An Improved Solov2 Based on Attention Mechanism and Weighted Loss Function for Electrical Equipment Instance Segmentation

The current existing problem of deep learning framework for the detection and segmentation of electrical equipment is dominantly related to low precision.Because of the reliable,safe and easy-to-operate technology provided by deep learning-based video surveillance for unmanned inspection of electrical equipment,this paper uses the bottleneck attention module(BAM)attention mechanism to improve the Solov2 model and proposes a new electrical equipment segmentation mode.Firstly,the BAM attention mechanism is integrated into the feature extraction network to adaptively learn the correlation between feature channels,thereby improving the expression ability of the feature map;secondly,the weighted sum of CrossEntropy Loss and Dice loss is designed as the mask loss to improve the segmentation accuracy and robustness of the model;finally,the non-maximal suppression(NMS)algorithm to better handle the overlap problem in instance segmentation.Experimental results show that the proposed method achieves an average segmentation accuracy of mAP of 80.4% on three types of electrical equipment datasets,including transformers,insulators and voltage transformers,which improve the detection accuracy by more than 5.7% compared with the original Solov2 model.The segmentation model proposed can provide a focusing technical means for the intelligent management of power systems.

Remaining Useful Life Prediction of Rail Based on Improved Pulse Separable Convolution Enhanced Transformer Encoder

In order to prevent possible casualties and economic loss, it is critical to accurate prediction of the Remaining Useful Life (RUL) in rail prognostics health management. However, the traditional neural networks is difficult to capture the long-term dependency relationship of the time series in the modeling of the long time series of rail damage, due to the coupling relationship of multi-channel data from multiple sensors. Here, in this paper, a novel RUL prediction model with an enhanced pulse separable convolution is used to solve this issue. Firstly, a coding module based on the improved pulse separable convolutional network is established to effectively model the relationship between the data. To enhance the network, an alternate gradient back propagation method is implemented. And an efficient channel attention (ECA) mechanism is developed for better emphasizing the useful pulse characteristics. Secondly, an optimized Transformer encoder was designed to serve as the backbone of the model. It has the ability to efficiently understand relationship between the data itself and each other at each time step of long time series with a full life cycle. More importantly, the Transformer encoder is improved by integrating pulse maximum pooling to retain more pulse timing characteristics. Finally, based on the characteristics of the front layer, the final predicted RUL value was provided and served as the end-to-end solution. The empirical findings validate the efficacy of the suggested approach in forecasting the rail RUL, surpassing various existing data-driven prognostication techniques. Meanwhile, the proposed method also shows good generalization performance on PHM2012 bearing data set.

Impact of Safety-Maintenance Practices on the Overall Performance of an Industry

The study aims to evaluate how safety-maintenance practices affect the mechanical engineering industry’s overall performance in Ghana. The study used a descriptive survey design technique to ascertain the type of maintenance engineering that was practiced in Ghanaian mechanical engineering workshops at the time of the study. In the mechanical engineering workshops, respondents provided both qualitative and quantitative data using a variety of data collecting instruments, with the quantitative approach being more common. The study employed Kumasi, Tamale, and Accra’s mechanical engineering workshops as a case study. The number of mechanical engineering workshop enterprises that made up the sample size for the questionnaire administration was sixty (60), chosen at random from the AGI membership registry. Primary data was gathered using interview guides and questionnaires. To analyse the data, descriptive statistics were employed. According to the study’s findings, mechanical engineering companies combined different maintenance techniques in order to best fit their organisational culture and equipment. Preventive shut-down, with a mean score of 4.78 and RII = 0.98, placing first (1st) in the Likert rating order, is the most frequently used maintenance system by respondents. The maintenance procedures employed by mechanical engineering organisations were influenced not only by their equipment and organisational culture but also by other factors such as cost, personnel expertise and external partnerships.

Research on the Internal Talent Training Path and Performance Evaluation Mechanism of New R&D Institutions in Zhejiang Province

New research and development(R&D)institutions are an important part of the national innovation system,playing an important role in promoting the transformation of scientific and technological achievements.In recent years,new R&D institutions have gradually become the driving force of innovation-driven development in China.Taking new R&D institutions in Zhejiang Province as the research object,this paper studies the internal talent training path and performance evaluation mechanism of new R&D institutions in Zhejiang Province by using the literature research method,comparison method,case verification method,and other methods.The investigation results show that there are problems such as lack of material and spiritual support and neglect of the absorption of local talents in the internal talent training,and there are problems such as unclear standards,insufficient data,and opaque processes in the performance evaluation mechanism,which greatly affect the establishment and improvement of the performance evaluation mechanism.Given the above problems,this paper puts forward a forward-looking,oriented,flexible,and compatible talent training path and performance evaluation mechanism,hoping to optimize the effective internal talent training path of new R&D institutions,improve the evaluation performance,and promote healthy development of new R&D institutions in Zhejiang Province.

Preface for Special Issue on“Key Mechanical Problems of Marine Energy Development Equipment”

There are abundant energy reserves such as oil,natural gas,hydrate,and wind energy in the ocean.Countries around the globe are competing to advance their marine energy development technologies.The exploitation of marine resources relies on cutting-edge industrial equipment.After decades of R&D endeavors,China has obtained most of the key technologies for the design,production,testing,and field application of marine energy development equipment(Xie and Zeng,2021).

Vibration Analysis and Fatigue Assessment of Floors.Part II:Mechanical Equipment

Floors subjected to mechanical equipment loads frequently present problems associated with excessive vibration which can cause human discomfort or even reduce the structure service life.In this context,this work aims to develop an analysis methodology in order to assess the fatigue performance of steel-concrete composite floors,when subjected to vibrations induced by mechanical equipment.The studied structural model corresponds to a steel-concrete composite floor spanning 10 m by 10 m,with a total area of 100 m^(2).The numerical model developed for the dynamic analysis adopted the usual mesh refinement techniques present in finite element method(FEM)simulations implemented in the ANSYS program.The investigated floor dynamic response was calculated through the consideration of the dynamic loadings imposed by the mechanical equipment,simulated based on the use of harmonic forces applied on the concrete slabs.Furthermore,the dynamic structural response was performed considering several scenarios for the positioning of the equipment,in order to verify the occurrence of excessive vibration.The fatigue assessment is based on a linear cumulative damage rule through the use of the Rainflow-counting algorithm and S-N curves from traditional design codes.The results of this investigation indicated that the equipment position affects directly the floor dynamic structural response and also significantly influences the structure service life.

Approach for Cost Determination of Electro-Mechanical Equipment in Ror Shp Projects

Electricity is one of the most widely used forms of energy. Being a renewable source of energy small hydropower is considered as an environment—friendly and cheap source of electricity. The installation cost of the small hydropower project depends mainly on two parts—civil works and electromechanical equipment. One of the most important element on the recovery of a small hydro-power plant is the electromechanical equipment (turbine-alternator). The present paper intends to develop a correlation to determine the cost based on the cost influencing parameters as power and head using three different methods, namely;sigma plot method, linest method and logest method. An attempt has also been made to identify the best correlation among the three models closer to the actual cost of electro-mechanical equipment as collected from recently developed projects.

基于VR技术和3D打印相结合的机械类课程教学改革探讨——以“机械制造装备设计”为例

随着机械行业的迅猛发展和计算机技术的不断进步,机械类专业课程的教学方式亟须改革,以适应时代潮流并提升教学效果。以“机械制造装备设计”课程为研究对象,探讨了利用虚拟现实技术(VR)和3D打印技术的结合,对教学模式进行改革的可行性和必要性。具体而言,提出了利用这两种先进技术的措施,以促进学生对机械结构的直观理解、加强理论与实践的融合、教学内容创新等。这些举措旨在激发学生的学习兴趣,拓展教学内容,提高教学质量,从而更好地满足当下机械设计教育的需求。

Discussion on Priorities of Railway 5G-R Research and Development

As the railway sector intensifies its efforts in the technology research,system R&D and technology application of 5G-R,the paper conducts a preliminary study on its application frequency in terms of its frequency propagation,network carrying capacity,its ability to work as industrial pillar,system applicability,and the compatibility of 5G-R with other systems.In line with China's GSM-R application practice and the application needs,the paper focuses on the study of key technologies such as model alignment of base station equipment,and optimization of 5G-R terminal and core network,identifying the priorities for the China's efforts to develop 5G-R and providing references for the research and application of related technologies.

Effects of Sowing Depth and Sowing Equipment on Growth and Yield of Mechanized Sowing Maize

Taking Zhongyu 3 as the experimental variety,this paper analyzed the effects of different sowing depths(5 cm and 8 cm)and sowing equipment(ZHSB-10 medium-sized sowing machine and 2B-2 small sowing machine)on the growth,yield and components of yield of mechanized sowing maize,to provide references for mechanized maize production in southwest ecological zone.The results showed that the germination rate,plant height uniformity,and most agronomic traits of maize plant were higher at the sowing depth of 5 cm;with the growth of the maize,the effects of the sowing depth on agronomic traits of maize gradually declined;the effects of the sowing depth on the empty stalk rate,double ear rate,lodging rate,and lodging and stem broken rate were smaller;the sowing depth of 5 cm could increase the yield of mechanized sowing maize and most yield traits of maize.Different sowing machines had smaller effects on the germination rate,plant height uniformity,and agronomic traits of all growth stages,empty stalk rate,double ear rate,lodging rate,lodging and stem broken rate,yield,and components of yield of mechanized sowing maize.

Fuzzy Comprehensive Judgment on the Mechanical Equipment Bid Sheet

The reasonable model of fuzzy comprehensive judgment is found by means of the theory and method of multi-level fuzzy judgment on the basis of the judging index system of mechanical equipment bid sheets. The scientific method is supplied for the judging bids, the key chain of the judging process of the mechanical equipment bid sheet. All factors are considered, especially quantitative factors or qualitative factors in the process of judgment.

Environment Adaptability Evaluation for Buffering Airbag of Heavy Equipment During Airdrop Landing

Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipment and its airbag system.The models' efficiency and correctness were validated by using on-site experiment data in vehicle airdrop landing.The simulation results agree very well with the experiment results.Then,the environment adaptability of airbag system of heavy equipment under high-altitude condition was studied by using the models.Finally,some solutions were given to solve the overturn problem in the landing.

Configuration and Maintenance Management of Highway Engineering Machinery and Equipment

Firstly,this paper analyzes the necessity of highway engineering construction machinery and equipment management,discusses the configuration management of highway engineering machinery and equipment,and then puts forward the problems existing in the management and maintenance of highway engineering machinery construction equipment.Finally,the management and maintenance measures of highway engineering machinery construction equipment are discussed in a targeted manner.

Application of Transfer Learningin Mechanical Equipment Intelligent Diagnosis:Literature Review

Accelerating the process of intelligent manufacturing and the demand for new industrial productivity,the operating conditions of machinery and equipment have become ever more severe.As an important link to ensure the stable operation of the production process,the condition monitoring and fault diagnosis of equipment have become equally important.The fault diagnosis of equipment in actual production is often challenged by variable working conditions,large differences in data distribution,and lack of labeled samples,etc.Traditional fault diagnosis methods are often difficult to achieve ideal results in these complex environments.Transfer learning(TL)as an emerging technology can effectively utilize existing knowledge and data to improve the diagnostic performance.Firstly,this paper analyzes the trend of mechanical equipment fault diagnosis and explains the basic concept of TL.Then TL based on parameters,TL based on features,TL based on instances and domain adaptive(DA)methods are summarized and analyzed in terms of existing TL methods.Finally,the problems faced in the current TL research are summarized and the future development trend is pointed out.This review aims to help researchers in related fields understand the latest progress of TL and promote the application and development of TL in mechanical equipment diagnosis.

Research on Cutting Force of Ultrasonic Diamond Wire Saw

Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.

3D打印技术在加工设备中的应用影响及实例分析

为提高基于3D打印的食品加工效果,以面粉的挤出式3D打印为研究对象,分析了水温、挤出头相对高度、喷嘴直径、水与面粉材料配比、活塞进给速率、挤出头相对速度6个工艺参数,以及3D打印效果的影响,并确定了最佳工艺参数组合为:水温100℃,挤出头相对平台高度为0.8 mm,喷嘴直径为0.6 mm,去离子水与面粉比例为0.8∶1,活塞进给速率为0.66 mm/min,挤出头相对平台速度为700 mm/min;应用结果表明,在上述最佳工艺参数组合下,3D打印的面团层数更高,精度更高,有效提高了面粉3D打印效果。

Research on Radial Friction Welding of 30 mm Shell's Band

A new radial friction welding technology of 30 mm shell's band is introduced.Bands are assembled to shell bodies without notches by using the process.The width of heat-affected zone(HAZ) is small,and the microstructure on steel side is incomplete quenching while that on cooper side is grain refining.The shear-strength of joint exceeds 200 MPa.The result of firing test indicates that radial friction welding can satisfy the assembly requirements of shell bands.

改进RetinaNet的电力设备目标检测方法

针对电力设备检测中小目标识别精度低的问题,提出一种基于RetinaNet的电力设备目标检测方法。通过K-means聚类方法优化原始网络的锚点框尺寸。然后在特征融合中加入拥有更高分辨率的浅层特征图,解决通过多层卷积后特征图包含信息过少的问题。在此基础上,引入ECA(Efficient Channel Attention)注意力机制,使网络定位电力设备的有效特征,抑制无用特征信息。实验结果表明,相比原始方法,本文方法对于电塔、销钉、工程车、绝缘子、电杆5种电力设备的平均识别精度提升了18.1个百分点,表明改进后的方法能显著提高电力设备的检测水平。

基于SAConvFormer算法的焊接故障诊断在非平衡数据集上的应用

预测性维护在制造业中扮演着重要角色,而焊接设备的有效维护更是关键,旨在减少企业支出并实现无人车间的目标。然而,焊接领域的研究尚处于初级阶段,而深度学习在此领域的应用也相对较少。针对这一问题,提出一种基于空间注意力卷积Transformer(SAConvFormer)的故障诊断模型,以解决焊接设备故障预测的挑战。通过收集焊接过程中的数据,该算法通过空间注意力机制增强卷积神经网络,从而更准确地预测焊接过程中的各种故障类型。实验结果显示,SAConvFormer模型在预测正常类型故障方面的召回率达到了95%,误差仅为2%。对焊接偏差类型的故障,模型的召回率稳定在80%左右,而不完全熔合类型的故障预测准确性相对较低,但仍保持在70%以上。与传统算法相比,SAConvFormer模型在召回率上表现优异。这一研究成果不仅在技术上取得了进展,也为焊接设备的故障诊断提供了一种新的有效方法,具有重要的理论和实践意义。

Mating model on production capacity for the system of cutting coal and drawing top-coal in FMMSC

Being a safe and highly-efficient mining method, fully mechanized mining with sublevel caving （FMMSC） was extensively employed in Chinese coal mines with thick seam. In order to make drawing top-coal furthest to parallel work with shearer cutting coal, decrease failure ratio of rear scraper conveyor and increase safe production capacity of equipments, based on production technology, set up the mating model of safe production capacity of equipments for the system of drawing top-coal and shearer cutting coal in coal face with sublevel caving. It is mean capability of drawing top-coal adapted to the capability of shearer cutting coal in a working circle in the coal face that was deduced. The type selection of equipment of rear scraper conveyor can be tackled with this mating model. The model was applied in FMMSC in Yangcun Coal Mine, Yima Coal Group of China. With the mating light-equipments, the coal output in coal face attained 1.05 Mt in 2004. It gained better technical-economic benefit.