Academic literature on the topic 'Length-at-detection'
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Journal articles on the topic "Length-at-detection"
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Jones, Alwen L., Richard C. Roberts, and Michael W. H. Coughtrie. "Detection of a Sacl restriction fragment length polymorphism at the human phenolsulphotransferase locus." Clinical Genetics 49, no. 3 (June 28, 2008): 164–65. http://dx.doi.org/10.1111/j.1399-0004.1996.tb03279.x.
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Wu, Jianqing, Hao Xu, Yongsheng Zhang, Yuan Tian, and Xiuguang Song. "Real-Time Queue Length Detection with Roadside LiDAR Data." Sensors 20, no. 8 (April 20, 2020): 2342. http://dx.doi.org/10.3390/s20082342.
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Real-time queue length information is an important input for many traffic applications. This paper presents a novel method for real-time queue length detection with roadside LiDAR data. Vehicles on the road were continuously tracked with the LiDAR data processing procedures (including background filtering, point clustering, object classification, lane identification and object association). A detailed method to identify the vehicle at the end of the queue considering the occlusion issue and package loss issue was documented in this study. The proposed method can provide real-time queue length information. The performance of the proposed queue length detection method was evaluated with the ground-truth data collected from three sites in Reno, Nevada. Results show the proposed method can achieve an average of 98% accuracy at the six investigated sites. The errors in the queue length detection were also diagnosed.
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Kausik, Ravinath, and Songi Han. "Ultrasensitive Detection of Interfacial Water Diffusion on Lipid Vesicle Surfaces at Molecular Length Scales." Journal of the American Chemical Society 131, no. 51 (December 30, 2009): 18254–56. http://dx.doi.org/10.1021/ja9060849.
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Liu, Bo Hang, Hong Yang Zhu, and Wen Sheng Zhang. "The Sedan Length Detection Algorithm Based on the Tail Features." Applied Mechanics and Materials 543-547 (March 2014): 917–21. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.917.
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Extracting effectively the vehicle length is beneficial to classification of vehicle in video traffic detection. In the traditional video traffic detection, vehicles can be approximately regarded as a rectangle to extract the vehicle length. However, it is not accurate enough to use rectangle method to extract the length of sedan. In this paper, based on the tail features of the sedan, the mathematical algorithm of trigonometric function and similar triangles were applied to calculate the sedan length. And then, we discuss the computing method of sedan length detected by video from the different camera angles and detection line locations, and analyze the influence on the accuracy of the measuring sedan length. At last, a study is conducted for example analysis, and the result shows that the approach of extracting sedan length is feasible. Compared with the traditional algorithm, the sedan length accuracy is improved by 3.18% using the algorithm in the paper. Thus, the algorithm is of great significance to improve the accuracy of measuring the sedan length.
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Romanov, Dmitry S., and Elena Yu Romanova. "A method of synthesis of irredundant circuits admitting single fault detection tests of constant length." Discrete Mathematics and Applications 29, no. 1 (February 25, 2019): 35–48. http://dx.doi.org/10.1515/dma-2019-0005.
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Abstract A constructive proof is given that in each of the bases B′ = {x&y, x⊕y, x ∼ y}, B1 = {x&y, x⊕y, 1} any n-place Boolean function may be implemented: by an irredundant combinational circuit with n inputs and one output admitting (under single stuck-at faults at inputs and outputs of gates) a single fault detection test of length at most 16, by an irredundant combinational circuit with n inputs and one output admitting (under single stuck-at faults at inputs and outputs of gates and at primary inputs) a single fault detection test of length at most 2n−2log2 n+O(1); besides, there exists an n-place function that cannot be implemented by an irredundant circuit admitting a detecting test whose length is smaller than 2n−2log2 n − Ω(1), by an irredundant combinational circuit with n inputs and three outputs admitting (under single stuck-at faults at inputs and outputs of gates and at primary inputs) a single fault detection test of length at most 17.
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Mastali, M., J. T. Babbitt, Y. Li, E. M. Landaw, V. Gau, B. M. Churchill, and D. A. Haake. "Optimal Probe Length and Target Location for Electrochemical Detection of Selected Uropathogens at Ambient Temperature." Journal of Clinical Microbiology 46, no. 8 (June 18, 2008): 2707–16. http://dx.doi.org/10.1128/jcm.00423-08.
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Avva, Jessica, John M. Kovac, Christian Miki, David Saltzberg, and Abigail G. Vieregg. "An in situ measurement of the radio-frequency attenuation in ice at Summit Station, Greenland." Journal of Glaciology 61, no. 229 (2015): 1005–11. http://dx.doi.org/10.3189/2015jog15j057.
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AbstractWe report an in situ measurement of the electric field attenuation length Lα at radio frequencies for the bulk ice at Summit Station, Greenland, made by broadcasting radio-frequency signals vertically through the ice and measuring the relative power in the return ground bounce signal. We find the depth-averaged field attenuation length to be at 75 MHz. While this measurement has clear radioglaciological applications, the radio clarity of the ice also has implications for the detection of ultra-high energy (UHE) astrophysical particles via their radio emission in dielectric media such as ice. Assuming a reliable extrapolation to higher frequencies, the measured attenuation length at Summit Station is comparable to previously measured radio-frequency attenuation lengths at candidate particle detector sites around the world, and strengthens the case for Summit Station as a promising northern site for UHE neutrino detection.
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Zhang, Yajun, Xu Liu, Zhixiong Yang, Zijian Li, Xinyue Zhang, and Bo Yuan. "Capturing Features and Performing Human Detection from Human Gaits Using RFID." Sensors 22, no. 21 (October 31, 2022): 8353. http://dx.doi.org/10.3390/s22218353.
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Recently, radio frequency identification (RFID) sensing has attracted much attention due to its contact-free nature, low cost, light weight and other advantages. RFID-based person detection has also become a hot research topic, but there are still some problems in the existing research. First, most of the current studies cannot identify numerous people at a time well. Second, in order to detect more accurately, it is necessary to evaluate the whole-body activity of a person, which will consume a lot of time to process the data and cannot be applied in time. To solve these problems, in this paper we propose RF-Detection, a person detection system using RFID. First of all, RF-Detection takes step length as the standard for person detection, divides step length into specific sections according to the relationship between step length and height, and achieves high accuracy for new user detection through a large amount of training for a specific step length. Secondly, RF-Detection can better identify the number of people in the same space by segmenting continuous people. Finally, the data collection was reduced by expanding the data set, and the deep learning method was used to further improve the accuracy. The results show that the overall recognition accuracy of RF-Detection is 98.93%.
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Popkov, K. A. "Complete Fault Detection Tests of Length 2 for Logic Networks under Stuck-at Faults of Gates." Journal of Applied and Industrial Mathematics 12, no. 2 (April 2018): 302–12. http://dx.doi.org/10.1134/s1990478918020102.
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Comert, Gurcan. "Effect of stop line detection in queue length estimation at traffic signals from probe vehicles data." European Journal of Operational Research 226, no. 1 (April 2013): 67–76. http://dx.doi.org/10.1016/j.ejor.2012.10.035.
Full textDissertations / Theses on the topic "Length-at-detection"
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Sharma, Sanjay. "Performance Demonstration of Guided Waves based Structural Health Monitoring system for Aerospace Application." Electronic Thesis or Diss., université Paris-Saclay, 2022. http://www.theses.fr/2022UPASG073.
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Les ondes élastiques guidées émises et reçues par des transducteurs piézoélectriques minces sont reconnues comme une technologie prometteuse pour plusieurs applications de surveillance de l'état de santé des structures (ou Structural Health Monitoring - SHM), en particulier pour les composants aérospatiaux. La démonstration des performances de ces systèmes, souvent exprimées en termes de courbe de probabilité de détection (POD), est un élément clé du déploiement réussi de cette technologie dans l'industrie. La détermination expérimentale de la courbe POD nécessite de nombreux échantillons instrumentés, ce qui rend son coût prohibitif. Une approche basée sur la simulation, ou assistée par un modèle, est une alternative intéressante. Cependant, la simulation de systèmes SHM basés sur les ondes guidées et la détermination de la courbe POD de tels systèmes sont jusqu'à présent limitées en raison d'un manque de méthodologie spécifique, de procédures, de méthodes statistiques appropriées et de validation. Cette thèse propose une méthodologie générale pour une approche POD assistée par la simulation de système SHM par ondes guidées, avec une démonstration sur la surveillance d'une fissure croissante à partir d'un trou dans une plaque d'aluminium. La méthodologie tire parti de l'outil de simulation par éléments finis spectraux transitoires dans le domaine temporel développé au CEA-List (module CIVA SHM) qui permet d'exécuter les grandes campagnes de simulation nécessaires pour déterminer une courbe POD. Un nouveau modèle d'actionneur hybride a été proposé dans ce travail en considérant le comportement dépendant de la fréquence du transducteur et la contrainte normale en plus de la contrainte radiale comme charges surfaciques afin de permettre l’utilisation de la simulation sur une plus grande gamme de fréquences d'excitation, adaptées à l'application visée. Deux méthodes récentes et appropriées d’un point de vue statistique : la « longueur à la détection » et « random effects », ont ensuite été adaptées pour estimer et comparer la courbe POD à partir des ensembles de données expérimentales et simulées. L'approche bayésienne s'est avérée plus utile que l'estimation du maximum de vraisemblance pour l'estimation des paramètres du modèle de la méthode random effects afin de comparer la limite d'incertitude pour chaque paramètre du modèle à partir des ensembles de données expérimentales et simulées. Enfin, une étude de détermination de la taille de l'échantillon a été menée sur la base de la méthode random effects afin d'identifier le nombre d'échantillons nécessaires pour répondre aux exigences d'une application SHM particulière. Tous ces résultats montrent une grande confiance dans l'approche assistée par la simulation pour l’estimation de la POD et confirment le potentiel de cette solution en tant qu'outil compatible avec les exigences industrielles pour la démonstration des performances des systèmes SHM basés sur les ondes guidéesGuided elastic waves emitted and received by thin piezoelectric transducers are recognized as a promising technology for several applications of Structural Health Monitoring, especially of aerospace components. Demonstration of the performances of such systems, often expressed in terms of Probability Of Detection (POD) curve, is a key enabler of the successful deployment of the technology in industry. POD curve experimental determination requires many instrumented samples making its cost prohibitive. A simulation-based approach, or model-assisted, is an attractive alternative. However, simulation in guided waves-based SHM and POD determination of such systems are so far limited due to a lack of specific methodology, procedures, appropriate statistical methods, and validation. This thesis proposes a general methodology for a model-assisted POD approach of guided waves based SHM, with a demonstration on monitoring of a growing crack from a hole in an aluminum plate. The methodology benefits from the efficient time domain transient spectral finite element simulation tool developed at CEA-List (CIVA SHM module) that allows to run the large simulation campaigns required to determine a POD curve. A new hybrid actuator model has been proposed in this work by considering the transducer frequency dependent behaviour and normal stress in addition to radial stress as a surface loads to enable the use of simulation on a higher range of excitation frequencies, suitable for the targeted application. Two recent suitable statistical methods: length-at-detection and random effects, have then been adapted to estimate and to compare the POD curve from both experimental and simulated datasets. The Bayesian approach is found to be more useful in model parameter estimation of random effects method for comparing the uncertainty bound for each model parameter from experimental and simulated datasets than Maximum Likelihood Estimation. Finally, a sample size determination study has been conducted based on the random effects method to identify how many samples are required to achieve the requirement of a particular SHM application. All these results show great confidence in the model-assisted approach to POD estimation methodology and confirm the potential of this solution as a cost-effective tool for performance demonstration of guided waves-based SHM systems
Books on the topic "Length-at-detection"
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Doyle, Arthur Conan. Sherlock Holmes. Selected Stories. Edited by Barry McCrea. Oxford University Press, 2014. http://dx.doi.org/10.1093/owc/9780199672066.001.0001.
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‘Detection is, or ought to be, an exact science.’ For more than a century the Holmes stories have held a strange, almost inexplicable grip on the popular imagination. They are intimately associated with late Victorian and Edwardian society, yet curiously timeless in their appeal. The characters of Sherlock Holmes and Dr Watson, together with their housekeeper Mrs Hudson and their address at 221B Baker Street are as familiar today as when they made their first appearance in the late 1880s. The stories have been endlessly interpreted, adapted, and modernized, but still it is to Arthur Conan Doyle's originals that we return. This new selection of some of the best of them is designed to give readers a full sense of their world: the brooding fog of London, ruined heirs in creaking mansions, and hidden crimes in the farthest–flung corners of the British Empire. The stories take Holmes's career from its early days to its close, and include the book–length Sign of the Four. Barry McCrea's introduction investigates the currents that lie beneath their surface.
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Steane, Andrew M. Relativity Made Relatively Easy Volume 2. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780192895646.001.0001.
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This is a textbook on general relativity and cosmology for a physics undergraduate or an entry-level graduate course. General relativity is the main subject; cosmology is also discussed in considerable detail (enough for a complete introductory course). Part 1 introduces concepts and deals with weak-field applications such as gravitation around ordinary stars, gravimagnetic effects and low-amplitude gravitational waves. The theory is derived in detail and the physical meaning explained. Sources, energy and detection of gravitational radiation are discussed. Part 2 develops the mathematics of differential geometry, along with physical applications, and discusses the exact treatment of curvature and the field equations. The electromagnetic field and fluid flow are treated, as well as geodesics, redshift, and so on. Part 3 then shows how the field equation is solved in standard cases such as Schwarzschild-Droste, Reissner-Nordstrom, Kerr, and internal stellar structure. Orbits and related phenomena are obtained. Black holes are described in detail, including horizons, wormholes, Penrose process and Hawking radiation. Part 4 covers cosmology, first in terms of metric, then dynamics, structure formation and observational methods. The meaning of cosmic expansion is explained at length. Recombination and last scattering are calculated, and the quantitative analysis of the CMB is sketched. Inflation is introduced briefly but quantitatively. Part 5 is a brief introduction to classical field theory, including spinors and the Dirac equation, proceeding as far as the Einstein-Hilbert action. Throughout the book the emphasis is on making the mathematics as clear as possible, and keeping in touch with physical observations.
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de Graaf, Michiel A., Arthur JHA Scholte, Lucia Kroft, and Jeroen J. Bax. Computed tomography angiography and other applications of computed tomography. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199687039.003.0022.
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Patients presenting with acute chest pain constitute a common and important diagnostic challenge. This has increased interest in using computed tomography for non-invasive visualization of coronary artery disease in patients presenting with acute chest pain to the emergency department; particularly the subset of patients who are suspected of having an acute coronary syndrome, but without typical electrocardiographic changes and with normal troponin levels at presentation. As a result of rapid developments in coronary computed tomography angiography technology, high diagnostic accuracies for excluding coronary artery disease can be obtained. It has been shown that these patients can be discharged safely. The accuracy for detecting a significant coronary artery stenosis is also high, but the presence of coronary artery atherosclerosis or stenosis does not imply necessarily that the cause of the chest pain is related to coronary artery disease. Moreover, the non-invasive detection of coronary artery disease by computed tomography has been shown to be related with an increased use of subsequent invasive coronary angiography and revascularization, and further studies are needed to define which patients benefit from invasive evaluation following coronary computed tomography angiography. Conversely, the implementation of coronary computed tomography angiography can significantly reduce the length of hospital stay, with a significant cost reduction. Additionally, computed tomography is an excellent modality in patients whose symptoms suggest other causes of acute chest pain such as aortic aneurysm, aortic dissection, or pulmonary embolism. Furthermore, the acquisition of the coronary arteries, thoracic aorta, and pulmonary arteries in a single computed tomography examination is feasible, allowing ‘triple rule-out’ (exclusion of aortic dissection, pulmonary embolism, and coronary artery disease). Finally, other applications, such as the evaluation of coronary artery plaque composition, myocardial function and perfusion, or fractional flow reserve, are currently being developed and may also become valuable in the setting of acute chest pain in the future.
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de Graaf, Michiel A., Arthur JHA Scholte, Lucia Kroft, and Jeroen J. Bax. Computed tomography angiography and other applications of computed tomography. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199687039.003.0022_update_001.
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Patients presenting with acute chest pain constitute a common and important diagnostic challenge. This has increased interest in using computed tomography for non-invasive visualization of coronary artery disease in patients presenting with acute chest pain to the emergency department; particularly the subset of patients who are suspected of having an acute coronary syndrome, but without typical electrocardiographic changes and with normal troponin levels at presentation. As a result of rapid developments in coronary computed tomography angiography technology, high diagnostic accuracies for excluding coronary artery disease can be obtained. It has been shown that these patients can be discharged safely. The accuracy for detecting a significant coronary artery stenosis is also high, but the presence of coronary artery atherosclerosis or stenosis does not imply necessarily that the cause of the chest pain is related to coronary artery disease. Moreover, the non-invasive detection of coronary artery disease by computed tomography has been shown to be related with an increased use of subsequent invasive coronary angiography and revascularization, and further studies are needed to define which patients benefit from invasive evaluation following coronary computed tomography angiography. Conversely, the implementation of coronary computed tomography angiography can significantly reduce the length of hospital stay, with a significant cost reduction. Additionally, computed tomography is an excellent modality in patients whose symptoms suggest other causes of acute chest pain such as aortic aneurysm, aortic dissection, or pulmonary embolism. Furthermore, the acquisition of the coronary arteries, thoracic aorta, and pulmonary arteries in a single computed tomography examination is feasible, allowing ‘triple rule-out’ (exclusion of aortic dissection, pulmonary embolism, and coronary artery disease). Finally, other applications, such as the evaluation of coronary artery plaque composition, myocardial function and perfusion, or fractional flow reserve, are currently being developed and may also become valuable in the setting of acute chest pain in the future.
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de Graaf, Michiel A., Arthur JHA Scholte, Lucia Kroft, and Jeroen J. Bax. Computed tomography angiography and other applications of computed tomography. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199687039.003.0022_update_002.
Full textAbstract:
Patients presenting with acute chest pain constitute a common and important diagnostic challenge. This has increased interest in using computed tomography for non-invasive visualization of coronary artery disease in patients presenting with acute chest pain to the emergency department; particularly the subset of patients who are suspected of having an acute coronary syndrome, but without typical electrocardiographic changes and with normal troponin levels at presentation. As a result of rapid developments in coronary computed tomography angiography technology, high diagnostic accuracies for excluding coronary artery disease can be obtained. It has been shown that these patients can be discharged safely. The accuracy for detecting a significant coronary artery stenosis is also high, but the presence of coronary artery atherosclerosis or stenosis does not imply necessarily that the cause of the chest pain is related to coronary artery disease. Moreover, the non-invasive detection of coronary artery disease by computed tomography has been shown to be related with an increased use of subsequent invasive coronary angiography and revascularization, and further studies are needed to define which patients benefit from invasive evaluation following coronary computed tomography angiography. Conversely, the implementation of coronary computed tomography angiography can significantly reduce the length of hospital stay, with a significant cost reduction. Additionally, computed tomography is an excellent modality in patients whose symptoms suggest other causes of acute chest pain such as aortic aneurysm, aortic dissection, or pulmonary embolism. Furthermore, the acquisition of the coronary arteries, thoracic aorta, and pulmonary arteries in a single computed tomography examination is feasible, allowing ‘triple rule-out’ (exclusion of aortic dissection, pulmonary embolism, and coronary artery disease). Finally, other applications, such as the evaluation of coronary artery plaque composition, myocardial function and perfusion, or fractional flow reserve, are currently being developed and may also become valuable in the setting of acute chest pain in the future.
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de Graaf, Michiel A., Arthur JHA Scholte, Lucia Kroft, and Jeroen J. Bax. Computed tomography angiography and other applications of computed tomography. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199687039.003.0022_update_003.
Full textAbstract:
Patients presenting with acute chest pain constitute a common and important diagnostic challenge. This has increased interest in using computed tomography for non-invasive visualization of coronary artery disease in patients presenting with acute chest pain to the emergency department; particularly the subset of patients who are suspected of having an acute coronary syndrome, but without typical electrocardiographic changes and with normal troponin levels at presentation. As a result of rapid developments in coronary computed tomography angiography technology, high diagnostic accuracies for excluding coronary artery disease can be obtained. It has been shown that these patients can be discharged safely. The accuracy for detecting a significant coronary artery stenosis is also high, but the presence of coronary artery atherosclerosis or stenosis does not imply necessarily that the cause of the chest pain is related to coronary artery disease. Moreover, the non-invasive detection of coronary artery disease by computed tomography has been shown to be related with an increased use of subsequent invasive coronary angiography and revascularization, and further studies are needed to define which patients benefit from invasive evaluation following coronary computed tomography angiography. Conversely, the implementation of coronary computed tomography angiography can significantly reduce the length of hospital stay, with a significant cost reduction. Additionally, computed tomography is an excellent modality in patients whose symptoms suggest other causes of acute chest pain such as aortic aneurysm, aortic dissection, or pulmonary embolism. Furthermore, the acquisition of the coronary arteries, thoracic aorta, and pulmonary arteries in a single computed tomography examination is feasible, allowing ‘triple rule-out’ (exclusion of aortic dissection, pulmonary embolism, and coronary artery disease). Finally, other applications, such as the evaluation of coronary artery plaque composition, myocardial function and perfusion, or fractional flow reserve, are currently being developed and may also become valuable in the setting of acute chest pain in the future.
Book chapters on the topic "Length-at-detection"
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Brebner, Gordon, and John Gray. "Use of reconfigurability in variable-length code detection at video rates." In Field-Programmable Logic and Applications, 429–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/3-540-60294-1_137.
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Iba, D., Y. Tsutsui, Y. Ishii, B. H. Kien, N. Miura, T. Iizuka, A. Masuda, A. Sone, and I. Moriwaki. "Performance Evaluation of Automatic Labeling System of Crack Length at Tooth Root and Examination of Erroneous Detection." In Advances in Mechanism and Machine Science, 947–56. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20131-9_94.
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Blicha, Martin, Grigory Fedyukovich, Antti E. J. Hyvärinen, and Natasha Sharygina. "Transition Power Abstractions for Deep Counterexample Detection." In Tools and Algorithms for the Construction and Analysis of Systems, 524–42. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99524-9_29.
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AbstractWhile model checking safety of infinite-state systems by inferring state invariants has steadily improved recently, most verification tools still rely on a technique based on bounded model checking to detect safety violations. In particular, the current techniques typically analyze executions by unfolding transitions one step at a time, and the slow growth of execution length prevents detection of deep counterexamples before the tool reaches its limits on computations. We propose a novel model-checking algorithm that is capable of both proving unbounded safety and finding long counterexamples. The idea is to use Craig interpolation to guide the creation of symbolic abstractions of exponentially longer sequences of transitions. Our experimental analysis shows that on unsafe benchmarks with deep counterexamples our implementation can detect faulty executions that are at least an order of magnitude longer than those detectable by the state-of-the-art tools.
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Govindarajan, Usha, and Narasimhan K. "Approximation-Aided Epilepsy Detection Using Linear and Non-Linear Classifiers." In Machine Learning and AI Techniques in Interactive Medical Image Analysis, 135–50. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-4671-3.ch008.
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Patients with brain-related symptoms and diseases are diagnosed using electrocardiogram (EEG) signals. Epilepsy in humans can be diagnosed from EEG signals. This chapter focuses on identification of seizure-free, seizure, epileptic, and normal EEG signals with minimum-length EEG signal. The algorithm could classify the seizure and normal EEG signals even for a length of 1000 samples per segment. The algorithm was tested on various EEG signals. The traits are extracted from the EEG signal and preprocessed and fed to five different classifiers to check the accuracy of the scheme. The algorithm provided a better accuracy of 99.8945%. The sample signals were taken from an EEG signal database available at University of Bonn. The proposed scheme was tested with performance measures such as specificity (SPE), NPV (negative predictive value), PPV (positive predictive value), ACC (accuracy), MCC (Matthews's correlation coefficient), and sensitivity (SEN). The test results proved that the proposed methodology could perform real-time epileptic seizure detection.
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Yu, Tao. "Passive Detection Method Based on Angle Measurement." In Passive Location Method Based on Phase Difference Measurement, 136–95. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815079425122010008.
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This chapter first studies the relationship between angle measurement and phase difference measurement. On the one hand, this helps to understand the physical properties, and on the other hand, it helps to simplify the process of error analysis. Then, two kinds of direction-finding methods which can improve the positioning accuracy are presented. One is a double - station cross – direction-finding algorithm involving higher - order geometric parameters. The other is to use the algorithm characteristic of adjacent path difference to virtually expand the baseline length of the detection array, to improve the accuracy of the bi-station direction-finding system. Whereafter, the passive ranging formula for two detection platforms with different motion directions is researched. The analytical formula of target distance based on angle measurement of two carriers is directly derived in different directions and at different speeds in planar polar coordinate system. In the end. Several methods of the azimuth-only estimation of the course of a moving target in a straight line is presented. Its analytical process has nothing to do with the detection of time, and the analytical formula obtained is purely related to the azimuth angle.
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Kumar, Pramod, and Sushil Kumar. "Detection of Bio-Relevant Metal Ions by Luminescent Ru(II)-Polypyridyl Based Sensors." In Ruthenium - an Element Loved by Researchers [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96453.
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Biorelevant metal ions such as Cu2+ and Fe2+/Fe3+ participate in various biological events which include electron transfer reactions, delivery and uptake of oxygen, DNA and RNA syntheses, and enzymatic catalysis to maintain fundamental physiological processes in living organisms. So far, several analytical techniques have been investigated for their precise detection; however, luminescence-based sensing is often superior due to its high sensitivity, selectivity, fast and easy operation and convenient cellular imaging. Owing to their immense photophysical and photochemical properties stemming from large Stokes shift, absorption in visible region, good photostability and long excited state lifetimes, Ru(II)-polypyridyl-based complexes have gained increasing interest as luminophores. Over past few decades, several Ru(II)-polypyridyl based chemosensors have rapidly been developed for detection of different biorelevant and other metal ions. The main object of this book chapter is to cover a majority of Ru(II)-polypyridyl based chemosensors showing a selective and sensitive detection of bio-relevant Cu2+ and Fe2+/Fe3+ ions. The photophysical properties of Ru(II) complexes, detection of metal ions, sensing mechanism and applications of these sensors are discussed at a length.
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MacLullich, Alasdair M. J., Edward R. Marcantonio, and David J. Meagher. "Delirium." In Oxford Textbook of Geriatric Medicine, 363–72. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198701590.003.0049.
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Delirium is a complex medical emergency affecting at least 15% of older hospitalized patients. It causes considerable patient and carer distress, and is associated with adverse outcomes including falls, increased length of stay, new institutionalization, new and exacerbated long-term cognitive impairment, and mortality. Causes include medical illness, trauma, surgery, psychological stress, and drugs. The mechanisms involve direct effects on the brain such as hypoxia, and likely altered inflammatory and stress pathways. Older age, neurodegeneration, and medical comorbities greatly increase vulnerability. Detection involves eliciting evidence of acute inattention, altered level of arousal, and/or psychosis; brief tools such as the 4AT can improve detection rates. Care involves multiple aspects: treating all precipitating causes, optimizing general care, communicating with patients and carers, preventing complications, and treating distress and agitation. Detection of undiagnosed underlying dementia is important. Risk reduction in vulnerable patients, involving optimizing medical status, the care environment, and patient experience, is effective.
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Luisa García-Betancourt, María, Sandra I. Ramírez Jiménez, Apsahara González-Hodges, Zandra E. Nuñez Salazar, Ismailia Leilani Escalante-García, and Jeannete Ramírez Aparicio. "Low Dimensional Nanostructures: Measurement and Remediation Technologies Applied to Trace Heavy Metals in Water." In Trace Metals in the Environment - New Approaches and Recent Advances. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93263.
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A nanostructure is a system in which at least one external dimension is in the nanoscale, it means a length range smaller than 100 nm. Nanostructures can be natural or synthetic and determine the physicochemical properties of bulk materials. Due to their high surface area and surface reactivity, they can be an efficient alternative to remove contaminants from the environment, including heavy metals from water. Heavy metals like mercury (Hg), cadmium (Cd), arsenic (As), lead (Pb), and chromium (Cr) are highly poisonous and hazardous to human health due to their non-biodegradability and highly toxic properties, even at trace levels. Thus, efficient, low-cost, and environmentally friendly methodologies of removal are needed. These needs for removal require fast detection, quantification, and remediation to have heavy metal-free water. Nanostructures emerged as a powerful tool capable to detect, quantify, and remove these contaminants. This book chapter summarizes some examples of nanostructures that have been used on the detection, quantification, and remediation of heavy metals in water.
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Buckle, V. J., and K. A. Rack. "Fluorescent in situ hybridization." In Human Genetic Disease Analysis, 59–82. Oxford University PressOxford, 1993. http://dx.doi.org/10.1093/oso/9780199633098.003.0004.
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Abstract The hybridization of RNA in situ to the DNA of a cytological preparation was first described by Gall and Pardue in 1969 (1) and the general principles of the technique they developed remain the basis of contemporary studies. During the 1970s this procedure was used to localize repeated sequences within the human genome by autoradiographic detection of radioactively labelled probes, and during the 1980s the sensitivity of this approach was refined sufficiently to permit detection of unique sequences of only 500 base pairs in length. At the same time non-isotopic detection procedures were being developed, which have several advantages over autoradiography including speed, safety, and resolution of signal. Advances in this area in recent years have revolutionized the applications for in situ hybridization as a tool in genome research. In particular the use of competitive hybridization means an enormous size range of cloned DNA sequences are now available for use as probes, and fluorescent detection systems now permit the concurrent visualization of multiple probes. These powerful new techniques provide a tool not only for examining the location and distribution of sequences on metaphase chromosomes but also for investigating organization within the interphase nucleus.
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Pradhan, Sonali, Mitrabinda Ray, and Srikanta Patnaik. "Coverage Criteria for State-Based Testing." In Research Anthology on Agile Software, Software Development, and Testing, 1222–44. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-3702-5.ch061.
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State-based testing (SBT) is known as deriving test cases from state machines and examining the dynamic behaviour of the system. It helps to identify various types of state-based faults within a system under test (SUT). For SBT, test cases are generated from state chart diagrams based on various coverage criteria such as All Transition, Round Trip Path, All Transition Pair, All Transition Pair with length 2, All Transition Pair with length 3, All Transition Pair of length 4 and Full Predicate. This article discuses a number of coverage criteria at the design level to find out various types of state-based faults in SBT. First, the intermediate graph is generated from a state chart diagram using an XML parser. The graph is traversed based on the given coverage criteria to generate a sequence of test cases. Then, mutation testing and sneak-path testing are applied on the generated test cases to check the effectiveness of the generated test suite. These two are common methods for checking the effectiveness of test cases. Mutation testing helps in the number of seeded errors covered whereas sneak-path testing basically helps to examine the unspecified behavior of the system. In round trip path (RTP), it is not possible to cover all paths. All transition is not an adequate level of fault detection with more execution time compared to all transition pair (ATP) with length 4 (LN4). In the discussion, ATP with LN4 is the best among all coverage criteria. SBT can able to detect various state-based faults-incorrect transition, missing transition, missing or incorrect event, missing or incorrect action, extra missing or corrupt state, which are difficult to detect in code-based testing. Most of these state-based faults can be avoided, if the testing is conducted at the early phase of design.
Conference papers on the topic "Length-at-detection"
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Overbeck, Jay A., Bradley Duncan, Paul McManamon, and Scott McCracken. "Eye-safe lidar at 2.09 μm." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.fmm1.
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A 2.09 μm eye-safe laser radar is being built that will have a coherent and an incoherent mode of operation. The trade-offs between coherent and incoherent detection methods will be investigated. In coherent detection a single pulse can be used for both velocity and range measurements. The problem that arises in coherent detection is that accurate velocity measurements require a long pulse and the longer the pulse the worse the range resolution. Another problem that exists in coherent detection is the longer the coherence length of the pulse the more degradation in the signal at the receiver caused by speckle. In an incoherent system velocity measurements can be made with two successive range measurements. The pulse length used can be shortened, increasing the range resolution and decreasing the degradation caused by speckle. This system will be used to compare the theoretical predictions with actual measurements as well as to examine the practical implementation of the different detection techniques.
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Peyton, Christian, Rachel S. Edwards, Steve Dixon, Ben Dutton, and Wilson Vesga. "Detection of Defects in Titanium Using Shear Horizontal Guided Waves." In 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/qnde2021-74942.
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Abstract This paper investigates the interaction behaviour between the fundamental shear horizontal guided wave mode and small defects, in order to understand and develop an improved inspection system for titanium samples. In this work, an extensive range of defect sizes have been simulated using finite element software. The SH0 reflection from a defect has been shown previously to depend on its length as the total reflection consists of reflections from both the front and back face. However, for small defect widths, this work has found that the width also affects this interference, changing the length at which the reflection is largest. In addition, the paper looks at how the size of the defect affects the mode converted S0 reflection and SH0 diffraction. The relationship between the SH0 diffraction and defect size is shown to be more complex compared to the reflections. The mode converted S0 reflection occurs at an angle to the incident wave direction; therefore, the most suitable angle for the detection has been found. Simultaneous measurement of multiple waves would bring benefits to inspection.
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Hatanaka, Shozo, Masahiko Tange, and Morio Sumiyama. "Remote Monitoring Systems for Detection of Contact by Unauthorized Construction Equipment and the Cathodic Protection Condition on Buried Pipelines." In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-3081.
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It is necessary to avoid spreading damage to the pipe when it is struck by construction equipment. It is difficult to install indirect methods (e.g. fiber optic sensors) for detection of construction equipment in heavy traffic areas. Therefore, remote monitoring systems, which can detect contact between such equipment and the steel of polyethylene-lined pipe, were developed and installed on a gas transmission pipeline (φ 600 mm, Length 9.4 km). Detection uses the change in pipe-to-earth resistance which is derived from inner pipe current and pipe to soil potential when contact occurs. Old and new data of pipe-to-earth resistance are continuously compared. If equipment contacts the steel pipe, pipe-to-earth resistance will drop below 100 Ω. The detection systems include maximal length sequence signal (pseudo-random signal) processing. This signal processing is superior for noise reduction. These systems also have remote monitoring of the cathodic protection condition (pipe to soil potential, current of coupons (probes), and transformer rectifier output voltage and current). From the office, pipeline lining and cathodic protection conditions are monitored at all times.
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Narahara, T., K. Aratani, A. Fukumoto, and S. Masuhara. "A Partial-Response Maximum-Likelihood Detection Method for MO Recording." In Symposium on Optical Memory. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/isom.1996.othb.4.
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Magnetic field modulation recording (MFM) on a magneto-optical (MO) disk has the advantage of being able to write shorter marks corresponding to higher linear recording density. We reported on an approach to increasing the recording density in an MO disk by improving the signal to noise-ratio (SNR) and optimizing the conventional media structure[1]. The conventional edge detection method combined with a run-length limited (RLL) code has the limitation of detecting recorded bits at linear densities where the minimum carrier level is small because of increasing intersymbol interference (ISI). The partial-response maximum-likelihood (PRML) detection method is well known for being efficient especially for channels that suffers severe ISI but has good linearity.
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Cassidy, Daniel T., Douglas M. Bruce, and Brian F. Ventrudo. "Detection of oxygen using short external cavity GaAs lasers." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/oam.1989.thnn3.
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AlGaAs semiconductor diode lasers with short external cavities (SXC) have been used for high sensitivity detection of O2 in the near infrared. The mode control provided by the SXC enhances the performance of diode lasers by forcing lasing on any one of a number (up to 10) of the laser modes. The lasing mode is selected by altering the length of the SXC and the selected mode can be continuously scanned over extended frequency intervals. This provides nearly complete spectral coverage in discrete segments of up to ~40 cm−1 at constant laser heat sink temperatures. When using second harmonic detection techniques these SXC controlled lasers were found to provide high sensitivity detection of O2 at atmospheric pressure. A minimum detectable absorbance of ~4 × 10−6 has been achieved with a SNR of 1. The stability of these laser systems has also allowed the continuous monitoring of an absorption signal over extended time intervals. Absorbances of 1 × 10−2 have been continuously monitored for 15-h (overnight) durations with a rms uncertainty of ±6 × 10−5.
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Dougherty, Joseph P., Francis R. Preli, and Robert G. Michel. ""Zeeman Electrothermal Atomizer Laser Excited Atomic Fluorescence Spectrometry"." In Laser Applications to Chemical Analysis. Washington, D.C.: Optica Publishing Group, 1987. http://dx.doi.org/10.1364/laca.1987.pdp22.
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The work of Bolshov et al. (1) demonstrated elemental limits of detection at the femtogram level (part-per-trillion in solution) using Laser Excited Atomic Fluorescence Spectrometry (LEAFS) in a graphite cup atomizer. We have now shown that these detection limits can be equaled by using a graphite tube atomizer. Detection limits for LEAFS of seven elements are reported in Table 1. In this work two different graphite tube atomizers were used. One atomizer was a Perkin Elmer HGA-500 furnace (approximately 28 mm in length). The other was a laboratory constructed furnace (approximately 8 mm in length). The excitation source used for this work was a dye laser pumped by an excimer laser (308 nm). The dye laser output was frequency doubled to excite atomic transitions below 350 nm. The detection system consisted of a monochromator, a photomultiplier tube (PMT), a boxcar integrator and a computer.
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Skow, Jason, and Len LeBlanc. "In-Line Inspection Tool Performance Evaluation Using Field Excavation Data." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33755.
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This paper is based on some of the findings resulting from the PRCI project NDE-4E which examined the performance of various crack ILI technologies based on an industry data mining exercise. One of the project deliverables was an extensive database of crack in-line inspection (ILI) and excavation information collected from operators. This was used to characterize the field performance of ILI technologies with respect to detection, identification and sizing of crack features. Thousands of feature measurements were collected from several operating companies. The data were validated to ensure completeness, consistency and accuracy, and stored in a database. The main results to date are as follows: • Most profiles have shallow areas along the feature length — they are not semi-elliptical or parabolic in shape as usually assumed in burst pressure computations. Shallow regions increase the defect length, but do not increase the defect cross-section proportionally. • If it is assumed that the ILI tool requires a minimum depth before a portion of a feature is reported, it follows that the length reported by the ILI tool would differ from that observed in the field. This is due to the fact that the ILI tool would be reporting the length of the crack at some threshold depth and the field would be reporting the feature length at the surface. • Using depth profiles, an effective detection depth was calculated, that is the average depth at which the ILI length aligns with the profile. This was determined to be an average value of 0.88 mm for cracks and 0.83 mm for crack-fields which exceeds published ILI tool specification. • Shallow parts of a crack profile have significant impact on the field-measured length, but do not significantly impact the burst pressure. • For 83% of the data, the remaining strength factor (RSF) calculated using ILI data is within 10% of the RSF value calculated using field profiles. • Feature depth recorded in depth categories by the ILI tools show sensitivity to their proximity to long seam welds for crack-like features. • Overall, Burst pressure is more relevant to pipeline integrity than either length or depth individually and burst pressure calculated from ILI measurements is conservatively biased compared to burst pressure calculated from profile data.
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Xue, Chuhui, Shijian Lu, and Wei Zhang. "MSR: Multi-Scale Shape Regression for Scene Text Detection." In Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California: International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/139.
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State-of-the-art scene text detection techniques predict quadrilateral boxes that are prone to localization errors while dealing with straight or curved text lines of different orientations and lengths in scenes. This paper presents a novel multi-scale shape regression network (MSR) that is capable of locating text lines of different lengths, shapes and curvatures in scenes. The proposed MSR detects scene texts by predicting dense text boundary points that inherently capture the location and shape of text lines accurately and are also more tolerant to the variation of text line length as compared with the state of the arts using proposals or segmentation. Additionally, the multi-scale network extracts and fuses features at different scales which demonstrates superb tolerance to the text scale variation. Extensive experiments over several public datasets show that the proposed MSR obtains superior detection performance for both curved and straight text lines of different lengths and orientations.
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Heigel, J. C., and B. M. Lane. "Measurement of the Melt Pool Length During Single Scan Tracks in a Commercial Laser Powder Bed Fusion Process." In ASME 2017 12th International Manufacturing Science and Engineering Conference collocated with the JSME/ASME 2017 6th International Conference on Materials and Processing. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/msec2017-2942.
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This work presents high speed thermographic measurements of the melt pool length during single track laser scans on nickel alloy 625 substrates. Scans are made using a commercial laser powder bed fusion machine while measurements of the radiation from the surface are made using a high speed (1800 frames per second) infrared camera. The melt pool length measurement is based on the detection of the liquidus-solidus transition that is evident in the temperature profile. Seven different combinations of programmed laser power (49 W to 195 W) and scan speed (200 mm/s to 800 mm/s) are investigated and numerous replications using a variety of scan lengths (4 mm to 12 mm) are performed. Results show that the melt pool length reaches steady state within 2 mm of the start of each scan. Melt pool length increases with laser power, but its relationship with scan speed is less obvious because there is no significant difference between cases performed at the highest laser power of 195 W. Although keyholing appears to affect the anticipated trends in melt pool length, further research is required.
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Sambasivan, Lokesh Kumar, Venkataramana Bantwal Kini, Srikanth Ryali, Joydeb Mukherjee, and Dinkar Mylaraswamy. "Comparison of a Few Fault Diagnosis Methods on Sparse Variable Length Time Series Sequences." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27843.
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Accurate gas turbine engine Fault Detection and Diagnosis (FDD) is essential to improving aircraft safety as well as in reducing airline costs associated with delays and cancellations. This paper compares broadly three methods of fault detection and diagnosis (FDD) dealing with variable length time sequences. Chosen methods are based on Dynamic Time Warping (DTW), k-Nearest Neighbor method, Hidden Markov Model (HMM) and a Support Vector Machine (SVM) which makes use of DTW ingeniously as its kernel. The time sequences are obtained from Turbo Propulsion Engines in their nominal conditions and two faulty conditions. Typically there is paucity of faulty exemplars and the challenge is to come up with algorithms which work reasonably well under such circumstances. Also, normalization of data plays a significant role in determining the performance of the classifiers used for FDD in terms of their detection rate and false positives. In particular spherical normalization has been explored considering the advantage of its superior normalization properties. Given sparse training data how well each of these algorithms performs is shown by means of tests performed on time series data collected at normal and faulty modes from a turbofan gas turbine propulsion engine and the results are presented.
Reports on the topic "Length-at-detection"
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Gafny, Ron, A. L. N. Rao, and Edna Tanne. Etiology of the Rugose Wood Disease of Grapevine and Molecular Study of the Associated Trichoviruses. United States Department of Agriculture, September 2000. http://dx.doi.org/10.32747/2000.7575269.bard.
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Rugose wood is a complex disease of grapevines, characterized by modification of the woody cylinder of affected vines. The control of rugose wood is based on the production of healthy propagation material. Detection of rugose wood in grapevines is difficult and expensive: budwood from tested plants is grafted onto sensitive Vitis indicators and the appearance of symptoms is monitored for 3 years. The etiology of rugose wood is complex and has not yet been elucidated. Several elongated clostero-like viruses are consistently found in affected vines; one of them, grapevine virus A (GVA), is closely associated with Kober stem grooving, a component of the rugose wood complex. GVA has a single-stranded RNA genome of 7349 nucleotides, excluding a polyA tail at the 3' terminus. The GVA genome includes five open reading frames (ORFs 1-5). ORF 4, which encodes for the coat protein of GVA, is the only ORF for which the function was determined experimentally. The original objectives of this research were: 1- To produce antisera to the structural and non-structural proteins of GVA and GVB and to use these antibodies to establish an effective detection method. 2- Develop full length infectious cDNA clones of GVA and GVB. 3- Study the roll of GVA and GVB in the etiology of the grapevine rugose wood disease. 4- Determine the function of Trichovirus (now called Vitivirus) encoded genes in the virus life cycle. Each of the ORFs 2, 3, 4 and 5 genes of GVA were cloned and expressed in E. coli and used to produce antisera. Both the CP (ORF 4) and the putative MP (ORF 3) were detected with their corresponding antisera in-GVA infected N. benthamiana and grapevine. The MP was first detected at an early stage of the infection, 6-12 h after inoculation, and the CP 2-3 days after inoculation. The MP could be detected in GVA-infected grapevines that tested negative for CP, both with CP antiserum and with a commercially available ELISA kit. Antisera to ORF 2 and 5 encoded proteins could react with the recombinant proteins but failed to detect both proteins in GVA infected plants. A full-length cDNA clone of grapevine virus A (GVA) was constructed downstream from the bacteriophage T7 RNA polymerase promoter. Capped in vitro transcribed RNA was infectious in N. benthamiana and N. clevelandii plants. Symptoms induced by the RNA transcripts or by the parental virus were indistinguishable. The infectivity of the in vitro-transcribed RNA was confirmed by serological detection of the virus coat and movement proteins and by observation of virions by electron microscopy. The full-length clone was modified to include a gus reporter gene and gus activity was detected in inoculated and systemic leaves of infected plants. Studies of GVA mutants suggests that the coat protein (ORF 4) is essential for cell to cell movement, the putative movement protein (ORF 3) indeed functions as a movement protein and that ORF 2 is not required for virus replication, cell to cell or systemic movement. Attempts to infect grapevines by in-vitro transcripts, by inoculation of cDNA construct in which the virus is derived by the CaMV 35S promoter or by approach grafting with infected N. benthamiana, have so far failed. Studies of the subcellular distribution of GFP fusion with each of ORF 2, 3 and 4 encoded protein showed that the CP fusion protein accumulated as a soluble cytoplasmatic protein. The ORF 2 fusion protein accumulated in cytoplasmatic aggregates. The MP-GFP fusion protein accumulated in a large number of small aggregates in the cytoplasm and could not move from cell to cell. However, in conditions that allowed movement of the fusion protein from cell to cell (expression by a PVX vector or in young immature leaves) the protein did not form cytoplasmatic aggregates but accumulated in the plasmodesmata.
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Siebenaler, Shane. PR-015-163766-R01 Field Testing of Distributed Acoustic Sensing Systems. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2018. http://dx.doi.org/10.55274/r0011503.
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Distributed acoustic sensing (DAS) technology utilizes a fiber-optic cable as a distributed vibration sensor that can be installed in a right-of-way to monitor for pipeline leaks and to identify third-party interference (TPI), such as mechanized excavation, hand digging, etc. Various laboratory tests have been performed to demonstrate that DAS has the potential to be a flexible solution for pipeline operators. A key gap that needs to be assessed is the ability of the technology to serve its intended leak detection and TPI functions while not generating alarms at any other times. The most comprehensive means of performing such an evaluation is through an actual field demonstration of DAS technology on an operational pipeline. This report documents a ten-week-long test of four commercially available DAS technologies on an operational pipeline. The pipeline segment is 25-kilometers in length, and the systems were configured to autonomously alarm to leaks and mechanical digging. This research demonstrates the real-world performance of such systems and provides qualitative information in regards to the operational requirements for sustained deployment of DAS technology. This document has a related webinar. (member login required)
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Levisohn, Sharon, Mark Jackwood, and Stanley Kleven. New Approaches for Detection of Mycoplasma iowae Infection in Turkeys. United States Department of Agriculture, February 1995. http://dx.doi.org/10.32747/1995.7612834.bard.
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Mycoplasma iowae (Mi) is a pathogenic avian mycoplasma which causes mortality in turkey embryos and as such has clinical and economic significance for the turkey breeder industry. Control of Mi infection is severely hampered by lack of adequate diagnostic tests, together with resistance to most antibiotics and resilience to environment. A markedly high degree of intra-species antigenic variation also contributes to difficulties in detection and control of infection. In this project we have designed an innovative gene-based diagnostic test based on specific amplification of the 16S rRNA gene of Mi. This reaction, designed Multi-species PCR-RFLP test, also amplifies the DNA of the pathogenic avian mycoplasmas M. gallisepticum (Mg) and M. synoviae (Ms). This test detects DNA equivalent to about 300 cfu Mi or either of the other two target mycoplasmas, individually or in mixed infection. It is a quick test, applicable to a wide variety of clinical samples, such as allantoic fluid or tracheal or cloacal swab suspensions. Differential diagnosis is carried out by gel electro-phoresis of the PCR amplicon digested with selected restriction enzymes (Restriction Fragment Length Polymorphism). This can also be readily accomplished by using a simple Dot-Blot hybridization assay with digoxigenin-labeled oligonucleotide probes reacting specifically with unique Mi, Mg or Ms sequences in the PCR amplicon. The PCR/OLIGO test increased sensitivity by at least 10-fold with a capacity for rapid testing of large numbers of samples. Experimental infection trials were carried out to evaluate the diagnostic tools and to study pathogenesis of Mi infection. Field studies and experimental infection of embryonated eggs indicated both synergistic and competitive interaction of mycoplasma pathogens in mixed infection. The value of the PCR diagnostic tests for following the time course of egg transmission was shown. A workable serological test (Dot Immunobinding Assay) was also developed but there was no clear-cut evidence that infected turkeys develop an immune response. Typing of a wide spectrum of Mi field isolates by a variety of gene-based molecular techniques indicated a higher degree of genetic homogeneity than predicted on the basis of the phenotypic variability. All known strains of Mi were detected by the method developed. Together with an M. meleagridis-PCR test based on the same gene, the Multi-species PCR test is a highly valuable tool for diagnosis of pathogenic mycoplasmas in single or mixed infection. The further application of this rapid and specific test as a part of Mi and overall mycoplasma control programs will be dependent on developments in the turkey industry.
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Zhang, Renduo, and David Russo. Scale-dependency and spatial variability of soil hydraulic properties. United States Department of Agriculture, November 2004. http://dx.doi.org/10.32747/2004.7587220.bard.
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Water resources assessment and protection requires quantitative descriptions of field-scale water flow and contaminant transport through the subsurface, which, in turn, require reliable information about soil hydraulic properties. However, much is still unknown concerning hydraulic properties and flow behavior in heterogeneous soils. Especially, relationships of hydraulic properties changing with measured scales are poorly understood. Soil hydraulic properties are usually measured at a small scale and used for quantifying flow and transport in large scales, which causes misleading results. Therefore, determination of scale-dependent and spatial variability of soil hydraulic properties provides the essential information for quantifying water flow and chemical transport through the subsurface, which are the key processes for detection of potential agricultural/industrial contaminants, reduction of agricultural chemical movement, improvement of soil and water quality, and increase of agricultural productivity. The original research objectives of this project were: 1. to measure soil hydraulic properties at different locations and different scales at large fields; 2. to develop scale-dependent relationships of soil hydraulic properties; and 3. to determine spatial variability and heterogeneity of soil hydraulic properties as a function of measurement scales. The US investigators conducted field and lab experiments to measure soil hydraulic properties at different locations and different scales. Based on the field and lab experiments, a well-structured database of soil physical and hydraulic properties was developed. The database was used to study scale-dependency, spatial variability, and heterogeneity of soil hydraulic properties. An improved method was developed for calculating hydraulic properties based on infiltration data from the disc infiltrometer. Compared with the other methods, the proposed method provided more accurate and stable estimations of the hydraulic conductivity and macroscopic capillary length, using infiltration data collected atshort experiment periods. We also developed scale-dependent relationships of soil hydraulic properties using the fractal and geostatistical characterization. The research effort of the Israeli research team concentrates on tasks along the second objective. The main accomplishment of this effort is that we succeed to derive first-order, upscaled (block effective) conductivity tensor, K'ᵢⱼ, and time-dependent dispersion tensor, D'ᵢⱼ, i,j=1,2,3, for steady-state flow in three-dimensional, partially saturated, heterogeneous formations, for length-scales comparable with those of the formation heterogeneity. Numerical simulations designed to test the applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots suggested that even in this complicated case, the upscaling methodology essentially compensated for the loss of sub-grid-scale variations of the velocity field caused by coarse discretization of the flow domain. These results have significant implications with respect to the development of field-scale solute transport models capable of simulating complex real-world scenarios in the subsurface, and, in turn, are essential for the assessment of the threat posed by contamination from agricultural and/or industrial sources.
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Hoekman, Steven, Jamie Womble, Thomas Ziomek, and Courtney Amundson. Monitoring Kittlitz’s and marbled murrelets in Glacier Bay National Park and Preserve: 2021 annual report. National Park Service, August 2023. http://dx.doi.org/10.36967/2299439.
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Since 2009, the Southeast Alaska Network (SEAN) has monitored the abundance and spatial distribution of Kittlitz’s (Brachyramphus brevirostris, “KIMU”) and marbled murrelets (B. marmoratus, “MAMU”) in Glacier Bay National Park, an important summer residence for both species. Species-specific, on-water density and abundance of murrelets is estimated from vessel-based line transect surveys, while accounting for detection probability and partial identification (identification only to genus). Design of the monitoring program focuses on KIMU, with secondary consideration of MAMU. Due to the global pandemic, surveys were not conducted in 2020. In 2021, we only surveyed permanent panel transects, which totaled 56% of the length of transects planned for 2021. Permanent panel transects are primarily located in the middle and upper areas of Glacier Bay and sample regions within the total survey area that have relatively high expected densities of KIMU. Inference was limited to the 339 km2 “high-density area” formed by these regions, which comprised 29% of the total survey area. To provide context for 2021 results, we also estimated species-specific densities in the high-density area from 2011 to 2019. We surveyed 25 transects totaling 130 km from 13 to 21 July 2021. Within the high-density area, we estimated an abundance of 2,921 (SE = 734) KIMU and 21,710 (2,421) MAMU and densities of 8.6 (2.2) and 64.0 (7.1) individuals/km2. Estimated densities of each species in the high-density area were similar between 2019 and 2021, with KIMU estimates near the lower end of the range from 2011 to 2021 and MAMU estimates near the upper end. Observations of KIMU were concentrated in smaller, glacially influenced middle and upper reaches of Glacier Bay, especially in Johns Hopkins Inlet in the upper West Arm (~40% of observations). MAMU were more evenly dispersed, with the densest aggregations located in the upper east side of the central bay and at the mouth of the East Arm. While estimated abundance of MAMU in the total survey area showed no clear trend from 2011 to 2019, the percent of MAMU occupying the high-density area steadily increased from ~20% to >40%, suggesting a northward shift in their spatial distribution. The estimated percent of the total KIMU population occupying the high-density area jumped from ~45% from 2011 to 2018 to 85% in 2019. This change coincided with exceptionally low estimated abundance in the total survey area, which resulted primarily from very low estimated density outside the high-density area. Resuming full survey effort should help clarify the nature and persistence of these changes and their implications for conservation and monitoring
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Quinn, Meghan. Geotechnical effects on fiber optic distributed acoustic sensing performance. Engineer Research and Development Center (U.S.), July 2021. http://dx.doi.org/10.21079/11681/41325.
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Distributed Acoustic Sensing (DAS) is a fiber optic sensing system that is used for vibration monitoring. At a minimum, DAS is composed of a fiber optic cable and an optic analyzer called an interrogator. The oil and gas industry has used DAS for over a decade to monitor infrastructure such as pipelines for leaks, and in recent years changes in DAS performance over time have been observed for DAS arrays that are buried in the ground. This dissertation investigates the effect that soil type, soil temperature, soil moisture, time in-situ, and vehicle loading have on DAS performance for fiber optic cables buried in soil. This was accomplished through a field testing program involving two newly installed DAS arrays. For the first installation, a new portion of DAS array was added to an existing DAS array installed a decade prior. The new portion of the DAS array was installed in four different soil types: native fill, sand, gravel, and an excavatable flowable fill. Soil moisture and temperature sensors were buried adjacent to the fiber optic cable to monitor seasonal environmental changes over time. Periodic impact testing was performed at set locations along the DAS array for over one year. A second, temporary DAS array was installed to test the effect of vehicle loading on DAS performance. Signal to Noise Ratio (SNR) of the DAS response was used for all the tests to evaluate the system performance. The results of the impact testing program indicated that the portions of the array in gravel performed more consistently over time. Changes in soil moisture or soil temperature did not appear to affect DAS performance. The results also indicated that time DAS performance does change somewhat over time. Performance variance increased in new portions of array in all material types through time. The SNR in portions of the DAS array in native silty sand material dropped slightly, while the SNR in portions of the array in sand fill and flowable fill material decreased significantly over time. This significant change in performance occurred while testing halted from March 2020 to August 2020 due to the Covid-19 pandemic. These significant changes in performance were observed in the new portion of test bed, while the performance of the prior installation remained consistent. It may be that, after some time in-situ, SNR in a DAS array will reach a steady state. Though it is unfortunate that testing was on pause while changes in DAS performance developed, the observed changes emphasize the potential of DAS to be used for infrastructure change-detection monitoring. In the temporary test bed, increasing vehicle loads were observed to increase DAS performance, although there was considerable variability in the measured SNR. The significant variation in DAS response is likely due to various industrial activities on-site and some disturbance to the array while on-boarding and off-boarding vehicles. The results of this experiment indicated that the presence of load on less than 10% of an array channel length may improve DAS performance. Overall, this dissertation provides guidance that can help inform the civil engineering community with respect to installation design recommendations related to DAS used for infrastructure monitoring.