Original Scheme Research Articles

The enriched quadrilateral overlapping finite elements for time-harmonic acoustics

The pronounced numerical dispersions and numerical anisotropy make solutions from the finite element model using low-order elements unreliable for the time-harmonic acoustic problems with fairly large wavenumber. In this work we propose a novel enriched quadrilateral overlapping elements for Helmholtz problems. In this scheme, the original overlapping elements are strengthened by the harmonic trigonometric functions stemming from the spectral techniques. Since all additional degrees of freedom are aligned on the vertex node of every overlapping element, the proposed method can be directly applied to the original finite element model without changing the mesh topology. Because of the enriched approximation space, the proposed method can significantly suppress the numerical dispersions with practically negligible numerical anisotropy, and can be more computationally efficient in providing comparable solution accuracy compared to the original scheme and the classic finite element method. Besides, the linear dependence issue is completely avoided and these enriched overlapping elements are distortion-insensitive. In this work, the original variational formulation is perturbed using the penalty method to impose the essential boundary conditions. Numerical experiments show that the developed method can reduce user interventions in mesh creation and adjustment, and is promising in practical engineering applications for time-harmonic acoustics.

Cluster variation method for investigation of multi-principal-element metallic alloys

We present atomic-scale investigations of the thermodynamic properties of quinary bcc-based multi-principal-element alloys (MPEAs) within {Al,Co,Cr,Fe,Mn,Mo,Ni}, by means of short-range pair energetics and the cluster variation method (CVM) in the irregular tetrahedron approximation. We focus on an essential couple of key-properties detrimental for potential applications of MPEAs, namely the trends to (i) long-range ordering (LRO) and (ii) phase separation (PS). While the CVM has been more commonly employed in a grand canonical frame controlled by chemical potentials (δμ), we propose an original δμ-driven CVM scheme which allows an easier exploration of wide composition spaces typical of MPEAs. This modified scheme yields a slice-by-slice analysis of this space, by means of pseudo-ternary isothermal sections, which demonstrates the ability of the CVM to lead, with moderate computational effort, to full phase diagrams of MPEAs. In particular, our CVM calculations provide elements to interpret recent unexpected experimental trends of AlCrFeMnMo. Comparison with earlier studies of the same MPEAs using the less accurate point-mean-field (PMF) approximation indicates that CVM and PMF have global agreement for LRO at higher temperatures, whereas CVM should definitely be preferred as soon as PS begins to occur. Both approaches, employed more systematically in future MPEA studies in conjunction with ab initio electron theory and dedicated experiments, may offer convenient tools to check the merits of, and even improve, the various sets of effective pair interactions nowadays increasingly available for atomic-scale simulations of MPEAs, thus helping to identify composition domains relevant to avoid trends (i) and (ii) and design more reliable MPEAs.

Violin Music Timeliness and Aesthetics Evaluation System Based on Melody Signal Cyclic Fluctuation Matching Algorithm

On the basis of the original spectrum allocation scheme based on the cyclostationary characteristics of the signal, a new spectrum allocation scheme is proposed. And take three kinds of digital signals widely used in real life as an example. From the perspective of modern art, this paper discusses and analyzes the aesthetic characteristics of Chinese violin music, taking the concerto "Liang Zhu" as an example. It is proposed that "unfinished" stimulates "re-creation", symbolic meaning evokes emotional resonance, contextual expression stimulates artistic conception association, and abstract lines lead to essential thinking. Starting with the demonstration strategy of violin performance and the innovation strategy of violin performance, it expounds the strategies of cultivating students' musical aesthetic awareness in violin performance.

A new HARQ scheme for 5G systems via interleaved superposition retransmission

Within the framework of the 5G new radio (NR), we propose a new hybrid automatic repeat request (HARQ) scheme to improve the throughput performance. The difference between the proposed scheme and the conventional one lies in the first retransmission, where the erroneous coded block group is interleaved and superimposed (XORed) onto a fresh coded block group. At the receiver, an iterative message-passing decoding algorithm can be employed to recover the target erroneous code block group (CBG). Only when the superposed retransmission fails, the conventional incremental redundancy (IR) or repetition redundancy (RR) retransmission is initiated. In any case, since the first retransmission is along with but has negligible effect on the fresh CBG, it costs neither transmitted power nor bandwidth. Monte-Carlo simulation results reveal that the presented HARQ schemes can achieve throughput improvements up to 10% over block fading channels and up to 50% over fast fading channels in comparison with the original 5G CBG-level HARQ scheme but without excessively increasing the implementation complexity.

Research on the Scheme Comparison of Xuzhou Urban Rail Transit Network Based on Network Form

The traditional urban rail network planning scheme comparison lacks the advantages and disadvantages of different schemes from the perspective of network form. In this paper, from the perspective of network form, a comparison scheme of urban rail transit network planning is proposed. Based on graph theory and complex network theory, this paper proposes quantitative indicators from the aspects of network development level, network form, and structure efficiency, and constructs an index system for comparing rail transit planning schemes. Taking Xuzhou urban rail transit planning network as an example, this paper analyzes the comparison between the two planning schemes and the original planning scheme. The results show that there are some differences among the three schemes in basic indexes and macro characteristic indexes. From the perspective of network form, scheme II is the best, the scheme I is the second, and both are optimized to the previous scheme.

Security Analysis and Improvement of Dual Watermarking Framework for Multimedia Privacy Protection and Content Authentication

The demand for using multimedia network infrastructure for transmission grows with each passing day. Research scholars continue to develop new algorithms to strengthen the existing network security framework in order to ensure the privacy protection and content authentication of multimedia content and avoid causing huge economic losses. A new technology for multimedia image copyright protection and content authentication has been proposed. The innovations lie in the use of an inter-block coefficient difference algorithm to embed robust watermarking in the transform domain, and the same fragile watermark is embedded twice in the spatial domain so that any tiny tampering can be identified and located. A new encryption algorithm combined with Arnold transform is used to encrypt data before embedding. However, some security vulnerabilities were found, and successful cryptanalysis and attack were conducted. Subsequently, an improved scheme was proposed to improve the security and tamper detection ability of the original watermarking scheme and recover the tampered robust watermark. The results show that the improved scheme is safer and more reliable and shows good performance in tampering detection and the recovery robustness of the watermark.

Comparative benefit-cost analysis for a resilient industrial power plant building with isolation system and energy dissipating devices

ABSTRACT While the use of innovative seismic control strategies has become widespread in industrial plants, assessment of benefits derived from these measures in a quantifiable form can significantly contribute to a more rational risk-informed decision-making of essential infrastructures. In this paper, a benefit–cost analysis is used to examine three retrofit design schemes of an actual thermal power plant building equipped with different seismic control systems, i.e. buckling-restrained brace (BRB), the hybrid shape memory alloy-buckling restrained brace (SMA-BRB), and the partial mass isolation of heavy industrial equipment. The original design scheme having concentrically braced frames as lateral resisting systems is considered as a benchmark model for comparison purposes. For each mitigation alternative, the benefits against seismic effects were quantified in terms of repair cost and recovery time. The results showed that the retrofit system using SMA-BRB leads to the best performance achieving average reduction in residual drift, peak story drift, resilience index, repair time, and average annual loss by 71%, 27%, 48%, 83%, and 89% compared to the original system, respectively. The proposed benefit–cost analysis framework for industrial power plant buildings can be considered as a practical approach of supporting decision-making for non-technical stakeholders and motivating practicing engineers.

Deformation Failure Characteristics and Maintenance Control Technologies of High-Stress Crossing-Seam Roadways: A Case Study

The surrounding rock structure of the crossing-seam roadway is poor and is susceptible to anchorage failure phenomena, such as top plate sinking and convergence deformation under high ground stress. These issues can cause significant deformation of the surrounding rock over time, resulting in challenging engineering problems. To address this issue, we studied the failure modes and destabilization mechanisms of the surrounding rock in different crossing-seam roadways by field tests and numerical simulations. The results show that since the rock strata in these roadways are extremely unstable and highly susceptible to high horizontal stress, the weak surrounding rock presents the mode of full-section plastic failure. The roof is damaged more seriously than the floor and both walls. In this case, the basic anchorage layer in the original scheme is not thick and rigid enough to support these roadways. Thus, the surrounding rock deforms severely and persistently, which is one of the engineering failure characteristics. To solve this problem, a new scheme of “prompt thick-layer end anchorage + full-length lag grouting anchorage + secondary continuous reinforcement” was proposed based on the continuous roof control theory. According to the industrial test, this scheme can successfully control the long-term large deformation of the weak surrounding rock in crossing-seam roadways. Notably, the deformation of the top plate decreased by 56.65% and the deformation of the two walls decreased by 66.35%. Its design concept will provide important references for controlling the surrounding rock in similar soft rock roadways.

A decision-making method for reservoir operation schemes based on deep learning and whale optimization algorithm.

Reservoir operation is an important part of basin water resources management. The rational use of reservoir operation scheme can not only enhance the capacity of flood control and disaster reduction in the basin, but also improve the efficiency of water use and give full play to the comprehensive role the reservoir. The conventional decision-making method of reservoir operation scheme is computationally large, subjectivity and difficult to capture the nonlinear relationship. To solve these problems, this paper proposes a reservoir operation scheme decision-making model IWGAN-IWOA-CNN based on artificial intelligence and deep learning technology. In view of the lack of data in the original reservoir operation scheme and the limited improvement of data characteristics by the traditional data augmentation algorithm, an improved generative adversarial network algorithm (IWGAN) is proposed. IWGAN uses the loss function which integrates Wasserstein distance, gradient penalty and difference item, and dynamically adds random noise in the process of model training. The whale optimization algorithm is improved by introducing Logistic chaotic mapping to initialize population, non-linear convergence factor and adaptive weights, and Levy flight perturbation strategy. The improved whale optimization algorithm (IWOA) is used to optimize hyperparameters of convolutional neural networks (CNN), so as to obtain the best parameters for model prediction. The experimental results show that the data generated by IWGAN has certain representation ability and high quality; IWOA has faster convergence speed, higher convergence accuracy and better stability; IWGAN-IWOA-CNN model has higher prediction accuracy and reliability of scheme selection.

Enhancing Mechanical Properties of 3D Printing Metallic Lattice Structure Inspired by Bambusa Emeiensis.

Metallic additive manufacturing process parameters, such as inclination angle and minimum radius, impose constraints on the printable lattice cell configurations in complex components. As a result, their mechanical properties are usually lower than their design values. Meanwhile, due to unavoidable process constraints (e.g., additional support structure), engineering structures filled with various lattice cells usually fail to be printed or cannot achieve the designed mechanical performances. Optimizing the cell configuration and printing process are effective ways to solve these problems, but this is becoming more and more difficult and costly with the increasing demand for properties. Therefore, it is very important to redesign the existing printable lattice structures to improve their mechanical properties. In this paper, inspired by the macro- and meso-structures of bamboo, a bionic lattice structure was partitioned, and the cell rod had a radius gradient, similar to the macro-scale bamboo joint and meso-scale bamboo tube, respectively. Experimental and simulated results showed that this design can significantly enhance the mechanical properties without adding mass and changing the printable cell configuration. Finally, the compression and shear properties of the Bambusa-lattice structure were analyzed. Compared with the original scheme, the bamboo lattice structure design can improve the strength by 1.51 times (β=1.5). This proposed strategy offers an effective pathway to manipulate the mechanical properties of lattice structures simultaneously, which is useful for practical applications.

An Efficient Threshold Access-Structure for RLWE-Based Multiparty Homomorphic Encryption

We propose and implement a multiparty homomorphic encryption (MHE) scheme with a t-out-of-N-threshold access-structure that is efficient and does not require a trusted dealer in the common random string model. We construct this scheme from the ring-learning-with-error assumptions and as an extension of the MHE scheme of Mouchet et al. (PETS 21). By means of a specially adapted share re-sharing procedure, this extension can be used to relax the N-out-of-N-threshold access-structure of the original scheme into a t-out-of-N-threshold one. This procedure introduces only a single round of communication during the setup phase, after which any set of at least t parties can compute a t-out-of-t additive sharing of the secret-key with no interaction; this new sharing can be used directly in the scheme of Mouchet et al. We show that, by performing Shamir re-sharing over the MHE ciphertext-space ring with a carefully chosen exceptional set, this reconstruction procedure can be made secure and has negligible overhead. Moreover, it only requires the parties to store a constant-size state after its setup phase. Hence, in addition to fault tolerance, lowering the corruption threshold also yields considerable efficiency benefits, by enabling the distribution of batched secret-key operations among the online parties. We implemented and open-sourced our scheme in the Lattigo library.

Water-Energy Nexus in the Antofagasta Mining District: Options for Municipal Wastewater Reuse from a Nearly Energy-Neutral WWTP

The region of Antofagasta is the mining hearth of Chile. The water requirement of the local mining sector is 65% of the total water uses, with a water consumption of approx. 9 m3/s in the year 2020. That determines an important pressure onto freshwater, which can only be alleviated by resorting to desalination or reuse of treated wastewater. At present, an amount equal to 90% of the wastewater generated in the city of Antofagasta is discharged into the ocean, after undergoing only preliminary treatments. The wastewater treatment plant (WWTP), which includes a conventional activated sludge (CAS) process, has a very low treatment capacity, insufficient to serve the whole population. A new WWTP will be built with the twofold aim of (i) purifying the totality of the wastewater generated from the city (approx. 320,000 equivalent inhabitants, e.i.), and (ii) allowing the reuse of 100% of the treated wastewater in the local mining sector, in agreement with the goals of the Chilean government. The new Antofagasta WWTP will include preliminary treatments and a conventional activated sludge (CAS) process with a higher treatment capacity. This study integrates a number of modeling tools, namely the Activated Sludge Model n.3 (ASM3), the Takacs model, and some stoichiometric and energy balances, to assess the impact that some changes, possibly introduced into the project of the new WWTP, could determine on its energy and environmental sustainability. Specifically, through an energy-economic-environmental (3-E) analysis, the original scheme of the planned WWTP was compared with three scenarios, of which Scenario 1 introduces anaerobic digestion (AD) of secondary sludge, Scenario 2 concerns primary sedimentation and AD of both primary and secondary sludge, and, finally, Scenario 3, other than primary sedimentation and AD, also includes a pre-denitrification process. The results of the study demonstrated that all the changes introduced by Scenario 3 were of capital importance to promote the transformation of the WWTP into a nearly energy-neutral water resource recovery facility (WRRF). Specifically, the processes/operations introduced with Scenario 3 can reduce the electric energy demand from external sources to only 20% of that of the original scheme, and consequently avoid the emission of 4390 tons CO2-equivalent/y.

Optimization of Recharge Schemes for Deep Excavation in the Confined Water-Rich Stratum

With the excavation of a metro station in a confined water-rich stratum as our background, the sensitivity of four typical recharge parameters is analyzed by using numerical simulation. Based on the orthogonal analysis method, an optimal recharge scheme was obtained. The results show that the main influential factors of ground settlement and groundwater recovery are recharge pressure and recharge depth. The main influential factor of retaining structure deformation and influence radius of recharge is the distance between the recharge wells and the foundation pit. For the groundwater recharging of a deep excavation in the water-rich confined area of Jinan, China, the optimal effect can be achieved when setting recharge wells with a depth of 50 m arranged in a line with a spacing of 10 m at a horizontal distance of 20 m away from the retaining wall and recharge pressure is 40 kPa. With the same construction difficulty, the maximum settlement in optimized scheme decreased 71.19%, the flux of groundwater recovery increased 11.96%, the maximum horizontal displacement of the wall decreased 15.61%, and the influence radius of recharge enlarged 8.62% compared to original scheme.

Construction and application of sponge city resilience evaluation system: a case study in Xi’an, China

Urban vulnerability is evident when highly complex flood risks overlap with diverse cities, and it is important to enhance the resilience of cities to flood shocks. In this study, a sponge city resilience assessment system is established considering engineering, environmental and social indicators, and the grey relational analysis method (GRA) is used to quantify sponge city resilience. At the same time, a multi-objective optimization model is established based on the three dimensions of water ecological environment, drainage safety, and waterlogging safety. The optimal configuration of grey-green infrastructure is weighed by combining the ideal point method, aiming to ensure that cities effectively reduce flood risk through the optimal configuration scheme. Taking the Xiaozhai area in Xi'an as the study area, the evaluation results show that the grey relational degree (GRD) of the resilience indexes of the original scheme is between 0.390 and 0.661 under the seven different return periods, while the optimization scheme ranges from 0.648 to 0.765, with the best sponge city resilience at a return period of 2a. Compared with the original scheme, the optimized sponge city resilience level increases from level II to nearly level I in the low return period and from level IV to level II in the high return period, indicating that city's ability to cope with waterlogging and pollution is enhanced significantly. Besides, the main factor affecting the sponge city resilience is the runoff control rate, followed by pollutant load reduction rate, which can provide a methodological framework for the assessment and improvement of sponge city resilience.

Examining the Implementation of Financial Incentives using the Framework of Monetary and Non-Monetary Incentives to Improve Employee Innovation Performance Case Study: Jordanian Islamic Banks

Jordan's banking industry has expanded significantly, and various Jordanian banks are now more competitive than ever. Therefore, all Jordanian banks strive to gain a greater competitive edge by luring more clients. In this context, Jordanian Islamic banks sought to strengthen their competitive advantage by offering high-quality banking services, luring highly experienced employees, and equipping them with a capable system of incentives and rewards to boost their performance. It has been suggested that monetary and non-monetary incentives could be used to address these issues. In order to evaluate the effects of incentives on the employees who worked in the Islamic Bank's branches in Jordan, the study set out to conduct a systematic review and analysis. Partial least squares (PLS) analysis was used to gather data that had been gathered through a survey method using questionnaires that were completed by 73 respondents. Simple linear regression (SLR) was used to assess how incentives affect performance. The results of the study revealed a statistically significant positive effect of monetary and non-monetary incentives on performance. In order to implement a fair incentive policy that has an impact on raising employee performance, and added value Islamic banks need to review their system of moral and financial rewards. Giving bonuses, recognizing outstanding employees, providing the ideal employee with monthly annual health benefits, and expressing gratitude and expressing gratitude and appreciation to others. Future knowledge in the field of management accounting will benefit from this study's contribution, which focuses on the existence of the principles based on the performance system, a distinctive and original compensation scheme that has unmistakably aided bank expansion.

A Non-Equilibrium Interpolation Scheme for IB-LBM Optimized by Approximate Force

A non-equilibrium scheme and an optimized approximate force are proposed for the immersed boundary–lattice Boltzmann method (IB-LBM) to solve the fluid–structure interaction (FSI) equations. This new IB-LBM uses the discrete velocity distribution function and non-equilibrium distribution function to establish the interpolation operator and the spread operator at the mesoscopic scale. In the interpolation operator, we use the force model of LBM to derive a direct force with a simple form. In the spread operator, we give a theoretical proof with local second-order accuracy of the spread process using the non-equilibrium theory from the LBM. A non-iterative explicit force approximation scheme optimizes the direct force in that the streamlines have no penetration phenomenon, and the no-slip condition is strictly satisfied. Different from other schemes for the IB-LBM, we try to apply the non-equilibrium theory from the LBM to the IB-LBM and obtain good results. The explicit force obtained using the non-equilibrium scheme and then optimized via the non-iterative streamline correction equation simplifies the explicit direct force scheme and the original implicit scheme previously proposed but obtains a similar streamline correction result compared with the implicit method. Numerical tests prove the applicability and accuracy of this method in the simulation of complex conditions such as moving rigid bodies and deforming flexible bodies.

Design and Construction of High-Performance Long-Span Steel Transfer Twin Trusses Applied in One Hospital Building in Hong Kong

Long-span steel trusses are increasingly used in high-rise buildings to replace reinforced concrete thick transfer plates due to their light weight but high load-bearing capacity. To support multiple stories above the steel transfer trusses, a comprehensive method based on second-order direct analysis has been applied for design optimization of long-span steel transfer trusses in one hospital redevelopment project in Hong Kong. In the project, several 35 m long-span steel transfer trusses are adopted at the 3rd to 5th floors to support the upper 15-story reinforced concrete structure. Innovative technologies such as integrated global and local optimization and integrated design and construction have been explored and made to achieve better uniformity and compatibility in structure. In particular, twin trusses with better structural performance, less fabrication cost and ease of constructability are studied and finally adopted in primary trusses to replace the original scheme of single trusses. The optimal scheme has brought both cost and time saving in fabrication, construction, operation and maintenance stages.

A Deterministic Kaczmarz Algorithm for Solving Linear Systems

We propose a new deterministic Kaczmarz algorithm for solving consistent linear systems . Basically, the algorithm replaces orthogonal projections with reflections in the original scheme of Stefan Kaczmarz. Building on this, we give a geometric description of solutions of linear systems. Suppose is , we show that the algorithm generates a series of points distributed with patterns on an -sphere centered on a solution. These points lie evenly on lower-dimensional spheres , with the property that for any , the midpoint of the centers of is exactly a solution of . With this discovery, we prove that taking the average of points on any effectively approximates a solution up to relative error , where characterizes the eigengap of the orthogonal matrix produced by the product of reflections generated by the rows of . We also analyze the connection between and , the condition number of . In the worst case , while for random matrices on average. Finally, we prove that the algorithm indeed solves the linear system , where is the lower-triangular matrix such that . The connection between this linear system and the original one is studied. The numerical tests indicate that this new Kaczmarz algorithm has comparable performance to randomized (block) Kaczmarz algorithms.

Study on the optimization for emergency evacuation scheme under fire in university building complex

The evacuation in the university building complex involving a variety of campus buildings and a high density of occupants is barely simulated, especially by considering the safety awareness of evacuees and the impact of measured stair evacuation speed. This paper simulates and optimizes the fire emergency evacuation scheme of a university building complex in Northwest China by using BIM technology and Pathfinder simulation evacuation software. The proposed evacuation optimization scheme of university building complex reduces the evacuation time by 15–20% compared with the original evacuation scheme of the university. Through the simulation, it is found that the evacuation time required for sleeping at night is the shortest, while the longest evacuation time is required during lunch, due to the dispersion of students. Therefore, in addition to considering the safety awareness of the evacuees and the measured evacuation speed of stairs, the corresponding campus evacuation plan should be formulated according to the distribution of buildings in the campus complex and the actual utilization in different periods, so as to avoid the safety exit congestion and being far away from the refuge, due to the dense population in a specific period of time. This study also provides a method for solving the problem of regional evacuation path planning.

Calculation and optimization of slope reinforcement at tunnel entrances—taking manyanpo tunnel as an example

Slope reinforcement is a common method to solve the problem of slope instability, and reasonable optimization of the corresponding support parameters is crucial for practical engineering. In this paper, the slope support method of Manyanpo tunnel entrance section is taken as an example, and the theoretical calculation method is used to optimize the project cost. Combined with the orthogonal test, the sensitivity analysis of the influencing factors of the stability of the support system and the selection of the optimal parameter combination scheme are carried out. Then, based on flac3d software, the optimization scheme is compared with the original design scheme. The results show that the safety factor of the optimized scheme is increased from 1.32 to 1.43 compared with the actual project. The optimized support parameters have better control effect on the displacement of the slope, especially in the Z direction. The optimized parameters have better support effect. This study can provide reference for the optimization design of slope engineering support.