The Hong Kong Observatory (HKO) provides low-level turbulence alerting service for the Hong Kong International Airport (HKIA) through the windshear and turbulence warning system (WTWS). In the WTWS, turbulence intensi...The Hong Kong Observatory (HKO) provides low-level turbulence alerting service for the Hong Kong International Airport (HKIA) through the windshear and turbulence warning system (WTWS). In the WTWS, turbulence intensities along the flight paths of the airport are estimated based upon correlation equations established between the surface anemometer data and the turbulence data from research aircraft before the opening of the airport. The research aircraft data are not available on day-to-day basis. The remote sensing meteorological instruments, such as the Doppler light detection and ranging (LIDAR) and radar, may be used to provide direct measurements of turbulence intensities over the runway corridors. The performances of LIDAR- and radar-based turbulence intensity data are studied in this paper based on actual turbulence intensity measurements made on 423 commercial jets for a typical case of terrain-induced turbulence in association with a typhoon. It turns out that, with the tuning of the relative operating characteristic (ROC) curve between hit rate and false alarm rate, the LIDAR-based turbulence intensity measurement performs better than the anemometer-based estimation of WTWS for turbulence intensity at moderate level or above. On the other hand, the radar-based measurement does not perform as well when compared with WTWS. By combining LIDAR- and radar-based measurements, the performance is slightly better than WTWS, mainly as a result of contribution from LIDAR-based measurement. As a result, the LIDAR-based turbulence intensity measurement could be used to replace anemometer-based estimate for non-rainy weather conditions. Further enhancements of radar-based turbulence intensity measurement in rain would be necessary.展开更多
迪特·拉姆斯被誉为德国工业设计之父,当代“简约主义风格”的代表人物,20世纪最有影响力的设计师之一。他提出了“less but better”的设计思想,对于每一位热爱工业设计的学者而言,都产生了深刻影响。他的“设计十诫”成为一代又...迪特·拉姆斯被誉为德国工业设计之父,当代“简约主义风格”的代表人物,20世纪最有影响力的设计师之一。他提出了“less but better”的设计思想,对于每一位热爱工业设计的学者而言,都产生了深刻影响。他的“设计十诫”成为一代又一代工业设计师的行为准则。本文将走进迪特·拉姆斯的世界,介绍迪特·拉姆斯的生平、设计思想以及设计影响等。展开更多
This paper presents a fault-tolerant computer system. It is designed as a double 2-out-of-2 architecture based on component redundant technique. Also, a quantitative probabilistic model is presented for evaluating the...This paper presents a fault-tolerant computer system. It is designed as a double 2-out-of-2 architecture based on component redundant technique. Also, a quantitative probabilistic model is presented for evaluating the reliability, availability, maintainability and safety (RAMS) of this architecture. Hierarchical modeling method and Markov modeling method are used in RAMS analysis to evaluate the system characteristics. The double 2-out-of-2 system is compared with the other two systems, all voting triple modular redundancy (AVTMR) system and dual-duplex system. According to the result, the double 2-out-of-2 system has the highest dependability. Especially, the system can satisfy the safety integrity level (SIL) 4, which means the system’s probability of catastrophic failure less than or equal to 10-8 per hour, therefore, it can be applied to life critical systems such as high-speed railway systems.展开更多
Robot-assisted microsurgery(RAMS)has many benefits compared to traditional microsurgery.Microsurgical platforms with advanced control strategies,high-quality micro-imaging modalities and micro-sensing systems are wort...Robot-assisted microsurgery(RAMS)has many benefits compared to traditional microsurgery.Microsurgical platforms with advanced control strategies,high-quality micro-imaging modalities and micro-sensing systems are worth developing to further enhance the clinical outcomes of RAMS.Within only a few decades,microsurgical robotics has evolved into a rapidly developing research field with increasing attention all over the world.Despite the appreciated benefits,significant challenges remain to be solved.In this review paper,the emerging concepts and achievements of RAMS will be presented.We introduce the development tendency of RAMS from teleoperation to autonomous systems.We highlight the upcoming new research opportunities that require joint efforts from both clinicians and engineers to pursue further outcomes for RAMS in years to come.展开更多
文摘The Hong Kong Observatory (HKO) provides low-level turbulence alerting service for the Hong Kong International Airport (HKIA) through the windshear and turbulence warning system (WTWS). In the WTWS, turbulence intensities along the flight paths of the airport are estimated based upon correlation equations established between the surface anemometer data and the turbulence data from research aircraft before the opening of the airport. The research aircraft data are not available on day-to-day basis. The remote sensing meteorological instruments, such as the Doppler light detection and ranging (LIDAR) and radar, may be used to provide direct measurements of turbulence intensities over the runway corridors. The performances of LIDAR- and radar-based turbulence intensity data are studied in this paper based on actual turbulence intensity measurements made on 423 commercial jets for a typical case of terrain-induced turbulence in association with a typhoon. It turns out that, with the tuning of the relative operating characteristic (ROC) curve between hit rate and false alarm rate, the LIDAR-based turbulence intensity measurement performs better than the anemometer-based estimation of WTWS for turbulence intensity at moderate level or above. On the other hand, the radar-based measurement does not perform as well when compared with WTWS. By combining LIDAR- and radar-based measurements, the performance is slightly better than WTWS, mainly as a result of contribution from LIDAR-based measurement. As a result, the LIDAR-based turbulence intensity measurement could be used to replace anemometer-based estimate for non-rainy weather conditions. Further enhancements of radar-based turbulence intensity measurement in rain would be necessary.
文摘迪特·拉姆斯被誉为德国工业设计之父,当代“简约主义风格”的代表人物,20世纪最有影响力的设计师之一。他提出了“less but better”的设计思想,对于每一位热爱工业设计的学者而言,都产生了深刻影响。他的“设计十诫”成为一代又一代工业设计师的行为准则。本文将走进迪特·拉姆斯的世界,介绍迪特·拉姆斯的生平、设计思想以及设计影响等。
文摘This paper presents a fault-tolerant computer system. It is designed as a double 2-out-of-2 architecture based on component redundant technique. Also, a quantitative probabilistic model is presented for evaluating the reliability, availability, maintainability and safety (RAMS) of this architecture. Hierarchical modeling method and Markov modeling method are used in RAMS analysis to evaluate the system characteristics. The double 2-out-of-2 system is compared with the other two systems, all voting triple modular redundancy (AVTMR) system and dual-duplex system. According to the result, the double 2-out-of-2 system has the highest dependability. Especially, the system can satisfy the safety integrity level (SIL) 4, which means the system’s probability of catastrophic failure less than or equal to 10-8 per hour, therefore, it can be applied to life critical systems such as high-speed railway systems.
基金supported by Royal Society Research,UK (No.RGSR1221122)
文摘Robot-assisted microsurgery(RAMS)has many benefits compared to traditional microsurgery.Microsurgical platforms with advanced control strategies,high-quality micro-imaging modalities and micro-sensing systems are worth developing to further enhance the clinical outcomes of RAMS.Within only a few decades,microsurgical robotics has evolved into a rapidly developing research field with increasing attention all over the world.Despite the appreciated benefits,significant challenges remain to be solved.In this review paper,the emerging concepts and achievements of RAMS will be presented.We introduce the development tendency of RAMS from teleoperation to autonomous systems.We highlight the upcoming new research opportunities that require joint efforts from both clinicians and engineers to pursue further outcomes for RAMS in years to come.
