bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and Method for In-line Inspection Technology of Girth Weld in Long-Distance Oil and Gas Pipeline
Authors: Chen Pengchao , Li Rui , Fu Kuan , Zhao Xiaoming
Published: August 2021

With the increasing demand for energy, long-distance oil and gas pipeline has become the main mode of transportation of oil and gas resources. High pressure, inflammable and explosive medium, complex and changeable route environment and other factors make the safe transportation of pipeline concerned. The girth welds of oil and gas pipeline have always been the weak part of the pipeline due to the technical level during the construction, on-site welding practices and operation environment, and the girth weld cracking is one of the main failure forms of oil and gas pipeline. It is an effective way to ensure the safety of pipeline to adopt various advanced and targeted inspection to identify pipeline defects, judge the types of defects, and then carry out safety evaluation and maintenance. This paper analyzes the main failure factors of girth weld of oil and gas pipeline, and systematically summarizes the content and methods of various in-line inspection on girth weld in view of these failure factors, so as to provide reference for the development and application of in-line inspection technology on girth weld of oil and gas pipeline.
Research on crack monitoring technology of multilayer structure based on TMR-eddy current sensor
Authors: Xianghong FAN , Jian YU , Tao CHEN
Published: August 2021

The flexible eddy current array sensor has the characteristics of flexibility, bendability and light weight, which has a great application prospect in the field of structural health monitoring. The traditional flexible eddy current array sensor is affected by the skin effect and the crack monitoring depth is relatively low. This paper proposes an eddy current array sensor which uses TMR (tunnel magneto-resistance) sensor as sensing channels. It reduces the excitation frequency and increases the eddy current skin depth. The TMR sensor realizes the quantitative monitoring of cracks by the array arrangement. First, the finite element model of the sensor is established, and the influence of the cracks on the different layers of the multilayer structure on the magnetic induction intensity at the test point is analyzed. The simulation and results show that when the crack passes through the sensor, the magnetic induction intensity at the three test points changes in sequence and gradually increases to the maximum value. The direct relative position of the maximum value of the three test points is approximately the same as the distance among the test points. Then, the simulated crack growth experiment of the corresponding sensor is carried out. The experimental results show that as the crack grows, the signals of the three TMR sensors on the eddy current sensor change in sequence, and the distance between the characteristic points is consistent with the distance between the TMR sensors. The output voltage of the sensor decrease with the crack depth increases. The experimental results are consistent with the simulation results, which further verifies the correctness of the simulation model.
Identification and compensation of stiffness and damping between short and long stroke in wafer stage
Authors: Yang Xu , Zhang Ming , Cheng Rong , Cheng Rong , Zhu Yu
Published: August 2021

The disturbance of cable force is an important aspect that should be taken into account for precision motion systems involved in CNC machine tools, wafer scanners, etc. In this paper, unlike paying attention to the cable force loaded on long stroke in previous works, the disturbance between long and short stroke had been analyzed in details. To minimize the disturbance force loaded on short stroke of motion system, a disturbance model identification and the corresponding compensation approach method was proposed. A two-step identification in frequency domain was developed such that the parameters of stiffness and damping between long and short stroke can be estimated. Then a state feedback method using ESO and estimated parameters had be applied to compensate the disturbance, which improved the servo performance of short stroke significantly. Finally, the effectiveness of the proposed method is illustrated through numerical simulation.
Key Technology of Directional Drilling for Water Prevention and Control of Bottom plate Limestone in Zhangji Coal Mine
Authors: Lei HAN
Published: August 2021

The coal of group A in Zhangji Coal Mine is seriously threatened by limestone water damage. we use the directional drilling equipment to construct along the strata long drilling and explore the limestone aquifer of the working face bottom plate. According to the characteristics of the formation, the directional drilling casing hole section, rotary drilling hole section, directional bevel hole section, and directional stability The construction methods and key technology of the inclined hole section are analyzed and researched, and the 1414A working face is selected for directional exploration drilling for practical verification. The results show that the directional long drilling technology realizes the full coverage exploration of the working face bottom plate. The target layer has a high drilling encounter rate. The one-time exploration distance is long, which effectively solves the safety risk caused by the bottom plate limestone water damage to the working face safety production. Realizing the promotion of directional drilling equipment in the field of water prevention and control in Huainan Coalfield.
Fault Diagnosis of Rolling Bearing Based on Local Mean Decomposition and Transient Extracting Transform
Authors: Zhao ZhiChuan , Chen ZhiGang , Chai Long , Jang YunLong
Published: August 2021

To solve the problem of inconspicuous feature extraction when LMD method is used to extract rolling bearing fault characteristic signals, A fault feature extraction method based on Local Mean Decomposition (LMD) and Transient- Extracting Transform (TET) was proposed. Firstly, the rolling bearing fault signals were processed by LMD and the feature components with rich fault information were screened out by using the kurtosis values. Then, the secondary feature extraction and envelope analysis of the acquired components were carried out by using TET method. The experimental results showing that this method can extract the pulse characteristics of the impact signal of rolling bearings efficiently, and is suitable for the fault diagnosis of rolling bearing.
Structural design and optimization of wellhead platform for coal mine rescue rig
Authors: Dong-sheng LI
Published: August 2021

The existing ground emergency rescue truck-mounted drilling rig integral wellhead platform has the following disadvantages: inflexible structure form, small opening aperture, difficult assembly and disassembly, and cannot meet the lowering of large diameter drill bits and casing. In response to the above-mentioned shortcomings, it is proposed that a general scheme of modular large-opening intelligent wellhead platform for vehicle-mounted drilling rigs which combines the requirements of the rescue construction. The modular wellhead platform has the characteristics of fast centering, clamping, automatic leveling and meeting the requirements of multi-series large diameter drilling tools. The numerical simulation method is used to analyze the U-shaped wellhead platform, and an optimized structure is proposed based on the analysis results of the original structure. The results show that the stress of optimized structure is better than that of original structure, which provides important support for product design.
Diagnosis method of turbine blade loosening
Authors: Niu Qingliang , Gong Yuli , Tian Guocheng , Liu Chuanling
Published: August 2021

Abnormal vibration of low-pressure rotor occurred after low-pressure cylinder cutting transformation of 330MW steam turbine generator unit in a power plant. Through the analysis of vibration data, the vibration spectrum was mainly manifested as low-frequency component of 18Hz, which fluctuates with time cycle, and it was judged that it might be related to the loosening of low-pressure rotor blades. After 6 months of operation, routine inspection after cylinder cutting showed that there were three loose roots and worn top steam seals on the secondary last stage blades of low pressure rotor. After repairing the blades, the abnormal vibration problem of the low pressure rotor of the turbine generator set was successfully solved.
Research Status and Development Trend of Coal Mine Tunnel Drilling Rig in China
Authors: Baizhan Gao , Qiyue Kang , Pengbo Xu
Published: August 2021

Aiming at the new progress and new trends of coal mine tunnel rigs in China, this paper introduces the development of conventional coal mine tunnel rigs, discusses the application of new technologies such as directional drilling and remote automatic control in the development of coal mine tunnel rigs, and points out the development trend of coal mine tunnel rigs in China. According to the development of domestic coal mine tunnel drilling rigs and related technologies, it is of great significance to construct intelligent drilling face and comprehensively improve the adaptability and reliability of mine tunnel drilling machine to ensure the safety and efficient production of coal mine.
Intelligent Service Scheduling Decision Technology under Artificial Intelligence Technology
Authors: Shi He , Cao Guohua , Ma Guoqing , Fan Junhua , Duan Jingsong , Bai Jimeng
Published: August 2021

The intelligent production line is a new intelligent production line resource formed by highly integrating modern sensor technology, communication technology, information technology, computer technology and control technology on the large physical real basis of the existing production line. It can finish data acquisition, information processing, dynamic virtual reconfiguration of variable batch production line, embedded algorithm, algorithm optimize the management of the production line manufacturing field, change the dynamic virtual reorganization of the mass production line, and become the choice of the development direction of the next generation of new production lines for mankind. Scheduling is the nerve center of the production line virtual reorganization system. The traditional main auxiliary decision-making tool management system can no longer fully meet the requirements of production line operation monitoring in the new environment, so the construction of an intelligent scheduling system is also one of the important contents of the construction of the production line virtual reorganization. Based on this, this article explores and researches intelligent service scheduling decision-making technology under artificial intelligence technology. The research topic of this article is intelligent scheduling of production lines, so this article first analyzes the current research status of intelligent service scheduling and decision support systems; then conducts research based on Agent decision support systems, and analyzes the framework and characteristics of decision support systems. realizes the intelligent production line scheduling DSS system; then this paper designs the system’s scheduling model with stochastic disturbance, system database and system fault diagnosis function, and realizes an intelligent service scheduling decision support system based on multi-agent technology. Finally, this article tests the data transmission speed and fault diagnosis function of the system. The test results show that the system is relatively fast in data transmission speed and the fault diagnosis function is also very reliable.
A Diffusion Prevention and Recovery Scheme for Spilled Oil on Land
Authors: Y L Zhang , Z L Li , W B Guo , H Peng
Published: August 2021

A set of quick response vehicle group and scheme was investigated to solve the current diffusion and recovery problems of spilled oil on land. A spilled oil recovery plant was simulated via FLUENT, the simulation result was verified by a control test, and it appeared that this plant could reach the recovery rate of above 50 m3/h and diffusion prevention scope of 4,000 m2. Hence, it can, to some extent, guarantee the quick response on the field, so as to reduce secondary disasters and protect the field environment.
Analysis of multiple failure behaviors of steering knuckle ball hinge of multi-axle heavy vehicle
Authors: Wang Zhenyu , Wei Shuo , Bao Ke , Peng Senye , Zhang Qing
Published: August 2021

The ball hinge is a key component of the vehicle chassis that connects the steering knuckle and the control arm. This study analyzed the multiple failure behaviors of the chassis ball hinge. First, according to the macroscopic failure characteristics of the ball hinge, the analysis method of the fault tree was adopted to identify the possible cause of the failure. The axial force and radial force of the ball joint were obtained by simulating the force of the vehicle under the typical extreme conditions. The stress distribution of the ball pin was obtained by finite element analysis of the ball joint. The calculation results are consistent with the fatigue crack position of the ball hinge. Then the ball hinge was disassembled. On the one hand, the macro morphology was observed. On the other hand, the chemical composition and microstructure of the ball pin material were analyzed by scanning electron microscope and infrared spectrum analyzer. Finally, the macro morphology and microstructure of the ball joint seat, ball bowl, dust cover and other parts matched with the ball hinge were analyzed to further verify the failure reason of the ball hinge. The results showed that the dust cover of the ball hinge was firstly aged and cracked, and the external dust and particles enter into the friction contact area of the ball hinge, which caused the ball pin and ball bowl to be stuck. During the driving process of the vehicle, the ball pin undergoes unidirectional bending fatigue fracture in the stress concentration area at the root of the conical surface.
Recognition of Fault State of RV Reducer Based on self-organizing feature map Neural Network
Authors: Zhao Zhuanzhe , Ye Guowen , Liu Yongming , Zhang Zhen
Published: August 2021

In order to accurately evaluate the working state of RV reducer, a fault identification method based on the fault identification model established by Self-Organizing Feature Map (SOM) Neural Network is proposed. Firstly, the data measured by the RV reducer test platform are analyzed by wavelet to obtain the wavelet coefficient. Then, combined with the efficiency data of RV reducer, the mean square frequency, center of gravity frequency and frequency variance of the two groups of data are calculated after Fourier transform and power spectrum analysis. After optimization, several eigenvalues are obtained. The eigenvalues are input into the competitive neural network and SOM neural network to establish the fault identification model. Finally, the results of the fault identification model established by the competitive neural network and SOM neural network are compared. The prediction results show that the fault identification model established by SOM neural network can effectively determine the working state of RV reducer.
Design and Simulation of Cam Curve for Automata
Authors: Rong Li , Lixin Wei , Hongliang Yang
Published: August 2021

Aiming at the problems of long movement stroke and complicated driving of the automatic machine breech block during the launching process of ammunition with large fineness ratio, it is proposed to use a crossed cam to drive the automata to complete the shooting progress. The three-dimensional model of the cam drive mechanism was established, and the maximum pressure angle of modified-sine curve and SMS-3 curve were compared according to the motion characteristics of the mechanism; the multi-rigid body dynamics and dynamics simulation software were used to obtain simulated displacement, speed and driving torque, and compared with the theoretical value. The simulation results show that under the same input conditions, the input torque required to complete the automata transport process using modified-sine curve is relatively small. This result provides a certain technical support for the research of automata on ammunition with large fineness ratio.
Dynamic Response of a Cat Head Type Transmission Tower-line System under Strong Wind
Authors: Wu Chuan , Yang Xiaohui , Zhang Bo , Liu Zehui , Zhao Yang
Published: August 2021

Transmission tower plays important role in the power system and it is security sensitive in various working conditions, such as wind and ice. In this paper, a method to obtain the dynamic response of a cat head type transmission tower under strong fluctuating wind was proposed. The coupled tower-lines finite element model was established in ABAQUS, and the equivalent acceleration of fluctuating wind was simulated by MATLAB. Then the displacements and stresses time histories were obtained. The method introduced in this paper can be used to assess the safety of tower under different fluctuating wind with different directions and provide a reference of the tower in the design stage.
Heat Transfer Simulation Study of Hot Oil Tubes Based on COMSOL
Authors: Shaohui Qu , Shuai Wang , Yuhuan Zhu , Jun Xiao , Yuxin Chen , Can Wang
Published: August 2021

Heat insulation board is added on the adjacent side of hot oil pipeline and other pipelines to increase thermal resistance and reduce the influence of hot oil pipeline on the temperature of the pipeline. Because the heat conduction problem of the soil around the hot oil pipeline after the addition of eat insulation board becomes very complex, this paper studies and analyzes the heat transfer process of the hot oil pipeline through constructing an equivalent simplified mathematical calculation model and heat transfer simulation based on COMSOL.
The Control System Design of Aircraft Wheel Device of Driving Rotary
Authors: Wenqiang LI , Xiangkun SUN
Published: August 2021

The aircraft wheel device of driving rotary is an important device as test of anti-slip brake system on the ground, according to the problems of inconvenience of input parameters adjustment, low speed detection accuracy, poor adaptability to the outside environment and low degree of automation, this paper designs a set of controlling system of aircraft wheel device of driving rotary, and giving chart with hardware design and programming flow chart in the control system of aircraft wheel device of driving rotary. The application result shows that this control system can meet actual requirement in the test of anti-slip brake system.
Analytical Calculation of Stiffness Characteristics of Swing Cylinder Hydro-Pneumatic Suspension
Authors: Chen Yijie , Gao Xiaodong , Xu Mengyan , Xu Long , Huang Long
Published: August 2021

The swing cylinder hydro-pneumatic suspension was mainly composed of balance elbow, rocker arm and oil-gas spring, which could convert the rotary motion of the balance elbow into the linear reciprocating motion of the piston. According to the mechanical transfer relationship, the suspension theoretical modelling research had been carried out, and the analytical relationship between key parameters such as suspension stiffness, leverage ratio and balance elbow swing angle were derived. The change trend of suspension characteristics with displacement was also given through programming, which provided a theoretical method for the design of actuators.
An effective iterated greedy algorithm for multi-AGVs dispatching problem in material distribution
Authors: Zhang Xujin , Sang Hongyan , Li Zhongkai , Li Junqing , Guo Hengwei
Published: August 2021

In this paper, the dispatching problem for multi-AGVs in the matrix manufacturing workshop from the practical factories is optimized. The goal is to reduce the transportation cost, including the cost of AGVs, distance cost and time cost. In order to solve the problem, we develop a mixed integer linear programming model. Then, an effective iterative greedy algorithm (IG) is proposed. The nearest-neighbor-based heuristic is used to generate high-quality initial solutions. An effective gradient unload method is designed. For the local search stage, three efficient operators are proposed. Finally, examples for experiment come from Foxconn electronic company. Comprehensive evaluation shows that the performance of the proposed IG is significantly better than some existing algorithms in the literature.
Research on Fuzzy Control Strategy and Genetic Algorithm Optimization for Parallel Hybrid Electric Vehicle
Authors: Luo Xiaoxiao , Deng Baojia , Gan Wenyan
Published: August 2021

In this paper, the fuzzy control strategy for parallel hybrid electric vehicle(HEV) is proposed. Based on fuzzy logic theory, SOC and torque demand scale factor are taken as the input, a fuzzy logic controller is designed. Combining with the rule-based control strategy(RBCS), the engine and motor output torque are gotten, so the whole energy control strategy is proposed. Then the genetic algorithm(GA) is used to get the optimal results: fuel consumption and emission level, to verify the accuracy of fuzzy control strategy.
Evaluation of the fatigue crack growth rate models under the action of tensile-compressive cyclic loading
Authors: Ningfei HUO , Yantao LIU , Gang SUN , Yanmao LIU , Peishuo LIU
Published: August 2021

In order to study the influence of compressive stress in cyclic load on the crack growth of the rib-to-deck joint, this paper analyzes the surface crack growth at the rib-to-deck joint under the action of overloaded vehicles based on the local three dimensional fracture mechanics model of the weld. The results show that the reverse plastic zone model is a better model to account for the effect of compressive stress in cyclic loading on the crack growth compared with the Paris Law either using the maximum tensile stress or using the full stress amplitude in cyclic loading.
A Study of Green Smart Inventory and Dynamic Programming Algorithm of SBS Modified Asphalt Based on Industrial Internet of Thing
Authors: Zhang Jiandong , Pang Dong
Published: August 2021

Start Based on the Industrial Internet of Things, this paper discusses the smart inventory management mode under the thermal storage of SBS modified asphalt, and preliminarily explores the smart inventory mode under the trend of smart logistics through the dynamic programming method, which provides a reference for the development direction of smart inventory of unconventional storage materials such as chemical and energy. At the same time, with the promotion and application of the Industrial Internet of Things, the dynamic, visual and intelligent development of each link in the logistics process brings a new round of intelligent reform to the logistics industry. As a kind of inventory management concept, smart inventory has gradually become one of the important links of smart logistics through measures such as Internet of Things technology, intelligent information management technology and visual management technology. The study proves that the dynamic programming method is suitable for the inventory cost optimization problem of SBS modified asphalt thermal storage. Finally, this paper uses the dynamic programming method to calculate the monthly data of a chemical raw material manufacturing enterprise in Liaoning province, and formulates the inventory management plan to optimize inventory costs.
Inverse Patch Transfer Function Method based on Steepest Gradient Descent Algorithm for Sound Field Reconstruction
Authors: Liu Chong , Lei Jianmei , Tang Chunpeng , Quan Daiyong
Published: August 2021

In the iPTF method with Green’s function, the classical regularization method used to solve the inverse problem can’t provide satisfactory reconstruction results around some eigen frequencies of the cavity in the iPTF method with Green’s function. In this paper, the steepest gradient descent (SGD) algorithm is introduced to solve the inverse problem in the iPTF method. In addition, to make the iPTF method with Green’s function more efficient, Contour-integration is used to split the Fourier series of Green’s function into one single-sum and one double-sum Fourier series. By applying Contour-integration, the computational efficiency of the iPTF method with Green’s function has been improved. The iPTF method with efficient Green’s function is examined in both simulations and application experiments. Experimental validations in the application are carried out in the end. The present results in experiments are also acceptable for field reconstruction.
Design and Test of Lightweight Long-life Electric Mechanism without Controller
Authors: Jiyuan  , Moupengtao  , Macuijuan  , Quanyunqing  , Liguoqiang
Published: August 2021

The traditional airborne electric mechanism is mostly controlled by mechanical switch, which seriously restricts the life and reliability of the system. This paper introduces a design method of a lightweight electric mechanism without a controller. The electric mechanism drives the motor directly by receiving the instructions of the control system, acts directly on the switch of the pipeline valve through the decelerator, breaks down the lock after reaching the specified position, and feeds back the current position signal. It is a high reliability, long life, compact structure, and widely used EMA product, which can adapt to all kinds of extreme environments required by the airborne equipment. And it has good maintainability.
Derivation of constitutive equation based on Miura-homogeneous equivalent model
Authors: Xiong Shaokun , Zhang Wei , Chen Jie
Published: August 2021

As a new type of sandwich structure, the Miura-folded sandwich structure shows excellent mechanical properties, and its internal transparent design is also conducive to the realization of multi-function. This kind of structure can solve the problem of the condensation of water vapor which will cause structural failure in the honeycomb sandwich structure. Based on the Miura origami structure, a homogenization mechanical analysis model of this folded sandwich is established. Through the model, we derived the theoretical expressions of structural modulus of sandwich panel under compression and shear loads, and the simulation results are verified in ABAQUS.
Study on the structure and virtual model of “xiezhi” gown in Ming dynasty
Authors: Yang Shuran , Yue Li , Wang Xiaogang
Published: August 2021

By now, there is still relatively blank area for studying the Chinese historical costume, which basically the traditional sample replicating method is used. It takes long time, and many clothing patterns and techniques can not be fully resembled. Since the development of CLO3D virtual simulation technology, the visual model of clothing can be set up on the virtual human body, and the model can simulate the fabric texture and physical properties. In this paper, by studying the color, fabric and structure of the Ming Dynasty “xiezhi” “side ear” round-neck gown, the structure is reproduced and simulated and reproduced through the CLO3D system. The use of digital technology to simulate and restore the Ming Dynasty “xiezhi” round-neck gowns is a new method of inheriting Chinese traditional clothing culture, and it is also the basis for establishing a visual clothing database.
Fault Detection for ZPW-2000A Jointless Track Circuit Based on Deep Belief Network Optimized by Grey Wolf Optimizer Algorithm
Authors: Yujie Li , Yunshui Zheng
Published: August 2021

At present, the fault detection for jointless track circuit still depends on the experience of electrical personnel, which leads to low maintenance efficiency and the phenomenon of misjudgment and missed judgment. A fault detection method for track circuit based on deep belief network (DBN) is proposed in this paper. According to the working principle and transmission characteristics of track circuit, 12 voltage and current monitoring parameters are selected to detect 15 types of track circuit fault. However, the selection of structural parameters for deep belief network is time-consuming, so grey wolf optimizer algorithm (GWO) is proposed to optimize DBN, which can adaptively select the number of neurons in each hidden layer. The simulation results show that by introducing the GWO algorithm to optimize the DBN detection model, the fault classification accuracy of the ZPW-2000A jointless track circuit can reach 96.96%, which significantly improves the fault detection level of the track circuit.
Information Transmission Scheme between Train and RBC Based on AES-ECC Algorithm
Authors: Junjie Zhang , Yunshui Zheng
Published: August 2021

The existing information encryption scheme between the Radio Block Center (RBC) and the ground has problems such as weak keys, and the vehicle-ground information has a potential threat of being stolen. In order to ensure the safety of driving, on the basis of ensuring the correct transmission of train and ground information, research on more efficient encryption schemes has become the focus of work. In response to this trend, a hybrid encryption scheme based on AES and ECC encryption algorithms is proposed. The AES algorithm replaces the original 3DES algorithm, and the elliptic curve encryption algorithm ECC is used to encrypt the session key to improve the encryption security level. The encryption simulation, avalanche effect verification and execution efficiency test of fixed-length data are completed on Visual Stduio 2013 platform, and compared with the original encryption scheme. The results show that the scheme can meet the avalanche effect and the accuracy of data transmission, and it takes less time than the original encryption scheme, and is more suitable for two-way large-capacity information transmission between vehicles and ground.
Research on Torque Control System Based on Fuzzy Logic
Authors: Qiyue Kang
Published: August 2021

Aiming at the needs of intelligent coal mining and construction of intelligent mines, based on fuzzy control language, the torque parameter control system of intelligent drilling rigs is analyzed and researched. The structure of the torque output fuzzy control system and the fuzzy adaptive PID controller are designed, and the system is simulated. The simulation research provides new ideas for the development of actual hardware controllers in the future, and lays the foundation for realizing unmanned operations in coal mines.
Quality Control Study on High Pressure Casting Based on Magma and Ultra-red Simulation
Authors: Jianmin TANG , Laijie WU , Haijun LIU , Bo LI , Dejun ZENG
Published: August 2021

The temperature control of high-pressure die casting mold is one difficult problem in die industry. The inner quality of product is greatly affected by mold temperature. Taking the automobile gearbox parts as an example, by the combination of waterproof thermocouple and TP700-16/TP700-40 multi-channel temperature tester, one set of device for monitoring mold real-time temperature is developed. The high pressure casting die and mold temperature field simulation are carried out by using Magma software. By simulating analysis and reducing process parameter interval of Magma, the ideal mold temperature is obtained and the quality problem of die casting is solved after the simulation parameters are copied to the die casting machine. The practical results show that the instability of die casting is decreased, the time cost of die casting is decreased by increasing die casting Overall Equipment Effectiveness (OEE), the risk of personal accident is reduced and the product scrap rate can be effectively reduced. Finally, the future research directions are pointed out.
Research on RCS Similarity Algorithm of Non-cooperative Target Model
Authors: Zhang Jianhua , Huangfu Huidong , Meng Xiaojun , Tao Wei , Su Kang , Ding Yijie , Xiong Sijin , Zang Ying
Published: August 2021

The RCS similarity evaluation is an important content of non-cooperative target model assessment. Aiming at the problems of the existing similarity measurement methods applied to the RCS similarity evaluation of non-cooperative target model, this paper proposes an algorithm which can quantitatively reflect the RCS similarity of non-cooperative target model. In order to better adapt to different data sets and make the algorithm more flexible, the weighting operators and penalty factors are introduced to further optimize the algorithm.
Control design of upper limb rehabilitation exoskeleton robot based on long and short-term memory network
Authors: Zhao Chenwei
Published: August 2021

The increasing human resources in rehabilitation training for patients with upper extremity impairment, more convenient and objective in rehabilitation training. Therefore, an upper limb rehabilitation exoskeleton robot controller based on a long-short-term memory network (LSTM), combined with impedance control is proposed. The design adopts the LSTM deep learning network to realize the preprocessing and classification of the collected patient’s subtle intention signals to obtain the patient’s real movement intention. The impedance controller based on the compliant control method is designed, and completed the auxiliary exercise for the patient. In the whole process, the LSTM algorithm effectively handles the timing problem, that is, effectively and continuously processes the patient’s data. The impedance control provides a good buffer for assisting the patient’s movement, ensuring the good physical compatibility of the patient-robot system with the outside world. Finally, through the model data test, the recognition and differentiation of 18 human body movements were tested, and the accuracy reached 59.3%.
Automated system based on open resonator for measuring the electrophysical parameters of sheet dielectrics
Authors: Kayro N S , Teterina D D , Badin A V , Bilinskii K V
Published: August 2021

In the article, the results of automation of the setup for measuring the dielectric permittivity of sheet dielectrics in an open resonator are presented. A program to control the positioning mechanism of the object under study, which allows setting the position of the sample with an accuracy of 6.25 μm in the longitudinal direction and 0.05625 ° in the angle, was written in the LabVIEW (National Instruments). For angular position of 30° of sheet dielectrics relative to the longitudinal axis of the open resonator resonance curves are experimentally obtained. Based on the data obtained, the calculation of the dielectric constant of the material is given.
Convex floating bodies of equilibrium
Authors: Florentin D. , Schütt C. , Werner E. , Zhang N.
Published: August 2021

We study a long standing open problem by Ulam, which is whether the Euclidean ball is the unique body of uniform density which will float in equilibrium in any direction. We answer this problem in the class of origin symmetric

n
n

-dimensional convex bodies whose relative density to water is

1
2

\frac {1}{2}

. For

n
=
3

n=3

, this result is due to Falconer.
Cytoskeleton integrity influences XRCC1 and PCNA dynamics at DNA damage
Authors: Hurst Verena , Challa Kiran , Shimada Kenji , Gasser Susan M.
Published: August 2021

Actin perturbation by latrunculins (Lat) reduces recruitment of base excision repair factors to laser-induced damage, while nocodazole treatment increases it. Surprisingly, LatA leads to the nuclear accumulation of both actin and tubulin. Since actin perturbation aggravates Zeocin-induced cell death, this links cytoskeletal integrity to base excision repair.
A systematic comparison of data- and knowledge-driven approaches to disease subtype discovery
Authors: Rintala Teemu J , Federico Antonio , Latonen Leena , Greco Dario , Fortino Vittorio
Published: August 2021

Typical clustering analysis for large-scale genomics data combines two unsupervised learning techniques: dimensionality reduction and clustering (DR-CL) methods. It has been demonstrated that transforming gene expression to pathway-level information can improve the robustness and interpretability of disease grouping results. This approach, referred to as biological knowledge-driven clustering (BK-CL) approach, is often neglected, due to a lack of tools enabling systematic comparisons with more established DR-based methods. Moreover, classic clustering metrics based on group separability tend to favor the DR-CL paradigm, which may increase the risk of identifying less actionable disease subtypes that have ambiguous biological and clinical explanations. Hence, there is a need for developing metrics that assess biological and clinical relevance. To facilitate the systematic analysis of BK-CL methods, we propose a computational protocol for quantitative analysis of clustering results derived from both DR-CL and BK-CL methods. Moreover, we propose a new BK-CL method that combines prior knowledge of disease relevant genes, network diffusion algorithms and gene set enrichment analysis to generate robust pathway-level information. Benchmarking studies were conducted to compare the grouping results from different DR-CL and BK-CL approaches with respect to standard clustering evaluation metrics, concordance with known subtypes, association with clinical outcomes and disease modules in co-expression networks of genes. No single approach dominated every metric, showing the importance multi-objective evaluation in clustering analysis. However, we demonstrated that, on gene expression data sets derived from TCGA samples, the BK-CL approach can find groupings that provide significant prognostic value in both breast and prostate cancers.
UPLC–MS/MS Method Validation for Estimation of Resveratrol in Rat Skin from Liposphere Gel Formulation and Its Application to Dermatokinetic Studies in Rats
Authors: Rahman Mahfoozur , Afzal Obaid , Panda Sunil K , Kazmi Imran , Ali Ahmed Mahmoud Abdelhaleem , Alossaimi Manal A , Al-Abbasi Fahad A , Almalki Waleed H , Katouah Hanadi A , Kumar Vikas , Barkat Md Abul , Rub Rehan A , Beg Sarwar
Published: August 2021

For the quantification of resveratrol (RV) in the Wistar rat skin, an ultra-performance liquid chromatography-mass spectrometric (UPLC–MS/MS) method was developed and validated on ACQUITY UPLC BEH C18 column (1.7 μm). The mobile phase ratio of methanol (A) and 2% formic acid (B) (ratio 10: 90% v/v, 80: 20 v/v) at isocratic elution with flow rate 0.3 mL/min, and run time 3 min was used for analysis. In addition, the use of multiple reaction monitoring (MRM)/ES+ mode to detect the analytes and to track parents to daughter ion transition of 229.17 > 107.04 m/z (time scan 3 min, retention time 1.48) for RV and curcumin as an internal standard shows 369.16 > 176.93m/z (scan time is 2.80 min, retention time is 1.11), respectively. Linearity was observed in the range of 2.5 to 2,000 ng/mL (R2 = 0.987). Precision and accuracy on rat skin were within the acceptability range (RE%: ±15; RSD%: ±15). Moreover, it showed a good percentage recovery and found within acceptance limit 90–110%. Lower limit of detection and quantitation for the method observed to be 2.5 and 20 ng.mL−1, respectively. Method application indicated successful determination of dermatokinetics parameters of RV from lipospheres gel and suspension in the rats.
An Algorithm to Construct Completely Independent Spanning Trees in Line Graphs
Authors: Wang Yifeng , Cheng Baolei , Fan Jianxi , Qian Yu , Jiang Ruofan
Published: August 2021

In the past few years, much importance and attention have been attached to completely independent spanning trees (CISTs). Many results, such as edge-disjoint Hamilton cycles, traceability, number of spanning trees, structural properties, topological indices, etc., have been obtained on line graphs, and researchers have applied the line graphs of some interconnection networks such as generalized hypercubes, augmented cubes, crossed cubes, etc., into data center networks, such as SWCube, AQLCube, BCDC, etc. At the meanwhile, few results of CISTs are reported on the line graphs. In this paper, we establish the relation of edge-disjoint spanning trees in an interconnection network $G$’ with its line graph $G$ by proposing a general algorithm for the first time. By this method, more CISTs can be obtained comparing with results in the literature. Then, the decrease of diameter is discussed and simulation experiments are shown on the line graphs of hypercubes.
A Method for Building the Quantitative and Qualitative Part of Bayesian Networks for Intelligent Tutoring Systems
Authors: Ramírez-Noriega Alan , Juárez-Ramírez Reyes , Leyva-López Juan Carlos , Jiménez Samantha , Figueroa-Pérez J Francisco
Published: August 2021

The Bayesian network (BN) is an important technique to represent and infer knowledge in an Intelligent Tutoring System (ITS); however, ITSs are complex to build. Diverse authors have built BNs based on ontologies to accelerate the building process; nonetheless, they did not fully automate the process, and did not follow the ontologies standard Web Ontology Language, or simplified the final domain. This work proposes a method to build BNs based on ontologies and Wikipedia information to be employed on ITSs. The proposed method constructs the qualitative part of the BN through classes and relations of ontologies; the quantitative part is created based on frequencies, hops, and a measure of similarity between concepts of the ontology represented by Wikipedia articles. This study carried out an experiment to determine the correlation of our method against domain experts opinions; the method obtained a positive correlation of $0.647$ according to the Spearman test. The method constructs a BN to represent the knowledge in ITSs, in a similar way as experts would, supporting the automatic build of these systems.
Peptipedia: a user-friendly web application and a comprehensive database for peptide research supported by Machine Learning approach
Authors: Quiroz Cristofer , Saavedra Yasna Barrera , Armijo-Galdames Benjamín , Amado-Hinojosa Juan , Olivera-Nappa Álvaro , Sanchez-Daza Anamaria , Medina-Ortiz David
Published: August 2021

Peptides have attracted attention during the last decades due to their extraordinary therapeutic properties. Different computational tools have been developed to take advantage of existing information, compiling knowledge and making available the information for common users. Nevertheless, most related tools available are not user-friendly, present redundant information, do not clearly display the data, and usually are specific for particular biological activities, not existing so far, an integrated database with consolidated information to help research peptide sequences. To solve these necessities, we developed Peptipedia, a user-friendly web application and comprehensive database to search, characterize and analyse peptide sequences. Our tool integrates the information from 30 previously reported databases with a total of 92 055 amino acid sequences, making it the biggest repository of peptides with recorded activities to date. Furthermore, we make available a variety of bioinformatics services and statistical modules to increase our tool’s usability. Moreover, we incorporated a robust assembled binary classification system to predict putative biological activities for peptide sequences. Our tools’ significant differences with other existing alternatives become a substantial contribution for developing biotechnological and bioengineering applications for peptides. Peptipedia is available for non-commercial use as an open-access software, licensed under the GNU General Public License, version GPL 3.0. The web platform is publicly available at peptipedia.cl.

Database URL: Both the source code and sample data sets are available in the GitHub repository https://github.com/ProteinEngineering-PESB2/peptipedia
Personalized paroxysmal atrial fibrillation ablation by tailoring ablation index to the left atrial wall thickness: the ‘Ablate by-LAW’ single-centre study—a pilot study
Authors: Teres Cheryl , Soto-Iglesias David , Penela Diego , Jáuregui Beatriz , Ordoñez Augusto , Chauca Alfredo , Carreño Jose Miguel , Scherer Claudia , San Antonio Rodolfo , Huguet Marina , Roque Albert , Ramírez Carlos , Oller Guillermo , Jornet Agustí , Palet Jordi , Santana David , Panaro Alejandro , Maldonado Giuliana , de Leon Gustavo , Jiménez Gustavo , Evangelista Arturo , Carballo Julio , Ortíz-Pérez José-Tomás , Berruezo Antonio
Published: August 2021

Aims

To determine if adapting the ablation index (AI) to the left atrial wall thickness (LAWT), which is a determinant of lesion transmurality, is feasible, effective, and safe during paroxysmal atrial fibrillation (PAF) ablation.

Methods and results

Consecutive patients referred for PAF first ablation. Left atrial wall thickness three-dimensional maps were obtained from multidetector computed tomography and integrated into the CARTO navigation system. Left atrial wall thickness was categorized into 1 mm layers and AI was titrated to the LAWT. The ablation line was personalized to avoid thicker regions. Primary endpoints were acute efficacy and safety, and freedom from atrial fibrillation (AF) recurrences. Follow-up (FU) was scheduled at 1, 3, 6, and every 6 months thereafter. Ninety patients [60 (67%) male, age 58 ± 13 years] were included. Mean LAWT was 1.25 ± 0.62 mm. Mean AI was 366 ± 26 on the right pulmonary veins with a first-pass isolation in 84 (93%) patients and 380 ± 42 on the left pulmonary veins with first-pass in 87 (97%). Procedure time was 59 min (49–66); radiofrequency (RF) time 14 min (12.5–16); and fluoroscopy time 0.7 min (0.5–1.4). No major complication occurred. Eighty-four out of 90 (93.3%) patients were free of recurrence after a mean FU of 16 ± 4 months.

Conclusion

Personalized AF ablation, adapting the AI to LAWT allowed pulmonary vein isolation with low RF delivery, fluoroscopy, and procedure time while obtaining a high rate of first-pass isolation, in this patient population. Freedom from AF recurrences was as high as in more demanding ablation protocols. A multicentre trial is ongoing to evaluate reproducibility of these results.
Olfaction and Physical Functioning in Older Adults: A Longitudinal Study
Authors: Yuan Yaqun , Li Chenxi , Luo Zhehui , Simonsick Eleanor M , Shiroma Eric J , Chen Honglei
Published: August 2021

Background

Poor olfaction is associated with worse functional performance in older adults, but longitudinal evidence is lacking. We investigated poor olfaction in relation to longitudinal changes in physical functioning among community-dwelling older adults.

Method

The analysis included 2 319 participants from the Health, Aging and Body Composition study (aged 71–82 years, 47.9% men, and 37.3% Blacks) who completed the Brief Smell Identification Test in 1999–2000. Olfaction was defined as good (test score 11–12), moderate (9–10), or poor (0–8). Physical functioning was assessed up to 4 times over 8 years, using the Short Physical Performance Battery (SPPB) and the Health Aging and Body Composition Physical Performance Battery (HABCPPB). We conducted joint model analyses and reported the differences in annual declines across olfaction groups.

Results

During the follow-up, compared to those with good olfaction, older adults with poor olfaction had greater annual declines in both the SPPB score (−0.137, 95% CI: −0.186, −0.088) and all its subscales: standing balance (−0.068, 95% CI: −0.091, −0.044), chair stand (−0.046, 95% CI: −0.070, −0.022), and gait speed (−0.022, 95% CI: −0.042, −0.001). A similar observation was made for the HABCPPB score (difference in annual decline: −0.032, 95% CI: −0.042, −0.021). These findings are robust and cannot be explained by measured confounding from demographics, lifestyle factors, and chronic diseases or by potential biases due to death and loss of follow-up. Similar associations were observed across subgroups of sex, race, and self-reported general health status.

Conclusion

This study provides the first epidemiological evidence that poor olfaction predicts a faster decline in physical functioning. Future studies should investigate potential mechanisms.