求解TSP的离散野马优化算法

针对求解TSP问题,提出一种新的元启发式算法离散野马优化算法(DWHO),应用最小位置匹配值法(MPMV)对求解结果进行离散化解码;为提高算法搜索能力,结合野马放牧、交配、领导者交流与选拔行为,引入变邻域搜索策略,增强了算法的局部搜索能力、加快算法收敛速度。选取TSPLIB标准库33个算例进行实验,并与交换序列人工蜂群算法(ABCSS)、离散蜘蛛猴优化算法(DSMO)两种算法进行比较。实验结果表明,DWHO求得的最优解与ABCSS、DSMO两种算法的最优解相比,最优解改进率最大值分别达到4.52%和3.41%。同时,将离散野马优化算法求解TSP收敛速度与以上两种算法进行比较,其收敛速度具有一定的优势。结果表明离散野马优化算法求解能力和精度具有优势。

智能算法在TSP问题中的应用研究

TSP问题是典型的路径优化问题,具有解决物流路径规划等实际应用意义。为解决TSP问题,文章研究了遗传算法、禁忌搜索算法、蚁群算法和模拟退火算法,以遍历31个省会城市为例,运用MATLAB软件编程仿真。结果表明:蚁群算法优化效果较好,且一致性高,但运行效率不高,可混合运用遗传算法和蚁群算法,以提高运行效率和求解质量。

基于信息熵的改进蚁群算法求解TSP问题

针对蚁群算法求解精度低、易陷入局部最优的缺点,提出一种基于信息熵的自适应改进蚁群算法。通过算法自身特性定义结合熵值对种群参数进行自适应优化;采用分组合作的信息素更新策略,通过较活跃性个体引导整个种群,扩大搜索范围;通过对较优路径的奖励,平衡收敛速度和搜索范围之间的关系;在种群信息熵过低时,加入局部搜索策略,进一步提高算法精度。实验结果表明,相较于蚁群算法,改进算法具有较好的求解精度以及跳出局部最优的能力。

Analysis of the interaction between bolt-reinforced rock and surface support in tunnels based on convergence-confinement method

To investigate the interaction of the bolt-reinforced rock and the surface support,an analytical model of the convergence-confinement type is proposed,considering the sequential installation of the fully grouted rockbolts and the surface support.The rock mass is assumed to be elastic-brittle-plastic material,obeying the linear Mohr-Coulomb criterion or the non-linear Hoek-Brown criterion.According to the strain states of the tunnel wall at bolt and surface support installation and the relative magnitude between the bolt length and the plastic depth during the whole process,six cases are categorized upon solving the problem.Each case is divided into three stages due to the different effects of the active rockbolts and the passive surface support.The fictitious pressure is introduced to quantify the threedimensional(3D)effect of the tunnel face,and thus,the actual physical location along the tunnel axis of the analytical section can be considered.By using the bolt-rock strain compatibility and the rocksurface support displacement compatibility conditions,the solutions of longitudinal tunnel displacement and the reaction pressure of surface support along the tunnel axis are obtained.The proposed analytical solutions are validated by a series of 3D numerical simulations.Extensive parametric studies are conducted to examine the effect of the typical parameters of rockbolts and surface support on the tunnel displacement and the reaction pressure of the surface support under different rock conditions.The results show that the rockbolts are more effective in controlling the tunnel displacement than the surface support,which should be installed as soon as possible with a suitable length.For tunnels excavated in weak rocks or with restricted displacement control requirements,the surface support should also be installed or closed timely with a certain stiffness.The proposed method provides a convenient alternative approach for the optimization of rockbolts and surface support at the preliminary stage of tunnel design.

TSP问题求解在电气设计过程中的应用

通过介绍求解旅行商问题(TSP)的特点,论述采用启发式算法中的最近邻点算法、交叉迂回优化算法的原理和计算方法,提出TSP问题高质量求解的思路,并实现基于AutoLISP编程开发技术在AutoCAD平台上计算机自动生成最优布线功能,可提高工程技术人员的设计效率。

TETSP在隧洞超前地质预报中的应用

笔者介绍了一种隧洞长距离预报地震反射成像系统TETSP,将TETSP与TSP303用于某配水工程隧洞超前地质预报,展示了TETSP观测系统布置方式及数据处理流程,阐述了TETSP在检波器耦合方式及声波干扰压制方面与TSP303的差异,对比了两者原始信号的特性,分析了强溶蚀区岩体对应地震反射异常规律,隧洞实际开挖结果验证了TSP303与TETSP预报的可靠性。结果表明:两种地震反射技术均能较好地探测掌子面前方岩体波阻抗存在显著差异的界面,偏移剖面反射界面集中以及纵横波波速偏低的区域对应岩体质量差。TETSP检波器灵敏度与数据噪比较TSP303更高,但TSP303数据处理软件相对更成熟,故预报准确度更高。

A methodology for damage evaluation of underground tunnels subjected to static loading using numerical modeling

We have proposed a methodology to assess the robustness of underground tunnels against potential failure.This involves developing vulnerability functions for various qualities of rock mass and static loading intensities.To account for these variations,we utilized a Monte Carlo Simulation(MCS)technique coupled with the finite difference code FLAC^(3D),to conduct two thousand seven hundred numerical simulations of a horseshoe tunnel located within a rock mass with different geological strength index system(GSIs)and subjected to different states of static loading.To quantify the severity of damage within the rock mass,we selected one stress-based(brittle shear ratio(BSR))and one strain-based failure criterion(plastic damage index(PDI)).Based on these criteria,we then developed fragility curves.Additionally,we used mathematical approximation techniques to produce vulnerability functions that relate the probabilities of various damage states to loading intensities for different quality classes of blocky rock mass.The results indicated that the fragility curves we obtained could accurately depict the evolution of the inner and outer shell damage around the tunnel.Therefore,we have provided engineers with a tool that can predict levels of damages associated with different failure mechanisms based on variations in rock mass quality and in situ stress state.Our method is a numerically developed,multi-variate approach that can aid engineers in making informed decisions about the robustness of underground tunnels.

Probabilistic analysis of tunnel face seismic stability in layered rock masses using Polynomial Chaos Kriging metamodel

Face stability is an essential issue in tunnel design and construction.Layered rock masses are typical and ubiquitous;uncertainties in rock properties always exist.In view of this,a comprehensive method,which combines the Upper bound Limit analysis of Tunnel face stability,the Polynomial Chaos Kriging,the Monte-Carlo Simulation and Analysis of Covariance method(ULT-PCK-MA),is proposed to investigate the seismic stability of tunnel faces.A two-dimensional analytical model of ULT is developed to evaluate the virtual support force based on the upper bound limit analysis.An efficient probabilistic analysis method PCK-MA based on the adaptive Polynomial Chaos Kriging metamodel is then implemented to investigate the parameter uncertainty effects.Ten input parameters,including geological strength indices,uniaxial compressive strengths and constants for three rock formations,and the horizontal seismic coefficients,are treated as random variables.The effects of these parameter uncertainties on the failure probability and sensitivity indices are discussed.In addition,the effects of weak layer position,the middle layer thickness and quality,the tunnel diameter,the parameters correlation,and the seismic loadings are investigated,respectively.The results show that the layer distributions significantly influence the tunnel face probabilistic stability,particularly when the weak rock is present in the bottom layer.The efficiency of the proposed ULT-PCK-MA is validated,which is expected to facilitate the engineering design and construction.

TSP与瞬变电磁成果三维化在隧道断层含水预报中的应用

隧道开挖过程中经常遇到断层、节理发育密集带等地质异常段落,并且断层带易形成地下水的运移通道。提前查清此类地质问题,可以最大程度降低施工过程中的安全风险。隧道超前地质预报为前期勘察工作的延续,在施工期间通过物探、钻探等手段可以有效判释隧道开挖前方一定距离的地质情况。首次将TSP法与瞬变电磁成果三维化相结合,应用于某在建铁路隧道的超前预报工作中。根据前期勘察资料,结合TSP探测成果确定断层发育段落,然后在掌子面附近实施多角度瞬变电磁探测;基于Voxler软件实现瞬变电磁成果的三维化展示,通过三维成果判断断层的含水性,综合分析瞬变电磁低阻异常三维分布特征及TSP波速异常段落,圈定出断层破碎范围及富水性空间分布情况,并对富水区域提前进行钻探泄水。通过实际开挖验证分析,结果表明:2种方法相结合可以准确探测隧道开挖前方的围岩完整性及含水情况,有效降低施工风险,为隧道开挖方案优化提供有效资料。

TSP/OSCE模式联合微课教学在临床护理实践教学中的应用价值

探究在临床护理实践教学中,采用教师模拟标准化病人(TSP)/临床医师技能培训考试系统(OSCE)联合微课模式的教学效果。方法 研究开展时间为2022年1月—2023年12月,对象为所选取240名医院实习护生,其中2022年的120名护生接受传统培训模式,作为对照组;2023年的120护生接受TSP/OSCE模式联合微课的教学模式,作为观察组;于实习期间、实习结束后考察护生的护理操作技能及理论考试平均成绩,利用改良版迷你临床演练评估量表(Mini-CEX)测评护生的临床实践能力,评估评判性思维能力,通过问卷调查形式评价护生对教学满意度。结果 培训后,2组护生护理操作技能、理论考试平均成绩均升高,且观察组升高幅度更大(P<0.05);与对照组做对比,观察组培训后的Mini-CEX(临床评估、查体操作、健康教育、临床判断、组织效能、人文关怀)评分高(P<0.05);实习后2组的CTDI-CV评分均提高,且观察组改变更明显(P<0.05);教学满意度对比,观察组护生明显高(P<0.05)。结论 临床护理实践教学中实行TSP/OSCE模式联合微课教学模式,有利于提高实习生的护理操作技能水平及理论知识掌握程度,并发展其临床实践能力,取得满意的教学效果。

Stability analysis of tunnel face reinforced with face bolts

Face bolting has been widely utilized to enhance the stability of tunnel face,particularly in soft soil tunnels.However,the influence of bolt reinforcement and its layout on tunnel face stability has not been systematically studied.Based on the theory of linear elastic mechanics,this study delved into the specific mechanisms of bolt reinforcement on the tunnel face in both horizontal and vertical dimensions.It also identified the primary failure types of bolts.Additionally,a design approach for tunnel face bolts that incorporates spatial layout was established using the limit equilibrium method to enhance the conventional wedge-prism model.The proposed model was subsequently validated through various means,and the specific influence of relevant bolt design parameters on tunnel face stability was analyzed.Furthermore,design principles for tunnel face bolts under different geological conditions were presented.The findings indicate that bolt failure can be categorized into three stages:tensile failure,pullout failure,and comprehensive failure.Increasing cohesion,internal friction angle,bolt density,and overlap length can effectively enhance tunnel face stability.Due to significant variations in stratum conditions,tailored design approaches based on specific failure stages are necessary for bolt design.

Ground settlement and tunnel response due to twin-curved shield tunnelling in soft ground with small clear distance

Twin curved tunnels are often encountered in shield tunnelling,where significant complexities in densely exploited underground space are observed.In this study,the ground settlement and tunnel deformation due to twin-curved shield tunnelling in soft ground were investigated using numerical simulation and field monitoring.Different curvature radii of twin curved tunnels and subsequent effects of tunnel construction were considered to reveal the tunnelling effect on ground surface settlement and tunnel deformation.The results show that the settlement trough yields one offset towards inside of curved shield tunnelling.The location of settlement trough and maximum settlement were affected by curvature radius but except for the shape and width of settlement trough.Adjacent parallel twin-curved shield tunnelling could increase the offset of existing settlement trough and maximum settlement.Then,an empirical prediction of surface settlement trough due to twin-curved shield tunnelling with same tunnel diameters in soft clay was proposed,which was applicable to curvature radius less than 800 m.Finally,a minimum radius of 600 m of curvature tunnel was proposed in terms of allowable convergence deformation of tunnel.The result could provide guidance on safety evaluation for twin curved shield tunnelling construction.

TSP结合TEM在风险围岩隧道超前地质预报中的应用

为了排查隧道施工过程中潜在的地质风险、指导隧道安全开挖掘进,针对某高速铁路风险围岩隧道浅埋段和可溶岩段,利用TSP和TEM两种方法开展超前地质预报。TSP预报可对掌子面前方围岩状况进行远距离宏观预测,能划定断层、破碎带、地下水等不良地质体的位置和大致规模;TEM预报可在掌子面附近开展多角度、多方位测量,能判定开挖面前方一定空间范围内不良围岩特征,特别是地下水、岩溶的分布及规模。研究表明,TSP震波对应的负反射和低速异常突出反映围岩岩性变化及岩体破碎程度,依据纵、横波速起伏特征可大致判定地下水发育情况;TEM低阻异常直观体现围岩富水状态,并可推测岩溶发育及分布状况,视电阻率阻值变化密集区对应了围岩岩体破碎。研究结果表明,采用两种或多种方法结合开展综合预报,可提升预报结论的准确度和可靠度,TSP结合TEM成功预报的应用实例可为类似风险围岩隧道的超前地质预报提供参考和借鉴。

Magnetic Switching Dynamics and Tunnel Magnetoresistance Effect Based on Spin-Splitting Noncollinear Antiferromagnet Mn_(3)Pt

In comparison to ferromagnets,antiferromagnets are believed to have superior advantages for applications in next-generation magnetic storage devices,including fast spin dynamics,vanishing stray fields and robust against external magnetic field,etc.However,unlike ferromagnetic orders,which could be detected through tunneling magnetoresistance effect in magnetic tunnel junctions,the antiferromagnetic order(i.e.,Néel vector)cannot be effectively detected by the similar mechanism due to the spin degeneracy of conventional antiferromagnets.Recently discovered spin-splitting noncollinear antiferromagnets,such as Mn_(3)Pt with momentum-dependent spin polarization due to their special magnetic space group,make it possible to achieve remarkable tunneling magnetoresistance effects in noncollinear antiferromagnetic tunnel junctions.Through first-principles calculations,we demonstrate that the tunneling magnetoresistance ratio can reach more than 800% in Mn_(3)Pt/perovskite oxides/Mn_(3)Pt antiferromagnetic tunnel junctions.We also reveal the switching dynamics of Mn_(3)Pt thin film under magnetic fields using atomistic spin dynamic simulation.Our study provides a reliable method for detecting Néel vector of noncollinear antiferromagnets through the tunnel magnetoresistance effect and may pave its way for potential applications in antiferromagnetic memory devices.

Carpal Tunnel Syndrome: A Marker for Amyloidosis

Introduction: Amyloidosis are systemic conditions and carpal tunnel syndrome (CTS) precedes the principal systemic complications and can be used as an early marker. Our objective was to determine the frequency of amyloid deposition in idiopathic CTS and its systemic impact. Methods: We retrospectively evaluated patients with CTS between September 2019 to January 2020. Samples from the anterior carpal ligament were pathologically evaluated and amyloid deposition was confirmed by apple-green birefringence on polarized light using Congo red stain. When amyloid was detected we performed genetic testing for transthyretin variants (ATTRv), immunofixation electrophoresis in serum and urine for light chains and multidisciplinary evaluation. Results: Thirty consecutive patients were included, 19 women, 11 men, mean age 70 years old (range 42 - 89 years). We identified 3 patients (10%) with amyloid deposits (mean age: 78.6 years, 2 men, 1 woman). Genetic testing for ATTRv and light chains studies were negative. During follow-up: The first patient required aortic valve replacement. The second patient developed progressive cardiac failure with syncopal episodes, atrioventricular block and atrial fibrillation and required a pacemaker and anticoagulation. The third patient had unexplained chronic edemas. The cardiac evaluation in all 3 patients revealed left ventricular hypertrophy and myocardial uptake (Perugini Score > 2) in their nuclear bone scintigraphies with technetium pyrophosphate. Two patients were treated with tafamidis and one patient died due to refractory cardiac insufficiency. Discussion: Our findings underline the importance of investigating amyloidosis in idiopathic CTS. The identification of deposits allows early diagnosis of cardiac amyloidosis leading to timely intervention and treatment.

On Klein tunneling of low-frequency elastic waves in hexagonal topological plates

Incident particles in the Klein tunnel phenomenon in quantum mechanics can pass a very high potential barrier.Introducing the concept of tunneling into the analysis of phononic crystals can broaden the application prospects.In this study,the structure of the unit cell is designed,and the low frequency(<1 k Hz)valley locked waveguide is realized through the creation of a phononic crystal plate with a topological phase transition interface.The defect immunity of the topological waveguide is verified,that is,the wave can propagate along the original path in the cases of impurities and disorder.Then,the tunneling phenomenon is introduced into the topological valley-locked waveguide to analyze the wave propagation,and its potential applications(such as signal separators and logic gates)are further explored by designing phononic crystal plates.This research has broad application prospects in information processing and vibration control,and potential applications in other directions are also worth exploring.

Mechanism of high-preload support based on the NPR anchor cable in layered soft rock tunnels

The control of large deformation problems in layered soft rock tunnels needs to solve urgently.The roof problem is particularly severe among the deformation issues in tunnels.This study first analyzes the asymmetric deformation modes in layered soft rock tunnels with large deformations.Subsequently,we construct a mechanical model under ideal conditions for controlling the roof of layered soft rock tunnels through high preload with the support of NPR anchor cables.The prominent roles of long and short NPR anchor cables in the support system are also analyzed.The results indicate the significance of high preload in controlling the roof of layered soft rock tunnels.The short NPR anchor cables effectively improve the integrity of the stratified soft rock layers,while the long NPR anchor cables effectively mobilize the self-bearing capacity of deep-stable rock layers.Finally,the high-preload support method with NPR anchor cables is validated to have a good effect on controlling large deformations in layered soft rock tunnels through field monitoring data.

油气田瓦斯隧道TSP图像智能识别研究

在传统的非煤系油气田区瓦斯隧道超前地质预报中,由于TSP(tunnel seismic prediction,隧道地震勘探)图像的复杂性,解译的效率低且结果准确度不高,利用智能识别技术可以有效解决相应问题。依托某油气田区高瓦斯隧道工程,结合深度学习理论,借助Python(计算机编程语言)平台建立智能识别预测模型,通过该模型识别TSP图像中的P波,判断不良地质情况。结果表明:建立的智能识别模型可有效识别P波,判断围岩裂缝情况,减小人工识别的误差,实现油气田区高瓦斯隧道的地质精准探测与瓦斯防治。

TSP和地质雷达在岩溶隧洞工程超前地质预报中的应用

为排查岩溶隧洞施工中潜在的地质风险、指导隧洞安全施工。利用TSP和地质雷达两种方法开展超前地质预报。TSP法能够对隧洞掌子面前方100~150 m的距离展开预报,其特性是预报距离长、快速分析围岩情况、预报精度无法控制;地质雷达法可实现隧洞短距离精准预测,能够有效弥补TSP法在短距离方面的不足。研究表明:采用二者相结合的方法开展综合预报,可提升在隧洞中对岩溶构造预报结论的准确度。TSP法结合地质雷达法成功预报的应用实例可为类似风险围岩隧洞的超前地质预报提供参考和借鉴。

TSP法超前地质预报技术在滇中引水断层的应用研究

通过当前借助隧道超前地质预报技术对隧洞中断层判定在业界已取得了一定的成果,但实际在引水隧道工程中往往也面临着地质条件复杂多变的断层,而能准确探测出这些断层对于保障引水隧洞的安全开挖是一项急需迫切解决的研究。此次研究采用TSP法进行,分析了在断层中对TSP的数据采集主要因素,并对滇中引水工程中两处隧道断层的地质情况进行探测,通过资料处理及对比分析,最终与开挖结果进行验证,取得了较好的预报效果,为引水隧洞断层段的预报分析提供了较好的参考。