RRT Autonomous Detection Algorithm Based on Multiple Pilot Point Bias Strategy and Karto SLAM Algorithm

A Rapid-exploration Random Tree(RRT)autonomous detection algorithm based on the multi-guide-node deflection strategy and Karto Simultaneous Localization and Mapping(SLAM)algorithm was proposed to solve the problems of low efficiency of detecting frontier boundary points and drift distortion in the process of map building in the traditional RRT algorithm in the autonomous detection strategy of mobile robot.Firstly,an RRT global frontier boundary point detection algorithm based on the multi-guide-node deflection strategy was put forward,which introduces the reference value of guide nodes’deflection probability into the random sampling function so that the global search tree can detect frontier boundary points towards the guide nodes according to random probability.After that,a new autonomous detection algorithm for mobile robots was proposed by combining the graph optimization-based Karto SLAM algorithm with the previously improved RRT algorithm.The algorithm simulation platform based on the Gazebo platform was built.The simulation results show that compared with the traditional RRT algorithm,the proposed RRT autonomous detection algorithm can effectively reduce the time of autonomous detection,plan the length of detection trajectory under the condition of high average detection coverage,and complete the task of autonomous detection mapping more efficiently.Finally,with the help of the ROS-based mobile robot experimental platform,the performance of the proposed algorithm was verified in the real environment of different obstacles.The experimental results show that in the actual environment of simple and complex obstacles,the proposed RRT autonomous detection algorithm was superior to the traditional RRT autonomous detection algorithm in the time of detection,length of detection trajectory,and average coverage,thus improving the efficiency and accuracy of autonomous detection.

Clinical Efficacy of Plasma Exchange Therapy for Treatment of Autoimmune Bullous Skin Disease

Objective:To investigate the clinical efficacy of plasma exchange therapy for autoimmune bullous skin disease.Methods:Fifty patients with autoimmune bullous skin disease enrolled in our hospital from January 2018 to January 2019 were selected.The patients were grouped by treatment method:25 control group patients were given conventional hormone therapy,while 25 experimental group patients were treated with plasma exchange therapy;efficacy of treatment was compared between two groups of patients.Results:Initial dose,maximum dose,and cumulative dose of glucocorticoids were lower in experimental group patients than those in control group(P<0.05).Incidence of complication was lower in experimental group patients than those in control group(P<0.05);the difference was significant.There was no significant difference in short-term efficacy between the two groups(P>0.05).Conclusion:The application of plasma exchange therapy was effective for treatment of autoimmune bullous skin disease.It could reduce dosage amount of glucocorticoids and incidence of complications;its application can be promoted.

Expression of MMP-2 and MMP-13 in Bullous Pemphigoid

Objective:To investigate the expression and significance of matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-13(MMP-13)in bullous pemphigoid(BP)skin lesions.Methods:Immunohistochemical SP method was used to detect the expression of MMP-2 and MMP-13 in 32 BP skin lesions,and compared with 15 normal skin tissues.Results:The expression of MMP-2 in the case group was significantly increased(38.56±10.06)compared to the normal control group(21.20±5.98);the expression of MMP-13 in the case group was significantly augmented(18.62±5.90)compared to the normal control group(11.47±8.484).The expressions of MMP-2 and MMP-13 in the skin lesions of patients with bullous pemphigoid were statistically different from those of normal people(both P<0.05).Compared with the expression of MMP-2 and MMP-13 in bullous pemphigoid,the expression of MMP-2 and MMP-13 was moderately correlated(correlation coefficient was 0.523).Conclusion:The expression of MMP-2 and MMP-13 is significantly increased in bullous pemphigoid skin lesions,suggesting that they may play an important role in the pathogenesis of BP.There is a certain correlation between the expression of MMP-2 and MMP-13,suggesting that the high expression of MMP-13 may play a role in the mechanism that further leads to the high expression of MMP-2.

Improved Double Deep Q Network Algorithm Based on Average Q-Value Estimation and Reward Redistribution for Robot Path Planning

By integrating deep neural networks with reinforcement learning,the Double Deep Q Network(DDQN)algorithm overcomes the limitations of Q-learning in handling continuous spaces and is widely applied in the path planning of mobile robots.However,the traditional DDQN algorithm suffers from sparse rewards and inefficient utilization of high-quality data.Targeting those problems,an improved DDQN algorithm based on average Q-value estimation and reward redistribution was proposed.First,to enhance the precision of the target Q-value,the average of multiple previously learned Q-values from the target Q network is used to replace the single Q-value from the current target Q network.Next,a reward redistribution mechanism is designed to overcome the sparse reward problem by adjusting the final reward of each action using the round reward from trajectory information.Additionally,a reward-prioritized experience selection method is introduced,which ranks experience samples according to reward values to ensure frequent utilization of high-quality data.Finally,simulation experiments are conducted to verify the effectiveness of the proposed algorithm in fixed-position scenario and random environments.The experimental results show that compared to the traditional DDQN algorithm,the proposed algorithm achieves shorter average running time,higher average return and fewer average steps.The performance of the proposed algorithm is improved by 11.43%in the fixed scenario and 8.33%in random environments.It not only plans economic and safe paths but also significantly improves efficiency and generalization in path planning,making it suitable for widespread application in autonomous navigation and industrial automation.

中国香港马鞍山基于三种被动式采集方法采集的甲虫标本数据集

本文提供了2017年5月27日至6月17日通过3种被动采集方法(飞行阻隔器法、马氏网法和埋罐法)在中国香港马鞍山郊野公园样地采集到的甲虫标本信息,并生成了1个数据集。该样地包含13个样点,每个样点的采集设备由1个飞行阻隔器、1个马氏网和10个埋罐组成,共收集到45科325种3,011头甲虫。该数据集由5个部分组成:(1)每个样点采集的甲虫原始照片(198张);(2)标注鉴定结果的甲虫照片;(3)甲虫标本数量统计表;(4)形态物种鉴定图;(5)经度、纬度、温度、降水量和海拔高度信息表。该数据集通过3种被动采集方式采集甲虫,为昆虫的采集提供了有效可行的方法。该数据集可以定量评估香港地区的甲虫多样性,从而丰富相关的研究。

Evaluating the Mechanism of Tropical Expansion Using Idealized Numerical Experiments

A wide range of evidence reveals that the tropical belt is expanding.Several mechanisms have been proposed to contribute to this expansion,some of which even contradict each other.The study of Yang et al.suggests that the poleward advancing mid-latitude meridional temperature gradient(MTG),originating from enhanced subtropical ocean warming,plays a leading role in driving tropical expansion.However,the abrupt4xCO_(2) experiment indicates that tropical expansion occurs at a faster rate than is indicated by changes related to ocean temperature rise.The idealized amip4K experiment illustrates that without introducing any ocean warming pattern,uniform ocean surface warming also drives tropical expansion.The results based on these idealized experiments seem to contradict the hypothesis proposed by Yang et al.In this study,we revisit these 2 experiments and show that both experiments actually support the hypothesis that MTG migration is driving tropical expansion.More specifically,in the abrupt4xCO_(2) experiment,although the rate of ocean warming is relatively slow,the poleward shift of the MTG is as rapid as tropical expansion.In the amip4K experiment,although ocean surface warming is uniform,the heating effect of the ocean on the atmosphere is nonuniform because of the nonlinear relationship between temperature,evaporation,and thermal radiation.The nonuniform oceanic heating to the atmosphere introduces a poleward shift of the MTG within the upper troposphere and drives a shift in the jet streams.By conducting an additional idealized experiment in which tropical expansion occurs under both a migrating MTG and a cooling climate,we argue that the migration of the MTG,rather than global warming,is the key mechanism in driving tropical expansion.