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The purpose of this paper is to model and analyze energy transfer through near‐field resonant coupling for high power light‐emitting diode (HPLED) illumination, with the intention to increase the appreciation and use of the coupled mode theory (CMT) other than the usual equivalent circuit method.

The CMT is extensively used to analyze the wireless energy transfer system because of its generality, simplicity, accuracy and intuitive understanding of near‐field resonant energy coupling mechanism.

The CMT forms a general way to model and analyze the non‐radiative magnetic resonant coupling systems. It is suitable not only for low frequency coupling but also for high frequency (of million‐Hertz) in which the circuit parameters are not easily obtained. Optimal coupling condition corresponding to the maximum power transfer is identified based on the CMT, and the multiple limit cycle phenomenon caused by the nonlinear nature of the HPLED is also described on the CMT model.

This paper takes advantages of CMT, i.e. generality, simplicity, accuracy and intuitive understanding to analyze the near‐field resonant energy coupling system. Key characteristics of the systems are explored based on the CMT, not the usual equivalent circuit method. The influence of nonlinear nature of the high power LED on energy transfer is also investigated. This work seeks a more general way than conventional equivalent circuit method to model and analyze the resonant magnetic system and the results obtained could facilitate better understanding of the resonant magnetic coupling mechanism and optimal design of the near‐field energy transfer system.

In order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.

In this work, a flame retardant with heterocyclic groups, HOMP, was acquired after removing the obstacle from triazines which was not readily soluble. The molecular structure, thermal and flame retardant properties were fully characterized and analyzed. Also, the mechanism was researched through multi-methodologies. As well, the authors evaluated the effects of HOMP on mechanical properties.

The results suggested that HOMP helped extinguish the combustion of specimens and could reach an LOI value of 29.2% and the V0 level in the UL-94 test with a phosphorus content of only 0.6wt%. With respect to the mechanism, HOMP was a gas-phase flame retardant and helped generate a thicker carbon protective coating. However, for the mechanical properties, the addition of HOMP enhanced the compressibility, while the tensile strength decreased significantly.

The approach not only simplified the operations but also obtained HOMP with excellent flame retardant properties.

Image classification is becoming a supporting technology in several image-processing tasks. Due to rich semantic information contained in the images, it is very popular for an image to have several labels or tags. This paper aims to develop a novel multi-label classification approach with superior performance.

Many multi-label classification problems share two main characteristics: label correlations and label imbalance. However, most of current methods are devoted to either model label relationship or to only deal with unbalanced problem with traditional single-label methods. In this paper, multi-label classification problem is regarded as an unbalanced multi-task learning problem. Multi-task least-squares support vector machine (MTLS-SVM) is generalized for this problem, renamed as multi-label LS-SVM (ML²S-SVM).

Experimental results on the emotions, scene, yeast and bibtex data sets indicate that the ML²S-SVM is competitive with respect to the state-of-the-art methods in terms of Hamming loss and instance-based F1 score. The values of resulting parameters largely influence the performance of ML²S-SVM, so it is necessary for users to identify proper parameters in advance.

On the basis of MTLS-SVM, a novel multi-label classification approach, ML²S-SVM, is put forward. This method can overcome the unbalanced problem but also explicitly models arbitrary order correlations among labels by allowing multiple labels to share a subspace. In addition, the multi-label classification approach has a wider range of applications. That is to say, it is not limited to the field of image classification.

The purpose of this paper was to prepare a fluorinated acrylate resin, which would be synthesised via solution polymerisation of fluorinated monomer, acrylate monomers and other functional monomers. Relevant characterisation and application studies were also carried out. Fluorinated polymers are expected to be adopted in specific coatings to afford outstanding advantages, such as high chemical and photochemical resistance, low surface tension and low refractive index. At present, fluorinated cathodic electrodeposition (CED) coatings are attracting the attention that they deserve and seldom reported.

Cationic fluorinated acrylic resin was successfully prepared by solution polymerisation of dodecafluoroheptyl methacrylate, butyl acrylate, methyl methacrylate, dimethylaminoethyl methacrylate and methacrylic acid initiated by 2,2,-azo-bis-iso-butyronitrile in a solvent of butyl cellosolve. The resultant resin was neutralised with acetic acid. The CED coatings are prepared when moderate amounts of blocked isocyanate and distilled water were added into the resultant resin.

The hydrophobicity of the film is improved when the fluorinated monomer is introduced to co-polymerise with other monomers. The optimum conditions of preparing the resin are as follows: the amount of azodiisobutyronitrile is controlled with the range of 3.0 and 4.0 per cent; the amine value of the resin is 70 mg KOH/g; the hydroxyl value of resin and mole ratio of hydroxyl to isocyanate is 60 mg KOH/g and 1.0/1.0, respectively; the degree of neutralisation of the resin is within the range of 35 and 40 per cent.

The cationic fluorinated acrylic resin can be used to be the binder of CED coatings, which can be applied to electrodeposition finishing for high demand of exterior decorative and weather resistance, such as hardware, accessories, office furniture and so on.

The cationic fluorinated acrylic resin was successfully prepared by solution polymerisation. The hydrophobicity of the film is improved.

The purpose of this paper is to make a contribution to understanding the influence of factors such as the water/cement (W/C) ratio and the granular class on the mechanical and physical properties of high-strength concretes (HSCs). In the formulations of HSC, aggregates by their high mass and volume proportion play an important role. When selecting aggregates, it is necessary to know their intrinsic properties. These properties influence the performance of concrete, in particular the quality of the granulate cimentary adhesion.

This experimental study focused on the effect of W/C ratio (0.25, 0.30, 0.35), the effect of replacing a part of cement by silica fume (SF) (8%), the effect of fraction of aggregate on properties of fresh and hardened concrete, the effect of different environment conversation like drinking water and sea water on compressive strength and the study of absorption of water and softening using the mix design method of the University of Sherbrooke combined with the Dreux-Gorisse method which gives good results.

At the end of our work, the examination of the results obtained made it possible to establish the correlations between the formulations studied and the physicomechanical characteristics of the concrete compositions (HSC25, HSC16, HSC8). The results of this study show that the use of three granular classifications (DMAX8, DMAX16 and DMAX25) and three report W/C (0.25, 0.30 and 0.35) in two different conservation environment (drinking water and sea water) give HSCs, HSC25 with an W/C = 0.25 ratio has reached the largest mechanical strength of 90 MPa for different environments of conservation. For selecting aggregates, it is necessary to know their intrinsic properties, these properties influence the strength of concrete. In general, there is a slight decrease in the compressive resistance of the specimens stored in seawater, it can be said that the conservation life has not had effect on the resistance (28 days). The effect of aggressive environment can appear in the long term.

Mixed design and concrete fabrication with a 28-day compressive strength of up to 68 MPa or more of 90 MPa can now be possible used in Jiel (Algeria), and it should no longer be considered to be used only in an experimental domain. Addition of SF in concrete showed good development of strength between 7 and 28 days, depending on the design of the mix.

Concrete containing 8% SF with W/B of 0.25 has higher compressive strength than the other concretes, and concretes with SF are more resistant than concretes without SF, so it is possible to have concrete with a compressive strength of 82 MPa for W/C 0.25 without SF. Like as a result, we can avoid the use of SF to affect the strength of concrete at compressive strength of 68 MPa, and a slump of 21 cm, because the SF is the most expensive ingredient used in the composition of concrete and is therefore very important economically. One of the main factors of production of HSC above 90 MPa is use of aggregate DMAX25, which is stronger with W/B of 0.25 and 0.30.

This mixtures leads to a very dense microstructure and low porosity and produces increased permeability of HSC and is able to resist the penetration of aggressive agents. This combination has a positive effect on the economy of concrete.

The combination of the Dreux-Gorisse method with the Sherbrook method is very beneficial for determining the percentage of aggregates used, and the use of coarse aggregates of Jijel to obtain HSC with 90 MPa and 16 cm of workability.

This article examines how personality types of tutors affect group interaction at a distance learning institution in Hong Kong. All participants of this study are Chinese, and they were given two personality assessment tools to complete: (1) the Myers‐Briggs Type Indicator which was developed in the West in the early 1940s; and (2) the Chinese Personality Assessment Inventory which was developed in Hong Kong in the early 1990s. The CPAI consists of personality constructs of specific interest to people of Chinese culture but that were not covered in most of the translated personality inventories. The purpose of using two personality tests is to explore whether a culturally specific instrument will be a more comprehensive measure that can reveal particular distinctive factors in the relevant culture.

Fluorinated silicon polymers are expected to be adopted in specific coatings to afford outstanding advantages, such as high chemical and photochemical resistance, low surface tension and low refractive index. The modified acrylate resin is prepared via solution polymerization of fluorine and silicon monomers, acrylate monomers and other functional monomers. The purpose of this paper is that the fluorine and silicon monomers such as vinyltriethoxysilane (VTES) and hexafluorobutyl methacrylate (HFMA) and some cheap monomers such as styrene are used to prepare the cationic acrylic resin.

The fluorine and silicon modified cationic acrylic resin is prepared via solution polymerization technology, which uses butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), HFMA, VTES, dimethylaminoethyl methacrylate (DMAEMA) and hydroxypropyl methacrylate (HPMA) as the co-polymerized monomers, propylene glycol monomethyl ether (PGME) as solvent and 2,2-Azo-bis-iso-butyronitrile (AIBN) as the initiator to create a resin to introduce the Si–O and C–F into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthetic resin and blocked isocyanate.

The influence of the amounts of HFMA and VETS on the resin and the resultant CED coatings is investigated in detail. The optimum amounts of HFMA and VETS are obtained, which is 7–8% and 4–5%, respectively. The hydrophobicity and the acid and alkaline resistance of the film are improved when VETS and HFMA are introduced to co-polymerize with other monomers.

The fluorine and silicon monomers such as VTES and HFMA and some cheap monomers such as styrene, which are used to prepare the cationic acrylic resin, are seldom reported in the open literature.

From the perspective of cause and effect, the operational processes of property insurance companies can be considered as historical events. The purpose of this study is to measure the operating efficiency of China's property insurance industry, explore the determinants that affect technical efficiency and outline the path to achieving high-quality development.

We chose 44 Chinese property insurance companies as research objects. The data were obtained from the Chinese Insurance Yearbook and China Statistical Yearbook 2015–2017. First, the data envelopment analysis (DEA) method was used to calculate the technical efficiency of property insurance companies. Then, Tobit regression and quantile regression were adopted to explore the influencing factors of technical efficiency. Finally, the fuzzy-set qualitative comparative analysis (fsQCA) method was employed to summarize the path to improving the operating efficiency of property insurance companies.

The empirical results in the first stage suggested that the operation efficiency of China's property insurance industry was technically inefficient, and the scale efficiency was relatively better than the pure technical efficiency. In the second stage, we observed that the drivers for firm size, reinsurance rate, claim ratio and equity restriction were important determinants of an insurance firm's efficiency.

We also put forward four applicable, targeted and proven ways to improve the technical efficiency of property insurance companies. These configurations are verified by cases of existing property insurance companies, which can provide practical references for the insurance industry.

Our research enriches the insurance literature and efficiency methods, particularly regarding the specific paths of improving the technical efficiency. The relationship between elements and results is analyzed from a systematic perspective, and the research results are not only more consistent with what logic might imply but also more instructive for the improvement of reality.

Based on the perspective of complexity theory, the operation process of property insurance companies can be regarded as a complex dynamic nonlinear chaotic system. This paper aims to measure the operating efficiency of 29 Chinese domestic property and casualty (P&C) companies and 18 foreign-invested P&C companies from 2011 to 2017 and outline the path to achieving high-quality development.

The data were obtained from the Chinese Insurance Yearbook and China Statistical Yearbook 2012–2018. The data envelopment analysis method was used to calculate the technical efficiency of property insurance companies and fuzzy set qualitative comparative analysis is used for configuration analysis of determinants affecting technical efficiency.

This paper founds the average technical efficiency of Chinese domestic P&C insurance companies was 0.914 and that of foreign-invested P&C insurance companies was 0.895. The average total factor productivity of Chinese domestic P&C insurance companies was 1.058 and that of foreign-invested P&C insurance companies was 1.051. There were three modes to improve the company’s technical efficiency, with high loss ratio and low reinsurance ratio, poor employee education and higher leverage ratio and high leverage ratio and low reinsurance ratio as the core conditions.

This study puts forward four applicable, targeted and proven ways to improve the technical efficiency of China’s P&C insurance industry. These configurations were verified by the cases of existing property insurance companies, which can provide practical references for the insurance industry.