Journal articles: 'Calculating time'

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Landa, Jiří, and Štefan Palágyi. "Simple method for calculating time dependence of individual radionuclide activities in decay series." Open Chemistry 5, no. 3 (September 1, 2007): 868–79. http://dx.doi.org/10.2478/s11532-007-0029-5.

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AbstractA rapid method for calculating the time dependence of activities of individual radionuclides in genetically coupled decay series has been proposed. The method is based on the mathematical procedure, in which the matrix method is used for calculating a set of decay equations given in the vector form. The developed method is computerized and uses the modern Scilab software. This simple method eliminates certain drawbacks of older methods used previously for this purpose and is applicable to even solve calculations which are not easily treatable with the older methods. Some practical examples of such calculations are presented. Moreover, the new method is universal and it also enables a more general approach to the problem of the calculation of decay series in nuclear chemistry.

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Singh*, Shashwat. "Theorem for Calculating Time Duration." International Journal of Innovative Technology and Exploring Engineering 10, no. 10 (August 30, 2021): 42–44. http://dx.doi.org/10.35940/ijitee.j9420.08101021.

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While developing an app the author came across the fact that while calculating time durations, certain variables are often overlooked which can result in errors. This paper provides an algorithm that considers the absolute values of the time slots and after a discrete set of steps results in the accurate time durations. The scope of this research is not limited to hours and minutes but, can be applied to seconds and milliseconds as well.

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Tkachenko, Yuri Y., Vladimir V. Latun, and Valeriy I. Denisov. "Estimation of Methods of Calculation of Values of Total Solar Radiation for Different Time Intervals." UNIVERSITY NEWS. NORTH-CAUCASIAN REGION. NATURAL SCIENCES SERIES, no. 1 (209) (March 31, 2021): 89–98. http://dx.doi.org/10.18522/1026-2237-2021-1-89-98.

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The article presents the results of evaluation of a number of methods for calculating total, scattered and direct radiation. The methods were tested on actinometric data of eight stations of the former USSR, located in different climatic and latitudinal zones, in order to clarify the spatial boundaries of their application and the time interval for which it is possible to carry out calculations with an error of not more than 10 %. It is established that the accuracy of calculations is influenced by the location of the station in relation to the seas and lakes. In addition, a number of methods do not take into account the tier and shape of the cloud, so at the same amount of cloud observed different amounts of total radiation, which in turn leads to errors in the calculation of the amounts of radiation. For stations with high atmospheric transparency and low air humidity, the calculation methods provide understated data compared to full-scale ones. For stations with high dust content of the surface layer of the atmosphere, the calculated data are overstated. For marine and lake stations, overestimation of the calculated data is caused by increased humidity throughout the year and as a result, even with a small cloud cover, incoming solar radiation is significantly weakened by water vapor. The considered calculation methods can be used to calculate monthly amounts of total radiation with an accuracy of 10-12 %. Calculation for shorter time intervals leads to an increase in calculation errors. Using the method of calculating the total radiation components gives an error in the calculation of monthly amounts from 10 to 30 %, depending on the latitude. Performing calculations using this method for time intervals less than a month leads to a sharp increase in the size of errors.

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KARPENKO, N. P., and M. A. SHIRYAEVA. "METHODS OF FORECAST CALCULATION OF GROUND WATER BACKWATER IN THE ZONE OF HYDRAULIC STRUCTURES INFLUENCE." Prirodoobustrojstvo, no. 5 (2020): 109–16. http://dx.doi.org/10.26897/1997-6011-2020-5-109-116.

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The purpose of the work is to consider methods for calculating the forecast of groundwater backwater in the zone of influence of hydraulic structures. The analysis of analytical dependences of calculation of the forecast of groundwater backwater for various calculation schemes is carried out. For a homogeneous scheme of the geofiltration structure, a numerical model is proposed and a computational program for calculating the groundwater backwater is developed. It allows calculating the groundwater backwater from the channel at any time in the discrete mode. To simplify the solution of the problem of calculating the groundwater backwater, a computer program was created in the programming language Phyton Version 8.3 which quickly solves this hydrogeological problem. A possible range of geofiltration parameters is proposed for calculating the groundwater backwater near main channels. The adaptation and implementation of the software model was carried out for a specific object – the Bolshoy Stavropol channel-5, for which forecast calculations were made. The results of predictive calculations of groundwater backwater are the basis for the assessment of areas of possible flooding – the territory within which the level of ground water increases as a result of their backup by a hydraulic structure.

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Iitaka, Toshiaki, and Toshikazu Ebisuzaki. "Calculating Feynman Diagrams in Time Domain." Progress of Theoretical Physics Supplement 138 (2000): 66–71. http://dx.doi.org/10.1143/ptps.138.66.

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Kobro, Katarzyna, and Władysław Strzemiński. "Composing Space/Calculating Space-Time Rhythms." October 156 (May 2016): 12–74. http://dx.doi.org/10.1162/octo_a_00251.

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In this treatise, Katarzyna Kobro and Władysław Strzemiński distinguish between the condition of painting (which features a picture on a support with physical imits) and of sculpture (which involves space, which is limitless) and propose that the ways in which each medium determines its own essence must be fundamentally different. While painting relies on what would later be called “deductive structure,” in sculpture the issue is how to relate the object to space. After conducting a chronological examination of the different ways in which the sculptural object has related to space (in the Ancient, Medieval, Renaissance, and Baroque epochs), Kobro and Strzemiński propose various ways in which sculpture can not only relate to space but to “unite” with it via such solutions as polychrony and a disjunctive syntax through which the object itself eludes the perception of its identity.

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Evans, David D. "Calculating sprinkler actuation time in compartments." Fire Safety Journal 9, no. 2 (July 1985): 147–55. http://dx.doi.org/10.1016/0379-7112(85)90002-5.

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Puschner, P., and Ch Koza. "Calculating the maximum execution time of real-time programs." Real-Time Systems 1, no. 2 (September 1989): 159–76. http://dx.doi.org/10.1007/bf00571421.

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Wei, Mao Xing, and Zhi Gang Bai. "A New Time Domain Analysis of the Wave Power." Applied Mechanics and Materials 253-255 (December 2012): 720–23. http://dx.doi.org/10.4028/www.scientific.net/amm.253-255.720.

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The present frequency domain method of calculating wave power may not be accurate enough for calculating the incident wave power of a specific site, which is primary measurement for evaluating the efficiency of wave energy converters (WECs) and an alternative measure, the time domain method, is proposed. Three sites including two nearshore sites and one deepwater site at Chengshantou sea area were selected, and a sample wave parameters data set was obtained from wave model SWASH to demonstrate the application of these two methods. A comparison of the results of each method was also performed and two influential parameters used in calculation were analyzed. The results show that frequency domain method is very likely to overestimate the wave power at both deepwater and nearshore site. The time domain method proposed in this paper is believed to be more superior in calculating the incident wave power during a short term.

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Tankoy, A., T. E. Shadrikov, A. V. Gusenkov, V. D. Lebedev, and A. M. Sokolov. "Improving the accuracy and time of calculating steady-state modes of increased frequency electrical systems." Vestnik IGEU, no. 3 (2019): 22–31. http://dx.doi.org/10.17588/2072-2672.2019.3.022-031.

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The authors of modern Russian and foreign works suggest using the method of frequency analysis with Fourier transforms for modeling alternating current systems with a non-sinusoidal supply voltage. By applying the above-mentioned method to calculating steady-state modes of increased frequency power electrical systems (IFPES), we have found that there are significant differences between the calculated and experimental results, and the model calculation time is long. These problems can be solved by obtaining generalized formula expressions for the internal resistance value of IGBT transistors and the amplitudes of the acting EMF (voltage) in the IFPES applying Fourier decomposition. The generalized expressions for determining the internal resistance of IGBT transistors were obtained by analyzing physical processes of charge diffusion. The amplitude of the acting EMF (voltage) was determined by numerical integration. Simplified analytical expressions suitable for determining the frequency dependence of the resistance of IGBT transistors in the open state in electrical devices have been obtained. The IFPES calculation rate model has been optimized by frequency analysis. The obtained generalized analytical expressions allow making more accurate calculations of the transistor internal resistance value (with a difference of 70 % compared to the previously used value). By optimizing the calculation method we were able to reduce the model calculation from 8 hours to 3 minutes with Nk = 3000 harmonics. The modernized method can be used not only for calculating the IFPES but also for analyzing any electrical circuits with power electronics components exposed to non-periodic and non-sinusoidal currents and voltages.

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Das, Taposh Kumar. "An Evaluation of an Improper Integral Arises from an Analytic Solution of a Model Boltzmann Equation for Photon Transport." GANIT: Journal of Bangladesh Mathematical Society 35 (June 28, 2016): 87–94. http://dx.doi.org/10.3329/ganit.v35i0.28572.

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In this article we adopted the Mathematical model of solution of an improper integral which is created from the solution of the Boltzmann Transport equation (BTE) for photons. For the dose calculation of radiotherapy for cancer treatment, we need to solve the Boltzmann Transport equation. This improper integral is the important part of the BTE. Also the calculating time of the dose calculation is mostly dependent on the calculating time of this improper integral. For reducing the calculating time we need the minimum integrating area which is explained in this paper.GANIT J. Bangladesh Math. Soc.Vol. 35 (2015) 87-94

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12

Zhelieznov, Konstantyn I., Artem S. Akulov, Oleksandr M. Zabolotniy, Lyudmila V. Ursulyak, Evgenij V. Chabanuk, Angela O. Shvets, Valeriy G. Kuznetsov, and Anatolii V. Radkevych. "The revised method for calculating of the optimal train control mode." Archives of Transport 51, no. 3 (September 30, 2019): 21–34. http://dx.doi.org/10.5604/01.3001.0013.6160.

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Development of a method for calculating the optimal mode of conducting a train in terms of energy saving meet the safety requirements and schedules. The method of calculation must solve the assigned tasks without significant time spent on the calculation. To implement this method of calculation was used a simplified model of the train as a controlled system. The existing mathematical and algorithmic methods for solving isoperimetric problems of finding the optimal solution in the presence of restrictions on resources were the information base for methodology development. Scientific works of domestic and foreign scientists, professional periodicals, materials of scientific and practical conferences, methodical and normative materials, currently in force on Ukrainian Railways. The results of these studies were used to create simulators on the basis of computer technology for the training of locomotive drivers. The scientific novelty of the proposed calculation method consists in applying the simplified calculations of the status of the train as a controlled system, without the use of differential equations of motion that allows to significantly increase the speed of the calculations. This, in turn, will solve the problems of finding optimal control in real time, taking into account changing conditions during the movement of the train. The practical significance of the obtained results is the use of such a calculation method that does not require significant time for its implementation and can be used as a subsystem of the on-board train control system capable of per-forming calculations taking into account changes in the current train situation.

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Liu, Jing, and Yi Jun Deng. "Research on the Recursive Method for Real Time Variance Calculation." Advanced Materials Research 433-440 (January 2012): 3196–99. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3196.

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In the area of manufacturing and industrial engineering, variance calculation is the basic method to monitor the performance of instrument. In this paper, the recursive formula of real-time variance calculation is been put forward. Then it is possible to calculate the variance at real time without save the historical data. Experiment results shows that the new method for calculate the variance can greatly improve the calculating efficiency with high precision.

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Dickson, David C. M., and Howard R. Waters. "The Distribution of the time to Ruin in the Classical Risk Model." ASTIN Bulletin 32, no. 2 (November 2002): 299–313. http://dx.doi.org/10.2143/ast.32.2.1031.

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AbstractWe study the distribution of the time to ruin in the classical risk model. We consider some methods of calculating this distribution, in particular by using algorithms to calculate finite time ruin probabilities. We also discuss calculation of the moments of this distribution.

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15

Salihu, Armend, and Fahri Marevci. "Chio’s-like Method for Calculating the Rectangular (non-square) Determinants: Computer Algorithm Interpretation and Comparison." European Journal of Pure and Applied Mathematics 14, no. 2 (May 18, 2021): 431–50. http://dx.doi.org/10.29020/nybg.ejpam.v14i2.3920.

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In this paper, we present an approach for the calculation of rectangular determinants, where in addition to the mathematical formula, we also provide a computer algorithm for their calculation. Firstly, we present a method similar to Sarrus method for calculating the rectangular determinant of the order 2 × 3. Secondly, we present an approach for calculating the rectangular determinants of order m ×n by adding a row with all elements equal to one (1) in any row, as well as an application of Chio’s rule for calculating the rectangular determinants. Thirdly, we find the time complexity and comparison of the computer execution time of calculation of the rectangular determinant based on the presented algorithms and comparing them with the algorithm based on the Laplace method.

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Saltanaeva, Elena Andreevna, and Andrey Vladimirovich Maister. "Optimization of calculations of the effects of spill fires during accidents on linear equipment." E3S Web of Conferences 140 (2019): 07002. http://dx.doi.org/10.1051/e3sconf/201914007002.

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The issue of industrial (in particular, fire) safety at hazardous production facilities is considered. The previously obtained optimization method is given for calculating the assessment of the influence of hazardous factors in the event of possible accidents on extended (linear) equipment during explosions of fuel-air mixtures. Optimization is based on accelerating the calculations of the potential damage probability of Qn(M0) using transformed formulas containing a single instead of a double integral. The transformed formulas for calculating the double integral obtained in were used to optimize the calculations for the case of a spill fire based on the recommended probit function Pr used to estimate the damage to people by thermal radiation. As an example of calculations, a rectilinear fragment of a pipeline on a plane, presented as a segment of a straight line, is considered. To obtain an assessment of effectiveness, 1000 sets of source data characterizing various emergency situations were randomly generated. Based on the calculations for these data sets, statistical results are presented that characterize the effectiveness of the proposed optimization method: a graph of the values of the multiplicity of the reduction in calculation time using the converted formulas; average value and standard deviation of the multiplicity of reduction of calculation time; the maximum deviation of the values calculated by the original and converted formulas.

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Parviainen, H., and J. Korth. "Going back to basics: accelerating exoplanet transit modelling using Taylor-series expansion of the orbital motion." Monthly Notices of the Royal Astronomical Society 499, no. 3 (September 25, 2020): 3356–61. http://dx.doi.org/10.1093/mnras/staa2953.

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ABSTRACT A significant fraction of an exoplanet transit model evaluation time is spent calculating projected distances between the planet and its host star. This is a relatively fast operation for a circular orbit, but slower for an eccentric one. However, because the planet’s position and its time derivatives are constant for any specific point in orbital phase, the projected distance can be calculated rapidly and accurately in the vicinity of the transit by expanding the planet’s x and y positions in the sky plane into a Taylor series at mid-transit. Calculating the projected distance for an elliptical orbit using the four first time derivatives of the position vector (velocity, acceleration, jerk, and snap) is ∼100 times faster than calculating it using the Newton’s method, and also significantly faster than calculating z for a circular orbit because the approach does not use numerically expensive trigonometric functions. The speed gain in the projected distance calculation leads to 2–25 times faster transit model evaluation speed, depending on the transit model complexity and orbital eccentricity. Calculation of the four position derivatives using numerical differentiation takes $\sim 1\, \mu$s with a modern laptop and needs to be done only once for a given orbit, and the maximum error the approximation introduces to a transit light curve is below 1 ppm for the major part of the physically plausible orbital parameter space.

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Mock, Adam. "Calculating Scattering Spectra using Time-domain Modeling of Time-modulated Systems." Applied Computational Electromagnetics Society 35, no. 11 (February 3, 2021): 1288–89. http://dx.doi.org/10.47037/2020.aces.j.351113.

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Obtaining agreement between theoretical predictions that assume single-frequency excitation and finite-difference time-domain (FDTD) simulations that employ broadband excitation in the presence of time-varying materials is challenging due to frequency mixing. A simple solution is proposed to reduce artifacts in FDTD-calculated spectra from the frequency mixing induced by harmonic refractive index modulation applicable to scenarios in which second order and higher harmonics are negligible. Advantages of the proposed method are its simplicity and applicability to arbitrary problems including resonant structures.

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Triantafyllis, N., E. Sokos, and A. Ilias. "SCISOLA: REAL-TIME MOMENT TENSOR MONITORING FOR SEISCOMP3." Bulletin of the Geological Society of Greece 50, no. 2 (July 27, 2017): 1120. http://dx.doi.org/10.12681/bgsg.11817.

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Automatic Moment Tensor (MT) calculation is exceptionally valuable in many realtime seismological applications, such as shake map generation or tsunami warning. Scisola, a new software for automatic MT retrieval, has been recently developed. This software binds the extensively used ISOLA MT inversion code with the widely known real-time seismological processing tool, SeisComP3. Automatic MT calculation is achieved by passing the event location information, the waveforms and the station meta-data produced by SeisComP3 to ISOLA. Scisola has been written in Python, many powerful libraries were used and significantly reduced the MT computation time by calculating the Green's functions and the centroid position/time grid search in parallel mode. This tool provides a graphical user interface for easy solution overview of the extended graphical output and a quick revision of the corresponding solution; a database for storing the results and an extensive configuration customized to the user's preferences. Apart from the real-time MT approach, scisola is capable of running in offline mode mostly for testing or playback purposes. Lately, a scisola plug-in was completed for real-time MT monitoring by automatically updating a Web page with the latest MT calculations. The code's performance was compared to manual MT solutions and proved to be satisfying.

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Gracheva, E. I., Z. M. Shakurova, and R. E. Abdullazyanov. "A comparative analysis of the most common deterministic methods for the calculation of electricity losses in industrial networks." Power engineering: research, equipment, technology 21, no. 5 (December 17, 2019): 87–96. http://dx.doi.org/10.30724//1998-9903-2019-21-5-87-96.

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: The work is devoted to the analysis of deterministic most common methods for determining electricity losses in low-voltage industrial power supply networks. The method of graphical integration, the method of calculating electricity losses using the maximum loss time, the method of determining losses by time 2t, the method of calculating electricity losses by the average node loads are considered. The features of the application of each method are revealed. It is shown that for the method of graphical integration, initial data on the dependences of load schedules for each network element are required, and the method of calculating losses by average node loads can be used in networks with relatively constant loads. We consider the methods of calculating the losses based on graphical integration, the time of largest losses, 2t and the root-mean-square loads.At the same time, the errors of the considered methods for calculating electricity losses can be due to such reasons as the neglect of the heating temperature of the conductors, the neglect of the resistances of the contact connections of switching devices, the inaccuracy of determining the values of losses during the highest and lowest power demand, the inaccuracy of determining the time of the largest losses,. disregarding the form of the load schedule of consumers.Using the example of an industrial radial network site with known load graphs of consumers, the electric power losses in the circuit lines with the specified methods were calculated with the determination of the error of each method and the identification of the causes of errors. In this case, the method of graphical integration was adopted as the reference method of calculation. As a result of the calculations, it was established that the method of calculating 2t has the smallest error. It is shown that when choosing a method for determining electricity losses, it is necessary to observe the condition of compliance with methodological and informational errors.

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Wang, Qibin, Bo Zhao, Xianguang Kong, Hongbo Ma, and Jiantao Chang. "Time-varying mesh stiffness analysis of a single-roller enveloping hourglass worm gear." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 2 (March 15, 2018): 578–92. http://dx.doi.org/10.1177/0954406218762951.

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As a new type of transmission, the single-roller enveloping hourglass worm gear (SEHWG) is widely used in precision mechanical transmission systems. Time-varying mesh stiffness (TVMS) is one of the most important excitations, which has great influences on the dynamic characteristics of SEHWG systems. In this paper, a model for calculating the TVMS of the SEHWG is proposed, in which bending stiffness, shear stiffness, radial compression stiffness, and foundation stiffness are considered in the worm stiffness calculation. And bending stiffness, shear stiffness, and foundation stiffness are considered in the worm wheel stiffness calculation. The process of calculating the periodical TVMS of the SEHWG is also presented. Then, the TVMS of the SEHWG by the proposed method is compared with that of the finite element method for the model validation. Finally, the influences of the roller radii on TVMS are analyzed. The results show that the mesh stiffness of the TVMS has a tendency to rise first and then fall with the increasing roller radii.

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Lawson, Thomas. "Calculating the Median Time to Device-Related Complications." Journal of Vascular Access Devices 3, no. 2 (January 1998): 31–33. http://dx.doi.org/10.2309/108300898776087396.

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23

Zoghbi, A., C. Reynolds, and E. M. Cackett. "CALCULATING TIME LAGS FROM UNEVENLY SAMPLED LIGHT CURVES." Astrophysical Journal 777, no. 1 (October 10, 2013): 24. http://dx.doi.org/10.1088/0004-637x/777/1/24.

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Dehler, M., M. Dohlus, and T. Weiland. "Calculating frequency-domain data by time-domain methods." International Journal of Numerical Modelling: Electronic Networks, Devices and Fields 6, no. 1 (February 1993): 19–27. http://dx.doi.org/10.1002/jnm.1660060104.

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Ciotti, C., U. Fritsch, and H. J. Schmitt. "Calculating nonlinear microwave circuits with undersampled time signals." Electronics Letters 27, no. 7 (1991): 568. http://dx.doi.org/10.1049/el:19910358.

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Vries, Pedrode, and Kristofer Döös. "Calculating Lagrangian Trajectories Using Time-Dependent Velocity Fields." Journal of Atmospheric and Oceanic Technology 18, no. 6 (June 2001): 1092–101. http://dx.doi.org/10.1175/1520-0426(2001)018<1092:cltutd>2.0.co;2.

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Gould, R. Clay. "Equation for calculating overall treatment time in radiotherapy." International Journal of Radiation Oncology*Biology*Physics 29, no. 1 (April 1994): 216–17. http://dx.doi.org/10.1016/0360-3016(94)90254-2.

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Martynov, V., O. Martynova, S. Makarova, and O. Vietokh. "METHOD FOR CALCULATING THE COMPOSITION OF CELLULAR CONCRETE." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 83 (June 4, 2021): 77–85. http://dx.doi.org/10.31650/2415-377x-2021-83-77-85.

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The analysis of existing methods for calculating concrete compositions was carried out. The characteristics and sequence of the calculation-experimental and experimental-calculation methods for the selection of concrete compositions are provided. The advantages and disadvantages of each of the methods are described. These methods are generalized by the general systemic cycle PDCA (Deming cycle), which is determined by the sequence of actions: P (plan) ‒ D (do) ‒ C (check) ‒ A (Action). It was established that for calculating the compositions of the cellular method there is no universal method, which would ensure the achievement of the required strength and average density at the same time. Based on the above, the aim of the thesis was formulated. The aim of the thesis is to develop a method for calculating the composition of cellular concrete, based on experimental-statistical models, which would ensure the production of concrete with the required properties while minimizing the cost of raw materials. A calculation algorithm, a block diagram and a computer program for designing cellular concrete compositions based on experimental-statistical modeling were developed. Using the example of the specified block diagram for calculating concrete compositions, the sequence of calculations is described in detail. The essence of the calculations is that the three-factor mathematical model of the property parameter of cellular concrete, which is supposed to be guaranteed, leads to a second order equation. After that, the roots of the equation are determined. They are substituted into a mathematical model and the composition of concrete is determined in natural values of variable factors. After that, the cost of the composition is determined, which is entered into the data array. Then one of the factors changes, according to the set step and the cycle repeats. At the last stage, the formed data array is processed and the composition with the minimum cost of materials is determined. Testing of the developed software was carried out by processing and calculating a three factor experiment. As a result, the composition of cellular concrete which provides the required strength of foam concrete with a minimum cost of materials, was determined.

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Roy, M. M., O. O. Akulshin, V. V. Solovyov, V. H. Usenko, and I. V. Limar. "The optimal method for assessing gas reserves based on the calculation of gas hydrodynamic parameters." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 2 (2021): 5–10. http://dx.doi.org/10.33271/nvngu/2021-2/005.

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Purpose. Development of a new methodology for calculating gas reserves for gas wells of any productivity. Methodology. The calculation method was developed using the theoretical provisions of gas dynamics. It is based on the actual data from the study on gas wells in one developed mode. Findings. For the first time, a methodology for calculating gas reserves was proposed during the development of one study mode. In parallel with the calculation of gas reserves, the possibility of analytical calculation of a significant number of gas-hydrodynamic parameters opens up. Originality. The developed methods for calculating the value of the initial gas reserves and gas-hydrodynamic parameters of the studied gas objects have no analogs in domestic and world practice. The first of the methods is distinguished by the simplicity of calculation and the availability of the initial data for its use. The second is based on the differential, differential-integral, and integral methods to improve the accuracy of the calculated results. Practical value. The new methods for calculating gas reserves will make it possible to quickly assess hydrocarbon raw materials in the investigated object. The availability, minimization, and accuracy of the initial data for calculating gas reserves are undoubtedly signs of the optimality of the method. The simplicity of the calculation makes it possible to widely use the technique. The use of a new methodology for interpreting the results of gas well research in one mode will make it possible to depart from the traditional research method. Due to this, the number of research modes is reduced by several times. It also means a reduction in emissions to the atmosphere if the well is not operated with backpressure at the wellhead. A significant reduction in the cost of the research process due to the reduction in research time is also a factor in significant savings in research funds.

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Shukla, Vandana, O. P. Singh, G. R. Mishra, and R. K. Tiwari. "Reversible Realization of 4-Bit Vedic Multiplier Circuit with Optimized Performance Parameters." Sensor Letters 17, no. 10 (October 1, 2019): 826–31. http://dx.doi.org/10.1166/sl.2019.4155.

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Low power high speed calculating devices are foremost requirement of this era. Moreover, multiplication is considered as the most vital part of any calculating system. Multiplication process is generally considered as the speed limiting process as it requires more time as compared to other basic arithmetic calculations. So, here we focus on multiplication calculation using vedic method. Moreover, Reversible realization of any digital circuit improves the performance of the system by reducing the power loss from it. Here, the concept of vedic multiplication and Reversible approach are combined to propose a 4-bit multiplier circuit with optimized performance parameters. Proposed design is also analyzed and compared with existing designs. This approach may be employed to propose other low loss devices.

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Melatos, A., and P. A. Robinson. "Systematic approximations for magnetized transit-time interactions." Journal of Plasma Physics 53, no. 1 (February 1995): 75–108. http://dx.doi.org/10.1017/s0022377800018031.

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A systematic procedure is given for generating analytic approximations to the wave–particle energy transfer in magnetized transit-time interactions. The procedure can be applied to any wave-packet field structure, and yields especially simple results in the physically important limits of (i) small and large Larmor radius and (ii) small and large values of the ratio of the wave frequency to the cyclotron frequency. In many applications, the approximations developed here are the only viable means of calculating the wave—particle energy transfer, because the exact analytic theory and numerical test-particle calculations are too demanding computationally.

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Konyushkov, V. V. "Analysis of methods for analytical calculation of foundation settlement in time." Вестник гражданских инженеров 17, no. 4 (2020): 106–14. http://dx.doi.org/10.23968/1999-5571-2020-17-4-106-114.

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Currently, there exist three main methods for calculating foundation settlement: the method of linearly compressible layer (introduced by Prof. K. E. Egorov), the method of layer-by-layer summation (described in SP 22.13330.2016), and the method of one-dimension virgin compression (a special case of the equivalent layer method introduced by Prof. N. A. Tsytovich). All the above-mentioned methods for calculating foundation settlement are based on the linear dependence of deformations on stresses. The principal differences between these methods are in taking the account of natural soil stress from its own weight, the technique of assessing the compressible soil strata and evaluating the distribution of stress in depth from external pressure. In the practice of bases and foundations design, the layer-by-layer summation method is considered to be the most highly reputable and widely used. It should be noted that each method was initially developed to solve some specific problem. However, not every engineer at present knows the limits of a particular method application for calculating foundation deformation. The article presents calculations of the non-linear settlement development in the foundation performed by various methods. Comparison with actual deformations is made based on the results of long-term monitoring of foundation settlement of a well-known building in Saint Petersburg, and recommendations are offered regarding the applicability of the discussed methods.

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Szalai, Róbert, and Gábor Stépán. "Period Doubling Bifurcation and Center Manifold Reduction in a Time-periodic and Time-delayed Model of Machining." Journal of Vibration and Control 16, no. 7-8 (June 2010): 1169–87. http://dx.doi.org/10.1177/1077546309341133.

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A closed-form calculation is presented for the analysis of the period-doubling bifurcation in the time-periodic delay-differential equation model of interrupted machining processes such as milling where the nonlinearity is essentially nonsymmetric. We prove the subcritical sense of this period-doubling bifurcation and approximate the emerging period-two oscillations by the Lyapunov—Perron method for computing the center manifold and by calculating the Poincaré—Lyapunov constant of the bifurcation analytically at certain characteristic parameter values. The existence of the unstable period-two oscillations around the stable stationary cutting is confirmed using a numerical continuation algorithm developed for time-periodic delay-differential equations.

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Wróblewski, Artur, and Jarosław Andrzejczak. "Wave propagation time optimization for geodesic distances calculation using the Heat Method." Open Physics 17, no. 1 (June 8, 2019): 263–75. http://dx.doi.org/10.1515/phys-2019-0027.

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Abstract Finding the geodesic path defined as the shortest paths between two points on three-dimensional surface P is a well known problem in differential and computational geometry. Surfaces are not differentiable in a discrete way, hence known geometry algorithms can’t be used directly - they have to be discretized first. Classic algorithms for geodesic distance calculation such as Mitchell-Mount-Papadimitriou method (MMP) are precise but slow. Therefore modern solutions are developed for fast calculations. One of them is Heat Method which approximates such paths with some accuracy. In this paper we propose the extension of Heat Method to reduce the approximation error. A new formula for calculating value of the parameter t (wave propagation time step) which outperforms the original one in terms of mean and median error is presented. Also, correlation between mesh properties and best wave propagation time step as well as influence of variable node spacing on heat map based method were thoroughly analysed.

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Zhang, Bo, Kim Wann Engebretsen, Gianluca Fiandaca, Hongzhu Cai, and Esben Auken. "3D inversion of time-domain electromagnetic data using finite elements and a triple mesh formulation." GEOPHYSICS 86, no. 3 (May 1, 2021): E257—E267. http://dx.doi.org/10.1190/geo2020-0079.1.

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Over several decades, much research has been done to develop 3D electromagnetic inversion algorithms. Due to the computational complexity and the memory requirements for 3D time-domain electromagnetic (TEM) inversion algorithms, many real-world surveys are inverted within one dimension. To speed up calculations and manage memory for 3D inversions of TEM data, we have developed an approach using three uncoupled meshes: an inversion mesh, a forward-model mesh, and a mesh for Jacobian calculations. The inversion mesh is a coarse regular and structured mesh, such that constraints are easily enforced between the model parameters. Forward responses are calculated on a dense unstructured mesh to obtain accurate electromagnetic fields, whereas the Jacobian is calculated on a coarse unstructured mesh. We found that using a coarse mesh for the Jacobian is sufficient for the inversion to converge and, equally important, that it provides a significant speed boost in the overall inversion process, compared to calculating it on the forward-modeling mesh. The unstructured meshes are made of tetrahedral elements, and the electromagnetic fields are calculated using the finite-element method. The inversion optimization uses a standard Gauss-Newton formulation. For further speed up and memory optimizing of the inversion, we use domain decomposition for calculating the responses for each transmitter separately and parallelize the problem over domains using OpenMP. Compared to a 1D solution, the accuracy for the Jacobian is 1%–5% for the dense mesh and 2%–7% for the coarse mesh, but the calculation time is approximately five times faster for the coarse mesh. We also examined the algorithm on a small ground-based TEM data set acquired in an area where a 3D earth distorts the electromagnetic fields to such a degree that a 1D inversion is not feasible.

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Nikolaev, P. M. "Improving the Efficiency of Calculating B-splines in parallel Programming Tasks." Programmnaya Ingeneria 12, no. 5 (August 6, 2021): 267–73. http://dx.doi.org/10.17587/prin.12.267-273.

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The use of parallel computing tools can significantly reduce the execution time of calculations in many engineering tasks. One of the main difficulties in the development of multithreaded programs remains the organization of simultaneous access from different threads to shared data. The most common solution to this problem is to use locking facilities when accessing shared data. There are a number of tasks where data sharing is not needed, but you need to synchronize access to a limited resource, such as a temporary buffer. In such tasks, there is no data exchange between different threads, but there is an object that at a given time can be used by the code of only one thread. One such task is calculating the value of a B-spline. The software implementation of the functions for calculating B-splines, performed according to classical algorithms, requires the use of blocking objects when accessing the common array of intermediate data from different threads. This reduces the degree of parallelism and reduces the efficiency of computational programs using B-splines running on multiprocessor computing systems. The article discusses a way to improve the efficiency of calculating B-splines in parallel programming tasks by eliminating locks when accessing general modified data. A software implementation is presented in the form of a C++ class template, which provides placement of a temporary array used for calculating a B-spline into a local buffer of a given size with the possibility of increasing it if necessary. Using the developed template in conjunction with the threadlocal qualifier reduces the number of requests for increasing the buffer for high degree B-splines (larger than the initially specified buffer size). It is also possible to implement this scheme using the std::vector template of the C++ STL Standard Library. The results of the application of the developed class when calculating the values of B-splines in a multithreaded environment, showing a reduction in the calculation time in proportion to an increase in the number of computational processors, are presented. The methods of specifying arrays for storing intermediate calculation results considered in this article can be used in other parallel programming tasks.

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Avramchuk, Valeriy V., E. E. Luneva, and Alexander G. Cheremnov. "Increasing the Efficiency of Using Hardware Resources for Time-Frequency Correlation Function Computation." Advanced Materials Research 1040 (September 2014): 969–74. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.969.

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In the article the techniques of increasing efficient of using multi-core processors for the task of calculating the fast Fourier transform were considered. The fast Fourier transform is led on the basis of calculating a time time-frequency correlation function. The time-frequency correlation function allows increasing the information content of the analysis as compared with the classic correlation function. The significant computational capabilities are required to calculate the time-frequency correlation function, that by reason of the necessity of multiple computing fast Fourier transform. For computing the fast Fourier transform the Cooley-Tukey algorithm with fixed base two is used, which lends itself to efficient parallelization and is simple to implement. Immediately before the fast Fourier transform computation the procedure of bit-reversing the input data sequence is used. For algorithm of calculating the time-frequency correlation function parallel computing technique was used that experimentally allowed obtaining the data defining the optimal number of iterations for each core of the CPU, depending on the sample size. The results of experiments allowed developing special software that automatically select the effective amount of subtasks for parallel processing. Also the software provides the choice of sequential or parallel computations mode, depending on the sample size and the number of frequency intervals in the calculation of time-frequency correlation function.

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Prihozhy, A. A., and O. N. Karasik. "HETEROGENIOUS BLOCKED ALL-PAIRS SHORTEST PATHS ALGORITHM." «System analysis and applied information science», no. 3 (November 2, 2017): 68–75. http://dx.doi.org/10.21122/2309-4923-2017-3-68-75.

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The problem of finding the shortest paths between all pairs of vertices in a weighted directed graph is considered. The algorithms of Dijkstra and Floyd-Warshall, homogeneous block and parallel algorithms and other algorithms of solving this problem are known. A new heterogeneous block algorithm is proposed which considers various types of blocks and takes into account the shared hierarchical memory organization and multi-core processors for calculating each type of block. The proposed heterogeneous block computing algorithms are compared with the generally accepted homogeneous universal block calculation algorithm at theoretical and experimental levels. The main emphasis is on using the nature of the heterogeneity, the interaction of blocks during computation and the variation in block size, the size of the block matrix and the total number of blocks in order to identify the possibility of reducing the amount of computation performed during the calculation of the block, reducing the activity of the processor’s cache memory and determining the influence of the calculation time of each block type on the total execution time of the heterogeneous block algorithm. A recurrent resynchronized algorithm for calculating the diagonal block (D0) is proposed, which improves the use of the processor’s cache and reduces the number of iterations up to 3 times that are necessary to calculate the diagonal block, which implies the acceleration in calculating the diagonal block up to 60%. For more efficient work with the cache memory, variants of permutation of the basic loops k-i-j in the algorithms of calculating the blocks of the cross (C1 and C2) and the updated blocks (U3) are proposed. These permutations in combination with the proposed algorithm for calculating the diagonal block reduce the total runtime of the heterogeneous block algorithm to 13% on average against the homogeneous block algorithm.

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De Souza E Silva and Gail. "Calculating Cumulative Operational Time Distributions of Repairable Computer Systems." IEEE Transactions on Computers C-35, no. 4 (April 1986): 322–32. http://dx.doi.org/10.1109/tc.1986.1676765.

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Siegel, Ronald A. "A laplace transform technique for calculating diffusion time lags." Journal of Membrane Science 26, no. 3 (April 1986): 251–62. http://dx.doi.org/10.1016/s0376-7388(00)82110-9.

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Elbasha, Elamin H. "Discrete time representation of the formula for calculating DALYs." Health Economics 9, no. 4 (2000): 353–65. http://dx.doi.org/10.1002/1099-1050(200006)9:4<353::aid-hec519>3.0.co;2-v.

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Havukainen, Martti, and Stig Stenholm. "An open-systems approach to calculating time-dependent spectra." Journal of Modern Optics 45, no. 8 (August 1998): 1699–716. http://dx.doi.org/10.1080/09500349808230663.

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Lei, Yaguo, Delong Wang, Zongyao Liu, and Xiao Yang. "A new model for calculating time-varying gearmesh stiffness." Vibroengineering PROCEDIA 14 (October 21, 2017): 334–39. http://dx.doi.org/10.21595/vp.2017.19139.

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Olszewski, Stanislaw, and Marek Gluzinski. "Calculating the Magnetoresistance Effect in Metals." Zeitschrift für Naturforschung A 66, no. 5 (May 1, 2011): 311–20. http://dx.doi.org/10.1515/zna-2011-0507.

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Transversal magnetoresistance is calculated for numerous metal cases on the basis of simple electron theory. Any metal can be represented by a single band of states having a closed Fermi surface which is assumed to be similar in shape to a sphere. In an external electromagnetic field the electron transport seems to be regulated by two kinds of relaxation times. The first one is due to the electric field, and its size is not appreciably influenced by that field. On the other hand, electron motion in the magnetic field is associated with a relaxation time that is strongly dependent on the strength of that field. Both time parameters combine to an effective relaxation time according to Matthiessen’s rule. A good agreement between experiment and theory is obtained for Li, Cu, Ag, Au and Pd, Pt metals.

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Yao, Peng, Gai Rong Chen, and Shao Hong Xu. "A Fast Algorithm to Choose Delay Time for Strange Attractors." Advanced Materials Research 230-232 (May 2011): 1379–83. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.1379.

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According to pseudo-periodicity and ergodicity of chaotic systems, we put forward a fast algorithm to determine delay time in phase state reconstruction. The traditional method to calculate mutual information is time-consuming and complicated to realize, which greatly restricts its application. In our algorithm we gradually reduce the feasible computing interval and adjust the calculating step until satisfactory result is gotten. This method overcomes the tedious calculation of mutual information and meanwhile guarantees high precision. Finally the simulation results of Rössler and Lorenz systems verify the feasibility of our algorithm.

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Xu, Ru Feng, and Zhi Tong Chen. "Study on Methods for Calculating Tool Position Error Distribution during 5-Axis Machining of Sculptured Surfaces." Advanced Materials Research 314-316 (August 2011): 1517–22. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1517.

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With the continuous improvement of the calculation speed of computer, tool positioning methods based on numerical calculation in five-axis NC programming will play a greater role. First, this paper introduces three numerical methods for calculating tool position error distribution between a torus cutter and design surface in 5-axis machining of sculptured surfaces, namely a method for discretizing design surface, a method for discretizing the torus central circle, and a longitude method. At the same time, the detailed calculating steps are also given. An example of a cylindrical surface machined with torus tool is then conducted to compare and analyze the calculation accuracy and efficiency of the above methods. Results obtained show that the calculating deviation for computing tool position error distribution using the method for discretizing the torus central circle is minimum, while that using another two methods are larger; the calculation time of the method for discretizing the torus central circle is shortest, while that of the longitude method is longest; within the given programming tolerance, the machining strip widths calculated by the above methods are appropriately same, and the maximum deviation of actual machining strip width is within 2% of the theoretical value.

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Revelle, John P., Ankit Kumar, and Alexander F. Kemper. "Theory of Time-Resolved Optical Conductivity of Superconductors: Comparing Two Methods for Its Evaluation." Condensed Matter 4, no. 3 (August 27, 2019): 79. http://dx.doi.org/10.3390/condmat4030079.

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Time-resolved optical conductivity is an often used tool to interrogate quantum materials driven out of equilibrium. Theoretically calculating this observable is a complex topic with several approaches discussed in the literature. Using a nonequilibrium Keldysh formalism and a functional derivative approach to the conductivity, we present a comparison of two particular approaches to the calculation of the optical conductivity and their distinguishing features, as applied to a pumped superconductor. The two methods are distinguished by the relative motion of the probe and gate times; either the probe or gate time is kept fixed while the other is swept. We find that both the methods result in same qualitative features of the time-resolved conductivity after pump is over. However, calculating the conductivity by keeping the gate fixed removes artifacts inherent to the other method. We provide software that, based on data for the first method, is able to construct the second approach.

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Pan, M., P. Rez, and J. M. Cowley. "A new method of computing the phase-grating function in multislice calculation." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 478–79. http://dx.doi.org/10.1017/s0424820100154366.

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In multislice calculations of electron diffraction from crystal surfaces and convergent beam electron microdiffraction as well as STEM images, it is essential to construct a supercell containing the 'crystal defect' and to avoid any interference from two adjacent cells. The computing time for the phase-grating function of such a supercell is no longer negligible and sometimes could become dominant in a complete calculation. This is especially true for systems with an array processor where the multislice calculation proceeds rapidly due to the fast implementation of multiplication and the Fourier transform. The current multislice programs are not suitable for this kind of phase-grating calculation since the projected potential is calculated from the Fourier transform of the structure factors. With an increasing number of atoms in the cell, calculating structure factors becomes a time-consuming procedure.

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Slávik, Richard, and Miloš Kalousek. "Comparing Methods for Calculating Thermal Stability of Rooms." Advanced Materials Research 649 (January 2013): 49–52. http://dx.doi.org/10.4028/www.scientific.net/amr.649.49.

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The main idea of the article compares methods for the calculation of thermal stability of rooms in wintertime. The article is focused on comparison of an analytical and a numerical method on the sample room and specification of their differences. The main advantage of the analytical method is calculation in arbitrary time from a steady state without calculation of some previous steps. However, the method doesn’t allow a great variability of composition of constructions. The numerical methods depend on previous steps of the calculation, therefore they require many calculations with little time steps. It enables to define of some complex compositions of constructions and complex modelling of an internal state in the room and its changes in time. The determination of difference rate for different methods will verify their suitability for calculation.

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Panichkin, Vyacheslav B., and Elena V. Panichkina. "TIME PERIOD CALCULATING PROCEDURES IN ROMANO-GERMANIC, RUSSIAN AND COMMON LAW AND THEIR LINK TO THE COMMORIENT FICTION." Law of succession 4 (December 24, 2020): 8–12. http://dx.doi.org/10.18572/2072-4179-2020-4-8-12.

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The article shows three models of calculating time in relation to civil law relations on the example of several jurisdictions representing the main private legal systems of the world. The author proves that adherence to the particular order of time computation is strongly related to the reception of one of the three traditional doctrines: Roman civil, Roman natural and Anglo-American. All three procedures of use of the order of time calculating are analyzed on the example of the institute of commorientes (heirs in simultaneous death and death in quick succession). Also author depicts the evolution of Russian Law and its transition from civil to natural time calculation in relation to the rules of succession by heirs in simultaneous death and death in quick succession.

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Journal articles on the topic 'Calculating time'

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