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Distracted walking:Examining the extent to pedestrian safety problems 被引量:3
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作者 Judith Mwakalonge Saidi Siuhi Jamario White 《Journal of Traffic and Transportation Engineering(English Edition)》 2015年第5期327-337,共11页
Pedestrians, much like drivers, have always been engaged in multi-tasking like using handheld devices, listening to music, snacking, or reading while walking. The effects are similar to those experienced by distracted... Pedestrians, much like drivers, have always been engaged in multi-tasking like using handheld devices, listening to music, snacking, or reading while walking. The effects are similar to those experienced by distracted drivers. However, distracted walking has not received similar policies and effective interventions as distracted driving to improve pedestrian safety. This study reviewed the state-of-practice on policies, campaigns, available data, identified research needs, and opportunities pertaining to distracted walking. A comprehensive review of literature revealed that some of the agencies/organizations disseminate useful information about certain distracting activities that pedestrians should avoid while walking to improve their safety. Various walking safety rules/tips have been given, such as not wearing headphones or talking on a cell phone while crossing a street, keeping the volume down, hanging up the phone while walking, being aware of traffic, and avoiding distractions like walking with texting. The majority of the past observational-based and experimental-based studies reviewed in this study on distracted walking is in agreement that there is a positive correlation between distraction and unsafe walking behavior. However, limitations of the existing crash data suggest that distracted walking may not be a severe threat to the public health. Current pedestrian crash data provide insufficient information for researchers to examine the extent to which distracted walking causes and/ or contributes to actual pedestrian safety problems. 展开更多
关键词 distracted walkingPedestrian distractionsPublic awareness campaignsWalking safety rules/tipsPedestrian fatalitiesTraffic fatalities
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Analysis of HAZMAT truck driver fatigue and distracted driving with warning-based data and association rules mining
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作者 Ming Sun Ronggui Zhou Chengwu Jiao 《Journal of Traffic and Transportation Engineering(English Edition)》 EI CSCD 2023年第1期132-142,共11页
Professional drivers are more frequently exposed to longer driving distance and travel time,leading to a higher possibility of safety risk for distraction and fatigue.The widespread and common use of commercial driver... Professional drivers are more frequently exposed to longer driving distance and travel time,leading to a higher possibility of safety risk for distraction and fatigue.The widespread and common use of commercial driver monitoring systems(DMS)provides a potential for data collection.It increases the amount of data characterizing driver behavior that can be used for further safety research.This study utilized DMS warning-based data and applied an association rule mining approach to explore risk factors contributing to hazardous materials(HAZMAT)truck driver inattention.A total of 499 HAZMAT truck driver inattentive warning events were used to find rules that will predict the occurrence of driver’s fatigue and distraction.First,Fisher’s exact tests were performed to examine the association between the frequency of driver inattentive behavior warnings and risk factors.Second,support,confidence,and lift values were used as measurements to quantify the relative strength of the association rules generated by the Apriori algorithm.Results show that speed between 40and 49 km/h,relatively longer travel time(3-6 h),freeway,tangent section,off-peak hour and clear weather condition are found to be highly associated with fatigue driving,while nighttime during 18:00 to 23:59,speed between 70 and 80 km/h,travel time between 1 and 3 h,freeways,acceleration less than 0.5 m/s^(2),visibility greater than 1000 m,and tangent roadway section are found to be highly associated with distracted driving.By focusing on the specific feature groups,these association rules would help in the development of mitigating distraction and fatigue driving countermeasures and enforcement approaches. 展开更多
关键词 Traffic safety DMS warning-based data Association rule mining HAZMAT truck driver distracted driving Fatigue driving
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Opportunities and challenges of smart mobile applications in transportation
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作者 Saidi Siuhi Judith Mwakalonge 《Journal of Traffic and Transportation Engineering(English Edition)》 2016年第6期582-592,共11页
Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become o... Smart mobile applications are software applications that are designed to run on smart phones, tablets, and other mobile electronic devices. In this era of rapid technological advances, these applications have become one of the primary tools we use daily both in our personal and professional lives. The applications play key roles in facilitating many applications that are pivotal in our today's society including communication, education, business, entertainment, medical, finance, travel, utilities, social, and transportation. This paper reviewed the opportunities and challenges of the applications related to transportation. The opportunities revealed include route planning, ridesharing/carpooling, traffic safety, parking information, transportation data collection, fuel emissions and consumption, and travel information. The potential users of these applications in the field of transportation include (I) transportation agencies for travel data collection, travel information, ridesharing/carpooling, and traffic safety, (2) engineering students for field data collection such as travel speed, travel time, and vehicle count, and (3) general traveling public for route planning, ridesharing/carpooling, parking, traffic safety, and travel information. Significant usage of smart mobile applications can be potentially very beneficial, particularly in automobile travel mode to reduce travel time, cost, and vehicle emissions. In the end this would make travel safer and living environments greener and healthier. However, road users' interactions with these applications could manually, visually, and cognitively divert their attention from the primary task of driving or walking. Distracted road users expose themselves and others to unsafe behavior than undistracted. Road safety education and awareness programs are vital to discourage the use of applications that stimulate unsafe driving/walking behaviors. Educating the traveling public about the dangers of unsafe driving/walking behavior could have significant 展开更多
关键词 Smart mobile applications distracted driving distracted walking Transportation safety Travel information
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Investigating the trip configured causal effect of distracted driving on aggressive driving behavior for e-hailing taxi drivers 被引量:3
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作者 Muhammad Sajjad Ansar Yongfeng Ma +2 位作者 Shuyan Chen Kun Tang Ziyu Zhang 《Journal of Traffic and Transportation Engineering(English Edition)》 CSCD 2021年第5期725-734,共10页
Risky driving behavior of taxi drivers typically evaluated for full operation or sometimes sorted into occupied and empty running trips.In this paper,we simultaneously analyze aggressive driving and distracted driving... Risky driving behavior of taxi drivers typically evaluated for full operation or sometimes sorted into occupied and empty running trips.In this paper,we simultaneously analyze aggressive driving and distracted driving of taxi drivers under three different trip categories.Trip origin is considered a transition from without ride-order to with ride-order travelling or from with ride-order to occupied travelling,and a destination as a transition from occupied to without ride-order travelling and vice versa.Distracted driving is characterized by driver interference,driver mobile use and some entertainment aspects,while specific harmful and risky actions are considered for aggressive driving.High-resolution and real-time kinematic parameters of taxis were recorded by the in-vehicle recorder VBOX for overall 562 trips.The distracted driving parameters and aggressive driving actions were monitored through python data collector web application that was specially programmed for this particular research.Besides dual dash cam(i.e.,front and inside car camera),drivers’ whole day driving history from their Chinese ride-hailing Di Di smart application was used to differentiate occupied trips,unoccupied trips with ride-order and unoccupied trips without ride-order.Structural equation modeling(SEM) is practiced in this paper to understand the influence of distracted driving indicators on aggressive driving behaviors.The multi-group model analysis of SEM indicated that handling distracted risky driving could control aggressive driving behavior up to 96% and 98% inunoccupied without ride-order trips and unoccupied trips with ride-order respectively.The model has also identified the sensitive risky driving indicators for each group separately. 展开更多
关键词 E-hailing taxi driver distracted driving Aggressive driving Naturalistic driving SEM
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An Investigation of Drivers’ Comprehension of Distracted Driving Slogans
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作者 Saidi Siuhi Judith Mwakalonge +1 位作者 Rebecca Wright Judy A. Perkins 《Journal of Transportation Technologies》 2021年第2期128-138,共11页
Distracted driving occurs when a driver diverts the primary attention from driving to another task. Using mobile devices such as a cellphone for texting, calls, or other manipulation while driving has the highest pote... Distracted driving occurs when a driver diverts the primary attention from driving to another task. Using mobile devices such as a cellphone for texting, calls, or other manipulation while driving has the highest potential for distraction because it combines both forms of distractions, manual, visual, and cognitive. Some states in the US have posted slogans including “</span><i><span style="font-family:Verdana;">W</span></i><span style="font-family:Verdana;">8 2 </span><i><span style="font-family:Verdana;">TXT</span></i><span style="font-family:Verdana;">, </span><i><span style="font-family:Verdana;">it</span></i><span style="font-family:Verdana;">’</span><i><span style="font-family:Verdana;">s</span></i> <i><span style="font-family:Verdana;">a</span></i> <i><span style="font-family:Verdana;">law</span></i><span style="font-family:Verdana;">”, “</span><i><span style="font-family:Verdana;">Don</span></i><span style="font-family:Verdana;">’</span><i><span style="font-family:Verdana;">t</span></i> <i><span style="font-family:Verdana;">Drive</span></i> <i><span style="font-family:Verdana;">inTEXTicated</span></i><span style="font-family:Verdana;">”, “</span><i><span style="font-family:Verdana;">PLS</span></i> <i><span style="font-family:Verdana;">dnt</span></i> <i><span style="font-family:Verdana;">txt</span></i> <i><span style="font-family:Verdana;">n</span></i> <i><span style="font-family:Verdana;">drv</span></i><span style="font-family:Verdana;">”, “</span><i><span style="font-family:Verdana;">Don</span></i><span style="font-family:Verdana;">’</span><i><span style="font-family:Verdana;">t</span></i> <i><span style="font-family:Verdana;">tempt</span></i> <i><span style="font-family:Verdana;">F</span></i><span style="font-family:Verdana;">8 </span><i><span style="font-family:Verdana;">that</span></i> <i><span style="font-family:Verdana;">txt</span></i> <i><span style="font-family:Verdana;">can</span></i> <i><span style="font-family:Verdana;">w</span></i><span style="font-family:Verdana;">8”, </ 展开更多
关键词 distracted Driving Road Safety Slogans Road Sign Comprehension Road Safety Campaign Road Safety Awareness
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论晏几道的伤心词境 被引量:1
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作者 高峰 戴月舟 《怀化学院学报》 2004年第6期97-100,共4页
晏几道将没落贵族公子的感伤情怀,投注到对于往事的深情追忆当中,通过悠缈的梦境描写,抒发出人生如梦的怅惘意绪。他的令词创作,意境空灵,结构顿挫,语言浅淡,从而创造出了独特的艺术审美境界。
关键词 晏几道 词境 词创作 感伤情怀 独特 往事 梦境 艺术审美 空灵 意境
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中文阅读材料难度和类型对走神的影响研究
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作者 李琳 《成才之路》 2022年第28期53-56,共4页
作为阅读中时常发生的一种现象,走神对学生的阅读绩效有着很大的影响。研究材料难度和类型对走神的影响对于如何改进阅读材料的内容、难度及编排,以及减少走神对阅读的消极影响有着重要的意义。研究以50名大学生为被试,使用探针检测的... 作为阅读中时常发生的一种现象,走神对学生的阅读绩效有着很大的影响。研究材料难度和类型对走神的影响对于如何改进阅读材料的内容、难度及编排,以及减少走神对阅读的消极影响有着重要的意义。研究以50名大学生为被试,使用探针检测的方法和逐句阅读范式,采用2(材料难度:难、易)×2(材料类型:自然科学、社会科学)混合实验,探讨在中文阅读条件下,材料难度和材料类型对走神的影响。结果发现,走神的频率在不同难度下具有显著差异,阅读难度越大的文章走神率也越高,材料难度和材料类型对走神率产生了交互作用的影响。 展开更多
关键词 走神 中文阅读 材料难度 材料类型
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An investigation on the link between driver demographic characteristics and distracted driving by using the SHRP 2 naturalistic driving data
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作者 Haotian Cao Zhenghao Zhang +4 位作者 Xiaolin Song Hong Wang Mingjun Li Song Zhao Jianqiang Wang 《Journal of Intelligent and Connected Vehicles》 2020年第1期1-16,共16页
Purpose–The purpose of this paper is to investigate the influence of driver demographic characteristics on the driving safety involving cell phone usages.Design/methodology/approach–A total of 1,432 crashes and 19,71... Purpose–The purpose of this paper is to investigate the influence of driver demographic characteristics on the driving safety involving cell phone usages.Design/methodology/approach–A total of 1,432 crashes and 19,714 baselines were collected for the Strategic Highway Research Program 2 naturalistic driving research.The authors used a case-control approach to estimate the prevalence and the population attributable risk percentage.The mixed logistic regression model is used to evaluate the correlation between different driver demographic characteristics(age,driving experience or their combination)and the crash risk regarding cell phone engagements,as well as the correlation among the likelihood of the cell phone engagement during the driving,multiple driver demographic characteristics(gender,age and driving experience)and environment conditions.Findings–Senior drivers face an extremely high crash risk when distracted by cell phone during driving,but they are not involved in crashes at a large scale.On the contrary,cell phone usages account for a far larger percentage of total crashes for young drivers.Similarly,experienced drivers and experienced-middle-aged drivers seem less likely to be impacted by the cell phone while driving,and cell phone engagements are attributed to a lower percentage of total crashes for them.Furthermore,experienced,senior or male drivers are less likely to engage in cell phone-related secondary tasks while driving.Originality/value–The results provide support to guide countermeasures and vehicle design. 展开更多
关键词 PREVALENCE distracted driving related to cell phones Driver demographic characteristics Naturalistic driving study Population attributable risk percentage
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Predictors and Risk Perceptions of Using Cell Phones while Driving among Young Adult Drivers
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作者 Scarlett Mia S.Tabunar 《Journal of Traffic and Transportation Engineering》 2019年第2期71-84,共14页
The Philippines is expecting a rise in the number of drivers that use mobile phones while driving.It is known as the“texting capital of the world”.The objectives of this study were to determine the predictors,risk p... The Philippines is expecting a rise in the number of drivers that use mobile phones while driving.It is known as the“texting capital of the world”.The objectives of this study were to determine the predictors,risk perceptions and the prevalence of cell phone use while driving among trainee residents of the University of the Philippines-Philippine General Hospital.This cross-sectional study employed total enumeration.A survey was first distributed to the target population,followed by a focus group discussion.Chi-square and multiple logistic regression were used to analyze data.Included in the final analysis were 175 drivers aged 25-30 years(mean=27.90+1.34).There was no significant difference in the risk perceptions of cell phone users vs.non-users,and most perceived hands-free devices safer to use(p=0.030).The reported prevalence is 90.68%;drivers have a significant overall unsafe attitude(p=0.007),and an unsafe attitude when using handsets when driving,even when this is known to be dangerous(p=0.003).In conclusion,driving with hands-free devices was perceived to be safer,although drivers have a high overall unsafe attitude.Driving for more than two years and having an unsafe attitude were found to be significant predictors of cell phone use while driving.Countermeasures must take into account these factors when instituting behavioral modification strategies and road safety policies concerning unsafe and distracted driving. 展开更多
关键词 Attitude cell PHONE use WHILE driving driving experience distracted driving risk PERCEPTIONS young ADULT DRIVERS
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机构投资者“分心”与公司杠杆操纵 被引量:38
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作者 吴晓晖 王攀 郭晓冬 《经济管理》 CSSCI 北大核心 2022年第1期159-175,共17页
本文以机构投资者在其投资组合中注意力分配差异而产生的不同“分心”程度作为识别监督外在变化的手段,验证了其对企业杠杆操纵的重要影响。研究发现,上市公司会趁机构投资者“分心”而监督弱化时实施更多杠杆操纵行为,经稳健性检验后... 本文以机构投资者在其投资组合中注意力分配差异而产生的不同“分心”程度作为识别监督外在变化的手段,验证了其对企业杠杆操纵的重要影响。研究发现,上市公司会趁机构投资者“分心”而监督弱化时实施更多杠杆操纵行为,经稳健性检验后该结论依然成立。影响机制分析发现,机构投资者“分心”通过弱化其监督治理效应、降低公司股价信息含量进一步加剧企业杠杆操纵现象,使得企业得以隐藏真实杠杆水平,从而促使企业以更低的成本获得所需的债务筹资,但也为企业的未来埋下隐患,致使企业潜在债务违约风险与财务风险增大。此外,在机构投资者“分心”加剧企业杠杆操纵的关系中,“去杠杆”政策实施和去杠杆压力发挥了正向调节作用。本文丰富了机构投资者“分心”经济后果研究,也为监管部门强化对企业监管提供了重要启示。 展开更多
关键词 机构投资者“分心” 注意力分配 企业杠杆操纵
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驾驶行为与驾驶风险国际研究进展 被引量:37
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作者 张旭欣 王雪松 +1 位作者 马勇 马青变 《中国公路学报》 EI CAS CSCD 北大核心 2020年第6期1-17,共17页
驾驶人在驾驶车辆的过程中总会面临由自身或外界条件所带来的或高或低的风险,即驾驶风险,通过对驾驶风险进行识别、分析及评估是对风险进行管理的有效对策,明确由人为因素(即驾驶人个体特征及驾驶行为)所带来的驾驶风险并对驾驶人进行... 驾驶人在驾驶车辆的过程中总会面临由自身或外界条件所带来的或高或低的风险,即驾驶风险,通过对驾驶风险进行识别、分析及评估是对风险进行管理的有效对策,明确由人为因素(即驾驶人个体特征及驾驶行为)所带来的驾驶风险并对驾驶人进行安全管理尤为重要。为了全面了解各类危险驾驶行为和各种驾驶人群体的驾驶风险行为研究进展,对驾驶风险领域重点问题进行了总体概述。从驾驶人个体特征及驾驶行为的角度出发,探究了驾驶风险领域目前的研究现状,并利用科学知识图谱展示驾驶风险领域研究的发展进程与结构关系。通过Web of Science核心合集数据库获取了3406篇在1986~2020年(截至2020年2月29日)间出版的驾驶风险研究相关英文文献,共涵盖8684位作者及6018个关键词,基于科学知识图谱对该领域文献进行梳理与分析。结果表明:驾驶风险领域的国外研究在驾驶人选择方面主要从年轻驾驶人、老年驾驶人、新手驾驶人及职业驾驶人的角度进行切入,重点围绕酒驾、药驾、分心驾驶及疲劳驾驶等主题开展研究。与国外研究相比,中国在分心驾驶、疲劳驾驶领域的研究相对丰富,而针对酒驾、药驾的研究试验手段较为单一,研究不够全面;在研究对象的选取上,有必要进一步增加老年驾驶人及新手驾驶人的深入研究,包括老年驾驶人适驾性评估与教育培训,以及新手驾驶人驾照分级制度的可行性探索。在研究方法方面,国外常见研究方法包括问卷调查、驾驶模拟器试验、实车试验以及自然驾驶研究等,而中国在自然驾驶研究领域尚未充分开发利用;未来应考虑多种方法相结合并从不同角度促进对驾驶行为及驾驶风险的全面理解。 展开更多
关键词 交通工程 驾驶行为 综述 驾驶风险 人为因素 科学知识图谱 酒驾 分心驾驶
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驾驶人分心时长对车道偏离影响的实车试验 被引量:20
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作者 马勇 石涌泉 +1 位作者 付锐 郭应时 《吉林大学学报(工学版)》 EI CAS CSCD 北大核心 2015年第4期1095-1101,共7页
为了明确分心过程中的车道偏离规律,从而降低分心驾驶时因车道偏离引发的碰撞事故,在实际道路中进行行车试验,对参试的12名驾驶人共记录了398次分心过程的车辆运动状态数据。选取车道偏离的均值、方差和偏离幅度来表征车道偏离的程度,... 为了明确分心过程中的车道偏离规律,从而降低分心驾驶时因车道偏离引发的碰撞事故,在实际道路中进行行车试验,对参试的12名驾驶人共记录了398次分心过程的车辆运动状态数据。选取车道偏离的均值、方差和偏离幅度来表征车道偏离的程度,分别对该3项统计指标与分心时长进行相关性检验和拟合分析,并按时长分组对比分析分心驾驶与正常驾驶时的该3项指标,得到了车道偏离随驾驶分心时长的变化关系。结果表明:驾驶分心过程中的车道偏离高于正常驾驶;车道偏离随着驾驶分心时长的增加而增大,并且增大速度越来越快;当分心时长超过3.0s时,车辆的车道偏离量在短时间内迅速增大。 展开更多
关键词 交通运输安全工程 分心驾驶 车道偏离 驾驶人 碰撞
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基于级联卷积神经网络的驾驶员分心驾驶行为检测 被引量:16
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作者 陈军 张黎 +2 位作者 周博 罗维平 马双宝 《科学技术与工程》 北大核心 2020年第14期5702-5708,共7页
针对驾驶员分心驾驶行为检测,设计一种级联卷积神经网络检测框架。检测框架由第一级分心行为预筛选卷积网络和第二级分心行为精确检测卷积网络两个全卷积网络级联构成。预筛选卷积网络是一个轻量级的图像分类网络,负责对原始数据进行快... 针对驾驶员分心驾驶行为检测,设计一种级联卷积神经网络检测框架。检测框架由第一级分心行为预筛选卷积网络和第二级分心行为精确检测卷积网络两个全卷积网络级联构成。预筛选卷积网络是一个轻量级的图像分类网络,负责对原始数据进行快速筛选,其网络层数少、训练速度快,结构特征冗余较少,能够减少后续网络的计算负担;分心行为精确检测卷积网络采用VGG(Visual geometry group)模型特征提取的深度迁移学习检测算法网络,通过迁移学习重新训练分类器和部分卷积层。提出的级联神经网络最终可以实现9种驾驶员分心驾驶行为的准确识别检测。实验结果表明,相比主流单模型检测方法,在保证算法效率的同时准确率均有明显提升,准确率达到93.3%,有效降低了误检率。该方法具有较好的鲁棒性和泛化能力。 展开更多
关键词 分心驾驶 卷积神经 特征提取 迁移学习 级联网络
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企业金融化影响技术创新的期限结构异质性研究——理论模型推演与中国经验证据 被引量:16
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作者 吴非 向海凌 《当代经济管理》 CSSCI 北大核心 2020年第2期84-91,共8页
基于中国经济创新驱动转型的现实要求,针对企业金融化对自身技术创新活动的影响,文章首先建构了企业投资活动的稳态模型,研究企业金融化与技术创新活动之间的关系,并将金融化期限结构差异视角引入了模型之中,得出了金融化期限结构差异... 基于中国经济创新驱动转型的现实要求,针对企业金融化对自身技术创新活动的影响,文章首先建构了企业投资活动的稳态模型,研究企业金融化与技术创新活动之间的关系,并将金融化期限结构差异视角引入了模型之中,得出了金融化期限结构差异可能存在的异质性影响。进一步地,借助2007-2016年中国沪深A股上市公司的数据集进行验证。研究发现,企业长期金融化行为对技术创新活动的抑制作用并不足够明显,而短期金融化则有着明显的创新减益效果,从而发现了金融化期限差异下的结构性表现,也进一步拓展了现有文献对于“企业金融化-技术创新”的视角。有鉴于此,不能简单对企业的金融化行为进行“一刀切”式的管理,应根据企业金融化的期限结构差异,制定具有精准导向的政策体系,才能有效中和乃至逆转企业金融化对研发创新活动的抑制作用。 展开更多
关键词 金融化 技术创新 期限结构 脱实向虚
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核桃分心木成分分析及其功能性研究进展 被引量:14
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作者 王嘉佳 高山 +2 位作者 何爱民 吉洋洋 牟德华 《食品工程》 2019年第1期12-17,共6页
核桃分心木又称核桃隔,是夹在核仁之间的木质隔膜。传统中医发现其具有健脾固肾,利尿清热,涩精等功效,有较高的药用价值,我国民间常用来饮用,其他功能性方面研究尚在起步阶段。探讨了核桃分心木的化学成分以及抗菌、抗氧化、降糖、抑制... 核桃分心木又称核桃隔,是夹在核仁之间的木质隔膜。传统中医发现其具有健脾固肾,利尿清热,涩精等功效,有较高的药用价值,我国民间常用来饮用,其他功能性方面研究尚在起步阶段。探讨了核桃分心木的化学成分以及抗菌、抗氧化、降糖、抑制脑功能衰退、抗肿瘤等多种功能活性,旨在为核桃分心木的深入研究和高效开发利用提供参考。 展开更多
关键词 核桃分心木 化学成分 功能性
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过度金融化及其资源错配效应研究 被引量:14
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作者 杨文溥 《西南金融》 北大核心 2019年第11期22-31,共10页
全球金融危机后,许多西方国家出现了过度金融化的迹象。随着经济金融全球化进程的加深,我国也出现了过度金融化的苗头,一是经过多年的快速发展,我国金融业的总体规模已相对较大;二是金融业与实体经济发展呈现出了负相关关系。本文通过... 全球金融危机后,许多西方国家出现了过度金融化的迹象。随着经济金融全球化进程的加深,我国也出现了过度金融化的苗头,一是经过多年的快速发展,我国金融业的总体规模已相对较大;二是金融业与实体经济发展呈现出了负相关关系。本文通过门限模型进行定量估算,发现当金融业增加值占GDP的比重超过5.62%后,我国即表现出了过度金融化的现象。过度金融化将通过扭曲资本配置、劳动力配置和企业决策对实体经济产生负面影响。因此,本文针对我国过渡金融化现象提出相应的对策,旨在提高金融服务实体经济质效。 展开更多
关键词 过度金融化 脱实向虚 虚拟经济 全要素生产率 门限模型 金融监管 资本配置 资源错配 金融危机 系统性金融风险 民营企业融资 金融支持实体经济
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响应面法优化云南核桃分心木多酚提取工艺 被引量:12
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作者 李瑞 梁永林 +1 位作者 阚欢 刘云 《西南林业大学学报(自然科学)》 CAS 北大核心 2021年第2期159-165,共7页
采用单因素试验,分析液料比、复合酶添加量、水浴温度3个因素对云南核桃分心木多酚提取的影响;采用3因素3水平的响应面设计试验,确定云南核桃分心木多酚提取的最优组合;通过AB-8大孔树脂以不同浓度梯度的乙醇初步洗脱纯化云南核桃分心... 采用单因素试验,分析液料比、复合酶添加量、水浴温度3个因素对云南核桃分心木多酚提取的影响;采用3因素3水平的响应面设计试验,确定云南核桃分心木多酚提取的最优组合;通过AB-8大孔树脂以不同浓度梯度的乙醇初步洗脱纯化云南核桃分心木多酚,分析适宜的洗脱液浓度和多酚的纯度。结果表明:当液料比为102.00 mL/g、复合酶添加量为0.90%、温度为45.33℃时,云南核桃分心木多酚的提取量达22.35 mg GAE/g,且实际值为理论值的99.73%;纯化前云南核桃分心木多酚的纯度仅为19.74%,纯化后云南核桃分心木多酚的纯度可达64.42%,且洗脱时最适乙醇浓度为90%。因此,通过水浴加热,液料比、复合酶添加量、水浴温度都对云南核桃分心木多酚提取量有影响,且不同浓度的乙醇对多酚的洗脱程度有所差异。 展开更多
关键词 云南核桃 分心木 多酚 提取工艺 响应面 洗脱纯化
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驾驶人视觉分心时转向操作和车道偏离特性研究 被引量:7
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作者 石涌泉 郭应时 +1 位作者 杨婉莹 张名芳 《中国安全科学学报》 CAS CSCD 北大核心 2014年第9期20-25,共6页
为研究视觉分心对驾驶人转向操作和车道偏离的影响,基于实车道路试验数据,采用统计方法分析视觉分心时驾驶人的分心时长、转向操作和车道偏离的变化特点。选取偏离距离均值、偏离距离方差和偏离幅度3个指标来表征车辆横向偏离程度,对比... 为研究视觉分心对驾驶人转向操作和车道偏离的影响,基于实车道路试验数据,采用统计方法分析视觉分心时驾驶人的分心时长、转向操作和车道偏离的变化特点。选取偏离距离均值、偏离距离方差和偏离幅度3个指标来表征车辆横向偏离程度,对比分析视觉分心过程中及其前后1 s时的车道偏离特点。结果表明:视觉分心时长集中在0.5~3.5 s,比例为87.16%;随着视觉分心时长的增加,驾驶人对方向盘的操作趋势减少;车道偏离发生在分心起始时刻的前或后约0.5 s,以一直偏向同一方向为主,比例为84.49%;车道偏离较视觉分心前后1 s更严重,且偏离程度随着分心时长的增加而增加。 展开更多
关键词 交通安全 分心驾驶 视觉分心 转向操作 车道偏离 驾驶人
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基于反向双目识别的驾驶员分心检测 被引量:9
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作者 王冠 李振龙 《科学技术与工程》 北大核心 2018年第17期82-88,共7页
为检测分心驾驶状态,研究了基于反向双目的驾驶状态检测方法。首先,根据Hough算法进行车道线检测和识别,计算车辆偏航率;同时采用多点透视算法对驾驶员头部姿态进行估计;然后建立基于高斯隶属度函数模糊判断规则,根据车辆偏航率与驾驶... 为检测分心驾驶状态,研究了基于反向双目的驾驶状态检测方法。首先,根据Hough算法进行车道线检测和识别,计算车辆偏航率;同时采用多点透视算法对驾驶员头部姿态进行估计;然后建立基于高斯隶属度函数模糊判断规则,根据车辆偏航率与驾驶员头部姿态对驾驶员驾驶状态进行识别。最后,采用所建立的驾驶员驾驶状态识别模型,对车道保持、换道行驶及分心行驶三种不同驾驶状态进行测试。结果表明,建立的驾驶员驾驶状态识别模型对上述三种状态检测准确率分别为99.0%、86.7%、80.8%。 展开更多
关键词 分心驾驶 车辆偏航率 头部姿态检测 驾驶状态识别 模糊规则
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基于人体姿态估计的分心驾驶行为检测 被引量:8
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作者 尹智帅 钟恕 +1 位作者 聂琳真 马晨 《中国公路学报》 EI CAS CSCD 北大核心 2022年第6期312-323,共12页
为弥补现有驾驶特征提取方法的不足,提高分心驾驶行为检测的准确性和鲁棒性,将2D/3D人体姿态估计应用于驾驶人行为检测,提出一种适用于驾驶舱环境下的驾驶特征提取方法。首先通过将2D姿态估计网络Simple Baseline和分类网络ResNet进行融... 为弥补现有驾驶特征提取方法的不足,提高分心驾驶行为检测的准确性和鲁棒性,将2D/3D人体姿态估计应用于驾驶人行为检测,提出一种适用于驾驶舱环境下的驾驶特征提取方法。首先通过将2D姿态估计网络Simple Baseline和分类网络ResNet进行融合,构建基于2D姿态估计的分心驾驶行为检测模型,并在分心驾驶数据集State Farm上分析不同数据增强方法、不同超参数、不同分类网络对模型性能的影响。其次,融合3D密集姿态估计网络DensePose与分类网络ResNet,构建基于3D姿态估计的分心驾驶行为检测模型。接着,在State Farm数据集上,针对模型的实时性和泛化能力,对比分析基于原始图像和基于2D/3D姿态的分心驾驶行为检测模型。最后,针对效果更优的基于2D姿态估计的分心驾驶行为检测模型,在分心驾驶数据集State Farm上,对使用不同姿态估计算法和分类网络的分心驾驶行为检测模型做了交叉试验,对比分析4个不同检测模型的优缺点。进一步地,将基于2D姿态估计的分心驾驶行为检测模型应用于实际采集的驾驶图片,对模型的泛化能力和有效性进行了测试验证。研究结果表明:与基于原始图像的检测模型相比,基于2D和3D姿态的检测模型都能显著提高分心驾驶行为的检测准确率;基于3D姿态的检测模型在检测精度方面略优,但基于2D姿态的检测实时性更好,检测效率是基于3D姿态检测的4倍;在驾驶舱单一环境下,基于2D姿态估计的分心驾驶行为检测模型能够满足分心驾驶行为检测的需求,在分心驾驶行为检测方面具有重要应用价值。 展开更多
关键词 汽车工程 驾驶分心 分心驾驶行为检测 人体姿态估计 人机共驾
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