Specific Subsystems Research Articles

Értékorientált vezetőképzés a református köznevelés szolgálatában

Value-Driven Training of Leaders in the Service of Reformed Public Education. Our paper focuses on a specific subsystem of the Hungarian public education system, the Reformed educational network. After a theoretical foundation, the study will review the characteristics and legislative environment of Reformed public education management and leadership training, and then examine the concept, reception, results, and further development potentials of the accredited training in Value-Driven Leadership, a relatively new element of the range of trainings. Some basic conclusions can be drawn from the survey as: (1) The target group is very interested in modern knowledge about Christian leadership, which is considered a priority area, which also coincides with the needs of the maintenance. (2) The management powers of headmasters of ecclesiastical institutions are much broader than those of headmasters of public institutions, but their knowledge and interest in these areas are insufficient. (3) More than ever before, the organization of training should aim at modularity and a variety of organizational methods.

ЗАСТОСУВАННЯ АЛГОРИТМУ ОПТИМІЗАЦІЇ МУРАШИНОЇ КОЛОНІЇ В СВІТЛОФОРНОМУ КЕРУВАННІ

Abstract: The relevance of the research is determined by the need to optimize traffic light control at intersections to reduce congestion and delays and increase the capacity of intersections. A practical solution to this problem is using intelligent transport systems and specific decision-making subsystems. However, automating such tasks requires scientific research to develop effective algorithms suitable for practical use. This work proposes an approach to optimizing traffic light control at intersections that considers the traffic flow parameters at a specific intersection and those at adjacent intersections, utilizing an ant colony optimization algorithm to optimize traffic light control at neighboring intersections. The results obtained show that this approach is more effective compared to existing methods and has the potential to reduce delays by 10% and increase intersection capacity by 15% and more. Keywords: Adaptive traffic management, cyber-physical system, intersections, jams, traffic, traffic light controller.

ЗАСТОСУВАННЯ АЛГОРИТМУ ОПТИМІЗАЦІЇ МУРАШИНОЇ КОЛОНІЇ В СВІТЛОФОРНОМУ КЕРУВАННІ

Abstract: The relevance of the research is determined by the need to optimize traffic light control at intersections to reduce congestion and delays and increase the capacity of intersections. A practical solution to this problem is using intelligent transport systems and specific decision-making subsystems. However, automating such tasks requires scientific research to develop effective algorithms suitable for practical use. This work proposes an approach to optimizing traffic light control at intersections that considers the traffic flow parameters at a specific intersection and those at adjacent intersections, utilizing an ant colony optimization algorithm to optimize traffic light control at neighboring intersections. The results obtained show that this approach is more effective compared to existing methods and has the potential to reduce delays by 10% and increase intersection capacity by 15% and more. Keywords: Adaptive traffic management, cyber-physical system, intersections, jams, traffic, traffic light controller.

Value-driven training of leaders in the service of Hungarian denominational (Reformed) public education

AbstractOur paper focuses on a specific subsystem of the Hungarian public education system, the Reformed educational network. After a theoretical foundation, the study will review the characteristics and legislative environment of Reformed public education management and leadership training, and then examine the concept, reception, results and further development potentials of the accredited training in Value-Driven Leadership, a relatively new element of the range of trainings. The training was developed in collaboration between Dutch and Hungarian specialists, taking into account the international context of Christian education. Our study uses a variety of research methods, such as document analysis, statistical analysis and analysis of a questionnaire survey on further needs. Some basic conclusions can be drawn from the survey as: (1) The target group is highly interested in modern knowledge about Christian leadership, which is considered a priority area, which also coincides with the needs of the maintenance. (2) The management powers of headmasters of ecclesiastical institutions are much broader than those of headmasters of public institutions, but their knowledge and interest in these areas are insufficient. (3) More than ever before, the organisation of training should aim at modularity and a variety of organisational methods. The tools of combined training organisation, which have already proved their worth in higher education, should also be applied to 30-h continuing training, possibly with the addition of distance learning elements.

Ant Colony Algorithm in Traffic Flow Control

The relevance of the research is determined by the need to optimize traffic light control at intersections to reduce congestion and delays and increase the capacity of intersections. A practical solution to this problem is using intelligent transport systems and specific decision-making subsystems. However, automating such tasks requires scientific research to develop effective algorithms suitable for practical use. This work proposes an approach to optimizing traffic light control at intersections that considers the traffic flow parameters at a specific intersection and those at adjacent intersections, utilizing an ant colony optimization algorithm to optimize traffic light control at neighboring intersections. The results obtained show that this approach is more effective compared to existing methods and has the potential to reduce delays by 10% and increase intersection capacity by 15% and more.

IMPLEMENTATION OF INTERNATIONAL EXPERIENCE OF STATE PROTECTION OF NATIONAL VALUES IN UKRAINE

The author of the article reveals the purpose of implementing the international experience of the system of state protection of national values through the prism of two important trends that should be implemented and and enshrined in the practice of state-building processes in modern Ukraine. One of them stipulates that national values are the central core of the national security system security system, they define the triad of ‘values-interests-goals’. The second trend defines the system of creating mechanisms for legislative support of guaranteeing and protecting of national values, which is embodied in the systemic nature of the state policy on national development and is the actual consolidation of the civilisational civilisational choice of the Ukrainian nation at the level of legal acts. The purpose of the article is to analyse practical aspects of implementation of the state mechanisms for protection of national values in foreign countries and their implementation in the Ukrainian State. The author emphasises that national values of of modern Ukraine should not be subject to political bargaining, speculation, etc. They are are always an element of political struggle. Without this, political processes are impossible, and therefore, national values should be defined and prohibited for political speculation on them, which, by the way, requires the development of an institution of for their criminal law protection; and - to have its own system of mechanisms of legislative protection. It is determined that the first step towards the implementation of the experience of foreign countries in protecting national values should be the introduction of an all-Ukrainian analytical study of the system of national values. It should should be based on long-term and medium-term forecasts of domestic development and the development of the system of world politics, its specific regional and functional subsystems. This means that the full potential of national research institutes in the field of public opinion, civil society, and sociological research should be used to society, and sociological research should be directed within the framework of a single state policy to study and define national values.

RF technology in wireless communications:From transceiver architecture to subsystem specifications

Radiofrequency (RF) technology is essential to wireless communication.The demand for RF technology research is growing as mobile, satellite, radar, and other fields advance. In recent years, the development of 5G and 6G technologies has raised the bar for in-depth RF technology research, requiring greater frequency and data transmission efficiency, among other things. In addition to providing a brief overview of the transceiver's components, the signal chain, and an introduction to the major RF technologies, this paper will concentrate on the architecture of RF transceivers in RF systems and the specification of sub-systems. It will also include references for the RF sub-system specifications and integration techniques. The comprehensive study of communication technology will benefit greatly from an in-depth grasp of the transceiver's capabilities. Lastly, an overview of the layout and features of RF transceivers is provided, along with a prediction of the future application-focused path of RF technology.

Exploring the psychometric properties of the Grammar Learning Strategy Inventory in the Chinese EFL context

Learning a second language is a life-long process requiring acquaintance with a repertoire of language learning strategies (LLS). Despite copious research on LLS and their role in fostering autonomous learning, few studies have examined strategies employed when trying to master specific subsystems of the target language, especially grammar. Meaningful communication in a second language hinges on implicit or highly automatized grammar knowledge, which, given the limitations of classroom-based grammar instruction, must for the most part be developed by learners themselves outside the classroom and this can best be achieved through adept use of grammar learning strategies (GLS). Our knowledge of the GLS, however, is scant, an issue that can be addressed either by designing reliable GLS measurement instruments or revalidating the few existing ones. This study adopts the latter approach by investigating the psychometric properties of Pawlak’s (2018) Grammar Learning Strategy Inventory (GLSI) in the Chinese context. The tool was administered to 923 English majors, and the responses were subjected to exploratory and confirmatory factor analyses. We found that all seven strategy categories included in the original instrument showed acceptable composite reliability and discriminant validity. The paper concludes by suggesting further revalidation of the GLSI and proposing avenues of research that employ methodological innovations to shed further light on GLS.

Tailoring of NASA‐STD‐3001 to Lunar Gateway Program Requirements

AbstractThe Gateway Program must meet NASA's Agency‐level human rating requirements, which are intended to accommodate human capabilities and limitations while protecting the safety of the crew, and providing to the maximum extent practical, the capability to safely recover the crew from hazardous situations. Human systems integration represents a key human rating component of Moon to Mars systems to support the execution of Artemis missions, including compliance with mandatory standards for Health and Medical, Safety and Mission Assurance, and Engineering. The human system requirements, together with the human systems integration plan, medical operations requirements, and Gateway subsystem specifications, represent the flow‐down of NASA Health and Medical Standards (NASA‐STD‐3001, Volumes 1 and 2) into the Gateway system. This paper discusses how these documents and other human systems integration activities provide full consideration of human capabilities and limitations as part of the total system design trade space, serving as an example on how the human must be effectively integrated as part of the system in order to achieve mission success. At a bigger scale, the paper contributes to the application of systems engineering standards to cutting‐edge space exploration initiatives and to the dialogue on how systems engineering can continue to evolve to meet the needs of such ambitious projects.

MEMORIAL URBAN NAMES OF UZHGOROD THROUGH THE PRISM OF ECOLINGUISTICS

At the current stage of the development of Ukrainian proper vocabulary, in particular in the post-Soviet period, the subsystem of modern Ukrainian urban names has undergone deeper and more systematic changes. According to linguists, this situation was caused by a distinct development trend such as de-ideologization. After all, the massive nature of the changes observed in Ukrainian urbanonymy, in particular in the western and central parts of Ukraine, is explained by the democratic procedure of replacing the proper names of streets, squares, parks, squares, microdistricts, etc., which, according to current Ukrainian legislation, is implemented on the basis of a resolution of the local council, and not the Verkhovna Rada of Ukraine, as provided by the procedure for changing the proper names of settlements. However, the democratic nature of the procedure for changing Ukrainian urban names, in our opinion, became the main reason for the insufficient or superficial linguistic examination of both urban neologisms and already traditional onims, which enables the functioning of many proper names of urban objects, the structure of which contradicts the norms of the Ukrainian language. Spelling errors are a characteristic type of violation of the norms of the Ukrainian literary language in the subsystem of Ukrainian urban names of the post-totalitarian era. Most often, when writing modern Ukrainian urban names, the rules of capitalization are violated. Urbanonymy is a specific onymic subsystem, which reacts extremely actively to social changes and is especially dependent on the political regime, which is connected with the memorial function of the names of inner-city objects. In this connection, the analysis of the concept of historical memory in urbanonymy becomes especially relevant. the negative influence of the environment affects the ecolinguistic state of various levels and even classes of the Ukrainian onymic vocabulary of the post-totalitarian era differently. Ukrainian anthroponymy, in particular people’s proper names and patronymic names, as well as oikonyms, urbanonyms, ergonyms, are adversely affected at the lexical level. Key words: concept, ecolinguistics, onim.

Decision-guidance method for knowledge discovery and reuse in multi-goal engineering design problems

When designing complex engineered systems, designers typically encounter different types of complexity in decision-making, such as learning trade-offs among conflicting system goals and concurrently meeting specifications of subsystems while complying with all constraints. Therefore, when managing knowledge of the concurrent design of multi-component systems, one must consider the decision interactions among designers with different interests and the coupling effects of subsystems. Conventional multi-objective optimization methods are inadequate in providing decision support on compromising the achievement of conflicting goals under various design circumstances; they are incompetent to provide knowledge from the supply side. They may also fail to solve the problems endorsed by decision-makers' evolving preferences; that is, they are incompetent in gaining knowledge from the demand side. Enhancing decision support and managing various stakeholders’ preferences is essential for engineering design problems. To address this issue, we propose a method to give systematic guidance for knowledge discovery and reuse in learning the trade-offs among conflicting goals with various preferences. Using the proposed method, a designer can (1) select appropriate design scenarios to compromise the achievement of system goals while maintaining an acceptable level of fidelity and (2) explore and refine the subsystems coupling in a structured and computable manner. We made the contributions above through (1) reusable knowledge identification and ontology development for creating and archiving the knowledge associated with the problem-solving process, (2) implementing interactive decision-making by adopting different guiding strategies, (3) working on satisfying solutions, and (4) developing icon-based knowledge representation and execution of decision workflows in the knowledge-based design guidance system. The whole process forms a loop, namely, the formulation-refinement-exploration-improvement loop. We demonstrate the efficacy of our method using a test problem, the design of a small-scale thermal system that is widely applied in freshwater production and agricultural irrigation.

Strategic triangle ‘Russia — India — China’: Structure and problems of interaction

A contemporary world order is based on an increasingly complex system of interstate relations, which implies the need to thoroughly consider the international context, even when analyzing bilateral interactions. From this point of view, the concept of a ‘strategic triangle’, developed during the Cold War and applied primarily to analyze the dynamics of relationships between the USSR, the USA and the PRC, appears to have significant epistemological potential. In current conditions, it is of particular interest to use this concept to study the logic of relations in the ‘Russia–India–China’ (RIC) triangle. This research pursues two interrelated goals. On the one hand, it is aimed at identifying specific features of this new ‘strategic triangle’, its inner structure and logic of interactions between its participants. On the other hand, it assesses the applicability of the theoretical models developed during the Cold War to the relations within the framework of the RIC strategic triangle. The author examines the history, general dynamics and contemporary features of interaction within each pair of bilateral relations in this ‘triangle’. The research has confirmed the hypothesis that the relations between Russia, India, and China, indeed, form a specific subsystem of international relations, which can be described as a ‘strategic triangle’. At the same time, unlike the Sino-American-Soviet ‘strategic triangle’, it is the logic of cooperation, rather than rivalry, which generally prevails within the framework of the RIC.However, the RIC ‘triangle’ can also be described as an inherently inconsistent system. While China and Russia maintain close strategic cooperation in almost all areas, in the case of India and Russia, economic cooperation does not match the achieved level of political contacts, and Sino-Indian relations, despite the generally positive dynamics during the recent years, remain at a low level. All this points to the need to develop a new theoretical and methodological framework for analyzing trilateral relations between Russia, India and China as a special subsystem of the contemporary world politics, one that will be free from Cold War stereotypes.

Bridging Qatar's food demand and self-sufficiency: A system dynamics simulation of the energy–water–food nexus

The food sector in Qatar is confronted with formidable challenges due to its harsh environmental conditions. Striving for total food self-sufficiency in such an environment would inevitably exert pressure on the energy and water sectors. This heightened demand for energy and water translates into increased costs and escalates environmental impacts. Consequently, this study embarks on an in-depth analysis of food production within the context of Qatar's energy-water-food nexus, aiming to demonstrate how varying degrees of food self-sufficiency may impact the demand on Qatar's water and energy sectors, as well as on greenhouse gas (GHG) emissions. Moreover, this study demonstrates to what extent specific subsystems within the nexus can be modified to enhance sustainability. An energy-water-food nexus is meticulously crafted within the proposed framework to elucidate the intricate interdependencies among these sectors, incorporating pertinent external variables. These interconnections are then transmuted into a system dynamics model (SDM), facilitating a nuanced exploration of potential transformations and their ripple effects. Furthermore, a life-cycle thinking approach explicitly tailored to Qatar was implemented to estimate GHG emissions accurately. Four distinct scenarios are rigorously examined using the SDM, spanning from a status quo perspective to ambitious transitions toward full food self-sufficiency. The findings of the scenarios indicate that scenario 4, which partially provides the country with its food demands locally using desalinated water, treated wastewater, and groundwater and satisfies 20 % of its energy demand from solar energy, is the most ideal with an annual 5.36 × 1010 kWh/year energy consumption, 1.73 × 1012 l/year water demand, and 3.26 × 1010 kg CO2 eq./year emissions. The outcomes underscore the imperative for prioritizing less energy-intensive resources to mitigate overall energy consumption. Additionally, achieving an optimal national scenario necessitates a judicious equilibrium between food imports and domestic production.

Разработка модели оценки влияния персонала на состояние системы комплексной безопасности, созданной на производственных предприятиях

The article presents an integrated safety system established at explosion- and fire-hazardous plants; the system requires continuous improvement and development. The transition of the system to a qualitatively new level is possible via using a justified expert method to determine the quantitative value (measure) of the influence of subsystems of industrial and fire safety, labor protection, and production structural units. This allows to detect significant gaps, develop measures to correct the deviations detected, and monitor the dynamics of improvement of influence factors within the established period for each subsystem (industrial and fire safety, labor protection, and structural production units). The article aims to improve the condition of the integrated safety system at an enterprise via the assessment of the influence of personnel (industrial and fire safety, labor protection, and structural production units) performing their labor functions to ensure the high-quality functioning of the system. To achieve the goal, two problems had to be solved. In the course of solving problem № 1, the justification for using the prioritizing method was provided; the method has a distinct advantage over the other expert methods of assessment, as it has no limits for boundary expansion in order to obtain adequate results. It has been demonstrated that the application of the prioritizing method and the Gaussian normal distribution function in conjunction enables solving problems by choosing a specific subsystem by experts (industrial and fire safety, labor protection, and structural production units) deviations of which, due to its flaws (errors), have caused the primary factors of damage from accidents and fires. In the course of solving problem № 2, an example confirming the adequacy of the application of the prioritizing method together with the Gaussian normal distribution function was demonstrated. Based on the systemic analysis of methods used in practice, the justification of application of the expert method that enables obtaining quantitative values displayed as the influence coefficient was obtained, which indicates certain deviations and enables the correction of the personnel management model (industrial and fire safety, labor protection, and structural production units).

Pathways to sustainable transitions in a complex agricultural system: a case study of swine waste management in North Carolina

North Carolina has a high density of swine farms with nearly half of the commercial operations located in two eastern counties. Lagoon and sprayfield (LS) is the dominant method of swine manure management despite pressure to transition to environmentally superior technologies. LS is an efficient and cost-effective method of waste management but has negatively impacted the environment and local communities from both discreet events (breeches, flooding) and ongoing issues (odor, disease vectors). The Multilevel Perspective Theory (MLP) is a frame for understanding the relationships between a sociotechnical regime, its surrounding landscape, and emerging niches for sustainable technology development to help align these different levels of perspective and support transitioning toward more sustainable practices. Here, a farm level is added to represent the user perspective of regime technology in complex agriculture systems (MLP + F). We demonstrate how change may influence the North Carolina swine waste management (NC SWM) system through alternative scenarios applied to a conceptual model developed with the MLP + F frame in a methodology for analyzing complex agricultural systems with input from a diverse panel of experts. This case study demonstrates how the methodology can be applied through two NC SWM model scenarios analyzed with fuzzy cognitive mapping techniques. The first scenario explores whether panel recommended changes generate a shift toward sustainable manure management. Inference results suggest that experts have a broad understanding of how these goals may be achieved, but strategies are needed to enhance the specificity of proposed changes. Testing scenarios with more targeted interventions within specific subsystems could provide greater guidance with regard to policy, economic factors, farm practices, or societal demands. The second scenario considers the systemic effect of introducing a manure dewatering process on swine operations, with and without landscape support. Results from this scenario indicate that the more landscape support is engaged, the greater the impact on desirable outcomes. However, contradictions emerged between different versions of this scenario such as increased negative public perceptions despite positive community outcomes. This may require further investigation to tease out potential misalignment between perceptions of a complex system and actual system behaviors.

A Sensing Integrated Metal Additive Manufacturing Platform for Exploring the Use of Non-Standard Powders

Abstract Research applications that rely on commercial directed energy deposition (DED) based metal additive manufacturing (AM) systems are commonly constrained by their inflexibility in handling various non-standard powders, lack of fine system control, and inherent difficulty with sensor integration. In this work, we present the design of a sensing-integrated platform for metal additive manufacturing. A modular design allows easy modification of specific sub-systems, such as laser integration or powder delivery mechanisms, to enable capabilities that are difficult to realize with commercial systems. As an example, we demonstrate DED performance using non-conventional inexpensive powders produced via abrasion and water atomization techniques. System performance is evaluated using integrated sensors and complemented by numerical/ analytical calculations. Based on these results, a nominal operation map combining thermal field with powder flow is generated for determining process parameters suitable for a given material/build combination and can be generally applicable for any DED AM system. In addition to handling non-spherical and alternatively sourced powders, the system capabilities for printing multi-material complex contours are demonstrated.

Digital Twin Technologies for Autonomous Environmental Control and Life Support Systems

Environmental control and life support systems will require enhanced self-awareness and self-sufficiency as human spaceflights are designed to reach further destinations. These requirements have led to the development of autonomous technologies and systems to enable more Earth independence, while at the same time relying more heavily on the knowledge contained in their computational models (as opposed to the knowledge of ground control experts). For environmental control and life support systems, these consist of disparate models often tailored to specific subsystems and use cases, such as temperature control and CO2 removal. Therefore, there is a need for technologies supporting the integration of existing models. We propose to extend existing digital twin frameworks to integrate models and serve as a tool for answering onboard queries during operation. Toward this vision, we identify research directions for three types of technologies: i) streamlining the process of merging information models without redundancies by leveraging model-based systems engineering languages; ii) the calibration of simulation models that requires a better understanding of how to encode domain knowledge into a probabilistic representation of subsystem states and model parameters; and iii) automating the query understanding process and constructing a mapping between information and simulation models.

The role of professional culture in the formation of future pedagogues of vocational education

The analysis of scientific works proved that, in general, the concept of “culture”, as a terminological unit, acquires various “specialist” or so-called “professional” colours in various fields of scientific research. It was revealed that the concept of “professional culture” is understudied in the system of training future teachers of professional education. The aim of the study was to determine the essence of the professional culture of future pedagogues of vocational training based on the specifics of the professional activity of a specialist in the field of “Vocational Education (Design)”. The author’s understanding of the essence of the professional culture of future pedagogues of professional training in the field of design is formulated, based on the general understanding of the concept of “professional culture” in the following interpretation: it is a specific subsystem of general culture, a systemic and holistic unity of cultural and social experience regarding the ways and means of interaction between generations, socio-cultural and value traditions professional activity and personal achievements of mankind. The professional culture of future pedagogues of professional training in the field of design is interpreted as follows: it is a specific type of professional and pedagogical culture, a universal (basic) characteristic of pedagogical reality, which reflects (decodes) specific markers of pedagogical activity and functions in the plane of both pedagogical (educational, didactic, developmental) and purely professional (design, construction, project, technological) self-realization of the teacher as a specialist and subject of professional activity.

A novel application of the CORAS framework for ensuring cyber hygiene on shipboard RADAR

Radio Detection and Ranging (RADAR) equipment is a significant information and navigational system onboard vessels and a critical part of a ship’s cyber space. It is an electronic system used not only for detecting surrounding objects, to indicate their positions, and tracking targets using radio waves, but also providing safe navigation by receiving and displaying data from other navigational devices. Therefore, it is concerning to see that marine RADAR systems have various cyber vulnerabilities, including data deletion and data relocation. These systems can be manipulated and penetrated via malicious software, unauthorised remote access, human error, or sabotage by internal and external attackers. This is critical to the cyber hygiene of the ship, which affects its reliability and safety. This study performs a cyber risk assessment using the CORAS framework for RADAR cyber security by developing case-based RADAR cyber scenarios in terms of both its specific information technology subsystems and the cyber security control measures. The output of this study includes a holistic and visual assessment of RADAR's cyber security for both its cyber vulnerabilities and cyber hygiene to better protect shipboard RADAR in the future.

NanoSMAD – A First Order System Configuration Design Tool for Nano and Micro Satellites

The emergence of nano and micro satellites, which weigh less than 100 kg, is causing a significant transformation in the space industry. The existing Space Mission Analysis and Design (SMAD) tools, which are primarily designed for larger satellites, often become irrelevant for these smaller satellites in terms of spacecraft mass, power, pointing requirement, total mission duration, fault tolerance, and design cost. To address this, we have developed a web based nanoSMAD tool specifically for designers of nano and micro satellites. This tool utilizes a comprehensive database of approximately 140 nano and micro satellites along with their internal subsystem specifications. By using the nanoSMAD tool, designers can efficiently develop nano and micro satellite systems by entering their requirements, which then generates high-level system design and requirement specifications. This process enables the tool to provide a basic satellite configuration design and generates a Master Equipment List (MEL) of subsystems. To further customize the design, users can provide more specific parameter inputs or select components from a drop-down menu, resulting in an iterative custom design approach. The satellite database used by the nanoSMAD tool is regularly updated through online surveys, including web scraping, to gather information on the latest non-space-grade off-the-shelf nano and micro satellite subsystems. This ensures that the tool stays up-to-date with the newest advancements in the field. Additionally, the nanoSMAD tool offers a unique feature of verifying the electrical interface compatibility of subsystems, which is an innovative aspect of the tool. Novice small satellite communities will greatly benefit from the nanoSMAD tool as it seamlessly generates an initial nano and micro satellite system design, providing a first-order understanding of the satellite’s configuration and requirements.