基于混沌天牛群算法优化的神经网络分类模型

针对传统BP神经网络受初始权阈值影响大且易陷入局部极值,标准天牛须搜索算法局部搜索能力差、寻优精度低等问题,提出一种自适应步长因子的混沌天牛群算法用于优化BP神经网络分类模型。通过增加天牛种群,引入自适应步长更新策略优化天牛须搜索算法的局部搜索能力,使其跳出局部最优,提高算法的计算精度;利用Logisitic混沌映射产生新个体,替换性能较差的个体,增强全局搜索效果。为了改善BP神经网络对非均衡数据集中少数类的分类效果,采用SMOTE算法处理非均衡数据集。将改进的天牛须搜索算法用于优化BP神经网络中的初始权值和阈值,建立IBAS-BPNN（Improved Beetle Antennae Search and Back Propagation Neural Network）分类模型,提高BP神经网络分类模型的准确率。为验证分类模型的性能,将改进的BP神经网络分类模型与其他六种典型的分类算法进行比较,实验结果表明IBAS-BPNN分类模型的平均分类正确率高于其他算法。改进的混沌天牛群算法泛化能力强,鲁棒性好,具有一定的优越性。     

基于改进天牛须算法优化的确定性跳跃循环状态网络的交通流预测

为了提高短时交通流速度预测的精度,提出一种基于改进天牛须算法优化的确定性跳跃循环状态网络的交通流预测模型.首先对交通流速度序列进行浑沌性分析,重构序列的相空间,将对交通流速度序列的研究映射到其所在的相空间中进行;然后引入变步长因子和模拟退火技术对天牛须算法(beetle antennae search,BAS)进行改进,并以改进算法优化确定性跳跃循环状态网络(cycle reservoir with regular jumps,CRJ)的参数构建预测模型;最后通过实例对比分析模型的有效性.结果表明:通过相空间重构对交通流速度序列处理,能够挖掘序列内部的动态特性,使之更加适用于网络的建模;所提模型的预测结果同对比模型相比,平均绝对百分比误差下降了1.05％ ～6.04％,有效地提高了短时交通流速度的预测精度.     

基于天牛须种群算法的整周模糊度解算算法

如何快速、准确的固定整周模糊度是载波相位测量中的一个关键问题。为了提高整周模糊度搜索速率,本文提出了一种基于天牛须种群算法(Beetle Antennae Colony Search, BACS)的整周模糊度解算算法。通过与BAS算法、BAS-Nadam算法、LAMBDA算法以及MLAMBDA算法进行解算速率、稳定性的对比实验,在三维模糊度解算时,BACS算法在与LAMBDA和MLAMBDA算法解算成功率相当的情况下,能利用更少的时间搜索到模糊度最优解。为了验证BACS算法在高维模糊度解算以及工程解算情况下是否适用,进行了高维模糊度解算的实验以及单频单GPS系统下BACS算法的应用实验。分析及实验表明,BACS算法能很好保证高维模糊度解算的实时性和鲁棒性,对于12维模糊度解算,平均解算时间0.068秒,解算成功率为92%,对于低维模糊度解算,解算速率更快,解算成功率更高。在单频单GPS系统工程解算中,x,y,z方向定位精度分别为±0.008米,±0.01米,±0.01米,能达到厘米级精度定位。     

用放射性~(14)C测定比较两种芫菁的血淋巴含量

用C~(14)菊粉通过稀释法测定了两种芫菁成虫的血淋巴体积。比较这两种不同属的芫菁发现,虽然它们在平均干重上差异显著,但平均血淋巴体积,血淋巴重量的百分含量上的差异不显著。其中原野豆芫菁和佛罗里达绿芫菁血淋巴重量的百分含量分别为27.8和28.4。     

Borneodessus zetteli,new genus and new species,notes on biogeography and a checklist of Dytiscidae from Borneo (Insecta: Coleoptera: Dytiscidae)

A new genus of Dytiscidae, Borneodessus gen. n., is described for Borneodessus zetteli zetteli sp. n. (Sabah, East Malaysia) and Borneodessus zetteli kalimantanensis ssp. n. (East Kalimantan, Indonesia). The new genus belongs to the tribe Bidessini because of the presence of two-segmented parameres of the aedeagus. A modified male clypeus is an apomorphy for Borneodessus zetteli. The species habitually resembles some species of Africodytes Biström, 1988 (Africa), Amarodytes Régimbart, 1900 (South America), and some Clypeodytes Régimbart, 1894 (Old World tropics). However, a sister group relation or closer affinities to any of the genera of Bidessini could not be established. Borneodessus is so far the first genus of Dytiscidae which is endemic to Borneo, but we suggest a certain probability of its occurrence in other Sundaic areas. The species is a rheobiont, being collected from forest streams. We briefly address biogeographical aspects and provide a checklist of Bornean Dytiscidae, indicating the currently known degree of endemism.     

Satellite DNA from the beetleTenebrio molitor

Summary A 142 base-pair satellite DNA from the mealworm beetle,Tenebrio molitor, has been cloned and sequenced. The satellite DNA is revealed by making a restriction digest of genomic DNA with either EcoRI or Hinfl, and constitutes approximately 49% of the genomic DNA. The presence of huge amounts of satellite DNA correlates well with the prominent blocks of heterochromatin found in tenebrionid beetles. A similar restriction digest ofXanthogaleruca luteola genomic DNA does not release a prominent satellite component.     

Morphology and contact mechanics influence adhesive characteristics of Dung Beetle’s bristle and Gecko’s setae

Geckos(Gekko gecko)use their hairy setae to adhere on various solid surfaces and dung beetles(Copris ochus Motschulsky)use their hairy bristles to anti-adhere in sticky environments.We study why two hairy systems express a conflict in functions by using SEM,histological approaches and functional experiments.Adhesion models and various parameters were collected and analyzed.Based on the morphological data and functional experimental results carried out by natural and denatured gecko setae and beetle bristles,we first demonstrated that the stiffness along the hair is 1000 to 30000 times that perpendicular to the hair.This stiffness difference is the key factor leading to the two hairy systems' functional differences.Slope of gecko setae reduces contact stiffness,increases contact points and real contact area that results in amazing adhesive abilities.On the other hand,stiff bristles in a beetle have higher contact stiffness,which reduces the real contact area and decreases the adhesion between two contact surfaces.Deformation of gecko setae destroys the hierarchical structure,increases the contact stiffness and results in a decrease of adhesion forces.Similarly,deformation of beetle bristles destroys the erect structure of the hair,interconnects the separated bristles and thus decreases the anti-adhesive functions.These observations inspire us in designing anti-adhesive and adhesive biomimetic systems     

Mechanical properties of a novel,lightweight structure inspired by beetle’s elytra

A new kind of bio-inspired, lightweight struc- ture was designed and built from carbon fibre prepreg based on the cross-sectional microstructure of a beetle＇s elytra. The compression strength and failure process of the resulting structure was analysed using the finite element method; while at the same time, a quasi-static compression experiment was performed using an electronic universal testing machine to verify the effectiveness and accuracy of this finite element method. This bioinspired structure was compared against a conventional honeycomb structure using FEM, revealing that for a given porosity and load parallel to the axis of the core tubes the respective compressive and specific compressive strengths of the bio- inspired structure are much higher at 84.3 MPa and 194.7 MPa/（g cm^-3）; thus demonstrating that this bioinspired structure has superior compressive capability.