Loading Problem Research Articles

Intensity of Dynamic Stresses of Longitudinal Shear in a Periodically Layered Composite with Penny-Shaped Cracks

We consider the problem of harmonic torsional loading of an infinite elastic composite formed by alternating plane layers made of two different materials in the presence of a penny-shaped crack in one of the components of periodic structure. By using the integral representations for displacements and stresses in the frequency domain and satisfying the conditions of periodicity and perfect contact on the interfaces, we deduce a system of uncoupled boundary integral equations for the functions of tangential dynamic crack-opening displacement in a two-layered representative element of the composite. We perform the numerical analysis of the mode-III dynamic stress intensity factors in the vicinity of the analyzed crack depending on the wave number, the thicknesses of constituent layers, and the properties of their materials.

Research on the Influence of Airfoil on the Flying Performance of Glider

Gliders are heavier-than-air fixed-wing aircraft that do not rely on power plants to fly, and are now widely used in scientific observation, daily entertainment, and other fields. After taking off, it only relies on the reaction force of air acting on its lifting surface for free flight. Different gliders can stay in the air for different amounts of time in different environments, which is mainly determined by the airfoil. Therefore, through literature reading, this paper understands its flight principle, and studies and analyzes the advantages and disadvantages of existing airfoils by comparing the influence of different airfoils on flight performance. In view of the problems existing in the airfoil, rationality calculations and improvements are put forward, hoping to promote the development of the aviation industry. After research, the concave wing is by far the most suitable gliding airfoil, which can provide relatively large lift and stability, but there is still the problem of insufficient load. In order to improve these deficiencies, the airfoil is optimized by increasing the contact area between the airflow and the wing. For example, the defect can be improved by lengthening the length of the entire wing, reducing lateral airflow, and increasing the upward curvature of the wingtip.

Construction of energy load balance model for interchange tunnel structure based on semi supervised learning model

BackgroundWith the current development of chemical energy and process engineering optimization, urbanization construction has been further promoted, and traffic tunnels have gradually increased, especially in the case of insufficient ground space, overpass tunnels have become an important traffic carrier. The structural energy load of interchange tunnel is an important factor. MethodBased on the semi supervised learning model, the energy load problem of interchange tunnel is modeled. Through the optimization of the structure and design requirements of the interchange tunnel, the energy problem in the structure was optimized. FindingsThrough the experiment of the monitoring effect, structure and data information under the semi supervised learning, it was found that the model based on the semi supervised learning model could well solve the settlement problem of the interchange tunnel. Compared with the actual measured values, it was found that the detection accuracy of the model reached 98.43%, and the data information processing efficiency index reached 0.832, It has high accuracy and processing efficiency. It can quickly adapt to the construction characteristics of the interchange tunnel, improve the test effect, and thus promote the smooth and effective development of the interchange tunnel construction project.

Application of metaheuristics algorithm on a multi-objective container loading problem considering container’s utilization and vehicle’s balance

The container loading problem (CLP) intends to arrange a set of boxes into a container by considering different aspects, such as the dimension and weight of the box, capacity of the container, etc. In the multi-destination delivery, box arrangement should also consider routing, or delivery order. In addition, it is crucial to balance the boxes for safety in order to avoid traffic accident. Therefore, in order to overcome the aforementioned problems, this study proposes a mathematical model with two objectives, maximizing container’s utilization and minimizing truck’s unbalance force penalty. The proposed model also considers some practical constraints including geometry, maximum weight, and delivery order, or loading priority. Two metaheuristics, non-dominated sorting genetic algorithm II (NSGA II) and multi-objective particle swarm optimization algorithm (MOPSO) are employed to solve the proposed model and verified by using seven benchmark datasets in terms of hypervolume and spacing. The experimental results show that both algorithms have their own merits.

Vibration and control optimization of pressure reducer based on genetic algorithm

Abstract A research challenge of vibration and control optimization of pressurized reducer is solved in this article; a method based on genetic algorithm (GA) is proposed to optimize the vibration and control of reducer. Considering the bending strength of helical gear root and tooth surface contact fatigue strength as constraints, the improved GA is used to solve it, and the optimal parameter combination is obtained. The size of center distance is reduced by 9.59% compared with that before. Based on the optimized results, the vibration becomes weaker with the increase of the load at the output end of the reducer, and its maximum value is only 1/8 of that when the load is 550 N. The experimental results show the optimized surface load distribution of driving gear teeth. The maximum normal load per unit length of the optimized output stage driving gear surface is 521.321 N/mm, which is significantly lower than the 662.455 N/mm before optimization. At the same time, the tooth surface load is evenly distributed. The larger tooth surface load is mainly distributed in the middle of the tooth surface with strong bearing capacity, which effectively solves the problem of unbalanced load before optimization and improves the bearing capacity of gear transmission. It is proved that GA can effectively realize the vibration and control optimization of pressurized reducer.

Weapon target assignment strategy for shipboard power system considering high power pulse loads integration

In the current naval combat environment, the instantaneous high-energy nonlinear high-power pulse load is gradually developed into a core equipment and facilities for military ships, and the nonlinear and transient impact characteristics of high-power pulse load are obvious. In this paper, the weapon–target assignment (WTA) modeling and solving problem are studied considering the pulse loads integration. Firstly, the multi-objective optimization method is used in this paper, and the optimization objective function is defined as maximizing the attack ability of high power pulse load in a short time and minimizing the total survival probability of incoming targets. The WTA model under multiple constraints is established. Then, genetic algorithm (GA) is used to solve the problem, taking into account the characteristics of impulsive load and WTA problem. Finally, simulation cases are constructed for experimental analysis. The simulation results show that the proposed model and algorithm can obtain an effective solution to the WTA problem with impulsive load, which has certain significance of reference.

Hybrid peptides as platform for synchronized combination therapy

Combination therapy, where two or more therapeutic agents are combined to target different cellular pathways, is an effective tool in cancer treatment but often difficult to execute. Here we present the collagen peptide-based platform that allows for synchronous and colocalized cellular delivery of three different agents. The peptide is a hybrid between collagen and cell penetrating peptide (CPP) that assembles into a heterotrimer helix and forms fully organic, high aspect ratio nanoparticles. The validity of the approach was tested with three chemically different agents (Paclitaxel, Doxorubicin, and 5-Fluorouracil; a combination used in clinical treatment of (ER)-positive and (PR)-positive breast cancer) conjugated to N-terminus of the peptide. The design of this peptide-based drug delivery system provides several advantages: it avoids drug loading problems; removes the need for orthogonal synthesis; and allows for colocalized delivery of up to three drugs (which leads to the same biodistribution for each drug). In addition, hybrid collagen/CPP peptides are known to enhance cellular uptake and improve solubility of drugs. The synergistic effect, in terms of enhanced efficacy, of the Paclitaxel-Doxorubicin-5-Fluorouracil combination was also calculated. We envision self-assembling peptides as a platform for drug codelivery that can be expanded into a library of personalized combinations that may also include other functionalities like targeting or imaging.

RIVER ECOSYSTEMS OF THE FOREST-STEP AND STEPPE: NATURAL CHARACTERISTICS AND PECULIARITIES OF URBAN DEVELOPMENT

Natural features of river ecosystems of forest-steppe and steppe zones are considered. The problems of anthropogenic loading of the rivers of the dissected plains and their coastal areas are indicated. Measures of urban planning organization of coastal territories of river ecosystems of forest-steppe and steppe zones are proposed.
 According to the type of river and the natural area of the river basin in Ukraine, there are 3 types of rivers: Polish rivers, rivers of forest-steppe and steppe zones (dismembered plains), and mountain rivers. The most common are the rivers of the dissected plains, to which this article is devoted. These rivers usually have wide valleys, gentle slopes, many rivulets and streams, the speed of the flow of these rivers is 0.2-0.3 m/sec. The geographical location of river basins gives special characteristics to rivers and their coastal areas, which must be taken into account during their urban development.
 In order to improve the ecological condition of forest-steppe and steppe river ecosystems, preserve and revive their natural component, and prevent the negative consequences of anthropogenic load on the river ecosystems of the dismembered plains, a complex of measures is required - state draft laws and programs with sufficient funding, scientific research developments, and public support. This publication is devoted to proposals for urban planning organization of coastal areas and preservation of the natural component of river ecosystems of dismembered plains.
 The natural state of forest-steppe and steppe river ecosystems will be preserved if the following economic and urban planning measures are carried out: - clearing of riverbeds from excess air-water vegetation; at the same time, reed stalks can be used as fuel and for roofing houses, which is a traditional ecological material;- clearing of springs and wells that have a hydraulic connection with water areas;- a complex of anti-slide measures, - a set of anti-erosion measures aimed at eliminating gullies by filling them in, landscaping them with special-purpose plantings; - protection against flooding; - reclamation of quarries; - banning the discharge of wastewater into rivers, which will preserve surface water resources and the purity of mineral springs; - the continuity of the annual period of carrying out scientifically based ecological releases from reservoirs - from April 15-20 to May 9-10; - establishment of coastal protection strips of rivers, restrictive Green and Blue lines; - improvement of recreational reservoirs; - compliance with the regime of economic activity.
 The implementation of the mentioned urban planning measures in combination with the adoption of legislative programs, scientific research, sufficient funding and an active position of the public will definitely lead to the revival and preservation of the natural component of the river ecosystems of the dismembered plains. More than 60% of Ukraine's water resources are formed in the basins of small rivers, therefore improving the ecological condition of small rivers is the key to the revival of medium and large rivers.

EFFICIENCY OF THE RENEWABLE ENERGY SOURCES APPLICATION FOR AN AUTONOMOUS HEAT SUPPLY SYSTEM

Description of the developed software and information complex for modeling autonomous heat supply systems provided, which allows optimizing the selection of units and their operation modes and ensuring the production and redistribution of thermal energy in accordance with the schedule of consumers. Optimized modes simulation operation of the autonomous heat supply system for a cottage village based on local energy resources with minimal use of external energy sources performed. The use of software and information complex made it possible to calculate the parameters that provide optimal coverage of the heat load schedule of a cottage settlement based on local energy resources. For the calculation, the predicted values of the installed thermal power of the units and the heat load graph which was obtained by adapting the real annual graph of the external temperature of Stockholm to the geographical location of the Kyiv region were used. The developed new software and information complex provide an opportunity for hourly modeling, research into the optimal modes of operation of heat units, and evaluation of the effectiveness of the use of renewable energy sources in autonomous heat supply systems. In the developed software and information complex, the model of optimization of operating modes is applied, which belongs to the class of problems of optimal loading of generating capacities of power systems with the criterion of minimizing costs for production, accumulation, and consumption of thermal energy. An example of simulation results using a heat load schedule for a selected typical day is presented. The obtained results indicate a decrease in the specific cost of hourly heat supply with an increase in the part of thermal energy supplied at the expense of renewable energy sources. This is due to a decrease in the share of gas, and in general, any other generation based on fossil fuel technologies, in the total volume of heat supply. Thus, the effectiveness of the use of renewable energy sources based on local energy resources as part of the heat supply system of the cottage village was confirmed. Keywords: autonomous heat supply, the efficiency of renewable energy sources based on local energy resources.

A Rolling-Adaptive Peak Clipping Control Strategy Coordinating RBE Recycling and PV Consumption

Electrified railway is one of the major users of electricity in the power system. The access of energy storage system (ESS) effectively solves the problems of peak traction load (TL) shock and regenerative braking energy (RBE) recycling, and the access of photovoltaic (PV) system improves environmental and economic benefits. However, in the current control strategy based on the electrified railway with ESS and PV, there are still problems of less optimal overall peak clipping effect of TL and insufficient penetration of renewable energy sources (RES) due to low utilization and lack of pre-processing capacity of ESS. Therefore, this paper proposes a rolling-adaptive peak clipping (RAPC) control strategy coordinating RBE recycling and PV consumption. Firstly, perform rolling peak clipping through dynamically divided implementation windows to make full use of the available energy in each time period. Secondly, according to the state of charge (SOC) of ESS and the specific working condition of TL, the ESS output is modified accordingly to perform adaptive deep peak clipping maximizing the consumption of PV energy and RBE. The simulation verified that the proposed strategy can improve the overall peak-clipping effect of TL, and achieve full recovery of RBE and complete consumption of PV energy under the same ESS configuration compared to the global optimization method. The results show that the RAPC control strategy can realize optimal peak-clipping and RBE utilization, and increase the PV penetration with limited ESS capacity, thus improving the economic benefits of the traction power supply system (TPSS) and promoting the energy transition of TPSS.

A Parallel Intelligence-Driven Resource Scheduling Scheme for Digital Twins-Based Intelligent Vehicular Systems

Real-time digital twin technology can enhance traffic safety of intelligent vehicular system and provide scientific strategies for intelligent traffic management. At the same time, real-time digital twin depends on strong computation from vehicle side to cloud side. Aiming at the problem of delay caused by the dual dependency of timing and data between computation tasks, and the problem of unbalanced load of mobile edge computing servers, a parallel intelligence-driven resource scheduling scheme for computation tasks with dual dependencies of timing and data in the intelligent vehicular systems (IVS) is proposed. First, the delay and energy consumption models of each computing platform are formulated by considering the dual dependence of sub-tasks. Then, based on the bidding idea of the auction algorithm, the allocation model of computing resources and communication resources is defined, and the load balance model of the mobile edge computing (MEC) server cluster is formulated according to the load status of each MEC server. Secondly, joint optimization problem for offloading, resource allocation, and load balance is formulated. Finally, an adaptive particle swarm with genetic algorithm is proposed to solve the optimization problem. The simulation results show that the proposed scheme can reduce the total cost of the system while satisfying the maximum tolerable delay, and effectively improve the load balance of the edge server cluster.

Manufacture of Load Bearing Concrete Masonry Units Using Waste Demolishing Material

The presence of construction wastes such as clay bricks, glass, wood, plastic, and others in large quantities causes serious environmental problems in the world. Where these wastes can be used to preserve the natural resources used in construction and reduce the impact of this problem on the environment, it also works to reduce the problem of high loads of concrete blocks. Clay bricks aggregate (AB) can be recycled as coarse aggregate and replaced with volumetric proportions of coarse aggregate by ( 5% and 10%), as well as the use of clay brick powder (PB) by replacing its weight of cement (5% and 10%) and reduced in the manufacture of concrete blocks (blocks). Four mixtures will be prepared and tested to learn how to reuse the brick coarse aggregate ACB and PB powder brick as substitute materials for producing concrete blocks, use the water spray method to treat concrete building blocks (blocks) and check the Dimensions and compressive strength, and absorption.

Weighted Sum Metrics – Based Load Balancing RPL Objective Function for IoT

The technological development of Internet of Things (IoT) applications is emerging and attracting the attention of the real world in the automated industry, agriculture, environment, and scientific community. In most scenarios, extending the network lifetime of an IoT network is highly challenging because of constrained nodes. The wireless sensor network (WSN) is the core component of IoT applications. In addition, the WSN nodes are required for the network processes, particularly routing, energy maintenance, load balance, congestion control, packet delivery, quick response, and more. The failure of any of the above network processes will affect the entire network operation. IPv6 Routing Protocol for Low-power and Lossy network (RPL) provides high routing solutions to IoT applications requirements. The load balance, congestion control, traffic load, and bottleneck problems are still open issues in the RPL. To resolve the load balance issue, we propose a weighted sum method objective function (WSM-OF), which provides the ability to select the alternative parent in routing by RPL metrics. WSM-OF adopts congestion control and load balancing to avoid heavy traffic and extend the network's node lifetime. The network parameters of control overhead, jitter, packet delivery ratio, parent switching, energy consumption, latency, and network lifetime are implemented and analyzed through the COOJA simulator. The result shows that the WSM-OF improves the network performance and significantly enhances the network lifetime by up to 7.8%.

Load Balancing Strategy of Power Communication Network Based on SDN Controller

A load balancing strategy based on SDN controller is proposed to solve the load and security problems caused by the large number of services carried by power communication network in this article. Firstly, integrated with the actual situation of the network, the basic framework of gradual hierarchical transformation of power communication network is put forward. Then, the SDN controller response delay model is discussed in detail in the modeling process, and a multi controller deployment model and its solution algorithm are also proposed. The simulation results verify the effectiveness of the SDN centralized control function, and optimize the load balance, QoS and resource utilization, so as to reduce the impact of power grid communication link failure on the control delay.

Numerical investigation of the aerodynamic and wake characteristics of a floating twin-rotor wind turbine under surge motion

To elevate the power capacity of floating wind turbines and cut costs, development towards large-scale systems is underway. However, this requires solving the problem of fatigue loading on large, flexible blades, as well as corresponding improvements to production and installation technology. As an alternative to larger turbines, twin-rotor floating wind turbines have been proposed. The aerodynamic and wake interference characteristics of this twin-rotor are not yet well understood. In this study, we have investigated the power and wake characteristics of a twin-rotor floating wind turbine based on unsteady Reynolds-averaged Navier-Stokes turbulence model for a comprehensive analysis. Specifically, the power and wake recovery of a twin-rotor floating horizontal-axis wind turbine (FHAWT) under surge motion are compared in detail with those of a single floating wind turbine and bottom-fixed case, while both the effects of the three wind directions (β = 0°, 45°, 90°) and spacing ratios (S/D = 1.2, 1.375, 1.5) are considered. The results suggest that the mean power of the twin-rotor is enhanced by a maximum of 13% under surge motion compared to the single rotor, the small spacing ratio promotes the power gain. Surge motion plays a significant role in wake interaction between the twin-rotor and facilitates wake recovery. As compared to the baseline case, both power and wake recovery performance of the twin-rotor are boosted at β = 45°, with an increase in power of 12.7% as opposed to the single rotor. The modified Jensen wake model is proposed for the far-wake region and a modified Gaussian wake model is also suggested for different cases. This study can provide affiliated guidance for the application of the twin-rotor floating wind turbine.

Design of Laser Quenching Equipment for Stainless Steel Dining Knife

Based on the research of laser quenching technology of thin blade edge, the laser quenching equipment of stainless steel dinner knife is developed. According to the structure of stainless steel knife and quenching process layout, the feeding mechanism, positioning mechanism and feeding mechanism are designed to meet the functional requirements of laser quenching automatic operation, which has high practical value to solve the problem of automatic loading and unloading of tool and accelerate the production speed of tool.

A dynamic and proactive multi-microgrid network reconfiguration model for load factor improvement

Independent operation of a single microgrid (MG) is facing significant operational challenges such as high operational expenses, limited self-consumption of local renewable energy, and fluctuating peak and valley load because of the increased uncertainty and variability of net load generation caused by high penetrations of renewable energy. In this paper, connected multiple microgrids reconfiguration strategy is proposed while considering renewable generation uncertainty. Reconfiguration strategy is proposed to aggregate different load patterns belonging to various microgrids and match them with a certain microgrid. Then, the new aggregation of loads is aimed to improve the load factor of each MG within the network. The contribution of this study is to solve the peak load problem within the power network without affecting the costumers’ life routine by using a mixed integer linear programming model for the dynamic proactive network reconfiguration of connected microgrids. The formulated model aims to maximize the load factor of each microgrid in the network and flatten the peak load curve without disturbance for the households’ consumption patterns. The proposed model determines the near optimal topology for the network, The proposed mixed integer linear programming model is used to solve the reconfiguration problem with respect to distribution losses, microgrids output and households’ consumption. Moreover, a linearization approach of the load factor equation is proposed to reduce the model complexity and computational time. An artificial dataset contains 3 microgrids and 15 households is used to validate the model performance. The obtained results show that the network reconfiguration could affect the average demand of each individual MG by reducing the fluctuations within the curve. Therefore, the load factor for the three microgrids increases with a percentage ranges from 8% to 53% in comparison with the unconnected system.

Closed-form consolidation solutions for known loading functions

In engineering practice, loading varies with time. However, the classical one-dimensional theory of consolidation assumes the stress increase is instantaneously applied. Many approaches to the problem of time-dependent loading have been proposed over the years, from approximate methods to full developments of differential equations. The paper presents a simple method for finding a closed-form consolidation solution for time-dependent loading without the need for differential equations. Two sets of general equations were derived for both excess pore pressure and average degree of consolidation. Equations were solved for linear, parabolic, sinusoidal, and exponential load functions. Stepped and cyclic loads were also addressed and a numerical solution was developed to verify the obtained result. The method proved to be easy to apply and provides solutions with great simplicity. A case study of non-instantaneous loading on soft clay was also analyzed, and settlement prediction showed good results when compared to readings of the settlement plates.

Improved wild horse optimization with levy flight algorithm for effective task scheduling in cloud computing

Cloud Computing, the efficiency of task scheduling is proportional to the effectiveness of users. The improved scheduling efficiency algorithm (also known as the improved Wild Horse Optimization, or IWHO) is proposed to address the problems of lengthy scheduling time, high-cost consumption, and high virtual machine load in cloud computing task scheduling. First, a cloud computing task scheduling and distribution model is built, with time, cost, and virtual machines as the primary factors. Second, a feasible plan for each whale individual corresponding to cloud computing task scheduling is to find the best whale individual, which is the best feasible plan; to better find the optimal individual, we use the inertial weight strategy for the Improved whale optimization algorithm to improve the local search ability and effectively prevent the algorithm from reaching premature convergence. To deliver services and access to shared resources, Cloud Computing (CC) employs a cloud service provider (CSP). In a CC context, task scheduling has a significant impact on resource utilization and overall system performance. It is a Nondeterministic Polynomial (NP)-hard problem that is solved using metaheuristic optimization techniques to improve the effectiveness of job scheduling in a CC environment. This incentive is used in this study to provide the Improved Wild Horse Optimization with Levy Flight Algorithm for Task Scheduling in cloud computing (IWHOLF-TSC) approach, which is an improved wild horse optimization with levy flight algorithm for cloud task scheduling. Task scheduling can be addressed in the cloud computing environment by utilizing some form of symmetry, which can achieve better resource optimization, such as load balancing and energy efficiency. The proposed IWHOLF-TSC technique constructs a multi-objective fitness function by reducing Makespan and maximizing resource utilization in the CC platform. The IWHOLF-TSC technique proposed combines the wild horse optimization (WHO) algorithm and the Levy flight theory (LF). The WHO algorithm is inspired by the social behaviours of wild horses. The IWHOLF-TSC approach's performance can be validated, and the results evaluated using a variety of methods. The simulation results revealed that the IWHOLF-TSC technique outperformed others in a variety of situations.

A Block-Building Based GRASP Method for Solving Container Loading Problem

The importance of container transportation is constantly increasing. For this reason, lower cost transportation is of great importance for companies in transportation by air, land, rail and sea in domestic and international markets. One way of reducing the costs is to utilize the container volume effectively. In this study, a block-building based GRASP method is proposed for solving the container loading problem. The results are compared with other GRASP methods and other heuristic or meta-heuristic algorithms in the literature. The results show improvements in comparison to the other methods.