Transmission Characteristics Research Articles

Effect of Learning Management Using the Orff Approach on Violin Playing Ability of Fourth-Grade Students

Background and Aims: In the past, Chinese music education exhibited characteristics of traditional transmission and indoctrination. Students were often in passive roles during their learning process, with teachers predominantly imparting knowledge and methods, neglecting student involvement in practical activities. This experimental research aimed to 1) compare violin playing ability before and after learning through learning management using the Orff approach and 2) compare violin playing ability after learning management using the Orff approach with the criteria at 70%. Methodology: This study used a cluster sampling method with 30 students as the sample. The research instruments were as follows: 1) Six lesson plans using the Orff approach 2) violin playing ability test, with a reliability of 0.78 3) a violin playing ability assessment form, with a reliability of 0.75. Data were analyzed using the statistical software program. The statistics used for data analysis are the mean, standard deviation, t-test for dependent samples, and t-test for one sample. Result: After using the learning management using the Orff approach: (1) Students' academic achievements were significantly higher than before use, with a statistically significant difference of 0.05; (2) The student's academic achievements are above the 70% standard, and the difference is statistically significant at 0.05. Conclusion: Through learning management using the Orff approach, learning efficiency has been improved and the personalized learning needs of students have been met. To help students improve their performance ability and enhance their learning interest.

A numerical simulation method for ultrasonic transmission in cancellous bone based on a four-parameter random growth method

Abstract Quantitative ultrasound (QUS) has been widely used in non-destructive evaluation of bone health in research and clinical practice. To make a more accurate bone evaluation, the transmission characteristics of ultrasound in the bone need to be understood in detail. In the two-dimensional finite element model, cancellous bone is usually simulated by a non-porous structure solid or by approximating bone trabeculae as ellipses, which is different from real bone. However, although the error of the model constructed by bone CT images is small, it needs to be based on real bone samples, and the samples are limited. Therefore, a modeling method of cancellous bone based on four-parameter random growth method was proposed in this paper, and on this basis, numerical simulation of ultrasonic transmission was carried out. Firstly, based on the four-parameter random growth method, the aggregation algorithm is used to concentrate discrete pixels and smooth the edge of pores. Meanwhile, the built-in algorithm ensures the same porosity before and after processing to reduce the discrete pore structure. Secondly, based on COMSOL to establish the simulation model of ultrasonic propagation in cancellous bone, we analyzed the change of acoustic field distribution, discussed the correlation between the porosity of cancellous bone and backscattering coefficient (BSC) based on the ultrasonic backscattering method, and compared the experimental results of CT scan images of bone samples. The experimental results show that the cancellous bone modeling method in this paper has the same conclusion as the method based on CT images, which verifies the feasibility of this method. This method can generate a geometric model of the cancellous bone microstructure with specified porosity and different bone trabecular distribution, which is similar to the real bone structure, and can be directly imported into the finite element software to facilitate the study of bone microstructure related problems. It provides a more convenient method to study the mechanism of ultrasonic propagation in cancellous bone and has important significance in solving the inverse problem of recovering effective bone parameters from the received ultrasonic signals.

The evolution and practice on design concepts of internal fixation devices for intertrochanteric femur fractures

Surgical treatment has been established as the standard method for the treatment of intertrochanteric fractures in the elderly. The design of internal fixation devices has become the key to improve surgical outcomes and reduce postoperative complications. Centered on optimizing biomechanical performance and minimally invasive implantation, coupled with continuous material improvements, the design philosophy of internal fixation devices has also been constantly evolving. There have been several milestone advancements, such as the transition from eccentric fixation to central fixation, the adoption of sliding compression fixation, the replacement of traditional screws with spiral blades, and the shift from single to double (combination) nails. However, the incidence of internal fixation-related complications has remained at a relatively high level of 5% to 10%, without significant breakthroughs. Increasing evidence suggests that in-depth analysis of the anatomy, physiological mechanisms, and mechanical transmission characteristics of the proximal femur can help elucidate the root causes of internal fixation failures. Based on this, the proximal femoral bionic nail (PFBN) has emerged as a new design concept. By fully mimicking the anatomical, mechanical, and biological characteristics of the proximal femur, the PFBN can regulate the local mechanical environment, providing a revolutionary solution and a new approach for the treatment of proximal femoral fractures. This innovative design also has the potential to drive the paradigm shift in the treatment strategies of other fractures.

Optical properties of the 1D quasiperiodic photonic crystals comprising gyroidal superconductor for THz applications

The present research proposes a quasiperiodic 1D photonic crystal structure, which is designed with a successive arrangement of gyroidal geometry-based Bismuth Strontium Calcium Copper Oxide (BSCCO) superconducting material and SiO2 following a 10th order of Fibonacci sequences. The numerical simulation is carried out using the transfer matrix method to study the transmittance characteristics over a broad band of THz frequency range. The effects of various structural parameters such as filling fraction of BSCCO in the gyroidal layer, hosting materials of the gyroidal layer, and the Fibonacci sequence order on the transmission spectrum are extensively analyzed. It is observed that by suitably dealing with these parameters, we can easily control the number of stop bands, and the cutoff frequency as well. Therefore, the designed structure can be considered as an apt candidate for multichannel filtering applications in the THz frequency regime.

Experimental Study of the Effect of Roller Shape Variations on the CVT System using Petrol-Pyrolytic Fuels toward the Power Characteristics of Automatic Motorcycles

There are two types of two-wheeled vehicles when viewed from the transmission system: manual and automatic. The automatic transmission circuit on the automatic motor, the roller (ballast), is on the primary pulley. In the market, various rollers (weights) are sold, starting from those that are standard and different from the standard with lighter or heavier weight variations. However, there are also aftermarket rollers produced in several automotive industries, one of which is UNIONMATERIAL. The difference lies in the shape and materials used. This study aims to analyze the effect of variations in the shape of the roller on the characteristics of power transmission on automatic motorcycles. The type of vehicle used is a motorcycle produced in 2009 using a dyno test test with two test methods. The first test is from low engine speed ± 1400-1600 rpm to 9000 rpm, while the second test is from medium engine speed ± 4000 rpm to 9000 rpm. In addition, the fuel consumption test was also carried out. The variation used is a roller shape consisting of a round roller, a sliding roller, and a flying roller weighing 12 grams. The highest results obtained at a power of 0.7 HP occurred on the flying roller with 7.1 HP/ 3916 rpm, while the torque was 5.19 N.m on the flying roller (23.96 N·m/1250 rpm). There is an effect on fuel consumption, but not too significant. The biggest difference occurred in the engine parameter RPM 5000 of 0.1 between the flying roller (0.9 L/h) and sliding roller (0.9 L/h) with the round roller (1 L/h) - this happens because the shape of the flying roller is not cylindrical and more dynamic, which is adapted to the movable drive face. There is an additional wing on the roller weight. The data from the results of this study have implications for increasing vehicle performance without changing engine capacity, which requires large costs.

Gain enhancement of mm-wave antenna using graded index lens integrated frequency selective surface for 5G NR FR2 applications

In this study, the gain of a printed antenna is boosted for utilization in 5G systems by employing a phase-oriented graded index-type lens system. In the prescribed design, various metamaterial unit cells are arranged as arrays with radial phases for the graded meta lens to optimize transmission characteristics. The suggested arrangement creates a meta lens with spatially varying surface impedance and locally varying refractive index, allowing the conversion of spherical wavefronts into planar wavefronts for beam collimation in the 5G band. The focal length-to-diameter ratio (f/d) is fixed at 0.38 in this prescribed design. The integration of the FSS structure with the patch antenna enhances the efficiency above 98% and increases gain by 2.635dBi owing to the focusing effect of the properly placed lens. The prescribed planar lens is easy to realize during manufacturing compared to 3D lenses. The meta lens integrated patch yields a gain of around 8.936dBi at 29 GHz. The performance of the lens antenna is evaluated through simulation studies and then validation of results is performed with experimental arrangement to ensure accuracy and reliability of the suggested methodology for gain enhancement of the functioning antenna at FR2 5G spectrum.

Radiation shielding calculation for interventional radiology: An updated workload survey using a dose monitoring software

Shielding design is an essential aspect of radiation protection. It is necessary to ensure that barriers safeguard workers, patients, the general public, and the environment from the harmful radiation emitted by X-ray machines. The National Council on Radiation Protection and Measurements (NCRP) 147 method is widely accepted within the radiation protection experts’ (RPEs) community for structural shielding design for medical X-ray imaging facilities. However, these indications are based on data collected in 1996. In recent years, interventional radiology procedures have seen significant developments. Therefore, it is important to evaluate whether updating the data on workload in the different specialities is necessary.We extracted all interventional radiology exposure data parameters from three angiographs from two vendors using dose monitoring software for 3066 procedures and 214,697 individual exposures. The workload distribution as a function of the kVp for five interventional rooms was calculated by summing all exposures and then normalising them by the number of patients.Analysing this data, we obtained new transmission curves through lead, concrete and gypsum wallboard, finding the parameters (α, β, and γ) in the Archer equation for the secondary radiation. Finally, our aim was to share an example of shielding calculations for haemodynamics and neuroangiography rooms to illustrate the impact of updated transmission data.

Study on the effect of nonlinear inertia on the vibration isolation performance of quasi-zero-stiffness isolators

Typically, when subjected to excessive external force, quasi-zero-stiffness isolators with low damping will cause a sharp rightward bending of the transmissibility curve, resulting in a substantial decline in the performance of vibration isolation. The scheme with parallel tunable nonlinear inertia (PTNI) based on the triple-spring quasi-zero-stiffness (TS-QZS) isolator is designed to solve the above problems. To begin with, the kinetic equations are derived. Subsequently, the analysis of the primary response and stability involved the utilization of the Harmonic Balance Method (HBM), and the accuracy of the model was validated through numerical calculations. Finally, the impact of essential parameters is examined. The findings suggest that the QZS-PTNI isolator, without compromising the high frequency transmissibility, is capable of reducing peaks, suppressing the rightward trend of the transmissibility curve, narrowing the range of jump-up and jump-down frequency, and enhancing the vibration isolation performance.

Considering traffic characteristics: Roadside unit deployment optimization algorithm based on dynamic division of road network subareas

AbstractGiven that the overall coverage deployment method fails to meet information needs in important areas, there are redundancies and deficiencies in the information provided. To enhance communication stability for roadside units (RSUs), improve information coverage at critical intersections and optimize algorithm efficiency. Here, a method for deploying RSUs is proposed that aims to optimize revenue in road network subareas. The road network is divided into several subareas based on critical intersections, node similarity, road segment correlations, and characteristics of RSU information transmission. Then, a roadway accessibility algorithm is developed that accounts for channel fading. Considering the robustness of wire network deployment, an improved traveling salesman problem (TSP) problem is proposed that includes candidate locations and constructs a model for optimal RSU deployment that maximizes consolidated revenue. Finally, using the Sioux Falls network as an example, the RSU deployment strategy is evaluated for the overall network and the road network after being subdivided. The results indicate that subdividing the road network improves the efficiency of the optimization solution, the information coverage of critical intersections increases by 1.8 times. The deployment optimization scheme of RSUs is directly influenced by various parameters such as bandwidth capacity and cost coefficient. When deploying RSUs in road network subareas, variations in total demand have minimal impact on RSU deployment, ensuring a stable deployment scheme.

In-situ growing Eu-MOF on TEMPO-oxidized cellulose nanofibers to form fluorescent films for Fe3+ detection

Metal-organic frameworks (MOFs) are porous hybrid materials made of metal and organic linkers. Combining MOFs with polymers enhances their performance and addresses the issue of low stability. In this study, a uniform nanoscale Eu(III)-based metal-organic framework (Eu-MOF) was synthesized and grown in situ on TEMPO(2,2,6,6-tetramethylpiperidinyl-1-oxide)-oxidized cellulose nanofibrils (TOCNF), resulting in the formation of Eu-MOF@TOCNF fluorescence films through vacuum filtration. These films exhibited favorable mechanical properties, high transmittance, and stable fluorescence characteristics within the pH range of 3–11. The film produced the characteristic emission peak of Eu3+, recognized the selective quenching of Fe3+ within 0–100μM, and displayed an inverse relationship between fluorescence intensity at 616 nm and Fe3+ concentration. This approach holds significant promise for Fe3+ detection in solutions and offers a novel strategy for developing highly efficient optical sensors based on fluorescence specificity.

Reconfigurable multi-band electromagnetically induced transparency metamaterial based on graphene

By utilizing the monolayer graphene, we propose a reconfigurable multiband EIT 3D structure in the THz region, which exhibits eight consecutive transparency windows spanning from 1.16 to 2.80 THz, and the according transmission intensities were in the range of 0.75–1.0. Furthermore, with the help of graphene and VO2, the transmission curves can be modulated efficiently. The research results demonstrate that the structure proposed can generate high-intensity slow light effects at multiple frequency points within the terahertz range. Compared to existing research on EIT metamaterials, this structure offers advantages such as operation in multiple frequency bands, high transmission coefficients, and flexible modulation capabilities. Therefore, this study helps design novel tunable THz devices.

Complex Dispersion Analysis of Flexural Wave Propagation in Periodic Track Structure

The periodic characteristics of the track structure have filtering characteristics for the propagation of vibration waves within it, and the dispersion analysis is of great significance to understand the vibration transmission characteristics of the track structure. The accuracy of the traditional virtual spring method depends on the value of spring stiffness, which leads to poor stability. Therefore, this paper adopts a null space method with both stability, accuracy and efficiency, and takes the CRTSIII ballastless track structure as the research object. Based on the null space method and energy functional variational principle, the damping factor and the material frequency variation effect are considered in detail, and the complex frequency dispersion of the CRTSIII ballastless track structure is analyzed. The accuracy of the proposed method is verified by comparing it with the results of the existing literature, and the influence of fastener stiffness frequency variation, fastener damping and concrete support layer damping on the complex dispersion characteristics of vibration waves of track structures is analyzed by using this method. The results show that the stiffness frequency effect, fastener damping and concrete support layer damping have a great influence on the attenuation domain and attenuation rate of vibration, which must be considered in the vibration transmission analysis of track structures.

Using the space-time evolution spectrum to investigate the transmission characteristics of lightning return stroke current

Exploring the physical characteristics of lightning discharge channels based on spectrum can help to reveal the microscopic mechanism of the discharge process and provide a theoretical basis for lightning protection research. According to the spectra of six cloud-to-ground lightning return stroke processes and plasma conduction theory, we investigated the evolution of the total intensity of ionic and atomic lines in the spectra, conductivity, and other parameters along the discharge channel at different stages of the return stroke. The results show that the intensity of ionic lines in the spectrum present an obvious decaying trend with increasing height along the channel during the initial current-rise phase of the return stroke. In the later stages, the decay of ionic line intensity along the channel height slowed down. The intensity of the atomic lines varied slightly with increasing height along the channel during the entire return stroke process. The different space-time evolution characteristics of the spectral line intensity with different excitation energies reflect the differences in the mechanism of light radiation in the core current-carrying and surrounding thermal channels. The spectral characteristics further confirm that the ionic line with higher excitation energy directly relates to the physical process in the core current-carrying channel, and its intensity can roughly reflect the change in current along the channel. The attenuation of the return stroke current along the channel was mainly manifested in the initial stage of the return stroke. The decay rate of conductivity along the channel height is slower than that of the ionic line intensity throughout the return stroke stage, which is related to the channel diameter, it is another key parameter affecting the current transmission in the discharge channel.

Heterogeneous characteristics of stress transmission within finer fraction of gap-graded soils and its relevance to suffusion\\suffosion

The heterogeneous transmission of particle stress within the finer fraction has a critical effect on the development of suffusion\\suffosion in gap-graded soils, while quantitative evaluations on it are still needed. To this end, the stress transmission within the finer fraction of gap-graded soils with packing fabrics covering all the four typical packing fabrics under isotropic confining pressure were studied using discrete-element simulations. The finer particles with at least one contact, termed connected finer particles are classified into two groups that carry obviously different particle stress and have different contact features: primarily- and secondarily-stressed finer particles, which is well indicated by the gap in the particle stress contribution distribution of the connected finer particles, and meanwhile by the transition limitations of particle connectivity. The primarily-stressed finer particles always play a primary role in supporting the soil skeleton, while the role of the secondarily-stressed finer particles is closely related to the stress-reduction factor, α. The transition limit was found to be α = 0.146–0.191, over which the secondarily-stressed finer particles play a primary role in supporting the soil skeleton, while below which they play a secondary role. It also sets the borderline to identify the suffusion and suffosion susceptibility of gap-graded soils.

Social Network Public Opinion Analysis Using BERT-BMA in Big Data Environment

The existing social network public opinion analysis methods have problems such as poor semantic expression quality and weak detection ability in short texts. Therefore, a social network public opinion analysis method based on BERT-BMA is proposed. To normalize the comment text, the rumor text is initially transferred to a word vector matrix using the BERT (Bidirectional Encoder Representations from Transformer) model. The BiLSTM-based network architecture is subsequently employed to acquire the trace features of data transmission. Ultimately, this study employs the multi-head attention mechanism to extract feature information that is more significant in the analysis of online public opinion by mining the dependency relationships between users, resulting in increasing ability to detect public opinion emergencies. The experimental outcomes indicate that the results on the Twitter data set and Weibo dataset are superior to other comparative models.

An all-dielectric chiral metasurface with circular dichroism and asymmetric transmission characteristics

An all-dielectric chiral metasurface with circular dichroism and asymmetric transmission characteristics

Nonlinear static and dynamic response of a metastructure exhibiting quasi-zero-stiffness characteristics for vibration control: an experimental validation

This work introduces a novel metastructure designed for quasi-zero-stiffness (QZS) properties based on the High Static and Low Dynamic Stiffness mechanism. The metastructure consists of four-unit cells arranged in parallel, each incorporating inclined beams and semicircular arches. Under vertical compression, the inclined beams exhibit buckling and snap-through behavior, contributing negative stiffness, while the semicircular arches provide positive stiffness through bending-dominated behavior. The design procedure to achieve QZS is established and validated through finite element analysis and experimental investigations. The static analysis confirms a QZS region for specific displacement. Dynamic behavior is analyzed using a nonlinear dynamic equation solved using the Harmonic Balance Method, validated experimentally with transmissibility curves showing sudden jump down with effective vibration isolation. Parametric studies with varied payload masses and excitation amplitudes further verify the ability to of metastructure to attenuate vibrations effectively in low-frequency ranges.

Candidatus Midichloria mitochondrii can be vertically transmitted in Hyalomma anatolicum

In this study, a tick intracellular symbiont, Candidatus Midichloria mitochondrii, was detected in Hyalomma anatolicum from Xinjiang, China. Morphological identification and cytochrome oxidase subunit I sequence alignment were used for molecular identification of the tick species. PCR detection further revealed the presence of endosymbiont C. M. mitochondrii in the tick. Specific primers were designed for Groel and 16S rRNA genes of C. M. mitochondrii for PCR amplification and phylogenetic analysis. To further investigate the vertical transmission characteristics of C. M. mitochondrii, specific primers were designed based on the FabⅠ gene fragment to detect C. M. mitochondrii in different developmental stages and organs of the tick using qPCR. Of the 336 tick specimens collected from the field, 266 samples were identified as H. anatolicum on the basis of morphological characteristics. The gene fragment alignment results of COI confirmed that these ticks were H. anatolicum. The phylogenetic analysis showed that Groel gene of C. M. mitochondrii clustered with Midichloria strains detected in Ixodes ricinus ticks from Italy and Ixodes holocyclus ticks from Australia, with 100% sequence similarity. Furthermore, the 16S rRNA gene of C. M. mitochondrii clusters with the strains isolated from Hyalomma rufipes ticks in Italy, exhibiting the highest degree of homology. qPCR results showed that C. M. mitochondrii was present at all developmental stages of H. anatolicum, with the highest relative abundance in eggs, and lower relative abundance in nymphs and unfed males. With female tick blood feeding, the relative abundance of C. M. mitochondrii increased, and a particularly high relative abundance was detected in the ovaries of engorged female ticks. This study provides information for studying the survival adaptability of H. anatolicum, and provides data for further investigation of the mechanisms regulating tick endosymbionts in ticks, enriching the reference materials for comprehensive prevention and control of tick-borne diseases.

Coupled topological edge and corner states in two-dimensional phononic heterostructures with nonsymmorphic symmetries

The exciting discovery of topological phononic states has aroused great interest in the field of acoustic wave control. However, conventional topological edge states and corner states localized at the interface and corner of the two-phase domain wall structures are limited by single channel transmission characteristics, which decreases the flexibility of designing multi-channel acoustic wave devices. Here, we propose a two-dimensional (2D) topological phononic heterostructure with nonsymmorphic symmetries to realize the multiple interface topological multimode interference effect based on the coupling of topological edge and corner states. Topological phase transitions are achieved by altering the rotation angle of the split-ring scatterers in a square lattice. The coupled edge states are generated by the coupling between the edge states of ordinary-topological-ordinary (OTO) interfaces. Moreover, the higher-order topology of the square phononic crystals (PCs) is characterized by nontrivial bulk polarization, the topological and coupled corner states splitting into two pairs appear in the square OTO bend structure owing to the nonsymmorphic PC lack of mirror symmetries. Finally, the topological robustness of the multimode interference effect of coupled edge and corner states against defects is demonstrated. Our results pave the way for guiding and trapping acoustic waves in topological nonsymmorphic heterostructures, whose multi-channel transmission capability can be employed for designing topological phononic filters, couplers and multiplexers.

Pure-quartic soliton attracted state and multi-soliton molecules in mode-locked fiber lasers

This article explores the dynamic model of pure-quartic solitons (PQSs) in mode-locked fiber lasers. Firstly, the formation and dynamic behavior of the PQS attracted state in fiber lasers are investigated to demonstrate their exceptional stability, robustness, and predictability. Next, the transmission characteristics of single PQS in mode-locked fiber lasers is subsequently analyzed and compared to those of solitons generated while considering the effect of second-order dispersion. Finally, the evolution of multi-PQS molecules is explored, and a stability analysis method for these soliton molecules is proposed. The findings of this research are not only significant for a deeper understanding of nonlinear interaction mechanisms but also contribute to the development of ultrafast optical devices and offer new insights into the understanding and application of complex nonlinear systems.