Tightly-coupled model for INS/WSN integrated navigation based on Kalman filter

Aiming at the problem of poor observability of measurement information in the loosely-coupled integration of the inertial navigation system （INS） and the wireless sensor network （WSN）, this paper presents a tightly-coupled integration based on the Kalman filter （KF）. When the WSN is available, the difference between the distances from the blind node（BN） to the reference nodes （RNs） measured by the INS and those measured by the WSN are used as measurement information for the KF due to its better observability and independence, which can effectively improve the accuracy of the KF. Simulations show that the proposed approach reduces the mean error of the position by about 50% compared with loosely-coupled integration, while the mean error of the velocity is a little higher than that of loosely-coupled integration.

Wave Hindcast for the Neighbouring Seas of Korea Based on Loosely Coupled Wave-Tide-Surge Model

A hindcast simulation of 75 typhoons and winter monsoons which affected the coastal areas of Korean Peninsula is performed by use of a third generation ocean wave prediction model, WAM-cycle 4 model, loosely coupled with a com-bined tide and surge model. Typhoon wind fields are derived from the planetary marine boundary layer model for effective neutral winds embedding the vortical storm wind from the parameterized Rankin vortex type model in the limited areas of the overall modeled region. The hindcasted results illustrate that significant wave heights (SWH) considering the wave-tide-surge coupled process are significantly different from the results via the decoupled case especially in the region of the estuaries of the Changjiang Estuary, The Hangzhou Bay, and the southwestern tip of Korean Peninsula. This extensive model simulation is the first attempt to investigate the strong wave-tide-surge interaction for the shallow depth area along the coasts of the Yellow Sea and the East China Sea Continental shelf.

A Loosely Coupled Control Architecture Based on Agent and CORBA for Multiple Robots

With the rapid development of information technology, adopting advanced distributed computing technology to construct robot control system is becoming an effective approach gradually. This paper proposes a distributed loosely coupled software architecture based on Agent and CORBA to control multiple robots. This model provides the robot user with agent control units at the semantic level and CORBA provides function interfaces to agent at the syntax level, which shows a good adaptability, flexibility and transparence.

Loose Body in the Knee Joint: A Case Report

Background: Loose bodies (LBs) within the knee joint are commonly encountered during clinical practice and are frequently observed during knee arthroscopy. The primary treatment involves the removal of loose bodies;however, their complete eradication is often challenging and may not address underlying diseases, leading to persistent symptoms and the risk of new loose body formation. Aim: This case report aims to present the findings and surgical management of a 52-year-old male with an unusually large osseous loose body in the knee joint and associated pathologies. Case Presentation: The patient, a 52-year-old male, experienced recurrent episodes of severe, sudden, and painful locking of the knee joint, leading to difficulties moving. A plain MRI study was conducted to evaluate the condition of the knee joint, which revealed various degenerative changes and the presence of a loose body. Subsequently, an arthroscopic examination was performed under general anesthesia, uncovering the presence of an abnormally large loose body, as well as other pathologies including chondropathy, meniscal degeneration, and Baker’s cyst. Conclusion: Loose bodies (LBs) in the knee joint pose significant challenges and may lead to debilitating symptoms. Timely diagnosis and appropriate surgical intervention are crucial for symptom relief and the prevention of further joint damage as arthroscopic excision. Comprehensive imaging has a vital role in guiding treatment decisions and optimizing patient outcomes. In this case, the removal of the loose body improved patient outcomes and helped prevent potential joint complications.

Stability analysis of loose accumulation slopes under rainfall:case study of a high‑speed railway in Southwest China

The high and steep slopes along a high-speed railway in the mountainous area of Southwest China are mostly composed of loose accumulations of debris with large internal pores and poor stability,which can easily induce adverse geological disasters under rainfall conditions.To ensure the smooth construction of the high-speed railway and the subsequent safe operation,it is necessary to master the stability evolution process of the loose accumulation slope under rainfall.This article simulates rainfall using the finite element analysis software’s hydromechanical coupling module.The slope stability under various rainfall situations is calculated and analysed based on the strength reduction method.To validate the simulation results,a field monitoring system is established to study the deformation characteristics of the slope under rainfall.The results show that rainfall duration is the key factor affecting slope stability.Given a constant amount of rainfall,the stability of the slope decreases with increasing duration of rainfall.Moreover,when the amount and duration of rainfall are constant,continuous rainfall has a greater impact on slope stability than intermittent rainfall.The setting of the field retaining structures has a significant role in improving slope stability.The field monitoring data show that the slope is in the initial deformation stage and has good stability,which verifies the rationality of the numerical simulation method.The research results can provide some references for understanding the influence of rainfall on the stability of loose accumulation slopes along high-speed railways and establishing a monitoring system.

Improved mesh-free SPH approach for loose top coal caving modeling

This study presents an innovative model in computational geotechnical engineering by improving the Smoothed Particle Hydrodynamics(SPH)method for simulating loose particle dynamics in coal caving processes.The improved model integrates an elastic-perfectly plastic constitutive model with the Drucker-Prager yield criterion and includes several improvements aimed at boosting accuracy,stability,and efficiency.These improvements include gravity loading coupled with particle damping,first-order stress field smoothing,and kernel gradient correction.A series of numerical experiments validates the effectiveness of the improved SPH model,demonstrating its capability to predict large deformations and track the evolution of the coal-rock interface in coal caving processes.Furthermore,the study analyzes the model's sensitivity to material parameters such as the angle of friction and material density,which aids in configuring the model for distinct coal mining situations.Results show that the non-cohesive elastic-perfectly plastic constitutive model can effectively simulate the flow behavior of granular particles,and the landslide simulation results are in good agreement with the experiments.The improved SPH algorithm with stress smoothing technique solves the problem of numerical noise,and the“double peak”stress distribution around the coal outlet is identified.The established SPH model offers an effective tool for understanding dynamics behaviors of loose top coal.Significantly,the model requires only five material parameters,which can be identified through standard experiments,avoiding the typically arduous process of parameter selection or calibration commonly existing in Discrete Element Method simulations.

A new algorithm of global tightly-coupled transient heat transfer based on quasi-steady flow to the conjugate heat transfer problem

Concerning the specific demand on solving the long-term conjugate heat transfer （CHT） problem, a new algorithm of the global tightly-coupled transient heat transfer based on the quasi-steady flow field is further put forward. Compared to the traditional loosely-coupled algorithm, the computational efficiency is further improved with the greatly reduced update frequency of the flow field, and moreover the update step of the flow field can be reasonably determined by using the engineering empirical formula of the Nusselt number based on the changes of the inlet and outlet boundary conditions. Taking a duct heated by inner forced air flow heating process as an example, the comparing results to the tightly-coupled transient calculation by Fluent software shows that the new algorithm can significantly improve the computational efficiency with a reasonable accuracy on the transient temperature distribution, such as the computing time is reduced to 22,8% and 40% while the duct wall temperature deviation are 7% and 5% respectively using two flow update time step of 100 s and 50 s on the variable inlet-flow rate conditions.

Uses of Quenchers Methodology in the Management of Loose Smut Disease(Ustilago nuda)of Barley(Hordeum vulgare)through Seed Dressing and SRAP Markers Associated with Resistance in Some Egyptian Barley Genotypes

Barley production has been constrained by various factors,of which loose smut(Ustilago nuda)is the main biotic factor.Molecular and agronomical screening analyses were evaluated to study the similarity levels and marker assisted selection associated with resistance to loose smut among eight barley genotypes using sequence-related amplified polymorphism(SRAP).Agronomical parameters during two consecutive 2021 and 2022 seasons were studied to identify their reaction to loose smut.The results exhibited significant differences among all studied genotypes for all studied characters,and the highest mean values for all studied traits were detected in Giza 136 and Giza 137.Six SRAP selected primer combinations were amplified and gave 56 total fragments,where primer combination me1+em3 gave the highest polymorphism(100%)and the highest polymorphic information content of PIC was 0.96.The dendrogram of SRAP markers had clustered all studied genotypes into two main clusters.Cluster I includes all the resistance genotypes Giza 136,Giza 137,Giza 123,Giza 132,Giza 138 and Line 2.However,cluster II includes only Line 1 and Line 3 as susceptible genotypes.Thus,SRAP marker could be efficiently used to assess genetic variation among barley genotypes and useful for barley germplasm management in terms of biodiversity protection and design of new crosses for loose smut breeding programs,and seed dressings are commonly used to prevent infected seed from developing smutted heads.Some effective seed dressings include Triticonazole,Black seed oil and gamma rays 150,200,250 Gy.The tested fungicide was highly effective in controlling the disease and gave more than 99%disease control with high grain yield while nature product as black seed oil and utilizing radiation gamma ray 250 GY was the most effective.Utilizing radiation and natural ingredients to manage loose barley smut is economical.

基于椭球体理论粘性土层隧道松动土压力研究

准确预测隧道上覆土压力对隧道支护结构的设计和开挖方式的选择具有重要意义.Terzaghi土拱效应理论是基于滑移面为垂直面这一假设建立的,但实际情况中由于受到地层扰动的影响,滑移面呈现出曲面形状.为研究粘性土层滑移面演化规律及松动土压力分布规律,首先,采用数值模拟软件计算隧道开挖后上覆土压力,并分析粘性土下土拱效应演化规律;其次,根据隧道拱的破裂面规律,从椭球体理论出发,并考虑粘性土层中主应力轨迹线为圆弧对Terzaghi松动土压力进行修正;最后,将理论计算结果与已有的实验数据及有限元计算结果进行对比,验证了本文公式在粘性土层中应用的合理性,并进一步研究了地层损失率S_(L)、内摩擦角φ、黏聚力c与隧道松动土压力的关系.研究结果表明:相较于无粘性土层,粘性土层滑移面的破坏程度更大,但两者滑移面变化规律基本一致.当隧道埋深比H/D≤1.5,出现三角形状滑移面,随着隧道埋深的持续增大,地层逐渐向内形成剪切面,最终形成塔形状滑移面;松动区内部侧土压力系数K_(v)在任意位置处都是不同的,且在Terzaghi建议的1.0上下浮动.对比浅埋隧道,深埋隧道的松动土压力受地层损失率S_(L)的影响更大.粘性土层隧道上覆荷载呈“半葫芦形”分布,表现为从拱顶附近向拱腰逐渐减小;同时,在内摩擦角φ较小的地层中,提高黏聚力c有利于减小隧道上覆土压力.

指轮式玉米株间除草装置的设计与仿真

针对玉米田间杂草需求,设计一种新型的指轮式玉米株间除草装置。该装置由除草盘与除草指组件构成,能对株间杂草及土壤进行同步剪切和翻耕,搭配行间除草铲刀协同完成玉米除草作业,确保了作业的高效性。仿真试验结果表明,当除草机前进速度范围为0.9—2.1m/s,除草轮指数为12—20个,除草指轮入土角度为55—75°时,除草效果最好。

不同速率下松散颗粒直剪试验声发射特征

松散颗粒堆积体在自然界和工业生产活动中广泛存在.为研究其力学性质和失稳过程,基于声发射(acoustic emission,AE)技术探究松散体剪切过程的声学特征演化规律.首先,分析松散颗粒在不同剪切速率下的AE特征参数;其次,结合加载过程的力学特征对AE演化阶段进行划分;最后,利用频谱变化和小波包能量占比进一步验证松散颗粒剪切破坏的AE演化规律.结果表明:能量和振铃计数随剪切过程而逐步增大,且剪切速率越快,能量和振铃计数增幅越大;小事件数与大事件数的比值(b值)在剪切过程中逐渐降低,剪切速率越大,b值越小;不同速率下的颗粒抗剪强度约为140kPa,剪切力峰值集中在400N左右,振铃计数、AE能量与b值在剪切运动过程中的变化与剪切破坏阶段密切相关;频谱重心会随剪切过程逐步降低,从大约350 kHz降低至250kHz,同时,较低频带能量占比增加、较高频带能量占比减少,导致频谱重心不断下移.

Optimization of Inducing Conditions for Loose Callus of Pinellia ternata

[Objective] The research aimed to establish the cell suspension culture system of Pinellia ternate.[Method] The petiole of Pinellia ternate was as the explant.The orthogonal test was used to study the influences of four plant growth substances（2,4-D,NAA,picloram and KT）and their mixture ratios on the formation of loose callus.[Result] The induction effect of 2,4-D and picloram on the petiole callus of Pinellia ternate was the most significant.Then,the second ones were KT and NAA.The optimal medium which induced Pinellia ternate petiole to form the loose callus was MS＋0.5 mg/L of 2,4-D＋1.0 mg/L of NAA＋1.0 mg/L of picloram＋1.5 mg/L of KT.[Conclusion] The research laid the foundation for extracting the active ingredient from the cell suspension of Pinellia ternate and producing the artificial seed.

KASP标记在松散型花椰菜杂交种纯度鉴定中的应用

我国不仅是花椰菜的主要生产国,也是花椰菜种子的重要生产大国,培育和生产的花椰菜种子不仅在国内大范围种植,而且大量出口到海外市场。为了确保品种的真实性和种子纯度,以松散型花椰菜杂交种浙农松花50天、浙农松花88天及其亲本为试材,基于23份甘蓝变种材料的基因组重测序数据,选取双亲特异性的SNP位点设计KASP引物,通过基因分型方法对杂交种及其亲本进行鉴定。结果表明,开发的KASP标记和基因分型方法能够准确鉴别浙农松花50天和浙农松花88天杂交种的纯度,采用2个父本特异性引物和1个母本特异性引物进行鉴定,准确率为100%。

露天矿区环境下GPS/INS组合导航算法研究

针对露天矿区道路窄、弯道多,沿途布满碎石、路面颠簸不平,导致运输车辆在定位时出现系统模型异常及量测噪声不确定性的问题,提出一种带有噪声估计器的SVD-AUKF算法。该算法通过对协方差矩阵进行奇异值分解,抑制滤波过程中出现的病态矩阵,利用Sage-Husa估计器对量测噪声进行估计,减少系统状态误差,引入自适应因子实时修正系统模型误差以抑制滤波发散。将提出的SVD-AUKF算法应用于GPS/INS组合导航系统模型,并在矿山环境下进行车载实验,结果表明,新算法适用性好,相较AUKF算法,每个定位点在东、北、天方向上的位置精度分别提高50.69%、51.20%、48.54%,速度精度分别提高31.24%、33.83%、31.30%,能够有效改善滤波性能,提高系统定位精度。

变转速工况下松动故障自适应时频模态分解

松动故障广泛存在于机械设备之中,而在变转速工况下的松动故障诊断仍存在一定挑战.为实现变转速工况下的松动故障诊断,本文提出了一种自适应时频模态分解方法.为提高该方法的多工况自适应能力,针对时频模态分解窗宽参数进行了优化选取,研究了窗宽参数与分解输出的非线性关联特征,实现了不同噪声下的自适应时频模态分解.为验证该方法的有效性,针对支承松动故障进行了实验验证,同时在某工程设备上进行了旋转部件松动故障实验验证.采用自适应时频模态分解算法对实验验证数据进行处理,实现了非平稳特征的模态分解.通过定义和计算各阶次能量占比,完成了振动信号的故障特征分析,实现了松动故障的特征提取与诊断.结果表明,所提方法能够实现非平稳信号的模态分解,对于松动故障具备有效的诊断能力.

《外科护理》新形态工作手册式活页教材开发实践

新形态工作手册式活页教材在我国发展较为滞后,《外科护理》新形态工作手册式活页教材的开发可满足外科护理人才培养需求,体现党和国家的职业教育思想,是护理专业人才培养中帮助学生掌握知识、发展能力、提升智力、提高素质的重要载体,在护理继续教育中发挥着良好的作用,对护理专业发展和护理教育研究具有深远意义。

基于地质雷达的巷道松动圈探测图像优化分析及支护改进

以河北中关铁矿井下巷道为工程背景,开展松动圈探测及图像处理优化分析及支护改进。首先依据雷达探测原理,提出了针对金属矿山井下巷道的松动圈探测方案,并优化了雷达探测图像处理方法;然后对探测结果进行了详细分析,讨论了不同岩性及不同埋深水平对巷道松动圈范围的影响。研究结果表明:采用探地雷达可以有效测得井下巷道松动圈范围,中关铁矿井下巷道松动圈分布复杂多变,巷道岩性越差,埋深越大,松动圈范围越大,反之亦然。依据松动圈范围和锚杆作用机理,在岩性较差的围岩段,松动圈厚度范围超过2.5 m,应优化支护方案采用长度更长的锚杆并加密锚杆间距。

商用车推力杆螺栓失效原因分析与改进

竖销型V型推力杆球头位置为典型的球座-法兰连接结构,其中螺栓作为重要的连接部件,对于保证产品的稳定性具有重要作用。为解决某款重型卡车用V型推力杆球头位置的螺栓失效问题,文章从螺栓的初始设计、螺栓松动的可能原因入手,结合理论计算,振动的计算机辅助工程(CAE)分析等,确定失效的主要原因为初始扭矩设计不足以及螺栓在振动工况下的自松动行为。基于此,文章针对性制定了改进措施,并通过横向振动试验对比选定了优化方案,不仅解决了实际问题,提高了产品的稳定性与耐久性能,也对后续螺栓连接的优化设计提供了指导。

基于Loose r-sample的网格质量保持技术

为保证虚拟手术系统中的网格质量,提出一种基于Loose r sample理论的快速表面网格重建算法。记录满足Loose r sample采样定理的点集,用以描述物体的轮廓。通过约束Delaunay方法对该点集进行三角化,标记顶点和Delaunay单元,重构新的网格。实验结果表明,该算法能够保证生成网格的质量,简化仿真复杂度。

“散茶发花”发酵贵州绿茶的工艺优化及其特征挥发性化合物解析

以贵州瓮安县有机欧标绿茶为原料,利用冠突散囊菌固态发酵制备发酵茶,并对其工艺进行优化。同时,利用顶空固相微萃取-气相色谱-质谱仪(HS-SPME-GC-MS)对绿茶原料和成品发酵茶的挥发性化合物进行检测,并对其特征挥发性化合物进行解析。将发酵茶的感官品质和特征功能性化学指标(水浸出物含量、茶多酚含量、游离氨基酸含量)相结合作为综合评价指标,通过单因素实验和响应面优化试验研究发酵茶的最佳制备工艺条件。响应面试验表明,利用绿茶制备发酵茶的最佳工艺条件为:温度28℃、含水量40%、接种量1‰、发酵时间8 d,通过该工艺制得的成品发酵茶滋味醇厚、汤色橙黄明亮、香气纯正,且综合评分达到83.75±1.29分。共检测出18种特征挥发性化合物(OAV>1),同时研究发现成品发酵茶具有浓郁的“金花”香,其是由芳樟醇、水杨酸甲酯等8种特征挥发性化合物组成的一种复合花香。在品质评价方面,成品发酵茶水分含量为3.9%±0.47%、灰分为5.92%±0.21%、水浸出物含量为43.92%±0.07%,以上指标均符合茯茶国家标准(GB/T 32719.5-2018《黑茶第5部分:茯茶》)的要求,本研究可为利用“散茶发花”制备发酵茶提供指导。