BI-RRT*: An improved path planning algorithm for secure and trustworthy mobile robots systems.

The optimal RRT in elliptic space sampling (Informed-RRT*) is an extension of RRT that provides asymptotic optimality, however, it experiences gradual progress and close to obstacles. In the paper, we propose a novel path planning algorithm guided bidirectional Informed-RRT* (BI-RRT*), that introduces extension range, dual-direction exploration, and refinement in trajectory design. The growth range refers to maintaining an additional area from the obstacle to enhance the dependability of the path through preventing impacts. Bidirectional search is a search strategy using both start and target points for a initial solution. Smoothing improves path robustness by using cubic spline. Furthermore, simulation tests for the BI-RRT* algorithm are executed, and the efficacy of the suggested algorithm is confirmed through its application in a robot operating system (ROS). Simulations and experimental tests verify that the proposed algorithm improves the path planning capability. We emphasize the importance of safety, privacy, and reliability in the deployment of AI systems. Our algorithm ensures that the planned paths maintain a safe distance from obstacles, reducing the risk of collisions. Additionally, we prioritize privacy by adhering to data protection regulations and implementing secure communication protocols within the AI system. Moreover, we have applied rigorous testing and validation processes to enhance the reliability of our algorithm, ensuring consistent and accurate path planning outcomes.

Dynamic nonlinear simplified neutrosophic sets for multiple-attribute group decision making.

In this paper, the concept of a dynamic nonlinear simplified neutrosophic set (DNSNS) is proposed for describing the real-time changing expert preference information. Furthermore, the DNSNS aggregation model and decision algorithm are provided to solve the actual multiple-attribute group decision making (MAGDM) problems. The basic notions, the similarity measure, the entropy measure, and the index of distance of DNSNS are presented first. Secondly, the univariate time series of DNSNS are projected into dynamic nonlinear simplified neutrosophic curves in three-dimensional space. The areas of the surface enclosed by the curves represent the variance among the DNSNSs. Thus, the DNSNS aggregation model is established correctly without preprocessing the original data. Afterward, the aggregation algorithm extended from the plant growth simulation algorithm (PGSA) is proposed for calculating the optimal aggregation preference curve and constructing the collective matrix. Additionally, a novel corresponding decision algorithm based on TOPSIS and projection theory is proposed for obtaining the overall ranking of alternatives in the actual MAGDM problem. Finally, a typical example is presented to illustrate the feasibility and effectiveness of the proposed model and algorithm.

Boosting the Electrochemical Storage Properties of Co3O4 Nanowires by the Mn Doping Strategy with Appropriate Mn Doping Concentrations.

High specific capacitance, high energy density, and high power density have always been important directions for the improvement of electrode materials for supercapacitors. In this paper, Co3O4 nanowire arrays with various Mn doping concentrations (Mn:Co molar ratio = 1:11, 1:5, 1:2) directly grown on nickel foam (NF) were prepared by a simple hydrothermal method and annealing process. The influence of Mn doping on the morphology, structure, and electrochemical behaviors of Co3O4 was investigated. The results show that partial substitution of Co ions with Mn ions in the spinel structure does not change the nanowire morphology of pure Co3O4 but increases the lattice parameter and decreases the crystallinity of cobalt oxide. Electrochemical measurements showed that Mn doping in Co3O4 could effectively enhance the redox activity, especially Co3O4 with a Mn doping ratio of 1:5, which exhibits the most excellent electrochemical performance, with the maximum specific capacitance of 1210.8 F·g-1 at 1 A·g-1 and a rate capability of 33.0% at 30 A·g-1. The asymmetric supercapacitor (ASC) device assembled with the optimal Mn-Co3O4 (1:5) and activated carbon (AC) electrode performs a high specific capacitance of 105.8 F·g-1, a high energy density of 33 Wh·kg-1 at a power density of 748.1 W·kg-1, and a capacitance retention of 60.2% after 5000 cycles. This work indicates that an appropriate Mn doping concentration in the Co3O4 lattice structure will have great potential in rationalizing the design of spinel oxides for efficient electrochemical performance.

Research of the impact of economic decline on air quality in Wuhan under COVID-19 epidemic.

A novel economic impact model is proposed by this paper to analyze the impact of economic downturn on the air quality in Wuhan during the epidemic period, and to explore the effective solutions to improve the urban air pollution. The Space Optimal Aggregation Model (SOAM) is used to evaluate the air quality of Wuhan from January to April in 2019 and 2020. The analysis results show that the air quality of Wuhan from January to April 2020 is better than that of the same period in 2019, and it shows a gradually better trend. This shows that although the measures of household isolation, shutdown and production stoppage adopted during the epidemic period in Wuhan caused economic downturn, it objectively improved the air quality of the city. In addition, the impact of economic factors on PM2.5, SO2 and NO2 is 19%, 12% and 49% respectively calculated by the SOMA. This shows that industrial adjustment and technology upgrading for enterprises that emit a large amount of NO2 can greatly improve the air pollution situation in Wuhan. The SOMA can be extended to any city to analyze the impact of the economy on the composition of air pollutants, and it has extremely important application value at the level of industrial adjustment and transformation policy formulation.

[Modified Stoppa approach in treatment of pelvic and acetabular fractures].

OBJECTIVE: To evaluate the modified Stoppa approach in treatment of pelvic and acetabular fractures. METHODS: From March 2010 to May 2012,16 patients with pelvic fractures and 7 patients with acetabutar fractures were treated by open reduction and internal fixation through the modified Stoppa approach,involving 18 males and 5 females with an average age of 39 years ranging from 17 to 65. By Tile classification, 16 cases of pelvic fractures included 1 case of B1, 2 of B2, 3 of B3, 4 of C1-1, 2 of C1-2, 2 of C1-3, and 1 of C2. By Letournel classification, 7 cases of acetabular fractures included 1 case of anterior column fractures, 1 of transverse fractures, 2 of type T, 1 of anterior column plus posterior transverse fractures, and 2 cases of both columns fractures. For 16 pelvic fractures, the modified Stoppa approach was used exclusively in 9 cases,in combination with the iliac fossa approach in 6 cases, and in combination with the posterior approach in 1 case. For 7 acetabular fractures, the modified Stoppa approach was used exclusively in 4 cases, in combination with the Kocher-Langenbeck approach in 2 cases, and in combination with the Kocher-Langenbeck and iliac fossa approaches in 1 case of both columns fractures. RESULTS: The average operation time was 130 min (50 to 350 min) and the blood loss averaged 320 ml (100 to 1200 ml). There were no operative complications. The reductions of the pelvic and acetabular fractures were all excellent and good. Twenty-one patients were followed-up from 4 to 24 months (averaged 8 months). The fractures were all healed,the fracture healing time was 2.5 to 5 months (means 3.2 months). Among them, 1 case occurrenced screw loosening, 1 case had mild limited of hip flexion, no case had plate breakage and lateral ventral syndrome. CONCLUSION: The modified Stoppa approach can be used to treat pelvic and acetabular fractures effectively, and it has advantages of easy manipulation and a low complication rate.

[A simulative biomechanical experiment on different position of none-cement acetabular components influencing the load distribution around acetabulum].

In the present study, a three dimensional finite-element model of the human pelvic was reconstructed, and then, under different acetabular component position (the abduction angle ranges from 30 degrees to 70 degrees and the anteversion ranges from 5 degrees to 30degrees) the load distribution around the acetabular was evaluated by the computer biomechanical analysis program (Solidworks). Through the obtained load distribution results, the most even and reasonable range of the distribution was selected; therefore the safe range of the acetabular component implantation can be validated from the biomechanics aspect.