Journal of Engineering Research最新文献

War-Gaming is recognized as a valuable tool for commanders, leaders, and managers. Well-executed War-Games have delivered significant competitive advantages in numerous conflicts. The war-game confirmed the commanders’ knowledge of weapon systems and performance, as well as the time and space necessary to carry out battlefield maneuvers. One of the primary missions of each army on the battlefield is weapon target assignment. The weapon target assignment (WTA) is a critical problem to command to be solved in battlefield decisions. In a WTA problem, we should assign available weapons to determined targets appropriately to optimize the performance criteria. This study discusses a problem in relation to allocating and scheduling in WTA considering the mobility weapons and mobility targets. Bi-level linear programming problem is defined so that each level independently optimizes its own objective functions but is influenced by actions taken by another unit. To solve the under studied problem, three famous meta-heuristic algorithms including simulated annealing (SA), genetic algorithm (GA) and grey wolf optimizer (GWO) methods are proposed. Since the performance of meta-heuristic algorithms depends on setting the parameters, the Taguchi method has been used statistically for set parameters of the developed Algorithms. Performance evaluation of the presented algorithms is conducted through numerical experiments involving randomly generated test problems. To compare the results of proposed meta-heuristic algorithms, ANOVA and Tukey tests were used. The Computational results have shown that proposed GWO algorithm worked better than the SA and GA algorithms.

In this work, simulation and techno-economic performance evaluation of a metal recovery process are performed using SuperPro Designer® simulation software. The aim is to simulate the recovery of metals, including molybdenum, vanadium, nickel, and alumina (Mo, V, Ni, and Al), present in spent hydroprocessing catalysts. The catalysts are usually discarded as solid wastes from the petroleum refining industries. The metal recovery process layout has been developed with reasonable assumptions and optimum reaction conditions that are carried out for hydrotreating (HDT) spent catalysts using EDTA as a leaching agent. The simulation process design included economic performance evaluation, the total cost of investment, unit production cost, internal rate of return, net present value, and project payback time, which gives promising results to utilize EDTA as an efficient metal recovery process.

Across workplaces, slip-and-fall accidents occur frequently due to reduced friction at the shoe-floor interaction. However, these events are typically ignored, and the importance of appropriate footwear is frequently overlooked. Mechanical-based slip and fall risk assessment devices are used to evaluate the frictional measurements at the shoe and floor contact. The available devices are however lab-based and have difficulty in replicating the realistic slipping biomechanics. Additionally, the current devices are expensive to be used in lower-middle-income nations. In this study, a biomimetic and cost-effective slip testing device was presented. The performance of the manufactured slip tester was thoroughly validated and examined utilising five formal shoes on three different flooring surfaces in different contaminant conditions. The findings showed that the slip tester effectively distinguished between the combinations of shoes, contaminant, and floorings. It was discovered that the slip tester's performance effectively distinguished between different shoe tread patterns across several slipping combinations.

The significance of emergency transfer point and facility location lies in its potential to save lives, optimize resource allocation, and enhance the efficiency of healthcare services during emergencies. It ensures timely patient access and cost-effective care. So, this study introduces a novel Mixed Integer Programming Model (MIP) for addressing the Multi-Facility and Multi-Transfer Point Location Problem (MFMTPLP). The problem involves determining the optimal locations for q facilities and p transfer points to facilitate direct customer access to facilities or through transfer points. The objective is to minimize the maximum expected weight distance for all the required points via transfer points. The study focuses on identifying the required points that carry weight and proposes a viable solution for solving the associated mathematical problems. An important contribution of this study, which has been overlooked in previous research, is the exploration of relevant costs associated with not transferring patients from demand points and hospitalizing them at transfer points. Additionally, the study emphasizes the significance of prioritizing different points and considering the costs associated with not transferring injured individuals from demand points and admitting them to transfer points. Previous models for locating facility and transfer points did not account for these factors. The study concludes by presenting the computed results, which validate the feasibility and effectiveness of the proposed model.

The main aim of this research study is to determine the risk ranking of 29 failure modes of rig-up operations using a well-known and highly effective MCDM method i.e. Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (FTOPSIS). This method takes into account the four criteria which comprise human impact, property damage, environmental effect and company reputation as risk criteria. Three Experts in the field were invited to present the risk ranking of the relative importance of criteria and criteria performance of each risk (as failure mode) by utilizing linguistic variables which are then integrated in triangular fuzzy numbers for further analysis using the Fuzzy TOPSIS method. The evaluation concluded that FM20 (Collision between the offshore platform and boats) is the most dangerous risk with a coefficient of closeness (CCi) equal to 0.992 while the risk level of FM26 (foggy weather) was found least having a coefficient of closeness (CCi) of 0. Subsequently, sensitivity analysis of ranks concluded that FM1 (H2S inaccurate monitoring) is the most sensitive alternative with standard deviation and frequency of rank change was 5.16 and 15 respectively whereas FM20 (Collision between offshore platform and boats) is observed to be the least sensitive alternative. Fuzzy TOPSIS results were found in excellent correlations with the other reliable MCDM methods which include Fuzzy VIKOR (VIseKriterijumska Optimizacija I Kompromisno Resenje) and Fuzzy COPRAS (COmplex PRoportional ASsessment) yielding correlation of around 1. This study proves to be a landmark in the petroleum industry and significantly contributes to verifying safe practices, by taking appropriate actions in minimizing the risk level associated with different activities during rig-up operations.

This study proposes a new insertion topology for Superconductor Fault Current Limiter (SFCL) to maintain and enhance the transient stability of a wind generation system in a standalone microgrid. The proposed topology is inserting the SFCL in series with the faulty phase only. The new insertion topology performance is compared with the traditional insertion method. The proposed insertion topology of the SFCL displays excellent performance compared to the traditional method. The overall performance of the Micro-Grid is improved. The performance of the wind generator is improved dramatically after employing the proposed controller. The proposed insertion topology suppresses the fluctuations of the wind generator speed (from ± 6% to less than ± 1%) as well as the post fault wind generator real power and imaginary power. For a single line to ground fault, the wind generator active power fluctuates between + 80 kW, and − 40 kW with traditional SFCL insertion topology. When using the proposed insertion topology, the wind generator active power fluctuates between + 27 kW, and + 12 kW. Also, the proposed SFCL insertion topology mitigates the fluctuations in voltage, real power and imaginary power not only at the generator bus but also at all other Micro-Grid buses (PV bus, and storage batteries bus). The voltage at all buses recover to steady state values fast (0.01 s) compared with the recovering time when using the traditional method (nearly 1 s). The proposed method is very simple and low cost because there is no additional hardware is required. This fact makes the proposed method highly attractive from the economical and implementation point of views.

Building sector accounts for a substantial part of energy consumption (EC) and carbon emissions, mainly serving for building services engineering systems. As a known advanced high-efficiency equipment, air source heat pump (ASHP) has been increasingly used for indoor heating ventilation and air conditioning (HVAC) for residential and public buildings. Thus how to pre-estimate the energy saving potential (ESP) for given ASHPs under different climatic conditions is of high value for practical engineering application. In this paper, upon thermodynamic perfectibility conception, a simplified ASHP model is proposed to simulate its dynamic thermal performance according to the disparity between real equipment and the ideal reverse Carnot cycle. Moreover, a novel thermodynamic approach is proposed to pre-estimate and compare the seasoning-based ESPs of ASHP used for both heating and cooling. For illustrative examples, a typical public building is chosen, and the AHSP-ESPs are obtained and analyzed for five cities of different climate zones in China (Qiqihar, Beijing, Chengdu, Kunming, and Guangzhou). Preliminary research results show that lower/higher ambient temperatures contribute to higher heating/cooling ESPs respectively. However, the correlation between building EC and thermodynamic perfectibility is in inverse proportion. At first, building EC decreases rapidly with the increase of thermodynamic perfectibility, but as the thermal performance of ASHP gets closer to the corresponding ideal ones, the impact of thermodynamic perfectibility on building EC gradually decreases. This work is of great significance in understanding the regional applicability of ASHP and building EC, and providing application references for real ASHP usage in building sectors.

In this article, Green-Naghdi type-II heat conduction law was used, and a new analysis of viscothermoelastic, homogeneous, and isotropic nanobeams has been developed. The first end of the beam is based on a graphene nanostrip connected to electricity with a low-voltage current. A thermal load has been applied to the nanobeam due to an electrical current causing a thermal effect. Under simply supported boundary conditions with a fixed aspect ratio, the Green-Naghdi theorem of Type-II has been applied. The Laplace transform domain has been used to calculate the solutions of governing equations. Hoing's approximation approach has been used to calculate the inverse Laplace transformation numerically. In this study, different values of electrical voltage and electrical resistance were used for different cases. Nanobeam functions were found to be significantly influenced by electrical voltage and electrical resistance. Thus, vibration and temperature increment could be controlled by varying electrical voltage and electrical resistance applied to the nanobeam.