Background Septal Surfing Technology （SST） is one of the most important techniques for collateral channels （CCs） crossing in retrograde chronic total occlusion （CTO） of percutaneous coronary intervention （PCI）...Background Septal Surfing Technology （SST） is one of the most important techniques for collateral channels （CCs） crossing in retrograde chronic total occlusion （CTO） of percutaneous coronary intervention （PCI）. We ex- amined this technique＇ s usefulness in retrograde CTO-PCI cases. Methods We retrospective analyzed 728 con-secutive CTO-PCI cases from January 2014 to September 2016. One hundred and forty-two patients who had un- dergone retrograde PCIs using septal collateral channels （CCs） were collected. Univariate and multivariate analyses were conducted to identify independent predictors for SST CCs crossing success. Results The CCs crossing success rate was 89.4% during retrograde PCI. Three factors were figured out as independent predictors, includ- ing CCs tortuosity （OR 0.164, 95%CI： 0.041-0.657; P=0.011）, diameter of distal CTO lesion （2.035, 95%CI： 1.011-4.099; P=0.047） and LAD-CTO （OR 0.244, 95%CI：0.067-0.894; P=0.033）. There were complications of CCs injury in 23.2% cases and 2.1% cases had cardiac tamponade without any in-hospital death. Conclusion SST is an effective method in collateral crossing during retrograde CTO-PCI. It has high successful rate regard-less of the Werner Collateral Class of interventional collaterals, especially in invisible collaterals. This technolo- gy is feasible in daily practice of retrograde PCI.展开更多
AIM To analyze all windsurfing and kitesurfing(kiteboarding) injuries presented at our coastal hospital over a 2-year period. METHODS Twenty-five windsurfers(21 male; aged 31 ± 8 years) and 32 kitesurfers(23 male...AIM To analyze all windsurfing and kitesurfing(kiteboarding) injuries presented at our coastal hospital over a 2-year period. METHODS Twenty-five windsurfers(21 male; aged 31 ± 8 years) and 32 kitesurfers(23 male; aged 29 ± 11 years) presented at our hospital during the 2-year study period. Various injury data were recorded,including transport to hospital and treatment. After a median follow-up of 16 mo(range,7-33 mo),18 windsurfers(72%) and 26 kitesurfers(81%) completed questionnaires on the trauma mechanisms,the use of protective gear,time spent on windsurfing or kitesurfing,time to return to sports,additional injuries,and chronic disability. RESULTS Most patients sustained minor injuries but severe injuries also occurred,including vertebral and tibial plateau fractures. The lower extremities were affected the most,followed by the head and cervical spine,the upperextremities,and the trunk. The injury rates were 5.2 per 1000 h of windsurfing and 7.0 per 1000 h of kitesurfing(P = 0.005). The injury severity was the same between groups(P = 1.0). Less than 30% of the study population used protective gear. Kitesurfers had a higher number of injuries,and required transport by ambulance,inpatient hospital stay and operative treatment more often than windsurfers,but these differences were not statistically significant(P > 0.05). The median time to return to windsurfing and kitesurfing was 5 and 4 wk,respectively(P = 0.79). Approximately one-third of the patients in each group experienced chronic symptoms.CONCLUSION Kitesurfing results in a significantly higher injury rate than windsurfing in the same environmental conditions but the severity of the injuries does not differ.展开更多
Measuring mobile calls data is an increasingly import issue,which will benefit to the understanding of the behavior of mobile users and assist telecom operators to optimize their business strategies.The existing resea...Measuring mobile calls data is an increasingly import issue,which will benefit to the understanding of the behavior of mobile users and assist telecom operators to optimize their business strategies.The existing researches on cell phone data measurement only focus on mobile calls or on mobile-internet surfing and little researches focus on the interactions of behaviors between them.In this paper,some basic factors of the association between mobile calls and mobile-internet surfing are measured.Then first their distributions are compared and the preference of users is quantified.After that experiments on the curve fitting of both the whole and parts of these distributions are done.Through the comparison of the correlation coefficients and Fourier fitting parameters,different behaviors is found between workdays and weekends,as well as Saturdays and Sundays in mobile-call distributions.Besides,the results of our observation show that the mobile-internet traffic does not always monotone increase with the increase of online time,significant changes are observed after 8hours of mobile-internet surfing.展开更多
As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, ...As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, many scholars have tried different techniques. Unfortunately, there is a lack of research on Redis’s transaction in the existing literatures. This paper proposes a transaction model for key-value NoSQL databases including Redis to make possible allowing users to access data in the ACID (Atomicity, Consistency, Isolation and Durability) way, and this model is vividly called the surfing concurrence transaction model. The architecture, important features and implementation principle are described in detail. The key algorithms also were given in the form of pseudo program code, and the performance also was evaluated. With the proposed model, the transactions of Key-Value NoSQL databases can be performed in a lock free and MVCC (Multi-Version Concurrency Control) free manner. This is the result of further research on the related topic, which fills the gap ignored by relevant scholars in this field to make a little contribution to the further development of NoSQL technology.展开更多
Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People’s Republic of China has logged more than 2 billion hits, from many coun...Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People’s Republic of China has logged more than 2 billion hits, from many countries and regions including China, the United States, the United Kingdom, Japan, Australia and Singapore. China National Defense News reporters recently interviewed Ji Guilin, the website’s Editor in Chief, on its performance and the feedback of netizens.展开更多
The present study aims to investigate the impact of texting and web surfing on the driving behavior and safety of young drivers on rural roads.For this purpose,driving data were gathered through a driving simulator ex...The present study aims to investigate the impact of texting and web surfing on the driving behavior and safety of young drivers on rural roads.For this purpose,driving data were gathered through a driving simulator experiment with 37 young drivers.Additionally,a survey was conducted to collect their demographic characteristics and driving behavior preferences.During the experiment,the drivers were distracted using contemporary smartphone internet applications i.e.,Facebook Messenger,Facebook and Google Maps.Regression analysis models were developed in order to identify and investigate the effect of distraction on accident probability,speed deviation,headway distance,as well as lateral distance deviation.Additionally,random forest(RF),a machine learning classification algorithm,was deployed for real-time distraction prediction.It was revealed that distraction due to web surfing and texting leads to a statistically significant increase in accident probability,headway distance and lateral distance deviation by 32%,27%and 6%,respectively.Moreover,the driving speed deviation was reduced by 47%during distraction.Apart from the real-time prediction,the RF revealed that headway distance,lateral distance,and traffic volume were important features.The RF outcomes revealed consistency with regression analysis and drivers during the distractive task are more defensive by driving at the edge of the road near the hard shoulder and maintaining longer headways.Overall,driving behavior and safety among young drivers were both significantly affected by the investigated internet applications.展开更多
针对目前视频拼接技术中的主要问题,即SURF(Speed Up Robust Features)特征提取算法与FLANN(Fast Library or Approximate Nearest Neighbors)特征匹配算法在综采工作面恶劣环境中存在特征点误提取和特征点匹配正确率低的问题,提出一种...针对目前视频拼接技术中的主要问题,即SURF(Speed Up Robust Features)特征提取算法与FLANN(Fast Library or Approximate Nearest Neighbors)特征匹配算法在综采工作面恶劣环境中存在特征点误提取和特征点匹配正确率低的问题,提出一种改进SURF-FLANN的综采工作面视频拼接特征提取与匹配算法。为了提高特征点提取正确率,该方法通过将传统的高斯滤波换为更为先进的双边滤波提取图像中的SURF关键特征点,同时在特征向量中引入特征点4-领域内的特征点描述符信息,从而改进了描述符算子,进一步提高了特征点的描述能力。为了提升特征点匹配速度,提出了R-FLANN(Random Sample Consensus-Fast Library or Approximate Nearest Neighbors)特征匹配算法,该算法利用RANSAC算法获取特征点的匹配先验信息剔除无匹配、误匹配的特征点,从而提高特征点匹配速度。为了验证改进效果,通过消融试验验证了改进SURF-FLANN的特征提取与匹配算法有效提升综采工作面视频图像特征提取和匹配正确率。通过本文方法与SIFT+FLANN,Hairrs与SURF+FLANN的特征提取与匹配算法进行特征点提取与匹配的对比试验,结果表明本文方法特征提取与匹配平均正确率和平均匹配速度最高,分别达到了81.47%和51.47帧/s。通过运用本文方法与SIFT+FLANN,Hairrs与SURF+FLANN的特征提取与匹配算法进行视频图像拼接对比试验,结果表明本文提出的方法在拼接效果清晰度、对比度、熵、拼接速率指标都最好,得到了最佳效果。展开更多
为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上...为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上得到模型筛选阈值,并运用随机抽样一致(RANSAC)算法进一步提纯匹配。通过实验分析比较,与传统算法相比,改进后算法正确率较高,具有较强鲁棒性。展开更多
文摘Background Septal Surfing Technology （SST） is one of the most important techniques for collateral channels （CCs） crossing in retrograde chronic total occlusion （CTO） of percutaneous coronary intervention （PCI）. We ex- amined this technique＇ s usefulness in retrograde CTO-PCI cases. Methods We retrospective analyzed 728 con-secutive CTO-PCI cases from January 2014 to September 2016. One hundred and forty-two patients who had un- dergone retrograde PCIs using septal collateral channels （CCs） were collected. Univariate and multivariate analyses were conducted to identify independent predictors for SST CCs crossing success. Results The CCs crossing success rate was 89.4% during retrograde PCI. Three factors were figured out as independent predictors, includ- ing CCs tortuosity （OR 0.164, 95%CI： 0.041-0.657; P=0.011）, diameter of distal CTO lesion （2.035, 95%CI： 1.011-4.099; P=0.047） and LAD-CTO （OR 0.244, 95%CI：0.067-0.894; P=0.033）. There were complications of CCs injury in 23.2% cases and 2.1% cases had cardiac tamponade without any in-hospital death. Conclusion SST is an effective method in collateral crossing during retrograde CTO-PCI. It has high successful rate regard-less of the Werner Collateral Class of interventional collaterals, especially in invisible collaterals. This technolo- gy is feasible in daily practice of retrograde PCI.
文摘AIM To analyze all windsurfing and kitesurfing(kiteboarding) injuries presented at our coastal hospital over a 2-year period. METHODS Twenty-five windsurfers(21 male; aged 31 ± 8 years) and 32 kitesurfers(23 male; aged 29 ± 11 years) presented at our hospital during the 2-year study period. Various injury data were recorded,including transport to hospital and treatment. After a median follow-up of 16 mo(range,7-33 mo),18 windsurfers(72%) and 26 kitesurfers(81%) completed questionnaires on the trauma mechanisms,the use of protective gear,time spent on windsurfing or kitesurfing,time to return to sports,additional injuries,and chronic disability. RESULTS Most patients sustained minor injuries but severe injuries also occurred,including vertebral and tibial plateau fractures. The lower extremities were affected the most,followed by the head and cervical spine,the upperextremities,and the trunk. The injury rates were 5.2 per 1000 h of windsurfing and 7.0 per 1000 h of kitesurfing(P = 0.005). The injury severity was the same between groups(P = 1.0). Less than 30% of the study population used protective gear. Kitesurfers had a higher number of injuries,and required transport by ambulance,inpatient hospital stay and operative treatment more often than windsurfers,but these differences were not statistically significant(P > 0.05). The median time to return to windsurfing and kitesurfing was 5 and 4 wk,respectively(P = 0.79). Approximately one-third of the patients in each group experienced chronic symptoms.CONCLUSION Kitesurfing results in a significantly higher injury rate than windsurfing in the same environmental conditions but the severity of the injuries does not differ.
基金Supported by the National High Technology Research and Development Programme of China(No.2011AA010706)the National Natural Science Foundation of China(No.61170041)
文摘Measuring mobile calls data is an increasingly import issue,which will benefit to the understanding of the behavior of mobile users and assist telecom operators to optimize their business strategies.The existing researches on cell phone data measurement only focus on mobile calls or on mobile-internet surfing and little researches focus on the interactions of behaviors between them.In this paper,some basic factors of the association between mobile calls and mobile-internet surfing are measured.Then first their distributions are compared and the preference of users is quantified.After that experiments on the curve fitting of both the whole and parts of these distributions are done.Through the comparison of the correlation coefficients and Fourier fitting parameters,different behaviors is found between workdays and weekends,as well as Saturdays and Sundays in mobile-call distributions.Besides,the results of our observation show that the mobile-internet traffic does not always monotone increase with the increase of online time,significant changes are observed after 8hours of mobile-internet surfing.
文摘As more and more application systems related to big data were developed, NoSQL (Not Only SQL) database systems are becoming more and more popular. In order to add transaction features for some NoSQL database systems, many scholars have tried different techniques. Unfortunately, there is a lack of research on Redis’s transaction in the existing literatures. This paper proposes a transaction model for key-value NoSQL databases including Redis to make possible allowing users to access data in the ACID (Atomicity, Consistency, Isolation and Durability) way, and this model is vividly called the surfing concurrence transaction model. The architecture, important features and implementation principle are described in detail. The key algorithms also were given in the form of pseudo program code, and the performance also was evaluated. With the proposed model, the transactions of Key-Value NoSQL databases can be performed in a lock free and MVCC (Multi-Version Concurrency Control) free manner. This is the result of further research on the related topic, which fills the gap ignored by relevant scholars in this field to make a little contribution to the further development of NoSQL technology.
文摘Following the start of its first test run on August 20, 2009, the website www.mod.gov.cn of the Ministry of National Defense (MOD) of the People’s Republic of China has logged more than 2 billion hits, from many countries and regions including China, the United States, the United Kingdom, Japan, Australia and Singapore. China National Defense News reporters recently interviewed Ji Guilin, the website’s Editor in Chief, on its performance and the feedback of netizens.
文摘The present study aims to investigate the impact of texting and web surfing on the driving behavior and safety of young drivers on rural roads.For this purpose,driving data were gathered through a driving simulator experiment with 37 young drivers.Additionally,a survey was conducted to collect their demographic characteristics and driving behavior preferences.During the experiment,the drivers were distracted using contemporary smartphone internet applications i.e.,Facebook Messenger,Facebook and Google Maps.Regression analysis models were developed in order to identify and investigate the effect of distraction on accident probability,speed deviation,headway distance,as well as lateral distance deviation.Additionally,random forest(RF),a machine learning classification algorithm,was deployed for real-time distraction prediction.It was revealed that distraction due to web surfing and texting leads to a statistically significant increase in accident probability,headway distance and lateral distance deviation by 32%,27%and 6%,respectively.Moreover,the driving speed deviation was reduced by 47%during distraction.Apart from the real-time prediction,the RF revealed that headway distance,lateral distance,and traffic volume were important features.The RF outcomes revealed consistency with regression analysis and drivers during the distractive task are more defensive by driving at the edge of the road near the hard shoulder and maintaining longer headways.Overall,driving behavior and safety among young drivers were both significantly affected by the investigated internet applications.
文摘为改善传统算法对量块特征匹配计算大、精度不足的问题,提出一种基于SURF(speed up robust feature)改进的算法。该算法对采集到的图像预处理得到有效匹配区域,筛除无关特征点的干扰;判断矩阵的迹进一步剔除无效点;在欧式距离的基础上得到模型筛选阈值,并运用随机抽样一致(RANSAC)算法进一步提纯匹配。通过实验分析比较,与传统算法相比,改进后算法正确率较高,具有较强鲁棒性。
