Runner Position Research Articles

Recognition of the game situation in baseball.

This study examines baseball players' recognition framework of out, ball, and strike counts in baseball games and clarifies the differences in psychological perspectives between batters and pitchers. The participants were 396 players (294 batters and 102 pitchers) belonging to baseball clubs at eight universities. Participants answered 288 questions for all game situations by combining out, ball, and strike counts and runner position. The advantages for batters or pitchers were evaluated using a 7-point Likert scale (from very advantageous for batters to very advantageous for pitchers). Factor analysis indicated four significant factors (36 items): "Batter's advantage count," "Pitcher's advantage count," "2 out young count," and "0 out young count." In a direct comparison of these factors between batters and pitchers, batters were more aware of their advantage over pitchers in the factors "Batter's advantage count" and "0 out young count" and disadvantage in the "Pitcher's advantage count." Significant differences in recognition of these factors were observed between batters and pitchers. Batters were more susceptible to game situations than were pitchers. Our findings suggest that baseball players recognize several types of game situations, although not an infinite number.

Modal decomposition of flow instabilities in a straight turbine diffuser around the best efficiency point

Hydraulic turbines sometimes exhibit a sharp efficiency drop around the best efficiency point. The drop is known to originate from large flow separations in their draft tubes, limiting their ability to recover part of the residual kinetic energy exiting the runner. While the conditions leading to the onset of these separations are not yet understood, the potentially unstable vorticity distribution at the runner exit led to the hypothesis that those separations are the result of an interaction between the flow at the center of the draft tube and the boundary layer at the walls. To study this hypothesis, the turbulent flow inside the draft tube of a bulb turbine was measured with time-resolved particle-image velocimetry (TR-PIV). In this work, coherent structures are identified from spectral proper orthogonal decomposition (SPOD) of the velocity fields to correlate changes in their topology with the efficiency drop. Special attention is given to the periodic vortical motions in the runner's wake, whose shape and energy content are found to be linked to the flow rate. Three-dimensional reconstructions of the underlying structure reveal a shift in its topology that correlates with the efficiency drop and separations at the wall. In addition, comparisons of the SPOD coefficients with the runner position show that the phase angle between the structure and the runner remains the same for each operating condition, suggesting a link with a rotating flow imbalance in the runner blade channels.

Simulation of Propeller Runner for Cylindrical Basin of Gravitational Water Vortex Power Plant

The gravitational water vortex power plant is an emerging technology of power generation from water vortex in a small amount. It can generate electricity in a low head of range (0.7-2m). This system is very simple and requires less keep-up. This research aims to develop the propeller type runner which gives optimum efficiency and cylindrical basin suitable for this propeller runner in GWVPP. The research has been conducted by developing a new propeller runner and cylindrical basin considering the top surface open as the atmosphere. Blade angle, discharge hole diameter of the basin, the position of runner, and rpm are optimized on CFD-based optimization. After the CFD analysis, the optimum blade angle was 43º, exit hole diameter of this basin was found 175 mm which is 20% of the basin diameter. The optimum height was found 785mm which is 65.42% of the total height. And the efficiency of the optimized system was 23.639 % at 40 rpm.

Properties of Liquid Crystal Injection Mouldings

Abstract The suitability of liquid crystal polymers for the injection moulding process was pointed out at the time of their discovery. However, up to now, it has been assumed that the unmodified liquid crystal polymers were less suited to processing by injection moulding due to their distinct anisotropies. The direction of developments in the application of liquid crystal polymers was done mainly in another direction. We, however, have been concerned for more than four years now with this subject [3, 4, 5], even when our practical experiments could not be as comprehensive as we would wish, due to the limited availability of the raw materials. We have also been able to use this time to develop CAE programs which support the constructor in the design of injection moulds, whereby these programs enable the flow process to be simulated and therefore enabling the orientation to be seen at every point in the injection moulded part [6]. This is naturally particularly important for those materials in which the orientation of the molecules plays such a large part for the respective properties, as these are caused by the direction of the flows in the flow process. A changed runner position causes other orientations. More details should therefore be reported about our investigations to date.

RUNNER ANGLE MODIFICATION FOR ENHANCED MACROSEGREGATION REDUCTION IN ALUMINIUM-ZINC ALLOY

Macro-segregation is an irreversible defect in non-ferrous alloy casts. This can only be significantly minimized by controlling the melt and its flow trajectory during casting. The study identified runner angle inclination as a critical parameter that impacts the development, size and volume of macro-segregation occurrence in binary alloys. The methodology entails variation of runner angles to include 90°, 105°, 120°, 135°, and 150° at a constant casting speed of 100mm/s being the optimum casting speed established in previous study. The casts microstructure was examined using both optical and electron microscopes complemented with energy dispersive spectrometry. Results show that runner position at 120° is the most appropriate for the casting of aluminium-zinc alloy as this gave a highly homogeneous distribution of solute element in the microstructure with corresponding improved mechanical properties

Versklavte Replikanten und die Konstruktion von »Whiteness« in Blade Runner und Blade Runner 2049

The release of the anticipated sequel to Blade Runner and the largely unaltered adoption of the spatial and discursive setting in Blade Runner 2049 gave newfound relevance to the topic of the Whiteness of the enslaved replicants. Because Blade Runner positions the enslaved replicants in a discursive framework that repeatedly references African American history and slave narratives, their hyperbolically white depiction has caused concern and criticism among Anglophone scholars. This essay examines the construction of Whiteness in Blade Runner and discursive differences in the sequel Blade Runner 2049 from the perspective of Critical Race Theory, based mainly on the theoretical groundwork of Richard Dyer and Daniel Bernardi. It will outline the construction of whiteness as a means to critically portray the oppressive discourse in both films, by discussing the detachment of the replicants »invisible privileges« of whiteness. In order to appropriately characterize the, on its face very questionable, positioning of enslaved white replicants within a framework of African American slavery, the analysis will establish how both films utilize whiteness to construct a critical depiction of the historically stereotypical connection between blackness and slavery. The epitome of this criticism is to be found in the hyperbolically white stylization of Roy Batty. The depiction of »White Flight« in Blade Runner and Blade Runner 2049 will be discussed against the backdrop of racial Othering. The implied migration of white humans to the superior »Off-World« establishes a fear of the Other and its assimilation in the white population. The exclusion of black characters in the original film, and their inclusion in the sequel, affect the way in which the movie portrays replicants within the framework of African American enslavement. Along with the distinct non-hyperbolic depiction of the white replicants in Blade Runner 2049, this necessitates an analysis of the perpetuation of the oppressive discourse. This essay aims to establish the analytical fertility of Critical Whiteness Studies within the Germanophone Blade Runner debate.

Parametric study of single-stage gravitational water vortex turbine with cylindrical basin

Gravitational water vortex turbine (GWVT) is one of the emerging micro-hydro power plants because it requires less expertise, low head and reduced setup space for installation. A detailed performance evaluation of the GWVT based on turbine performance curves is yet to be explored. With the help of mathematical expressions along with the experimentation, the present study presents different performance parameters (PPs) such as; rotational speed, torque, brake power and mechanical efficiency of single-stage GWVT under various flow and design conditions. The effect of vortex height, runner position, percentage submergence of blades, notch angle, blades aspect ratio, blades curvature, blades inclination, hub diameter, straight and conical edged blades on the PPs has been investigated. The analytical and experimental results are in a good agreement both qualitatively and quantitatively. The experimental results show that the vortex height and a good vortex shape with fully developed air core are the major parameters in deciding the performance of GWVT. Better performance of GWVT can be achieved at middle of the rotational speed range i.e. between the minimum and maximum load conditions with minimum possible notch angle and hub diameter, using inclined blades of zero curvature fixed near the bottom of the basin.

Developing a method to design and simulation of a very low head axial turbine with adjustable rotor blades

Very low head (VLH) axial hydraulic turbines classified as micro-hydropower plants are capable of harvesting energy from sites with elevations below 4.5 m. The VLH turbine output power can be controlled by varying the rotational speed and the runner blade opening angles. In this paper, a design method for the VLH runner blade is developed. The numerical simulation of the designed system is presented and validated against the experimental data of an industrial prototype. The procedure is started by determining the velocity components and angles at the inlet and outlet of 2D radial sections, followed by choosing a hydrofoil for each radial section and calculating the hydrodynamic coefficients. The stagger angle and the chord-length of the section are computed using a MATLAB code coupled with XFoil. The multi-section product of 3D spherical radial sections in ANSYS TurboGrid 15.0 meshing tool forms the runner blade and the guide vane. Importing the generated structured grid into ANSYS CFX 15.0 solver, the RANS equations are solved using the SST turbulence model to capture the turbulent structures. The simplified Rayleigh-Plesset equation for bubble growth rate in the homogenous two-phase model is applied to study the cavitation phenomenon for different states of runner opening angles and rotational speeds. The maximum hydraulic efficiencies for most of the runner positions (at constant angular velocity of 40 rpm) are more than 80%. We demonstrate the effects of runner blade opening angle and the turbine rotational speed on the hydraulic efficiency curves and turbine efficiency hill chart. The cavitation simulation demonstrates leading edge and tip gap cavitation in some off-design points at different blade opening angles.

Head-to-head Running Race Simulation Alters Pacing Strategy, Overall Performance, And Mood State

It is believed that the presence of other competitors during running races would provide a greater number of external cues (e.g., competitive environment, runner position during the race, etc), which might alter the pacing strategy (PS) and psychological stress relative to that typical of the individual condition. However, it was not still fully elucidated whether the PS and mood state can be altered in the presence of other competitors. PURPOSE: The main objective of the present study was to analyze the influence of other competitors on PS, overall running performance, and mood state during a 3-km running. METHODS: Nine recreational runners (VO2max 56.1 ± 5.3 ml/kg/min) were submitted to the following tests: 1) familiarization with the 3-km running; 2) individual 3-km running (IND); 3) collective 3-km running (COL). In the COL condition, the participants were placed in one of two groups (4-5 runners per group) based on their previous running performance as determined during the familiarization session. A mood state questionnaire (POMS) was completed before and after the 3-km. RESULTS: Overall running performance was better in COL (11:75 ± 0:05 min) compared with IND (12:25 ± 0.06 min, p = 0.04). The running speeds during the first 500 m were greater in COL (16.8 ± 2.2 km/h) than in IND (15.3 ± 2.4 km/h, p = 0.03). The vigor score decreased after COL (16.4 ± 3.4 scores, p = 0.03), but not after IND (21.4 ± 4.2 scores, p = 0.20). CONCLUSION: The results of the present study demonstrated that the presence of competitors induces a more aggressive fast start, improving the overall performance. However, the exercise-induced reduction in vigor was exacerbated during head-to-head running compared with individual running. These findings suggest that the external cues resulting from the presence of the competitor may have overlapped the perception of discomfort primarily during the first part of the race, resulting in a higher ability to sustain high intensities and unpleasant emotions following the race.

Tactical behaviour of winning athletes in major championship 1500-m and 5000-m track finals

This article analyses the tactics employed by middle-distance (1500-m) and long-distance (5000-m) runners from an observational methodology perspective. The subject of investigation has received little attention from specialists in the field of athletics, with most research focusing on physiological studies of athlete performance. Using an ad hoc observation tool and a database containing systematically recorded data we detected time patterns (T-patterns) within the data recorded using the Theme software program (version 5.0), and analysed the tactics employed by winners of the men's 1500-m and 5000-m finals of the World Championships in Athletics [Edmonton 2001, Paris 2003, Helsinki 2005 (1500-m final only), Osaka 2007 (1500-m final only), Berlin 2009 and Daegu 2011], the European Athletics Championships (Munich 2002, Göteborg 2006, and Barcelona 2010) and the Olympic Games (Sydney 2000, Athens 2004, Beijing 2008 and London 2012). T-pattern detection and investigation of the relationship between category systems corresponding to the criteria comprising the observation tool revealed both similarities (starting lane and lane used during race, runner's position during race and sprint zone and lane) and differences (variations in pace, zones in which changes of pace occur, sprint initiation zone and winner's position at the start of the sprint) between the two disciplines.

Correlation between runner pressure and cavity pressure within injection mold

Cavity pressure in the injection molding process is closely related to the quality of the molded products and is used for process monitoring and control to upgrade the quality of molded products. However, the sensor installed inside the cavity makes the molded product of the cavity defective, reducing productivity. In view of this, this study investigates the correlation between melt pressure and cavity pressure in different runner positions and determines the appropriate runner position, where the runner pressure can represent the cavity pressure, in order to increase productivity. First, the Taguchi method is used to obtain the optimal parameter combination of injection molding, and then, the experiment is conducted based on this condition in order to discuss the difference between runner and cavity pressure history profiles. According to the experimental results, the quality of molded products can be monitored and controlled by installing sensors at different runner positions, and the maximum value of the cavity pressure profile varies with the runner position. When the distance between the top of the pressure sensor mounted in the secondary runner and the outside diameter of the runner is greater than the maximum thickness of the molded product, the obtained pressure history profile approximates to that inside the cavity. In other words, the runner pressure can represent the cavity pressure. Mold temperature significantly influences the runner pressure history profile and form accuracy (contour precision) of the lens during the injection molding process, which can be used as a process monitoring and control parameter. In addition, the cavity pressure profile at the cooling stage is closely related to the form accuracy of the lens and is the key to determining process monitoring and control parameter.

Effect of Runner Position on Performance for Open Type Cross-Flow Turbine Utilizing Waterfalls

The aim of this investigation is to develop an open type cross-flow turbine for environmental friendly nano-hydraulic turbine utilizing extra-low head waterfall. A relative position between the runner and the waterfall is one of the important factors for turbine efficiency. More often, it is necessary to precisely adjust this distance according to changes of the flow rate. In this study, we focused on the influence of the horizontal and vertical position of the runner on performance. First, the effect on the performance of the horizontal relative position between the runner and the falling water is verified. Next, two condition of the vertical relative position are concerned; one is the clearance between the runner and the water surface of the pool, the other is that between the runner and the solid surface as the runner placed closer to the ground or the riverbed. The result highlights that the horizontal relative position was an effect on the power performance. When the solid surface is presented under the runner, the performance is not effected when the water thickness is equivalent to 7.5% or more. On the other hand, when water surface is presented below the runner, the clearance between them has insignificant effect on the performance even though the runner underside is partly submerged.

Experimental investigation of the draft tube inlet flow of a bulb turbine

In the BulbT project framework, a bulb turbine model was studied with a strongly diverging draft tube. At high discharge, flow separation occurs in the draft tube correlated to significant efficiency and power drops. In this context, a focus was put on the draft tube inlet flow conditions. Actually, a precise inlet flow velocity field is required for comparison and validation purposes with CFD simulation. This paper presents different laser Doppler velocimetry (LDV) measurements at the draft tube inlet and their analysis. The LDV was setup to measure the axial and circumferential velocity on a radius under the runner and a diameter under the hub. A method was developed to perform indirect measurement of the mean radial velocity component. Five operating conditions were studied to correlate the inlet flow to the separation in the draft tube. Mean velocities, fluctuations and frequencies allowed characterizing the flow. Using this experimental database, the flow structure was characterized. Phase averaged velocities based on the runner position allowed detecting the runner blade wakes. The velocity gradients induced by the blade tip vortices were captured. The guide vane wakes was also detected at the draft tube inlet. The recirculation in the hub wake was observed.

Experimental Investigation of Draft Tube Inlet Velocity Field of a Propeller Turbine

The draft tube of reaction hydraulic turbines is subject to numerous investigations since it accounts for a significant portion of the energy recovery. But even with up-to-date computational fluid dynamics methodologies, simulating the draft tube flow remains highly challenging since it is a diverging swirling flow that may undergo flow separations and become dominated by unsteady secondary flows. Within the framework of a collaborative research project on the flow dynamics of a propeller turbine model, the flow at the inlet region of the draft tube was studied using 2D-laser Doppler velocimetry (2D-LDV). Measurements were used to detect and characterize the flow structures at three operating conditions: partial discharge, near best efficiency, and full-load conditions. The paper presents analysis based on phased-averaged velocity fields to yield information on fluctuations and dominant frequencies according to runner positions. The main features detected are the flow nonuniformity at the runner exit and the secondary flow structures associated with the runner hub wake. Those results are part of a larger database aimed at providing test cases for the validation of numerical simulation strategies.

S0503-1-2 滝用水車の開発 : 曲面流路による水流方向制御([S0503-1]自然の流体エネルギー利用技術(1))

The aim of this investigation was to develop an environmentally friendly nano-hydraulic turbine utilizing extreme low head waterfall. The relative distance between a runner and a waterfall is one of the important factors for stable supply of electricity. Flow rate always changes day by day. So, it is often necessary to determine precisely the relative position of the runner every time flow rate changes. It is necessary to keep the stable generation by changing the runner position or controlling the waterfall direction. The former is unrealistic method because of sophisticated mechanism to adjust the runner position. Accordingly, open type cross-flow runner was selected, and control method of flow direction by use of curved channel was investigated. As a result, the maximum power coefficient reaches at 74% even when the flow rate changes by 3.0 times.

Smoothing and statistical evaluation of laser Doppler velocimetry data of turbulent flows in rotating and reciprocating machinery

Arbitrarily time-distributed velocity information acquired by laser Doppler velocimeter systems needs special care when evaluated wrt. the mean velocity and the components of the Reynolds stress tensor. In rotating machinery, the arrival time information can be uniquely mapped to the angular position ϕ of the runner blades by using encoder signals relating a fixed runner position to an arrival time. It is convenient to statistically evaluate the velocity information of the detected particles in an angular window [ϕ0−Δϕ/2,ϕ0+Δϕ/2] in order to obtain mean velocities and turbulence values for an angular position ϕ0. This approach has the inconvenience that turbulence values calculated from standard deviations are influenced by a possible variation in the mean velocity in the evaluation window. Other problems that arise with this “evaluation window” method are the influence of unevenly angular-distributed velocity information on the mean velocity or the poor resolution of maxima and minima of the mean velocity, which is similar to the problem pointed out by Jakoby et al. but being of second-order nature. In this paper, different improvements in the “evaluation window” method wrt these problems based on ideas found in a paper by McDonald and Owen are presented. A confidence interval calculation, generalizing the methods of Boutier, for all calculated values is included, which allows an appropriate window size Δϕ to be chosen for each particular situation. The different methods are compared using examples from wake flows of axial hydraulic turbomachinery measured in air and water.

Spectrum Normalization Method in Vibro-Acoustical Diagnostic Measurements of Hydroturbine Cavitation

Full-scale vibro-acoustical diagnostic measurements of cavitation in four Francis 6 MW double runner turbines were performed. Two types of sensors were used—a hydrophone sensing waterborne noise at the pressure side of a runner and an accelerometer mounted at various points at the outer turbine casing, facing the runner’s pressure side. The correlation of noise and acceleration intensity with suction-side pressure fluctuations and runner position was checked. A simple but efficient method of spectrum normalization, which rejects the influence of the measurement set characteristics and vibro-acoustical characteristics of a turbine, was developed. The resulting spectra reveal the dependence of cavitation source strength on the turbine power as a function of noise or acceleration frequency.

A note on jogging on a windy day.

A minimum-time, fixed energy strategy for running a circular track on a windy day is derived which expresses velocity and acceleration as simple trigonometric functions of the runner's position on the track. Rather surprisingly, the strategy directs the runner to begin accelerating when the wind is directly in his face and decelerating with the wind directly at his back.