This paper investigates the passing events between electric bicycles and conventional bicycles and explores the relationships between passing events and traffic parameters in bicycle facilities.Three exclusive bicycle...This paper investigates the passing events between electric bicycles and conventional bicycles and explores the relationships between passing events and traffic parameters in bicycle facilities.Three exclusive bicycle paths in Nanjing, China,were observed with cameras.Then,the field data including vehicle number,velocity characteristics and passing event features were analyzed in detail.Data analysis and fitting reveal that the speed difference has little impact on the passing event number,as does the bicycle ratio.The Gaussian function can better describe the relationship between the passing event number and bicycle volume (density).The valid use level of bicycle path width influences the inflexion of the passing events-density fitting curve.The conclusions can be applied for estimating the passing events in mixed bicycle flows and for choosing a suitable width of separate bicycle path.展开更多
In order to analyze the risky factors that affect vehicle-cyclist crash injury severity at the intersection area,especially the factors relating to the road users behaviors,an empirical study was conducted by collecti...In order to analyze the risky factors that affect vehicle-cyclist crash injury severity at the intersection area,especially the factors relating to the road users behaviors,an empirical study was conducted by collecting accident records from 2011 to 2015 from the General Estimates System.After preliminary screening,the variables were classified into 5 main categories including cyclists characteristic and behavior,drivers characteristic and behavior,vehicle characteristic,intersection condition,and time.The random parameter ordinal probit(RPOP)was used to study the significant influencing factors and corresponding heterogeneity.The results show that failing to obey traffic signals,failing to yield to right-of-way,dash and drinking before cycling can increase the injury severity for cyclists,and the corresponding fatal injury likelihoods increase by 53.2%,40.0%,86.3%,and 211.5%,respectively.Moreover,drivers inattention,speeding,going straight and left turning increase the risk of crashing for cyclists.The corresponding fatal injury likelihoods increase by 134.5%,186.5%,69.3%,and 22.7%,respectively.Other indicators such as age,gender,vehicle type,traffic signal and intersection type can also affect injury severity.展开更多
With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficienc...With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on militaryvehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems.展开更多
The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that ope...The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.展开更多
Objective: To study the relationship between the amount of consumed alcohol, blood alcohol concentration (BAC), and driving ability among a part of the population in Southwest China and to provide reference for the fo...Objective: To study the relationship between the amount of consumed alcohol, blood alcohol concentration (BAC), and driving ability among a part of the population in Southwest China and to provide reference for the formulation of the legal limits for safe driving. Methods: Seventy-six randomly selected volunteer drivers each had three times of alcohol intake (100 ml each time). After each drank, BAC was measured with gas chromatograph and driving ability was evaluated. The drivers were grouped according to age, weight, alcohol tolerance and driving experience respectively and changes in BAC and driving ability were analyzed. Results: Average BAC and the percentage of drivers showing impaired driving ability in the groups increased after each intake of 100 ml alcohol. BAC in Group≤60 kg was more susceptible to alcohol than that in Group>60 kg. When each drank, alcohol had greater influence on drivers who had comparatively shorter driving experience. Conclusion: Volume of consumed alcohol, BAC and driving ability have direct associations among one another and are all under the influence of various factors including individual conditions. To set an appropriate legal BAC limit for safe driving should take an overall consideration of all factors.展开更多
To better understand the characteristics of air quality and the relationship between the chemical composition evolution and source variation,an intensive atmospheric campaign was conducted in Tianjin,a megacity of the...To better understand the characteristics of air quality and the relationship between the chemical composition evolution and source variation,an intensive atmospheric campaign was conducted in Tianjin,a megacity of the North China Plain,from 10 February to 6 March 2015.There were 20 days exceeding the threshold value of secondary Chinese Ambient Air Quality Standards for PM2.5(75 μg m-3,daily average over 24 h)during the study period.Five air pollution episodes were selected for investigation.During the pre-holiday pollution episode,NH^+_4,NO^-_3,and SO^(2-)_4 were more abundant,indicating that air pollution was caused by motor vehicle exhaust emissions and coal consumption under unfavorable meteorological conditions.During Chinese Lunar New Year's Eve,widespread use of fireworks resulted in extremely high aerosol concentrations.Firework displays caused increases in K+ and also enrichment of SO^(2-)_4 relative to NO^-_3.The holiday pollution episode was caused by regional transport,characterized by abundant SO^(2-)_4 and NH^+_4.In addition,the aging processes of the particles from fireworks discharge played an important role in the formation of NO-3and SO^(2-)_4.The Lantern Festival episode was characterized by a transition from the enrichment of K+ to secondary inorganic ions(NO^-_3,SO^(2-)_4,and NH^+_4).The results of this study are useful for a detailed understanding of the variation in atmospheric compositions and sources caused by anthropogenic activity,and highlight the importance of controlling intensive fireworks discharge.展开更多
Setting reliable speed limits on roads has always been a challenging process of designers and road agencies. In this paper the results of a methodology for setting speed limits on rural roads of all categories in Gree...Setting reliable speed limits on roads has always been a challenging process of designers and road agencies. In this paper the results of a methodology for setting speed limits on rural roads of all categories in Greece is presented based on international research and an extensive drivers attitudes' survey. The 85th percentile speed has proven in this case to be the decisive criterion for establishing reliable speed limits or advisory speeds in most cases. The resulted 10 km/la increase in legal speed limits on freeways and express rural highways did not validate any fears that accident rates or frequencies would increase. On the contrary an 8% decrease of crashes was observed in a period of about three years after the implementation of the increased speed limits level on the rural highway network of the country.展开更多
Involvement in road traffic crashes as vehicle occupants is a leading cause of death and serious injury among children. The objective of this study was to investigate crash severity factors and child safety restraint ...Involvement in road traffic crashes as vehicle occupants is a leading cause of death and serious injury among children. The objective of this study was to investigate crash severity factors and child safety restraint use characteristics in order to identify effective countermeasures to increase children's highway safety. Characteristics and percentages of restraint use among child passengers aged 4-13 years were examined using highway crash data from Kansas. The association between restraint use, injury severity and characteristics of children involved in crashes were investigated using OR (odds ratios) and a logistic regression model, which was used to identify risk factors. Results showed that children, who were unrestrained, were seated in the front seat, traveling with drunk drivers and on rural roads, and traveling during nighttime was more vulnerable to severe injury in the case of motor vehicle crashes. The most frequent contributing causes related to crashes involving children included driver's inattention while driving, failure to yield right-of-way, driving too fast, wet roads and animals in the road. Based on identified critical factors, general countermeasure ideas to improve children's traffic safety were suggested, including age-appropriate and size-appropriate seat belt restraints and having children seated in the rear seat. Parents and children must gain better education regarding these safety measures in order to increase child safety on the road.展开更多
In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and ...In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types: control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.展开更多
This paper is based on the author's work shop which provides educators with information on how to utilize "Soft Toy Theory". The workshop is based on a set of theoretical concepts taken from: psychology, play ther...This paper is based on the author's work shop which provides educators with information on how to utilize "Soft Toy Theory". The workshop is based on a set of theoretical concepts taken from: psychology, play therapy, and literacy theory which have been blended together to form a set of teaching approaches and lesson plan ideas that can be used in Literacy/English classes. The paper will also discuss the value of using "Story Sacks" to develop and raise levels of comprehension and understanding in extensive reading and reading programs. The application of "Soft Toy Theory" could also provide a positive social-psychological affect on the students. It is designed to creating bonding between teacher and student and student and student and to raise levels of self-esteem and enable the teachers to be able to access the thoughts and feelings of a child or young adu/t which can often be hard to discern from traditional direct question and answer sessions. "Soft Toy Theory" is a term that the author has adopted herself for using play, creativity, and art resources and soft toys to create dialogues in the Kindergarten and Elementary classroom: It is even possible to extend the use "Soft Toy Theory" to middle school, high school, and adult classrooms if the resources and topics and "tone" and tenor of teaching are appropriately adapted. Soft Toy Theory assumes that soft toys can include: actual soft toys, art resources, and other play resources: such as, sand, water, puppets, masks and clay. Story Sacks employ much of the theory that supports "soft toy usage" within the classroom. Story Sacks aim to provide inspiring resources whilst encouraging enjoyment and a greater comprehension of "real" books or "graded" readers. Additionally, Story Sacks can support extensive reading in the school and at home, and are a useful adjunct to Soft Toy Theory and supporting literacy activities in any classroom.展开更多
Motor vehicle accidents (MVAs) are serious social issues worldwide and driver illness is an important cause of MVAs. Minimal hepatic encephalopathy (MHE) is a com- plex cognitive dysfunction with attention deficit, wh...Motor vehicle accidents (MVAs) are serious social issues worldwide and driver illness is an important cause of MVAs. Minimal hepatic encephalopathy (MHE) is a com- plex cognitive dysfunction with attention deficit, which frequently occurs in cirrhotic patients independent of severity of liver disease. Although MHE is known as a risk factor for MVAs, the impact of diagnosis and treatment of MHE on MVA-related societal costs is largely unknown. Recently, Bajaj et al demonstrated valuable findings that the diagnosis of MHE by rapid screening using the inhibitory control test (ICT), and subsequent treatment with lactulose could substantially reduce the societal costs by preventing MVAs. Besides the ICT and lactulose, there are various diagnostic tools and therapeutic strategies for MHE. In this commentary, we discussed a current issue of diagnostic tools for MHE, including neuropsychological tests. We also discussed the advantages of the other therapeutic strategies for MHE, such as intake of a regular breakfast and coffee, and supplementation with zinc and branched chain amino acids, on the MVA-related societal costs.展开更多
Traffic management in underground mines,especially on production ramps,is a difficult problem to optimize and control.Most operations use one of a few common policies;e.g.,the so-called ‘‘lock-out" and‘‘loade...Traffic management in underground mines,especially on production ramps,is a difficult problem to optimize and control.Most operations use one of a few common policies;e.g.,the so-called ‘‘lock-out" and‘‘loaded-vehicle-priority" policies.The work presented in this paper uses discrete-event simulation to study the efficiency of multiple policies.Based on simulation results,an improvement to the common lock-out policy is proposed.This new policy utilizes the rules of the lock-out policy but integrates an option that allows a group of vehicles to be given temporary priority in a certain direction of travel.Quantitative results are provided and,based on these,a systematic technique for ramp design that aims to optimize the efficiency of underground mine ramp traffic flow is described.展开更多
Duodenal trauma is uncommon but nowadays seen more and more frequently due to the increased automobile accidents and violent events. The management of duodenal trauma can be complicated, especially when massive injury...Duodenal trauma is uncommon but nowadays seen more and more frequently due to the increased automobile accidents and violent events. The management of duodenal trauma can be complicated, especially when massive injury to the pancreatic-duodenal-biliary complex occurs simultaneously. Even the patients receive surgeries in time, multiple postoperative complications and high mortality are common. To know and manage duodenal trauma better, we searched the recent related literature in PubMed by the keywords of duodenal trauma, therapy, diagnosis and abdomen. It shows that because the diagnosis and management are complicated and the mortality is high,duodenal trauma should be treated in time and tactfully.And application of new technology can help improve the management. In this review, we discussed the incidence,diagnosis, management, and complications as well as mortality of duodenal trauma.展开更多
Objective: To identify the main character- istics of victims of motorcycle accidents in Fars Province, Iran. Methods: This cross-sectional study was conducted in Fars Province which has the fourth largest populatio...Objective: To identify the main character- istics of victims of motorcycle accidents in Fars Province, Iran. Methods: This cross-sectional study was conducted in Fars Province which has the fourth largest population of all 31 provinces in Iran from March 2009 to June 2010. We included data from all 542 recorded cases of fatalities due to motor vehicle accidents. Data were recorded from the foren- sic medicine registry consisting of demographic and acci- dent-related information. Demographic information con- sisted of name, age, sex, status of fatal victim (motorcycle driver vs passenger) and educational level. Results: Of the 2 345 autopsy records from the foren- sic medicine archives, 542 (23.1%) gave the cause of death as motor vehicle accidents. Mean age of these victims was (31.4±16.5) years, and the male to female ratio was 28. Head injury was the most common cause of death in these victims, and overall they tended to have a low level of education. Motorcycle accidents frequently involved younger age groups (15-35 years), and head trauma related with non-use of a helmet was the most common cause of death. Conclusions: Head injury is frequent among victims in the province we studied. This situation may be related to the victims' low socioeconomic status and little education regarding traffic laws leading to speeding and disregard of these laws along with their weak enforcement.展开更多
Hoffa fracture associated with ipsilateral femoral shaft fracture is very rare. Three cases of this rare type of injury were retrospectively reviewed. The sites of femoral shaft fractures and Hoffa fractures were docu...Hoffa fracture associated with ipsilateral femoral shaft fracture is very rare. Three cases of this rare type of injury were retrospectively reviewed. The sites of femoral shaft fractures and Hoffa fractures were documented. All femoral shall fractures were managed with internal tixation. The rate ofmisdiagnosis for the Hoffa fractures was documented. Functions of the affected knees were evaluated according to the modified Hospital for Special Surgery (HSS) scores at two years follow-up. Femoral fractures were either transverse or composite in all three cases. Ipsilateral Hoffa fractures occurred at medial condyle in two cases, and lateral condyle in one case. Only one Hoffa fracture was identified preoperatively. All the femoral shaft fiattures healed uneventfully. In the patient whose Hoffa fracture was correctly diagnosed, the modified HSS score was 94. In another patient, whose Hoffa fracture was treated by a second operation, the modified HSS score was 93. And in the third case, who refused additional operation for the Hoffa fracture, the modified HSS score was only 70. Conclusively femoral shall fracture can be associated with ipsilateral Hoffa fracture, especially in motorcycle accident. This type of iniury is very rare and misdiagnosis is common.展开更多
Objective: To compare fatalities and injuries in road traffic crashes (RTC) in Iran with other countries. Methods: Data were obtained from national health sources of Iran. These data included population number, r...Objective: To compare fatalities and injuries in road traffic crashes (RTC) in Iran with other countries. Methods: Data were obtained from national health sources of Iran. These data included population number, registered motor-vehicles number, number of RTCs and consequent fatalities and injuries from 1997 to 2006. Results: RTC fatality and injury rates increased from 1997 to 2005, but decreased in 2006. The overall men/women ratio in the RTC fatalities was 4.2:1. High RTC fatality rate of 39 per 100 000 population in Iran was almost the same as some other developing countries. In Iran, RTC fatalities in recent years were almost twice as much as the highest rate among the European countries. Conclusions: This investigation shows that in spite of reduction of RTC fatality in Iran in 2006, it is still one of the highest in the world. Moreover, this paper describes the state of RTC-related parameters in a developing country in comparison with the developed countries.展开更多
Objective: The association of scapular fractures with other life-threatening injuries including blunt thoracic aortic injury is widely recognized. Few studies have investigated this presumed association. In this stud...Objective: The association of scapular fractures with other life-threatening injuries including blunt thoracic aortic injury is widely recognized. Few studies have investigated this presumed association. In this study, we investigated the incidence of significant associated injuries with scapular fracture and their outcomes. Methods: A retrospective study was conducted from 2005 to 2009 in a level I trauma center in Thailand. All blunt trauma patients were identified. Patients' demographics, injury mechanism, associated injuries, Injury Severity Score (ISS), and survival outcomes were recorded. The manage- ment of associated injuries with scapular fracture was reviewed, and the risk factors for mortality were identified. Results: Among the 7 345 trauma patients admitted, scapular fractures occurred in 84 cases (1.1%). The mean age was (37.98±15.21) years. Motorcycle crash was the most frequent mechanism of injury, occurring in 51 cases (60.7%).Seventyour patients (88.1%) suffering from scapular fractures had associated injuries: 5 (6.0%) had significant chest injuries, but none of them had blunt thoracic aortic injury. Two patients (2.4%) with scapular fractures died. Factors determining the likelihood of mortality were: (1) ISS〉25 (LR=8.5, P〈0.05); (2) significant associated chest injury (AIS〉3, LR=5.3, P〈0.05) and (3) significant associated abdominal injury (AIS〉3, LR=5.3, P〈0.05). Conclusion: A blunt scapular fracture may not accompany a blunt thoracic aortic injury but it is strongly related to other injuries like chest injury, extremity injury, head injury, etc. If a scapular fracture is found with a high ISS score, high chest or abdomen AIS score, the patient would have a high risk of mortality.展开更多
Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was consi...Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was considered from the Department of Forensic Medicine, Shahid Bahonar University of Kerman, involving drivers of all ages and covering a four-year period. Results: The male fatality rates were significantly higher than female ones. The groups at 15-30 years old and at 30-55 years old had the first and second highest numbers of deaths (40% and 34%, respectively). There were substantial differences in distribution of injuries in motor vehicle occupants and pedestrians and bicyclists. Among motor vehicle occupants, there were more head injuries, such as skull fracture, brain contusion, subdural haemorrhage, and epidural haemorrhage. Nearly 77% of fatalities occurred during 08:00-22:00 in Sirjan. Internal bleeding was also higher in motor vehicle occupants. Pedestrians and bicyclists also had head injuries frequently. Conclusions: In spite of reduction of road traffic fatalities in Sirjan in 2007, it is still one of the cities with high road traffic fatality in the world. These results underline the importance of preventive strategies in transportation, suggesting that different methods are necessary to reduce fatalities of various traffic participants.展开更多
基金The National Natural Science Foundation of China(No.51238008,51408322)
文摘This paper investigates the passing events between electric bicycles and conventional bicycles and explores the relationships between passing events and traffic parameters in bicycle facilities.Three exclusive bicycle paths in Nanjing, China,were observed with cameras.Then,the field data including vehicle number,velocity characteristics and passing event features were analyzed in detail.Data analysis and fitting reveal that the speed difference has little impact on the passing event number,as does the bicycle ratio.The Gaussian function can better describe the relationship between the passing event number and bicycle volume (density).The valid use level of bicycle path width influences the inflexion of the passing events-density fitting curve.The conclusions can be applied for estimating the passing events in mixed bicycle flows and for choosing a suitable width of separate bicycle path.
基金The National Key Research and Development Program of China(No.2017YFC0803902).
文摘In order to analyze the risky factors that affect vehicle-cyclist crash injury severity at the intersection area,especially the factors relating to the road users behaviors,an empirical study was conducted by collecting accident records from 2011 to 2015 from the General Estimates System.After preliminary screening,the variables were classified into 5 main categories including cyclists characteristic and behavior,drivers characteristic and behavior,vehicle characteristic,intersection condition,and time.The random parameter ordinal probit(RPOP)was used to study the significant influencing factors and corresponding heterogeneity.The results show that failing to obey traffic signals,failing to yield to right-of-way,dash and drinking before cycling can increase the injury severity for cyclists,and the corresponding fatal injury likelihoods increase by 53.2%,40.0%,86.3%,and 211.5%,respectively.Moreover,drivers inattention,speeding,going straight and left turning increase the risk of crashing for cyclists.The corresponding fatal injury likelihoods increase by 134.5%,186.5%,69.3%,and 22.7%,respectively.Other indicators such as age,gender,vehicle type,traffic signal and intersection type can also affect injury severity.
基金supported by the National Moon Exploration Program of China (No. TY3Q20110020)in part supported by the 13th Five-Year Community Technology Research Program of National Equipment Development Department of China (No.41409020301)the National Natural Science Foundation of China (50971094)
文摘With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on militaryvehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems.
基金Research Fund from Science and Technology on Underwater Vehicle Laboratory
文摘The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.
文摘Objective: To study the relationship between the amount of consumed alcohol, blood alcohol concentration (BAC), and driving ability among a part of the population in Southwest China and to provide reference for the formulation of the legal limits for safe driving. Methods: Seventy-six randomly selected volunteer drivers each had three times of alcohol intake (100 ml each time). After each drank, BAC was measured with gas chromatograph and driving ability was evaluated. The drivers were grouped according to age, weight, alcohol tolerance and driving experience respectively and changes in BAC and driving ability were analyzed. Results: Average BAC and the percentage of drivers showing impaired driving ability in the groups increased after each intake of 100 ml alcohol. BAC in Group≤60 kg was more susceptible to alcohol than that in Group>60 kg. When each drank, alcohol had greater influence on drivers who had comparatively shorter driving experience. Conclusion: Volume of consumed alcohol, BAC and driving ability have direct associations among one another and are all under the influence of various factors including individual conditions. To set an appropriate legal BAC limit for safe driving should take an overall consideration of all factors.
基金supported by the Beijing Natural Science Foundation[grant number 8142034]Strategic Priority Research Program(B)of the Chinese Academy of Sciences[grant numbers XDB0502050 and XDB05030203]
文摘To better understand the characteristics of air quality and the relationship between the chemical composition evolution and source variation,an intensive atmospheric campaign was conducted in Tianjin,a megacity of the North China Plain,from 10 February to 6 March 2015.There were 20 days exceeding the threshold value of secondary Chinese Ambient Air Quality Standards for PM2.5(75 μg m-3,daily average over 24 h)during the study period.Five air pollution episodes were selected for investigation.During the pre-holiday pollution episode,NH^+_4,NO^-_3,and SO^(2-)_4 were more abundant,indicating that air pollution was caused by motor vehicle exhaust emissions and coal consumption under unfavorable meteorological conditions.During Chinese Lunar New Year's Eve,widespread use of fireworks resulted in extremely high aerosol concentrations.Firework displays caused increases in K+ and also enrichment of SO^(2-)_4 relative to NO^-_3.The holiday pollution episode was caused by regional transport,characterized by abundant SO^(2-)_4 and NH^+_4.In addition,the aging processes of the particles from fireworks discharge played an important role in the formation of NO-3and SO^(2-)_4.The Lantern Festival episode was characterized by a transition from the enrichment of K+ to secondary inorganic ions(NO^-_3,SO^(2-)_4,and NH^+_4).The results of this study are useful for a detailed understanding of the variation in atmospheric compositions and sources caused by anthropogenic activity,and highlight the importance of controlling intensive fireworks discharge.
文摘Setting reliable speed limits on roads has always been a challenging process of designers and road agencies. In this paper the results of a methodology for setting speed limits on rural roads of all categories in Greece is presented based on international research and an extensive drivers attitudes' survey. The 85th percentile speed has proven in this case to be the decisive criterion for establishing reliable speed limits or advisory speeds in most cases. The resulted 10 km/la increase in legal speed limits on freeways and express rural highways did not validate any fears that accident rates or frequencies would increase. On the contrary an 8% decrease of crashes was observed in a period of about three years after the implementation of the increased speed limits level on the rural highway network of the country.
文摘Involvement in road traffic crashes as vehicle occupants is a leading cause of death and serious injury among children. The objective of this study was to investigate crash severity factors and child safety restraint use characteristics in order to identify effective countermeasures to increase children's highway safety. Characteristics and percentages of restraint use among child passengers aged 4-13 years were examined using highway crash data from Kansas. The association between restraint use, injury severity and characteristics of children involved in crashes were investigated using OR (odds ratios) and a logistic regression model, which was used to identify risk factors. Results showed that children, who were unrestrained, were seated in the front seat, traveling with drunk drivers and on rural roads, and traveling during nighttime was more vulnerable to severe injury in the case of motor vehicle crashes. The most frequent contributing causes related to crashes involving children included driver's inattention while driving, failure to yield right-of-way, driving too fast, wet roads and animals in the road. Based on identified critical factors, general countermeasure ideas to improve children's traffic safety were suggested, including age-appropriate and size-appropriate seat belt restraints and having children seated in the rear seat. Parents and children must gain better education regarding these safety measures in order to increase child safety on the road.
文摘In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types: control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.
文摘This paper is based on the author's work shop which provides educators with information on how to utilize "Soft Toy Theory". The workshop is based on a set of theoretical concepts taken from: psychology, play therapy, and literacy theory which have been blended together to form a set of teaching approaches and lesson plan ideas that can be used in Literacy/English classes. The paper will also discuss the value of using "Story Sacks" to develop and raise levels of comprehension and understanding in extensive reading and reading programs. The application of "Soft Toy Theory" could also provide a positive social-psychological affect on the students. It is designed to creating bonding between teacher and student and student and student and to raise levels of self-esteem and enable the teachers to be able to access the thoughts and feelings of a child or young adu/t which can often be hard to discern from traditional direct question and answer sessions. "Soft Toy Theory" is a term that the author has adopted herself for using play, creativity, and art resources and soft toys to create dialogues in the Kindergarten and Elementary classroom: It is even possible to extend the use "Soft Toy Theory" to middle school, high school, and adult classrooms if the resources and topics and "tone" and tenor of teaching are appropriately adapted. Soft Toy Theory assumes that soft toys can include: actual soft toys, art resources, and other play resources: such as, sand, water, puppets, masks and clay. Story Sacks employ much of the theory that supports "soft toy usage" within the classroom. Story Sacks aim to provide inspiring resources whilst encouraging enjoyment and a greater comprehension of "real" books or "graded" readers. Additionally, Story Sacks can support extensive reading in the school and at home, and are a useful adjunct to Soft Toy Theory and supporting literacy activities in any classroom.
文摘Motor vehicle accidents (MVAs) are serious social issues worldwide and driver illness is an important cause of MVAs. Minimal hepatic encephalopathy (MHE) is a com- plex cognitive dysfunction with attention deficit, which frequently occurs in cirrhotic patients independent of severity of liver disease. Although MHE is known as a risk factor for MVAs, the impact of diagnosis and treatment of MHE on MVA-related societal costs is largely unknown. Recently, Bajaj et al demonstrated valuable findings that the diagnosis of MHE by rapid screening using the inhibitory control test (ICT), and subsequent treatment with lactulose could substantially reduce the societal costs by preventing MVAs. Besides the ICT and lactulose, there are various diagnostic tools and therapeutic strategies for MHE. In this commentary, we discussed a current issue of diagnostic tools for MHE, including neuropsychological tests. We also discussed the advantages of the other therapeutic strategies for MHE, such as intake of a regular breakfast and coffee, and supplementation with zinc and branched chain amino acids, on the MVA-related societal costs.
基金funded by the Natural Science and Engineering Research Council of Canada (NSERC) under project CRDPJ 44SBO4-12funding provided by Barrick Gold Corporation and Peck Tech Consulting Ltd
文摘Traffic management in underground mines,especially on production ramps,is a difficult problem to optimize and control.Most operations use one of a few common policies;e.g.,the so-called ‘‘lock-out" and‘‘loaded-vehicle-priority" policies.The work presented in this paper uses discrete-event simulation to study the efficiency of multiple policies.Based on simulation results,an improvement to the common lock-out policy is proposed.This new policy utilizes the rules of the lock-out policy but integrates an option that allows a group of vehicles to be given temporary priority in a certain direction of travel.Quantitative results are provided and,based on these,a systematic technique for ramp design that aims to optimize the efficiency of underground mine ramp traffic flow is described.
基金This research was supported by the National Natural Science Foundation of China (NSFC 30973113 NSFC 81020108023) and Chongqing Science & Technology Commission (CSTC2008BA5006).
文摘Duodenal trauma is uncommon but nowadays seen more and more frequently due to the increased automobile accidents and violent events. The management of duodenal trauma can be complicated, especially when massive injury to the pancreatic-duodenal-biliary complex occurs simultaneously. Even the patients receive surgeries in time, multiple postoperative complications and high mortality are common. To know and manage duodenal trauma better, we searched the recent related literature in PubMed by the keywords of duodenal trauma, therapy, diagnosis and abdomen. It shows that because the diagnosis and management are complicated and the mortality is high,duodenal trauma should be treated in time and tactfully.And application of new technology can help improve the management. In this review, we discussed the incidence,diagnosis, management, and complications as well as mortality of duodenal trauma.
文摘Objective: To identify the main character- istics of victims of motorcycle accidents in Fars Province, Iran. Methods: This cross-sectional study was conducted in Fars Province which has the fourth largest population of all 31 provinces in Iran from March 2009 to June 2010. We included data from all 542 recorded cases of fatalities due to motor vehicle accidents. Data were recorded from the foren- sic medicine registry consisting of demographic and acci- dent-related information. Demographic information con- sisted of name, age, sex, status of fatal victim (motorcycle driver vs passenger) and educational level. Results: Of the 2 345 autopsy records from the foren- sic medicine archives, 542 (23.1%) gave the cause of death as motor vehicle accidents. Mean age of these victims was (31.4±16.5) years, and the male to female ratio was 28. Head injury was the most common cause of death in these victims, and overall they tended to have a low level of education. Motorcycle accidents frequently involved younger age groups (15-35 years), and head trauma related with non-use of a helmet was the most common cause of death. Conclusions: Head injury is frequent among victims in the province we studied. This situation may be related to the victims' low socioeconomic status and little education regarding traffic laws leading to speeding and disregard of these laws along with their weak enforcement.
文摘Hoffa fracture associated with ipsilateral femoral shaft fracture is very rare. Three cases of this rare type of injury were retrospectively reviewed. The sites of femoral shaft fractures and Hoffa fractures were documented. All femoral shall fractures were managed with internal tixation. The rate ofmisdiagnosis for the Hoffa fractures was documented. Functions of the affected knees were evaluated according to the modified Hospital for Special Surgery (HSS) scores at two years follow-up. Femoral fractures were either transverse or composite in all three cases. Ipsilateral Hoffa fractures occurred at medial condyle in two cases, and lateral condyle in one case. Only one Hoffa fracture was identified preoperatively. All the femoral shaft fiattures healed uneventfully. In the patient whose Hoffa fracture was correctly diagnosed, the modified HSS score was 94. In another patient, whose Hoffa fracture was treated by a second operation, the modified HSS score was 93. And in the third case, who refused additional operation for the Hoffa fracture, the modified HSS score was only 70. Conclusively femoral shall fracture can be associated with ipsilateral Hoffa fracture, especially in motorcycle accident. This type of iniury is very rare and misdiagnosis is common.
文摘Objective: To compare fatalities and injuries in road traffic crashes (RTC) in Iran with other countries. Methods: Data were obtained from national health sources of Iran. These data included population number, registered motor-vehicles number, number of RTCs and consequent fatalities and injuries from 1997 to 2006. Results: RTC fatality and injury rates increased from 1997 to 2005, but decreased in 2006. The overall men/women ratio in the RTC fatalities was 4.2:1. High RTC fatality rate of 39 per 100 000 population in Iran was almost the same as some other developing countries. In Iran, RTC fatalities in recent years were almost twice as much as the highest rate among the European countries. Conclusions: This investigation shows that in spite of reduction of RTC fatality in Iran in 2006, it is still one of the highest in the world. Moreover, this paper describes the state of RTC-related parameters in a developing country in comparison with the developed countries.
文摘Objective: The association of scapular fractures with other life-threatening injuries including blunt thoracic aortic injury is widely recognized. Few studies have investigated this presumed association. In this study, we investigated the incidence of significant associated injuries with scapular fracture and their outcomes. Methods: A retrospective study was conducted from 2005 to 2009 in a level I trauma center in Thailand. All blunt trauma patients were identified. Patients' demographics, injury mechanism, associated injuries, Injury Severity Score (ISS), and survival outcomes were recorded. The manage- ment of associated injuries with scapular fracture was reviewed, and the risk factors for mortality were identified. Results: Among the 7 345 trauma patients admitted, scapular fractures occurred in 84 cases (1.1%). The mean age was (37.98±15.21) years. Motorcycle crash was the most frequent mechanism of injury, occurring in 51 cases (60.7%).Seventyour patients (88.1%) suffering from scapular fractures had associated injuries: 5 (6.0%) had significant chest injuries, but none of them had blunt thoracic aortic injury. Two patients (2.4%) with scapular fractures died. Factors determining the likelihood of mortality were: (1) ISS〉25 (LR=8.5, P〈0.05); (2) significant associated chest injury (AIS〉3, LR=5.3, P〈0.05) and (3) significant associated abdominal injury (AIS〉3, LR=5.3, P〈0.05). Conclusion: A blunt scapular fracture may not accompany a blunt thoracic aortic injury but it is strongly related to other injuries like chest injury, extremity injury, head injury, etc. If a scapular fracture is found with a high ISS score, high chest or abdomen AIS score, the patient would have a high risk of mortality.
文摘Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was considered from the Department of Forensic Medicine, Shahid Bahonar University of Kerman, involving drivers of all ages and covering a four-year period. Results: The male fatality rates were significantly higher than female ones. The groups at 15-30 years old and at 30-55 years old had the first and second highest numbers of deaths (40% and 34%, respectively). There were substantial differences in distribution of injuries in motor vehicle occupants and pedestrians and bicyclists. Among motor vehicle occupants, there were more head injuries, such as skull fracture, brain contusion, subdural haemorrhage, and epidural haemorrhage. Nearly 77% of fatalities occurred during 08:00-22:00 in Sirjan. Internal bleeding was also higher in motor vehicle occupants. Pedestrians and bicyclists also had head injuries frequently. Conclusions: In spite of reduction of road traffic fatalities in Sirjan in 2007, it is still one of the cities with high road traffic fatality in the world. These results underline the importance of preventive strategies in transportation, suggesting that different methods are necessary to reduce fatalities of various traffic participants.