In this paper, the ADS-B (automatic dependent surveillance-broadcast) used for manned aircrafts is chosen for aSee-and-Avoid sensor of UAV (unmanned aerial vehicle), then GDL90 type is selected among three type...In this paper, the ADS-B (automatic dependent surveillance-broadcast) used for manned aircrafts is chosen for aSee-and-Avoid sensor of UAV (unmanned aerial vehicle), then GDL90 type is selected among three types of ADS-B. The serialcommunication data protocol which communicates between GDL90 and control panel of GDL90 is analyzed and tailored for theinterface of the GDL90 simulator here. This ADS-B (GDL90) simulator sends intruder information to FCC (flight control computer)of UAV for collision avoidance function.展开更多
Objective:The Consolidated Standards for Reporting of Trials(CONSORT) statement has already proved to be an efficient standard for reporting quality of randomized controlled trials(RCTs).However,most of the Chinese me...Objective:The Consolidated Standards for Reporting of Trials(CONSORT) statement has already proved to be an efficient standard for reporting quality of randomized controlled trials(RCTs).However,most of the Chinese medical journals have not endorsed the CONSORT statement.The current situation about the reporting quality of RCTs in Chinese medical journals is still unclear.The purpose of the study was to evaluate the reporting quality of RCTs on papers published in 5 leading Chinese medical journals.Methods:We evaluated 232 original RCT papers using a reporting quality scale based on CONSORT statement from 2001 to 2006 in 5 Chinese medical journals(Journal type 1) without adoption of CONSORT and Chinese Journal of Evidence-based Medicine(Journal type 2) which adopted CONSORT in 2004.We measured the inclusion of 26 items for the reporting quality scale and 6 core items of each RCT report,gave score to each item and calculated the total score obtained in each report and the proportion of reports including individual items.The reporting quality of RCT trials from 2001 to 2003(pre-adoption period) was compared with that from 2004 to 2006(post-adoption period).Results:The average reporting quality of RCTs was moderate(mean score,15.18),and the mean score of the 6 core items was low(mean score,1.09) in 5 leading journals.The difference in the total score and the score of the 6 core items between pre-adoption period(2001-2003) and post-adoption period(2004-2006) was statistically significant(P=0.003;P=0.000).Interaction between journal type and period was not significant(F=0.76;P=0.383).We concluded that the change tendency of reporting quality between Journal type 1 and 2 was not different.But as to the core items of sequence concealment and intention-to-treat analysis,the increases were greater for Journal type 2 when evaluated against Journal type 1(P=0.038;P=0.016).Conclusion:The reporting quality of RCT trials in 5 leading Chinese medical journals is improving.However,the lack of important items in RCT trials remains a serious problem.We recommend the endorsement of the Consolidated Standards for Reporting of Trials statement in Chinese medical journals and the continuing education on evidence-based medicine in China.展开更多
This paper presents a detailed investigation, via field experiment, into the mechanism of high-order polygonal wear of wheels of a new type of high-speed train. The investigation was carried out during the performance...This paper presents a detailed investigation, via field experiment, into the mechanism of high-order polygonal wear of wheels of a new type of high-speed train. The investigation was carried out during the performance acceptance test of the train and its initial commercial operation. The investigation covered the performance acceptance test of 150 000 km and the commercial operation of about 150 000 km. In the performance acceptance test of the first stage of about 70 000 km, at 200-250 km/h with full loading and sometimes overloading by 30%, the serious polygonal wear of 23-order took place on all the wheels of the train, and was measured and analyzed in detail. All the potygonized wheels were re-profiled because the polygonal wear had caused strong vibration and damage to the train parts. After re-profiling, the vibration of the train and track and the wear status of the wheels were measured and analyzed at different test mileages according to the polygonal wear situation of the wheels. The measured vibration of the train includes the accelerations at different positions of a motor car and a trail car. The vibration modes of the key parts of the bogies of the two cars were calculated. Meanwhile, the track resonant frequencies were investigated at the site. The purpose of the above tests and analysis is try to find the frequency of work mode matching the passing frequency of the high-order wheel polygon. The present investigation shows that one of the working models causes the formation and development of the high-order wheel polygonal wear. The growth of this wear was effectively reduced through the frequent changing of the running speed of the train operating on the way back and forth every day.展开更多
文摘In this paper, the ADS-B (automatic dependent surveillance-broadcast) used for manned aircrafts is chosen for aSee-and-Avoid sensor of UAV (unmanned aerial vehicle), then GDL90 type is selected among three types of ADS-B. The serialcommunication data protocol which communicates between GDL90 and control panel of GDL90 is analyzed and tailored for theinterface of the GDL90 simulator here. This ADS-B (GDL90) simulator sends intruder information to FCC (flight control computer)of UAV for collision avoidance function.
文摘Objective:The Consolidated Standards for Reporting of Trials(CONSORT) statement has already proved to be an efficient standard for reporting quality of randomized controlled trials(RCTs).However,most of the Chinese medical journals have not endorsed the CONSORT statement.The current situation about the reporting quality of RCTs in Chinese medical journals is still unclear.The purpose of the study was to evaluate the reporting quality of RCTs on papers published in 5 leading Chinese medical journals.Methods:We evaluated 232 original RCT papers using a reporting quality scale based on CONSORT statement from 2001 to 2006 in 5 Chinese medical journals(Journal type 1) without adoption of CONSORT and Chinese Journal of Evidence-based Medicine(Journal type 2) which adopted CONSORT in 2004.We measured the inclusion of 26 items for the reporting quality scale and 6 core items of each RCT report,gave score to each item and calculated the total score obtained in each report and the proportion of reports including individual items.The reporting quality of RCT trials from 2001 to 2003(pre-adoption period) was compared with that from 2004 to 2006(post-adoption period).Results:The average reporting quality of RCTs was moderate(mean score,15.18),and the mean score of the 6 core items was low(mean score,1.09) in 5 leading journals.The difference in the total score and the score of the 6 core items between pre-adoption period(2001-2003) and post-adoption period(2004-2006) was statistically significant(P=0.003;P=0.000).Interaction between journal type and period was not significant(F=0.76;P=0.383).We concluded that the change tendency of reporting quality between Journal type 1 and 2 was not different.But as to the core items of sequence concealment and intention-to-treat analysis,the increases were greater for Journal type 2 when evaluated against Journal type 1(P=0.038;P=0.016).Conclusion:The reporting quality of RCT trials in 5 leading Chinese medical journals is improving.However,the lack of important items in RCT trials remains a serious problem.We recommend the endorsement of the Consolidated Standards for Reporting of Trials statement in Chinese medical journals and the continuing education on evidence-based medicine in China.
基金Project supported by the National Natural Science Foundation of China (No. U 1134202)
文摘This paper presents a detailed investigation, via field experiment, into the mechanism of high-order polygonal wear of wheels of a new type of high-speed train. The investigation was carried out during the performance acceptance test of the train and its initial commercial operation. The investigation covered the performance acceptance test of 150 000 km and the commercial operation of about 150 000 km. In the performance acceptance test of the first stage of about 70 000 km, at 200-250 km/h with full loading and sometimes overloading by 30%, the serious polygonal wear of 23-order took place on all the wheels of the train, and was measured and analyzed in detail. All the potygonized wheels were re-profiled because the polygonal wear had caused strong vibration and damage to the train parts. After re-profiling, the vibration of the train and track and the wear status of the wheels were measured and analyzed at different test mileages according to the polygonal wear situation of the wheels. The measured vibration of the train includes the accelerations at different positions of a motor car and a trail car. The vibration modes of the key parts of the bogies of the two cars were calculated. Meanwhile, the track resonant frequencies were investigated at the site. The purpose of the above tests and analysis is try to find the frequency of work mode matching the passing frequency of the high-order wheel polygon. The present investigation shows that one of the working models causes the formation and development of the high-order wheel polygonal wear. The growth of this wear was effectively reduced through the frequent changing of the running speed of the train operating on the way back and forth every day.