Reasonable Scheme Research Articles

Research on the Cuckoo Algorithm for Flexible Workshop Scheduling Problems

As a typical combinatorial optimization problem, the essence of the solution to the scheduling problem is to formulate a reasonable scheduling scheme to arrange and allocate production resources, thereby obtaining the optimal scheduling result. The Cuckoo Search Algorithm (CS), a revolutionary meta-heuristic, is based on the cuckoo's breeding behavior and combines Lévy flight and random walk strategies to more efficiently attain the search goal. CS algorithm has been extensively employed in a variety of intricate combinatorial optimization issues, with its few parameters, precise resolution, random search path optimization, robust search aptitude, and uncomplicated implementation leading to satisfactory outcomes. After in-depth research, we found that the cuckoo search algorithm excels in dealing with flexible workshop scheduling problems. We conduct a series of comparative experiments to further confirm the efficacy of this algorithm. The results show that the cuckoo algorithm performs well in global search and can be used to solve complex flexible workshop scheduling models.

Optimizing Water Distribution in Transboundary Rivers Based on a Synthesis–Dynamic–Harmonious Approach: A Case Study of the Yellow River Basin, China

It has been difficult to revise and adjust the water distribution of the Yellow River in 1987 (1987 water distribution scheme). By gathering data and studies from previous literature, this paper summarized some water distribution ideas, principles and rules in transboundary rivers. We proposed the “synthesis–dynamic–harmonious” water distribution method (SDH), and applied it to the actual conditions of the Yellow River basin. Through the SDH method, we calculated a new scheme for water distribution in the Yellow River and analyzed the results. The key findings of this study are summarized below. Firstly, the water distribution of transboundary rivers required the establishment of advanced water distribution ideas. Secondly, the proposed water distribution method took into account a variety of factors: with the change in distributable water volume, the same ratio changes and meets the minimum water demand and water efficiency constraints. Thirdly, the 1987, the water distribution scheme needed some adjustment. Fourthly, under the new Yellow River basin water distribution scheme (“19ZQT” water distribution scheme), Shandong, Inner Mongolia, and Henan account for 50% of the total water distribution. Sichuan accounts for only 0.3% of the total. Compared with the 1987 water distribution scheme, Hebei and Tianjin reduced the amount of water allocated by 51.2%, while Shaanxi increased it by 24.89%. In this paper, considering the changes in the total distributable water volume, the new Yellow River water distribution scheme (“19ZQT” water distribution scheme) assumed water distribution of 37 billion m3 and 30 billion m3, upon which calculations were performed. This study should provide a scientific and reasonable scheme for water distribution of transboundary rivers, and rational utilization of water resources. It should lay a solid foundation for the high-quality development of the Yellow River basin.

Numerical investigation on meshing temperature of multicomponent nylon gears by incorporating viscoelasticity

This study concerns a numerical analysis of the meshing temperature for a multicomponent nylon gear by incorporating typical viscoelastic responses of polymers. Firstly, the generalized Maxwell model parameters were calibrated by the dynamic mechanical analysis to capture the viscoelasticity of polyamide 66. Next, the finite element model predicting the meshing temperature was established, including the heat generation analysis model, which calculates the generation of the frictional and hysteretic heat, and the heat propagation analysis model, which simulates the heat transmission. Different material models were used for polyamide 66 to investigate the influences of temperature dependence, strain rate dependence, and hysteretic effect. The effect of the iteration sequence on the meshing temperature calculation was also analyzed, i.e., how the heat generation should be updated as the loading cycles increase. A reasonable iteration scheme was determined by balancing the computational precision and consumption. It is noteworthy that the evolution of the ambient temperature around the gear and the worm within the housing was also considered. Finally, the accuracy of such meshing temperature analysis was validated on a self-developed gear test rig, in terms of the peak temperature evolution on the gear side surface. The experimental results and the simulation with the ambient temperature correction match well and the maximum error is 5 °C.

Multi-objective decision making of natural gas distribution optimization considering clean heating——evidence from Beijing

ABSTRACT Since the implementation of China’s clean heating plan in 2017, the progress of natural gas replacing coal for heating is still not ideal. With the proposal of the goal of carbon neutralization and the impact of international war, the price, supply, and demand of natural gas have attracted attention. In case of gas shortage, reasonable schemes are required to be allocated to different industries and categories. Therefore, this research divides the gas field into four levels according to the social utility, and establishes the multi-objective distribution optimization model considering the social and economic benefits. The solution of the model is based on genetic algorithm and realized on MATLAB. Multi-objective optimization strategies and several constraints are used to make the algorithm’s process of the search is continuously moving closer to the Pareto optimal front. Taking Beijing as an example, two scenarios are set to simulate and optimize, so as to verify the optimization effect of the model. Better quantitative results are created after reallocation of natural gas. The ideal scenario realizes 5.64% more social benefits than 2019 through additional allocation of 117.288 million cubic meters of reserve gas. The constraint scenario creates 0.67% more socialbenefits with only 0.07% decrease of the economic benefits. The conclusions show that allocating more gas to three main industries can improve the optimization effect and it is necessary to expand the supply of natural gas reserve volume. This paper provides a new perspective of natural gas allocation category and priority, providing theoretical and practical ideas for the planning of natural gas security emergency plan and the development of gas sales plan.

A fine-grained task scheduling mechanism for digital economy services based on intelligent edge and cloud computing

Digital economy is regarded countries as an inevitable choice to promote economic growth and provides new opportunities and new paths for the high-quality development of economy. For the Chinese market, the strong base behind cloud computing is the unstoppable development trend of the digital economy. In digital economy, the cloud as infrastructure becomes the base of the pyramid to build the digital economy. To relieve the pressure on the servers of the digital economy and develop a reasonable scheduling scheme, this paper proposes a fine-grained task scheduling method for cloud and edge computing based on a hybrid ant colony optimization algorithm. The edge computing task scheduling problem is described, and assumptions are set to simplify the difficulty of a scheduling solution. The multi-objective function is solved by using a hybrid ant colony optimization algorithm which solves computational problems by finding the optimal solution with the help of graphs. Ant colony optimization algorithm is easy to use and effective in scheduling problems. The proposed scheduling model includes an end-device layer and an edge layer. A terminal device layer consists of devices used by the clients that may generate computationally intensive tasks and are sometime uncapable to complete the tasks. The proposed scheduling policy migrates these tasks to a suitable place where they can be completed while meeting the latency requirements. The CPUs of the idle users on the end-device layer are used for other CPU-overloaded terminals. The simulation results, in terms of energy consumptions, and task scheduling delays, show that the task scheduling performance is better under the application of this method and the obtained scheduling scheme is more reasonable.

Post-acquisition upsampling method for scanning x-ray microscopy.

A method of post-acquisition upsampling for scanning x-ray microscopy is developed in this study to improve the spatial resolution beyond the Nyquist frequency as determined by the intervals of a raster scan grid. The proposed method is applicable only when the probe beam size is not negligibly small compared with the pixels that constitute a raster micrograph-the Voronoi cells of a scan grid. The unconvoluted spatial variation in a photoresponse is estimated by solving a stochastic inverse problem at a higher resolution than that at which the data are acquired. This is followed by a rise in the spatial cutoff frequency due to a reduction in the noise floor. The practicability of the proposed method was verified by applying it to raster micrographs of x-ray absorption in Nd-Fe-B sintered magnets. The improvement thus achieved in spatial resolution was numerically demonstrated via spectral analysis by using the discrete Fourier transform. The authors also argue for a reasonable decimation scheme for the spatial sampling interval in relation to an ill-posed inverse problem and aliasing. The computer-assisted enhancement in the viability of scanning x-ray magnetic circular dichroism microscopy was illustrated by visualizing magnetic field-induced changes in domain patterns of the Nd2Fe14B main-phase.

Secure-Enhanced Federated Learning for AI-Empowered Electric Vehicle Energy Prediction

Although AI-empowered schemes bring some sound solutions to stimulate more reasonable energy distribution schemes between charging stations (CSs) and CS providers, frequent data sharing between them is possible to incur many security and privacy breaches. To solve these problems, federated learning (FL) is an ideal solution that only requires CSs to upload local models instead of detailed data. Although the CSs’ electricity consumption need not to be exposed to the server directly, FL-based schemes still have been excavated several security threats such as information exploiting attacks, data poisoning attacks, model poisoning attacks, and free-riding attacks. Hence, in this article, both the effectiveness of energy management and the potential risks of FL for electric vehicle infrastructures (EVIs) are considered, we propose a lightweight authentication FL-based energy demand prediction for EVIs with premium-penalty mechanism. Security analysis and performance evaluation prove that our proposed framework can generate an accurate electricity demand prediction framework to defend multiple FL attacks for EVIs.

Sensitivity of predicted stresses in thick‐walled steel/ceramics spherical FGM‐structures to parameter uncertainties

AbstractThe effects of both material data uncertainties of the constituents and of volume fraction deviations from the design values caused by the manufacturing process on the forecasted stresses in a spherical container of functionally graded material (FGM) are investigated. Specifically, a steel/alumina hollow sphere subject to internal pressure and homogeneous heating is studied. It is shown that even moderate uncertainties and deviations may cause large expectation ranges of von Mises equivalent stresses, and this issue may yet predominate over the question for the most reasonable homogenization scheme(s).

Priority-Based Resource Allocation Optimization for Multi-Service LoRaWAN Harmonization in Compliance with IEEE 2668.

Given the advantage of LoRaWAN private networks, multiple types of services have been implemented by users in one LoRaWAN system to realize various smart applications. With an increasing number of applications, LoRaWAN suffers from multi-service coexistence challenges due to limited channel resources, uncoordinated network configuration, and scalability issues. The most effective solution is establishing a reasonable resource allocation scheme. However, existing approaches are not applicable for LoRaWAN with multiple services with different criticalities. Therefore, we propose a priority-based resource allocation (PB-RA) scheme to coordinate multi-service networks. In this paper, LoRaWAN application services are classified into three main categories, including safety, control, and monitoring. Considering the different criticalities of these services, the proposed PB-RA scheme assigns spreading factors (SFs) to end devices on the basis of the highest priority parameter, which decreases the average packet loss rate (PLR) and improves throughput. Moreover, a harmonization index, namely HDex, based on IEEE 2668 standard is first defined to comprehensively and quantitively evaluate the coordination ability in terms of key quality of service (QoS) performance (i.e., PLR, latency and throughput). Furthermore, Genetic Algorithm (GA)-based optimization is formulated to obtain the optimal service criticality parameters which maximize the average HDex of the network and contribute to a larger capacity of end devices while maintaining the HDex threshold for each service. Simulations and experimental results show that the proposed PB-RA scheme can achieve the HDex score of 3 for each service type at 150 end devices, which improves the capacity by 50% compared to the conventional adaptive data rate (ADR) scheme.

Research on Profit Allocation of Agricultural Products Co-Delivery Based on Modified Interval Shapley Value

Most of the domestic wholesale markets have many operating entities, and the level of organization and scale is not high; therefore, at this stage, building a shared business platform and carrying out common distribution is an important way to improve the overall efficiency of the wholesale market distribution operations and the level of the intensive utilization of key resources such as vehicles. Carrying out common distribution requires the formation of a good synergy mechanism among the participating subjects, in which the design of a scientific and reasonable benefit distribution scheme, especially in balancing the relationship between government resources and social resources, is particularly important. As the benefit distribution of cooperation is affected by the dynamic changes of the resource input ratio, the distribution operation scale, the risk taking, and other factors, this paper establishes a multi-weight interval Shapley value method benefit distribution model, which reflects the effect of the key parameter variables. Through the empirical analysis of Beijing’s wholesale markets for agricultural products, the results show that the revised benefit distribution is more in line with the interest demands among multiple subjects and is positively correlated with the contribution degree among the participating subjects, which can better mobilize the cooperation enthusiasm of the participating enterprises and provide a new methodological path to solve the problem of common distribution in wholesale markets. The distribution model constructed in this paper further enriches the relevant research content in the field of common distribution and is of reference value for the benefit distribution problem that requires comprehensive consideration of the dynamic change in the multiple parameters affecting the relationship.

A Cost–Benefit Analysis Framework for City-Scale Seismic Retrofitting Scheme of Buildings

To improve urban seismic resilience, a reasonable seismic retrofitting scheme for buildings is required. Urban cities contain a large number of buildings, making it challenging to precisely assess the seismic retrofitting benefits of each one. This paper proposes a cost–benefit assessment framework that takes into account seismic risk, seismic damage, retrofit costs, economic losses, and cost–benefit analyses for the city-scale seismic retrofitting of buildings. The proposed framework adopts readily available building parameters, including the number of stories, construction year, total height, structural type, floor area, and response spectrum for structural design. It makes use of empirical seismic retrofitting models and a newly developed story-level seismic loss assessment method combining the physical mechanism and empirical loss ratios. For city-scale cost–benefit analysis, the framework can strike a good balance between data accessibility, computational workload, level of result details, and result accuracy. It can adapt nimbly to earthquake-induced indirect losses and budgetary constraints on retrofitting. The analysis of 98,618 buildings in Xi’an city, China, is carried out. The findings indicate that, when potential indirect economic loss ratios of buildings are neglected, the retrofitting benefits of unreinforced masonry and old buildings are the most significant.

The clinical application effects of artificial dermis scaffold and autologous split-thickness skin composite grafts combined with vacuum-assisted closure in refractory wounds.

To investigate the clinical application effects of artificial dermis scaffold and autologous split-thickness skin composite grafts combined with vacuum-assisted closure (V.A.C) in refractory wounds. A retrospective analysis was performed on 70 patients with refractory wounds admitted to the First Affiliated Hospital of Soochow University from June 2019 to December 2021 (44 males and 25 females, with an average age of 49.3 ± 21.4 years). There were 26 patients with chronic ulcers; 3 patients with cancerous wounds; 16 patients with hot crush injuries; and 25 patients with traumatic wounds, including 21 cases of hands, 33 cases of feet, 6 cases of upper limbs, and 10 cases of lower limbs. The patients were divided into an artificial dermis scaffold group (35 patients, including 21 males and 14 females, aged 49.5 ± 21.3 years) and a skin graft group (35 patients, including 23 males and 11 females, aged 49.1 ± 21.5 years). In the artificial dermis scaffold group, after debridement, the artificial dermis scaffold was transplanted for approximately 2 weeks until the wound surface was well vascularized, after which the autologous split-thick skin graft was transplanted. Negative pressure wound therapy was performed throughout the treatment. In the skin grafting group, after debridement, the autologous split-thickness skin graft (aSTSG) was transplanted, and negative pressure wound therapy was performed continuously. The wound healing rate; skin graft survival rate; postoperative wound infection; exudative fluid volume; subcutaneous haematoma; hospitalisation time; hospitalisation cost; Vancouver Scar Scale (VSS) score, used to evaluate the scar of the recipient area at 6months after the operation; and the sensory disorder grading method, used to evaluate the sensory recovery of the recipient area, were compared between the two groups. All 70 refractory wounds healed. In the artificial dermis scaffold group, the skin graft survival rate was 90% (86%-95%), the hospitalisation time was 38 (29-45) days, the hospitalisation cost was 148 102 (118242-192327) yuan, and the VSS score was 1.9 ± 1.3. There were significant differences in skin graft survival rate (70% [60%-80%]), length of hospital stay (21 [14-28] days), hospitalisation cost (76 201 [39228-135 919] yuan) and VSS score [6.1 ± 3.6] between the skin graft group and the artificial dermis scaffold group (P < .05). The skin graft survival rate, scar hyperplasia and sensory recovery of the recipient area in the artificial dermis scaffold group were better than those in the skin graft group, but the hospitalisation time was relatively longer, and the hospitalisation cost was relatively higher. Wound healing rate, postoperative wound infection, exudate volume, and subcutaneous haematoma of patients in the two groups were similar, and there were no significant differences (P > .05). The artificial dermis scaffold and composite transplantation of autologous aSTSG with V.A.C can promote painless wound healing and improve the skin survival rate, skin colour and lustre, and flexible smooth texture and is conducive to less scar hyperplasia and postoperative functional exercise and recovery. This method provides a reasonable and effective scheme for the treatment of clinical refractory wounds.

PointGLR: Unsupervised Structural Representation Learning of 3D Point Clouds.

This work explores the use of global and local structures of 3D point clouds as a free and powerful supervision signal for representation learning. Local and global patterns of a 3D object are closely related. Although each part of an object is incomplete, the underlying attributes about the object are shared among all parts, which makes reasoning about the whole object from a single part possible. We hypothesize that a powerful representation of a 3D object should model the attributes that are shared between parts and the whole object, and distinguishable from other objects. Based on this hypothesis, we propose a new framework to learn point cloud representations by bidirectional reasoning between the local structures at different abstraction hierarchies and the global shape. Moreover, we extend the unsupervised structural representation learning method to more complex 3D scenes. By introducing structural proxies as the intermediate-level representations between local and global ones, we propose a hierarchical reasoning scheme among local parts, structural proxies, and the overall point cloud to learn powerful 3D representations in an unsupervised manner. Extensive experimental results demonstrate that the unsupervised representations can be very competitive alternatives of supervised representations in discriminative power, and exhibit better performance in generalization ability and robustness. Our method establishes the new state-of-the-art of unsupervised/few-shot 3D object classification and part segmentation. We also show our method can serve as a simple yet effective regime for model pre-training on 3D scene segmentation and detection tasks. We expect our observations to offer a new perspective on learning better representations from data structures instead of human annotations for point cloud understanding.

Numerical Investigation of a Local Precise Reinforcement Method for Dynamic Stability of Rock Slope under Earthquakes Using Continuum–Discontinuum Element Method

The slope reinforcement scheme has an important influence on the prevention and control of landslides. A reasonable reinforcement scheme can improve the reliability, economy and efficiency of landslide resistance. It is urgent to establish a local precise reinforcement method for landslides on the basis of clear process and the instability modes of landslides. Taking a high-steep anti-dip rock slope as an example, six numerical models are established by using the continuum–discontinuum element method (CDEM) to carry out seismic damage and dynamic analysis of slopes. By comparing the seismic response and damage characteristics of being unstrengthened, local precise reinforcement and overall reinforcement models, the applicability of the proposed local precise reinforcement method for the slopes is discussed. The results show that the determination of the dynamic amplifying effect and seismic damage characteristics of slopes is the primary prerequisite of the local precise reinforcement method. The dynamic amplification effect of the slope toe, crest and shallow slope surface are much larger, that is, they are the potential reinforcement areas. The local precision reinforcement times should be controlled within a certain number of times, and the slope after the first three times of the local reinforcement effect is the best. However, more than three times after the reinforcement effect it becomes worse. Moreover, the dynamic amplification effect, the equivalent crack ratio and the mechanical energy of the slope after three times of local precision reinforcement are similar to the overall reinforcement effect, which indicates that local precision reinforcement has good feasibility. This work can provide references for landslide disasters prevention and control.

Influence of temperature rising inhibitor on temperature and stress field of mass concrete

As a new type of concrete admixture, concrete temperature rising inhibitor (TRI) can slow down the heat release rate of the initial hydration reaction of concrete. However, due to the lack of a clear feasibility analysis, its application in engineering is limited. In this paper, the thermodynamic parameters of concrete with different TRI are obtained by fitting the experimental data. At the same time, taking the sluice as an example, the influence of TRI on the temperature and stress field of mass concrete is studied by numerical simulation. The results show that when the content of TRI reaches 0.6% of the cementitious material, the temperature and stress peak value are obviously reduced, and the temperature control effect is obvious. Furthermore, the effect of TRI is inversely proportional to structure thickness, and its temperature control effect is more noticeable for mass thin-walled concrete structures. Compared with other temperature control measures, such as lowering the peak value of adiabatic temperature rise and the pouring temperature, the effect of TRI is more effective. It can be used as a means of temperature control in engineering and combined with other measures to put forward a more reasonable and economical temperature control scheme.

Modeling and Vibration Control of Sandwich Composite Plates.

A finite element dynamic model of the sandwich composite plate was developed based on classical laminate theory and Hamilton's principle. A 4-node, 7-degree-of-freedom three-layer plate cell is constructed to simulate the interaction between the substrate, the viscoelastic damping layer, and the piezoelectric material layer. Among them, the viscoelastic layer is referred to as the complex constant shear modulus model, and the equivalent Rayleigh damping is introduced to represent the damping of the substrate. The established dynamics model has too many degrees of freedom, and the obtained dynamics model has good controllability and observability after adopting the joint reduced-order method of dynamic condensation in physical space and equilibrium in state space. The optimal quadratic (LQR) controller is designed for the active control of the sandwich panel, and the parameters of the controller parameters, the thickness of the viscoelastic layer, and the optimal covering position of the sandwich panel are optimized through simulation analysis. The results show that the finite element model established in this paper is still valid under different boundary conditions and different covering methods, and the model can still accurately and reliably represent the dynamic characteristics of the original system after using the joint step-down method. Under different excitation signals and different boundary conditions, the LQR control can effectively suppress the vibration of the sandwich plate. The optimal cover position of the sandwich plate is near the solid support end and far from the free-degree end. The parameters of controller parameters and viscoelastic layer thickness are optimized from several angles, respectively, and a reasonable optimization scheme can be selected according to the actual requirements.

Geopolitical Risk Evolution and Obstacle Factors of Countries along the Belt and Road and Its Types Classification.

As a great practice of building a community of shared future for mankind, the Belt and Road Initiative is facing geopolitical risk brought by great power games, regional conflicts and terrorism. It is an important mission of geopolitical research to scientifically deal with the geopolitical risk along the Belt and Road. This study systematically constructs the geopolitical risk assessment index system and analyzes the spatiotemporal evolution, obstacle factors and risk types of geopolitical risk of countries along the Belt and Road by using the entropy weight TOPSIS model, obstacle degree model and minimum variance method. The research results showed that: (1) From 2005 to 2020, the polarization of geopolitical risk in countries along the Belt and Road was very significant, and the overall trend of geopolitical risk tended to deteriorate. (2) The Middle East and Eastern Europe were the most important geopolitical risk zones along the Belt and Road, and Afghanistan, Iraq, Russia and Ukraine were the main high geopolitical risk centers, with significant risk spillover effects from these centers. (3) Terrorism and close relations with the United States were the most important obstacle factors for geopolitical risk in countries along the Belt and Road, and military intervention politics, trade dependence degree and foreign debt burden were important obstacle factors for geopolitical risk in countries along the Belt and Road. (4) Geopolitical risk along the Belt and Road can be divided into sovereign risk dominant type, sovereign and military risk dominant type, sovereign and major power intervention risk dominant type, and sovereign and military and major power intervention risk jointly dominated type, among which sovereign and military and major power intervention risk jointly dominated type was the most important geopolitical risk type. In order to scientifically deal with geopolitical risk in countries along the Belt and Road, it is necessary to strengthen geopolitical risk awareness, pay attention to the dominant geopolitical risk factors, strengthen the control of regional geopolitical risk spillover and formulate reasonable risk prevention and control scheme based on geopolitical risk types.

Study on the influence of the tectonic evolution of Shuangyashan Basin on gas occurrence and extraction in mines

The formation and later evolution of coal-bearing basins in eastern Heilongjiang are controlled by multi-phase tectonic movements, and the Shuangyashan Basin is tectonically located at the southern end of the Sanjiang Basin in the northeast. The paper focuses on the regional geological and tectonic evolution of the Shuangyashan Basin and its influence on the gas occurrence law and extraction difficulty of the Jixian Coal Mine. The study determined that the gas occurrence of the mine in the Suibin-Jixian depression basin has regional aggregation and caprock sealing characteristics. The gas pressure and content of the 9# Coal Seam were measured in the underground test, and the results showed that the 9# coal seam is a hard-to-extract coal seam with low permeability. Aiming at the issue of hard-to-extract gas in 904 Working Face of 9# Coal Seam which is affected by depression basin and derived secondary tectonic conditions, numerical calculation and analysis of gas extraction effect of working face with different extraction parameters were carried out by COMSOL software, the results showed that: negative extraction pressure has less influence on gas extraction effect under basin conditions; when 113 mm diameter borehole is used for gas extraction, gas pressure decreases to 0.72 MPa; when the spacing of extraction borehole is 2 m, the gas pressure is reduced by 20%; when the coal seam permeability is increased by 10 times to more than 0.015 mD, the gas pressure is reduced by more than 50%. The optimized gas extraction scheme with 113 m diameter, 2 m borehole spacing, and 15 kPa negative pressure was proposed for the test working face, and combined with supercritical CO2 fracturing and permeability enhancement technology. Under underground measurement, the coal seam gas content was reduced by 39.7% compared to the original gas extraction scheme. It can be seen that the reasonable gas extraction scheme and coal seam pressure relief and permeability enhancement technology can significantly improve the gas extraction rate, and the extraction effect is remarkable.

Emergency shelter allocation planning technology for large-scale evacuation based on quantum genetic algorithm.

Shelter allocation is one of the most important measures in urban disaster prevention and mitigation planning. Meanwhile, it is essentially a comprehensive planning problem combining resource allocation and traffic routing. A reasonable allocation scheme can avoid congestion, improve evacuation efficiency, and reduce the casualty rate. Owing to the large region and large evacuation population demand, quickly solving the complex allocation problem is somewhat challenging, and thus, the optimal results are difficult to obtain with the increase of evacuation scale by traditional allocation methods. This article aims to establish a shelter allocation model for large-scale evacuation, which employs an improved quantum genetic algorithm (IQGA) based on spreading operation and considering the total evacuation distance, the capacity constraint of evacuation sites, and the dispersion of allocation results, and compare allocation schemes of the spreading model with those of models that consider different constraints. Results show that the allocation model with the spreading operation has better allocation results than that without the spreading operation. For the allocation model with spreading operation, the spreading model with different spreading speeds is more reasonable than that with the same spreading speed, and the allocation results are closer to the ideal results with the increase of constraints. In addition, according to the allocation results, the evacuation route map and the evacuation heat map are drawn to intuitively understand the distribution scheme of each shelter.

Effects of climate change and anthropogenic activities on runoff change of the Weihe River basin, Northwest China

AbstractThe Weihe River has experienced a significant runoff decline in the past few decades, but the detailed and systematic analysis of different sub‐regions of the Weihe River basin (WRB) for a long time is insufficient. Based on the data of five hydrological stations from 1957 to 2018, this study investigated the variation of annual runoff both in the whole Weihe River basin (WWRB) and its sub‐regions: the upper, middle, and lower reaches of the Weihe River (URWR, MRWR, LRWR, respectively), the Jing River basin (JRB), and the Beiluo River basin (BLRB). Moreover, the contribution of climate change and anthropogenic activities on runoff change was quantified by double mass curve (DMC) and hydrological sensitivity analysis (HSA) methods. The results showed that runoff of the URWR, MRWR, JRB, BLRB, and WWRB showed significant downward trends, and with the change‐point years of 1993, 1990, 1996, 1994, and 1993, respectively. Both results of DMC and HSA showed that anthropogenic activities were the main factors for runoff reduction. The contribution of human activities was largest in the JRB and BLRB, whereas lowest in the MRWR. Over the study period, land use has changed significantly in the basin, mainly manifested in the reduction of farmland, and the increase of construction land and grassland, indicating that intense anthropogenic activities have taken place. Moreover, the total water consumption of the WWRB increased evidently, which exacerbated the contradiction between supply and demand of water resources. The results of HSA showed that runoff was more sensitive to precipitation than to Ep. Precipitation reduced the runoff, while Ep increased runoff in the basin. The results of this study are helpful for understanding the regional hydrological situation in more detail, and can act as a reference for formulating reasonable water resources allocation schemes.