Pomiędzy technologią i bezpieczeństwem. Ukraiński sektor kosmiczny po 1992 roku

The aim of the article is to analyze the possibilities and directions of development of the Ukrainian space industry in the context of using Ukraine’s space potential. The discourse, as well as political decisions and legal acts, constitute the main research material. The main conclusion of the article is that the technological premises are secondary for the decision-makers who perceive Ukrainian space activity through the prism of state security and strategic advantages resulting from the status of a state involved in the exploitation and exploration of outer space. Moreover, the technological and scientific potential of the Ukrainian space sector from the perspective of cooperation with the European Union is still growing, although it is not effectively used.

Development Tools for Mining Regions of the Country

The article is devoted to the main tools for the development of mining regions of Russia, and it is noted that the lack of real implementation of the principle of consistency of the plan and strategy for the development of a mining region can lead to an irrational and uncontrolled use of resources and space potential in the subsequent development of the economy. The article presents analytical data on the restructuring of budgetary debts in some mining regions of the Russian Federation. The author concludes that there is a need to create a policy that takes into account the following guidelines for zoning: strengthening partnerships between urban and rural areas, promoting the development of all types of transport and communications, development and preservation of cultural heritage through competent management of the region.

Assessing Green Space Potential Accessibility through Urban Artificial Building Data in Nanjing, China

Green spaces play an important role in improving the health and quality of life of urban residents, and environmental justice has become one of the most debated topics for scholars and governments in China. The accessibility of green space has been recognized as an effective method for the assessment of environmental justice. Population and green space are the two basic elements for evaluating green space accessibility. However, high-precision population data are difficult to obtain. To address this issue, we propose a straightforward method to assess green space accessibility using urban artificial building data and investigate how green space distribution is correlated with the population. Our analysis uses urban artificial building data and green space data from 2018 in Nanjing, China. The results show that the overall amount of green space, is not only very low, but also unevenly distributed. From the urban center to the city outskirts, the green space changed representing an M-shaped pattern, while the population sharply declined. Given the serious mismatch between the population and green space, only about 26.4% and 51.8% of Nanjing residents could access green space within 400 and 800 m, respectively, which was far below that in cities in developed countries. For residents’ wellbeing, governments must consider increasing green space provision and promoting equal access.

Modeling and Parametric Analysis of Multilayer Piezocomposite Actuators

Design space for morphing structures using single layer commercial piezocomposite actuators are often restricted due to limitations in actuation authority. Optimal designs are those in which the substrate-actuator composite is stiff enough to maintain shape when subjected to surface pressures but allow for the desired curvature under excitation. This trade-off limits substrate to actuator thickness ratios in applications where dynamic pressures are high. One way to improve actuation authority while maintaining stiffness is to use multiple piezocomposite actuators. This paper explores the benefits and drawbacks of using multilayer piezocomposite actuators. The actuators are modeled using the finite element method and are characterized using well-known free strain and blocked force conditions in a four-point loading condition. Material properties for substrate, piezocomposite, and glue layers are modeled based on previous experimental analysis of curvature over a range of thickness ratios for single element actuators. A parametric analysis is conducted on multilayer piezocomposites varying thickness ratio, substrate material and number of piezocomposite layers. Results for the parametric analysis are presented in the form of maximum curvature, work done, and work done normalized by number of layers. A discussion of new design space potential for multilayer actuators is provided.

A Generalized Dynamic Potential Energy Model for Multiagent Path Planning

Path planning for the multiagent, which is generally based on the artificial potential energy field, reflects the decision-making process of pedestrian walking and has great importance on the field multiagent system. In this paper, after setting the spatial-temporal simulation environment with large cells and small time segments based on the disaggregation decision theory of the multiagent, we establish a generalized dynamic potential energy model (DPEM) for the multiagent through four steps: (1) construct the space energy field with the improved Dijkstra algorithm, and obtain the fitting functions to reflect the relationship between speed decline rate and space occupancy of the agent through empirical cross experiments. (2) Construct the delay potential energy field based on the judgement and psychological changes of the multiagent in the situations where the other pedestrians have occupied the bottleneck cell. (3) Construct the waiting potential energy field based on the characteristics of the multiagent, such as dissipation and enhancement. (4) Obtain the generalized dynamic potential energy field by superposing the space potential energy field, delay potential energy field, and waiting potential energy field all together. Moreover, a case study is conducted to verify the feasibility and effectiveness of the dynamic potential energy model. The results also indicate that each agent’s path planning decision such as forward, waiting, and detour in the multiagent system is related to their individual characters and environmental factors. Overall, this study could help improve the efficiency of pedestrian traffic, optimize the walking space, and improve the performance of pedestrians in the multiagent system.