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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Post activation potentiation; is it present in children? / Post activation potentiation; kan det observeras hos barn?

Hjortsberg, samuel, Mattson, Jesper January 2022 (has links)
No description available.
322

Why We Jump and How We Fall (For It) : An Overview of the Concept of Jumping as a Video Game Mechanic and How it Affects Gameplay / Varför vi hoppar och hur vi faller (för det) : En översikt av konceptet av hopp som en spelmekanik och hur det påverkar spel

El Idrissi, Christoffer, Ettehag, Eskil January 2022 (has links)
In this paper we analyze the existing methods for exploring and evaluating the characteristics of the jump mechanic in video games by comparing qualitative research done in the field of game studies. For this study we are using the jump as a centerpiece, starting with an analysis of different methodologies that break down game mechanics and assessing their functionality and possible effects on players. Primarily this focus will be on how mechanics are broken down from different perspectives and how these methodologies compare. The intent behind the review of these methodologies is to objectively simplify the process of collecting and comparing relevant research in order to familiarize the reader with the concept of game mechanics and their parts from an assortment of perspectives while also retaining knowledge on their similarities and differences. This paper comes to the conclusion that one could argue for the discovery of three thematic similarities between the methodologies.These similarities are then presented to shape an understanding of how a resonating or “Harmonic”(Swink, 2008, p.297) systems could be developed.
323

Coyote Time och Jump Buffers påverkan på spelupplevelsen / Impact of Coyote Time and Jump Buffer on the game experience

Larsson, Jesper, Perkhed, Peter January 2023 (has links)
I den här studien har frågeställningen “Vilken påverkan på spelupplevelsen har Coyote Time och Jump Buffer i 2D-Plattformsspel?” studerats. Coyote Time och Jump Buffer är två hjälpmekaniker som hjälper spelare att prestera bättre i plattformsspel där deras timing kan påverkas negativt av latens i hård- och mjukvara. En kvantitativ metodansats användes där data insamlades från två källor, en enkät baserad på modellen Player Experience Inventory (PXI) samt data från ett enkelt plattformsspel som skapats utifrån studiens behov av författarna. Data från spelet bestod av missade hopp, antal gånger som Coyote Time användes, antal gånger som Jump Buffer användes samt hur lång tid det tog för spelarna att klara nivån. I ett laboratorium, inrett som en lägenhet, fick tolv testdeltagare spela två spelnivåer i spelet. Vid varje testsession fick testdeltagarna spela en spelnivå med aktiva hjälpmedel och en spelnivå med inaktiva hjälpmedel. Efter avslutad spelnivå svarade testdeltagarna på den del av enkäten som hörde ihop med spelnivån. En analys av den insamlade datan tyder på att aktiva hjälpmedel generellt, med några få undantag, påverkar spelupplevelsen positivt. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet.</p><p>There are other digital material (eg film, image or audio files) or models/artifacts that belongs to the thesis and need to be archived.</p>
324

The Relationship between Isometric Force Characteristics and Vertical Jump Height under Various Loading Conditions.

Kraska, Jenna Marie 12 August 2008 (has links) (PDF)
Purpose: to examine the relationship between isometric force characteristics (IF) and vertical jump height under various loading conditions. Sixty-three collegiate athletes participated in this investigation. Athletes performed static jump (SJ) and countermovement jumps (CMJ) with 0 and 20kg, and isometric mid-thigh pulls on a force plate. Force-time curve analysis was conducted for each isometric pull and jump to determine force related characteristics. Jump height (JH) was derived from flight time. Isometric forces were normalized using allometric scaling: absolute force/ (body mass(kg)0.67)= IPFa. Results: There was a strong positive correlation between isometric peak force and isometric rate of force development (IRFD). Stronger athletes had smaller decrements in jump height with additional loading. Conclusion: The ability to produce higher peak and instantaneous forces and IRFD is related to JH and smaller differences between weighted and unweighted jumps. A weighted jump may be a practical method of assessing relative strength levels.
325

Preparing for a National Weightlifting Championship: A Case Series

Travis, Spencer K. 01 August 2018 (has links) (PDF)
The purpose of this thesis was to observe psychological, physiological, and performance changes to determine when two high-level weightlifters were peaked for a major competition. We addressed this purpose by conducting a two-part case study series with one USA international level female and one USA national level male weightlifter. Both athletes were considered to be peaked on competition day. The results support our hypothesis that jumping performance would be peaked on competition day corresponding with an increased recovery and decreased stress state. However, contrary to our hypothesis, each athlete exhibited small decreases in muscle size leading into the competition relative to baseline values. Further, changes in inflammatory markers were inconsistent for each athlete and were not reduced as hypothesized. Based on our findings, this investigation supports the use of overreaching and tapering for individual strength-power athletes providing insight into underlying psychological and physiological basis for observed changes in performance.
326

Relationship of the SRSS Questionnaire with Physiological and Performance Measures

Perkins, Alec 01 August 2018 (has links) (PDF)
The overall purpose of this thesis was to validate the SRSS questionnaire. This was accomplished by conducting a single investigation using eleven well-trained weightlifters with at least one year of competition experience. These weightlifters completed five testing sessions over the course of five microcycles leading up to a competition. Every testing session took place on Monday morning prior to regular training and included: hydration testing, SRSS questionnaire, blood draws followed by a standardized warm-up protocol and squat jumps (SJ) with 0kg and 20kg. While the majority of SRSS recovery and stress items did not change with changes in VL or VLd, emotional balance and lack of activation did correlate with changes in VLd. Additionally, decreases in SRSS recovery items physical performance capability and emotional balance coincide with decreases in squat jump height and increases in cortisol following the first taper microcycle. The findings of this investigation partly support the SRSS as a monitoring tool for weightlifters.
327

Theoretical Determination of Subcritical Sequent Depths for Complete and Incomplete Hydraulic Jumps in Closed Conduits of Any Shape

Lowe, Nathan John 01 December 2008 (has links) (PDF)
In order to predict hydraulic jump characteristics for channel design, the jump height may be determined by calculating the subcritical sequent depth from momentum theory. In closed conduits, however, outlet submergence may fill the conduit entirely before the expected sequent depth is reached. This is called an incomplete or pressure jump (as opposed to a complete or free-surface jump), because pressure flow conditions prevail downstream. Since the momentum equation involves terms for the top width, area, and centroid of flow, the subcritical sequent depth is a function of the conduit shape in addition to the upstream depth and Froude number. This paper reviews momentum theory as applicable to closed-conduit hydraulic jumps and presents general solutions to the sequent depth problem for four commonly-shaped conduits: rectangular, circular, elliptical, and pipe arch. It also provides a numerical solution for conduits of any shape, as defined by the user. The solutions conservatively assume that the conduits are prismatic, horizontal, and frictionless within the jump length; that the pressure is hydrostatic and the velocity is uniform at each end of the jump; and that the effects of air entrainment and viscosity are negligible. The implications of these assumptions are briefly discussed. It was found that these solutions may be applied successfully to determine the subcritical sequent depth for hydraulic jumps in closed conduits of any shape or size. In practice, this may be used to quantify jump size, location, and energy dissipation.
328

A Comparison of the Traditional, Swing, and Chicken Wing Arm Movements on Volleyball Blocking in NCAA Division 1 Female Athletes

Neves, Taubi J. 08 March 2010 (has links) (PDF)
Blocking is highly correlated with team success. The identification of specific techniques that produce a more successful block would be helpful knowledge for coaches and players. This study compared the traditional, swing, and chicken wing arm swings in combination with the running step footwork pattern in order to determine which arm swing enabled athletes to perform a more effective block. The time it took the athletes to get off the ground and get their hands above (vertically) the net was calculated. The distance the hand reached over the net or hand penetration (displacement between the net and finger in the anterior and vertical planes) was also measured. Lastly, jump height was calculated. High-speed videography was used to capture the blocking movements of thirteen female NCAA Division I athletes. Data were analyzed using a repeated measures ANOVA test, pairwise comparison, and co-variate analysis. The chicken wing block arm swing was quickest in getting the athlete off the ground and getting their hands above the net. The swing block was greatest for hand penetration and jump height. These results can help coaches and players decide which arm swing will benefit them most as a blocking team and as individual blockers.
329

The Influence of Superhydrophobicity on Laminar Jet Impingement and Turbulent Flow in a Channel with Walls Exhibiting Riblets

Prince, Joseph Fletcher 28 August 2013 (has links) (PDF)
The object of this work is to explore the influence superhydrophobic (SH) surfaces exert in laminar jet impingement and when they are combined with riblets in turbulent channel flow. A SH surface generates an apparent slip due to the combination of micropatterning and chemical hydrophobicity. Because of surface tension, water does not enter the cavities between the features, increasing the contact angle of a water droplet on the surface and reducing the liquid-solid contact area. An analysis based on the integral momentum approach of Karman and Pohlhausen is presented that predicts jet impingement behavior on SH surfaces. The model is first applied to the scenario where the slip at the surface is isotropic and a downstream depth is imposed such that a circular hydraulic jump occurs. The model predicts the thin film parameters downstream of the jet and the radial location of the hydraulic jump. An increase in the hydraulic jump radius occurs as slip increases, momentum of the jet increases, or the downstream depth decreases. Modifications to the model are made for the scenario where the slip at the surface varies azimuthally, as would be the case for a surface patterned with microribs. The average behavior is similar, although now an elliptically shaped jump forms with the major axis aligned parallel to the rib/cavity structures. The ellipse eccentricity increases as the slip increases, the jet momentum increases, or the downstream depth decreases. Where there is no downstream depth imposed on SH surfaces, the thin film breaks up into droplets instead of forming a hydraulic jump. Further changes are made to the model to incorporate this behavior for isotropic and anisotropic surfaces resulting in circular and elliptically shaped breakups respectively. This work also explores SH surfaces with riblets in turbulent channel flow. Pressure drop measurements across surfaces exhibiting superhydrophobicity, riblets, and surfaces with both drag reducing mechanisms are presented. The SH surface reduces drag because the effective surface area is reduced and riblets are able to reduce drag by dampening the spanwise turbulence. Photolithography was used to fabricate all surface types. An aluminum channel with a control and a test section was used for testing. Pressure transducers recorded the pressure drop across smooth silicon wafers and patterned test surfaces simultaneously allowing for computation of the friction factors.
330

Break Point Detection for Strategic Asset Allocation / Detektering av brytpunkter för strategisk tillgångsslagsallokering

Madebrink, Erika January 2019 (has links)
This paper focuses on how to improve strategic asset allocation in practice. Strategic asset allocation is perhaps the most fundamental issue in portfolio management and it has been thoroughly discussed in previous research. We take our starting point in the traditional work of Markowitz within portfolio optimization. We provide a new solution of how to perform portfolio optimization in practice, or more specifically how to estimate the covariance matrix, which is needed to perform conventional portfolio optimization. Many researchers within this field have noted that the return distribution of financial assets seems to vary over time, so called regime switching, which makes it dicult to estimate the covariance matrix. We solve this problem by using a Bayesian approach for developing a Markov chain Monte Carlo algorithm that detects break points in the return distribution of financial assets, thus enabling us to improve the estimation of the covariance matrix. We find that there are two break points during the time period studied and that the main difference between the periods are that the volatility was substantially higher for all assets during the period that corresponds to the financial crisis, whereas correlations were less affected. By evaluating the performance of the algorithm we find that the algorithm can increase the Sharpe ratio of a portfolio, thus that our algorithm can improve strategic asset allocation over time. / Detta examensarbete fokuserar på hur man kan förbättra tillämpningen av strategisk tillgångsslagsallokering i praktiken. Hur man allokerar kapital mellan tillgångsslag är kanske de mest fundamentala beslutet inom kapitalförvaltning och ämnet har diskuterats grundligt i litteraturen. Vårt arbete utgår från Markowitz traditionella teorier inom portföljoptimering och utifrån dessa tar vi fram ett nytt angreppssätt för att genomföra portföljoptimering i praktiken. Mer specifikt utvecklar vi ett nytt sätt att uppskatta kovar-iansmatrisen för avkastningsfördelningen för finansiella tillgångar, något som är essentiellt för att kunna beräkna de optimala portföljvikterna enligt Markowitz. Det påstås ofta att avkastningens fördelning förändras över tid; att det sker så kallade regimskiften, vilket försvårar uppskattningen av kovariansmatrisen. Vi löser detta problem genom att använda ett Bayesiansk angreppssätt där vi utvecklar en Markov chain Monte Carlo-algoritm som upptäcker brytpunkter i avkastningsfördelningen, vilket gör att uppskattningen av kovar-iansmatrisen kan förbättras. Vi finner två brytpunkter i fördelningen under den studerade tidsperioden och den huvudsakliga skillnaden mellan de olika tidsperioderna är att volatiliten var betydligt högre för samtliga tillgångar under den tidsperiod som motsvaras av finanskrisen, medan korrelationerna mellan tillgångsslagen inte påverkades lika mycket. Genom att utvärdera hur algoritmen presterar finner vi att den ökar en portföljs Sharpe ratio och således att den kan förbättra den strategiska allokeringen mellan tillgångsslagen över tid.

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