rss_2.0Sciendo RSS Feed for European Journal of Formal Sciences and Engineeringhttps://sciendo.com/journal/EJFEhttps://www.sciendo.comhttps://sciendo-parsed-data-feed.s3.eu-central-1.amazonaws.com/6372237198240f0297d59070/cover-image.jpghttps://sciendo.com/journal/EJFE140216https://sciendo.com/article/10.26417/ejef.v3i3.p32-38<abstract> <title style='display:none'>Abstract</title> <p>Solitons are structurally stable solitary waves that propagate in a nonlinear medium. In this paper, solitons will be considered as the basis for solving many classical nonlinear equations of motion. Some classical solutions that were modeled through the application of Wolfram Mathematica System and MATLAB programming language. In this paper some soliton solutions will also be compared and some types of solitons were modeled.The dynamics of solitons was studied in consideration of solutions of some equations, such as the Korteweg - de Vries equation and as a particular solution for the nonlinear Schrödinger equation provided that the nonlinearity parameter R&gt;0 in the equation. We concluded by showing solitons in more detail which are often used in practice as a simpler method for explaining complex phenomena and solving non-classical equations</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v3i3.p32-382023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v3i3.p47-55<abstract> <title style='display:none'>Abstract</title> <p>The growing importance of the tourism sector to the global economy contributes to the increase of research in tourism risks assessment. In view of this tendency, the results of research in the field of the risk analysis on tourists’ travels in various countries during the last decades have been analyzed. Commonly used in these studies statistical methods allow to reveal and identify country-specific tourism risks and threats. But it is necessary to underline that relevant statistical data on risks are available not in all cases and countries. Moreover, in most cases, the reliability of the information available is questionable. In order to improve the reliability and quality of the tourist risk assessment, it is proposed to consider tourist travel as a project. The proposed project approach to tourist risk analysis provides an opportunity to go beyond assessment based on available country-specific inferior statistical data and allows to develop a more flexible and versatile method for risk evaluation. Common risk factors and sub-factors for tourists were identified for further risk assessment using suggested by L. Zadeh Z-number. A bi-component Z-number Z = (A, B) with perception-based and imprecise parts A and B, allows taking into account the reliability of the information. Risk experts deal with the prediction like this one “very likely that the level of threat N is medium” or “extremely likely that this factor is very important”. This prediction can be formalized as a Z-number based evaluation and a pack of Z-valuations is considered as Z-information. Experts evaluate identified risk factors and sub-factors and their importance weight using Z-numbers.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v3i3.p47-552023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v4i1.p64-74<abstract> <title style='display:none'>Abstract</title> <p>Nowadays there are growing interests in vibration serviceability assessments of composite footbridges. The new design trends of composite footbridges make them slender civil structures that may be affected by the load action of walking pedestrians resulting in large deflections or even uncomfortable vibrations. Furthermore, the presence of people on the footbridges causes the addition of mass to the structural system and due to the human body’s ability to absorb vibrational energy, an increase in structural damping. In this paper, the interaction between pedestrian and structure is modelled using data from pedestrian characteristics and vibration data from a measured footbridge as a comparison basis. A previously developed numerical model was used, this model called Biodynamic Synchronized Coupled Model (BSCM) consists of a fully synchronized force model in the longitudinal and lateral direction of pedestrian’s movement and a biodynamic model with mass, damping and stiffness parameters. The model is coupled with the structure using the Finite Element Method at the feet’s contact points. Pedestrians are treated as individuals with intrinsic kinetic and kinematic parameters following a measured correlation matrix obtained by the use of an especially designed force platform. Finally, the adequacy of the proposed model to represent the pedestrians as BSCM for the walking effects on the structure is investigated by experimentally measured accelerations on a footbridge (freely walking). The numerical results show good agreement with the experimental results.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v4i1.p64-742023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v4i1.p24-45<abstract> <title style='display:none'>Abstract</title> <p>This research paper we use a fast elitist multiobjective genetic algorithm to solve the new approach that we propose to quarterly disaggregating of the Gross Domestic Product (GDP) by multiobjective programming. Thus, the quarterly disaggregation of the GDP is described as a quadratic multiobjective programming problem that generalizes Denton’s proportional method. The proposed approach has the advantage reduce to one the number of optimization programs to be solved. Our proposed method can be applied to the national accounts of any country that has adopted the National Accounting System. The simulation results are compared to those obtained using Denton’s proportional method and these results revealed the overall performance of the multiobjective programming approach for the quarterly disaggregation of GDP. Our approach is more suitable for taking into account the links between branches of national accounts, in terms of volumes and prices of products demanded during the production process. Also, it reduces forecast error and volatility of quarterly GDP. Besides, it is worth noting that our method is a usfull step for data processing such as chain-linked measures, overlap growth techniques, seasonal adjustment and calendar effects adjustment, in time series and econometrics analysis.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v4i1.p24-452023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v4i1.p75-78<abstract> <title style='display:none'>Abstract</title> <p>The dimensional stability and durability of Acrylamide- and Methacrylate-based acrylic resins have been studied. The dimensional stability was characterized by measuring the volume expansion of samples immersed in water for a period up to 240 days or by exposing the samples to 23°C and 50 %, 90 % relative humidity and by monitoring the shrinkage. The durability was investigated by exposing the resins to cyclic variations of temperature in air and in water. The resins generally exhibit a significant volume change up to 160 % of the initial volume when immersed in water or exposed to a relatively dry atmosphere (23°C and 50 %). A general increase in the material stiffness and/or crack formation on the surface of the resin is observed. On a long-term basis, the durability of the resins may significantly vary with occasionally a partial or complete deterioration of the some resins. A general better dimensional stability and durability is observed for the Methacrylate-based resins as compared to the Acrylamide-based resins.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v4i1.p75-782023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/484ccz15b<abstract> <title style='display:none'>Abstract</title> <p>Most of the work on resilience of urban infrastructures focuses on their technical performance and reliability in disaster situations. In general, when we link urban infrastructure and Civil Engineering, we think of technology, engineering, constructions and technical or control buildings. In a state of pandemic like the current one, the study of the relationship between urban infrastructures and resilience is a phenomenon scarcely studied in the literature. The main objectives of the article are to analyse, from a Civil Engineering and actors’ perspective, the role and behaviour of urban infrastructures for the maintenance of the wellbeing of the community in a pandemic situation, and to fill a gap in the existing bibliography. The authors argue that the human factor is the most important element for infrastructure to be resilient in a Covid-19 situation. To achieve the objectives, a review of the literature was carried out considering the works published in the last 10 years. Then, a reflection is made about the influence of the resilience in infrastructures during a pandemic situation considering the relevant sustainability factors. As practical implications of this article, the drawn conclusions are expected to represent value for the societies of the future.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/484ccz15b2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/328uno67t<abstract> <title style='display:none'>Abstract</title> <p>Web 2.0 has given to all people the right to become a representative of a huge cast of informal media. The importance of this power is getting more evident everyday. Every social media actor can influence the rest of the world by one’s own opinions, feelings, and thoughts generously shared on multiple media. This information belonging to various fields of life can be very handy and be used to one’s advantage, gaining precious experience. One of the greatest problems that this poses is the huge number of data spread everywhere, which are difficult to process as row data per se. Social media and general sentiment text analysis is of much valuable use, accomplishing the task extracting pure gold out of raw mineral. The key point of this investigation is to characterize new reviews automatically. To start with, features selected out of all the word roots appearing in the comments were used to train the system according to known machine learning algorithms. Next, critical words determining positive or negative sense were extracted. Another strategy was attempted eliminating common terms and dealing only with the significant class-determining words to build vocabulary with them. Aparts from linear approach, vector based feature sets were prepared out all or some of the features. The outcomes acquired were analyzed and compared leading to important conclusions, emphasizing the importance of feature selection in text classification.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/328uno67t2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v2i2.p96-100<abstract> <title style='display:none'>Abstract</title> <p>This study aims to indicate the role of the communication process and new technologies in the crisis management, by showing deferent concepts related to the crisis management, its phases, how can we manage crisis using communication, and how can we use technology to manage crisis. The main idea of this study is that stakeholders (internal or external) are very important to overcome on a crisis, and every organization must identify the full range of its stakeholders, so it can receive their help when it is necessary.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v2i2.p96-1002023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v2i2.p108-116<abstract> <title style='display:none'>Abstract</title> <p>The occurrence of successive economic crises, strong competitive pressures, and the degradation of natural and ecological resources are some of the major threats that make energy transition the new holy grail of the 21st century. This awareness of the urgency of the situation opens of the possibility for adopting an alternative approach - one of alliances, partnerships, and cooperation within the framework of exchange and sharing. This is, as Harari put it, the secret of the success of man. It can contribute sure to the goal of sustainable economic development. In line with this, new organizational forms have emerged, with the restructuring of the economy, integration of the principles of sustainable development, and development of renewable energies and clean technologies. These so-called Cleantech ecosystems, clusters focused on sustainable development projects, serve the dual function of at once contributing to economic growth and the attractiveness of an economy for investors and preserving the environment.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v2i2.p108-1162023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/959iso21t<abstract> <title style='display:none'>Abstract</title> <p>Time management and control are crucial for project success, and it has known an increasing interest by researchers around the world since the appearance of project management and until now. The aim of the present paper is to provide a comprehensive overview of researches in this field. A bibliometric analysis of researches in time management and control published in the Web of Science (WoS) during 2012-2021 was conducted in order to find the most influential publications in this field, as well as, the countries that contribute the most to these researches, and the most used key words. The VOS Viewer was used for mapping and visualizing bibliometric networks. The results show an increased trend of publications in this field. And that the major contributors to researches in Time Management and Control are People’s Republic of China, the United States of America, and England. Moreover, Labadie (2004) was the most cited author. Also, the results show 3 main levels of keywords, the first was related to time management in general, the second was related to the models and systems using and the third concerning the tools, the methods used in time management and control. These findings could help researchers to understand more the topic of time management and control, and it opens up the scope of view to conduct studies in related fields.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/959iso21t2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v4i1.p46-63<abstract> <title style='display:none'>Abstract</title> <p>The use of information is inextricably linked with its security. The presence of vulnerabilities enables a third party to breach the security of information. Threat modeling helps to identify those infrastructures, which would be most likely exposed to cyberattacks. In some cases, however, threat modeling can not be classified as sufficient method of protection. This paper entitled “Determining the probability of cyberattacks” presents an analysis of different techniques with an attempt to identify the most informative parameters and cyberattack prediction markers, which would lay the foundation for the development of cyberattack probability functions. Next, it would be relevant to design such cyberattack probability functions, which would be used upon the initial identification of a cyberattack. The findings of this research could be applied during the future assessment of risk levels of information systems to ensure more effective information security management.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v4i1.p46-632023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v2i1.p66-72<abstract> <title style='display:none'>Abstract</title> <p>A great deal of researchers elaborated on the importance of the urban spaces and human life. Urban spaces are necessary types of spaces for a city and they have a timeless value. This research is focused on people’s perception about urban spaces in Larisa, Greece, a medium-sized city selected as case study. An electronic questionnaire survey was conducted and conclusions are drawn on how adequate are the urban spaces in Larisa. Moreover, people are asked to propose ideas on how other spaces, function more as urban gaps, can be integrated on the urban grid. In that way, it is easy to study what people believe about the city’s life and how the existing urban spaces function. Some conclusions derived from this research can be also useful in succeeding a combined traffic and urban planning in other Greek, in the context of the implementation of a Sustainable Urban Mobility Plan (SUMP).</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v2i1.p66-722023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v2i1.p80-82<abstract> <title style='display:none'>Abstract</title> <p>This quantitative research, has the objective of measuring the impact on the users of Interactive multimedia services, in the systems engineering career of the Instituto Tecnológico de Mexicali. The method is a survey applied to a sample of students of the Systems Engineering degree at the Instituto Tecnológico de Mexicali. The results of a survey applied about Interactive multimedia services is Interactive multimedia services, is a new tool of the Acrobat DC professional suite, which allows the user to generate PDF documents which contain various multimedia elements, such as MP3 audios, Videos, Photos, which are intended to be a valuable tool in the student teaching process and is used successful for the 402 students enrolled in systems engineering career of the Instituto Tecnológico de Mexicali. Based on the results obtained from this research, it can be seen that the students of the systems engineering career of the Technological Institute of Mexicali, consider themselves to be enthusiastic about information and communication technologies, such as interactive multimedia services, and they wish to use these technologies, as an area of opportunity we discovered that this technology is not currently used in the systems engineering career of the Technological Institute of Mexicali, nor in other academic departments, the students surveyed show that they know these technologies and that they would recommend them as a means to improve the learning, besides that they consider these technologies reliable.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v2i1.p80-822023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/580igz64a<abstract> <title style='display:none'>Abstract</title> <p>This research reveals the change that occurs in a university course when using narratives, which allows facing monumentalism in the classrooms, considering that, in most of them, classes are still being held in a traditional way without taking into account what the students think about the topics covered in the courses. The research is within the qualitative method. The results obtained allow to establish the influence of the course on the learning strategies used by the students, as stable learning indicators, two networks are presented: one corresponding to the use of narratives, and the second, incorporation of the question. Students are motivated to work collaboratively and have a favorable opinion of implementation.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/580igz64a2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/640ghd74t<abstract> <title style='display:none'>Abstract</title> <p>The article studies the properties of interior color schemes and finishing materials in order to find optimal combination for improving indoor conditions in higher education study room and to contribute to better educational process. Optical, physical, physiological and emotional properties of colors and materials are compared to living and study requirements in the context of their complexity. Recommendations for appropriate combinations of finishing materials and colors are given.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/640ghd74t2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/895smz95i<abstract> <title style='display:none'>Abstract</title> <p>Simulated laboratories are an effective tool to complement teaching and learning processes, in this case, in the area of nuclear physics and related sciences. They can be used in universities, schools, and research centers for personnel ramp up and training. This work presents the development of a simulator of a nuclear radiation counter and the elements used in experiments alongside it, such as simulated radioactive sources, absorbing materials and dispersing materials of radiation. This simulator allows us to verify the scientific laws that are involved in the interaction of radiation with matter, in a safe and reproducible way. The simulated laboratory experiments include determining the plateau curve of a Geiger-Müller tube, beta particle absorption and backscattering, and radioactive background. The data obtained from the simulations is based on the real experiments, eliminating the inherent risks of the manipulation of radioactive materials. This also allows to verify theoretical concepts in practice, strengthening the learning process and incentivizing research, interpretation, integration and communication of the obtained results. By incorporating this simulator in the multidisciplinary teaching and learning processes in STEM fields, it is possible to run these laboratories in a simple manner using non-radioactive materials.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/895smz95i2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/953drr33w<abstract> <title style='display:none'>Abstract</title> <p>The study was aimed at providing a device to estimate the range of values of the <italic>u-</italic> and <italic>d-</italic>quark masses through the elastic <italic>ep</italic>-scattering form factors at the low energy regime. ROOT generated <italic>dcsep</italic> data sets, from theoretical and experimental form factors, were compared to modified <italic>dcseq</italic> and their intersections were determined from the average of a total of 3000 events for each <italic>dcs</italic> at various scattering angles selected randomly from 0° to 180°. The proton mass was required as a parameter used in the relativistic recoil factor of <italic>dcseq</italic> to shift its distribution closer to <italic>dcsep</italic> thereby attaining the critical intersections. For quarks carrying effective masses, the extrapolated energy intersection of <italic>dcsep</italic> generated from the average of all form factors with the modified <italic>dcseu</italic> is 226.00013<italic>MeV</italic>² and this is lesser than that of the modified <italic>dcsed</italic> at 1093.00004<italic>MeV</italic>² with bin size of 1<italic>MeV</italic>² and their respective <italic>dcs</italic> intersections are 10.07049x10-4 and 0.36976x10-4, in barns. Summary of results are also given for quark masses derived from MS scheme and Lattice QCD. By considering all possible scattering angles at fixed transfer momentum, the relativistic recoil factor was treated as a constant that shifted the distribution and gave rise to a tool in estimating quark mass range.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/953drr33w2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/633bir74y<abstract> <title style='display:none'>Abstract</title> <p>Present work has studied potential barrier of Phenosafranin dye based organic device and has observed influence of different concentrations of titanium dioxide nanoparticles on this parameter. We have made different devices by taking different weight ratios of the dye – nanoparticles blend which are 1:1, 1:2, 1:3 and 1:4. These organic devices have been formed by varying the concentrations of titanium dioxide nanoparticles keeping same dye content. One device is also formed without any nanoparticle to compare influence of nanoparticle on potential barrier of the device. These devices are formed by sandwiching the dye – nanoparticle blend in between the Indium Tin Oxide coated glass and Aluminium coated mylar sheet. The potential barrier is measured from device’s I-V plot and also by Norde function. These two methods remain in good agreement showing that potential barrier is mostly decreased when the concentration of the titanium dioxide nanoparticles is highest in the blend of Phenosafranin dye and titanium dioxide nanoparticles. The ratio of dye –nanoparticle blend of 1:4 shows lowest potential barrier and it is highest when Phenosafranin dye based organic device is made without any nanoparticle. The reduced potential barrier in the presence of higher concentration of nanoparticles can be ascribed to improved filling of traps. Lowered potential barrier at metal – organic contact will improve the charge flow resulting in better performance of the device.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/633bir74y2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/619jkp27w<abstract> <title style='display:none'>Abstract</title> <p>The importance of cities and their populations grow more and more, as well as the need to apply ICT in their management to reduce their environmental impact and improve the services they offer to their citizens. Hence the concept of smart city arises, a transformation of urban spaces that the European Union is strongly promoting which is largely based on the use of data and its treatment using Big data and Artificial Intelligence techniques based in algorithms. For the development of smart cities it is basic, from a legal point of view, EU rules about open data and the reuse of data and the reconciliation of the massive processing of citizens’ data with the right to privacy, non-discrimination and protection of personal data. The use of Big data and AI needed for the development of smart city projects requires a particular respect to data protection regulations. In this sense, the research explores in depth the specific hazards of vulnerating this fundamental right in the framework of smart cities due to the use of Big Data and AI.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/619jkp27w2023-03-06T00:00:00.000+00:00https://sciendo.com/article/10.26417/ejef.v2i1.p73-79<abstract> <title style='display:none'>Abstract</title> <p>The urban space is characterized by specific qualities that may contribute to, or mitigate the social life. These qualities were described by James Gibson as “environmental affordances”. But beyond social life, such environmental affordances can affect other human behaviors, such as driving behavior. Such an approach can be particularly useful, since the objective in most European cities is to regain the social character of roads and streets and thus to reduce the speeds on the roads and the number of cars. Through this research, conclusions can be drawn related to road elements that contribute to the development of high traffic speeds to prevent their use during urban planning while encouraging the use of other qualities that will support the maintenance of low speeds of cars. In the light of the above, the specific research focuses on a neighborhood of the southern suburbs of Athens, Ilioupolsi. Through observations and an electronic survey, conclusions are drawn on the behavior of drivers in Ilioupolis. Finally, an attempt is made to generalize the effects of the specific physical characteristics in order to optimize the design of cities where the roads will be social spaces in addition to vehicle traffic channels.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.26417/ejef.v2i1.p73-792023-03-06T00:00:00.000+00:00en-us-1