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971.
Efficient and High-quality Recommendations via Momentum-incorporated Parallel Stochastic Gradient Descent-Based Learning
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Xin Luo Wen Qin Ani Dong Khaled Sedraoui MengChu Zhou 《IEEE/CAA Journal of Automatica Sinica》2021,8(2):402-411
A recommender system (RS) relying on latent factor analysis usually adopts stochastic gradient descent (SGD) as its learning algorithm. However, owing to its serial mechanism, an SGD algorithm suffers from low efficiency and scalability when handling large-scale industrial problems. Aiming at addressing this issue, this study proposes a momentum-incorporated parallel stochastic gradient descent (MPSGD) algorithm, whose main idea is two-fold: a) implementing parallelization via a novel data-splitting strategy, and b) accelerating convergence rate by integrating momentum effects into its training process. With it, an MPSGD-based latent factor (MLF) model is achieved, which is capable of performing efficient and high-quality recommendations. Experimental results on four high-dimensional and sparse matrices generated by industrial RS indicate that owing to an MPSGD algorithm, an MLF model outperforms the existing state-of-the-art ones in both computational efficiency and scalability. 相似文献
972.
973.
Gong-Ping Zheng Shuai-Feng Qin Wen-Tian Jian Shou-Yang Wang 《Journal of Low Temperature Physics》2013,172(3-4):289-298
The ground states of ultracold spin-1 atoms trapped in an optical superlattice in a weak magnetic field with incommensurate filling of three atoms in one double-well are obtained. It is shown that the ground-state diagrams of the reduced double-well model are remarkably different for the antiferromagnetic and ferromagnetic atoms. These novel spin-states can be controlled easily and exactly by modulating the tunneling parameter and the quadratic Zeeman energy, which may be a tool for the study of spin-entanglement. 相似文献
974.
Abstract Distillation separation sequences can be described as binary tree data structures, because of the analogous structures of distillation separation sequences and binary trees, and then by applying graph theory, the change mechanism of neighborhood separation points based on binary trees is built, correspondingly a kind of highly effective, evolutionary neighborhood structure is constructed. For the purpose of researching further tabu search algorithms, adaptive mechanisms and parallel techniques are introduced. That is, according to memory frequency information, the tabu length and the number of candidates are adaptively adjusted, and multitask parallel technology is realized through the arrangement of the search assignments. The example shows that adaptive parallel tabu searches can solve, successfully, large‐scale distillation separation sequence synthesis problems. 相似文献
975.
Zhang Haitao Zuo Kesheng Han Xing Shao Bo Qin Ke Cui Jianzhong 《中国铸造》2014,(6):481-486
Large and segregated primary Si particles may drastically decrease the mechanical properties of AI-Si alloys. To solve this problem, a P-Cr complex modifier was added into the alloy, and the effects of P-Cr complex modification and solidification conditions on the microstructure of hypereutectic Al-Si alloys casting produced in wedge-shaped copper mould were studied. The thermal analysis technique was applied to calculate the cooling rate during solidification. The microstructures were observed by means of optical and scanning electron microscopies. Results showed that the primary Si segregates in the as-cast hypereutectic AI-Si alloys. The segregation of primary Si can be inhibited by adding a P+Cr complex modifier and increasing the cooling rate during solidification. The refinement of primary Si particles by P+Cr complex modification is due to the formation of CrSi2 and AlP particles which act as the heterogeneous nuclei for the primary Si phase. The segregation of Si was also inhibited through the adherence of heavier CrSi2 particles to the primary Si particles. 相似文献
976.
The application of spray towers for CO2 capture is a development trend in recent years. However, most of the previous jobs were conducted in a cylindrical tower by using a single spray nozzle, whose configuration and performance is not good enough for industrial application. To solve this problem, the present work proposed a diameter-varying spray tower and a new spray mode of dual-nozzle opposed impinging spray to enhance the heat and mass transfer of CO2 absorption process. Experiments were performed to investigate the mass transfer performance (in terms of the CO2 removal rate (η) and the overall mass transfer coefficient (KGae2 are major factors, which affect the absorption performance and the maximums of η and KGae that are 94.0% and 0.574 kmol·m-3·h-1·kPa-1, respectively, under the experimental conditions. Furthermore, new correlations to predict the mass transfer coefficient of the proposed spray tower are developed in various CO2 concentrations with a Pearson Correlation Coefficient over 90%. 相似文献
977.
结合工程实例,简单阐述酸性水罐的氮封系统设计。本设计采用安全水封罐确保酸性水罐压力,通过脱臭罐排放硫化氢气体;在脱臭罐出现事故情况下则通过安全水封罐排放硫化氢气体。该流程与储运常规氮风系统流程相比,更加安全可靠,更有利于减少环境污染。 相似文献
978.
979.
Comparative studies of quality changes in white and dark muscles from common carp (Cyprinus carpio) during refrigerated (4 °C) storage
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Qian Li Dongping Li Na Qin Hui Hong Yongkang Luo 《International Journal of Food Science & Technology》2016,51(5):1130-1139
Differences between white and dark muscles from common carp (Cyprinus carpio) in sensory assessment, total viable counts (TVC), total volatile basic nitrogen (TVB‐N), pH, electrical conductivity (EC), biogenic amines (BAs), nucleotide degradation products and colours were investigated under air and vacuum conditions during refrigerated (4 °C) storage. Compared with white muscle, dark muscle had a higher lipid content, but lower crude protein and moisture content. TVC, TVB‐N, pH, and L* value were higher in white muscle, while K value and a* value were higher in dark muscle. Under both conditions, white and dark muscles had significant (P < 0.05) differences in tyramine and cadaverine content. Although dark muscle was significantly (P < 0.05) lower in ATP content, it had higher rate of IMP degradation and K value increase. Taking sensory and microbial indexes into consideration, dark muscle appeared to have a longer shelf life than white muscle under both conditions. 相似文献
980.
在分析液压动力滑台工作原理的基础上,针对传统的继电器—接触器控制线路中出现的诸多问题,采用可编程控制器PLC对其控制系统进行了改进设计.在满足生产工艺的前提下,改进后的程序变得简单、灵活,从而克服了原有的缺点,提高了系统的可靠性和灵活性. 相似文献