The paper proposes a novel metaheuristic based on integrating chaotic maps into a Henry gas solubility optimization algorithm (HGSO). The new algorithm is named chaotic Henry gas solubility optimization (CHGSO). The hybridization is aimed at enhancement of the convergence rate of the original Henry gas solubility optimizer for solving real-life engineering optimization problems. This hybridization provides a problem-independent optimization algorithm. The CHGSO performance is evaluated using various conventional constrained optimization problems, e.g., a welded beam problem and a cantilever beam problem. The performance of the CHGSO is investigated using both the manufacturing and diaphragm spring design problems taken from the automotive industry. The results obtained from using CHGSO for solving the various constrained test problems are compared with a number of established and newly invented metaheuristics, including an artificial bee colony algorithm, an ant colony algorithm, a cuckoo search algorithm, a salp swarm optimization algorithm, a grasshopper optimization algorithm, a mine blast algorithm, an ant lion optimizer, a gravitational search algorithm, a multi-verse optimizer, a Harris hawks optimization algorithm, and the original Henry gas solubility optimization algorithm. The results indicate that with selecting an appropriate chaotic map, the CHGSO is a robust optimization approach for obtaining the optimal variables in mechanical design and manufacturing optimization problems.
With the aim of reforming the control system of the levels of deaerator and condenser of a 200 MW thermal power unit, a multivariable fuzzy PID control system was proposed and has been used to practice. The novel control system has worked well since it was put into operation in March 1997. 相似文献
The solar radiation model SRAD was applied to a Mediterranean mountainous environment in southern California for estimating land surface temperature (LST). The simulated SRAD LST results were compared with high- and meso-resolution satellite-based LST data at daily, monthly and annual temporal scales to identify potential ways of improving the LST accuracy in either the SRAD or satellite-based approaches. It was found that mean monthly and annual LST from SRAD closely matched the MODIS LST observations (but for the fact they were from 0.7 to 1.5 °C lower) while the daily LST from SRAD agreed less well with ASTER observations and were 2.1 °C and 4.8 °C higher for 01/23/05 and 07/21/06, respectively. High mountainous, steep and south/north facing slopes resulted in large discrepancies in LST estimates and the winter LST estimates are more sensitive to terrain factors and their associated land use/cover characteristics than the summer estimates. It is therefore suggested that vertically variable elevation lapse rates, spatially distributed surface albedo and leaf area index for the time-specific simulations that represent the heterogeneity of land surface characteristics be used in SRAD inputs. The results also show how instantaneous model outputs rather than lumped average daily outputs offer better comparisons with satellite based data as well. 相似文献
For the sustainability of the polyurethane resin (PUR) industry, petroleum-based materials must be replaced with renewable resource and economic aspects must be considered. Lignin is a renewable, thermostable biomass consisted with a phenolic polymer. As a thermostable bio-filler for PUR adhesives, acidic or basic lignin was blended with an amphiprotic inorganic filler, to reduce the resins and product costs due to cheap, unmodified materials. The thermal resistance of the PUR adhesives was evaluated by measuring adhesion before and after heating and with and without a mechanical effect caused by substrate penetration. The results show that after heating at 200°C, the PURs containing 7.5 or 15 wt% of dealkaline lignin or 7.5 wt% of alkaline lignin decomposed more slowly than the lignin-free PUR. The properties of the PURs were also analyzed using Fourier-transform infrared spectroscopy and differential scanning calorimetry. Additionally, the PURs containing over 30 wt% of dealkaline lignin show potential as environmentally friendly water-blown PUR foams. 相似文献
Low-density lipoprotein receptor-related protein 5 (LRP5) has been studied as a co-receptor for Wnt/β-catenin signaling. However, its role in the ischemic myocardium is largely unknown. Here, we show that LRP5 may act as a negative regulator of ischemic heart injury via its interaction with prolyl hydroxylase 2 (PHD2), resulting in hypoxia-inducible factor-1α (HIF-1α) degradation. Overexpression of LRP5 in cardiomyocytes promoted hypoxia-induced apoptotic cell death, whereas LRP5-silenced cardiomyocytes were protected from hypoxic insult. Gene expression analysis (mRNA-seq) demonstrated that overexpression of LRP5 limited the expression of HIF-1α target genes. LRP5 promoted HIF-1α degradation, as evidenced by the increased hydroxylation and shorter stability of HIF-1α under hypoxic conditions through the interaction between LRP5 and PHD2. Moreover, the specific phosphorylation of LRP5 at T1492 and S1503 is responsible for enhancing the hydroxylation activity of PHD2, resulting in HIF-1α degradation, which is independent of Wnt/β-catenin signaling. Importantly, direct myocardial delivery of adenoviral constructs, silencing LRP5 in vivo, significantly improved cardiac function in infarcted rat hearts, suggesting the potential value of LRP5 as a new target for ischemic injury treatment. 相似文献