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The recommendation algorithm based on collaborative filtering is currently the most successful recommendation method. It recommends items to the user based on the known historical interaction data of the target user. Furthermore, the combination of the recommended algorithm based on collaborative filtration and other auxiliary knowledge base is an effective way to improve the performance of the recommended system, of which the Co-Factorization Model (CoFM) is one representative research. CoFM, a fusion recommendation model combining the collaborative filtering model FM and the graph embedding model TransE, introduces the information of many entities and their relations in the knowledge graph into the recommendation system as effective auxiliary information. It can effectively improve the accuracy of recommendations and alleviate the problem of sparse user historical interaction data. Unfortunately, the graph-embedded model TransE used in the CoFM model cannot solve the 1-N, N-1, and N-N problems well. To tackle this problem, a novel fusion recommendation model Joint Factorization Machines and TransH Model (JFMH) is proposed, which improves CoFM by replacing the TransE model with TransH model. A large number of experiments on two widely used benchmark data sets show that compared with CoFM, JFMH has improved performance in terms of item recommendation and knowledge graph completion, and is more competitive than multiple baseline methods. [ABSTRACT FROM AUTHOR]

In recent years, the Internet of Things technology has developed rapidly, and smart Internet of Things devices have also been widely popularized. A large amount of data is generated every moment. Now we are in the era of big data in the Internet of Things. The rapid growth of massive data has brought great challenges to storage technology, which cannot be well coped with by traditional storage technology. The demand for massive data storage has given birth to cloud storage technology. Load balancing technology plays an important role in improving the performance and resource utilization of cloud storage systems. Therefore, it is of great practical significance to study how to improve the performance and resource utilization of cloud storage systems through load balancing technology. On the basis of studying the read strategy of Swift, this article proposes a reread strategy based on load balancing of storage resources to solve the problem of unbalanced read load between interruptions caused by random data copying in Swift. The storage asynchronously tracks the I/O conversion to select the storage with the smallest load for asynchronous reading. The experimental results indicate that the proposed strategy can achieve a better load balancing state in terms of storage I/O utilization and CPU utilization than the random read strategy index of Swift. [ABSTRACT FROM AUTHOR]

The primary objective of this study was to establish a model for predicting the jet trajectory of a firewater monitor. The jet trajectory is mainly affected by its own gravity and air resistance, and the magnitude of the air resistance changes with the cross-sectional area of the jet. The model is established by combining air resistance changes and breakup theory, and the factors affecting the location of jet trajectory are studied. The accuracy and reliability of the model is verified by comparative analysis of theoretical simulation data and experimental data. The error between the prediction and experimental data that can be maintained is about 10% on average, which can meet the engineering application requirements. In addition, the shape of the jet and analyses of the causes of shape asymmetry are discussed. [ABSTRACT FROM AUTHOR]

Fire remains one of the most pervasive threats to public safety and social development in real life. Fire water monitors have been used as tools for ending the fire all the time. The impact point accuracy of the water jet and the accurate prediction of the water jet trajectory have a significant effect on the efficiency of fire extinction. The quadratic drag model is selected on the basis of the analysis of the mechanical model of fluidic control volume considering the change of the cross-sectional area caused by the velocity and breakup of the water jet. The change of diameter and area of the droplet are also discussed, based on the theory of liquid jet breakup, to build a dynamic breakup model of air resistance and broken jet. The water jet simulations are performed on two different scales by researching several main performance parameters, such as discharge angle and initial velocity, which can affect the jet trajectory of fire water monitor. The influences of various parameters on the jet trajectory are summarized through the simulations of two kinds of water jet experimental data, and an accurate prediction of the jet trajectory of fire water monitor is realized. [ABSTRACT FROM AUTHOR]

Active noise control (ANC) is used to reduce undesirable noise, particularly at low frequencies. There are many algorithms based on the least mean square (LMS) algorithm, such as the filtered-x LMS (FxLMS) algorithm, which have been widely used for ANC systems. However, the LMS algorithm cannot balance convergence speed and steady-state error due to the fixed step size and tap length. Accordingly, in this article, two improved LMS algorithms, namely, the iterative variable step-size LMS (IVS-LMS) and the variable tap-length LMS (VT-LMS), are proposed for active vehicle interior noise control. The interior noises of a sample vehicle are measured and thereby their frequency characteristics. Results show that the sound energy of noise is concentrated within a low-frequency range below 1000 Hz. The classical LMS, IVS-LMS and VT-LMS algorithms are applied to the measured noise signals. Results further suggest that the IVS-LMS and VT-LMS algorithms can better improve algorithmic performance for convergence speed and steady-state error compared with the classical LMS. The proposed algorithms could potentially be incorporated into other LMS-based algorithms (like the FxLMS) used in ANC systems for improving the ride comfort of a vehicle. [ABSTRACT FROM AUTHOR]

Jinxi County in Jiangxi Province and Yangxin County in Hubei Province enjoy similar physical geographic conditions, and boast existing traditional residences that primarily date back to the Qing Dynasty. Moreover, the structures' external wall material primarily uses blue brick. However, the exterior quality of the blue brick used for traditional residences in both areas have distinct differences. By conducting electronic microanalysis and x-ray diffraction analysis testing of samples of blue brick from both sites, comparative analysis of the differences in the blue bricks' elemental composition and microstructure was carried out. The results showed that the samples have differences in fusion degree of the microstructure of crystalline grain, uniformity degree of the distribution of various element content, and contents of TiO2 and Ca0, leading discrepancies in the degree of smoothness of the surface, the uniformity of color, and the variation in color of the blue brick. [ABSTRACT FROM AUTHOR]

The fatigue failure of automobile structures has drawn much attention recently in reliability and endurance design. Therefore, in order to predict the fatigue life accurately, complex variable-amplitude loads must be compiled into the appropriate load spectrum. The rain-flow counting method is adopted to extract the load cycles from the random loads. A statistical method based on the mixture distribution model is proposed to analyze the multimodality of load cycles. Meanwhile, the collected random loads are extrapolated to the full life of vehicles based on the Peaks-Over-Threshold model. Finally, the one- and two-dimensional load spectrums are compiled according to the load cycles and joint probability density. [ABSTRACT FROM AUTHOR]

The four-microphone method of the standing wave tube can be used to effectively measure the transmission loss (TL) of acoustic materials. However, large errors in the measurement results may be observed at specific frequencies. To investigate the mechanism and lower the error, in this paper, experiments are conducted with a standing wave tube, fabricated for these experiments, using a four-microphone method. Specific factor analysis for the error is carried out. Three structure parameters of the standing wave tube are varied to minimize measurement errors. A finite element method (FEM) is employed to calculate the internal sound field distribution and TL in the standing wave tube. Based on the comparison between the experiments and the calculations, the orthogonal experimental design (OED) is performed to optimize the three structure parameters and improve the measurement accuracy to reduce the error in testing TL. The result of this work can be used as a reference for the measurement of acoustic material, which can benefit the noise control community. [ABSTRACT FROM AUTHOR]

The article presents a study which examines new nanometer scaffolds that regulate neural stem cells biological behaviors. The study used electronic spinning technology to align and randomly oriented collagen nanofiber scaffolds, and the nanofiber scaffolds were characterized. Results showed that there was no important difference in neural stem cells differentiation into neurons on aligned and randomly oriented collagen nanofiber scaffolds.

The article discusses a study on the negative effects of Notch 1 on the differentiation of muscle-derived stem cells (MDSCs) into neuronal-like cells. The study discovered that MDSCs in the induced group cultured with differentiation medium multiplied well after being induced for 7 days, with cell bodies and processes strongly neuron-specific enolase (NSE) positive. The study also determined that Notch1 mRNA of induced group cells was largely decreased as compared to other group cells.

A compliance operator is often utilized to evaluate the elastic displacement of surfaces in the simulation of transient and steady-state elastohydrodynamic lubrication of conformal-contact systems. The values of the compliance operator represent the elastic: responses of all nodes when only one node is under a unit load. The accuracy of compliance operator values, computational cost, and storage size are important issues. Our study of steady-state conformal-contact elastohydrodynamic lubrication analyses suggests a method of selective-fine-mesh with selective-storage, as well as a special technique of the combined selective-fine-mesh with selective-storage mapping. These two techniques enable an efficient elasticity procedure for the simulation of steady-state and transient conformal-contact elastohydrodynamic lubrication systems by means of the finite element method. [ABSTRACT FROM AUTHOR]

A series of Polyacrylic acid (PAA)/Poly (Sodium-p-styrenesulfonate) (PSS) and Polyacrylamide (PAAm)/PSS semi-IPN hydrogel with different contents of PSS were prepared. The swelling behaviour of PAA hydrogel in alkaline environment was improved while the swelling ratio of PAAm hydrogel was decreased after PSS was added. With the increase of ionic strength in solution, the swelling ratios of PAA/PSS and PAAm/PSS showed a decreasing trend. Moreover the swelling ratio of PAAm/PSS decreased more quickly than that of PAA/PSS. The swelling speed of PAA and PAAm both decreased after adding PSS and a more rapid responsive speed was found in the former system. The experiment of in vitro drug release showed that the drug release speed from PAAM/PSS semi-IPN hydrogel was slower than that from PAA/PSS semi-IPN hydrogel. These results suggested that the polymer composition and the trapped polyelectrolyte made a great influence on the drug release behavior. [ABSTRACT FROM AUTHOR]

The article presents a study which explored whether muscle-derived stem cells (MDSCs) can act as seed cells during spinal cord injury repair. In the experiment, MDSCs were selected as seed cells and implanted into the rat spinal cord injury area. It was shown that the MDSCs endured, migrated, and were distributed along the spinal nerves. It was found that the motor function of rat lower limbs improved considerably, indicating that MDSCs could be used as seed cells to repair spinal cord injury.

The article provides information on a study which investigated whether transplanting brain-derived neurotrophic factor (BDNF)-green fluorescent protein (GFP) transgenics neural stem cells (NSC) could improve the recovery of motor function in rats after spinal cord injury (SCI). The study examined a hemisection model of rats, wherein BDNF-GFP transgenic neural stems cells were transplanted. The research found that compared with stem cells alone, rats with BDNF-GFP stem cells showed significant increase in BDNF expression and better locomotor function.