As statistics characterizing the strength of statistical relationship between two random variables,correlation coefficients have found wide applications in nearly all science and technology  fields.This  paper attempts to provide a detailed review on 5 commonly used correlation coeffcients in the literature, including a relatively detailed discussion on their statistical properties under the fundamental bivariate normal model and their suitable application scenarios. Specifically,(1) if the sample follows normal distribution, then the  Pearsons Product Moment Correlation Coefficient is optimal;(2) if the monotone nonlinear distortion in the sample is small, then the Order Statistics Correlation Coefficient should be used;(3) if the monotone nonlinear distortion in the sample is severe, then the Spearmans rho or Kendalls tau are feasible;(4) if only one channel is distorted by monotone nonlinearity, then the Gini Correlation is best choice; and (5) if there exsits impulsive noise in the sample, then  the Spearmans rho or Kendalls tau should be employed.

Rain-flow counting method is adopted to cycles from the fatigue stress spectra of a truss nodegain different stress amplitudes and their corresponding stress The W eibull probability distribution fitting is applied to the above resuhs．Based on Miner linear cumulative damage theory of fatigue，the datum of rain—flow counting results and Weibull probability distribution fitting results are used to estimate the fatigue life of the truss node．The experimental results show that the combination of the rain．flow counting method with the probability distribution fitting technique makes the estimation of the fatigue life more authentic．

The peptides in the field of cosmeceutical applications were reviewed, the synthetic method and study of peptides were presented, and the peptides were classified by function and mechanism. There are three main categories of cosmeceutical peptides: signal peptides, neurotransmitteraffecting peptides and carrier peptides. Finally, the development of peptide industry in China was described.

The key challenge of large scale face clustering is to extract effective facial features and construct an accurate model with less time complexity. In this research, effective features are first extracted based on convolutional neural network (CNN). Then K-means, a classical cluster algorithm, and a state-of-art algorithm named CFSFDP (Clustering by Fast Search and Find of Density Peaks) are used to cluster large scale face images. Rand Index, entropy, F₁-measure and the visualization of confusion matrix are further applied to comprehensively assess clustering quality. All the tests are under the condition of the increasing numbers of clustering centers. Experiment results demonstrate that K-means has a better performance as well as a much higher speed than CFSFDP. This conclusion is believed to shed new light in the area of face clustering.

It focuses on ways of optimizing the formulas to calculate intermittent water usage. By analyzing the conditions and deducing some formulas, it derived optimized formulas, which can curtail the long process of calculation considerably, making the calculation more comprehensible and convenient.

This paper introduces the concept and function of an intelligent garbage can and puts forward a component plan.An infrared sensing and controlling system and a wireless communication system based on Single Chip Micyoco,which can realize some functions such as move,are adopted.Compared to the intelligent garbage can which has been used,the new one has more functions and aptitudes.

According to the huge market demand for the PWM dimming lamps of two-channel cold/warm LED lighting source and the existing problems in dimming technique, a lighting source system control algorithm based on time hybrid color mode is proposed in this paper and the independent modulation of hybrid lighting source luminance and color temperature are realized by this method. Experimental result shows that, in the process of color temperature adjustment, luminance keeps constant basically. And in the process of brightness adjustment, color temperature is also constant. This algorithm reduces the computing load of controller. At the same time, it improves the dimming control precision and eliminates the transient power overload phenomena for reliability of lighting system.

Research on magnetorheological finishing technology at home and abroad is reviewed. According to the development of magnetorheological finishing technology, the current main application of ultra-precision machining principle and progress of magnetorheological compound polishing technology are elaborated, mainly focusing on Magnetorheological Jet Polishing, Ultrasonic-magnetorheological Compound Polishing, Chemo-mechanical Magnetorheological Finishing and Cluster of MRF processing methods and mechanism of material removal. Then the MRF method is compared in terms of surface precision machining, surface integrity and processing efficiency. Finally, a discussion is conducted on how to improve the precision polishing efficiency, forecasting the development of ultra-precision magnetorheological finishing and pointing out the key research direction in the future.

A collagen GTR membrane was made with a bi-layer structure, one of whose face is loose while the other is tight. The tight face can effectively prevent the cells from growing into the defective tissue zone while the loose face is rough, which is helpful to cells growth and blood clot. In order to improve the physicochemical properties of the membranes, EDC/NHS was used as a cross-linking agent for the membranes. And the effects of cross-linking agent dosage on the physicochemical properties of membranes were investigated. The measurements of DSC, SEM were used to test the structure and properties of the membranes. The properties of water absorption, collagen resistance were also tested. According to the study, 0.5 mol/L EDC/NHS, cross-linking 24 h in the pH of 5.5 are the best processing conditions. Increasing further the concentration of EDC can not improve the physicochemical properties of the membranes. The research shows that the physicochemical properties of collagen membranes are improved significantly after being crosslinked. The denaturation temperature, anti-collagen activities are both increased, and the bi-layer structure is kept well.

Considering comments' objectivity, subjectivity, the angle of time dimension and critics and network environment, combining with the elaboration likelihood model (ELM), a research is conducted into the center path of comments' quality and timeliness and the edge path of comment number, commenters' creditworthiness and influence of the network environment cognition on purchase decisions, and a theoretical model built and verified in order to enrich the mechanism of online reviews on purchasing decision. A questionnaire survey is used to collect data, and SPSS22.0 software used to analyze the questionnaire data so that the main effect of online comments on purchase decisions, mediating effect of the trust tendency and comments' credibility can be tested. The results indicate that the comments' timeliness, number and commenters' creditworthiness positively affect customers' purchase decisions through comments credibility, and that the trust tendency will adjust the consumers' credibility perception of the high quality review. High trust tendencies can regulate consumers' perception of the credibility of different quality reviews, and high trust tendencies also have a higher perception of the credibility of high quality reviews.

The analytical methods available for the separation of species and determination of heavy metals in soil were briefly described. The main factors affecting heavy metal species and bioavailability were analyzed, and the development prospects for technology in this domain were also discussed.

Because sequential pattern mining needs a lot of computing time and storage space, how to reduce the amount of calculation and storage space becomes the key of the sequential pattern mining algorithm. Combining the PrefixSpan algorithm with Bitmap data structure, this text proposes an improved sequential pattern mining algorithm BM-PrefixSpan. The PFPBM (Prefix of First Position on BitMap) table was designed and implemented. When a new item appeared in a sequence, it was recorded in the PFPBM table. The experimental results show that the BM-prefixspan algorithm mines sequential patterns faster and better than others.

K nearest neighbor query algorithm is one of the commonly used algorithms in massive spatial data query. First, it construct an index of largescale spatial data by Kd-Tree, and hierarchical division of the search space. Then, it used the k nearest neighbor query to ensure the efficiency of the search. However, the traditional Kd-Tree construction has two drawbacks: the use of test data points are required for each k nearest neighbor query back to the root, thus affecting the efficiency of the query; Kd-Tree uses the splitlevel domain for the space division of space into cubes (twodimensional data are rectangular), extra space appears in polygonal space at the intersection of judgment, making the comparison of data unnecessary,   thus affecting the efficiency of the query. Regarding these two shortcomings, it proposed the corresponding improved algorithmRB algorithm. Experimental results show that the algorithm has a higher query efficiency than the traditional KD algorithm.There are two main contribution from this paper: (1) This paper construct a quickly create Kd-Tree indexes to support queries KNN akgorithm to classify largescale data. (2) RB algorithm is proposed to improve the traditional Kd-Tree index construction method,and improving query efficiency for KNN algorithm.

The power system simulation software is an important tool for programming,research,operating and teaching of the power system.BPA(Bonneville Power Administration) in Chinese copyright has many traits,such as,complete models,strong functions,flexible uses and convenient operation.Especially,it adapts to the simulation of large scale AC/DC power system.It introduces BPA from the aspects of mathematical models,software functions,input and output.It sets out the functions of BPA by the simulation ba...

The key problem to solve in a sentiment analysis of texts is the sentiment polarity classification. Based on the analysis of various factors affecting sentiment classification of texts, it built the sentiment lexicon, extracted affective characteristics, and weighted sentimental features. Then, it used support vector machine (SVM)  classifier for emotion recognition and text classification. Finally, it performed the classification model with the corpus data sets on the single platform and the Spark distributed computing platform to analyze its classification accuracy and time cost. The experimental results verify the effectiveness of the text sentimental polarity categorization model on the single platform and on the spark distributed computing platform.

It proposes a circuit about multioutput constant current LED drivers, based on LLC resonant. The LLC resonant was adopted in the DC/DC circuit, improving the frequency of conversion. The switches on the primary side could work in zerovoltageswitching mode(ZVS)，and the diodes on the secondary side could work in zero-current-switching(ZCS)mode，which decreased the loss of switching and improved the efficiency of the system．The balance capacitor was used in the LED driver circuit, and it was easy to achieve the balance of the current. Meanwhile, a prototype was proposed to test in the laboratory. It focused on the mechanism of the resonant and the balance of the current. The system has been simulated and verified, based on PSIM. 

With passive infrared pyroelectric sensors and ultrasonic sensors as the detecting element, and the STM8S105C4 microcontroller as the core controller, the direction and number of traffic foot are detected. The data communication at all entrances and exits and  the counting of people in public areas are conducted through the NRF24L01 wireless module.

An improved potential field grid method is presented in this paper to solve the problems of general artificial potential field method including the trap situation, no path existing among adjacent obstacles and not up to the object near the obstacle. With the full coverage path planning algorithm of cattle farming, a global optimal sweep path of the robot in the known environment model is given. By combining the laser radar and the potential field force, it has the ability to avoid dynamic collision. The verifying experiment indicates that the algorithm has practical value. It can make cleaning robot in a shorter path traversal environment and enhance the obstacle avoidance capability, improve safety and efficiency of cleaning robot.

Receiver operating characteristic curve analysis can be used to evaluate the performance of classifiers and find the optimal segmentation points of different categories. Among them, the non-parametric method has been widely used in practice because of its simplicity and flexibility.How to construct and evaluate receiver operating characteristic curve for the classified data by ROC nonparametric method was introduced .

The application of the differential scanning calorimetry in the studies of the transesterification reaction in PBT/PC and PBT/PET alloys was researched.The effects of reaction inhibitor on the transesterification reaction were compared with those of the pure system.The results show that by observing the difference of the melting and crystallization temperature during the heating and cooling cycles in DSC,the degree of the transesterification reaction can be judged.Based on this,the kinds of inhi...

In video-monitor system, the synchronous transmission of audio and video is a key issue. The audio and video being out of synchronization was caused by the difference among the size of audio data and video data in the procedure of capturing, transmitting and encoding. To solve these problems, a solution is proposed which defines a data structure to store the time-related frames of audio and video data and control the synchronization of audio and video data through all the procedure. At last, the FFMPEG project is ported to Android device to do the experiment. It turns out that the algorithm proposed in this research has a good effect of synchronization. It can meet the need of synchronization in the specified scenes. At the same time, the new method of audio and video processing of Android platform is proposed, which is of great significance in engineering practice.

Covalent organic frameworks (COFs) are a class of crystalline porous polymers that allow the atomically precise integration of organic units to create predesigned skeletons and nano-pores. Since the seminal work of Yaghi on covalent organic frameworks, this subject has attracted extensive interest not only from chemists’ science and organic synthesis, but also from various researchers in the fields of gas storage, heterogeneous catalysis, semi-conduction and photoconduction. This review describes the building blocks of COFs and synthetic methods. The applications are also studied and evaluated. Concerning COFs for future research, some suggestions are proposed and conclusions are given.

While cloud computing provides high efficiency calculation and massive storage for workflow application, it also brings challenges to the protection of private data such as trade secrets. Because protecting private data will result in an increase in data transmission time, a new data distribution algorithm based on data collaboration failure degree is proposed to improve the existing data allocation strategies. Relying on private cloud safety and public cloud computer capacity in the initial stage, the non-privacy data is divided by the static allocation method to improve the initial data, and in the running stage, the generated data is constantly adjusted to get the data distribution plan. Experiments show that the improved method is effective in reducing the data transmission time.

In this paper each kind of equipment was systematically introduced,and the factors to affect the carbon preparation are in detail narrated.Synthesis of Multiwall carbon nanotubes by CVD Method need the following main equipment: fixed catalytic bed,boiling catalytic bed,spray catalytic bed,two-temperature fluidized catalytic bed,etc.The main influencing factors are the catalyst,the reaction gases,pyrolysis temperature,reaction time and so on.

Convolutional neural network (CNN) is a deep learning model with strong expression and classification ability, and is currently widely used, but there are a variety of specific algorithms. In this paper, the realization of deep learning algorithm based on convolutional neural network CNN, including the function of convolution kernel, the role of pooling, the selection of activation function and the training process are discussed. And one example is explained, which facilitates the mastery of CNN. Finally, the future research direction of convolution neural network is summarized and forecasted.

A battery management system (BMS) is designed to manage 15 lithium battery cells by using STM32 microcomputer. Firstly, a battery monitoring chip BQ76940 is used to design measurement unit, a switched-capacitor-based circuit is used to design active equalization unit. Then, the SOC of battery is estimated by the current integration method and open-circuit voltage method, while the internal resistance augmentation failure of battery is detected on-line by battery equivalent model and parameter identification method. The design of both hardware and software of the BMS is introduced in detail. And experimental results for measurement unit, equalization unit and internal resistance identification are provided. The results show that the battery management system can collect the voltage, current and temperature of the battery, balance the single battery with different voltage, and effectively identify the internal resistance of the battery, and it has the advantages of high measurement accuracy, well equalization performance and online detection of the internal resistance for batteries.

To solve the problem of high cost in updating the fingerprint database in terms of time and effort, the theory of compressed sensing and focus Lagrange interpolation algorithm are proposed in the offline phase. The process of fingerprint vector refactoring is transformed into the problem of minimum  l₀ norm optimization by compressed sensing, and total variation is used to recover the original fingerprint vector. Focus Lagrange interpolation algorithm takes the advantage of spatial correlation of sample nodes, by which the fingerprint database can be rebuilt through measuring a small amount of fingerprints. Finally a practical experiment in real indoor environment shows that the theory of compressed sensing achieves higher accuracy than focus Lagrange interpolation algorithm.

The existence and uniqueness of the common fixed points for four maps in the complete cone metric space are discussed.The main results in the papers improve and generalize the conclusions of a pair of self-mappings in the cone metric space.

With LED selected as the light source of side-incident light guide plates, it solves the difficult problems with the design of scattering netted dots with various distances on light guide plates of side-incident LED backlight efficiently by deriving a rule of scattering netted dots arrangement, based on the optics theories such as total reflection, refraction and the principle of luminous flux conservation. The critical array pitch of LED is deduced, which can effectively eliminate the different light intensity caused by LED arrays. Then, the optical design software TracePro was used to establish the physical simulation model. Through repeated experimental investigation, optimum parameters have been obtained. The simulation results show that the illumination uniformity of the designed light guide plate is close to 93%(over 80%), which satisfies the requirements of the national illumination standard.

For a real project in a variable condition, the risk analysis by Monte Carlo simulation is down in this paper. The simulation model involves correlative random variables and different kind of probability distribution. A computer program is developed for risk analysis. Several comparative schemes of the project are analyzed for their risk and foundation of decision-making is provided after that.

Aiming at the enlargement of the difference of income distribution among people,this paper is contributed to study and discuss Gini coefficient,which is one of the most efficient indexes and methods to measure income inequality.The paper systematically introduces Gini’s familiar algorithm,and applies it to the measurement of the income inequality among city dwellers and to the measurement between cities and countries.Finally the data results are analyzed.

When the Xgboost framework is in use, it is often involved in the adjustment of various parameters, and the selection of parameters has a great influence on the classification performance of the model. The traditional parameter optimization method usually first derives a penalty function, and then the empirical or exhaustive method is used to adjust the parameter value to maximize or minimize the penalty function, but often encounters a model without an explicit expression. The optimization of the parameters of this model is very troublesome, also bringing some uncertainty and randomness to the algorithm. The Bayesian optimization algorithm based on Gaussian method (GP) is used to optimize the parameters of the Xgboost framework. A new algorithm, GP_Xgboost, is proposed and experimented by multiple sets of numerical values. The results show that the proposed algorithm is superior to the manual tuning and exhaustive method, which proves the feasibility and effectiveness of the proposed algorithm.

The Malthus population model is used to analyse and predict the population data of Guangzhou．It finds that Malthus population model is good for Guangzhou population data，and it can reveal the changes in the population of Guangzhou．The prediction can offer useful information for Guangzhou policymakers．The key index of Malthus population model xk= x0(1+r) is r，and it finds that the good value of r is 1．54% for Guangzhou population data，searched for by a computer．

Aiming at the influence of illumination in face recognition process, a method of illumination normalization based on CycleGAN is presented. By using the Generative Adversarial Nets and the principle of image translation, the illumination style of the darker image was shifted to the brighter image, while the surface and the structure of the face kept smooth at the same time. Unpaired data sets without labels are used, in order to achieve unsupervised removal of illumination, and greatly simplify the work of data preprocessing. Finally, the CroppedYale data set is used to train a deep learning face recognition model, using this CycleGAN model to process the test set, and comparing the accuracy before and after processing. Experiments show that this method has a strong ability to reduce the influence of human face illumination on recognition rate while basically not changing the face structure, and therefore is helpful to improve the accuracy of face recognition.

Due to the scheduling inefficiency in a large number of job requests for the network operation and maintenance of field operations and the jobs being unable to change adjustment issue, an on-site job scheduling algorithm based on improved genetic algorithm for network operation and maintenance is established. The algorithm is based on job-indirect encoding resources, combined with network operation and maintenance of on-site job resource scheduling features, by setting the upper limit of the number of jobs for each maintenance personnel to avoid excessive burden on maintenance staff, thus helping to improve the quality of service and resource utilization. The simulation results show that the use of genetic algorithms is effective in solving the network operation and maintenance resource scheduling.