Abnormal Flight Passenger Recovery Algorithm Based on Itinerary Acceptance

Under the background of the rapid development of the air transport industry, the abnormal phenomenon of flights has become increasingly serious due to various factors such as the gradual reduction of resources, adverse climatic conditions, problems in air traffic control and mechanical failures. In order to reduce losses, it has become a major problem for airlines to use optimization algorithm to study the recovery of abnormal flights. By upgrading the passenger recovery engine, the purpose of this paper is to provide the optimal recovery scheme for passengers, so as to reduce the risk of transferring overseas flights, and thus reduce the economic loss of airlines. In this paper, the optimization model and algorithm based on network flow, combined with actual business requirements, comprehensively consider multiple optimization objectives to quickly generate passenger recovery solutions, and at the same time achieve the optimal income of airlines and the acceptance rate of passenger recovery, so as to balance the two. The practicability and effectiveness of the proposed model and algorithm are proved by some concrete examples.

Apply to the Micro Grid Data Limit Learning Algorithm

More and more microgrid projects are put into operation and completed, and the load data are becoming more and more multidimensional and massive. This requires effective classification of load data. Most of the traditional processing methods are based on neural network to classify the grid data. However, with the development of microgrid, the traditional neural network algorithm is having a hard time meeting the requirement of the classification and operation of massive microgrid data. In this paper, the back propagation neural network (BPNN) algorithm is parallelized based on the traditional reverse neural network algorithm. Multiple algorithms are applied for data learning, for example, the combined application of extreme learning algorithm and simulated annealing algorithm, artificial fish swarm algorithm and other evolutionary algorithms. The input variables in BPNN are optimized in the network training process. After adding the algorithm fitness evaluation function, the combined algorithm of improved back propagation neural network algorithm came out. It is most in line with the real-time data of power grid by means of root mean square error. This result could provide data support and theoretical basis for load management, microgrid optimization, energy storage management and electricity price modeling of microgrid.

An Application of the Ramsey Number in the Electricity Pricing

The Ramsey number is a foundational result in combinatorics. This article will introduce Ramsey number with the method of graph theory, and the Ramsey pricing theory is applied to the sales price and study of cross subsidy. Based on the status of our sales price and cross subsidy, Ramsey pricing methods theoretically guide adjustment thoughts of sales price and solve the practical problems in our life.

Dynamic contrast-enhanced MRI versus ^(18)F-FDG PET/CT: Which is better in differentiation between malignant and benign solitary pulmonary nodules?

Objective： To prospectively compare the discriminative capacity of dynamic contrast enhanced-magnetic resonance imaging（DCE-MRI） with that of^18F-fluorodeoxyglucose（^18F-FDG） positron emission tomography/computed tomography（PET/CT） in the differentiation of malignant and benign solitary pulmonary nodules（SPNs）.Methods： Forty-nine patients with SPNs were included in this prospective study. Thirty-two of the patients had malignant SPNs, while the other 17 had benign SPNs. All these patients underwent DCE-MRI and ^18F-FDG PET/CT examinations. The quantitative MRI pharmacokinetic parameters, including the trans-endothelial transfer constant（K^trans）, redistribution rate constant（Kep）, and fractional volume（Ve）, were calculated using the Extended-Tofts Linear two-compartment model. The ^18F-FDG PET/CT parameter, maximum standardized uptake value（SUV（max））, was also measured. Spearman＇s correlations were calculated between the MRI pharmacokinetic parameters and the SUV（max） of each SPN. These parameters were statistically compared between the malignant and benign nodules. Receiver operating characteristic（ROC） analyses were used to compare the diagnostic capability between the DCE-MRI and ^18F-FDG PET/CT indexes.Results： Positive correlations were found between K^trans and SUV（max）, and between K（ep） and SUV（max）（P〈0.05）.There were significant differences between the malignant and benign nodules in terms of the K^trans, K（ep） and SUV（max） values（P〈0.05）. The areas under the ROC curve（AUC） of K^trans） K（ep） and SUV（max） between the malignant and benign nodules were 0.909, 0.838 and 0.759, respectively. The sensitivity and specificity in differentiating malignant from benign SPNs were 90.6% and 82.4% for K^trans; 87.5% and 76.5% for K（ep）; and 75.0% and 70.6%for SUV（max）, respectively. The sensitivity and specificity of K^trans and K（ep） were higher than those of SUV（max）, but there was no significant difference between them（P〉0.05）.Conclusions： DCE-MRI can be used to differentiate between benign and malignant SPNs and has the advantage of being radiation free.

A Survey of Blind Forensics Techniques for JPEG Image Tampering

Blind forensics of JPEG image tampering as a kind of digital image blind forensics technology is gradually becoming a new research hotspot in the field of image security. Firstly, the main achievements of domestic and foreign scholars in the blind forensic technology of JPEG image tampering were briefly described. Then, according to the different methods of tampering and detection, the current detection was divided into two types: double JPEG compression detection and block effect inconsistency detection. This paper summarized the existing methods of JPEG image blind forensics detection, and analyzed the two methods. Finally, the existing problems and future research trends were analyzed and prospected to provide further theoretical support for the research of JPEG image blind forensics technology.

Review of Carbon Dots from Lignin: Preparing, Tuning, and Applying

Carbon dots(CDs),emerging carbon materials with unique physical and chemical properties,have drawn extensive attention from researchers.In recent years,many carbon sources have been used as precursors for preparing CDs.In contrast to other types of precursors,lignin,as a renewable and available source of natural aromatic biopolymers,is believed to be a low-cost precursor for the large-scale preparation of CDs.However,the preparation of CDs with excellent optical properties from lignin has some drawbacks because of the complex structure of lignin.Hence,the methods for preparing the CDs from lignin are summarized in this paper,and the mechanism and physical and chemical properties of lignin-based CDs are discussed.Moreover,some approaches to tuning the optical properties of lignin-based CDs have been proposed.Additionally,the use of lignin-based CDs in the fields of sensing,supercapacitor,bioimaging,anti-counterfeiting,and information encryption is reviewed.

Nonlinear Switching Transient Field Simulation of Cable Joint without Residual Charge

The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.

Economic Load Dispatch Based on Efficient Population Utilization Strategy for Particle Swarm Optimization

In this paper, the efficient population utilization strategy for particle swarm optimization (EPUSPSO) is proposed to solve the economic load dispatch (ELD) problem of power system. This algorithm improves the accuracy and the speed of its convergence by changing the number of particles effectively, and improving the velocity equation and position equation. In order to verify the effectiveness of the algorithm, this algorithm is tested in three different ELD cases of power system include IEEE 3-unit case, 13-unit case, and 40-unit case, and the obtained results are compared with those obtained from other algorithms using the same system parameters. The compared results show that the algorithm can find the optimal solution effectively and accurately, and avoid falling into the local optimal problem;meanwhile, faster speed can be ensured in the case.

Simulation Analysis of Suppression of Resonant Overcurrent by Nonlinear Components

For the development of distributed power supply active distribution network system, the instability of the power supply side causes the system frequency to be disturbed, and harmonics, voltage fluctuations, or ferromagnetic saturation causes resonance and other series of power quality problems;what resulting in the over-voltage and over-current can easily damage components and threaten the system's safe and stable operation. In order to solve these problems, this paper compares some harmonic detection and filtering methods, devices and methods for suppressing resonance in recent years, and combines the principle of resonance to design a nonlinear inductive circuit that can suppress resonant overcurrent according to the characteristics of nonlinear inductors. Compared with the Resistance (R) series Induct Capacitance (LC) parallel circuit composed of common inductors, the circuit described in this paper is not affected by overcurrent, and the influence of overvoltage is relatively greatly reduced. The simulate-on proves that this circuit suppresses the effects of resonant overvoltage and overcurrent.

氨基纤维素功能材料的合成与应用

氨基化改性可有效地破坏纤维素固有的结晶结构,赋予纤维素一定的碱性,改善纤维素的水溶性,极大地提升了纤维素的利用价值。文中对氨基纤维素的合成路径及结构特征进行了归纳总结。通过具体实例分析,总结了氨基纤维素在吸附、生物医药、催化剂和酶蛋白固载领域的应用,提出了氨基纤维素绿色合成、生物相容性分析、仿生材料设计等研究发展方向。期望为氨基纤维素的利用提供理论参考,为氨基纤维素的研究提供方向。

Improvement of Counting Sorting Algorithm

By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting sort while maintaining the original stability. Compared with the original counting sort, it has a wider scope of application and better time and space efficiency. In addition, the accuracy of the above conclusions can be proved by a large amount of experimental data.

An Improved Differential Evolution Whale Algorithm for Economic Load Distribution

An improved optimization algorithm combining the differential evolution algorithm and the whale algorithm is proposed for the problem of not being able to get rid of the local optimum in the economic load distribution algorithm. The algorithm adopts a nonlinear convergence strategy, a crossover strategy of differential evolution and the introduction of an elimination mechanism, which balances the global search and local exploitation ability of the algorithm and improves the accuracy of the solved optimal solution. The 13-unit and 40-unit systems are selected for economic load distribution calculation, and the experimental results show that the proposed improved algorithm is superior in distributing the economic load of the power system and can effectively reduce the economic cost.

QC_(0.44)-g-PLA两亲性共聚物合成及自组装纳米胶束在疏水性药物水系载体中的应用

在绿色溶剂1-丁基-3-甲基咪唑氯盐中,通过纤维素季铵盐的羟基与疏水单体乳酸(LA)之间的开环接枝聚合反应(ROP),在二甲氨基吡啶(DMAP)或1,8-二氮杂二环十一碳-7-烯(DBU)的催化作用下制备QC_(0.44)-g-PLA两亲性共聚物。利用红外光谱、核磁共振、X射线衍射、热重分析、透射电镜、粒径分布和荧光光谱等技术对QC_(0.44)-g-PLA共聚物的结构、性能及自组装行为进行表征。透射电镜和粒径分布结果表明,QC_(0.44)-g-PLA共聚物在水溶液中可自组装成均一球形纳米胶束,其粒径为92~226 nm,疏水链段PLA的摩尔取代度(MS)为0.83~2.54,共聚物临界胶束浓度(CMC)为215~272μg/m L,胶束的粒径和CMC值均随MS的增加而降低。胶束表面电荷呈阳电性,并且对紫杉醇(PTX)和吴茱萸碱(EVO)的包封率随共聚物中PLA的MS值增加而增加,其最大包封率分别为69.7%和66.4%。

Research on Rosenbrock Function Optimization Problem Based on Improved Differential Evolution Algorithm

The Rosenbrock function optimization belongs to unconstrained optimization problems, and its global minimum value is located at the bottom of a smooth and narrow valley of the parabolic shape. It is very difficult to find the global minimum value of the function because of the little information provided for the optimization algorithm. According to the characteristics of the Rosenbrock function, this paper specifically proposed an improved differential evolution algorithm that adopts the self-adaptive scaling factor F and crossover rate CR with elimination mechanism, which can effectively avoid premature convergence of the algorithm and local optimum. This algorithm can also expand the search range at an early stage to find the global minimum of the Rosenbrock function. Many experimental results show that the algorithm has good performance of function optimization and provides a new idea for optimization problems similar to the Rosenbrock function for some problems of special fields.

Research on Simulation Methods of Electric Field Intensity on Surface of 10 kV Cable Joint

The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.

Embedding and Extracting Digital Watermark Based on DCT Algorithm

The principle of digital watermark is the method of adding digital watermark in the frequency domain. The digital watermark hides the watermark in digital media, such as image, voice, video, etc., so as to realize the functions of copyright protection, and identity recognition. DCT for Discrete Cosine Transform is used to transform the image pixel value and the frequency domain coefficient matrix to realize the embedding and extracting of the blind watermark in the paper. After success, the image is attacked by white noise and Gaussian low-pass filtering. The result shows that the watermark signal embedded based on the DCT algorithm is relatively robust, and can effectively resist some attack methods that use signal distortion to destroy the watermark, and has good robustness and imperceptibility.

A Short-Term PV Power Forecasting Method Using a Hybrid Kmeans-GRA-SVR Model under Ideal Weather Condition

With the continuous increase of solar penetration rate, it has brought challenges to the smooth operation of the power grid. Therefore, to make photovoltaic power generation not affect the smooth operation of the grid, accurate photovoltaic power prediction is required. And short-term forecasting is essential for the deployment of daily power generation plans. In this paper, A short-term photovoltaic power generation forecast method based on K-means++, grey relational analysis (GRA) and support vector regression (SVR) (Hybrid Kmeans-GRA-SVR, HKGSVR) was proposed. The historical power data was clustered through the multi-index K-means++ algorithm. And the similar days and the nearest neighbor similar day of the prediction day were selected by the GRA algorithm. Then, similar days and nearest neighbor similar days were used to train SVR to obtain an accurate photovoltaic power prediction model. Under ideal weather, the average values of MAE, RMSE, and R2 were 0.8101 kW, 0.9608 kW, and 99.66%, respectively. The average computation time was 1.7487 s, which was significantly better than the SVR model. Thus, the demonstrated numerical results verify the effectiveness of the proposed model for short-term PV power prediction.

Homogeneous Synthesis and Characterization of Quaternized Cellulose Derivatives in NaOH-urea Aqueous Solutions

Quaternized cellulose( QC) derivatives were synthesized by reacting cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHPTAC) in an aqueous solution of Na OH-urea. The chemical structures and physical properties of the obtained QC derivatives were characterized using nitrogen content analysis,Fourier transform infrared spectroscopy( FT-IR),~1H-nuclear magnetic resonance(1H-NMR),X-ray diffraction( XRD),and thermal gravity analysis( TGA). The FT-IR and ~1H-NMR results confirmed the successful introduction of cationic quaternary ammonium groups into the main chain of cellulose. A series of QC derivatives with the degree of substitution( DS) values ranging from 0. 33 to 0. 80 were derived by adjusting the molar ratio of CHPTAC to anhydroglucose unit( AGU) of cellulose,concentration of cellulose in the Na OH-urea solution,as well as reaction temperature and time. According to the DS values of the QC derivatives,the optimized synthetic conditions were as follows: 25℃ reaction temperature,3% cellulose in Na OH-urea solution,the molar ratio of etherification agent to glycosidic cellulose of 15∶ 1,and 12 h reaction time. The TGA and XRD results revealed that the crystalline structure was destroyed during etherification,and the thermal stability of the QC derivatives was lower than that of cellulose.

Impacts of Agricultural Mechanization on Agricultural Production in Guangdong Province

Agricultural machinery represents modern method and modern condition of production, and Agricultural mechanization is the key basis and symbol of modern agriculture. Based on analyses of agricultural mechanization development in Guangdong Province from 1988 to 2008, production function was developed to estimate the effects of agricultural mechanization on agricultural production. The results indicated that the contribution of agricultural mechanization to production continues to increase. The agricultural mechanization increased by 1%, and grain production by0.35%. Therefore, government should encourage development of agricultural mechanization in order to improve agricultural production in Guangdong Province.

Replay Attack and Defense of Electric Vehicle Charging on GB/T 27930-2015 Communication Protocol

The GB/T 27930-2015 protocol is the communication protocol between the non-vehicle-mounted charger and the battery management system (BMS) stipulated by the state. However, as the protocol adopts the way of broadcast communication and plaintext to transmit data, the data frame does not contain the source address and the destination address, making the Electric Vehicle (EV) vulnerable to replay attack in the charging process. In order to verify the security problems of the protocol, this paper uses 27,655 message data in the complete charging process provided by Shanghai Thaisen electric company, and analyzes these actual data frames one by one with the program written by C++. In order to enhance the security of the protocol, Rivest-Shamir-Adleman (RSA) digital signature and adding random numbers are proposed to resist replay attack. Under the experimental environment of Eclipse, the normal charging of electric vehicles, RSA digital signature and random number defense are simulated. Experimental results show that RSA digital signature cannot resist replay attack, and adding random numbers can effectively enhance the ability of EV to resist replay attack during charging.