Bonneville Power Administration Communication Alarm Processor expert system:
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goeltz, R.; Purucker, S.; Tonn, B.
This report describes the Communications Alarm Processor (CAP), a prototype expert system developed for the Bonneville Power Administration by Oak Ridge National Laboratory. The system is designed to receive and diagnose alarms from Bonneville's Microwave Communications System (MCS). The prototype encompasses one of seven branches of the communications network and a subset of alarm systems and alarm types from each system. The expert system employs a backward chaining approach to diagnosing alarms. Alarms are fed into the expert system directly from the communication system via RS232 ports and sophisticated alarm filtering and mailbox software. Alarm diagnoses are presented to operatorsmore » for their review and concurrence before the diagnoses are archived. Statistical software is incorporated to allow analysis of archived data for report generation and maintenance studies. The delivered system resides on a Digital Equipment Corporation VAX 3200 workstation and utilizes Nexpert Object and SAS for the expert system and statistical analysis, respectively. 11 refs., 23 figs., 7 tabs.« less
The Distinctions of False and Fuzzy Memories.
ERIC Educational Resources Information Center
Schooler, Jonathan W.
1998-01-01
Notes that fuzzy-trace theory has been used to understand false memories of children. Demonstrates the irony imbedded in the theory, maintaining that a central implication of fuzzy-trace theory is that some errors characterized as false memories are not really false at all. These errors, when applied to false alarms to related lures, are best…
Memory for temporally dynamic scenes.
Ferguson, Ryan; Homa, Donald; Ellis, Derek
2017-07-01
Recognition memory was investigated for individual frames extracted from temporally continuous, visually rich film segments of 5-15 min. Participants viewed a short clip from a film in either a coherent or a jumbled order, followed by a recognition test of studied frames. Foils came either from an earlier or a later part of the film (Experiment 1) or from deleted segments selected from random cuts of varying duration (0.5 to 30 s) within the film itself (Experiment 2). When the foils came from an earlier or later part of the film (Experiment 1), recognition was excellent, with the hit rate far exceeding the false-alarm rate (.78 vs. 18). In Experiment 2, recognition was far worse, with the hit rate (.76) exceeding the false-alarm rate only for foils drawn from the longest cuts (15 and 30 s) and matching the false-alarm rate for the 5 s segments. When the foils were drawn from the briefest cuts (0.5 and 1.0 s), the false-alarm rate exceeded the hit rate. Unexpectedly, jumbling had no effect on recognition in either experiment. These results are consistent with the view that memory for complex visually temporal events is excellent, with the integrity unperturbed by disruption of the global structure of the visual stream. Disruption of memory was observed only when foils were drawn from embedded segments of duration less than 5 s, an outcome consistent with the view that memory at these shortest durations are consolidated with expectations drawn from the previous stream.
Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus
NASA Astrophysics Data System (ADS)
Yan, Zhaoli; Chen, Bin; Tian, Hao; Cheng, Xiaobin; Yang, Jun
2015-12-01
A large-volume cubic high-pressure apparatus with three pairs of tungsten carbide anvils is the most popular device for synthetic diamond production. Currently, the consumption of anvils is one of the important costs for the diamond production industry. If one of the anvils is fractured during the production process, the other five anvils in the apparatus may be endangered as a result of a sudden loss of pressure. It is of critical importance to detect and replace cracked anvils before they fracture for reduction of the cost of diamond production and safety. An acoustic detection method is studied in this paper. Two new features, nested power spectrum centroid and modified power spectrum variance, are proposed and combined with linear prediction coefficients to construct a feature vector. A support vector machine model is trained for classification. A sliding time window is proposed for decision-level information fusion. The experiments and analysis show that the recognition rate of anvil cracks is 95%, while the false-alarm rate is as low as 5.8 × 10-4 during a time window; this false-alarm rate indicates that at most one false alarm occurs every 2 months at a confidence level of 90%. An instrument to monitor anvil cracking was designed based on a digital signal processor and has been running for more than eight months in a diamond production field. In this time, two anvil-crack incidents occurred and were detected by the instrument correctly. In addition, no false alarms occurred.
Acoustic detection of cracks in the anvil of a large-volume cubic high-pressure apparatus
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Zhaoli, E-mail: zl-yan@mail.ioa.ac.cn; Tian, Hao; Cheng, Xiaobin
2015-12-15
A large-volume cubic high-pressure apparatus with three pairs of tungsten carbide anvils is the most popular device for synthetic diamond production. Currently, the consumption of anvils is one of the important costs for the diamond production industry. If one of the anvils is fractured during the production process, the other five anvils in the apparatus may be endangered as a result of a sudden loss of pressure. It is of critical importance to detect and replace cracked anvils before they fracture for reduction of the cost of diamond production and safety. An acoustic detection method is studied in this paper.more » Two new features, nested power spectrum centroid and modified power spectrum variance, are proposed and combined with linear prediction coefficients to construct a feature vector. A support vector machine model is trained for classification. A sliding time window is proposed for decision-level information fusion. The experiments and analysis show that the recognition rate of anvil cracks is 95%, while the false-alarm rate is as low as 5.8 × 10{sup −4} during a time window; this false-alarm rate indicates that at most one false alarm occurs every 2 months at a confidence level of 90%. An instrument to monitor anvil cracking was designed based on a digital signal processor and has been running for more than eight months in a diamond production field. In this time, two anvil-crack incidents occurred and were detected by the instrument correctly. In addition, no false alarms occurred.« less
Using GPS to Detect Imminent Tsunamis
NASA Technical Reports Server (NTRS)
Song, Y. Tony
2009-01-01
A promising method of detecting imminent tsunamis and estimating their destructive potential involves the use of Global Positioning System (GPS) data in addition to seismic data. Application of the method is expected to increase the reliability of global tsunami-warning systems, making it possible to save lives while reducing the incidence of false alarms. Tsunamis kill people every year. The 2004 Indian Ocean tsunami killed about 230,000 people. The magnitude of an earthquake is not always a reliable indication of the destructive potential of a tsunami. The 2004 Indian Ocean quake generated a huge tsunami, while the 2005 Nias (Indonesia) quake did not, even though both were initially estimated to be of the similar magnitude. Between 2005 and 2007, five false tsunami alarms were issued worldwide. Such alarms result in negative societal and economic effects. GPS stations can detect ground motions of earthquakes in real time, as frequently as every few seconds. In the present method, the epicenter of an earthquake is located by use of data from seismometers, then data from coastal GPS stations near the epicenter are used to infer sea-floor displacements that precede a tsunami. The displacement data are used in conjunction with local topographical data and an advanced theory to quantify the destructive potential of a tsunami on a new tsunami scale, based on the GPS-derived tsunami energy, much like the Richter Scale used for earthquakes. An important element of the derivation of the advanced theory was recognition that horizontal sea-floor motions contribute much more to generation of tsunamis than previously believed. The method produces a reliable estimate of the destructive potential of a tsunami within minutes typically, well before the tsunami reaches coastal areas. The viability of the method was demonstrated in computational tests in which the method yielded accurate representations of three historical tsunamis for which well-documented ground-motion measurements were available. Development of a global tsunami-warning system utilizing an expanded network of coastal GPS stations was under consideration at the time of reporting the information for this article.
Chair alarm for patient fall prevention based on gesture recognition and interactivity.
Knight, Heather; Lee, Jae-Kyu; Ma, Hongshen
2008-01-01
The Gesture Recognition Interactive Technology (GRiT) Chair Alarm aims to prevent patient falls from chairs and wheelchairs by recognizing the gesture of a patient attempting to stand. Patient falls are one of the greatest causes of injury in hospitals. Current chair and bed exit alarm systems are inadequate because of insufficient notification, high false-alarm rate, and long trigger delays. The GRiT chair alarm uses an array of capacitive proximity sensors and pressure sensors to create a map of the patient's sitting position, which is then processed using gesture recognition algorithms to determine when a patient is attempting to stand and to alarm the care providers. This system also uses a range of voice and light feedback to encourage the patient to remain seated and/or to make use of the system's integrated nurse-call function. This system can be seamlessly integrated into existing hospital WiFi networks to send notifications and approximate patient location through existing nurse call systems.
Despins, Laurel A
2017-12-01
This study examines what prompts the intensive care unit (ICU) nurse to go to the patient's bedside to investigate an alarm and the influences on the nurse's determination regarding how quickly this needs to occur. A qualitative descriptive design guided data collection and analysis. Individual semi-structured interviews were conducted. Thematic analysis guided by the Patient Risk Detection Theoretical Framework was applied to the data. Four specialty intensive care units in an academic medical center. ICU nurses go the patient's bedside in response to an alarm to catch patient deterioration and avert harm. Their determination of the immediacy of patient risk and their desire to prioritize their bedside investigations to true alarms influences how quickly they proceed to the bedside. Ready visual access to physiological data and waveform configurations, experience, teamwork, and false alarms are important determinants in the timing of ICU nurses' bedside alarm investigations. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Caglayan, A. K.; Godiwala, P. M.; Morrell, F. R.
1985-01-01
This paper presents the performance analysis results of a fault inferring nonlinear detection system (FINDS) using integrated avionics sensor flight data for the NASA ATOPS B-737 aircraft in a Microwave Landing System (MLS) environment. First, an overview of the FINDS algorithm structure is given. Then, aircraft state estimate time histories and statistics for the flight data sensors are discussed. This is followed by an explanation of modifications made to the detection and decision functions in FINDS to improve false alarm and failure detection performance. Next, the failure detection and false alarm performance of the FINDS algorithm are analyzed by injecting bias failures into fourteen sensor outputs over six repetitive runs of the five minutes of flight data. Results indicate that the detection speed, failure level estimation, and false alarm performance show a marked improvement over the previously reported simulation runs. In agreement with earlier results, detection speed is faster for filter measurement sensors such as MLS than for filter input sensors such as flight control accelerometers. Finally, the progress in modifications of the FINDS algorithm design to accommodate flight computer constraints is discussed.
46 CFR 34.15-30 - Alarms-T/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Alarms-T/ALL. 34.15-30 Section 34.15-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS FIREFIGHTING EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 34.15-30 Alarms—T/ALL. (a) Spaces required to have a delayed discharge by § 34.15-10(f...
46 CFR 35.40-7 - Carbon dioxide alarm-T/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 1 2011-10-01 2011-10-01 false Carbon dioxide alarm-T/ALL. 35.40-7 Section 35.40-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Posting and Marking Requirements-TB/ALL. § 35.40-7 Carbon dioxide alarm—T/ALL. Adjacent to all carbon dioxide fire extinguishing...
Review of "Do High Flyers Maintain Their Altitude?"
ERIC Educational Resources Information Center
Lee, Jaekyung
2011-01-01
The research report reviewed here concludes that many initially high-achieving students are falling further and further behind over the course of their years in school. The report intends to raise the alarm and to advocate for improved programs for these students. It is, however, a false alarm due to biased methodology and misleading arguments.…
46 CFR 167.40-5 - Alarm bells.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 7 2012-10-01 2012-10-01 false Alarm bells. 167.40-5 Section 167.40-5 Shipping COAST... bells so located as to warn all occupants. The system shall operate from a continuous source of electric energy capable of supplying the system for a period of at least 8 hours without being dependent upon the...
46 CFR 167.40-5 - Alarm bells.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 7 2013-10-01 2013-10-01 false Alarm bells. 167.40-5 Section 167.40-5 Shipping COAST... bells so located as to warn all occupants. The system shall operate from a continuous source of electric energy capable of supplying the system for a period of at least 8 hours without being dependent upon the...
46 CFR 167.40-5 - Alarm bells.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 7 2014-10-01 2014-10-01 false Alarm bells. 167.40-5 Section 167.40-5 Shipping COAST... bells so located as to warn all occupants. The system shall operate from a continuous source of electric energy capable of supplying the system for a period of at least 8 hours without being dependent upon the...
46 CFR 78.47-7 - General alarm bells.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 3 2013-10-01 2013-10-01 false General alarm bells. 78.47-7 Section 78.47-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire... identified by red lettering at least 1/2 inch high: “GENERAL ALARM—WHEN BELL RINGS GO TO YOUR STATION.” (b...
46 CFR 78.47-7 - General alarm bells.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 3 2012-10-01 2012-10-01 false General alarm bells. 78.47-7 Section 78.47-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire... identified by red lettering at least 1/2 inch high: “GENERAL ALARM—WHEN BELL RINGS GO TO YOUR STATION.” (b...
46 CFR 78.47-7 - General alarm bells.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 3 2014-10-01 2014-10-01 false General alarm bells. 78.47-7 Section 78.47-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire... identified by red lettering at least 1/2 inch high: “GENERAL ALARM—WHEN BELL RINGS GO TO YOUR STATION.” (b...
46 CFR 78.47-7 - General alarm bells.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 3 2011-10-01 2011-10-01 false General alarm bells. 78.47-7 Section 78.47-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Markings for Fire... identified by red lettering at least 1/2 inch high: “GENERAL ALARM—WHEN BELL RINGS GO TO YOUR STATION.” (b...
46 CFR 62.35-40 - Fuel systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 2 2011-10-01 2011-10-01 false Fuel systems. 62.35-40 Section 62.35-40 Shipping COAST... Requirements for Specific Types of Automated Vital Systems § 62.35-40 Fuel systems. (a) Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate...
46 CFR 62.35-40 - Fuel systems.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 46 Shipping 2 2013-10-01 2013-10-01 false Fuel systems. 62.35-40 Section 62.35-40 Shipping COAST... Requirements for Specific Types of Automated Vital Systems § 62.35-40 Fuel systems. (a) Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate...
46 CFR 62.35-40 - Fuel systems.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 46 Shipping 2 2012-10-01 2012-10-01 false Fuel systems. 62.35-40 Section 62.35-40 Shipping COAST... Requirements for Specific Types of Automated Vital Systems § 62.35-40 Fuel systems. (a) Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate...
46 CFR 62.35-40 - Fuel systems.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 46 Shipping 2 2014-10-01 2014-10-01 false Fuel systems. 62.35-40 Section 62.35-40 Shipping COAST... Requirements for Specific Types of Automated Vital Systems § 62.35-40 Fuel systems. (a) Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate...
Clinically relevant hypoglycemia prediction metrics for event mitigation.
Harvey, Rebecca A; Dassau, Eyal; Zisser, Howard C; Bevier, Wendy; Seborg, Dale E; Jovanovič, Lois; Doyle, Francis J
2012-08-01
The purpose of this study was to develop a method to compare hypoglycemia prediction algorithms and choose parameter settings for different applications, such as triggering insulin pump suspension or alerting for rescue carbohydrate treatment. Hypoglycemia prediction algorithms with different parameter settings were implemented on an ambulatory dataset containing 490 days from 30 subjects with type 1 diabetes mellitus using the Dexcom™ (San Diego, CA) SEVEN™ continuous glucose monitoring system. The performance was evaluated using a proposed set of metrics representing the true-positive ratio, false-positive rate, and distribution of warning times. A prospective, in silico study was performed to show the effect of using different parameter settings to prevent or rescue from hypoglycemia. The retrospective study results suggest the parameter settings for different methods of hypoglycemia mitigation. When rescue carbohydrates are used, a high true-positive ratio, a minimal false-positive rate, and alarms with short warning time are desired. These objectives were met with a 30-min prediction horizon and two successive flags required to alarm: 78% of events were detected with 3.0 false alarms/day and 66% probability of alarms occurring within 30 min of the event. This parameter setting selection was confirmed in silico: treating with rescue carbohydrates reduced the duration of hypoglycemia from 14.9% to 0.5%. However, for a different method, such as pump suspension, this parameter setting only reduced hypoglycemia to 8.7%, as can be expected by the low probability of alarming more than 30 min ahead. The proposed metrics allow direct comparison of hypoglycemia prediction algorithms and selection of parameter settings for different types of hypoglycemia mitigation, as shown in the prospective in silico study in which hypoglycemia was alerted or treated with rescue carbohydrates.
Personal Cabin Pressure Monitor and Warning System
NASA Technical Reports Server (NTRS)
Zysko, Jan A. (Inventor)
2002-01-01
A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.
Personal Cabin Pressure Monitor and Warning System
NASA Astrophysics Data System (ADS)
Zysko, Jan A.
2002-09-01
A cabin pressure altitude monitor and warning system provides a warning when a detected cabin pressure altitude has reached a predetermined level. The system is preferably embodied in a portable, pager-sized device that can be carried or worn by an individual. A microprocessor calculates the pressure altitude from signals generated by a calibrated pressure transducer and a temperature sensor that compensates for temperature variations in the signals generated by the pressure transducer. The microprocessor is programmed to generate a warning or alarm if a cabin pressure altitude exceeding a predetermined threshold is detected. Preferably, the microprocessor generates two different types of warning or alarm outputs, a first early warning or alert when a first pressure altitude is exceeded. and a second more serious alarm condition when either a second. higher pressure altitude is exceeded, or when the first pressure altitude has been exceeded for a predetermined period of time. Multiple types of alarm condition indicators are preferably provided, including visual, audible and tactile. The system is also preferably designed to detect gas concentrations and other ambient conditions, and thus incorporates other sensors, such as oxygen, relative humidity, carbon dioxide, carbon monoxide and ammonia sensors, to provide a more complete characterization and monitoring of the local environment.
Explosive hazard detection using MIMO forward-looking ground penetrating radar
NASA Astrophysics Data System (ADS)
Shaw, Darren; Ho, K. C.; Stone, Kevin; Keller, James M.; Popescu, Mihail; Anderson, Derek T.; Luke, Robert H.; Burns, Brian
2015-05-01
This paper proposes a machine learning algorithm for subsurface object detection on multiple-input-multiple-output (MIMO) forward-looking ground-penetrating radar (FLGPR). By detecting hazards using FLGPR, standoff distances of up to tens of meters can be acquired, but this is at the degradation of performance due to high false alarm rates. The proposed system utilizes an anomaly detection prescreener to identify potential object locations. Alarm locations have multiple one-dimensional (ML) spectral features, two-dimensional (2D) spectral features, and log-Gabor statistic features extracted. The ability of these features to reduce the number of false alarms and increase the probability of detection is evaluated for both co-polarizations present in the Akela MIMO array. Classification is performed by a Support Vector Machine (SVM) with lane-based cross-validation for training and testing. Class imbalance and optimized SVM kernel parameters are considered during classifier training.
Adjustable electronic load-alarm relay
Mason, Charles H.; Sitton, Roy S.
1976-01-01
This invention is an improved electronic alarm relay for monitoring the current drawn by an AC motor or other electrical load. The circuit is designed to measure the load with high accuracy and to have excellent alarm repeatability. Chattering and arcing of the relay contacts are minimal. The operator can adjust the set point easily and can re-set both the high and the low alarm points by means of one simple adjustment. The relay includes means for generating a signal voltage proportional to the motor current. In a preferred form of the invention a first operational amplifier is provided to generate a first constant reference voltage which is higher than a preselected value of the signal voltage. A second operational amplifier is provided to generate a second constant reference voltage which is lower than the aforementioned preselected value of the signal voltage. A circuit comprising a first resistor serially connected to a second resistor is connected across the outputs of the first and second amplifiers, and the junction of the two resistors is connected to the inverting terminal of the second amplifier. Means are provided to compare the aforementioned signal voltage with both the first and second reference voltages and to actuate an alarm if the signal voltage is higher than the first reference voltage or lower than the second reference voltage.
Neyman Pearson detection of K-distributed random variables
NASA Astrophysics Data System (ADS)
Tucker, J. Derek; Azimi-Sadjadi, Mahmood R.
2010-04-01
In this paper a new detection method for sonar imagery is developed in K-distributed background clutter. The equation for the log-likelihood is derived and compared to the corresponding counterparts derived for the Gaussian and Rayleigh assumptions. Test results of the proposed method on a data set of synthetic underwater sonar images is also presented. This database contains images with targets of different shapes inserted into backgrounds generated using a correlated K-distributed model. Results illustrating the effectiveness of the K-distributed detector are presented in terms of probability of detection, false alarm, and correct classification rates for various bottom clutter scenarios.
Target attribute-based false alarm rejection in small infrared target detection
NASA Astrophysics Data System (ADS)
Kim, Sungho
2012-11-01
Infrared search and track is an important research area in military applications. Although there are a lot of works on small infrared target detection methods, we cannot apply them in real field due to high false alarm rate caused by clutters. This paper presents a novel target attribute extraction and machine learning-based target discrimination method. Eight kinds of target features are extracted and analyzed statistically. Learning-based classifiers such as SVM and Adaboost are developed and compared with conventional classifiers for real infrared images. In addition, the generalization capability is also inspected for various infrared clutters.
1981-06-01
for a de- tection probability of PD and associated false alarm probability PFA (in dB). 21 - - - II V. REFERENCE MODEL A. INTRODUCTION In order to...space for which to choose HI . PFA = P (wI 0o)dw = Q(---) (26) j 0 Similarity, the miss probability=l-detection probability is obtained by integrating...31) = 2 (1+ (22 [()BT z] ~Z The input signal-to-noise ratio: S/N(input) - a2 (32) The probability of false alarm: PFA = Q[ tB(j-I) 1 (33) The
Fire Protection System for Hardened Aircraft Shelters. Volume 1. Discussion and Appendixes A-C
1987-10-01
in any configuration, for exanple IR, lR-lR, UV -IR, UV , UV -IR- UV . The advantage of multiwavelength detectors is a reduced likelihood of false alarm. B...11late is ,ai led the work function if the metal. Th, operating envelope of a UV detector is . function u (i) the Inc-tal used fir the cathode, and Ŗ...second or two longer. E. DI1AL-CHANNEL UV /IR JETIT .OIRS iiarmy false alar.m sources for UV and IR detectors are mutally exclusive. Th -. has led to the
NASA Astrophysics Data System (ADS)
Nguyen, Minh Q.; Allebach, Jan P.
2015-01-01
In our previous work1 , we presented a block-based technique to analyze printed page uniformity both visually and metrically. The features learned from the models were then employed in a Support Vector Machine (SVM) framework to classify the pages into one of the two categories of acceptable and unacceptable quality. In this paper, we introduce a set of tools for machine learning in the assessment of printed page uniformity. This work is primarily targeted to the printing industry, specifically the ubiquitous laser, electrophotographic printer. We use features that are well-correlated with the rankings of expert observers to develop a novel machine learning framework that allows one to achieve the minimum "false alarm" rate, subject to a chosen "miss" rate. Surprisingly, most of the research that has been conducted on machine learning does not consider this framework. During the process of developing a new product, test engineers will print hundreds of test pages, which can be scanned and then analyzed by an autonomous algorithm. Among these pages, most may be of acceptable quality. The objective is to find the ones that are not. These will provide critically important information to systems designers, regarding issues that need to be addressed in improving the printer design. A "miss" is defined to be a page that is not of acceptable quality to an expert observer that the prediction algorithm declares to be a "pass". Misses are a serious problem, since they represent problems that will not be seen by the systems designers. On the other hand, "false alarms" correspond to pages that an expert observer would declare to be of acceptable quality, but which are flagged by the prediction algorithm as "fails". In a typical printer testing and development scenario, such pages would be examined by an expert, and found to be of acceptable quality after all. "False alarm" pages result in extra pages to be examined by expert observers, which increases labor cost. But "false alarms" are not nearly as catastrophic as "misses", which represent potentially serious problems that are never seen by the systems developers. This scenario motivates us to develop a machine learning framework that will achieve the minimum "false alarm" rate subject to a specified "miss" rate. In order to construct such a set of receiver operating characteristic2 (ROC) curves, we examine various tools for the prediction, ranging from an exhaustive search over the space of the nonlinear discriminants to a Cost-Sentitive SVM3 framework. We then compare the curves gained from those methods. Our work shows promise for applying a standard framework to obtain a full ROC curve when it comes to tackling other machine learning problems in industry.
Improved security monitoring method for network bordary
NASA Astrophysics Data System (ADS)
Gao, Liting; Wang, Lixia; Wang, Zhenyan; Qi, Aihua
2013-03-01
This paper proposes a network bordary security monitoring system based on PKI. The design uses multiple safe technologies, analysis deeply the association between network data flow and system log, it can detect the intrusion activities and position invasion source accurately in time. The experiment result shows that it can reduce the rate of false alarm or missing alarm of the security incident effectively.
Evaluation of Standard Gear Metrics in Helicopter Flight Operation
NASA Technical Reports Server (NTRS)
Mosher, M.; Pryor, A. H.; Huff, E. M.
2002-01-01
Each false alarm made by a machine monitoring system carries a high price tag. The machine must be taken out of service, thoroughly inspected with possible disassembly, and then made ready for service. Loss of use of the machine and the efforts to inspect it are costly. In addition, if a monitoring system is prone to false alarms, the system will soon be turned off or ignored. For aircraft applications, one growing concern is that the dynamic flight environment differs from the laboratory environment where fault detection methods are developed and tested. Vibration measurements made in flight are less stationary than those made in a laboratory, or test facility, and thus a given fault detection method may produce more false alarms in flight than might be anticipated. In 1977. Stewart introduced several metrics, including FM0 and FM4, for evaluating the health of a gear. These metrics are single valued functions of the vibration signal that indicate if the signal deviates from an ideal model of the signal. FM0 is a measure of the ratio of the peak-to-peak level to the harmonic energy in the signal. FM4 is the kurtosis of the signal with the gear mesh harmonics and first order side bands removed. The underlying theory is that a vibration signal from a gear in good condition is expected to be dominated by a periodic signal at the gear mesh frequency. If one or a small number of gear teeth contain damage or faults, the signal will change, possibly showing increased amplitude, local phase changes or both near the damaged region of the gear. FM0 increases if a signal contains a local increase in amplitude. FM4 increases if a signal contains a local increase in amplitude or local phase change in a periodic signal. Over the years, other single value metrics were also introduced to detect the onset and growth of damage in gears. These various metrics have detected faults in several gear tests in experimental test rigs. Conditions in these tests have been steady state in the sense that the rpm, torque and forces on the gear have been held steady. For gears used in a dynamic environment such as that occurring in aircraft, the rpm, torque and forces on the gear are constantly changing. The authors have measured significant variation in rpm and torque in the transmissions of helicopters in controlled steady flight conditions flown by highly proficient test pilots. Statistical analyses of the data taken in flight show significant nonstationarity in the vibration measurements. These deviations from stationarity may increase false alarms in gear monitoring during aircraft flight. In the proposed paper, the authors will study vibration measurements made in flight on an AH- 1 Cobra and an OH-58C Kiowa helicopters. The primary focus will be the development of a methodology to assess the impact of nonstationarity on false alarms. Issues to be addressed include how time synchronous averages are constructed from raw data as well as how lack of stationarity effects the behavior of single value metrics. Emphasis will be placed on the occurrence of false alarms with the use of standard metrics. In order to maintain an acceptable level of false alarms in the flight environment, this study will also address the determination of appropriate threshold levels, which may need to be higher than for test rigs.
2007-02-01
almost identical system call sequences and triggering the same alarm at different hosts. The alarm propagation effect can be used to distinguish “true...different hosts. The alarm propagation effect can be used to distinguish “true alarms” from “false positives”. At the host-level, a new anomaly...0H ( ) ( )∑∑ = = ⎟⎟ ⎠ ⎞ ⎜⎜ ⎝ ⎛ − + − = 2 1 1, 2 2 2 2 1 1 ),( ),(),()( ),( ),(),()( k m ji jiT jiTjiTiN jiT jiTjiTiNW where - marginal observed
False alarm reduction by the And-ing of multiple multivariate Gaussian classifiers
NASA Astrophysics Data System (ADS)
Dobeck, Gerald J.; Cobb, J. Tory
2003-09-01
The high-resolution sonar is one of the principal sensors used by the Navy to detect and classify sea mines in minehunting operations. For such sonar systems, substantial effort has been devoted to the development of automated detection and classification (D/C) algorithms. These have been spurred by several factors including (1) aids for operators to reduce work overload, (2) more optimal use of all available data, and (3) the introduction of unmanned minehunting systems. The environments where sea mines are typically laid (harbor areas, shipping lanes, and the littorals) give rise to many false alarms caused by natural, biologic, and man-made clutter. The objective of the automated D/C algorithms is to eliminate most of these false alarms while still maintaining a very high probability of mine detection and classification (PdPc). In recent years, the benefits of fusing the outputs of multiple D/C algorithms have been studied. We refer to this as Algorithm Fusion. The results have been remarkable, including reliable robustness to new environments. This paper describes a method for training several multivariate Gaussian classifiers such that their And-ing dramatically reduces false alarms while maintaining a high probability of classification. This training approach is referred to as the Focused- Training method. This work extends our 2001-2002 work where the Focused-Training method was used with three other types of classifiers: the Attractor-based K-Nearest Neighbor Neural Network (a type of radial-basis, probabilistic neural network), the Optimal Discrimination Filter Classifier (based linear discrimination theory), and the Quadratic Penalty Function Support Vector Machine (QPFSVM). Although our experience has been gained in the area of sea mine detection and classification, the principles described herein are general and can be applied to a wide range of pattern recognition and automatic target recognition (ATR) problems.
Matched-filter algorithm for subpixel spectral detection in hyperspectral image data
NASA Astrophysics Data System (ADS)
Borough, Howard C.
1991-11-01
Hyperspectral imagery, spatial imagery with associated wavelength data for every pixel, offers a significant potential for improved detection and identification of certain classes of targets. The ability to make spectral identifications of objects which only partially fill a single pixel (due to range or small size) is of considerable interest. Multiband imagery such as Landsat's 5 and 7 band imagery has demonstrated significant utility in the past. Hyperspectral imaging systems with hundreds of spectral bands offer improved performance. To explore the application of differentpixel spectral detection algorithms a synthesized set of hyperspectral image data (hypercubes) was generated utilizing NASA earth resources and other spectral data. The data was modified using LOWTRAN 7 to model the illumination, atmospheric contributions, attenuations and viewing geometry to represent a nadir view from 10,000 ft. altitude. The base hypercube (HC) represented 16 by 21 spatial pixels with 101 wavelength samples from 0.5 to 2.5 micrometers for each pixel. Insertions were made into the base data to provide random location, random pixel percentage, and random material. Fifteen different hypercubes were generated for blind testing of candidate algorithms. An algorithm utilizing a matched filter in the spectral dimension proved surprisingly good yielding 100% detections for pixels filled greater than 40% with a standard camouflage paint, and a 50% probability of detection for pixels filled 20% with the paint, with no false alarms. The false alarm rate as a function of the number of spectral bands in the range from 101 to 12 bands was measured and found to increase from zero to 50% illustrating the value of a large number of spectral bands. This test was on imagery without system noise; the next step is to incorporate typical system noise sources.
PT-SAFE: a software tool for development and annunciation of medical audible alarms.
Bennett, Christopher L; McNeer, Richard R
2012-03-01
Recent reports by The Joint Commission as well as the Anesthesia Patient Safety Foundation have indicated that medical audible alarm effectiveness needs to be improved. Several recent studies have explored various approaches to improving the audible alarms, motivating the authors to develop real-time software capable of comparing such alarms. We sought to devise software that would allow for the development of a variety of audible alarm designs that could also integrate into existing operating room equipment configurations. The software is meant to be used as a tool for alarm researchers to quickly evaluate novel alarm designs. A software tool was developed for the purpose of creating and annunciating audible alarms. The alarms consisted of annunciators that were mapped to vital sign data received from a patient monitor. An object-oriented approach to software design was used to create a tool that is flexible and modular at run-time, can annunciate wave-files from disk, and can be programmed with MATLAB by the user to create custom alarm algorithms. The software was tested in a simulated operating room to measure technical performance and to validate the time-to-annunciation against existing equipment alarms. The software tool showed efficacy in a simulated operating room environment by providing alarm annunciation in response to physiologic and ventilator signals generated by a human patient simulator, on average 6.2 seconds faster than existing equipment alarms. Performance analysis showed that the software was capable of supporting up to 15 audible alarms on a mid-grade laptop computer before audio dropouts occurred. These results suggest that this software tool provides a foundation for rapidly staging multiple audible alarm sets from the laboratory to a simulation environment for the purpose of evaluating novel alarm designs, thus producing valuable findings for medical audible alarm standardization.
Bruno, Thiers; Abrahão, Julia
2012-01-01
This study examines the actions taken by operators aimed at preventing and combating information security incidents at a banking organization. The work utilizes the theoretical framework of ergonomics and cognitive psychology. The method is workplace ergonomic analysis. Its focus is directed towards examining the cognitive dimension of the work environment with special attention to the occurrence of correlations between variability in incident frequency and the results of sign detection actions. It categorizes 45,142 operator decisions according to the theory of signal detection (Sternberg, 2000). It analyzes the correlation between incident proportions (indirectly associated with the cognitive efforts demanded from the operator) and operator decisions. The study demonstrated the existence of a positive correlation between incident proportions and false positive decisions (false alarms). However, this correlation could not be observed in relation to decisions of the false-negative type (incorrect rejection).
Comprehensive Evaluation of GPM and TRMM: A Case Study of the Winter 2015-2016 over California
NASA Astrophysics Data System (ADS)
Li, J.; Liu, H.
2016-12-01
The Global Precipitation Measurement (GPM) has been established to provide the next-generation observations of precipitation globally. It gives the opportunities to measure the snow and lighter rainfall rates, which are relatively difficult to be retrieved by the previous missions. Recently, the state of California experienced with El Nino in the winter of 2015-2016, which brought more-than-average rainfall and snow to the much of areas in the state. This study focused on the state of California to examine how well GPM can capture the winter precipitation compared to the Tropical Rainfall Measuring Mission (TRMM). The Integrated Multi-satellitE Retrievals for GPM (IMERG) final-run and TRMM Multi-satellite Precipitation Analysis (TMPA) version 7 were evaluated against the ground reference of NOAA stage IV multi-sensor composite rain analysis. This study employed both the pixel-based and object-based verification measures to conduct a comprehensive evaluation for GPM and TRMM in the winter season. Probability of Detection, False Alarm Ratio, Bias Ratio, Taylor Diagram, Object-based Missing Ratio, Object-based False Alarm Ratio and Overall Interest Score were used as evaluation metrics. We found the IMERG-final has a better overall performance. We anticipate that the IMERG will benefit the applications of satellite remote-sensed precipitation, such as, hydrological flood modeling, watershed management and climate studies.
Deep learning algorithms for detecting explosive hazards in ground penetrating radar data
NASA Astrophysics Data System (ADS)
Besaw, Lance E.; Stimac, Philip J.
2014-05-01
Buried explosive hazards (BEHs) have been, and continue to be, one of the most deadly threats in modern conflicts. Current handheld sensors rely on a highly trained operator for them to be effective in detecting BEHs. New algorithms are needed to reduce the burden on the operator and improve the performance of handheld BEH detectors. Traditional anomaly detection and discrimination algorithms use "hand-engineered" feature extraction techniques to characterize and classify threats. In this work we use a Deep Belief Network (DBN) to transcend the traditional approaches of BEH detection (e.g., principal component analysis and real-time novelty detection techniques). DBNs are pretrained using an unsupervised learning algorithm to generate compressed representations of unlabeled input data and form feature detectors. They are then fine-tuned using a supervised learning algorithm to form a predictive model. Using ground penetrating radar (GPR) data collected by a robotic cart swinging a handheld detector, our research demonstrates that relatively small DBNs can learn to model GPR background signals and detect BEHs with an acceptable false alarm rate (FAR). In this work, our DBNs achieved 91% probability of detection (Pd) with 1.4 false alarms per square meter when evaluated on anti-tank and anti-personnel targets at temperate and arid test sites. This research demonstrates that DBNs are a viable approach to detect and classify BEHs.
NASA Astrophysics Data System (ADS)
Loreggia, D.; Tataranni, F.; Trivero, P.; Biamino, W.; Di Matteo, L.
2017-10-01
We present the implementation of a procedure to adapt an Asymmetric Wiener Filtering (AWF) methodology aimed to detect and discard ghost signal due to azimuth ambiguities in SAR images to the case for X-band Cosmo Sky Med (CSK) images in the framework of SEASAFE (Slick Emissions And Ship Automatic Features Extraction) project, developed at the Department of Science and Technology Innovation of the University of Piemonte Orientale, Alessandria, Italy. SAR is a useful tool to daily and nightly monitoring of the sea surface in all weather conditions. SEASAFE project is a software platform developed in IDL language able to process data in C- Land X-band SAR images with enhanced algorithm modules for land masking, sea pollution (oil spills) and ship detection; wind and wave evaluation are also available. In this contest, the need to individuate and discard false alarms is a critical requirement. The azimuth ambiguity is one of the main causes that generate false alarm in the ship detection procedure. Many methods to face with this problem were proposed and presented in recent literature. After a review of different approach to this problem, we describe the procedure to adapt the AWF approach presented in [1,2] to the case of X-band CSK images by implementing a selective blocks approach.
Enhanced detection and visualization of anomalies in spectral imagery
NASA Astrophysics Data System (ADS)
Basener, William F.; Messinger, David W.
2009-05-01
Anomaly detection algorithms applied to hyperspectral imagery are able to reliably identify man-made objects from a natural environment based on statistical/geometric likelyhood. The process is more robust than target identification, which requires precise prior knowledge of the object of interest, but has an inherently higher false alarm rate. Standard anomaly detection algorithms measure deviation of pixel spectra from a parametric model (either statistical or linear mixing) estimating the image background. The topological anomaly detector (TAD) creates a fully non-parametric, graph theory-based, topological model of the image background and measures deviation from this background using codensity. In this paper we present a large-scale comparative test of TAD against 80+ targets in four full HYDICE images using the entire canonical target set for generation of ROC curves. TAD will be compared against several statistics-based detectors including local RX and subspace RX. Even a perfect anomaly detection algorithm would have a high practical false alarm rate in most scenes simply because the user/analyst is not interested in every anomalous object. To assist the analyst in identifying and sorting objects of interest, we investigate coloring of the anomalies with principle components projections using statistics computed from the anomalies. This gives a very useful colorization of anomalies in which objects of similar material tend to have the same color, enabling an analyst to quickly sort and identify anomalies of highest interest.
ERIC Educational Resources Information Center
Olszewska, Justyna M.; Reuter-Lorenz, Patricia A.; Munier, Emily; Bendler, Sara A.
2015-01-01
False working memories readily emerge using a visual item-recognition variant of the converging associates task. Two experiments, manipulating study and test modality, extended prior working memory results by demonstrating a reliable false recognition effect (more false alarms to associatively related lures than to unrelated lures) within seconds…
NASA Astrophysics Data System (ADS)
Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara
2015-07-01
We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.
Coordinated Optimization of Aircraft Routes and Locations of Ground Sensors
2014-09-17
d U γ P p w dw r sr s , (6) where γ is the detection threshold determined from the following equa- tion for some given faP : ( )( ) ,fa N γ...normal with the mean Uμ 7 and variance Uσ 2 3 . Suppose, the threshold for the false alarm is faP 410 . Then, from equation (7), .γ6 7190 ; and...functions; and the joint probability of false alarm would be ( , ) faP s s 4 4 81 2 10 10 10 whereas the joint probabil- ity of detection would
Synthetic aperture radar target detection, feature extraction, and image formation techniques
NASA Technical Reports Server (NTRS)
Li, Jian
1994-01-01
This report presents new algorithms for target detection, feature extraction, and image formation with the synthetic aperture radar (SAR) technology. For target detection, we consider target detection with SAR and coherent subtraction. We also study how the image false alarm rates are related to the target template false alarm rates when target templates are used for target detection. For feature extraction from SAR images, we present a computationally efficient eigenstructure-based 2D-MODE algorithm for two-dimensional frequency estimation. For SAR image formation, we present a robust parametric data model for estimating high resolution range signatures of radar targets and for forming high resolution SAR images.
Baijot, S; Deconinck, N; Slama, H; Massat, I; Colin, C
2013-12-01
This study compares behavioral and electrophysiological (P300) responses recorded in a cued continuous performance task (CPT-AX) performed by children with attention deficit hyperactivity disorder-combined subtype (ADHD-com) and age-matched healthy controls. P300 cognitive-evoked potentials and behavioral data were recorded in eight children with ADHD (without comorbidity) and nine control children aged 8-12 years while performing a CPT-AX task. Such task enables to examine several kinds of false alarms and three different kinds of P300 responses: the "Cue P300", the "Go P300" and the "NoGo P300", respectively, associated with preparatory processing/attentional orienting, motor/response execution and motor/response inhibition. Whereas hit rates were about 95% in each group, ADHD children made significantly more false alarm responses (inattention- and inhibition-related) than control children. ADHD children had a marginally smaller Cue P300 than the control children. Behavioral and electrophysiological findings both highlighted inhibition and attention deficits in ADHD-com children in the CPT-AX task. A rarely studied kind of false alarm, the "Other" FA, seems to be a sensitive FA to take into account, even if its interpretation remains unclear.
On the Use of Low-Cost Radar Networks for Collision Warning Systems Aboard Dumpers
González-Partida, José-Tomás; León-Infante, Francisco; Blázquez-García, Rodrigo; Burgos-García, Mateo
2014-01-01
The use of dumpers is one of the main causes of accidents in construction sites, many of them with fatal consequences. These kinds of work machines have many blind angles that complicate the driving task due to their large size and volume. To guarantee safety conditions is necessary to use automatic aid systems that can detect and locate the different objects and people in a work area. One promising solution is a radar network based on low-cost radar transceivers aboard the dumper. The complete system is specified to operate with a very low false alarm rate to avoid unnecessary stops of the dumper that reduce its productivity. The main sources of false alarm are the heavy ground clutter, and the interferences between the radars of the network. This article analyses the clutter for LFM signaling and proposes the use of Offset Linear Frequency Modulated Continuous Wave (OLFM-CW) as radar signal. This kind of waveform can be optimized to reject clutter and self-interferences. Jointly, a data fusion chain could be used to reduce the false alarm rate of the complete radar network. A real experiment is shown to demonstrate the feasibility of the proposed system. PMID:24577521
On the use of low-cost radar networks for collision warning systems aboard dumpers.
González-Partida, José-Tomás; León-Infante, Francisco; Blázquez-García, Rodrigo; Burgos-García, Mateo
2014-02-26
The use of dumpers is one of the main causes of accidents in construction sites, many of them with fatal consequences. These kinds of work machines have many blind angles that complicate the driving task due to their large size and volume. To guarantee safety conditions is necessary to use automatic aid systems that can detect and locate the different objects and people in a work area. One promising solution is a radar network based on low-cost radar transceivers aboard the dumper. The complete system is specified to operate with a very low false alarm rate to avoid unnecessary stops of the dumper that reduce its productivity. The main sources of false alarm are the heavy ground clutter, and the interferences between the radars of the network. This article analyses the clutter for LFM signaling and proposes the use of Offset Linear Frequency Modulated Continuous Wave (OLFM-CW) as radar signal. This kind of waveform can be optimized to reject clutter and self-interferences. Jointly, a data fusion chain could be used to reduce the false alarm rate of the complete radar network. A real experiment is shown to demonstrate the feasibility of the proposed system.
Nilakantan, Aneesha S; Voss, Joel L; Weintraub, Sandra; Mesulam, M-Marsel; Rogalski, Emily J
2017-06-01
Primary progressive aphasia (PPA) is clinically defined by an initial loss of language function and preservation of other cognitive abilities, including episodic memory. While PPA primarily affects the left-lateralized perisylvian language network, some clinical neuropsychological tests suggest concurrent initial memory loss. The goal of this study was to test recognition memory of objects and words in the visual and auditory modality to separate language-processing impairments from retentive memory in PPA. Individuals with non-semantic PPA had longer reaction times and higher false alarms for auditory word stimuli compared to visual object stimuli. Moreover, false alarms for auditory word recognition memory were related to cortical thickness within the left inferior frontal gyrus and left temporal pole, while false alarms for visual object recognition memory was related to cortical thickness within the right-temporal pole. This pattern of results suggests that specific vulnerability in processing verbal stimuli can hinder episodic memory in PPA, and provides evidence for differential contributions of the left and right temporal poles in word and object recognition memory. Copyright © 2017 Elsevier Ltd. All rights reserved.
Age differences in accuracy and choosing in eyewitness identification and face recognition.
Searcy, J H; Bartlett, J C; Memon, A
1999-05-01
Studies of aging and face recognition show age-related increases in false recognitions of new faces. To explore implications of this false alarm effect, we had young and senior adults perform (1) three eye-witness identification tasks, using both target present and target absent lineups, and (2) and old/new recognition task in which a study list of faces was followed by a test including old and new faces, along with conjunctions of old faces. Compared with the young, seniors had lower accuracy and higher choosing rates on the lineups, and they also falsely recognized more new faces on the recognition test. However, after screening for perceptual processing deficits, there was no age difference in false recognition of conjunctions, or in discriminating old faces from conjunctions. We conclude that the false alarm effect generalizes to lineup identification, but does not extend to conjunction faces. The findings are consistent with age-related deficits in recollection of context and relative age invariance in perceptual integrative processes underlying the experience of familiarity.
Design of remote car anti-theft system based on ZigBee
NASA Astrophysics Data System (ADS)
Fang, Hong; Yan, GangFeng; Li, Hong Lian
2015-12-01
A set of remote car anti-theft system based on ZigBee and GPRS with ARM11 built-in chip S3C6410 as the controller is designed. This system can detect the alarm information of the car with vibration sensor, pyroelectric sensor and infrared sensor. When the sensor detects any alarm signal, the ZigBee node in sleep will be awakened and then directly send the alarm signal to the microcontroller chip S3C6410 in the control room of the parking lot through ZigBee wireless transceiver module. After S3C6410 processes and analyzes the alarm signal, when any two sensors of the three collect the alarm signal, the LCD will display and generate an alarm and meanwhile it will send the alarm signal to the phone of the user in a wireless manner through the form of short message through GPRS module. Thus, the wireless remote monitoring of the system is realized.
Rainfall threshold definition using an entropy decision approach and radar data
NASA Astrophysics Data System (ADS)
Montesarchio, V.; Ridolfi, E.; Russo, F.; Napolitano, F.
2011-07-01
Flash flood events are floods characterised by a very rapid response of basins to storms, often resulting in loss of life and property damage. Due to the specific space-time scale of this type of flood, the lead time available for triggering civil protection measures is typically short. Rainfall threshold values specify the amount of precipitation for a given duration that generates a critical discharge in a given river cross section. If the threshold values are exceeded, it can produce a critical situation in river sites exposed to alluvial risk. It is therefore possible to directly compare the observed or forecasted precipitation with critical reference values, without running online real-time forecasting systems. The focus of this study is the Mignone River basin, located in Central Italy. The critical rainfall threshold values are evaluated by minimising a utility function based on the informative entropy concept and by using a simulation approach based on radar data. The study concludes with a system performance analysis, in terms of correctly issued warnings, false alarms and missed alarms.
ERIC Educational Resources Information Center
Anaki, D.; Faran, Y.; Ben-Shalom, D.; Henik, A.
2005-01-01
The mirror effect refers to a phenomenon where the hit rate is higher for low frequency words while the false alarm rate is higher for high frequency distractors. Using a false memory paradigm (Roediger & McDermott, 1995), we examined whether false memory for non-presented lures would be influenced by the lure's familiarity. The results revealed…
A description of nurses' decision-making in managing electrocardiographic monitor alarms.
Gazarian, Priscilla K; Carrier, Natalie; Cohen, Rachel; Schram, Haley; Shiromani, Samara
2015-01-01
To describe the cues and factors that nurses use in their decision-making when responding to clinical alarms. Alarms are designed to be very sensitive, and as a result, they are not very specific. Lack of adherence to the practice standards for electrocardiographic monitoring in hospital settings has been observed, resulting in overuse of the electrocardiographic monitoring. Monitoring without consideration of clinical indicators uses scarce healthcare resources and may even produce untoward circumstances because of alarm fatigue. With so many false alarms, alarm fatigue represents a symptom of a larger problem. It cannot be fixed until all of the factors that contribute to its existence have been examined. This was a qualitative descriptive study. This study was conducted at an academic medical centre located in the Northeast United States. Eight participants were enrolled using purposive sampling. Nurses were observed for two three-hour periods. Following each observation, the nurse was interviewed using the critical decision method to describe the cognitive processes related to the alarm activities. Qualitative data from the conducted interviews were analysed via an a priori framework founded in the critical decision method. This study reveals information, experience, guidance and decision-making as the four prominent categories contributing to nurses' decision-making in relation to alarm management. Managing technology was a category not identified a priori that emerged in the data analysis. Nurses revealed a breadth of information needed to adequately identify and interpret monitor alarms, and how they used that information to put the alarms into the particular context of an individual patient's situations. Understanding the cues and factors nurses use when responding to cardiac alarms will guide the development of learning experiences and inform policies to guide practice. © 2014 John Wiley & Sons Ltd.
Giving radioiodine? Think about airport security alarms.
Kaniuka-Jakubowska, S; Lewczuk, A; Mizan-Gross, K; Obołończyk, L; Lass, P; Sworczak, K
2012-01-01
An increased sensitivity of airport detectors, a growing number of isotopic tests, and globalization of the society have raised a number of false positive radioactive alarms at airports and public places. This paper presents two new cases of patients who triggered airport security alarms after receiving 740MBq of (131)I for non-toxic goitre and attempts to compare surprisingly limited literature concerning this problem. A 57-year-old man triggered a security alarm at three different airports on the 17th, 28th, and 31st day after radioiodine exposure. Interestingly enough, in the meantime, on the 18th and 22nd day, no radiation was detected in him at the airport where he was twice detained as a source of radiation later on. The second case presents a 45-year-old woman who activated security alarm detectors while crossing a border on her coach trip 28 days after radioiodine administration. Copyright © 2011 Elsevier España, S.L. and SEMNIM. All rights reserved.
Ansari, A H; Cherian, P J; Dereymaeker, A; Matic, V; Jansen, K; De Wispelaere, L; Dielman, C; Vervisch, J; Swarte, R M; Govaert, P; Naulaers, G; De Vos, M; Van Huffel, S
2016-09-01
After identifying the most seizure-relevant characteristics by a previously developed heuristic classifier, a data-driven post-processor using a novel set of features is applied to improve the performance. The main characteristics of the outputs of the heuristic algorithm are extracted by five sets of features including synchronization, evolution, retention, segment, and signal features. Then, a support vector machine and a decision making layer remove the falsely detected segments. Four datasets including 71 neonates (1023h, 3493 seizures) recorded in two different university hospitals, are used to train and test the algorithm without removing the dubious seizures. The heuristic method resulted in a false alarm rate of 3.81 per hour and good detection rate of 88% on the entire test databases. The post-processor, effectively reduces the false alarm rate by 34% while the good detection rate decreases by 2%. This post-processing technique improves the performance of the heuristic algorithm. The structure of this post-processor is generic, improves our understanding of the core visually determined EEG features of neonatal seizures and is applicable for other neonatal seizure detectors. The post-processor significantly decreases the false alarm rate at the expense of a small reduction of the good detection rate. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
A State-Space Approach to Optimal Level-Crossing Prediction for Linear Gaussian Processes
NASA Technical Reports Server (NTRS)
Martin, Rodney Alexander
2009-01-01
In many complex engineered systems, the ability to give an alarm prior to impending critical events is of great importance. These critical events may have varying degrees of severity, and in fact they may occur during normal system operation. In this article, we investigate approximations to theoretically optimal methods of designing alarm systems for the prediction of level-crossings by a zero-mean stationary linear dynamic system driven by Gaussian noise. An optimal alarm system is designed to elicit the fewest false alarms for a fixed detection probability. This work introduces the use of Kalman filtering in tandem with the optimal level-crossing problem. It is shown that there is a negligible loss in overall accuracy when using approximations to the theoretically optimal predictor, at the advantage of greatly reduced computational complexity. I