Search

Abstract The development of DC microgrids is reliant on multi-input converters, which offer several advantages, including enhanced DC power generation and consumption efficiency, simplified quality, and stability. This paper describes the development of a multiple input supply based modified SEPIC DC–DC Converter for efficient management of DC microgrid that is powered by two DC sources. Here Multi-Input SEPIC converter offers both versatility in handling output voltage ranges and efficiency in power flow, even under challenging operating conditions like lower duty cycle values. These features contribute to the converter's effectiveness in managing power within a DC microgrid. In this configuration, the DC sources can supply energy to the load together or separately, depending on how the power switches operate. The detailed working states with equivalent circuit diagrams and theoretical waveforms, under steady-state conditions, are shown along with the current direction equations. This paper also demonstrates the typical analysis of large-signal, small-signal, steady-state modeling techniques and detailed design equations. The proposed configuration is validated through the conceptual examination using theoretical and comprehensive MATLAB simulation results. Detailed performance analysis has been done for different cases with various duty ratios. Finally, to show the competitiveness, the multi-input SEPIC topology is compared with similar recent converters.

This study explores the innovative path of ideological and political education in colleges and universities under the perspective of cultural self-confidence, and enhances the cultural self-confidence of college students, which is of great significance in improving the quality of national education and promoting national rejuvenation. The digital empowerment of teaching resources and efficient management algorithms significantly improve the efficiency of resource acquisition and application. The average score of teachers in accessing the resources of the Civics and Political Science course increased to 0.7182, indicating the effect of optimization of teaching resources. Meanwhile, the teacher team was optimized through rotation and exchange and professional training, and the proportion of teacher exchange and rotation increased to 18.22% in 2023, reflecting the rationalization of the teacher team structure. Students’ attitudes toward Civics and Politics reading differ significantly among different grades, with the best performance of juniors, with an average score of 4.53. In addition, creating a cultural atmosphere promotes students’ cultural self-confidence by increasing cooperation with all sectors of the society and building an influential “trinity” community of responsibility. The innovative strategy of Civic and Political Education in the perspective of cultural self-confidence has achieved remarkable results in improving the quality of education, optimizing the teaching staff’s structure and enhancing students’ cultural self-confidence.

The aim of the article is to study the main factors influencing the success of logistics companies in the current economic environment. The authors analyze current trends in the logistics industry, consider the main strategies used by logistics companies to achieve success. The main success factors are illuminated, such as: efficient supply chain management, use of modern technologies and innovations, development of partnerships with customers and suppliers, as well as the ability to respond quickly to changes in the market environment. The authors discuss the problems faced by logistics companies in the current economic environment: increased competition, increased customer demands, volatile fuel prices and other factors that may adversely affect the activities of logistics companies. Despite these challenges, logistics companies have great potential for development and expansion of their operations. Among the prospects for development are the increased use of new technologies such as drones and autonomous vehicles, improved supply chain management, and the development of environmentally friendly solutions. The authors of the article also draw attention to the importance of human resource management, maintaining a high level of employee motivation, ensuring the quality of services, assessing and managing risks, managing costs, and improving the efficiency of business processes. It is substantiated that the development of the logistics industry will take place in the direction of strengthening the integration of technologies, increasing the quality of services and improving risk management. Recommendations for improving the work of logistics companies are proposed, and it is concluded that the success of logistics companies depends on an integrated approach to management, as well as flexibility and adaptability to changing market conditions. The results of the study can be useful both for managers of logistics companies and for those interested in developing in this area. The article is an important study that allows us to better understand current trends in the logistics industry, as well as to identify problems and prospects for its development.

Knowledge about the residual effect of herbicides is important in order to increase agronomic efficacy and reduce environmental problems. Therefore, the objective of this study was to evaluate the residual effect of oxyfluorfen and linuron in three soils. Pots of 0.35 dm3 were filled with three Brazilian soils: Ultisol, Oxisol, and Inceptisol. Then, the herbicides were applied at different times at 0, 15, 30, 45, 60, 90, 120, 150, 180, and 200 days and the bioindicator species of linuron and oxyfluorfen were sown. Then, the injury was evaluated at 7, 14, and 21 days after emergence (DAE) to find the half-life of the herbicide residue level (RL50) and the dose of herbicide that provides a 50% reduction in dry matter (GR50). In the soil with oxyfluorfen application, the RL50 at 21 DAE was 59, 57, and 51 days and GR50 was 49, 47, and 31 days for Ultisol, Oxisol, and Inceptisol, respectively. Soils with linuron application had RL50 of 75, 92, and 149 days and GR50 of 52, 48, and 120 days for Ultisol, Oxisol, and Inceptisol, respectively. The higher organic matter and clay content of Ultisol compared to Oxisol and Inceptisol resulted in a lower residual effect of linuron. There was little difference between soil type and the residual effect of oxyfluorfen, which may be related to the physicochemical characteristics of the molecule.

Subject and purpose of the article: The subject of this study is the relationship between individual emotions and the management of public financial resources and its purpose is to investigate the effect of positive and negative individual emotions on the decision of financial managers of a governmental university in the optimal use of public financial resources.Research method: In this study, preliminary data were collected through a researcher-made questionnaire for managers' willingness to manage public financial resources (based on the Beleski et al. Questionnaire), and the Panas Emotions Questionnaire. 70 questionnaires were used for analysis. Also, multivariate regression and descriptive and non-parametric statistics have been used to analyze the results. In inferential analysis, Kolmogorov-Smirnov test and regression test have been performed to test the hypotheses.Research findings: The results show that both positive and negative aspects of financial managers' personal emotions have a significant impact on their decisions in the efficient and inefficient management of public financial resources. Evidence also suggests that education and work experience have a direct and significant impact on the efficient management of public financial resources and a significant and inverse impact on the inefficient management of public financial resources.Conclusion, originality and its contribution to the knowledge: Based on the findings of this study, the financial managers of public universities should, as an adaptation, select and implement appropriate strategies in the process of spending steps in order to prevent any waste of public financial resources.

This paper examines the application of strategic planning in Serbia. The research focus is on the definition of strategic goals and on the selection of strategic priorities. In order to meet goals, each strategy defines appropriate action plans for its implementation. Action plans thoroughly define activities, measures and projects, activity-bearers, implementation deadlines, success indicators, funds, financing sources, legal and institutional framework. Paper investigates the current practice of strategic documents implementation. Further, issues with monitoring, reporting and evaluation are examined. Finally, recommendations have been made for more transparent and efficient management, aiming to improve the allocation of budgetary and non-budgetary funds.

The world financial crisis began in the USA in 2007 due to the social irresponsibility of banks and other actors of financial market. In 2008, it outgrew in a world economic crisis. For many countries, including some EU countries, the crisis also proceeds in 2020, sharply enhancing the instability of the external management systems of companies and the competition. With December 2019 the pandemic of COVID-19 has begun, that substantially strengthened the negative consequences of the global economic crisis in countries. The article is aimed at a further development of the author’s own conception regarding the social responsibility of enterprises of all types of activity and all forms of ownership in the modern circumstances. It is expressed in providing of comfort, safe terms of labor and decent payment of the staff, development of social infrastructure, in prevention of avoiding the tax payment, in providing the proper security to environment, and also in the use of the socially responsible marketing (SRM). The author’s own approaches to the estimation of competitiveness of the socially irresponsible enterprises are provided. The competitiveness of products both in the short-term and in the long-term period can be erroneous, achieved due to social irresponsibility of enterprise and its marketing. For a bright illustration one can refer to the scandal around the German automotive company «Volkswagen», known as «Dieselgate». Also the criteria of efficiency of the economic system of Ukraine and other countries are substantiated. The author believes that the UNO has estimated the potential socio-economic consequences of not only pandemic of COVID-19 but also the world economic crisis that proceeds for most countries. These consequences in a great deal coincide and it is not possible to divide them.

In order to carry out its activity in optimum conditions and achieve its goal, either to develop a product, to do a job or perform a service, any entity must maintain a balanced level of stocks of raw materials and materials. However, very careful attention should be paid to the stocks’ level, since this level should not record values too high, or too low. These values lead to overstocking or stockouts situations, which should be avoided. The blockage of liquidity and the deterioration of raw materials and materials stored over a long period of time are the main consequences of overstocking, and, among the consequences of the stockout we can list: discontinuation of business, which may mean diminishing profits but also loss of customers’ confidence through termination of contracts. In order to achieve the optimal stock level, we recommend an efficient administration of this activity, which implies the implementation of a well-designed information system that provides information at all times to the management and the supply department and, at the same time, effective management, since it has consequences on the company’s profitability and requires good communication with both the internal and external environment. We aim to focus in this study on the factors influencing the achievement and preservation of an optimal stock level, the importance of safety stock, the role of stock administration and inventory management within an entity.

The 2008 crisis outlined the great importance of treasury departments in companies and the change of mentality towards proactive and non-reactive management. In this work, a detailed explanation of the centralization system of the treasury, also known as cash pooling, is carried out. Nowadays this system is used by numerous companies worldwide, especially large companies with an international focus. Finally, information and communication technologies are of great importance within the company, especially in treasury management. The paper is illustrated by the case study of a water management company.

Dramatic increases in populations of wild ungulates have brought a new ecological issue in the Qinling mountains. Information on species’ niche differentiation will contribute to a greater understanding of the mechanisms of coexistence, so as to ultimately benefit the conservation and management of ecological communities. In this study, camera trapping was used to investigate spatial and temporal activity patterns of sympatric wild ungulates in the Qinling Mountains of China, where top predators were virtually absent. We obtained 15,584 independent detections of seven wild ungulate species during 93,606 camera-trap days from April 2014 to October 2017. Results showed that (i) the capture rate differed significantly across species, with the capture rate of reeve muntjac being significantly higher than that of other species; (ii) the wild boar had a higher occupancy rates (ψ = 0.888) than other six ungulates, and distance to settlements had a negative relationship with wild boar (β = −0.24 ± 0.17); (iii) the forest musk deer and mainland serow had low spatial overlaps with other five wild ungulates, while spatial overlap indices of any two given pairs of wild ungulates were relatively high; (iv) all wild ungulates species (expect wild boar) were mainly active during crepuscular and diurnal periods, and showed bimodal activity peaks at around 05:00–07:00 and 17:00–19:00; and finally, (v) all wild ungulates showed moderate to high temporal overlaps. The results provided detailed information of the spatial and temporal ecology of wild ungulate communities in forest ecosystems of China, which also would be a guide to establish conservation priorities as well as efficient management programs.

Safety and proactive vision are key aspects for an efficient management of dams. The reduced accessibility and the large time needed for an inspection by traditional methods do not facilitate their direct visual inspection. Therefore, the use of Unmanned Aerial Vehicle (UAV) is suitable for this purpose, although the support of traditional topographic instruments (i.e. Total Station, GPS Station and Laser Scanner) is still necessary. The UAV survey provides qualitative information, with the aim of recognizing the condition of the materials (i.e. photos, videos), as well as quantitative information, with the aim of modelling the structure (i.e. geo-referenced dense point cloud). Since multidisciplinary aspects are involved in the management of dams, the possibility to share data (i.e. photos, videos) of every detail of the structure, also on different times and in different places, between a large number of specialists (i.e. engineers, architects, geologists, technicians, managers) allows for the effective and efficient resolution of problems. The UAV dense point cloud, integrated also with pre-existing data sets, is the base for the extraction of surfaces which describe important elements of the structure. The solid model is employed in Finite Element Method (FEM) analyses or, including additional information concerning volumes, mechanical characteristics, monitoring data, etc., it could be able to be the basis for a Building Information Modelling (BIM) of the dam system. The aim of the present paper is to explain the products of a UAV survey of a dam useful for storing and sharing information and for developing the starting point of a BIM of the structure. Case of study is the arch-gravity dam of Ridracoli, it has been the object of a technological comparison between traditional topographic instrument and the innovative UAV technique. The photo/video database captures the reference state of the structure and allows to investigate possible damage phenomena over time, moreover, by means of photomodelling technique, it provides the dense point cloud as a basis for a BIM.

Crisis phenomena in the construction services market can be overcome by a number of measures both at the national level and at certain enterprises. Top management of the construction companies is offered to form a leadership block – a new working group with special status – power of decision.

The goal of any firm is to make enough profit to properly capitalize its capital, maintain its technical and economic potential, and ensure rational expansion taking into account market developments and short-term trends. Two categories of indicators are used to measure profitability: profitability and profitability rates. the absolute value of profitability is reflected by profit, and the extent to which capital or use of company resources generates profit is reflected by the rate of return. as indicators of absolute profitability can be taken into account: the result of the turnover, the result of the exploitation, the financial result, the current result, the extraordinary result, the gross result of the year, the net result of the year. The following rates are typically used for expressing relative profitability: the rate of return on trade, the rate of return on consumed resources, the rate of economic profitability and the rate of financial return.

Communication is the primary factor in the success of an education organization. Understanding and knowing the mission and goals of the organization by all its members lead to the success of the organization if they were promoted by the manager through effective communication and were timely and accurately transmitted in an appropriate manner. The purpose of internal communication is to increase the motivation of members of the organization by facilitating understanding of the tasks the organization has and, implicitly, its staff. Quality management is based on active communication, in which the manager has as main objective the continuous optimization of communication at all levels, and the removal of barriers to it, in order to achieve the proposed objectives, by synchronizing and harmonizing the actions of all the members of the organization. In the first chapter I will present the role and importance of managerial communication, in the second that a manager communicates and in the third of the communication bottlenecks. As a research method I used the theoretical method.

Objectives. Relevant problems related to the adoption of unprogrammed solutions in the process of managing the production activity of a construction enterprise in unstable, a priori underdetermined economic environments are addressed.The aim of the study is todevelop tools and methods for assessing the effectiveness of the current state of construction production and on this basis to identify the most effective management of a construction organisation under unstable market conditions.Methods. The methodology of the conducted research is based on the application of the mathematical apparatus of fuzzy sets for the processing of expert data and the formation on this basis of linguistic functions that determine the analytical relationship between various indicators of the production activity of the construction organisation.Results. A method is developed for processing expert data using fuzzy logic, making it possible to form an analytical relationship between the performance indicators of the production activity of the construction organisation and the management parameters that determine its current state. An alternative means for selecting the most effective management approach, accounting for its influence on the efficiency of the production activity of the construction organisation, is developed.Conclusion. An information-economic model of situational management of the development of a construction organisation is developed. The proposed tools and methods allow the effective management of the production activity of the construction organisation to be organised, and on this basis to increase the efficiency of production under different economic conditions in the presence of spontaneously arising perturbative factors. The methodical approach to the organisation of management of the production activity efficiency of the construction organisation allows the effective subsystems of management of other activities of the construction organisation concerning the rejection and indignation in the unstable conditions of the modern market environment to be formed without fundamental changes in the organisational structure.

Water is a critically important element of human life. The best practice of effective water management comes from ancient civilizations that, despite their technologies and practices, were unable to prevent collapse from water scarcity. In the 21st century, in an era of climate change, pollution or population explosion, cities are looking for innovative ways to effectively manage scarce resources for future generations. Which elements should cities of the future follow to avoid water collapse? The following article aims to identify the key elements of effective management and to represent them graphically in the form of a recommended model, which will be verified in the future in Slovakia. The article uses case analysis of best past and current practices, comparison and summarization to identify the elements, creativity, and logic in the development of the model, including induction and deduction. The article serves as a basis for fellow researchers (analyses carried out) and strategic urban management (effective urban water management). The main finding of the article is that ecological change puts pressure on social elements and therefore it is necessary to focus on the area of strategic management. Cities should not only know how to manage resource abundance or short-term scarcity, but also long-term scarcity. They should use elements of trust, awareness and continuous improvement through modern monitoring technologies (UAVs, sensors) and prediction (machine learning). This is the only way to generate water sustainability in the urban concept of the future.

Efficient management of energy resources is crucial in smart buildings. In this work, model predictive control (MPC) is used to minimize the economic costs of prosumers equipped with production units, energy storage systems, and electric vehicles. To this purpose, the predictive control manages the available energy resources by exploiting future information about energy prices, absorption and production power profiles, and electric vehicle (EV) usage, such as times of departure and arrival and predicted energy consumption. The predictive control is compared with a rule-based technique, herein referred to as a heuristic approach, that acts in an instant-by-instant fashion without considering any future information. The reported results show that the studied predictive approach allows one to achieve charging profiles that adapt to variable operating conditions, aiming at optimal performances in terms of economic cost minimization in time-varying price scenarios, reduction of rms current stresses, and recharging capability of EV batteries. Specifically, unlike the heuristic method, the MPC approach is proven to be capable of efficiently managing the available energy resources to ensure a full recharge of the EV battery during nighttime while always respecting all system constraints. In addition, the proposed control is shown to be capable of keeping the peak power absorption from the grid constrained within set limits, which is a valuable feature in scenarios with widespread adoption of EVs in order to limit the stress on the electrical system.

Electric vehicles (E.V.) are one of the feasible solutions to address the challenges of sustainable development that require particular attention, such as climate change, depletion of fossil fuel reserves, and greenhouse gas emissions. In addition to the environmental benefits of electric vehicles, they can also be used as a storage system to alleviate the challenges posed by the variability of renewable electricity sources and to provide the network with ancillary benefits, such as voltage regulation and frequency regulation. Furthermore, using removable batteries by electric vehicles to store renewable energy is an innovative and effective solution to combat the increase in GHG emissions. In this article, using the autoregressive integrated moving average forecast model, we estimate the necessary storage capacity to contribute to the adjustment of the energy system increasingly powered by renewable energy sources. Also, we estimate the number of electric vehicles needed to take over the excess energy produced by renewable sources when the conventional grid cannot take over this surplus. The forecasts have the year 2050 as a time horizon. The results show that removable E.V. batteries can be an efficient solution for managing and storing energy lost in the temporal incongruity of demand with supply in the energy market.

The article discusses issues of practical HR management, which are used by liner managers in their everyday work. The author puts forward effective technologies and methods of HR work for practical application. The material provides full and objective idea about problems connected with HR management and methods of their resolving. Special attention is paid to innovative managerial conceptions and settlement of the most widely-spread situations in HR work.

This paper aims to analyze the importance of an efficient administration of working capital, as a strategy to achieve the operation of SMEs and their permanence in time. Working capital is the minimum cash that every company needs to execute its operating activities normally. Proper management of the asset enables to have the necessary liquidity to cover short-term obligations, as a result of the efficient application of the cash conversion cycle. For this, a methodology of documentary analysis was applied taking as reference secondary research sources, such as books and scientific papers. Based on the above, the theoretical foundations of working capital, their methods of calculation and a review of research on the management of working capital in Latin American SMEs were analyzed. As a result, it was determined that working capital is a financial tool that every manager must pay attention and spend time, because it determines the survival of a company in the early years of its existence. On the other hand, there are some calculation methods to estimate working capital, each has its essential characteristics and its application depends on the activity to which the organization is committed.

Romania's budgetary policy has as one of its objectives to maintain a particular level of aggregate demand in the economy through public expenditures and tax rates. The increase of the Romanian government debt in the latest period was driven mainly by engaging the debt to finance the budget deficit, refinancing of the public debt, enhancing the financial reserve in currency etc. For an economy that seeks to be in a permanent rise, it becomes appropriate a well-founded budget policy that will take into account the concrete circumstances of the economic and social life, needs of the present and the imperatives of the future. It may prove beneficial to progress, but if they are not mattered or disregarded it can brake the growth, can lead to social tensions and involution.

The article describes the mainstream of municipal economy crisis management, tactical activities in order to reconcile a disputes on the use of municipal property, arising between economic entities. The characteristics of existing municipal economy models are represented. The concrete methods of new principals of municipal property management are defined.

This research represents a novel contribution regarding the application of digital technology to the management and cultural promotion of industrial heritage. The study answers questions about the level of digital transformation of certain preselected buildings and areas of great historical and technical interest. It includes an extensive bibliographic review and analyzes different variables linked to webpages, which are the main source of information for visitors, and studies the level of digitization using a survey of the technical managers. The results are valuable because they offer an original profile of selected industrial heritage sites, characterized by an important connection between visitors, visited spaces, and available resources; the interaction of these three elements with the surrounding territory, fostering a new competitive capacity; the projection of each place in a modern and attractive way; and the commitment to an efficient and sustainable local management model. The results provide a fresh look at the technological changes embodied by new uses in old industrialization sites. In addition, the performed analysis could easily be applied and operationally compared in other different heritage environments.

Basing on the analysis of the works by thinkers and researchers, classical and behavioral concepts of management, as well as modern managerial paradigms, the author views the evolution of managerial technologies; defines the manipulative essence of managerial activity; reveals the peculiar features and consequences of implementing the manipulative technologies of management.

Crisis phenomena in the construction services market can be overcome by a number of measures both at the national level and at certain enterprises. Top management of the construction companies is offered to form a leadership block – a new working group with special status – power of decision.

This paper is about the principles of proper governance codes, which even tough have blossomed in all parts of the world for more than a decade, the degree in which companies adopt the codes vary in different countries, and the decision to adopt a certain code does not automatically guarranty efficient corporate governance. The paper trys to identify the mechanisms needed for implementing the codes and that will lead to higher efficiency.

En este trabajo se explica el diseño, e implementación de una herramienta capaz de controlar y gestionareficientemente los motores eléctricos de una industria. Para ello se elaboró un software de fácil manejoque resolviera el problema y que además brindara otras opciones a los usuarios que hicieran uso delmismo. EFICAL®, controla el inventario de los motores y sus equipos accionados, sus parámetrosnominales, mantenimientos y ensayos, permite calcular la eficiencia por distintos métodos y brinda ademásdatos de catálogos de diversos fabricantes. This work explains the developing and application of a software tool for efficient management of electricmotors in the industry. For this it was develop friendly software that solve the problem and more over givesanother option to users. EFICAL®, controls the motor inventory and the equipment that they drive, theirnominal parameters, maintenance, and testing; also allow the efficiency calculations by various methodsand gives the catalog data of some manufacturers.