scholarly journals Design and Experimental Characterization of a Discovery and Tracking System for Optical Camera Communications

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2925
Author(s):  
Antonio Mederos-Barrera ◽  
Cristo Jurado-Verdu ◽  
Victor Guerra ◽  
Jose Rabadan ◽  
Rafael Perez-Jimenez
Keyword(s):  
Tracking System ◽  
Region Of Interest ◽  
Experimental Methodology ◽  
Visible Light Communications ◽  
Spatial Features ◽  
Tracking Algorithms ◽  
Receiver Architecture ◽  
Vehicle Networks ◽  
Time Required ◽  
Static Conditions

Visible light communications (VLC) technology is emerging as a candidate to meet the demand for interconnected devices’ communications. However, the costs of incorporating specific hardware into end-user devices slow down its market entry. Optical camera communication (OCC) technology paves the way by reusing cameras as receivers. These systems have generally been evaluated under static conditions, in which transmitting sources are recognized using computationally expensive discovery algorithms. In vehicle-to-vehicle networks and wearable devices, tracking algorithms, as proposed in this work, allow one to reduce the time required to locate a moving source and hence the latency of these systems, increasing the data rate by up to 2100%. The proposed receiver architecture combines discovery and tracking algorithms that analyze spatial features of a custom RGB LED transmitter matrix, highlighted in the scene by varying the cameras’ exposure time. By using an anchor LED and changing the intensity of the green LED, the receiver can track the light source with a slow temporal deterioration. Moreover, data bits sent over the red and blue channels do not significantly affect detection, hence transmission occurs uninterrupted. Finally, a novel experimental methodology to evaluate the evolution of the detection’s performance is proposed. With the analysis of the mean and standard deviation of novel K parameters, it is possible to evaluate the detected region-of-interest scale and centrality against the transmitter source’s ideal location.

Object-Selective Cortex Exhibits Performance-Independent Repetition Suppression

2006 ◽  
Vol 95 (2) ◽  
pp. 995-1007 ◽  
Author(s):  
Rory Sayres ◽  
Kalanit Grill-Spector
Keyword(s):  
Response Time ◽  
Response Times ◽  
Recognition Performance ◽  
Region Of Interest ◽  
Stimulus Presentation ◽  
Repetition Suppression ◽  
Fmri Study ◽  
Bold Responses ◽  
Cortical Regions ◽  
Time Required

Object-selective cortical regions exhibit a decreased response when an object stimulus is repeated [repetition suppression (RS)]. RS is often associated with priming: reduced response times and increased accuracy for repeated stimuli. It is unknown whether RS reflects stimulus-specific repetition, the associated changes in response time, or the combination of the two. To address this question, we performed a rapid event-related functional MRI (fMRI) study in which we measured BOLD signal in object-selective cortex, as well as object recognition performance, while we manipulated stimulus repetition. Our design allowed us to examine separately the roles of response time and repetition in explaining RS. We found that repetition played a robust role in explaining RS: repeated trials produced weaker BOLD responses than nonrepeated trials, even when comparing trials with matched response times. In contrast, response time played a weak role in explaining RS when repetition was controlled for: it explained BOLD responses only for one region of interest (ROI) and one experimental condition. Thus repetition suppression seems to be mostly driven by repetition rather than performance changes. We further examined whether RS reflects processes occurring at the same time as recognition or after recognition by manipulating stimulus presentation duration. In one experiment, durations were longer than required for recognition (2 s), whereas in a second experiment, durations were close to the minimum time required for recognition (85–101 ms). We found significant RS for brief presentations (albeit with a reduced magnitude), which again persisted when controlling for performance. This suggests a substantial amount of RS occurs during recognition.

scholarly journals A secure and rapid query-software for COVID-19 test results that can easily be integrated into the clinical workflow to avoid communication overload

2020 ◽  
Author(s):  
Gunnar Völkel ◽  
Axel Fürstberger ◽  
Julian D. Schwab ◽  
Silke D. Kühlwein ◽  
Thomas Gscheidmeier ◽  
...  
Keyword(s):  
Mobile Apps ◽  
Tracking System ◽  
Public Healthcare ◽  
Test Results ◽  
Clinical Workflow ◽  
Knowing That ◽  
The Status ◽  
New Ideas ◽  
Massive Number ◽  
Time Required

AbstractOvercoming the COVID-19 crisis requires new ideas and strategies. Rapid testing of a large number of subjects is essential to monitor, and delay, the spread of SARS-CoV-2 to mitigate the consequences of the pandemic. People not knowing that they are infected may not stay in quarantine and, thus, are a risk for infecting others. Unfortunately, the massive number of COVID-19 tests performed is challenging for both laboratories and the units that take the throat swab and have to communicate test results. Here, we present a secure tracking system (CTest) to report COVID-19 test results online as soon as they become available. The system can be integrated into the clinical workflow with very modest effort and avoids excessive load to telephone hotlines. With this open-source and browser-based online tracking system, we aim to minimize the time required to inform the tested person but also the test units, e.g. hospitals or the public healthcare system. Instead of personal calls, CTest updates the status of the test automatically when the test results are available. Test reports are published on a secured web-page enabling regular status checks also by patients not using smartphones with dedicated mobile apps which has some importance as smartphone usage diminishes with age.The source code, as well as further information to integrate CTest into the IT environment of other clinics or test-centres, are freely available from https://github.com/sysbio-bioinf/CTest under the Eclipse Public License v2.0 (EPL2).

scholarly journals Swimmer’s Head Detection Based on a Contrario and Scaled Composite JTC Approaches

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
D. Benarab ◽  
T. Napoléon ◽  
A. Alfalou ◽  
A. Verney ◽  
P. Hellard
Keyword(s):  
Moving Objects ◽  
Tracking System ◽  
Random Noise ◽  
Region Of Interest ◽  
Reference Image ◽  
Correlation Technique ◽  
Head Detection ◽  
Linear Transform ◽  
High Level ◽  
Direct Linear Transform

In order to accompany the swimming coaches in evaluating high-level swimmers, we developed a prototype for instantaneous speed estimation. To achieve this, we proposed and validated, in a previous work, a swimmer tracking system based on data fusion. However, the initialization phase is done manually, and our aim, in this paper, is to automate this process. First, we propose a region of interest localization module that allows the detection of the first appearance of the swimmer in the lane as well as the restriction of the region of interest around him. This module is based on the method a contrario which consists of modeling the random noise corresponding to the water and detecting the structured movement relative to the swimmer motion. To do that, we calibrate the pool using DLT (Direct Linear Transform) technique, extract the concerned lane, apply the frame difference approach to detect the moving objects, and then decompose the lane into blocs and classify them into swimmer motion or noise. Second, in order to detect the swimmer’s head, we propose the Scaled Composite JTC which is based on the NL-JTC correlation technique. The input plane of this latter includes a target and a reference image. The first is the region of interest detected by the method a contrario. The second consists of a Scaled Composite Reference. The tests conducted on real video sequences of French swimming championships (Limoges 2015) showed very good results in terms of region of interest localization and swimmer’s head detection which allows a reliable initialization for the tracking system.

scholarly journals Are suggestions from coupled file changes useful for perfective maintenance tasks?

2017 ◽  
Vol 3 ◽  
pp. e135 ◽  
Author(s):  
Jasmin Ramadani ◽  
Stefan Wagner
Keyword(s):  
Software Maintenance ◽  
Tracking System ◽  
Minor Effect ◽  
New Members ◽  
Team Members ◽  
Using Data ◽  
Time Required ◽  
A Minor ◽  
The Impact ◽  
Important Activity

Background Software maintenance is an important activity in the development process where maintenance team members leave and new members join over time. The identification of files which are changed together frequently has been proposed several times. Yet, existing studies about coupled file changes ignore the feedback from developers as well as the impact of these changes on the performance of maintenance and rather these studies rely on the analysis findings and expert evaluation. Methods We investigate the usefulness of coupled file changes during perfective maintenance tasks when developers are inexperienced in programming or when they were new on the project. Using data mining on software repositories we identify files that are changed most frequently together in the past. We extract coupled file changes from the Git repository of a Java software system and join them with corresponding attributes from the versioning and issue tracking system and the project documentation. We present a controlled experiment involving 36 student participants in which we investigate if coupled file change suggestions influence the correctness of the task solutions and the required time to complete them. Results The results show that the use of coupled file change suggestions significantly increases the correctness of the solutions. However, there is only a minor effect on the time required to complete the perfective maintenance tasks. We also derived a set of the most useful attributes based on the developers’ feedback. Discussion Coupled file changes and a limited number of the proposed attributes are useful for inexperienced developers working on perfective maintenance tasks where although the developers using these suggestions solved more tasks, they still need time to understand and organize this information.

Methodological aspects of extracting heavy metals from soils and sediments

2020 ◽  
Author(s):  
Marina Burachevskaya ◽  
Tatiana Minkina ◽  
Saglara Mandzhieva ◽  
Valery Kalinichenko
Keyword(s):  
Heavy Metals ◽  
Sample Preparation ◽  
Significant Risk ◽  
Total Content ◽  
Terrestrial Ecosystems ◽  
Contamination Level ◽  
Russian Scientific ◽  
Time Required ◽  
Static Conditions ◽  
Preparation Techniques

<p>Soil and sediment contamination by heavy metals (HMs) can create a significant risk to human health. Quite a few human activities produce waste, much of which is discharged in soils as well as rivers and other water bodies where they accumulate in sediments. The behavior of pollutants in the terrestrial ecosystems is characterized by their fractional composition rather than their total content in the soil and sediments. To determine HMs there are different sample preparation techniques: sifted through a sieve with a hole diameter of 1 mm (AAB; McLaren, Crawford 1973; Miller et al, 1986; etc), of 2 mm (EDTA, EDTPA, etc), of 0.25 mm (Tessier et al, 1979). Another problem is the readsorption of metals that depends on the extraction conditions. Due to the fact that there are a number of difficulties in comparing the results obtained by different methods of extraction.</p><p>The main objective of this work was to study the influence of sample preparation and readsorption processes on the extractability of HMs from soil and bottom sediments in the model experiment. The experimental design included the control (original uncontaminated soil - Haplic Chernozem), treatments with the addition of Cu, Ni, Zn, Cd and Pb at a rates of 2, 10 and 20 maximum permissible concentration. The metal compounds extracted with the 1 N CH<sub>3</sub>COONH<sub>4 </sub>(AAB) are classified as exchangeable. Different sample preparation techniques has been used: the air-dry soil was sieving through a sieve with holes in 1 mm and with holes in 0.25 mm. The assessment of HM readsorption processes in soil was based on the comparative analysis of the results of multiple extraction of metals by AAB static extraction (shake for 1 hour and set aside for a day, 10 times) and dynamic conditions (10 times continuous processing).</p><p>It was found that the extraction of HM during sample preparation through a sieve of 0.25 mm was higher than through a sieve of 1 mm (to 3-17%). This is due to the larger surface of soil particles. These differences were manifested both in unpolluted soil and sediments and at different levels of their pollution. With the increasing contamination level the differences were more noticeable. Under static conditions a single AAB extraction does not extract the entire stock of mobile forms of HMs. Dynamic extraction of heavy metals from the soil and sediments, when conditions do not allow to achieve equilibrium, the processes of metal readsorption are eliminated, which leads to greater HM extraction from the soil and sediments.</p><p>Thus, the state of the analyzed sample has a significant influence of HMs extraction. To analyze and compare the results of fractionation of HM compounds from soils, it is necessary to take into account the sample preparation used and extraction time required in each method.</p><p>This work was supported by grant of the Russian Scientific Foundation, project no. 19-74-00085.</p>

scholarly journals Is Ultra-Short-Term Heart Rate Variability Valid in Non-static Conditions?

2021 ◽  
Vol 12 ◽  
Author(s):  
Jin Woong Kim ◽  
Hyeon Seok Seok ◽  
Hangsik Shin
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Measurement Time ◽  
Exercise Recovery ◽  
Short Term ◽  
Post Exercise ◽  
Hrv Analysis ◽  
Time Required ◽  
Static Conditions ◽  
Post Exercise Recovery

In mobile healthcare, heart rate variability (HRV) is increasingly being used in dynamic patient states. In this situation, shortening of the measurement time is required. This study aimed to validate ultra-short-term HRV in non-static conditions. We conducted electrocardiogram (ECG) measurements at rest, during exercise, and in the post-exercise recovery period in 30 subjects and analyzed ultra-short-term HRV in time and frequency domains by ECG in 10, 30, 60, 120, 180, and 240-s intervals, and compared the values to the 5-min HRV. For statistical analysis, null hypothesis testing, Cohen’s d statistics, Pearson’s correlation coefficient, and Bland-Altman analysis were used, with a statistical significance level of P < 0.05. The feasibility of ultra-short-term HRV and the minimum time required for analysis showed differences in each condition and for each analysis method. If the strict criteria satisfying all the statistical methods were followed, the ultra-short-term HRV could be derived from a from 30 to 240-s length of ECG. However, at least 120 s was required in the post-exercise recovery or exercise conditions, and even ultra-short-term HRV was not measurable in some variables. In contrast, according to the lenient criteria needed to satisfy only one of the statistical criteria, the minimum time required for ultra-short-term HRV analysis was 10–60 s in the resting condition, 10–180 s in the exercise condition, and 10–120 s in the post-exercise recovery condition. In conclusion, the results of this study showed that a longer measurement time was required for ultra-short-term HRV analysis in dynamic conditions. This suggests that the existing ultra-short-term HRV research results derived from the static condition cannot applied to the non-static conditions of daily life and that a criterion specific to the non-static conditions are necessary.

scholarly journals QuickFigures: A toolkit and ImageJ PlugIn to quickly transform microscope images into scientific figures

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0240280
Author(s):  
Gregory Mazo
Keyword(s):  
Fluorescent Microscopy ◽  
Region Of Interest ◽  
File Format ◽  
Object Type ◽  
Large Numbers ◽  
Adobe Illustrator ◽  
Time Required ◽  
Free Open Source ◽  
Microscopy Images ◽  
Imagej Plugin

Publications involving fluorescent microscopy images generally contain many panels with split channels, merged images, scale bars and label text. Similar layouts of panels are used when displaying other microscopy images, electron micrographs, photographs, and other images. Assembling and editing these figures with even spacing, consistent font, text position, accurate scale bars, and other features can be tedious and time consuming. In order to save time, I have created a toolset and ImageJ Plugin called QuickFigures. QuickFigures includes many helpful features that streamline the process of creating, aligning, and editing scientific figures. Those features include tools that automatically create split channel figures from a region of interest (“Quick Figure” button and “Inset Tool”), layouts that make it easy to rearrange panels, multiple tools to align objects, and “Figure Format” menu options that help a user ensure that large numbers of figures have consistent appearance. QuickFigures was compared to previous tools by measuring the amount of time needed for a user to create a figure using each software (QuickFigures, OMERO.figure. EZFig, FigureJ and PowerPoint). QuickFigures significantly reduced the amount of time required to create a figure. The toolsets were also compared by checking each software against a list of features. QuickFigures had the most extensive set of features. Therefore, QuickFigures is an advantageous alternative to traditional methods of constructing scientific figures. After a user has saved time by creating their work in QuickFigures, the figures can be exported to a variety of formats including PowerPoint, PDF, SVG, PNG, TIFF and Adobe Illustrator. Export was successfully tested for each file format and object type. Exported objects and text are editable in their target software, making them suitable for sharing with collaborators. The software is free, open source and can be installed easily.

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