bluuebunny/crossref_metadata_2025 huggingface dataset:
First Study of the Prevalence and Characterization of Brachial Plexus Injuries in Guatemala
Authors: González Lemus Carmen Joanna , Romero Prieto Fernando Xavier
Published: July 2021

Objective This study aimed to estimate the prevalence of brachial plexus injuries and to characterize clinically and epidemiologically patients with brachial plexus injury.

Materials and Methods In this cross-sectional descriptive study, 2,923 medical records of patients aged 1 to 64 years who presented at outpatient peripheral nerve unit of the Orthopedic Surgery Department of Hospital Roosevelt, Guatemala, from January 2017 to December 2017, were prospectively analyzed to identify the prevalence and factors associated with brachial plexus injuries.

Results The prevalence rate of brachial plexus injuries in patients was 5.74%. This injury is more common in men (90.5%) aged 24 to 64 years. Brachial plexus injuries occurred secondary to motorcycle accident in 72% of the cases, with the majority affecting the dominant upper extremity. In addition, 64.28% of the patients took 1 to 6 months to seek consultation, whereas only 16.07% requested medical assistance <1 month from the onset of symptoms, and this result was associated with early diagnosis and adequate recovery during follow-up. Furthermore, 66.67% presented upper brachial plexus injury with no associated fractures or vascular injury, manifesting distress while performing daily activities that required hand, arm, and elbow movements.

Conclusion The risk of suffering BPIs in Guatemala increases in economically active male patients that use motorcycles as main mode of transportation. Patients should consult immediately after injury onset to optimize management results. For this reason, hospitals must develop specialized clinical guidelines to speed up the identification and treatment of BPI injuries.
Gastric Foreign Bodies in Prison Inmates
Authors: Kumar Manish , Sachdeva Sanjeev , Kumar Ajay , Sonika Ujjwal , Gupta Manish , Srivastava Siddharth , Dahale Amol , Dalal Ashok
Published: July 2021

Objective Gastric foreign bodies are a common problem brought to an endoscopist. Prisoners are more prone to ingesting unusual foreign bodies for a secondary gain. The objective of this study was to study the profile of foreign body ingestion among the prisoners brought to a tertiary care center.

Methods This is a retrospective case series. All the prisoners brought for endoscopic removal of foreign bodies between January 2018 to December 2019 were included in the analysis. Patients’ baseline characteristics, type of foreign body, management, and outcome were noted

Results A total of eight inmates presented with ingestion of foreign body to our department. Most common foreign bodies ingested were drug packets and mobile phones. All ingestions were for secondary gain. Endoscopic removal was successful in all cases.

Conclusion Endoscopic removal can be tried with all necessary precautions by an expert endoscopist.
Sexuality of Female Spina Bifida Patients: Predictors of a Satisfactory Sexual Function
Authors: Motta Guilherme Lang , Bujons Anna , Quiróz Yesica , Llorens Erika , Zancan Maira , Rosito Tiago Elias
Published: July 2021

Objective To assess the sexual function of women with spina bifida (SB), and to verify the factors that influence their sexual function.

Methods A cross-sectional study in which a validated female-specific questionnaire was applied to 140 SB female patients from four different cities (Porto Alegre, Brazil; and Barcelona, Madrid, and Málaga, Spain) between 2019 and 2020. The questionnaires collected data on the clinical characteristics of SB, and female sexual function was assessed using the 6-item version of the Female Sexual Function Index (FSFI-6) validated to Portuguese and Spanish.

Results Half of the patients had had sexual activity at least once in the life, but most (57.1%) did not use any contraception method. Sexual dysfunction was present in most (84.3%) patients, and all sexual function domains were impaired compared those of non-neurogenic women. The presence of urinary and fecal incontinence significantly affected the quality of their sexual activity based on the FSFI-6.

Conclusion The specific clinical aspects of the SB patients, such as urinary and fecal incontinence, should be properly addressed by their doctors, since they are associated with reduced sexual activity and lower FSFI-6 scores in the overall or specific domains. There is also a need to improve gynecological care among sexually-active SB patients, since most do not use any contraceptive methods and are at risk of inadvertent pregnancy.
Severity of Maternal SARS-CoV-2 Infection in Pregnancy Predicts Neonatal Outcomes
Authors: Yasa Beril , Memur Seyma , Ozturk Dilek Yavuzcan , Bagci Onur , Uslu Sait Ilker , Polat Ibrahim , Cetinkaya Merih
Published: July 2021

Objective The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak had an enormous global impact. Pregnant women with SARS-CoV-2 appear to have higher morbidity and mortality. This study aimed to evaluate the effect of the severity of maternal SARS-CoV-2 infection on neonatal outcomes.

Study Design The clinical and laboratory data of 40 women and neonates evaluated retrospectively.

Results This retrospective study showed that SARS-CoV-2 infection had an adverse impact on neonatal outcomes proportionally with the maternal disease severity including increased prematurity rates, postnatal resuscitation need, prolonged hospital stay and longer ventilatory support requirement in infants born to mothers with moderate or severe disease.

Conclusion Maternal disease severity had adverse effects on neonatal outcomes. The severity of maternal disease was found to be associated with increased rates of prematurity, requirement of postnatal resuscitation, prolonged hospital stay, and longer ventilatory support.

Key Points
The Status of Interventional Radiology as a Specialty among Medical Students in India—Knowledge, Interest, and Exposure
Authors: Sebastian Bibin , Keshava Shyamkumar N. , Lakshminarayan Raghuram
Published: July 2021

Purpose Interventional radiology (IR) is a young medical specialty where image guidance is utilized in minimally invasive procedures as a treatment option and/or as a diagnostic tool. There is an exponential increase in awareness and interest in IR amongst medical students. This trend is continuing despite lack of proportionate representation of IR in the current medical curriculum. This study aims to understand the exposure to IR as a specialty amongst medical students in India.

Materials and Methods Anonymous, voluntary, online questionnaire was sent to medical students from different parts of the country. The survey comprised 15 questions regarding exposure and awareness on IR.

Results The responses were obtained from 1,024 medical students from 98 medical colleges across the country, majority (57.0%) in the clinical years of their training. Thirty-six percent of them were interested in an IR career. Lack of awareness was the most (61.6%) cited reason for not choosing an IR career. Majority (57.9%) would consider IR as a clinical management option and believe that IR holds an important place in medical practice (68.4%).

Conclusion There is an evident under-representation of IR in the medical curriculum. However, an increasing awareness and interest among medical students toward IR as a specialty is demonstrated. Incorporation of IR into current medical curriculum in a systematic way is the need of the hour. This would ultimately benefit a wide cohort of patients across multiple specialties.
Analysis of Factors Affecting Air Kerma Area Product Obtained during Uterine Artery Embolization Procedures Using Logistic Regression
Authors: Soliman Khaled , Almutairi Ahmed , AlHarbi Murdhi , Almutairi Khaleel , Almutairi Turky , Bakkari Mousa
Published: July 2021

Purpose Uterine artery embolization (UAE) is a common interventional radiology procedure used in medicine; the procedure is safe but there is always a concern regarding radiation dose received by the patient. The aim of this study was to use multivariable logistic regression analysis (MLRA) to study a certain number of independent prognostic variables believed to provide an estimate of the likelihood of obtaining a high kerma area product (P
KA) at the end of the procedure.

Method Radiation dose indices registered by the angiographic system structured dose report, the total fluoroscopy time (FT), the patient’ body mass index (BMI), the number of images taken during the procedures (IMGS), and the performing physician experience (EXPER) were used to drive a logistic regression model (LRM).

Results The LRM found was: Logit (P
KA) = −6.1525 + 0.0416 (FT) + 0.1028 (IMGS) + 0.1675 (BMI) – 0.1012 (EXPER). The prediction accuracy of the LRM was assessed using receiver operating characteristic (ROC) curve; by calculating the area under the curve (AUC), we found AUC = 0.7896, with optimal ROC point of 0.3261, 0.8036.

Conclusion The suggested LRM seems to indicate that patients with higher BMI, have taken longer FT, acquired higher IMGS and the procedure done by a less experienced performing physician is more susceptible to receive a higher P
KA at the end. The proposed LRM is useful in predicting the occurrence of higher radiation exposure interventions and can be used in patients’ radiation dose optimization strategies during UAE procedures.
Idiopathic Pulmonary Hemosiderosis: An Unexplored Cause of Treatment Refractory Pediatric Iron Deficiency Anemia
Authors: Reghunath Anjuna , Biswas Joyutpal , Mittal Mahesh Kumar , Kanaujiya Reeta , Khanna Geetika
Published: July 2021

Idiopathic pulmonary hemosiderosis (IPH) is an unusual cause of pediatric iron deficiency anemia (IDA) characterized by alveolar hemorrhage leading to hemosiderin deposition and fibrosis in the lungs. Though the typical triad of presentation is hemoptysis, IDA, and lung opacities on thoracic radiographs, often the sole manifestation of IPH may be severe IDA in children.
Evaluation of White Matter Tracts Fractional Anisotropy Using Tract-Based Spatial Statistics and Its correlation with Amyotrophic Lateral Sclerosis Functional Rating Scale Score in Patients with Motor Neuron Disease
Authors: Mohan Amutha Bharathi , Adithan Subathra , Narayan Sunil , Krishnan Nagarajan , Mathews Donna
Published: July 2021

Background Motor neuron diseases cause progressive degeneration of upper and lower motor neurons. No Indian studies are available on diffusion tensor imaging (DTI) findings in these patients.

Aims This study was done to identify white matter tracts that have reduced fractional anisotropy (FA) in motor neuron disease (MND) patients using tract-based spatial statistics and to correlate FA values with Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) score.

Settings and Design A case–control study in a tertiary care hospital.

Materials and Methods We did DTI sequence (20 gradient directions, b-value 1,000) in 15 MND patients (10 men and 5 women; mean age: 46.5 ± 16.5 years; 11 amyotrophic lateral sclerosis [ALS], 2 monomelic amyotrophy, 1 progressive muscular atrophy, and 1 bulbar ALS) and 15 age- and sex-matched controls. The data set from each subject was postprocessed using FSL downloaded from the FMRIB Software Library, Oxford, United Kingdom (http://www.fmrib.ox.ac.uk/fsl).

Statistical Analysis The statistical permutation tool “randomize” with 5,000 permutations was used to identify voxels that were different between the patient data set and the control data set. Mean FA values of these voxels were obtained separately for each tract as per “JHU white-matter tractography atlas.” SPSS was used to look to correlate tract-wise mean FA value with ALSFRS-R score.

Results We found clusters of reduced FA values in multiple tracts in the brain of patients with MND. Receiver operating characteristic curves plotted for individual tracts, showed that bilateral corticospinal tract, bilateral anterior thalamic radiation, bilateral uncinate fasciculus, and right superior longitudinal fasciculus were the best discriminators (area under the curve > 0.8, p < 0.01). FA values did not correlate with ALFRS-R severity score.

Conclusion In MND patients, not only the motor tracts, but several nonmotor association tracts are additionally affected, reflecting nonmotor pathological processes in ALS.
Multifocal Osseous Tuberculosis Mimicking Langerhans’ Cell Histiocytosis: A Case Series
Authors: Singh Rashmi , Naranje Priyanka , Kandasamy Devasenathipathy , Jana Manisha , Gupta Aditya K. , Ramateke Prashant P.
Published: July 2021

Langerhans cell histiocytosis (LCH) is a common cause of multifocal lytic skeletal lesions in children. However, multifocal osseous tuberculosis can affect children and mimics LCH on imaging, especially in endemic regions. We report cases with atypical manifestations of multifocal osseous tuberculosis which were presumptively diagnosed as LCH. The findings of our series of cases suggest that on computed tomography (CT) irregular sclerotic margins, abscess formation, sclerosis of involved bone, and button sequestrum point toward a diagnosis of multifocal osseous tuberculosis, especially in endemic regions.
Imaging in a Rare Case of Unilateral External and Middle Ear Anomalies Associated with Inner Ear Malformation
Authors: Joshi Anagha R. , Talreja Anisha O. , Rahatgaonkar Mrinalini M. , Badgujar Harshal A.
Published: July 2021

External ear malformations are commonly associated with middle ear malformations due to their closely related embryogenesis. Inner ear anomalies are less consistently seen due to their independent development. Cross-sectional imaging has come to play a critical role in the workup of congenital deafness in the pediatric age group. To optimize speech and language development, early diagnosis and treatment are very crucial. Identification of these anomalies is additionally important when operative intervention is being planned because they may complicate or perhaps preclude the surgery.
The Bubble Eye Sign: Understanding the Radiological Imaging of Gas inside the Orbit
Authors: Au Sunny C. L. , Ko Callie K. L.
Published: July 2021

Gas, appears as radiolucent on X-ray, is normally absent in the orbit. However, intraocular surgeries occasionally utilize retained intraocular gas for tamponade effect. Intravitreal gas persists after retinal surgery, being confounded by the scleral shell of the operated eye, outlines the shape of the eyeball, and gives the characteristic bubble appearance on skull X-ray. This is different from orbital emphysema caused by orbital fracture when gas is located outside the globe but confined by the orbit, giving a crescent or concave shape over the superior orbit usually. Falls is common after intraocular retinal surgeries due to change of usual stereopsis, prolonged prone posturing, and other systemic comorbidities. By identifying the “Bubble Eye sign” described, attending physician should alert the presence of intravitreal gas, most commonly iatrogenic. Further ophthalmological history taking and examinations are thus indicated, instead of exposing patients to unnecessary radiation under computed tomography scan for orbital fracture investigation.
Who are the dominant players in the experimental field of quantum entanglement? A bibliometric analysis
Authors: Xie Y.D. , Wu Q. , Li X.C. , Gao Y. , Zhang P. , Wu S.J. , Liu Y.Y. , Zhang N.
Published: July 2021

Quantum entanglement is a major research resource in quantum information science, which has obtained increasing attention and has been intensively studied experimentally in recent years. Based on 7089 research papers in the experimental field of quantum entanglement obtained from the Web of Science Core Collection database, this study investigates the 400 top-cited papers which were written by 498 first or corresponding authors from188 institutions in 32 countries/territories. This study not only relies on traditional methods with first author full counting and corresponding author full counting to present the critical authors, institutions, and countries as designers or executors but also uses distinctive methods with first/corresponding author full counting and first/corresponding author fractional counting to find the dominant players in the experimental field of quantum entanglement. Considering authors, A. Zeilinger and J.W. Pan are the most dominant scientists in this field. The University of Vienna has the best institutional performance in this field, and other institutions such as the University of Science and Technology of China also do fairly well. The results show that the USA, Germany, Austria, the UK, and mainland China fit their reputations as dominant players in the field.
A Risk Management Solution Designed to Facilitate Risk-Based Qualification, Validation, and Change Control Activities within GMP and Pharmaceutical Regulatory Compliance Environments in the EU—Part I
Authors: O'Donnell Kevin , Greene Anne
Published: July 2021

A risk management solution is described that is designed to facilitate risk-based qualification, validation, and change control activities within GMP and regulatory compliance environments in the EU. This solution is based upon a set of pre-defined, fundamental principles and design criteria, which were considered important. It offers a documented and ready-to-use ten-step process for determining and managing, on a risk basis, the scope and extent of qualification and validation, and the likely impact of changes.
Asymptotic stability of viscous shocks in the modular Burgers equation
Authors: Le Uyen , Pelinovsky Dmitry E , Poullet Pascal
Published: July 2021

Dynamics of viscous shocks is considered in the modular Burgers equation, where the time evolution becomes complicated due to singularities produced by the modular nonlinearity. We prove that the viscous shocks are asymptotically stable under odd and general perturbations. For the odd perturbations, the proof relies on the reduction of the modular Burgers equation to a linear diffusion equation on a half-line. For the general perturbations, the proof is developed by converting the time-evolution problem to a system of linear equations coupled with a nonlinear equation for the interface position. Exponential weights in space are imposed on the initial data of general perturbations in order to gain the asymptotic decay of perturbations in time. We give numerical illustrations of asymptotic stability of the viscous shocks under general perturbations.
Minimal constraints in the parity formulation of optimization problems
Authors: Lanthaler Martin , Lechner Wolfgang
Published: July 2021

As a means to solve optimization problems using quantum computers, the problem is typically recast into an Ising spin model whose ground-state is the solution of the optimization problem. An alternative to the Ising formulation is the Lechner–Hauke–Zoller model, which has the form of a lattice gauge model with nearest neighbor four-body constraints. Here we introduce a method to find the minimal strength of the constraints which are required to conserve the correct ground-state. Based on this, we derive upper and lower bounds for the minimal constraints strengths. We find that, depending on the problem class, the exponent ranges from constant α = 0 to quadratic α = 2 scaling with the number of logical qubits.
Low-cost dual-stage offset-cancelled sense amplifier with hybrid read reference generator for improved read performance of RRAM at advanced technology nodes
Authors: Wang Qiao , Zhang Donglin , Zhao Yulin , Liu Chao , Xu Xiaoxin , Yang Jianguo , Lv Hangbing
Published: July 2021

In this work, two process-variation-tolerant schemes for a current-mode sense amplifier (CSA) of RRAM were proposed: (1) hybrid read reference generator (HRRG) that tracks process-voltage-temperature (PVT) variations and solve the nonlinear issue of the RRAM cells; (2) a two-stage offset-cancelled current sense amplifier (TSOCC-SA) with only two capacitors achieves a double sensing margin and a high tolerance of device mismatch. The simulation results in 28 nm CMOS technology show that the HRRG can provide a read reference that tracks PVT variations and solves the nonlinear issue of the RRAM cells. The proposed TSOCC-SA can tolerate over 64% device mismatch.
Targeted transfer of self-assembled CdSe nanoplatelet film onto WS2 flakes to construct hybrid heterostructures
Authors: Song Zeguo , Wang Yunkun , Zhu Yunke , Bai Peng , Hu An , Gao Yunan
Published: July 2021

Colloidal CdSe nanoplatelets are thin semiconductor materials with atomic flatness surfaces and one-dimensional strong quantum confinement, and hence they own very narrow and anisotropic emission. Here, we present a polydimethylsiloxane (PDMS) assisted transferring method that can pick up single layer CdSe nanoplatelet films self-assembled on a liquid surface and then precisely transfer to a target. By layer-by-layer picking up and transferring, multiple layers of CdSe films can be built up to form CdSe stacks with each single layer having dominant in-plane transition dipole distribution, which both material and energic structures are analogous to traditional multiple quantum wells grown by molecular-beam epitaxy. Additionally, with the great flexibility of colloidal nanoplatelets and this transferring method, CdSe nanoplatelets films can be combined with other materials to form hybrid heterostructures. We transferred a single-layer CdSe film onto WS2 flakes, and precisely studied the fast energy transfer rate with controlled CdSe nanoplatelet orientation and by using a streak camera with a ps time resolution.
Observation of self-organized FRC formation in a collisional-merging experiment
Authors: Asai Tomohiko , Kobayashi Daichi , Seki Taichi , Tamura Yasuaki , Watanabe Tatsuhiro , Sahara Naoto , Takahashi Tsutomu , Morelli Jordan , Gota Hiroshi , Roche Thomas , Magee Richard , Binderbauer Michl , Tajima Toshiki , Inomoto Michiaki , Takahashi Toshiki
Published: July 2021

Self-organized field-reversed configuration (FRC)-like formation was observed after the super-sonic/Alfvénic collisional merging of two FRCs in the FAT-CM device at Nihon University. In this experiment, two FRCs were generated initially in two separate field-reversed theta-pinch type formation regions. Those two formation regions are coaxially connected to opposite ends of a cylindrical confinement chamber. The formed FRCs are oppositely-translated and collide in the middle of the confinement chamber at super-sonic/Alfvénic velocity. During the collision, the merged plasmoid experiences destructive disturbance and loses its fast toroidal flow and characteristic FRC property of having a field-reversed magnetic configuration to become a magnetized plasma without ordered structure. After this dynamic collision, a magnetic configuration of FRC with fast toroidal rotation is self-organized within a few tens of microseconds. This observation indicates robustness of the extremely high-beta, simple magnetic configuration.
Research on DDS-based Portable Signal Generation Testing Device
Authors: Hao Dawen
Published: July 2021

The signal generator has a wide range of applications in the fields of communication, measurement and control, navigation, radar, and medical treatment. At present, most of the signal generators in the laboratory are purchased precision instruments, which are not only expensive, but also can not fully perform their functions, resulting in a waste of resources [1]. Based on the analysis of the working principle of the existing signal generator, this paper takes the programmable DDS integrated chip as the core, and designs a sine wave and square wave signal generator that is simple in structure, high in accuracy, small in size, and suitable for laboratory requirements. The precision and error analysis are carried out on it. The signal generator is composed of a power supply system, a single-chip computer system, a DDS waveform generation module, an amplitude adjustment module, a square wave generation module, and a relay output module. A multiplier is used to multiply the sine signal and the analog signal of the single-chip microcomputer to achieve the purpose of amplitude modulation of the waveform. Compared with the general signal source, the signal generator has the advantages of small output signal frequency error, high resolution, full digital realization, easy integration, small size, light weight, convenient use, stable work, etc.
Liquid Level Detection of Syringe Pump and Syringe Based on Machine Vision
Authors: Liu Yunxi , Guo Miao , Gao Jingmin , Li Yue
Published: July 2021

When a nurse uses a syringe pump to infuse the patient, the nurse needs to contact the patient several times at a close range. This article proposes a method to detect the infusion of the syringe pump to reduce the frequency of contact between the nurse and the patient and reduce the labour intensity of the nurse. Using machine vision technology, filter and Prewitt operator are combined to process the acquired syringe pump pictures to obtain the accurate liquid level position. The image is captured by an industrial camera. After grayscale processing and image filtering, the Prewitt edge detection algorithm is used to obtain a clear edge image, and then the corner detection algorithm and pixel coordinate display are used to detect the liquid level of the syringe without external auxiliary measuring equipment. After performing multiple tests on 26 different liquid level images of a 50ml syringe, the results show that proposed method is effective to measure the liquid level in a non-contact way. The test result shows that the relative error is When the scale is 2ml to 16ml, the relative error range is -66% to -0.63%. When the scale is 18ml to 50ml, the relative error range is -1.86% to -1.19%. Among the 26 pictures, the absolute error of 22 pictures is within ±1ml, and the absolute error of 19 pictures is within ±0.5ml.
Scale recognition of non-electronic thermometers based on image features
Authors: Si Yao , Guo Miao , Gao Jingmin , Li Yue
Published: July 2021

At present, in terms of clinical temperature measurement in China, most hospitals use traditional mercury thermometers to obtain patient temperature data through human readings and records. In order to improve the work efficiency of medical staff and reduce the frequency of their contact with patients, machine vision is adopted. A scale recognition method of non-electronic thermometer based on image features is proposed. The reading data of clinical thermometers is calculated through pixels. The automatic reading record of the clinical thermometer is realized, and the relative error does not exceed 0.25% in the temperature range of 35.5 to 37.5°C, which has certain practical significance for the research in the field of intelligent medical treatment.
Research on Mechanical Antenna Performance Based on Rotating Permanent Magnet Triangle Array
Authors: Bao Jianqiang , Tian Yanwei , Wang Yan , Yi Qiuping , Li Na
Published: July 2021

Traditional low-frequency antennas have larger volume and higher energy consumption. These characteristics make the traditional antennas easy to be destroyed by the enemy and expensive to maintain. In this paper, a mechanical antenna based on triangular array of rotating permanent magnets is introduced, and a prototype is made according to the proposed theoretical assumptions. Different from the traditional electric antenna, the mechanical antenna adopts the way of motor driving the permanent magnet to rotate, which realizes the miniaturization of the low-frequency transmitting antenna. In this paper, the analytical model of the rotating magnetic dipole is presented. By comparing the simulation results and the experimental data with the theoretical calculation results, it is proved that the mechanical antenna based on the rotating permanent magnet array can emit low-frequency sinusoidal electromagnetic waves, which has a broad application prospect in the Ultra-Low-Frequency/Very-Low-Frequency (ULF/VLF) communication field.
Improved 2D-MUSIC estimation for low intercept coprime MIMO radar
Authors: Zhao Xiaotong , Zhou Jianjiang , Fan Huang , Wu Jiale
Published: July 2021

In electronic warfare, airborne multiple input multiple output (MIMO) radar must not only accurately detect the Angle of moving target, but also ensure the low interception performance of radar. In order to solve this problem, a low interception bistatic MIMO radar with improved coprime array is proposed in this paper. By expanding the coprime array of the bistatic MIMO radar, the array spacing is further expanded to form a sparse array, which reduces the hardware and software cost and improves the anti-jamming capability. In addition, based on the two-dimensional MUSIC algorithm to detect the Angle of the maneuvering target, Taylor expansion method is added to realize the Angle estimation under low SNR. The research results show that, compared with the joint DOD and DOA estimation in a bistatic MIMO radar, the improved method in this paper increases the estimation accuracy, reduces the computational cost of the algorithm, applies to low SNR environment, and ensures low interception performance.
Driving collision detection method based on VMD-KICA
Authors: Han Xu , Jianbing Li , Xueyu Dong , Xutao  , Jianbang Sun
Published: July 2021

With the rapid development of China’s transportation, higher requirements are put forward for the handling capacity of traffic accidents. Therefore, it is of great practical significance to study the effective monitoring methods of high-speed traffic accidents for timely guiding the traffic and saving the lives of the injured. The VMD is used to decompose the vehicle vibration signal, and the cross-correlation coefficient is used as the index to screen the components, and the KICA algorithm is used to extract the components of the screened component matrix, so as to further eliminate the environmental noise. The signal is recombined by the denoised components to highlight the time-domain statistical characteristics of the signal. The feature vector based on time-domain statistical parameters is constructed, and the recognition model is built by using the support vector mechanism optimized by genetic algorithm. The experimental results show that the accuracy of the method for vehicle driving state can be 95.5%.
Research on Simulation and Test of Antenna Isolation of Airplane and Spacecraft Platform
Authors: Yuan Wang , Rong Kong , Wei Tan , Lidong Cui
Published: July 2021

In order to discover in time the potential interference coupling relationship caused by the installation of multiple types of frequency-using equipment and antennas on an aircraft or spacecraft platform, and to improve the rationality and compatibility of the antenna layout. The antenna isolation must be simulated at the beginning of the aircraft or spacecraft platform design, and the antenna isolation must be tested before the antenna is installed. In this article, the simulation and test results of the real case show that the model construction error during simulation, the actual spatial attenuation, the actual diffraction attenuation, the actual occlusion factor and the test error during the test process have formed the preliminary error relationship between simulation results and test results.
New Adaptive Beamforming for Coherent Interference based on Covariance Matrix Reconstruction
Authors: Pu Mingang , Li Lichun , Jiang Heng
Published: July 2021

Conventional beamforming fail to derive the full-rank covariance matrix due to the existent of coherent interference in the spatial domain. Most of the existing methods suppress the correlation interference by sacrificing the degree of freedom (DOF). In this paper, we develop a new adaptive beamforming for coherent interference without the loss of DOF, and the process of this new algorithm is as follows. First, the steering vector of the interference signal is estimated through convex optimization. Then we estimate the interference signal power by decomposing the covariance matrix and reconstruct the interference plus noise covariance matrix (INCM). Finally, the array weights are obtained based on the maximum SNR criterion. The proposed method has no loss of DOF and the array gain is adjacent to the ideal value. The feasibility of the technique is proved by theoretical derivation, and the effectiveness of the method is also verified by numerical results.
Design and Analysis of a Series-Parallel Compliant Manipulator
Authors: Zhao JinZhi , Zhu ChunYi , Wang Wei , Ma ZiMeng , Sun WenPei
Published: July 2021

Because of friction and assembly clearance, the accuracy of traditional rigid parallel mechanism cannot be maintained for a long time. Compliant mechanism has the advantages of light weight, high precision and low wear. Combining the characteristics of the two mechanisms, this paper designs a series-parallel compliant manipulator structure, and studies its forward and backward kinematics. Finally, it uses MATLAB software to study its workspace. Motion analysis was carried out.
A WSN system for high-precision cable manhole cover movement detection uses TDOA ranging method
Authors: Luo Ping , Wang Huajun , Xiang Changcheng , Huang Chengbing
Published: July 2021

In the research of the power cable anti-theft problem, the demand for high-precision positioning of the cable manhole cover is proposed. For this reason, a wireless sensor WSN node with ranging function is studied. The system uses the Stm32 chip as the MCU core, uses 433MH radio frequency signals and ultrasonic signals to implement a ranging circuit based on the TODA principle of arrival time difference, and sends data to the cloud server through the NB-IoT module to achieve the purpose of alarming. The system has the characteristics of good real-time performance and high positioning accuracy. It can be applied to the theft prevention of cable manhole covers, and can also be extended to the detection of indoor moving objects.
Design of a Multi-Channel Expandable High-Precision Isolated Current Source Module
Authors: Chuanxi Jin , Minghui Liu , Panhui Chen
Published: July 2021

Small current source module has low accuracy, big ripple and cannot be used for multi-channel expansion and isolated output. In view of this, a high-precision isolated current source module for multi-channel expansion is designed. The current source module consists of an isolated power supply circuit, an A/D conversion circuit, a linear current stabilizer circuit, and a digital isolation circuit. MCU can implement control of the module through only three ordinary IO ports, and one MCU can simultaneously control multiple current source modules to complete multi-channel isolated output. The output accuracy of each channel can reach a level of 0.001mA.
Design and verification of SPI bus IP core
Authors: Wang Dawei , Yan Jiang , Qiao Ying
Published: July 2021

With the development of chip design technology, the complexity of the chip is getting bigger and bigger, and various IP (Intellectual Property) is integrated to form SoC (System on Chip). In order to improve the efficiency of designing SoC, IP reuse technology is often used, so the development of IP has a wide range of significance and use value. The SPI bus is a bus protocol often used in chip communication and has many application scenarios. Therefore, this research mainly develops the SPI bus IP. During the development process, the SPI bus design is carried out, then based on the UVM verification methodology the designed IP has been functionally verified, and finally, a fully functional SPI bus design is obtained.
Application of Multidimensional Features and GRNN in Electronic Nose for Detection of Hepatocellular Carcinoma
Authors: Lijun Hao , Min Zhang , Geng Zhu , Xuan Wang
Published: July 2021

A model based on multidimensional features and GRNN was designed for electronic nose (eNose) in the paper. It can be applied to distinguish hepatocellular carcinoma from normal controls. Hepatocellular carcinoma patients have altered composition of exhaled gas due to abnormal metabolism. Thus, we can detect them by the exhaled gas. In the paper, the exhaled gas signals of hepatocellular carcinoma patients and health controls were first collected with eNose. And then the features were extracted and the multidimensional combined features were achieved. Furthermore, the PCA method was applied to optimize the features. Next, the classification model based on GRNN was constructed for training and generalization ability testing. Finally, the constructed model was adopted to predict the test and the performance was calculated. The result shows that, with the limited training set, the performance of the GRNN model is better than the BPNN model. The prediction accuracy could reach to 91.3%. Therefore, the proposed model is well suited for the classification detection with small training set and this will contribute to the study of the practical application of the eNose in the clinic.
Unmanned Aerial Vehicle system layout based on two-layer interconnection model
Authors: Wang Qiwei , Liu Xinyu
Published: July 2021

Based on the Australian wildfire in 2019, this paper obtains the grid risk coefficient through the cellular automata model, and linear model and uses the cluster gravity method to select the location of EOC. Finally it gives the two-layer interconnection model constructed by SSA UAV and radio repeater UAV and the UAV system model of UAV two-layer interconnection coverage planning. It aims to create a safe and economic disaster monitoring system. The security, that is, the connectivity coverage rate of UAV system and the economy, that is, the total number of UAVs, are taken as the objective functions. The constraints are the minimum standard limit of coverage rate and connectivity rate, the limit of divided area, the limit of divided area inspection cycle, and the limit of the relationship between the built-in battery consumption and the number of on-the-job UAVs. According to the PSO-ACO fusion algorithm, the optimal number and combination of the two types of UAVs are obtained. The adaptability of the model to extreme fire events in the next ten years is verified by grey weight Markov prediction.
Indoor Positioning Experiment Based on Phase Ranging with Bluetooth Low Energy (BLE)
Authors: Lu Xingyu , Yin Yufang , Zhao Na , Wei Hua
Published: July 2021

In this paper, we propose and demonstrate an indoor positioning scheme based on phase ranging with Bluetooth low energy (BLE). It is to deal with the contradiction between the cost and accuracy of today’s indoor positioning system. The experiment is based on BLE multi-carrier phase ranging, and the DA14695 BLE module from Dialog Semiconductor is selected as the experimental hardware module. The linearized pseudo range observation equation and least square estimation are used to construct a positioning platform to verify its positioning effect. The experimental results show that the indoor positioning method based on BLE phase-based ranging has high positioning accuracy, and in view of the low-power and low-cost advantages of BLE itself, it shows that this indoor positioning scheme is feasible and has further research value.
Research on functional safety inspection method for functional safety of escalators in service
Authors: Zhang Xupeng , Yong Zhao
Published: July 2021

As a new technology, functional safety technology has been widely used in escalators. Functional safety inspection is the basis of escalator maintenance operations. This paper introduces the distribution and application of escalator functional safety, proposes a functional safety inspection method for escalator functional safety based on functional safety theory, and constructs a technical framework for escalator functional safety maintenance operation guidance, including data integrity, working environment, and daily inspection, Sensors, cabinets and control panels, wires and connectors, etc. and inspection methods. On this basis, taking the overspeed inspection of the escalator as an example, the escalator function safety maintenance operation guidance technology is explained.
Parallel Large-scale MOSFET Circuit Simulation using Multi-core CPU and Time-saving Techniques
Authors: Chen Chun-Jung , Yang Tai-Ning , Lee Chih-Jen , Chou Li-Ping , Hsu Sheng-Hsuan , Chang Allen Y. , Liu Chung-Hsin
Published: July 2021

In this paper, we investigate the acceleration properties of fine-grain parallel large-scale MOSFET circuit simulation using multi-core CPU. Several CPU have been tested for understanding maximum possible accelerations. A parallel circuit simulator, MOSTIME, is used to simulate experimental circuits. Performing tests on CPU and MOSTIME, we find that more advanced accelerations on large-scale fine-grain parallel circuit simulation would rely on time-saving software techniques and GPU (Graphic Processing Unit) cards. A newly implemented time-saving technique for MOSTIME has been tested to show promising effects.
Pierson-Moscowitz spectrum simulation based on the rough sea surface
Authors: Xiu Menglei , Li Lihua , Wang Yongbin , Wang Longfei , Hou Wenda
Published: July 2021

By analyzing a variety of traditional wave spectrum models, combining the actual wavelength and wave surface displacement to compare the electromagnetic field propagation process, the P-M (Pierson-Moscowitz) spectrum is used to theoretically derive the electrical characteristics of the rough sea surface and its influence on the propagation process of high-frequency electromagnetic waves. Based on the bilinear superposition algorithm and Matlab numerical calculation software, the electrical characteristics of rough seas and the theoretical results of electromagnetic wave propagation in rough seas are simulated and verified. The results show that the modeling of rough sea surface based on P-M spectrum has the advantages of high reducibility and stable frequency spectrum.
Accurate Aspect Ratio Estimation in Scale Adaptive Tracking
Authors: Lu Weikang , Su Ang , Zhang Wenlong , Shang Yang
Published: July 2021

In visual object tracking, robust scale estimation is always a challenging problem. Because of the fast movement of the target, the background, the relative distance and relative azimuth angle between the target and the background usually change greatly. However, traditional correlation filtering tracking method cannot track the target accurately or even lose the target when the target scale and aspect ratio change. To address these problems, this paper adds two independent filters for the length and width scale estimation to complete the adaptive tracking on the basis of the translation filter. The experimental results in the public data set show that: compared with the original trackers, our method improves the tracking accuracy significantly, and meets the needs of real-time target tracking.
A revocable attribute-based access control system using blockchain
Authors: Liu Xin , Zheng Yue-guang , Li Xu-zhou
Published: July 2021

Attribute-based access control is an effective cryptographic mechanism that allows a data owner to perform attribute-level access control over users’ access capabilities. In the application background of blockchain, it is urgent to use attribute-based access control to solve a series of security problems. Although there exist several similar schemes, they do not consider attribute revocation. By adopting the attribute revocation technique based on binary trees, we extended Waters’ ciphertext policy attribute-based encryption (CP-ABE) scheme into a revocable CP-ABE (RCP-ABE) scheme. By combining our RCP-ABE with blockchain, we constructed a revocable attribute-based access control system. The new system supports expressive access control policies and allows the attribute authority to revoke users’ attributes or part of their attributes. The security analysis shows that the new system satisfies several ideal properties, i.e., forward security, backward security, confidentiality, and integrity.
Application of State Transition Simulated Annealing Algorithm in Community Detection
Authors: Qin Xiaowei , Han Xiaoxia
Published: July 2021

Community detection is one of the most important attributes to reveal the hidden structure of complex networks. The way of community detection based on the intelligent optimization algorithm has been widely used. Aiming at the initialization problem of the solution, the paper uses the density peaks clustering (DPC) algorithm to obtain a stable and high-quality solution. Aiming at the search strategy, state transition simulated annealing algorithm (STASA) is proposed. On the basis, three types of operators are designed: vertex replacement operator, community fusion operator and cross mutation are designed. In the initial optimization stage, the vertex substitution operator is used to generate diverse solution. The community fusion operator speeds up the optimization in a certain sense. The introduction of the cross mutation operator in the later optimization stage is only suitable for high-quality solution and enhances the local search ability of the algorithm. Finally, the experimental results on the GN benchmark and the real-world networks show that the algorithm is superior to other classic community detection algorithms in terms of stability and accuracy.
Sound source localization based on improved adaptive beamforming
Authors: Xu Keni , Liu Wenhong , Wang Mianmian
Published: July 2021

In adaptive systems, the least mean square error (LMS) adaptive algorithm is widely used. The variable step size LMS algorithm (SVSLMS) based on the Sigmoid function has greatly improved the convergence speed, and the normalized LMS algorithm is stable Sexual performance has certain advantages. Therefore, improvement is made on this basis, the SVSLMS algorithm is normalized, and the iteration speed is increased by changing the iteration factor, and the stability of the algorithm is also improved. This paper uses MATLAB simulation tools to verify the superiority of the new algorithm. Finally, the improved algorithm is applied to beamforming to estimate the azimuth of arrival of the simulated sound source signal at the partial discharge point of the submarine power cable.
A GM-CPHD Filtering Algorithm Assisted by Luminance Information
Authors: Li Yue , Sun Quan , Wang Dongya , Huang Jian , Li Pengyuan , Wang Yupeng , Niu Zhaodong
Published: July 2021

Optical tracking of small and weak targets in space, has problems such as a large and unknown number of targets, dense clutter, close measurement of neighboring targets, and false detection and missed detection. In this paper, a Gaussian mixture cardinalized probability hypothesis density (GM-CPHD) filtering algorithm assisted by luminance information is proposed. By establishing the luminance likelihood function, the luminance information is introduced into the CPHD filtering process, and the Gaussian mixture implementation method is given. The simulation results indicate that the proposed algorithm can effectively adapt to the dense clutter environment, and compared with the traditional GM-CPHD filtering algorithm, its tracking accuracy for multiple targets is significantly improved.
An improved Simhash algorithm based malicious mirror website detection method
Authors: Chen Guangxuan , Chen Guangxiao , Wu Di , Liu Qiang , Zhang Lei , Fan Xiaoshi
Published: July 2021

There are a large number of similar or even identical webpages on the Internet. These webpages will cause unnecessary loss of network resources, including waste of storage space, decreased web search speed, and decreased user experience. And some malicious mirror websites will become tools for criminals to carry out illegal activities such as phishing attacks. In this paper, the autours analyzed the mainstream text similarity detection algorithms and webpage deduplication algorithms, and proposed an improved webpage deduplication algorithm based on Simhash. The algorithm converts the text collection into Simhash fingerprints for storage through mapping, and calculates the similarity of the two fingerprints through Hamming distance, thereby obtaining the similarity of the webpage. Experiments show that the algorithm proposed in this paper has a higher accuracy rate and recall rate, and can be better applied to the identification and detection of malicious mirror websites.