The article presents a comprehensive study of a visual-inertial simultaneous localization and mapping (SLAM) algorithm designed for aerial vehicles. The goal of the research is to propose an improvement to the particle filter SLAM system that allows for more accurate and robust navigation of unknown environments. The authors introduce a modification that utilizes a homography matrix decomposition calculated from the camera frame-to-frame relationships. This procedure aims to refine the particle filter proposal distribution of the estimated robot state. In addition, the authors implement a mechanism of calculating a homography matrix from robot displacement, which is utilized to eliminate outliers in the frame-to-frame feature detection procedure. The algorithm is evaluated using simulation and real-world datasets, and the results show that the proposed improvements make the algorithm more accurate and robust. Specifically, the use of homography matrix decomposition allows the algorithm to be more efficient, with a smaller number of particles, without sacrificing accuracy. Furthermore, the incorporation of robot displacement information helps improve the accuracy of the feature detection procedure, leading to more reliable and consistent results. The article concludes with a discussion of the implemented and tested SLAM solution, highlighting its strengths and limitations. Overall, the proposed algorithm is a promising approach for achieving accurate and robust autonomous navigation of unknown environments.

For centuries, the roof has been a reminiscence, the symbol of basic human shelter and territory. Using the example of several ethnic groups living in Southeast Asia, Bhutan and Poland, the basic determinants of roof shape creation in vernacular architecture are discussed and similarities highlighted. In wooden architecture in different regions of the world, the form and construction of the roof are determined primarily by local conditions: climatic conditions, available materials, local tradition, culture, customs. Often it is the shape of the roof that determines the visual identity of a given ethnic group, with its traditions and way of life. The author points out that societies from different regions of the world with no cultural ties created wooden architecture based on the same factors and that the similarities are already present at the level of thinking patterns resulting, for example, from the need to emphasize the importance of religious buildings by means of the stacked, pent hip form of the basic roof.

The reverse bending and straightening test is conducted on wires used for civil engineering applications to detect laminations which can pose a threat to the integrity of the wires. The FE simulations of the reverse bending and straightening of wires with laminations revealed that the reverse bending and straightening test is only effective in revealing or detecting near-surface laminations with lengths from 25 mm located up to 30% of the wire’s thickness and may not be an effective test to detect mid-thickness, near-mid-thickness, and short near-surface laminations with lengths below 15 mm. This is because wires with mid-thickness, near-mid-thickness and short near-surface laminations will pass through the reverse bending and straightening procedures without fracturing and therefore mid-thickness, near-mid-thickness and short near-surface laminations may go undetected. Consequently, other in-line non destructive testing methods might have to be used to detect mid-thickness, near-mid-thickness and short near-surface laminations in the wires.