Single Rider Research Articles

현대인의 초상 ‘기러기 가족’ 탐색을 통한 위기 분석

This study attempted to explore the effects of family separation on the process of maintaining wild geese family relationships through the movie 'Single Rider'. This study collected significant data from the wild goose family in the film, such as their dialogue, nonverbal components, and major daily lives or events that cause behavioral changes. This data changed to texts were analyzed with a Matrix analysis by applying A Crisis Model of the Wild Geese Family Relationship. The results of analysis were these. Firstly, the lack or absence of intimacy, sex life, and trust between wild goose couples has had a dangerous effect on their relationship. Secondly, the loss of role due to the fathers’ absence brought a crisis to the relationship between fathers and children. Finally, from the perspective of each of the couples, wild goose fathers spend a long time living alone, which causes problems and reduces their health-related quality of life, and wild goose mothers also experienced identity confusion and crisis due to role changes caused by living separately. These results show that due to the instability of family separation itself, these wild geese families eventually raised possibilities of family disruptions or break-up's.

The aerodynamic assessment of tandem cyclists in preparation for the 2021 Paralympic Games: A case study

Reducing the level of aerodynamic drag (CdA) via use of a wind tunnel will ultimately improve a competitive cyclists performance. Whilst this tool is widely considered a ‘gold standard’, previous studies have centred on single riders or scale models to evaluate aerodynamic drag. No study to date has assessed the precision of wind tunnel testing with the additional perceived complexity of a tandem bicycle with a pair of competitive paracyclists. The first part of this investigation evaluated the use of a wind tunnel in the assessment of tandem paracyclists. A male and female team of paracyclists riding tandem versions of either a time trial track bicycle or a road/time trial bicycle undertook a series of measurement intervals in a wind tunnel. Three different combinations of these riders and bicycles obtained a Coefficient of Variation of their mean CdA of 1.8%–2.6%. The second part of this investigation acted as a case study by implementing a range of aerodynamic interventions to potentially reduce the male team’s CdA. For example, progressive efforts reduced a team’s CdA from the baseline of 0.338 m2 to ultimately 0.321 m2 predominately by lowering both tandem riders heads Whilst tandem cyclist performance enhancement has recieved scant attention in the past, this case study only highlights the value of doing so in the future.

Sagittal spine disposition and pelvic tilt during outdoor fitness equipment use and their associations with kinanthropometry proportions in middle-aged and older adults.

BackgroundOutdoor fitness training has become popular as a tool for improving the health, especially middle-aged and older adults. For this purpose, outdoor fitness equipment (OFE) have been installed in public areas. However, their safety and effectiveness are still unknown. The aim of the present research was to analyze the sagittal disposition of the spine and pelvic tilt during the use of OFE, and to determine the influence of anthropometric variables on these factors in middle-aged and older adults.MethodsSeventy healthy volunteers, 56 women and 14 men (age: 63.14 ± 8.19 years) participated in the study. Sagittal spine disposition and pelvic tilt were measured using a Spinal Mouse®, in the relaxed standing position, and during the use of the OFE. In addition, kinanthropometry variables were also measured according to the guidelines of the International Society for the Advancement of Kinanthropometry.ResultsRegarding thoracic kyphosis, a significant decrease was found in thoracic kyphosis in the initial position (IP) in single bonny rider (SBR) (p = 0.006) and row (p = 0.046), and a significant increase in the final position (FP) in the row (p = 0.011), surfboard (p < 0.001) and air walker (p = 0.027) machines. In relation to the lumbar curvature and pelvic tilt, a significant decrease in lumbar lordosis and a decrease in pelvic anteversion were observed in the IP and FP in SBR and row; and in the bike (p < 0.001) machine. In the surfboard machine, a significant decrease in lumbar lordosis was found (p = 0.002), with no changes in pelvic tilt. According to the multiple linear regression analysis, the subjects with a higher cormic index and height were more at risk of increasing their thoracic kyphosis, decreasing lumbar lordosis and/or decreasing pelvic anteversion towards pelvic retroversion.ConclusionsMiddle-aged and older adults show spinal misalignments when using the OFE with respect to the standing position, showing a decrease in the thoracic kyphosis in IP of SBR and ROW, and a significant increase in the surfboard and air walker, and in the FP of Row, in the lumbar lordosis in all the OFE in sitting and some in standing, and in the pelvic anteversion in all the OFE in sitting. The variables height and the cormic index explained most of the changes in sagittal spine disposition.

한국 멜로드라마 영화에서의 이병헌 캐릭터 연구

This paper aims to study Byung-hun Lee’s character in Korean melodrama movies from the 1990s to the 2000s. The subjects of the study are eight melodrama movies, i.e. Who Makes Me Crazy (1995), The Harmonium In My Memory (1999), Bungee Jumping Of Their Own (2000), Addiction (2002), Everybody Has Secrets (2004), A Bittersweet Life (2005), Once In A Summer (2006) and A single rider (2016). The research methodology analyzes the axis of protagonist, the axis of communication, and the axis of desire, focusing on the main character played by Byung-hun Lee.<BR> First, protagonist

Women cycling in Queensland: Results from an observational study

Women are less likely to ride than men in low cycling countries such as Australia. In Australia, self-reported cycling participation appears to be declining, particularly for women. This paper examines the rider and road environment correlates of women’s cycling. While most earlier studies relied on self-report data to understand gender differences in cycling, this study video-recorded 24,868 riders (22 % female) at 17 sites across Queensland, Australia. The probabilities of an observed rider being female under different circumstances (e.g., speed limit, riding location, time of riding, group riding) at these sites were modelled in a binomial logistic regression framework. The likelihood of a rider being a woman was greater during the day (9am-8pm) than the early morning (5–9 a.m.); on weekends than on weekdays; in groups of two or more riders than among single riders; in lower speed zones than speed zones of 60 km/h or over; on roads with bike lanes or multiple traffic lanes or raised medians than on roads without these, and in urban areas than suburban areas. The likelihood of the rider being a woman was lower among those riding road bikes than other types of bicycles. The use of a naturalistic study design marks the key strength of this paper. Findings of this study should help better understand women’s cycling patterns and preferred cycling locations, which cycling communities and organisations can use to advocate for better roads and paths that make female riders feel safe.

Centralized Routing for Bike-sharing Systems

Bike-sharing systems, where people rent bikes typically for last-mile commuting, has gained great popularity in recent years due to the rapid development of mobile networks. Station-based bike-sharing systems have been widely studied in both academia and industry, where problems like bike rental demand prediction and bike redistribution have been discussed. In contrast, not much attention has been paid to the routing algorithms for shared-bike riders. A routing solution consists of two stations, suggesting where to rent and return a bike. Existing routing works generally target a single rider. However, during the rush hours, there often exist routing requests from multiple riders simultaneously, which has not been carefully investigated before. In this paper, we study the routing problem for multiple shared-bike riders with hardness analyses and approximation algorithms. The challenge lies in how to allocate the limited resources (bikes/docks at the stations) among the competing riders. We show that this problem is NP-hard, and thus propose two heuristics. We also propose an optimization technique on routing plan generations, to improve the efficiency of the algorithms. Extensive experiments have been carried out to verify the performance of the proposed algorithms. It turns out that the greedy-based routing algorithm, which has an approximation factor of 1/3, is both effective and efficient.

The relationships between correct helmet use, enforcement presence, and mortality in a Latin-America city: The case study of Bogotá, Colombia

Objective In Bogotá, Colombia, motorcyclists represent a concern as the proportion of motorcycle users between 2013 and 2018 has increased from 18% to 35%. Despite available risk reduction strategies, the fatality rates are also growing, notably in young adults (15–29 years old). This study aims at identifying correct helmet use patterns and its relationship with official records of injuries and casualties in the city over time. Methods Between 2015 and 2018, semiannual observational studies of motorcycle users in six randomly selected sites in Bogotá were conducted. Data was collected and analyzed on the number of occupants per vehicle (driver and passengers), gender, approximate age, type of helmet, and whether it was correctly used (strapped) or not. Bivariate and multivariate analyses were performed to identify the determinants of correct helmet use. Additionally, a spatial analysis was conducted to estimate the relationship between motorcycle’s casualties and correct use of the helmet (full-face helmet use) prevalence. Results A total of 77,932 motorcycles were observed, showing a high prevalence of helmet use (99% for drivers and passengers), but only 88% use it correctly (89% drivers and 82% passengers). The presence of enforcement (camera or police personnel) increases the correct use of the helmet, especially in principal roads. Female, adults, and single riders are more likely to correctly wear the helmet. Finally, there is a relationship between the concentration of the fatalities and the incorrect helmet use in 80% of the observational sites. Conclusions Incorrect helmet use has been found by the study to be related to higher mortality among motorcycle occupants in Bogotá. Our data shows that enforcement increases correct helmet use with the potential to reduce deaths among motorcycle occupants.

Bicycle Braking Performance Testing and Analysis

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;The goal of this study was to determine bicycle braking performance, while considering different brake designs and applications. Eight bicycles were used to perform brake-to-stop tests: two full suspension mountain bikes, two hybrid bikes, one beach cruiser, one BMX bike, one road bike, and one single speed bicycle. The standardized brake testing procedure consisted of rear only brake application and both front and rear brake application. In order to maintain brake application consistency, a single rider performed all series of the brake tests at the same location, within a designated brake zone on dry asphalt. The tests were performed at initial velocities of 11 to 21 mph. For each test, the rider accelerated to the test speed and, upon entering the brake zone, applied maximum braking effort while maintaining a natural upright position in order to minimize lean. The associated skid marks deposited from wheel lock-up were verified, measured, and documented onsite. Bicycle wheel lock-up was verified if needed via video analysis. The bicycles’ deceleration rates were measured with a Midé Slam Stick X accelerometer, VBOX Sport, and calculated from the deposited skid marks. The deceleration rates measured using the Slam Stick X ranged between 0.40 - 0.71 g for front and rear brake application and 0.25 - 0.37 g for rear only brake application, across all bicycle types. Bicycles with rear coaster brake setups, such as the beach cruiser, braked at an average deceleration rate of 0.25 - 0.36 g. Bicycles with caliper and disc brake setups exhibited an average deceleration rate range of 0.27 - 0.36 g for rear only brake application. Additionally, the incipient lock-up phase was analyzed for distance travelled, speed change, duration, and kinetic energy loss.&lt;/div&gt;&lt;/div&gt;

A resource sharing (sharing platform) scheme on online taxi services

This paper will review the match between single driver and single rider in online taxi services through a resource sharing (sharing platform) for the operators with the objectives to maximize the profit for drivers (operators) and minimize waiting time for passengers so that the matching rate is higher. A low matching rate between rider and driver can cause the consumer to drop the services. The matching between single driver and single rider in online taxi services through a sharing platform scheme is formulated in maximum weighted bipartite matching problem. To solve the proposed model, we use Kuhn Munkres Algorithm, while to solve the shortest path for the driver to pick up the passenger and the shortest path of passenger's origin destination, modified Dijkstra with adaptive algorithm based on Wei Peng et.al (2012) is used. Based on illustrative example with several cases, we found a resource sharing scenario can optimize the matching between driver and rider and moreover can solve the surge pricing problem which is deemed as less transparant to customer

Modeling in Road Cycling for Optimal Pacing Strategies : Theory vs. Practice

Introduction: The right choice of a pacing strategy for a time trial race is important and often difficult to establish. With the increasing popularity of online sports data platforms like Strava (www.strava.com), pacing strategies may become interesting even for recreational cyclists since they can compete against each other virtually on selected segments. Methods are now available to generate pacing strategies that are optimal, however, only in a mathematical sense. Until now, they were tested in practice only under laboratory conditions [1]. Pacing strategies are generally based on two mathematical models: (1) to describe the relation between power output and speed [2], and (2) to describe the fatigue of the rider related to the power output [3]. The quality and validity of these pacing strategies relies on the accuracy of the predictions made by those models.In this paper, we describe our findings on a pilot study during a two week period of cycling with regard to the prediction quality of the two models while following precalculated optimal pacing strategies in the field rides. This is not meant to be a fully-fledged study applying, e.g., a statistical analysis for a sufficiently large number of participants. This pilot study rather intended to demonstrate that, in principle, the theoretically optimal pacing strategies can in fact be implemented for field rides in practice. Moreover, it was the purpose of the study to identify the problems of the approach occurring in practice, and to outline solutions for these.Methods: The physiological model is similar to the one used in [1]: an extension of the critical power (CP) concept with reduced recovery. The physical model to predict speed from the rider’s power output is taken from [4]. The optimization of the pacing strategy for an uphill time trial proceeded as in [1]. To calibrate the CP model, four tests were performed in the laboratory for a single hobbyist rider, followed by a number of rides on Strava segments with the goal to achieve personal bests by pursuing the given optimal pacing strategies.The precalculated pacing strategies were communicated during the field rides by means of a custom developed App on a smartphone mounted on the handle bar. Feedback was given numerically, e.g., the current deviation from the optimal speed, and visually by a dash board type gauge. Accumulated deviations from the optimal pacing were attempted to be corrected using a PID control mechanism. These rides were taken to update the parameters of the CP model continually.Results and Discussion: Four rides with optimal feedback were performed on three different Strava Segments. These segments were mainly climbs with a length of 3.5 to 5 km and an average grade from 5.6 to 7 %. The rider’s critical power ranged from 230 to 257 W depending on which tests were used for calibration. The feedback was followed with a root-mean-square error of 0.77 m/s in speed and 48 W in power. Modelling errors and deviations from theoptimal strategy lead to time differences at the end of the segment ranging from 15 s quicker to 100 s slower than the optimal strategy predicted.This discrepancy in time is partly explained by having short downhill parts within the segments and errors in the estimation of the slope profile, which is shown in Figure 1. In the downhill parts, the optimal strategy suggested speeds higher than those during the field ride in which additionally braking was necessary. This error could be reduced by adding a more realistic speed constraint to the optimization and consider braking in the pacing strategy.While the physiological model first was calibrated using tests with a length of about 30 min, the model prediction for the first ride on a shorter segment showed quite poor performance. Adding this segment to the parameter estimation changed the parameters in a way that critical power was reduced and anaerobic capacity increased. With this new parameter set, short as well as mid-range segments were predicted quite well. This shows how important it is to use a range of test durations that covers the future applications.Conclusions: The results showed, that the models work quite well in general and they can be applied to uncontrolled conditions when considering some limitations. Downhill parts are difficult to model and time differences between prediction and ride must be expected in these scenarios. The physiological model needs to be calibrated using segments similar in length and load to the ones that are predicted. With proper model parameter selection and visual feedback with respect to an optimal pacing strategy, significant performance gains for uphill time-trials of hobbyist, amateur, and perhaps also professional athletes can be expected.

An Efficient Ride-Sharing Framework for Maximizing Shared Route

Ride-sharing (RS) has great values in saving energy and alleviating traffic pressure. Existing studies can be improved for better efficiency. Therefore, we propose a new ride-sharing model, where each driver has a requirement that if the driver shares a ride with a rider, the shared route percentage (i.e., the ratio of the shared route's distance to the driver's total travel distance) exceeds an expectation rate of the driver, e.g., 0.8. We consider two variants of this problem. The first considers multiple drivers and multiple riders and aims to compute driver-rider pairs to maximize the overall shared route percentage (SRP). We model this problem as the maximum weighted bigraph matching problem, where the vertices are drivers and riders, edges are driver-rider pairs, and edge weights are driver-rider's SRP. However, it is rather expensive to compute the SRP values for large numbers of driver-rider pairs on road networks. To address this problem, we propose an efficient method to prune many unnecessary driver-rider pairs and avoid computing the SRP values for every pair. To improve the efficiency, we propose an approximate method with error bound guarantee. The basic idea is that we compute an upper bound and a lower bound for each driver-rider pair in constant time. Then, we estimate an upper bound and a lower bound of the graph matching. Next, we select some driver-rider pairs, compute their real shortest-route distance, and update the lower and upper bounds of the maximum graph matching. We repeat above steps until the ratio of the upper bound to the lower bound is not larger than a given approximate rate. The second considers multiple drivers and a single rider and aims to find the top- $k$ drivers for the rider with the largest SRP. We first prune a large number of drivers that cannot meet the SRP requirements. Then, we propose a best-first algorithm that progressively selects the drivers with high probability to be in the top- $k$ results and prunes the drivers that cannot be in the top- $k$ results. Extensive experiments on real-world datasets demonstrate the superiority of our method.

A robust low cost device for measuring road induced vibrations

Road induced vibrations have been linked to cycling comfort and fatigue. Currently, vibration tests are preformed using expensive equipment which is often unsuitable for tests involving large numbers of cyclists riding in real-world conditions in inclement weather. A robust low-cost device was developed to address this shortcoming. The device is capable of measuring vibrations at both axles for extended periods of time. Data collected includes vibrational information, GPS coordinates and time. The system uses custom hardware base on readily available components, costing approximately $100 US, and a smartphone. It weighs 130 g plus the weight of the smartphone and can collect data for over 12 hours on a single charge. The syste was validated using controlled tests with a single rider on a closed course, and on commuter bicycles in an urban setting.

The Effect of Passengers on All-Terrain Vehicle Crash Mechanisms and Injuries

Traditional all-terrain vehicles (ATVs) are designed for single riders. Although carrying passengers is a known risk factor for injury, how passengers contribute to ATV crashes remains poorly understood. To address this question, we performed a retrospective chart review of ATV crash victims at a U.S. trauma center (2002–2013). Of 537 cases, 20% were passengers or drivers with passengers. The odds of backward rollovers, falls/ejections, crashes on sloped terrain, and collisions with motorized vehicles were all significantly greater when passengers were present. In contrast, the odds of self-ejection or falls/ejections over the handlebars were significantly lower than falls/ejections to the side or rear, in crashes with multiple riders. Among all ejections, self-ejections had the lowest head and highest extremity injury scores and being ejected over the handlebars or to the rear resulted in worse head injury scores than being ejected to the side. In summary, our study found that passengers increased the odds of specific crash and injury mechanisms and that head and extremity injury severity varied by ejection type. Safety interventions including seat design changes that prevent carrying passengers, and a strict, well-enforced no-rider rule are needed to effectively prevent passenger–related deaths and injuries.

Motorcycle Accident Profile in Manipal Teaching Hospital

This is a prospective descriptive study conducted at Manipal Teaching Hospital (MTH), where 140 patients seen at Emergency Room and OPD with a history of motorcycle accident from May 2015 to August 2015 were studied. Results showed that a high percentage of males 121 (86.4%) were involved in motorcycle accidents. Peak age range was 31-40 years old (61) (43.5%). Most of the motorcycles were manufactured in India (118) (84.2%). Single rider type of motorcycle accounted for 32(22.8%) of cases with a average speed of 50-70 km/hr (76.4%). The driver of the motorcycle was significantly involved in 106(75.7%) of cases. Alcohol intake was found in 40(28.6%) and non-license holder was 22 (15.7%) among accident victims. Abrasions 92(65.7%) was the predominant injury sustained followed by fractures 28(20%), lacerations 15(10.7%), and hematoma 10 (7.1%) in isolation or in combination. Combination of pain relievers128(91.4%), antibiotics 95(67.8%), suturing 18(12.8%), antitetanus 107(76.4%) and fracture management 21(15%) were the mode of management for these accidents. Most patients seen were discharged 116(82.8%) with home medications, wound care and follow-up, and only 24(17.2%) were admitted for observation and specific medical and surgical management.

The Effect of Spatial Position on the Aerodynamic Interactions between Cyclists

Aerodynamic drag contributes the majority of the resistance acting on elite cyclists. At speeds of 50km/h, over 90% of an athlete's power output is expended overcoming drag. As a result, reducing the drag of cyclists significantly improves their performance. To date research on cycling aerodynamics has primarily focused on a single rider, despite the fact that many cycling events are mass start or team based, which necessarily involve athletes travelling in close proximity. Fundamental investigations of multiple less complex bluff bodies have shown strong aerodynamic interactions that significantly affect the forces they experience. Whilst practical experience has shown this to also be true for cycling, such effects are not well understood.This paper reports the results of wind tunnel experiments that measured the variation in aerodynamic drag for cyclists in various two rider formations. Both drafting and overtaking formations were investigated; being inline parallel and perpendicular to the flow respectively. Loads experienced by both riders were mapped as a function of their relative spatial position. Results show that drag and side force are strong functions of spatial position. For two riders drafting directly inline there was a maximum drag reduction of 49% for the trailing rider and over 5% for the lead rider. During overtaking a drag increase of over 6% was recorded with riders positioned side-by-side.

CAD based modeling of flywheel motor with multiple operator

The Human powered flywheel motor (HPFM) is the integral part of the various manually energized machines such as brick making machine, chaff cutter, pedal operated flour mill etc .Since its invention continuous efforts are being made for its optimization with objective of the efficient energy utilization of human energy. In an attempt this paper presents the development of flywheel motor for multiple rider as till now only single rider system is developed. Further the CAD modeling of this system is developed by using the CAD software SOLID EGDE. Keywords - CAD modeling, HPFM, Solid edge.

Comparison of pressure distribution under a conventional saddle and a treeless saddle at sitting trot

It can be a challenge to find a conventional saddle that is a good fit for both horse and rider. An increasing number of riders are purchasing treeless saddles because they are thought to fit a wider range of equine back shapes, but there is only limited research to support this theory. The objective of this study was to compare the total force and pressure distribution patterns on the horse's back with conventional and treeless saddles. The experimental hypotheses were that the conventional saddle would distribute the force over a larger area with lower mean and maximal pressures than the treeless saddle. Eight horses were ridden by a single rider at sitting trot with conventional and treeless saddles. An electronic pressure mat measured total force, area of saddle contact, maximal pressure and area with mean pressure >11 kPa for 10 strides with each saddle. Univariate ANOVA (P<0.05) was used to detect differences between saddles. Compared with the treeless saddle, the conventional saddle distributed the rider's bodyweight over a larger area, had lower mean and maximal pressures and fewer sensors recording mean pressure >11 kPa. These findings suggested that the saddle tree was effective in distributing the weight of the saddle and rider over a larger area and in avoiding localized areas of force concentration.

Making the message meaningful: a qualitative assessment of media promoting all-terrain vehicle safety

BackgroundMillions of all-terrain vehicles (ATV) are used around the world for recreation by both adults and youth. This increase in use has led to a substantial increase in the number...

Sledding: How Fast Can They Go?

Sledding, a fun and easily accessible winter sport, can potentially generate significant speed and energy posing a risk of injury. The objective of this study was to determine the speeds and potential kinetic energy generated by sledders. Observational study conducted of single sledders at sledding hills located in Monroe County, NY during February 2007. Participant's weight, age, and sled type were recorded. Speeds were recorded using Stalker police grade radar guns. Multiple runs by each sledder were measured. The kinetic energy for each run was calculated. Investigators recorded observations about injuries, near misses, and other safety issues. Seventy-six participants were enrolled with ages ranging from 4 year old to adult, including 54 children (18 years) with median age 9 years (range, 4-14 years). Of the 145 runs by single riders, 54 were on inner tubes, 89 on plastic/hard foam sleds, and 2 on other. The average speed was 19 mph (range, 14-25 mph). The average kinetic energy was 1,872 J (range, 329-6,441 J). Sledders on inner tubes went faster and generated more kinetic energy than those on plastic/hard foam sleds; mean 20.3 mph (95% CI 19.5-21.0) versus 18.3 mph (95% CI 17.8-18.7), p < 0.0001 and mean 2,136 J (95% CI 1,752-2,520) versus 1,707 J (95% CI 1,478-1,936), p < 0.05, respectively. None of the sledder wore a helmet and no injuries were observed. The potential for injury with sledding increases with weight and use of inner tubes, thus safe sledding practices and helmet use should be encouraged.

The Effect of Occlusal Equilibration on Sport Horse Performance

The objective of this study was to investigate the effect of routine dental occlusal equilibration treatment on dressage horse performance. Sixteen horses (11 treated; 5 untreated) ridden by a single rider performed a standardized dressage test twice and were scored by two experienced dressage judges according to recognized movements and rider cues. All horses were sedated and a full-mouth speculum was used to facilitate a complete oral examination. Treated horses had dental equilibration performed using a motorized dental instrument. The horses performed a second test 48-hours after dental equilibration, exactly as the baseline test, with the judges and rider blinded as to treatment group. The total test score as well as the individual movement scores were evaluated for equality of variance and statistical tests were applied to determine the influence of treatment. There was no significant improvement in the test score of horses that had received occlusal equilibration.