Modern Models Research Articles

Effects of student-owned and provided mobile devices on mathematical modeling competence: investigating interaction effects with problematic smartphone use and fear of missing out

IntroductionNowadays, more and more digital resources are used in modern mathematical modeling classes. In order to access these resources, students need a suitable digital device—often mobile devices are used for this purpose. There are several concepts to enable students access to such devices. For example, students can be allowed to use their self-owned devices [Bring Your Own Device (BYOD) concept] or teachers can hand out school-owned devices to their students [device pool (pool) concept]. Currently, little is known about possible effects of different mobile device access concepts on student learning. Hence, in this study, we investigated their effects on students’ mathematical modeling competence. In doing so, we also considered an interaction between the access concept and the effects of (a) students’ problematic smartphone use and (b) students’ fear of missing out on learning mathematical modeling.MethodTo this end, we conducted an experiment, measured students’ mathematical modeling competence as the outcome variable, and analyzed data of 263 German students in grades 8 and 9 using a multilevel model. In the experiment, students were randomly assigned to one of two study conditions and completed a mathematics modeling workshop. In the BYOD condition, students utilized their self-owned smartphones to work on the workshop tasks, whereas in the pool condition, students utilized institutionally provided smartphones.ResultsAs a main finding, our results showed an interaction effect between the mobile device access concept and students’ problematic smartphone use on their competence (β = −0.24, 95% CI [−0.47, −0.01]). Students utilizing their self-owned smartphones were negatively affected by their problematic smartphone use (B = −1.45, 95% CI [−2.45, −0.46]), whereas students utilizing provided smartphones were not affected (B = 0.04, 95% CI [−1.01, 1.09]). Students with maximal problematic smartphone use achieved higher competences when utilizing provided devices (BBYOD−Pool = −1.20, 95% CI [–2.35, –0.05]).DiscussionOur study demonstrates the importance of thinking about effects of student-owned and provided digital devices on mathematics learning. Finally, we discuss (a) that our results do not reveal a general preferability for one of the two access concepts, as well as (b) the relevance of student characteristics when choosing an access concept.

Recognize the Value of the Sum Score, Psychometrics' Greatest Accomplishment.

The sum score on a psychological test is, and should continue to be, a tool central in psychometric practice. This position runs counter to several psychometricians' belief that the sum score represents a pre-scientific conception that must be abandoned from psychometrics in favor of latent variables. First, we reiterate that the sum score stochastically orders the latent variable in a wide variety of much-used item response models. In fact, item response theory provides a mathematically based justification for the ordinal use of the sum score. Second, because discussions about the sum score often involve its reliability and estimation methods as well, we show that, based on very general assumptions, classical test theory provides a family of lower bounds several of which are close to the true reliability under reasonable conditions. Finally, we argue that eventually sum scores derive their value from the degree to which they enable predicting practically relevant events and behaviors. None of our discussion is meant to discredit modern measurement models; they have their own merits unattainable for classical test theory, but the latter model provides impressive contributions to psychometrics based on very few assumptions that seem to have become obscured in the past few decades. Their generality and practical usefulness add to the accomplishments of more recent approaches.

POLITICAL IDEOLOGICAL PRINCIPLES PROPOSED BY SUN YAT-SEN

Based on the formation of China’s historical political culture, it is considered that it has unique national values compared to other countries. China’s cultural and political ideologies are based on the idea of loyalty to historical heritage and traditions, and it is necessary to promote nationalism and identity by preserving ideological and humanitarian principles from the influence of globalization. For millennia, the Chinesenation has gone through periods of rejection of social traditions and modernity and acceptance as a necessary condition for the nation’s development.At the beginning of the 20th century, the influence of the Western model of development and the model of modernization entered, but from the end of the 20th century, the national path of development was revived and the system of national ideological values became popular.

THE FORMATION OF THE IDEOLOGY OF NATIONALISM PROPOSED BY SUN YAT-SEN

Political principles in China, formed under traditional Chinese ideology, were in some ways opposed to the teachings of Confucianism. Sun Yat-sen, the father of the Chinese state, mainly sought to create a strong liberal political state within society, based on the formation of China’s historical political culture, which is called “the reverse direction of totalitarianism”, and is considered to have unique national values compared to other countries. China's cultural and political ideologies are based on the idea of loyalty to historical heritage and traditions, and it is necessary to promote nationalism and identity by preserving ideological and humanitarian principles from the influence of globalization. At the beginning of the 20th century, the influence of the Western modernization model of development entered, and from the end of the 20th century, the national path of development was revived and the system of national ideological values became popular. The Chinese have never claimed economic, political or intellectual equality. An individual's upward or downward mobility economically, politically, or academically was believed to be slowed or accelerated by the influence of his family. However, hard work and mobility were constantly noticeable.

ENERGY EFFICIENCY MANAGEMENT STRATEGIES OF CONSTRUCTION ENTERPRISES: TYPES AND FEATURES

Purpose. The aim of the article is to systematize the modern types and features of energy efficiency management strategies of construction enterprises. Methodology of research. The method of systematization was used in research, which made it possible to classify the leading strategies of the specified category. The characteristics of the evaluated strategies were established with the help of the induction method, determined by the analysis of individual provisions of scientific works. Findings. Features of modern types of energy efficiency management strategies of construction enterprises are singled out and defined, including: strategies of intelligent energy efficiency management in the construction of office buildings, intersectoral network strategies of energy efficiency management, which include the participation of construction enterprises as structural participants, the strategy of standardization, certification and specifications of energy management of construction enterprises. The systematization of strategies of this type was carried out on the basis of the analysis of the provisions of scientific approaches of foreign authors and it was proved that their selected types are innovative, as they are based on modern models of interaction of participants, mechanisms that are acceptable for the current conditions of ICT development in the field of the construction sector. It has been established that the reference to the defined strategies can make it possible to improve the level of energy efficiency of construction enterprises and construction objects in the conditions of the development of a sustainable society and economy, aimed at the energy transition from fossil fuels and renewable energy, saving energy use. It was found that the implementation of strategies of the specified type has an effect both for socially responsible construction enterprises and for those that are focused only on compliance with existing norms and requirements. It is noted that the adaptation of the specified strategies to the conditions of operation of construction enterprises of Ukraine can be carried out given the fact that there are different positions of the business sector in this field. It was determined that the adoption of the trend of society and consumers regarding the choice of construction objects that have high energy saving indicators and involve the use of renewable energy is relevant for making decisions about the transition to energy efficiency of construction enterprises. Originality. The theoretical provision of types and features of modern energy efficiency management strategies of construction enterprises has gained further development. Practical value. The strategies identified in the study can be implemented in the conditions of Ukrainian construction enterprises, focused on achieving their own energy efficiency and energy efficiency of construction objects. Key words: energy efficiency, construction enterprises, CO2, construction objects, cross-sectoral network strategies, standardization, certification and specification of energy management, ICT, energy transition.

Enhanced Crowd Dynamics Simulation with Deep Learning and Improved Social Force Model

The traditional social force model (SFM) in crowd simulation experiences difficulty coping with the complexity of the crowd, limited by singular physical formulas and parameters. Recent attempts to combine deep learning with these models focus more on simulating specific states of crowds. This paper introduces an advanced deep social force model, influenced by crowd states. It utilizes deep neural networks to accurately fit crowd trajectory features, enhancing behavior simulation capabilities. Geometrical constraints within the model provide control over varied crowd behaviors, adjustable to simulate different crowd types. Before training, we use the SFM to refine behaviors in real trajectories with excessively small distances, aiming to enhance the general applicability of the model. Comparative experiments affirm the effectiveness of the model, showing comparable performance to both classic physical models and modern learning-based hybrid models in pedestrian simulations, with reduced collisions. In addition, the model has a certain ability to simulate crowds with high density and diverse behaviors.

Case Article—Racial Bias in Automated Traffic Law Enforcement and the Price of Unjustness

This case study has been developed for students to practice their data analysis and optimization skills in a contemporary societal issue: that of injustice in automated traffic law enforcement. Specifically, this case study is for students of modern data analysis and statistical modeling courses that focus on hypothesis testing; it also has a component for students in optimization and mathematical modeling courses that focus on linear and network optimization. The case study has been used since Spring 2023 in a combination of two courses from the Industrial Engineering (Analysis of Data, an introduction to probability and statistics) and Civil Engineering (Transportation Systems, an introduction to mathematical modeling and optimization for civil engineers with a focus on transportation) curricula. History: This paper has been accepted for the INFORMS Transactions on Education Special Issue on DEI in ORMS Classrooms. Supplemental Material: The Teaching Note and data files are available at https://www.informs.org/Publications/Subscribe/Access-Restricted-Materials .

Extracardial pathology as an additional risk factor in the correction of congenital heart defects in children

Introduction. Concomitant diseases as a risk factor for surgery remain an urgent problem in pediatric cardiac surgery. The article presents the role of comorbidity in pediatric cardiac surgery. A comparative analysis of the indicators of cardiac surgical treatment of patients with and without extracardiac pathology was carried out. Aim: to determine the significance of extracardiac causes as an additional risk factor in the correction of congenital heart lesions in children. 
 Materials and methods. Prospective analysis of five hundred patients who had undergone cardiac surgery in the departments of cardiac surgery and interventional cardiology. Patients were divided into a main group of patients with concomitant pathology 
 (n = 350) and a control group (n = 150) without concomitant pathology. A complex of modern therapeutic and diagnostic procedures and a multidisciplinary approach were used. 
 Results. A high incidence of complications was shown in the main group (70%). Hospital mortality was higher in patients with concomitant pathology and amounted to 17.4%, compared to 3.3% in the group without concomitant pathology. The average duration in the ICU for patients with concomitant pathology was 18 ± 2 bed days, for patients without concomitant pathology — 4 ± 2 bed days. 
 Conclusion. The presence of concomitant pathology has been shown to influence significantly on the development of complications and be a prognostic risk factor that must be included in modern prediction models.

Case—Racial Bias in Automated Traffic Law Enforcement and the Price of Unjustness

This case study has been developed for students to practice their data analysis and optimization skills in a contemporary societal issue: that of injustice in automated traffic law enforcement. Specifically, this case study is for students of modern data analysis and statistical modeling courses that focus on hypothesis testing; it also has a component for students in optimization and mathematical modeling courses that focus on linear and network optimization. The case study has been used since Spring 2023 in a combination of two courses from the Industrial Engineering (Analysis of Data, an introduction to probability and statistics) and Civil Engineering (Transportation Systems, an introduction to mathematical modeling and optimization for civil engineers with a focus on transportation) curricula. History: This paper has been accepted for the INFORMS Transactions on Education Special Issue on DEI in ORMS Classrooms.

Модель социальной политики в современной России

This article analyzes the modern model of social policy in the Russian Federation. It examines the main prob-lems and directions of development of social institutions in the context of strategic tasks for building a socially oriented state. The research focuses on the need to integrate global experience and national peculiarities to form an effective system of social protection. Particular attention is paid to the proposal of a model of social policy focused on achieving social justice and improving the social security system in accordance with constitu-tional principles and guarantees. The central element of the proposed model is the strengthening of social guarantees in key sectors, including healthcare, education, labor relations, and social insurance. Emphasis is placed on the necessity of ensuring sustainable social development and improving the quality of life of the population.

Influence of mechanical impurities composition on formation of organic deposits

Relevance. The need to study the effect of solid particles in the oil stream on formation, composition and structure of deposits. Modern models of formation of asphalt-resin-paraffin deposits, based on correlation dependencies or empirical data, do not take into account the influence of the content of solid particles in oil to the proper extent. Recent studies show that various solid particles in oil can affect both the critical velocity and the structure of the formed deposits, but the effect of various particles on the intensity of formation of asphalt-resin-paraffin deposits remains unexplored. Aim. To study the effect of various sand fractions on the intensity of formation, composition and structure of asphalt-resin-paraffin deposits Methods. Modeling of formation of asphalt-resin-paraffin deposits at the laboratory installation “Cold Finger” when adding various sand fractions to oil; studying composition and structure of deposits after the conducted investigations using a microscope. Results. According to the research results, there is a significant increase in the intensity of formation of asphalt-resin-paraffin deposits when large fractions of sand are added to oil at a concentration of 5% or higher. It is worth noting that small fractions have almost no effect on the amount of deposits formed. Also, if various fractions are added to oil in equal proportions, there is almost no effect on the intensity of formation of asphalt-resin-paraffin deposits. When analyzing the deposits images from a microscope, it can be concluded that paraffin molecules, when interacting with sand particles of a dimension greater than 0.05 mm, form homols, and with an increase in the fraction, their structural strength grows. Conclusions. The study of modern models of formation of asphalt-resin-paraffin deposits and current articles made it possible to understand that the issue of studying the factors of formation of asphalt-resin-paraffin deposits, in particular the effect of the presence of solid particles in oil, remains open. The results of this article can be aimed at improving existing technologies in the field of modeling paraffin formation, as well as contribute to the further work of researchers in this direction.

TRADITIONS AND INNOVATIONS AS DETERMINING FACTORS IN THE DEVELOPMENT OF UKRAINIAN THEATRICAL ART

This article analyzes the trends in the use of the most important means of artistic expression in theatrical art and cinema, marked by the influence of evolutionary changes in modern cultural life and the emergence of new genre modalities in today's staging decisions, related to the ideological reorientation of social consciousness and the formation of innovative artistic features in the modern theater. The compositional portrait of modern theater highlights the possibilities of dramatic genre modeling, modern technologies and their transformational processes, which are interrelated with the democratization of Ukrainian society, and therefore artistic life, raising the tone of the national scene, cinema, and opening up new opportunities for stage art. A feature of the scientific research of symbolic forms in this area of art is the analysis of the possible addition of the mutual enrichment of theater and myth at the level of mythological narratives, status oppositions, plot matrices, communicative strategies and symbolic forms, a new mythocentric discourse of modern dramatic genre modeling. And also a multimedia lighting technician with the latest information and digital technologies and the possibilities of using Artificial Intelligence (AI) in the newest Ukrainian theater. The use of compositional techniques in combination with the latest technologies, AI in creating the atmosphere of a modern theater allows you to focus on the performers and the performance, and not on the complex decor. In addition, stage spaces are becoming more flexible, able to adapt to different types of performances and events. The use of the latest intellectual technologies is especially valuable and extraordinary. Modern theaters and Ukrainian cinema are constantly introducing advanced technologies to improve the impression of the audience. This may include the use of projection mapping, virtual and augmented reality, interactive elements and other innovations that help create a unique atmosphere and attract the audience.

Efficient electricity generation forecasting from solar power plants using technology: Integration, benefits and prospects

Accurate prediction of electricity generation from renewable sources is an essential element to ensure the stability of electricity systems and the transition to more sustainable energy production. The study aims to optimise the operation of Ukrainian power systems through the introduction of the required share of renewable energy sources to ensure the reliability of the power system. To study the accuracy of forecasting electricity generation by photovoltaic power plants in Ukraine, data analysis, a review of existing forecasting models and methods, and comparative analysis using satellite images and meteorological observations were used. Low accuracy of forecasting output is a feature of electricity generation from renewable energy sources, which is explained by the random nature of energy sources and related meteorological conditions. In Ukraine, the problem of qualitative forecasting of electricity generation from renewable sources is becoming more relevant. The importance of finding effective methods for forecasting electricity generation in Ukraine has increased with the emergence of the electricity market. This study addresses the issue of forecasting electricity generation by photovoltaic power plants for the day ahead in the conditions of the Ukrainian energy market. As part of the study, the issues of Ukrainian legislation regarding the requirements for the accuracy of electricity generation forecasting and the consequences of their failure were considered. The study also reviewed modern models and methods for forecasting electricity generation by photovoltaic power plants and explored the new “forecasting system market” in Ukraine. The study presents accepted forecasting metrics that allow estimating errors and comparing the effectiveness of different forecasting methods. Considering the dependence of electricity generation forecasting on meteorological parameters, a comparative analysis of forecasting accuracy using satellite images and meteorological observations was carried out. The study will determine the material presented in determining the model for forecasting electricity generation, thus increasing the efficiency of energy companies in the conditions of the Ukrainian energy market. The study will also reduce the negative impact of the energy sector on the environment and contribute to a more efficient and stable electricity system in the future

The Importance of the Structure of Federal Executive Authorities in Public Administration

The paper shows that the current system of federal executive authorities, being an abstract category, is implemented only through the functioning of a specific structure of these bodies. As a set of real subjects, this structure materializes the management strategy embedded in the system of federal executive authorities, which, however, does not arise chaotically, but is formed in the process of development of the system of bodies and their corresponding structure. The paper examines the dynamics of the system and structure of the central executive bodies in the USSR and federal executive authorities in the Russian Federation. The author has analyzed the advantages and disadvantages of corresponding systems and structures that existed in post-Soviet Russia before 2004, as well as structures functioning currently. The information problems of the modern model of federal executive bodies, types and features of communication channels peculiar to the system under consideration have been analyzed. It is argued that the nature of information links between the elements of the system structure determines the degree of stability of the structure itself and, as a result, the entire mechanism of public administration, i.e., the probability of their preservation or destruction. It is concluded that the importance of the structure of federal executive authorities is explained not only in optimizing management activities, but also in forming such a configuration of information communication channels in a specific system of executive bodies that stabilizes the functioning of the entire mechanism of public administration.

Technical note: Bimodal parameterizations of in situ ice cloud particle size distributions

Abstract. The cloud particle size distribution (PSD) is a key parameter for the retrieval of microphysical and optical properties from remote-sensing instruments, which in turn are necessary for determining the radiative effect of clouds. Current representations of PSDs for ice clouds rely on parameterizations that were largely based on aircraft in situ measurements where the distribution of small ice crystals were uncertain. This makes current parameterizations deficient to simulate remote-sensing observations sensitive to small ice, such as from lidar and thermal infrared instruments. In this study we fit the in situ PSDs of ice crystals from the JULIA (JÜLich In situ Aircraft data set) database, which consists of 11 campaigns covering the tropics, midlatitudes and the Arctic, consistently processed and considered more robust in their measurements of small ice. For the fitting, we implement an established approach to PSD parameterizations, which consists of finding an adequate set of parameters for a modified gamma function after normalization of both PSD axes. These parameters are constrained to match in situ measurements when predicting microphysical properties from the PSDs, via a cost function minimization method. We selected the ice water content and the ice crystal number concentration, which are currently key parameters for modern satellite retrievals and model microphysics schemes. We found that a bimodal parameterization yields better results than a monomodal one. The bimodal parameterization has a lower spread for almost all ice crystal sizes over the entire range of analyzed temperatures and fits better the observations, especially for particles between 20 and about 110 µm at temperatures between −60 and −20 ∘C. For this temperature range, the root mean square error for the retrieved Nice is reduced from 0.36 to 0.20. This demonstrates a clear advantage to considering the bimodality of PSDs, e.g., for satellite retrievals.

Western Caucasus regional hydroclimate controlled by cold-season temperature variability since the Last Glacial Maximum

The Caucasus region is key for understanding early human dispersal and evolution in Eurasia, and characterizing the environmental contrast between Last Glacial Maximum and Holocene is crucial for investigating human adaptation strategies to large climatic shifts. However, a paucity of high-resolution paleoclimate records leave this context largely unknown for early human populations in the Caucasus region. Based on our model-proxy comparison of high- and low-resolution records of 24 stalagmites from three caves, we find spatially distinct changes in vegetation and seasonality of precipitation, especially under glacial conditions. Supported by modern oxygen-isotope data and climate modeling, we identify a supraregional cold-season temperature control for oxygen isotopes in Black Sea speleothems, which previously had been interpreted as a local moisture-source signal. Carbon-isotope and trace-element data further suggest disproportionate changes in vegetation cover and soil dynamics at high altitudes, which would have resulted in a reduction but not a disappearance of human refugia during the Last Glacial Maximum, relative to the current interglacial. Our findings imply that abrupt climatic pressures from harsh conditions were overcome by adaptive strategies in the past.

Transformation of the Russian economic model in the context of a changing world structure: prerequisites and principles

In the conditions of rapid qualitative changes in socio-economic relations in the Russian society and cardinal transformation of the world structure, the authors set the goal to present a conceptual approach and theoretical foundations of the national economy model transformation. The methods of content and logical analysis, as well as general scientific methods of abstraction, generalization, and synthesis were used in the problem formulation within the framework of historical and systemic approach to studying complex issues and challenges characteristic of socio-economic formations development transitional periods. The political and economic aspects of the influence of the world structure transformation on the tasks and foundations of the national state economic mechanism adaptation have been considered. The interrelation of the social structure evolution and the increasing role of national wealth effective management to ensure sovereign development and increase public welfare has been outlined. The preconditions have been analyzed and the necessity of updating the modern nation-state economic model substantiated, as well as the conceptual provisions and basic principles of updating the economic model formulated. Possible ensuring solutions in the sphere of public power, including improving the mechanism of state control over the effective use of national assets for implementing the justice principle in the economic relations system have been defined.

A Missing Well-Logs Imputation Method Based on Conditional Denoising Diffusion Probabilistic Models

Summary Well logs comprise sequential data detailing the geological properties of formations at varying depths encountered during drilling. They are fundamental for various applications in the petroleum industry. However, acquired well logs often contain noise and missing data, which impedes their utility. To address this, numerous methods have been developed to impute missing components in well logs, ranging from traditional deterministic methods to modern data-driven models. Despite their effectiveness, these methods face several challenges. First, many are deterministic, lacking the ability to capture and represent the inherent uncertainties in the data. In addition, they often require complete logging data as input, which presents challenges in data sets with substantial missing data. Moreover, most are predictive models designed with specific targets that require retraining for different variables, which limits their versatility in handling data sets with diverse missing components. This work proposes the use of a generative model based on the conditional denoising diffusion probabilistic model (CDDPM) to impute missing components within well logs. The CDDPM offers several advantages. Its inherent probabilistic nature allows it to capture uncertainties in the data, providing predictions in the form of probability distributions rather than single-point estimates. This helps engineers make more robust and informed decisions in practice, thus mitigating potential risks. More importantly, due to its generative nature, the model is trained to learn the underlying data distribution, not the specific input-output map, which enables it to impute all missing data simultaneously. Through experiments on a real-world data set, we demonstrate that our proposed method surpasses conventional data-driven techniques in performance. Both qualitative and quantitative evaluations confirm the effectiveness of the model in imputing missing components. This research highlights the potential of modern deep generative models in petroleum engineering applications.

Жизнеобеспечение пожилых людей в Китае: основные практики и проблемы

The article raises the problem of the crisis of the traditional model of life support for elderly people in China and its replacement with a modern model. The main ways (social practices) of life support for older people in modern China are determined. The dynamics of the income structure of older people in the process of socio-economic reforms carried out in the country is analyzed. The problems that the public social security system for older people is aimed at solving are highlighted. Major difficulties of realization of modern public practices of support of age citizens in China are marked. It is concluded that it is necessary to develop a unified state pro-gram for the development of a social security system for older people in the country instead of disparate pro-grams implemented at different levels of government and in different regions of the country.

ПІДВИЩЕННЯ ТОЧНОСТІ БАГАТОФАКТОРНИХ КОРОТКОСТРОКОВИХ ПРОГНОЗІВ ГЕНЕРАЦІЇ СЕС НА ОСНОВІ ШТУЧНОЇ НЕЙРОННОЇ МЕРЕЖІ

The paper focuses on the development of models for forecasting the electricity generation of industrial solar power plants using artificial neural networks and numerical weather prediction. The relevance of the research is driven by the need to reduce costs related to imbalances in electricity generation from renewable sources, which can sometimes reach 50% of the released electricity. Additionally, the imbalances of such producers are increasing in Ukraine's power system. Currently, the general imbalances of renewable energy producers in Ukraine have led to a 45% reduction in green electricity production, especially due to the damage or destruction of 75% of wind power plants and 15% of solar power plants in southern and southeastern regions as a result of hostilities. Increasing the accuracy and stability of electricity generation forecasts for such producers could significantly reduce costs associated with imbalances.. Various aggregation methods have been developed for 15-minute values of green energy generation to enhance forecasting accuracy for 1, 2, and 24-hour intervals. The study investigated the potential benefits of using numerical weather prediction (NWP) forecast values to enhance forecasting accuracy. The study revealed the significance of different factors for forecasting at each bias interval. The study employed two modern recurrent neural network models, LSTM and GRU, with varying time sequences. References 14, figures 5, table 2.