Every decision maker’s internal scale is different based on a myriad of possible factors unique to that decision maker. Conflicting criteria within and between alternatives in multicriteria decision making can create negative effects within the weighting schemes and amplify preference biases and scale disparities between decision makers in a group decision context. Additionally, the weighting of group decision-making frameworks can intensify the already skewed criteria values. When making judgments against requirements, it may be preferable to reduce scale trend distortions between decision makers as much as possible. Previous research supports that certain information presentation modes can significantly reduce preference bias and strengthen criteria independence against requirements through cross alternative anchoring. This paper expands that research and proposes a new optimization model for strengthening criteria independence and consensus in group decision making. Initial results... [more]

This work presents a superstructure optimization study for the production of renewable fuels with a focus on jet fuel. Power-to-X via the methanol (MTJ) and Fischer−Tropsch (FT) route is combined with Biomass-to-X (BtX) via an algae-based biorefinery to an integrated Power- and Biomass-to-X (PBtX) process. Possible integration by algae remnant utilization for H2/CO2 production, wastewater recycling and heat integration is included. Modeling is performed using the novel Open sUperstrucTure moDeling and OptimizatiOn fRamework (OUTDOOR). Novel methods to account for advanced mass balances and uncertain input data are included. Economic optimization proposes a PBtX process. This process combines algae processing with MTJ and depicts a highly mass- and energy integrated plant. It produces fuels at 211 EUR/MWhLHV (ca. 2530 EUR/t), a cost reduction of 21% to 11.5% compared to stand-alone electricity- or bio-based production at algae costs of 25 EUR/tAlgae-sludge and electricity costs of 72 EU... [more]

Decanter centrifuges are widely used for solid−liquid separation. Although parameter analysis for decanter centrifuges was performed by numerical simulation in previous studies, some structural parameters are rarely mentioned and investigated. At the same time, the results obtained by the single-parameter analysis in previous studies are difficult to truly realize the comprehensive performance optimization of decanter centrifuges. In this paper, the influences of the window structure and bowl−conveyor gap on the separation performance are systematically analyzed with the employment of a numerical computation method. The results show that the increase in the window angle and window height will accelerate the flow of the upper layer, while the increase in the bowl−conveyor gap may make particles flow through it directly and further form a solid retention zone. Both of the structural changes will lead to deterioration of the separation performance. On the basis of numerical simulation ana... [more]

It is extremely critical for an emergency response to quickly and accurately use source term estimation (STE) in the event of hazardous gas leakage. To determine the appropriate algorithm, four swarm intelligence optimization (SIO) algorithms including Gray Wolf optimizer (GWO), particle swarm optimization (PSO), genetic algorithm (GA) and ant colony optimization (ACO) are selected to be applied in STE. After calculation, all four algorithms can obtain leak source parameters. Among them, GWO and GA have similar computational efficiency, while ACO is computationally inefficient. Compared with GWO, GA and PSO, ACO requires larger population and more iterations to ensure accuracy of source parameters. Most notably, the convergence factor of GWO is self-adaptive, which is in favor of obtaining accurate results with lower population and iterations. On this basis, combination of GWO and a modified Gaussian diffusion model with surface correction factor is used to estimate the emission source... [more]

The increasing occurrence of toxic cyanobacteria in water sources, driven by climate change and eutrophication, is of great concern worldwide today. Cyanobacterial blooms can negatively affect water bodies and generate harmful secondary metabolites, namely microcystins (MCs), which significantly impair water quality. Various adsorbents used for MC removal from water sources were assessed in this investigation. Activated carbon constitutes the most widely used adsorbent for treating contaminated waters due to its high affinity for adsorbing MCs. Alternative adsorbents have also been proposed and reported to provide higher efficiency, but the studies carried out so far in this regard are still insufficient. The mechanisms implicated in MC adsorption upon different adsorbents should be further detailed for a better optimization of the adsorption process. Certainly, adsorbent characteristics, water pH and temperature are the main factors influencing the adsorption of MCs. In this context,... [more]

Grape pomace (grape skin and seeds) and stems are major by-products of winemaking, of lignocellulosic nature. The aim of this study was to value grape pomace and stems to produce prebiotic oligosaccharides (OS). Grapes from Touriga Nacional and Marselan cultivars (Vitis vinifera L.) were used for conventional red winemaking. The total of extractives, obtained by sequential extraction with dichloromethane, ethanol, and water, was approx. 64.0% (d.w.) for both pomaces, and 46.2% and 59.5% for Marselan and Touriga Nacional stems, respectively. Lignin contents in Marselan stems (26.4%) and pomace (20.4%) were higher than in Touriga Nacional pomace (19.3%) or stems (17.3%). Polysaccharides (hemicelluloses and cellulose) represented 9 and 8.2% of Marselan and Touriga pomaces, and 22.3 and 18.7% of respective stems. After extractives removal, the pomaces and stems were submitted to a hydrothermal treatment (autohydrolysis) to release oligosaccharides from the hemicellulose fraction. Autohydro... [more]

Multi-response optimization problems investigation is a crucial element in initiatives designed to enhance quality and overall productivity for manufacturing processes. Since no particular algorithm can be employed for all multi-response problems, defining the method that is utilized as a problem-solving technique is a vital step in the process factors optimization. Identifying a formal procedure of implementing the improvement approach in a multi-criteria decision-making problem is a critical need to ensure the consistency and sustainability of the enhancement methods. In this study, a Plan−Do−Check−Act (PDCA) framework is implemented for a case study in the food industry under which a multi-response optimization problem is investigated. The design of experiment (DOE) is used to examine the effect of process parameters on the quality responses by using the Taguchi method to find the optimal setting for each parameter. An orthogonal array (OA) and signal-to-noise (SNR) ratio is employe... [more]

Distillation is important to chemical processes but it is energy intensive, and its optimization is of great significance to energy savings and emissions reduction. Varying the operating pressures of distillation columns could assist heat integration of distillation columns into the overall process, thereby reducing energy consumption. However, influences of varying column pressures on the energy profiles of the overall process have not been systematically analyzed in previous studies. This paper presents an insightful analysis of heat integration of distillation into the overall process considering the change of operating pressure. Firstly, effects of changing the operating pressure of a distillation column on its own utility requirements and the related process streams are studied. Next, such effects are graphically represented and incorporated into the grand composite curve (GCC). The change tendencies of the GCC, pinch temperature, and total utility consumption are analyzed and pre... [more]

This study aims to address the issues of volatile energy access to the active distribution network (ADN), which are the difficulty of frequency regulation, the increased voltage deviation of the ADN, the decrease in operational security and stability, etc. In this study, a two-stage majorization configuration model is established to identify and understand how volatility energy affects a hybrid energy storage system (HESS). The ADN and HESS with lead-acid batteries and supercapacitors (SC) are examined using day forecast data for wind, solar, and load. In this planning stage, the integrated cost, network loss, and node voltage deviation are considered as optimal objectives in a multi-objective optimization model, while the revised multi-objective optimization particle swarm approach is used to solve the initial value of capacity configuration. In the operation stage, optimizing objectives like wind output power fluctuations, the frequency deviation of HESS is used to solve the modified... [more]

Although constructing a dam can bring significant economic and social benefits to a region, it can be catastrophic for the population living downstream when it breaks. Given the dynamic and nonlinear characteristics of dam deformation, the traditional dam prediction model has been unable to meet the actual engineering demands. Consequently, this paper advocates for a novel method to solve this issue. The proposed method is based on the optimization of improved chicken swarm (ICSO) and support vector machine (SVM). To begin with, the mean square error is used as the objective function, and then, we apply the improved chicken swarm algorithm to iterate continuously, and finally, the optimal SVM parameters are obtained. Through the modeling and simulation experiments of a nonlinear system, the validity of the improved chicken swarm algorithm to optimize an SVM model has been verified. Based on the horizontal displacement monitoring data of FengMan Dam, this paper analyzed the influencing... [more]

Unmanned aerial vehicle edge networks (UENs) can reduce the cache load of the core network and improve system performance to provide users with efficient content services. However, the time-varying characteristics of content popularity in UENs lead to a low accuracy of popularity prediction, and the capacity limitations of wireless channel conditions lead to a lower cache hit rate than the rates of traditional fiber-optic-based cache strategies. Therefore, this paper proposes the discrete artificial bee colony cache strategy of UENs (DABCCSU). First, the information−dynamics−dissemination model of UENs (IDDMU) is established to deduce the coupling relationship between the channel capacity and the service probability in IDDMU. The influence of the service probability change on the content dissemination process is discussed, and the content popularity in UENs is predicted by the state iteration matrix. Then, the discrete artificial bee colony cache (DABCC) optimization algorithm is propo... [more]

Aiming at the problem of the difficult separation of film in the process of farmland residual film recovery, a clamping conveying residual film recovery device was designed and studied. The device was mainly composed of a clamp plate, clamp plate conveying chain, chain wheel drive shaft, and the residual film conveying chain and frame. Firstly, the structure and working principle of the device are introduced. The tensile properties of the residual film are investigated to determine the relationship between the average clamping force, the height of the clamp plate, the spacing of the clamp plate, and the rotational speed of the sprocket. Then, the mechanical properties of the residual film are discussed. The influence weight of each factor on the film impurity separation rate is summarized by single factor tests. The regression equation between the factors and film impurity separation rate is established. The results of the variance analysis of regression equation show that the film imp... [more]

With the gradual liberalization of China’s energy market, the distributed characteristics of each entity in the community integrated energy system are more and more obvious, and the traditional centralized optimization is difficult to reveal the interaction between the entities. This paper aims to improve the profit of the community operator and the users’ value-added benefit of energy use, and proposes a multi-energy transaction decision of a community integrated energy system considering user interaction. First, a refined model of user interaction, including energy conversion, is established, and then the optimization model of multi-energy transaction decision between the community operator and the users is constructed based on the master−slave game. The upper layer aims to maximize the profit of the community operator according to the energy use strategies’ feedback from the users, decides the retail energy prices of the community operator to the users, and optimization variables in... [more]

The research on the layout of multi-layer manufacturing cells for smart factories is still in its infancy, but there is an urgent need to address this issue in building smart factories. This paper presents the Manufacturing Cell Integrated Layout (MCIL) Method, which integrates multiple layout forms of multi-layer and single-layer manufacturing cells. The paper develops a mathematical model of the MCIL problem which considers the multi-objective functions of logistics handling, occupied space, cell stability, lost time, and non-logistics relations, as well as the constraints between equipment in the cell and cells. An adaptive RNS-FOA algorithm is proposed to solve the high-dimensional and large-scale characteristics of the MCIL problem based on the research of academics. Lastly, a case demonstrates the outstanding contribution of the mathematical model to the solution of the MCIL problem, while simultaneously validating the efficiency and stability of the RNS-FOA algorithm for solving... [more]

In order to improve the hydraulic performance of the integrated pump gate, the flow pattern of the inlet and outlet of the pump gate is improved. This paper adopts the SST k-ω turbulence model to numerically calculate the initial scheme of the integrated pump gate, verifies its internal flow pattern through experiments, then adds and optimizes the design of the inlet and outlet horn pipes of the integrated pump gate through orthogonal optimization. The research results conclude that the hydraulic performance of the integrated pump gate is significantly improved after adding the inlet and outlet horn. Under the design flow condition (Qd = 11.5 L/s), the efficiency of the pump gate increased from 60.50% to 67.19%, the head increased from 2.7569 m to 3.1178 m, the hydraulic loss in the inlet channel decreased from 0.064 m to 0.027 m, and the hydraulic loss in the outlet channel decreased from 1.337 m to 1.027 m. The optimized trumpet pipe can improve the inlet conditions of the pump while... [more]

This study discusses the calculation of entropy of discrete-time stochastic biological systems. First, measurement methods of the system entropy of discrete-time linear stochastic networks are introduced. The system entropy is found to be characterized by system matrices of the discrete-time biological systems. Secondly, the system entropy of nonlinear discrete-time stochastic biological systems is discussed and is calculated based on a global linearization method. The approximation of the values of system entropy of nonlinear stochastic systems needs to solve an optimization problem that is constrained by a kind of linear matrix inequality (LMI). Finally, a practical biochemical system is provided to verify the effectiveness of the proposed calculation method.

The performance of artificial neural networks (ANNs) is highly influenced by the selection of input variables and the architecture defined by hyper parameters such as the number of neurons in the hidden layer and connections between network variables. Although there are some black-box and trial and error based studies in the literature to deal with these issues, it is fair to state that a rigorous and systematic method providing global and unique solution is still missing. Accordingly, in this study, a mixed integer nonlinear programming (MINLP) formulation is proposed to detect the best features and connections among the neural network elements while propagating parameter and output uncertainties for regression problems. The objective of the formulation is to minimize the covariance of the estimated parameters while by (i) detecting the ideal number of neurons, (ii) synthesizing the connection configuration between those neurons, inputs and outputs, and (iii) selecting optimum input v... [more]

To improve the battery state of charge (SOC) of the electric vehicle (EV), this paper proposes a master−slave electro-hydraulic hybrid electric vehicle (MSEH-HEV). The MSEH-HEV uses a planetary row as the core transmission component to realize the interconversion between mechanical energy, hydraulic energy and electrical energy. Meanwhile, this paper introduces the six working modes in vehicle operation, matches the parameters of key components to the requirements of the vehicle’s performance and designs a rule-based control strategy to dominate the energy distribution and the operating mode switching. The research uses AMESim and Simulink to perform a co-simulation of the MSEH-HEV, and the superiority of MSEH-HEV is testified by comparing it with an AMESim licensed EV. The simulation results show that in the Economic Commission for Europe (ECE) and the Extra Urban Driving Cycle (EUDC), the MSEH-HEV has a 15% reduction in battery consumption, and the motor peak torque is greatly reduce... [more]

Desalination is set to become a major source of drinking water in several Middle Eastern countries over the coming decades. Solar distillation is a simple power-independent method of water desalination, which can be carried out in active or passive modes. This study is among the first attempts to investigate the possibility of desalinating brackish groundwater resources under the threat of saltwater intrusion in the southern areas of Razavi Khorasan province in Iran. For this purpose, a pilot solar distillation unit was constructed to analyze the effects of the unit orientation, depth of the water pool, atmospheric conditions, input salinity, and flow continuity on the solar distillation performance. The results showed that the unit exhibited the highest efficiency when it had a 3 cm deep water pool. It was oriented facing southward while operating a continuous flow for at least 3 days under sunny weather conditions. It was found that among the studied parameters, the unit orientation... [more]

Minimizing the makespan is an important research topic in manufacturing engineering because it accounts for significant production expenses. In bakery manufacturing, ovens are high-energy-consuming machines that run throughout the production time. Finding an optimal combination of makespan and oven idle time in the decisive objective space can result in substantial financial savings. This paper investigates the hybrid no-wait flow shop problems from bakeries. Production scheduling problems from multiple bakery goods manufacturing lines are optimized using Pareto-based multi-objective optimization algorithms, non-dominated sorting genetic algorithm (NSGA-II), and a random search algorithm. NSGA-II improved NSGA, leading to better convergence and spread of the solutions in the objective space, by removing computational complexity and adding elitism and diversity strategies. Instead of a single solution, a set of optimal solutions represents the trade-offs between objectives, makespan and... [more]

On account of its small size and poor sedimentation performance, microalgae harvesting is restricted from a wider application. Air flotation is an efficient and fast solid−liquid separation technology, which has the potential to overcome the impediments of microalgae harvesting. In this study, factors influencing microalgae harvesting by air flotation were investigated. The results illustrated that bound extracellular organic matter (bEOM) had a greater effect on microalgae harvesting by air flotation, compared with dissolved extracellular organic matter (dEOM). Microalgae harvesting by air flotation in different growth stages proceeded, and the effect of air flotation in the heterotrophic stage was better than the autotrophic stage. The molecular weight distributions demonstrated that after air flotation, the proportion of high MW substance increased, while the proportion of low MW substance decreased, regardless of whether dEOM or bEOM. Membrane filtration was carried out for the alg... [more]

In the present industry revolution, operations management teams emphasize implementing an efficient process optimization approach with a suitable strategy for achieving operational excellence on the shop floor. Process optimization is used to enhance productivity by eliminating idle activities and non-value-added activities within limited constraints. Various process optimization approaches are used in operations management on the shop floor, including lean manufacturing, smart manufacturing, kaizen, six sigma, total quality management, and computational intelligence. The present study investigates strategies used to implement the process optimization approach provided in the previous research to eliminate problems encountered in shop floor management. Furthermore, the authors suggest an idea to industry individuals, which is to understand the operational conditions faced in shop floor management. The novelty of the present study lies in the fact that a methodology for implementing a p... [more]

Currently, reducing energy consumption and fossil fuel emissions are key factors placed in the first position on the European agenda. District heating technology is an attractive solution, able to satisfy the energy and environmental goals of policymakers and designers. In line with this, a different approach to planning a district heating grid based on the optimization of building clusters is presented. The case study is Wilhelmsburg, a district of Hamburg city. This approach also investigates the usage of industrial waste heat as the grid’s heat source, which is CO2-neutral. First, the data acquisition regarding the buildings’ location and heat demand are described in detail. Based on the derived data and the source of the industrial waste heat, the district heating grid is created by clustering the buildings and connecting the obtained nodes. Furthermore, the grid’s efficiency is improved by eliminating nodes, which are too distant from the heat source, or have lower heat demand. Fi... [more]

The structural fracture of the compressor blade is the main cause of fatigue failure. The novelty of this paper is the creative application of bent swept-back modeling to the blade of the turbocharger impeller. This paper is based on a compressor impeller satisfying the k-ε turbulence model. A simulation model was established in ANSYS software, the fluid−structure interaction was calculated in the three models before and after improvement, and the results were compared and analyzed. The optimized blade could improve the blade structure, reduce stress and deformation, and improve the pressurization ratio. In this paper, the optimization scheme of different parameters was discussed in line with the optimal solution. Based on the combination of fuzzy and grey correlation theory, it was concluded that the correlation between pressure and total deformation was higher than that of equivalent stress, and these two values reached 0.8596 and 0.8001, respectively. The results showed that the pre... [more]

Based on a combination of physical and simulation experiments, a set of basic physical characteristic parameters and contact parameters suitable for granular fungal fertilizers were calibrated, which up to now have received little attention. The physical morphological characteristic parameters (overall dimension, 1000 grain weight, density, and moisture content), mechanical characteristic parameters (Poisson’s ratio, elastic modulus, and shear modulus), and contact parameters (static friction coefficient, rolling friction coefficient and recovery coefficient) of particles were measured through physical experiments. The parameters were screened for significance using the Plackett−Burman test. The results showed that the impact recovery coefficient, static friction coefficient, and rolling friction coefficient for the granular fungal fertilizer particles had a significant effect on the repose angle. The best range for the three parameters was determined using the steepest climbing test.... [more]