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Journal articles on the topic 'Optical detectors – Mathematical models'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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1

Kolobrodov, V. G., N. I. Lykholit, V. M. Tiagur, B. Yu Pinchuk, and M. M. Lutsiuk. "The distortion of images in remote sensing systems at arbitrary angles of sight." Kosmìčna nauka ì tehnologìâ 27, no. 3 (2021): 51–65. http://dx.doi.org/10.15407/knit2021.03.051.

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Background. The main problem in launching space optical and electronic viewing systems (OEVS) for remote sensing of the Earth can be regarded as their high price, which even the leading countries of the world are not always ready to pay. Therefore, the quality of spacecraft systems imposed the most stringent requirements. One of the economically expedient options to increase the efficiency of space OEVS is scanning the Earth’s surface at arbitrary angles of sighting, which allows for the same time of service life to collect more information, but this in turn leads to image distortion. Therefore, analysis of the resulting image quality depending on the angles of sighting of the OEVS is an actual task that will assess the capabilities of the system and its conformance with the established requirements. Objective. Improving the physical and mathematical model of the modulation transfer function of the system “lens – matrix detector” and the study of the dependence of spatial and radiometric resolution on the angles of sight for the space OEVS when the sighting axis deviates from the nadir. Methods. Based on the analysis of signal generation models for television and thermal imaging space OEVS, it is proposed to use the concept – the contrast gray body. In the physical and mathematical model, it is proposed normalize to the spatial frequencies of objects at different angles of sight to the spatial frequencies in the nadir, and to calculate the radiometric resolution take into account the transmission and rarefied of the atmosphere, the image movement speed on the detector and its integration time. Results. Practical results of calculations of the offered physical and mathematical model for space OEVS showed that at deviation from nadir the effective spatial bandwidth worsens and at the specified parameters of system it is inexpedient scanning at angles of sighting greater than 30º. Accordingly, a comparative analysis of radiometric resolution for different type of detectors showed that the use of a photonic detector gives ~1.4 times better resolution in the nadir as opposed to the use of thermal detector and almost identical results are obtained at maximum angles of sighting. Also, a significant impact is made by a decrease a coefficient of atmospheric transmittance due to the rarefied of the atmosphere, which reaches from 26% to 45% that depends on the spectral range. Conclusions. Analysis of the results of the study confirms the possibility that photonic detectors can be replaced by modern thermal detectors with insignificant loss of image quality of the resulting image, which can significantly increase the service life of space OEVS.
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Zhu, Tao. "Research and Simulation of Optical Measurement Model in Chemical Pollution of Water." Applied Mechanics and Materials 644-650 (September 2014): 1042–45. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.1042.

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Currently, the chemical pollution of water detection is mainly based on optical method. However, the optical detector is easily restricted by light and weather conditions. Optical measurement can be set on the target feature point, such as the laser reflection apparatus in laser measurement. This article applied the optical measurement method to research detection of water chemical pollution. Use theoretical and mathematical models of optical measurement method to perform the detection of chemical contamination in water. Optical measurement method is the trend of future development.
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Soteriades, Elpidoforos S., Loukas Petrokokkinos, Michael A. Talias, et al. "Environmental assessment of radon levels in Cyprus." Management of Environmental Quality: An International Journal 27, no. 4 (2016): 407–18. http://dx.doi.org/10.1108/meq-03-2015-0029.

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Purpose – Radon is responsible for approximately 50 per cent of public exposure to environmental radiation. The purpose of this paper is to quantitatively assess indoor radon levels in Cyprus. Design/methodology/approach – In total, 500 passive radon detectors were used to estimate radon levels in the areas of Nicosia (capital), Paphos, Nisou and Famagusta. A total of 240 different public and private buildings were randomly selected in the above districts and two passive radon detectors were placed inside each building. The detectors were collected on average, three months following placement. Findings – The average radon level from all passive detectors was 53.7 and 49.2 Bq/m3 after excluding the seven highest values. The two highest measurements were observed in Paphos, Tsada-Kili elementary school (429 Bq/m3) and Emba, Paphos district (410 Bq/m3), respectively. Differences were also seen in public buildings compared to private buildings (p=0.058). In addition, rural buildings had higher radon levels compared to urban buildings (p=0.001). Predictive multilevel regression models for logarithmic radon levels were employed and differences were seen on point estimates regarding building- and district-level radon measurements. Most of the random variability observed was due to building-level variation. Practical implications – Residents from different geographic areas in Cyprus are reassured about the safety of indoor radon levels in public and private buildings. Originality/value – The estimation of indoor radon levels was done by the optical microscopy technique using a specific mathematical formula. Observed radon levels do not raise concern regarding residents’ radon exposure in Cyprus. Paphos district and Nisou area may require further investigation.
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Hernandez-Martin, Estefania, and José Luis Gonzalez-Mora. "Diffuse optical tomography in the human brain: A briefly review from the neurophysiology to its applications." Brain Science Advances 6, no. 4 (2020): 289–305. http://dx.doi.org/10.26599/bsa.2020.9050014.

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The present work describes the use of noninvasive diffuse optical tomography (DOT) technology to measure hemodynamic changes, providing relevant information which helps to understand the basis of neurophysiology in the human brain. Advantages such as portability, direct measurements of hemoglobin state, temporal resolution, non‐restricted movements as occurs in magnetic resonance imaging (MRI) devices mean that DOT technology can be used in research and clinical fields. In this review we covered the neurophysiology, physical principles underlying optical imaging during tissue‐light interactions, and technology commonly used during the construction of a DOT device including the source‐detector requirements to improve the image quality. DOT provides 3D cerebral activation images due to complex mathematical models which describe the light propagation inside the tissue head. Moreover, we describe briefly the use of Bayesian methods for raw DOT data filtering as an alternative to linear filters widely used in signal processing, avoiding common problems such as the filter selection or a false interpretation of the results which is sometimes due to the interference of background physiological noise with neural activity.
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5

JUNG, GU-IN, JI-SUN KIM, TAE-HEE LEE, et al. "FIBER-OPTIC GONIOMETER FOR MEASURING JOINT ANGLES." Journal of Mechanics in Medicine and Biology 14, no. 06 (2014): 1440014. http://dx.doi.org/10.1142/s0219519414400144.

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Measuring joint angles is an important task for therapists to monitor and evaluate a patient's recovery progress. A fiber-optic goniometer with modified fiber tips was developed and employed to measure joint angles. The effects of the fiber tip's angle in various off-center positions of the detector on the output beam pattern were investigated. The proper combination of these variables increased the measuring range of joint angles with asymmetric light signals from the modified fiber tips. With inverse mathematical models and LabVIEW computer program, the joint angle was obtained and displayed in real time. The reference joint angle correlated well with the calculated output angle over the test range. This method can be used not only in hospitals and laboratories, but also at home, with a simple and cost-effective optical sensor. This method can be applied in the field of rehabilitation and sports science.
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XIE, G. Z., H. T. LIU, G. W. CHA, et al. "SEVERAL OBSERVED FEATURES AND THEIR IMPLICATIONS FOR GAMMA-RAY-LOUD BLAZAR PKS 1510-089." International Journal of Modern Physics D 14, no. 07 (2005): 1173–84. http://dx.doi.org/10.1142/s0218271805006742.

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The new results of spectrophotometry, and X-ray imaging spectroscopy observations for the high-polarization, radio-loud and Gev gamma-ray-loud blazar PKS 1510-089 have been observed. The main results show that: (1) A double-horned broad Hβ line in the spectrum of PKS 1510-089 has been discovered. The Hβ double-peaked emission profiles are impressive with the line asymmetry that the red peak seems to be higher than the blue peak; (2) The observation of X-rays, performed with the ACIS-S detector aboard the Chandra X-ray observatory, led to the discovery of a bending X-ray jet, coincident with the radio arcsecond jet of PKS 1510-089; (3) According to the reverberation mapping method and the empirical relation between the broad line region (BLR) size and the optical continuum luminosity at 5100 Å (the rest frame), we obtained the Virial mass of the central primary black hole, which coincides with our previous result by extremely rapid optical variability method. In addition, based on these new observational results mentioned above and the other previous observations, we have discussed the theoretical models for PKS 1510-089.
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7

Ostroff, Rachel M., Diana Maul, Gregory R. Bogart, et al. "Fixed polarizer ellipsometry for simple and sensitive detection of thin films generated by specific molecular interactions: applications in immunoassays and DNA sequence detection." Clinical Chemistry 44, no. 9 (1998): 2031–35. http://dx.doi.org/10.1093/clinchem/44.9.2031.

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Abstract Biological thin films may form on a surface by specific molecular interactions. The fixed polarizer ellipsometer (FPE) is a sensitive instrument that detects biological thin films either qualitatively or quantitatively. The design is simple and inexpensive. The assays are formatted on an optical surface, and the FPE detection is based on the phase shift of linearly polarized light after reflection through a thin film. We have constructed mathematical models of the FPE response to reflection through single-layer and two-layer films that agree closely with experimental data. Several biological assays have been measured with the FPE to demonstrate the application of this technology to clinical targets, including ultrasensitive immunoassays for hepatitis B surface antigen (0.1 ng/mL) and α-fetoprotein (0.01 ng/mL) and DNA hybridization (0.5 fmol/μL target probe). A clinical study for detection of group A streptococcus from patient throat swabs demonstrated the qualitative application of the FPE to infectious disease targets. The flexibility and sensitivity of the FPE makes this technology suitable for numerous target analytes and applications.
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8

Drake, G., W. S. Fernando, R. W. Stanek, and D. G. Underwood. "Modulator based high bandwidth optical readout for HEP detectors." Journal of Instrumentation 8, no. 02 (2013): C02023. http://dx.doi.org/10.1088/1748-0221/8/02/c02023.

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9

Кисляковский, Oleg Kislyakovsky, Чистякова, et al. "Automatic Flaw Detector Channels Sensitivity Adjustment with the Use of an Adaptive Threshold." NDT World 19, no. 3 (2016): 77–80. http://dx.doi.org/10.12737/21179.

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Introduction. With high-speed total ultrasonic testing (UT) of the rails, the urgent task is to provide the required testing sensitivity under the impact of a significant number of adverse factors caused by the following reasons:
  unstable acoustic contact;
  incorrect flaw detector channel settings due to underskilled staff;
  a misalignment, for example when passing a small radius curve or when rails have significant lateral wear.
 The listed factors lead to level changing of echo signals within a wide dynamic range as well as to echo amplitudes ratio changing of useful and noise signals. In contrast to manual testing when an operator has the possibility of multiple scanning, total rails testing by a mobile diagnostic system is fulfilled by only a single scan.
 The objective of the work was to develop an optimal algorithm of flaw detector channels sensitivity adjustment and formulate the reasonable requirements for a mathematical model and hardware.
 Method. Theoretical researches and experimental work were conducted and resulted in the development of a multichannel flaw detector for inspection of rails by mobile means. The analysis of different mathematical models has enabled the optimal algorithm for automatic channels sensitivity adjustment to be developed.
 Results. The developed algorithm has allowed minimizing the impact of the negative factors and compensating the sensitivity to the level that enables high-speed single-scan rails testing to be fulfilled and maximum information at a high level of reliability to be recorded. Implementation of the adaptive threshold principle has made it possible to develop and offer the technique and technology for automatic flaw detector channels sensitivity adjustment.
 Conclusion. The offered technique and technology can be fully put into practice with the developed flaw detector and its control software.
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10

Li, C., C. Q. Feng, D. Y. Zhu, S. B. Liu, and Q. An. "An optical fiber-based flexible readout system for micro-pattern gas detectors." Journal of Instrumentation 13, no. 04 (2018): P04013. http://dx.doi.org/10.1088/1748-0221/13/04/p04013.

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Jones, B. J. P. "A simulation of the optical attenuation of TPB coated light-guide detectors." Journal of Instrumentation 8, no. 10 (2013): C10015. http://dx.doi.org/10.1088/1748-0221/8/10/c10015.

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12

Meo, S. Lo, P. Bennati, M. N. Cinti, et al. "A Geant4 simulation code for simulating optical photons in SPECT scintillation detectors." Journal of Instrumentation 4, no. 07 (2009): P07002. http://dx.doi.org/10.1088/1748-0221/4/07/p07002.

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13

Chramowicz, J., S. Kwan, T. Moretti, A. Sugg, and A. Prosser. "Free-space optical interconnects for cable-less readout in particle physics detectors." Journal of Instrumentation 5, no. 12 (2010): C12038. http://dx.doi.org/10.1088/1748-0221/5/12/c12038.

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14

Maia Oliveira, A., S. Braccini, P. Casolaro, et al. "Radiation-induced effects in glass windows for optical readout GEM-based detectors." Journal of Instrumentation 16, no. 07 (2021): T07009. http://dx.doi.org/10.1088/1748-0221/16/07/t07009.

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15

Udod, V. A., S. E. Vorobeichikov, and S. Yu Nazarenko. "Mathematical Models of Radiation Transparency of Test Objects When Using Sandwich X-Ray Radiation Detectors." Russian Journal of Nondestructive Testing 56, no. 2 (2020): 161–70. http://dx.doi.org/10.1134/s1061830920020096.

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16

Chan, Kheong Sann, Rathnakumar Radhakrishnan, Kwaku Eason, et al. "Channel Models and Detectors for Two-Dimensional Magnetic Recording." IEEE Transactions on Magnetics 46, no. 3 (2010): 804–11. http://dx.doi.org/10.1109/tmag.2009.2035635.

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17

AFTALION, AMANDINE, and BERNARD HELFFER. "ON MATHEMATICAL MODELS FOR BOSE–EINSTEIN CONDENSATES IN OPTICAL LATTICES." Reviews in Mathematical Physics 21, no. 02 (2009): 229–78. http://dx.doi.org/10.1142/s0129055x0900361x.

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Our aim is to analyze the various energy functionals appearing in the physics literature and describing the behavior of a Bose–Einstein condensate in an optical lattice. We want to justify the use of some reduced models and control the error of approximation. For that purpose, we will use the semi-classical analysis developed for linear problems related to the Schrödinger operator with periodic potential or multiple wells potentials. We justify, in some asymptotic regimes, the reduction to low dimensional problems and analyze the reduced problems.
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18

Rittscher, Jens, Andrew Blake, Anthony Hoogs, and Gees Stein. "Mathematical modelling of animate and intentional motion." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, no. 1431 (2003): 475–90. http://dx.doi.org/10.1098/rstb.2002.1259.

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Our aim is to enable a machine to observe and interpret the behaviour of others. Mathematical models are employed to describe certain biological motions. The main challenge is to design models that are both tractable and meaningful. In the first part we will describe how computer vision techniques, in particular visual tracking, can be applied to recognize a small vocabulary of human actions in a constrained scenario. Mainly the problems of viewpoint and scale invariance need to be overcome to formalize a general framework. Hence the second part of the article is devoted to the question whether a particular human action should be captured in a single complex model or whether it is more promising to make extensive use of semantic knowledge and a collection of low–level models that encode certain motion primitives. Scene context plays a crucial role if we intend to give a higher–level interpretation rather than a low–level physical description of the observed motion. A semantic knowledge base is used to establish the scene context. This approach consists of three main components: visual analysis, the mapping from vision to language and the search of the semantic database. A small number of robust visual detectors is used to generate a higher–level description of the scene. The approach together with a number of results is presented in the third part of this article.
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Vavrik, D., A. Fauler, M. Fiederle, et al. "Dynamic defectoscopy with flat panel and CdTe Timepix X-ray detectors combined with an optical camera." Journal of Instrumentation 8, no. 04 (2013): C04009. http://dx.doi.org/10.1088/1748-0221/8/04/c04009.

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20

Krishnamurthy, A., J. Villasenor, S. Kissel, G. Ricker, and R. Vanderspek. "An optical test bench for the precision characterization of absolute quantum efficiency for the TESS CCD detectors." Journal of Instrumentation 12, no. 05 (2017): C05013. http://dx.doi.org/10.1088/1748-0221/12/05/c05013.

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21

Wac-Wlodarczyk, A., R. Goleman, D. Czerwinski, and T. Gizewski. "Mathematical models applied in inductive non-destructive testing." Journal of Magnetism and Magnetic Materials 320, no. 20 (2008): e1044-e1048. http://dx.doi.org/10.1016/j.jmmm.2008.04.179.

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22

Nesteruk, Igor. "Detections and SIR simulations of the COVID-19 pandemic waves in Ukraine." Computational and Mathematical Biophysics 9, no. 1 (2021): 46–65. http://dx.doi.org/10.1515/cmb-2020-0117.

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Abstract Background. Unfortunately, the COVID-19 pandemic is still far from stabilizing. Of particular concern is the sharp increase in the number of diseases in June-July, September-October 2020 and February-March 2021. The causes and consequences of this sharp increase in the number of cases are still waiting for their researchers, but there is already an urgent need to assess the possible duration of the pandemic, the expected number of patients and deaths. Correct simulation of the infectious disease dynamics needs complicated mathematical models and many efforts for unknown parameters identification. Constant changes in the pandemic conditions (in particular, the peculiarities of quarantine and its violation, situations with testing and isolation of patients) cause various epidemic waves, lead to changes in the parameter values of the mathematical models. Objective. In this article, pandemic waves in Ukraine will be detected, calculated and discussed. The estimations for durations and final sizes of the epidemic waves will be presented. Methods. We propose a simple method for the epidemic waves detection based on the differentiation of the smoothed number of cases. We use the generalized SIR (susceptible-infected-removed) model for the dynamics of the epidemic waves. The known exact solution of the SIR differential equations and statistical approach were used. We will use different data sets for accumulated number of cases in order to compare the results of simulations and predictions. Results. Nine pandemic waves were detected in Ukraine and corresponding optimal values of the SIR model parameters were identified. The number of cases and the number of patients spreading the infection versus time were calculated. In particular, the pandemic in Ukraine probably began in January 2020. If current trends continue, the end of the pandemic should be expected no earlier than in summer 2021. Conclusions. The differentiation of the smoothed number of cases, the SIR model and statistical approach to the parameter identification are helpful to select COVID-19 pandemic waves and make some reliable estimations and predictions. The obtained information will be useful to regulate the quarantine activities, to predict the medical and economic consequences of the pandemic.
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Chang, Ya-Chiao, Richard Woollam, and Mark E. Orazem. "Mathematical Models for Under-Deposit Corrosion." Journal of The Electrochemical Society 161, no. 6 (2014): C321—C329. http://dx.doi.org/10.1149/2.034406jes.

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Harding, Alice K. "Gamma-Ray Pulsar Emission Models." International Astronomical Union Colloquium 160 (1996): 315–22. http://dx.doi.org/10.1017/s0252921100041804.

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AbstractWith the increased sensitivity of gamma-ray detectors on the Compton Gamma-Ray Observatory (CGRO) the number of presently known gamma-ray pulsars has grown. The new detections are beginning to provide clues to the origin of the high-energy radiation in the form of emerging patterns and correlations among observed quantities such as gamma-ray efficiency and spectral index vs. age. But there are still many questions about the location of the emission and its relation to the radio, optical and X-ray pulses. This paper will review models for gamma-ray emission from pulsars and will examine how well the detailed predictions of these models account for the existing observations.
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Mihaljevic, Nikola, Slobodan Jovanovic, and Aleksandar Dlabac. "A generalized mathematical model for efficiency calibration of gamma detectors: Application to practical cases." Nuclear Technology and Radiation Protection 34, no. 1 (2019): 34–46. http://dx.doi.org/10.2298/ntrp181031006m.

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Efficiency calibration, i. e. determination of detection efficiency, ?p, is a crucial issue in gamma spectrometry (quantification of gamma spectroscopic measurements) with semiconductor and scintillation detectors. Comparing three possible ways to addressing the problem ? relative, absolute and semi empirical ? advantages of the latter are emphasized. Among semi empirical models, efficiency transfer using effective solid angles, ??, is sorted out and briefly elaborated. This approach reduces the problem of efficiency calibration to the determination of ??. It proved reliable and has been broadly used in practice, mainly in the form of the long existing ANGLE software. Progressing further, a generalized mathematical formula for calcu- lations is developed ? first of the kind ? offering an opportunity for advanced applications of gamma spectrometry. The formula enables unlimited flexibility in application, as it conveniently separates the source data from the detector data during the integration procedures ?? calculations). Its practicality is demonstrated for a number of typically encountered counting arrangements, as well as for some exotic ones. The relevant formulae are used in PC calculations and numerical testing is further performed so as to check the validity of the mathematical method and the computer code. Care was taken of the optimization of complex numerical procedures employed (involving fivefold numerical integration), so as to keep computation times as low as possible (in order of minutes or even seconds on ordinary PC). Results obtained are affirmative for both the method and the code. The model will be gradually incorporated into ANGLE software, thus making it readily available for routine use by gamma spectrometry community.
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Minh, Vu Trieu, Nitin Afzulpurkar, and W. M. Wan Muhamad. "Fault Detection and Control of Process Systems." Mathematical Problems in Engineering 2007 (2007): 1–20. http://dx.doi.org/10.1155/2007/80321.

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This paper develops a stochastic hybrid model-based control system that can determine online the optimal control actions, detect faults quickly in the control process, and reconfigure the controller accordingly using interacting multiple-model (IMM) estimator and generalized predictive control (GPC) algorithm. A fault detection and control system consists of two main parts: the first is the fault detector and the second is the controller reconfiguration. This work deals with three main challenging issues: design of fault model set, estimation of stochastic hybrid multiple models, and stochastic model predictive control of hybrid multiple models. For the first issue, we propose a simple scheme for designing faults for discrete and continuous random variables. For the second issue, we consider and select a fast and reliable fault detection system applied to the stochastic hybrid system. Finally, we develop a stochastic GPC algorithm for hybrid multiple-models controller reconfiguration with soft switching signals based on weighted probabilities. Simulations for the proposed system are illustrated and analyzed.
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An, Hong Ki, and Ahmed N. Abdalla. "Prediction of queuing length at metering roundabout using adaptive neuro fuzzy inference system." Measurement and Control 52, no. 5-6 (2019): 432–40. http://dx.doi.org/10.1177/0020294019839415.

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A metering roundabout where traffic is controlled by signals where phase times are influenced by queue detector occupancy may be the solution to reduce queue lengths under unbalanced traffic flows. In the past decades, a number of studies have attempted to evaluate the effectiveness of metering roundabout, especially on the dominant approach. Little studies, however, have been directed on prediction of the queuing lengths, which is essential to determine the detector locations. This paper introduces a queue length estimation model using adaptive neuro fuzzy inference system for unbalanced roundabout traffic flows. The adaptive neuro fuzzy inference system model consists of an input layer representing four parameters as arrival volumes, conflicting volumes, phase green and red time, and output layer with four neuron representing queuing length. MATLAB software and additional statistical tests were used as the tool to develop the models for the data. In order to conduct credible model validations, model output data were compared against the observed data collected using drones. The results from the analysis demonstrated that adaptive neuro fuzzy inference system model is able to estimate the queuing length at metering roundabouts. Thus, it is expected that the adaptive neuro fuzzy inference system model will help practitioners in determining optimal detector locations and will be a foundation research for roundabouts with signals.
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Maass, Peter, Bernd Kuhfuß, and Oltmann Riemer. "Mathematical models for surface characterization of machining processes." Microsystem Technologies 14, no. 12 (2008): 1989–93. http://dx.doi.org/10.1007/s00542-008-0687-z.

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STECKER, F. W. "TESTING RELATIVITY AT HIGH ENERGIES USING SPACEBORNE DETECTORS." International Journal of Modern Physics D 16, no. 12b (2007): 2343–55. http://dx.doi.org/10.1142/s021827180701170x.

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The Gamma-Ray Large Area Space Telescope (GLAST), to be launched in the fall of 2007, will measure the spectra of distant extragalactic sources of high energy γ-rays, particularly active galactic nuclei and γ-ray bursts. GLAST can look for energy-dependent γ-ray propagation effects from such sources as a signal of Lorentz invariance violation (LIV). These sources should also exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions with low energy photons having a flux level as determined by various astronomical observations. Such annihilations result in electron–positron pair production above a threshold energy given by 2me in the center-of-momentum frame of the system, assuming Lorentz invariance. If Lorentz invariance is violated, this threshold can be significantly raised, changing the predicted absorption turnover in the observed spectrum of the sources. Stecker and Glashow have shown that the existence of such absorption features in the spectra of extragalactic sources puts constraints on LIV. Such constraints have important implications for some quantum gravity and large extra dimension models. Future spaceborne detectors dedicated to measuring γ-ray polarization can look for birefringence effects as a possible signal of loop quantum gravity. As shown by Coleman and Glashow, a much smaller amount of LIV has potential implications for possibly suppressing the "GZK cutoff" predicted to be caused by the interactions of cosmic rays having multijoule energies with photons of the 2.7 K cosmic background radiation in intergalactic space. Owing to the rarity of such ultrahigh energy cosmic rays, their spectra are best studied by a UV-sensitive satellite detector which looks down on a large volume of the Earth's atmosphere to study the nitrogen fluorescence tracks of giant air showers produced by these ultrahigh energy cosmic rays. We discuss here, in particular, a two-satellite mission called OWL, which would be suited for making such studies.
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Pereira, José Carlos Garcia, Jorge Cruz Fernandes, and Luís Guerra Rosa. "Mathematical Models for Simulation and Optimization of High-Flux Solar Furnaces." Mathematical and Computational Applications 24, no. 2 (2019): 65. http://dx.doi.org/10.3390/mca24020065.

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High-flux solar furnaces distributed throughout the world have been designed and constructed individually, i.e., on a one-by-one basis because there are several possible optical configurations that must take into account the geographical location and the maximum power to be attained. In this work, three ray-tracing models were developed to simulate the optical paths travelled by sun rays in solar furnaces of high concentration using as an example, the solar furnace SF60 of the Plataforma Solar de Almería, in Spain. All these simulation models are supported by mathematical constructions, which are also presented. The first model assumes a random distribution of sun rays coming from a concentrator with spherical curvature. The second model assumes that a random distribution of parallel rays coming from the heliostat is reflected by a concentrator with spherical curvature. Finally, the third model considers that the random parallel rays are reflected by a concentrator with a paraboloid curvature. The three models are all important in optical geometry, although the paraboloid model is more adequate to optimize solar furnaces. The models are illustrated by studying the influence of mirror positioning and shutter attenuation. Additionally, ray-tracing simulations confirmed the possibility to attain homogenous distribution of flux by means of double reflexion using two paraboloid surfaces.
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Apeanti, Wilson Osafo, Dianchen Lu, David Yaro, and Saviour Worianyo Akuamoah. "Dispersive traveling wave solutions of nonlinear optical wave dynamical models." Modern Physics Letters B 33, no. 10 (2019): 1950120. http://dx.doi.org/10.1142/s0217984919501203.

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In this work, we apply the extended simple equation method to study the dispersive traveling wave solutions of (2+1)-dimensional Nizhnik–Novikov–Vesselov (NNV), Caudrey–Dodd–Gibbon (CDG) and Jaulent–Miodek (JM) hierarchy nonlinear equations. A set of exact, periodic and soliton solutions is obtained for these models confirming the effectiveness of the proposed method. The models studied are important for a number of application areas especially in the field of mathematical physics. Interesting figures are used to illustrate the physical properties of some obtained results. A comparison between obtained solutions and established results in the literature is also given.
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Chen, Rong-Chang, Jhy-Ping Wu, and Hsin-Sen Chu. "Bolometric Response of High-Tc Superconducting Detectors to Optical Pulses and Continuous Waves." Journal of Heat Transfer 117, no. 2 (1995): 366–72. http://dx.doi.org/10.1115/1.2822531.

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This work presents a thermal analysis on predicting the temperature increase and the voltage response of high-Tc superconducting bolometers. Two heat transfer models, that is, the surface heating model and the heat generation model considering the skin depth, are introduced and compared. The surface heating model is found to be valid only for situations where the skin depth is much smaller than the film thickness. To consider the thermal boundary resistance between film and substrate, a radiation-boundary-condition model based on acoustic mismatch model (AMM) and an interfacial-layer model (ILM) are employed. The thermal boundary resistance significantly influences the voltage response. Additionally, several common substrates are examined. SrTiO3 (100) or LaAlO3 (100) is a better substrate for high-Tc superconducting bolometers. One interesting finding was that when compared with experimental data, all the theoretical values from the present study as well as the other previously theoretical treatment overestimate the voltage response near the transition temperature.
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Ghal-Eh, N., M. Aliannezhadi, and S. V. Bedenko. "Optical photon transport and geometry contributions to time response of scintillation detectors." International Journal of Modern Physics C 29, no. 09 (2018): 1850091. http://dx.doi.org/10.1142/s0129183118500912.

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The sensitivities of both time and energy resolutions of a typical scintillation detector to major optical parameters (i.e. paint reflectivity, quantum efficiency of photomultiplier tube and attenuation coefficient) have been estimated using a dedicated Monte Carlo (MC) optical photon transport (OPT) simulation code, PHOTRACK, and the OPT capabilities of general-purpose code, FLUKA. Both cylindrical and parallelepiped geometries have been considered for the scintillator cell and lightguide. The results determine the scintillation light wavelength regions that the energy and time resolution represent enhanced sensitivities to small change/uncertainty in optical parameters.
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Bondar, O. G., E. O. Brezhneva, O. G. Dobroserdov, K. G. Andreev, and N. V. Polyakov. "Synthesis and Parameterization of Gas Sensor Models." Proceedings of the Southwest State University 25, no. 1 (2021): 138–61. http://dx.doi.org/10.21869/2223-1560-2021-25-1-138-161.

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Purpose of research: search and analysis of existing models of gas-sensitive sensors. Development of mathematical models of gas-sensitive sensors of various types (semiconductor, thermocatalytic, optical, electrochemical) for their subsequent use in the training of artificial neural networks (INS). Investigation of main physicochemical patterns underlying the principles of sensor operation, consideration of the influence of environmental factors and cross-sensitivity on the sensor output signal. Comparison of simulation results with actual characteristics produced by the sensor industry. The concept of creating mathematical models is described. Their parameterization, research and assessment of adequacy are carried out.Methods. Numerical methods, computer modeling methods, electrical circuit theory, the theory of chemosorption and heterogeneous catalysis, the Freundlich and Langmuir equations, the Buger-Lambert-Behr law, the foundations of electrochemistry were used in creating mathematical models. Standard deviation (MSE) and relative error were calculated to assess the adequacy of the models.Results. The concept of creating mathematical models of sensors based on physicochemical patterns is described. This concept allows the process of data generation for training artificial neural networks used in multi-component gas analyzers for the purpose of joint information processing to be automated. Models of semiconductor, thermocatalytic, optical and electrochemical sensors were obtained and upgraded, considering the influence of additional factors on the sensor signal. Parameterization and assessment of adequacy and extrapolation properties of models by graphical dependencies presented in technical documentation of sensors were carried out. Errors (relative and RMS) of discrepancy of real data and results of simulation of gas-sensitive sensors by basic parameters are determined. The standard error of reproduction of the main characteristics of the sensors did not exceed 0.5%.Conclusion. Multivariable mathematical models of gas-sensitive sensors are synthesized, considering the influence of main gas and external factors (pressure, temperature, humidity, cross-sensitivity) on the output signal and allowing to generate training data for sensors of various types.
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Wainwright, P. R., and M. J. Whillock. "Measurements and mathematical models in the assessment of optical radiation hazards to the eye." Journal of Radiological Protection 10, no. 4 (1990): 263–69. http://dx.doi.org/10.1088/0952-4746/10/4/001.

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Zhang, Haiqing, and Jun Han. "Mathematical models for information classification and recognition of multi-target optical remote sensing images." Open Physics 18, no. 1 (2020): 951–60. http://dx.doi.org/10.1515/phys-2020-0123.

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Abstract Traditionally, three-dimensional model is used to classify and recognize multi-target optical remote sensing image information, which can only identify a specific class of targets, and has certain limitations. A mathematical model of multi-target optical remote sensing image information classification and recognition is designed, and a local adaptive threshold segmentation algorithm is used to segment multi-target optical remote sensing image to reduce the gray level between images and improve the accuracy of feature extraction. Remote sensing image information is multi-feature, and multi-target optical remote sensing image information is identified by chaotic time series analysis method. The experimental results show that the proposed model can effectively classify and recognize multi-target optical remote sensing image information. The average recognition rate is more than 95%, the maximum robustness is 0.45, the recognition speed is 98%, and the maximum time-consuming average is only 14.30 s. It has high recognition rate, robustness, and recognition efficiency.
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Pielecha, Ireneusz, Maciej Skowron, and Krzysztof Wisłocki. "Mathematical models of delaying opening of SIDI injectors formulated on basis of optical tests." Combustion Engines 167, no. 4 (2016): 8–21. http://dx.doi.org/10.19206/ce-2016-402.

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An appropriate moment of the fuel injection start is one of the parameters determining the characteristics of fuel flow from the injector and preparation of fuel-air mixture for combustion. However, knowledge of the characteristics of signals controlling the beginning of the injector opening does not provide enough information about the time of the actual fuel injection, which often leads to incorrect conclusions and decisions in relation to the required changes in the map of injection control. What was undertaken in this research was an attempt to evaluate the delay times of the actual opening of the high-pressure injectors of gasoline in relation to the time of triggering the current control signals opening the solenoid and piezoelectric injectors. The conducted tests take into account the variability of fuel injection pressure and backpressure prevailing in the operational chamber of the engine. To accurately determine the time of actual start of injection, the optical tests analysing the optical image of the tip of the dispenser were used. Such high resolution images were obtained thanks to high-speed filming with a frequency of 250 kHz (Dt = 0.004 ms). Correlation of the results of these analyses with the records of parameters of the fast-varying processes (voltage and current in the injector) allowed determining the times of the electric and hydraulic delay of the injection for piezoelectric and solenoid fuel injectors. Based on a comparison of the results obtained, it was found that the delay time of fuel injection for a piezoelectric injector of gasoline is about 3.5 times shorter than for a solenoid injector. It was also found that for the injection pressure above 10 MPa the delay is constant and does not depend on the pressure of fuel and the medium. Experimentally obtained results of the injection time delay were a basis to formulate mathematical models describing the delay of the actual fuel injection in relation to the signal controlling the opening of the injectors. These models take into account the dependence of the injector reaction on the injection pressure and the backpressure in the operational chamber of the engine. The correctness of the obtained models is confirmed by high values of the coefficient of determination (above 0.84).
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Yang, Hong Ying, Su Kang Zhu, Ke Jing Li, and Ning Pan. "Modelling Fabric’s Optical Behaviors." Materials Science Forum 575-578 (April 2008): 1266–71. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.1266.

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In this paper, existing models of fabric’s optical behaviors are classified and estimated briefly. Then, basing on the optical theories, this paper abstracts the commonness of fabric’s optical behaviors and put forward an improved model of them, which includes a physical model and its corresponding mathematical model. The physical model describes the light falling on fabrics splits into six components, which compose another four components. The ten light components divided by the incident light yields ten light component parameters, which are functions of the wavelength. The mathematical model connects the ten light component parameters and gives formulas to calculate them. Thus, the light component parameters are connected with the basic optical parameters and structural parameters of fabric. This improved model provides a fundamental and theoretical guide for studying fabric’s optical properties systematically, which has been proved to be effective in solving some problems related fabric optical properties.
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Wu, Kai, Liang Tu, Diqing Su, and Jian-Ping Wang. "Magnetic dynamics of ferrofluids: mathematical models and experimental investigations." Journal of Physics D: Applied Physics 50, no. 8 (2017): 085005. http://dx.doi.org/10.1088/1361-6463/aa590b.

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HORVATH, J. E. "DETECTABILITY OF GRAVITATIONAL WAVE BURSTS FROM A CLASS OF NEUTRON STAR STARQUAKE GRB MODELS." International Journal of Modern Physics D 05, no. 01 (1996): 35–43. http://dx.doi.org/10.1142/s0218271896000047.

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A large class of gamma-ray burst (GRB) models (overwhelming until recently) involve-the release of energy in a neutron star quake. Even though the extreme isotropy of the GRB sky established by the BATSE experiment has now shifted the interest to cosmological models, the former starquake scenarios are still attractive and may naturally produce a gravitational wave burst which carries most of the released energy. We discuss the prospects for detection of these high-frequency bursts by the forthcoming interferometers and spheroidal antennas, emphasizing the most recent results on the distribution and nature of the GRB sources. We find that, even if the overall picture is correct, the positive detection of GRB-associated gravitational wave bursts is unlikely and therefore these events will not be a prime target for the detectors.
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41

Babák, Libor, P. Šupinová, and R. Burdychová. "Growth models of Thermus aquaticus and Thermus scotoductus." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 60, no. 5 (2012): 19–26. http://dx.doi.org/10.11118/actaun201260050019.

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Members of the genusThermusfamily are signifiant producers of secondary metabolites, which are very commonly used in industry. Beside the productivity, it is also important to study the growth curve of each strain. The mathematical models which are commonly used to describe behavior of microbial strains under different physical and chemical conditions can reduce measured data.In this study, the mathematical models which describe only the microbial count were used. For analysis, Verhulst model, von Bertalanffy model and Richards model were chosen.During the cultivation ofThermus aquaticusandThermus scotoductusstrains, optical density (OD) and concentration of microorganisms were measured. The mathematical models were fitted to experimental data. The fitting was made in program MATLAB. The coefficients of models and statistical evaluation of goodness of fit of models were identified from mathematical analyses. Graphs of individual models were plotted with prediction bounds. 95% confidence levels were used to statistical evaluation of goodness of fit of models and prediction bounds.Richards model was evaluted as the most corresponding with experimental data. Similar results were reached using Verhulst model. Von Bertalanffy model was not coresponded with experimental data.
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GOLOVASHKIN, A. I., G. V. KULESHOVA, A. M. TZHOVREBOV, and G. N. IZMAILOV. "DETECTION OF NON-STATIONARY VARIATIONS OF METRICS BY INTERFERENCE METHODS." International Journal of Modern Physics D 13, no. 01 (2004): 187–95. http://dx.doi.org/10.1142/s0218271804004207.

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The principal features in the detection of non-stationary undulatory metric disturbances based on interference effects are considered. The advantage for these the Aharonov–Bohm effect in superconductors in comparison with conventional optical interference is shown. Schemes of interferometric detectors with SQUID are offered.
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Maggi, Lorenzo, Pietro Savazzi, and Stefano Valle. "Comparison Between Viterbi Detectors for Magnetic Recording Channels Based on Regressive and Autoregressive Noise Models." IEEE Transactions on Magnetics 46, no. 1 (2010): 105–11. http://dx.doi.org/10.1109/tmag.2009.2028137.

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44

Benjamin, Earl, Aron Reznik, Ellis Benjamin, Saroj K. Pramanik, Louise Sowers, and Arthur L. Williams. "Mathematical models for Enterococcus faecalis recovery after microwave water disinfection." Journal of Water and Health 7, no. 4 (2009): 699–706. http://dx.doi.org/10.2166/wh.2009.132.

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Microwave water disinfection is a rapid purification technique which can give billions of people access to clean drinking water. However, better understanding of bacterial recovery after microwave heating over time is necessary to determine parameters such as delayed bacterial growth rates and maximum bacterial yields. Mathematical models for Enterococcus faecalis recovery after microwave treatment in optimum growth conditions were developed for times up to 5 minutes using an optical absorbance method. Microwave times below 3 minutes (2,450 MHz, 130 W) showed that bacterial recovery maintained a time-dependent sigmoidal form which included a maximum value. At microwave times greater than three minutes, bacterial recovery, with a time-dependent exponential form, significantly decreased and did not reach the maximum value within the interval of observance (0–8 hours). No bacterial growth was found after 6 minutes of microwave treatment. The prepared mathematical models were produced by transforming the given variables to the logistic or exponential functions. We found that time-dependent maximum growth rates and lag times could be approximated with second order polynomial functions. The determined models can be used as a template to illustrate bacterial survival during water purification using microwave irradiation, in both commercial and industrial processes.
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Frolov, S. V., A. Yu Potlov, and S. V. Sindeev. "Selection of Flow-Diverter Stent Models Using Optical Coherence Tomography and Mathematical Modeling of Hemodynamics." Biomedical Engineering 51, no. 6 (2018): 381–84. http://dx.doi.org/10.1007/s10527-018-9754-7.

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46

Brida, Giorgio, Marco Genovese, Marco Gramegna, Matteo G. A. Paris, E. Predazzi, and E. Cagliero. "On the Reconstruction of Diagonal Elements of Density Matrix of Quantum Optical States by on/off Detectors." Open Systems & Information Dynamics 13, no. 03 (2006): 333–41. http://dx.doi.org/10.1007/s11080-006-9003-5.

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We discuss a scheme for reconstructing experimentally the diagonal elements of a density matrix representing quantum optical state. Applications to PDC heralded photons, multi-thermal and attenuated coherent states are illustrated and discussed in more detail.
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Yin, Q., G. H. Kelsall, D. J. Vaughan, and N. P. Brandon. "Mathematical Models for Time-Dependent Impedance of Passive Electrodes." Journal of The Electrochemical Society 148, no. 3 (2001): A200. http://dx.doi.org/10.1149/1.1345956.

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48

Cirilo-Lombardo, D. J., and L. S. Ridao. "Optical properties of Einstein–Born–Infeld gravastar models in plasmas." International Journal of Modern Physics D 29, no. 12 (2020): 2050080. http://dx.doi.org/10.1142/s0218271820500807.

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Gravastar models have recently been proposed as an alternative to black holes, mainly to avoid the problematic issues associated with event horizons and singularities. Recently, in [D. J. Cirilo-Lombardo and C. D. Vigh, Int. J. Mod. Phys. D 28 (2019) 1950108], a regular variety of gravastar models within the context of Einstein–Born–Infeld (EBI) nonlinear electrodynamics were built. These original models are truly regular in the sense that both the metric and its derivatives are continuous throughout spacetime, contrary to other cases in the literature where matching conditions are necessary in the interior and exterior regions of the event horizon. In this work, in the same theoretical context from [D. J. Cirilo-Lombardo and C. D. Vigh, Int. J. Mod. Phys. D 28 (2019) 1950108], we study some optical phenomena, such as the weak gravitational lens for the case of the magnetized plasma and the influence of working with a nonlinear field of BI in observables such as the Einstein ring or the total delay time. These important issues allow us to compare the results obtained in the context of these new static Born–Infeld gravastars with the standard linear ones (e.g. Reissner–Nordström).
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Wang, Jindong, Shengchuan Jiang, Yue Qiu, Yang Zhang, Jianguo Ying, and Yuchuan Du. "Traffic Signal Optimization under Connected-Vehicle Environment: An Overview." Journal of Advanced Transportation 2021 (August 10, 2021): 1–16. http://dx.doi.org/10.1155/2021/3584569.

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Traffic signal optimization is a significant means for smoothing urban traffic flow. However, the operation of traffic signals is currently seriously constrained by the data available from traditional point detectors. In recent years, an emerging technology, connected vehicle (CV), which can percept the overall traffic environment in real time, has drawn researchers’ attention. With the new data source, traffic controllers should be able to make smarter decisions. A lot of work has been done to develop a new traffic signal control pattern under connected-vehicle environment. This paper provides a comprehensive review of these studies, aiming at sketching out the state of the arts in this research field. Several basic control problems, communication, control input, and objectives, are briefly introduced. The commonly used optimization models for this problem are summarized into three types: rule-based models, mathematical programming-based models, and artificial intelligence-based models. Then some major technical issues are discussed in detail. Finally, we raise the limitation of the existing studies and give our perspectives of the future research directions.
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Milburn, G. J., T. Ralph, A. White, E. Knill, and R. Laflamme. "Efficient linear optics quantum computation." Quantum Information and Computation 1, Special (2001): 13–19. http://dx.doi.org/10.26421/qic1.s-4.

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Two qubit gates for photons are generally thought to require exotic materials with huge optical nonlinearities. We show here that, if we accept two qubit gates that only work conditionally, single photon sources, passive linear optics and particle detectors are sufficient for implementing reliable quantum algorithms. The conditional nature of the gates requires feed-forward from the detectors to the optical elements. Without feed forward, non-deterministic quantum computation is possible. We discuss one proposed single photon source based on the surface acoustic wave guiding of single electrons.
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