Multiobjective Particle Swarm Optimization Based on PAM and Uniform Design

In MOPSO (multiobjective particle swarm optimization), to maintain or increase the diversity of the swarm and help an algorithm to jump out of the local optimal solution, PAM (Partitioning Around Medoid) clustering algorithm and uniform design are respectively introduced to maintain the diversity of Pareto optimal solutions and the uniformity of the selected Pareto optimal solutions. In this paper, a novel algorithm, the multiobjective particle swarm optimization based on PAM and uniform design, is proposed. The differences between the proposed algorithm and the others lie in that PAM and uniform design are firstly introduced to MOPSO. The experimental results performing on several test problems illustrate that the proposed algorithm is efficient

Effects of Light and pH on Cell Density of Chlorella Vulgaris

AbstractImproving the cell density of microalgae cultivation is one of the keys to reduce the cost of microalgae biodiesel. Many studies showed that the adjustment of pH and light intensity could increase cell density. The effects of light intensities, pH and pH adjustments on the growth of Chlorella vulgaris were studied in light incubator. The light intensities were set at 3960, 7920 and 11920lux; values of pH were 7, 8, 9 and 10 respectively; and pH adjustment methods included without and with pH control. Results show that: (1) In terms of light intensity, without pH control, the cell density under 3960lux is highest. With pH control, the cell density under 7920lux is higher than other levels. (2) In terms of pH, under the same light intensity, the cell density with pH control at 10 is highest, which indicates the light intensity will not affect the optimal pH value. And the pH fluctuates between 10 and 10.5 with pH control at 10, which is the most suitable range of pH for Chlorella vulgaris cultivation. (3) For pH adjustment methods, under 7920lux, the cell density with pH control at 10.0 is 56.7% higher than that with initial pH at 10.0, while the cell density with initial pH at 7.0 is 34.7% than that with pH control at 7.0, which indicates the method with pH control at values of the optimum pH makes better growth of microalgae

Two-Stage Submodular Optimization of Dynamic Thermal Rating for Risk Mitigation Considering Placement and Operation Schedule

Cascading failure causes a major risk to society currently. To effectively mitigate the risk, dynamic thermal rating (DTR) technique can be applied as a cost-effective strategy to exploit potential transmission capability. From the perspectives of service life and Braess paradox, it is important and challenging to jointly optimize the DTR placement and operation schedule for changing system state, which is a two-stage combinatorial problem with only discrete variables, suffering from no approximation guarantee and dimension curse only based on traditional models. Thus, the present work proposes a novel two-stage submodular optimization (TSSO) of DTR for risk mitigation considering placement and operation schedule. Specifically, it optimizes DTR placement with proper redundancy in first stage, and then determines the corresponding DTR operation for each system state in second stage. Under the condition of the Markov and submodular features in sub-function of risk mitigation, the submodularity of total objective function of TSSO can be proven for the first time. Based on this, a state-of-the-art efficient solving algorithm is developed that can provide a better approximation guarantee than previous studies by coordinating the separate curvature and error form. The performance of the proposed algorithms is verified by case results

Behavioral/Cognitive Acute and Long-Term Suppression of Feeding Behavior by POMC Neurons in the Brainstem and Hypothalamus, Respectively

POMC-derived melanocortins inhibit food intake. In the adult rodent brain, POMC-expressing neurons are located in the arcuate nucleus (ARC) and the nucleus tractus solitarius (NTS), but it remains unclear how POMC neurons in these two brain nuclei regulate feeding behavior and metabolism differentially. Using pharmacogenetic methods to activate or deplete neuron groups in separate brain areas, in the present study, we show that POMC neurons in the ARC and NTS suppress feeding behavior at different time scales. Neurons were activated using the DREADD (designer receptors exclusively activated by designer drugs) method. The evolved human M3-muscarinic receptor was expressed in a selective population of POMC neurons by stereotaxic infusion of Cre-recombinase–dependent, adenoassociated virus vectors into the ARC or NTS of POMC-Cre mice. After injection of the human M3-muscarinic receptor ligand clozapine-N-oxide (1 mg/kg, i.p.), acute activation of NTS POMC neurons produced an immediate inhibition of feeding behavior. In contrast, chronic stimulation was required for ARC POMC neurons to suppress food intake. Using adeno-associated virus delivery of the diphtheria toxin receptor gene, we found that diphtheria toxin–induced ablation of POMC neurons in the ARC but not the NTS, increased food intake, reduced energy expenditure, and ultimately resulted in obesity and metabolic and endocrine disorders. Our results reveal different behavioral functions of POMC neurons in the ARC and NTS, suggesting that POMC neurons regulate feeding and energy homeostasis by integrating long-term adiposity signals from the hypothalamus and short-term satiety signals from the brainstem

High temperature reactions between Si3N4 bonded SiC materials and Cu, Cu2O and matte

Si3N4 bonded SiC (Si3N4-SiC) is a conventional refractory material and has broad applications. In the present study, Si3N4-SiC refractory materials were systematically investigated in the copper-making environment. Si3N4SiC was reacted with Cu, Cu2O, industrial matte, Cu2S and FeS melts at 1200 degrees C in argon gas atmosphere, and all samples were directly quenched in water after the experiments. Phase changes and compositions of the phases were measured by electron probe X-ray microanalysis. The present investigations demonstrate that Cu and Cu2S do not react with Si3N4-SiC at high temperatures and the wettability between this material and the melts is low. However, significant reactions occur between Si3N4-SiC and Cu2O, industrial matte and FeS. The results imply that Si3N4-SiC material has limited oxidation-resistance and can only be used under reducing conditions

Increase in cotton yield through improved leaf physiological functioning under the soil condition of reduced chemical fertilization compensated by the enhanced organic liquid fertilization

IntroductionLow agricultural nutrient input efficiency remains a significant impediment for crop production globally. To address this issue in cotton agroecosystems, there is a need to develop sustainable crop nutrient management strategies to achieve high crop yields. We hypothesized that organic liquid fertilizer (OF) combined with reduced chemical fertilizer (CF) would enhance cotton yield by improving leaf functioning and soil properties. However, the underlying mechanism and its related process is poorly understood.MethodsThis study explored the effects of OF combined with reduced CF on cotton yield, physiology and soil properties. Treatments included a single application of CF (CF: N, P2O5 and K2O applied at 228, 131 and 95 kg ha−1) and combined applications of OF and CF (OF0.6−OF1.4) in the following ratios: OF0.6, OF+60% CF; OF0.8, OF+80% CF; OF1.0, OF+100% CF; OF1.2, OF+120% CF; OF1.4, OF+140% CF. Results and discussionThe result showed that compared with CF, OF0.8, OF1.0 and OF1.2 increased soil organic matter (SOM) content by 9.9%, 16.3% and 23.7%, respectively. Compared with CF, the OF0.6, OF0.8, OF1.0, and OF1.2 treatments increased leaf area (LA) by 10.6−26.1%, chlorophyll content (Chl content) by 6.8−39.6%, and the efficiency of photosystem II (PSII) light energy (Y(II)), electron transfer rate of PSII (ETR) and photochemical quenching (qP) by 3.6−26.3%, 4.7−15.3% and 4.3−9.8%, respectively. The OF0.8 treatment increased net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (E) by 22.0%, 27.4% and 26.8%, respectively, resulting in higher seed cotton yield. The seed cotton yield and economic coefficient were positively correlated with Pn, E, Gs and Y(II) from the full boll stage to the boll opening stage. In summary, the OF0.8 treatment can maintain a high SOM content and photosynthetic performance with reduced chemical fertilizer input without sacrificing yield. The integration of OF+80% CF (OF0.8) is a promising nutrient management strategy for highly efficient cotton production under mulch drip irrigation systems

Computational efficiency improvement for analyzing bending and tensile behavior of woven fabric using strain smoothing method

The tensile and bending behavior of woven fabrics are among the most important characteristics in complex deformation analysis and modelling of textile fabrics and they govern many aesthetics and performance aspects such as wrinkle/buckle, hand and drape. In this paper, a numerical method for analyzing of the tensile and bending behavior of plain-woven fabric structure was developed. The formulated model is based on the first-order shear deformation theory (FSDT) for a four-node quadrilateral element (Q4) and a strain smoothing method in finite elements, referred as a cell-based smoothed finite element method (CS-FEM). The physical and low-stress mechanical parameters of the fabric were obtained through the fabric objective measurement technology (FOM) using the Kawabata evaluation system for fabrics (KES-FB). The results show that the applied numerical method provides higher efficiency in computation in terms of central processing unit (CPU) time than the conventional finite element method (FEM) because the evaluation of compatible strain fields of Q4 element in CS-FEM model is constants, and it was also appropriated for numerical modelling and simulation of mechanical deformation behavior such as tensile and bending of woven fabric.The author (UMINHO/BPD/9/2017) and co-authors acknowledge the FCT funding from FCT – Foundation for Science and Technology within the scope of the project “PEST UID/CTM/00264; POCI-01-0145-FEDER-007136”