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81.
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83.
Utilizing fountain codes to control the peak-to-average power ratio (PAPR) is a classic scheme in Orthogonal Frequency Division Multiplexing (OFDM) wireless communication systems. However, because the robust soliton distribution (RSD) produces large-degree values, the decoding performance is severely reduced. In this paper, we design statistical degree distribution (SD) under a scenario that utilizes fountain codes to control the PAPR. The probability of the PAPR produced is combined with RSD to design PRSD, which enhances the smaller degree value produced. Subsequently, a particle swarm optimization (PSO) algorithm is used to search the optimal degree value between the binary exponential distribution (BED) and PRSD distribution according to the minimum average degree principle. Simulation results demonstrate that the proposed method outperforms other relevant degree distributions in the same controlled PAPR threshold, and the average degree value and decoding efficiency are remarkably improved. 相似文献
84.
Emilia Neag Zamfira Stupar Cerasel Varaticeanu Marin Senila Cecilia Roman 《Molecules (Basel, Switzerland)》2022,27(20)
The present study uses the Taguchi method of experimental design to optimize lipid extraction from Spirulina spp. by ultrasound application and mechanical stirring. A Taguchi L9 orthogonal array was used to optimize various parameters, such as methanol: chloroform (M:C) ratio, biomass: solvent ratio, and extraction time for lipid extraction. The results were analyzed using the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The biomass: solvent ratio significantly influenced lipid content (p < 0.05) with 92.1% and 92.3% contributions to the lipid and S/N ratio data, respectively. The extraction time presented a contribution value of 5.0%, while the M:C ratio presented the most negligible contribution of 0.4% for S/N data. The optimum extraction conditions were: M:C ratio of 1:1, biomass: solvent ratio of 1:60, and extraction time of 30 min. The predominant fatty acids were palmitic acid (44.5%), linoleic acid (14.9%), and gamma-linolenic acid (13.4%). The confirmation experiments indicated a lipid content of 8.7%, within a 95% confidence interval, proving the Taguchi method’s effectiveness in optimizing the process parameters for lipid extraction. 相似文献
85.
Yolanda Carmona-Jimnez Jose M. Igartuburu Dominico A. Guilln-Snchez M. Valme García-Moreno 《Molecules (Basel, Switzerland)》2022,27(20)
Grape pomace and seeds are important winemaking by-products. Their oils are rich in bioactive compounds such as fatty acids and tocopherols. We have characterized oils from both by-products from five Spanish grape varieties (Palomino Fino, Pedro Ximénez, Muscat of Alexandria, Tempranillo and Tintilla de Rota). A high content of UFAs was found in all the analyzed samples. Grape pomace oils generally had the same oleic acid (PUFAω-6) content as seed oils, and lower PUFA contents; they also had a markedly higher linolenic acid (PUFAω-3) content, improving the PUFAω-6/PUFAω-3 ratio. All the oil studied show good indicators of nutritional quality: low values of the atherogenicity (0.112–0.157 for pomace, 0.097–0.112 for seed) and thrombogenicity indices (0.30–0.35 for pomace, 0.28–0.31 for seed) and high values of the relationship between hypo- and hypercholesterolemic fatty acids (6.93–9.45 for pomace, 9.11–10.54 for seed). Three tocopherols were determined: α-, γ- and δ-tocopherol. Pomace oils have higher relative contents of α- and δ-tocopherol, whereas seed oils have higher relative contents of γ-tocopherol. A significantly higher content of total tocopherols has been found in pomace oil; it is higher in the oils from red varieties of pomace (628.2 and 706.6 mg/kg by-product), and in the oils from pomace containing stems (1686.4 mg/kg by-product). All the oils obtained can be considered as a source of vitamin E, and their consumption is beneficial for health. 相似文献
86.
Timoth Mkilima Davud Devrishov Kydyrbekova Assel Nurbala Ubaidulayeva Almas Tleukulov Alissa Khassenova Nargiza Yussupova Dinara Birimzhanova 《Molecules (Basel, Switzerland)》2022,27(22)
Groundwater is one of the main sources of water for irrigation used worldwide. However, the application of the resource is threatened by the possibility of high saline levels, especially in low-lying coastal regions. Furthermore, the lack of readily accessible materials for successful treatment procedures makes the purification of such water a constant challenge. Based on the fact that natural zeolite is one of the easily accessible and relatively cheap filter materials, this study examined the potential use of high-salinity groundwater filtered by natural zeolite for irrigation. Zeolite-filled filters at two different depths (0.5 m and 1 m) were studied. The samples were collected from the low-lying areas of Dar es Salaam City, Tanzania. The study observed that when the raw groundwater samples were exposed to the 0.5 m column depth, sodium (Na+) had the lowest removal efficiency at 40.2% and calcium (Ca2+) had the highest removal efficiency at 98.9%. On the other hand, magnesium (Mg2+) had the lowest removal efficiency, at about 61.2%, whereas potassium (K+) had up to about 99.7% removal efficiency from the 1 m column depth treatment system. Additionally, from the salinity hazard potential analysis, most of the samples fell within C4 (based on the electrical conductivity), which is a “very high salinity” class, and based on the quality it means the water cannot be directly applied for irrigation purposes. From the 0.5 m column depth, most of the samples fell within C3 (the “high salinity” class), and from the 1 m column depth most of the samples fell within C1 (“low salinity” class). The findings of this study offer some valuable insight into the prospective use of natural zeolite for the filtration of saline groundwater before its application for irrigation. 相似文献
87.
Yue Sun Aidong Xu Kai Wang Xiufang Zhou Haifeng Guo Xiaojia Han 《Entropy (Basel, Switzerland)》2022,24(7)
One of the biggest challenges for the fault diagnosis research of industrial robots is that the normal data is far more than the fault data; that is, the data is imbalanced. The traditional diagnosis approaches of industrial robots are more biased toward the majority categories, which makes the diagnosis accuracy of the minority categories decrease. To solve the imbalanced problem, the traditional algorithm is improved by using cost-sensitive learning, single-class learning and other approaches. However, these algorithms also have a series of problems. For instance, it is difficult to estimate the true misclassification cost, overfitting, and long computation time. Therefore, a fault diagnosis approach for industrial robots, based on the Multiclass Mahalanobis-Taguchi system (MMTS), is proposed in this article. It can be classified the categories by measuring the deviation degree from the sample to the reference space, which is more suitable for classifying imbalanced data. The accuracy, G-mean and F-measure are used to verify the effectiveness of the proposed approach on an industrial robot platform. The experimental results show that the proposed approach’s accuracy, F-measure and G-mean improves by an average of 20.74%, 12.85% and 21.68%, compared with the other five traditional approaches when the imbalance ratio is 9. With the increase in the imbalance ratio, the proposed approach has better stability than the traditional algorithms. 相似文献
88.
Jaime Aspas-Caceres Marc Rico-Pasto Isabel Pastor Felix Ritort 《Entropy (Basel, Switzerland)》2022,24(7)
Nonequilibrium work relations and fluctuation theorems permit us to extract equilibrium information from nonequilibrium measurements. They find application in single-molecule pulling experiments where molecular free energies can be determined from irreversible work measurements by using unidirectional (e.g., Jarzynski’s equality) and bidirectional (e.g., Crooks fluctuation theorem and Bennet’s acceptance ratio (BAR)) methods. However, irreversibility and the finite number of pulls limit their applicability: the higher the dissipation, the larger the number of pulls necessary to estimate G within a few . Here, we revisit pulling experiments on an RNA three-way junction (3WJ) that exhibits significant dissipation and work-distribution long tails upon mechanical unfolding. While bidirectional methods are more predictive, unidirectional methods are strongly biased. We also consider a cyclic protocol that combines the forward and reverse work values to increase the statistics of the measurements. For a fixed total experimental time, faster pulling rates permit us to efficiently sample rare events and reduce the bias, compensating for the increased dissipation. This analysis provides a more stringent test of the fluctuation theorem in the large irreversibility regime. 相似文献
89.
甲基丙烯酸缩水甘油酯与甲基丙烯酸甲酯的共聚合及竞聚率测定 总被引:1,自引:0,他引:1
以N,N-二甲基甲酰胺(DMF)为溶剂,实施了甲基丙烯酸缩水甘油酯(GMA)与甲基丙烯酸甲酯(MMA)的溶液共聚合,测定了共聚物P(GMA-co-MMA)的红外光谱(FT-IR),对其化学结构进行了表征,并采用差示扫描量热法(DSC)测定了共聚物的玻璃化转变温度(Tg).改变两单体投料比进行共聚合,采用化学分析法测定低转化率下(<7%)共聚物组成,重点研究了两单体的竞聚率.结果表明:GMA与MMA的共聚合易于进行,P(GMA-co-MMA)的玻璃化转变温度(Tg)介于均聚物PGMA(72℃)与PMMA(106℃)之间,当n(GMA)/n(MMA)=4/6时,共聚物的Tg为9l℃.采用FR和KT 2种作图法及YBR计算法对单体的竞聚率进行了计算和比较,结果表明:KT和YBR法较为准确,以DMF为溶剂时,GMA与MMA的竞聚率分别为2.14与0.69. 相似文献
90.
Energy saving is one of the main technique routes for net zero carbon emissions. Air compressor systems take up a large part of energy consumption in the industrial field. A pre-cooling air compressor system was proposed for energy saving by cooling the air before it flows in a compressor. The energy efficiency of the proposed system was analyzed. As additional energy consumption is required for air cooling, the feasibility of the pre-cooling method for energy saving was analyzed. As the efficiency of the pre-cooling air compressor system is mainly influenced by the environment temperature and humidity, applicability of the system in different regions and at different seasons was discussed. A pilot project was performed to verify the technical feasibility and economics of the proposed system. When the precooling temperature of the pilot system was set to 2 °C, the annual pneumatic-electrical ratio of the system can be increased by approximately 2% in several regions of China. This paper shows the pre-cooling air compressor system is feasible for energy saving. 相似文献