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CNC system has improved greatly upon machining precision and speed over the past six decades but remains vendor-proprietary and working in a stand-alone pattern. Open CNC aims to deal with the vend...

The development of open CNC systems is a popular topic in the past three decades. From the perspective of software engineering, most open CNC prototypes are developed based on the component-based software development (CBSD) approach. That is, they are constructed by composing functional or logical components. This paper retrospects the development of CBSD-based open CNC systems. These systems are analyzed from three aspects. For the component granularity aspect, CNC domain analysis and component reusability are discussed. For the component model aspect, component models used in open CNC systems are summarized, illustrated, and discussed. Likewise, for the software architecture aspect, architecture styles are summarized, described, and analyzed. But due to the diversity and platform dependency of component models, there is no widely accepted platform that can collect and execute heterogeneous CNC components. Service is an evolution of components. It makes a traditional component to be platform-independent and supports communication via message. Thus, a service-oriented architecture (SOA)-based universal open CNC platform is an attractive development trend of diverse CBSD-based open CNC systems. And its development is similar to the development of the CBSD-based system, but more complicated because it contains more domain logic. Therefore, this paper provides a technical foundation for developing SOA-based open CNC platform which is a part of novel automation patterns, such as cloud manufacturing and cyber-physical production system.

This paper illustrates the direct and indirect effects of democracy on CO2 emissions in the BRICS countries (Brazil, Russia, India, China, and South Africa) from 1992 to 2018. In view of the distribution heterogeneity of CO2 emissions, the panel quantile regression model is especially used to explore the nexus among different variables. Furthermore, in order to predict the trends of CO2 emissions in different countries, we also estimate the kernel density function of CO2 emissions in the BRICS countries by the quantile-fitted values. The results indicate that the direct impact of democracy on carbon dioxide emissions is significantly negative and great at high-emission countries. Although the indirect effect of democracy is positive in China and negative in Brazil and South Africa, the total effect of democracy on CO2 emissions remains negative in all BRICS countries. The estimation of kernel density function shows that the distribution of CO2 emissions in each country is gradually concentrated. Moreover, there is an environmental Kuznets curve depicting the linkage of urbanization and carbon dioxide emissions in Brazil and South Africa. These findings further highlight that the impact of democracy on high-emission and low-emission countries should be taken into account in policymaking to achieve sustainable developments.

Objective To investigate the referral rate, prevalence and aetiology of neonatal hearing loss. Methods A total of 11,894 infants were screened by two-stage transient evoked otoacoustic emission testing. Those who failed were diagnosed by distortion product otoacoustic emission, 1000 Hz probe tone tympanometry and auditory brainstem response. The results of these tests were analysed by statistical software SPSS16.0. Results The initial referral rate was 17.36%. The rescreening referral rate was 21.29%. The referral rate of initial screening in maternity wards (15.37%) was lower than in neonatal intensive care unit wards (22%) (chi-square [ χ2], P < 0.05). There were 68 cases (106 ears) diagnosed with hearing loss (incidence 0.571%). Of these, 31 cases were conductive, 16 cases were sensorineural, and 21 cases were mixed hearing loss. The prevalence of hearing loss was 12.92% (38/294) in the bilateral referred group and 5.00% (30/600) in the unilateral referred group. The moderate/severe hearing loss was 33.33% (10/30) and 86.84% (66/76), respectively ( χ2, P < 0.05). The causes of hearing loss included jaundice (24.56%, 14/57), infection (24.56%, 14/57), asphyxia (19.30%, 11/57), low birth weight (17.54%, 10/57) and other factors (14.04%, 8/57). Conclusion Bilateral referrals were more likely to suffer greater degrees of hearing loss than unilateral referrals. Jaundice, infection, asphyxia and low birth weight were the major aetiologies of neonatal hearing loss.

Two rare cases of benign submucosal pharyngo-oesophageal mesenchymoma are presented in this paper. One patient was treated by tumour removal via a combined thoracic and laterocervical approach and the other by resection through a laterocervical approach. The paper discusses the pathology and diagnosis of benign mesenchymomas. The authors suggest that for large tumours located in the pharynx and extending down the oesophagus without adhesion to the oesophageal wall, the laterocervical approach can avoid complications associated with the thoracic approach. The new technique caused less tissue damage and provided a quicker recovery and shorter hospitalization.