1,720,962 research outputs found
[[alternative]]The Study of The Dynamic Modeling For the Support Phase in Running
No full text[[abstract]]Department of Physical Education National Taiwan Normal University Doctor's Thesis
Graduate Student : Chiu, Ching-Hua
Advisor: Wang, Jin-Cherng
The Study of The Dynamic Modeling For the Support Phase in Running
Abstract
The purpose of this study was to construct a human dynamic modeling system about the motion for the support phase in running. The function of this system was to simulate for the support phase the ground reaction force as well as the moment, the power , and the relative angular momentum of major body joints. As to the research methods, the structure of the body joints was claimed to be a multivariable system divided into thirty-eight degrees of freedom. In order for this system to be expanded into a human motion control system, this study adopted Lagrange-Euler equtions. But the Denavit-Hartenberg matrix used by other scholars in the past was not applied; instead, this study utilized Basic Homogeneous Rotational Matrices and Basic Homogeneous Translation Matrices to define seven-type homogeneous transformation matrix, thus making this dynamic system both applicable to branching body system and convertible into state space equations. Then one force plate (Kislter)and two cameras (Peak Performance) were used to obtain the relative data about the motion of the subject(age:22 ;height:1.81m; weight:75kg) for the support phase in running. After simulating by means of C++ programs designed in person, the findings showed that this dynamic system was really competent in simulating the ground reaction force,the moment , the power , and the relative angular momentum of major body joints.
Keywords: Support phase、Matrix、Moment、Power、Angular momentum
[[alternative]]analysis of Pressure Distribution of Palm When Perform Two Styles of Forward Handspring
No full text[[abstract]]The purpose of this study was to analyze the pressure distribution of palm between performing forward handspring and forward handspring with legs straddled. We use Novel Emed-SF-2 Platform to collect pressure data of palm form 60 Chinese traditional opera performers when they were doing forward handspring motion. We developed analysis program by Matlab 5.0TM to calculate the pressure distribution of palm, observing the motional parameter and relationship between pressure occurs at fingers and palms during action time.
In the result, by observing the location of pressure, there is no significant difference between two forward handspring motions. By distribution of pressure, thenar hold 34%, hypothenar 21%, joint of metacarpal and fingers 16% and fingers 29%.
Although the data size of the motion images and forces are so large that we primarily focus our research on the analyzing of palm's pressure. We hope a continuous research to eatable better module to provide teaching guide and suggestion for the training exercise.
[[alternative]]The study of the dynamic modeling for the takeoff phase in long jump
No full text[[abstract]]本研究之動力學模式理論，是根據彈簧振動力學及指數函數建立而成。經由運用建立
的模式，模擬受試者起跳期間施於地面的蹬力，重心速度，起跳角，跳遠成績，起跳
腳負載的能量與功率。為了提高研究資料的精確度，在攝影方面係採用最小平方法，
將kodak 分析系統取得的資料轉換為實際的空間座標值。在測力板方面克服傳統僅作
垂直軸的校正，而使用本研究自行發展的測力板校正器來校正水平軸的力量，使測力
板的資料誤差減至最小。在同步效應方面，應用短路干擾法，使得攝影機與測力板能
確實達成同步效應。
本研究模擬之結果發現，水平軸與垂直軸的力量函數，相對誤差在4.8%以下，可用來
模擬受試者對地蹬力，起跳速度，實跳成績，及起跳腳所負蹬力，起跳速度，起跳腳
所負載的能量與功率，其次，根據建立之跳遠動力學模式，受試者在踩板起跳期間之
重心水平速度從8.4 公尺/ 秒增至10.2公尺/ 秒的模擬範圍，成績由6.62公尺增至
9.78公尺範圍，受試者在踩板起跳期間之重心垂直速度從-0.4公尺/ 秒至-1.2公尺/
秒的模擬範圍，成績由7.79公尺減至6.23公尺。
[[alternative]]The Study of Optimal Stride Length Estimation for Distance
No full text[[abstract]]本研究主要目的在於建立一多項式迴歸模式(Polynomial regression
model),模擬人體在不同步幅與不同跑步速度下之跑步動作,並利用身體重
心垂直振幅為指標,以探討跑者之最佳步幅.研究對象為受過長期耐力跑訓
練之男選手一人,使用Peak 動作分析系統 , 蒐集其在正常步幅,加大步幅
以及縮小步幅等跑步資料,並根據其步幅以及速度兩個變數,與跑步時身體
各關節點間已經標準化之座標值,建立一組多項式迴歸函數,用來推估跑步
週期中身體各關節點座標值隨步幅以及速度改變之變化情形,並以估計標
準誤差值(Standard error of estimate )檢驗模擬座標值與實驗座標值
之精確度.為提高本研究最佳步幅之可證性,再根據先前模擬得出之最佳步
幅,讓受試者在跑步機上跑步,求出跑者之身體重心垂直振幅實驗值,再與
先前之模擬值進行估計標準誤差考驗 .本研究結果經分析與討論後,獲至
結論如下:一.身體各肢段位置與跑步步幅.跑步速度間存有漸進互動之關
係,且每種跑步速度下均有其步幅範圍之限制 .二.本模式模擬全身總肢段
在水平方向之估計標準誤差值為4.6207公分(3.4968%);垂直方向之估計標
準誤差值為 1.3698公分(1.5814%) .三.本模式推估跑步時最佳步幅垂直
方向之估計標準誤差值在1.121公分(1.157%)至2.744公分(2.838%) 之間;
最佳步幅跑步身體重心垂直振幅之模擬值與實驗值之估計標準誤差值
為0.184公分. 基於上列之結果,本研究之結論為此多項式迴歸模式確實可
適用於跑者個別化之跑步動作模擬,提供跑者對於最佳步幅之判定,有助於
跑步動作之診斷與改善.
The purpose of this study was to establish a polynomial
regression model to simulate the motion of distance running
during the controlled conditions ofspeed and stride length.
Subsequently,the simulated values of vertical oscilla-tion of
center of gravity was utilized as a criterion to estimate the
runnersoptimal stride length.One elite distance runner was
selected as the subject ofthis study. Peak motion system was the
major equipment to collect the data. Polynomial regression
technique was used for the running modeling based on
thevariables of running speed and stride length. The standard
error of estimateexamined the difference between the
experimental data and simulated data. Afterdata calculating and
data analyzing, the following results have been reached:1.There
was a close relationship among the variables of segment
position, stri-de length, and running speed, and different
running speeds existed in the diff-erent range of the stride
length. 2.The standard error of estimate of the body position
between experimental value and simulated value was 4.62 cm
(3.50%) inhorizontal direction, and was 1.37 cm (1.58%) in
vertical direction. 3.For thecondition of the optimal stride
length, the standard error of estimate betweenexperimental value
and simulated value was found from 1.12 cm (1.16%) to 2.74cm
(2.84%), and there was 0.18 cm of standard error of estimate
between experi-mental vertical oscillation and simulated
vertical oscillation. Finally, thisstudy concluded that the
polynomial regression model could be used for the distance
running simulation individually to estimate the runners optimal
stridelength. Keywords:running model,simulation,distance
running,optimal stride length
The purpose of this study was to establish a polynomial
[[alternative]]A study of Application of the Delphi Method of Identification for Table Tennis Talents
No full text[[abstract]]The appropriate methods of sports science should be used to identify, train and manage the sport talents and predict the results of competition, not only judge by previous experience. The Delphi method is an objective and scientific way for choosing table tennis talents, and can be adopted to achieve the goals of performance more efficiently and accurately. The purposes of this study were to investigate the method for table tennis talent identification; and set up an evaluation system for coach to select talent players and training. This study was designed to conduct the investigational questionnaire; Delphi Method was adopted to compile “ Investigation Questionnaire for Opinions of Selection Experts of Taiwan Table Tennis Players” as the tool of study. The five domestic highly potential players, included Chuan Chi-Yuan, were asked to participate in this study. By applying “Simple Additive Weight Method” into the questionnaires, the following conclusions were drawn after analysis and discussion:
1.The selection of table-tennis players in Taiwan should include the critical characters: physical type, quality, physiological function, sport skill, fitness for competition, genetic, development and growth, and mentality as evaluation indexes of the selection for talent table-tennis players.
2.The sport talent selection, training and competition procedures should be based on sport science principles.
3.After selection of table tennis talents, the scientific training methods should combine modern biochemistry techniques, proper nutrition supplements and physical and psychology recovery strategy to enhance the competition capability of the table tennis players.
4.Since the selection of table tennis talents in Taiwan is not fully based on the scientific method, the performance of table tennis sport is not so good as expected.
Key words：table-tennis, sport talent identification, Delphi method
[[alternative]]The Study of Cooperative Movement Between Knee
No full text[[abstract]]本研究的目的在探討雙手插腰垂直跳起跳期，膝、踝關節聯合運動的現象
。以十五位男性運動員與十五位男性非運動員為受試者，以 KINEMETRIX
3D 動作分析系統為主要研究儀器，經資料處理歸納為以下結論：
（一）在角度上：膝關節彎曲範圍自平均 173.94 度至平均 61.06 度，
伸展範圍自平均 61.06 度至平均 158.29 度；踝關節彎曲範圍自平均
118.30 度至平均 85.17度；伸展範圍自平均85.17度至平均143.97度。
（二）在時間上：膝關節的彎曲時間平均為 0.63 秒，伸展時間平均為
0.28 秒； 踝關節的彎曲時間平均為 0.59 秒，伸展時間平均為 0.27
秒。
（三）在關節屈、伸時間比率上：膝、踝關節的屈、伸時間比率約為
7：3。
（四）在相對時間比率上：膝關節開始彎曲時踝關節慢了 6﹪的膝總動作
時間才開始彎曲；於 69﹪膝總動作時間時，膝關節彎曲達最小角度，踝
關節則是在 70﹪膝總動作時間時彎曲達最小角度；最後在 100﹪膝總動
作時間時，腳尖離地。
（五）優秀運動員較非運動員在動作上具有較大的腳尖離地角度、較快的
關節伸展速度及較一致的膝、踝關節屈、伸時間比率等特徵。
The purpose of this study was to explore the phenomenon of the
cooperative movement between knee and ankle joints during
takeoff phase of vertical jumping performance with arms
akimboed. 15 elit male athletes and 15 male non-athletes were
subjects at this study . KINEMETRIX 3D motion analysis system
were used to collect data . After data treatment , the results
were reached followings：
1.In angles：The range of knee bending was from average 173.94°
to 61.06°；knee extending was{EMBED Equation.2 \* mergeformat|
from average 61.06° to 158.29°； ankle bending was from }
average 118.30° to 85.17°；ankle extending was from average
85.17°to 143.97°.
2. In motion times：The average time of knee bending was 0.63
second , knee extending was 0.28 second ；ankle bending was
0.59 second , ankle extending was 0.27 second .
3. In time ratio betwen joint bending and extending ：The time
ratio between bending and extending of knee and ankle joints was
7：3 .
4. In relative time ratios：Knee joint started bending at first,
and then ankle joint started bending after 6 ﹪total motion time
of knee joint (TKM)；at the time of 69 ﹪TKM , knee joint bended
to the smallest angle, ankle joint bended to the same situation
at 70﹪ TKM；finally, toe leaved the ground at the time of 100﹪
TKM.
5. By comparing with non-athletes , the characteristics of elit
athletes' motion were larger joint angles of toe-off , faster
joint extending velocity and more constent time ratio of bending
and extending of knee and ankle joint .
The purpose of this study was to explore the phenomenon of the
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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