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The paper aims to investigate the effectiveness of ultrawideband localization in the path planning of multiple quadrotors performing inventory management in warehouses. As studies investigating warehouse automation became prevalent, researchers have looked into integrating quadrotors to aid inventory management with their ability to equip a wide array of sensors and reach high altitudes. Indoor localization has been one of the main foci of research where simultaneous localization and mapping (SLAM) and radio frequency identification (RFID) were commonly used due to their reliability and accuracy. Ultrawideband (UWB) can be viable for quadrotor navigation with their effectiveness even in nonideal lighting conditions and its relatively inexpensive infrastructure. A path planning algorithm was designed which optimizes quadrotor energy consumption and yaw movement. Simulations were performed to verify the feasibility of the system, and field experiments were carried out to assess the accuracy of UWB to localize the quadrotor. Results have shown that UWB maintained an accuracy of 0.43 m with 95% reliability, even if two quadrotors were used. Moreover, the quadrotor energy consumption was minimized successfully, with the maximum energy consumption difference below 23% for multiple inventory management. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAV) are widely used in literature for object detection utilizing convolutional neural networks (CNN). However, most UAVs make use of GNSS sensors for localization, which have low reception in indoor situations. Therefore, this study aimed to investigate the implementation of a multi-UAV object detection system and navigation with the aid of particle swarm optimization (PSO) in ultra-wideband (UWB) positioning systems for GNSSdenied environments, such as inside factories and warehouses. The performance of UWB systems was investigated to determine its viability in the PSO model. An object detection system based on the YOLOv5 network was trained with custom training images and subsequently evaluated with test images. The results of the object detection network were fed as inputs into PSO algorithms. Furthermore, different PSO algorithms were evaluated to determine the suitability for multi-UAV navigation and object detection. The results showed that UWB systems had sufficient accuracy for indoor localization, object detection, and navigation applications. YOLOv5 detection model detected objects with an F1 score of 0.93, given the optimal threshold of 0.8. Regarding the evaluation of PSO algorithms, the stochastic inertia weight variant of PSO algorithms (Sto-IW PSO) performed effectively across all metrics considered in the study compared to other algorithms that only performed effectively in one. Recommendations included the actual implementation of the system with multiple UAVs through field experiments and further refinements to PSO algorithms in order to match the kinematics and response time of the UAVs. [ABSTRACT FROM AUTHOR]

Direct-fed microbials (DFM) support the health and performance of the herd through different modes of action, including improvements on nutrient digestibility. In fact, Bacillus spp. has been identified as an important enzyme-producing bacteria that could benefit overall nutrient utilization by the beef and dairy cattle herd. Based on this rationale, we hypothesized that incubation of a Bacillus-based DFM would improve nutrient digestibility of feedstuffs often fed to ruminants. Therefore, our objective was to evaluate the effects of a Bacillus-based DFM on in vitro nutrient digestibility of different single feedstuffs. Six individual feedstuffs were sampled from China and South Africa and used herein. Feedstuffs were incubated or not (CON) with a Bacillus-based DFM (DFM; BOVACILLUS; B. licheniformis and B. subtilis; 3.2 × 109 CFU/gram; Chr. Hansen A/S., Hørsholm, Denmark) over a 48-h in vitro period. The dose of DFM was adjusted to the volume of the flasks being used and to represent the commercial dose of 3 grams/head per day (9.6 × 109 CFU/head). In vitro gas production, dry matter (DM), and neutral detergent fiber (NDF) digestibility were evaluated at 24 and 48 h. Data were analyzed using PROC MIXED of SAS (version 9.4). Mean total in vitro gas production increased by 5.1 and 6.5% when DFM was incubated at 24 and 48 h, respectively (P < 0.01). At 24 h, NDF digestibility was 12.6% greater for DFMtreated feedstuffs vs. CON (P = 0.02; 27.7 vs. 24.6% for DFM and CON, respectively), but no effects were observed on DM digestibility (P = 0.26). Conversely, 48-h DM and NDF digestibility were greater for DFM vs. CON (P = 0.05), with improvements that were in the order of 3.7 and 15.1%, respectively. In conclusion, we observed greater in vitro fiber degradability and gas production of feedstuffs collected from China and South Africa over a 48-h period when the DFM BOVACILLUS was added at a dose representative of 9.6 × 109 CFU per head. Greater improvements in fiber degradability are likely due to the enzymes produced by the DFM BOVACILLUS. [ABSTRACT FROM AUTHOR]