Articles de revues : « Express highways Mathematical models »

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Kassu, Aschalew, et Michael Anderson. « Analysis of Nonsevere Crashes on Two- and Four-Lane Urban and Rural Highways : Effects of Wet Pavement Surface Condition ». Journal of Advanced Transportation 2018 (2 août 2018) : 1–10. http://dx.doi.org/10.1155/2018/2871451.

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This study examines the effects of wet pavement surface conditions on the likelihood of occurrences of nonsevere crashes in two- and four-lane urban and rural highways in Alabama. Initially, sixteen major highways traversing across the geographic locations of the state were identified. Among these highways, the homogenous routes with equal mean values, variances, and similar distributions of the crash data were identified and combined to form crash datasets occurring on dry and wet pavements separately. The analysis began with thirteen explanatory variables covering engineering, environmental, and traffic conditions. The principal terms were statistically identified and used in a mathematical crash frequency models developed using Poisson and negative binomial regression models. The results show that the key factors influencing nonsevere crashes on wet pavement surfaces are mainly segment length, traffic volume, and posted speed limits.

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Burinskienė, Marija, Denis Kapski, Valery Kasyanik, Anton Pashkevich, Aleksandra Volynets et Oleg Kaptsevich. « Estimating Parameters for Traffic Flow Using Navigation Data on Vehicles ». Baltic Journal of Road and Bridge Engineering 15, n^o 4 (28 septembre 2020) : 1–21. http://dx.doi.org/10.7250/bjrbe.2020-15.492.

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The article describes the method for estimating transport flow parameters using the two-fluid Herman-Prigogine mathematical model developed considering the proposed method of estimating parameters for the system based on the passive processing of navigation data on the movement of vehicles. The efficiency of the suggested algorithms and mathematical models for estimating road traffic flow parameters and the system as a whole was confirmed performing tests using a set of tracks on the main highways of Belarus.

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Sukharev, R. Yu. « Mathematical models of wheel turning processes road construction vehicles ». Nauchno-tekhnicheskiy vestnik Bryanskogo gosudarstvennogo universiteta 7, n^o 3 (25 septembre 2021) : 259–69. http://dx.doi.org/10.22281/2413-9920-2021-07-03-259-269.

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The construction of highways is a complex, multi-stage process. Most of the construction works are carried out according to the projects of structures and quite high requirements are imposed on the quality of execution. The fulfillment of these requirements is associated with great difficulties in view of the limited accuracy of the road construction machine itself, the lack of on-board control systems and the limited capabilities of the human operator, who is unable to determine the required exact parameters of the structure being built «by eye». To meet the requirements, three-dimensional control systems are used, which allow determining 3 coordinates of the working order of the machine – the vertical coordinate and the location of the machine on the construction site. At the same time, the digital project of the constructed structure should be the setter in such a system. The system determines the current position and compares it with the project. On the basis of this information, a control effect on the operating organ of the machine is formed. The course of movement and the speed of the machine when using such systems are determined by the machine operator. Further development of these systems should be four-dimensional systems – in which all control actions are assigned to the control system, starting from calculating the trajectory of the machine, choosing the speed, determining the required number of passes and ending with controlling the position of the working body of the machine at each moment of time. For the functioning of these systems, adequate mathematical models of the turning processes of road construction machines with different steering options are necessary.

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Kapski, Denis, Valery Kasyanik, Oleksii Lobashov, Aleksandra Volynets, Oleg Kaptsevich et Andrii Galkin. « Estimating the Parameters of Traffic Flows on the Basis of Processing of Localization Data on the Movement of Vehicles ». Communications - Scientific letters of the University of Zilina 21, n^o 2 (24 mai 2019) : 89–99. http://dx.doi.org/10.26552/com.c.2019.2.89-99.

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The article describes the method of estimating the parameters of transport flows using the two-fluid mathematical model of Herman-Prigogine and developed and based on the proposed method of estimating the parameters of the system on the basis of passive processing of navigation data on the movement of vehicles. The efficiency of the proposed algorithms, mathematical models for estimating the parameters of road traffic flow and system as a whole was confirmed during its testing using a set of tracks on the main highways of Commonwealth of Independent States.

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Akalili, Imania Aufi. « PROFIL KEMAMPUAN KOMUNIKASI MATEMATIS SISWA DALAM MENYELESAIKAN MASALAH GEOMETRI DITINJAU DARI LEVEL VAN HIELE ». KadikmA 11, n^o 3 (5 février 2021) : 40. http://dx.doi.org/10.19184/kdma.v11i3.22580.

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Mathematical communication skills are needed to express ideas, messages, and ideas through written or oral. The research subjects were five students of class XII SMAN Ambulu who were categorized in van Hiele level. The results of the data analysis obtained were students with informal deduction had the ability to express mathematical ideas through written or oral, the ability to understand mathematical ideas both orally and in writing and the ability to use terms and notations to present data, and had the ability to present ideas. mathematics in solving or describing models of mathematical problems. Students of analysis have the ability to express mathematical ideas through oral, the ability to understand and evaluate mathematical ideas both orally and in writing, and are able to use mathematical terms and notations in presenting mathematical ideas. Visualization students are able to explain how to describe geometric transformations orally and are able to use notations and terms in presenting data.

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Kapskiy, D. V., V. V. Kasyanik, A. V. Evtuh et O. F. Kaptsevich. « EVALUATION OF TRANSPORT FLOW EFFICIENCY ON THE BASIS OF TRAFFIC MOVEMENT DATA ». Science & ; Technique 16, n^o 5 (5 octobre 2017) : 444–54. http://dx.doi.org/10.21122/2227-1031-2017-16-5-444-454.

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The paper considers a method for evaluation of transport flow parameters and determine an efficiency of variants concerning organization of traffic movement and provision of qualitative transportation. A method for evaluation of main traffic flow parameters while using a two-fluid mathematical model of Herman – Prigogine has been developed and it is based on passive processing of navigation data for road transport facilities on highways and urban road and street networks. The main advantages and novelty of the method (in contrast with the traditional usage of a mathematical model of Her- man – Prigogine on the basis of active processing of navigation data) are the following: a passive treatment of GPS-tracks and support of their formats that make it possible significantly improve quality and adequacy of the model results; cloud com-puting (usage of cloud storage for storing large bulk of data); presence of client mobile application for Android operating system which is used for data collection in addition to operation with already collected navigation data from navigation and information center and other sources; application for calculation and processing of modern web technologies; scalability and configurability of the system. Efficiency of the proposed algorithms, mathematical models for evaluation of transport flow parameters and system as a whole have been proved in the process of their approbation while using a set of tracks on main highways of Belarus

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Zayyadi, Moh, et Kuratul Aini Saleh. « WRITTEN MATHEMATICAL COMMUNICATION SKILLS ON OPEN-ENDED PROBLEMS : IS IT DIFFERENT BASED ON THE LEVEL OF MATHEMATICS ABILITY ? » MaPan 8, n^o 2 (15 décembre 2020) : 179–204. http://dx.doi.org/10.24252/mapan.2020v8n2a2.

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This study aims to describe students' written mathematical communication skills in open-ended problems based on their mathematical abilities. This research was conducted at grade VII-A of SMPN 1 Pamekasan. This research uses descriptive qualitative research. The instruments used were the Mathematical Ability Test (MAT), Written Mathematical Communication Skills Test (WMCST) on open-ended problems, and Interview Guidelines. The results showed that subjects with high and moderate mathematical ability were able to meet three indicators of written mathematical communication skills, namely being able to express mathematical ideas through writing, demonstrate and convey visually; able to understand, interpret and evaluate mathematical ideas in writing, as well as in other visual forms; and able to use mathematical notations in the structure to write down ideas and relationships with situation models in writing. Meanwhile, subjects with low mathematics ability can fulfill 2 out of 3 indicators of written mathematical communication skills, namely being able to express mathematical ideas through writing, demonstrate and convey visually; unable to understand, interpret and evaluate mathematical ideas in writing or other visual forms; and able to use mathematical notations in the structure to write ideas and relationships with situation models.

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Mullakkal-Babu, Freddy Antony, Meng Wang, Haneen Farah, Bart van Arem et Riender Happee. « Comparative Assessment of Safety Indicators for Vehicle Trajectories on Highways ». Transportation Research Record : Journal of the Transportation Research Board 2659, n^o 1 (janvier 2017) : 127–36. http://dx.doi.org/10.3141/2659-14.

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Safety measurement and its analysis have been challenging and well-researched topics in transportation. Conventionally, surrogate safety measures have been used as safety indicators in simulation models for safety assessment, in control formulations for driver assistance systems, and in data analysis of naturalistic driving studies. However, surrogate indicators give partial insights on traffic safety; that is, these indicators only indicate a predetermined set of possible precrash situations for an interacting vehicle pair. Recently, a safety indicator called the “driving safety field,” based on field theory, was proposed for two-dimensional vehicle interactions. However, the objectivity of its functional form and its validity have yet to be tested. A qualitative and quantitative comparison of different safety indicators was provided as a risk measure to demarcate their mathematical properties and evaluate their usefulness in quantifying trajectory risk. Five relevant safety indicators were compared: inverse time to collision, postencroachment time, potential indicator of collision with urgent decceleration, warning index, and safety field force. Their formulations were mathematically analyzed to yield qualitative insights and their values over simulated vehicle trajectories were evaluated to yield quantitative insights. The results acknowledge the limitations and demarcate the functional utilities of the selected safety indicators.

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Liu, Tin Tin, Guo Jin Chen, You Ping Gong et Zhi Hua Li. « Research on Unified Expression Method of Multi-Domain Constraint Models ». Advanced Materials Research 971-973 (juin 2014) : 938–41. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.938.

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This paper is mainly discussed the establishment of the unified constraint expression of simulation optimization model. Express all kinds of element constraints with unified physical mathematical mapping mechanism, uniform the model representation of product components in each domain and establish the unified expression model, in order to facilitate the follow-up simulation solution of multi-domain constraint system.

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Montejo-Gámez, Jesús, Elvira Fernández-Ahumada et Natividad Adamuz-Povedano. « A Tool for the Analysis and Characterization of School Mathematical Models ». Mathematics 9, n^o 13 (3 juillet 2021) : 1569. http://dx.doi.org/10.3390/math9131569.

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This paper shows a tool for the analysis of written productions that allows for the characterization of the mathematical models that students develop when solving modeling tasks. For this purpose, different conceptualizations of mathematical models in education are discussed, paying special attention to the evidence that characterizes a school model. The discussion leads to the consideration of three components, which constitute the main categories of the proposed tool: the real system to be modeled, its mathematization and the representations used to express both. These categories and the corresponding analysis procedure are explained and illustrated through two working examples, which expose the value of the tool in establishing the foci of analysis when investigating school models, and thus, suggest modeling skills. The connection of this tool with other approaches to educational research on mathematical modeling is also discussed.

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Ma, Guoliang, Kaixian Ba, Zhiwu Han, Zhengguo Jin, Bin Yu et Xiangdong Kong. « A Mathematical Model Including Mechanical Structure, Hydraulic and Control of LHDS ». Robotica 39, n^o 7 (20 janvier 2021) : 1328–43. http://dx.doi.org/10.1017/s0263574720001204.

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SUMMARYIn this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

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Wang, Xiao Yu, Xiang Bao Meng, Ji Xin Wang et Ke Gao. « Implementation of Mathematical Modeling for Wire Rope Strands ». Advanced Materials Research 608-609 (décembre 2012) : 1769–72. http://dx.doi.org/10.4028/www.scientific.net/amr.608-609.1769.

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Modeling for complex spiral wire rope structures, on which the mechanical performances largely depend, are paramount to finite element analysis application. Three mathematical modeling thoughts were brought out to create the geometric models of wire rope strands. The first one was presented based on the centerline times of the helical structures, as the centerline times can be decreased through transitional coordinate system. For the second, the centerlines of the wire rope were formed by the helical movement of predefined point. In the third one, a local coordinate system which can be transformed into the world coordinate system by their relationship was employed. The above three ideas were implemented by different kinds of derivation. The geometric parameter equations were presented to express the accurate wire rope models. These approaches are beneficial for parametric modeling and analysis of wire rope strands.

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Kim, S. H., et N. P. Suh. « Mathematical Foundations for Manufacturing ». Journal of Engineering for Industry 109, n^o 3 (1 août 1987) : 213–18. http://dx.doi.org/10.1115/1.3187121.

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For the field of manufacturing to become a science, it is necessary to develop general mathematical descriptions for the analysis and synthesis of manufacturing systems. Standard analytic models, as used extensively in the past, are ineffective for describing the general manufacturing situation due to their inability to deal with discontinuous and nonlinear phenomena. These limitations are transcended by algebraic models based on set structures. Set-theoretic and algebraic structures may be used to (1) express with precision a variety of important qualitative concepts such as hierarchies, (2) provide a uniform framework for more specialized theories such as automata theory and control theory, and (3) provide the groundwork for quantitative theories. By building on the results of other fields such as automata theory and computability theory, algebraic structures may be used as a general mathematical tool for studying the nature and limits of manufacturing systems. This paper shows how manufacturing systems may be modeled as automatons, and demonstrates the utility of this approach by discussing a number of theorems concerning the nature of manufacturing systems. In addition symbolic logic is used to formalize the Design Axioms, a set of generalized decision rules for design. The application of symbolic logic allows for the precise formulation of the Axioms and facilitates their interpretation in a logical programming language such as Prolog. Consequently, it is now possible to develop a consultive expert system for axiomatic design.

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Givargis, Sh, et H. Karimi. « Mathematical, statistical and neural models capable of predicting LA,max for the Tehran–Karaj express train ». Applied Acoustics 70, n^o 7 (juillet 2009) : 1015–20. http://dx.doi.org/10.1016/j.apacoust.2008.11.003.

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Briani, Maya, Emiliano Cristiani et Paolo Ranut. « Macroscopic and Multi-Scale Models for Multi-Class Vehicular Dynamics with Uneven Space Occupancy : A Case Study ». Axioms 10, n^o 2 (24 mai 2021) : 102. http://dx.doi.org/10.3390/axioms10020102.

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In this paper, we propose two models describing the dynamics of heavy and light vehicles on a road network, taking into account the interactions between the two classes. The models are tailored for two-lane highways where heavy vehicles cannot overtake. This means that heavy vehicles cannot saturate the whole road space, while light vehicles can. In these conditions, the creeping phenomenon can appear, i.e., one class of vehicles can proceed even if the other class has reached the maximal density. The first model we propose couples two first-order macroscopic LWR models, while the second model couples a second-order microscopic follow-the-leader model with a first-order macroscopic LWR model. Numerical results show that both models are able to catch some second-order (inertial) phenomena such as stop and go waves. Models are calibrated by means of real data measured by fixed sensors placed along the A4 Italian highway Trieste–Venice and its branches, provided by Autovie Venete S.p.A.

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Srinivasan, R. Srini, Wayne A. Gerth et Michael R. Powell. « Mathematical models of diffusion-limited gas bubble dynamics in tissue ». Journal of Applied Physiology 86, n^o 2 (1 février 1999) : 732–41. http://dx.doi.org/10.1152/jappl.1999.86.2.732.

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Mathematical models of bubble evolution in tissue have recently been incorporated into risk functions for predicting the incidence of decompression sickness (DCS) in human subjects after diving and/or flying exposures. Bubble dynamics models suitable for these applications assume the bubble to be either contained in an unstirred tissue (two-region model) or surrounded by a boundary layer within a well-stirred tissue (three-region model). The contrasting premises regarding the bubble-tissue system lead to different expressions for bubble dynamics described in terms of ordinary differential equations. However, the expressions are shown to be structurally similar with differences only in the definitions of certain parameters that can be transformed to make the models equivalent at large tissue volumes. It is also shown that the two-region model is applicable only to bubble evolution in tissues of infinite extent and cannot be readily applied to bubble evolution in finite tissue volumes to simulate how such evolution is influenced by interactions among multiple bubbles in a given tissue. Two-region models that are incorrectly applied in such cases yield results that may be reinterpreted in terms of their three-region model equivalents but only if the parameters in the two-region model transform into consistent values in the three-region model. When such transforms yield inconsistent parameter values for the three-region model, results may be qualitatively correct but are in substantial quantitative error. Obviation of these errors through appropriate use of the different models may improve performance of probabilistic models of DCS occurrence that express DCS risk in terms of simulated in vivo gas and bubble dynamics.

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Fischer, B., et H. Weber. « Express saccades and visual attention ». Behavioral and Brain Sciences 16, n^o 3 (septembre 1993) : 553–67. http://dx.doi.org/10.1017/s0140525x00031575.

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AbstractOne of the most intriguing and controversial observations in oculomotor research in recent years is the phenomenon of express saccades in monkeys and man. These are saccades with such short reaction times (100 msec in man, 70 msec in monkeys) that some experts on eye movements still regard them as artifacts or as anticipatory reactions that do not need any further explanation. On the other hand, some research groups consider them not only authentic but also a valuable means of investigating the mechanisms of saccade generation, the coordination of vision and eye movements, and the mechanisms of visual attention.This target article puts together pieces of experimental evidence in oculomotor and related research – with special emphasis on the express saccade – to enhance our present understanding of the coordination of vision, visual attention, and the eye movements subserving visual perception and cognition.We hypothesize that an optomotor reflex is responsible for the occurrence of express saccades, one that is controlled by higher brain functions involved in disengaged visual attention and decision making. We propose a neural network as the basis for more elaborate mathematical models or computer simulations of the optomotor system in primates.

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Al-Munirah Ayob, Maryam Rukayyah, et Azizah Mohd Rohni. « Mathematical Approach for Predicting the Gross Domestic Product of Malaysia ». Malaysian Journal of Social Sciences and Humanities (MJSSH) 5, n^o 10 (2 octobre 2020) : 247–57. http://dx.doi.org/10.47405/mjssh.v5i10.491.

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Gross domestic product (GDP) is a monetary measure of the market value of overall final goods and services produced in a given year, and serves as a gauge of the economy’s overall health and size. The GDP prediction is significant, as it can capture and understand the future developments of a country’s economy. In this paper, three different mathematical models have been used to predict Malaysia’s gross domestic product using regressions. The models discussed in this paper are linear, exponential and parabolic regressions. In developing the models, data from year 1970 to 2014 has been employed and data from year 2015 to 2019 has been used to examine the models' accuracy. The models are then observed to identify the most appropriate to express the relationship between the years and Malaysia’s gross domestic product. In this study, it is found that the parabolic regression model is more accurate compared to the linear and exponential regression models. The parabolic regression model is also the most appropriate since it is adjusted to the real conditions of Malaysia's gross domestic product which is the main subject of this paper. Finally, it is obtained that the prediction values of GDP in Malaysia will increase for the next ten years (2020 - 2029). Keywords: Gross domestic product, Linear regression, Exponential regression, Parabolic regression

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Alawiyah, Siti Tuti, et Jarnawi Afgani Dahlan. « PENINGKATAN KEMAMPUAN REPRESENTASI MATEMATIS SISWA KELAS IX-G SMP NEGERI 2 BANDUNG PADA MATERI PERSAMAAN KUADRAT DENGAN DISCOVERY LEARNING MODEL ». JURNAL PENELITIAN DAN KARYA ILMIAH 19, n^o 1 (2 février 2019) : 38–46. http://dx.doi.org/10.33592/pelita.vol19.iss1.72.

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Representative ability is the ability to express mathematical ideas that are used to show the results of his work in certain ways as a result of the interpretation of his mind. Based on the results of observations obtained data that the class on IX-G SMP 2 Bandung experienced a difficulty in presenting mathematical ideas. Difficulties experienced by students of class IX-G are a problem that must be addressed immediately because of how students can express mathematical ideas if students cannot develop representations properly. After the initial test, it turns out that the representation ability of students in class IX-G is in the low category. Based on the background of the problem found, the researcher carried out classroom action research to overcome the problems experienced by class IX-G. The objectives of this study are: (1) Knowing the increase in students' mathematical representation abilities with discovery learning models in class IX-G of SMP Negeri 2 Bandung. (2) Describing the response of students of class IX-G SMP Negeri 2 Bandung to the implementation of learning using discovery learning models. (3) Analyzing the effectiveness of the implementation of mathematics learning by using discovery learning models in improving the ability of mathematical representation. This classroom action research was conducted in 2 cycles. The subjects in this study were class IX-G, which amounted to 32 students consisting of 18 men and 14 women. Data collection was done using formative tests of mathematical representation abilities, student response questionnaires, and observation sheets of teacher and student activities. The results of this study as a whole have been successful because they have been able to improve students' representation abilities significantly and student learning outcomes are completed in a classical manner. This can be seen by the increase in the value of classical absorption ability of students' mathematical representation abilities from cycle I to cycle II. The absorption ability of students' mathematical representation in the first cycle was 31.25%, in the second cycle it increased to 87.50%. In addition, students' responses to learning are in good criteria. The effectiveness of implementing mathematics learning by using discovery learning models in improving the ability of mathematical representation is good.

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Hassein, Udai, Maksym Diachuk et Said Easa. « Development of Warning System and Driving Model for Overtaking Trucks on Two-Lane Highways ». Transportation Research Record : Journal of the Transportation Research Board 2673, n^o 11 (5 juin 2019) : 1–12. http://dx.doi.org/10.1177/0361198119850470.

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Passing collisions are one of the most serious traffic safety problems on two-lane highways. These collisions occur when a driver overestimates the available sight distance. This paper presents a framework for a passing collision warning system (PCWS) that assists drivers in avoiding passing collisions by reducing the likelihood of human error. The system uses a combination of a camera and radar sensors to identify the impeding vehicle type and to detect the opposing vehicles traveling in the left lane. The study involved the development of a steering control model providing lane-change maneuvers, the design of a driving simulator experiment that allows for the collection of data necessary to estimate passing parameters, and the elaboration of the algorithm for the PCWS based on sensor signals to detect impeding vehicles such as trucks. Simulation tests were carried out to confirm the effectiveness of the proposed PCWS algorithm. The impact of driver behavior on passing maneuvers was also investigated. Mathematical and imitation models were enhanced to implement Simulink for replications of real-life driving scenarios. The different factors that affect system accuracy were also examined.

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MODARRES, MOHAMMAD, EBRAHIM NASRABADI et MOHAMMAD MEHDI NASRABADI. « FUZZY LINEAR REGRESSION ANALYSIS FROM THE POINT OF VIEW RISK ». International Journal of Uncertainty, Fuzziness and Knowledge-Based Systems 12, n^o 05 (octobre 2004) : 635–49. http://dx.doi.org/10.1142/s0218488504003120.

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In this paper, fuzzy linear regression models with fuzzy/crisp output, fuzzy/crisp input are considered. In this regard, we define risk-neutral, risk-averse and risk-seeking fuzzy linear regression models. In order to do that, two equality indices are applied to express the degree of equality between a pair of fuzzy numbers. We also develop three mathematical models to obtain the parameters of fuzzy linear regression models. Minimizing the difference between the total spread of the observed and estimated values is the objective of these models. The advantage of our proposed models is the simplicity in programming and computation.

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Pratama, Ryan Angga, et Ari Musdolifah. « Teka-Teki Logika untuk Meningkatkan Minat Belajar Siswa Sanggar Kegiatan Belajar Balikpapan Timur ». Abdimas Universal 1, n^o 1 (18 mai 2019) : 48–53. http://dx.doi.org/10.36277/abdimasuniversal.v1i1.22.

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The success of mathematics learning is supported by the teacher's proficiency in carrying out teaching activities and awareness of students in participating in learning activities. Therefore, learning requires the ability of teachers to manage learning and / or their ability to manage classes. Teachers must have capable skills in the fields of strategy and learning models that vary. For this reason, it is necessary to have active, fun, creative learning, and be able to provide attraction so that students can express themselves in learning and experience no saturation, so students can understand the material well. In learning activities, one way that can be done by teachers to overcome these problems is to provide a learning that is able to optimize the logic of students' thinking in solving non-routine problems in school, namely Mathematical Logic Puzzle. Through the provision of challenge questions in the form of Mathematical Logic Puzzles, students gain knowledge and understanding of mathematical logic puzzles, gain new learning experiences, dare to express ideas and be able to answer various kinds of non-routine problems and problems of logic related to life everyday, and students are more motivated in learning mathematics. Keywords: mathematical logic puzzles, mathematics learning

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Banihashemi, Mohamadreza, et Michael Dimaiuta. « Maximizing Safety Improvement Benefits in Crash Prediction Models with Accident Modification Factors ». Transportation Research Record : Journal of the Transportation Research Board 1908, n^o 1 (janvier 2005) : 9–18. http://dx.doi.org/10.1177/0361198105190800102.

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A linear optimization model that maximizes the safety benefits of improve-ments on an existing highway within specific budget constraints is presented. This model works in conjunction with crash prediction models that predict the expected number of crashes for highways by using a base model and productive accident modification factors (AMFs). The base model predicts the expected number of crashes for a base highway. The AMFs modify the prediction on the basis of the actual characteristics of the highway. If there were multiple alternative improvements for several highway features, then there would be many combined alternatives, each with a certain cost and a certain degree of improvement in highway safety. The proposed model uses linear optimization to find the combined alternative that has the best safety improvement within the available budget. The mathematical optimization model is studied in a general form as well as a detailed form in the context of an existing crash prediction model, the crash prediction module of the interactive highway safety design model. The procedure for building the optimization problem is described. A C programming code was developed to build the linear optimization problem. A test case study is defined, and the problem is built and solved by using the CPLEX optimization solver. The variation of the safety measures versus improvement costs is studied, and the results are discussed.

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Longley, J. P. « A Review of Nonsteady Flow Models for Compressor Stability ». Journal of Turbomachinery 116, n^o 2 (1 avril 1994) : 202–15. http://dx.doi.org/10.1115/1.2928354.

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This paper presents a review of the different approaches to modeling the nonsteady fluid dynamics associated with two-dimensional compressor flow fields. These models are used to predict the time development of flow field disturbances and have been found useful in both the study of rotating stall and the development of active control. The opportunity to digest the earlier investigations has now made it possible to express the modeling ideas using only a very simple mathematical treatment. Here, the emphasis is on the underlying physical processes that the models simulate and how the assumptions within the models affect predictions. The purpose of this work is to produce, in a single document, a description of compressor modeling techniques, so that prospective users can assess which model is the most suitable for their application.

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Delle Monache, Maria, Karen Chi, Yong Chen, Paola Goatin, Ke Han, Jing-mei Qiu et Benedetto Piccoli. « A Three-Phase Fundamental Diagram from Three-Dimensional Traffic Data ». Axioms 10, n^o 1 (7 février 2021) : 17. http://dx.doi.org/10.3390/axioms10010017.

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This paper uses empirical traffic data collected from three locations in Europe and the US to reveal a three-phase fundamental diagram with two phases located in the uncongested regime. Model-based clustering, hypothesis testing and regression analyses are applied to the speed–flow–occupancy relationship represented in the three-dimensional space to rigorously validate the three phases and identify their gaps. The finding is consistent across the aforementioned different geographical locations. Accordingly, we propose a three-phase macroscopic traffic flow model and a characterization of solutions to the Riemann problems. This work identifies critical structures in the fundamental diagram that are typically ignored in first- and higher-order models and could significantly impact travel time estimation on highways.

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Garzon, Julius R., et Leomarich F. Casinillo. « Visualizing Mathematics : The Use of Block Models for Strategic Problem Solving ». Journal of Education Research and Evaluation 5, n^o 1 (13 février 2021) : 112. http://dx.doi.org/10.23887/jere.v5i1.30888.

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The ability to visually manipulate problem quantities is often the key to understand effectively the concept towards proper solution process. Modeling blocks in a problem text is a visual mathematical technique that utilizes bar models to express relationship between known and unknown numerical elements. Facing a dismal performance among students entering high school with poor basic problem-solving skills, this study is an attempt to investigate how block model approach potentially reinforce students’ heuristic skills (analytical & procedural) in solving mathematical problems. Two classes of grade 7 students in Ibarra National High School, Maasin City, Philippines were used as participants which is assigned into groups, that is, control and experimental groups. Control group was taught using conventional method while the experimental group was taught using the concept of block model. Using quasi-experimental design, the data analysis revealed significant increase in scores and significant mean difference in problem-solving skills between groups who used and did not use block model method. In conclusion, utilization of block models gives high potential in developing strategic problem-solving ability of learners. Hence, this approach should be incorporated by mathematics teachers in their teaching strategies.

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Birr, Krystian, et Barbara Strzebrakowska. « Modelling the loss of time caused by traffic incidents on motorways ». MATEC Web of Conferences 231 (2018) : 01002. http://dx.doi.org/10.1051/matecconf/201823101002.

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For each road incident important factors like location, capacity reduction, traffic management, duration of road incidents and amount of traffic should be defined. All performer operations and effects of incidents affect the capacity of the road, average speed, time loss, vehicle queues and traffic jams. In the article road incidents were divided into planned and unexpected. Statistical analysis prepared using the database of traffic events which occurred on highways and expressways in Pomeranian Voivodeship is presented considering location of incidents on each road, frequency and duration of incidents and duration of rescue operation. Furthermore, the cases used to calibrate the model are characterised. Subsequently, the method of estimation of time loss resulting from incidents is presented. Within the methodology, mathematical and simulation models are distinguished. The tools for dynamic traffic modelling are also presented. In the last part of the article, the method of calculation value of time loss is presented.

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Deng, Wei. « The Analysis of Energy and Environmental Efficiency Based on Input-Output Model ». Applied Mechanics and Materials 34-35 (octobre 2010) : 1253–57. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.1253.

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Input-output method can conveniently analyze energy consumption and environmental load for iron and steel enterprises. It can visually express production manufacturing statement and the consumption of energy and non-energy. Mathematical models are helpful for quantitative analysis and data handling. In addition, it’s useful to analyze main affected factors. Unit process energy consumption and steel ratio directly affect energy efficiency, which can be analyzed by e-p method.

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Clark, Colin W. « Modelling the behaviour of fishers and fishes ». ICES Journal of Marine Science 75, n^o 3 (9 décembre 2017) : 932–40. http://dx.doi.org/10.1093/icesjms/fsx212.

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Abstract I describe my personal evolution as a modeller of behaviour, both human and (non-human) animal behaviour, using dynamic state-variable models. At first I worked in renewable resource Economics, especially the economics of marine fisheries where I collaborated extensively with Gordon R. Munro. Subsequently, in collaboration with Marc Mangel (and many field biologists) I worked in Behavioural Ecology. Mathematical models have played a major role in both of these subjects, but until recently mostly static models were used, on the grounds that dynamic (not to mention stochastic) models were too difficult to work with. I express the hope that our use of relatively simple (but not too simple) dynamic models has established the fact that such models can be extremely helpful, perhaps essential, in understanding many aspects of behaviour.

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Xu, Kaijie, Hanyu E, Yinghui Quan, Ye Cui et Weike Nie. « From granulation-degranulation mechanisms to fuzzy rule-based models : Augmentation of granular-based models with a double fuzzy clustering ». Journal of Intelligent & ; Fuzzy Systems 40, n^o 6 (21 juin 2021) : 12243–52. http://dx.doi.org/10.3233/jifs-210336.

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In this study, we develop a novel clustering with double fuzzy factors to enhance the performance of the granulation-degranulation mechanism, with which a fuzzy rule-based model is designed and demonstrated to be an enhanced one. The essence of the developed scheme is to optimize the construction of the information granules so as to eventually improve the performance of the fuzzy rule-based models. In the design process, a prototype matrix is defined to express the Fuzzy C-Means based granulation-degranulation mechanism in a clear manner. We assume that the dataset degranulated from the formed information granules is equal to the original numerical dataset. Then, a clustering method with double fuzzy factors is derived. We also present a detailed mathematical proof for the proposed approach. Subsequently, on the basis of the enhanced version of the granulation-degranulation mechanism, we design a granular fuzzy model. The whole design is mainly focused on an efficient application of the fuzzy clustering to build information granules used in fuzzy rule-based models. Comprehensive experimental studies demonstrate the performance of the proposed scheme.

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Campione, Giuseppe. « The effects of fibers on the confinement models for concrete columns ». Canadian Journal of Civil Engineering 29, n^o 5 (1 octobre 2002) : 742–50. http://dx.doi.org/10.1139/l02-066.

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A mathematical model is developed to express the stressstrain relationships in compression of fiber-reinforced concrete (FRC) columns for both normal- and high-strength concrete, with and without conventional steel reinforcement. This model allows one to determine the maximum strength and strain capacity by determining the effective concrete core of the confining devices at rupture. Analytical expressions are also given for the ultimate load corresponding to the complete formation of the concrete failure plane. The proposed model incorporates the most relevant parameters of confinement, i.e., type of confinement, volumetric ratio, spacing, yielding strength, shape of the member cross section, type of fiber (length, diameter, shape), and fiber volume. The model has been verified against data obtained from concentric compressive tests on concrete specimens reinforced with transverse steel and fibers.Key words: high-strength concrete, fiber-reinforced concrete, lateral reinforcement, stressstrain curves.

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Bostanov, B. О. « Unstressed combined trajectory of robot ». Bulletin of the National Engineering Academy of the Republic of Kazakhstan 4, n^o 78 (10 janvier 2020) : 29–34. http://dx.doi.org/10.47533/2020.1606-146x.29.

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The problem of forming a smooth combined trajectory of the robot and determining the position of the connection points, providing kinematic and dynamic smoothness conditions, is considered. Mathematical relations are obtained that express the conditions for connecting arcs of a trajectory without a jump in the radii of curvature at the joints. The proposed method provides the formation of complex technical forms and creates on their basis new models of the combined trajectory of a robot of continuous curvature.

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Bostanov, B. О. « Unstressed combined trajectory of robot ». Bulletin of the National Engineering Academy of the Republic of Kazakhstan 4, n^o 78 (10 janvier 2020) : 29–34. http://dx.doi.org/10.47533/2020.1606-146x.29.

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The problem of forming a smooth combined trajectory of the robot and determining the position of the connection points, providing kinematic and dynamic smoothness conditions, is considered. Mathematical relations are obtained that express the conditions for connecting arcs of a trajectory without a jump in the radii of curvature at the joints. The proposed method provides the formation of complex technical forms and creates on their basis new models of the combined trajectory of a robot of continuous curvature.

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Cardei, Petru, Florin Nenciu, Nicoleta Ungureanu, Mirabela Augustina Pruteanu, Valentin Vlăduț, Dan Cujbescu, Iuliana Găgeanu et Oana Diana Cristea. « Using Statistical Modeling for Assessing Lettuce Crops Contaminated with Zn, Correlating Plants Growth Characteristics with the Soil Contamination Levels ». Applied Sciences 11, n^o 17 (6 septembre 2021) : 8261. http://dx.doi.org/10.3390/app11178261.

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The aim of the study was to identify new mathematical models and strategies that can characterize the behavior of pollutants accumulating in the soil over time, considering the special characteristics of these chemicals that cannot be degraded or destroyed easily. The paper proposes a statistical model for assessing the accumulation of Zn in the lettuce (Lactuca sativa L.), based on three indicators that characterize the development of lettuce plants over time. The experimental data can be used to obtain interpolated variations of the mass increase functions and to determine several functions that express the time dependence of heavy metal accumulation in the plant. The resulting interpolation functions have multiple applications, being useful in generating predictions for plant growth parameters when they are grown in contaminated environments, determining whether pollutant concentrations may be hazardous for human health, and may be used to verify and validate dynamic mathematical contamination models.

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Fitriani, Fitriani, Yulia Anita Siregar et Wiwik Novitasari. « Analisis kesulitan kemampuan komunikasi matematika mahasiswa menggunakan aplikasi google classroom pada matakuliah aljabar ». Journal of Didactic Mathematics 2, n^o 1 (29 avril 2021) : 18–25. http://dx.doi.org/10.34007/jdm.v2i1.596.

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Mathematical communication skills are one of the abilities that students must have to make it easier to solve problems contained in mathematics itself and in everyday life. Because if students have mastered mathematical communication skills, it will make it easier for students to take deeper learning. This study aims to analyze the difficulty of students' mathematical communication skills using the Google Classroom Application in the Algebra course. This type of research is descriptive qualitative. The subjects of this study were tree semester students who took Algebra courses in the Mathematics Education study program at Universitas Muhammadiyah Tapanuli Selatan, academic year 2020/2021 as many as 15 people. The instrument used in this study was Test and interview. The results showed that based on the test results obtained: difficulties in the ability to interpret mathematical ideas rationally in writing, difficulties in mathematical problems into mathematical models and difficulties in the ability to express mathematical ideas in the form of descriptions. Meanwhile, based on the results of the interview, namely: (1) technical difficulties, and (2) student adaptation difficulties. To overcome these difficulties, it is necessary which is a combination of Online and Offline learning or also called blended learning.

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Qin, Yanyan, Hao Wang et Daiheng Ni. « Lighthill-Whitham-Richards Model for Traffic Flow Mixed with Cooperative Adaptive Cruise Control Vehicles ». Transportation Science 55, n^o 4 (juillet 2021) : 883–907. http://dx.doi.org/10.1287/trsc.2021.1057.

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In the future, road traffic will incorporate a random mix of manual vehicles and cooperative adaptive cruise control (CACC) vehicles, where a CACC vehicle will degrade to an adaptive cruise control (ACC) vehicle when vehicle-to-vehicle communications are not available. This paper proposes a generalized framework of the Lighthill-Whitham-Richards (LWR) model for such mixed vehicular flow under different CACC penetration rates. In this approach, the kinematic wave speed propagating through the mixed platoon was theoretically proven to be the slope of mixed fundamental diagram. In addition, the random degradation from CACC to ACC was captured in mathematical expectation for traffic scenarios where the CACC only monitors one vehicle ahead. Three concrete car-following models, the intelligent driver model (IDM) and CACC/ACC models validated by Partners for Advanced Transit and Highways (PATH) program, were selected as examples to investigate the propagation of small perturbations and shock waves. Numerical simulations were also performed based on the selected car-following models. Moreover, the derived mixed LWR model was applied to solve some traffic flow problems. It indicates that the proposed LWR model is able to describe the propagation properties of both small perturbations and shock waves. The mixed LWR model can also be used to solve some practical problems, such as the queue caused by a traffic accident and the impact of a moving bottleneck. More importantly, the proposed generalized framework admits other CACC/ACC/regular car-following models, including those developed from further experiments.

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de Groot, Daan H., Julia Lischke, Riccardo Muolo, Robert Planqué, Frank J. Bruggeman et Bas Teusink. « The common message of constraint-based optimization approaches : overflow metabolism is caused by two growth-limiting constraints ». Cellular and Molecular Life Sciences 77, n^o 3 (22 novembre 2019) : 441–53. http://dx.doi.org/10.1007/s00018-019-03380-2.

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AbstractLiving cells can express different metabolic pathways that support growth. The criteria that determine which pathways are selected in which environment remain unclear. One recurrent selection is overflow metabolism: the simultaneous usage of an ATP-efficient and -inefficient pathway, shown for example in Escherichia coli, Saccharomyces cerevisiae and cancer cells. Many models, based on different assumptions, can reproduce this observation. Therefore, they provide no conclusive evidence which mechanism is causing overflow metabolism. We compare the mathematical structure of these models. Although ranging from flux balance analyses to self-fabricating metabolism and expression models, we can rewrite all models into one standard form. We conclude that all models predict overflow metabolism when two, model-specific, growth-limiting constraints are hit. This is consistent with recent theory. Thus, identifying these two constraints is essential for understanding overflow metabolism. We list all imposed constraints by these models, so that they can hopefully be tested in future experiments.

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RAZAVI HAJIAGHA, Seyed Hossein, Meisam SHAHBAZI, Hannan AMOOZAD MAHDIRAJI et Hossein PANAHIAN. « A BI-OBJECTIVE SCORE-VARIANCE BASED LINEAR ASSIGNMENT METHOD FOR GROUP DECISION MAKING WITH HESITANT FUZZY LINGUISTIC TERM SETS ». Technological and Economic Development of Economy 24, n^o 3 (25 mai 2018) : 1125–48. http://dx.doi.org/10.3846/20294913.2016.1275878.

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Decision makers usually prefer to express their preferences by linguistic variables. Classic fuzzy sets allowed expressing these preferences using a single linguistic value. Considering inevitable hesitancy of decision makers, hesitant fuzzy linguistic term sets allowed them to express individual evaluation using several linguistic values. Therefore, these sets improve the ability of humans to determine believes using their own language. Considering this feature, in this paper a method upon linear assignment method is proposed to solve group decision making problems using this kind of information, when criteria weights are known or unknown. The performance of the proposed method is illustrated in a numerical example and the results are compared with other methods to delineate the models efficiency. Following a logical and well-known mathematical logic along with simplicity of execution are the main advantages of the proposed method.

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Chen, Bo, Jia Di Qiu et Ming Ming Chen. « Designing Access Control Policy Using Formal Concept Analysis ». Applied Mechanics and Materials 602-605 (août 2014) : 3822–25. http://dx.doi.org/10.4028/www.scientific.net/amm.602-605.3822.

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The need to securely share information among collaborating entities is increasingly becoming important. It often needed to implement access control (AC) models. The objective of this paper is to design access control policy using formal concept analysis, which is based on mathematical lattice and order theory. We provide discussion on how FCA can be used to capture RBAC constraints. We show with FCA, we can express more intend constrains than it can be done in traditional RBAC approach. The experimental results show that the approach is more resilient to dynamic computer environment.

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Kassenova, L. G., G. S. Yensebaeva et G. Zh Shuitenov. « CONSTRUCTION OF A PHYSICAL AND MATHEMATICAL MODEL OF THE GRAVITATIONAL FIELD ». BULLETIN Series of Physics & ; Mathematical Sciences 73, n^o 1 (29 mars 2021) : 91–95. http://dx.doi.org/10.51889/2021-1.1728-7901.13.

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The problem of gravitational field physics is to identify the relationship between the gravitational field and the expansion of the space-time continuum. Therefore, the creation of models, the study of which makes it possible to identify these relationships and express them in formulas, is relevant. In the modern theory of the gravitational field, small quantities appear, which are neglected in the derivation of formulas of practical application. This paper presents a model of the gravitational field that combines quantum properties with the expansion of the space-time continuum. Also, using a simplified model of the coordinate system, the gravitational field of a stationary centrally symmetric object is studied and the limiting distance of the test particle capture by the gravitational field is calculated. Calculations made without neglecting small quantities gave interesting results: the limiting radius of capture by the gravitational field of the test particle; the formula for the mass defect of the black hole Schwarzschild; relations expressing the dependence of the quantities of quantum physics on the Hubble constant.

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Abuzeid, Osama M., Anas N. Al-Rabadi et Hashem S. Alkhaldi. « Recent Advancements in Fractal Geometric-Based Nonlinear Time Series Solutions to the Micro-Quasistatic Thermoviscoelastic Creep for Rough Surfaces in Contact ». Mathematical Problems in Engineering 2011 (2011) : 1–29. http://dx.doi.org/10.1155/2011/691270.

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To understand the tripological contact phenomena, both mathematical and experimental models are needed. In this work, fractal mathematical models are used to model the experimental results obtained from literature. Fractal geometry, using a deterministic Cantor structure, is used to model the surface topography, where recent advancements in thermoviscoelastic creep contact of rough surfaces are introduced. Various viscoelastic idealizations are used to model the surface materials, for example, Maxwell, Kelvin-Voigt, Standard Linear Solid and Jeffrey media. Such media are modelled as arrangements of elastic springs and viscous dashpots in parallel and/or in series. Asymptotic power laws, through hypergeometric series, were used to express the surface creep as a function of remote forces, body temperatures and time. The introduced models are valid only when the creep approach of the contact surfaces is in the order of the size of the surface roughness. The obtained results using such models, which admit closed-form solutions, are displayed graphically for selected values of the systems' parameters; the fractal surface roughness and various material properties. Results obtained showed good agreement with published experimental results, where the utilized methodology can be further extended to the utilization for the contact of surfaces within micro- and nano-electronic devices, circuits and systems.

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Kërënxhi, Svjetllana, et Pranvera Gjoci. « Involvement of Algebraic-Geometrical Duality in Shaping Fraction’s Meaning and Calculation Strategies with Fractions ». Journal of Educational and Social Research 7, n^o 1 (26 janvier 2017) : 151–57. http://dx.doi.org/10.5901/jesr.2017.v7n1p151.

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Abstract Many mathematical concepts and processes, besides the algebraic form of their presentation, can be modeled as well geometrically through diagrams and graphics. Both these aspects of concepts demonstration (algebraic and geometrical aspect) are present on mathematical textbooks of pre-university education. In this paper we consider algebraic and geometrical aspect on 6th grade math textbooks and in particular algebraic-geometrical duality, aiming that the fraction concept and the fraction calculation strategy to be assimilated better by the students. A study was made with 78 students to understand their abilities to express using algebraic symbols and to introduce mathematical situations with geometrical models for “Fractions” chapter. After the analysis of calculative strategies applied by students, in the article it is suggested that algebraic-geometrical duality must be included in teaching based on a complete framework. This will enable students to fully realize the deep understanding of concepts and the calculative strategies they are using.

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Bolotin, Yu L., V. A. Cherkaskiy et O. A. Lemets. « New cosmographic constraints on the dark energy and dark matter coupling ». International Journal of Modern Physics D 25, n^o 05 (avril 2016) : 1650056. http://dx.doi.org/10.1142/s0218271816500565.

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We propose a novel approach to obtain limitations on the dark energy (DE) and dark matter (DM) coupling. The suggested approach allows us to express the coupling constant in terms of the cosmographic parameters (CPs). It enables us to find constraints on the coupling constant directly based on observational data and to restrict number of numerous models describing interaction in the dark sector.

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Zhang, Jian Ping, Zhi Jiang Yan et Quan Fei Ding. « Processing Method for the Node of Wind Farm in Power Flow Calculation ». Advanced Materials Research 383-390 (novembre 2011) : 3598–604. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.3598.

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At present, there are two kinds of common generators in wind farms, which are induction generators (IG) and doubly-fed induction generators (DFIG). Based on the steady state mathematical models of these two kinds of generators, the processing methods of wind farms in power flow calculation are given. The core idea is to express active power of the generator by a function of wind speed and to express the reactive power by a function of active power, slip and terminal voltage, and then the Jacobian matrix will be corrected according to the relation between terminal voltage and reactive power in the wind farm node. Finally, the IEEE 14-bus test system including wind farm is applied for power flow calculation and analysis. The numerical results show that the mentioned methods are feasible and can satisfy the requirements of the engineering application, which can pave a foundation for further research.

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Rabbani, Masoud, Farahnaz Alipour, Hamed Farrokhi-Asl et Neda Manavizadeh. « Using metaheuristic algorithms for solving a mixed model assembly line balancing problem considering express parallel line and learning effect ». Brazilian Journal of Operations & ; Production Management 15, n^o 2 (1 juin 2018) : 254–69. http://dx.doi.org/10.14488/bjopm.2018.v15.n2.a8.

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Mixed-model assembly line attracts many manufacturing centers' attentions, since it enables them to manufacture different models of one product in the same line. The present work proposes a new mathematical model to balancing mixed-model assembly two parallel lines, in which first one is a common line and the other is an express line due to more modern technology or operators with higher skills. Therefore, the cost of equipment and skilled labor in the express line is higher, and also, the learning effect on resource dependent task times and setup times is considered in the assemble-to-order environment. The aim of this study is to minimize the cycle time and the total operating cost and smoothness index by configuration of tasks in stations, according to their precedence diagrams. Also, assigning the assistants to some tasks in some stations and for some models is allowed. This problem is categorized as an NP-hard problem and for solving this multi-objective problem, non-dominated sorting genetic algorithm ІІ (NSGA-II) and multi-objective particle swarm optimization (MOPSO) are applied. Finally, for comparing the proposed methods some numerical examples are implemented and the result show that MOPSO outperforms NSGAII.

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Nowak, Martin A. « Evolutionary biology of language ». Philosophical Transactions of the Royal Society of London. Series B : Biological Sciences 355, n^o 1403 (29 novembre 2000) : 1615–22. http://dx.doi.org/10.1098/rstb.2000.0723.

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Language is the most important evolutionary invention of the last few million years. It was an adaptation that helped our species to exchange information, make plans, express new ideas and totally change the appearance of the planet. How human language evolved from animal communication is one of the most challenging questions for evolutionary biology. The aim of this paper is to outline the major principles that guided language evolution in terms of mathematical models of evolutionary dynamics and game theory. I will discuss how natural selection can lead to the emergence of arbitrary signs, the formation of words and syntactic communication.

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Martin, Benjamin T., Stephan B. Munch et Andrew M. Hein. « Reverse-engineering ecological theory from data ». Proceedings of the Royal Society B : Biological Sciences 285, n^o 1878 (16 mai 2018) : 20180422. http://dx.doi.org/10.1098/rspb.2018.0422.

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Ecologists have long sought to understand the dynamics of populations and communities by deriving mathematical theory from first principles. Theoretical models often take the form of dynamical equations that comprise the ecological processes (e.g. competition, predation) believed to govern system dynamics. The inverse of this approach—inferring which processes and ecological interactions drive observed dynamics—remains an open problem in ecology. Here, we propose a way to attack this problem using a machine learning method known as symbolic regression, which seeks to discover relationships in time-series data and to express those relationships using dynamical equations. We found that this method could rapidly discover models that explained most of the variance in three classic demographic time series. More importantly, it reverse-engineered the models previously proposed by theoretical ecologists to describe these time series, capturing the core ecological processes these models describe and their functional forms. Our findings suggest a potentially powerful new way to merge theory development and data analysis.

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Qu, Ji-ting, et Hong-nan Li. « Optimal Placement of Passive Energy Dissipation Devices by Genetic Algorithms ». Mathematical Problems in Engineering 2012 (2012) : 1–21. http://dx.doi.org/10.1155/2012/474282.

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A mathematical model is proposed in this paper for locating optimal positions for passive energy dissipative dampers. Three control indices of structural responses with the storey-drift angle, storey displacement, and acceleration are taken in this model. Firstly, six combination modes of these indices are presented. On the premise that the number of dampers is fixed, this paper deals with the optimal placement of two types of passive dampers for several building models with different number of storeys and seismic ground motions at four types of sites using genetic algorithm. Secondly, two estimating indices are presented to assess the reasonable combination mode of coefficients under different conditions, which can generally express the best response control. Numerical examples are illustrated to verify the effectiveness and feasibility of the proposed mathematical model. At last, several significant conclusions are given based on numerical results.

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Rahman, Md Mijanoor, Mohd Tahir Ismail et Majid Majahar Ali. « Car following and lane changing behavior using NGSIM and China data ». International Journal of Advances in Applied Sciences 8, n^o 1 (1 mars 2019) : 14. http://dx.doi.org/10.11591/ijaas.v8.i1.pp14-25.

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Road safety is imperative theme because increasing road fatalities deaths in world. Besides road fatalities, traffic jam is increasing, human is frustrated for uncomfortable journey. The roads safety and passengers comfortable of the roadway system are vastly depended on the Car following (CF) and Lane Changing (LC) features of drivers. CF and LC theory describe the driver behavior by following paths in a traffic stream. In this research, researchers have compared to US-101 Next-Generation-Simulation (NGSIM) data with Beijing forth ring road, China freeways real trajectory data by CF and LC models. The CF data has been calibrated with Genetic Algorithm (GA). Reproducing Kernel Hilbert Space (RKHS) is generated the LC beginning and finishing points. Findings revealed that the CF parameters as maximum acceleration, minimum deceleration, free speed, minimum headway and stopping distance percentages of Chinese data are 74.71%, 79.95%, 66.57%, 0.018% and 65.65% respectively of NGSIM data. After completing the comparison, researchers have been found out optimization safety and comfortable acceleration-deceleration and LC beginning-finishing points of driver behavior. Here this analysis generates the driver behavior at real traffic network on the express highways of specific two roads US-101 (NGSIM) data and Chinese freeways data. Since NGSIM data is well simulated so road traffic is more safety and comfortable for journey.

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Dumont, Grégory, Jacques Henry et Carmen Oana Tarniceriu. « A theoretical connection between the Noisy Leaky integrate-and-fire and the escape rate models : The non-autonomous case ». Mathematical Modelling of Natural Phenomena 15 (2020) : 59. http://dx.doi.org/10.1051/mmnp/2020017.

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Finding a mathematical model that incorporates various stochastic aspects of neural dynamics has proven to be a continuous challenge. Among the different approaches, the noisy leaky integrate-and-fire and the escape rate models are probably the most popular. These two models are generally thought to express different noise action over the neural cell. In this paper we investigate the link between the two formalisms in the case of a neuron subject to a time dependent input. To this aim, we introduce a new general stochastic framework. As we shall prove, our general framework entails the two already existing ones. Our results have theoretical implications since they offer a general view upon the two stochastic processes mostly used in neuroscience, upon the way they can be linked, and explain their observed statistical similarity.

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