bluuebunny/crossref_metadata_2025 huggingface dataset:
Typical doses and typical values for fluoroscopic diagnostic and interventional procedures
Authors: Tristram Juliana , Steuwe Andrea , Kröpil Feride , Thomas Christoph , Rubbert Christian , Antoch Gerald , Boos Johannes
Published: February 2022

To implement typical doses (TD) and typical values (TV) for fluoroscopic diagnostic and interventional procedures. A total of 3811 fluoroscopic procedures performed within 34 months on three devices were included in this retrospective study. Dose-, patient- and procedure-related information were extracted using the institutional dose management system (DMS). TD/TV were defined as median dose and calculated for the five most frequent procedures per device for dose area product (DAP), cumulative air kerma (CAK) and fluoroscopy time (FT). National diagnostic reference levels and other single facility studies were compared to our results. Additionally, the five procedures with the highest doses of each device were analysed. To evaluate the data coverage of the DMS compared to the picture archiving and communication system (PACS), procedure lists were extracted from the PACS and compared to the procedure information extracted from the DMS. TD/TV for 15 procedures were implemented. Among all devices, TD for DAP ranged between 0.6 Gycm2 for port catheter control (n = 64) and 145.9 Gycm2 for transarterial chemoembolisation (n = 84). TD for CAK ranged between 5 mGy for port catheter control and 1397 mGy for aneurysm treatment (n = 129) and TV for FT ranged between 0.3 min for upper cavography (n = 67) and 51.4 min for aneurysm treatment. TD for DAP and CAK were lower or within the range of other single facility studies. The five procedures with the highest median DAP per device were identified, 6 of 15 procedures were also found to be among the most frequent procedures. Data coverage of the DMS compared to the PACS ranged between 71% (device 2, stroke treatment) and 78% (device 1, lower limb angiography) for the most common procedure per device. Thus, in 22%–29% of cases dose data of the performed procedure was not transferred into the DMS. We implemented TD/TV for fluoroscopic diagnostic and interventional procedures which enable a comprehensive dose analysis and comparison with previously published values.
Mathematical reformulation of the Kolmogorov–Richardson energy cascade in terms of vortex stretching
Authors: Yoneda Tsuyoshi , Goto Susumu , Tsuruhashi Tomonori
Published: February 2022

In this paper, with the aid of direct numerical simulations (DNS) of forced turbulence in a periodic domain, we mathematically reformulate the Kolmogorov–Richardson energy cascade in terms of vortex stretching. By using the description, we prove that if the Navier–Stokes flow satisfies a new regularity criterion in terms of the enstrophy production rate, then the flow does not blow up. Our DNS results seem to support this regularity criterion. Next, we mathematically construct the hierarchy of tubular vortices, which is statistically self-similar in the inertial range. Under the assumptions of the scale-locally of the vortex stretching/compressing (i.e. energy cascade) process and the statistical independence between vortices that are not directly stretched or compressed, we can derive the −5/3 power law of the energy spectrum of statistically stationary turbulence without directly using the Kolmogorov hypotheses.
How likely can a point be in different Cantor sets
Authors: Jiang Kan , Kong Derong , Li Wenxia
Published: February 2022

Given

m
∈

N

⩾
2

, let

K
=

K

λ

:
λ
∈

(

0
,
1
/
m

]

be a class of self-similar sets with each

K

λ

=

∑

i
=
1

∞

d

i

λ

i

:

d

i

∈

{

0
,
1
,
…
,
m
−
1

}

,
i
⩾
1

. In this paper we investigate the likelyhood of a point in the self-similar sets of

K

. More precisely, for a given point x ∈ (0, 1) we consider the parameter set

Λ

(

x

)

=

λ
∈

(

0
,
1
/
m

]

:
x
∈

K

λ

, and show that Λ(x) is a topological Cantor set having zero Lebesgue measure and full Hausdorff dimension. Furthermore, by constructing a sequence of Cantor subsets of Λ(x) with large thickness we show that for any x, y ∈ (0, 1) the intersection Λ(x) ∩ Λ(y) also has full Hausdorff dimension.
Thermal conductivity and phonon scattering of AlGaN nanofilms by elastic theory and Boltzmann transport equation
Authors: Huang Lihong , Fan Senping , Sang Liwen , Mei Yang , Ying Leiying , Zhang Baoping , Long Hao
Published: February 2022

Aluminum gallium nitride (AlGaN) plays an essential role in deep ultra-violet light emitting diodes and high electron mobility transistors etc. For example, 2 nm – 5 nm AlGaN nanofilms consist of the quantum wells in ultra-violet light emitting diodes, which have been attracting extensive attention since the rise of COVID 2019. Since most photons and heat are generated in these AlGaN nanofilms, the thermal properties of AlGaN nanofilms are strongly influenced by the heat dissipation of devices. In this paper, utilizing elastic theory and the Boltzmann transport equation, the phonon dispersion relations, density of states, specific heat capacities and thermal conductivities of 2 nm Al
δ
Ga1−δ
N nanofilms with various δ are theoretically calculated at different temperatures. The thermal conductivity of nanofilm is significantly smaller than that of its bulk counterpart. In contrast with bulk AlGaN, due to the dominance of boundary scattering and alloy disorder scattering, the thermal conductivity of Al
δ
Ga1−δ
N exhibits a similar dependence on Al concentration to bulk Al
δ
Ga1−δ
N. Meanwhile, since the screening of Umklapp scattering, the saturation temperature of thermal conductivity is delayed from 50 to 100 K in bulks to about 300 K in nanofilms. The shrinkage of nanofilms’ thermal conductivity is also slower than for bulks. We believe that our work will be helpful in controlling the self-heating effect of devices based on AlGaN nanofilms.
Particle control in long-pulse discharge using divertor pumping in LHD
Authors: Motojima G , Masuzaki S , Morisaki T , Watanabe K Y , Kobayashi M , Ida K , Sakamoto R , Yoshinuma M , Seki R , Nuga H , Tsujimura T , Suzuki C , Emoto M , Tsuchibushi Y , Murase T , Takeiri Y
Published: February 2022

Density control is crucial for maintaining stable confined plasma. Divertor pumping, where neutral particles are compressed and exhausted in the divertor region, was developed for this task for the Large Helical Device. In this study, neutral particle pressure, which is related to recycling, was systematically scanned in the magnetic configuration by changing the magnetic axis position. High neutral particle pressure and compression were obtained in the divertor for a high plasma electron density and the inner magnetic axis configuration. Density control using divertor pumping with gas puffing was applied to electron cyclotron heated plasma in the inner magnetic axis configuration, which provides high neutral particle compression and exhaust in the divertor. Stable plasma density and electron temperature were maintained with divertor pumping. A heat analysis shows that divertor pumping did not affect edge electron heat conductivity, but it led to low electron heat conductivity in the core caused by electron-internal-transport-barrier-like formation.
Dynamics of breathers and rogue waves in scalar and multicomponent nonlinear systems
Authors: Wang Weiying , Wang Xiubin
Published: February 2022

In this paper, we propose a new method, the variable separation technique, for obtaining a breather and rogue wave solution to the nonlinear evolution equation. Integrable systems of the derivative nonlinear Schrödinger type are used as three examples to illustrate the effectiveness of the presented method. We then obtain a family of rational solutions. This family of solutions includes the Akhmediev breather, the Kuznetsov-Ma breather, versatile rogue waves, and various interactions of localized waves. Moreover, the main characteristics of these solutions are discussed and some graphics are presented. More importantly, our results show that more abundant and novel localized waves may exist in the multicomponent coupled equations than in the uncoupled ones.
Precision measurements and tau neutrino physics in a future accelerator neutrino experiment
Authors: Tang Jian , Vihonen Sampsa , Xu Yu
Published: February 2022

We investigate prospects of building a future accelerator-based neutrino oscillation experiment in China, including site selection, beam optimization and tau neutrino physics aspects. CP violation, non-unitary mixing and non-standard neutrino interactions are discussed. We simulate neutrino beam setups based on muon and beta decay techniques and compare Chinese laboratory sites by their expected sensitivities. A case study on the Super Proton–Proton Collider and the China JinPing Laboratory is also presented. It is shown that the muon-decay-based beam setup can measure the Dirac CP phase by about 14.2° precision at 1σ CL, whereas non-unitarity can be probed down to ∣α

ij
∣ ≲ 0.37 (i ≠ j = 1, 2, 3) and non-standard interactions to

∣

ϵ

ℓ
ℓ
′

m

∣
≲

0.11 (

ℓ
≠
ℓ
′
=
e

, μ, τ) at 90% CL, respectively.
Gold nanolens for chiral single molecule spectroscopy
Authors: Shutova Mariia , Quintero-Torres Rafael , Kamble Mrunal , Sokolov Alexei V
Published: February 2022

High demand for techniques to study molecular chirality inspires us to develop a nanolens for light with orbital angular momentum (OAM). The proposed nanolens can efficiently focus light with OAM onto the nanoscale, and create a so-called plasmonic vortex, which is much smaller than the diffraction limited vortex focused by an ordinary lens. The generated plasmonic vortex can efficiently differentiate between left- and right-handed molecules and probe electronic dipole-forbidden transitions. The nanolens consists of several radially aligned rods, and exploits surface plasmons to generate a plasmonic vortex-like structure in the center. We optimize this design to be suitable for beams with various topological charges, and to be easy to manufacture for the visible wavelengths range. We prove that nanolens can work efficiently with both even and odd number of rods. We study the efficiency of the nanolens for both left- and right-handed light, and show the resultant electric field and phase distributions.
Manipulation of nonreciprocal unconventional photon blockade in a cavity-driven system composed of an asymmetrical cavity and two atoms with weak dipole–dipole interaction
Authors: Zhang Xinqin , Xia Xiuwen , Xu Jingping , Li Haozhen , Fu Zeyun , Yang Yaping
Published: February 2022

We present a work of manipulating collective unconventional photon blockade (UCPB) and nonreciprocal UCPB (NUCPB) in a cavity-driven system composed of an asymmetrical single-mode cavity and two interacting identical two-level atoms (TLAs). When the atoms do not interact directly, the frequency and intensity restrictions of collective UCPB can be specified, and a giant NUCPB exists due to the splitting of optimal atom–cavity coupling strength in proper parameter regime. However, if a weak atom–atom interaction which provides a new and feeble quantum interference pathway to UCPB is taken into account, two restrictions of UCPB are combined complexly, which are rigorous to be matched simultaneously. Due to the push-and-pull effect induced by weak dipole–dipole interaction, the UCPB regime is compressed more or less. NUCPB is improved as a higher contrast is present when the two complex UCPB restrictions are matched, while it is suppressed when the restrictions are mismatched. In general, whether NUCPB is suppressed or promoted depends on its working parameters. Our findings show a prospective access to produce giant quantum nonreciprocity by a couple of weakly interacting atoms.
The potential of energy storage systems associated with PV generation to postpone investments in capacity expansion
Authors: Manito A R A , Almeida M P , Filho G F P , Almeida J C , Rodrigues M A C , Torres P F , Pinho J T , Zilles R
Published: February 2022

Postponement of infrastructure investment is often regarded as a potential benefit of distributed PV generation. However, PV has questionable impact on the postponement of investments for infrastructure capacity increase. This paper evaluates under which conditions and to which extent distributed photovoltaics and energy storage systems are able to aid the distribution system in terms of alleviating the loading of feeders. The methodology consists of a sensitivity analysis, in different demand and generation scenarios, on the impacts that photovoltaic generation and energy storage systems would have in alleviating distribution feeders. In each scenario, the synergy between energy storage and PV generation is evaluated by estimating the amount of energy storage capacity needed to reduce the peak demand to a desired level. Results show that the existence of PV generation may reduce the storage capacity needed (and consequently the cost) to achieve a desired peak demand reduction only if proper conditions are found in the demand curve.
Estimation of cycling aging of lithium-ion batteries for photovoltaic applications
Authors: Nakama V , Lafoz M , Nájera J , Sal y Rosas D
Published: February 2022

The installation of photovoltaic microgrids to meet energy needs has had a significant increase in recent years. Likewise, the use of lithium batteries to improve the performance of the microgrid is an issue that is being studied. In this sense, it is important to know the electrical response of the lithium battery under such environment and its degradation. In this sense, this paper presents a methodology developed for the mathematical modelling of the electrical behaviour of a lithium battery. This methodology has been developed from the integration of three mathematical models: dynamic model, thermal model and aging model. During its operation, the lithium battery will be subjected to constant charging and discharging processes (dynamic model), as well as to thermal stress, because of the combined effect of the current flow and the ambient temperature (thermal model), which will generate a lithium battery capacity loss (aging model). For the analysis, real data on photovoltaic production, residential consumption profile, ambient temperature and 48V 100Ah LFP battery datasheet have been used. The developed methodology allows estimating the aging of a lithium battery in real time.
Average photon energy assessment based on modelled spectra from the National Solar Radiation Database for Lima, Peru
Authors: Sevillano-Bendezú M A , Conde L A , de la Casa J , Töfflinger J A
Published: February 2022

The photovoltaic performance under operating outdoor conditions is affected by the variability of the solar spectrum. The spectral distribution is quantifiable using the average photon energy (APE). In the present study, we characterize the spectral distribution in a low-latitude location such as Lima - Peru through a decade of simulated solar spectra obtained on demand from the National Solar Radiation Database and taking as a reference one year of ground-based experimental data following the decade of theoretical spectra. This characterization utilizes annual and monthly averages of irradiance-weighted APEs. The results indicate a difference of only 0.2% between the average annual APE for the decade and the annual ground-based experimental APE. Additionally, the theoretical monthly APEs for the decade show a seasonality consistent with our experimental data for the summer months but not for the winter months.
Application of Dijkstra algorithm in finding the shortest path
Authors: He Baoyi
Published: February 2022

As the development of Automotive, people are doing research on self-driving and innovation of public transportation. The coming of 5G will made these come true soon in the future. And this paper is about an algorithm useful on transportation. Using Dijkstra algorithm to match two people who have the similar source and destination, then find the shortest path for them. For each person, the source and destination are two regions but not two points. This paper includes some methods to implement Dijkstra algorithm in detail and two examples to display the results. The algorithm is written in C language.
Multi Classification ERT Flow Pattern Recognition Method Based on Deep Learning
Authors: Wang Pai , Miao Yueying
Published: February 2022

Electrical resistance tomography (ERT) is the frontier technology of modern industrial detection, in which flow pattern is an important index of two-phase flow detection. Affected by many factors, ERT flow pattern recognition is difficult. In this paper, an ERT flow pattern recognition method based on deep learning is designed in order to obtain the real situation of flow pattern in pipeline in practical application. The original ERT measured voltage is transformed from one-dimensional data information to two-dimensional dot matrix information by pseudo image coding method. According to the characteristics, the flow patterns are divided into 27 categories, and then ERT voltage image databases with different scales are established in time domain and frequency domain. Convolutional neural network is used to construct ERT flow pattern recognition network model based on deep learning, and experiments are designed to verify its performance. The results show that the average accuracy of each flow pattern recognition of this algorithm can reach 98.74%, of which the accuracy of 14 types of flow pattern recognition is 100%. This method can achieve high-precision ERT flow pattern recognition task.
Deep Learning Applications in Simultaneous Localization and Mapping
Authors: Zhang Haoyang
Published: February 2022

Simultaneous Location and Mapping (SLAM) is a research hotspot in the field of intelligent robots in recent years. Its processing object is the visual image. Deep learning has achieved great success in the field of computer vision, which makes the combination of deep learning and slam technology a feasible scheme. This paper summarizes some applications of deep learning in SLAM technology and introduces its latest research results. The advantages and disadvantages of deep-learning-based-SLAM technology are compared with those of traditional SLAM. Finally, the future development direction of SLAM plus deep learning technology is prospected.
Heat Supply Optimization Based On Machine Learning And Knowledge Graph
Authors: Xie Chunfu , Xie Yutong
Published: February 2022

At present, heating companies mostly use a set-point temperature control curve. The operator adjusts the temperature control curve according to watching the outdoor weather conditions, which usually results in economic conditions. Given the above condition, we analyze the heating system’s mechanism first, then compile and analyze much historical data. According to the analysis results, we establish the heat exchange station-user room temperature joint model based on the machine learning method. Using the above model, the system is deeply explored, and the optimized secondary heating curve is designed and simulated. The results show that the user’s room temperature stability has an obvious control effect, which is of great significance to meet the room temperature compliance rate. At the same time, the knowledge graph of the heating field and some applications based on the knowledge graph are also built to provide more convenient and friendly operating advice for operators.
An aerodynamic surrogate model of launch vehicle based on relevance vector machine
Authors: Peng Bo , Ma Cheng , Wang Guodong , Hu Fengyan , Mei Ke , Yang Jian
Published: February 2022

In the process of launch vehicle multidisciplinary design optimization, aerodynamic calculation takes a long time, which affects the overall design cycle. In order to solve the above problems, based on the idea of machine learning, this paper constructs the surrogate model of relevance vector machine and calculates the aerodynamic coefficients of launch vehicles quickly. Firstly, the aerodynamic model of launch vehicle is established, and the orthogonal design method is used to generate test sample points. Then, the aerodynamic coefficients of the sample points are calculated by using Fluent software, and the training data of the surrogate model are obtained. On this basis, the relevance vector machine model is trained with training data, generating correlation vector machine agent model. Finally, the calculation accuracy of the surrogate model is evaluated by simulation, and the feasibility and validity of the method are verified.
The Efficient Implementation of Face Mask Detection Using MobileNet
Authors: Zhou Yuan
Published: February 2022

Under the condition of the global pandemic, Wearing the mask in the public area is the direct and ordered action to prevent the spreading of the virus. Therefore, developing the machine learning model to detect whether the mask is appropriately wearing is practical and meaningful. This paper unfolded the mask recognition based on the MobileNet model, which belongs to one of the branches of Convolutional Neural Network, CNN for short, in the deep learning field. With the background and tremendous needs of face mask detection, in the beginning, we go through the review of the MobileNet’s history and the practicability of it on demanding functions. After that, we explained in a more detailed way to help gain a better understanding of MobileNet’s structure and how those differences make it outstanding. During the experiment, approximately 9000 images were used as inputs by the model for training and optimizing. The result turns to the less weighted model presenting an acceptable accuracy of 87.96% and 93.5% for testing whether a person wears a mask and whether the mask is covered correctly correspondingly. We also discovered several shortcomings and limitations during the testing process. Those problems and some of the possible further directions of MobileNet will be discussed. As a result, the MobileNet shows the huge probability for further improvement to be equipped into the small-scale but sophisticated utensil.
Mechanical analysis of shield machine cutter head under multiple working conditions based on elastoplastic model
Authors: Min R , Zhang QL , Qin JY
Published: February 2022

The shield machine’s ability to simultaneously cut soft soil and hard rock makes it widely used in subway tunnels, diversion tunnels and other underground engineering constructions. As the core component of the composite shield machine, the shield cutter head has a decisive effect on the work efficiency of the shield machine. When the cutter head of the shield machine is working, the positive pressure of the cutter head directly affects the working performance of the shield machine. However, when the shield machine is working, the positive pressure of its cutter head has been influenced by many factors. Therefore, the problems of evaluating positive pressure of shield machine cutter head and optimizing structure of machine cutter heat are needed. In this study, the force balance equation has been used to derive the calculation formula of the positive pressure of the soil on the cutter head. This formula can analyze the positive pressure value of the cutter head under various working conditions under different friction coefficients. At the same time, this research uses Hypermesh software to integrate the cutter head body and the force transmission ring, and uses ANSYS statics simulation analysis method to perform mechanical calculations on the shield machine cutter head. The analysis of the cutter head is 1/6, 1/3, and 1/2 effect of soil on the cutter head when the rotor is locked, and the overall stress distribution of the cutter head is analyzed to optimize the structure design of the cutter head.
A method based on the transmission line information for normal operation and fault of solving transfer impedance
Authors: Li Mengjiao , Yu Haifeng , Xie Yuzheng , Chen Zehong , Li Xinran , Lu Chunjing
Published: February 2022

Under the background of UHV project, the level of power system short-circuit current increasing has been one of the challenges of these power grid is facing. Therefore, it is necessary to analyze the characteristics of short-circuit current in power grid. The traditional method of calculating transfer impedance is to form node impedance matrix through network, and then calculate transfer impedance by formula. The precondition of the traditional method is to know the parameter information of each element in power grid, however, it is difficult to accurately give the parameter information of each element in engineering application. Based on the limitations of the traditional method, a method based on the transmission line information for normal operation and fault of solving transfer impedance is proposed, which treats the grid as a black box except for the short circuit point, so it is not necessary to know the parameter information of each element in the power grid as a known condition. Applying the method to solve for transfer impedance in a ring network, and the results are compared with the results of the traditional method to verify that the method is feasible.
Analysis on the mechanical properties of crawler doubles - arm degree-dividing bar car bolt drill
Authors: Wang W H , Deng H S , Zhang Y , Zhou W
Published: February 2022

In view of the low efficiency of roadway support in coal mine, a crawler double arm bolts drill with indexing function is proposed, in view of the low efficiency of roadway support in coal mines, a crawler double-arm bolt drill with indexing function is proposed. The mechanical characteristics of its key components in the telescopic action of the spindle arm are calculated and analyzed, and the binding force of the spindle arm and the variation rule of the telescopic acceleration and rotation Angle parameters are obtained. And the torque of the spindle arms decreases slightly with the decrease of the rotation Angle of the spindle arm, and increases greatly with the increase of the length of the spindle arm. The results show that the maximum torque is 6914Mpa when the length of the spindle arm is 2.4m and the rotation Angle is 45°, which lays a foundation for the subsequent design of the drill car and the improvement of the efficiency of anchor guard operation.
Design of ECG Signal Generator Based on Motion Scene
Authors: Jiang Haoyu , Li Dongyu , Li Lanfei
Published: February 2022

With the normalization of cardiovascular diseases(CVD) in many countries, portable ECG monitoring devices have gradually become popular. However, since the current portable ECG monitoring equipment lacks a unified testing standard specification, a suitable calibration device is required for restraint. This research simulates a multi-state ECG signal generation system built using Arduino uno board for calibration of portable ECG monitoring devices. The system can generate human ECG signals of different intensities under different heart rates based on the operation of the host computer. The equipment has the advantages of simple, easy-to-use and low cost, and can be used as an ECG signal source for a portable ECG monitoring device in a simple laboratory environment.
Research on Dynamic Characteristics of Asphalt Graded Crushed Stone Ballast Bed Based on Discrete Element Method
Authors: Liu Li , Song Shanyi , Zhang Xianheng , Yuan Yingqiang
Published: February 2022

Through laboratory test, field test and discrete element simulation calculation, the dynamic characteristics of asphalt graded crushed stone ballast bed are studied, and the influence of asphalt graded crushed stone layer thickness on the dynamic performance of different structural layers of ballast bed is analyzed. The results show that compared with the traditional subgrade structure, the dynamic stress, dynamic deformation and vibration acceleration of asphalt graded crushed stone subgrade are smaller, and asphalt graded crushed stone is the main bearing structure layer. With the increase of the thickness of asphalt graded crushed stone layer, the stress state of subgrade is improved. It is recommended that the thickness of asphalt graded crushed stone layer is 16cm.
Study on Dynamic Response of Buried Pipeline Rolled by Heavy Vehicle Based on Co-simulation by ADAMS and ABAQUS
Authors: Jiang Wanlin , Miao Liu , Wang Yan , Gan Yutao , Jiao Shoutian , Zhang Hao , Xu Taolong
Published: February 2022

At present, the rolling load of heavy vehicles has become one of the main ground loads threatening the safety of buried pipelines. In this paper, the vehicle simulation is carried out based on ADAMS to extract the wheel force. At the same time, the pipeline soil coupling model is established based on ABAQUS. The amplitude of the random moving load extracted by ADAMS is used for finite element simulation calculation, the dynamic response process of the pipeline is simulated, and the stress distribution of the buried pipeline under the vehicle rolling load is obtained. Aiming at the pipeline stress concentration area, that is, the most vulnerable area of the pipeline, the pipeline load reduction and prevention and control measures are proposed, and the four measures are compared, which provides theoretical support for the actual engineering prevention and control.
The Influence of Seat Occlusion on Driver’s Binaural Signal in Automobile based on FEM-RTM Simulation
Authors: Cao Yuntao , Liang Linda , Tan Wei , Zhang Zhichao , Lei Cheng , Yu Guangzheng , Lu Bingwu , Liu Yingjie , Li Yun
Published: February 2022

Automotive environment is increasingly becoming an indispensable listening space in our daily life. Affected by the seat occlusions on sound propagation between the front-row and rear-row space, the speech communication between front and rear passengers in automobile is a well-known problem. However, this issue has been paid less attention. To this issue, the numerical simulation is a common, low-cost and high-efficiency technical approach. However, it is a well-known limitation on the effective frequencies to common numerical methods. To extend the region of effective frequencies, a combined approach of the finite element method (FEM) for low-frequency and the ray-tracing method (RTM) for high-frequency (i.e., FEM-RTM) was adopted in current work. The full-bandwidth binaural room impulse responses for a listener in driver’s seat were simulated with the speaker at mid-right seats, and both conditions with seats and without seats were taken into account. Result showed that the seats occlusions mainly affected the left ear (i.e., contralateral ear). The seat occlusions reduced the early decay time, speech transmission index and magnitude spectrum for left ear considerably. The inter-aural correlation coefficient under condition without seats was lower than that under condition with seats.
The Sound Field Characteristics in Automobile under Different Speaker Height based on Numerical Simulation
Authors: Liu Yingjie , Liang Linda , Zhang Zhichao , Tan Wei , Lei Cheng , Yu Guangzheng , Cao Yuntao , Lu Bingwu , Li Yun
Published: February 2022

The automotive acoustic environment has become an indispensable listening space in people’s daily lives. However, due to the complexity of the acoustic environment inside automobiles, the sound reproduction in automobile is particularly problematic compared with that in ordinary domestic environments. From the perspective of sound reproduction, it is an effective approach to improve the reproduction performance by raising the speaker height such that nearer to the height of listener’s ear. However, this issue has been less studied quantitatively. In current work, we aim to explore how the speaker height affects the sound field characteristics at target listening region by using the finite element method. The speakers at front door inner panels were mounted to three different heights, respectively, and the sound field characteristics at target listening region in driver seat were analysed. Result showed that for higher speaker layout resulted in larger sound pressure levels at the target listening point, and the sound field distribution tends to be more homogeneous. Also, raising the speaker height is conducive to giving a constant frequency response at the target listening point. This works can provide the reference for the design of automotive audio system.
Robust Optimization Design of Supply Chain Based on Correlated Multi-Performance Responses
Authors: Zhu Lianyan , Ouyang Linhan , Wu Feng
Published: February 2022

Aiming at the problem of supply chain robust optimization with multiple performance responses, a robust optimization method was proposed by combining principal component analysis with double response surface method based on Kriging meta-model. Firstly, through principal component analysis, the location characteristics and divergence characteristics of multiple related performance responses were transformed into the principal component comprehensive score of supply chain performance; secondly, the Kriging metamodels of location characteristics and divergence characteristics of multiple performance responses were constructed respectively, and the principal component comprehensive score model of comprehensive performance based on Kriging meta-model was constructed. Thus the optimal operating conditions by optimizing the constructed robust optimization strategy were obtained in order to realize the robust optimization of supply chain system with correlated multiple responses. Finally, a supply chain simulation case was given to illustrate the effectiveness of our proposed optimization method, and the robustness of different methods was also discussed. The comparison results showed that our proposed was more robust.
A Method of Computer-aided Design for Machine Center
Authors: Wang Zhun
Published: February 2022

This paper studies the conceptual design of MC (machining center), and the main findings are as follows: The RW (representative workpiece) is the data source of designing an MC. The mechanical matrix of an MC can be figured out by the requirement arising from NC manufacturing of the RW, in which the layout of an MC matrix is constructed with the FPCNMT (functional parts consisting of an NC machine tool). In any CAD system, the design jobs of an MC’s layout involve three different fields. The first work deals with the preconstruction of the feature-model repository of FPCNMT, and the methods of building the repository are introduced by the author. The second design issue focuses on the construction of the mechanical matrix of an MC, in which the writer presents assembling the matrix by calling the FPCNMT based on the PP of a RW. The last job involves correctness and optimum of the layout design of the MC.
Lightweight Design and Test of Electric Experimental Car
Authors: Song Fei , Wan Maosong , Duan Fude , Wu Huibo
Published: February 2022

A light-weight electric experimental vehicle is designed. According to the light-weight design requirements, the power battery, the battery manager and the driving Motor controller are designed and selected, the chassis frame, anti-rolling frame, steering system and driving system are designed and validated with CAD and CAE software respectively. On this basis, we have carried out the production, assembly and commissioning of the real vehicle. The test results show that the electric experimental vehicle has high practical value and can meet the requirements of experimental teaching. It is worthy of further study, performance optimization and application.
Research on Microstructure and Mechanical Properties of CMT and MIG Welded Joints of A6N01 Aluminum Alloy
Authors: Wang Hongguang , Cen Shengbo
Published: February 2022

Cold metal transition welding (CMT) and molten inert gas shielded welding (MIG) two welding processes were used to conduct butt welding tests on 2mm thick 6N01 aluminum alloy, and the microstructure and mechanical properties of the welded joints obtained by the two processes were tested.The results show that the welded joints of 6N01 aluminum alloy welded by CMT process have better appearance and less welding defects and welding spatter. The tensile strength of CMT welded joints is 213MPa and the elongation after fracture is 10.64%, which is slightly higher than that of MIG welded joints. The hardness distribution of CMT and MIG welded joints and the hardness values of each zone are basically the same. Compared with MIG welded joints, the grain structure of CMT welded joints and the equiaxed crystals on the side of the fusion zone near the base metal are smaller and more uniform.
Research on Hysteretic Behavior of Cold-Formed Thin-Wall Rolled Edge Channel Steel Flexural Members
Authors: Yang Jiabao , Guo Yanli , Yu Lipeng , Hu Chengli , Liu Yafei
Published: February 2022

The finite element software ABAQUS is used to calculate and analyze the mechanical performance of cold-formed thin-walled curved channel steel members under horizontal reciprocating load. Double nonlinear finite element model needs to be considered, the influence of geometric imperfection and residual stress. The accuracy of the results was verified by comparing with the relevant test results. On the basis of controlling the main parameters such as width-thickness ratio, axial compression ratio, slenderness ratio and buckling mode, the numerical simulation results of 9 hysteretic specimens were selected to research the influence of the above factors on the hysteretic performance of the flexural members. The analysis results show that the width to thickness ratio, axial compression ratio and slenderness ratio have great influence on the hysteretic performance of the flexural members. The larger the three main parameters are, the worse the bearing capacity, ductility and energy consumption of the members will be. Therefore, the design should avoid as far as possible to choose a larger width-thickness ratio and slenderness ratio section components.
Study on Lining Mechanical Behavior of Super Large Diameter Shield Tunnel during Segment Opening
Authors: Luo Ciyou , Yan Zihai , Wang Zijuan , Cui Hao
Published: February 2022

The mechanical behavior and risks of the lining of the super large shield tunnel during segment opening are still unclear. In order to study the characteristics of the mechanical behavior of the lining of the super-large-diameter shield tunnel during segment opening, Take the cross-passage project of Hangzhou Zhijiang Road Water Conveyance Corridor and Road Improvement Project as the engineering background. The MIDAS finite element numerical calculation model of the opening on the double-track main tunnel lining is established. The influence of the opening size and support stiffness on the mechanical behavior of the lining is analyzed separately. The main conclusions are: (1) The maximum deformation of the lining when opening occurs in the middle area directly above the opening. It is necessary to strengthen the deformation monitoring of the segment in this area during construction to prevent excessive deformation or even damage and accidents; (2) The reduction of the opening area within a certain range and the increase of the stiffness of the temporary support can reduce the deformation of the lining after the opening. Based on the determined parameters of the main tunnel lining and opening, the stiffness of the temporary support can be increased to reduce the deformation of the lining opening; (3) Setting up temporary supports and increasing the stiffness of the temporary supports cannot affect the final deformation of the lining after the temporary supports are removed. Therefore, to stabilize the lining in the open area, it is necessary to rely on pouring ring beams.
CPTU Interpretation for Silty Sand in Binh Dai Offshore Wind Farm
Authors: Wang Kuanjun , Lu Linfeng , Shen Kanmin , Xie Wei
Published: February 2022

Geotechnical engineering parameters are of significant effect on foundation design. In-situ tests such as piezocone penetration test (CPTU) are widely used for estimate of effective internal friction angle of sand. How to choose appropriate interpretation method for CPTU is a big problem for geotechnical design. As a case study, the laboratory test results and CPTU results of two Phases (Phase 2 and Phase 3) in Binh Dai offshore wind farm of Vietnam were analysed to establish the correlation between effective internal friction angle φ' and corrected tip resistance qt. The effective internal friction angles of the four sand layers in Binh Dai are found to be linear dependent on the soil depth. Meanwhile, linear expressions between effective internal friction angle φ' and corrected tip resistance qt are proposed, which have high quality in prediction of effective internal friction angle φ' for silty sand in Binh Dai. It worth noting that direct use of CPTU method established by other site’s data without any site specific experience would lead to misestimate at offshore wind farm in Vietnam. New correlations should be established by using site specific data cautiously.
Four-Parameter Shifts Control Chaos and Lead to Physical Behaviour in a Dual-Ring Erbium-Doped Fiber Laser
Authors: Yan Senlin
Published: February 2022

We study on a four-parameter shift (FPS) chaos-control method to obtain control of a chaotic dual-ring erbium-doped fiber laser and lead to physics behaviours of two laser rings. To control two chaotic laser rings, the pump parameters and gain parameters of dual-ring lasers are modulated simultaneously by four shift digital signals. It is found that controls of the two chaotic laser rings are realized and physics behaviours of two laser rings can be guided by FPS. As a result, chaos is led to two periodic behaviours. And physics movements of dual-ring lasers are guided to period-4, period-5, period-6, period-7, and some high-order-period. The obtained results have a large helpfulness for people’ study of control of dynamics system, control of chaos, optic control science, laser physics, and erbium-doped fiber laser application.
Domestic and International Mainstream BIM Software Application and Comparison Study
Authors: Wang Ying , Zhu Jiwei , Wei Baojun
Published: February 2022

With the rapid development of science and technology, the construction industry is showing the trend of informatization. BIM has emerged to bring vitality into the construction industry. This paper introduces the application of BIM software in various phases and the mainstream BIM software at home and abroad, and conducts a comparative study on each BIM software from the design phase, construction phase and operation and maintenance phase, analyses the advantages and disadvantages of each software, and helps relevant practitioners to quickly choose the appropriate software according to their needs.
Food flows between counties in the United States from 2007 to 2017
Authors: Karakoc Deniz Berfin , Wang Junren , Konar Megan
Published: February 2022

Food supply chains are essential for distributing goods from production to consumption points. These complex supply chains are important for food security and availability. Recent research has developed novel methods to estimate food flows with high spatial resolution, but we do not currently understand how fine-grained food supply chains vary in time. In this study, we use an improved version of the Food Flow Model to estimate food flows (kg) between all county pairs across all food commodity groups for the years 2007, 2012, and 2017 (which requires estimating 206.3 million links). We then determine the core counties to the US food flow networks through time with a multi-criteria decision analysis technique. Our estimates of county-to-county food flows in time are freely available with this paper and could be useful for future research, policy, and decision-making.
Climate change-related risks and adaptation potential in Central and South America during the 21st century
Authors: Hagen I , Huggel C , Ramajo L , Chacón N , Ometto J P , Postigo J C , Castellanos E J
Published: February 2022

Climate-related risks in Central and South America have received increased attention and concern in science and policy, but an up-to-date comprehensive review and synthesis of risks and adaptation potential is currently missing. For this paper we evaluated over 200 peer-reviewed articles and grey literature documents published since 2012. We found that climate change in Central and South America during the 21st century may increase the risk to severe levels for the following topical risk clusters: (a) Food insecurity; (b) Floods and landslides; (c) Water scarcity; (d) Epidemics of vector-borne diseases; (e) Amazon Forest biome shift; (f). Coral bleaching; (g) Coastal risks of sea level rise, storm surges and erosion; (h) Systemic failure due to cascading impacts of hazards and epidemics. Our synthesis also identified feasible adaptation measures for each risk. The impacts of the risks will be heterogeneous throughout the region, with rural communities, Indigenous peoples, Afro-Latin Americans, women, disabled people, and migrants identified as being the most severely affected. We refer to a number of adaptation options for each risk. However, unabated climate change together with low adaptive capacity will strictly limit adaptation options. Immediate strengthening of policies for building adaptive capacity and increase of research on the risk-adaptation nexus in Central and South America are paramount. Our findings might contribute to guide the adjustment and emphasis of adaptation policies and climate risk management strategies from local to national level.
Production of biogas using AnF2B reactor from cassava starch wastewater with consortium bacteria as biocatalyst
Authors: Prayitno  , Rulianah S
Published: February 2022

Cassava starch wastewater contains organic biodegradable (BOD, COD) with high concentrations so that it can be used as raw material for biogas through an anaerobic decomposition process. The purpose of this study was to evaluate the behavior of the continuous flow AnF2B reactor, related to the production of biogas in a variety of organic loads, from cassava starch wastewater. The AnF2B reactor has three parts of space with a total volume of 50 L, where each space contains biofilter (wasp nest-shaped) which is useful for the growth of bacterial consortium. The experiments were carried out by flowing wastewater into the AnF2B reactor continuously with organic loading of 2 g, 3 g, 4 g, and 5 g. The decomposition time was 1-10 days. The temperature in the reactor was maintained at 37 - 39 C and pH: 6.5 - 8. The results showed that biogas production was influenced by the organic load of wastewater, where the maximum biogas production of 6.926 L was obtained at an organic load of 5 g of COD and a biodegradation time of 3 days. The biogas produced contains CH4 (85%), CO2 (14.5%), and CO (0.5%).
Utilization of HVS paper waste with collage art and paper quilling techniques as a 2-dimensional medium for hair styling in beauty education program
Authors: Widowati T , Marwiyah  , Apriyani D , Achmadi T A , Wahyuni I E , Pangastuti N W , Dewani F S H
Published: February 2022

The accumulation of paper waste encourages the utilization of HVS paper waste with Collage and Paper Quilling Techniques as a 2-dimensional medium for hair styling learning. The purpose of this study was to understand the process of utilizing HVS paper waste with collage and paper quilling techniques as a 2-dimensional medium for hair styling learning; to explore the design and shape produced in the utilization of HVS paper waste with collage and paper quilling techniques as a 2-dimensional medium for hair styling learning; to learn the validity of 2-Dimensional media for Hair Styling Learning by utilizing HVS Paper Waste using Collage and Paper Quilling Techniques. Development research with qualitative descriptive data analysis was carried out, the process of utilizing HVS paper waste with collage and paper quilling techniques using loose scrolls and multi strips scrolls was explored. Design and shape of hair styling for 5 face shapes. Validity by 5 experts with an average of 89.33% and, the results of final product assessment by 60 students obtained an average of 92.70% based on indicators of aspects of regulation, balance, color, conformity, attractiveness. Utilization of HVS paper waste with Collage and Paper Quilling Techniques as a 2-dimensional medium for hair styling learning is declared very feasible.