Sample records for bicycle helmets

  1. Head injuries and bicycle helmet laws. (United States)

    Robinson, D L


    The first year of the mandatory bicycle helmet laws in Australia saw increased helmet wearing from 31% to 75% of cyclists in Victoria and from 31% of children and 26% of adults in New South Wales (NSW) to 76% and 85%. However, the two major surveys using matched before and after samples in Melbourne (Finch et al. 1993; Report No. 45, Monash Univ. Accident Research Centre) and throughout NSW (Smith and Milthorpe 1993; Roads and Traffic Authority) observed reductions in numbers of child cyclists 15 and 2.2 times greater than the increase in numbers of children wearing helmets. This suggests the greatest effect of the helmet law was not to encourage cyclists to wear helmets, but to discourage cycling. In contrast, despite increases to at least 75% helmet wearing, the proportion of head injuries in cyclists admitted or treated at hospital declined by an average of only 13%. The percentage of cyclists with head injuries after collisions with motor vehicles in Victoria declined by more, but the proportion of head injured pedestrians also declined; the two followed a very similar trend. These trends may have been caused by major road safety initiatives introduced at the same time as the helmet law and directed at both speeding and drink-driving. The initiatives seem to have been remarkably effective in reducing road trauma for all road users, perhaps affecting the proportions of victims suffering head injuries as well as total injuries. The benefits of cycling, even without a helmet, have been estimated to outweigh the hazards by a factor of 20 to 1 (Hillman 1993. Cycle helmets-the case for and against. Policy Studies Institute, London). Consequently, a helmet law, whose most notable effect was to reduce cycling, may have generated a net loss of health benefits to the nation. Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection. Helmets for motor

  2. Rates of bicycle helmet use in an affluent Michigan County. (United States)

    Jacques, L B


    Bicycle helmet use in the United States has remained low despite clear demonstration of its beneficial effect on reducing the incidence of serious head injury. Several interventions have been reported, with variable results and costs. Much of the recent literature has focused on child cyclists and on demographic factors associated with helmet use. This paper reports on helmet use by children and adults in a sample of 652 riders in an affluent southeast Michigan region, chosen to minimize the effect of previously recognized socioeconomic negative predictors that are not readily changed by intervention. Subjects were classified by age, sex, location, riding surface, type of bicycle, child bicycle seat use, child bicycle trailer use, and helmet use by companions. Overall helmet use was 24 percent; infants and toddlers had the highest rate of helmet use at 61 percent, followed by adults at 26 percent and school-aged children at 17 percent. The strongest predictor of helmet use in all age categories was the presence of a helmeted companion. Adult helmet use was also positively predicted by riding in the street and by riding a racing-type bicycle. The use of a city-type bicycle negatively predicted helmet use. For non-adults, female sex and the use of a child seat or trailer were positive predictors. Fostering peer pressure to increase helmet use may be an effective yet relatively inexpensive way to achieve the goal of widespread use of bicycle helmets.

  3. Bicycle helmet ventilation and comfort angle dependence. (United States)

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A


    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  4. The Bicycle Helmet Attitudes Scale: Using the Health Belief Model to Predict Helmet Use among Undergraduates (United States)

    Ross, Thomas P.; Ross, Lisa Thomson; Rahman, Annalise; Cataldo, Shayla


    Objective: This study examined bicycle helmet attitudes and practices of college undergraduates and developed the Bicycle Helmet Attitudes Scale, which was guided by the Health Belief Model (HBM; Rosenstock, 1974, in Becker MH, ed. "The Health Belief Model and Personal Health Behavior". Thorofare, NJ: Charles B. Slack; 1974:328-335) to predict…

  5. Rates of bicycle helmet use in an affluent Michigan County.


    Jacques, L B


    Bicycle helmet use in the United States has remained low despite clear demonstration of its beneficial effect on reducing the incidence of serious head injury. Several interventions have been reported, with variable results and costs. Much of the recent literature has focused on child cyclists and on demographic factors associated with helmet use. This paper reports on helmet use by children and adults in a sample of 652 riders in an affluent southeast Michigan region, chosen to minimize the ...

  6. The Effect of an All-Ages Bicycle Helmet Law on Bicycle-Related Trauma. (United States)

    Kett, Paula; Rivara, Frederick; Gomez, Anthony; Kirk, Annie Phare; Yantsides, Christina


    In 2003, Seattle implemented an all-ages bicycle helmet law; King County outside of Seattle had implemented a similar law since 1994. For the period 2000-2010, the effect of the helmet legislation on helmet use, helmet-preventable injuries, and bicycle-related fatalities was examined, comparing Seattle to the rest of King County. Data was retrieved from the Washington State Trauma Registry and the King County Medical Examiner. Results comparing the proportions of bicycle related head injuries before (2000-2002) and after (2004-2010) the law show no significant change in the proportion of bicyclists admitted to the hospital and treated for head injuries in either Seattle (37.9 vs 40.2 % p = 0.75) nor in the rest of King County (30.7 vs 31.4 %, p = 0.84) with the extension of the helmet law to Seattle in 2003. However, bicycle-related major head trauma as a proportion of all bicycle-related head trauma did decrease significantly in Seattle (83.9 vs 64.9 %, p = 0.04), while there was no significant change in King County (64.4 vs 57.6 %, p = 0.41). While the results do not show an overall decrease in head injuries, they do reveal a decrease in the severity of head injuries, as well as bicycle-related fatalities, suggesting that the helmet legislation was effective in reducing severe disability and death, contributing to injury prevention in Seattle and King County. The promotion of helmet use through an all ages helmet law is a vital preventative strategy for reducing major bicycle-related head trauma.

  7. Observational study of compliance with Queensland bicycle helmet laws. (United States)

    Debnath, Ashim Kumar; Haworth, Narelle; Schramm, Amy; Williamson, Amy


    Mandatory bicycle helmet laws have been found to increase helmet wearing rates in Australia and internationally. However, much of the research on factors influencing compliance with the Australian helmet laws is dated or focuses on commuters and city areas only. To address this gap, video recordings of bicycle riders were undertaken at 17 sites across Queensland, Australia, representing a mixture of on- and off-road locations, speed limits and regions. Helmet status was able to be determined for 98% of riders observed. The level of compliance with the laws was very high, with 98.3% of the more than 27,000 riders observed wearing helmets. Riders riding on roads were less compliant than those riding on bicycle paths, but no significant differences were observed between the school-holiday and school-term periods. Among the on-road riders, boys were less compliant than girls and overall children were less compliant than adults. Higher compliance levels were found for group riders, road bike riders, lycra-clad riders, during morning hours, and on 50km/h or lower speed limit roads. While the overall level of compliance was very high, certain subgroups were identified as a possible focus for interventions to further improve the compliance level, for example children (particularly boys) riding mountain bikes away from groups during the afternoon hours on 60km/h roads.

  8. Bicycle helmet use and non-use - recently published research. (United States)

    Uibel, Stefanie; Müller, Daniel; Klingelhoefer, Doris; Groneberg, David A


    Bicycle traumata are very common and especially neurologic complications lead to disability and death in all stages of the life. This review assembles the most recent findings concerning research in the field of bicycle traumata combined with the factor of bicycle helmet use. The area of bicycle trauma research is by nature multidisciplinary and relevant not only for physicians but also for experts with educational, engineering, judicial, rehabilitative or public health functions. Due to this plurality of global publications and special subjects, short time reviews help to detect recent research directions and provide also information from neighbour disciplines for researchers. It can be stated that to date, that although a huge amount of research has been conducted in this area more studies are needed to evaluate and improve special conditions and needs in different regions, ages, nationalities and to create successful prevention programs of severe head and face injuries while cycling.Focus was explicit the bicycle helmet use, wherefore sledding, ski and snowboard studies were excluded and only one study concerning electric bicycles remained due to similar motion structures within this review. The considered studies were all published between January 2010 and August 2011 and were identified via the online databases Medline PubMed and ISI Web of Science.

  9. The impact response of traditional and BMX-style bicycle helmets at different impact severities. (United States)

    DeMarco, Alyssa L; Chimich, Dennis D; Gardiner, John C; Siegmund, Gunter P


    Bicycle helmets reduce the frequency and severity of severe to fatal head and brain injuries in bicycle crashes. Our goal here was to measure the impact attenuation performance of common bicycle helmets over a range of impact speeds. We performed 127 drop tests using 13 different bicycle helmet models (6 traditional style helmets and 7 BMX-style helmets) at impact speeds ranging from 1 to 10m/s onto a flat anvil. Helmets were struck on their left front and/or right front areas, a common impact location that was at or just below the test line of most bicycle helmet standards. All but one of the 10 certified helmet models remained below the 300g level at an impact speed of 6m/s, whereas none of the 3 uncertified helmets met this criterion. We found that the helmets with expanded polystyrene liners performed similarly and universally well. The single certified helmet with a polyurethane liner performed below the level expected by the Consumer Product Safety Commission (CPSC) standard at our impact location and the helmet structure failed during one of two supplemental tests of this helmet above the test line. Overall, we found that increased liner thickness generally reduced peak headform acceleration, particularly at higher impact speeds.

  10. Factors associated with bicycle-helmet use among 8-16 years aged Turkish children: a questionnaire survey. (United States)

    Secginli, Selda; Cosansu, Gulhan; Nahcivan, Nursen O


    The purpose of this cross-sectional, descriptive study was to assess the rates of helmet and to examine variables related to bicycle helmet use in a sample of 8-16 year old Turkish children. Data were collected from a purposive sample of 1180 students who self-identified as cyclists and 1128 parents or guardians in two state primary schools in two urban municipalities in the northern part of Istanbul, Turkey. Results showed that self-reported helmet use was found prevalent in 4.4% of the children. The most cited reasons for not wearing a helmet were: 'don't own one', 'helmets are uncool', and 'uncomfortable'. Significant differences between helmet users and non-users correlated to gender, age, owning a bicycle helmet, wearing a friend's bicycle helmet and parents or guardian's bicycle helmet use while riding. Only three variables--helmet ownership (OR = 10.028, 95% CI 5.08, 19.79), parents' helmet use (OR = 2.62, 95% CI 1.22, 5.66) and friends' helmet use (OR = 0.16, 95% CI 0.07, 0.37) emerged as significant predictors of the likelihood of helmet use. The relatively low helmet use prevalence points to an urgent need for a multipronged campaign, including strategies such as raising awareness, educating primarly parents and friends, and distributing bicycle helmets for free or at a reduced cost.

  11. Evaluation of a promotional strategy to increase bicycle helmet use by children. (United States)

    Parkin, P C; Spence, L J; Hu, X; Kranz, K E; Shortt, L G; Wesson, D E


    Bicycle-related head injuries are an important cause of death and disability, despite the availability of helmets. The objective of this study was to evaluate the effectiveness of a school-based bicycle helmet promotion program in increasing helmet use by children while controlling for secular trends. Two high-income and two low-income schools in an urban Canadian community were selected to receive a bicycle helmet promotion intervention, with the remaining 18 schools serving as controls. Approximately 1800 observations of bicycling children were made at randomly selected observational sites 2 to 5 months after the intervention to assess changes in behavior. Helmet use at all observation sites tripled from 3.4% (1990, preintervention) to 16% (1991, postintervention). In the high-income intervention area, observed helmet use rose dramatically from 4% to 36% in contrast to the more modest increase in the high-income control area from 4% to 15%. In the low-income intervention area, there was a modest increase from 1% to 7%, but it did not differ from the increase in the low-income control area from 3% to 13%. The program was highly successful in children of high-income families but not in children of low-income families. Developing strategies for low-income families remains a priority.

  12. Angular Impact Mitigation system for bicycle helmets to reduce head acceleration and risk of traumatic brain injury. (United States)

    Hansen, Kirk; Dau, Nathan; Feist, Florian; Deck, Caroline; Willinger, Rémy; Madey, Steven M; Bottlang, Michael


    Angular acceleration of the head is a known cause of traumatic brain injury (TBI), but contemporary bicycle helmets lack dedicated mechanisms to mitigate angular acceleration. A novel Angular Impact Mitigation (AIM) system for bicycle helmets has been developed that employs an elastically suspended aluminum honeycomb liner to absorb linear acceleration in normal impacts as well as angular acceleration in oblique impacts. This study tested bicycle helmets with and without AIM technology to comparatively assess impact mitigation. Normal impact tests were performed to measure linear head acceleration. Oblique impact tests were performed to measure angular head acceleration and neck loading. Furthermore, acceleration histories of oblique impacts were analyzed in a computational head model to predict the resulting risk of TBI in the form of concussion and diffuse axonal injury (DAI). Compared to standard helmets, AIM helmets resulted in a 14% reduction in peak linear acceleration (pbicycle helmet, and may enhance prevention of bicycle-related TBI. Further research is required.

  13. Relationship between Locations of Facial Injury and the Use of Bicycle Helmets: A Systematic Review. (United States)

    Hwang, Kun; Jeon, Yun Moon; Ko, Yeong Seung; Kim, Yeon Soo


    The aim of this study is to review the protective effect of a bicycle helmet on each facial location systematically. PubMed was searched for articles published before December 12, 2014. The data were summarized, and the odds ratio (OR) between the locations of facial injury was calculated. A statistical analysis was performed with Review Manager (The Nordic Cochrane Centre). Bicycle helmets protect the upper and middle face from serious facial injury but do not protect the lower face. Non-wearers had significantly increased risks of upper facial injury (OR, 2.07; Pchin cap might decrease the risk of lower facial injury.

  14. Adult headform impact tests of three Japanese child bicycle helmets into a vehicle. (United States)

    Mizuno, Koji; Ito, Daisuke; Yoshida, Ryoichi; Masuda, Hiroyuki; Okada, Hiroshi; Nomura, Mitsunori; Fujii, Chikayo


    The head is the body region that most frequently incurs fatal and serious injuries of cyclists in collisions against vehicles. Many research studies investigated helmet effectiveness in preventing head injuries using accident data. In this study, the impact attenuation characteristics of three Japanese child bicycle helmets were examined experimentally in impact tests into a concrete surface and a vehicle. A pedestrian adult headform with and without a Japanese child bicycle helmet was dropped onto a concrete surface and then propelled into a vehicle at 35 km/h in various locations such as the bonnet, roof header, windshield and A-pillar. Accelerations were measured and head injury criterion (HIC) calculated. In the drop tests using the adult headform onto a concrete surface from the height of 1.5m, the HIC for a headform without a child helmet was 6325, and was reduced by around 80% when a child helmet was fitted to the headform. In the impact tests, where the headform was fired into the vehicle at 35 km/h at various locations on a car, the computed acceleration based HIC varied depending on the vehicle impact locations. The HIC was reduced by 10-38% for impacts headforms with a child helmet when the impact was onto a bonnet-top and roof header although the HIC was already less than 1000 in impacts with the headform without a child helmet. Similarly, for impacts into the windshield (where a cyclist's head is most frequently impacted), the HIC using the adult headform without a child helmet was 122; whereas when the adult headform was used with a child helmet, a higher HIC value of more than 850 was recorded. But again, the HIC values are below 1000. In impacts into the A-pillar, the HIC was 4816 for a headform without a child helmet and was reduced by 18-38% for a headform with a child helmet depending on the type of Japanese child helmet used. The tests demonstrated that Japanese child helmets are effective in reducing accelerations and HIC in a drop test using

  15. Long-Term Effects of Education and Legislation Enforcement on All-Age Bicycle Helmet Use: A Longitudinal Study. (United States)

    Huybers, Sherry; Fenerty, Lynne; Kureshi, Nelofar; Thibault-Halman, Ginette; LeBlanc, John C; Clarke, David B; Walling, Simon


    Bicycle-related injuries are a leading cause of child and youth hospitalizations in Canada. The use of helmets while bicycling reduces the risk of brain injuries. This study investigated the long-term effect of legislation coupled with enforcement to improve helmet use rates. We conducted a longitudinal observational study of helmet use at 9, 11, and 14 years after bicycle helmet legislation was enacted. Data were compared to baseline observations collected after legislation was passed in 1997. A comprehensive enforcement and educational diversion program, Operation Headway-Noggin Knowledge (OP-NK), was developed and implemented in partnership with regional police during the study period. Helmet use was sustained throughout the post-legislation period, from 75.3 % in the year legislation was enacted to 94.2 % 14 years post-legislation. The increase in helmet use was seen among all age groups and genders. Helmet legislation was not associated with changes in bicycle ridership over the study years. OP-NK was associated with improved enforcement efforts as evidenced by the number of tickets issued to noncompliant bicycle riders. This observational study spans a 16-year study period extending from pre-legislation to 14 years post all-age bicycle helmet legislation. Our study results demonstrate that a comprehensive approach that couples education and awareness with ongoing enforcement of helmet legislation is associated with long-term sustained helmet use rates. The diversion program described herein is listed among best practices by the Public Health Agency of Canada.

  16. Bicycle helmets are highly effective at preventing head injury during head impact: head-form accelerations and injury criteria for helmeted and unhelmeted impacts. (United States)

    Cripton, Peter A; Dressler, Daniel M; Stuart, Cameron A; Dennison, Christopher R; Richards, Darrin


    Cycling is a popular form of recreation and method of commuting with clear health benefits. However, cycling is not without risk. In Canada, cycling injuries are more common than in any other summer sport; and according to the US National Highway and Traffic Safety Administration, 52,000 cyclists were injured in the US in 2010. Head injuries account for approximately two-thirds of hospital admissions and three-quarters of fatal injuries among injured cyclists. In many jurisdictions and across all age levels, helmets have been adopted to mitigate risk of serious head injuries among cyclists and the majority of epidemiological literature suggests that helmets effectively reduce risk of injury. Critics have raised questions over the actual efficacy of helmets by pointing to weaknesses in existing helmet epidemiology including selection bias and lack of appropriate control for the type of impact sustained by the cyclist and the severity of the head impact. These criticisms demonstrate the difficulty in conducting epidemiology studies that will be regarded as definitive and the need for complementary biomechanical studies where confounding factors can be adequately controlled. In the bicycle helmet context, there is a paucity of biomechanical data comparing helmeted to unhelmeted head impacts and, to our knowledge, there is no data of this type available with contemporary helmets. In this research, our objective was to perform biomechanical testing of paired helmeted and unhelmeted head impacts using a validated anthropomorphic test headform and a range of drop heights between 0.5m and 3.0m, while measuring headform acceleration and Head Injury Criterion (HIC). In the 2m (6.3m/s) drops, the middle of our drop height range, the helmet reduced peak accelerations from 824g (unhelmeted) to 181g (helmeted) and HIC was reduced from 9667 (unhelmeted) to 1250 (helmeted). At realistic impact speeds of 5.4m/s (1.5m drop) and 6.3m/s (2.0m drop), bicycle helmets changed the

  17. Age Does Not Affect the Material Properties of Expanded Polystyrene Liners in Field-Used Bicycle Helmets. (United States)

    Kroeker, Shannon G; Bonin, Stephanie J; DeMarco, Alyssa L; Good, Craig A; Siegmund, Gunter P


    Bicycle helmet foam liners absorb energy during impacts. Our goal was to determine if the impact attenuation properties of expanded polystyrene (EPS) foam used in bicycle helmets change with age. Foam cores were extracted from 63 used and unused bicycle helmets from ten different models spanning an age range of 2-20 yrs. All cores were impact tested at a bulk strain rate of 195 s(-1). Six dependent variables were determined from the stress-strain curve derived from each impact (yield strain, yield stress, elastic modulus, plateau slope, energy at 65% compression, and stress at 65% compression), and a general linear model was used to assess the effect of age on each dependent variable with density as a covariate. Age did not affect any of the dependent variables; however, greater foam density, which varied from 58 to 100 kg/m(3), generated significant increases in all of the dependent variables except for yield strain. Higher density foam cores also exhibited lower strains at which densification began to occur, tended to stay within the plateau region of the stress-strain curve, and were not compressed as much compared with the lower density cores. Based on these data, the impact attenuation properties of EPS foam in field-used bicycle helmets do not degrade with the age.

  18. Bicycle helmets.

    NARCIS (Netherlands)


    One third of the cyclists who are admitted to hospital with serious injury after a road crash are diagnosed with head or brain injury. Approximately three-quarters of the head and brain injuries among cyclists are caused by crashes that do not involve motorized traffic; as many as nine out of ten yo

  19. The cost-effectiveness of compulsory bicycle helmets in New Zealand. (United States)

    Hansen, P; Scuffham, P A


    This paper examines the cost-effectiveness for primary school children (age 5-12 years), secondary school children (13-18 years) and adults (over 18 years) of the legislation enacted on 1 January 1994 requiring road-cyclists in New Zealand to wear helmets. The cost to cyclists not in possession of a helmet before they became compulsory of either obtaining one or quitting cycling was compared with the number of deaths and hospitalisations expected to be prevented over the average life of a helmet. Corresponding to Victorian and United States estimates of the efficacy of cycle helmets at preventing serious head injuries, the cost per life saved was $88 379 to $113 744 for primary school children, $694 013 to $817 874 for secondary school children, and $890 041 to $1 014 850 for adults (New Zealand dollars = approximately 0.95 Australian dollars). The cost per hospitalisation avoided was $3304 to $4252, $17 207 to $20 278, and $49 143 to $56 035 respectively. These estimates are extremely sensitive to the estimated efficacy of helmets at protecting cyclists. Mainly anecdotal evidence for New Zealand suggests that they are not to be very effective at preventing serious head injuries; future research into the change in injury patterns as a result of the helmet regulation would be valuable. Nonetheless, the ranking of the abovementioned estimates does not contradict the policy in some parts of the world requiring helmets for children and/or teenagers, but not adults.

  20. Aerodynamics of cyclist posture, bicycle and helmet characteristics in time trial stage. (United States)

    Chabroux, Vincent; Barelle, Caroline; Favier, Daniel


    The present work is focused on the aerodynamic study of different parameters, including both the posture of a cyclist's upper limbs and the saddle position, in time trial (TT) stages. The aerodynamic influence of a TT helmet large visor is also quantified as a function of the helmet inclination. Experiments conducted in a wind tunnel on nine professional cyclists provided drag force and frontal area measurements to determine the drag force coefficient. Data statistical analysis clearly shows that the hands positioning on shifters and the elbows joined together are significantly reducing the cyclist drag force. Concerning the saddle position, the drag force is shown to be significantly increased (about 3%) when the saddle is raised. The usual helmet inclination appears to be the inclination value minimizing the drag force. Moreover, the addition of a large visor on the helmet is shown to provide a drag coefficient reduction as a function of the helmet inclination. Present results indicate that variations in the TT cyclist posture, the saddle position and the helmet visor can produce a significant gain in time (up to 2.2%) during stages.

  1. Corrigendum to: “Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: a re-analysis of Attewell, Glase and McFadden, 2001” [Accid. Anal. Prev. 43 (2011) 1245–1251]. (United States)

    Elvik, Rune


    This paper is a corrigendum to the previously published paper: “Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001” [Accid. Anal. Prev. (2011) 1245–1251]. This corrigendum was prepared to correct errors in data and analysis in the previously published paper. Like the previously published paper, this paper confirms that the meta-analysis of bicycle helmet efficacy reported by Attewell, Glase and McFadden (Accident Analysis and Prevention, 2001, 345–352) was influenced by publication bias and time-trend bias that was not controlled for. As a result, the analysis reported inflated estimates of the effects of bicycle helmets. This paper presents a re-analysis of the study. The re-analysis included: (1) Ensuring the inclusion of all published studies by means of continuity corrections of estimates of effect relying on zero counts; (2) detecting and adjusting for publication bias by means of the trim-and-fill method; (3) detecting and trying to account for a time-trend bias in estimates of the effects of bicycle helmets; (4) updating the study by including recently published studies evaluating the effects of bicycle helmets. The re-analysis shows smaller safety benefits associated with the use of bicycle helmets than the original study.

  2. Traffic safety behaviour among young people in different residential settings: the use of seat belts, bicycle helmets, and reflectors by young people in Sweden. (United States)

    Wall, Erika


    This study examines if, and how, the size of the community in which people live may contribute to explaining differences in traffic safety behaviour (self-reported behaviour regarding the use of seat belts, bicycle helmets and reflectors) among young people in Sweden. The study is based on a Swedish nationwide traffic safety survey with a net sample of 2854 respondents aged 16-25. Ordered logit regressions were performed, and place of residence is shown to have an impact on traffic safety behaviour. The results are presented and discussed in relation to risk exposure and traffic safety facilities in different settings. The implications of the study are considered, and the importance of investigating the way in which young people see traffic safety behaviour is emphasised.

  3. Bicycle accidents. (United States)

    Lind, M G; Wollin, S


    Information concerning 520 bicycle accidents and their victims was obtained from medical records and the victims' replies to questionnaires. The analyzed aspects included risk of injury, completeness of accident registrations by police and in hospitals, types of injuries and influence of the cyclists' age and sex, alcohol, fatigue, hunger, haste, physical disability, purpose of cycling, wearing of protective helmet and other clothing, type and quality of road surface, site of accident (road junctions, separate cycle paths, etc.) and turning manoeuvres.

  4. A Bicycle Safety Education Program for Parents of Young Children (United States)

    Lohse, Julie L.


    This study examined parental perceptions of the benefits and barriers to bicycle helmet use and their level of knowledge about bicycle safety issues. A school-based bicycle safety education program was taught to first- and second-grade students in a rural/suburban school district by a graduate nursing student. Pender's Health Promotion Model was…

  5. [Prevention of bicycle accidents]. (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T


    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  6. Bicycle safety (United States)

    ... states have bike lanes and laws that protect bicycle riders. But riders are still at risk of ... stop or take evasive action. While riding your bicycle: Watch for opening car doors, potholes, children, and ...

  7. Helmet blastometer

    Energy Technology Data Exchange (ETDEWEB)

    Moss, William C; King, Michael J


    A helmet blastometer for characterizing the direction, speed, magnitude, and duration of a blast event to determine the likelihood of blast-induced traumatic brain injury (biTBI). Time of arrival (TOA) gage sensors are mounted on a rigid outer shell of the helmet each producing a TOA signal in response to a fast rising blast induced positive pressure change above a predetermined threshold. A receiver analyzes the positive pressure changes from the gages to determine direction, speed, and magnitude of a blast. Other TOA gauge sensors can be used to produce a TOA signal in response to a negative pressure change below a predetermined threshold. The positive and negative pressure change TOA signals are used to determine blast duration. A second set of internal contact pressure sensors is connected to an inner liner of the helmet to detect contact pressure on a user's head to determine if biTBI has been sustained.

  8. Bicycling injuries. (United States)

    Silberman, Marc R


    Bicycling injuries can be classified into bicycle contact, traumatic, and overuse injuries. Despite the popularity of cycling, there are few scientific studies regarding injuries. Epidemiological studies are difficult to compare due to different methodologies and the diverse population of cyclists studied. There are only three studies conducted on top level professionals. Ninety-four percent of professionals in 1 year have experienced at least one overuse injury. Most overuse injuries are mild with limited time off the bike. The most common site of overuse injury is the knee, and the most common site of traumatic injury is the shoulder, with the clavicle having the most common fracture. Many overuse and bicycle contact ailments are relieved with simple bike adjustments.

  9. Bicycle Wheel (United States)


    An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.

  10. 16 CFR Figure 5 to Part 1203 - Location of Tesr Lines for Helmets Intended for Persons Ages 1 and Older (United States)


    ... for Persons Ages 1 and Older 5 Figure 5 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt. 1203, Fig. 5 Figure 5 to Part 1203—Location of Tesr Lines for Helmets Intended for Persons Ages 1 and Older...

  11. A transient finite element study reveals the importance of the bycicle helmet material properties on head protection during an impact


    Asiminei, Aida Georgeta; Van der Perre, Georges; Verpoest, Ignace; Goffin, Jan


    This paper is focused on understanding the mechanism that gives the bicycle helmet the role of protecting the head during an impact. The finite element method is used here as a first step in the helmet optimisation and improvement process. The relation between different helmet mechanical parameters and the risk of head injury during the impact is described using MSC Marc Mentat finite element software. The reduction in resulting head linear acceleration by more than 80% and in resulting stres...

  12. Crash helmets for moped riders.

    NARCIS (Netherlands)

    Noordzij, P.C. & Paar, H.G.


    Research has been done into the requirements for crash helmets for moped drivers not only in relation to their comfort but also to their protection. It is stated that any helmet is better than no helmet.

  13. Evaluation of a pilot program in rural schools to increase bicycle and motor vehicle safety. (United States)

    Floerchinger-Franks, G; Machala, M; Goodale, K; Gerberding, S


    Concerned with high bicycle-and motor vehicle-related mortality rates among children, Idaho's South Central District Health Department provided a competition to increase use of 1) seat belts, 2) motor vehicle rear seating, and 3) bicycle helmets among children attending elementary schools in the eight rural counties it serves. Nine of the 44 elementary schools in the health district chose to participate in the contest. Eight schools addressed increasing helmet use, four schools also addressed increasing seat belt use and rear seating, and one school addressed safety in general. A $1,000 prize was awarded to each of four schools judged to have the highest levels of student and community involvement, outreach, creativity, and changes in safety behavior (based on perceptions of outside judges). In 1997, baseline observations were collected for 1) seat belt use and rear seating for children in 28 schools, and for 2) bicycle helmet use among children in 25 schools. In 1998, follow up data were collected for 1) seat belt and rear seating in 42 schools, and 2) bicycle helmet use in 35 schools. Data were analyzed using SAS. Adjusting for differences in baseline rates, regression analysis was used to compare 1997 and 1998 rates for seat belt use, rear seating, and bicycle helmet use for those schools having baseline data. Results showed that although there was no significant difference between participating and non-participating schools in rear-seating behaviors, there was an increase in seat belt and bicycle helmet use for participating schools. Since schools self-selected participation, it is unknown whether those schools were fundamentally different from nonparticipating schools.

  14. HOPE: Helmet Optimization in Europe. The final report of COST Action TU1101.

    NARCIS (Netherlands)

    Bogerd, C.P. Annaheim, S. Halldin, P. Houtenbos, M. Otte, D. Shinar, D. Walker, I. & Willinger, R.


    The primary purpose of COST Action TU1101 was to stimulate collaboration and networking amongst European scientists working in the field of bicycle helmet safety and improvement. By gathering together in a single, collective Action, researchers can improve the collection and dissemination of data fr

  15. HOPE: Helmet Optimization in Europe. Final report of Working Group 2: Traffic psychology.

    NARCIS (Netherlands)

    Shinar, D. Bogerd, C.P. Chliaoutakis, J. Cavallo, V. Crundall, D. Dias, J. Haworth, N. Holt, N. Houtenbos, M. Kuklane, K. Lajunen, T. Morandi, A. Oron-Gilad, T. Orsi, C. Papadakaki, M. Parkkari, K. Rus, D. Saplioglu, M. Tzamalouka, G. Valero-Mora, P. Walker, I. Wardlow, M. & Weber, T.


    The HOPES workgroup of Traffic Psychology is concerned with the social, behavioral, and perceptual aspects that are associated with use and non-use of bicycle helmets, in their various forms and under various cycling conditions. The objectives of WG2 are to (1) share current knowledge among the peop

  16. Lost Kingdom of Bicycles?

    Institute of Scientific and Technical Information of China (English)


    For most people born in the 1950s and '60s, the bicycle was a faithful companion of their youth, when China was known as a kingdom of bicycles. A bicycle ride was a favorite pastime during a colorful spring day or in the crisp

  17. Bikes, helmets, and public health: decision-making when goods collide. (United States)

    Bateman-House, Alison


    How ought public officials address policy choices that entail trade-offs between desirable public health goods? Increasing cycling improves public health both by promoting physical activity and by decreasing vehicle use, thus reducing vehicular emissions. Proponents of bicycle helmets argue that, used properly, they protect individual cyclists; however, there is concern that mandating helmet use may result in a decrease in cycling. In 2012, New York City Mayor Michael Bloomberg opposed a bicycle helmet mandate, concerned that it would have a negative impact on the city's cycling rate, which he had sought to increase. The mayor did not explain his rationale, leaving constituents unsure why he opposed the proposal. This case study underscores the challenge of creating public policy in the context of competing public health goods.

  18. Advanced Extravehicular Helmet Assembly Project (United States)

    National Aeronautics and Space Administration — The current NASA spacesuit community is focusing on utilizing a 13" hemispherical helmet for the next generation of extravehicular activity spacesuits. This helmet...

  19. Effects of Wearing a Helmet on Thermal Balance While Cycling in the Heat. (United States)

    Gisolfi, C V; Rohlf, D P; Navarude, S N; Hayes, C L; Sayeed, S A


    In brief: Many cyclists refuse to wear helmets because they produce discomfort and drag. To determine the effects of wearing a helmet on thermal balance and rating of perceived exertion while cycling in the heat, six male competitive cyclists aged 19 to 32 rode a stationary bicycle attached to a road-racing simulator in an environmentally controlled chamber for two hours at 70% V O2 max. Measurements were taken of rectal and skin temperatures, V O2, heart rate, sweat rate, and rating of perceived exertion. The results showed that (under the experimental conditions used) wearing a helmet while cycling in the heat does not alter thermal balance or cardiovascular strain compared with not wearing a helmet.

  20. Bicycle Braking System


    Brady, Noel


    A bicycle braking system for permitting controlled rotation and continuous power to the wheels of a bicycle during braking of the bicycle to enhance control of the bicycle during braking includes a cylindrical brake pad that is spring loaded within angled slots in a casing. The brake pad is positioned proximate the rim of a wheel and a cable assembly is coupled to the brake pad for urging the brake pad towards an end of the angled slots and against the rim of the wheel to slow rotation of the...

  1. Cyclists' helmet usage and characteristics in central and southern Malawi: a cross-sectional study. (United States)

    Kraemer, John D; Honermann, Brian J; Roffenbender, Jason S


    The objective of this study was to determine the prevalence of, and factors associated with, bicycle helmet usage in southern and central Malawi. This study was across-sectional observation of public behaviour. The urban and rural roadways in southern and central Malawi were studied during the dry season. In total, 1900 bicyclists were observed along the roadways of southern and central Malawi over a four-day period. Observer ascertainment of cyclists' helmet status, approximate age, sex and bicycle operator or passenger status were measured. Of the 1900 cyclists observed, no cyclist was identified as wearing a helmet (exact 95% CI: 0.0-0.2%). There was no variation by age, sex or operator/passenger status. Nearly, 91.5% of observed cyclists were males and 87.7% were operating the bicycle. The sizeable majority of male cyclists were classified as young adults from adolescence to 25 years old (47.2%) or adults over age 25 (44.9%); 7.9% of male cyclists were pre-adolescent. Passengers were more likely to be female than operators (39.1% versus 4.2%), though, even for passengers, a higher proportion were males than females (p Malawi, helmet usage is so rare as to be non-existent. This suggests an opportunity for significant improvement. Based on the observed cyclists' characteristics, interventions should be targeted to adult and young adult males.

  2. Public bike sharing in New York City: helmet use behavior patterns at 25 Citi Bike™ stations. (United States)

    Basch, Corey H; Ethan, Danna; Zybert, Patricia; Afzaal, Sarah; Spillane, Michael; Basch, Charles E


    Urban public bicycle sharing programs are on the rise in the United States. Launched in 2013, NYC's public bicycle share program, Citi Bike™ is the fastest growing program of its kind in the nation, with nearly 100,000 members and more than 330 docking stations across Manhattan and Brooklyn. The purpose of this study was to assess helmet use behavior among Citi Bike™ riders at 25 of the busiest docking stations. The 25 Citi Bike™ Stations varied greatly in terms of usage: total number of cyclists (N = 96-342), commute versus recreation (22.9-79.5% commute time riders), weekday versus weekend (6.0-49.0% weekend riders). Helmet use ranged between 2.9 and 29.2% across sites (median = 7.5 %). A total of 4,919 cyclists were observed, of whom 545 (11.1%) were wearing helmets. Incoming cyclists were more likely to wear helmets than outgoing cyclists (11.0 vs 5.9%, p = .000). NYC's bike share program endorses helmet use, but relies on education to encourage it. Our data confirm that, to date, this strategy has not been successful.

  3. Bicycles made to measure

    NARCIS (Netherlands)

    Van Dijk, T.


    For almost a century and a half, mathematicians have been racking their brains about the bike. How can a rolling bicycle be so stable of its own accord? Delft researchers now say they have completed the model to end all models. Bicycle manufacturer Batavus intends to use it to make better bikes for

  4. Bicycle Promotion Plan

    Energy Technology Data Exchange (ETDEWEB)

    Simone, G. A.


    The objective of this Bicycle Promotion Plan is to outline a set of recommendations and supporting strategies for implementation by the US DOE toward increased use of the bicycle for energy conservation. The recommendations are designed in such a way as to function in concert with: (1) bicycle programs administered by other Federal government agencies; and (2) related programs and activities already sponsored by DOE. The approach to preparation of the Plan involved a review of all current and planned bicycle promotion programs at the Federal level as well as a review of the array of lierature on the subject. The UniWorld project staff also interacted with several DOE program offices, in order to determine the extent to which they might appropriately contribute to the implementation of bicycle promotional efforts. A synthesis of all the information gathered was published in January of 1981 as a part of the project (The Bicycle Program Review). Based upon this information and an examination of the barriers to bicycle use identified by bicycle transportation specialists in the field, UniWorld developed a series of the most potentially effective recommendations and program strategies for implementation by DOE. The recommendations address activities that could be undertaken in conjunction with existing DOE programs, new developments that might be considered to fulfill critical needs in the field, and interagency efforts that DOE could play a role in.

  5. Helmet-Mounted Displays (HMD) (United States)

    Federal Laboratory Consortium — The Helmet-Mounted Display labis responsible for monocular HMD day display evaluations; monocular HMD night vision performance processes; binocular HMD day display...


    Directory of Open Access Journals (Sweden)

    P. A. Sheeju


    Full Text Available BACKGROUND Motor vehicle crashes are a major cause of fatality all over the world. By 2020, motor vehicle injury is projected to become the third leading contributor to the global burden of disease in the world. Motor cyclists are about 25 times more likely than car occupants to die in Road Traffic Accidents. Data on the incidence and types of crashes is required to guide safety policy. Knowledge of how injuries are caused and of what type they are of valuable instrument for identifying interventions and monitoring the effectiveness of intervention. The present study was done to find out the factors that contribute for motor cycle crashes and to study the injury pattern seen in helmeted and non-helmeted victims. MATERIAL AND METHODS Victims of two wheeler accidents brought for autopsy in a Govt. Medical College were studied from October 2010 to August 2011. Two wheelers include motor cycles, scooters and mopeds. Bicycles were excluded from the study. Accidents include all types; against all types of vehicles running on the road, collision with any object, surface or any animal or fall from vehicle. The details of the accident were collected in a printed proforma from relative/witnesses and from police officials. The injuries were entered in the specific columns of proforma. Data was analysed with MS Excel. RESULTS Death due to head injury is more in non-helmeted (52.5% compared to helmeted drivers (43.8 % whereas injury to chest and abdomen and limbs are more in helmeted. Combination of injuries (Head+Chest+Abdomen predominated in helmeted drivers (18.8% compared to 5% in non-helmeted drivers. Spinal injuries were more in helmeted than in non-helmeted. CONCLUSION The pattern of head injury was analysed in detail in helmeted and non-helmeted drivers. This will help in detailing of pattern of head injury in both groups.

  7. Quantifying bicycle network connectivity. (United States)

    Lowry, Michael; Loh, Tracy Hadden


    The intent of this study was to compare bicycle network connectivity for different types of bicyclists and different neighborhoods. Connectivity was defined as the ability to reach important destinations, such as grocery stores, banks, and elementary schools, via pathways or roads with low vehicle volumes and low speed limits. The analysis was conducted for 28 neighborhoods in Seattle, Washington under existing conditions and for a proposed bicycle master plan, which when complete will provide over 700 new bicycle facilities, including protected bike lanes, neighborhood greenways, and multi-use trails. The results showed different levels of connectivity across neighborhoods and for different types of bicyclists. Certain projects were shown to improve connectivity differently for confident and non-confident bicyclists. The analysis showed a positive correlation between connectivity and observed utilitarian bicycle trips. To improve connectivity for the majority of bicyclists, planners and policy-makers should provide bicycle facilities that allow immediate, low-stress access to the street network, such as neighborhood greenways. The analysis also suggests that policies and programs that build confidence for bicycling could greatly increase connectivity.

  8. Consequences of Underestimating Impalement Bicycle Handlebar Injuries in Children. (United States)

    Ramos-Irizarry, Carmen T; Swain, Shakeva; Troncoso-Munoz, Samantha; Duncan, Malvina

    Impalement bicycle handlebar trauma injuries are rare; however, on initial assessment, they have the potential of being underestimated. We reviewed our prospective trauma database of 3,894 patients for all bicycle injuries from January 2010 to May 2015. Isolated pedal bike injuries were reported in 2.6% (N = 101) of the patients who were admitted to the trauma service. Fifteen patients suffered direct handlebar trauma. Patients were grouped into blunt trauma (n = 12) and impalement trauma (n = 3). We examined gender, age, injury severity score (ISS), Glasgow Coma Scale score, use of protective devices, need for surgical intervention, need for intensive care (ICU), and hospital length of stay. Mean age was 9.6 years. All children with penetrating injuries were males. Mean ISS was less than 9 in both groups. None of the children were wearing bicycle helmets. Three patients who sustained blunt injuries required ICU care due to associated injuries. All of the children with impalement injuries required several surgical interventions. These injuries included a traumatic direct inguinal hernia, a medial groin and thigh laceration with resultant femoral hernia, and a lateral deep thigh laceration. Impalement bicycle handlebar injuries must be thoroughly evaluated, with a similar importance given to blunt injuries. A high index of suspicion must be maintained when examining children with handlebar impalement injuries, as they are at risk for missed or underestimation of their injuries.

  9. On a Bicycle in Beijing

    Institute of Scientific and Technical Information of China (English)



    @@ Other expats here in Beijing have all bought bicycles.One friend who was excited about his new bicycle told me he spent about 2,100 yuan($300).Another mentioned he had spent what would be equivalent to $500.

  10. 16 CFR Figure 4 to Part 1203 - Location of Test Lines for Helmets Intended for Persons Five (5) Years of Age and Older (United States)


    ... for Persons Five (5) Years of Age and Older 4 Figure 4 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt...) Years of Age and Older ER10MR98.004...

  11. Bicycles and Valentines

    Institute of Scientific and Technical Information of China (English)


    Shanghai municipality's announcement late last year that bicycles were to be banned from the city's main thoroughfares was ill received by many residents. The measure was taken to relieve traffic congestion and reflects how traditional modes of transport fail to meet the changing needs of Chinese contemporary life.

  12. Bicycle Trailers Increase Mobility (United States)

    Exceptional Parent, 2006


    This article describes the experiences of an exceptional parent who always takes his daughter for rides in a CycleTote special needs bicycle trailer. Dennis Foster, an exceptional parent from Commerce, Oklahoma, found that taking his twenty-eight-year-old daughter Hasha for rides has made her happy. Hasha has been diagnosed with cerebral palsy.

  13. The safety of electrically assisted bicycles compared to classic bicycles. (United States)

    Schepers, J P; Fishman, E; den Hertog, P; Wolt, K Klein; Schwab, A L


    Use of electrically assisted bicycles with a maximum speed of 25 km/h is rapidly increasing. This growth has been particularly rapid in the Netherlands, yet very little research has been conducted to assess the road safety implications. This case-control study compares the likelihood of crashes for which treatment at an emergency department is needed and injury consequences for electric bicycles to classic bicycles in the Netherlands among users of 16 years and older. Data were gathered through a survey of victims treated at emergency departments. Additionally, a survey of cyclists without any known crash experience, drawn from a panel of the Dutch population acted as a control sample. Logistic regression analysis is used to compare the risk of crashes with electric and classical bicycles requiring treatment at an emergency department. Among the victims treated at an emergency department we compared those being hospitalized to those being send home after the treatment at the emergency department to compare the injury consequences between electric and classical bicycle victims. The results suggest that, after controlling for age, gender and amount of bicycle use, electric bicycle users are more likely to be involved in a crash that requires treatment at an emergency department due to a crash. Crashes with electric bicycles are about equally severe as crashes with classic bicycles. We advise further research to develop policies to minimize the risk and maximize the health benefits for users of electric bicycles.

  14. The role of bicycle sharing systems in normalising the image of cycling: An observational study of London cyclists. (United States)

    Goodman, Anna; Green, Judith; Woodcock, James


    Bicycle sharing systems are increasingly popular around the world and have the potential to increase the visibility of people cycling in everyday clothing. This may in turn help normalise the image of cycling, and reduce perceptions that cycling is 'risky' or 'only for sporty people'. This paper sought to compare the use of specialist cycling clothing between users of the London bicycle sharing system (LBSS) and cyclists using personal bicycles. To do this, we observed 3594 people on bicycles at 35 randomly-selected locations across central and inner London. The 592 LBSS users were much less likely to wear helmets (16% vs. 64% among personal-bicycle cyclists), high-visibility clothes (11% vs. 35%) and sports clothes (2% vs. 25%). In total, 79% of LBSS users wore none of these types of specialist cycling clothing, as compared to only 30% of personal-bicycle cyclists. This was true of male and female LBSS cyclists alike (all p>0.25 for interaction). We conclude that bicycle sharing systems may not only encourage cycling directly, by providing bicycles to rent, but also indirectly, by increasing the number and diversity of cycling 'role models' visible.

  15. Requirements for crash helmets for moped riders.

    NARCIS (Netherlands)


    In proposals for the legal obligation for riders of motorised two-wheelers to wear helmets, requirements will be included for the construction of the helmet relating to protection against injuries in accidents, without the risk of causing other serious injuries. In order to make the helmet acceptab

  16. Combat Helmets and Blast Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Duncan Wallace


    Full Text Available Background: The conflicts in Iraq and Afghanistan and the prominence of traumatic brain injury (TBI, mostly from improvised explosive devices, have focused attention on the effectiveness of combat helmets. Purpose: This paper examines the importance of TBI, the role and history of the development of combat helmets, current helmet designs and effectiveness, helmet design methodology, helmet sensors, future research and recommendations. Method: A literature review was conducted using search terms – combat helmets, traumatic brain injury, concussion, Iraq, Afghanistan and helmet sensors, searching PubMed, MEDLINE, ProQuest and Google Scholar. Conclusions: At present, no existing helmet is able to fully protect against all threats faced on the battlefield. The prominence of traumatic brain injury from improvised explosive devices in the current conflicts in Iraq and Afghanistan has highlighted the limitations in knowledge about blast and how to provide protection from it. As a result, considerable research is currently occurring in how to protect the head from blast over-pressure. Helmet sensors may provide valuable data. Some new combat helmets may be able to protect against rifle rounds, but may result in injuries occurring behind body armour. Optimal combat helmet design requires a balance between the need for protection from trauma and the comfort and practicality of the helmet for the user to ensure the best outcomes.

  17. Butchers and Bicycles

    DEFF Research Database (Denmark)

    Kahle, Lynn; Eriksen, Steen Mandsfelt


    Morten Wagener is a Danish design, and innovator who founded the cargo and personal transportation bicycle company, ”Butchers and Bicycles,”. He identified a business opportunity to improve the future of urban transport. His idea was that most of the trikes) on the market lacked good design......, maneuverability and styling. With his engineering and design background, Wagener set out to design a new trike; which would meet the needs of the target market, which his research identified as well- educated individuals who were very interested in aesthetics. Furthermore, Wagener was convinced that trikes were...... between order and delivery. From a marketing perspective, one of the differentiating factors of Morten’s product is the quality of the ride (compared to competing products) and so his marketing team coined the slogan “Built-to-Tilt” because even though it’s a trike it feels like riding a two...

  18. Land of Bicycles

    Institute of Scientific and Technical Information of China (English)

    ZhangHua; LuRucai


    There are currently more than 500 million cyclists in China,10million of them in Bejing.Despite efficient bus networks,legions of taxis and surging private car ownership,the bicycle remains a firm fixture in Chinese daily life.But it is much more than just a means of transport to cyclists today,who demand a afr greater chioce of design and function than ever before.

  19. Teaching children about bicycle safety: an evaluation of the New Jersey Bike School program. (United States)

    Lachapelle, Ugo; Noland, Robert B; Von Hagen, Leigh Ann


    There are multiple health and environmental benefits associated with increasing bicycling among children. However, the use of bicycles is also associated with severe injuries and fatalities. In order to reduce bicycle crashes, a bicycling education program was implemented in selected New Jersey schools and summer camps as part of the New Jersey Safe Routes to School Program. Using a convenience sample of participants to the program, an opportunistic study was designed to evaluate the effectiveness of two bicycle education programs, the first a more-structured program delivered in a school setting, with no on-road component, and the other a less structured program delivered in a summer camp setting that included an on-road component. Tests administered before and after training were designed to assess knowledge acquired during the training. Questions assessed children's existing knowledge of helmet use and other equipment, bicycle safety, as well as their ability to discriminate hazards and understand rules of the road. Participating children (n=699) also completed a travel survey that assessed their bicycling behavior and their perception of safety issues. Response to individual questions, overall pre- and post-training test scores, and changes in test scores were compared using comparison of proportion, t-tests, and ordinary least-squares (OLS) regression. Improvements between the pre-training and post-training test are apparent from the frequency distribution of test results and from t-tests. Both summer camps and school-based programs recorded similar improvements in test results. Children who bicycled with their parents scored higher on the pre-training test but did not improve as much on the post-training test. Without evaluating long-term changes in behavior, it is difficult to ascertain how successful the program is on eventual behavioral and safety outcomes.

  20. The Bicycle Assembly Line Game (United States)

    Klotz, Dorothy


    "The Bicycle Assembly Line Game" is a team-based, in-class activity that helps students develop a basic understanding of continuously operating processes. Each team of 7-10 students selects one of seven prefigured bicycle assembly lines to operate. The lines are run in real-time, and the team that operates the line that yields the…

  1. Chest Traumas due to Bicycle accident in Childhood

    Directory of Open Access Journals (Sweden)

    Ufuk Cobanoglu


    absence of external signs of trauma. Pulmonary contusion and pneumothorax are frequently present without rib fractures. Pulmonary contusion, pneumothorax, and rib fractures are the most common injuries. In order to prevent bicycle accidents; bicycle drivers should have specific education, helmet use must become widespread and special traffic regulations have to be settled. Increasing the education level if family will contribute to the prevention of childhood trauma.

  2. 36 CFR 13.914 - Bicycle use. (United States)


    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Bicycle use. 13.914 Section... § 13.914 Bicycle use. The use of a bicycle is prohibited— (a) On the Savage River Loop Trail; the... in public parking areas, or on trails and areas designated for bicycle use by the Superintendent....

  3. 15 CFR 265.22 - Bicycle traffic. (United States)


    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Bicycle traffic. 265.22 Section 265.22... Bicycle traffic. No person shall ride a bicycle other than in a manner exercising due caution for pedestrian and other traffic. No person shall ride a bicycle on sidewalks or inside any building, nor...

  4. Bicycle Rider Control: Observations, Modeling & Experiments

    NARCIS (Netherlands)

    Kooijman, J.D.G.


    Bicycle designers traditionally develop bicycles based on experience and trial and error. Adopting modern engineering tools to model bicycle and rider dynamics and control is another method for developing bicycles. This method has the potential to evaluate the complete design space, and thereby dev

  5. [Where are all the Viking helmets?]. (United States)

    Wester, K


    Based on archaeological finds and old Norse literature, this article describes the Scandinavian helmet tradition from the Bronze Age to the Viking Age, as well as the Viking culture, with special emphasis on weaponry, burial customs, and head protection. Contrary to what is commonly believed, metal helmets must have been used very infrequently by the Vikings. Only one Viking helmet has been retrieved in Scandinavia. Possible reasons for the wide-spread misunderstanding that the Vikings wore helmets are discussed. The archaeological profession must partly bear the responsibility for not correcting this misunderstanding.

  6. The mystery of the missing Viking helmets. (United States)

    Wester, K


    Based on archaeological finds and old Norse literature, this study describes the Scandinavian helmet tradition from the Bronze Age to the Viking Age, as well as the Viking culture, with special emphasis on weaponry and head protection. Contrary to what is commonly believed, the study shows that metal helmets must have been used very infrequently by the Vikings. In fact, only one Viking helmet has been retrieved in Scandinavia. Possible reasons for the widespread misconception that the Vikings wore helmets are discussed, and the responsibility for not correcting this misunderstanding is placed with the archaeological profession.

  7. [Attitudes of winter sport participants toward ski helmet mandatory]. (United States)

    Ruedl, G; Kopp, M; Hotter, B; Ledochowski, L; Burtscher, M


    The aim of this study was to examine attitudes of winter sport participants toward a ski helmet mandatory. In total, 959 persons who had to estimate statements regarding ski helmet and helmet mandatory with the aid of a five level Likert scale were interviewed. About 85 % of interviewed persons totally agreed that a ski helmet reduces head injury risk although only 64 % are wearing a ski helmet. Significant more helmet wearers and females compared to non-wearers and males totally agreed that all winter sport participants should wear ski helmets on slopes as well as that all children on slopes should wear a ski helmet. Also, significant more helmet wearers and females compared to non-wearers and males totally agreed that a ski helmet mandatory for all people has to be recommended as well as that a ski helmet mandatory for children under 16 years has to be recommended. However, the acceptance for a helmet mandatory for all people as well as for children was significantly lower compared to recommendations for helmet use irrespective of helmet use or gender. Therefore, we conclude that preventive helmet campaigns possibly attain a higher acceptance leading to a higher helmet use compared to a helmet mandatory.

  8. Bicycle Use and Cyclist Safety Following Boston’s Bicycle Infrastructure Expansion, 2009–2012 (United States)

    Angriman, Federico; Bellows, Alexandra L.; Taylor, Kathryn


    Objectives. To evaluate changes in bicycle use and cyclist safety in Boston, Massachusetts, following the rapid expansion of its bicycle infrastructure between 2007 and 2014. Methods. We measured bicycle lane mileage, a surrogate for bicycle infrastructure expansion, and quantified total estimated number of commuters. In addition, we calculated the number of reported bicycle accidents from 2009 to 2012. Bicycle accident and injury trends over time were assessed via generalized linear models. Multivariable logistic regression was used to examine factors associated with bicycle injuries. Results. Boston increased its total bicycle lane mileage from 0.034 miles in 2007 to 92.2 miles in 2014 (P cyclist safety. PMID:27736203

  9. Disparity in motorcycle helmet use in Thailand. (United States)

    Suriyawongpaisa, Paibul; Thakkinstian, Ammarin; Rangpueng, Aratta; Jiwattanakulpaisarn, Piyapong; Techakamolsuk, Pimpa


    The dispersion of motorcycle related injuries and deaths might be a result of disparity in motorcycle helmet use. This study uses national roadside survey data, injury sentinel surveillance data and other national data sets in 2010 of Thailand, a country with high mortality related to motorcycle injuries, to explore the disparity in helmet use, explanatory factors of the disparity. It also assessed potential agreement and correlation between helmet use rate reported by the roadside survey and the injury sentinel surveillance. This report revealed helmet use rate of 43.7%(95% CI:43.6,43.9) nationwide with the highest rate (81.8%; 95% CI: 44.0,46.4) in Bangkok. Helmet use rate in drivers (53.3%; 95% CI: 53.2,53.8) was 2.5 times higher than that in passengers (19.3%; 95% CI:18.9,19.7). In relative terms (highest-to-lowest ratio,HLR), geographical disparity in helmet use was found to be higher in passengers (HLR = 28.5). Law enforcement activities as indicated by the conviction rate of motorcyclists were significantly associated with the helmet use rate (spline regression coefficient = 3.90, 95% CI: 0.48,7.33). Together with the finding of HLR for conviction rate of 87.24, it is suggested that more equitable improvement in helmet use could be achieved by more equitable distribution of the police force. Finally, we found poor correlation (r = 0.01; p value = 0.76) and no agreement (difference = 34.29%; 95% CI:13.48%, 55.09%) between roadside survey and injury sentinel surveillance in estimating helmet use rate. These findings should be considered a warning for employing injury surveillance to monitor policy implementation of helmet use.

  10. Children and cycle helmets -- the case against. (United States)

    McCarthy, M


    Much of the literature on child cycling accidents appears to blame the child as a victim, as though children's activities of playing and travelling were somehow wrong and that children are at fault when an adult drives a car over them. This adult-centred approach then leads to the idea that children should protect themselves with helmets, and that they are to blame if they are injured. However, adults who continue to hold the fantasy that helmets might be of value should know that the British Standard for cycle helmets protects only in a vertical fall of 1 m -- certainly not motor vehicle crashes. Thicker motor cycle helmets would give better protection but, of course, are heavier (and therefore unsaleable). Yet even with compulsory wearing helmets, more motor cyclists still die of head injuries than pedal cyclists. In the Newcastle study, five times as many child pedestrians died of road accidents as child cyclists. Convinced helmeteers should recommend all children playing or travelling in the streets to wear helmets (presumably heavy motor-cycle helmets). Slightly more sceptical proponents might prefer half of them -- in a randomized controlled trial. Car driving appears to have as serious health consequences as tobacco, alcohol and drugs, and to be as addictive (McCarthy 1992). Helmets are similar to filters in cigarettes -- they give the illusion of safety to both consumer and producer of the product, but the illusion is fatal. Yet, for their cardiovascular and mental health, children should have the freedom to cycle in safety around where they live. A profound change in the habits of adults is needed, rather than suits of armour for children.

  11. Helmets in sport: fact and fallacy. (United States)

    Gammons, Matthew R


    Head injuries and the prevention of both the short-term and long-term consequences have received heightened awareness in recent years. Education and legislative efforts have promoted both appropriate treatment of concussion and pushed the use of helmets for protection from head injuries. Current scientific data would suggest that helmets are effective at decreasing the risk of serious head injuries. However there is no evidence to suggest that helmets are protective against concussive injuries or the long-term impact of repetitive head trauma.

  12. Assessing the reliability and validity of direct observation and traffic camera streams to measure helmet and motorcycle use. (United States)

    Zaccaro, Heather N; Carbone, Emily C; Dsouza, Nishita; Xu, Michelle R; Byrne, Mary C; Kraemer, John D


    There is a need to develop motorcycle helmet surveillance approaches that are less labour intensive than direct observation (DO), which is the commonly recommended but never formally validated approach, particularly in developing settings. This study sought to assess public traffic camera feeds as an alternative to DO, in addition to the reliability of DO under field conditions. DO had high inter-rater reliability, κ=0.88 and 0.84, respectively, for cycle type and helmet type, which reinforces its use as a gold standard. However, traffic camera-based data collection was found to be unreliable, with κ=0.46 and 0.53 for cycle type and helmet type. When bicycles, motorcycles and scooters were classified based on traffic camera streams, only 68.4% of classifications concurred with those made via DO. Given the current technology, helmet surveillance via traffic camera streams is infeasible, and there remains a need for innovative traffic safety surveillance approaches in low-income urban settings.

  13. The Bicycle Rental Market In Hangzhou

    Institute of Scientific and Technical Information of China (English)


    On May 1, 2008, Hangzhou, capital of east China’s Zhejiang Province, included bicycle rentals in the public transportation system. Now, bicycles have become the most convenient form of transport for Hangzhou residents. Data from the Hangzhou Bureau of Transportation show that on average each bicycle gets rented five times a day.

  14. Biomechanical performance of leather and modern football helmets. (United States)

    Rowson, Steven; Daniel, Ray W; Duma, Stefan M


    With the increased national concern about concussions in football, recent research has focused on evaluating the impact performance of modern football helmets. Specifically, this technical note offers a biomechanical analysis of classic leather helmets compared with modern helmets. Furthermore, modern helmets were examined to illustrate the performance differences between the better- and worse-performing ones. A total of 1224 drop tests were performed from a range of drop heights and impact locations on 11 different helmet types (10 modern and 1 leather helmet model). The resulting head acceleration was used to assess the risk of concussion for each drop test. The results of this analysis demonstrate that modern helmets are significantly and substantially superior to leather helmets in all impact scenarios, and that notable differences exist among modern helmets.

  15. Respiratory Protection Performance: Impact of Helmet Integration (United States)


    Integrated system donning procedures. The volunteer put on the helmet first but left the chin strap detached. A forehead latch tab built into the C50 mask was...administered, and the volunteer’s facial anthropometric data were collected. Test administrators trained the volunteers on how to put on and...remove each piece of equipment properly. For the nonintegrated system, the C50 mask was put on first. The helmet was then donned, and the chin strap was


    CERN Multimedia

    EP-SMI Help Desk


    The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

  17. Bicycle Safety: Sport Education Style (United States)

    Sinelnikov, Oleg A.; Hastie, Peter A.; Cole, Amy; Schneulle, Deanna


    Although the benefits of regular physical activity are well-documented and very well known, Americans are still becoming more sedentary and obese. As some experts envision the potential of nonmotorized transport in the future, especially in urban settings, it is not surprising that diverse groups view walking and bicycling as a solution to an…

  18. Car Hits Boy on Bicycle (United States)

    Ruiz, Michael J.


    In this article we present the fascinating reconstruction of an accident where a car hit a boy riding his bicycle. The boy dramatically flew several metres through the air after the collision and was injured, but made a swift and complete recovery from the accident with no long-term after-effects. Students are challenged to determine the speed of…

  19. Road characteristics and bicycle accidents. (United States)

    Nyberg, P; Björnstig, U; Bygren, L O


    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  20. Electric-bicycle propulsion power

    Energy Technology Data Exchange (ETDEWEB)

    Oman, H.; Morchin, W.C. [Electro-Bicycle, Inc., Auburn, WA (United States); Jamerson, F.E. [Electric Battery Bicycle Co., Naples, FL (United States)


    In a human-powered hybrid electric vehicle (HPHEV) the travel distance available from a single battery charge can be lengthened with power from another source, the cyclist`s leg muscles. In a battery-powered electric bicycle the propulsion power goes mostly into overcoming aerodynamic drag. For example, at 18 km per hour (11 miles per hour) this drag represents 200 watts at the tire-to-road interface for a typical cyclist`s shape and clothing. Today`s typical electrical bicycle is propelled by a high-speed dc motor which is powered from a lead-acid battery. The combined efficiency of the motor and its speed-reducing gears is 50 to 65 percent. In this paper we calculate available travel distances, as a function of speed, grade, and the battery energy-content as measured in watt-hours per kg. We show the effect of battery cost and charge/discharge cycle-life on travel cost in terms of cents per kilometer travelled. Designs used in today`s electric bicycles are illustrated.

  1. An Evaluation of a Classroom Science Intervention Designed to Extend the Bicycle Helmet Safety Message (United States)

    McPherson, Moira N.; Marsh, Pamela K.; Montelpare, William J.; Van Barneveld, Christina; Zerpa, Carlos E.


    Background: Wizards of Motion is a program of curriculum delivery through which experts in Kinesiology introduce grade 7 students to applications of physics for human movement. The program is linked closely to Ministry of Education curriculum requirements but includes human movement applications and data analysis experiences. Purpose: The purpose…

  2. BMX bicycles: accident comparison with other models.



    A comparison has been made between BMX bicycle accidents and those occurring when children ride other types of bicycle. The injuries sustained are compared to see if the clinical impressions that BMX are more dangerous, and produce more facial injuries, are correct. This was found not to be true as half the children involved rode BMX bicycles, and the injuries sustained were similar to those occurring to non BMX riders. BMX riders had a lower proportion of serious injuries than riders of raci...

  3. SOFIE, a bicycle that supports older cyclists? (United States)

    Dubbeldam, R; Baten, C; Buurke, J H; Rietman, J S


    Older cyclists remain at high risk of sustaining an injury after a fall with their bicycle. A growing awareness for the need and possibilities to support safety of older cyclists has been leading to bicycle design ideas. However, the effectiveness and acceptance of such designs has not been studied yet. This study aims to analyse the effect of 3 support systems: an automatic adjustable saddle height, optimised frame and wheel geometry and drive-off assistance. The support systems are integrated on the SOFIE bicycle, a prototype bicycle designed to support older cyclists during (dis-)mounting and at lower cycling speeds. Nine older cyclists (65-80 years) were asked to cycle on a 'normal' and on the 'SOFIE' bicycle. They cycled on a parking lot to avoid interaction with traffic. The following tasks were analysed: cycling at comfortable and low speed avoiding an obstacle and (dis-)mounting the bicycle. Bicycle and cyclist motions were recorded with 10 Inertial Measurement Units and by 2 video cameras. FUSION software (LABVIEW) was used to assess kinematic parameters. First, a subjective analysis of the different cycling tasks was made, supported by video analysis. Second, differences in cyclist and bicycle kinematic parameters between the normal and SOFIE bicycle were studied for the various cycling tasks. The SOFIE bicycle was experienced as a 'supportive' and comfortable bicycle and objectively performed 'safer' on various cycling tasks. For example: The optimised frame geometry with low step-in enabled a faster (dis-)mounting time and less sternum roll angle and angular acceleration. The adjustable saddle height enabled the participants to keep both feet on the ground till they started cycling with the 'drive-off' support. The latter reduces steering activity: maximum steer angle and angular acceleration. During sudden obstacle avoidance, less upper body and thigh accelerations are recorded. In conclusion, the SOFIE bicycle was able to support older cyclists during

  4. Two Wheeler Helmets with Ventilation and Metal Foam

    Directory of Open Access Journals (Sweden)

    Praveen K. Pinnoji


    Full Text Available Three different two wheeler helmets were studied to investigate their dynamic performance.First is helmet with ABS shell, second is helmet with metal foam, and third is helmet with singlegroove in the liner foam for providing ventilation. Front and side impact analyses were carriedout at 10 m/s velocity by using LS-DYNATM. Forces on the helmet and on the head due to impactwere studied with function of time. Pressure and stresses in the brain were investigated andfound not to change significantly due to the presence of groove in the liner foam, which wasprovided to improve the ventilation in helmets. The dynamic performance of a helmet with outershell as metal foam was examined and compared with ABS material.

  5. Compliance of proper safety helmet usage in motorcyclists. (United States)

    Kulanthayan, S; Umar, R S; Hariza, H A; Nasir, M T; Harwant, S


    Motorcyclists make up the largest group of fatalities on Malaysian roads, majority succumbing to head injuries despite the compulsory safety helmet laws in the country. One possible reason for this high fatality is improper usage of safety helmets. This study examines the compliance of proper safety helmet use in motorcyclists in a typical Malaysian town. Five hundred motorcyclists were studied. Only 54.4% of motorcyclists used helmets properly, 21.4% used them improperly; and 24.2% did not wear helmets. Six variables were found to be significant in improper safety helmet use. They were age, gender, race, formal education level, prior accident experience and type of license held. Marital status and riding experience were not significant. Efforts promoting proper use of safety helmets should focus on the young, male, less formally educated, unlicensed rider, who has had a prior accident.

  6. A study on electric bicycle energy efficiency

    Directory of Open Access Journals (Sweden)

    Ivan EVTIMOV


    Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

  7. Evaluation electric bicycles; Evaluation velos electriques

    Energy Technology Data Exchange (ETDEWEB)



    Leovelo service is the first measure in favor of the bicycle to control the air pollution and to conserve energy. It provides in the city of Clermont-Ferrand (France) a service of bicycle hiring. This document evaluates the project after two years of operating. It provides a technical evaluation (maintenance, equipment, financing) and also the socio-economic impacts. (A.L.B.)

  8. Stabilizing a Bicycle: A Modeling Project (United States)

    Pennings, Timothy J.; Williams, Blair R.


    This article is a project that takes students through the process of forming a mathematical model of bicycle dynamics. Beginning with basic ideas from Newtonian mechanics (forces and torques), students use techniques from calculus and differential equations to develop the equations of rotational motion for a bicycle-rider system as it tips from…

  9. Bicycle parking preferences: costs versus walking time

    NARCIS (Netherlands)

    Molin, E.J.E.; Maat, K.


    Successful bicycle stimulating policies may increase the need for bicycle parking capacity, especially at main railway stations located in city centers. A potential solution for this problem involves combining paid surveyed indoor parking near the platforms and free open-air parking without surveill

  10. Good Practices Guide for Bicycle Safety Education. (United States)

    Department of Transportation, Washington, DC.

    The purpose of this guide is to serve as an informational resource for educators and other interested professionals in planning and developing bicycle safety education programs. The guide examines 15 existing bicycle safety education programs in the United States and one from Canada. (Author)

  11. Pedal cyclists, crash helmets and risk. (United States)

    McCarthy, M


    As a rate per million kilometres travelled, the 'risk' of cycling appears to be high in relation to other forms of transport. Yet, in absolute numbers, there are far fewer cyclist deaths than pedestrian or motor vehicle occupant deaths, and most deaths and serious injuries to pedal cyclists are caused by other road users--principally motor vehicles. The large majority of pedal cyclist deaths are due to head injuries after collision with a motor vehicle. It is therefore commonly proposed that cyclists should wear crash helmets for their own 'safety'. Helmets may protect against fall injuries, but current models are not designed to withstand the impact of collisions with motor vehicles. Evidence for the benefit of pedal cyclists wearing helmets is limited: the existing studies cannot exclude the possibility of different risk-taking behaviour, either by cyclists or by motor vehicle drivers, for helmet wearers compared with non-wearers. A public health policy towards reducing pedal cyclist deaths should seek prevention of accidents, rather than protection from their consequences. Cycling in greater safety would reduce the 'risk' per kilometre travelled, but more cycling might not reduce total cyclist deaths or injuries--because of greater exposure. The 'risk' of cycling--the risk of injury or death--is a complex mix of exposure, 'danger' of the environment, and the perceived risk affecting our precautionary preventive behaviour.


    Directory of Open Access Journals (Sweden)



    Full Text Available This paper deals with the stress analysis of bicycle frame by using Finite Element Method. The analysis is carried out in Ansys, The F.E.A. results are compared with theoretical results. In theoretical analysis the frame is treated as truss like structure and the stresses in various members of frame like top tube, down tube, seat tube, chain stay and seat stay are determined, considering various condition like, static start up, steady state paddling, vertical impact, horizontal impact, rear wheel braking. Also Finite Element Analysis is done considering the above conditions. From the analysis it is found that there is a good agreement between analytical and F.E.A. results. Result of all the cases reveals that maximum stress is found in top tube of the bicycle frame as compared to other frame members and is equal to 24.84 MPa which is less than yield strength in tension (i.e.Syt = 290 MPa for the material (aluminum T 6061 selected.

  13. Current and future concepts in helmet and sports injury prevention. (United States)

    Hoshizaki, T Blaine; Post, Andrew; Oeur, R Anna; Brien, Susan E


    Since the introduction of head protection, a decrease in sports-related traumatic brain injuries has been reported. The incidence of concussive injury, however, has remained the same or on the rise. These trends suggest that current helmets and helmet standards are not effective in protecting against concussive injuries. This article presents a literature review that describes the discrepancy between how helmets are designed and tested and how concussions occur. Most helmet standards typically use a linear drop system and measure criterion such as head Injury criteria, Gadd Severity Index, and peak linear acceleration based on research involving severe traumatic brain injuries. Concussions in sports occur in a number of different ways that can be categorized into collision, falls, punches, and projectiles. Concussive injuries are linked to strains induced by rotational acceleration. Because helmet standards use a linear drop system simulating fall-type injury events, the majority of injury mechanisms are neglected. In response to the need for protection against concussion, helmet manufacturers have begun to innovate and design helmets using other injury criteria such as rotational acceleration and brain tissue distortion measures via finite-element analysis. In addition to these initiatives, research has been conducted to develop impact protocols that more closely reflect how concussions occur in sports. Future research involves a better understanding of how sports-related concussions occur and identifying variables that best describe them. These variables can be used to guide helmet innovation and helmet standards to improve the quality of helmet protection for concussive injury.

  14. Electric bicycles in The Netherlands: Current developments and future possibilities

    NARCIS (Netherlands)

    Rooijen, T. van


    Developments with electric bicycles in the Netherlands are progressing rapidly. The number of electric bicycles sold is rises every year. Cycling is a very popular mode of transport in The Netherlands. In 2008 more than one million bicycles were sold. At the moment one out of ten bicycles sold is al

  15. Muscle fatigue based evaluation of bicycle design. (United States)

    Balasubramanian, V; Jagannath, M; Adalarasu, K


    Bicycling posture leads to considerable discomfort and a variety of chronic injuries. This necessitates a proper bicycle design to avoid injuries and thereby enhance rider comfort. The objective of this study was to investigate the muscle activity during cycling on three different bicycle designs, i.e., rigid frame (RF), suspension (SU) and sports (SP) using surface electromyography (sEMG). Twelve male volunteers participated in this study. sEMG signals were acquired bilaterally from extensor carpi radialis (ECR), trapezius medial (TM), latissimus dorsi medial (LDM) and erector spinae (ES), during 30 min of cycling on each bicycle and after cycling. Time domain (RMS) and frequency domain (MPF) parameters were extracted from acquired sEMG signals. From the sEMG study, it was found that the fatigue in right LDM and ES were significantly (p bicycle. This was corroborated by a psychophysical assessment based on RBG pain scale. The study also showed that there was a significantly lesser fatigue with the SU bicycle than the RF and SP bicycles.

  16. Survey of options on legalizing bicycling (VB)

    DEFF Research Database (Denmark)

    Zwahlen, Jurg; Sulewski, Sharon; Sacovitch, Stephen;


    the opposition against the proposal was.The goal of this project was to identify categories of users that were opposed to bicycling on the Dosseringen of the Østerbro and Nørrebro District lakes in Copenhagen. The identification of the opposition and its strength, rationale and organization was in terms of age......, gender, residency, frequency of use and their utilization of the area (i.e. walking, jogging, bicycling) as compared to the support for bicycling in the area. This was an Interactive Qualifying Project (IQP), that was designed to merge technical and scientific knowledge with society, and stresses...

  17. The self-stabilising dynamics of bicycles

    CERN Document Server

    Warner, Mark


    We analyse the classical problem of the stability of bicycles when moving quickly and upright. Developing a lean causes the front wheel to turn thereby setting the bicycle instantaneously into circular motion. The centripetal force associated with the lean-dependent turning circle gives a restoring torque which corrects the lean. The force also helps self-steer the front wheel, ensuring the bicycle continues in an essentially straight path. We give the frequency of lean oscillations about the vertical executed during riding. As in the literature, we discuss the neglect of gyroscopic effects, which experiment suggests are negligible.

  18. Policy to promote bicycle use or bicycle to promote politicians? Bicycles in the imagery of urban mobility in Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Milani Medeiros


    Full Text Available During the last 15 years an increasing number of presidents, prime ministers, governors and mayors in developed and developing countries have been riding bicycles to promote a more sustainable and friendly form of urban mobility. We believe that these images also reveal and influence the image of contemporary urban mobility – the way in which people see what urban mobility is and how it should be. In this paper we discuss how the image of the bicycle has changed in Brazil and how this may influence an increase in its actual 1% bicycle modal share in big cities. We conclude that the importance of the bicycle in the image of urban mobility has been changing cyclically, and what seems to be a positive trend today might end up as being just an ephemeral positive image, with the risk of having no further practical consequences.

  19. A Sociological Analysis of the Relationship between Attitude towards Bicycle and Using Bicycle in Short Trips in Isfahan

    Directory of Open Access Journals (Sweden)

    Siroos Ahmadi


    The main goal of this research is to investigate relationship between attitude toward bicycle and using bicycle among the men in Isfahan. Based on the descriptive research findings, mean using bicycle score is low in Iran. This situation is not satisfactory for a metropolis such as Isfahan that has an increasing population and motor vehicles, and also has many difficulties in urban base facilities and must be changed. In addition to mean attitude toward bicycle is high that is an opportunity for urban planners. Inferential findings show that attitude toward bicycle has a significant impact on using bicycle. In other words, increase attitude toward bicycle means an increase in using bicycle for short trips. This research finding theoretically confirm relation between attitude and behavior. Moreover it is compatible with results of the research that show there is significant relationship between attitude toward bicycle and using bicycle. There is an inverse significant relationship between age and using bicycle and with rising age using bicycle is decreased. This research finding shows that urban infrastructure in Isfahan for using bicycle is not available and consequently with rising age, bicycle risk is increased. There is a direct significant relationship between income rate and using bicycle and with increasing income rate, using bicycle is also increased. This research finding is rooted in social prestige bicycle and higher classes prefer to use motor vehicle for transportation instead of bicycle. There is a significant relationship between marital status and using bicycle and single men use bicycle more than married men but there is no significant relationship between education level and using bicycle. This research findings show that with rising education level in spite of rising income, using bicycle is not decreased. And finally there is no significant relationship between employed and unemployed persons in using bicycle. On the basis of the evidences such

  20. External foam layers to football helmets reduce head impact severity. (United States)

    Nakatsuka, Austin S; Yamamoto, Loren G


    Current American football helmet design has a rigid exterior with a padded interior. Softening the hard external layer of the helmet may reduce the impact potential of the helmet, providing extra head protection and reducing its use as an offensive device. The objective of this study is to measure the impact reduction potential provided by external foam. We obtained a football helmet with built-in accelerometer-based sensors, placed it on a boxing mannequin and struck it with a weighted swinging pendulum helmet to mimic the forces sustained during a helmet-to-helmet strike. We then applied layers of 1.3 cm thick polyolefin foam to the exterior surface of the helmets and repeated the process. All impact severity measures were significantly reduced with the application of the external foam. These results support the hypothesis that adding a soft exterior layer reduces the force of impact which may be applicable to the football field. Redesigning football helmets could reduce the injury potential of the sport.

  1. SAFETY ALERT: Electrical insulation defect on safety helmets

    CERN Multimedia

    HSE Unit


    Contrarily to the information provided until 31 May 2013, some “Euro Protection” safety helmets do not respect any of the requirements for electrical insulation.   This alert concerns the safety helmets identified under the following SCEM numbers: white yellow blue This amounts up to several hundreds of helmets on the CERN site. People who need to wear an electrically insulated safety helmet for their activities, must from now on acquire a duly insulated item to be found on the CERN store under the following SCEM numbers: Petzl Vertex ST Helmet (without vent) IDRA Helmet with a visor for electrical work As for the people who do not need to wear an electrically insulated helmet for their activities, they can continue working with the aforementioned helmets. For your information, please take note of the maximum use limit of each helmet: “Euro Protection” Safety Helme...

  2. Synthesis of Caged Bicyclic Phosphate Derivatives

    Institute of Scientific and Technical Information of China (English)

    FANG Xiao-min; OU Yu-xiang; LUO Rui-bin; WANG Yong; LIAN Dan-jun; LI Xin


    Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethy1-2,6,7-trioxa-1-pho-sphabicyclo[2.2.2] octane (PEPA) as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure(1a,2a,3a), another three PEPA deviratives containing two caged bicyclic phosphate structures(1b,2b,3b) and one devirative(1c) containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, 1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant elements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

  3. On-road Bicycle Pavement Markings (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

  4. A Geographical Analysis of Bicycle Sharing Systems


    Médard De Chardon, Cyrille


    This thesis evaluates the performance of bicycle sharing systems (BSS), autonomous systems of accessible bicycles that can be easily used for one way trips, and determines whether they are successful at achieving promoted social and environmental outcomes through quantitative and qualitative methods. Such systems are typically surrounded by positive narratives of success, health, environmental and social benefits. This work challenges these notions. This thesis begins with the formalisation o...

  5. 77 FR 48105 - Federal Motor Vehicle Safety Standards; Motorcycle Helmets (United States)


    ... National Highway Traffic Safety Administration 49 CFR Part 571 Federal Motor Vehicle Safety Standards... rule amended the Federal Motor Vehicle Safety Standard for motorcycle helmets. Specifically, the final...\\ Final Rule, Federal Motor Vehicle Safety Standards; Motorcycle Helmets, 76 FR 28132 (May 13, 2011)....

  6. Motorcycle riders' perception of helmet use: complaints and dissatisfaction. (United States)

    Orsi, C; Stendardo, A; Marinoni, A; Gilchrist, M D; Otte, D; Chliaoutakis, J; Lajunen, T; Ozkan, T; Pereira, J Dias; Tzamalouka, G; Morandi, A


    In accidents which involve two-wheeled vehicles the helmet plays a life-saving role, but very little is known about the motorcycle rider's perception of the helmet. We evaluated the relationships between having been involved in an accident and dissatisfaction with the helmet, and between the perception of motorcycle riders and the objective features of the helmet. This was a case-control study: riders of motorized two-wheelers who had been involved in accidents (accident cases) were compared against a similarly interviewed sample of riders that had not been in accidents (control cases). Information about the driver, the vehicle and the helmet was collected in all interviews. To evaluate the relationships, logistic regressions were carried out. The majority of drivers were dissatisfied with their helmets, but no evidence was found to link this dissatisfaction with having been involved in an accident. The two most common complaints related to noisiness, followed by the helmet visor. Complaints did not seem to be statistically associated with physical features of the helmet.

  7. Great helms and their development into helmets

    Directory of Open Access Journals (Sweden)

    Williams, Alan


    Full Text Available This article shows the results from the analysis made on a group of helmets dated from late 12th century to early 15th century. Metallographic advances recorded on them are considered as determinating factors on its evolution.

    Este trabajo expone los resultados de los análisis realizados sobre un grupo de yelmos datados desde finales del siglo XII hasta principios del XV. Los avances metalográficos documentados en ellos se revelan como un factor clave en la evolución de estos yelmos

  8. New Materials and Construction for Improved Helmets (United States)


    basis of laboratory te!sts for fragment protection capabilities and for durability. The mate- rials considered were (1) phenolic/ polyvinyl butyral ...phenolic/ polyvinyl butyral resin (221) were prepared Sanne • • mam • • - no , UI d n~udr aton:, a t 31 :i ~w~te i I l lewcd hy cot;l Ing prior It...Helmet kevlar fabric laminates u,,ing phenolic/ polyvinyl butyral resin withstand thermol stressing ’ad have low water absorption (2.5 percent in 24 hours

  9. Helmet Ownership and Use among Skateboarders: Utilisation of the Health Belief Model (United States)

    Peachey, Andrew A.; Sutton, Debra L.; Cathorall, Michelle L.


    Introduction: The purpose of this study was to determine the proportion of skateboarders who owned and who wore a helmet and which constructs from the Health Belief Model predicted helmet ownership and helmet use among undergraduate skateboarders. Methods: From March 2013 through March 2014, 83 skateboarders completed a helmet attitude and use…

  10. 40 CFR 52.1162 - Regulation for bicycle use. (United States)


    ...: (i) For present bicycle riders, the origin, destination, frequency, travel time, distance and purpose... Section 52.1162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS..., regional and local planning staffs, state, regional and local agencies, bicycle organizations and...

  11. Bicycling for transportation and health: the role of infrastructure. (United States)

    Dill, Jennifer


    This paper aims to provide insight on whether bicycling for everyday travel can help US adults meet the recommended levels of physical activity and what role public infrastructure may play in encouraging this activity. The study collected data on bicycling behavior from 166 regular cyclists in the Portland, Oregon metropolitan area using global positioning system (GPS) devices. Sixty percent of the cyclists rode for more than 150 minutes per week during the study and nearly all of the bicycling was for utilitarian purposes, not exercise. A disproportionate share of the bicycling occurred on streets with bicycle lanes, separate paths, or bicycle boulevards. The data support the need for well-connected neighborhood streets and a network of bicycle-specific infrastructure to encourage more bicycling among adults. This can be accomplished through comprehensive planning, regulation, and funding.

  12. Bicycling to school improves the cardiometabolic risk factor profile

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Børrestad, Line A B; Tarp, Jakob;


    To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.......To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children....

  13. Associations between a walkability index and bicycle use in Denmark

    DEFF Research Database (Denmark)

    Madsen, T.; Christiansen, L.; Nielsen, Thomas Alexander Sick;


    associations between measures of walkability and bicycle use for transport and the present study focuses on exploring whether these findings can be applied to a Danish setting where cycling culture differs and bicycle share is much higher (17% of all trips are by bicycle)...

  14. On the Stability of a Bicycle on Rollers (United States)

    Cleary, Patricia A.; Mohazzabi, Pirooz


    Riding a bicycle on the newest form of indoor training, rollers, presents a unique experiment on bicycle stability. The stability factors eliminated by riding on rollers are discussed in terms of refined handling and control of the centre of mass on a bicycle. This paper is intended for undergraduate physics majors as well as any other general…

  15. An Analysis of Florida Physical Educators' Knowledge of Bicycle Laws (United States)

    Connaughton, Daniel P.; Egberts, John B.; Spengler, J. O.; Zhang, James J.; Jin, Liyan


    Bicycling among youth is a popular activity, but like all modes of travel it is not without risk. Florida has a particularly high rate of bicycle-related fatalities and injuries. To reduce such risks, the Florida Department of Transportation and Florida Department of Education have developed a youth bicycle safety educational program (Florida…

  16. Helmet use among motorcyclists who died in crashes and economic cost savings associated with state motorcycle helmet laws--United States, 2008-2010. (United States)


    In 2010, the 4,502 motorcyclists (operators and passengers) killed in motorcycle crashes made up 14% of all road traffic deaths, yet motorcycles accounted for laws. Universal helmet laws require all motorcyclists to wear helmets whenever they ride. To examine the association between states' motorcycle helmet laws and helmet use or nonuse among fatally injured motorcyclists, CDC analyzed 2008-2010 National Highway Traffic Safety Administration (NHTSA) data from the Fatality Analysis Reporting System (FARS), a census of fatal traffic crashes in the United States. Additionally, economic cost data from NHTSA were obtained to compare the costs saved as a result of helmet use, by type of state motorcycle helmet law. The findings indicated that, on average, 12% of fatally injured motorcyclists were not wearing helmets in states with universal helmet laws, compared with 64% in partial helmet law states (laws that only required specific groups, usually young riders, to wear helmets) and 79% in states without a helmet law. Additionally, in 2010, economic costs saved from helmet use by society in states with a universal helmet law were, on average, $725 per registered motorcycle, nearly four times greater than in states without such a law ($198).

  17. A Lightweight Innovative Helmet Airborne Display And Sight (HADAS) (United States)

    Naor, Daniel; Arnon, Oded; Avnur, Arie


    The Helmet Airborne Display and Sight (HADAS) system under development, has succeeded in surmounting many of the problems experienced by current, as well as past helmet mounted display and sight designs for operation in fighter aircraft. The goal has been achieved by combination of holographic optical elements and fiber optics for the display function, as well as real-time image processing of the helmet location for the sight function. The integrated system can provide "all aspect head-up display" performance in the cockpit.

  18. Revitalization of Cycling in a Former Bicycle Kingdom: Beijing

    DEFF Research Database (Denmark)

    Zhao, Chunli; Carstensen, Trine Agervig; Olafsson, Anton Stahl;

    This paper scrutinizes and analyses the relevant historical policy documents chronologically - from the 1960s to the present - in order to figure out the potentials of revitalizing the bicycle mode share in Beijing. Firstly, we targeted two top-drawer conflicts of the bicycle use, which are travel......- or commuting distance and motorised vehicle-oriented urban development. Secondly, we analysed how the various related policies resulted in the changing landscape of the bicycle mode share, including increasing in the bicycle mode share, created the conflicts and declined the bicycle mode share. The results...

  19. Bicyclic semigroups of left I-quotients

    CERN Document Server

    Ghroda, Nassraddin


    In this article we study left I-orders in the bicyclic monoid $\\mathcal{B}$. We give necessary and sufficient conditions for a subsemigroup of $\\mathcal{B}$ to be a left I-oreder in $\\mathcal{B}$. We then prove that any left I-order in $\\mathcal{B}$ is straight.

  20. Safety effects of permanent running lights for bicycles

    DEFF Research Database (Denmark)

    Madsen, Jens Chr. Overgaard; Andersen, T.; Lahrmann, Harry


    3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group...... and 2000 other bicyclists, the latter serving as a control group without bicycle running lights. The safety effect of the running lights is analysed by comparing incidence rates – number of bicycle accidents recorded per man-month – for the treatment group and the control group. The incidence rate......, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle...

  1. Can helmet design reduce the risk of concussion in football? (United States)

    Rowson, Steven; Duma, Stefan M; Greenwald, Richard M; Beckwith, Jonathan G; Chu, Jeffrey J; Guskiewicz, Kevin M; Mihalik, Jason P; Crisco, Joseph J; Wilcox, Bethany J; McAllister, Thomas W; Maerlender, Arthur C; Broglio, Steven P; Schnebel, Brock; Anderson, Scott; Brolinson, P Gunnar


    Of all sports, football accounts for the highest incidence of concussion in the US due to the large number of athletes participating and the nature of the sport. While there is general agreement that concussion incidence can be reduced through rule changes and teaching proper tackling technique, there remains debate as to whether helmet design may also reduce the incidence of concussion. A retrospective analysis was performed of head impact data collected from 1833 collegiate football players who were instrumented with helmet-mounted accelerometer arrays for games and practices. Data were collected between 2005 and 2010 from 8 collegiate football teams: Virginia Tech, University of North Carolina, University of Oklahoma, Dartmouth College, Brown University, University of Minnesota, Indiana University, and University of Illinois. Concussion rates were compared between players wearing Riddell VSR4 and Riddell Revolution helmets while controlling for the head impact exposure of each player. A total of 1,281,444 head impacts were recorded, from which 64 concussions were diagnosed. The relative risk of sustaining a concussion in a Revolution helmet compared with a VSR4 helmet was 46.1% (95% CI 28.1%-75.8%). When controlling for each player's exposure to head impact, a significant difference was found between concussion rates for players in VSR4 and Revolution helmets (χ(2) = 4.68, p = 0.0305). This study illustrates that differences in the ability to reduce concussion risk exist between helmet models in football. Although helmet design may never prevent all concussions from occurring in football, evidence illustrates that it can reduce the incidence of this injury.

  2. Traffic conflicts on bicycle paths: a systematic observation of behaviour from video

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Goede, M. de; Hair-Buijssen, S.H.H.M. de; Methorst, R.


    In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised tra

  3. System identification of the brompton bicycle (United States)

    Hladun, Monique Victoria Teresa

    The Brompton (a European folding design) bicycle was instrumented with a variety of sensors including acceleration, angular rate, speed, and steering sensors. A bicycle state estimator was designed to obtain additional information from this data including heading, turn rate, lean angle, steer rate, and positions of the wheels during a trajectory. The first part of the thesis describes the model setup for system identification including the Steer-to-Lean dynamics and Lean-to-Steer dynamics reduced models. CIFER software was used in the system identification process of these models. The second part describes the validation of the Empirical model by using the Rider Control model ([1]) and the Complete Rider/Vehicle model ([1]) to determine the feedback gains. The Theoretical model feedback gains were also determined by using the Rider Control model ([1]) and the Complete Rider/Vehicle model ([1]).

  4. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks (United States)

    Kuriyama, Andrew M; Nakatsuka, Austin S


    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play.

  5. Maximum Estrada Index of Bicyclic Graphs

    CERN Document Server

    Wang, Long; Wang, Yi


    Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.

  6. Free Use of Bicycles at CERN

    CERN Multimedia


    Imagine you have just arrived at CERN. You are from Russia or Japan and have no car but you do need to get around and do not like depending on public transport. What do you do? You go to the EP Service Point (Building 124) and meet Boris Cabaud to get a CERN bicycle. Use of the bicycle is free but you have to fill in an application form which needs to be signed by your Group or Division Secretary. Then the application is filled in, you are put on the waiting list and it might take you from one to four weeks to get your bike depending on the season. “Normally the bikes are only for Users in the EP division as they are paid for by the EP budget,” says Boris, “but some other divisions have made arrangements to cover the costs.” Boris takes care of 350 bicycles at present. Each bike can be lent for maximum one year. During the winter the bikes can be stored in building 301 as it is difficult to ride them in the snow. If a bike is broken or lost all costs will be billed to the group or team account of the bo...

  7. Estimating Bicycle and Pedestrian Demand in San Diego


    Jones, Michael; Buckland, Lauren


    This paper introduces the concepts behind estimating bicycle and pedestrian demand and provides an example of the development of a sketch-plan method for estimating bicycle and pedestrian demand from land use in San Diego County. The paper describes the methodology involved in collecting counts for the currently ongoing Seamless Travel project. The Seamless Travel project intends to develop a model for estimating bicycle and pedestrian demand within San Diego County. The project methodology i...

  8. Bicycling and walking are associated with different cortical oscillatory dynamics

    Directory of Open Access Journals (Sweden)

    Lena eStorzer


    Full Text Available Although bicycling and walking involve similar complex coordinated movements, surprisingly Parkinson’s patients with freezing of gait typically remain able to bicycle despite severe difficulties walking. This observation suggests functional differences in the motor networks subserving bicycling and walking. However, a direct comparison of brain activity related to bicycling and walking has never been performed, neither in healthy participants nor in patients. Such a comparison could potentially help elucidating the cortical involvement in motor control and the mechanisms through which bicycling ability may be preserved in patients with freezing of gait. The aim of this study was to contrast the cortical oscillatory dynamics involved in bicycling and walking in healthy participants.To this end, EEG and EMG data of 14 healthy participants were analyzed, who cycled on a stationary bicycle at a slow cadence of 40 revolutions per minute (rpm and walked at 40 strides per minute (spm, respectively.Relative to walking, bicycling was associated with a stronger power decrease in the high beta band (23-35 Hz during movement initiation and execution, followed by a stronger beta power increase after movement termination. Walking, on the other hand, was characterized by a stronger and persisting alpha power (8-12 Hz decrease. Both bicycling and walking exhibited movement cycle-dependent power modulation in the 24-40 Hz range that was correlated with EMG activity. This modulation was significantly stronger in walking.The present findings reveal differential cortical oscillatory dynamics in motor control for two types of complex coordinated motor behavior, i.e., bicycling and walking. Bicycling was associated with a stronger sustained cortical activation as indicated by the stronger high beta power decrease during movement execution and less cortical motor control within the movement cycle. We speculate this to be due to the more continuous nature of

  9. HElmet therapy Assessment in infants with Deformed Skulls (HEADS): protocol for a randomised controlled trial

    NARCIS (Netherlands)

    Wijk, R.M. van; Boere-Boonekamp, M.M.; Groothuis-Oudshoorn, C.G.; Vlimmeren, L.A. van; MJ, I.J.


    BACKGROUND: In The Netherlands, helmet therapy is a commonly used treatment in infants with skull deformation (deformational plagiocephaly or deformational brachycephaly). However, evidence of the effectiveness of this treatment remains lacking. The HEADS study (HElmet therapy Assessment in Deformed

  10. HElmet therapy Assessment in infants with Deformed Skulls (HEADS): protocol for a randomised controlled trial

    NARCIS (Netherlands)

    Wijk, van R.M.; Boonekamp, M.M.; Groothuis-Oudshoorn, C.G.M.; Vlimmeren, van L.A.; IJzerman, M.J.


    Background In The Netherlands, helmet therapy is a commonly used treatment in infants with skull deformation (deformational plagiocephaly or deformational brachycephaly). However, evidence of the effectiveness of this treatment remains lacking. The HEADS study (HElmet therapy Assessment in Deformed

  11. A Novel and High Performance System for Enhancing Speech in Helmet Project (United States)

    National Aeronautics and Space Administration — We propose a highly innovative system for enhancing speech in helmet. First, we propose to apply a circular array with 8 microphones that are inside the helmet. In...

  12. Potential risk and its influencing factors for separated bicycle paths. (United States)

    Xu, Cheng; Yang, Ying; Jin, Sheng; Qu, Zhaowei; Hou, Lei


    In this paper, we propose two potential risk indicators to define and evaluate the safety of bicycle path at the microscopic level. Field bicycle data were collected from three survey sites under different traffic conditions. These two risk indicators based on speed dispersion were proposed and calculated during each 5-min interval. The risk influences of various widths of bicycle path and traffic conditions were analyzed by using one-way ANOVA. We further proposed a generalized linear model (GLM) for modeling and analyzing the relationships between bicycle risks and v/c ratio and percentages of electric bicycles, male cyclists, young cyclists, and loaded cyclists. The stepwise regression models were applied for determination of coefficients. The results show that the influences of gender and age of cyclists on potential risks are not significant. The risks increase with the width of bicycle path and percentage of electric bicycles, while only for wider bicycle path (4-lane case in this study), the risks are associated with whether or not cyclists are loaded. The findings could contribute for analysis and evaluation of the safety for bicycle path.

  13. The Cognitive Pilot Helmet: enabling pilot-aware smart avionics (United States)

    Schnell, Thomas; Melzer, James E.; Robbins, Steve J.


    We hypothesize that human-aware helmet display systems can drastically improve situation awareness (SA), reduce workload, and become the cognitive gateway to two-way human-systems information. We designed a ruggedized prototype helmet liner that was fitted with active electroencephalogram (EEG) electrodes and pulse oxymetry sensor. This liner was integrated into a helmet that was fitted with a binocular SR-100A helmet mounted display. We modified the SR-100A to include dual-eye tracking capability. The resulting system is able to pick up physiological signals from the wearer in real-time for cognitive state characterization by the Cognitive Avionics Tool Set (CATS). We conducted a preliminary test of the cognitive state estimation system in a simulated close-air-support task in the laboratory and found that workload throughout the mission could be gauged using physiological parameters. Cognitively-linked helmet systems can increase situation awareness by metering the amount of information based on available cognitive bandwidth and eventually, we feel that they will be able to provide anticipatory information to the user by means of cognitive intent recognition. Considerable design challenges lie ahead to create robust models of cognitive state characterization and intent recognition. However, the rewards of such efforts could be systems that allow a dramatic increase in human decision making ability and productivity in dynamical complex situations such as air combat or surface warfare.

  14. Determinants of safety helmet use among motorcyclists in Kerala, India

    Directory of Open Access Journals (Sweden)

    Jeesha C Haran


    Full Text Available Background: Motorcycles account for a large proportion of road traffic accidents in India and the riders of these vehicles run a high risk of injuries or death. This study aims to explore the determinants of helmet use among motorcyclists in Kerala, India. Methods: A cross-sectional study conducted in Kerala, India, over a period of six months. 309 motorcyclists in Kerala were interviewed for this study using a pretested structured questionnaire. Results: Among 309 motorcyclists, 80% were less than 40 years of age, and only 24% were females. Among the total, only 31.4% used a helmet. There was a statistically significant association between the use of helmet and gender, marital status, drunken driving, use of alcohol and attitude towards implementing legislative measures. Odds Ratios observed were 5.3 for female gender compared to male, 4.5 for those with a positive attitude towards the implementation of legislative measures on helmet use, 3.7 for those who were not drunk while driving and 2.3 for unmarried compared to married persons. Conclusions: The study concludes that the determinants associated with the practice of helmet use were gender, drunken driving, marital status and positive attitude towards legal measures.

  15. 40° image intensifier tubes in an integrated helmet system (United States)

    Schreyer, Herbert; Boehm, Hans-Dieter V.; Svedevall, B.


    EUROCOPTER has been under contract to the French and German ministries of defence for five years to develop the TIGER, a second generation anti-tank helicopter. A piloting thermal imager has been installed on a steerable platform in the helicopter nose in order to achieve the possibility of flying round the clock. In addition to this sensor, which is sensitive at a wavelength of 10 micrometers , the German side has proposed using an Integrated Helmet System in the PAH 2. This helmet, manufactured by GEC-Marconi Avionics, incorporates two cathode ray tubes (CRT) and two image intensifier tubes which allow the pilot to use an additional sensor in the visible and near infrared spectrum. The electronic part will be built by Teldix. EUROCOPTER DEUTSCHLAND has received the first demonstrator of this helmet for testing in the EUROCOPTER Visionics Laboratory. Later, the C-prototype will be integrated into a BK 117 helicopter (AVT Avionik Versuchstrager). This new helmet has a field of view of 40 degree(s), and exit pupil of 15 mm and improved possibilities of adjusting the optical part. Laboratory tests have been carried out to test important parameters like optical resolution under low light level conditions, field of view, eye relief or exit pupil. The CRT channels have been tested for resolution, distortion, vignetting and homogeneity. The requirements and the properties of the helmet, test procedures and the results of these tests are presented in the paper.

  16. A Decision Analysis Framework for Evaluation of Helmet Mounted Display Alternatives for Fighter Aircraft (United States)


    platform. Based on the senior decision maker preferences and available system data, Alternative 1 - Scorpion Helmet Mounted Cueing System, scored 0.481... Scorpion Helmet Mounted Cueing System ............................................................ 89 viii Joint Helmet Mounted Cueing System (JHMCS...Alternative 1- Scorpion (Thales Visionix Technical Overview).................... 89 Figure 33 : Alternative 2 - JHMCS

  17. Angles of entry of ultraviolet radiation into welding helmets. (United States)

    Tenkate, T S; Collins, M J


    To investigate the angles of entry of ultraviolet (UV) radiation into welding helmets, a UV detector was placed in the eye socket of a head form that was then fitted with a range of welding helmets. The head form was exposed to a collimated beam of UV radiation from various orientations, and the amount of infiltration was measured. Radiation was found to be reflected from the filter plate and into the detector (eye) after entering through (1) an opening between the edge of the shield and the side of the face, and (2) an opening between the top edge of the shield and the top of the head. These results have significance for UV exposure when welding is performed in highly reflective and enclosed situations, and for the design of welding helmets.


    Directory of Open Access Journals (Sweden)

    Aniekpeno Elijah


    Full Text Available Microorganisms associated with commercial motorcycle helmets were investigated in the commercial city of Lagos, Nigeria. 300 motorcycle helmets were randomly collected from different commercial motor cyclists in two densely populated areas of Lagos: Yaba College of Technology (YABATECH and Lagos University Teaching Hospital (LUTH main gates respectively. Two sterile swabs moistened with sterile water were rotated over the inner surface of each helmet and cultured on MacConkey Agar and Nutrient Agar for bacterial growth and Sabouraud Dextrose Agar for fungi growth. The plates for bacteria growth were incubated aerobically at 37 ºC for 48 h, while plates for fungi at 28 ºC for 2 weeks. Biochemical tests were used to identify bacteria; while, cultural characteristics were used for fungi identification. The microorganisms consistently common to the samples investigated in the two locations were similar and included (with respective frequency of occurrence for both location: Staphylococcus aureus (80%; 7%, Pseudomonas aeruginosa (75%; 12%, Staphylococcus epidermis (60%; 8%, Enterobacter aerogenes (52%; 27%, Escherichia coli (40%; 13%, Bacillus spp (37%; 10%, Aspergillus spp (82%; 7%, Candida spp (55%; 22%, Rhizopus spp (40%; 27%, and Penicilium spp (35%; 12%. The motorcycle helmets collected at YABATECH had higher microbial colonization than LUTH irrespective of the isolates. This trend was similar for bacterial and fungi. Results showed that helmets could serve as vehicles for transmission of pathogens. Good hygiene practice (GHP and regular cleaning of motor cycle helmets with sterilants is strongly advocated in order to reduce the incidence of microbial transmission and its associated infection.

  19. Solar Electric Bicycle Body Modeling and Simulation

    Directory of Open Access Journals (Sweden)

    Zhikun Wang


    Full Text Available A new solar electric bicycle design and study were carried out on in this paper. Application of CAD technology to establish three-dimension geometric model, using the kinetic analysis on the frame and other parts for numerical simulation and static strength analysis for the vehicle model design, virtual assembly, complete frame dynamics analysis and vibration analysis, with considering other factors, first on the frame structure improvement, second on security of design calculation analysis and comparison, finally get the ideal body design.

  20. On Wiener polarity index of bicyclic networks (United States)

    Ma, Jing; Shi, Yongtang; Wang, Zhen; Yue, Jun


    Complex networks are ubiquitous in biological, physical and social sciences. Network robustness research aims at finding a measure to quantify network robustness. A number of Wiener type indices have recently been incorporated as distance-based descriptors of complex networks. Wiener type indices are known to depend both on the network’s number of nodes and topology. The Wiener polarity index is also related to the cluster coefficient of networks. In this paper, based on some graph transformations, we determine the sharp upper bound of the Wiener polarity index among all bicyclic networks. These bounds help to understand the underlying quantitative graph measures in depth.

  1. Methods to assess the stability of a bicycle rider system

    NARCIS (Netherlands)

    Cooke, A.G.; Bulsink, V.E.; Beusenberg, C.M.; Dubbeldam, R.; Bonnema, G.M.; Poelman, W.A.; Koopman, H.F.J.M.


    The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced rider/bicy

  2. Bicycle-related maxillofacial injuries: a double-center study

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.


    Objective Bicycle-related injuries account for an important proportion of road injuries all over the world. As only few reports have focused on the characteristics of maxillofacial fractures sustained in bicycle accidents, the purpose of this study was to present and compare epidemiological data abo

  3. 77 FR 39927 - Vehicles and Traffic Safety-Bicycles (United States)


    ... that, at a minimum, the plan: Evaluates the suitability of existing trail surface and soil condition for accommodating bicycle use, or prescribes a sustainable trail design for the construction of new... to look at whether to designate an existing trail or build a trail for bicycle use, but also as...

  4. Bicycle facilities on road segments and intersections of distributor roads.

    NARCIS (Netherlands)


    A sustainably safe road environment requires bicycle facilities that separate motorized traffic from relatively vulnerable road users like cyclists. Research indicates that on distributor roads the road sections with adjoining or separate bicycle tracks are safer than the road sections without any b

  5. On Sum--Connectivity Index of Bicyclic Graphs

    CERN Document Server

    Du, Zhibin


    We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\\le m\\le \\lfloor\\frac{n}{2}\\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\\ge 5$ vertices. The extremal graphs are characterized.

  6. Bicycle Freewheeling with Air Drag as a Physics Experiment (United States)

    Janssen, Paul; Janssens, Ewald


    To familiarize first-year students with the important ingredients of a physics experiment, we offer them a project close to their daily life: measuring the effect of air resistance on a bicycle. Experiments are done with a bicycle freewheeling on a downhill slope. The data are compared with equations of motions corresponding to different models…

  7. Bicycle-related maxillofacial injuries : a double-center study

    NARCIS (Netherlands)

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K. Hakki; Forouzanfar, Tymour


    Objective. Bicycle-related injuries account for an important proportion of road injuries all over the world. As only few reports have focused on the characteristics of maxillofacial fractures sustained in bicycle accidents, the purpose of this study was to present and compare epidemiological data ab

  8. Factors of the physical environment associated with walking and bicycling

    NARCIS (Netherlands)

    Wendel-Vos, G.C.W.; Schuit, A.J.; Niet, de R.; Boshuizen, H.C.; Saris, W.H.M.; Kromhout, D.


    PURPOSE: The purpose of this study was to identify factors of the physical environment that may influence time spent on walking and bicycling. METHODS: Demographic factors and time spent on walking and bicycling (during leisure time and for commuting purposes) were assessed with a self-administered

  9. Modeling of speed distribution for mixed bicycle traffic flow

    Directory of Open Access Journals (Sweden)

    Cheng Xu


    Full Text Available Speed is a fundamental measure of traffic performance for highway systems. There were lots of results for the speed characteristics of motorized vehicles. In this article, we studied the speed distribution for mixed bicycle traffic which was ignored in the past. Field speed data were collected from Hangzhou, China, under different survey sites, traffic conditions, and percentages of electric bicycle. The statistics results of field data show that the total mean speed of electric bicycles is 17.09 km/h, 3.63 km/h faster and 27.0% higher than that of regular bicycles. Normal, log-normal, gamma, and Weibull distribution models were used for testing speed data. The results of goodness-of-fit hypothesis tests imply that the log-normal and Weibull model can fit the field data very well. Then, the relationships between mean speed and electric bicycle proportions were proposed using linear regression models, and the mean speed for purely electric bicycles or regular bicycles can be obtained. The findings of this article will provide effective help for the safety and traffic management of mixed bicycle traffic.

  10. A method for detecting miners based on helmets detection in underground coal mine videos

    Institute of Scientific and Technical Information of China (English)

    Cai Limei; Qian Jiansheng


    In order to monitor dangerous areas in coal mines automatically,we propose to detect helmets from underground coal mine videos for detecting miners.This method can overcome the impact of similarity between the targets and their background.We constructed standard images of helmets,extracted four directional features,modeled the distribution of these features using a Gaussian function and separated local images of frames into helmet and non-helmet classes.Out experimental results show that this method can detect helmets effectively.The detection rate was 83.7%.

  11. Injury outcome among helmeted and non-helmeted motorcycle riders and passengers at a tertiary care hospital in north-western Tanzania. (United States)

    Chalya, Phillipo L; Ngayomela, Isidori H; Mabula, Joseph B; Mbelenge, Nkinda; Dass, Ramesh M; Chandika, Alphonce; Gilyoma, Japhet M; Kapesa, Anthony; Ngallaba, Sospatro E


    Motorcycle helmets have been reported to reduce the risk of death and head injuries following motorcycle accidents. The aim of this descriptive prospective study was to determine the injury outcome among helmeted and non-helmeted motorcyclists and passengers at a tertiary hospital in north-western Tanzania. A total of 654 patients involved in the motorcycle accident were studied. Of these, 468 (71.6%) were motorcyclists (riders) and the remaining 186 (28.4%) were passengers. The median age of patients at presentation was 26 years. Male outnumbered females by a ratio of 4.5: 1. Helmet use was reported in 312 (47.7%) patients. Non- helmeted patients were young compared with helmeted patients and this was statistically significant (p = 0.021). The rate of helmet use was significantly higher among motorcyclists than among passengers (p = 0.004). History of alcohol consumption prior to the accident was reported in 212 (32.4%) patients. The rate of helmet use was significantly low among alcohol consumers compared with non-alcohol consumers (p = 0.011). Lack of helmet use was significantly associated with abnormal head Computed Tomography scans, admission to the Intensive care unit, severe trauma, and worse traumatic brain injury severity (p < 0.001). Helmet use was significantly associated with shorter period of hospitalization and reduced mortality rate (p < 0.001). Motorcycle helmet use is still low in this part of Tanzania and this poses a great impact on injury outcome among motorcycle injury patients. This observation calls for action to implement more widespread injury prevention and helmet safety education and advocacy.

  12. Infiuence of Bicycle Traffic on Capacity of Typical Signalized Intersection

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; SHAO Chunfu; YUE Hao


    Bicycle traffic has a significant effect on the capacity of signalized intersections. This paper divides the influence of bicyclists on vehicular flow into four types with the time durations estimated based on probability, shock wave, and gap acceptance theory. Vehicular saturation flow rate is predicted for various conditions on the basis of the speed-flow curve for the capacity of typical intersections influenced by bicycle traffic.The model overcomes the limitations of the Highway Capacity Manual (HCM, 2000) method for left-turns due to data collection, and takes into account the effect of trapped bicycles on the through vehicular traffic.The numerical results show that the left-turn and through capacities predicted by the model are lower than those of the HCM method. The right-turn capacity is close to that of the HCM method at Iow bicycle volumes and higher than that of the HCM method at high bicycle volumes.

  13. A mixed methods investigation of bicycle exposure in crash rates. (United States)

    Fournier, Nicholas; Christofa, Eleni; Knodler, Michael A


    Crash rates are an essential tool enabling researchers and practitioners to assess whether a location is truly more dangerous, or simply serves a higher volume of vehicles. Unfortunately, this simple crash rate is far more difficult to calculate for bicycles due to data challenges and the fact that they are uniquely exposed to both bicycle and automobile volumes on shared roadways. Bicycle count data, though increasingly more available, still represents a fraction of the available count data for automobiles. Further compounding on this, bicycle demand estimation methods often require more data than automobiles to account for the high variability that bicycle demand is subject to. This paper uses a combination of mixed methods to overcome these challenges and to perform an investigation of crash rates and exposure to different traffic volumes.

  14. Bicyclic Peptide Inhibitor of Urokinase-Type Plasminogen Activator

    DEFF Research Database (Denmark)

    Roodbeen, Renée; Paaske, Berit; Jiang, Longguang;


    The development of protease inhibitors for pharmacological intervention has taken a new turn with the use of peptidebased inhibitors. Here, we report the rational design of bicyclic peptide inhibitors of the serine protease urokinase-type plasminogen activator (uPA), based on the established...... monocyclic peptide, upain-2. It was successfully converted to a bicyclic peptide, without loss of inhibitory properties. The aim was to produce a peptide cyclised by an amide bond with an additional stabilising across-the-ring covalent bond. We expected this bicyclic peptide to exhibit a lower entropic...... burden upon binding. Two bicyclic peptides were synthesised with affinities similar to that of upain-2, and their binding energetics were evaluated by isothermal titration calorimetry. Indeed, compared to upain-2, the bicyclic peptides showed reduced loss of entropy upon binding to uPA. We also...

  15. Predicting bicycle setup for children based on anthropometrics and comfort. (United States)

    Grainger, Karl; Dodson, Zoe; Korff, Thomas


    Bicycling is a popular activity for children. In order for children to enjoy cycling and to minimize injury, it is important that they are positioned appropriately on the bicycle. The purpose of this study was therefore to identify a suitable bicycle setup for children aged between 7 and 16 years which accommodates developmental differences in anthropometrics, flexibility and perceptions of comfort. Using an adjustable bicycle fitting rig, we found the most comfortable position of 142 children aged 7 to 16. In addition, a number of anthropometric measures were recorded. Seat height and the horizontal distance between seat and handlebars were strongly predictable (R(2) > 0.999, p bicycle manufacturers.

  16. An Examination of Concussion Injury Rates in Various Models of Football Helmets in NCAA Football Athletes

    Institute of Scientific and Technical Information of China (English)

    Ryan Moran; Tracey Covassin


    While newer, advanced helmet models have been designed with the intentions of decreasing concussions, very little research exists on injury rates in various football helmets at the collegiate level. The aim of this study was to examine concussion injury rates in various models of football helmets in collegiate football athletes. In addition, to compare injury rates of newer, advanced football helmets to older, traditional helmets among collegiate football athletes, a total of 209 concussions and 563,701 AEs (athlete-exposures) among 2,107 collegiate football athletes in seven helmet models were included in the analyses. Concussion injury rates revealed that the Riddell Revolution~ had the highest rate of 0.41 concussions per 1,000 AEs. The Schutt ION 4DTM helmet had the lowest rate of 0.25 concussions per 1,000 AEs. These newer helmet models did not significantly differ from one another (P = 0.74), however, all models significantly differed from the older, traditional helmet model (P 〈 0.001). The findings of this study suggest that concussion rates do not differ between newer and more advanced helmet models. More importantly, there are currently no helmets available to prevent concussions from occurring in football athletes.

  17. Injuries of the head from backface deformation of ballistic protective helmets under ballistic impact. (United States)

    Rafaels, Karin A; Cutcliffe, Hattie C; Salzar, Robert S; Davis, Martin; Boggess, Brian; Bush, Bryan; Harris, Robert; Rountree, Mark Steve; Sanderson, Ellory; Campman, Steven; Koch, Spencer; Dale Bass, Cameron R


    Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed "behind armor blunt trauma" (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400-460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear.

  18. Do helmets worn for hurling fail to protect the ear? Identification of an emerging injury pattern.

    LENUS (Irish Health Repository)

    Martin-Smith, James D


    Hurling is an Irish national game of stick and ball known for its ferocity, played by 190 000 players. Facial injuries were common but have been significantly reduced by legislation enforcing compulsory helmet wearing. Current standard helmets worn by hurlers do not offer protection to the external ear. Here we describe an emerging pattern of ear injuries and demonstrate the risk of external ear injuries in hurlers complying with current helmet safety standards. A 6-month retrospective analysis was carried out of patients attending Cork University Hospital (CUH) with ear lacerations sustained while hurling. Patient notes were reviewed and helmet manufacturers were interviewed. Seven patients were identified, all of whom sustained complex through ear lacerations while wearing helmets complying with current safety standards. Current helmet design fails to protect the external ear placing it at an increased risk of injury, a potential solution is to include ear protection in the helmet design.

  19. Dynamic Study of Bicycle Frame Structure (United States)

    Sani, M. S. M.; Nazri, N. A.; Zahari, S. N.; Abdullah, N. A. Z.; Priyandoko, G.


    Bicycle frames have to bear variety of loads and it is needed to ensure the frame can withstand dynamic loads to move. This paper focusing on dynamic study for bicycle frame structure with a purpose to avoid the problem regarding loads on the structure and to ensure the structure is safe when multiple loads are applied on it. The main objectives of dynamic study are to find the modal properties using two method; finite element analysis (FEA) and experimental modal analysis (EMA). The correlation between two studies will be obtained using percentage error. Firstly, 3D model of mountain bike frame structure has been draw using computer-aided design (CAD) software and normal mode analysis using MSC Nastran Patran was executed for numerical method meanwhile modal testing using impact hammer was performed for experimental counterpart. From the correlation result, it show that percentage error between FEA and EMA were below 10% due to noise, imperfect experiment setup during perform EMA and imperfect modeling of mountain bike frame structure in CAD software. Small percentage error differences makes both of the method can be applied to obtain the dynamic characteristic of structure. It is essential to determine whether the structure is safe or not. In conclusion, model updating method is required to reduce more percentage error between two results.

  20. Safe bicycling – Problems and solutions

    Directory of Open Access Journals (Sweden)

    Grecka M.


    Full Text Available Herewith a popularity of bicycling, various safety problems of cyclists are researched. Studies are connected with infrastructure, riding culture, choice of cyclist's suit and riding equipment. Overall, 382 respondents (159 cyclists, 119 drivers, 104 pedestrians were involved in the survey. The road participants' mutual communication problems in the traffic and opportunities of solving them were clarified. Most of cyclists wear comfortable daily or sporty clothing with reflective elements, and in their opinion, clothing with light emissive elements must be like daily clothing. The drivers could better notice cyclists, if they wear brightly colored suit with light emissive and reflective elements, but pedestrians – if cyclists use warning sound signals. The opinions of road participants about the placement of light emissive and reflective elements in cyclist's clothing were clarified. The prototype of cycling belt (Fig. 1e has been drawn up with LED stop signals, which are activated by the accelerometer placed in the central back pocket. The results of approbation have shown that the sensor does not provide the proper functioning of signals, due to a high level of riding movements. Using Motion Capture technology and bicycle exercise equipment, the research of oscillation of anthropometric points on the back has been carried out. The accelerometer should be placed between scapulae to design the cycling jacket.

  1. The Design of Sport Bicycle Speed Odometer

    Directory of Open Access Journals (Sweden)

    Dongbing Liu


    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  2. Finite element modelling of helmeted head impact under frontal loading

    Indian Academy of Sciences (India)

    Praveen Kumar Pinnoji; Puneet Mahajan


    Finite element models of the head and helmet were used to study contact forces during frontal impact of the head with a rigid surface. The finite element model of the head consists of skin, skull, cerebro-spinal fluid (CSF), brain, tentorium and falx. The finite element model of the helmet consists of shell and foam liner. The foam is taken as elasto-plastic, the brain is assumed to be viscoelastic and all other components are taken as elastic. The contact forces and coup pressures with helmet on the head are much lower than in the absence of the helmet. A parametric study was performed to investigate the effect of liner thickness and density on the contact forces, pressures and energy absorption during impact. For 4 ms-1 velocity, expanded poly styrene (EPS) foam of density 24 kg m-3 gave the lowest contact forces and for the velocities considered, thickness of the foam did not affect the contact forces.

  3. Parents’ decision for helmet therapy in infants with skull deformation

    NARCIS (Netherlands)

    Wijk, van Renske M.; Til, van Janine A.; Groothuis-Oudshoorn, Catharina G.M.; L'Hoir, Monique P.; Boere-Boonekamp, Magda M.; IJzerman, Maarten J.


    Purpose Helmet therapy is regularly prescribed in infants with positional skull deformation. Evidence on the effectiveness is lacking, which complicates decision making. This study aims to assess the relation between parents’ decision for treatment of skull deformation in their infant and their leve

  4. Parents' decision for helmet therapy ion infants with skull deformation

    NARCIS (Netherlands)

    Wijk, R.M. van; Til, J.A. van; Groothuis-Oudshoorn, C.G.M.; Hoir, M.P. L; Boere-Boonekamp, M.M.; IJzerman, M.J.


    Purpose. Helmet therapy is regularly prescribed in infants with positional skull deformation. Evidence on the effectiveness is lacking, which complicates decision making. This study aims to assess the relation between parents’ decision for treatment of skull deformation in their infant and their lev

  5. The frequency of single-bicycle crashes (SBCs) in countries with varying bicycle mode shares

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;

    In  order  to  encourage  cycling,  we  need  to  reduce  the  hazards  that  cyclists  face. Single-bicycle crashes or ‘bicycle-only crashes’ are falls and obstacle collisions in which only one cyclist is involved. Between 60 and 95% of cyclists admitted to hospital or treated at an emergency...... department are victims of single-bicycle crashes. As proportion of the total number of traffic casualties  the  share  exceeds  20%  in  most  countries  with  medium  to  high  levels  of cycling.  This paper  discusses  the  prevalence  of  the  problem  and  describes  measures  that  may  both reduce...

  6. Determinants and barriers of helmet use in Iranian motorcyclists: a systematic review

    Directory of Open Access Journals (Sweden)

    Homayoun Sadeghi Bazargani


    Full Text Available Background: Use of helmet by motorcyclists decreases the incidence and severity of an injury and its related death. Unfortunately, the helmet use rate is not in an acceptable level in Iran. This study aimed to systematically identify the determinants and barriers of helmet use among Iranian motorcyclists. Methods: A systematic search of literature was done using PubMed, Scopus, Science Direct and Web of knowledge databases for English literature and SID for Persian articles by specified keywords. Manual searching and reference of references were used to improve the articles identification. Articles published before 1995 and those which did not report the barriers and determinants of helmet use were excluded. Data were extracted using an extraction table. Results: Out of 49 retrieved articles, 13 articles were included in the study. Most of them (70% had a cross-sectional design. Personal factors (such as older age, marital status and education and motorcyclist's attitude and beliefs about the helmet effectiveness were reported as important determinants of helmet use. Helmet weight and its visual and audial limitation for motorcyclists were known as the main reported barriers to use a helmet. Conclusions: Interventions affecting the motorcyclists' attitude must be employed along with the legal interventions. Moreover, cost-effective engineering improvements in helmet production remain an important policy to improve the compliance of helmet use.

  7. Determinants and barriers of helmet use in Iranian motorcyclists: a systematic review (United States)

    Sadeghi Bazargani, Homayoun; Saadati, Mohammad; Rezapour, Ramin; Abedi, Leili


    Abstract: Background: Helmet use by motorcyclists decreases the incidence and severity of an injury and its related death. Unfortunately, the helmet use rate is not in an acceptable level in Iran. This study aimed to systematically identify the determinants and barriers of helmet use among Iranian motorcyclists. Methods: A systematic search of literature was done using PubMed, Scopus, Science Direct and Web of knowledge databases for English literature and SID for Persian articles by specified keywords. Manual searching and reference of references were used to improve the articles identification. Articles published before 1995 and those which did not report the barriers and determinants of helmet use were excluded. Data were extracted using an extraction table. Results: Out of 49 retrieved articles, 13 articles were included in the study. Most of them (70%) had a cross-sectional design. Personal factors (such as older age, marital status and education) and motorcyclist's attitude and beliefs about the helmet effectiveness were reported as important determinants of helmet use. Helmet weight and its visual and audial limitation for motorcyclists were known as the main reported barriers to use a helmet. Conclusions: Interventions affecting the motorcyclists' attitude must be employed along with the legal interventions. Moreover, cost-effective engineering improvements in helmet production remain an important policy to improve the compliance of helmet use. PMID:28042961

  8. Beijing Bicycle - Stories from a Transformative Space

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin


    Ideas, words, images and stories travel from west to east – and from east to west. Stories are chosen and retold in different settings and images are reproduced and appropriated into new contexts – and in new times. Cinema, in this case the mainland Chinese, becomes both a space of production...... and a production of space that reveals how transnational and translocal mechanisms affect the cinematic language, transforming the images and stories chosen for the cinematic representation. Wang Xiaoshuai’s Beijing Bicycle (Shiqi Sui de Danche) (2001) is a result of transnational currents weaving the carpet...... relevant in a new context – that of the Chinese mainland society in the 21st century. Doreen Massey (2005: 9) defines space as “a simultaneity of stories-so-far”, a space that is constantly exploding and imploding with the influx of new and old stories. Within this theoretical framework Wang Xiaoshuai...

  9. Bicyclic graphs with maximal revised Szeged index

    CERN Document Server

    Li, Xueliang


    The revised Szeged index $Sz^*(G)$ is defined as $Sz^*(G)=\\sum_{e=uv \\in E}(n_u(e)+ n_0(e)/2)(n_v(e)+ n_0(e)/2),$ where $n_u(e)$ and $n_v(e)$ are, respectively, the number of vertices of $G$ lying closer to vertex $u$ than to vertex $v$ and the number of vertices of $G$ lying closer to vertex $v$ than to vertex $u$, and $n_0(e)$ is the number of vertices equidistant to $u$ and $v$. Hansen used the AutoGraphiX and made the following conjecture about the revised Szeged index for a connected bicyclic graph $G$ of order $n \\geq 6$:

  10. Bamboo Bicycle – Past or Future?

    Directory of Open Access Journals (Sweden)

    Suzana Jakovljević


    Full Text Available In this article the experiment was carried out to establish tensile strength values of two different bamboo species, which are obtained by the static tensile test. The tensile strength results of two tested species Tonkin Cane and Ku Zhu bamboo are presented and compared with traditional materials used for bicycle frame to determine their suitability for designing a frame. Physiology and other properties of bamboo were elaborated as well. The purpose of this study was to gain more knowledge on bamboo and prove his suitability in use as an alternative for ecologically unacceptable materials. Therefore, application of the natural materials is essential for the sustainable development. The fact that they have unlimited resources the use of bamboo has great potential and this article explains why.

  11. Associations between bicycling and carotid arterial stiffness in adolescents

    DEFF Research Database (Denmark)

    Ried-Larsen, M; Grøntved, A; Østergaard, Lars;


    The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European...... Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys...... modulus [standard beta -0.48 (95% CI -0.91 to -0.06)]. Similar trends were observed when investigating the association between commuter bicycling and carotid arterial stiffness. These associations were not observed in girls. Our observations suggest that increasing bicycling in adolescence may...

  12. Motorcycle helmet use in Mar del Plata, Argentina: prevalence and associated factors. (United States)

    Ledesma, Rubén D; López, Soledad S; Tosi, Jeremías; Poó, Fernando M


    Injuries resulting from motorcycle crashes constitute a growing problem in Argentina and other Latin American countries. The problem is aggravated because helmet use is not widespread. This observational study analysed the prevalence of helmet use and related factors in a city in Argentina. The sample consisted of 2542 observations of motorcyclists. The results show an incidence of helmet use of 69.8% for drives and 43.4% for passengers. Helmet use was greater among women. Environmental and temporal conditions were related with the rate of helmet use. The findings indicate a considerable increase in helmet use with respect to prior years, providing evidence in favour of government policies. However, the number of motorcycles in circulation has tripled in the past five years, and therefore, the public health impact of injuries due to motorcycle crashes persists.

  13. On the Skill of Balancing While Riding a Bicycle.

    Directory of Open Access Journals (Sweden)

    Stephen M Cain

    Full Text Available Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle and less steer control (quantified by cross-correlating steer rate and bicycle roll rate than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate and less rider lean angle variation (measured by the standard deviation of the rider lean angle independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  14. On the Skill of Balancing While Riding a Bicycle. (United States)

    Cain, Stephen M; Ashton-Miller, James A; Perkins, Noel C


    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  15. The influence of ski helmets on sound perception and sound localisation on the ski slope

    Directory of Open Access Journals (Sweden)

    Lana Ružić


    Full Text Available Objectives: The aim of the study was to investigate whether a ski helmet interferes with the sound localization and the time of sound perception in the frontal plane. Material and Methods: Twenty-three participants (age 30.7±10.2 were tested on the slope in 2 conditions, with and without wearing the ski helmet, by 6 different spatially distributed sound stimuli per each condition. Each of the subjects had to react when hearing the sound as soon as possible and to signalize the correct side of the sound arrival. Results: The results showed a significant difference in the ability to localize the specific ski sounds; 72.5±15.6% of correct answers without a helmet vs. 61.3±16.2% with a helmet (p < 0.01. However, the performance on this test did not depend on whether they were used to wearing a helmet (p = 0.89. In identifying the timing, at which the sound was firstly perceived, the results were also in favor of the subjects not wearing a helmet. The subjects reported hearing the ski sound clues at 73.4±5.56 m without a helmet vs. 60.29±6.34 m with a helmet (p < 0.001. In that case the results did depend on previously used helmets (p < 0.05, meaning that that regular usage of helmets might help to diminish the attenuation of the sound identification that occurs because of the helmets. Conclusions: Ski helmets might limit the ability of a skier to localize the direction of the sounds of danger and might interfere with the moment, in which the sound is firstly heard.

  16. Evaluation of Aircraft Ejection Seat Safety When Using Advanced Helmet Sensors (United States)


    survivability and equipment airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or both during ejection...and equipment airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or both during

  17. Test Verification and Design of the Bicycle Frame Parameters

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long; XIANG Zhongxia; LUO Huan; TIAN Guan


    Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders’ worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers’ height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes’ function, and the new direction on future design of bicycle frame parameters is presented.

  18. [Bicycle spoke-related injuries in children: emphasise prevention]. (United States)

    Kramer, William L M; Haaring, Gert-Jan


    Three children, a 6-year-old boy and two girls aged 5 and 4 years, were seen at an emergency department due to distal lower-leg injuries sustained from the spokes of bicycle wheels. All three patients had been passengers on rear carrying seats of moving bicycles. Only the third bicyclist had used a special child safety seat. The second girl had drawn her foot up from underneath a strap and suffered a tibial fracture later treated with an osteosynthetic plate. The other two patients recovered after conservative casting treatment. Bicycle spoke-related injuries are sustained when the foot or lower limb makes contact with the spokes of a bicycle wheel and usually by children who are bicycle passengers. In the Netherlands, approximately 4600 children are seen at emergency departments with such injuries each year. Bicycle spoke-related accidents can cause severe damage that can result in lengthy recovery periods. Not only physical complications but also psychological ones can occur. The latter are often overlooked but do deserve proper treatment. The physician treating a spoke-related injury is in a good position to advice parents as to preventive measures, particularly on the use of special child safety seats.

  19. Cockpit to helmet optical wireless link: prototype hardware demonstration (United States)

    Watson, M. A.; White, H. J.; Aldridge, N. B.; Lam, J.; Atkinson, R.


    This paper describes recent progress in developing a wireless optical link between the fuselage of a cockpit and an aviation helmet. Such a link is desired to replace the physical umbilical cable existing in current cockpit systems, for reasons of potential bandwidth, immunity to EM interference, and freedom from physical constraints within the cockpit. The link concept consists of multiple transmitters embedded in the cockpit fuselage, each sending video (or symbology) data out in a cone of light over free space, which is detected by an array of receivers positioned on the helmet - the data is then sent to the eyepieces or visor of the pilot (after any intermediate processing). The design is such that one of these links is always maintained throughout possible movement of the head. In a recent proof-of-principle demonstration we showed uncompressed, 100 Mbps video data streamed live from the fuselage of a cockpit simulator to an angled cluster of silicon-based receivers mounted on the helmet, via a pair of ~1 Watt free-space lasers operating at 810 nm. Fast Ethernet media converters were used here for convenience and cost. The bespoke optical and electrical link components were developed in close collaboration with suppliers. The system performance arises from: the high dynamic range of the receivers (up to 25 dB), which are equipped with optical antennae to magnify the optical gain; the high power of the lasers; and the switching electronics used to control the signal path on the helmet. Future potential improvements to the technology are discussed, with an indication of wireless link requirements for relevant BAE Systems applications.

  20. Safety Aspect Analysis of Helmet Mounted Millimeter Wave Radio

    Directory of Open Access Journals (Sweden)

    K. Nageswari


    Full Text Available Measurements of millimetric wave (MMW power density from two-helmet-mounted MMW radiating horn antennas were made at various distances on the three axes. These three axes are representing three planes: (i in the direction of propagation (Z-axis, (ii horizontal axis perpendicular to the direction of propagation (Y-axis, i.e., 15 cm to the left or right of Z-axis, and (iii vertical axis (X-axis also perpendicular to the direction of propagation and extending up and down an imaginary central reference line passing through the centre of the horn and the centre of the microwave measuring probe. Measurements were also made inside the helmet close to the metallic plate at 17 locations and 10 cm away from it. The Narda-8723 broadband isotropic microwave probe [frequency of operation (0.3-40 GHz power density range 0.05-100 mW/cm1 was placed at various distance points marked at 15 nm intervals and also at distances of relevance on Z-axis. For each of the distance points on Z-axis, measurements were taken at 7 probe locations on X-axis. For Y-axis measurements, 4 probe locations were selected (on vertical or X-axis. The results revealed no leakage of microwave power inside the helmets. In the transmitting mode of operation, there was a great variability of microwave power emitted closest to the horn antennas (2.5-5.0 mW / 2 and 6.0-105 mW /cm2 for helmet Nos.11 and2, respectively. As the distance from the antenna increased in the direction of propagation, the power density dropped to 0.04 m W / cm2 or 0.075 m W / cm{ maximum value at 1 m. As the values recorded are within American National Standards Institute (ANSI safety guidelines (10mW/cm2 at 35 GHz.

  1. Neck Muscle Fatigue Resulting from Prolonged Wear of Weighted Helmets (United States)


    documented neck injury rates of 50% or higher ranging from minor neck strain to cervical vertebral fracture3,11-14,17. Lighter helmets were developed...greater neck fatigue and susceptibility to neck injury. There may be an increase in cervical loads during aircraft ejections (catapult, windblast...and compromised effectiveness for long missions. The neck load limits ( flexion , extension, and rotation) under operational conditions are

  2. Comparative life cycle assessment of ghana-made bamboo-frame bicycle and conventional bicycles assembled and used in the Netherlands

    NARCIS (Netherlands)

    Agyekum, E.O.; Fortuin, K.P.J.; Harst, van der E.J.M.


    In order to assess the sustainability of bamboo-framed bicycles produced in Ghana, an environmental and social life cycle assessments (LCA) were performed. For the environmental LCA, a bamboo-frame bicycle was compared with aluminium- and steel-frame bicycles, focussing on processes related to the f

  3. An international review of the frequency of single-bicycle crashes (SBCs) and their relation to bicycle modal share

    DEFF Research Database (Denmark)

    Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle;


    Objectives To study cyclists’ share of transport modes (modal share) and single-bicycle crashes (SBCs) in different countries in order to investigate if the proportion of cyclist injuries resulting from SBCs is affected by variation in modal share. Methods A literature search identified figures...... (largely from western countries) on SBC casualties who are fatally injured, hospitalised or treated at an emergency department. Correlation and regression analyses were used to investigate how bicycle modal share is related to SBCs. Results On average, 17% of fatal injuries to cyclists are caused by SBCs...... of SBC casualties among the total number of road crash casualties increases proportionally less than the increase in bicycle modal share. Conclusions While most fatal injuries among cyclists are due to motor vehicle–bicycle crashes, most hospital admissions and emergency department attendances result...

  4. Capabilities of Helmets for Preventing Head Injuries Induced by Ballistic Impacts

    Directory of Open Access Journals (Sweden)

    D.V. Balandin


    Full Text Available The limiting performance of ballistically loaded helmets designed to reduce head injuries is studied analytically. The projectile does not penetrate the helmet. This analysis evaluates the absolute minimum of the peak displacement of the helmet shell relative to the head, provided that criteria measuring the severity of head injuries lie within prescribed limits. Rather than optimize a specific design configuration, e.g. a viscoelastic foam liner, characteristics of a time-dependent force representing the helmet liner are calculated. The formulation reduces the limiting performance analysis to an optimal control problem.

  5. Helmet Use Amongst Equestrians: Harnessing Social and Attitudinal Factors Revealed in Online Forums

    Directory of Open Access Journals (Sweden)

    Laura Haigh


    Full Text Available Equestrian activities pose significant head injury risks to participants. Yet, helmet use is not mandatory in Australia outside of selected competitions. Awareness of technical countermeasures and the dangers of equestrian activities has not resulted in widespread adoption of simple precautionary behaviors like helmet use. Until the use of helmets whilst riding horses is legislated in Australia, there is an urgent need to improve voluntary use. To design effective injury prevention interventions, the factors affecting helmet use must first be understood. To add to current understandings of these factors, we examined the ways horse riders discussed helmet use by analyzing 103 posts on two helmet use related threads from two different Australian equestrian forums. We found evidence of social influence on helmet use behaviors as well as three attitudes that contributed towards stated helmet use that we termed: “I Can Control Risk”, “It Does Not Feel Right” and “Accidents Happen”. Whilst we confirm barriers identified in previous literature, we also identify their ability to support helmet use. This suggests challenging but potentially useful complexity in the relationship between risk perception, protective knowledge, attitudes, decision-making and behavior. Whilst this complexity is largely due to the involvement of interspecies relationships through which safety, risk and trust are distributed; our findings about harnessing the potential of barriers could be extended to other high risk activities.

  6. Analysis of EMG measurements during bicycle pedalling. (United States)

    Jorge, M; Hull, M L


    Activity of eight leg muscles has been monitored for six test subjects while pedalling a bicycle on rollers in the laboratory. Each electromyogram (EMG) data channel was digitized at a sampling rate of 2 kHz by a minicomputer. Data analysis entailed generating plots of both EMG activity regions and integrated EMG (IEMG). For each test subject, data were recorded for five cases of pedalling conditions. The different pedalling conditions were defined to explore a variety of research hypotheses. This exploration has led to the following conclusions: Muscular activity levels of the quadriceps are influenced by the type of shoes worn and activity levels increase with soft sole shoes as opposed to cycling shoes with cleats and toeclips. EMG activity patterns are not strongly related to pedalling conditions (i.e. load, seat height and shoe type). The level of muscle activity, however, is significantly affected by pedalling conditions. Muscular activity bears a complex relationship with seat height and quadriceps activity level decreases with greater seat height. Agonist (i.e. hamstrings) and antagonist (i.e. quadriceps) muscles of the hip/knee are active simultaneously during leg extension. Regions of peak activity levels, however, do not overlap. The lack of significant cocontraction of agonist/antagonist muscles enables muscle forces during pedalling action to be computed by solving a series of equilibrium problems over different regions of the crank cycle. Regions are defined and a solution procedure is outlined.

  7. Bicycle, city and education: search moves

    Directory of Open Access Journals (Sweden)

    Sheila Hempkemeyer


    Full Text Available This study comes from a Master’s degree in Education research, which investigates narratives of “pedaling beings” starting from the relationship bicycle-city. The theoretical assumptions lean on the Cultural Studies and concepts about education, culture, everyday life, experience and narratives. Researching with narratives closes everyday life and promotes co-authorship to the subjects in the paper. The article puts in discussion some forms of contemporary subjectivity, resistance techniques and expression. A study that builds narratives and reflections about the experiences of theses hybrid subjects and their everyday life, questioning their way of life in the city. Thinking in this urban medley is connect the environment and the dynamic of these pedaling bodies, emerging other ways of education and interaction with the medium, weaving multiple affectations in aesthetics, poetry, politics, opening breaches to reflect in the everyday happenings. The article also discusses the movements in research and the effects in those who research and are researched.

  8. Reviving a ghost in the history of technology: the social construction of the recumbent bicycle. (United States)

    Ahmed, Hassaan; Qureshi, Omer Masood; Khan, Abid Ali


    Recumbent bicycles have never truly been associated with international cycling. Conventional safety (upright) bicycles have long been at the center of the cycling world, for both sport and transportation. This is despite the fact that recumbent bicycles are faster, more comfortable, and more efficient than the upright bicycles. The aim of this article is to explain the historical and social perspectives that led to the rejection of the recumbent bicycle by utilizing the theory of Social Construction of Technology (SCOT) and Bijker's two power theory, providing a contrast with the adoption of the safety bicycle.

  9. Built environment influences on healthy transportation choices: bicycling versus driving. (United States)

    Winters, Meghan; Brauer, Michael; Setton, Eleanor M; Teschke, Kay


    A growing body of evidence links the built environment to physical activity levels, health outcomes, and transportation behaviors. However, little of this research has focused on cycling, a sustainable transportation option with great potential for growth in North America. This study examines associations between decisions to bicycle (versus drive) and the built environment, with explicit consideration of three different spatial zones that may be relevant in travel behavior: trip origins, trip destinations, and along the route between. We analyzed 3,280 utilitarian bicycle and car trips in Metro Vancouver, Canada made by 1,902 adults, including both current and potential cyclists. Objective measures were developed for built environment characteristics related to the physical environment, land use patterns, the road network, and bicycle-specific facilities. Multilevel logistic regression was used to model the likelihood that a trip was made by bicycle, adjusting for trip distance and personal demographics. Separate models were constructed for each spatial zone, and a global model examined the relative influence of the three zones. In total, 31% (1,023 out of 3,280) of trips were made by bicycle. Increased odds of bicycling were associated with less hilliness; higher intersection density; less highways and arterials; presence of bicycle signage, traffic calming, and cyclist-activated traffic lights; more neighborhood commercial, educational, and industrial land uses; greater land use mix; and higher population density. Different factors were important within each spatial zone. Overall, the characteristics of routes were more influential than origin or destination characteristics. These findings indicate that the built environment has a significant influence on healthy travel decisions, and spatial context is important. Future research should explicitly consider relevant spatial zones when investigating the relationship between physical activity and urban form.

  10. How similar are two-unit bicycle and motorcycle crashes? (United States)

    Haworth, Narelle; Debnath, Ashim Kumar


    This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.

  11. The Theory of Planned Behavior and Helmet Use among College Students (United States)

    Ross, Lisa Thomson; Ross, Thomas P.; Farber, Sarah; Davidson, Caroline; Trevino, Meredith; Hawkins, Ashley


    Objectives: To assess undergraduate helmet use attitudes and behaviors in accordance with the theory of planned behavior (TPB). We predicted helmet wearers and nonwearers would differ on our subscales. Methods: Participants (N = 414, 69% female, 84% white) completed a survey. Results: Principal component analysis and reliability analysis guided…

  12. Helmet therapy in infants with positional skull deformation: randomised controlled trial

    NARCIS (Netherlands)

    Wijk, R.M. van; Vlimmeren, L.A. van; Groothuis-Oudshoorn, C.G.; Ploeg, C.P. van der; IJzerman, M.J.; Boere-Boonekamp, M.M.


    OBJECTIVE: To determine the effectiveness of helmet therapy for positional skull deformation compared with the natural course of the condition in infants aged 5-6 months. DESIGN: Pragmatic, single blinded, randomised controlled trial (HEADS, HElmet therapy Assessment in Deformed Skulls) nested in a

  13. Helmet therapy in infants with positional skull deformation: randomised controlled trial

    NARCIS (Netherlands)

    Wijk, van Renske M.; Vlimmeren, van Leo A.; Groothuis-Oudshoorn, Catharina G.M.; Ploeg, van der Catharina P.B.; IJzerman, Maarten J.; Boere-Boonekamp, Magda M.


    Objective To determine the effectiveness of helmet therapy for positional skull deformation compared with the natural course of the condition in infants aged 5-6 months. Design Pragmatic, single blinded, randomised controlled trial (HEADS, HElmet therapy Assessment in Deformed Skulls) nested in a p

  14. Helmet therapy in infants with positional skull deformation: randomised controlled trial

    NARCIS (Netherlands)

    Wijk, R.M. van; Vlimmeren, L.A. van; Groothuis-Oudshoorn, C.G.M.; Ploeg, C.P.B. van der; Ijzerman, M.J.; Boere-Boonekamp, M.M.


    Objective To determine the effectiveness of helmet therapy for positional skull deformation compared with the natural course of the condition in infants aged 5-6 months.Design Pragmatic, single blinded, randomised controlled trial (HEADS, HElmet therapy Assessment in Deformed Skulls) nested in a pro

  15. Do crash helmets retain their position on the head in case of an impact ?

    NARCIS (Netherlands)

    Beusenberg, M.C.


    This report gives the description and results of three sled tests with each four dummy heads, to record the behaviour of the head and neck of the dummy and the helmet in case of a simulated accident. The simulated accident resulted in a motions of the head, neck and helmet owing to the effects of in

  16. HElmet therapy Assessment in infants with Deformed Skulls (HEADS): protocol for a randomised controlled trial

    NARCIS (Netherlands)

    Wijk, R.M. van; Boere-Boonekamp, M.M.; Groothuis-Oudshoorn, C.G. van; Vlimmeren, L.A. van; IJzerman, M.J.


    In The Netherlands helmet therapy is a commonly used treatment in infants with skull deformation (deformational plagiocephaly or deformational brachycephaly). However, evidence on the effectiveness of this treatment is lacking. The HEADS study (Helmet therapy Assessment in Deformed Skulls) aims to d

  17. Prevalence rates of helmet use among motorcycle riders in a developed region in China. (United States)

    Xuequn, Yu; Ke, Liang; Ivers, Rebecca; Du, Wei; Senserrick, Teresa


    This study aimed to determine the prevalence rates of helmet use, and of correct helmet use (chinstrap firmly fastened) among motorcycle riders and their passengers in Zhongshan, Guangdong Province, China. A cross-sectional survey involving direct observation of motorcycle riders was conducted at 20 randomly selected intersections. A total of 13,410 motorcycles were observed during a 10-day period in February 2009. The overall prevalence of helmet use was 72.6% (95% CI: 71.8-73.3%) among drivers and 34.1% (95% CI: 32.7-35.5%) among pillion passengers. The prevalence of correct use was 43.2% (95% CI: 42.4-44.0%) and 20.9% (95% CI: 19.8-22.1%) for drivers and passengers respectively. The helmet wearing rate on city streets was almost 95%, however city riders were more likely than rural riders to wear non-motorcycle helmets while riding. In multivariate analyses, factors associated with increased helmet use included riding on city streets, male gender, being a driver, carrying less passengers and riding a registered motorcycle. The results indicated enforcement and education activities need to be strengthened with respect to both helmet use and helmet quality, especially in rural areas, in order to improve wearing rates.

  18. An Evaluation of the Compressive Properties of Helmet Pads Pre- and Post-Shock Wave Overpressure Exposure (United States)


    by ANSI Std. Z39.18 BLAST DROP TESTS BRAIN DAMAGE VISCOELASTICITY BRAIN CONCUSSION...HELMET PADS HEAD(ANATOMY) TRAUMATIC BRAIN INJURY HELMETS SHOCK TUBES ACH(ADVANCED COMBAT HELMET) U.S...did not have ears or a well-formed nose . The headform was attached to a Hybrid III 50th percentile neck during the shock tube treatments. The

  19. Legislation and research in The Netherlands in the field of traffic safety regarding seat belts and crash helmets.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Edelman, A.


    Legislation on seat belts and crash helmets has been introduced since 1975. Safety belts are used by 50-75% of car drivers and passengers. Crash helmets are used by virtually all motorcyclists and moped riders. Fatalities have been reduced due to the use of seat belts by 60%, and due to the helmets

  20. Predicting Public Bicycle Adoption Using the Technology Acceptance Model

    Directory of Open Access Journals (Sweden)

    Benjamin T. Hazen


    Full Text Available Bicycle sharing programs provide a sustainable mode of urban transportation. Although cities across the globe have developed these systems for their citizens and visitors, usage rates are not as high as anticipated. This research uses the technology acceptance model as the basis to understand one’s intention to adopt bicycle sharing programs. Using survey data derived from 421 participants in Beijing, China, the proposed covariance-based structural equation model consisting of perceived quality, perceived convenience, and perceived value is found to predict 50.5% of the variance in adoption intention. The findings of this research contribute to theory and practice in the burgeoning literature on public bicycle systems and sustainable urban transportation by offering a theoretical lens through which to consider system adoption, and providing information to practitioners as to what factors might contribute most to adoption.

  1. Interventions in Bicycle Infrastructure, Lessons from Dutch and Danish Cases

    DEFF Research Database (Denmark)

    van Goeverden, K.; Nielsen, Thomas Alexander Sick; Harder, Henrik


    of interventions in bicycle infrastructure on travel choices, safety, design appreciation, and other factors. These clarify under which conditions certain measures are effective or not and inform about the effectiveness of improving a single route versus upgrading a whole network. The information from the studies...... to be still generally valid. In addition to studies that traditionally focus on dedicated bicycle infrastructure, two cases of shared space are discussed, a rather new type of intervention that assumes mixed use of infrastructure. One case is from Denmark, the other from the Netherlands. The paper will so...... uncover the valuable results of the possibly largest evaluations of interventions in bicycle infrastructure ever made, verify these by examining more recent studies, and contribute to the discussion of shared space....

  2. Bicycling to Work and Primordial Prevention of Cardiovascular Risk

    DEFF Research Database (Denmark)

    Grøntved, Anders; Koivula, Robert W; Johansson, Ingegerd


    BACKGROUND: Bicycling to work may be a viable approach for achieving physical activity that provides cardiovascular health benefits. In this study we investigated the relationship of bicycling to work with incidence of obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance...... across a decade of follow-up in middle-aged men and women. METHODS AND RESULTS: We followed 23 732 Swedish men and women with a mean age of 43.5 years at baseline who attended a health examination twice during a 10-year period (1990-2011). In multivariable adjusted models we calculated the odds......% CI 0.74-0.91) compared with participants not cycling to work at both times points or who switched from cycling to other modes of transport during follow-up. CONCLUSIONS: These data suggest that commuting by bicycle to work is an important strategy for primordial prevention of clinical cardiovascular...

  3. Use and activity levels on newly built bicycle playgrounds

    DEFF Research Database (Denmark)

    Schipperijn, Jasper; Hansen, Christine Kier; Rask, Simon


    Increasing the use of urban green space (UGS) as well as increasing cycling could potentially help address the growing inactivity problem. Three bicycle playgrounds were designed based on a participatory process and afterwards constructed in the UGS along a cycle-route on the historic outer defence...... circle around the City of Copenhagen, the Copenhagen Fortifications. The concept of a bicycle playground is new, and to examine how the three areas were used, and explore how users experience the areas, this study was designed as a combination of systematic observations, using the System for Observing...... Play and Recreation in Communities (SOPARC), and short on-site interviews with ‘typical users’. Based on the structural observations and 12 short interviews it became clear that 63% of the users were active during their use. The bicycle playgrounds main users were teenagers and children, especially...

  4. Evaluation of integrated night vision goggle (NVG) helmets under sustained +Gz. (United States)

    McCloskey, K; Esken, R L


    Three integrated night vision goggle (NVG) helmets from different manufacturers were evaluated under high-G conditions. Structural and operational integrity, as well as neck forces in pounds, were determined via instrumented manikin testing before human exposure with the helmets during sustained +Gz. Results of the manikin testing showed that the helmets could withstand the rigors of high-G, and that predicted forces (using helmet weights and centers-of-gravity) matched those obtained experimentally from load cells in the x-axis of the manikin's neck. After manikin testing, 10 subjects were randomly exposed to four different high-G profiles on the Dynamic Environmental Simulator (DES) man-rated centrifuge located at Wright-Patterson AFB, OH: gradual onset to +8 Gz, a simulated aerial combat maneuver (SACM) profile, and two +4 Gz profiles, one with the mask dangling from the helmet and the other with the mask removed. Fit assessments were conducted before high-G exposure, and one helmet was affected significantly by failure of fit. The degree of migration of the NVG intensified image away from the eyes was affected most by the following helmet characteristics: design of the nape strap, size of the NVG image provided by each helmet system, goodness of helmet fit, and the use of the mask as a stabilizer. Although neck strength of each subject was measured and compared to the degree of head stability while wearing each helmet, no effects were found. However, subjects were not allowed to perform fast, high-amplitude head movements in the centrifuge for safety reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Bicycle cycles and mobility patterns - Exploring and characterizing data from a community bicycle program

    CERN Document Server

    Kaltenbrunner, Andreas; Grivolla, Jens; Codina, Joan; Banchs, Rafael


    This paper provides an analysis of human mobility data in an urban area using the amount of available bikes in the stations of the community bicycle program Bicing in Barcelona. The data was obtained by periodic mining of a KML-file accessible through the Bicing website. Although in principle very noisy, after some preprocessing and filtering steps the data allows to detect temporal patterns in mobility as well as identify residential, university, business and leisure areas of the city. The results lead to a proposal for an improvement of the bicing website, including a prediction of the number of available bikes in a certain station within the next minutes/hours. Furthermore a model for identifying the most probable routes between stations is briefly sketched.

  6. Will a bicycle friendly policy make passenger travel more sustainably?

    DEFF Research Database (Denmark)

    Christensen, Linda; Jensen, Thomas Christian

    The purpose of this paper is to analyse the possibility to transfer a larger part of the short car trips to walking or bicycling in order to obtain environmental and health benefits. The project contains a logistic choice model used to explain which circumstances are particularly important...... and bicycling. The study shows that instruments that improve the cyclists’ speed and increase the car drivers’ time consumption and costs will influence the competition conditions significantly. The total transfer potential will be between 12 and 16 % of the car trips in case of short tours, equivalent to 1...

  7. Efficiency of choice set generation methods for bicycle routes

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Rieser-Schussler, Nadine; Axhausen, Kay W.


    The current study analyses the efficiency of choice set generation methods for bicycle routes and proposes the extension of cost functions to bicycle-oriented factors not limited to distance and time. Three choice set generation methods for route choice were examined in their ability to generate...... relevant and heterogeneous routes: doubly stochastic generation function, breadth first search on link elimination, and branch & bound algorithm. Efficiency of the methods was evaluated for a high-resolution network by comparing the performances with four multi-attribute cost functions accounting...... generated realistic routes, while the former outperformed in computation cost and the latter produced more heterogeneous routes....

  8. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device (United States)


    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion... HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512—Reflectorized Bicycle Wheel Rim Abrasion Test Device EC03OC91.074...

  9. 16 CFR Figure 1 to Part 1512 - Bicycle Front Fork Cantilever Bending Test Rig (United States)


    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Bicycle Front Fork Cantilever Bending Test Rig 1 Figure 1 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 1 Figure 1 to Part 1512—Bicycle...

  10. Bicycle Training for Youth with Down Syndrome and Autism Spectrum Disorders (United States)

    MacDonald, Megan; Esposito, Phil; Hauck, Janet; Jeong, Irully; Hornyak, Joseph; Argento, Angela; Ulrich, Dale A.


    Children with Down syndrome (DS) and autism spectrum disorders (ASD) frequently have difficulty riding a two-wheel bicycle. The purpose of this study was to investigate an intervention using an adapted bicycle and individualized instruction to teach 71 youth to ride a standard two-wheel bicycle. Youth with DS (n = 30) and ASD (n = 41) between the…

  11. Bike Helmets and Black Riders: Experiential Approaches to Helping Students Understand Natural Hazard Assessment and Mitigation Issues (United States)

    Stein, S. A.; Kley, J.; Hindle, D.; Friedrich, A. M.


    Defending society against natural hazards is a high-stakes game of chance against nature, involving tough decisions. How should a developing nation allocate its budget between building schools for towns without ones or making existing schools earthquake-resistant? Does it make more sense to build levees to protect against floods, or to prevent development in the areas at risk? Would more lives be saved by making hospitals earthquake-resistant, or using the funds for patient care? These topics are challenging because they are far from normal experience, in that they involve rare events and large sums. To help students in natural hazard classes conceptualize them, we pose tough and thought-provoking questions about complex issues involved and explore them together via lectures, videos, field trips, and in-class and homework questions. We discuss analogous examples from the students' experiences, drawing on a new book "Playing Against Nature, Integrating Science and Economics to Mitigate Natural Hazards in an Uncertain World". Asking whether they wear bicycle helmets and why or why not shows the cultural perception of risk. Individual students' responses vary, and the overall results vary dramatically between the US, UK, and Germany. Challenges in hazard assessment in an uncertain world are illustrated by asking German students whether they buy a ticket on public transportation - accepting a known cost - or "ride black" - not paying but risking a heavy fine if caught. We explore the challenge of balancing mitigation costs and benefits via the question "If you were a student in Los Angeles, how much more would you pay in rent each month to live in an earthquake-safe building?" Students learn that interdisciplinary thinking is needed, and that due to both uncertainties and sociocultural factors, no unique or right strategies exist for a particular community, much the less all communities. However, we can seek robust policies that give sensible results given

  12. Sport helmet design and virtual impact test by image-based finite element modeling. (United States)

    Luo, Yunhua; Liang, Zhaoyang


    Head injury has been a major concern in various sports, especially in contact sports such as football and ice hockey. Helmet has been adopted as a protective device in such sports, aiming at preventing or at least alleviating head injuries. However, there exist two challenges in current helmet design and test. One is that the helmet does not fit the subject's head well; the other is that current helmet testing methods are not able to provide accurate information about intracranial pressure and stress/strain level in brain tissues during impact. To meet the challenges, an image-based finite element modeling procedure was proposed to design subject-specific helmet and to conduct virtual impact test. In the procedure, a set of medical images such as computed tomography (CT) and magnetic resonance image (MRI) of the subject's head was used to construct geometric shape of the helmet and to develop a helmet-head finite element model that can be used in the virtual impact test.

  13. A Formal Synthesis of ( + )-Cassiol Exploiting Meyers' Bicyclic Lactam Methodology

    Institute of Scientific and Technical Information of China (English)

    SHEN,Xin(沈鑫); WU,Yi-Kang(伍贻康); ZHANG,Fan(张帆)


    A formal synthesis of ( + )-cassiol using (1S,2S)-2-amino-1-(4- nitrophenyl)-1,3-propanediol as chiral auxiliary is reported.The quaternary chiral center in the molecule was constructed by sequential alkylation of a bicyclic lactam (prepared from the aforementioned auxiliary and 5-oxo-heptanlic acid) with methyl iodide and benzyloxymethyl chloride.

  14. Experimental and mathematical car-bicycle collision simulations.

    NARCIS (Netherlands)

    Huybers, J.J.W. & Janssen, E.G.


    The results of 35 mathematical simulations will be used to get a better insight in car-bicycle collisions. This information will be used later on to formulate hypotheses to be tested in an accident investigation project. In this paper special attention is given to the influence of the shape of the

  15. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    CERN Document Server

    Guemez, Julio


    We describe the kinematics, dynamics and also some energetic issues related to the Marta mouse motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-to-go round, as presented recently by Paul Hewitt in the Figuring Physics section of this magazine.

  16. Nonfatal bicycle accident risk after an evening of alcohol consumption

    NARCIS (Netherlands)

    Verster, J.C.; van Herwijnen, J.; Volkerts, E.R.; Olivier, B.


    Introduction: After an evening of alcohol consumption, blood alcohol concentration (BAC) may reach intoxication levels above legal limits for operating a car or bicycle. In the Netherlands, legal limits for participating in traffic are 0.05% for experienced drivers and 0.02% for novice drivers. The

  17. The safety impact of a yellow bicycle jacket

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Madsen, Tanja Kidholm Osmann; Olesen, Anne Vingaard


    The hypothesis of this project is that the safety of cyclists can be improved by increasing their visibility in traffic. This is explored by testing whether or not a high-visibility bicycle jacket (colour and reflectors) will increase the safety of cyclists. The project has been carried out...... as a randomized controlled trial with 6,800 volunteer cyclists. After random selection, half of the group – the test group – got the bicycle jacket at once and promised to wear it each time they biked during a year. The other half of the group composed a control group that got the bicycle jacket after the closing...... of the project, i.e. after a year. The safety effect of the bicycle jacket was analysed by comparing the number of self-reported accident for the test and control group. The self-reported accidents showed that the test group had 38 % fewer personal injury accidents with other road users – so-called multi...

  18. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round) (United States)

    Güémez, J.; Fiolhais, M.


    We describe the kinematics, dynamics, and also some energy issues related to Marta mouse's motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-go-round, as presented recently by Paul Hewitt in the "Figuring Physics" section of this journal. The situation is represented in Fig. 1, which was…

  19. Bicyclic graphs with exactly two main signless Laplacian eigenvalues

    CERN Document Server

    Huang, He


    A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main eigenvalues are determined.

  20. Embedding the bicyclic semigroup into countably compact topological semigroups

    CERN Document Server

    Banakh, Taras; Gutik, Oleg


    We study algebraic and topological properties of topological semigroups containing a copy of the bicyclic semigroup $C(p,q)$. We prove that each topological semigroup $S$ with pseudocompact square contains no dense copy of $C(p,q)$. On the other hand, we construct a consistent example of a Tychonov countably compact semigroup containing a copy of $C(p,q)$.

  1. Utilizing the Bicycle for Non-Traditional Activities (United States)

    Maina, Michael P.; Maina, Julie Schlegel; Sebek, Ludek; Hoffmanova, Jana; Kane, Jennifer Jackson


    This article examines the bicycle as not simply a means of transportation or as an exercise device, but rather as a vehicle for teambuilding and problem solving activities within a physical education curriculum. The activities described in this article focus on bike-centered initiatives that foster creative problem solving. They have universal…

  2. How Fast Can You Go on a Bicycle? (United States)

    Dunning, R. B.


    The bicycle provides a context-rich problem accessible to students in a first-year physics course, encircling several core physics principles such as conservation of total energy and angular momentum, dissipative forces, and vectors. In this article, I develop a simple numerical model that can be used by any first-year physics student to…

  3. Expedition Paris-Beijing by Bicycle 2008 Launched

    Institute of Scientific and Technical Information of China (English)


    <正>From March 15 to17, at the invitation of the Euro-Chinese Friendship Association (ECFA) of France, a CPAFFC representative attended the launching ceremony of the Expedition Paris-Beijing by Bicycle 2008 in Paris, during which he met with officials of the National Commission on Decentralized Cooperation (Commission Nationale de la Cooperation Decentralisee-CNCD) of France.

  4. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele


    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  5. Preventive Effects of Safety Helmets on Traumatic Brain Injury after Work-Related Falls

    Directory of Open Access Journals (Sweden)

    Sang Chul Kim


    Full Text Available Introduction: Work-related traumatic brain injury (TBI caused by falls is a catastrophic event that leads to disabilities and high socio-medical costs. This study aimed to measure the magnitude of the preventive effect of safety helmets on clinical outcomes and to compare the effect across different heights of fall. Methods: We collected a nationwide, prospective database of work-related injury patients who visited the 10 emergency departments between July 2010 and October 2012. All of the adult patients who experienced work-related fall injuries were eligible, excluding cases with unknown safety helmet use and height of fall. Primary and secondary endpoints were intracranial injury and in-hospital mortality. We calculated adjusted odds ratios (AORs of safety helmet use and height of fall for study outcomes, and adjusted for any potential confounders. Results: A total of 1298 patients who suffered from work-related fall injuries were enrolled. The industrial or construction area was the most common place of fall injury occurrence, and 45.0% were wearing safety helmets at the time of fall injuries. The safety helmet group was less likely to have intracranial injury comparing with the no safety helmet group (the adjusted odds ratios (ORs (95% confidence interval (CI: 0.42 (0.24–0.73, however, there was no statistical difference of in-hospital mortality between two groups (the adjusted ORs (95% CI: 0.83 (0.34–2.03. In the interaction analysis, preventive effects of safety helmet on intracranial injury were significant within 4 m height of fall. Conclusions: A safety helmet is associated with prevention of intracranial injury resulting from work-related fall and the effect is preserved within 4 m height of fall. Therefore, wearing a safety helmet can be an intervention for protecting fall-related intracranial injury in the workplace.

  6. Effect of wearing a ski helmet on perception and localization of sounds. (United States)

    Ruedl, G; Kopp, M; Burtscher, M; Zorowka, P; Weichbold, V; Stephan, K; Koci, V; Seebacher, J


    Helmet use on ski slopes has steadily increased worldwide over the past years. A common reason reported for helmet non-use, however, is impaired hearing. Therefore, an intra-subject design study was conducted to compare hearing thresholds and sound source localization of 21 adults with normal hearing in an anechoic chamber when wearing a ski helmet and ski goggles or wearing a ski cap and ski goggles to the condition head bare. Hearing thresholds while wearing a ski helmet (6.8 ± 1.6 dB HL) and ski cap (5.5 ± 1.6 dB HL) were significantly different (p = 0.030, d = 0.44). Compared to head bare (2.5 ± 1.2 dB HL), a significant difference was found for the ski helmet only (p = 0.040, d = 1.57). Regarding sound source localization, correct scores in the condition head bare (90%) showed a highly significant difference compared with those of condition cap (65%) and helmet (58%), respectively (p 2.5). Compared to the ski cap, wearing the helmet significantly reduced correct scores (p = 0.020, d = 0.59) irrespective of the tested sound pressure levels. In conclusion, wearing a ski helmet impairs hearing to a small though significantly greater extent compared with a cap, the degree, however, being less than what is termed as a hearing impairment. Compared to the condition head bare, wearing a ski cap or a ski helmet significantly reduced one's ability of sound source localization.

  7. Helmet Use Amongst Equestrians: Harnessing Social and Attitudinal Factors Revealed in Online Forums (United States)

    Haigh, Laura; Thompson, Kirrilly


    Simple Summary Epidemiological research details a high rate of horse-related injury, despite technical countermeasures being widely available and largely affordable. Whilst barriers to engaging in preventative behavior such as helmet-use have been identified, less attention has been given to enabling factors. These factors could contribute to the design of more effective injury prevention interventions. To identify barriers as well as enablers in an Australian context, we explored how riders discussed helmet use amongst one another in an online setting. Our analysis revealed that social relations heavily influenced safety behavior. In particular, we identified three attitudes that affected helmet use: “I Can Control Risk”, “It Does Not Feel Right” and “Accidents Happen”. Abstract Equestrian activities pose significant head injury risks to participants. Yet, helmet use is not mandatory in Australia outside of selected competitions. Awareness of technical countermeasures and the dangers of equestrian activities has not resulted in widespread adoption of simple precautionary behaviors like helmet use. Until the use of helmets whilst riding horses is legislated in Australia, there is an urgent need to improve voluntary use. To design effective injury prevention interventions, the factors affecting helmet use must first be understood. To add to current understandings of these factors, we examined the ways horse riders discussed helmet use by analyzing 103 posts on two helmet use related threads from two different Australian equestrian forums. We found evidence of social influence on helmet use behaviors as well as three attitudes that contributed towards stated helmet use that we termed: “I Can Control Risk”, “It Does Not Feel Right” and “Accidents Happen”. Whilst we confirm barriers identified in previous literature, we also identify their ability to support helmet use. This suggests challenging but potentially useful complexity in the

  8. Power assist control of electric bicycle taking environment and rider's condition into account (United States)

    Niki, Hiroshi; Miyata, Junichi; Murakami, Toshiyuki


    Recently, bicycles are widely used as a convenient transportation tool. But from a viewpoint of wide use for the future aging society, it is problem to pedal on rider's own. As well known, power assistance bicycle has already been used. The power assistance bicycle helps the elderly people or the people who has weak legs to expand their field. However, existing power assistance bicycle doesn't take running environment and rider's condition into account. The new control algorithm for power assistance bicycle is proposed in this paper. Human input and running friction are estimated as a disturbance torque with a disturbance observer. By using high pass filter (HPF), human input is separated from running friction. This method realizes power assistance bicycle without torque sensor. Disturbance observer compensates running friction. Compliance control is applied to make the bicycle have desired compliance. The effectiveness of this control algorithm is verified by numerical and experimental results.

  9. Bicycle Conversion Factor Calibration at Two-Phase Intersections in Mixed Traffic Flows

    Institute of Scientific and Technical Information of China (English)

    WANG Dianhai; LIANG Chunyan; JING Chunguang; WANG Guohua


    Chinese traffic is typically composed of bicycles and motor vehicles on the same road. The efficiency of bicycle traffic in time and space at intersections was investigated for eight typical intersections in the cities of Tianjin, Shenyang, and Changchun, all in China, by means of video recording. Models were developed to calculate the through bicycle traffic and the left-turn bicycle traffic conversion factors in intersections where bicycles and motor vehicles share the same road. The results indicate that the through bicycle conversion factor is 0.28 and the left-turn bicycle conversion factor is 0.33. This conclusion differs from the current value used in China. More research on the conversion factor is necessary to evaluate the impact of intersections.

  10. Microphone Array Signal Processing and Active Noise Control for the In-Helmet Speech Communication Project (United States)

    National Aeronautics and Space Administration — For in-helmet voice communication, the currently used Communication-Cap-based Audio (CCA) systems have a number of recognized logistical issues and inconveniences...

  11. Auditory and visual reaction time and peripheral field of vision in helmet users

    Directory of Open Access Journals (Sweden)

    Abbupillai Adhilakshmi


    Full Text Available Background: The incidence of fatal accidents are more in two wheeler drivers compared to four wheeler drivers. Head injury is of serious concern when recovery and prognosis of the patients are warranted, helmets are being used for safety purposes by moped, scooters and motorcycle drivers. Although, helmets are designed with cushioning effect to prevent head injuries but there are evidences of increase risk of neck injuries and reduced peripheral vision and hearing in helmet users. A complete full coverage helmets provide about less than 3 percent restrictions in horizontal peripheral visual field compared to rider without helmet. The standard company patented ergonomically designed helmets which does not affect the peripheral vision neither auditory reaction time. Objective: This pilot study aimed to evaluate the peripheral field of vision and auditory and visual reaction time in a hypertensive, diabetic and healthy male and female in order to have a better insight of protective characteristics of helmet in health and disease. Method: This pilot study carried out on age matched male of one healthy, one hypertensive and one diabetic and female subject of one healthy, one hypertensive and one diabetics. The field of vision was assessed by Lister’s perimeter whereas auditory and visual reaction time was recorded with response analyser. Result : Gender difference was not noted in peripheral field of vision but mild difference was found in auditory reaction time for high frequency and visual reaction time for both red and green colour in healthy control. But lateral and downward peripheral visual field was found reduced whereas auditory and visual reaction time was found increased in both hypertensive and diabetic subject in both sexes. Conclusion: Peripheral vision, auditory reaction time and visual reaction time in hypertensive and diabetics may lead to vulnerable accident. Helmet use has proven to reduce extent of injury in motorcyclist and

  12. Spring-Based Helmet System Support Prototype to Address Aircrew Neck Strain (United States)

    The Royal Canadian Air Force Griffon helicopter aircrew are known to have extremely high incidence of chronic, debilitating neck pain. Fischer et al...2013) identified that unbalanced moments due to head-borne equipment (i.e. helmet with NVG ) were a particular concern since the current solution add more weight (battery pack and counterweight (CW)) as a counterbalancing force. Three concepts were proposed to improve the helmet- NVG system


    Toi, Satoshi; Kajita, Yoshitaka; Nishikawa, Shuichirou

    This study aims to find an effective removal method of illegal parking bicycles based on the analysis on the numerical change of illegal bicycles. And then, we built the time and space quantitative distribution model of illegal parking bicycles after removal, considering the logistic increase of illegal parking bicycles, several behaviors concerning of direct return or indirect return to the original parking place and avoidance of the original parking place, based on the investigation of real condition of illegal bicycle parking at TENJIN area in FUKUOKA city. Moreover, we built the simulation model including above-mentioned model, and calculated the number of illegal parking bicycles when we change the removal frequency and the number of removal at one time. The next interesting four results were obtained. (1) Recovery speed from removal the illegal parking bicycles differs by each zone. (2) Thorough removal is effective to keep the number of illegal parking bicycles lower level. (3) Removal at one zone causes the increase of bicycles at other zones where the level of illegal parking is lower. (4) The relationship between effects and costs of removing the illegal parking bicycles was clarified.

  14. Personal and behavioral factors associated with bicycling in adults from Curitiba, Parana State, Brazil

    Directory of Open Access Journals (Sweden)

    Marilson Kienteka


    Full Text Available Bicycling is an important form of physical activity that can promote health benefits. The objective of this study was to analyze the association between personal and behavioral aspects in transportation bicycling and leisure time bicycling in adults. Data was drawn from a household survey involving 677 adults (53.1% female in Curitiba, Paraná State, Brazil. The prevalence of bicycling was 11.2% for transportation and 16.7% for leisure. The frequency of leisure time bicycling was higher among men (PR = 2.08; p < 0.001, young people < 30 and adults aged between 30 and 39.9, bicycle owners (PR = 8.76; p < 0.001 and among the physically active. Transportation bicycling occurred more frequently among men (PR = 3.63; p < 0.001, individuals aged 30 to 39.9, those with a low socioeconomic status (PR = 5.00; p = 0.006, bicycle owners (PR = 10.2; p < 0.001 and individuals with a negative perception of their quality of life. The prevalence of bicycling is low in Curitiba considering its potential as a means of physical activity. Personal and behavioral factors were associated with each form of bicycling.

  15. The fastest bicycle in the world; how a team of Delft students is building a bicycle to break the world speed record

    NARCIS (Netherlands)

    Annega, G.


    The Netherlands is a country known for its extensive use of bicycles as a means of everyday transport. However, while it has existed for about two centuries, todays bicycles only differ from those of the 19th century in relatively small details. Human Power Team Delft is building a whole new type of

  16. Experimental investigations on the cooling of a motorcycle helmet with phase change material (PCM

    Directory of Open Access Journals (Sweden)

    Fok S.C.


    Full Text Available The thermal comfort of motorcycle helmet during hot weather is important as it can affect the physiological and psychological condition of the rider. This paper examines the use of phase change material (PCM to cool a motorcycle helmet and presents the experimental investigations on the influences of the simulated solar radiation, wind speed, and heat generation rate on the cooling system. The result shows that the PCM-cooled helmet is able to prolong the thermal comfort period compared to a normal helmet. The findings also indicate that the heat generation from the head is the predominant factor that will affect the PCM melting time. Simulated solar radiation and ram-air due to vehicle motion under adiabatic condition can have very little influences on the PCM melting time. The results suggested that the helmet usage time would be influenced by the amount of heat generated from the head. Some major design considerations based on these findings have been included. Although this investigation focuses on the cooling of a motorcyclist helmet, the findings would also be useful for the development of PCM-cooling systems in other applications.

  17. Application of Technology Acceptance Model in Predicting Behavioral Intention to Use Safety Helmet Reminder System

    Directory of Open Access Journals (Sweden)

    Kamarudin Ambak


    Full Text Available Motorcycle is a common and popular mode of transportation in many developing countries. However, statistic of road accidents by the Royal Malaysian Police reveals that motorcyclists are found to be the most vulnerable road users as compared to users of other vehicles. This is due to the lack of safety protection and instability of motorcycles themselves. Despite the usefulness and effectiveness of safety helmet to prevent head injuries, majority of motorcycle users do not wear and fasten their helmet properly. This study presents a new approach in enhancing the safety of motorcycle riders through proper usage of safety helmet. The Technology Acceptance Model (TAM was adopted in predicting the behavioral intention to use Safety Helmet Reminder (SHR system towards a more proper helmet usage among motorcyclists. A multivariate analysis technique, known as Structural Equation Modeling (SEM was used in modeling exercise. Results showed that the construct variables in TAM were found to be reliable and statistically significant. The evaluation of full structural model (TAM showed the goodness-of-fit indices such as Goodness of Fit Index (GFI, Adjusted Goodness of Fit Index (AGFI, Comparative of Fit Index (CFI and Tucker Lewis Index (TLI were greater 0.9 and Root Means Square Error Approximation (RMSEA was less than 0.08. Perceived ease of use was found as strong predictors than perceived usefulness regarding behavioral intention to use SHR. In addition, this study postulates that behavioral intention to use SHR has direct effect on the proper usage of safety helmet significantly.

  18. Helmet Use and Associated Factors among Thai Motorcyclists during Songkran Festival

    Directory of Open Access Journals (Sweden)

    Sompong Morarit


    Full Text Available The aim of this study was to assess helmet use and associated factors among motorcycle riders during Songkran festival in Thailand. A cross-sectional survey was conducted to determine the prevalence of helmet use among Thai motorcycle riders (sample size = 18,998 during four days of the Songkran festival. For this sample, the population of motorcycle riders was consecutively selected using quota sampling from 12 petrol stations in four provinces from each of the four main geographical regions of Thailand. The study was conducted at petrol stations at roads in town, outside town and highway at different time intervals when trained field staff administered a structured questionnaire and performed an observation checklist. Results indicate that 44.2% of the motorcycle riders and 72.5% of the motorcycle passengers had not been using a helmet. In multivariable analysis demographics, environmental factors, helmet use experiences and attitudes and recalling a lower exposure to road safety awareness (RSA campaign were associated with non-helmet use among motorcyclists. It appears that the RSA campaign may have some positive effect on reducing non-helmet use among motorcycle riders during the Songkran festival.

  19. Finite element modeling of human brain response to football helmet impacts. (United States)

    Darling, T; Muthuswamy, J; Rajan, S D


    The football helmet is used to help mitigate the occurrence of impact-related traumatic (TBI) and minor traumatic brain injuries (mTBI) in the game of American football. While the current helmet design methodology may be adequate for reducing linear acceleration of the head and minimizing TBI, it however has had less effect in minimizing mTBI. The objectives of this study are (a) to develop and validate a coupled finite element (FE) model of a football helmet and the human body, and (b) to assess responses of different regions of the brain to two different impact conditions - frontal oblique and crown impact conditions. The FE helmet model was validated using experimental results of drop tests. Subsequently, the integrated helmet-human body FE model was used to assess the responses of different regions of the brain to impact loads. Strain-rate, strain, and stress measures in the corpus callosum, midbrain, and brain stem were assessed. Results show that maximum strain-rates of 27 and 19 s(-1) are observed in the brain-stem and mid-brain, respectively. This could potentially lead to axonal injuries and neuronal cell death during crown impact conditions. The developed experimental-numerical framework can be used in the study of other helmet-related impact conditions.

  20. BUGS at work : a bicycle user group guide

    Energy Technology Data Exchange (ETDEWEB)



    This guide provides practical advice to cyclists on how start a Bicycle User Group (BUG) at their workplace. It offers tools to encourage employers to be proactive in improving facilities in support of cycle commuting. Several BUGs across Canada have worked towards getting better bicycle parking, lockers and shower facilities at their workplace. Other incentives include policies such as flexible work hours for cyclist commuters; casual dress on Friday; reimbursement for the subsidized cost of free parking provided by employers; and, use of a company car if needed for company business during the work day. The advantages to employers include: reduced health care costs because cyclists are physically fit; decreased absenteeism; increased productivity; reduced parking costs; lower company transportation bills; and, a greener corporate image. BUGs provide cycling information ranging from cycling maps to pamphlets and they raise cycle awareness. This guide includes cycling survey samples and examples of successful BUG activities across Canada. refs., tabs., figs.

  1. Simultaneous optimization of transit network and public bicycle station network

    Institute of Scientific and Technical Information of China (English)

    刘洋; 朱宁; 马寿峰


    The traditional manner to design public transportation system is to sequentially design the transit network and public bicycle network. A new public transportation system design problem that simultaneously considers both bus network design and public bicycle network design is proposed. The chemical reaction optimization (CRO) is designed to solve the problem. A shortcoming of CRO is that, when the two-molecule collisions take place, the molecules are randomly picked from the container. Hence, we improve CRO by employing different mating strategies. The computational results confirm the benefits of the mating strategies. Numerical experiments are conducted on the Sioux-Falls network. A comparison with the traditional sequential modeling framework indicates that the proposed approach has a better performance and is more robust. The practical applicability of the approach is proved by employing a real size network.

  2. Optimal Design of Mountain Bicycle Based on Biomechanics

    Institute of Scientific and Technical Information of China (English)

    卜研; 黄田; 项忠霞; 吴小凡; 陈春


    To achieve better cycling performance and vibration comfort of mountain bicycle, the optimization of frame structural parameters and rear suspension scale parameters is investigated based on biomechanics.Firstly, the quadratic sum of rider lower limb muscles stresses is presented as the evaluation criterion of muscle fatigue.By taking the criterion as the objective function, the relative positions of three pivot points of frame are optimized to ensure that the frame structural parameters match the stature o...

  3. Traffic conflicts on bicycle paths: a systematic observation of behaviour from video. (United States)

    van der Horst, A Richard A; de Goede, Maartje; de Hair-Buijssen, Stefanie; Methorst, Rob


    In The Netherlands, on bicycle paths, single-bicycle accidents, bicycle-bicycle and bicycle-moped accidents constitute a considerable share of all bicyclist injuries. Over three quarters of all hospitalised bicyclist victims in the Netherlands cannot be directly related to a crash with motorised traffic. As the usage of bicycle paths steadily increases, it is to be expected that safety on bicycle paths will become a major issue in the coming years in The Netherlands. A study was conducted into the behaviour of bicyclists and moped riders to improve traffic safety on bicycle paths. By behavioural observations with video, mutual conflicts and bicyclist behaviour on bicycle paths were recorded and analysed, among other things by means of the conflict observation method DOCTOR (Dutch Objective Conflict Technique for Operation and Research). The explorative phase of the study (phase 1), included two research locations, one in the city of Amsterdam and one in Eindhoven. The results gave guidance for a better understanding of the behaviour between different users of separate two-directional bicycle paths. An example includes the relationship between bicyclist-moped rider behaviour and the width of the bicycle path. For a condition with busy bicycle traffic in both directions the width of the bicycle path in Amsterdam (effectively 3.55m) is relatively narrow, whereas the bicycle path width in Eindhoven (>4.94m) appears to be sufficient to accommodate large flows of bicyclists. Because of a large flow of crossing pedestrians resulting in (severe) conflicts with bicyclists in Amsterdam, additional countermeasures to better control these interactions are needed. The DOCTOR conflict observation method from video appears to be applicable for conflicts between intersecting road users and for head-on conflicts on the bicycle path. Conflict situations between bicyclists in the same direction (constituting an important share of injury accidents on bicycle paths) require an

  4. [Mortality due to bicycle accidents in Pernambuco, Brazil]. (United States)

    Galvão, Pauliana Valéria Machado; Pestana, Luciana Pinto; Pestana, Valter Mário; Spíndola, Michelline Oliveira Pedrosa; Campello, Reginaldo Inojosa Carneiro; de Souza, Eliane Helena Alvim


    The scope of this paper was to conduct a quantitative analysis of deaths resulting from bicycle accidents in the state of Pernambuco by studying secondary data between 2001 and 2010. The sample consisted of all the Deaths recorded in the Mortality Information System of the Unified Health System Database that reported bicycle accidents between 2001 and 2010. Descriptive measures were determined for all variables. Socio-demographic variables were paired with the basic cause of death in order to find a statistical correlation. In Pernambuco, the aforementioned information system recorded 517 deaths resulting from bicycle accidents, with greater frequency in men between 25 and 59 years of age, Afro-Brazilians, single and of unknown schooling. The mean age was 36.82 years (SD = 17.026), and the minimum and maximum age of 4 and 86 years old, respectively. The findings highlight the need for the creation of adequate infrastructure and effective legal measures to prevent traffic accidents involving this type of vehicle, relying on the evidence of distribution of cases in most Pernambuco municipalities.

  5. Harvesting energy from the counterbalancing (weaving) movement in bicycle riding. (United States)

    Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank


    Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  6. Design Analysis And Applications Of A Regenerative Bicycle Ergometer

    Directory of Open Access Journals (Sweden)

    Chukwuneke J. L.


    Full Text Available Man needs to do some form of physical work in other to remain healthy this work is similar to the work done by any machine or equipment and thus should be channeled to give useful output but rather it is usually dissipated into the environment in form of heat. The regenerative bicycle ergometer takes advantage of the greater power generated by the limbs and arms thus conserves converts and stores the energy dissipated by the rider with an ideal mechanical advantage of 7.6 it strategically uses simple mechanisms to magnify its work and then converts this mechanical energy into electrical energy by the use of a dynamo with a speed ratio of 108.5 and a transmission efficiency of 89 the rider pedals 27rpm to obtain the dynamos rated input of 2600rpm giving an output of 12.6volts. The regenerative bicycle ergometer is designed and constructed to perform all the core functions of a bicycle ergometer having an allowable load of 116.5kg and a maximum resistance of 65.33N which is equivalent to a mass of 6.66kg. The energy converted is stored in a 12volts battery making its use flexible clean and meeting the energy demands of man.

  7. Electric motor assisted bicycle as an aerobic exercise machine. (United States)

    Nagata, T; Okada, S; Makikawa, M


    The goal of this study is to maintain a continuous level of exercise intensity around the aerobic threshold (AT) during riding on an electric motor assisted bicycle using a new control system of electrical motor assistance which uses the efficient pedaling rate of popular bicycles. Five male subjects participated in the experiment, and the oxygen uptake was measured during cycling exercise using this new pedaling rate control system of electrical motor assistance, which could maintain the pedaling rate within a specific range, similar to that in previous type of electrically assisted bicycles. Results showed that this new pedaling rate control system at 65 rpm ensured continuous aerobic exercise intensity around the AT in two subjects, and this intensity level was higher than that observed in previous type. However, certain subjects were unable to maintain the expected exercise intensity because of their particular cycling preferences such as the pedaling rate. It is necessary to adjust the specific pedaling rate range of the electrical motor assist control according to the preferred pedaling rate, so that this system becomes applicable to anyone who want continuous aerobic exercise.

  8. It's not just about speed: Reviewing the recumbent bicycle once more. (United States)

    Wieser, Bernhard


    Why did the recumbent bicycle never become a dominant design, despite the fact that it was faster than the safety bicycle on the racetrack? Hassaan Ahmed et al. argue in their recently published paper that the main reason for the marginalization of the recumbent bicycle was semiotic power deployed by the Union Cycliste Internationale (UCI). Here, I demonstrate that the authors drew their conclusions from an incomplete application of the Social Construction of Technology (SCOT) framework. Understanding the diffusion of alternative bicycle designs requires considering more than speed, and more than the UCI as a powerful actor. The recumbent bicycle was fast, but rather tricky to ride, and was not really feasible for the transport needs of the working classes, which constituted the most relevant social group of bicycle users during the 1930s.

  9. Determinants of helmet use behaviour among employed motorcycle riders in Yazd, Iran based on theory of planned behaviour. (United States)

    Ali, Mehri; Saeed, Mazloomy Mahmoodabad Seyed; Ali, Morowatisharifabad Mohammad; Haidar, Nadrian


    This paper reports on predictors of helmet use behaviour, using variables based on the theory of planned behaviour model among the employed motorcycle riders in Yazd-Iran, in an attempt to identify influential factors that may be addressed through intervention efforts. In 2007, a cluster random sample of 130 employed motorcycle riders in the city of Yazd in central Iran, participated in the study. Appropriate instruments were designed to measure the variables of interest (attitude, subjective norms, perceived behaviour control, intention along with helmet use behaviour). Reliability and validity of the instruments were examined and approved. The statistical analysis of the data included descriptive statistics, bivariate correlations, and multiple regression. Based on the results, 56 out of all the respondents (43.1%) had history of accident by motorcycle. Of these motorcycle riders only 10.7% were wearing their helmet at the time of their accident. Intention and perceived behavioural control showed a significant relationship with helmet use behaviour and perceived behaviour control was the strongest predictor of helmet use intention, followed by subjective norms, and attitude. It was found that that helmet use rate among motorcycle riders was very low. The findings of present study provide a preliminary support for the TPB model as an effective framework for examining helmet use in motorcycle riders. Understanding motorcycle rider's thoughts, feelings and beliefs about helmet use behaviour can assist intervention specialists to develop and implement effective programs in order to promote helmet use among motorcycle riders.

  10. Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research



    An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Techn...

  11. Modeling cyclist acceleration process for bicycle traffic simulation using naturalistic data


    Ma, Xiaoliang; Luo, Ding


    Cycling is a healthy and sustainable form of transportation. The recent increase of daily cyclists in Sweden has triggered broad interest in finding how policies and measures may facilitate the planning of bicycle traffic in the urban area. However, in comparison to car traffic, bicycle traffic is still far from well understood. This study is part of the research effort to investigate microscopic cyclist behavior, model bicycle traffic and finally build a simulation tool for applications in t...

  12. Bicycle-related injuries: a survey in a pediatric emergency department.


    Cushman, R; Down, J; MacMillan, N; Waclawik, H


    The number of bicycle-related injuries has risen significantly with the increased popularity of bicycle riding in Canada. The risk of injury is highest among children. To assess the magnitude of the problem and to identify the contributing factors we used a questionnaire, injury reports and patient charts to survey bicycle-related injuries among children brought to the emergency department of the Children's Hospital of Eastern Ontario, Ottawa, between May 1 and Sept. 30, 1988. The questionnai...

  13. Bicyclic graphs with maximum sum of the two largest Laplacian eigenvalues

    Directory of Open Access Journals (Sweden)

    Yirong Zheng


    Full Text Available Abstract Let G be a simple connected graph and S 2 ( G $S_{2}(G$ be the sum of the two largest Laplacian eigenvalues of G. In this paper, we determine the bicyclic graph with maximum S 2 ( G $S_{2}(G$ among all bicyclic graphs of order n, which confirms the conjecture of Guan et al. (J. Inequal. Appl. 2014:242, 2014 for the case of bicyclic graphs.

  14. Improvement of Freezing of Gait in Patients with Parkinson's Disease by Imagining Bicycling

    Directory of Open Access Journals (Sweden)

    Akio Kikuchi


    Full Text Available Freezing of gait (FOG is one of the factors that reduce the quality of life in patients with Parkinson's disease (PD. Imagining bicycling before gait start provided improvement in FOG in 2 PD patients. Imagining and mimicking bicycling after the initiation of gait allowed the rhythmic gait to continue without interruption. We suggest that imagining and mimicking bicycling, which are nonexternal cues, could serve as a helpful therapeutic approach for the intractable freezing and interruption of gait of PD patients.

  15. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason


    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  16. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicyclic compound and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew


    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  17. The Effect of Sharrows, Painted Bicycle Lanes and Physically Protected Paths on the Severity of Bicycle Injuries Caused by Motor Vehicles

    Directory of Open Access Journals (Sweden)

    Stephen P. Wall


    Full Text Available We conducted individual and ecologic analyses of prospectively collected data from 839 injured bicyclists who collided with motorized vehicles and presented to Bellevue Hospital, an urban Level-1 trauma center in New York City, from December 2008 to August 2014. Variables included demographics, scene information, rider behaviors, bicycle route availability, and whether the collision occurred before the road segment was converted to a bicycle route. We used negative binomial modeling to assess the risk of injury occurrence following bicycle path or lane implementation. We dichotomized U.S. National Trauma Data Bank Injury Severity Scores (ISS into none/mild (0–8 versus moderate, severe, or critical (>8 and used adjusted multivariable logistic regression to model the association of ISS with collision proximity to sharrows (i.e., bicycle lanes designated for sharing with cars, painted bicycle lanes, or physically protected paths. Negative binomial modeling of monthly counts, while adjusting for pedestrian activity, revealed that physically protected paths were associated with 23% fewer injuries. Painted bicycle lanes reduced injury risk by nearly 90% (IDR 0.09, 95% CI 0.02–0.33. Holding all else equal, compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical (adjusted odds ratio 1.94; 95% confidence interval (CI 0.91–4.15. Painted bicycle lanes and physically protected paths were 1.52 (95% CI 0.85–2.71 and 1.66 (95% CI 0.85–3.22 times as likely to be associated with more than mild injury respectively.

  18. Manufacturing development of visor for binocular helmet mounted display (United States)

    Krevor, David; Edwards, Timothy; Larkin, Eric; Skubon, John; Speirs, Robert; Sowden, Tom


    The HMD (Helmet Mounted Display) visor is a sophisticated article. It is both the optical combiner for the display and personal protective equipment for the pilot. The visor must have dimensional and optical tolerances commensurate with precision optics; and mechanical properties sufficient for a ballistic shield. Optimized processes and tooling are necessary in order to manufacture a functional visor. This paper describes the manufacturing development of the visor for the Joint Strike Fighter (JSF) HMD. The analytical and experimental basis for the tool and manufacturing process development are described; as well as the metrological and testing methods to verify the visor design and function. The requirements for the F-35 JSF visor are a generation beyond those for the HMD visor which currently flies on the F-15, F-16 and F/A-18. The need for greater precision is manifest in the requirements for the tooling and molding process for the visor. The visor is injection-molded optical polycarbonate, selected for its combination of optical, mechanical and environmental properties. Proper design and manufacture of the tool - the mold - is essential. Design of the manufacturing tooling is an iterative process between visor design, mold design, mechanical modeling and polymer-flow modeling. Iterative design and manufacture enable the mold designer to define a polymer shrinkage factor more precise than derived from modeling or recommended by the resin supplier.

  19. HElmet therapy Assessment in infants with Deformed Skulls (HEADS: protocol for a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    van Wijk Renske M


    Full Text Available Abstract Background In The Netherlands, helmet therapy is a commonly used treatment in infants with skull deformation (deformational plagiocephaly or deformational brachycephaly. However, evidence of the effectiveness of this treatment remains lacking. The HEADS study (HElmet therapy Assessment in Deformed Skulls aims to determine the effects and costs of helmet therapy compared to no helmet therapy in infants with moderate to severe skull deformation. Methods/design Pragmatic randomised controlled trial (RCT nested in a cohort study. The cohort study included infants with a positional preference and/or skull deformation at two to four months (first assessment. At 5 months of age, all children were assessed again and infants meeting the criteria for helmet therapy were asked to participate in the RCT. Participants were randomly allocated to either helmet therapy or no helmet therapy. Parents of eligible infants that do not agree with enrolment in the RCT were invited to stay enrolled for follow up in a non-randomisedrandomised controlled trial (nRCT; they were then free to make the decision to start helmet therapy or not. Follow-up assessments took place at 8, 12 and 24 months of age. The main outcome will be head shape at 24 months that is measured using plagiocephalometry. Secondary outcomes will be satisfaction of parents and professionals with the appearance of the child, parental concerns about the future, anxiety level and satisfaction with the treatment, motor development and quality of life of the infant. Finally, compliance and costs will also be determined. Discussion HEADS will be the first study presenting data from an RCT on the effectiveness of helmet therapy. Outcomes will be important for affected children and their parents, health care professionals and future treatment policies. Our findings are likely to influence the reimbursement policies of health insurance companies. Besides these health outcomes, we will be able to

  20. A computational study of influence of helmet padding materials on the human brain under ballistic impacts. (United States)

    Salimi Jazi, Mehdi; Rezaei, Asghar; Karami, Ghodrat; Azarmi, Fardad; Ziejewski, Mariusz


    The results of a computational study of a helmeted human head are presented in this paper. The focus of the work is to study the effects of helmet pad materials on the level of acceleration, inflicted pressure and shear stress in a human brain model subjected to a ballistic impact. Four different closed cell foam materials, made of expanded polystyrene and expanded polypropylene, are examined for the padding material. It is assumed that bullets cannot penetrate the helmet shell. Finite element modelling of the helmet, padding system, head and head components is used for this dynamic nonlinear analysis. Appropriate contacts and conditions are applied between the different components of the head, as well as between the head and the pads, and the pads and the helmet. Based on the results of simulations in this work, it is concluded that the stiffness of the foam has a prominent role in reducing the level of the transferred load to the brain. A pad that is less stiff is more efficient in absorbing the impact energy and reducing the sudden acceleration of the head and consequently lowers the brain injury level. Using the pad with the least stiffness, the influence of the angle of impacts as well as the locations of the ballistic strike is studied.

  1. Head Position in the MEG Helmet Affects the Sensitivity to Anterior Sources (United States)

    Marinkovic, K; Cox, B; Reid, K; Halgren, E


    Current MEG instruments derive the whole-head coverage by utilizing a helmet-shaped opening at the bottom of the dewar. These helmets, however, are quite a bit larger than most people’s heads so subjects commonly lean against the back wall of the helmet in order to maintain a steady position. In such cases the anterior brain sources may be too distant to be picked up by the sensors reliably. Potential “invisibility” of the frontal and anterior temporal sources may be particularly troublesome for the studies of cognition and language, as they are subserved significantly by these areas. We examined the sensitivity of the distributed anatomically-constrained MEG (aMEG) approach to the head position (“front” vs. “back”) secured within a helmet with custom-tailored bite-bars during a lexical decision task. The anterior head position indeed resulted in much greater sensitivity to language-related activity in frontal and anterior temporal locations. These results emphasize the need to adjust the head position in the helmet in order to maximize the “visibility” of the sources in the anterior brain regions in cognitive and language tasks. PMID:16012659

  2. Thermoregulation during prolonged actual and laboratory-simulated bicycling. (United States)

    Brown, S L; Banister, E W


    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Neck pain among fighter pilots after the introduction of the JHMCS helmet and NVG in their environment

    DEFF Research Database (Denmark)

    Lange, Britt; Torp-Svendsen, J; Toft, Palle


    Neck pain is a common complaint among fighter pilots. With implementation of the joint helmet mounted cuing system (JHMCS), the strain on the pilot's neck has increased.......Neck pain is a common complaint among fighter pilots. With implementation of the joint helmet mounted cuing system (JHMCS), the strain on the pilot's neck has increased....

  4. Optimization of the Chin Bar of a Composite-Shell Helmet to Mitigate the Upper Neck Force (United States)

    Farajzadeh Khosroshahi, S.; Galvanetto, U.; Ghajari, M.


    The chin bar of motorcycle full-face helmets is the most likely region of the helmet to sustain impacts during accidents, with a large percentage of these impacts leading to basilar skull fracture. Currently, helmet chin bars are designed to mitigate the peak acceleration at the centre of gravity of isolated headforms, as required by standards, but they are not designed to mitigate the neck force, which is probably the cause of basilar skull fracture, a type of head injury that can lead to fatalities. Here we test whether it is possible to increase the protection of helmet chin bars while meeting standard requirements. Fibre-reinforced composite shells are commonly used in helmets due to their lightweight and energy absorption characteristics. We optimize the ply orientation of a chin bar made of fibre-reinforced composite layers for reduction of the neck force in a dummy model using a computational approach. We use the finite element model of a human head/neck surrogate and measure the neck axial force, which has been shown to be correlated with the risk of basilar skull fracture. The results show that by varying the orientation of the chin bar plies, thus keeping the helmet mass constant, the neck axial force can be reduced by approximately 30% while ensuring that the helmet complies with the impact attenuation requirements prescribed in helmet standards.

  5. 42 CFR 84.175 - Half-mask facepieces, full facepieces, hoods, helmets, and mouthpieces; fit; minimum requirements. (United States)


    ..., helmets, and mouthpieces; fit; minimum requirements. 84.175 Section 84.175 Public Health PUBLIC HEALTH....175 Half-mask facepieces, full facepieces, hoods, helmets, and mouthpieces; fit; minimum requirements. (a) Half-mask facepieces and full facepieces shall be designed and constructed to fit persons...

  6. 42 CFR 84.198 - Half-mask facepieces, full facepieces, mouthpieces, hoods, and helmets; fit; minimum requirements. (United States)


    ..., hoods, and helmets; fit; minimum requirements. 84.198 Section 84.198 Public Health PUBLIC HEALTH SERVICE..., full facepieces, mouthpieces, hoods, and helmets; fit; minimum requirements. (a) Half-mask facepieces and full facepieces shall be designed and constructed to fit persons with various facial shapes...

  7. 42 CFR 84.135 - Half-mask facepieces, full facepieces, hoods, and helmets; fit; minimum requirements. (United States)


    ... helmets; fit; minimum requirements. 84.135 Section 84.135 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT... facepieces, hoods, and helmets; fit; minimum requirements. (a) Half-mask facepieces and full facepieces shall be designed and constructed to fit persons with various facial shapes and sizes either: (1)...

  8. 42 CFR 84.1135 - Half-mask facepieces, full facepieces, hoods, helmets, and mouthpieces; fit; minimum requirements. (United States)


    ..., helmets, and mouthpieces; fit; minimum requirements. 84.1135 Section 84.1135 Public Health PUBLIC HEALTH..., full facepieces, hoods, helmets, and mouthpieces; fit; minimum requirements. (a) Half-mask facepieces and full facepieces shall be designed and constructed to fit persons with various facial shapes...

  9. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;


    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... (notably chickens, ducks and guinea fowl) in the Republic of Benin. For this purpose, we applied the hedonic price method on field data collected from retailers in four urban and five rural markets. We found that meatier drake and meatier guinea fowl with white plumage are preferred by consumers who...

  10. Consumers’ preferences for “bicycle poultry” in Benin

    DEFF Research Database (Denmark)

    Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.;

    Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... (notably chickens, ducks and guinea fowl) in the Republic of Benin. For this purpose, we applied the hedonic price method on field data collected from retailers in four urban and five rural markets. We found that meatier drake and meatier guinea fowl with white plumage are preferred by consumers who...

  11. Exploring the Chemistry of Bicyclic Isoxazolidines for the Multicomponent Synthesis of Glycomimetic Building Blocks

    NARCIS (Netherlands)

    Hoogenboom, Jorin; Lutz, Martin; Zuilhof, Han; Wennekes, Tom


    Starting from a chiral furanone, the nitrone-olefin [3 + 2] cycloaddition can be used to obtain bicyclic isoxazolidines for which we report a set of reactions to selectively modify each functional position. These synthetically versatile bicyclic isoxazolidines allowed us to obtain complex glycomi

  12. Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?

    NARCIS (Netherlands)

    Boon, K.M.; Klap, P.; Van Lanen, J.A.; Letsoin, G.J.; Jansen, A.J.


    The paper presents the answer to the question how pedalling on a specific recumbent bicycle, such as the VeloX3, influences a cyclist’s ability to steer the bicycle. The research aims to find the correlation between pedalling and the undesired steering movements it creates. To test this assumption a

  13. Bicycle Design: A different approach to improving on the world human powered speed records

    NARCIS (Netherlands)

    Epema, H.K.; Van den Brand, S.; Gregoor, W.; Kooijman, J.D.G.; Pereboom, H.P.; Wielemaker, D.C.; Van der Zweep, C.J.


    The current International Human Powered Vehicle Association world records for faired bicycles stand at 133.284km/h for the 200m flying start speed record and 91.562 km for the hour record. Traditionally the recumbent bicycles that have been developed for breaking one of either of these records have

  14. Getting Bicycles on Trains - Inter-modal Transport Developments in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik; Pedersen, Bjørn Brix


    The combined use of bicycles and trains has been favored in contemporary public transport policies in Denmark. Although bicycling has played a major role in Danish personal transportation in more than hundred years, the attitude from public transport authorities towards supporting bicyclists has...

  15. The Dutch Reference Study: Cases of interventions in bicycle infrastructure reviewed in the framework of Bikeability

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Godefrooij, T.


    The Netherlands have a tradition of high bicycle usage and a long history of research on effective policies for promoting cycling. Findings in Dutch studies can be useful in the Danish Bikeability-project that has the objective to increase the level of knowledge in relation to bicycle based transpor

  16. Envisioning Competence: Learning, Problem Solving, and Children at Work in the Exploratory Bicycle Shop (United States)

    Hammond, Charles Florian


    This study examines the conceptual learning and cognitive development processes of schoolchildren engaged in problem solving activities in a non-school, workplace setting known as the exploratory bicycle shop. The exploratory bike shop is a commercial bicycle shop: a) that has been adapted for combined retail and educational purposes and b) where…

  17. The unexpected stable market share of the bicycle in The Netherlands

    NARCIS (Netherlands)

    Van Goeverden, C.D.; Van Arem, B.; Godefrooij, T.


    In the Netherlands, the share of the bicycle as the main mode in all person trips has been highly constant in the past three decades (about 27%). A constant share is remarkable because a number of developments in this period were unfavourable for bicycle use, like ageing of the population, growing n

  18. Advocating Green Transport and Promoting Healthy Urban Development: Strategies for Bicycle Transport Development in Jinan

    Institute of Scientific and Technical Information of China (English)


    <正>As a green transport means,the bicycle has a history of over two hundred years.Since the 1970s,due to the inf luence of energy crisis and the consciousness of environment protection,the bicycle has regained its popularity in the public for its

  19. Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process (United States)

    McFarland, Shane


    Field of view has always been a design feature paramount to helmets, and in particular space suits, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view will be required. Through taxonimization of various parameters that affect suited field of view, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was employed to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables while sacrificing minimal fidelity.

  20. The burden of motorcycle-related neuro-trauma in Ireland and associated helmet usage.

    LENUS (Irish Health Repository)

    Murphy, R K J


    Motorcycles represent less than 2% of the licensed vehicles but motorcyclists account for 12% of road deaths in Ireland. The British Road Safety Authority has introduced the Sharp programme, which hopes to save 50 lives in the U.K. each year alone by helping riders to choose the best-fitting and safest helmets. We evaluated the pattern of head injuries sustained by motorcyclists referred to the two neurosurgical centres Beaumont Hospital and Cork University Hospital in Ireland and ascertained if the new SHARP guidelines could be of benefit in reducing the burden of motorcycle related neurotrauma and disability in Ireland. Despite Ireland having mandatory helmet laws almost a quarter of our motorcyclists with traumatic brain injury were unhelmeted. A significant reduction in mortality and morbidity is predicted if all motorcyclists in Ireland were to wear helmets that satisfied the SHARP criteria.

  1. Toward reducing impact induced brain injury: Lessons from a computational study of army and football helmet pads

    CERN Document Server

    Moss, W C; Blackman, E G


    We use computational simulations to compare the impact response of different football and U.S. Army helmet pad materials. We conduct experiments to characterize the material response of different helmet pads. We simulate experimental helmet impact tests performed by the U.S. Army to validate our methods. We then simulate a cylindrical impactor striking different pads. The acceleration history of the impactor is used to calculate the Head Injury Criterion for each pad. We conduct sensitivity studies exploring the effects of pad composition, geometry, and material stiffness. We find that: (1) The football pad materials do not outperform the currently used military pad material in militarily-relevant impact scenarios; (2) Optimal material properties for a pad depend on impact energy; and (3) Thicker pads perform better at all velocities. Our analysis suggests that by using larger helmet shells with correspondingly thicker pads, impact-induced traumatic brain injury may be significantly reduced. Keywords: helmet,...

  2. Can You Ride a Bicycle? The Ability to Ride a Bicycle Prevents Reduced Social Function in Older Adults With Mobility Limitation

    Directory of Open Access Journals (Sweden)

    Ryota Sakura


    Full Text Available Background: The health benefits of bicycling in older adults with mobility limitation (ML are unclear. We investigated ML and functional capacity of older cyclists by evaluating their instrumental activities of daily living (IADL, intellectual activity, and social function. Methods: On the basis of interviews, 614 community-dwelling older adults (after excluding 63 participants who never cycled were classified as cyclists with ML, cyclists without ML, non-cyclists with ML (who ceased bicycling due to physical difficulties, or non-cyclists without ML (who ceased bicycling for other reasons. A cyclist was defined as a person who cycled at least a few times per month, and ML was defined as difficulty walking 1 km or climbing stairs without using a handrail. Functional capacity and physical ability were evaluated by standardized tests. Results: Regular cycling was documented in 399 participants, and 74 of them (18.5% had ML; among non-cyclists, 49 had ML, and 166 did not. Logistic regression analysis for evaluating the relationship between bicycling and functional capacity revealed that non-cyclists with ML were more likely to have reduced IADL and social function compared to cyclists with ML. However, logistic regression analysis also revealed that the risk of bicycle-related falls was significantly associated with ML among older cyclists. Conclusions: The ability and opportunity to bicycle may prevent reduced IADL and social function in older adults with ML, although older adults with ML have a higher risk of falls during bicycling. It is important to develop a safe environment for bicycling for older adults.

  3. The spatio-temporal Development of Copenhagen's bicycle infrastructure 1912-2013

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Olafsson, Anton Stahl; Bech, Nynne Marie


    Cycling plays an important role in low-carbon transitions. Around the globe, cities are constructing bicycle infrastructure. The city of Copenhagen has a bicycle-friendly infrastructure celebrated for its fine-meshed network. This study documents the spatio-temporal development of Copenhagen......’s bicycle infrastructure and explores how the development corresponds to other processes of urban transformation. The study builds on historical maps of bicycle infrastructure that are digitised into geographical information, which allows for a comprehensive analysis of the formation of the network....... In search for identifying drivers, the study analyses the city’s spatial growth pattern, migration pattern, development of road network and changes in the transport culture. Analyses reveal that the bicycle infrastructure expanded at a relatively constant pace during distinct periods of urban transformation...

  4. Vision-Based Bicycle Detection Using Multiscale Block Local Binary Pattern

    Directory of Open Access Journals (Sweden)

    Hongyu Hu


    Full Text Available Bicycle traffic has heavy proportion among all travel modes in some developing countries, which is crucial for urban traffic control and management as well as facility design. This paper proposes a real-time multiple bicycle detection algorithm based on video. At first, an effective feature called multiscale block local binary pattern (MBLBP is extracted for representing the moving object, which is a well-classified feature to distinguish between bicycles and nonbicycles; then, a cascaded bicycle classifier trained by AdaBoost algorithm is proposed, which has a good computation efficiency. Finally, the method is tested with video sequence captured from the real-world traffic scenario. The bicycles in the test scenario are successfully detected.

  5. 76 FR 61266 - Special Regulations; Areas of the National Park System, Grand Teton National Park, Bicycle Routes... (United States)


    ..., Grand Teton National Park, Bicycle Routes, Fishing and Vessels AGENCY: National Park Service, Interior... (Park) as routes for bicycle use. National Park Service (NPS) regulations require issuance of a special regulation to designate bicycle routes that are located off park roads and outside developed areas. The...

  6. Analysis and Design of Phase Change Thermal Control for Light Emitting Diode (LED) Spacesuit Helmet Lights (United States)

    Bue, Grant C.; Nguyen, Hiep X.; Keller, John R.


    LED Helmet Extravehicular Activity Helmet Interchangeable Portable (LEHIP) lights for the Extravehicular Mobility Unit (EMU) have been built and tested and are currently being used on the International Space Station. A design is presented of the passive thermal control system consisting of a chamber filled with aluminum foam and wax. A thermal math model of LEHIP was built and correlated by test to show that the thermal design maintains electronic components within hot and cold limits for a 7 hour spacewalk in the most extreme EVA average environments, and do not pose a hazard to the crew or to components of the EMU.

  7. Factors associated with the enactment of safety belt and motorcycle helmet laws. (United States)

    Law, Teik Hua; Noland, Robert B; Evans, Andrew W


    It has been shown that road safety laws, such as motorcycle helmet and safety belt laws, have a significant effect in reducing road fatalities. Although an expanding body of literature has documented the effects of these laws on road safety, it remains unclear which factors influence the likelihood that these laws are enacted. This study attempts to identify the factors that influence the decision to enact safety belt and motorcycle helmet laws. Using panel data from 31 countries between 1963 and 2002, our results reveal that increased democracy, education level, per capita income, political stability, and more equitable income distribution within a country are associated with the enactment of road safety laws.

  8. Investigating helmet promotion for cyclists: results from a randomised study with observation of behaviour, using a semi-automatic video system.

    Directory of Open Access Journals (Sweden)

    Aymery Constant

    Full Text Available INTRODUCTION: Half of fatal injuries among bicyclists are head injuries. While helmet use is likely to provide protection, their use often remains rare. We assessed the influence of strategies for promotion of helmet use with direct observation of behaviour by a semi-automatic video system. METHODS: We performed a single-centre randomised controlled study, with 4 balanced randomisation groups. Participants were non-helmet users, aged 18-75 years, recruited at a loan facility in the city of Bordeaux, France. After completing a questionnaire investigating their attitudes towards road safety and helmet use, participants were randomly assigned to three groups with the provision of "helmet only", "helmet and information" or "information only", and to a fourth control group. Bikes were labelled with a colour code designed to enable observation of helmet use by participants while cycling, using a 7-spot semi-automatic video system located in the city. A total of 1557 participants were included in the study. RESULTS: Between October 15th 2009 and September 28th 2010, 2621 cyclists' movements, made by 587 participants, were captured by the video system. Participants seen at least once with a helmet amounted to 6.6% of all observed participants, with higher rates in the two groups that received a helmet at baseline. The likelihood of observed helmet use was significantly increased among participants of the "helmet only" group (OR = 7.73 [2.09-28.5] and this impact faded within six months following the intervention. No effect of information delivery was found. CONCLUSION: Providing a helmet may be of value, but will not be sufficient to achieve high rates of helmet wearing among adult cyclists. Integrated and repeated prevention programmes will be needed, including free provision of helmets, but also information on the protective effect of helmets and strategies to increase peer and parental pressure.

  9. Harvesting Energy from the Counterbalancing (Weaving Movement in Bicycle Riding

    Directory of Open Access Journals (Sweden)

    Shashank Priya


    Full Text Available Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle’s handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  10. Methodology to determine skull bone and brain responses from ballistic helmet-to-head contact loading using experiments and finite element analysis. (United States)

    Pintar, Frank A; Philippens, Mat M G M; Zhang, JiangYue; Yoganandan, Narayan


    The objective of the study was to obtain helmet-to-head contact forces from experiments, use a human head finite element model to determine regional responses, and compare outputs to skull fracture and brain injury thresholds. Tests were conducted using two types of helmets (A and B) fitted to a head-form. Seven load cells were used on the head-form back face to measure helmet-to-head contact forces. Projectiles were fired in frontal, left, right, and rear directions. Three tests were conducted with each helmet in each direction. Individual and summated force- and impulse-histories were obtained. Force-histories were inputted to the human head-helmet finite element model. Pulse durations were approximately 4 ms. One-third force and impulse were from the central load cell. 0.2% strain and 40 MPa stress limits were not exceeded for helmet-A. For helmet-B, strains exceeded in left, right, and rear; pressures exceeded in bilateral directions; volume of elements exceeding 0.2% strains correlated with the central load cell forces. For helmet-A, volumes exceeding brain pressure threshold were: 5-93%. All elements crossed the pressure limit for helmet-B. For both helmets, no brain elements exceeded peak principal strain limit. These findings advance our understanding of skull and brain biomechanics from helmet-head contact forces.

  11. A Novel Method for Quantifying Helmeted Field of View of a Spacesuit - And What It Means for Constellation (United States)

    McFarland, Shane M.


    Field of view has always been a design feature paramount to helmet design, and in particular spacesuit design, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. Historically, suited field of view has been evaluated either qualitatively in parallel with design or quantitatively using various test methods and protocols. As such, oftentimes legacy suit field of view information is either ambiguous for lack of supporting data or contradictory to other field of view tests performed with different subjects and test methods. This paper serves to document a new field of view testing method that is more reliable and repeatable than its predecessors. It borrows heavily from standard ophthalmologic field of vision tests such as the Goldmann kinetic perimetry test, but is designed specifically for evaluating field of view of a spacesuit helmet. In this test, four suits utilizing three different helmet designs were tested for field of view. Not only do these tests provide more reliable field of view data for legacy and prototype helmet designs, they also provide insight into how helmet design impacts field of view and what this means for the Constellation Project spacesuit helmet, which must meet stringent field of view requirements that are more generous to the crewmember than legacy designs.

  12. Outcome analysis after helmet therapy using 3D photogrammetry in patients with deformational plagiocephaly: the role of root mean square. (United States)

    Moghaddam, Mahsa Bidgoli; Brown, Trevor M; Clausen, April; DaSilva, Trevor; Ho, Emily; Forrest, Christopher R


    Deformational plagiocephaly (DP) is a multifactorial non-synostotic cranial deformity with a reported incidence as high as 1 in 7 infants in North America. Treatment options have focused on non-operative interventions including head repositioning and the use of an orthotic helmet device. Previous studies have used linear and two dimensional outcome measures to assess changes in cranial symmetry after helmet therapy. Our objective was to demonstrate improvement in head shape after treatment with a cranial molding helmet by using Root Mean Square (RMS), a measure unique to 3D photogrammetry, which takes into account both changes in volume and shape over time. Three dimensional photographs were obtained before and after molding helmet treatment in 40 infants (4-10 months old) with deformational plagiocephaly. Anatomical reference planes and measurements were recorded using the 3dMD Vultus(®) analysis software. RMS was used to quantify symmetry by superimposing left and right quadrants and calculating the mean value of aggregate distances between surfaces. Over 95% of the patients demonstrated an improvement in symmetry with helmet therapy. Furthermore, when the sample of infants was divided into two treatment subgroups, a statistically significant correlation was found between the age at the beginning of treatment and the change in the RMS value. When helmet therapy was started before 7 months of age a greater improvement in symmetry was seen. This work represents application of the technique of RMS analysis to demonstrate the efficacy of treatment of deformational plagiocephaly with a cranial molding helmet.

  13. Predicting Free Flow Speed and Crash Risk of Bicycle Traffic Flow Using Artificial Neural Network Models

    Directory of Open Access Journals (Sweden)

    Cheng Xu


    Full Text Available Free flow speed is a fundamental measure of traffic performance and has been found to affect the severity of crash risk. However, the previous studies lack analysis and modelling of impact factors on bicycles’ free flow speed. The main focus of this study is to develop multilayer back propagation artificial neural network (BPANN models for the prediction of free flow speed and crash risk on the separated bicycle path. Four different models with considering different combinations of input variables (e.g., path width, traffic condition, bicycle type, and cyclists’ characteristics were developed. 459 field data samples were collected from eleven bicycle paths in Hangzhou, China, and 70% of total samples were used for training, 15% for validation, and 15% for testing. The results show that considering the input variables of bicycle types and characteristics of cyclists will effectively improve the accuracy of the prediction models. Meanwhile, the parameters of bicycle types have more significant effect on predicting free flow speed of bicycle compared to those of cyclists’ characteristics. The findings could contribute for evaluation, planning, and management of bicycle safety.

  14. An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)


    This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

  15. Effects of police enforcement of protection devices and moped helmet use and red light running.

    NARCIS (Netherlands)


    Not wearing a seat belt or moped helmet, and red light running lead to a higher crash rate or a more serious crash. That is why they have been spearheads of intensified police enforcement in the Netherlands since 1999. The extra seat belt enforcement together with large-scale media campaigns have le

  16. Using Structural Equation Modeling and the Behavioral Sciences Theories in Predicting Helmet Use

    Directory of Open Access Journals (Sweden)

    Kamarudin Ambak


    Full Text Available In Malaysia, according to road accidents data statistics motorcycle users contributes more than 50% of fatalities in traffic accidents, and the major cause due to head injuries. One strategy that can be used to reduce the severity of head injuries is by proper usage of helmet. Although the safety helmet is the best protective equipment to prevents head injury, majority motorcycle user did not use or did not fasten properly. In understanding this problem, the behavioral sciences theory and engineering aspect are needed to provide better explanation and comprehensive insights into solutions. The Theory Planned Behavior (TPB and Health Belief Model (HBM were used in predicting the behavioral intention toward proper helmet usage among motorcyclist. While, a new intervention approach were used in Technology Acceptance Model (TAM that based on the perception of a conceptual system called Safety Helmet Reminder System (SHR. Results show that the constructs variables are reliable and statistically significant with the exogenous and endogenous variables. The full structured models were proposed and tested, thus the significant predictors were identified. A multivariate analysis technique, known as Structural Equation Model (SEM was used in modeling exercise.  Finally, the good-of-fit models were used in interpreting the implication of intervention strategy toward motorcyclist injury prevention program.

  17. Evaluation of a flexible force sensor for measurement of helmet foam impact performance. (United States)

    Ouckama, Ryan; Pearsall, David J


    The association between translational head acceleration and concussion remains unclear and provides a weak predictive measure for this type of injury; thus, alternative methods of helmet evaluation are warranted. Recent finite element analysis studies suggest that better estimates of concussion risk can be obtained when regional parameters of the cranium, brain and surrounding tissues are included. Lacking, however, are empirical data at the head-helmet interface with regards to contact area and force. Hence, the purpose of this study was to evaluate a system to capture the impact force distribution of helmet foams. Thirteen Flexiforce(®) sensors were arranged in a 5 × 5 cm array, secured to a load cell. Three densities of foam were repeatedly impacted with 5 J of energy during ambient (20°C) and cold (-25°C) conditions. RMS error, calculated relative to the global force registered by the load cell, was Flexiforce(®) sensors. RMS error was 5% of the measured range for the global force estimated by the sensor array. Load distribution measurement revealed significant differences between repeated impacts of cold temperature foams for which acceleration results were non-significant. The sensor array, covering only 36% of the total area, possessed sufficient spatial and temporal resolution to capture dynamic load distribution patterns. Implementation of this force mapping system is not limited to helmet testing. Indeed it may be adopted to assess other body regions vulnerable to contact injuries (e.g., chest, hip and shin protectors).

  18. Experimental Methodology using Digital Image Correlation (DIC) to Assess Ballistic Helmet Blunt Trauma (United States)


    helmets. Additional details pertinent to the firing sequence are as follows: • Gun was a 9 mm Aero tube, 8.25 in long, 1:10 twist, 6 groove (Bill Wiseman...speeds of 50,000 frames per second and shutter speeds of 1/(frame speed) seconds. At these camera speeds, an intense light source is needed to uniformly

  19. Helmet Versus Active Repositioning for Plagiocephaly: A Three-Dimensional Analysis

    DEFF Research Database (Denmark)

    Lipira, A.B.; Gordon, S.; Darvann, Tron Andre;


    to rigorously compare outcomes of these 2 treatment methods. PATIENTS AND METHODS: Whole-head 3D surface scans of 70 infants with DP were captured before and after treatment by using stereophotogrammetric imaging technology. Helmeted (n = 35) and nonhelmeted/actively repositioned (n = 35) infants were matched...

  20. A series of student design projects for improving and modernizing safety helmets

    NARCIS (Netherlands)

    Beurden, van K.M.M. (Karin); Boer, de J. (Johannes); Stilma, M. (Margot); Teeuw, W.B. (Wouter)


    The Saxion Research Centre for Design and Technology employs many students during research projects. This paper discusses a series of student design projects on safety helmets in the Safety@Work project. At construction sites workers are required to wear personal protective equipment during their wo

  1. Effect of Helmet Pads on the Load Transfer to Head under Blast Loadings (United States)


    318. [2] Moss W., and King M., 2011, “Impact Response of US Army and National Football League Helmet Pad Systems”, LLNL-SR-464951, Lawrence Livermore...Cavitation pressure in water”, Physical Review E, 74. [13] Caupin F, and Herbert E, 2006, “Cavitation in water: a review”, Comptes Rendus

  2. Motorcycle-Related Traumatic Brain Injuries: Helmet Use and Treatment Outcome

    Directory of Open Access Journals (Sweden)

    Mathias Ogbonna Nnanna Nnadi


    Full Text Available Summary. With increasing use of motorcycle as means of transport in developing countries, traumatic brain injuries from motorcycle crashes have been increasing. The only single gadget that protects riders from traumatic brain injury is crash helmet. Objective. The objectives were to determine the treatment outcome among traumatic brain injury patients from motorcycle crashes and the rate of helmet use among them. Methods. It was a prospective, cross-sectional study of motorcycle-related traumatic brain injury patients managed in our center from 2010 to 2014. Patients were managed using our unit protocol for traumatic brain injuries. Data for the study were collected in accident and emergency, intensive care unit, wards, and outpatient clinic. The data were analyzed using Environmental Performance Index (EPI info 7 software. Results. Ninety-six patients were studied. There were 87 males. Drivers were 65. Only one patient wore helmet. Majority of them were between 20 and 40 years. Fifty-three patients had mild head injuries. Favorable outcome among them was 84.35% while mortality was 12.5%. Severity of the injury affected the outcome significantly. Conclusion. Our study showed that the helmet use by motorcycle riders was close to zero despite the existing laws making its use compulsory in Nigeria. The outcome was related to severity of injuries.

  3. Cyclist safety on bicycle boulevards and parallel arterial routes in Berkeley, California. (United States)

    Minikel, Eric


    This study compares the safety of bicyclists riding on bicycle boulevards to those riding on parallel arterial routes in Berkeley, California. Literature on the impact of motor vehicle traffic characteristics on cyclist safety shows that high motor vehicle speeds and volumes and the presence of heavy vehicles are all detrimental to cyclist safety. This suggests that cyclists may be safer on side streets than on busy arterials. Bicycle boulevards-traffic-calmed side streets signed and improved for cyclist use-purport to offer cyclists a safer alternative to riding on arterials. Police-reported bicycle collision data and manually collected cyclist count data from bicycle boulevards and parallel arterial routes in Berkeley, California from 2003 to 2010 are used to test the hypothesis that Berkeley's bicycle boulevards have lower cyclist collision rates and a lower proportion of bicycle collisions resulting in severe injury. While no significant difference is found in the proportion of collisions that are severe, results show that collision rates on Berkeley's bicycle boulevards are two to eight times lower than those on parallel, adjacent arterial routes. The difference in collision rate is highly statistically significant, unlikely to be caused by any bias in the collision and count data, and cannot be easily explained away by self-selection or safety in numbers. Though the used dataset is limited and the study design is correlational, this study provides some evidence that Berkeley's bicycle boulevards are safer for cyclists than its parallel arterial routes. The results may be suggestive that, more generally, properly implemented bicycle boulevards can provide cyclists with a safer alternative to riding on arterials.

  4. Enhanced recycling network for spent e-bicycle batteries: A case study in Xuzhou, China. (United States)

    Chen, Fu; Yang, Baodan; Zhang, Wangyuan; Ma, Jing; Lv, Jie; Yang, Yongjun


    Electric bicycles (e-bicycles) are a primary means of commuting in China because of their light weight, speed, and low maintenance costs. Owing to short service life and environmental pollution hazards, recycling and reuse of e-bicycle batteries has always been a focus of industry and academia. As a typical case of both production and use of large electric bicycles, 113 major sellers, 378 corporate and individual buyers, 147 large e-bicycle repair centers, and 1317 e-bicycle owners in Xuzhou City were investigated in order to understand the sales, use, recycling, and disposal of spent e-bicycle batteries. The findings show that the existing distempered recycling system is the main limitation of spent battery recovery, and the actual recovery rate of spent batteries is lower than the estimated output (QW) for the years 2011-2014. Electric bicycle sellers play a fundamental role in the collection of spent batteries in Xuzhou, accounting for 42.3±8.3% of all batteries recovered. The widespread use of lithium batteries in recent years has resulted in a reduction in spent battery recycling because of lower battery prices. Furthermore, consumer preferences are another important factor affecting the actual recovery rate according to survey results evaluated using canonical correspondence analysis. In this paper, we suggest that a reverse logistics network system for spent battery recycling should be established in the future; in addition, enhancing producer responsibility, increasing publicity, raising of public awareness, developing green public transport, and reducing dependence on e-bicycles also should be pursued. This study seeks to provide guidance for planning construction and management policies for an effective spent battery recycling system in China and other developing countries.

  5. Synthesis of bicyclic alkaloids from the iridoid antirrhinoside

    DEFF Research Database (Denmark)

    Frederiksen, Signe Maria

    The present thesis describes the isolation of the iridoid glucoside antirrhinoside from Antirrhinum majus, and the approaches made towards its transformation into analogues of biologically active compounds, with special interest in syntheses of bicyclic alkaloids.A synthetic piperidine monoterpene...... alkaloid was prepared from antirrhinoside by means of an enzymatic cleavage to afford the aglucone, followed by a double reductive amination with benzylamine hydrochloride and sodium cyanoborohydride. The resulting piperidine was modified by opening of the epoxide on the cyclopropane ring by azide...... strategy was therefore abandoned.A one-pot reaction involving ozonolysis and subsequent reduction of the 5,6-O-isopropylidene-2',3',4',6'-tetra-O-acetyl antirrhinoside yielded a diol, which was considered a potential intermediate in the preparation of enantiopure 3-azabicyclo[3.3.0]octane alkaloids...

  6. Bicycle messengers: energy expenditure and exposure to air pollution. (United States)

    Bernmark, Eva; Wiktorin, Christina; Svartengren, Magnus; Lewné, Marie; Aberg, Samuel


    The purpose of the study was to determine the level of energy expenditure and exposure to air pollution for bicycle messengers. Relationships between heart rate (HR) and oxygen uptake, and between HR and pulmonary ventilation (VE) for each participant were established in laboratory tests. Air pollution and HR were measured during one working day. The total oxygen uptake was then described as the total energy expenditure in Joule (J) and in multiples of the energy expenditure at rest (MET). The mean energy expenditure during a working day (8 h) was 12 MJ, (4.8 MET). The level of air pollution exposure when cycling seemed to be comparable with the levels of exposure when sitting inside a vehicle. The VE during cycling was four times higher than resting value. Increased VE led to increased exposure to air pollution.

  7. Fatal truck-bicycle accident involving dragging for 45 km. (United States)

    Klintschar, M; Darok, M; Roll, P


    Vehicle-bicycle accidents with subsequent dragging of the rider over long distances are extremely rare. The case reported here is that of a 16-year-old mentally retarded bike rider who was run over by a truck whose driver failed to notice the accident. The legs of the victim became trapped by the rear axle of the trailer and the body was dragged over 45 km before being discovered under the parked truck. The autopsy revealed that the boy had died from the initial impact and not from the dragging injuries which had caused extensive mutilation. The reports of the technical expert and the forensic pathologist led the prosecutor to drop the case against the truck driver for manslaughter.

  8. Aromatic Esters of Bicyclic Amines as Antimicrobials against Streptococcus pneumoniae. (United States)

    de Gracia Retamosa, María; Díez-Martínez, Roberto; Maestro, Beatriz; García-Fernández, Esther; de Waal, Bas; Meijer, E W; García, Pedro; Sanz, Jesús M


    A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues.

  9. Optimal Time-Trial Bicycle Racing with Headwinds and Tailwinds

    CERN Document Server

    Anton, A Brad


    Many time-trial and triathlon bicycle races take place on relatively flat, closed-circuit courses. In the absence of hills, riding-speed is limited almost solely by aerodynamic drag; consequently, winds can have a big effect on elapsed times. I analyze the special case of a straight out-and-back race in a steady wind, assuming the rider has a given total amount of energy to expend and can choose only two speeds - the aided speed with tailwind and the hindered speed into headwind. In this ideal circumstance the problem of choosing optimal riding speeds reduces to a constrained nonlinear optimization that can be solved with elementary calculus. My analysis reveals a practical rule of thumb that can be used more generally to choose optimal riding speeds for time-trial racing on closed-circuit courses in the presence of headwinds and tailwinds.

  10. [Prognostic significance of bicycle ergometry test in patients with myocarditis]. (United States)

    Gavalova, R F; Borodina, V I


    A total of 42 patients with rheumatic carditis were examined in the acute-subacute period and following 3-5 years. Seventeen patients were diagnosed as having primary rheumatic carditis, 9 presented with tonsillogenic rheumatic carditis, and 16 had viral rheumatic carditis. The diagnosis of myocarditis was established on the basis of clinical, immunological, and virological findings. The study involved ECG, PhCG, PCG, and bicycle ergometer testing recordings. Groups of patients with good and poor prognosis were identified. Low threshold exercise, exercise-inadequate tachycardia, complex cardiac arrhythmias, phasic myocardial hypodynamic syndrome and volume exercise syndrome that are formed during performance are prognostically poor indicators. More profound electric and mechanic dysfunctions were observed in patients with tonsillogenic or viral myocarditis.

  11. Optimal protruding node length of bicycle seats determined using cycling postures and subjective ratings. (United States)

    Chen, Yi-Lang; Liu, Yi-Nan


    This study examined body posture, subjective discomfort, and stability, requiring the participants to ride a stationary bicycle for 20 min (cadence: 60 rpm; workrate: 120 W), using various combinations of two handle heights and five seat-protruding node lengths (PNLs). The results indicated that bicycle handle height significantly influenced body posture, and that seat PNL caused differences in the riders' subjective discomfort and stability scores. The various PNLs affected only the trunk angle (approximately 6°), but had significantly positive (r = 0.994, p optimal reference for bicycle seat designs.

  12. Evaluation of the Performance of New Laminated Composite Shells for Motorcycle Helmets

    Directory of Open Access Journals (Sweden)

    Nermin M. Aly


    Full Text Available Motorcycles are considered a cost-effective and major means of transportation, particularly in the developing countries. However, motorcyclists are at higher risk of head and brain injuries in road crashes, which is the primarily cause of most of the fatalities occurred. Wearing a protective helmet is an efficient way for the safety of the motorcyclist, since it reduces the severity of head injuries through absorbing the impact energy during accidents. The main components of the helmet are the outer shell and the shock absorbing foam liner. The helmet performance depends to a great extent on the enhancement of the properties of the materials used to provide protection. This paper studied experimentally the protection performance of new laminated composite shells compared with that of an Acrylonitrile Butadiene Styrene (ABS shell. The shell prototypes were fabricated in the form of an open face helmet, composed of a laminated composite structure reinforced with various fabric performs and materials. Expanded polystyrene foam was used for the shock absorbing liner and its compressive properties were examined. The shell prototypes including the foam liner were tested mechanically to investigate their damage behaviour under applying low velocity impacts and penetration loads. Non Destructive Inspection (NDI methods were used, such as visual inspection and X-ray radiography to detect and evaluate the damages found in the prototypes. It was illustrated that, the laminated composite shell reinforced with the polyester/glass woven fabric and glass fiber mat achieved the best performance, can sustain impact loads and provide better protection to the head from penetration. When compared it with the ABS helmet, it approaches to its effectiveness in protection and the produced shell prototypes are promising for using in motorcycling.

  13. Use of suitable helmet and its relation with maxillofacial and skull fractures in motorcyclists in Cali

    Directory of Open Access Journals (Sweden)

    Hernández Jesús Alberto


    Full Text Available Introduction: The accidents of motorcyclists constitute a growing cause of dead and injuries in the cities being most of them attack if they are fulfilled the effective traffic norms and it is used a helmet of facial protection appropriately. Objective: The main objective of the investigation is the relationship that exists among fractures of the maxillofacial area and the use of a helmet adapted in motorcyclists in the city of Cali to settle down. Study design: We design a prospective study gathering the information in the emergency rooms of the University Hospitals of the Valley, San Juan of God and Clinical Rafael Uribe Uribe of the city of Cali, Colombia. The period of the study was of one year with a field work carried out among November from 2.001 to June of 2.002. The statistical package EPIINFO version was used 6.04. Results and conclusion: The size of the sample belonged to 108 people, 88 men (81.5% and 20 women (18.5%. The most important conclusion in this investigation is that most (57=52.8% of the motorcyclists that had fractures they didn’t use helmet in the moment of the collision, and that the 51 motorcyclists that if they used it, only 3 (5.8% they used a helmet that fulfills the effective norms and that he/she allows to give appropriate protection to the user. It is for this reason that the causes should be investigated of the why don’t use of a helmet adapted in uneven motorcyclists to implement massive campaigns directed to counteract this behavior with the purpose of diminishing remarkable.

  14. Characteristics of bicyclic sesquiterpanes in crude oils and petroleum products. (United States)

    Yang, Chun; Wang, Zhendi; Hollebone, Bruce P; Brown, Carl E; Landriault, Mike


    This study presents a quantitative gas chromatography-mass spectrometry analysis of bicyclic sesquiterpanes (BSs) in numerous crude oils and refined petroleum products including light and mid-range distillate fuels, residual fuels, and lubricating oils collected from various sources. Ten commonly recognized bicyclic sesquiterpanes were determined in all the studied crude oils and diesel range fuels with principal dominance of BS3 (C(15)H(28)), BS5 (C(15)H(28)) and BS10 (C(16)H(30)), while they were generally not detected or in trace in light fuel oils like gasoline and kerosene and most lubricating oils. Laboratory distillation of crude oils demonstrated that sesquiterpanes were highly enriched in the medium distillation fractions of approximately 180 to 481 degrees C and were generally absent or very low in the light distillation fraction (boiling point to approximately 180 degrees C) and the heavy residual fraction (>481 degrees C). The effect of evaporative weathering on a series of diagnostic ratios of sesquiterpanes, n-alkanes, and biomarkers was evaluated with two suites of weathered oil samples. The change of abundance of sesquiterpanes was used to determine the extent of weathering of artificially evaporated crude oils and diesel. In addition to the pentacyclic biomarker C(29) and C(30) alphabeta-hopane, C(15) and C(16) sesquiterpanes might be alternative internal marker compounds to provide a direct way to estimate the depletion of oils, particularly diesels, in oil spill investigations. These findings may offer potential applications for both oil identification and oil-source correlation in cases where the tri- to pentacyclic biomarkers are absent due to refining or environmental weathering of oils.

  15. Evaluating the effectiveness of on-street bicycle lane and assessing risk to bicyclists in Charlotte, North Carolina. (United States)

    Pulugurtha, Srinivas S; Thakur, Vidya


    The objectives of this manuscript are (1) to evaluate the effectiveness of on-street bicycle lane in reducing crashes involving bicyclists on urban roads, (2) to quantify and compare risk to bicyclists on road segments with and without on-street bicycle lane, (3) to evaluate the effect of on-street bicycle lane on other road network users (all crashes), and, (4) to assess the role of on-network characteristics (speed limit, the number of lanes, the width of on-street bicycle lane, the width of the right-most travel lane, and, the numbers of driveways, unsignalized approaches and signalized intersections per unit distance) on risk to bicyclists. Data for thirty-six segments with on-street bicycle lane and twenty-six segments without on-street bicycle lane in the city of Charlotte, North Carolina were extracted to compute and compare measures such as the number of bicycle crashes per center-lane mile, the number of bicycle crashes per annual million vehicle miles traveled (MVMT), the number of all crashes per center-lane mile, and the number of all crashes per MVMT. The results obtained from analysis indicate that bicyclists are three to four times at higher risk (based on traffic conditions) on segments without on-street bicycle lane than when compared to segments with on-street bicycle lane. An analysis conducted considering all crashes showed that on-street bicycle lanes do not have a statistically significant negative effect on overall safety. An increase in annual MVMT (exposure) and the number of signalized intersections per mile increases the number of bicycle crashes, while an increase in on-street bicycle lane width or right-most travel lane width (if on-street bicycle lane cannot be provided) decreases the number of bicycle crashes. Installing wider on-street bicycle lanes, limiting driveways to less than 50 per mile and unsignalized approaches to less than 10 per mile, increasing spacing between signalized intersections, and, facilitating wider right

  16. Prioritization of Integrated Bicycle Network Clusters in Istanbul Using Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Dilek Çol Yılmaz


    Full Text Available In this study, the impact of the integration of nonmotorized transport and public transport on hypermobility was evaluated. The role of bicycle in non-motorized transportation, and its contribution to sustainable travel goals were examined. A decision support model was established in order to plan the phases of a bicycle network integrated with the public transport sytem in Istanbul Metropolitan Area. Data such as public transport routes planned for the target year 2023, locations of transfer centers, number of passengers at transfer centers, and a revised bicycle network were used as layers for the Geographic Information Systems (GIS map produced. Based on the survey data collected from the experts, Analytic Hierarchy Process (AHP which is a multi-criteria decision-making procedure that contains both qualitative and quantitative factors was used to prioritize the bicycle network clusters integrated with public transport system in Istanbul.

  17. The relation between mechanical impact parameters and most frequent bicycle related head injuries

    NARCIS (Netherlands)

    Monea, A.G.; Perre, G. van der; Baeck, K.; Delye, H.H.; Verschueren, P.; Forausebergher, E.; Lierde, C. van; Verpoest, I.; Sloten, J. van der; Goffin, J.; Depreitere, B.


    The most frequent head injuries resulting from bicycle accidents include skull fracture acute subdural hematoma (ASDH), cerebral contusions, and diffuse axonal injury (DAI). This review includes epidemiological studies, cadaver experiments, in vivo imaging, image processing techniques, and computer

  18. Health in All Policies? The case of policies to promote bicycle use in the Netherlands. (United States)

    den Broeder, Lea; Scheepers, Eline; Wendel-Vos, Wanda; Schuit, Jantine


    To gather insight on how Health in All Policies (HiAP) is applied in practice, we carried out a case study on transport policies intended to stimulate a shift from car use to bicycling. We reviewed 3 years (2010, 2011, and 2012) of national budgets and policy documents in the Netherlands, followed by two focus group sessions and a second round of document analysis. We found to our surprise, given the country's history of bicycle promotion, that no HiAP approaches for bicycle promotion remain in place in national transport policies. The Netherlands may face serious challenges in the near future for facilitating bicycle use. Inclusion of health goals requires that the health sector work towards acquiring a better understanding of core values in other sector's policies.

  19. An Analyses of Bicycle Accidents in Ankara: Analyses of 5 Years

    Directory of Open Access Journals (Sweden)

    Muhittin Yilmaz


    Full Text Available Aim: Bicycles are used for transportation, exercise and recreation. In this study we aimed to investigate the epidemiological, clinical and economic aspects of bicycle injuries. Material and Method: We included in the study who admitted to the Emergency Department with a bicycle accident between January 2008 and July 2012. Patient age and sex, accident pattern, presence of personal protective measures, injured body part, Glasgow Coma Scale (GCS score, Revised Trauma Score (RTS, radiological findings, requested consultations, duration of hospital stay, season of injury, and average cost rates were recorded. The study population was divided into 2 age groups as 0-14 years and over 14 years. Results: A patients were 238 (81.2% male and their mean age was 31.5±14.1 years. Fifty-five (18.8% patients were female and their mean age was 34.5±15.9 years. Males had significantly higher rate of bicycle injury (p

  20. EU to Continue 48.5% Anti-dumping Duties on Chinese Bicycles

    Institute of Scientific and Technical Information of China (English)


    On June 10, European Commission informed the Business Office of the Mission of Ministry of Commerce in EU and disclosed the adjudication on the review of the EU imposing anti-dumping on Chinese bicycles.

  1. Formation of isoprostane bicyclic endoperoxides from the autoxidation of cholesteryl arachidonate. (United States)

    Yin, Huiyong; Havrilla, Christine M; Morrow, Jason D; Porter, Ned A


    Autoxidation of polyunsaturated fatty acids and esters leads to a complex mixture containing hydroperoxides and cyclic peroxides. Prostaglandin bicyclic endoperoxides have been detected from the autoxidation of cholesteryl arachidonate by LC-MS and GC-MS techniques. All four possible types (I-IV) of bicyclic endoperoxides have been found starting from different regioisomeric hydroperoxides of cholesteryl arachidonate. Furthermore, the stereochemistry of Type IV bicyclic endoperoxides has been determined by conversion to pentafluorobenzyl (PFB) ester, trimethylsilyl (TMS) derivatives, and comparison with synthetic standards by the use of GC-MS. All eight possible diastereomers of the derivatized isoprostanes were observed and were separated by gas chromatography. The bicyclic endoperoxides with the two alkyl chains syn on the cyclopentane ring were formed preferentially to those with anti configuration, a result anticipated from earlier work. Substantial amounts of the anti-substituted isoprostanes, including PGF(2)(alpha), were, however, observed in the product mixture.

  2. Isn't it time to take bicycles seriously again in Beijing ?%Isn't it time to take bicycles seriously again in Beijing ?

    Institute of Scientific and Technical Information of China (English)

    Shannon Bufton; Florian Lorenz


    The humble bicycle was once the predominant mode of transport in Beijing and it can be argued that the city has previously been one of the best bicycle cities in the world. Now the streets are littered with rusting old bikes and it seems as if Beijing has turned its back on the bicycle in its quest for modernity and evolution. The resultant re-configuration of the city and the rapid speed of development of modern transportation systems (particularly the lightening growth of personal automobiles) have created a complex set of issues and challenges which now put the city under pressure such as sustainability, air quality, health and traffic congestion problems.

  3. Integration, development, and qualification of the helmet-mounted sight and display on the Rooivalk Attack Helicopter (United States)

    Mace, Timothy K.; Van Zyl, Petrus H.; Cross, Trevor


    The Rooivalk Attack Helicopter is designed and manufactured by Denel Aviation of South Africa, and in service with the South African Air Force. The Helmet Mounted Sight and Display (HMSD) hardware is manufactured by Sextant Avionique of France. The HMSD symbology is developed by Denel Aviation and is specific to the weapons and roles of the aircraft. The HMSD has visor projected NVG and PNVS images, and Flight and Weapon Symbology incorporating head slaved weapon aiming, helmet-to-helmet cueing, and helmet to main sight cueing. The NVG/PNVS image selection and main image controls are incorporated in the flight controls. The paper gives an overview of the aircraft visionic design and describes the integration process. The development of the displayed flight and weapon symbols is discussed. Aeronautical Design Standard 33E was chosen as a basis for the qualification process, and the development of the qualification criteria and the flight testing program are discussed.

  4. Association of Sociodemographic and Perceived Environmental Factors with Public Bicycle Use among Taiwanese Urban Adults

    Directory of Open Access Journals (Sweden)

    Yung Liao


    Full Text Available Background: This study examined the sociodemographic and perceived environmental factors associated with public bicycle use among Taiwanese urban adults. Methods: A random-digit-dialing telephone-based cross-sectional survey was administered to Taiwanese urban adults aged 20–64 years in 2015. Data on sociodemographic variables, perceived environmental factors (for attributes identified in the International Physical Activity Questionnaire-Environmental Module, and public bicycle use were obtained from 1002 adults in three cities. Adjusted logistic regression was used. Results: After adjustment for potential confounders, the results showed that adults aged 20–29 years (odds ratio (OR = 4.42 with a university degree or higher (OR = 2.03 were more likely to use public bicycles. In addition, adults living in Kaohsiung City were less likely to use public bicycles (OR = 0.24. Adults who saw people being active (OR = 1.76; 95% CI: 1.05–2.86 and had positive aesthetic experiences of their environment (OR = 1.69 were more likely to use public bicycles. Conclusions: Our findings suggest that seeing physically active people and positive aesthetic perceptions of the environment are key factors for developing transportation policies and intervention strategies for promoting public bicycle use among Taiwanese urban adults.

  5. Effects of localized auditory information on visual target detection performance using a helmet-mounted display. (United States)

    Nelson, W T; Hettinger, L J; Cunningham, J A; Brickman, B J; Haas, M W; McKinley, R L


    An experiment was conducted to evaluate the effects of localized auditory information on visual target detection performance. Visual targets were presented on either a wide field-of-view dome display or a helmet-mounted display and were accompanied by either localized, nonlocalized, or no auditory information. The addition of localized auditory information resulted in significant increases in target detection performance and significant reductions in workload ratings as compared with conditions in which auditory information was either nonlocalized or absent. Qualitative and quantitative analyses of participants' head motions revealed that the addition of localized auditory information resulted in extremely efficient and consistent search strategies. Implications for the development and design of multisensory virtual environments are discussed. Actual or potential applications of this research include the use of spatial auditory displays to augment visual information presented in helmet-mounted displays, thereby leading to increases in performance efficiency, reductions in physical and mental workload, and enhanced spatial awareness of objects in the environment.

  6. Study for verification testing of the helmet-mounted display in the Japanese Experimental Module. (United States)

    Nakajima, I; Yamamoto, I; Kato, H; Inokuchi, S; Nemoto, M


    Our purpose is to propose a research and development project in the field of telemedicine. The proposed Multimedia Telemedicine Experiment for Extra-Vehicular Activity will entail experiments designed to support astronaut health management during Extra-Vehicular Activity (EVA). Experiments will have relevant applications to the Japanese Experimental Module (JEM) operated by National Space Development Agency of Japan (NASDA) for the International Space Station (ISS). In essence, this is a proposal for verification testing of the Helmet-Mounted Display (HMD), which enables astronauts to verify their own blood pressures and electrocardiograms, and to view a display of instructions from the ground station and listings of work procedures. Specifically, HMD is a device designed to project images and data inside the astronaut's helmet. We consider this R&D proposal to be one of the most suitable projects under consideration in response to NASDA's open invitation calling for medical experiments to be conducted on JEM.

  7. Incorporating Human Body Mass in Standards of Helmet Impact Protection against Traumatic Brain Injury

    CERN Document Server

    Blackman, Eric G


    Impact induced traumatic brain injury (ITBI) describes brain injury from head impact not necessarily accompanied by skull fracture. For sufficiently abrupt head impact decelerations, ITBI results from brain tissue stress incurred as the brain crashes into the inside of the skull wall, displacing the surrounding cerebral spinal fluid (CSF). Proper helmet cushioning can damp the impact force and reduce ITBI. But force is mass times acceleration and commonly used helmet blunt impact standards are based only on acceleration thresholds. Here I show how this implies that present standards overestimate the minimum acceleration onset for ITBI by implicitly assuming that the brain is mechanically decoupled from the body. I quantify how an arbitrary orientation of the body with respect to impact direction increases the effective mass that should be used in calculating the required damping force and injury threshold accelerations. I suggest a practical method to incorporate the body mass and impact angle into ITBI helme...

  8. Incidence and costs of bicycle-related traumatic brain injuries in the Netherlands. (United States)

    Scholten, Annemieke C; Polinder, Suzanne; Panneman, Martien J M; van Beeck, Ed F; Haagsma, Juanita A


    The main cause of death and serious disability in bicycle accidents is traumatic brain injury (TBI). The aim of this population-based study was to assess the incidence and costs of bicycle-related TBI across various age groups, and in comparison to all bicycle-related injuries, to identify main risk groups for the development of preventive strategies. Data from the National Injury Surveillance System and National Medical Registration were used for all patients with bicycle-related injuries and TBI who visited a Dutch emergency department (ED) between 1998 and 2012. Demographics and national, weighted estimates of injury mechanism, injury severity and costs were analysed per age group. Direct healthcare costs and indirect costs were determined using the incidence-based Dutch Burden of Injury Model. Between 1998 and 2012, the incidence of ED treatments due to bicycle-related TBI strongly increased with 54%, to 43 per 100,000 persons in 2012. However, the incidence of all bicycle-related injuries remained stable, from 444 in 1998 to 456/100,000 in 2012. Incidence of hospital admission increased in both TBI (92%) and all injuries from cycling (71%). Highest increase in incidence of both ED treatments and hospital admissions was seen in adults aged 55+. The injury rate of TBI per kilometre travelled increased (44%) except in children, but decreased (-4%) for all injuries, showing a strong decrease in children (-36%) but an increase in men aged 25+, and women aged 15+. Total costs of bicycle-related TBI were €74.5 million annually. Although bicycle-related TBI accounted for 9% of the incidence of all ED treatments due to cycling, it accounted for 18% of the total costs due to all bicycle-related injuries (€410.7 million). Children and adolescents (aged 0-24) had highest incidence of ED treatments due to bicycle-related injuries. Men in the working population (aged 15-64) had highest indirect costs following injuries from cycling, including TBI. Older cyclists (aged

  9. The effects of surface-induced loads on forearm muscle activity during steering a bicycle. (United States)

    Arpinar-Avsar, Pinar; Birlik, Gülin; Sezgin, Onder C; Soylu, Abdullah R


    On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road) and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB) and Mountain Bike (MTB) are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s(-2) when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s(-2). The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction). During RB trials performed on rough road conditions, rmsEMG (%MVC) values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider can be

  10. The Current Practices in Injury Prevention and Safety Helmet Use in an Air Force Medical Center (United States)


    Clinic at Malcom Grow Medical Center, Andrews Air Force Base, Maryland. Preventive counseling Preventing the occurrence of both mental and physical ...of their care. The primary care provider assumes ongoing responsibility for health maintenance and therapy for illness, including consultation with...PA) or a Medical Doctor (M.D.). Doctor of Osteopathy (D.O.), or Registered Nurse (R.N.). Safety helmet For the purpose of this study, the safety

  11. Helmet-mounted display technology on the VISTA NF-16D (United States)

    Underhill, Gregory P.; Bailey, Randall E.; Markman, Steve


    Wright Laboratory's Variable-Stability In-Flight Simulator Test Aircraft (VISTA) NF-16D is the newest in-flight simulator in the USAF inventory. A unique research aircraft, it will perform a multitude of missions: to develop and evaluate flight characteristics of new aircraft that have not yet flown, and perform research in the areas of flying qualities, flight control design, pilot-vehicle interface, weapons and avionics integration, and to train new test pilots. The VISTA upgrade will enhance the simulation fidelity and research capabilities by adding a programmable helmet-mounted display (HMD) and head-up display (HUD) in the front cockpit. The programmable HMD consists of a GEC- Marconi Avionics Viper II Helmet-Mounted Optics Module integrated with a modified Helmet Integrated Systems Limited HGU-86/P helmet, the Honeywell Advanced Metal Tolerant tracker, and a GEC-Mounted Tolerant tracker, and a GEC- Marconi Avionics Programmable Display Generator. This system will provide a real-time programmable HUD and monocular stroke capable HMD in the front cockpit. The HMD system is designed for growth to stroke-on-video, binocular capability. This paper examines some of issues associated with current HMD development, and explains the value of rapid prototyping or 'quick-look' flight testing on the VISTA NF-16D. A brief overview of the VISTA NF-16D and the hardware and software modifications made to incorporate the programmable display system is give, as well as a review of several key decisions that were made in the programmable display system implementation. The system's capabilities and what they mean to potential users and designers are presented, particularly for pilot-vehicle interface research.

  12. Alcohol consumption, helmet use and head trauma in cycling collisions in Germany. (United States)

    Orsi, Chiara; Ferraro, Ottavia E; Montomoli, Cristina; Otte, Dietmar; Morandi, Anna


    Cycling, being easy, inexpensive and healthy, is becoming one of the most popular means of transport. Cyclists, however, are among the most vulnerable road users in traffic collisions. The aims of this study were to establish which cyclist and cycling accident characteristics are associated with alcohol consumption and helmet use in Germany and to identify risk factors related to head trauma sustained in cycling accidents. The source used for the present analysis was the database of the German in-depth accident study (GIDAS). All cyclists who had been involved in a road accident between 2000 and 2010 and submitted to an alcohol test were selected. Logistic regression analyses were carried out to evaluate various aspects: alcohol consumption, helmet use, head trauma, and cyclist/accident characteristics. Female riders were less likely to have consumed alcohol (OR=0.23, 95% CI: 0.08-0.66); cyclists who did not wear a helmet were more likely to have consumed alcohol (OR=2.41, 95% CI: 1.08-5.38); cyclists who were not responsible for the collision were less likely to have consumed alcohol than those who were partially responsible for the accident (OR=0.22, 95% CI: 0.08-0.61). Cyclists involved in collisions with another vehicle, motorised or not, had a lower risk of suffering a head injury compared with those involved in single-vehicle accidents (OR=0.27, 95% CI: 0.12-0.62, and OR=0.08, 95% CI: 0.03-0.22, respectively). The prevention or limiting of alcohol consumption among cyclists and the corresponding testing of cyclists must be improved. Training initiatives on helmet protection should be encouraged.

  13. Big Bicycle Data Processing: from Personal Data to Urban Applications (United States)

    Pettit, C. J.; Lieske, S. N.; Leao, S. Z.


    Understanding the flows of people moving through the built environment is a vital source of information for the planners and policy makers who shape our cities. Smart phone applications enable people to trace themselves through the city and these data can potentially be then aggregated and visualised to show hot spots and trajectories of macro urban movement. In this paper our aim is to develop procedures for cleaning, aggregating and visualising human movement data and translating this into policy relevant information. In conducting this research we explore using bicycle data collected from a smart phone application known as RiderLog. We focus on the RiderLog application initially in the context of Sydney, Australia and discuss the procedures and challenges in processing and cleaning this data before any analysis can be made. We then present some preliminary map results using the CartoDB online mapping platform where data are aggregated and visualised to show hot spots and trajectories of macro urban movement. We conclude the paper by highlighting some of the key challenges in working with such data and outline some next steps in processing the data and conducting higher volume and more extensive analysis.

  14. How does the edge height of curb ramps obstruct bicycles? (United States)

    Hayashi, Masahiro; Uetake, Teruo; Shimoda, Masahiro


    The aim of this study is to recommend revisions, based on empirical data, to the current curb ramp standards for keeping bicyclists safe. Four types of curb ramps were tested: (1) concrete with a 50 mm edge height, (2) concrete reinforced by a metal plate with a 50 mm edge height, (3) plastic with a 20 mm edge height, and (4) recycled rubber with a 10 mm edge height. Twenty subjects aged 20-60 years ascended the curbs on a bicycle under various conditions. The angles of approach were 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees. Experiments were executed under both wet and dry conditions. We found that when approaching from an angle of 45 degrees or more, all subjects could ascend all ramps under both conditions. From a 15 degrees approach under wet conditions, no subjects ascended the concrete ramps. Some could not ascend at a 15 degrees approach on the concrete ramps in dry conditions, and some could not ascend from a 30 degrees approach on the reinforced concrete ramp in wet conditions. Bicyclists riding on roadways cannot easily ascend a curb ramp with a 50 mm edge, even in dry conditions. We thus recommend that curb ramp edge heights be lower than 50 mm. Keywords: friction coefficient; approach angle

  15. Environmental Determinants of Bicycling Injuries in Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Nicole T. R. Romanow


    Full Text Available This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV or with severe injuries (hospitalized. Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27], intersections (OR 6.89; 95% CI [1.48, 32.14], retail establishments (OR 5.56; 95% CI [1.72, 17.98], and path obstructions (OR 3.83; 95% CI [1.03, 14.25]. Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96] and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82] were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety.

  16. Environmental Determinants of Bicycling Injuries in Alberta, Canada (United States)

    Romanow, Nicole T. R.; Couperthwaite, Amy B.; McCormack, Gavin R.; Nettel-Aguirre, Alberto; Rowe, Brian H.; Hagel, Brent E.


    This study examined environmental risk factors for bicycling injuries, by combining data on bicyclist injuries collected by interviews in the emergency department (ED) with street-level environmental audits of injury locations, capturing path, roadway, safety, land use, and aesthetic characteristics. Cases were bicyclists struck by a motor vehicle (MV) or with severe injuries (hospitalized). Controls were bicyclists who were not hit by a car or those seen and discharged from the ED, matched on time and day of injury. Logistic regression odds ratios (ORs) adjusted for age, sex, peak time, and bicyclist speed with 95% confidence intervals (CIs) were estimated to relate injury risk to environmental characteristics. Factors contributing to MV events included greater traffic volume (OR 5.13; 95% CI [1.44, 18.27]), intersections (OR 6.89; 95% CI [1.48, 32.14]), retail establishments (OR 5.56; 95% CI [1.72, 17.98]), and path obstructions (OR 3.83; 95% CI [1.03, 14.25]). Locations where the road was in good condition (OR 0.25; 95% CI [0.07, 0.96]) and where there was high surveillance from surrounding buildings (OR 0.32; 95% CI [0.13, 0.82]) were associated with less severe injuries. These findings could be used by bicyclists and transportation planners to improve safety. PMID:23251192

  17. On the closure of the extended bicyclic semigroup

    CERN Document Server

    Fihel, Iryna


    In the paper we study the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ which is a generalization of the bicyclic semigroup. We describe main algebraic properties of the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ and prove that every non-trivial congruence $\\mathfrak{C}$ on the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ is a group congruence, and moreover the quotient semigroup $\\mathscr{C}_{\\mathbb{Z}}/\\mathfrak{C}$ is isomorphic to a cyclic group. Also we show that the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ as a Hausdorff semitopological semigroup admits only the discrete topology. Next we study the closure $\\operatorname{cl}_T(\\mathscr{C}_{\\mathbb{Z}})$ of the semigroup $\\mathscr{C}_{\\mathbb{Z}}$ in a topological semigroup $T$. We show that the non-empty remainder of $\\mathscr{C}_{\\mathbb{Z}}$ in a topological inverse semigroup $T$ consists of a group of units $H(1_T)$ of $T$ and a two-sided ideal $I$ of $T$ in the case when $H(1_T)\

  18. Optimization of electric bicycle for youths with disabilities. (United States)

    Blumenstein, Tobias; Zeitlmann, Hilar; Alves-Pinto, Ana; Turova, Varvara; Lampe, Renée


    Cerebral palsy is a group of neurodevelopmental disorders that affect a person's ability to move and to maintain balance and posture. People with cerebral palsy have also perception and space orientation deficits so that special assistance devices should be developed to compensate these handicaps. The objective was to optimize an adapted electric bicycle (E-bike) for youths with neurodevelopmental disorders. An adapted E-bike was provided with ultrasonic sensors that measure distances to objects. If the distance to other objects reduces, an acoustic signal is sent. Additionally, a self-created force plate was fixed on the pedal to evaluate the muscle performances during biking. An experiment with the ultrasound warning system confirmed that acoustic feedback was helpful in avoiding obstacles. The measurement of the blood pressure, the heart frequency and the pedaling force during biking approved that the training condition of the test person can be registered and enables tuning the power of the electric motor to individual requirements. The results demonstrate that an adapted E-bike can be improved to provide better space orientation for people with perceptual disorders and to measure training conditions of patients. Moreover, these enable individual adjustment of the electric motor power to optimize comfort and therapy effect.

  19. Helmet Exhalation Capture System (HECS) Sizing Evaluation for an Advanced Space Suit Portable Life Support System (United States)

    Paul, Heather L.; Waguespack, Glenn M.; Paul, Thomas H.; Conger, Bruce C.


    As part of NASA s initiative to develop an advanced portable life support system (PLSS), a baseline schematic has been chosen that includes gaseous oxygen in a closed circuit ventilation configuration. Supply oxygen enters the suit at the back of the helmet and return gases pass over the astronaut s body to be extracted at the astronaut s wrists and ankles through the liquid cooling and ventilation garment (LCVG). The extracted gases are then treated using a rapid cycling amine (RCA) system for carbon dioxide and water removal and activated carbon for trace gas removal before being mixed with makeup oxygen and reintroduced into the helmet. Thermal control is provided by a suit water membrane evaporator (SWME). As an extension of the original schematic development, NASA evaluated several Helmet Exhalation Capture System (HECS) configurations as alternatives to the baseline. The HECS configurations incorporate the use of full contact masks or non-contact masks to reduce flow requirements within the PLSS ventilation subsystem. The primary scope of this study was to compare the alternatives based on mass and volume considerations; however other design issues were also briefly investigated. This paper summarizes the results of this sizing analysis task.

  20. Computed Tomography is Diagnostic in the Cervical Imaging of Helmeted Football Players With Shoulder Pads (United States)

    Rothman, Michael; Foley, Jack; Heller, Michael


    Objective: Prospective, observational case series evaluating the value of cervical spine computed tomography (CT) scans in the initial evaluation of a helmeted football player with suspected cervical spine injury. Subjects: Five asymptomatic male football players, fully equipped and immobilized on a backboard. Design: Multiple 3.0-mm, helically acquired, axially displayed CT images of the cervical spine were obtained from the skull base inferiorly through T1, with images filmed at soft tissue and bone windows. Sagittal and coronal reformatted images were performed. Software was used to minimize metallic artifact. Measurements: All series were reviewed by a Board-certified neuroradiologist for image clarity and diagnostic capability. Results: Lateral scout films demonstrated mild segmental degradation, depending on the location of the metallic snaps overlying the spine. Anteroposterior scout films and bone window images were of diagnostic quality. The soft tissue windows showed minimal localized artifact occurring at the same levels as in the lateral scout views. This minimal beam-hardening streak artifact did not affect the diagnostic quality of the soft tissue windows. Reconstructed images were uniformly of clinical diagnostic quality. Discussion: When CT scans were reviewed as a unit, sufficient information was available to allow reliable clinical decisions about the helmeted football player. In light of recent publications demonstrating the difficulty of obtaining adequate radiographs to evaluate cervical spine injury in equipped football players, helmeted athletes may undergo CT scanning without any significant diagnostic limitations. PMID:15496989

  1. Virtual MEG Helmet: Computer Simulation of an Approach to Neuromagnetic Field Sampling. (United States)

    Medvedovsky, Mordekhay; Nenonen, Jukka; Koptelova, Alexandra; Butorina, Anna; Paetau, Ritva; Mäkelä, Jyrki P; Ahonen, Antti; Simola, Juha; Gazit, Tomer; Taulu, Samu


    Head movements during an MEG recording are commonly considered an obstacle. In this computer simulation study, we introduce an approach, the virtual MEG helmet (VMH), which employs the head movements for data quality improvement. With a VMH, a denser MEG helmet is constructed by adding new sensors corresponding to different head positions. Based on the Shannon's theory of communication, we calculated the total information as a figure of merit for comparing the actual 306-sensor Elekta Neuromag helmet to several types of the VMH. As source models, we used simulated randomly distributed source current (RDSC), simulated auditory and somatosensory evoked fields. Using the RDSC model with the simulation of 360 recorded events, the total information (bits/sample) was 989 for the most informative single head position and up to 1272 for the VMH (addition of 28.6%). Using simulated AEFs, the additional contribution of a VMH was 12.6% and using simulated SEF only 1.1%. For the distributed and bilateral sources, a VMH can provide a more informative sampling of the neuromagnetic field during the same recording time than measuring the MEG from one head position. VMH can, in some situations, improve source localization of the neuromagnetic fields related to the normal and pathological brain activity. This should be investigated further employing real MEG recordings.

  2. Structural Equation Modelling in Behavioral Intention to Use Safety Helmet Reminder System

    Directory of Open Access Journals (Sweden)

    Rosli Naida


    Full Text Available Motorcycle is one of private transportation which has been widely used in many countries including Malaysia. However, motorcycles are the most dangerous form of motorized transport. Royal Malaysian Police (PDRM statistics recorded that motorcycle is the highest vehicle (45.9% involved in traffic accident compared to other vehicles. The potential cause of the death to the motorcyclist was due to the head injury. One of strategy to mitigate this problem is through proper usage of safety helmet. Therefore, this paper was introduce a new approach on motorcyclist safety by using the Technology Acceptance Model (TAM with additional determinants that contribute to behavioral intention and to increase the proper usage of safety helmets among Malaysian motorcyclists. The Structural Equation Modelling (SEM was used to test the structural TAM proposed. The evaluation for structural model showed the goodness of fit indices are excellent fit. This study found that perceived ease of use, perceived usefulness and social norm are significant towards behavioral intention to use Safety Helmet Reminder System (SHR.

  3. Innovation and the Interrelatedness of Core Competencies: How Taiwan's Giant Bicycles broke into the US Bicycle Market

    Directory of Open Access Journals (Sweden)

    S. Phineas Upham


    Full Text Available I argue that capabilities and barriers to entry are, in certain circumstances, interconnected in such a way that sacrificing one of them can lead to the subsequent vulnerability or erosion of another capability or barrier to entry. I illustrate this through a study of the US bicycle market in the 1980's in general, and Schwinn Corporation and Giant Manufacturing in particular, arguing that both the barriers to entry and the firm capabilities were interrelated. A specific set of decisions by Schwinn had broad and unanticipated effects that went beyond the capacity they explicitly relinquished. In this case manufacturing and distribution were tightly linked in such a way that without some form of tight link between them successful incremental innovation became difficult. Seemingly unrelated capabilities and strengths become mutually reinforcing or interconnected. Instead of being able to choose to add a single capability, or choose to discard one, companies may instead be choosing between sets, groups of interlinked, or patterned capabilities. A seemingly small change may require a major reorganization of other core capabilities that its ostensible status belies.

  4. Latent segmentation based count models: Analysis of bicycle safety in Montreal and Toronto. (United States)

    Yasmin, Shamsunnahar; Eluru, Naveen


    The study contributes to literature on bicycle safety by building on the traditional count regression models to investigate factors affecting bicycle crashes at the Traffic Analysis Zone (TAZ) level. TAZ is a traffic related geographic entity which is most frequently used as spatial unit for macroscopic crash risk analysis. In conventional count models, the impact of exogenous factors is restricted to be the same across the entire region. However, it is possible that the influence of exogenous factors might vary across different TAZs. To accommodate for the potential variation in the impact of exogenous factors we formulate latent segmentation based count models. Specifically, we formulate and estimate latent segmentation based Poisson (LP) and latent segmentation based Negative Binomial (LNB) models to study bicycle crash counts. In our latent segmentation approach, we allow for more than two segments and also consider a large set of variables in segmentation and segment specific models. The formulated models are estimated using bicycle-motor vehicle crash data from the Island of Montreal and City of Toronto for the years 2006 through 2010. The TAZ level variables considered in our analysis include accessibility measures, exposure measures, sociodemographic characteristics, socioeconomic characteristics, road network characteristics and built environment. A policy analysis is also conducted to illustrate the applicability of the proposed model for planning purposes. This macro-level research would assist decision makers, transportation officials and community planners to make informed decisions to proactively improve bicycle safety - a prerequisite to promoting a culture of active transportation.

  5. Assessing the Bicycle Network in St. Louis: A PlaceBased User-Centered Approach

    Directory of Open Access Journals (Sweden)

    Bram Boettge


    Full Text Available To transition towards sustainability and increase low-impact transportation, city planners are integrating bicycle infrastructure in urban landscapes. Yet, this infrastructure only promotes cycling according to how well it is sited within a specific city. How to best site bicycle facilities is essential for sustainability planning. We review approaches to assessing and siting new bicycle facilities. Following sustainability science, we argue that active cyclists should be consulted to incorporate users’ site-specific knowledge into bicycle infrastructure assessments. We then pilot an approach that surveys cyclists concerning level of stress along routes ridden in St. Louis, MO, USA. Among the active cyclists surveyed (n = 89, we found stress correlates with speed limit, roadway classification, and number of lanes. Although cyclists surveyed in St. Louis prefer roads with bike lanes over roads with sharrows or no infrastructure, the presence of bicycle infrastructure had no correlation with reported levels of stress. The piloted survey and spatial analytic tool are transferable to other localities. For planners, the maps generated by this participant data approach identify high-stress routes as targets of new infrastructure or information to direct cyclists to safer routes. For bicyclists, the maps generated identify low-stress routes for recreation and commuting.

  6. Johnson Space Center's Free Range Bicycle Program.- Fall 2015 Intern Report (United States)

    Lee-Stockton, Willem


    NASA's Johnson Space Center is a big place, encompassing 1,620 acres and more than a hundred buildings. Furthermore, there are reportedly 15 thousand employees, all of which have somewhere to be. To facilitate the movement of all these people JSC has historically relied on human power. Pedaling their way towards deep space, bicycles have been the go to method. Currently there are about 200 Free Range Bicycles at JSC. Free Range Bicycles belong to nobody, except NASA, and are available for anybody to use. They are not to be locked or hidden (although frequently are) and the intention is that there will always be a bike to hop on to get where you're going (although it may not be the bike you rode in on). Although not without its own shortcomings, the Free Range Bicycle Program has continued to provide low cost, simple transportation for NASA's JSC. In addition to the approximately 200 Free Range Bicycles, various larger divisions (like engineering) will often buy a few dozen bikes for their team members to use or individuals will bring their own personal bike to either commute or use on site. When these bicycles fall into disrepair or are abandoned (from retirees etc) they become a problem at JSC. They are an eye sore, create a safety hazard and make it harder to find a working bike in a time of need. The Free Range Program hopes to address this first problem by "tagging out" abandoned or out of service bicycles. A bright orange "DO NOT OPERATE" tag is placed on the bike and given a serial number for tracking purposes. See picture to the right. If the bike has an active owner with intentions to repair the bike the bottom of the tag has instructions for how to claim the abandoned bicycle. After being tagged the owner of the bicycle has 30 days to claim the bicycle and either haul it off site or get it repaired (and labeled) in accordance with Johnson's Bicycle Policy. If the abandoned bicycle is not claimed within 30 days it becomes the property of the Government. The

  7. Investigation of Bicycle Travel Time Estimation Using Bluetooth Sensors for Low Sampling Rates

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei


    Full Text Available Filtering the data for bicycle travel time using Bluetooth sensors is crucial to the estimation of link travel times on a corridor. The current paper describes an adaptive filtering algorithm for estimating bicycle travel times using Bluetooth data, with consideration of low sampling rates. The data for bicycle travel time using Bluetooth sensors has two characteristics. First, the bicycle flow contains stable and unstable conditions. Second, the collected data have low sampling rates (less than 1%. To avoid erroneous inference, filters are introduced to “purify” multiple time series. The valid data are identified within a dynamically varying validity window with the use of a robust data-filtering procedure. The size of the validity window varies based on the number of preceding sampling intervals without a Bluetooth record. Applications of the proposed algorithm to the dataset from Genshan East Road and Moganshan Road in Hangzhou demonstrate its ability to track typical variations in bicycle travel time efficiently, while suppressing high frequency noise signals.

  8. Prevalence and evolution of helmet use in motorcycle riders in an Argentine city (Mar del Plata, 2006-2014

    Directory of Open Access Journals (Sweden)

    Jeremías David Tosi


    Full Text Available Traffic collisions involving motorcyclists are a growing problem in low and middle income countries. Helmet use is the foremost protective measure for this group of road users, however many riders do not wear them. The objective of the present study is to report the changes in helmet use during the period 2006-2014 in an Argentine city and discover associated factors for the year 2014. The sample includes more than 6,900 observations of motorcyclists carried out during the years 2006 (n=962, 2008 (n=977, 2012 (n=2,542, and 2014 (n=2,466. The data indicates a progressive increase in helmet use over time, but differences due to gender and type of rider remain. Factors associated to helmet use in motorcycle drivers during 2014 were: passenger helmet use, motorcycle type, license plate use and gender. Although the results are positive, it is necessary to be attentive to the negative consequences of the growing fleet of motorcycles.

  9. Get Wheelin' in Westlawn: Mounting a Bicycling Program in a Low-Income Minority Urban Community

    Directory of Open Access Journals (Sweden)

    Anne Dressel


    Full Text Available Located in Milwaukee, Wisconsin, USA, the Westlawn neighborhood is home to the State of Wisconsin’s largest public housing development. Westlawn is a low-income, African-American urban community that suffers from a wide range of health and environmental disparities. A community-based participatory action (CBPA team was formed to address environmental health issues in Westlawn, and found asthma rates there are among the highest in the State. Decreasing air pollution, and corresponding asthma triggers, became a priority for the community. The CBPA team developed a bicycling program to reduce trips made by car and improve air quality in the Westlawn neighborhood. Input from focus group meetings shaped the development, implementation and expansion of the bicycling program. While the program was originally conceived to address environmental health issues, it provided key findings about how to encourage bicycling in low-income minority urban communities.

  10. Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research

    Directory of Open Access Journals (Sweden)

    Marius Janavičius


    Full Text Available An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Technology” company’s electric front wheel conversion kit MagicPie3 and 16 cell 10Ah LiFePO4 battery. After installation of the engine and other components, experiments were conducted to evaluate the performance characteristics of the electric bike and check the manufacturer’s specifications.

  11. Synthetic strategy for bicyclic tetrapeptides HDAC inhibitors using ring closing metathesis

    Indian Academy of Sciences (India)

    Md Nurul Islam; Md Shahidul Islam; Md Ashraful Hoque; Tamaki Kato; Norikazu Nishino


    Cyclic peptides show diverse biological activities and are considered as good therapeutic agents due to structural rigidity, receptor selectivity and biochemical stability. We have developed bicyclic tetrapeptide HDAC inhibitors based on different cyclic tetrapeptide scaffolds. For the synthesis of these bicyclic tetrapeptides, two cyclization steps, namely, peptide cyclization and fusion of aliphatic side chains by ring closing metathesis (RCM) were involved. In the course of these syntheses, we have established two facts: a lower limit of aliphatic loop length and better synthetic route for bicyclic tetrapeptide synthesis. It was found that nine methylene loop length is the lower limit for aliphatic loop and the synthetic route selection depended on the configuration of amino acids in the cyclic tetrapeptide scaffold. RCM followed by peptide cyclization was the proper route for LDLD configuration and the reverse route was suitable for LLLD configuration.

  12. Study of the health effects of bicycling in an urban atmosphere. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, M.; Weiss, S.; Articola, W.


    This report analyzes data on the health effects of bicycling in an urban environment through intensive study of ten healthy male subjects bicycling or driving in systematically varied conditions in the streets of Washington, D.C. Evaluation criteria for available technology and instrumentation are included and a methodology is developed for route selection. Specific air pollutants (carbon monoxide, ozone, sulfates, nitrates, and particulates) are measured concurrently with exposure and subsequent changes in health status identified through pulmonary function testing, cardiovascular testing, and blood and symptoms analysis. The report concludes that no major adverse short-term health effects were noted for ten healthy male subjects while bicycling or driving in levels of pollution and thermal stress encountered during the study period. Recommendations for further research are also presented.

  13. Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents

    DEFF Research Database (Denmark)

    Carlson, Jordan A.; Saelens, Brian E.; Kerr, Jacqueline;


    Objectives: To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth. Methods: Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density......, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted...... for nesting of days (N=2987) within participants within block groups. Results: Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time...

  14. Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic (United States)

    Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.


    This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

  15. The effects of operating a touch screen smartphone and other common activities performed while bicycling on cycling behaviour

    NARCIS (Netherlands)

    de Waard, Dick; Lewis Evans, Ben; Jelijs, Bart; Tucha, Oliver; Brookhuis, Karel


    Although it has been shown that making phone calls or sending text messages while riding a bicycle can have a negative impact on bicyclist’s behaviour, in countries such as the Netherlands the operation of a mobile phone while cycling on a bicycle is not illegal and is actually quite common. In rece

  16. Mapping cyclist activity and injury risk in a network combining smartphone GPS data and bicycle counts. (United States)

    Strauss, Jillian; Miranda-Moreno, Luis F; Morency, Patrick


    In recent years, the modal share of cycling has been growing in North American cities. With the increase of cycling, the need of bicycle infrastructure and road safety concerns have also raised. Bicycle flows are an essential component in safety analysis. The main objective of this work is to propose a methodology to estimate and map bicycle volumes and cyclist injury risk throughout the entire network of road segments and intersections on the island of Montreal, achieved by combining smartphone GPS traces and count data. In recent years, methods have been proposed to estimate average annual daily bicycle (AADB) volume and injury risk estimates at both the intersection and segment levels using bicycle counts. However, these works have been limited to small samples of locations for which count data is available. In this work, a methodology is proposed to combine short- and long-term bicycle counts with GPS data to estimate AADB volumes along segments and intersections in the entire network. As part of the validation process, correlation is observed between AADB values obtained from GPS data and AADB values from count data, with R-squared values of 0.7 for signalized intersections, 0.58 for non-signalized intersections and between 0.48 and 0.76 for segments with and without bicycle infrastructure. The methodology is also validated through the calibration of safety performance functions using both sources of AADB estimates, from counts and from GPS data. Using the validated AADB estimates, the factors associated with injury risk were identified using data from the entire population of intersections and segments throughout Montreal. Bayesian injury risk maps are then generated and the concentrations of expected injuries and risk at signalized intersections are identified. Signalized intersections, which are often located at the intersection of major arterials, witness 4 times more injuries and 2.5 times greater risk than non-signalized intersections. A similar

  17. Aminocyclopentanols as sugar mimics. Synthesis from unsaturated bicyclic lactones by Overman rearrangement

    DEFF Research Database (Denmark)

    Bøjstrup, Marie; Fanefjord, Mette; Lundt, Inge


    Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta-D-N-acetylglucosaminid......Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta...

  18. Action of bicyclic isoxazole GABA analogues on GABA transporters and its relation to anticonvulsant activity

    DEFF Research Database (Denmark)

    Bolvig, T; Larsson, O M; Pickering, D S;


    The inhibitory action of bicyclic isoxazole gamma-aminobutyric acid (GABA) analogues and their 4,4-diphenyl-3-butenyl (DPB) substituted derivatives has been investigated in cortical neurones and astrocytes as well as in human embryonic kidney (HEK 293) cells transiently expressing either mouse GABA...... anticonvulsant activity, lack of proconvulsant activity and the ability of THPO to increase extracellular GABA concentration, indicate that these bicyclic isoxazole GABA analogues and their DPB derivatives may be useful lead structures in future search for new antiepileptic drugs....

  19. The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material




    [EN] ABSTRACT Nicholas Brent Taylor: The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material The bicycle is often considered as one of the most important inventions of all time. In addition, it is the most efficient form of human transport in the world. It is non pollutant, uses no fuel other than human power and its carbon footprint is neutralised in a short time. Today, faced with the threat of global warming brought about by fossil fuels, countries such as De...

  20. Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders. (United States)

    Langford, Brian Casey; Chen, Jiaoli; Cherry, Christopher R


    As electric bicycles (e-bikes) have emerged as a new transportation mode, their role in transportation systems and their impact on users have become important issues for policy makers and engineers. Little safety-related research has been conducted in North America or Europe because of their relatively small numbers. This work describes the results of a naturalistic GPS-based safety study between regular bicycle (i.e., standard bicycle) and e-bike riders in the context of a unique bikesharing system that allows comparisons between instrumented bike technologies. We focus on rider safety behavior under four situations: (1) riding in the correct direction on directional roadway segments, (2) speed on on-road and shared use paths, (3) stopping behavior at stop-controlled intersections, and (4) stopping behavior at signalized intersections. We find that, with few exceptions, riders of e-bike behave very similarly to riders of bicycles. Violation rates were very high for both vehicles. Riders of regular bicycles and e-bikes both ride wrong-way on 45% and 44% of segments, respectively. We find that average on-road speeds of e-bike riders (13.3kph) were higher than regular bicyclists (10.4kph) but shared use path (greenway) speeds of e-bike riders (11.0kph) were lower than regular bicyclists (12.6kph); both significantly different at >95% confidence. At stop control intersections, both bicycle and e-bike riders violate the stop signs at the similar rate with bicycles violating stop signs at a slightly higher rate at low speed thresholds (∼80% violations at 6kph, 40% violations at 11kph). Bicycles and e-bikes violate traffic signals at similar rates (70% violation rate). These findings suggest that, among the same population of users, e-bike riders exhibit nearly identical safety behavior as regular bike riders and should be regulated in similar ways. Users of both technologies have very high violation rates of traffic control devices and interventions should occur to

  1. Orthogonal ring-closing alkyne and olefin metathesis for the synthesis of small GTPase-targeting bicyclic peptides. (United States)

    Cromm, Philipp M; Schaubach, Sebastian; Spiegel, Jochen; Fürstner, Alois; Grossmann, Tom N; Waldmann, Herbert


    Bicyclic peptides are promising scaffolds for the development of inhibitors of biological targets that proved intractable by typical small molecules. So far, access to bioactive bicyclic peptide architectures is limited due to a lack of appropriate orthogonal ring-closing reactions. Here, we report chemically orthogonal ring-closing olefin (RCM) and alkyne metathesis (RCAM), which enable an efficient chemo- and regioselective synthesis of complex bicyclic peptide scaffolds with variable macrocycle geometries. We also demonstrate that the formed alkyne macrocycle can be functionalized subsequently. The orthogonal RCM/RCAM system was successfully used to evolve a monocyclic peptide inhibitor of the small GTPase Rab8 into a bicyclic ligand. This modified peptide shows the highest affinity for an activated Rab GTPase that has been reported so far. The RCM/RCAM-based formation of bicyclic peptides provides novel opportunities for the design of bioactive scaffolds suitable for the modulation of challenging protein targets.

  2. The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia. (United States)

    Walter, Scott R; Olivier, Jake; Churches, Tim; Grzebieta, Raphael


    The study aimed to assess the effect of compulsory cycle helmet legislation on cyclist head injuries given the ongoing debate in Australia as to the efficacy of this measure at a population level. We used hospital admissions data from New South Wales, Australia, from a 36 month period centred at the time legislation came into effect. Negative binomial regression of hospital admission counts of head and limb injuries to cyclists were performed to identify differential changes in head and limb injury rates at the time of legislation. Interaction terms were included to allow different trends between injury types and pre- and post-law time periods. To avoid the issue of lack of cyclist exposure data, we assumed equal exposures between head and limb injuries which allowed an arbitrary proxy exposure to be used in the model. As a comparison, analyses were also performed for pedestrian data to identify which of the observed effects were specific to cyclists. In general, the models identified a decreasing trend in injury rates prior to legislation, an increasing trend thereafter and a drop in rates at the time legislation was enacted, all of which were thought to represent background effects in transport safety. Head injury rates decreased significantly more than limb injury rates at the time of legislation among cyclists but not among pedestrians. This additional benefit was attributed to compulsory helmet legislation. Despite numerous data limitations, we identified evidence of a positive effect of compulsory cycle helmet legislation on cyclist head injuries at a population level such that repealing the law cannot be justified.

  3. Flight performance using a hyperstereo helmet-mounted display: aircraft handling (United States)

    Jennings, Sion A.; Craig, Gregory L.; Stuart, Geoffrey W.; Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.


    A flight study was conducted to assess the impact of hyperstereopsis on helicopter handling proficiency, workload and pilot acceptance. Three pilots with varying levels of night vision goggle and hyperstereo helmet-mounted display experience participated in the test. The pilots carried out a series of flights consisting of low-level maneuvers over a period of two weeks. Four of the test maneuvers, The turn around the tail, the hard surface landing, the hover height estimation and the tree-line following were analysed in detail. At the end of the testing period, no significant difference was observed in the performance data, between maneuvers performed with the TopOwl helmet and maneuvers performed with the standard night vision goggle. This study addressed only the image intensification display aspects of the TopOwl helmet system. The tests did not assess the added benefits of overlaid symbology or head slaved infrared camera imagery. These capabilities need to be taken into account when assessing the overall usefulness of the TopOwl system. Even so, this test showed that pilots can utilize the image intensification imagery displayed on the TopOwl to perform benign night flying tasks to an equivalent level as pilots using ANVIS. The study should be extended to investigate more dynamic and aggressive low level flying, slope landings and ship deck landings. While there may be concerns regarding the effect of hyperstereopsis on piloting, this initial study suggests that pilots can either adapt or compensate for hyperstereo effects with sufficient exposure and training. Further analysis and testing is required to determine the extent of training required.

  4. Impact response of US Army and National Football League helmet pad systems

    Energy Technology Data Exchange (ETDEWEB)

    Moss, W C; King, M J


    Lawrence Livermore National Laboratory [LLNL] was tasked to compare the impact response of NFL helmet pad systems and U.S. Army pad systems compatible with an Advanced Combat Helmet [ACH] at impact velocities up to 20 ft/s. This was a one-year study funded by the U.S. Army and JIEDDO. The Army/JIEDDO point of contact is COL R. Todd Dombroski, DO, JIEDDO Surgeon. LLNL was chosen by committee to perform the research based on prior published computational studies of the mechanical response of helmets and skulls to blast. Our collaborators include the U.S. Army Aeromedical Research Laboratory [USAARL] (a DoD laboratory responsible for impact testing helmets), Team Wendy and Oregon Aero (current and former ACH pad manufacturers), Riddell and Xenith (NFL pad manufacturers), and d3o (general purpose sports pad manufacturer). The manufacturer-supplied pad systems that were studied are shown in the figure below. The first two are the Army systems, which are bilayer foam pads with both hard and soft foam and a water-resistant airtight wrapper (Team Wendy) or a water-resistant airtight coating (Oregon Aero). The next two are NFL pad systems. The Xenith system consists of a thin foam pad and a hollow air-filled cylinder that elastically buckles under load. The Riddell system is a bilayer foam pad that is encased in an inflatable airbag with relief channels to neighboring pads in the helmet. The inflatable airbag is for comfort and provides no enhancement to impact mitigation. The d3o system consists of a rate-sensitive homogeneous dense foam. LLNL performed experiments to characterize the material properties of the individual foam materials and the response of the complete pad systems, to obtain parameters needed for the simulations. LLNL also performed X-ray CT scans of an ACH helmet shell that were used to construct a geometrically accurate computational model of the helmet. Two complementary sets of simulations were performed. The first set of simulations reproduced the

  5. Target detection performance in helmet-mounted and conventional dome displays. (United States)

    Hettinger, L J; Nelson, W T; Haas, M W


    An experiment was conducted to assess visual target detection performance using a helmet-mounted display (HMD) and a conventional flight simulation dome display. Measures of workload and mood were also obtained. Participants in both viewing conditions scanned an area 120 degrees vertical by 240 degrees horizontal while attempting to locate targets that appeared to be approaching them from one of a possible 18 locations. Results indicated significantly superior performance in the conventional dome display. Workload and mood measures also showed a significant advantage for the dome display. Results are discussed in terms of their implications for the design and use of HMD systems as components of airborne virtual environment interfaces.

  6. Health studies on a group of captive helmeted guineafowl (Numida meleagris) in Tanzania. (United States)

    Cooper, J E; Max, R A; Mbassa, G K


    A small group of housed helmeted guineafowl (Numida meleagris) was studied over a 6-week period. Blood samples were taken on three occasions and basic haematology was performed. Clinical examination of the birds revealed a number of abnormalities including bumblefoot, inflammatory lesions on the wings and body, impaction of the preen gland and traumatic injuries. Supporting laboratory tests provided further information on the aetiology and pathogenesis of some of these disorders. Four birds died during the study: postmortem findings included oviductitis and septicaemia, visceral gout and nephropathy. Virological investigations were not carried out. The importance, when keeping guineafowl, of good husbandry, including regular handling and examination, is stressed.

  7. Development of an aviator's helmet-mounted night-vision goggle system (United States)

    Wilson, Gerry H.; McFarlane, Robert J.


    Helmet Mounted Systems (HMS) must be lightweight, balanced and compatible with life support and head protection assemblies. This paper discusses the design of one particular HMS, the GEC Ferranti NITE-OP/NIGHTBIRD aviator's Night Vision Goggle (NVG) developed under contracts to the Ministry of Defence for all three services in the United Kingdom (UK) for Rotary Wing and fast jet aircraft. The existing equipment constraints, safety, human factor and optical performance requirements are discussed before the design solution is presented after consideration of these material and manufacturing options.

  8. Traumatic tentorial hematoma in two-wheeler riders: Correlation with helmet use (United States)

    Agrawal, Deepak; Dawar, Pankaj


    Background: Tentorial hematoma is frequently seen in traumatic brain injury (TBI) patients, especially in motorized two-wheeler riders following head injury. However its relevance and prognostic significance are not known. Objective: To evaluate patients of TBI with tentorial hematoma using a simple grading system and attempt to correlate this grading with factors like helmet use and neurological outcome. Materials and Methods: This prospective study over a 1-year period included patients with TBI who had tentorial hematoma in the initial plain head. Patients were divided into three grades based on the initial CT findings: Grade I: Isolated tentorial hematoma, grade II: tentorial hematoma with midline shift but open cisterns and grade III: Tentorial hematoma with effaced cisterns. Clinical and radiological records of patients including admission GCS and GOS at discharge were assessed in all cases. Observations: A total of 1786 patients of TBI were admitted during the study period. Of these, 106 (5.9%) patients had tentorial hematoma. 84.9% (n = 90) were male and 15.1% (n = 16) were female with the mean age being 36.5 years (range 2-66 years). The mean admission GCS was 13, 11 and 8 in patients with grade I, II and III tentorial hematoma respectively. 43.4% (n = 46) of the patients had grade I, 32.1% (n = 34) had grade II and 24.5% (n = 26) patients had grade III tentorial hematoma. Seventy-one patients (84.5%) were riding motorized two wheelers with 63 (89%) wearing helmets. The majority of the patients wearing helmets (58.8%) had grade I hematoma with 35% (n = 22) having grade II hematoma and only 6.3% (n = 4) having grade III hematoma. Overall, there were 20 deaths. 50% (n = 10) of the deaths were in patients with grade III hematoma and 40% (n = 8) of the deaths were in patients with grade II hematoma. There were two (10%) deaths in patients with grade I hematoma (both unrelated to head injury). The mean GOS at the time of discharge was 5, 4.1 and 2.2 in patients

  9. Impact response of US Army and National Football League helmet pad systems

    Energy Technology Data Exchange (ETDEWEB)

    Moss, W C; King, M J


    Lawrence Livermore National Laboratory [LLNL] was tasked to compare the impact response of NFL helmet pad systems and U.S. Army pad systems compatible with an Advanced Combat Helmet [ACH] at impact velocities up to 20 ft/s. This was a one-year study funded by the U.S. Army and JIEDDO. The Army/JIEDDO point of contact is COL R. Todd Dombroski, DO, JIEDDO Surgeon. LLNL was chosen by committee to perform the research based on prior published computational studies of the mechanical response of helmets and skulls to blast. Our collaborators include the U.S. Army Aeromedical Research Laboratory [USAARL] (a DoD laboratory responsible for impact testing helmets), Team Wendy and Oregon Aero (current and former ACH pad manufacturers), Riddell and Xenith (NFL pad manufacturers), and d3o (general purpose sports pad manufacturer). The manufacturer-supplied pad systems that were studied are shown in the figure below. The first two are the Army systems, which are bilayer foam pads with both hard and soft foam and a water-resistant airtight wrapper (Team Wendy) or a water-resistant airtight coating (Oregon Aero). The next two are NFL pad systems. The Xenith system consists of a thin foam pad and a hollow air-filled cylinder that elastically buckles under load. The Riddell system is a bilayer foam pad that is encased in an inflatable airbag with relief channels to neighboring pads in the helmet. The inflatable airbag is for comfort and provides no enhancement to impact mitigation. The d3o system consists of a rate-sensitive homogeneous dense foam. LLNL performed experiments to characterize the material properties of the individual foam materials and the response of the complete pad systems, to obtain parameters needed for the simulations. LLNL also performed X-ray CT scans of an ACH helmet shell that were used to construct a geometrically accurate computational model of the helmet. Two complementary sets of simulations were performed. The first set of simulations reproduced the

  10. Building the fastest bicycle in the world; a year with the Human Power Team Delft & Amsterdam

    NARCIS (Netherlands)

    Schuurman, M.; Roks, G.


    “Third time lucky” is the saying, but for the third Human Power Team it almost turned out as a year for nothing. The team has been attempting to set the world record for the fastest bicycle powered only by human muscles for two years already. This endeavor to let a Dutchman be the fastest human on e

  11. Bicyclic and tricyclic heterocycle derivatives as histamine H3 receptor antagonists for the treatment of obesity. (United States)

    de Lera Ruiz, Manuel; Zheng, Junying; Berlin, Michael Y; McCormick, Kevin D; Aslanian, Robert G; West, Robert; Hwa, Joyce; Lachowicz, Jean; van Heek, Margaret


    A novel series of non-imidazole bicyclic and tricyclic histamine H3 receptor antagonists has been discovered. Compound 17 was identified as a centrally penetrant molecule with high receptor occupancy which demonstrates robust oral activity in rodent models of obesity. In addition compound 17 possesses clean CYP and hERG profiles and shows no behavioral changes in the Irwin test.

  12. Use of automated video analysis for the evaluation of bicycle movement and interaction (United States)

    Twaddle, Heather; Schendzielorz, Tobias; Fakler, Oliver; Amini, Sasan


    With the purpose of developing valid models of microscopic bicycle behavior, a large quantity of video data is collected at three busy urban intersections in Munich, Germany. Due to the volume of data, the manual processing of this data is infeasible and an automated or semi-automated analysis method must be implemented. An open source software, "Traffic Intelligence", is used and extended to analyze the collected video data with regard to research questions concerning the tactical behavior of bicyclists. In a first step, the feature detection parameters, the tracking parameters and the object grouping parameters are calibrated, making it possible to accurately track and group the objects at intersections used by large volumes of motor vehicles, bicycles and pedestrians. The resulting parameters for the three intersections are presented. A methodology for the classification of road users as cars, bicycles or pedestrians is presented and evaluated. This is achieved by making hypotheses about which features belong to cars, or bicycles and pedestrians, and using grouping parameters specified for that road user group to cluster the features into objects. These objects are then classified based on their dynamic characteristics. A classification structure for the maneuvers of different road users is presented and future applications are discussed.

  13. Bicycle fatalities : trends in crashes with and without motor vehicles in The Netherlands.

    NARCIS (Netherlands)

    Schepers, P. Stipdonk, H.L. Methorst, R. & Olivier, J.


    Boufous and Olivier (2015) recently found an increasing trend of police-reported cyclist deaths in single-vehicle crashes while a decreasing trend was found for fatal bicycle-motor vehicle crashes. This study sets out to conduct the same trend analyses for the Netherlands using causes of death stati

  14. Balance and control of a rear-wheel steered speed-record recumbent bicycle

    NARCIS (Netherlands)

    Schwab, A.L.; Kooijman, J.D.G.


    The goal of the Human Power Team from the TU Delft and the Free University of Amsterdam is to break the world speed record in unpaced cycling (Sam Whittingham, 133.28 km/h). The design of such a faired recumbent bicycle is a challenge. The Delft design, called VeloX (Human Power Team (2013)), is a f

  15. Design of an aluminium bicycle path integrated in a steel bridge

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Burggraaf, H.G.


    This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of alumin

  16. Effect of Toe Clips During Bicycle Ergometry on VO2 max. (United States)

    Moffat, Roger S.; Sparling, Phillip B.


    Eight men participated in three randomized maximal oxygen uptake tests to investigate the hypothesis that the use of toe clips on bicycle ergometers produced a higher VO2 max. No significant difference in mean VO2 max or performance time was observed. (Author/MT)

  17. Environmental and social life cycle assessment of bamboo bicycle frames made in Ghana

    NARCIS (Netherlands)

    Agyekum, Eric Ofori; Fortuin, K.P.J.; Harst-Wintraecken, van der E.J.M.


    This case study assessed the environmental and social impact of bicycle frames made from wild Ghanaian bamboo. The environmental life cycle assessment (LCA) of the bamboo frame was compared to the LCA results of an aluminium frame and a steel frame. The results show that the overall environmental im

  18. Environmental and social life cycle assessment of bamboo bicycle frames made in Ghana

    NARCIS (Netherlands)

    Agyekum, Eric Ofori; Fortuin, K.P.J.; Harst-Wintraecken, van der E.J.M.


    This case study assessed the environmental and social impact of bicycle frames made from wild Ghanaian bamboo. The environmental life cycle assessment (LCA) of the bamboo frame was compared to the LCA results of an aluminium frame and a steel frame. The results show that the overall environmental im

  19. Responses to kayak ergometer performance after kayak and bicycle ergometer training. (United States)

    Ridge, B R; Pyke, F S; Roberts, A D


    Ten moderately active male volunteers, age 19-30 years, completed one month of training on either a kayak or a bicycle ergometer (five men in each group). The men completed sixteen 30 minute sessions of continuous work at an intensity which maintained their HR within 85-90% of its maximum, as previously determined on the kayak ergometer. After this training period the kayak group demonstrated significant decreases in VO2, VE, HR and blood lactate in submaximal kayak ergometer work and a significant increase in VO2 during maximal kayak ergometer work. These changes contributed to a significantly higher maximal kayaking work output. The bicycle-trained group did not make any of these improvements on the kayak ergometer. However in their last training session on the bicycle ergometer they were able to work at a higher submaximal load while maintaining the same heart rate as in the first training session. It was concluded that the circulatory and metabolic adjustments to kayak work are greater with kayak training than with bicycle training.

  20. Synthesis of bicyclic guanidines via cascade hydroamination/Michael additions of mono-N-acryloylpropargylguanidines. (United States)

    Kwon, Ki-Hyeok; Serrano, Catherine M; Koch, Michael; Barrows, Louis R; Looper, Ryan E


    A cascade silver(I)-catalyzed hydroamination/Michael addition sequence has been developed to deliver highly substituted bicyclic guanidines. This transformation gives rise to geometrically and constitutionally stable ene-guanidines and generates a remote stereocenter with moderate to high diastereoselectivity.

  1. Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks

    NARCIS (Netherlands)

    Schepers, Paul; Heinen, Eva; Methorst, Rob; Wegman, Fred


    Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch urba

  2. Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks.

    NARCIS (Netherlands)

    Schepers, P. Heinen, E. Methorst, R. & Wegman, F.


    Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch urba

  3. The Bicycle Illusion: Sidewalk Science Informs the Integration of Motion and Shape Perception (United States)

    Masson, Michael E. J.; Dodd, Michael D.; Enns, James T.


    The authors describe a new visual illusion first discovered in a natural setting. A cyclist riding beside a pair of sagging chains that connect fence posts appears to move up and down with the chains. In this illusion, a static shape (the chains) affects the perception of a moving shape (the bicycle), and this influence involves assimilation…

  4. On a finite group having a normal series whose factors have bicyclic Sylow subgroups

    CERN Document Server

    Monakhov, V S


    We consider the structure of a finite groups having a normal series whose factors have bicyclic Sylow subgroups. In particular, we investigated groups of odd order and $A_4$-free groups with this property. Exact estimations of the derived length and nilpotent length of such groups are obtained.

  5. A New Method for Computing the Centre of Mass of a Bicycle and Rider (United States)

    Yizhaq, Hezi; Baran, Gil


    For developing riding skills on mountain bikes, it is important to know how the centre of mass of a bicycle and its rider changes with ground inclination or with rider position. We show here a new method for finding the location of this point by measuring the normal forces acting on the wheels in two positions with a digital weight indicator. This…

  6. Tertiary Student Attitudes to Bicycle Commuting in a Regional Australian University (United States)

    Whannell, Patricia; Whannell, Robert; White, Richard


    Purpose: The purpose of this paper is to provide executive management at a regional university with empirical data to justify, or otherwise, a substantial outlay of funds to support bicycle commuting as a viable strategy for the reduction of traffic congestion. Design/methodology/approach: A custom designed questionnaire was completed by 270…

  7. Macroscopic modeling of pedestrian and bicycle crashes: A cross-comparison of estimation methods. (United States)

    Amoh-Gyimah, Richard; Saberi, Meead; Sarvi, Majid


    The paper presents a cross-comparison of different estimation methods to model pedestrian and bicycle crashes. The study contributes to macro level safety studies by providing further methodological and empirical evidence on the various factors that influence the frequency of pedestrian and bicycle crashes at the planning level. Random parameter negative binomial (RPNB) models are estimated to explore the effects of various planning factors associated with total, serious injury and minor injury crashes while accounting for unobserved heterogeneity. Results of the RPNB models were compared with the results of a non-spatial negative binomial (NB) model and a Poisson-Gamma-CAR model. Key findings are, (1) the RPNB model performed best with the lowest mean absolute deviation, mean squared predicted error and Akaiki information criterion measures and (2) signs of estimated parameters are consistent if these variables are significant in models with the same response variables. We found that vehicle kilometers traveled (VKT), population, percentage of commuters cycling or walking to work, and percentage of households without motor vehicles have a significant and positive correlation with the number of pedestrian and bicycle crashes. Mixed land use is also found to have a positive association with the number of pedestrian and bicycle crashes. Results have planning and policy implications aimed at encouraging the use of sustainable modes of transportation while ensuring the safety of pedestrians and cyclist.

  8. The Effects of Prompting and Reinforcement on Safe Behavior of Bicycle and Motorcycle Riders (United States)

    Okinaka, Takeru; Shimazaki, Tsuneo


    A reversal design was used to evaluate the effects of vocal and written prompts as well as reinforcement on safe behavior (dismounting and walking bicycles or motorcycles on a sidewalk) on a university campus. Results indicated that an intervention that consisted of vocal and written prompts and reinforcement delivered by security guards was…

  9. The Synthesis of cis- and trans-Fused Bicyclic Sugar Amino Acids

    NARCIS (Netherlands)

    Risseeuw, Martijn D.P.; Grotenbreg, Gijsbert M.; Witte, Martin D.; Tuin, Adriaan W.; Leeuwenburgh, Michiel A.; Marel, Gijsbert A. van der; Overkleeft, Herman S.; Overhand, Mark


    Four isomeric bicyclic sugar amino acids (SAAs) were prepared from an α-acetylenic-C-glucoside by employing a Petasis olefination and a ring-closing metathesis (RCM) as key steps. The applicability of the resulting SAAs in solid-phase peptide synthesis was demonstrated by the synthesis of a tetrapep

  10. A description of bicycle and moped rider accidents aimed to indicate priorities for injury prevention research.

    NARCIS (Netherlands)

    Huijbers, J.J.W.


    The aim of the study is to indicate priorities in the field of bicycle and moped injury prevention research, based on criteria given. The study is a part of a preparation for a SWOV accident investigation project that has to identify and to gratify factors influencing injuries of pedestrians, cyclis

  11. [Changes in ECG indicators during bicycle ergometry in patients having suffered myocardial infarction]. (United States)

    Kheifets, Z N


    Altogether 218 patients with a history of myocardial infarction were subjected to bicycle ergometry. The ECG recorded at the height of the exercise showed a significant increase in the heart rate and in the amplitudes of P and R waves. The diastole and electric systole shortened. As the load was raised, the rate of A-B conduction was relatively decelerated.

  12. Modeling Mixed Bicycle Traffic Flow: A Comparative Study on the Cellular Automata Approach

    Directory of Open Access Journals (Sweden)

    Dan Zhou


    Full Text Available Simulation, as a powerful tool for evaluating transportation systems, has been widely used in transportation planning, management, and operations. Most of the simulation models are focused on motorized vehicles, and the modeling of nonmotorized vehicles is ignored. The cellular automata (CA model is a very important simulation approach and is widely used for motorized vehicle traffic. The Nagel-Schreckenberg (NS CA model and the multivalue CA (M-CA model are two categories of CA model that have been used in previous studies on bicycle traffic flow. This paper improves on these two CA models and also compares their characteristics. It introduces a two-lane NS CA model and M-CA model for both regular bicycles (RBs and electric bicycles (EBs. In the research for this paper, many cases, featuring different values for the slowing down probability, lane-changing probability, and proportion of EBs, were simulated, while the fundamental diagrams and capacities of the proposed models were analyzed and compared between the two models. Field data were collected for the evaluation of the two models. The results show that the M-CA model exhibits more stable performance than the two-lane NS model and provides results that are closer to real bicycle traffic.

  13. Sandia bicycle commuters group -- pollution prevention at Sandia National Laboratories, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Wrons, R.


    The Sandia Bicycle Commuters Group (SBCG) formed three years ago for the purpose of addressing issues that impact the bicycle commuting option. The meeting that launched the SBCG was scheduled in conjunction with National Bike-to-Work day in May 1995. Results from a survey handed out at the meeting solidly confirmed the issues and that an advocacy group was needed. The purpose statement for the Group headlines its web site and brochure: ``Existing to assist and educate the SNL workforce bicyclist on issues regarding Kirtland Air Force Base (KAFB) access, safety and bicycle-supporting facilities, in order to promote bicycling as an effective and enjoyable means of commuting.`` The SNL Pollution Prevention (P2) Team`s challenge to the SNL workforce is to ``prevent pollution, conserve natural resources, and save money``. In the first winter of its existence, the SBCG sponsored a winter commute contest in conjunction with the City`s Clean Air Campaign (CAC). The intent of the CAC is to promote alternative (to the single-occupant vehicle) commuting during the Winter Pollution Advisory Period (October 1--February 28), when the City runs the greatest risk of exceeding federal pollution limits.

  14. 75 FR 27734 - Agency Information Collection Activities; Proposed Collection; Comment Request; Safety Standard... (United States)


    ... manufacture or import bicycle helmets subject to the standard. There are an estimated 200 different models of... for Bicycle Helmets AGENCY: Consumer Product Safety Commission. ACTION: Notice. SUMMARY: The Consumer... of bicycle helmets. DATES: Submit written or electronic comments on the collection of information...

  15. 75 FR 53680 - Agency Information Collection Activities; Submission for Office of Management and Budget Review... (United States)


    ... follows. Approximately 30 firms manufacture or import bicycle helmets subject to the standard. There are...; Comment Request; Safety Standard for Bicycle Helmets AGENCY: Consumer Product Safety Commission. . Written comments should be captioned ``Safety Standard for Bicycle Helmets.''...


    Directory of Open Access Journals (Sweden)

    Pinar Arpinar-Avsar


    Full Text Available On the bicycle, the human upper extremity has two essential functions in steering the bicycle and in supporting the body. Through the handlebar, surface- induced loads are transmitted to the hand and arm of the bicycle rider under vibration exposure conditions. Thus, the purpose of the study was to investigate the effect of vibration exposure on forearm muscle activity for different road surfaces (i.e. smooth road, concrete stone pavement, rough road and for different bicycles. Ten subjects participated in experiments and two types of bicycles, i.e. Road Bike (RB and Mountain Bike (MTB are compared. The acceleration magnitudes were dominant along x and z-axes. The r.m.s acceleration values in the z direction at the stem of MTB were at most 2.56, 7.04 and 10.76 m·s-2 when pedaling respectively on asphalt road, concrete pavement and rough road. In the case of RB the corresponding values were respectively 4.43, 11.75 and 27.31 m·s-2. The cumulative normalized muscular activity levels during MTB trials on different surfaces had the same tendency as with acceleration amplitudes and have ranked in the same order from lowest to highest value. Although road bike measurements have resulted in a similar trend of increment, the values computed for rough road trials were higher than those in MTB trials. During rough road measurements on MTB, rmsEMG of extensor muscles reached a value corresponding to approximately 50% of MVC (Maximum Voluntary Contraction. During RB trials performed on rough road conditions, rmsEMG (%MVC values for the forearm flexor muscles reached 45.8% of their maximal. The level of muscular activity of forearm muscles in controlling handlebar movements has been observed to be enhanced by the increase in the level of vibration exposed on the bicycle. Since repeated forceful gripping and pushing forces to a handle of a vibratory tool can create a risk of developing circulatory, neurological, or musculoskeletal disorder, a bicycle rider

  17. Visual field information in Nap-of-the-Earth flight by teleoperated Helmet-Mounted displays (United States)

    Grunwald, Arthur J.; Kohn, S.; Merhav, S. J.


    The human ability to derive Control-Oriented Visual Field Information from teleoperated Helmet-Mounted displays in Nap-of-the-Earth flight, is investigated. The visual field with these types of displays originates from a Forward Looking Infrared Radiation Camera, gimbal-mounted at the front of the aircraft and slaved to the pilot's line-of-sight, to obtain wide-angle visual coverage. Although these displays are proved to be effective in Apache and Cobra helicopter night operations, they demand very high pilot proficiency and work load. Experimental work presented in the paper has shown that part of the difficulties encountered in vehicular control by means of these displays can be attributed to the narrow viewing aperture and head/camera slaving system phase lags. Both these shortcomings will impair visuo-vestibular coordination, when voluntary head rotation is present. This might result in errors in estimating the Control-Oriented Visual Field Information vital in vehicular control, such as the vehicle yaw rate or the anticipated flight path, or might even lead to visuo-vestibular conflicts (motion sickness). Since, under these conditions, the pilot will tend to minimize head rotation, the full wide-angle coverage of the Helmet-Mounted Display, provided by the line-of-sight slaving system, is not always fully utilized.

  18. A versatile photogrammetric camera automatic calibration suite for multispectral fusion and optical helmet tracking (United States)

    de Villiers, Jason; Jermy, Robert; Nicolls, Fred


    This paper presents a system to determine the photogrammetric parameters of a camera. The lens distortion, focal length and camera six degree of freedom (DOF) position are calculated. The system caters for cameras of different sensitivity spectra and fields of view without any mechanical modifications. The distortion characterization, a variant of Brown's classic plumb line method, allows many radial and tangential distortion coefficients and finds the optimal principal point. Typical values are 5 radial and 3 tangential coefficients. These parameters are determined stably and demonstrably produce superior results to low order models despite popular and prevalent misconceptions to the contrary. The system produces coefficients to model both the distorted to undistorted pixel coordinate transformation (e.g. for target designation) and the inverse transformation (e.g. for image stitching and fusion) allowing deterministic rates far exceeding real time. The focal length is determined to minimise the error in absolute photogrammetric positional measurement for both multi camera systems or monocular (e.g. helmet tracker) systems. The system determines the 6 DOF position of the camera in a chosen coordinate system. It can also determine the 6 DOF offset of the camera relative to its mechanical mount. This allows faulty cameras to be replaced without requiring a recalibration of the entire system (such as an aircraft cockpit). Results from two simple applications of the calibration results are presented: stitching and fusion of the images from a dual-band visual/ LWIR camera array, and a simple laboratory optical helmet tracker.

  19. Determining the Optimal Layout Design for Public Bicycle System within the Attractive Scope of a Metro Station

    Directory of Open Access Journals (Sweden)

    Jingxu Chen


    Full Text Available Public bicycle acts as a seamless feeder mode in combination with the citywide public transit, as well as a competitor for the inner-city short trips. The primary objective of this study is to address the layout planning of public bicycle system within the attracted scope of a metro station. Based on the land use function, population, and bicycle mode share, bicycle rental stations are divided into three types, namely, the metro station, district station, and resident station, and later the quantity of bicycle facilities in each rental station is estimated. Then, the service stations are selected from these bicycle rental stations to provide the service of periodical bicycle redistribution. An improved immune algorithm is proposed to determine the number and locations of service stations and the optimal route options for the implement of redistributing strategy. Finally, a case study of Nanjing Tianyin Road metro station is conducted to illustrate the proposed model and clarify some of its implementation details.

  20. 16 CFR 1203.32 - Definitions. (United States)


    ... STANDARD FOR BICYCLE HELMETS Certification § 1203.32 Definitions. The following definitions shall apply to this subpart: (a) Foreign manufacturer means an entity that manufactured a bicycle helmet outside the... manufactured a helmet in the United States or imported a helmet manufactured outside the United States....

  1. Using data mining techniques to predict the severity of bicycle crashes. (United States)

    Prati, Gabriele; Pietrantoni, Luca; Fraboni, Federico


    To investigate the factors predicting severity of bicycle crashes in Italy, we used an observational study of official statistics. We applied two of the most widely used data mining techniques, CHAID decision tree technique and Bayesian network analysis. We used data provided by the Italian National Institute of Statistics on road crashes that occurred on the Italian road network during the period ranging from 2011 to 2013. In the present study, the dataset contains information about road crashes occurred on the Italian road network during the period ranging from 2011 to 2013. We extracted 49,621 road accidents where at least one cyclist was injured or killed from the original database that comprised a total of 575,093 road accidents. CHAID decision tree technique was employed to establish the relationship between severity of bicycle crashes and factors related to crash characteristics (type of collision and opponent vehicle), infrastructure characteristics (type of carriageway, road type, road signage, pavement type, and type of road segment), cyclists (gender and age), and environmental factors (time of the day, day of the week, month, pavement condition, and weather). CHAID analysis revealed that the most important predictors were, in decreasing order of importance, road type (0.30), crash type (0.24), age of cyclist (0.19), road signage (0.08), gender of cyclist (0.07), type of opponent vehicle (0.05), month (0.04), and type of road segment (0.02). These eight most important predictors of the severity of bicycle crashes were included as predictors of the target (i.e., severity of bicycle crashes) in Bayesian network analysis. Bayesian network analysis identified crash type (0.31), road type (0.19), and type of opponent vehicle (0.18) as the most important predictors of severity of bicycle crashes.

  2. Bicyclic proline analogues as organocatalysts for stereoselective aldol reactions: an in silico DFT study. (United States)

    Shinisha, C B; Sunoj, Raghavan B


    Density functional theory has been employed in investigating the efficiency of a series of bicyclic analogues of proline as stereoselective organocatalysts for the aldol reaction. Three classes of conformationally restricted proline analogues, as part of either a [2.2.1] or [2.1.1] bicyclic framework, have been studied. Transition states for the stereoselective C-C bond formation between enamines derived from [2.2.1] and [2.1.1] bicyclic amino acids and p-nitrobenzaldehyde, leading to enantiomeric products, have been identified. Analysis of the transition state geometries revealed that the structural rigidity of catalysts, improved transition state organization as well as other weak interactions influence the relative stabilities of diastereomeric transition states and help contribute to the overall stereoselectivity in the aldol reaction. These bicyclic catalysts are predicted to be substantially more effective in improving the enantiomeric excess than the widely used organocatalyst proline. Enantiomeric excesses in the range 82-95% are predicted for these bicyclic catalysts when a sterically unbiased substrate such as p-nitrobenzaldehyde is employed for the asymmetric aldol reaction. More interestingly, introduction of substituents, as simple as a methyl group, at the ortho position of the aryl aldehyde bring about an increase in the enantiomeric excess to values greater than 98%. The reasons behind the vital energy separation between diastereomeric transition states has been rationalized with the help of a number of weak interactions such as intramolecular hydrogen bonding and Coulombic interactions operating on the transition states. These predictions could have wider implications for the rational design of improved organocatalysts for stereoselective carbon-carbon bond-forming reactions.

  3. Highly Constrained Bicyclic Scaffolds for the Discovery of Protease-Stable Peptides via mRNA Display. (United States)

    Hacker, David E; Hoinka, Jan; Iqbal, Emil S; Przytycka, Teresa M; Hartman, Matthew C T


    Highly constrained peptides such as the knotted peptide natural products are promising medicinal agents because of their impressive biostability and potent activity. Yet, libraries of highly constrained peptides are challenging to prepare. Here, we present a method which utilizes two robust, orthogonal chemical steps to create highly constrained bicyclic peptide libraries. This technology was optimized to be compatible with in vitro selections by mRNA display. We performed side-by-side monocyclic and bicyclic selections against a model protein (streptavidin). Both selections resulted in peptides with mid-nanomolar affinity, and the bicyclic selection yielded a peptide with remarkable protease resistance.

  4. Head injury resulting from scooter accidents in Rome: Differences before and after implementing a universal helmet law

    NARCIS (Netherlands)

    G. La Torre (Giuseppe); E.F. van Beeck (Ed); G. Bertazzoni (Giuliano); W. Ricciardi


    textabstractObjectives: To estimate the incidence rates and related determinants of head injuries before and after the implementation of a new universal helmet law in Italy. Methods: The investigation took place in the Emergency Room of the Accident and Emergency Department, Teaching Hospital 'Umber

  5. Impact of North Carolina's motorcycle helmet law on hospital admissions and charges for care of traumatic brain injuries. (United States)

    Naumann, Rebecca B; Marshall, Stephen W; Proescholdbell, Scott K; Austin, Anna; Creppage, Kathleen


    BACKGROUND North Carolina requires motorcyclists of all ages to wear federally approved safety helmets. The purpose of this article is to estimate the impact of this state law in terms of hospital admissions for traumatic brain injury (TBI) and associated hospital charges. METHODS Hospital admissions of North Carolina motorcyclists with TBIs and associated hospital charges in 2011 were extracted from the North Carolina Hospital Discharge Data system. We estimated hospital admissions and charges for the same year under the counterfactual condition of North Carolina without a universal motorcycle helmet law by using various substitutes (Florida, Pennsylvania, and South Carolina residents treated in North Carolina). RESULTS North Carolina's universal helmet law prevented an estimated 190 to 226 hospital admissions of North Carolina motorcyclists with TBI in 2011. Averted hospital charges to taxpayer-funded sources (ie, government and public charges) were estimated to be between $9.5 million and $11.6 million for 2011, and total averted hospital charges for 2011 were estimated to be between $25.3 million and $31.0 million. LIMITATIONS Cost estimates are limited to inpatients during the initial period of hospital care. This study was unable to capture long-term health care costs and productivity losses incurred by North Carolina's TBI patients and their caregivers. CONCLUSIONS North Carolina's universal motorcycle helmet law generates health and economic benefits for the state and its taxpayers.

  6. Illumination-parameter adjustable and illumination-distribution visible LED helmet for low-level light therapy on brain injury (United States)

    Wang, Pengbo; Gao, Yuan; Chen, Xiao; Li, Ting


    Low-level light therapy (LLLT) has been clinically applied. Recently, more and more cases are reported with positive therapeutic effect by using transcranial light emitting diodes (LEDs) illumination. Here, we developed a LLLT helmet for treating brain injuries based on LED arrays. We designed the LED arrays in circle shape and assembled them in multilayered 3D printed helmet with water-cooling module. The LED arrays can be adjust to touch the head of subjects. A control circuit was developed to drive and control the illumination of the LLLT helmet. The software portion provides the control of on and off of each LED arrays, the setup of illumination parameters, and 3D distribution of LLLT light dose in human subject according to the illumination setups. This LLLT light dose distribution was computed by a Monte Carlo model for voxelized media and the Visible Chinese Human head dataset and displayed in 3D view at the background of head anatomical structure. The performance of the whole system was fully tested. One stroke patient was recruited in the preliminary LLLT experiment and the following neuropsychological testing showed obvious improvement in memory and executive functioning. This clinical case suggested the potential of this Illumination-parameter adjustable and illuminationdistribution visible LED helmet as a reliable, noninvasive, and effective tool in treating brain injuries.

  7. Bicycle transport as an object of ecological marketing and innovations in urban transportations

    Directory of Open Access Journals (Sweden)

    O.S. Teletov


    Full Text Available The aim of the article. In the modern world society is faced with problems of growing population, increasing environmental problems, lack of minerals and social-economic globalization when necessity of both individual and humanity survival is becoming extremely important. By next few years 80% of the world’s population will live in the cities. This is the main reason which force us to think about the more effective usage of urban space and transport people in cities. Nowadays ecological pollution and increased costs on transport service highlight the importance of seeking alternative types of transport. The youth of many European countries prefer bikes as main transport. Usage of bicycles in Europe is constantly growing due to European and local urban and mobility policies. Therefore, we may consider an opportunity to promote bicycle transport in Ukraine, that requires complex investigation of this question. The purpose of the article is to define features and the ways of bicycle transport implementation in Ukrainian cities as a priority for youth; it includes the best world practices of bicycle transport implementation into urban space and searching for possible ways to apply the European experience in Ukraine. The results of the analysis. As a part of our research we considered investigating international experience of cycling in Europe as an alternative to the public transport and as an example of ecological marketing. The best methods of usage cycling in the urban space were described and analysed. Moreover, we identified the main problems (and the potential solutions with implementation of cycling infrastructure in urban space based on international and national experience (special signs, traffic lights etc.. In the article different opportunities for realization in city Sumy were proposed. Our focus was on atomized network of bike rental services and we confirmed the effectiveness of such program in this city. The bicycle infrastructure

  8. Measurement of Hybrid III Head Impact Kinematics Using an Accelerometer and Gyroscope System in Ice Hockey Helmets. (United States)

    Allison, Mari A; Kang, Yun Seok; Maltese, Matthew R; Bolte, John H; Arbogast, Kristy B


    Helmet-based instrumentation is used to study the biomechanics of concussion. The most extensively used systems estimate rotational acceleration from linear acceleration, but new instrumentation measures rotational velocity using gyroscopes, potentially reducing error. This study compared kinematics from an accelerometer and gyroscope-containing system to reference measures. A Hybrid III (HIII) adult male anthropometric test device head and neck was fit with two helmet brands, each instrumented with gForce Tracker (GFT) sensor systems in four locations. Helmets were impacted at various speeds and directions. Regression relationships between GFT-measured and reference peak kinematics were quantified, and influence of impact direction, sensor location, and helmet brand was evaluated. The relationship between the sensor output and the reference acceleration/velocity experienced by the head was strong. Coefficients of determination for data stratified by individual impact directions ranged from 0.77 to 0.99 for peak linear acceleration and from 0.78 to 1.0 for peak rotational velocity. For the data from all impact directions combined, coefficients of determination ranged from 0.60 to 0.80 for peak resultant linear acceleration and 0.83 to 0.91 for peak resultant rotational velocity. As expected, raw peak resultant linear acceleration measures exhibited large percent differences from reference measures. Adjustment using regressions resulted in average absolute errors of 10-15% if regression adjustments were done by impact direction or 25-40% if regressions incorporating data from all impact directions were used. Average absolute percent differences in raw peak resultant rotational velocity were much lower, around 10-15%. It is important to define system accuracy for a particular helmet brand, sensor location, and impact direction in order to interpret real-world data.

  9. Influence of an enforcement campaign on seat-belt and helmet wearing, karachi-hala highway, pakistan. (United States)

    Bhatti, Junaid A; Ejaz, Kiran; Razzak, Junaid A; Tunio, Israr Ali; Sodhar, Irshad


    This study assessed to what extent an enforcement campaign influenced seat-belt and helmet wearing on a Pakistani highway. The study setting was the Karachi-Hala highway where a traffic enforcement campaign was conducted from Dec 2009 to Feb 2010. Seat-belt and helmet wearing were observed in Nov 2009 and Apr 2010 at Karachi toll plaza. Differences in wearing rates as a function of occupants' age, sex, and vehicle type were compared between the two periods. On average, 9 119 (Standard deviation=1 896) traffic citations were issued per month from Aug 2009 to Feb 2010; 4.2% of which were for not wearing helmet. A 22.5% increase in citations was observed for Dec 2009 to Feb 2010 periods compared with Aug 2009 to Oct 2009 periods. Nearly six thousand four-wheeled and four hundred two-wheeled motorized vehicle occupants were observed in Nov 2009 and Apr 2010. Overall, two of the five drivers and one of the five front seat occupants wore seat belts. This proportion was significantly higher in drivers and front-seat occupants of cars than those of heavier vehicles. Similarly, one of two motorcyclists used a helmet but this proportion was 5.8% for pillion riders in Nov 2009. The increased enforcement had a limited influence on belt wearing in drivers (+4.0%; 95% Confidence Interval [95%CI]=1.8-6.1) and occupants (+6.2%; 95%CI=4.2-8.2). A higher increase was observed for motorcyclists (+9.8%; 95%CI=2.6-16.8) and pillion riders (+12.8%; 95%CI=5.4, 20.5). These results suggested that serious efforts are required to increase seat-belt and helmet use on Pakistani highways. Improving enforcement resources, increased fines, not allowing such vehicles on roads, and awareness campaigns targeting drivers of heavy vehicles might increase wearing rates in Pakistan.

  10. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

    Directory of Open Access Journals (Sweden)

    George Hess

    Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  11. "Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety. (United States)

    Hess, George; Peterson, M Nils


    Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

  12. Skull Flexure from Blast Waves: A New Mechanism for Brain Injury with Implications for Helmet Design

    CERN Document Server

    Moss, William C; Blackman, Eric G


    Traumatic brain injury [TBI] has become the signature injury of current military conflicts. The debilitating effects of TBI on society are long-lasting and costly. Although the mechanisms by which impacts cause TBI have been well researched, the mechanisms by which blasts cause TBI are not understood. Various mechanisms, including impacts caused by the blast, have been investigated, but blast-induced deformation of the skull has been neglected. Through the use of hydrodynamical numerical simulations, we have discovered that non-lethal blasts can induce sufficient flexure of the skull to generate potentially damaging loads in the brain, even if no impact occurs. This mechanism has implications for the diagnosis of TBI in soldiers and the design of protective equipment such as helmets.

  13. Skull flexure from blast waves: a mechanism for brain injury with implications for helmet design

    Energy Technology Data Exchange (ETDEWEB)

    Moss, W C; King, M J; Blackman, E G


    Traumatic brain injury [TBI] has become a signature injury of current military conflicts. The debilitating effects of TBI are long-lasting and costly. Although the mechanisms by which impacts cause TBI have been well researched, the mechanisms by which blasts cause TBI are not understood. Various possibilities have been investigated, but blast-induced deformation of the skull has been neglected. From numerical hydrodynamic simulations, we have discovered that nonlethal blasts can induce sufficient flexure of the skull to generate potentially damaging loads in the brain, even if no impact occurs. The possibility that this mechanism may contribute to TBI has implications for the diagnosis of soldiers and the design of protective equipment such as helmets.

  14. A universal and smart helmet-mounted display of large FOV (United States)

    Zhang, Nan; Weng, Dongdong; Wang, Yongtian; Li, Xuan; Liu, Youhai


    HMD (head-mounted display) is an important virtual reality device, which has played a vital role in VR application system. Compared with traditional HMD which cannot be applied in the daily life owing to their disadvantage on the price and performance, a new universal and smart Helmet-Mounted Display of large FOV uses excellent performance and widespread popularity as its starting point. By adopting simplified visual system and transflective system that combines the transmission-type and reflection-type display system with transflective glass based on the Huggens-Fresnel principle, we have designed a HMD with wide field of view, which can be easy to promote and popularize. Its resolution is 800*600, and field of view is 36.87°(vertical)* 47.92°(horizontal). Its weight is only 1080g. It has caught up with the advanced world levels.

  15. The neurosurgeon as baseball fan and inventor: Walter Dandy and the batter's helmet. (United States)

    Brewster, Ryan; Bi, Wenya Linda; Smith, Timothy R; Gormley, William B; Dunn, Ian F; Laws, Edward R


    Baseball maintains one of the highest impact injury rates in all athletics. A principal causative factor is the "beanball," referring to a pitch thrown directly at a batter's head. Frequent morbidities elicited demand for the development of protective gear development in the 20th century. In this setting, Dr. Walter Dandy was commissioned to design a "protective cap" in 1941. His invention became widely adopted by professional baseball and inspired subsequent generations of batting helmets. As a baseball aficionado since his youth, Walter Dandy identified a natural partnership between baseball and medical practice for the reduction of beaning-related brain injuries. This history further supports the unique position of neurosurgeons to leverage clinical insights, inform innovation, and expand service to society.

  16. Mediorhynchus gallinarum (Acanthocephala: Gigantorhynchidae) in Helmeted guineafowls, Numida meleagris, in the Kruger National Park, South Africa. (United States)

    Junker, K; Boomker, J


    Mediorhynchus gallinarum was recovered from the small intestines of 36 of 50 Helmeted guineafowls sampled from August 1988 to May 1989. The intensity of infection ranged from 1-141 worms per host, with a mean intensity of 23.2 (+/- 34) and a median intensity of 5. The Wilcoxon-Mann-Whitney test revealed no significant differences between the mean worm burdens of male and female birds at the 5% level (P > 0.05). Slightly more female than male acanthocephalans were collected. The majority (63.4%) of females had eggs with fully-developed embryos, 9% had immature eggs, 21.2% had no eggs and the egg status of 6.4% could not be determined. No seasonal pattern of intensity of infection emerged from the data, but worm burdens were markedly higher after good rains in February 1989. South Africa constitutes a new geographic record for M. gallinarum.

  17. Unusual cause of a facial pressure ulcer: the helmet securing the Sengstaken-Blakemore tube. (United States)

    Kim, S M; Ju, R K; Lee, J H; Jun, Y J; Kim, Y J


    Many medical devices, such as pulse oximetry, ventilation masks and other splints are put on critically ill patients. Although these devices are designed to deliver relatively low physical pressure to the skin of the patient, they can still cause pressure ulcers (PUs) in critically ill patients. There are reports of medical device-related PUs on the face. Here we describe forehead skin necrosis caused by the securing helmet for the Sengstaken-Blakemore tube. It is difficult to detect this kind of PU early, because most of the patients have decreased mental status or delirium due to varix bleeding. For this reason, medical staff should be aware of the risk of developing a PU by the device and take preventive measures accordingly.

  18. Development of an experimental methodology to evaluate the influence of a bamboo frame on the bicycle ride comfort (United States)

    Thite, A. N.; Gerguri, S.; Coleman, F.; Doody, M.; Fisher, N.


    In the current environment of increased emphasis on sustainable transport, there is manifold increase in the use of bicycles for urban transport. One concern which might restrict the use is the ride comfort and fatigue. There has been limited research in addressing the difficulty in bicycle ride comfort quantification. The current study aims to develop a methodology to quantify bicycle discomfort so that performance of bicycles constructed from bamboo and aluminium alloy can be compared. Experimentally obtained frequency response functions are used to establish a relation between the road input and the seat and rider response. A bicycle track input profile based on standard road profiles is created so as to estimate the acceleration responses. The whole-body-vibration frequency weighting is applied to quantify the perception of vibration intensity so that eventual discomfort ranking can be obtained. The measured frequency response functions provide an insight into the effect of frame dynamics on the overall resonant behaviour of the bicycles. The beneficial effect of frame compliance and damping on lower modes of vibration is very clear in the case of bamboo frame, in turn affecting seat and rider response. In the bamboo frame, because of multiple resonances, the frequency response of the handlebar is smaller at higher frequencies suggesting effective isolation. Further improvements may have come from the joints made from natural composites. Overall, based on the comparative analysis and the methodology developed, bamboo frame shows significant improvement in ride comfort performance compared with the aluminium frame.

  19. Optimal design parameters of the bicycle-rider system for maximal muscle power output. (United States)

    Yoshihuku, Y; Herzog, W


    The purpose of this study was to find the optimal values of design parameters for a bicycle-rider system (crank length, pelvic inclination, seat height, and rate of crank rotation) which maximize the power output from muscles of the human lower limb during bicycling. The human lower limb was modelled as a planar system of five rigid bodies connected by four smooth pin joints and driven by seven functional muscle groups. The muscles were assumed to behave according to an adapted form of Hill's equation. The dependence of the average power on the design parameters was examined. The instantaneous power of each muscle group was studied and simultaneous activity of two seemingly antagonistic muscle groups was analyzed. Average peak power for one full pedal revolution was found to be around 1100 W. The upper body position corresponding to this peak power output was slightly reclined, and the pedalling rate was 155 rpm for a nominal crank length of 170 mm.

  20. The effect of cannabis on regular cannabis consumers' ability to ride a bicycle. (United States)

    Hartung, Benno; Schwender, Holger; Roth, Eckhard H; Hellen, Florence; Mindiashvili, Nona; Rickert, Annette; Ritz-Timme, Stefanie; Grieser, Almut; Monticelli, Fabio; Daldrup, Thomas


    To assess the effects of cannabis on the ability required to ride a bicycle, repetitive practical cycling tests and medical examinations were carried out before and after inhalative consumption of cannabis. A maximum of three joints with body weight-adapted THC content (300 μg THC per kg body weight) could be consumed by each test subject. Fourteen regular cannabis-consuming test subjects were studied (12 males, 2 females). In summary, only a few driving faults were observed even under the influence of very high THC concentrations. A defined THC concentration that leads to an inability to ride a bicycle cannot be presented. The test subjects showed only slight distinctive features that can be documented using a medical test routinely run for persons under suspicion of driving under the influence of alcohol or drugs.

  1. Præventiv effekt af cykelhjelme

    DEFF Research Database (Denmark)

    Nielsen, C T; Larsen, C F; Nordentoft, E


    The total number of persons injured following bicycle accidents in Denmark is estimated to be more than 50,000 annually. In half of the injured cyclists, lesions localized to the region of the head occur. Bicycle helmets provide considerable protection against brain injuries which constitute 13...... with bicycle accidents. When a bicycle helmet is purchased, it is important to ensure that the helmet fits the head, that vision is not impeded and that the chinstrap secures the helmet correctly. Legislation is necessary to ensure that bicycle helmets sold in Denmark fulfill the minimum safety requirements....

  2. A sketch planning methodology for determining interventions for bicycle and pedestrian crashes: an ecological approach


    Thakuriah, P.; Cottrill, C.; Thomas, N.; Vaughn, S.


    Bicycle and pedestrian safety planning have recently been gaining increased attention. With this focus, however, comes increased responsibilities for planning agencies and organizations tasked with evaluating and selecting safety interventions, a potentially arduous task given limited staff and resources. This study presents a sketch planning framework based on ecological factors that attempts to provide an efficient and effective method of selecting appropriate intervention measures. A Chica...

  3. Using Evolutionary Multiobjective Optimization Algorithms to Evolve Lacing Patterns for Bicycle Wheels


    Svensson, Mats Krüger


    This thesis investigates the use of evolutionary algorithms (EAs) to evolve and optimize lacing patterns of spokes for a bicycle wheel. There are multiple objectives and tradeoffs to be considered when evaluating a lacing pattern, for instance, strength versus balance. To handle this, an evolutionary multiobjective optimization (EMO) method has been used. Various EMO algorithms and approaches are tested. Among these, the new NSGA-III algorithm is used. Different representations of the lac...

  4. Synthesis and Structure of A Novel Caged Bicyclic Phosphate Flame Retardant

    Institute of Scientific and Technical Information of China (English)


    A novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-l-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-l-phosphabicyclo [2.2.2] octane (PEPA) and phosphorus oxychloride in this paper.Its structure was characterized by elemental analysis, FTIR, 1H NMR, 31P NMR and X-ray diffraction analysis.

  5. A holistic approach to the integration of bicycle traffic into the urban landscape


    Polonca Andrejčič Mušič; Ilka Čerpes


    Qualitative and quantitative indicators can be used to assess the quality of public space. The coherence of cycling infrastructure connectivity is an indicator of a public space's attractiveness as a basis for the quality of the bicycle traffic operation. We would like to find an optimal balance between the space's form and its image to provide good conditions for cycling as one of the most important forms of sustainable mobility, and consequently a factor facilitating a healthy lifestyle. Th...

  6. 'Cycle thieves, we are watching you': impact of a simple signage intervention against bicycle theft.

    Directory of Open Access Journals (Sweden)

    Daniel Nettle

    Full Text Available BACKGROUND: Bicycle theft is a serious problem in many countries, and there is a lack of evidence concerning effective prevention strategies. Displaying images of 'watching eyes' has been shown to make people behave in more socially desirable ways in a number of settings, but it is not yet clear if this effect can be exploited for purposes of crime prevention. We report the results of a simple intervention on a university campus where signs featuring watching eyes and a related verbal message were displayed above bicycle racks. METHODOLOGY AND PRINCIPAL FINDINGS: We installed durable signs at three locations which had experienced high levels of bicycle theft, and used the rest of the university campus as a control location. Reported thefts were monitored for 12 months before and after the intervention. Bicycle thefts decreased by 62% at the experimental locations, but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs. The Odds Ratio for the effect of the intervention was 4.28 (95% confidence interval 2.04-8.98, a large effect compared to other place-based crime prevention interventions. CONCLUSIONS AND SIGNIFICANCE: The effectiveness of this extremely cheap and simple intervention suggests that there can be considerable crime-reduction benefits to engaging the psychology of surveillance, even in the absence of surveillance itself. Simple interventions for high-crime locations based on this principle should be considered as an adjunct to other measures, although a possible negative consequence is displacement of offending.

  7. Product Variety, Supply Chain Structure, and Firm Performance: Analysis of the U.S. Bicycle Industry


    Taylor Randall; Karl Ulrich


    Using data from the U.S. bicycle industry, we examine the relation among product variety, supply chain structure, and firm performance. Variety imposes two types of costs on a supply chain: production costs and market mediation costs. Production costs include, among other costs, the incremental fixed investments associated with providing additional product variants. Market mediation costs arise because of uncertainty in product demand created by variety. In the presence of demand uncertainty,...

  8. Synthesis and Insecticidal Activity of Bicyclic Phosphorothionates and Related Monocyclic Phosphorothionates


    Wu, Shao-yong; Hirashima, Akinori; Takeya, Ryuko; Eto, Morifusa


    Some thiono-type bicyclic phosphorus esters (BPS) were synthesized and bioassayed for insecticidal activity against susceptible (SRS) houseflies. n-Propyl was most favorable as a substituent at position 4 for insecticidal activity. The introduction of substituents at position 3 did not improve the activity. Some functionized monocyclic phosphorothionates (MPs) were also synthesized as proBP candidates. Although some MPs were cyclized to the corresponding BPS by oxidation or by action of a bas...

  9. Factors of the safety in bicycle traffic in the City of Zagreb and its surrounding

    Directory of Open Access Journals (Sweden)

    Sindik Joško


    Full Text Available The aim of this study was to determine the differences in underlying factors of Zagreb cycling, compared to the "types of cyclists" (driving style, i.e. different ways of using bicycles as a means of transport. The study included over 3,000 frequent participants in urban traffic cycling, sample of members of the association Cyclist Union (N = 1259 and snowball sample of "typical" of cyclists, i.e. people who are using the bike, but are not the members of the Cyclist Union (N = 1831, using the conveniently assembled questionnaire. Study participants who bike used in various applications prefer the safest driving style (only on sidewalks and bike paths / lines. Barriers of the weather conditions are ubiquitous in the safest driving style. Daily, weekly and yearly riding a bicycle are more often found in those who prefer the safest driving style. Cyclists who drive with medium secure style (roads with less traffic and lower speeds, more often ride a bike, as compared with those who prefer the safest driving style. Having a better bike line / track and other infrastructure is the most often considered at those with the highest risk driving style. The results provide the guidance for local authorities and for the cyclists to improve the conditions for a safer and more often by bicycle circulation in the City of Zagreb and its surroundings.

  10. A Geo-Aware and VRP-Based Public Bicycle Redistribution System

    Directory of Open Access Journals (Sweden)

    J. H. Lin


    Full Text Available Public Bicycle System (PBS has been developed for short-distance transportation as a part of the mass transportation system. The supply and demand of bikes in PBS is usually unbalanced at different stations and needs to be continuously and widely monitored and redistributed. The bicycle redistribution is a part of the vehicle routing problem (VRP. We can apply solutions to the VRP to redistribute bicycle efficiently. However, most solutions to the VRP use the Euclidean distance as the condition factor, which does not take road conditions, traffic regulations, and geographical factors into account, resulting in unnecessary waste of delivery time and human resources. In this work, we propose an actual path distance optimization method for the VRP to adapt the several additional constraints of road problems. We also implement a system that integrates real-time station information, Web GIS, the urban road network, and heuristics algorithms for PBS. The system includes a simulator inside that can assist PBS managers to do the route planning efficiently and find the best scheduling strategy to achieve hotspot analysis and the adjustment of station deployment strategies to reduce PBS operation cost.

  11. Changes in human cervical and lumbar spine curves while bicycling with different handlebar heights. (United States)

    Chen, Yi-Lang; He, Kuo-Chang


    Cycling is a daily activity that needs a high demand of human-bicycle fitness. However, studies into the fitness or ergonomic aspects are very little. In this study, the simulated 20 min bicycling test were performed by 26 male participants under 5 handle height conditions. Body joint angles and external cervical/lumbar spine lordosis were measured at the initial and cycling after 20 min. Results show that different handle heights did cause various trunk inclinations. Trunk inclination was negatively and positively correlated with lumbosacral angle (r = -0.620, p < 0.001) and cervical angle (r = 0.510, p < 0.001), respectively. In this study, regression models were also developed to predict the internal cervical and lumbar spine movements by external trunk inclination and head extension, respectively. The explanatory abilities for the variance of the models were 67.2% for LSA and 82.8% for CE prediction. This can be used to understand the cyclist's spine movements while field study of bicycling.

  12. A solid solution to a conjecture on the maximal energy of bipartite bicyclic graphs

    CERN Document Server

    Huo, Bofeng; Li, Xueliang; Shi, Yongtang


    The energy of a simple graph $G$, denoted by $E(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix. Let $C_n$ denote the cycle of order $n$ and $P^{6,6}_n$ the graph obtained from joining two cycles $C_6$ by a path $P_{n-12}$ with its two leaves. Let $\\mathscr{B}_n$ denote the class of all bipartite bicyclic graphs but not the graph $R_{a,b}$, which is obtained from joining two cycles $C_a$ and $C_b$ ($a, b\\geq 10$ and $a \\equiv b\\equiv 2\\, (\\,\\textmd{mod}\\, 4)$) by an edge. In [I. Gutman, D. Vidovi\\'{c}, Quest for molecular graphs with maximal energy: a computer experiment, {\\it J. Chem. Inf. Sci.} {\\bf41}(2001), 1002--1005], Gutman and Vidovi\\'{c} conjectured that the bicyclic graph with maximal energy is $P^{6,6}_n$, for $n=14$ and $n\\geq 16$. In [X. Li, J. Zhang, On bicyclic graphs with maximal energy, {\\it Linear Algebra Appl.} {\\bf427}(2007), 87--98], Li and Zhang showed that the conjecture is true for graphs in the class $\\mathscr{B}_n$. However, they could not...

  13. The effect of alcohol hangover on the ability to ride a bicycle. (United States)

    Hartung, Benno; Schwender, Holger; Mindiashvili, Nona; Ritz-Timme, Stefanie; Malczyk, Axel; Daldrup, Thomas


    To investigate the effects of alcohol on the ability to ride a bicycle, practical cycling tests were carried out at different blood alcohol concentrations (BAC). For this purpose, various alcoholic beverages could be consumed from around 2 p.m. until 11 p.m. Afterwards, the test persons spent the night on the trial site and were provided with dormitory sleeping accommodation. On the following morning, beginning at around 8 a.m., a final cycling test was performed. The performances of those test persons who had returned to state of soberness and of those with residual blood alcohol levels were compared to the performances on the day before. The practical ability to ride a bicycle was significantly reduced in the postalcoholic state compared to the rides of the day before. The relative cycling performance in the postalcoholic state was comparable to the rides under the influence of BAC of around 0.30 g/kg. There were no remarkable differences between the groups with and without residual blood alcohol levels regarding the rides on the next morning. Therefore, it can be assumed that the direct influence of residual blood alcohol levels plays a minor role for the ability to ride a bicycle in the postalcoholic state. Instead, the side effects of the high amounts of alcohol that were consumed the night before are crucial.

  14. Built environment effects on cyclist injury severity in automobile-involved bicycle crashes. (United States)

    Chen, Peng; Shen, Qing


    This analysis uses a generalized ordered logit model and a generalized additive model to estimate the effects of built environment factors on cyclist injury severity in automobile-involved bicycle crashes, as well as to accommodate possible spatial dependence among crash locations. The sample is drawn from the Seattle Department of Transportation bicycle collision profiles. This study classifies the cyclist injury types as property damage only, possible injury, evident injury, and severe injury or fatality. Our modeling outcomes show that: (1) injury severity is negatively associated with employment density; (2) severe injury or fatality is negatively associated with land use mixture; (3) lower likelihood of injuries is observed for bicyclists wearing reflective clothing; (4) improving street lighting can decrease the likelihood of cyclist injuries; (5) posted speed limit is positively associated with the probability of evident injury and severe injury or fatality; (6) older cyclists appear to be more vulnerable to severe injury or fatality; and (7) cyclists are more likely to be severely injured when large vehicles are involved in crashes. One implication drawn from this study is that cities should increase land use mixture and development density, optimally lower posted speed limits on streets with both bikes and motor vehicles, and improve street lighting to promote bicycle safety. In addition, cyclists should be encouraged to wear reflective clothing.

  15. Pedaling into high gear for bicycle policy in Canada : lessons from bike summit 2008 in Toronto

    Energy Technology Data Exchange (ETDEWEB)



    The 2008 bike summit provided a forum for the discussion of international and Canadian best practices related to bicycles and bicycling policy. The aim of the summit was to assist communities across Canada to improve conditions for cycling in the urban environment and help to generate a cultural shift towards greater acceptance of cycling on roads. This paper discussed lessons learned during the summit and outlined new methods of improving cycling in communities. The City of London has recently increased the amount of cyclists using its roads by 200 per cent. Cycling infrastructure is more affordable than constructing major public transit or road infrastructure. Savings in healthcare costs will be accrued over time as a result of the healthier lifestyles promoted by regular cycling activity. Bicycle trips can help to alleviate over-demand on heavy transit routes. Encouraging commuters to cycle will also reduce the amounts of greenhouse gases (GHGs) emitted in urban areas. Lane width reductions will help to reduce speeds as drivers are forced to pay more attention when driving. Public bike sharing programs and bike stations are now being used in many North American cities. It was concluded that strong advocacy is needed to ensure the growth and acceptance of cycling in urban centres. 23 figs.

  16. The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

    Directory of Open Access Journals (Sweden)

    Cripton Peter A


    Full Text Available Abstract Background Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists. Methods We reviewed studies of the impact of transportation infrastructure on bicyclist safety. The results were tabulated within two categories of infrastructure, namely that at intersections (e.g. roundabouts, traffic lights or between intersections on "straightaways" (e.g. bike lanes or paths. To assess safety, studies examining the following outcomes were included: injuries; injury severity; and crashes (collisions and/or falls. Results The literature to date on transportation infrastructure and cyclist safety is limited by the incomplete range of facilities studied and difficulties in controlling for exposure to risk. However, evidence from the 23 papers reviewed (eight that examined intersections and 15 that examined straightaways suggests that infrastructure influences injury and crash risk. Intersection studies focused mainly on roundabouts. They found that multi-lane roundabouts can significantly increase risk to bicyclists unless a separated cycle track is included in the design. Studies of straightaways grouped facilities into few categories, such that facilities with potentially different risks may have been classified within a single category. Results to date suggest that sidewalks and multi-use trails pose the highest risk, major roads are more hazardous than minor roads, and the presence of bicycle facilities (e.g. on-road bike routes, on-road marked bike lanes, and off-road bike paths was associated with the lowest

  17. The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia: a rejoinder. (United States)

    Rissel, Chris


    This paper challenges the conclusion of a recent paper by Walter et al. (Accident Analysis and Prevention 2011, doi:10.1016/j.aap.2011.05.029) reporting that despite numerous data limitations repealing the helmet legislation in Australia could not be justified. This conclusion is not warranted because of the limited time period used in their analysis and the lack of data beyond a few years before the introduction of legislation, the failure to adequately account for the effect of the phasing in of the legislation, the effect of the marked reduction in child cyclists, and the non-comparability of the pedestrian and cycling injuries and related lack of consideration of the severity of head injuries. The extent to which helmet legislation deters people from cycling is discussed.

  18. A Finite-Element Model Analysis of the Protection Provided by Army Aviator Helmets to the Human Head and Neck (United States)


    aviator, football ); Shell; Stiffness properties; Inertial properties; Contact; Impact; Biomechanics; Three-dimensional digitizer Mt A*SrRhACr mentmtm...01.’ OL rsa .0 Time tsec) Pig. 14(c) Time History of the Acceleration of Shell and Headform at Lhe Crowns for SPH4 38 SPH4 Helmet SSOO. 2000. 0 2000...procedure for the experimental determination of m/mmtemix• the mass moment of inertia matrix using either a torsional FOOTBALL .LMET. AVIATOR HELMETr. CDNTER

  19. Evaluation of brain tissue responses because of the underwash overpressure of helmet and faceshield under blast loading. (United States)

    Sarvghad-Moghaddam, Hesam; Rezaei, Asghar; Ziejewski, Mariusz; Karami, Ghodrat


    Head protective tools such as helmets and faceshields can induce a localized high pressure region on the skull because of the underwash of the blast waves. Whether this underwash overpressure can affect the brain tissue response is still unknown. Accordingly, a computational approach was taken to confirm the incidence of underwash with regards to blast direction, as well as examine the influence of this effect on the mechanical responses of the brain. The variation of intracranial pressure (ICP) as one of the major injury predictors, as well as the maximum shear stress were mainly addressed in this study. Using a nonlinear finite element (FE) approach, generation and interaction of blast waves with the unprotected, helmeted, and fully protected (helmet and faceshield protected) FE head models were modeled using a multi-material arbitrary Lagrangian-Eulerian (ALE) method and a fluid-structure interaction (FSI) coupling algorithm. The underwash incidence overpressure was found to greatly change with the blast direction. Moreover, while underwash induced ICP (U-ICP) did not exceed the peak ICP of the unprotected head, it was comparable and even more than the peak ICP imposed on the protected heads by the primary shockwaves (Coup-ICP). It was concluded that while both helmet and faceshield protected the head against blast waves, the underwash overpressure affected the brain tissue response and altered the dynamic load experienced by the brain as it led to increased ICP levels at the countercoup site, imparted elevated skull flexure, and induced high negative pressure regions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. The usefulness of GPS bicycle tracking data for evaluating the impact of infrastructure change on cycling behaviour. (United States)

    Heesch, Kristiann C; Langdon, Michael


    Issue addressed: A key strategy to increase active travel is the construction of bicycle infrastructure. Tools to evaluate this strategy are limited. This study assessed the usefulness of a smartphone GPS tracking system for evaluating the impact of this strategy on cycling behaviour.Methods: Cycling usage data were collected from Queenslanders who used a GPS tracking app on their smartphone from 2013-2014. 'Heat' and volume maps of the data were reviewed, and GPS bicycle counts were compared with surveillance data and bicycle counts from automatic traffic-monitoring devices.Results: Heat maps broadly indicated that changes in cycling occurred near infrastructure improvements. Volume maps provided changes in counts of cyclists due to these improvements although errors were noted in geographic information system (GIS) geo-coding of some GPS data. Large variations were evident in the number of cyclists using the app in different locations. These variations limited the usefulness of GPS data for assessing differences in cycling across locations.Conclusion: Smartphone GPS data are useful in evaluating the impact of improved bicycle infrastructure in one location. Using GPS data to evaluate differential changes in cycling across multiple locations is problematic when there is insufficient traffic-monitoring devices available to triangulate GPS data with bicycle traffic count data.So what?: The use of smartphone GPS data with other data sources is recommended for assessing how infrastructure improvements influence cycling behaviour.

  1. A Comparison of Static and Dynamic Measures of Lower Limb Joint Angles in Cycling: Application to Bicycle Fitting

    Directory of Open Access Journals (Sweden)

    Bini Rodrigo Rico


    Full Text Available Purpose. Configuration of bicycle components to the cyclist (bicycle fitting commonly uses static poses of the cyclist on the bicycle at the 6 o’clock crank position to represent dynamic cycling positions. However, the validity of this approach and the potential use of the different crank position (e.g. 3 o’clock have not been fully explored. Therefore, this study compared lower limb joint angles of cyclists in static poses (3 and 6 o’clock compared to dynamic cycling. Methods. Using a digital camera, right sagittal plane images were taken of thirty cyclists seated on their own bicycles mounted on a stationary trainer with the crank at 3 o’clock and 6 o’clock positions. Video was then recorded during pedalling at a self-selected gear ratio and pedalling cadence. Sagittal plane hip, knee and ankle angles were digitised. Results. Differences between static and dynamic angles were large at the 6 o’clock crank position with greater mean hip angle (4.9 ± 3°, smaller knee angle (8.2 ± 5° and smaller ankle angle (8.2 ± 5.3° for static angles. Differences between static and dynamic angles (< 1.4° were trivial to small for the 3 o’clock crank position. Conclusions. To perform bicycle fitting, joint angles should be measured dynamically or with the cyclist in a static pose at the 3 o’clock crank position.

  2. Helmet-mounted acoustic array for hostile fire detection and localization in an urban environment (United States)

    Scanlon, Michael V.


    The detection and localization of hostile weapons firing has been demonstrated successfully with acoustic sensor arrays on unattended ground sensors (UGS), ground-vehicles, and unmanned aerial vehicles (UAVs). Some of the more mature systems have demonstrated significant capabilities and provide direct support to ongoing counter-sniper operations. The Army Research Laboratory (ARL) is conducting research and development for a helmet-mounted system to acoustically detect and localize small arms firing, or other events such as RPG, mortars, and explosions, as well as other non-transient signatures. Since today's soldier is quickly being asked to take on more and more reconnaissance, surveillance, & target acquisition (RSTA) functions, sensor augmentation enables him to become a mobile and networked sensor node on the complex and dynamic battlefield. Having a body-worn threat detection and localization capability for events that pose an immediate danger to the soldiers around him can significantly enhance their survivability and lethality, as well as enable him to provide and use situational awareness clues on the networked battlefield. This paper addresses some of the difficulties encountered by an acoustic system in an urban environment. Complex reverberation, multipath, diffraction, and signature masking by building structures makes this a very harsh environment for robust detection and classification of shockwaves and muzzle blasts. Multifunctional acoustic detection arrays can provide persistent surveillance and enhanced situational awareness for every soldier.

  3. From Dalek half balls to Daft Punk helmets: Mimetic fandom and the crafting of replicas

    Directory of Open Access Journals (Sweden)

    Matt Hills


    Full Text Available Mimetic fandom is a surprisingly understudied mode of (culturally masculinized fan activity in which fans research and craft replica props. Mimetic fandom can be considered as (inauthentic and (immaterial, combining noncommercial status with grassroots marketing or brand reinforcement as well as fusing an emphasis on material artifacts with Web 2.0 collective intelligence. Simply analyzing mimetic fandom as part of fannish material culture fails to adequately assess the nonmaterial aspects of this collaborative creativity. Two fan cultures are taken as case studies: Dalek building groups and Daft Punk helmet constructors. These diverse cases indicate that mimetic fandom has a presence and significance that moves across media fandoms and is not restricted to the science fiction, fantasy, and horror followings with which it is most often associated. Mimetic fandom may be theorized as an oscillatory activity that confuses binaries and constructions of (academic/fan authenticity. This fan practice desires and pursues a kind of ontological bridging or unity—from text to reality—that is either absent or less dominant in many other fan activities such as cosplay, screen-used prop collecting, and geographical pilgrimage. Fan studies may benefit from reassessing the place of mimesis, especially in order to theorize fan practices that are less clearly transformative in character.

  4. A revision of African helmeted terrapins (Testudines: Pelomedusidae: Pelomedusa), with descriptions of six new species. (United States)

    Petzold, Alice; Vargas-Ramírez, Mario; Kehlmaier, Christian; Vamberger, Melita; Branch, William R; Preez, Louis Du; Hofmeyr, Margaretha D; Meyer, Leon; Schleicher, Alfred; Siroký, Pavel; Fritz, Uwe


    Using nearly range-wide sampling, we analyze up to 1848 bp of mitochondrial DNA of 183             helmeted terrapins and identify a minimum of 12 deeply divergent species-level clades. Uncorrected p distances of these clades equal or clearly exceed those between the currently recognized species of Pelusios, the genus most closely related to Pelomedusa. We correlate genetic discontinuities of Pelomedusa with data on morphology and endoparasites and describe six new Pelomedusa species. Moreover, we restrict the name Pelomedusa subrufa (Bonnaterre, 1789) to one genetic lineage and resurrect three further species from its synonymy, namely P. galeata (Schoepff, 1792), P. gehafie (Rüppell, 1835), and P. olivacea (Schweigger, 1812). In addition to these ten Pelomedusa species, we identify two further clades from Cameroon and Sudan with similar levels of genetic divergence that remain unnamed candidate species. We also note that some problematical terrapins from South Africa and Somalia may represent two additional candidate species. Some of the Pelomedusa species are morphologically distinctive, whilst others can only be identified by molecular markers and are therefore morphologically cryptic taxa.

  5. Motorcycle fatalities among out-of-state riders and the role of universal helmet laws. (United States)

    French, Michael T; Gumus, Gulcin; Homer, Jenny F


    Several studies have demonstrated that universal helmet laws (UHLs) and other motor vehicle policies are effective in reducing fatal and non-fatal motorcycle injuries. Although state policies can improve traffic safety overall, very little is known about how they affect different segments of motorcycle riders. In this paper, we investigate the differential effectiveness of such policies by license state of the rider (i.e., in-state versus out-of-state). From a policy perspective, this information gap is noteworthy because variations in state regulations may influence where individuals choose to ride. We use state-level longitudinal (1988-2008) data on motorcycle fatalities in the United States from the fatality analysis reporting system (FARS). Our results reconfirm the effectiveness of UHLs and offer new evidence suggesting that states without such policies may attract more risky riders from out-of-state. In particular, not having a UHL increases out-of-state rider fatalities by 18 percent and this effect is more pronounced for out-of-state riders who reside in a UHL state. These findings have important implications regarding unintended spillover effects of state-specific motor vehicle policies.

  6. Evaluation of helmet-mounted display targeting symbology based on eye tracking technology (United States)

    Wang, Lijing; Wen, Fuzhen; Ma, Caixin; Zhao, Shengchu; Liu, Xiaodong


    The purpose of this paper is to find the Target Locator Lines (TLLs) which perform best by contrasting and comparing experiment based on three kinds of TTLs of fighter HMD. 10 university students, male, with an average age of 21-23, corrected visual acuity 1.5, participated in the experiment. In the experiment, head movement data was obtained by TrackIR. The geometric relationship between the coordinates of the real world and coordinates of the visual display was obtained by calculating the distance from viewpoint to midpoint of both eyes and the head movement data. Virtual helmet system simulation experiment environment was created by drawing TLLs of fighter HMD in the flight simulator visual scene. In the experiment, eye tracker was used to record the time and saccade trajectory. The results were evaluated by the duration of the time and saccade trajectory. The results showed that the symbol"locator line with digital vector length indication" cost most time and had the longest length of the saccade trajectory. It is the most ineffective and most unacceptable way. "Locator line with extending head vector length symbol" cost less time and had less length of the saccade trajectory. It is effective and acceptable;"Locator line with reflected vector length symbol" cost the least time and had the least length of the saccade trajectory. It is the most effective and most acceptable way. "Locator line with reflected vector length symbol" performs best. The results will provide reference value for the research of TTLs in future.

  7. Perceptual issues for color helmet-mounted displays: luminance and color contrast requirements (United States)

    Harding, Thomas H.; Rash, Clarence E.; Lattimore, Morris R.; Statz, Jonathan; Martin, John S.


    Color is one of the latest design characteristics of helmet-mounted displays (HMDs). It's inclusion in design specifications is based on two suppositions: 1) color provides an additional method of encoding information, and 2) color provides a more realistic, and hence more intuitive, presentation of information, especially pilotage imagery. To some degree, these two perceived advantages have been validated with head-down panel-mounted displays, although not without a few problems associated with visual physiology and perception. These problems become more prevalent when the user population expands beyond military aviators to a general user population, of which a significant portion may have color vision deficiencies. When color is implemented in HMDs, which are eyes-out, see-through displays, visual perception issues become an increased concern. A major confound with HMDs is their inherent see-through (transparent) property. The result is color in the displayed image combines with color from the outside (or in-cockpit) world, possibly producing a false perception of either or both images. While human-factors derived guidelines based on trial and error have been developed, color HMD systems still place more emphasis on colorimetric than perceptual standards. This paper identifies the luminance and color contrast requirements for see-through HMDs. Also included is a discussion of ambient scene metrics and the choice of symbology color.

  8. Enhanced flight symbology for wide-field-of-view helmet-mounted displays (United States)

    Rogers, Steven P.; Asbury, Charles N.; Szoboszlay, Zoltan P.


    A series of studies was conducted to improve the Army aviator's ability to perform night missions by developing innovative symbols that capitalize on the advantages of new wide field-of-view (WFOV) helmet-mounted displays (HMDs). The most important outcomes of the research were two new symbol types called the Cylinder and the Flight Path Predictor. The Cylinder provides a large symbolic representation of real-world orientation that enables pilots to maintain the world frame of reference even if the visibility of the world is lost due to dust, smoke, snow, or inadvertent instrument meteorological conditions (IMC). Furthermore, the Cylinder is peripherally presented, supporting the "ambient" visual mode so that it does not require the conscious attention of the viewer. The Flight Path Predictor was developed to show the predicted flight path of a maneuvering aircraft using earth-referenced HMD symbology. The experimental evidence and the pilot interview results show that the new HMD symbology sets are capable of preventing spatial disorientation, improving flight safety, enhancing flight maneuver precision, and reducing workload so that the pilot can more effectively perform the critical mission tasks.

  9. 3D Simulations of Helmet Streamer Dynamics and Implications for the Slow Solar Wind (United States)

    Higginson, Aleida K.; Antiochos, Spiro K.; DeVore, C. R.; Zurbuchen, Thomas H.


    The source of the slow solar wind at the Sun is still an issue of intense debate in solar and heliospheric physics. Because the majority of the solar wind observed at Earth is slow wind, understanding its origin is essential for understanding and predicting Earth’s space weather environment. In-situ and remote observations show that, when compared to the fast wind, the slow solar wind corresponds to higher freeze-in temperatures, as indicated by charge-state ratios, and more corona-like elemental abundance ratios. These results indicate that the most likely source for the slow wind is the hot plasma in the closed-field corona, but the release mechanism(s) for the wind from the closed-field regions is far from understood. We perform fully dynamic, 3D MHD simulations in order to the study the opening and closing of the Sun’s magnetic field that leads to the escape of the slow solar wind. In particular, we calculate the dynamics of helmet streamers that are driven by photospheric motions such as supergranular flows. We determine in detail the opening and closing of coronal flux, and discuss the implications of our results for theories of slow wind origin, especially the S-Web model. We also determine observational signatures for the upcoming inner heliosphere missions Solar Orbiter and Solar Probe Plus.This work was supported by the NASA SR&T and TR&T Programs.

  10. The Physics of Motorcycles and Fast Bicycles : Lean, Stability and Counter-steering

    CERN Document Server

    Shayak, B


    In this work I will obtain the system of nonlinear equations that correctly describes the motion of motorcycles and fast bicycles (above 30 km/hr) for the first time in literature. I will use it to calculate the lean angle during a turn and prove that the motion of the vehicle is unconditionally stable at all operating speeds under consideration. I will then employ it to give a quantitative model of counter-steering - the phenomenon by which a turning mobike first goes the wrong way and then starts going the right way.

  11. Enantiospecific Synthesis of All Four Stereoisomers of Novel Bicyclic Arylacetamides as κ-Opioid Agonists

    Institute of Scientific and Technical Information of China (English)

    LONG,Ya-Qiu(龙亚秋); MOU,Qi-Yong(牟奇勇); QIU,Da-Ping(仇达萍); WU,Rui-Qin(吴瑞琴)


    Conformationally constrained bicyclic derivatives of the potent and selective κ-opioid receptor agonist 2-(3,4-dichlorophenyl)-N-methyl- N- [ (1S ) - 1-phenyl-2- (1-pyrrolidinyl)-ethyl] acetamide (3, ICI-199,441) were designed to explore the effect of the conformational restriction and stereochemistry of the pharmacophoric ethylenediamine incorporated into the pyrrolidine on the affinity and κ-selectivity. A facile enantiospecific synthetic route was established to afford all four stereoisomers starting from readily available amino acids through mild cyclization and amide formation.

  12. Enantiospecific Synthesis of All Four Stereoisomers of Novel Bicyclic Arylacetamides as κ—Opioid Agonists

    Institute of Scientific and Technical Information of China (English)

    龙亚秋; 牟奇勇; 仇达萍; 吴瑞琴


    Conformationally constrained bicyclic derivatives of the potent and selective κ-opioid receptor agonist 2-(3,4-dichlorophenyl)-N-methyl-N-[(1S)-1-Phenyl-2-(1-Pyrrolidinyl)-ethyl]acetamide(3,ICI-199,441)were designed to explore the effect of the conformational restriction and stereochemistry of the pharmacophoric ethylenediamine incorporated into the pyrrolidine on the affinity and κ-selectivity.A facile enantiosipecitfic synthetic route was extablished to afford all four stereoisomers starting from readily available amino acids through mild cyclization and amide formation.

  13. Synthesis and Antibacterial Activity of Novel Oxazolidinone Analogs Containing Substituted Thiazole/Fused-Bicyclic Groups

    Institute of Scientific and Technical Information of China (English)


    Sixteen novel oxazolidinone analogs containing substituted thiazole/fused-bicyclic(imidazo[1,2-b] pyridazine/imidazo[2,1-b]thiazole) groups were designed and synthesized. A new method for the preparation of the key intermediate compound 11 was proposed. The structures of the target compounds were confirmed by 1H NMR, IR and MS, and their in vitro antibacterial activities against staphylococcus aureus were evaluated. Among them, compound 16a displays a promising antibacterial activity comparable to that of linezolid.

  14. Synthesis of fused bicyclic piperidines: potential bioactive templates for medicinal chemistry. (United States)

    Zhou, Jinglan; Campbell-Conroy, Erica L; Silina, Alina; Uy, Johnny; Pierre, Fabrice; Hurley, Dennis J; Hilgraf, Nicole; Frieman, Bryan A; DeNinno, Michael P


    An array of six pyridyl-substituted fused bicyclic piperidines was prepared as novel cores for medicinal chemistry. For maximum diversity, the size of the fused ring varied from three to six atoms and contained up to two oxygen atoms. The pyridine ring was incorporated to improve physicochemical properties and to challenge the robustness of the chemistry. The presence of the pyridine did interfere with our initial approaches to these molecules, and in several instances, a blocking strategy had to be employed. These new scaffolds possess high sp3 character and may prove useful in multiple medicinal chemistry applications.

  15. Feasibility study on a perceived fatigue prediction dependent power control for an electrically assisted bicycle. (United States)

    Kiryu, T; Minagawa, H


    Several types of electric motor assists have been developed, as a result, it is important to control muscular fatigue on-site in terms of health promotion and motor rehabilitation. Predicting the perceived fatigue by several biosignal-related variables with the multiple regression model and polynomial approximation, we try to propose a self control design for the electrically assisted bicycle (EAB). We also determine the meaningful muscles during pedaling by muscle synergies in relation to the motion maturity. In field experiments, prediction of ongoing perceived physical fatigue could have the potential of suitable control of EAB.

  16. [The electrical stimulation bicycle: a neuroprosthesis for the everyday use of paraplegic patients]. (United States)

    Szecsi, J; Fiegel, M; Krafczyk, S; Straube, A; Quintern, J; Brandt, Th


    Until recently, few patients with complete paraplegia could walk or stand with the help of functional electrical stimulation (FES) of the leg muscles regularly at home. In comparison, FES cycling with an adapted tricycle is easy to put into practice because the legs remain connected to the pedals and through the use of a tricycle or stationary bicycle, the balancing problems of the patient recedes into the background. In the first German feasibility studies for paraplegic cycling, eleven completely paraplegic patients have been tested so far. The goal is to make FES cycling a daily activity in the lives of as many patients as possible.

  17. Analysis of vehicle-bicycle interactions at unsignalized crossings: A probabilistic approach and application. (United States)

    Silvano, Ary P; Koutsopoulos, Haris N; Ma, Xiaoliang


    In the last decades, bicycle usage has been increasing in many countries due to the potential environmental and health benefits. Therefore, there is a need to better understand cyclists' interactions with vehicles, and to build models and tools for evaluating multimodal transportation infrastructure with respect to cycling safety, accessibility, and other planning aspects. This paper presents a modeling framework to describe driver-cyclist interactions when they are approaching a conflicting zone. In particular, the car driver yielding behavior is modeled as a function of a number of explanatory variables. A two-level hierarchical, probabilistic framework (based on discrete choice theory) is proposed to capture the driver's yielding decision process when interacting with a cyclist. The first level models the probability of the car driver perceiving a situation with a bicycle as a potential conflict whereas the second models the probability of yielding given that a conflict has been perceived by the driver. The framework also incorporates the randomness of the location of the drivers' decision point. The methodology is applied in a case study using observations at a typical Swedish roundabout. The results show that the conflict probability is affected differently depending on the user (cyclist or driver) who arrives at the interaction zone first. The yielding probability depends on the speed of the vehicle and the proximity of the cyclist.

  18. Antiproliferative activity of bicyclic benzimidazole nucleosides: synthesis, DNA-binding and cell cycle analysis. (United States)

    Sontakke, Vyankat A; Lawande, Pravin P; Kate, Anup N; Khan, Ayesha; Joshi, Rakesh; Kumbhar, Anupa A; Shinde, Vaishali S


    An efficient route was developed for synthesis of bicyclic benzimidazole nucleosides from readily available d-glucose. The key reactions were Vörbruggen glycosylation and ring closing metathesis (RCM). Primarily, to understand the mode of DNA binding, we performed a molecular docking study and the binding was found to be in the minor groove region. Based on the proposed binding model, UV-visible and fluorescence spectroscopic techniques using calf thymus DNA (CT-DNA) demonstrated a non-intercalative mode of binding. Antiproliferative activity of nucleosides was tested against MCF-7 and MDA-MB-231 breast cancer cell lines and found to be active at low micromolar concentrations. Compounds and displayed significant antiproliferative activity as compared to and with the reference anticancer drug, doxorubicin. Cell cycle analysis showed that nucleoside induced cell cycle arrest at the S-phase. Confocal microscopy has been performed to validate the induction of cellular apoptosis. Based on these findings, such modified bicyclic benzimidazole nucleosides will make a significant contribution to the development of anticancer drugs.

  19. Comparison between treadmill and bicycle ergometer exercise tests in mild-to-moderate hypertensive Nigerians

    Directory of Open Access Journals (Sweden)

    Abiodun OO


    Full Text Available Olugbenga O Abiodun, Michael O Balogun, Anthony O Akintomide, Rasaaq A Adebayo, Olufemi E Ajayi, Suraj A Ogunyemi, Valentine N Amadi, Victor O Adeyeye Cardiology Unit, Department of Medicine, Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC, Ile-Ife, Osun state, Nigeria Background: Comparative cardiovascular responses to treadmill and bicycle ergometer (bike exercise tests in hypertensive Nigerians are not known. This study compared cardiovascular responses to the two modes of exercise testing in hypertensives using maximal exercise protocols. Methods: One hundred and ten male subjects with mild-to-moderate hypertension underwent maximal treadmill and bike test one after the other at a single visit in a simple random manner. Paired-sampled t-test was used to compare responses to both exercise tests while chi-squared test was used to compare categorical variables. Results: The maximal heart rate (P<0.001, peak systolic blood pressure (P=0.02, rate pressure product (P<0.001, peak oxygen uptake (P<0.001, and exercise capacity (P<0.001 in metabolic equivalents were significantly higher on the treadmill than on the bike. Conclusion: Higher cardiovascular responses on treadmill in Nigerian male hypertensives in this study, similar to findings in non-hypertensives and non-Nigerians in earlier studies, suggest that treadmill may be of better diagnostic utility in our population. Keywords: maximal exercise, treadmill, bicycle ergometer, hypertension, Nigerians

  20. Solution and Structural Investigations of Ligand Preorganization in Trivalent Lanthanide Complexes of Bicyclic Malonamides

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Bevin W.; Gilbertson, Robert D.; Hutchison, J. E.; Rather Healey, Elisabeth; Weakley, Timothy J R; Rapko, Brian M.; Hay, Benjamin P.; Sinkov, Sergei I.; Broker, Grant A.; Rogers, Robin D.


    This report describes an investigation into the coordination chemistry of trivalentlanthanides in solution and the solid state with acyclic and preorganized bicyclic malonamide ligands. Two experimental investigations were performed: solution bindingaffinities were determined through single-phase spectrophotometric titrations and the extent of conformational change upon binding was investigated with single-crystal X-raycrystallography. Both experimental methods compare the bicyclic malonamide (BMA), which is designed to be preorganized for binding trivalent lanthanides, to an analogousacyclic malonamide. Results from the spectrophotometric titrations indicate that BMA exhibits a 10-100 times increase in binding affinity to Ln(III) over acyclic malonamide.In addition, BMA forms compounds with high ligand-metal ratios, even when competing with water and nitrate ligands for binding sites. The crystal structures exhibit nosignificant differences in the nature of the binding between Ln(III) and the BMA or acyclic malonamide. These results support the conclusion that rational ligand design canlead to compounds that enhance the binding affinities within a ligand class.

  1. Cardiovascular and hormonal responses to bicycle exercise during lower body negative pressure (United States)

    Bonde-Petersen, F.; Suzuki, M.; Christensen, N. J.

    The purpose was to combine bicycle exercise and LBNP as a model to investigate the mechanisms regulating circulation during gravitatiobal stresses. METHODS: Cardiac Output (CO) by acetylene-, argon-, oxygen rebreathing; Heart Rate (HR) from ECG; Mean Arterial Pressure (MAP) by arm cuff; Plasma Nor-Epinephrine (NE), Epinephrine (E), and Lactate (HLa) by isotope and enzymatic techniques respectively. Total Peripheral Resistance (TPR)=MAP/CO and stroke volume (SV)=CO/HR. Six subjects exercised at 180-200 Watts in the upright position on a mechanically braked computer controlled small bicycle ergometer placed in a LBNP box. The above parameters were measured at rest and at 5 and 9 min of exercise without and with LBNP at -30 or -40 mmHg (depending on LBNP tolerance). RESULTS AND CONCLUSIONS: In the face of an increased sympathetic nervous activity (Ne+E, TPR, and HR increased) during exercise in LBNP, there was a decrease in CO and SV indicating that the venous return was insufficient. However, HLa was unchanged demonstrating that the blood flow to the working muscles did not suffer.

  2. A holistic approach to the integration of bicycle traffic into the urban landscape

    Directory of Open Access Journals (Sweden)

    Polonca Andrejčič Mušič


    Full Text Available Qualitative and quantitative indicators can be used to assess the quality of public space. The coherence of cycling infrastructure connectivity is an indicator of a public space's attractiveness as a basis for the quality of the bicycle traffic operation. We would like to find an optimal balance between the space's form and its image to provide good conditions for cycling as one of the most important forms of sustainable mobility, and consequently a factor facilitating a healthy lifestyle. The new approach brings a completely different view on planning cycling infrastructure, while rather than physical infrastructure characteristics, humans are placed at the forefront of the cycling infrastructure design as the most important measure of its quality. Since the complexity of human beings cannot be controlled with only one science or profession, solving the problem of bicycle traffic is not just a technical problem, but its design and management also lend a multidisciplinary character. From the perspective of different cycling infrastructure users, the study will define integrated multidisciplinary methodology for evaluating the quality of cycling infrastructure, which will equally include the criteria of sensing and perceiving of space. The new approach seeks a system of criteria, which enables the integrated planning of cycling infrastructure in all spatial, organizational, sectoral, and professional levels. All theoretical findings will be tested and demonstrated on the pilot case of the long-distance cycling connection in the area of four Slovenian coastal municipalities, namely Koper, Izola, Piran, and Ankaran.

  3. 150 bicycle injuries in children: a comparison with accidents due to other causes. (United States)

    Illingworth, C M; Noble, D; Bell, D; Kemn, I; Roche, C; Pascoe, J


    One hundred and fifty bicycle accidents seen at the Children's Hospital Sheffield over a 6-month period from mid-August 1979 were analysed and 9.3 per cent of the cases were admitted. Twenty-two per cent had fractures, 20 per cent had soft tissue injuries of face or scalp, 8 children having damaged their teeth. Of the accidents 17.3 per cent were due to hitting an obstruction, 30.7 per cent were due to loss of control on a hill or corner and 8 per cent were of mechanical origin. Eighty-eight per cent had cycling experience of a year or more, and 32.7 per cent had had previous cycling accidents. Comparison with other types of accidents previously studied at the hospital, involving skateboards, playground equipment or road traffic accidents affecting child pedestrians, showed that by far the most serious were those involving child pedestrians. The injuries from bicycle accidents were similar in severity to those involving skateboards.

  4. Energy cost and mechanical efficiency of riding a human-powered recumbent bicycle. (United States)

    Capelli, Carlo; Ardigo, Luca Paolo; Schena, Federico; Zamparo, Paola


    When dealing with human-powered vehicles, it is important to quantify the capability of converting metabolic energy in useful mechanical work by measuring mechanical efficiency. In this study, net mechanical efficiency (eta) of riding a recumbent bicycle on flat terrain and at constant speeds (v, 5.1-10.0 m/s) was calculated dividing mechanical work (w, J/m) by the corresponding energy cost (C(c), J/m). w and C(c) increased linearly with the speed squared: w = 9.41 + 0.156 . v(2); C(c) = 39.40 + 0.563 . v(2). eta was equal to 0.257 +/- 0.0245, i.e. identical to that of concentric muscular contraction. Hence, i) eta seems unaffected by the biomechanical arrangement of the human-vehicle system; ii) the efficiency of transmission seems to be close to 100%, suggesting that the particular biomechanical arrangement does not impair the transformation of metabolic energy in mechanical work. When dealing with human-powered vehicles, it is important to quantify mechanical efficiency (eta) of locomotion. eta of riding a recumbent bicycle was calculated dividing the mechanical work to the corresponding energy cost of locomotion; it was practically identical to that of concentric muscular contraction (0.257 +/- 0.0245), suggesting that the power transmission from muscles to pedals is unaffected by the biomechanical arrangement of the vehicle.

  5. Long-term use of computerized bicycle ergometry for spinal cord injured subjects. (United States)

    Sipski, M L; Alexander, C J; Harris, M


    Twenty-eight spinal cord injured subjects who participated in an electrical stimulation bicycle ergometry home program were surveyed to determine perceived benefits, home exercise adherence, and predictors of continued home exercise with electrical stimulation. Subjects were classified as users or nonusers depending upon if they used the electrical stimulation ergometry on a regular basis in the home during the past four months. Nineteen subjects qualified as users and nine were nonusers. Ninety-five percent of the users cycled at least twice per week whereas the majority of the nonusers stopped regular home exercise within one month postclinic discharge. All subjects generally perceived increases in muscle bulk and endurance. Users and nonusers perceived inconsistent results related to spasticity. Minimal effects were noted with neurogenic pain and swelling. Adherence to the home exercise program was significantly related to sex of subject and pre-injury exercise habits. Results are discussed in relation to the costs and benefits of electrical stimulation bicycle ergometry in the home.

  6. Præventiv effekt af cykelhjelme

    DEFF Research Database (Denmark)

    Nielsen, C T; Larsen, C F; Nordentoft, E


    with bicycle accidents. When a bicycle helmet is purchased, it is important to ensure that the helmet fits the head, that vision is not impeded and that the chinstrap secures the helmet correctly. Legislation is necessary to ensure that bicycle helmets sold in Denmark fulfill the minimum safety requirements.......The total number of persons injured following bicycle accidents in Denmark is estimated to be more than 50,000 annually. In half of the injured cyclists, lesions localized to the region of the head occur. Bicycle helmets provide considerable protection against brain injuries which constitute 13......%. Several investigations from abroad and from Denmark have demonstrated that protection of the head can reduce the number of deaths and of acute brain injuries due to bicycle accidents. On the basis of the literature, it is concluded that bicycle helmets provide good protection of the head in connection...

  7. Proposed helmet PET geometries with add-on detectors for high sensitivity brain imaging (United States)

    Tashima, Hideaki; Yamaya, Taiga


    For dedicated brain PET, we can significantly improve sensitivity for the cerebrum region by arranging detectors in a compact hemisphere. The geometrical sensitivity for the top region of the hemisphere is increased compared with conventional cylindrical PET consisting of the same number of detectors. However, the geometrical sensitivity at the center region of the hemisphere is still low because the bottom edge of the field-of-view is open, the same as for the cylindrical PET. In this paper, we proposed a helmet PET with add-on detectors for high sensitivity brain PET imaging for both center and top regions. The key point is the add-on detectors covering some portion of the spherical surface in addition to the hemisphere. As the location of the add-on detectors, we proposed three choices: a chin detector, ear detectors, and a neck detector. For example, the geometrical sensitivity for the region-of-interest at the center was increased by 200% by adding the chin detector which increased the size by 12% of the size of the hemisphere detector. The other add-on detectors gave almost the same increased sensitivity effect as the chin detector did. Compared with standard whole-body-cylindrical PET, the proposed geometries can achieve 2.6 times higher sensitivity for brain region even with less than 1/4 detectors. In addition, we conducted imaging simulations for geometries with a diameter of 250 mm and with high resolution depth-of-interaction detectors. The simulation results showed that the proposed geometries increased image quality, and all of the add-on detectors were equivalently effective. In conclusion, the proposed geometries have high potential for widespread applications in high-sensitivity, high-resolution, and low-cost brain PET imaging.

  8. Evaluation of anti-glare applications for a tactical helmet-mounted display (United States)

    Roll, Jason L.; Trew, Noel J. M.; Geis, Matthew R.; Havig, Paul R.


    Non see-through, monocular helmet mounted displays (HMDs) provide warfighters with unprecedented amounts of information at a glance. The US Air Force recognizes their usefulness, and has included such an HMD as part of a kit for ground-based, Battlefield Airmen. Despite their many advantages, non see-through HMDs occlude a large portion of the visual field when worn as designed, directly in front of the eye. To address this limitation, operators have chosen to wear it just above the cheek, angled up toward the eye. However, wearing the HMD in this position exposes the display to glare, causing a potential viewing problem. In order to address this problem, we tested several film and HMD hood applications for their effect on glare. The first experiment objectively examined the amount of light reflected off the display with each application in a controlled environment. The second experiment used human participants to subjectively evaluate display readability/legibility with each film and HMD hood covering under normal office lighting and under a simulated sunlight condition. In this test paradigm, participants had to correctly identify different icons on a map and different words on a white background. Our results indicate that though some applications do reduce glare, they do not significantly improve the HMD's readability/legibility compared with an uncovered screen. This suggests that these post-production modifications will not completely solve this problem and underscores the importance of employing a user-centered approach early in the design cycle to determine an operator's use-case before manufacturing an HMD for a particular user community.

  9. Measurement and reduction of system latency in see-through helmet mounted display (HMD) systems (United States)

    Vincenzi, Dennis A.; Deaton, John E.; Blickenderfer, Elizabeth L.; Pray, Rick; Williams, Barry; Buker, Timothy J.


    Future military aviation platforms such as the proposed Joint Strike Fighter F-35 will integrate helmet mounted displays (HMDs) with the avionics and weapon systems to the degree that the HMDs will become the aircraft's primary display system. In turn, training of pilot flight skills using HMDs will be essential in future training systems. In order to train these skills using simulation based training, improvements must be made in the integration of HMDs with out-thewindow (OTW) simulations. Currently, problems such as latency contribute to the onset of simulator sickness and provide distractions during training with HMD simulator systems that degrade the training experience. Previous research has used Kalman predictive filters as a means of mitigating the system latency present in these systems. While this approach has yielded some success, more work is needed to develop innovative and improved strategies that reduce system latency as well as to include data collected from the user perspective as a measured variable during test and evaluation of latency reduction strategies. The purpose of this paper is twofold. First, the paper describes a new method to measure and assess system latency from the user perspective. Second, the paper describes use of the testbed to examine the efficacy of an innovative strategy that combines a customized Kalman filter with a neural network approach to mitigate system latency. Results indicate that the combined approach reduced system latency significantly when compared to baseline data and the traditional Kalman filter. Reduced latency errors should mitigate the onset of simulator sickness and ease simulator sickness symptomology. Implications for training systems will be discussed.

  10. Ownship status helmet-mounted display symbology for off-boresight tactical applications (United States)

    Jenkins, J. Chris; Thurling, Andrew J.; Brown, Becky D.


    Ownship status helmet-mounted display (HMD) symbology for off-boresight use in fixed-wing tactical aircraft serves to convey aircraft state information (e.g., airspeed, heading, altitude, and attitude) to the pilot for increased situation awareness and maintenance of spatial orientation. A recent flight test evaluation of HMD symbology conducted by the Air Force Research Laboratory (AFRL) and the Edwards AFB Test Pilot School (TPS) indicated a clear performance advantage afforded by the use of off-boresight symbology compared to HUD use alone. The results indicated that the Non-Distributed Flight Reference (NDFR) was the best format of the HMD symbol sets evaluated and served as a good information/orientation aid off-boresight but needs further development to realize its tactical benefit. Specifically, the TPS recommendations pointed to a need for an improved rate-of-change (i.e., trend) indicator for airspeed and altitude, as well as an improvement to the off-boresight attitude reference concerning attitude precision (i.e., climb-dive), particularly near straight and level flight. Based on these recommendations, AFRL modified the original design of the NDFR symbology to satisfy the deficiencies noted by the Edwards AFB TPS. Two variants of the NDFR format with modifications for conveying trend information for airspeed and altitude as well as precision of aircraft attitude were evaluated along with the Mil-Std-1787D HUD symbology and baseline NDFR format. The study examined the four symbol sets during two simulated operationally representative air-to-air intercept tasks that employed the use of an HMD for the off-boresight visual acquisition of a target aircraft. Overall, the NDFR/Odometer symbology allowed a significantly higher amount of off-boresight viewing time while equaling the HUD and other off-boresight symbol sets for primary task performance and proved to be the preferred format for trend mechanization based on pilot comments.

  11. Improving Situational Awareness in Noisy Environments: A Helmet-Based System for Speech Enhancement, Hearing Protection, and Shock Localization (United States)


    incorporates the main speech processing features of the Smart Helmet. This model is implemented in MATLAB and combines the basic processing modes and...Le troisième volet est un modèle de logiciel complet qui intègre les fonctions de traitement de discours principal de la casque dynamique. Ce...modèle est mis en œuvre dans MATLAB et combine les modes de traitement de base et les mécanismes de basculement de mode. Résultats d’exemples montrent

  12. [Fatal motorcycle, motorbike and bicycle accidents. Cases from the medico-legal sector of Parma (1973-82)]. (United States)

    Gennari, M; Laudano, M


    The data of the Institute of Legal Medicine and Insurance of the University of Parma regarding mortal motorcycle, motorbicycle and cycling accidents for a ten year period is cited (1973-1982) (296 cases). The data show a very high incidence of cranio-facial lesions (83.5%) which is the absolute most frequent cause of death (58.5%). The appeal for the promulgation of a rider's helmet as obligatory in Italy thus becomes an urgency. The high percentage of mortal accidents amongst cyclists and the substantial correspondence to the traumatology of motorcyclists senders towards this category of road users the need for similar preventive measures, if these can't be resolved with helmets for practical reasons, it is necessary to solicit more severe and drastic control for the respect of circulation regulations by them. On the other hand it is necessary to take measures capable of guaranteeing a way (lane for cyclists).

  13. A Balanced Scorecard of Sustainable Management in the Taiwanese Bicycle Industry: Development of Performance Indicators and Importance Analysis

    Directory of Open Access Journals (Sweden)

    Chih-Chao Chung


    Full Text Available The main purpose of this study is to investigate the development of the performance indicators of sustainable management in the Taiwanese bicycle industry and to perform an importance analysis. Based on the Balanced Scorecard concept, the framework of sustainable management is added. Ten experts evaluated the performance indicators of a sustainable Balanced Scorecard in the Taiwanese bicycle industry using five major categories: (1 Financial, (2 Customer, (3 Internal Business Processes, (4 Learning and Growth, and (5 Sustainable Development, and a total of 21 performance indicators were used. The analytic network process (ANP was used to perform an importance analysis of the various performance indicators. Most of the experts suggested that for the introduction of a sustainable management strategy into the bicycle industry in Taiwan, it is necessary to include the definition of sustainable management and to improve five performance indicators: innovation process, customer satisfaction, operations process, after-sales service, and market share. According to the analysis results, this study proposed relevant management definitions and suggestions to be used as important references for decision-makers to understand the introduction of sustainable management strategies to the current bicycle industry in Taiwan.

  14. Changes in VO2 Max. Resulting from Bicycle Training at Different Intensities Holding Total Mechanical Work Constant. (United States)

    Burke, Edmund A., Jr.; Franks, B. Don

    Effects of different training intensities on oxygen intake were determined in this study. Sixteen male subjects aged 16-18 were randomly assigned to one of three training groups or a control group. The training groups trained 3 days per week on bicycle ergometers at different intensities (85 percent, 75 percent, or 65 percent of heart rate…

  15. The effect of depressive symptomatology on plasma cortisol responses to acute bicycle exercise among post-menopausal women

    NARCIS (Netherlands)

    van der Pompe, G.; Bernards, N; Meijman, T.F.; Heijnen, C.J


    The present study was designed to elucidate the effect of depressive symptomatology on the cortisol response to strenuous exercise. Thirteen healthy, post-menopausal women participated in this study. The results show that acute bicycle exercise activates the hypothalamic-pituitary-adrenal (HPA) axis

  16. Examining the potential for modal change : motivators and barriers for bicycle commuting in Dar-es-Salaam

    NARCIS (Netherlands)

    Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; Maarseveen, van M.F.A.M.


    The paper examines the effect of various motivators, barriers and policy related interventions (i.e., personal, social and physical–environmental factors) on bicycle commuting in Dares-Salaam, Tanzania. The research shows that these factors have different effects on people depending on the stage of

  17. Synthesis of novel N1-substituted bicyclic pyrazole amino acids and evaluation of their interaction with glutamate receptors

    DEFF Research Database (Denmark)

    Conti, Paola; Grazioso, Giovanni; di Ventimiglia, Samuele Joppolo


    N1-substituted bicyclic pyrazole amino acids (S)-9a-9c and (R)-9a-9c, which are conformationally constrained analogues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested for activity at ionotropic and metabotropic glutamate receptors...

  18. Solar battery powered bicycle lamp SKL050. Final report; Solar/Akkufahrradleuchte SKL050. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Lang, O.


    Up to now there are no functional or high quality mobile solar powered chargers and lamps available for the outdoor and bicycle consumer. Hence the project SKL050 was concerned with the development of a novel combination of battery powered multi-functional lamp and solar charger. All components such as solar module, bulb, electronics and housing were supposed to be involved in the development. The goal was a ready-for-production development well placed in the field of high quality bicycle, camping and household appliances by efficient, well matched components and an exclusive and functional design. Another issue in the development was a cost effective production by automated assembling in order to maintain the maximum customer price of 129,- DM (incl. VAT). Most of the stated goals were reached at the end of the project. Only the detailed construction of the housing parts and final approvals have to be carried out by a bicycle accessories company which is interested to produce and market the SKL050 in licence. Apart from the product SKL050 several important results regarding automation processes of small solar modules have been collected and are supposed to be integrated in future products of the SOLARC GmbH. (orig.) [German] Im Bereich mobiler solarbetriebener Ladegeraete und Leuchten fuer den Outdoor- und Fahrradkonsumenten sind bislang keine funktionell oder aesthetisch brauchbaren Produkte verfuegbar. Das Vorhaben SKL050 umfasste daher gezielt die Entwicklung einer neuartigen Kombination aus akkubetriebener Mehrzweckleuchte und Solar-Akkulader. Saemtliche Basiskomponenten wie Solarmodul, Leuchtmittel, Elektronik und Gehaeuse sollten mit in die Entwicklung einbezogen werden. Ziel des Vorhabens war ein zur Serienreife entwickeltes Produkt, welches durch leistungsfaehige, optimal aufeinander abgestimmte Komponenten sowie durch ein exklusives und funktionelles Design einen Platz im Bereich der hochwertigen Fahrrad-, Camping-, und Haushaltsaccessoires findet. Bei

  19. Conformational Preference and Donor Atom Interaction Leading to Hexacoordination vs Pentacoordination in Bicyclic Tetraoxyphosphoranes(1). (United States)

    Sherlock, David J.; Chandrasekaran, A.; Prakasha, T. K.; Day, Roberta O.; Holmes, Robert R.


    New bicyclic tetraoxyphosphoranes all containing a six-membered oxaphosphorinane ring, C(6)H(8)(CH(2)O)(2)P(OC(12)H(8))(OXyl) (1), (C(6)H(4)O)(2)P(OC(12)H(8))(OXyl) (2), CH(2)[(t-Bu)(2)C(6)H(2)O](2)P(OC(12)H(8))(OXyl) (3), O(2)S[(t-Bu)MeC(6)H(2)O](2)P(OC(12)H(8))(OXyl) (4), and S[(t-Bu)MeC(6)H(2)O](2)P(OC(12)H(8))(OXyl) (5), were synthesized by the oxidative addition reaction of the cyclic phosphine P(OC(12)H(8))(OXyl) (6) with an appropriate diol in the presence of N-chlorodiisopropylamine. X-ray analysis revealed trigonal bipyramidal (TBP) geometries for 1-4 where the dioxa ring varied in size from six- to eight-membered. With a sulfur donor atom as part of an eight-membered ring in place of a potential oxygen donor atom of a sulfone group as in 4, the X-ray study of 5 showed the formation of a hexacoordinated structure via a P-S interaction. Ring constraints are evaluated to give an order of conformational flexibility associated with the (TBP) tetraoxyphosphoranes 4 > 3 approximately 1 > 2 which parallels the degree of shielding from (31)P NMR chemical shifts: 4 > 3 > 1 > 2. The six- and seven-membered dioxa rings in 1 and 2, respectively, are positioned at axial-equatorial sites, whereas the eight-membered dioxa ring in 3 and 4 occupies diequatorial sites of a TBP. V-T (1)H NMR data give barriers to xylyl group rotation about the C-OXyl bond. The geometry of 5 is located along a coordinate from square pyramidal toward octahedral to the extent of 60.7%. Achieving hexacoordination in bicyclic tetraoxyphosphoranes of reduced electrophilicity relative to bicyclic pentaoxyphosphoranes appears to be dependent on the presence of a sufficiently strong donor atom.

  20. Universal flow-density relation of single-file bicycle, pedestrian and car motion (United States)

    Zhang, J.; Mehner, W.; Holl, S.; Boltes, M.; Andresen, E.; Schadschneider, A.; Seyfried, A.


    The relation between flow and density is an essential quantitative characteristic to describe the efficiency of traffic systems. We have performed experiments with single-file motion of bicycles and compared the results with previous studies for car and pedestrian motion in similar setups. In the space-time diagrams we observe three different states of motion (free flow state, jammed state and stop-and-go waves) in all these systems. Despite their obvious differences they are described by a universal fundamental diagram after proper rescaling of space and time which takes into account the size and free velocity of the three kinds of agents. This indicates that the similarities between the systems go deeper than expected.

  1. Commuter Transport Mode Choice and Typologies in the Bicycle City Copenhagen

    DEFF Research Database (Denmark)

    Olesen, Anne Vingaard; Kjems, Erik; Reinau, Kristian Hegner;


    Bicycle Cities” such as Copenhagen can serve as role models: how far can we push the commuter modal shares in the direction of more sustainable transport? This paper presents a study that aims to give a state-of-the-art picture of a Copenhagen that provides wide cycling highways and the politica...... restricted our analysis to commuters both living and working within the city center. The characterization of these commuter types was strikingly short of personal attitudes about environmental concerns....... transport and car use. Furthermore, we derived a typology of four commuter types: “cyclists because of short distances” (40 percent), ”commuters by car or public transport out of necessity” (35 percent), ”more eco-oriented cyclists and others” (16 percent) and ”passionate motorists” (8 percent) when we...

  2. Synthesis of bicyclic molecular scaffolds (BTAa): an investigation towards new selective MMP-12 inhibitors. (United States)

    Mannino, Claudia; Nievo, Marco; Machetti, Fabrizio; Papakyriakou, Athanasios; Calderone, Vito; Fragai, Marco; Guarna, Antonio


    Starting from 3-aza-6,8-dioxa-bicyclo[3.2.1]octane scaffold (BTAa) a virtual library of molecules was generated and screened in silico against the crystal structure of the Human Macrophage Metalloelastase (MMP-12). The molecules obtaining high score were synthesized and the affinity for the catalytic domain of MMP-12 was experimentally proved by NMR experiments. A BTAa scaffold 20 having a N-hydroxyurea group in position 3 and a p-phenylbenzylcarboxy amide in position 7 showed a fair inhibition potency (IC50 = 149 microM) for MMP-12 and some selectivity towards five different MMPs. These results, taken together with the X-ray structure of the adduct between MMP-12, the inhibitor 20 and the acetohydroxamic acid (AHA), suggest that bicyclic scaffold derivatives may be exploited for the design of new selective matrix metalloproteinase inhibitors (MMPIs).

  3. Laser dye stability. Pt. 4. Photodegradation relationships for bicyclic dyes in alcohol solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, A.N. (Naval Weapons Center, China Lake, Calif. (USA). Research Dept.)


    Changes in the absorption of a dye laser solution are examined after excitation with a xenon flashlamp. It is found that the rate of bleaching as a function of the total input energy of coumarin or quinolone dyes in ethanol increases in direct proportion to the dye concentration. This relationship suggests that the dye reacts with a photoproduct of the solvent rather than being directly decomposed by the xenon flash. We have measured the conversion of the dye to form products, P, absorbing at the lasing wavelength. Results correspond to the dye reacting with a precursor of P to form either insoluble products or ones not absorbing at the lasing wavelength. Thus larger total amounts of bleached dye do not proportionately increase P, and hence do not proportionately inhibit lasing. Furthermore, we find that P increases with the total input energy fairly independent of the rate of bleaching for a given bicyclic dye in an alcohol solution.

  4. Universal flow-density relation of single-file bicycle, pedestrian and car motion

    CERN Document Server

    Zhang, Jun; Holl, Stefan; Boltes, Maik; Andresen, Erik; Schadschneider, Andreas; Seyfried, Armin


    The relation between flow and density, also known as the fundamental diagram, is an essential quantitative characteristic to describe the efficiency of traffic systems. We have performed experiments with single-file motion of bicycles and compare the results with previous studies for car and pedestrian motion in similar setups. In the space-time diagrams we observe three different states of motion (free flow state, jammed state and stop-and-go waves) in all these systems. Despite of their obvious differences they are described by a universal fundamental diagram after proper rescaling of space and time which takes into account the size and free velocity of the three kinds of agents. This indicates that the similarities between the systems go deeper than expected.

  5. Universal flow-density relation of single-file bicycle, pedestrian and car motion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J., E-mail: [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Mehner, W., E-mail: [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Holl, S., E-mail: [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Boltes, M., E-mail: [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Andresen, E., E-mail: [Department of Computer Simulation for Fire Safety and Pedestrian Traffic, Bergische Universität Wuppertal, 42285 Wuppertal (Germany); Schadschneider, A., E-mail: [Institut für Theoretische Physik, Universität zu Köln, 50937 Köln (Germany); Seyfried, A., E-mail: [Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Department of Computer Simulation for Fire Safety and Pedestrian Traffic, Bergische Universität Wuppertal, 42285 Wuppertal (Germany)


    The relation between flow and density is an essential quantitative characteristic to describe the efficiency of traffic systems. We have performed experiments with single-file motion of bicycles and compared the results with previous studies for car and pedestrian motion in similar setups. In the space–time diagrams we observe three different states of motion (free flow state, jammed state and stop-and-go waves) in all these systems. Despite their obvious differences they are described by a universal fundamental diagram after proper rescaling of space and time which takes into account the size and free velocity of the three kinds of agents. This indicates that the similarities between the systems go deeper than expected.

  6. Laplacian spectral characterization of products of complete graphs with trees, unicyclic graphs, and bicyclic graphs

    CERN Document Server

    Wang, Suijie


    In this paper, we give a Laplacian characterization of the product of the complete graphs $K_m$ with trees, unicyclic graphs, and bicyclic graphs. More precisely, let $G$ be a connected graph with at most two independent cycles. If $G$ is neither $C_{6}$ nor $\\Theta_{3,2,5}$ and determined by its Laplacain spectrum, then the product $G\\times K_{m}$ is also a graph determined by its Laplacian spectrum. In addition, we find the cosepctral graphs of $C_{6}\\times K_{m}$ and $\\Theta_{3,2,5}\\times K_{m}$, where the case $m=1$ is shown in Figure \\ref{F1} and \\ref{F2}.

  7. Deciphering characteristics of bicyclic aromatics--mediators for reductive decolorization and bioelectricity generation. (United States)

    Xu, Bin; Chen, Bor-Yann; Hsueh, Chung-Chuan; Qin, Lian-Jie; Chang, Chang-Tang


    This first-attempt study quantitatively assessed electron-mediating characteristics of bicyclic aromatics - 1-amino-2-naphthol, 4-amino-1-naphthol (i.e., decolorized intermediates of azo dyes - orange I and II) for color removal and power generation in MFCs. According to cyclic-voltammetric profiles, the presence of reduction and oxidation peak potentials clearly suggested a crucial role of these intermediates as electron-shuttling mediators. Shake-flask cultures also showed that appropriate accumulation of 1A2N, 4A1N apparently enhanced color-removal efficiencies of bacterial decolorization. This study clearly suggested that suitable supplementation of electrochemically active electron shuttle(s) to dye-bearing MFCs is a promising strategy to stimulate reductive decolorization and bioelectricity generation.

  8. Compliant mechanism road bicycle brake: a rigid-body replacement case study

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Brian M [Los Alamos National Laboratory; Howell, Larry L [NON LANL; Magleby, Spencer P [NON LANL


    The design of high-performance bicycle brakes is complicated by the competing design objectives of increased performance and low weight. But this challenge also provides a good case study to demonstrate the design of compliant mechanisms to replace current rigid-link mechanisms. This paper briefly reviews current road brake designs, demonstrates the use of rigid-body replacement synthesis to design a compliant mechanism, and illustrates the combination of compliant mechanism design tools. The resulting concept was generated from the modified dual-pivot brake design and is a partially compliant mechanism where one pin has the dual role of a joint and a mounting pin. The pseudo-rigid-body model, finite element analysis, and optimization algorithms are used to generate design dimensions, and designs are considered for both titanium and E-glass flexures. The resulting design has the potential of reducing the part count and overall weight while maintaining a performance similar to the benchmark.

  9. 深圳市自行车交通系统发展策略%Development Strategies for Bicycle Transportation System in Shenzhen

    Institute of Scientific and Technical Information of China (English)



    The percentage of bicycle travel in Shenzhen has decreased 38%from early 1980s to 2010, indi-cating the urgent need for bicycle transportation system reconstruction. By analyzing the bicycle travel de-mand, characteristics and public opinions in Shenzhen, this paper reveals that the low percentage of bicy-cle travel is mainly caused by inadequate bicycle lanes and parking facilities. Based on analyses of influen-tial factors and future development of bicycle transportation, along with the comprehensive transportation system planning in Shenzhen, the paper proposes the functionalities and objectives of bicycle transporta-tion development. Development strategies for establishing a harmonious and friendly bicycle transporta-tion system are further elaborated from six aspects, including differentiating development for different re-gions, bicycle lane network, bicycle lanes, bicycle parking facilities, bike share system, and electric bicy-cles.%20世纪80年代初至2010年,深圳市自行车出行比例下降38%,未来如何构建自行车交通系统亟须探讨。首先通过对深圳市自行车交通出行需求与特征、公众意见调查等分析,指出自行车道、停放设施不完善是导致自行车出行比例低的主要原因。基于深圳市自行车交通发展影响因素及前景分析,结合深圳市综合交通体系规划,提出自行车交通发展的定位和目标。重点从区域差异化发展、自行车道网络、自行车道、自行车停放设施、公共自行车以及电动自行车六个方面阐述构建与公共交通和谐发展、骑行环境友好的深圳市自行车交通系统发展策略。

  10. Driver behavior during bicycle passing maneuvers in response to a Share the Road sign treatment. (United States)

    Kay, Jonathan J; Savolainen, Peter T; Gates, Timothy J; Datta, Tapan K


    The interaction of motorists and bicyclists, particularly during passing maneuvers, is an area of concern to the bicycle safety community as there is a general perception that motor vehicle drivers may not share the road effectively with bicyclists. This is a particular concern on road sections with centerline rumble strips where motorists are prone to crowd bicyclists during passing events. One potential countermeasure to address this concern is the use of a bicycle warning sign with a "Share the Road" plaque. This paper presents the results of a controlled field evaluation of this sign treatment, which involved an examination of driver behavior while overtaking bicyclists. A series of field studies were conducted concurrently on two segments of a high-speed, rural two-lane highway. These segments were similar in terms of roadway geometry, traffic volumes, and other relevant factors, except that one of the segments included centerline rumble strips while the other did not. A before-and-after study design was utilized to examine changes in motor vehicle lateral placement and speed at the time of the passing event as they relate to the presence of centerline rumble strips and the sign treatment. Centerline rumble strips generally shifted vehicles closer to the bicyclists during passing maneuvers, though the magnitude of this effect was marginal. The sign treatment was found to shift motor vehicles away from the rightmost lane positions, though the signs did not significantly affect the mean buffer distance between the bicyclists and passing motorists or the propensity of crowding events during passing. The sign treatment also resulted in a 2.5miles/h (4.0km/h) reduction in vehicle speeds. Vehicle type, bicyclist position, and the presence of opposing traffic were also found to affect lateral placement and speed selection during passing maneuvers.

  11. Prediction of oxygen uptake on a bicycle wind-loaded simulator. (United States)

    Dengel, D R; Graham, R E; Jones, M T; Norton, K I; Cureton, K J


    The primary purpose of this study was to determine the accuracy of estimating oxygen uptake (VO2) from the flywheel revolution rate of a bicycle wind-loaded simulator. VO2 at four different flywheel revolution rates was measured on a Findlay Road Machine (FRM). Ten male trained cyclists, 10 male untrained cyclists, 10 female trained cyclists and 10 female untrained cyclists served as subjects. Significant curvilinear relationships (P less than 0.01) were found between road speed estimated from flywheel revolution rate and VO2 expressed as 1.min-1,, 1.min-1.m-2 (r = 0.97, 0.96, 0.98, respectively). The absolute standard error of the mean VO2 was 0.21 l.min-1 (9.6%), 3.71 (11.5%) and 0.10 l.min-1.m-2 (7.9%), respectively. The relationship between VO2 and speed was similar to that reported during road cycling. To determine the magnitude of between-machine differences in VO2, six subjects randomly performed cycling using two different FMR. Significant (P less than 0.05) differences between machines were found at only the highest speed. The present study indicates that it is possible to accurately predict VO2 from flywheel revolution rate using a FRM. Since the FRM appears to approximate the resistance a cyclist experiences on the road and allows cyclists to use their own bicycle, it provides a good alternative to traditional laboratory ergometers.

  12. 基于网络的农业运输车头盔定制系统%Customization System of Helmets for Agricultural Transporters Based on Network

    Institute of Scientific and Technical Information of China (English)

    吕群华; 郭彩玲; 时君伟


    通过分析农业运输车头盔的现状和特点,提出了个性化网络定制系统对于农业运输车头盔销售和购买的重要意义.探讨了农业运输车头盔定制系统的结构和系统实施路线.研究了系统实现的2项%The status and characters of the helmets for agricultural transporters are analyzed.The personalized customization system based on network plays important roles in selling and purchasing the helmets for agricultural transporters.The structure and implementation route of customization system of helmets for agricultural transporters are discussed.Two key technologies to realize the system including network database technology and network virtual presentation technology are studied.The prototype system of the network customization and presentation of the helmets for agricultural transporters is developed.

  13. Human Factors Assessment of U.S. Marine Lightweight Helmet Suspension Systems: Standard A Pad System vs. a Proposed Suspension System B HeadGard (United States)


    7  3.7  Measurement Devices: Anthropometry ..........................................................................7...56  Figure H-11. Participant negotiating the high fence . ....................................................................56...helmet. 3.7 Measurement Devices: Anthropometry Anthropometry is the systematic measurement of the human body. These measurements are used to guide

  14. Analysis of the Influencing Factors of the Public Willingness to Participate in Public Bicycle Projects and Intervention Strategies—A Case Study of Jiangsu Province, China

    Directory of Open Access Journals (Sweden)

    Ranran Yang


    Full Text Available In this study, factors influencing the willingness to participate in public bicycle projects were analyzed using the binary logistic model. The study builds on a broad and practical conceptual framework that embraces four dimensions of influencing factors, including household demographic, psychological, external, and public bicycle variables. The empirical results are based on a questionnaire survey that was sent to 520 urban residents in Xuzhou, Taizhou, and Suzhou in Jiangsu province. The survey indicates that environmental responsibility, improvement of the public transport system, health and safety considerations in relation to public bicycles, and environmental crisis consciousness have appreciable impacts upon the willingness to participation in public bicycle projects. The first three of these have a positive impact, whereas the last (environmental crisis consciousness has a negative impact. Consequently, some policy suggestions are proposed.

  15. 施工碎石对安全帽撞击的可靠度分析%Reliability Analysis of Safety Helmets Impacted by Constructioning Macadam

    Institute of Scientific and Technical Information of China (English)

    郝宪武; 王仕珏; 王晓明


    随着桥梁高度的不断加高,安全施工变得越来越重要.施工碎石坠落做为施工中一种高发、高危事件,对施工人员的安全构成了严重的威胁.本文以安全帽的抵抗能力与施工碎石对安全帽的撞击力作为极限状态方程的抗力和效应,通过分析影响抗力和效应的各种不确定性因素,包括碎石的质量、形状,安全帽的材料、厚度、变形量、剪切周长等,建立了相应的概率模型.最后,以柳沟大桥为实例,分析了相关参数对安全帽可靠度指标的影响.%With the increase of the height of bridge, the safe construction becomes more and more important. Construction macadam as one of the most high incidences in construction which poses severe threats on safety of construction personnel. Based on the macadam with the helmet impact, this paper will give a limit state equation in reliability analysis, in which the safety helmet resistance capacity is taken as the resistance, while macadam' s impact force on safety helmet is taken as load, analysed the uncertainties which affect resistance and load, including quality and shape of macadam, material, thickness and deformation of safety helmet, shear perimeter, and other random variables, established the corresponding probabilistic assessment model. Finally, takes the Liugou Bridge as an example analyse the effects of correlation parameter on reliability index of safety helmet.

  16. 中国电动自行车市场结构分析%Analysis of China electric bicycle market structure

    Institute of Scientific and Technical Information of China (English)



    the paper discusses the electric bicycle market development on the base of analysis of China electric bicycle market structure according to the Western industrial organization theory.%本文在以西方产业组织理论对我国电动自行车市场结构进行分析的的基础上,对未来电动自行车市场的发展进行了探讨。

  17. New and Concise Syntheses of the Bicyclic Oxamazin Core Using an Intramolecular Nitroso Diels-Alder Reaction and Ring-Closing Olefin Metathesis (United States)

    Watson, Kyle D.; Carosso, Serena


    Herein two new and concise synthetic approaches for making an unsaturated bicyclic oxamazin core are reported. The first involves the use of an intramolecular Diels-Alder reaction to form both of the fused rings in one step. The second approach incorporates ring-closing olefin metathesis in the final step to form the second fused ring of the core. The scope of the second approach was also expanded further to afford larger ringed bicyclic systems. PMID:23276301

  18. New and concise syntheses of the bicyclic oxamazin core using an intramolecular nitroso Diels-Alder reaction and ring-closing olefin metathesis. (United States)

    Watson, Kyle D; Carosso, Serena; Miller, Marvin J


    Herein two new and concise synthetic approaches for making an unsaturated bicyclic oxamazin core are reported. The first involves the use of an intramolecular Diels-Alder reaction to form both of the fused rings in one step. The second approach incorporates ring-closing olefin metathesis in the final step to form the second fused ring of the core. The scope of the second approach was also expanded further to afford larger ringed bicyclic systems.

  19. Analysis of the Influencing Factors of the Public Willingness to Participate in Public Bicycle Projects and Intervention Strategies—A Case Study of Jiangsu Province, China



    In this study, factors influencing the willingness to participate in public bicycle projects were analyzed using the binary logistic model. The study builds on a broad and practical conceptual framework that embraces four dimensions of influencing factors, including household demographic, psychological, external, and public bicycle variables. The empirical results are based on a questionnaire survey that was sent to 520 urban residents in Xuzhou, Taizhou, and Suzhou in Jiangsu province. The s...

  20. Teste de Conconi adaptado para bicicleta aquática Conconi test adapted to aquatic bicycle

    Directory of Open Access Journals (Sweden)

    Jonas Neves Martins


    Full Text Available A prática regular de exercícios físicos tem sido considerada um dos mecanismos que auxiliam a melhoria de padrões da saúde e de qualidade de vida. Em conseqüência do crescimento da procura por academias de ginástica, as atividades físicas no meio líquido, com destaque para a bicicleta aquática, têm aumentado nos últimos anos. No entanto, há ainda carência de métodos para a avaliação e prescrição do treinamento aeróbio neste tipo de equipamento. O objetivo deste estudo foi propor uma adaptação do teste de Conconi et al. (1982 para bicicleta aquática. Foram testados 27 participantes (24 ± 6 anos, 171 ± 8cm, 66 ± 12kg 15 do sexo masculino e 12 do feminino. Os participantes foram submetidos a um teste progressivo, realizado em bicicleta aquática, com carga inicial de 50RPM e incremento de 3RPM a cada minuto, até a exaustão. A FC foi registrada durante todo o teste. Para análise dos dados, foi utilizada estatística descritiva e o teste "t" de Student (P Physical exercise has been considered one of the mechanisms that improve health and quality of life. As a consequence of the enhanced demand for fitness centers, physical activities in liquid environment, especially aquatic cycling, have increased in the last years. However, methods of assessment and prescription of aerobic training in these equipments are still scarce. The objective of this study was to propose an adapted test of Conconi et al (1982 to aquatic bicycle. 27 participants (24 ± 6 years, 171 ± 8 cm, 66 ± 12 kg, 15 male and 12 female, were assessed. The participants have been submitted to a graded test in aquatic bicycle, with initial load of 50 RPM and increments of 3 RPM each minute, until exhaustion. HR was registered during the entire test. For data analysis, descriptive statistics were used as well as Student "t" test for comparison between genders. HRDP was identified in 85% of the subjects. There were not significant differences in HRmax (181 ± 12