Speed

The purpose of this study was to compare key magnitude and timing parameters of the kinematic sequence between amateur recreational players (amateurs) and PGA touring professionals (pros). It was hypothesized that the key magnitude parameters would be significantly higher in the pros than the amateurs, and that the key timing parameters would be significantly different between the two groups. A representative swing from each of 19 amateurs and 19 pros was captured using three-dimensional (3D) motion analysis techniques. Eighteen key kinematic sequence performance variables that occur during the downswing were computed from the data. Student t-test’s were used to compare the group means for each parameter with an experiment-wise level of significance set at p<0.2, and a corresponding test-wise significance of p<0.011. All the magnitude variables including rotational accelerations; rotational decelerations, (except pelvis); peak rotational speeds; rotational speed gains; and lin...

The increase in traffic intensity and complexity of the railway system demands new methods for real-time traffic control. This paper introduces the architecture, the approach and the current implementation of an advanced Traffic Management System (TMS) able to optimise traffic fluency in large railway networks equipped with either fixed or moving block signalling systems.The TMS takes into account both the actual position and speed of each train in the area and the actual status of the infrastructure, and the dynamic characteristics of the train and the characteristics of the infrastructure such gradients, admissible speeds, signal positions and signal patterns.Potential conflicts can be predicted in advance and solved in real time, by managing the order of trains, or using alternative routes if possible, and by issuing proper speed recommendations to train drivers. In this way, the TMS prevents or limits the number of unplanned stops and the accompanying journey time loss.

Densities (ρ), ultrasonic speeds (u), and excess molar volumes () of binary mixtures of some aromatic ketones in acrylonitrile have been measured over the entire range of composition at 308.15 K. From these experimental results, parameters such as the isentropic compressibilities K S , interaction parameter χ 12, Flory parameters, A i coefficients, standard deviations σ(Y E), and molar sound

This paper presents the implementation of the recent methodology called Adaptable Time Warping (ATW) for the automatic identification of mixture of crystallographic phases from powder X-ray diffraction data, inside the framework of a new integrative platform named hITeQ. The methodology is encapsulated into a so-called workflow, and we explore the benefits of such an environment for streamlining discovery in R&D.

The finding that drivers may react to safety interventions in a way that is contrary to what was intended is the phenomenon of behavioural adaptation. This phenomenon has been demonstrated across various safety interventions and has serious implications for road safety programs the world over. The present research used a driving simulator to assess behavioural adaptation in drivers’ speed and lateral displacement in response to manipulations of road width. Of interest was whether behavioural adaptation would occur and whether we could determine whether it was the result of explicit, conscious decisions or implicit perceptual processes. The results supported an implicit, zero perceived risk model of behavioural adaptation with reduced speeds on a narrowed road accompanied by increased ratings of risk and a marked inability of the participants to identify that any change in road width had occurred.

Schnelligkeit ist ein komplexer physischer und psychischer Leistungsfaktor, der für alle Sportarten einen sehr hohen Stellenwert einnimmt. Die Einflüsse der verschiedenen Arten von Ermüdung auf die Schnelligkeit sind am meistens mit niedrigeren Leistungen bewiesen, die durch trainingswissenschaftliche, physiologische, psychologische und biomechanische Wege erklärt wurden. In dieser Studie soll untersucht werden, welche Auswirkung eine Fahrradergometer- und Schnellkraftausbelastung auf die Parameter der elementar reaktiv- und Frequenzschnelligkeit hat, dargestellt am Beispiel von EMG Parameter. Dazu wurden insgesamt 16 Probanden auf zwei Gruppen aufgeteilt, die anhand des Schnnelligkeitsquotients nach Lehmann (1992) zu Schnellen und zu Langsamen aufgeteilt wurden. Die Probanden der beiden Gruppen „Schnell“ und „Langsam“ werden alle mit der Fahrradergometer- und Schnellkraftausbelastung konfrontiert. Zwischen den beiden Interventionsprogrammen liegt ein Erholungszeitraum von ca. einer Woche. Vor und nach jeder Ermüdungsintervention wurden die Parameter der Schnelligkeitstests (Drop Jump und Foot Tapping Test) und der EMG (Am, At, IEMG, MDF) erfasst und analysiert.

No theory of driver behaviour has yet managed to achieve widespread acceptance and use in the field of Traffic Psychology, partly due to the difficulty in testing many of the theories. However, one class of theories, the motivational theories, can be usefully split into two groups and the differences between them can then be examined. One group posits the constant monitoring and targeting of a certain subjective variable, often risk, as the controlling factor in driving. The other group however states that subjective variables such as risk are only relevant once a certain threshold has been passed.In this study we aimed to examine this difference by manipulating both speed of travel and the amount of cognitive load participants were under. Participants were asked to initially drive at their preferred speed for 1 min in a driving simulator. Participant's speed was then automatically increased or decreased by 10, 20 30 km/h or left unchanged. Participants were then required to maintain the new speed for 1 min. After this 1 min the speed was again automatically changed and had to be maintained for one more minute, but this time participants also carried out a secondary mental arithmetic task. Finally participants were asked to again drive for another 1 min at their preferred speed. This procedure was repeated seven times, once for each speed manipulation; −30, −20, −10, +0, +10, +20 and +30 km/h. After each 1 min interval verbal ratings of task difficulty, effort, feeling of risk and the typicality of the speed were collected.The results show a threshold effect in ratings of task difficulty, effort and feeling of risk, with no significant difference given between the ratings during the baseline period and the experimentally decreased speed periods until after participant's preferred speed of travel had been exceeded. Furthermore, even when under cognitive load the threshold relationship was still apparent, if diminished. Finally it appears that when under cognitive load drivers have difficulty maintaining a travelling speed which is lower than the speed at which they would prefer to drive. However, driving at a speed in excess of their preferred speed appears to be easier to maintain, at least in the short term.► Examines the constant risk/feeling monitoring and threshold accounts of driving. ► Finds support for the threshold account. ► Threshold is crossed when participants first go faster than they would freely choose. ► Threshold perception persists under external cognitive load.

Disputado em 25 de Agosto de 1991, o Grande Prêmio da Bélgica viu o Brasil colocar 3 pilotos entre os 4 primeiros colocados na classificação final (na época 6 pilotos pontuavam). Nunca antes na história do país e da categoria isso aconteceu. Nunca depois.

O Brasil de 1991 era contraditório. Suas possibilidades pareciam imperfeitamente maiores. Seus limites eram expostos de forma dolorosa, mas sincera. No país do futuro o futuro parecia promissor.

This study identified the physiological profile: speed, reaction time, lower extremity power, muscular endurance, and flexibility, of Filipino Sepak Takraw college players. A descriptive and comparative design were used in investigating the physiologic profiles among the three playing positions (striker, server, and feeder) in Sepak Takraw. A total of 30 male Filipino Sepak Takraw varsity players, aged 18 to 22 years old, with at least three intercollegiate tournament playing experience, and with three to five times physical training for Sepak Takraw weekly in a year, were chosen. The 40 meter running, time ruler, sargent vertical jump, one-minute sit-up, sit and reach flexibility test were used in evaluating the physiologic profiles identified. No significant differences among the three Sepak Takraw playing positions were found in terms of speed, muscular endurance, and flexibility. However, significant results were found when differentiating the strikers, feeders, and servers in terms of reaction time and lower extremity power. Strikers demonstrated to have faster reaction times and stronger lower extremity strength. The findings of the study provide crucial insights as to the physiological profile of Filipino Sepak Takraw players that could reinforce talent detection and identification, performance appraisal, and improvement metrics.

Sensor devices are an integral part of human movement analysis.  The use of sensors in sports performance and injury prevention is extremely useful.  Over the years wireless systems have become increasingly popular and the analysis of human movement has been therefore simplified.  Inertial measurement units are very popular in physical activity monitoring and have become readily available for consumers.  The use of more advanced sensors to measure electrical and mechanical muscle activity tend to be tethered devices, thus data collection on more complex movements is limited.  This paper looks at the need for wireless solutions to these sensors and the proposal for a multi-channel sensor which incorporates all the necessary sensors for complete human movement analysis.  Wireless systems have the advantage of allowing the participant or athlete to perform the movement in their ecologically valid environment while giving both reliable and accurate results to the practitioner.  In terms of human movement, to achieve accurate information about the position, kinematic and external forces of the segments of the body being studied, a single multi-channel sensor device is necessary.  The combination of sensors in one device can give accurate information on muscle activity, forces, directionality and acceleration.

The aim of traffic reconstruction is to recreate mo tor vehicle collision scenes in order to analyze th e dynamics of the collision events, to provide evidence in court case s and allow the manufacturers to evaluate the vehic le’s design. However, at the scene of the accident it is not kno wn exactly the amount of information that will be r equired for the analysis and often relevant data are missing. The e mergence of terrestrial laser scanning has enabled the 3D documentation of accident events in a safer way, as information can be collected without any lane clos ures or traffic interruptions, and in a more flexible and faster wa y, as a single user can operate the instrument in c omplete darkness or direct sunlight. The notion of this paper is to model accident scene using terrestrial laser scanni ng data. With the intersection-related crashes making up a high propo rtion of total fatal crashes, there is a need for r ecording their current status in order to improve the design an...

The introduction of the shorter match formats in cricket (i.e. Twenty20 cricket) has led to a greater emphasis placed upon the successful performance of a quick single in match play. Therefore, the study aim was to investigate the kinematic variables between batsmen and fast bowlers when completing a quick single. Eighteen male cricketers completed 17.68-meter (m) sprints utilizing a match-specific start (walking start, bat dragged through crease and leg guards worn). Timing gates recorded 0-5 and 0-17.68 m time. Joint and step kinematics were analyzed through the first and second steps via motion analysis. Participants were split into batsmen and fast bowler groups based on their primary role within a team. A one-way analysis of variance determined significant (p< 0.05) differences between the batsmen and fast bowler groups. Effect sizes (Cohen's d) were also calculated. Selected between-group kinematic differences were found. Fast bowlers had a significantly greater non-dominant elbow flexion, and second step swing leg ankle dorsi flexion. The requirements of fast bowling may have resulted in a cross-training effect, as increased range of motion in the bowling arm, and increased dorsi flexion on front and back foot landing, is associated with fast bowling technique. Nevertheless, there were no differences between the groups regarding quick single sprint performance. All cricket players should be proficient in the mechanisms of quick single sprint acceleration, regardless of their primary role in the team.

To effectively design a science-and individualized program, the Strength & Conditioning coach, must perform a needs analyses on the athlete. Incorporating advancements in the modern sport-and exercise science literature should include a substantial portion of the establishment of the program. On completion of the needs analyses, an effective program is designed to enhance-and optimize the athletes' performance. During this case study, all of these steps are manifested, including the rationale behind the program design.

Mechanics: Oldest of the Physical Sciences: Archimedes (287-212 BC): Principles of Lever and Buoyancy. Mechanics is a branch of the physical sciences that is concerned with the state of rest or motion of bodies subjected to the action of forces.
Statics: Deals with equilibrium of bodies under action of forces (bodies may be either at rest or move with a constant velocity).
Dynamics: Deals with motion of bodies (accelerated motion)

Controlling the projection speed of films was once a life-threatening profession: Th e highly inflammable nitrate film had to move slowly — but not too slowly — past the burning heat of the arc lamp, and projectionists who tried to meddle with this mechanical apparatus (or simply fell asleep while working) risked burning down both the projection booth and the movie theater. In the early days of cinema, silent films were projected at varying speeds regulated by the theater management, rather than by the filmmakers or production studios (see Brownlow 1980, 164). On May 9, 1908, the Moving Picture World warned: " Th ere is no hard and fast rule that can be laid down governing speed.. .. It is as likely as not that the speed should be changed several times in different portions of the same film " (qtd. in Brownlow 1980, 167). During the silent era, projecting a film at a speed slower than 40 feet per minute was deemed unsafe. This correlation between projection speed, potential danger, and possible death might seem a relic of the pre-digital days of yore. However, by closely studying a new spectatorial mode called " speed watching, " this chapter will argue that the specters of the flammable celluloid strip surprisingly morphed into new — and often denied — correlations between the digital apparatus and the fear of dying (manifested and sublimated as a fear of boredom, inefficiency, or slowing down). In the digital mediascape, the "viewser" — to borrow Dan Harries ' amalgam of " viewer " and " user " (2002) — now occupies the place of the projectionist.

Research has shown that guiding learners’ attention in animations by cueing does not necessarily improve conceptual understanding. This study investigated whether the number of elements that are presented per unit of time influences the effectiveness of cueing by showing a cued or an uncued animation about the cardiovascular system at a high or at a low speed. It was hypothesized that cueing would be most helpful for learning when the animation was shown at a high rather than at a low speed. Unexpectedly, students showed equal performances on comprehension and transfer tests irrespective of cueing and the animation’s speed. However, the low speed groups invested more mental effort to obtain this performance than the high speed groups. The findings and their implications for the design of animations are discussed in terms of cognitive load theory.

The present study demonstrates applicability of VISSIM software to determine capacity of multilane highways under mixed traffic flow conditions. Traffic flow data collected on a section of four-lane divided highway are used to develop the speed-flow curve. The same set of field data is used in VISSIM and simulated speed-flow curve is compared with field curve. It was found that VISSIM in its original form overestimates both speed and capacity of the highway. Driver behaviour parameters CC0 and CC1 are first determined for homogeneous traffic conditions having only one of the four types of vehicles in the stream and then results are aggregated to get the values of these parameters for a mixed traffic stream. Further analysis of field data with calibrated values of CC0 and CC1 indicated a good match between field and simulated capacity. The procedure is shown to work on another section of four-lane divided highway with paved shoulders, whereas simulated capacity was 5329 pcu/hr agains...

Pump technology is a proven technology in the world. The application and use of pump today are universal. Modern public utilities, chemical plants, municipal water and sewage works and other fields, too numerous to mention would be seriously handicapped if these machines did not exit. A single-suction centrifugal pump is widely used in domestic application, water supply process and agricultural process. A single-suction centrifugal pump includes an impeller rotating inside a pump housing, volute casing. The impeller comprises an essential circular disk-shaped carrier with a number of blades arranged at an angle out from the disk plane. In this paper, design of impeller of single-suction centrifugal pump that can develop a head of 16 m and deliver 0.17 m 3 /min of water at the high speed of 2850 rpm. The designed impeller has 51 mm inlet diameter, 117 mm outlet diameter, 13º inlet vane angle and 14 º outlet vane angles. The number of vane is 3. The inlet width and outlet width are 12.6 mm and 6 mm respectively. The designed single-suction centrifugal pump can fulfill the requirements of chemical plants, domestic applications, water supply process and agricultural process and then can improve pump efficiency.