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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.
21

Individual Musculoskeletal Characteristics of Runners and Advanced Footwear Technology

Stattin, Sebastian January 2022 (has links)
Background: In recent years, sudden improvements in long-distance running performance have been suggested to be due to the latest technological innovations in running footwear. However, inter-individual differences appear to be large in the performance enhancing effect these shoes elicit where some runners experience a decline in performance while others improve substantially. The reason for this is not yet fully understood but may be due to differences in anthropometric and neuromuscular characteristics between runners. Aim: The aim of this thesis was to investigate the association between individual anthropometrical and neuromuscular characteristics of runners with changes in running mechanics while wearing these new generation shoes. Method: Eight male endurance runners performed four different testing protocols during one single visit. These consisted of an anthropometrical protocol where measurements of height, weight, leg length and Achilles tendon moment arm length were determined; a jumping protocol where vertical stiffness and eccentric utilization ratio (EUR) were recorded using a force platform; a running protocol where contact time, step length, ankle propulsive power and knee absorption power were measured using a force platform and a 12-camera motion analysis system; and finally a force-velocity protocol where each participant performed calf raises and back squats with incremental loads in a smith machine while barbell velocity was simultaneously recorded. The collected data were then statistically analyzed using Wilcoxon Signed-Rank Test and Spearman’s Rank Correlation Coefficient. Results: Greater peak power in the back squat was associated with a greater reduction in peak knee absorption power (r = -0,905, p = 0,005) and less vertical stiffness during jumping was associated with longer step lengths with the advanced footwear technology (AFT) shoes (r = -0,738, p = 0,046). No associations were found between vertical stiffness during jumping and contact time, EUR with step length and contact time, peak power in the calf raise and Achilles tendon moment arm with peak ankle propulsive power. Conclusion: Runners with less vertical stiffness in the lower limb during jumping exhibited greater step length increase with AFT shoes. This may be due to the spring-like behavior the shoes possess. However, the larger step length increases the demands on lower limb strength and runners with less power in the lower limb may increase their knee absorption power during ground contact, leading to potentially less efficient running mechanics. Those with greater power in the lower limb may, on the other hand, run more efficiently by decreasing their knee absorption power leading to less muscular effort. / Bakgrund: De senaste årens förbättringar inom långdistanslöpning har föreslagits bero på de teknologiska framstegen som gjorts inom löparskokonstruktion. Det verkar emellertid finnas en skillnad i den prestationshöjande effekt som dessa skor framkallar, där vissa löpare upplever en försämring medan andra förbättras avsevärt. Orsaken till detta är fortsatt okänt men kan ha att göra med skillnader i antropometriska och neuromuskulära egenskaper mellan löpare. Syfte: Syftet med denna uppsats var att undersöka sambandet mellan individuella antropometriska och neuromuskulära egenskaper hos löpare med förändringar i löpmekanik som dessa nya generationens skor framkallar.Metod: Åtta manliga långdistanslöpare utförde fyra olika testprotokoll under ett enda besök. Dessa bestod av ett antropometriskt protokoll där längd, vikt, benlängd och momentarmslängd av Akillessenan mättes; ett hopprotokoll där vertikal styvhet och EUR registrerades med hjälp av en kraftplatta; ett löpprotokoll där kontakttid, steglängd, fotledskraft och knäledskraft mättes med hjälp av kraftplattor och ett rörelseanalyssystem med 12 kameror; och slutligen ett kraft-hastighetsprotokoll där varje deltagare utförde tåhävningar och knäböj med stigande belastning i en smith-maskin medan skivstångshastighet samtidigt registrerades. Den insamlade data analyserades därefter med Wilcoxon Signed-Rank Test och Spearman’s Rank Correlation Coefficient. Resultat: Högre peak power i benböj var associerat med en större minskning av maximal knäabsorptions power (r = -0,905, p = 0,005) och mindre vertikal styvhet under vertikalhopp var associerad med längre steglängd med AFT-skorna (r = -0,738, p = 0,046). Inget samband hittades mellan vertikal styvhet under vertikalhopp och kontakttid, EUR med steglängd och kontakttid, maximal power i tåhävningar och hälsenans momentarm med maximal propulsionspower i fotleden. Konklusion: Löpare med mindre vertikal styvhet i de nedre extremiteten under vertikalhopp uppvisade större steglängdsökning med AFT-skor. Detta kan bero på det fjäderliknande beteende skorna har. Den längre steglängden ökar dock kraven på styrkan i den nedre extremiteten och löpare med mindre kraft, har potentiell ökad knäabsorptions power under markkontakt vilket kan resultera i en mindre effektiv löpmekanik. De med bättre kraftutveckling i de nedre extremiteten kan däremot potentiellt springa mer effektivt med dessa nya generationens skor genom en minskning i knäabsorptions power vilket i sin tur leder till mindre muskulär ansträngning.
22

Navigating the Shadows : Overcoming Obstacles Posed by Anti-forensic Tools

Svensson, Jonny, Wouters, Samuel January 2024 (has links)
This thesis explores the landscape of Anti-forensics tools (AFTs) and their impact on digital forensic investigations. It begins with a comprehensive review of relevant literature and then delves into the methods employed by AFTs, including data encryption and file manipulation. A survey of popular AFTs, such as GnuPG, AESCrypt, Tails, StegHide, or CCleaner, provides insights into their functionalities and implications for forensic analysis. Results from experimentation and discussions on method validation, hardware benchmarks, and the ethical implications of AFT usage contribute to a comprehensive analysis. Key findings highlight the effectiveness of AFTs in circumventing forensic analysis, raising ethical concerns regarding their valid use. The thesis concludes with reflections on the scope of the study, ethical considerations, and avenues for future research. Through this exploration, the thesis provides valuable insights into the challenges posed by Anti-forensics tools in digital investigations. It underscores the need for continued research and ethical considerations in this evolving field.
23

Ověření možnosti syntetické přípravy ettringitu a thaumasitu / Verification of the synthetic preparation of ettringite and thaumasite

Hrdina, Matěj January 2015 (has links)
The work is focused on the possibilities of using FBC fly ash for composite cements, monitoring their hydration processes, especially the creation of AFt phase. The possibility of preparing synthetic ettringite and thaumasite and their detection.
24

Ověření termodynamické stability ettringitu / Verification of the Thermodynamic Stability of Ettringite

Pekárková, Jana January 2016 (has links)
The thesis deals with possibilities of FBC fly ash utilization for composite cements. It focuses on thermodynamic stability of ettringite, which is produced during composite cements hydration. Specific tasks are dedicated to observation of influence of outdoor environment and influence of calciumhydrosilicate environment to stability of ettringite.
25

台灣地區基因檢測之意向及願付價格調查 / The Investigation of people's intention and their willingness to pay toward genetic testing in Taiwan

王荷惠, Wang, Ho Hui Unknown Date (has links)
本研究的目的主要是想要探討台灣地區的人民對於基因檢測的意向及願付價格。資料來自於中央研究院所主導的一項電話訪問,其中有關願付價格的部分是透過條件評估法的方式來取得。針對願付價格的分析,我們藉由潛在變數模型將受訪者對於基因檢測的知識、態度和自我認知等資訊萃取出來,並視為新的解釋變數來進行分析。此外,僅完成單界詢價過程的受訪者的資訊也和提供完整回答的受訪者一併納入分析。 結果顯示一個人的性別、教育程度、宗教信仰傾向及對基因檢測的態度會顯著影響是否願意免費參加基因檢測的意願。而在詢價過程中,一開始受訪者被問及的金額和此人其基因檢測相關的知識程度影響了他(她)是否願意付錢參加基因檢測。至於在願意付合理價格的人們之中,他們的健康程度、收入和自家人的癌症病史則皆為影響價格高低的因素。 / This study is aimed to explore people’s intention and their willingness to pay (WTP) for genetic testing in Taiwan. A telephone survey using contingent valuation method (CVM) was conducted by the Academia Sinica to collect the data. There are three unique features that distinguish our data analysis approach from the others. First, the covariates related to a respondent’s knowledge, attitude and perception (KAP) on genetic testing are generated through the use of a latent trait model. Second, the information collected from a respondent who completed only the single-bounded part of the survey is also included in the analysis. Third, reasons given by a respondent is used to decide whether he/she is willing to pay a lower price or unwilling to pay any price. It is shown that one’s gender, education level, religious tendency and attitude all have significant impact on whether a respondent is willing to try a free genetic test. When it comes to pay for it, the initial bid asked and the degrees of knowledge affect his/her decision a lot. For those who are willing to pay a reasonable price for genetic testing, their WTP depend largely on their health conditions, incomes, and cancer histories.
26

Full-Scale Testing of Blast-Induced Liquefaction Downdrag on Driven Piles in Sand

Kevan, Luke Ian 01 July 2017 (has links)
Deep foundations such as driven piles are often used to bypass liquefiable layers of soil and bear on more competent strata. When liquefaction occurs, the skin friction around the deep foundation goes to zero in the liquefiable layer. As the pore pressures dissipate, the soil settles. As the soil settles, negative skin friction develops owing to the downward movement of the soil surrounding the pile. To investigate the magnitude of the skin friction along the shaft three driven piles, an H-pile, a closed end pipe pile, and a concrete square pile, were instrumented and used to measure soil induced load at a site near Turrell, Arkansas following blast-induced liquefaction. Measurements were made of the load in the pile, the settlement of the ground and the settlement of piles in each case. Estimates of side friction and end-bearing resistance were obtained from Pile Driving Analyzer (PDA) measurements during driving and embedded O-cell type testing. The H-pile was driven to a depth of 94 feet, the pipe pile 74 feet, and the concrete square pile 72 feet below the ground surface to investigate the influence of pile depth in response to liquefaction. All three piles penetrated the liquefied layer and tipped out in denser sand. The soil surrounding the piles settled 2.5 inches for the H-pile, 2.8 inches for the pipe pile and 3.3 inches for the concrete square pile. The piles themselves settled 0.28 inches for the H-pile, 0.32 inches for the pipe pile, and 0.28 inches for the concrete square pile. During reconsolidation, the skin friction of the liquefied layer was 43% for the H-pile, 41% for the pipe pile, and 49% for the concrete square pile. Due to the magnitude of load felt in the piles from these tests the assumption of 50% skin friction developing in the liquefied zone is reasonable. Reduced side friction in the liquefied zone led to full mobilization of skin friction in the non-liquefied soil, and partial mobilization of end bearing capacity. The neutral plane, defined as the depth where the settlement of the soil equals the settlement of the pile, was outside of the liquefied zone in each scenario. The neutral plane method that uses mobilized end bearing measured during blasting to calculate settlement of the pile post liquefaction proved to be accurate for these three piles.
27

Globalizing Solidarity: Explaining Differences in U.S Labor Union Transnationalism

Keida, Mark Stephen 01 December 2006 (has links)
No description available.
28

台灣地區公共電視使用之願付價格分析 / Assessing willingness to pay for maintaining the operation of Public Television Service in Taiwan.

黃慧甄, Huang, Huei Jhen Unknown Date (has links)
本研究主要目的是想要探討台灣地區民眾對於維持公共電視的營運與發展之願付價格。資料來自於中央研究院人文社會科學研究中心調查研究專題中心所進行的一項公共電視願付價格調查,其中關於願付價格的部分是透過條件評估法的方式取得,受訪者隨機分配至兩個題組之一,其中A題組為考慮公共電視帶給家人的好處,而B題組為考慮公共電視帶給全國民眾及社會的好處。 建模時我們採用一或二要素混成模型,這是一個可以將不理性受訪者分離,僅針對理性受訪者的願付價格進行估計的一個模型。分析結果顯示考慮到公共電視帶給家人的好處時,年齡50歲以上的受訪者中存在著一群無論什麼價格都不願意支付或Ney-sayers的人,估計的比例大約為21.13%;而考慮到公共電視帶給全國民眾及社會的好處時,很少看文化教育節目的受訪者中也存在著一群無論什麼價格都不願意支付或Ney-sayers的人,估計比例大約為13.53%。 針對願意支付合理價格的受訪者配適加速失敗模型時,我們不僅就位置參數引進解釋變數,同時也引進解釋變數至尺度參數。分析結果顯示願意支付合理價格的受訪者,在考慮公共電視帶給家人的好處時,每年願意支付價格之平均值為1477元;而考慮到公共電視帶給全國民眾及社會的好處時,每年願意支付價格之平均值為1663元。顯示受訪者在考慮到全國民眾及社會的好處,願意付出較高的價錢。 / This study aimed to explore people’s willingness to pay (WTP) for maintaining the operation of Public Television Service (PTS) in Taiwan. The survey using contingent valuation method was conducted by the Center for Survey Research, Academia Sinica. The survey sample was split into two groups, A and B. Each group was presented with the same scenario but different scope of benefits. Group A considered the benefits that PTS might bring to one’s family, while Group B considered the benefits that PTS might bring to the whole society. The model used in this study was a one/two-component hybrid model, a model that is able to separate those who are willing to pay a reasonable price from these who are not, and obtain their mean WTP estimate. Multinomial logistic part of the model, indicated that for Group A, among those who were 50 years of age or older, about 24.48% were not willing to pay any price or Ney-sayers. And for Group B, among those who seldom watched cultural or educational programs, about 12.91% were not willing to pay any price or Ney-sayers. Appling accelerated failure time model to those who were willing to pay for reasonable prices enabled us to evaluate the WTP. We not only introduced explanatory variables in the location parameter but also the scale parameter. The estimated mean WTP for Group A was found to be NT$1477 per year, while the mean WTP for Group B was NT$1663 per year.
29

Globalizing solidarity explaining differences in U.S. labor union transnationalism /

Keida, Mark Stephen. January 2006 (has links)
Thesis (Ph. D.)--Miami University, Dept. of Political Science, 2006. / Title from second page of PDF document. Includes bibliographical references (p. 216-251).
30

Is there a benefit of super spikes in long jump performance?

Svensson, Erik January 2023 (has links)
Background and aim The pace of development of distance running shoes has been fast-forward since 2016 when Nike introduced their model Nike Zoom Vaporfly, with an imbedded carbon fiber plate and an advanced newly developed Pebax®-foam. The shoe-development has continued to track events, with the introduction of carbon fiber plate in several shoe-models for running and sprint- events. The research area for track events has not reached the level as for distance running shoes, therefore the aim of this study was to examine the effects on long jump performance when using long jump spikes with (AFT) compared to without (non-AFT) a carbon fiber plate.  Method Nine experienced male (n=6, age 22 ± 4.8 years, body mass 76.4 ± 3.5 kg, height 182 ± 4.9 cm), and female (n=3, age 20.3 ± 3.5 years, body mass 64.8 ± 6.0 kg, height 172 ± 2.0 cm) Swedish long jumpers performed three maximal effort long jumps in AFT and non-AFT long jump shoes. Three-dimensional kinematic data was captured with eight markerless motion capture cameras, and the take-off was performed from a force plate. Run-up velocity was measured using a lidar laser and step characteristics using an optical contact grid. Pearson’s correlation coefficient was calculated for jump distance and maximal run-up velocity and paired samples t-tests and a Wilcoxon rank sum test were conducted to examine differences between the shoes.  Results Peak run-up velocity correlated with jump distance both for AFT (Pearson’s r=0.919, p<0.001) and non-AFT shoes (Pearson’s r=0.910, p<0.001). At a group-level no statistical differences were found between the shoes for the run-up variables. The AFT shoes showed significantly greater horizontal velocity at touchdown (p=0.046) and vertical velocity difference from touchdown to toe-off (p=0.029) compared to the non-AFT shoes. No other significant difference was found on group level for the take-off variables. Conclusion The results in this study did not show a longer jump distance in long jump specific AFT shoes compared to non-AFT on a group level, but individual differences were seen. To further understand the effect of AFT shoes on long jump performance, more studies on different individual characteristics and their relation to long jump performance is needed. Keywords Long jump, super spikes, AFT-shoes, carbon fiber plate, biomechanics. / Bakgrund och syfte Sedan Nike 2016 introducerade sin skomodell Nike Zoom Vaporfly har utvecklingen av löparskor med en inbäddad kolfiberplatta och nyutvecklade med energiåtergivande material snabbt fortskridit. Utvecklingen av skor har fortsatt från löparspåren till friidrottsbanan för flera grenar. Forskningsområdet för grenspecifika skor har inte kommit lika långt som för distanslöparskor, därför var syftet med denna studie att undersöka effekterna på längdhoppsprestation av att använda längdhoppsspecifika spikskor med (AFT) jämfört med utan (non-AFT) kolfiberplatta. Metod Nio erfarna manliga (n=6, ålder 22 ± 4,8 år, kroppsvikt 76,4 ± 3,5 kg, längd 182 ± 4,9 cm) och kvinnliga (n=3, ålder 20,3 ± 3,5 år, kroppsvikt 64,8 ± 6 kg, längd 172 ± 2 cm) svenska längdhoppare gjorde tre maximala längdhopp i AFT och non-AFT längdhoppsskor. Tredimensionell kinematisk data samlades in med åtta markörlösa motion capture-kameror och uthoppet skedde från en kraftplatta. Ansatshastigheten mättes med en laserkamera och steg-specifik data med ett optiskt kontaktnät. Pearson’s korrelations koefficient beräknades for hopplängd och maximal ansatshastighet samt så genomfördes paired samples t-test och Wilcoxon rank sum test för att undersäka skillnaderna mellan skorna. Resultat Maximal ansatshastighet korrelerade med maximal hopplängd både för AFT skor (Pearsons r=0,919, p<0,001) och non-AFT skor (Pearsons r=0,910, p<0,001). På gruppnivå hittades ingen statistisk skillnad mellan skorna vad gäller ansatslöpningens variabler. AFT skorna visade en signifikant högre horisontell hastighet vid första markkontakt med kraftplatta (p=0,046) och vertikal hastighetsdifferens från första markkontakt med kraftplatta till sista markkontakt med kraftplatta (p=0,029) jämfört med non-AFT-skor. Ingen annan signifikant skillnad hittades på gruppnivå vad gäller uthoppsvariabler. Slutsats Resultaten i denna studie visade inte på en längre hopplängd i längdhoppsspecifika AFT skor jämfört med icke-AFT skor på gruppnivå men skillnader sågs på individnivå. För att ytterligare förstå effekten av AFT skor på längdhoppsprestation behövs fler studier om olika individuella egenskaper och dess relation till längdhoppsprestation. Nyckelord Längdhopp, super spikes, AFT-skor, karbonfiberplatta, biomekanik.

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