According to the unattended loading requirements of the new generation launch vehicles,auto-docking technology for the first stage fill-drain connector and zero-second quick detachment technology for the second stage ...According to the unattended loading requirements of the new generation launch vehicles,auto-docking technology for the first stage fill-drain connector and zero-second quick detachment technology for the second stage fill-drain connector were proposed based on the analysis and summary of unattended loading connector technology at home and abroad.These technical solutions were verified to be reasonable and feasible by tests,and they had been successfully applied to the Long March 6 A(LM-6 A),laying a foundation for the unattended test and launch of the new generation launch vehicles.展开更多
The design of distributed ledger,Asymmetric Key Algorithm(AKA)blockchain systems,is prominent in administering security and access control in various real-time services and applications.The assimilation of blockchain ...The design of distributed ledger,Asymmetric Key Algorithm(AKA)blockchain systems,is prominent in administering security and access control in various real-time services and applications.The assimilation of blockchain systems leverages the reliable access and secure service provisioning of the services.However,the distributed ledger technology’s access control and chained decisions are defaced by pervasive and service unawareness.It results in degrading security through unattended access control for limited-service users.In this article,a service-aware access control procedure(SACP)is introduced to address the afore-mentioned issue.The proposed SACP denes attended access control for all the service session by identifying the users and service provider availability.The distributed nature of the ledger systems and classication tree learning are combined to determine unattended access.The sole access is determined by summarizing the closed and open access requests and the service provider’s availability and integrity checks.In this process,the learning process classies the secured access request and completed the integrity checks of the current and previous service dissemination.This classication-based access administration reduces the service disconnections and false access rate of the applications.展开更多
The prevalence and severity of obstructive sleep apnea(OSA) is higher in specific population: children, elderly,obese and patients with pulmonary and cardiovascular diseases, compared to the general population. OSA is...The prevalence and severity of obstructive sleep apnea(OSA) is higher in specific population: children, elderly,obese and patients with pulmonary and cardiovascular diseases, compared to the general population. OSA is associated with greater morbidity and mortality in these patients. Although full-night polysomnography is still the gold standard diagnostic sleep study for OSA, it is a time consuming, expensive and technically demanding exam. Over the last few years, there is growing evidence on the use of portable monitors(PM) as an alternative for the diagnosis of OSA. These devices were developed specially for sleep evaluation at home, at a familiar environment, with easy selfapplication of monitoring, unattended. The use of PM is stablished for populations with high pre-test probability of OSA. However, there is a lack of studies on the use of PM in age extremes and patients with comorbidities. The purpose of this review is to present the studies that evaluated the use of PM in specific population, as well as to describe the advantages, limitations and applications of these devices in this particular group of patients. Although the total loss rate of recordings is variable in different studies, the agreement with fullnight polysomnography justifies the use of PM in this population.展开更多
China’s first solid-liquid bundled launch vehicle,the Long March 6 A(LM-6 A)successfully adopted a number of key new technologies,launching the Pujiang 2 and Tiankun 2 satellites precisely into their predetermined or...China’s first solid-liquid bundled launch vehicle,the Long March 6 A(LM-6 A)successfully adopted a number of key new technologies,launching the Pujiang 2 and Tiankun 2 satellites precisely into their predetermined orbits,thus demonstrating that China has mastered solid-liquid bundled launch vehicle technology and has a new member in the new generation launch vehicle family.For the first time in China,a booster adopted a 2 m-diameter solid motor and a 270 V,20 k W high-voltage and high-power electric servo system was used to control the swing of the solid motor nozzles.A health diagnosis system for the core first stage engine and unattended automation technology were also adopted for the first time.展开更多
文摘According to the unattended loading requirements of the new generation launch vehicles,auto-docking technology for the first stage fill-drain connector and zero-second quick detachment technology for the second stage fill-drain connector were proposed based on the analysis and summary of unattended loading connector technology at home and abroad.These technical solutions were verified to be reasonable and feasible by tests,and they had been successfully applied to the Long March 6 A(LM-6 A),laying a foundation for the unattended test and launch of the new generation launch vehicles.
基金supported by the Deanship of Scientic Research(DSR),King Abdulaziz University,Jeddah,under Grant No.(DF-444-611-1441)。
文摘The design of distributed ledger,Asymmetric Key Algorithm(AKA)blockchain systems,is prominent in administering security and access control in various real-time services and applications.The assimilation of blockchain systems leverages the reliable access and secure service provisioning of the services.However,the distributed ledger technology’s access control and chained decisions are defaced by pervasive and service unawareness.It results in degrading security through unattended access control for limited-service users.In this article,a service-aware access control procedure(SACP)is introduced to address the afore-mentioned issue.The proposed SACP denes attended access control for all the service session by identifying the users and service provider availability.The distributed nature of the ledger systems and classication tree learning are combined to determine unattended access.The sole access is determined by summarizing the closed and open access requests and the service provider’s availability and integrity checks.In this process,the learning process classies the secured access request and completed the integrity checks of the current and previous service dissemination.This classication-based access administration reduces the service disconnections and false access rate of the applications.
文摘The prevalence and severity of obstructive sleep apnea(OSA) is higher in specific population: children, elderly,obese and patients with pulmonary and cardiovascular diseases, compared to the general population. OSA is associated with greater morbidity and mortality in these patients. Although full-night polysomnography is still the gold standard diagnostic sleep study for OSA, it is a time consuming, expensive and technically demanding exam. Over the last few years, there is growing evidence on the use of portable monitors(PM) as an alternative for the diagnosis of OSA. These devices were developed specially for sleep evaluation at home, at a familiar environment, with easy selfapplication of monitoring, unattended. The use of PM is stablished for populations with high pre-test probability of OSA. However, there is a lack of studies on the use of PM in age extremes and patients with comorbidities. The purpose of this review is to present the studies that evaluated the use of PM in specific population, as well as to describe the advantages, limitations and applications of these devices in this particular group of patients. Although the total loss rate of recordings is variable in different studies, the agreement with fullnight polysomnography justifies the use of PM in this population.
文摘China’s first solid-liquid bundled launch vehicle,the Long March 6 A(LM-6 A)successfully adopted a number of key new technologies,launching the Pujiang 2 and Tiankun 2 satellites precisely into their predetermined orbits,thus demonstrating that China has mastered solid-liquid bundled launch vehicle technology and has a new member in the new generation launch vehicle family.For the first time in China,a booster adopted a 2 m-diameter solid motor and a 270 V,20 k W high-voltage and high-power electric servo system was used to control the swing of the solid motor nozzles.A health diagnosis system for the core first stage engine and unattended automation technology were also adopted for the first time.
