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The paper seeks to identify key features of prenatal care utilization and quality in western regions of China and to determine the factors affecting the quality of prenatal care.

A descriptive, cross‐sectional study was conducted. The instrument for the study was a 10‐stem respondent‐administered, structured questionnaire, designed in Chinese, composed of two segments: general information on infants who were under two years old; and their mothers. The authors determined the quality (both amount and content) of prenatal care using recommendations made by UNICEF and the Chinese Ministry of Health (MOH) jointly for rural areas of China.

The median number of prenatal visits was three and rate of first trimester visits was 53.6 per cent (n=1,474). Over three quarters (75.3 per cent) of respondents had fewer than five prenatal visits, with this proportion highest in Gansu (95.8 per cent) and lowest in Shanxi (55.4 per cent) provinces. The percentage of women who received qualitatively adequate prenatal care services was only 1.8 per cent. No respondents in Gansu received a completely correct prenatal test, while this rate was 4.0 per cent in Shanxi and 0.2 per cent in Sichuan. Mothers' age (p=0.05), level of educational attainment (p=0.07) and place of prenatal care (p=0.01) were related to the quality of care.

The prenatal care utilization among women in western regions of China is not adequate. Those women who have received prenatal care seldom receive qualitatively adequate prenatal care services, according to national standards. This situation clearly requires urgent attention and improvement.

The purpose of this paper is to improve adolescents’ nutrition knowledge and to examine the effect of interventions component to improve adolescents’ nutrition knowledge.

The study design was multi-factorial with repeated measures, at two points in time, of dependent samples from three schools, which were randomly selected from 15 middle schools in Miyun County, Beijing, and then randomly assigned to control school or intervention school. The instrument for baseline survey was a 14-item and for follow-up survey was a 26-item, self-administered, structured questionnaire, designed in Chinese.

Students’ nutrition knowledge improved significantly in intervention schools after intervention compared with controls. The extent to which students felt that peer support activities were helpful and that what they learned in class about nutrition was helpful, was related to their resultant level of nutrition knowledge.

To the authors’ knowledge there have been no previous studies which explore the effect of specific intervention components on levels of nutrition knowledge among adolescents.

Path planning is an important part of UAV mission planning. The main purpose of this paper is to overcome the shortcomings of the standard particle swarm optimization (PSO) such as easy to fall into the local optimum, so that the improved PSO applied to the UAV path planning can enable the UAV to plan a better quality path.

Firstly, the adaptation function is formulated by comprehensively considering the performance constraints of the flight target as well as the UAV itself. Secondly, the standard PSO is improved, and the improved particle swarm optimization with multi-strategy fusion (MFIPSO) is proposed. The method introduces class sigmoid inertia weight, adaptively adjusts the learning factors and at the same time incorporates K-means clustering ideas and introduces the Cauchy perturbation factor. Finally, MFIPSO is applied to UAV path planning.

Simulation experiments are conducted in simple and complex scenarios, respectively, and the quality of the path is measured by the fitness value and straight line rate, and the experimental results show that MFIPSO enables the UAV to plan a path with better quality.

Aiming at the standard PSO is prone to problems such as premature convergence, MFIPSO is proposed, which introduces class sigmoid inertia weight and adaptively adjusts the learning factor, balancing the global search ability and local convergence ability of the algorithm. The idea of K-means clustering algorithm is also incorporated to reduce the complexity of the algorithm while maintaining the diversity of particle swarm. In addition, the Cauchy perturbation is used to avoid the algorithm from falling into local optimum. Finally, the adaptability function is formulated by comprehensively considering the performance constraints of the flight target as well as the UAV itself, which improves the accuracy of the evaluation model.

This paper aims to introduce a method based on the optimizer of the particle swarm optimization (PSO) algorithm to improve the efficiency of a Kriging surrogate model.

PSO was first used to identify the best group of trend functions and to optimize the correlation parameter thereafter.

The Kriging surrogate model was used to resolve the fuselage optimization of an unmanned helicopter.

The optimization results indicated that an appropriate PSO scheme can improve the efficiency of the Kriging surrogate model.

Both the STANDARD PSO and the original PSO algorithms were chosen to show the effect of PSO on a Kriging surrogate model.

The purpose of this paper is to propose a novel resource management strategy, which needs no special frameworks and directory servers.

The key idea is to piggyback a little extra packet header on the normal routing message by resource providers randomly. The clients can obtain the resource information gradually and need no dedicated resource queries.

The results of simulation confirm the good performance of our algorithms in different situations in terms of query latency and power consumption.

A novel resource management strategy, which needs no special frameworks and directory servers. The approach can be used in many current routing protocols. The quality of service issue is also considered for resource discovery algorithm and broadcasting method.

It is greatly important to select the parameters for support vector machines (SVM), which is usually determined by cross-validation. However, the cross-validation is very time-consuming and complicated to create good parameters for SVM. The parameter tuning issue can be solved in the optimization framework. The paper aims to discuss these issues.

In this paper, the authors propose a novel variant of particle swarm optimization (PSO) for the selection of parameters in SVM. The proposed algorithm is denoted as PSO-TS (PSO algorithm with team-search strategy), which is with team-based local search strategy and dynamic inertia factor. The ultimate design purpose of the strategy is to realize that the algorithm can be suitable for different problems with good balance between exploration and exploitation and efficiently control the inertia of the flight. In PSO-TS, the particles accomplish the assigned tasks according to different topology and detailedly search the achieved and potential regions. The authors also theoretically analyze the behavior of PSO-TS and demonstrate they can share the different information from their neighbors to maintain diversity for efficient search.

The validation of PSO-TS is conducted over a widely used benchmark functions and applied to tuning the parameters of SVM. The experimental results demonstrate that the proposed algorithm can tune the parameters of SVM efficiently.

The developed method is original.

The purpose of this paper is to examine how credit ratings affect corporate financial behavior from the perspective of merger and acquisition (M&A) decisions. The goal is to test the financing and supervisory effects of credit ratings and study the economic consequences of credit ratings in the context of China.

Using a sample of Chinese A-share listed companies over the 2008–2017 period, this paper empirically examines the effect of credit ratings on firms’ M&A decisions. The authors used a probit model for regression when they tested the effect of credit rating on M&A likelihood and a tobit model when they tested the effect of credit rating on M&A intensity.

First, rated enterprises tend to make more acquisitions compared with non-rated enterprises, consistent with the hypothesis that credit ratings alleviate financing constraints. Second, high-rated enterprises are more cautious toward M&As due to concerns about preserving their ratings, which indicates that credit ratings also play a supervisory role in the M&A process. Additional tests show that enterprises reduce M&A activity after a rating downgrade to avoid further deterioration in their ratings; this further supports the supervisory role of credit ratings.

This paper adds incremental evidence to the literature on the impact of credit ratings on corporate financial behavior and extends the literature on the factors influencing M&As. The authors provided empirical evidence from emerging capital markets for the financing and supervisory effects of credit ratings and provided theoretical guidance for promoting the stable, long-term development of China’s credit rating industry.

This study aims to evaluate enterprise technology innovation capability in prefabricated construction (PC) from an input-output perspective, using six integrated enterprises in China as cases.

An evaluation system for enterprise technology innovation capability in PC was constructed, including total input, technology output (TO) and project output. All the evaluation indexes were quantified, and the subject and object indexes weights were determined using the fuzzy cognitive map and information entropy, respectively. The final scores and ranks were evaluated through gray relational analysis (GRA) based on the combined weights.

It was found that enterprise technology innovation capability in PC was low in China, with its unbalanced development in different dimensions and the poorest performance in TO, currently.

This research has developed an evaluation system for technology innovation capability in PC at the enterprise level and scientifically quantified all the indexes, which is a breakthrough over existing studies. The GRA model based on the combined weights proposed in this study can be applied to other comparable fields and regions, with its easy operation.

This paper aims to quantify the dependence relationship of bat algorithm’s (BA) behaviour on the factors that could possibly affect the outputs, and rank the importance of the various uncertain factors thus suggesting research priorities.

This paper conducts a sensitivity analysis based on variance decomposition of factors in both of original and improved BA. The data sets for sensitivity analysis are generated by optimal Latin hyper sampling in the design of experiment. The optimal factor sets are screened by stochastic error bar measures for the effective and robust implementation of BA.

The paper reveals the inner dependent relationship between factors and output in both of original and improved BA. It figures out the weakness in original BA and improves that. It suggests that uncertainty brought about by factors are mainly caused by the interaction effect and all the higher-order term in sensitivity indices for both of original and improved BA. It ranks the main effect and the total effect of factors and screens out some optimal factor sets for BA.

This paper quantifies the dependence relationship of BA’s behaviour on the factors that could affect outputs using sensitivity analysis based on variance decomposition.

Based on the social exchange theory, this study explores the mechanism of leader–subordinate power distance orientation (PDO) congruence with employees' taking charge behavior (TCB) and also verifies the moderated mediation effect of employees' promotion regulatory focus (PROM-F) on leader–subordinate PDO congruence and on employees' TCB through trust in the leader (which is the mediator).

Based on 296 questionnaires from 46 teams of Chinese enterprises, the authors use cross-level polynomial regressions and response surface techniques to analyze the effect of leader–subordinate PDO congruence on employees' TCB and use the block variable technique to test the mediating effect of trust in the leader.

(1) When leader–subordinates' PDO is congruent, the leader–subordinate low-low PDO matching pattern leads to more employees' TCB than the leader–subordinate high-high PDO matching pattern. (2) When leader–subordinate PDO is incongruent, the leader–subordinate low–high PDO matching pattern will lead to more TCB than the high-low PDO pattern.

(1) Encourage and promote the development of diverse cultures in enterprises. (2) Respect the power and status of employees and encourage a low-PDO leadership style. (3) Increase credibility by developing and establishing a good corporate leader image.

(1) The unique background of this survey offers important cross-cultural information on the effects of leader–subordinate PDO congruence. (2) The results of this research enrich the theoretical understanding of the factors that influence TCB. (3) Reveal the internal mechanisms of CPD congruence with TCB and demonstrate an indirect effect of trust in leader. (4) The discussion of the moderating role of employee's PROM-F will also deepen the understanding of the exchange relationship between leaders and subordinates.