Original Scheme Research Articles

Rainfall simulation analysis of front windshield lower trim panel system based on SPH method

Based on the smooth particle hydrodynamics method, a rain simulation model of the front windshield lower trim panel system was established in AVL PreonLab simulation software, and it was found that the risk of air conditioning inlet and wiper motor is low risk under the original scheme, but the risk of water in the cabin is greater. Considering the weakening of the sealing effect after the durability of the sealing cotton, the water may flow into the cabin; secondly, the water barrier bars on both sides of the wiper cover are not wide enough in the Y direction, and the water will flow into the cabin when the rain is heavy. Through the simulation analysis of the optimization scheme, the problem of water in the cabin can be solved, and the problem can be found in advance at the design stage, and the optimization scheme can be proposed to reduce the development cost of the whole vehicle, which is an important guidance for the development of water management of the whole vehicle.

Implicit direct time integration of the heat conduction problem in the Method of Matched Sections

The paper is devoted to further elaboration of the Method of Matched Sections as a new branch of finite element method in application to the transient 2D temperature problem. The main distinction of MMS from conventional FEM consist in that the conjugation is provided between the adjacent sections rather than in the nodes of the elements. Important feature is that method is based on approximate strong form solution of the governing differential equations called here as the Connection equations. It is assumed that for each small rectangular element the 2D problem can be considered as the combination of two 1D problems – one is x-dependent, and another is y-dependent. Each problem is characterized by two functions – the temperature, , and heat flux . In practical realization for rectangular finite elements the method is reduced to determination of eight unknowns for each element – two unknowns on each side, which are related by the Connection equations, and requirement of the temperature continuity at the center of element. Another salient feature of the paper is an implementation of the original implicit time integration scheme, where the time step became the parameter of shape function within the element, i.e. it determines the behavior of the Connection equations. This method was early proposed by first author for number of 1D problem, and here in first time it is applied for 2D problems. The number of tests for rectangular plate exhibits the remarkable properties of this “embedded” time integration scheme with respect to stability, accuracy, and absence of any restrictions as to increasing of the time step.

Implementation and evaluation of a spectral cumulus parametrization for simulating tropical cyclones in JMA‐GSM

AbstractA spectral cumulus parametrization (spectral scheme) developed using a cloud‐resolving model simulation was implemented in Global Spectral Model of the Japan Meteorological Agency (JMA‐GSM, GSM hereafter). The performance of the spectral scheme in terms of mean state, variability, and tropical cyclone (TC) properties was evaluated using atmosphere‐only model experiments by comparing results of the original convection scheme (based on Arakawa–Schubert scheme, AS scheme) and the spectral scheme. Parameter tunings were first conducted for the spectral scheme, through which the climatological errors of the cloud cover in the Southern Ocean and temperature were greatly improved. The spectral scheme showed comparable climatological errors to the AS scheme in the increased resolutions. The spectral scheme greatly improved tropical variability, that is, response to El Niño/Southern Oscillation and Madden–Julian Oscillation. Analyses on TC statistical data revealed that the spectral scheme improved TC properties in terms of genesis frequency, intensity, and the response of TC to tropical variability. Specifically, significant improvements were seen in the Northern Hemisphere. Further analyses on the TC structure revealed that higher TC intensity was sustained for longer times by the spectral scheme than by the AS scheme. The reason for this is that the spectral scheme better simulates convective heating by considering coexistence of different cloud types with parametrized vertically varying entrainment rates, especially from low to mid‐altitudes. The convective heating leads to a sharper vertical‐radial circulation in the TC structure, causing stronger incoming moisture flux toward the TC centre, and resulting in a stronger TC intensity. Consequently, the spectral scheme can simulate a comparable mean state, better variability, and better TC properties compared with the original scheme by simulating a more detailed convective structure. Therefore, it has a potential to increase the TC forecast skill for operational GSM.

Consensus algorithms based on collusion resistant publicly verifiable random number seeds

Publicly verifiable random number seeds are widely used in distributed systems and applications, especially in consensus algorithms. The purpose was to distribute the tasks and benefits among the participants fairly. A secure and efficient consensus algorithm is the foundation and guarantee of blockchain. We have been working on more concise, fair, and secure blockchain consensus algorithms. In this paper, we propose a new, more concise, efficient, and publicly verifiable random number seed generation scheme based on the existing secret sharing scheme and one-way function. We combined it with two blockchain consensus algorithms to improve the security and efficiency of the original scheme.

Gravity-induced entanglement between two massive microscopic particles in curved spacetime: I. The Schwarzschild background

The experiment involving the entanglement of two massive particles through gravitational fields has been devised to discern the quantum attributes of gravity. In this paper, we present a scheme to extend this experiment’s applicability to more generalized curved spacetimes, with the objective of validating universal quantum gravity within broader contexts. Specifically, we direct our attention towards the quantum gravity induced entanglement of masses (QGEM) in astrophysical phenomena, such as particles traversing the interstellar medium. Notably, we ascertain that the gravitational field within curved spacetime can induce observable entanglement between particle pairs in both scenarios, even when dealing with particles significantly smaller than mesoscopic masses. Furthermore, we obtain the characteristic spectra of QGEM across diverse scenarios, shedding light on potential future experimental examinations. This approach not only establishes a more pronounced and extensive manifestation of the quantum influences of gravity compared to the original scheme but also opens avenues for prospective astronomical experiments. These experiments, aligned with our postulates, hold immense advantages and implications for the detection of quantum gravity and can be envisioned for future design.

Robust and accurate Roe-type Riemann solver with compact stencil: Rotated-RoeM scheme

In this study, we aim to develop a robust and accurate Riemann solver to resolve strong shock waves with compact stencil information by applying the rotated hybrid concept to the RoeM scheme. The original RoeM scheme offers good robustness from the perspective of avoiding shock instability, also called the carbuncle phenomenon, in hypersonic flows by introducing Mach-number-based functions. These functions rely on multi-dimensional shock discontinuity sensing terms to capture grid-aligned shock waves, thus necessitating sharing of values of cells adjacent to each vertex. Consequently, constructing a data structure that can handle such a wide stencil is necessary, particularly for implementations on unstructured grids. Moreover, communication of this stencil information on parallel computation can increase computational costs.To overcome these complexities, the rotated hybrid concept is applied to the RoeM scheme, to replace the multi-dimensional terms while still resolving the grid-aligned shock instability. In addition, a Mach-number-based weighting function is introduced to distinguish between the flow around the boundary layer and the onset of shock instability. The damping characteristic of the proposed scheme is compared to that of the original RoeM scheme by conducting a linear perturbation analysis. The findings reveal that the proposed scheme effectively controls spurious oscillations across strong shock waves. Numerous test cases are presented to demonstrate the robustness and accuracy of the proposed approach. Notably, the proposed scheme successfully resolves thermal boundary layers and accurately predicts the heat transfer rate around stagnation points in hypersonic flows.

Photon subtraction with a Mach–Zehnder interferometer and its application to entanglement enhancement

Photon subtraction (PS) is an important operation for optic quantum information processing. Conventional PS is implemented using a single linear beam splitter (BS) and photon detector. However, in this study, we show that the PS effect can be enhanced using two beam splitters and an optional phase modulator. This can be considered PS with an extended version of the well-known Mach–Zehnder (MZ) interferometer. By tuning the transmittance of the two beam splitters and phase modulator, the probability of success can be considerably improved over that of the original PS scheme with a single BS and photon detector. Moreover, if applied to a single-photon input, our proposed scheme can even implement deterministic PS, which is almost impossible for the original scheme with a single BS and photon detector. Owing to the higher probability of success, applying the PSMZ method to the entanglement enhancement of a very weak two-mode squeezed vacuum state is straightforward. Our result is helpful for improving the yield of output entanglement.

Design and Simulation of Hydraulic Integrated Valve based on SLM Technology

Intelligent robots put forward the need for miniaturization and integration of hydraulic systems. Based on SLM technology, this paper designs a hydraulic integrated valve, integrates flow channels, adapters and other facilities on the valve body, replaces the original linear movement scheme with a rotating spool scheme, studies parameters such as runner diameter and minimum wall thickness, and simulates and analyzes the flow performance of liquid when the main control runner and a single valve work. The results show that the integrated valve has the advantages of light weight, small size and good performance.

Excavation compensation and bolt support for a deep mine drift

To overcome large deformation of deep phosphate rock roadways and pillar damage, a new type of constant-resistance large-deformation negative Poisson's ratio (NPR) bolt that can withstand a high pre-stress of at least 130 KN was developed. In the conducted tests, the amount of deformation was 200–2000 mm, the breaking force reached 350 KN, and a high constant-resistance pre-stress was maintained during the deformation process. A stress compensation theory of phosphate rock excavation based on NPR bolts is proposed together with a balance system for bolt compensation of the time-space effect and high NPR pre-stress. Traditional split-set rock bolts are unable to maintain the stability of roadway roofs and pillars. To verify the support effect of the proposed bolt, field tests were conducted using both the proposed NPR bolts and split-set rock bolts as support systems on the same mining face. In addition, the stress compensation mechanism of roadway mining was simulated using the particle flow code in three dimensions (PFC3D)-fast Lagrangian analysis of continua (FLAC3D) particle-flow coupling numerical model. On-site monitoring and numerical simulations showed that the NPR excavation compensation support scheme effectively improves the stress state of the bolts and reduces the deformation of the surrounding rock. Compared to the original support scheme, the final deformation of the surrounding rock was reduced by approximately 70%. These results significantly contribute to domestic and foreign research on phosphate-rock NPR compensation support technology, theoretical systems, and engineering practices, and further promote technological innovation in the phosphate rock mining industry.

Multi-Modal Urban Traffic Transfer Schedule Timetable Bi-Objective Optimization: Model, Algorithm, Comparison, and Case Study

The optimization of the connection between urban rail transit and the bus is an essential issue that benefits passenger travel and the urban structure and has social benefits, which can be realized by reasonably adjusting the bus departure schedule. This study is necessary because the development status quo of China’s urban transportation network planning is unreasonable, travel efficiency is not high, and operating costs are high. This paper sets up the decision variables of bus departure time and departure interval at each station, establishes a dual-objective optimization model with the minimum schedule change and the minimum transfer time, and studies the application of the augmented Chebyshev algorithm in the dual-objective optimization model. Secondly, based on the Shenzhen metro and public transportation integrated circuit card data, the case analysis uses the generalized Chebyshev algorithm and the non-dominated sorting genetic algorithm, respectively. The optimization results show that using the improved augmented and generalized Chebyshev algorithm in the bus schedule alteration time within a reasonable range can maximize the total transfer time, which compared with the original scheme is shortened by 68.06%. In contrast, genetic algorithms will make the complete bus schedule alteration prominent, and the whole transfer time is substantially increased. The results show that the improved augmented generalized Chebyshev algorithm is more suitable for solving the dual-objective rail transit connection problem.

Chiral resolution based on non-adiabatic holonomic quantum control via a transmon qutrit

Once the concept of chiral molecules was proposed, the task of chiral resolution has accompanied around in the related area. Naturally, scientists need fast and accurate methods to distinguish different chiralities. Here, we show a feasible method based on non-adiabatic holonomic quantum computation (NHQC), which can achieve over 99% discrimination of different chiralities. Based on the original scheme, we studied the modified version, NHQC+. The experimental data proved that it has better robustness than the original protocol, indicating a promising development in the relevant fields.

Performance measurement and configuration optimization based on orthogonal simulation method of earth-to-air heat exchange system in cold-arid climate

The earth-to-air heat exchanger (EAHE) is a remarkable technology that taps into the Earth’s subsurface heat to either heat or cool the air circulating within buried underground pipes, which can effectively reduce building energy consumption. In cold-arid regions of northwest China, outdoor climate parameters vary considerably throughout the year, and shallow soil temperatures also fluctuate dramatically. This dynamic thermal environment significantly impacts the practical application of the EAHE system. Furthermore, the operation efficiency of the EAHE system can be influenced by the configuration of system parameters. Therefore, this paper takes an EAHE project in Lanzhou as the research object to investigate the operation performance, energy consumption and economy of EAHE in the cold-arid regions of Northwest China. The research results show that heat exchange potential is high in summer and winter, and the outlet temperature varies more gently in winter. During the summer, the cooling capacity of the system is sufficient to the cooling demands of the building, without using auxiliary equipment for cooling; compared to an air-cooled unit with a COP of 3.2, the system reduces cooling energy consumption by 2063.4 kWh. Moreover, we determined the influence degree and optimal scheme of each factor under different evaluation indexes through orthogonal simulation. The specific parameters of the optimal scheme are as follows: pipe length 20 m, pipe diameter 100 mm, buried depth 4 m, and airflow velocity 7 m/s. Compared with the original scheme, the heat transfer efficiency and heat transfer power of this scheme are increased by 37.91 % and 17.6 %, respectively, and the cost per unit heat transfer power is 11,700 CNY/kW, which is 8000 CNY/kW lower than the original scheme.

Numerical coupling of aerosol emissions, dry removal, and turbulent mixing in the E3SM Atmosphere Model version 1 (EAMv1) – Part 2: A semi-discrete error analysis framework for assessing coupling schemes

Abstract. Part 1 (Wan et al., 2024) of this study discusses the motivation and empirical evaluation of a revision to the aerosol-related numerical process coupling in the atmosphere component of the Energy Exascale Earth System Model version 1 (EAMv1) to address the previously reported issue of strong sensitivity of the simulated dust aerosol lifetime and dry removal rate to the model's vertical resolution. This paper complements that empirical justification of the revised scheme with a mathematical justification leveraging a semi-discrete analysis framework for assessing the splitting error of process coupling methods. The framework distinguishes the error due to numerical splitting from the error due to the time integration method(s) used for each individual process. Such a distinction results in a framework that provides an intuitive understanding of the causes of the splitting error. The application of this framework to the dust life cycle in EAMv1 confirms (i) that the original EAMv1 scheme artificially strengthens the effect of dry removal processes and (ii) that the revised splitting reduces that artificial strengthening. While the error analysis framework is presented in the context of the dust life cycle in EAMv1, the framework can be broadly leveraged to evaluate process coupling schemes, both in other physical problems and for any number of processes. This framework will be particularly powerful when the various process implementations support a variety of time integration approaches. Whereas traditional local truncation error approaches require separate consideration of each combination of time integration methods, this framework enables evaluation of coupling schemes independent of particular time integration approaches for each process while still allowing for the incorporation of these specific time integration errors if so desired. The framework also explains how the splitting error terms result from (i) the integration of individual processes in isolation from other processes and (ii) the choices of input state and time step size for the isolated integration of processes. Such a perspective has the potential for the rapid development of alternative coupling approaches that utilize knowledge both about the desired accuracy and about the computational costs of individual processes.

MRLWE-CP-ABE: A revocable CP-ABE for post-quantum cryptography

Abstract We address the problem of user fast revocation in the lattice-based Ciphertext Policy Attribute-Based Encryption (CP-ABE) by extending the scheme originally introduced by Zhang and Zhang [Zhang J, Zhang Z. A ciphertext policy attribute-based encryption scheme without pairings. In: International Conference on Information Security and Cryptology. Springer; 2011. p. 324–40. doi: https://doi.org/10.1007/978-3-642-34704-7_23.]. While a lot of work exists on the construction of revocable schemes for CP-ABE based on pairings, works based on lattices are not so common, and – to the best of our knowledge – we introduce the first server-aided revocation scheme in a lattice-based CP-ABE scheme, hence being embedded in a post-quantum secure environment. In particular, we rely on semi-trusted “mediators” to provide a multi-step decryption capable of handling mediation without re-encryption. We comment on the scheme and its application, and we provide performance experiments on a prototype implementation in the Attribute-Based Encryption spin-off library of Palisade to evaluate the overhead compared with the original scheme.

A novel Cosine-Cosine chaotic map-based video encryption scheme

The surge in online activities has led to the increasing popularity of sharing video data across diverse applications, including online education tutorials, social networking, video calling, and OTT platforms. Encryption prevents unauthorized access to the transmitted data over unreliable channels. The well-known features of chaos theory such as random behaviour, unpredictability, and initial parameters dependency facilitate its use in cryptography. Many security issues are faced by chaos-based cryptosystems because of their less complexity. Hence, a new Cosine-Cosine chaotic map characterized by intricate chaotic behaviour is designed in the current study. Additionally, we formulate an original video encryption scheme employing this Cosine-Cosine chaotic map. The encryption process involves five steps, beginning with the segmentation of the original video into frames based on its frame rate. In the second phase, a 384 bits pseudorandom key is generated that is further divided into three subkeys of 128 bits each. The novel Cosine-Cosine chaotic map-based sequence is generated. In the fourth step, red, green, and blue components are encrypted using the pseudorandom key and the chaotic sequence. In the last step, we combine encrypted frames to get cipher video. The security analysis validates that the proposed encryption protects against eavesdropping.

Multi‐hop anonymous payment channel network based on onion routing

AbstractPayment channel networks (PCNs) are one of the most promising off‐chain solutions to the blockchain scalability problem. However, most current payment channel schemes suffer from overly ideal routing assumptions or fail to provide complete path privacy protection. To address the above problems, the multi‐hop anonymous and privacy‐preserving PCN scheme are analyzed and a multi‐hop anonymous PCN based on onion routing is proposed based on it. The scheme removes the routing assumptions of the original scheme, designs an onion routing‐based payment channel network, and modifies the way relay nodes construct elliptic curve discrete logarithmic problems to resist wormhole attacks. Finally, the security analysis shows that the scheme in this paper has atomicity, relational anonymity and resistance to wormhole attacks. The latest bilinear pairing anonymous multi‐hop payment (EAMHL+) scheme is used to compare communication and computing overhead. The results show that the scheme in this paper requires less communication overhead and is more efficient in terms of computational overhead when the average hop number of the payment channel network is 3 hops and the network diameter is 6 hops.

МЕТОДЫ МАГНИТНО-ИМПУЛЬСНОЙ СВАРКИ (ОБЗОР)

The article presents the features of various methods of pulsed welding in the solid phase using magnetic pressure according to a scheme with normal loading. A scheme of magnetic-pulse welding, implemented through electrical discharge cleaning without oblique impact, is described. Magnetic pressure is used for forming and welding. The authors proposed an original scheme for producing enclosing structures from dissimilar alloys by preheating the assembled unit in a vacuum, followed by crimping through the transmitting medium «shell» with an inductor according according to the «crimp» scheme. To obtain joints of the «rod-sheet» type in a heterogeneous combination of materials and structures of different thicknesses, the authors proposed to carry out a sequential connection of a magnetic hammer with the parts being welded, which allows synchronizing the process of thermal and force effects on the surfaces being welded. Various schemes for mating parts to be welded have been developed, including those using powder compositions as a connecting element. To implement the presented technological processes, universal special technological discharge-pulse equipment has been created, which makes it possible to implement the processes of welding, stamping, pressing, crimping, electric explosion of conductors and electrohydropulse processing of materials.

Cryptanalysis and Improvement of a Blockchain-Based Certificateless Signature for IIoT Devices

With the rapid development of the Industrial Internet of Things (IIoT), security and privacy issues have become increasingly prominent when the data from IIoT devices is shared across public networks. Very recently, Wang <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et</i> <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">al.</i> presented a blockchain-based certificateless signature (CLS) scheme for IIoT devices in order to achieve secure and lightweight communication (IEEE Transactions on Industrial Informatics, DOI: 10.1109/TII.2021.3084753). Wang et al. claimed that their CLS scheme is secure under the assumption of the elliptic curve discrete logarithm problem. Unfortunately, by providing two attack methods to analyze the security of Wang et al.'s CLS scheme, we find that it is insecure against universal forgery attacks. Without knowing any information about the target user's private key, the two categories of attackers can successfully forge the valid signature of any message. Hence, Wang et al.'s CLS scheme fails to achieve the claimed security goals. To fix the security flaws, we propose an enhanced blockchain-based and pairing-free CLS scheme, and prove its security in the random oracle model. Furthermore, the analysis results demonstrate that our revised scheme has higher security while keeping the performance of the original scheme.

Modification of Microphysical Parameterization Schemes and Their Application in the Simulation of an Extremely Heavy Rainfall Event in Zhengzhou

AbstractIn the present study, the Morrison and Thompson microphysics schemes in the Weather Research and Forecasting model were improved and used to simulate a record‐breaking heavy rainfall event occurred in Henan Province over central China during 19–21 July 2021. In the modified schemes, the terminal velocity of graupel and initial cloud droplet concentration were adjusted based on sensitivity tests. Results showed that the modified Morrison scheme (MORR_MOD) better captured the spatial distribution and temporal evolution of precipitation than the original scheme (MORR). Specifically, it produced a 40‐hr cumulative rainfall amount of 963 mm and an extreme hourly rainfall rate of 157.7 mm, which were closer to observations than MORR. Analysis of the dynamic and microphysical structures of the extreme‐rain‐producing convective clusters revealed that MORR_MOD predicted stronger updrafts, higher rain mass content and larger mean mass diameter of raindrops than MORR. By analyzing the tendencies of rain mass and number concentration, it was found that MORR_MOD predicted stronger accretion rates of cloud droplets by rain and weaker auto‐conversion rates of cloud droplets than MORR, which contributed to the high rain mixing ratio and low number concentration, respectively. In addition, MORR_MOD predicted stronger diabatic heating rates than MORR, which were primarily attributed to stronger condensation of water vapor, and may have been the reason why MORR_MOD simulated stronger updrafts.

Study on failure mechanism and control of surrounding rock of inclined strata crossing roadway in deep coal mine

China’s coal mines are mainly underground mines, and a large number of roadways have to be excavated underground. It is of great significance for coal mine production to adopt safe and reasonable roadway support methods. In the process of roadway excavation, the rock stratum is inclined and the roadway pass through the layer. Since the surrounding rock conditions of the roadway passing through the layer are more complicated, it is easy to cause deformation of surrounding rock, failure and floor heave, which makes the support work difficult. In order to solve this problem, the mechanical properties of roadway surrounding rock were tested and the failure of roadway surrounding rock was analyzed using the +260 horizontal centralized transportation roadway in Changcheng No.2 mine. The surrounding rock of the roadway was divided into 8 regions, and the stress analysis of the surrounding rock in different regions was carried out. It is found that the left shoulder pit, the right side and the floor of the roadway are prone to damage. The influence of the lateral pressure coefficient, the rock dip angle and the lithology on the failure of the roadway surrounding rock was analyzed by Mohr-Coulomb failure criterion, and the specific failure range of the roadway surrounding rock was obtained. The support optimization design of the roadway was carried out, and the weak area of the surrounding rock was reinforced. The deformation monitoring of roadway surrounding rock after support optimization was carried out. The field monitoring results show that after the optimized support, the displacement of the roof and floor of the roadway section and the two sides are reduced by 43.6% and 40.8% respectively compared with the original scheme, and the deformation of the surrounding rock also shows a trend of gradual stability, and the surrounding rock of the roadway is effectively controlled. The research can provide a new way for the stress and failure analysis of the surrounding rock of the inclined rock roadway.