scholarly journals A performance evaluation of despiking algorithms for eddy covariance data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Domenico Vitale

AbstractSpike detection for raw high-frequency eddy covariance time series is a challenging task because of the confounding effect caused by complex dynamics and the high level of noise affecting such data. To cope with these features, a new despiking procedure rooted on robust functionals is proposed. By processing simulated data, it is demonstrated that the proposed procedure performs better than the existing algorithms and can be therefore considered as a candidate for the implementation in data center environmental monitoring systems, where the availability of automatic procedures ensuring a high quality standard of released products constitutes an essential prerequisite.

Author(s):  
Orlando Jorge M TORRES ◽  
Eduardo de Souza M FERNANDES ◽  
Rodrigo Rodrigues VASQUES ◽  
Fabio Luís WAECHTER ◽  
Paulo Cezar G. AMARAL ◽  
...  

ABSTRACT Background: Pancreatoduodenectomy is a technically challenging surgical procedure with an incidence of postoperative complications ranging from 30% to 61%. The procedure requires a high level of experience, and to minimize surgery-related complications and mortality, a high-quality standard surgery is imperative. Aim: To understand the Brazilian practice patterns for pancreatoduodenectomy. Method: A questionnaire was designed to obtain an overview of the surgical practice in pancreatic cancer, specific training, and experience in pancreatoduodenectomy. The survey was sent to members who declared an interest in pancreatic surgery. Results: A total of 60 questionnaires were sent, and 52 have returned (86.7%). The Southeast had the most survey respondents, with 25 surgeons (48.0%). Only two surgeons (3.9%) performed more than 50% of their pancreatoduodenectomies by laparoscopy. A classic Whipple procedure was performed by 24 surgeons (46.2%) and a standard International Study Group on Pancreatic Surgery lymphadenectomy by 43 surgeons (82.7%). For reconstruction, pancreaticojejunostomy was performed by 49 surgeons (94.2%), single limb technique by 41(78.9%), duct-to-mucosa anastomosis by 38 (73.1%), internal trans-anastomotic stenting by 26 (50.0%), antecolic route of gastric reconstruction by 39 (75.0%), and Braun enteroenterostomy was performed by only six surgeons (11.5%). Prophylactic abdominal drainage was performed by all surgeons, and somatostatin analogues were utilized by six surgeons (11.5%). Early postoperative enteral nutrition was routine for 22 surgeons (42.3%), and 34 surgeons (65.4%) reported routine use of a nasogastric suction tube. Conclusion: Heterogeneity was observed in the pancreatoduodenectomy practice patterns of surgeons in Brazil, some of them in contrast with established evidence in the literature.


Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 264
Author(s):  
Felix Bernauer ◽  
Kathrin Behnen ◽  
Joachim Wassermann ◽  
Sven Egdorf ◽  
Heiner Igel ◽  
...  

Interest in measuring displacement gradients, such as rotation and strain, is growing in many areas of geophysical research. This results in an urgent demand for reliable and field-deployable instruments measuring these quantities. In order to further establish a high-quality standard for rotation and strain measurements in seismology, we organized a comparative sensor test experiment that took place in November 2019 at the Geophysical Observatory of the Ludwig-Maximilians University Munich in Fürstenfeldbruck, Germany. More than 24 different sensors, including three-component and single-component broadband rotational seismometers, six-component strong-motion sensors and Rotaphone systems, as well as the large ring laser gyroscopes ROMY and a Distributed Acoustic Sensing system, were involved in addition to 14 classical broadband seismometers and a 160 channel, 4.5 Hz geophone chain. The experiment consisted of two parts: during the first part, the sensors were co-located in a huddle test recording self-noise and signals from small, nearby explosions. In a second part, the sensors were distributed into the field in various array configurations recording seismic signals that were generated by small amounts of explosive and a Vibroseis truck. This paper presents details on the experimental setup and a first sensor performance comparison focusing on sensor self-noise, signal-to-noise ratios, and waveform similarities for the rotation rate sensors. Most of the sensors show a high level of coherency and waveform similarity within a narrow frequency range between 10 Hz and 20 Hz for recordings from a nearby explosion signal. Sensor as well as experiment design are critically accessed revealing the great need for reliable reference sensors.


Author(s):  
Travis Eiles ◽  
Patrick Pardy

Abstract This paper demonstrates a breakthrough method of visible laser probing (VLP), including an optimized 577 nm laser microscope, visible-sensitive detector, and an ultimate-resolution gallium phosphide-based solid immersion lens on the 10 nm node, showing a 110 nm resolution. This is 2x better than what is achieved with the standard suite of probing systems using typical infrared (IR) wavelengths today. Since VLP provides a spot diameter reduction of 0.5x over IR methods, it is reasonable, based simply on geometry, to project that VLP using the 577 nm laser will meet the industry needs for laser probing for both the 10 nm and 7 nm process nodes. Based on its high level of optimization, including high resolution and specialized solid immersion lens, it is highly likely that this VLP technology will be one of the last optically-based fault isolation methods successfully used.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 204
Author(s):  
Igor Siedlecki ◽  
Michał Gorczak ◽  
Alicja Okrasińska ◽  
Marta Wrzosek

Studies on carton nesting ants and domatia−dwelling ants have shown that ant–fungi interactions may be much more common and widespread than previously thought. Until now, studies focused predominantly on parasitic and mutualistic fungi–ant interactions occurring mostly in the tropics, neglecting less−obvious interactions involving the fungi common in ants’ surroundings in temperate climates. In our study, we characterized the mycobiota of the surroundings of Formica polyctena ants by identifying nearly 600 fungal colonies that were isolated externally from the bodies of F. polyctena workers. The ants were collected from mounds found in northern and central Poland. Isolated fungi were assigned to 20 genera via molecular identification (ITS rDNA barcoding). Among these, Penicillium strains were the most frequent, belonging to eight different taxonomic sections. Other common and widespread members of Eurotiales, such as Aspergillus spp., were isolated very rarely. In our study, we managed to characterize the genera of fungi commonly present on F. polyctena workers. Our results suggest that Penicillium, Trichoderma, Mucor, Schwanniomyces and Entomortierella are commonly present in F. polyctena surroundings. Additionally, the high diversity and high frequency of Penicillium colonies isolated from ants in this study suggest that representatives of this genus may be adapted to survive in ant nests environment better than the other fungal groups, or that they are preferentially sustained by the insects in nests.


2020 ◽  
Vol 14 (4) ◽  
pp. 445-453
Author(s):  
Qian Fan ◽  
Yiqun Zhu

AbstractIn order to solve the problem that the moving span of basic local mean decomposition (LMD) method is difficult to choose reasonably, an improved LMD method (ILMD), which uses three cubic spline interpolation to replace the sliding average, is proposed. On this basis, with the help of noise aided calculation, an ensemble improved LMD method (EILMD) is proposed to effectively solve the modal aliasing problem in original LMD. On the basis of using EILMD to effectively decompose the data of GNSS deformation monitoring series, GNSS deformation feature extraction model based on EILMD threshold denoising is given by means of wavelet soft threshold processing mode and threshold setting method in empirical mode decomposition denoising. Through the analysis of simulated data and the actual GNSS monitoring data in the mining area, the results show that denoising effect of the proposed method is better than EILMD, ILMD and LMD direct coercive denoising methods. It is also better than wavelet analysis denoising method, and has good adaptability. This fully demonstrates the feasibility and effectiveness of the proposed method in GNSS feature extraction.


2019 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Nazanin Reza Zadeh Mottaghi ◽  
Mahmoud Talkhabi

This study compares the national curriculum of Iran and the UK to find out how the educational system indeveloping countries such as Iran can be improved. Because of implementing thinking skills and cognitive education,the educational system in the UK benefits from a high-quality standard. The science of mind, brain, educationintroduces some principles to improve teaching and learning methods and provide thoughtful and lifelong learnersfor the societies. In this study, we specified the main parts of the national curriculum in both countries and selectedsome of the principles to determine whether these two countries apply them in their national curriculum. Some ofthese principles focus on some significant issues: teaching models, the use of Meta-discipline and HolisticTechniques, authentic learning experiences, use of products, processing and progressing Evaluations, developingexplicit learning objectives, how to benefit from thinking and reflective practices, using collaborative and democraticactivities, preparing students to set personal objectives, giving themselves feedbacks, technology and flippedclassrooms, and beginning Year- Round Schooling. The results show that Iran needs more precise and detailedlearning objectives in its curriculum, use of democratic and collaborative activities with academics and students,develop thinking and reflective practices which play vital roles in upgrading the educational system. Moreover, it issuggested that the UK and Iran should consider embedded evaluations and flipped classrooms to meet the needs ofnew generation of learners.


2015 ◽  
Vol 114 (6) ◽  
pp. 3351-3358 ◽  
Author(s):  
Stefania de Vito ◽  
Marine Lunven ◽  
Clémence Bourlon ◽  
Christophe Duret ◽  
Patrick Cavanagh ◽  
...  

When we look at bars flashed against a moving background, we see them displaced in the direction of the upcoming motion (flash-grab illusion). It is still debated whether these motion-induced position shifts are low-level, reflexive consequences of stimulus motion or high-level compensation engaged only when the stimulus is tracked with attention. To investigate whether attention is a causal factor for this striking illusory position shift, we evaluated the flash-grab illusion in six patients with damaged attentional networks in the right hemisphere and signs of left visual neglect and six age-matched controls. With stimuli in the top, right, and bottom visual fields, neglect patients experienced the same amount of illusion as controls. However, patients showed no significant shift when the test was presented in their left hemifield, despite having equally precise judgments. Thus, paradoxically, neglect patients perceived the position of the flash more veridically in their neglected hemifield. These results suggest that impaired attentional processes can reduce the interaction between a moving background and a superimposed stationary flash, and indicate that attention is a critical factor in generating the illusory motion-induced shifts of location.


Geophysics ◽  
1987 ◽  
Vol 52 (11) ◽  
pp. 1535-1546 ◽  
Author(s):  
Ping Sheng ◽  
Benjamin White ◽  
Balan Nair ◽  
Sandra Kerford

The spatial resolution of gamma‐ray logs is defined by the length 𝓁 of the gamma‐ray detector. To resolve thin beds whose thickness is less than 𝓁, it is generally desirable to deconvolve the data to reduce the averaging effect of the detector. However, inherent in the deconvolution operation is an amplification of high‐frequency noise, which can be a detriment to the intended goal of increased resolution. We propose a Bayesian statistical approach to gamma‐ray log deconvolution which is based on optimization of a probability function which takes into account the statistics of gamma‐ray log measurements as well as the empirical information derived from the data. Application of this method to simulated data and to field measurements shows that it is effective in suppressing high‐frequency noise encountered in the deconvolution of gamma‐ray logs. In particular, a comparison with the least‐squares deconvolution approach indicates that the incorporation of physical and statistical information in the Bayesian optimization process results in optimal filtering of the deconvolved results.


PEDIATRICS ◽  
1977 ◽  
Vol 60 (3) ◽  
pp. 312-312
Author(s):  
P. H. Rhodes

The value judgments about medicine are contributed to by the public image. Formerly this has been one of a devoted, caring, self-sacrificing, somewhat unworldly group of people, dedicated to their work for the suffering and diseased. But the doctors are not separate from society and they are affected by its values. These have been adopted by the profession so that it is coming to be seen as no worse and no better than any other group of comparable education and training. Its status has diminished and this has called into question its compensation at a high level. Status cannot be maintained when its base has been eroded.


Author(s):  
Bo Wang ◽  
Xiaoting Yu ◽  
Chengeng Huang ◽  
Qinghong Sheng ◽  
Yuanyuan Wang ◽  
...  

The excellent feature extraction ability of deep convolutional neural networks (DCNNs) has been demonstrated in many image processing tasks, by which image classification can achieve high accuracy with only raw input images. However, the specific image features that influence the classification results are not readily determinable and what lies behind the predictions is unclear. This study proposes a method combining the Sobel and Canny operators and an Inception module for ship classification. The Sobel and Canny operators obtain enhanced edge features from the input images. A convolutional layer is replaced with the Inception module, which can automatically select the proper convolution kernel for ship objects in different image regions. The principle is that the high-level features abstracted by the DCNN, and the features obtained by multi-convolution concatenation of the Inception module must ultimately derive from the edge information of the preprocessing input images. This indicates that the classification results are based on the input edge features, which indirectly interpret the classification results to some extent. Experimental results show that the combination of the edge features and the Inception module improves DCNN ship classification performance. The original model with the raw dataset has an average accuracy of 88.72%, while when using enhanced edge features as input, it achieves the best performance of 90.54% among all models. The model that replaces the fifth convolutional layer with the Inception module has the best performance of 89.50%. It performs close to VGG-16 on the raw dataset and is significantly better than other deep neural networks. The results validate the functionality and feasibility of the idea posited.


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