rss_2.0Mathematics FeedSciendo RSS Feed for Mathematics Feed Differences and Common Aspects of Logistics and Supply Chain Management<abstract> <title style='display:none'>Abstract</title> <p>Supply chain management and logistics are two concepts between which there may be differences and common aspects. The purpose of this article is to describe the two concepts as well as a comparison between the common aspects and the differences between them. The term logistics is an older term and on the other hand the term of supply chain management refers to several processes. Logistics is an activity in supply chain management. There are many differences between them, but also many common aspects but both are inseparable. Therefore, they do not contradict each other, but complement each other. Supply chain management helps logistics to stay in touch with the transport, warehousing and distribution team.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Novel Flower-Shaped Multiple Input Multiple Output Dielectric Resonator Antenna<abstract> <title style='display:none'>Abstract</title> <p>In modern communication systems, dielectric resonator antennas (DRA) play an important role due to its several advantages over contemporary antennas. In this paper, novel flower-shaped multiple input multiple output (MIMO) DRA is proposed for wireless applications in X- band. The proposed antenna with four ports displays more than -15 dB isolation between ports with defected ground technique. The antenna exhibits 7.2-7.5 GHZ impedance bandwidth and 4.66 dBi gain at 7.3 GHz. MIMO performance parameters: Envelope Correlation Coefficient (ECC) and Diversity Gain (DG) of the proposed antenna are also studied and calculated.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Extensions of Steffensen’s Method to the Space ℝ<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this paper is to give some extensions of Steffensen’s method to the space ℝ<italic><sup>n</sup></italic>.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Macroeconomic Predictor for Recovery Rate of Construction and Demolition Waste. A Neural Networks Model for Romania<abstract> <title style='display:none'>Abstract</title> <p>The common values of a circular economy are concentrated in decoupling economic growth from resource consumption; resource efficiency; waste management; sharing; reducing greenhouse gas emissions; lifecycle assessments and closing loops. With the increasing cost of natural resources as a real EU scenario, industries will significantly benefit from shifting towards a more circular approach. The aim of this paper is to analyses the waste management actions, especially for construction and demolition sector, in Romania in the EU-28 context by applying statistical methods and neural network modelling to find the best macroeconomic predictor for recovery rate of construction and demolition waste for period 2010-2020.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Underwater Image Detection for Cleaning Purposes; Techniques Used for Detection Based on Machine Learning<abstract> <title style='display:none'>Abstract</title> <p>Serious problems are on the rise, especially in these current times. The world is facing too many environmental threats. Water pollution is one of the main issues threatening the future. In some parts of the world, the water’s surface is covered by mucilage, which is dangerous for both aquatic animals and humans. This article firstly defines mucilage and highlights the reasons for its production. Afterwards to tackle water pollution, cleaning systems using image detection with the help of machine learning supervised classification algorithms are highlighted. This paper showcases the machine learning and classification used as well as the best solution for convolutional neural network and region-based convolutional neural network methods.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Study and Analysis, the Partnership that Reveals the Best Solutions<abstract> <title style='display:none'>Abstract</title> <p>The field of engineering is a complex and well-developed one and thus offers various opportunities to students. Design engineering is a branch of this field that has several categories. The field of engineering involves logic and reason and imagination. The strength of 3D and 2D design is the engineer’s ability to see in space. This skill is cultivated over time and requires practice and work. Time management in favour of effort is also a very important aspect of engineering tool. Design develops with technology because nowadays everything is designed in 3D/2D CAD and CAM space. Thus, technology is the basis of computer-aided design and manufacturing. Automotive design engineering involves continuous study and analysis of the CAD working environment (programs such as CATIA, NX Siemens), the processes to be performed (welding, marking and checking stations) and the materials that can meet the project requirements (such as C45 and PA6).</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Iot and its Benefit in Feeding Domestic Pets<abstract> <title style='display:none'>Abstract</title> <p>The Internet of things (IoT) is playing an important role in nowadays world due to its ability in describing physical objects with sensors that leads to exchanging data with other devices. For this case, we use the IoT technology in this study for solving the daily feeding problem of domestic animals and offering practical solutions to pet owners leads to respond to all requests that may be needed during the regular feeding of our pets. These requests can be pouring the determined amount of food into the pet’s food container at the specified time intervals, controlling this process via the phone application created, giving an extra food with a button if desired, checking whether the pet has eaten the food by means of the weight sensor and informing the user via the phone application when necessary, controlling the pet or the environment with the camera, controlling the amount of food in the food storage tank via the ultrasonic distance sensor and informing the user. For validating this technology, we develop this method systematically and examine with practical development.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Obtaining and Characterizing the Pb(MgNb)O–Ln(MgTi)O Doped System<abstract> <title style='display:none'>Abstract</title> <p>The Pb(Mg<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub>-based ceramic system was obtained by using a modified variant of the conventional ceramic method in order to get pyrochlore-free compositions. Solid solutions obtained from Pb(Mg<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub> and Ln(Mg<sub>1/2</sub>Ti<sub>1/2</sub>)O<sub>3</sub> with Ln = Y3+, La<sup>3+</sup>, Pr<sup>3+</sup>, Nd<sup>3+</sup> and Sm3+, were synthesized using a 3-step columbite precursor method and appropriate milling and sintering conditions. The structural phases of all sintered compositions were investigated in detail. The X-ray diffraction results demonstrate that all the samples possess a perovskite structure. The influence of dopant on the incorporation degree in the solid solutions was studied. The dielectric constants at three frequencies were measured and the influence of the dopant on these values was discussed.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00Experimental Examination on Performance and Emission of a Coated Diesel Engine Fueled with Diesel and Pre-Heated Coriander Oil Blends<abstract> <title style='display:none'>Abstract</title> <p>The aim of the study is to determine the effects of the preheated coriander seed oil, used as fuel, on the performance and the emission characteristics of the ceramic coated single-cylinder diesel engine. In this study, the piston, exhaust, and inlet valve of a single-cylinder air-cooled diesel engine were coated with Cr<sub>3</sub>C<sub>2</sub> at 300 µm thickness. Pure coriander oil was mixed with diesel fuel volumetrically at the rates of 30% and 50%. The plasma spray method was used as the coating method. It was determined that the preheating process provided a more suitable fuel flow, decreased the viscosity of the coriander oil and also the coating process decreased CO, soot and HC emissions but increased NOx, thermal efficiency, and EGT.</p> </abstract>ARTICLE2022-05-19T00:00:00.000+00:00A contrastive study on the production of double vowels in Mandarin<abstract> <title style='display:none'>Abstract</title> <p>The concept of ‘global village’ has linked all countries in the world as a whole. The exchanges and cooperation between different countries in politics, economy, culture, and education are becoming more and more frequent. To master a language, the study of its pronunciation is crucial. Based on the above considerations, this paper uses the Chinese pronunciation corpus of 30 learners and 10 Chinese native speakers as basic data to discuss the pronunciation patterns of learners’ mandarin diphthongs and their similarities to standard pronunciations. In this paper, by using the theory and methods of experimental phonetics, comparative analysis and error analysis, we exam and analyse the acoustic features of different levels of learners in the learning process, and the pronunciation and bias of learners’ mandarin diphthongs are obtained. From the experimental results, it can be seen that all three groups of learners have some difficulties in pronunciation of mandarin diphthongs. In particular, the learners have the greatest differences to standard pronunciations when pronouncing the diphthongs [ua] and [uo]. And some important rules and conclusions are summarised through experiments. This provides an important reference for learners to solve the problems of diphthongs pronunciation in Chinese speech synthesis and recognition.</p> </abstract>ARTICLE2022-04-08T00:00:00.000+00:00Polynomial mapped bases: theory and applications<abstract> <title style='display:none'>Abstract</title> <p>In this paper, we collect the basic theory and the most important applications of a novel technique that has shown to be suitable for scattered data interpolation, quadrature, bio-imaging reconstruction. The method relies on polynomial mapped bases allowing, for instance, to incorporate data or function discontinuities in a suitable mapping function. The new technique substantially mitigates the Runge’s and Gibbs effects.</p> </abstract>ARTICLE2022-05-16T00:00:00.000+00:00ARMA analysis of the green innovation technology of core enterprises under the ecosystem – Time series data<abstract> <title style='display:none'>Abstract</title> <p>From the perspective of innovation ecology, the green innovation of core enterprises is a key to high-quality economic development. This paper researches BYD, makes a discussion on the evolution and characteristics of green innovation, and clarifies the driving force of green innovation of core enterprises in the green innovation ecosystem. In addition, the 2002–2019 green patent authorisation data of BYD is selected as the green output indicator of the core enterprise. And through testing the data, the findings are that the perturbation term <italic>ε</italic> is white noise, which meets the zero expectation E(<italic>ε<sub>t</sub></italic>) = 0, and the same variance Var(<italic>ε<sub>t</sub></italic>) = <italic>σ</italic><sup>2</sup> and that there is no autocorrelation Cov(<italic>ε<sub>t</sub></italic>, <italic>ε<sub>s</sub></italic>) = 0, t ≠ s. The ARMA model is hence constructed for analysis. Through analysis, conclusions are drawn that when the core enterprises and other entities in the green innovation ecosystem collaborate to innovate, the complexity and dynamics could be found in the green innovation evolution process and that as an important driving force for green innovation, innovation input not only raises current green output but also facilitates future green output.</p> </abstract>ARTICLE2022-03-31T00:00:00.000+00:00Study on the crushing mechanism and parameters of the two-flow crusher<abstract> <title style='display:none'>Abstract</title> <p>Based on a Chinese enterprise's single-mouth crusher, the ‘waterfall flow’ inlet crusher is developed from a foreign two-flow crusher. The two-inlet crushing mode has advantages of continuous particle feeding, controlled particle flow and low wear of housing. By analysing the working principle of the equipment, the three-dimensional model of the crusher is established. Based on the discrete element method, the simulation data are obtained by EDEM simulation software. The crushing energy, the wear of the housing and the counter boards are analysed to obtain the optimal parameters. The crushing efficiency is significantly improved and the wear of the housing is controlled to some extent. The overall performance of the crusher is improved and the cost is reduced.</p> </abstract>ARTICLE2022-03-31T00:00:00.000+00:00Development of main functional modules for MVB and its application in rail transit<abstract> <title style='display:none'>Abstract</title> <p>In this work, multi-function vehicle bus (MVB) controller-based Field Programmable Gate Array (FPGA) and MVB manager based on the real-time multitasking operating system were explored and developed. The function of the MVB controller data link layer was realised by using FPGA. The embedded real-time multitasking operating system uCOS-II was applied to the development of MVB manager’s processing data, device state management, message data and bus management function. The network consistency test was performed to validate data communication of MVB link layer control protocol and the management function of MVB manager; the equipment was shown to be compatible with each other and met the requirements of IEC61375-1.</p> </abstract>ARTICLE2022-04-29T00:00:00.000+00:00A Levi–Civita Equation on Monoids, Two Ways<abstract> <title style='display:none'>Abstract</title> <p>We consider the Levi–Civita equation <disp-formula> <alternatives> <graphic xmlns:xlink="" xlink:href="graphic/j_amsil-2022-0009_eq_001.png"/> <mml:math xmlns:mml="" display="block"><mml:mrow><mml:mi>f</mml:mi><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>x</mml:mi><mml:mi>y</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:msub><mml:mrow><mml:mi>g</mml:mi></mml:mrow><mml:mn>1</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>x</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:msub><mml:mrow><mml:mi>h</mml:mi></mml:mrow><mml:mn>1</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>y</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo><mml:msub><mml:mrow><mml:mi>g</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>x</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:msub><mml:mrow><mml:mi>h</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:mi>y</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math> <tex-math>f\left( {xy} \right) = {g_1}\left( x \right){h_1}\left( y \right) + {g_2}\left( x \right){h_2}\left( y \right)</tex-math> </alternatives> </disp-formula> for unknown functions <italic>f, g</italic><sub>1</sub>, <italic>g</italic><sub>2</sub>, <italic>h</italic><sub>1</sub>, <italic>h</italic><sub>2</sub> : <italic>S →</italic> ℂ, where <italic>S</italic> is a monoid. This functional equation contains as special cases many familiar functional equations, including the sine and cosine addition formulas. In a previous paper we solved this equation on groups and on monoids generated by their squares under the assumption that <italic>f</italic> is central. Here we solve the equation on monoids by two different methods. The first method is elementary and works on a general monoid, assuming only that the function <italic>f</italic> is central. The second way uses representation theory and assumes that the monoid is commutative. The solutions are found (in both cases) with the help of the recently obtained solution of the sine addition formula on semigroups. We also find the continuous solutions on topological monoids.</p> </abstract>ARTICLE2022-05-12T00:00:00.000+00:00A Functional Equation with Biadditive Functions<abstract> <title style='display:none'>Abstract</title> <p>Let <italic>S</italic>, <italic>H</italic>, <italic>X</italic> be groups. For two given biadditive functions <italic>A</italic> : <italic>S</italic><sup>2</sup> → <italic>X</italic>, <italic>B</italic> : <italic>H</italic><sup>2</sup> → <italic>X</italic> and for two unknown mappings <italic>T</italic> : <italic>S</italic> → <italic>H</italic>, <italic>g</italic> : <italic>S</italic> → <italic>S</italic> we will study the functional equation</p> <p><italic>B</italic>(<italic>T</italic> (<italic>x</italic>), <italic>T</italic> (<italic>y</italic>)) = <italic>A</italic>(<italic>x, g</italic>(<italic>y</italic>)), <italic>x, y</italic> ∈ <italic>S,</italic></p> <p>which is a generalization of the orthogonality equation in Hilbert spaces.</p> </abstract>ARTICLE2022-05-02T00:00:00.000+00:00Reconstruction of multimodal aesthetic critical discourse analysis framework<abstract> <title style='display:none'>Abstract</title> <p>The paper starts with a theoretical discussion of the possible introduction of aesthetic linguistics into the research field of multimodal critical discourse analysis for analysing tourist news of two modalities: visual and text. Thanks to the successful stories of analysis concerning aesthetic linguistics, systemic functional grammar and visual grammar; first, a framework of multimodal aesthetic critical discourse analysis is carefully redesigned based on multimodal aesthetic critical discourse analysis framework of version 1, originally designed for the same purpose. Then, the validity of the reconstructed framework is verified via analysing a piece of Shannxi tourist news with it. The result indicated that the multimodal aesthetic critical discourse analysis framework re-designed in this paper is of practical significance and can be applied to the analysis of news of multiple modalities.</p> </abstract>ARTICLE2022-03-31T00:00:00.000+00:00What does students’ experience of e-portfolios suggest<abstract> <title style='display:none'>Abstract</title> <p>This research presents a critical examination of 102 undergraduate students’ experience with e-portfolios in a university based in Northwest China. Qualitative data are collected via interviews to explore the advantages and disadvantages of e-portfolios in order to examine the possibility for popularization of the application and further improvement as well. Findings reveal that e-portfolios are beneficial in the aspects of new knowledge creation, learning management, reflective learning, test anxiety elimination, as well as student performance assessment. Meanwhile, some problems have also been revealed, which have pedagogical implications.</p> </abstract>ARTICLE2022-03-31T00:00:00.000+00:00Innovations to Attribute Reduction of Covering Decision System Based on Conditional Information Entropy<abstract> <title style='display:none'>Abstract</title> <p>Traditional rough set theory is mainly used to reduce attributes and extract rules in databases in which attributes are characterised by partitions, which the covering rough set theory, a generalisation of traditional rough set theory, covers. In this article, we posit a method to reduce the attributes of covering decision systems, which are databases incarnated in the form of covers. First, we define different covering decision systems and their attributes’ reductions. Further, we describe the necessity and sufficiency for reductions. Thereafter, we construct a discernible matrix to design algorithms that compute all the reductions of covering decision systems. Finally, the above methods are illustrated using a practical example and the obtained results are contrasted with other results.</p> </abstract>ARTICLE2022-04-15T00:00:00.000+00:00Satisfactory consistency judgement and inconsistency adjustment of linguistic judgement matrix<abstract> <title style='display:none'>Abstract</title> <p>In this study, first, the definitions of the preference relation matrix and the 0-1 permutation preference matrix of the linguistic judgement matrix are given. The method of judging the satisfactory consistency of the linguistic judgement matrix by the standard 0-1 arrangement matrix is obtained. This method not only solves the problem of satisfactory consistency when there are no equivalent objects but is also simple and effective. Then, the definition of the cyclic circle matrix of the three objects is given. According to the size of the preference value of the object line, the cyclic cycle and the adjusted language judgement matrix are obtained. Finally, the rationality and validity of the method are verified by examples.</p> </abstract>ARTICLE2022-04-15T00:00:00.000+00:00en-us-1