The paper deals with security issues in a globalized, economically oriented world. The authors present a general, theoreticalpractical view of a systemic, object-process approach to analysing security threats of various categories. The paper generally analyses and categorises the sources and characteristics of threats according to various factors, which in practice may pose a threat to objects of interest or processes that have significant value for their owners. Emphasis is placed on threats of an economic, social, societal, or political nature that are typical of societies today, primarily unilaterally oriented towards economic gain. The authors' approach is purposefully general so that it can be applied to all sectors where security analysis is necessary i) to identify threats, weak spots in protected objects, states, or processes, ii) to discover vulnerabilities, iii) to realistically assess risks and propose protective measures.
The aim of this research is to reduce the noise level of air distribution grilles using 3D
printed infill structures. The grilles are installed on a newly developed autonomous ventilation system, which is used for decentralised ventilation of e.g., school classrooms. Several supply and return grilles with functional gyroid and honeycomb shaped infill structures were created and subsequently printed on an FDM 3D printer. Based on measurements and analysis of the maximum sound pressure levels at different microphone positions around the system and at different airflows, the combination of grilles with the greatest noise reduction was selected. The research is complemented by other data such as spectral analysis of the noise, measurement of the airflow velocity through the grilles and measurement of the room reverberation time. Significant noise reduction was achieved by using the proposed grilles and further conclusions were drawn. 3D printing technology proved to be a very useful tool in this case.
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