# Special Issue on Advances in Database Engineered Applications
###### Abstract  
The 27 th International Database Engineering and Applications Symposium (IDEAS-2023) was held in Heraklion, Crete, Greece, on 5-7 May 2023. This conference is an international forum for data engineering researchers, practitioners, developers, and application users to explore revolutionary ideas and results, and to exchange techniques, tools, and experiences. Following the long history of IDEAS events, proceedings have been published by ACM Press, plus Special Issues are being published with selected-invited papers. More information can be found on the conference website: [[https://conferences.sigapprf.org/ideas2023/](https://conferences.sigapprf.org/ideas2023/)]([https://conferences.sigapprf.org/ideas2023/](https://conferences.sigapprf.org/ideas2023/)), accessed on 11 March 2024. The authors of a number of high-quality full papers were invited after the conference to submit revised and extended versions of their originally accepted conference papers to this Special Issue of _Computers_, published by MDPI, in an open access format. Each submission to this Special Issue should contain at least 50% new material, e.g., in the form of technical extensions, more in-depth evaluations, or additional use cases, and a change in the title, abstract, and keywords. These extended submissions underwent a peer-review process according to the journal's rules of action. At least two technical committees acted as reviewers for each extended article submitted to this Special Issue; in some cases, additional external reviewers were invited to guarantee a high-quality reviewing process. The present Special Issue contains six papers, which are briefly introduced as follows. Contribution 1 by [PERSON] and [PERSON] (University of Wuppertal) examines the doubly linked tree of singly linked rings to provide hard real-time database operations on an FPGA. The authors present a hardware data structure specifically designed for FPGAs that enables the execution of the hard real-time database CRUD operations using a hybrid data structure that combines trees and rings. While the number of rows and columns has to be limited for hard real-time execution, the actual content can be of any size. Their structure restricts full navigational freedom to everything but the leaf layer, thus keeping the memory overhead for the data stored in the leaves low. Although its nodes differ in function, they all have exactly the same size and structure, reducing the number of cascaded decisions required in database operations. This enables fast and efficient hardware implementation on FPGAs. In addition to the usual comparison with known data structures, they also analyze the tradeoff between the memory consumption of our approach and a simplified version that is doubly linked in all layers. Contribution 2 by [PERSON], [PERSON] (Manipal University Jaipur), [PERSON] (Arya College of Engineering and Information Technology, Jaipur), [PERSON], [PERSON] (Manipal University Jaipur), [PERSON], and [PERSON] (University of Calabria) examines low-cost multisensory robots for optimized path planning in diverse environments. The automation industry faces the challenge of avoiding interference with obstacles, estimating the next move of a robot, and optimizing its path in various environments. Although researchers have predicted the next move of a robot inlinear and non-linear environments, there is a lack of precise estimation of sectorial error probability while moving a robot on a curvy path. Additionally, existing approaches use visual sensors, incur high costs for robot design, and are ineffective in achieving motion stability on various surfaces. To address these issues, the authors propose a low-cost and multisensory robot capable of moving on an optimized path in diverse environments with eight degrees of freedom. They use the extended Kalman filter and an unscented Kalman filter for localization and position estimation of the robot.