Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|声学代写Acoustics代考|Normal Error Function or the Gaussian Distribution

“Everyone believes that the Gaussian distribution describes the distribution of random errors; mathematicians because they think physicists have verified it experimentally, and physicists because they think mathematicians have proved it theoretically.” [21]

When we think about random processes, a common example is the coin toss. If we flip a fair coin, there is a $50 \%$ probability that the coin will land “heads” up and an equal probability that it will land “tails” up. If we toss $N$ coins simultaneously, the probability of any particular outcome, say $h$ heads and $t=N-h$ tails, is given by a binomial distribution. The average of that distribution will still be $\bar{h}=$ $\bar{t}=N / 2$, but the likelihood of getting exactly $N / 2$ heads in any given toss is fairly small and grows smaller with increasing $N$.

The probability, $P_B(h, p, N)$, of obtaining $h$ heads and $t=N-h$ tails is given by a binomial distribution where the probability of obtaining a head is $p=0.5$. Of course, the probability of a tail is $q=0.5$.
$$P_B(h, p, \mathrm{~N})=\frac{N !}{h !(N-h) !} p^h q^{(N-h)}$$
For the binomial distribution, the average outcome with the largest probability is the mean, $\bar{h}=N p$, and the standard deviation about that mean is $\sigma=[N p(1-p)]^{1 / 2}$. It is worthwhile to recognize that $\bar{h}$ is proportional to the number of trials $N$, whereas $\sigma$ is proportional to $\sqrt{N}$. Therefore, the relative width of the distribution function, $\sigma / \bar{h}$, decreases in proportion to $\sqrt{N}$. This “sharpening” of the distribution with increasing $N$ is evident in Fig. 1.11.

## 物理代写|声学代写Acoustics代考|Systematic Errors (Bias)

Systematic error is not reduced by increasing the number of measurements. In the “target” example on the right-hand side of Fig. 1.10, taking more shots will not bring the average any closer to the bull’seye. On the other hand, an adjustment of the sighting mechanism could produce results that are far better than those shown in the left-hand side of Fig. $1.10$ by bringing the much tighter cluster of holes on the right-hand side toward the center of the target.

The right-hand side of the target example in Fig. $1.10$ represents a type of systematic error that I call a “calibration error.” These can enter a measurement in a number of ways. If a ruler is calibrated at room temperature but used at a much higher temperature, the thermal expansion will bias the readings of length. In acoustic and vibration experiments, often each component of the measurement system may be calibrated, but the calibration could be a function of ambient pressure and temperature. The “loading” of the output of one component of the system by a subsequent component can reduce the output or provide a gain that is load-dependent.

For example, a capacitive microphone capsule with a capacitance of $50 \mathrm{pF}$ has an electrical output impedance at $100 \mathrm{~Hz}$ of $Z_{e l}=(\omega C)^{-1}=32 \mathrm{M} \Omega$. If it is connected to a preamplifier with an input impedance of $100 \mathrm{M} \Omega$, then the signal amplified by that stage at $100 \mathrm{~Hz}$ is reduced by $(100 / 132) \cong 0.76$. Even though the capsule may be calibrated with a sensitivity of $1.00 \mathrm{mV} / \mathrm{Pa}$, it will present a sensitivity to the preamplifier of $0.76 \mathrm{mV} / \mathrm{Pa}$. At $1.0 \mathrm{kHz}$, the capsule’s output impedance drops to $3.2 \mathrm{M} \Omega$, so the effective sensitivity at that higher frequency will be $(100 / 103) \times 1.00 \mathrm{mV} /$ $\mathrm{Pa}=0.97 \mathrm{mV} / \mathrm{Pa}$. A typical acoustic measurement system may concatenate many stages from the sensor to its preamplifier, through the cabling, to the input stage of the data acquisition system, through some digital signal processing, and finally out to the display or some recording (storage) device.
As important as it is to know the calibration or gain (i.e., transfer function) of each stage in the measurement system, it is also imperative that the entire system’s overall behavior be tested by an endto-end calibration that can confirm the calculation of the overall system’s sensitivity. This is usually accomplished by providing a calibrated test signal to the sensor and reading the output at the end of the signal acquisition chain. Commercial calibrators are available for microphones, hydrophones, and accelerometers. If a commercial calibrator is not available for a particular sensor, some end-to-end calibration system should be designed as part of the test plan for every experiment.

## 物理代写|声学代写声学代考|正态误差函数或高斯分布

“大家都认为高斯分布描述了随机误差的分布;数学家是因为他们认为物理学家已经通过实验验证了它，物理学家是因为他们认为数学家已经从理论上证明了它。”[21]

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|声学代写Acoustics代考|Geometrical Interpretation on the Argand Plane

To develop and exploit this geometric interpretation of exponential functions, which contain complex numbers within their arguments (hereafter referred to as complex exponentials), we can represent a complex number on a two-dimensional plane known as the “complex plane” or the Argand plane. In that representation, we define the $x$ axis as the “real axis” and the $y$ axis as the “imaginary axis.” This is shown in Fig. 1.7. In this geometric interpretation, multiplication by $j$ would correspond to making a “left turn” [12], that is, making a $90^{\circ}$ rotation in the counterclockwise direction. Since $j * j=j^2=-1$ would correspond to two left turns, a vector pointing along the real axis would be headed backward, which is the equivalent of multiplication by $-1$.

In this textbook, complex numbers will be expressed using bold font. A complex number, $z=x+j y$, where $x$ and $y$ are real numbers, would be represented by a vector of length, $|\vec{r}|=\sqrt{x^2+y^2}$, from the origin to the point, $z$, on the Argand plane, making an angle with the positive real axis of $\theta=\tan ^{-1}(y / x)$. The complex number could also be represented in polar coordinates on the Argand plane as $z=A e^{j \theta}$, where $A=|\vec{r}|$. The geometric and algebraic representations can be summarized by the following equation:
$$\mathbf{z}=x+j y=|\mathbf{z}|(\cos \theta+j \sin \theta)=|\mathbf{z}| e^{j \theta}$$

## 物理代写|声学代写Acoustics代考|Phasor Notation

In this textbook, much of our analysis will be focused on response of a system to a single-frequency stimulus. We will use complex exponentials to represent time-harmonic behavior by letting the angle $\theta$ increase linearly with time, $\theta=\omega_o t+\phi$, where $\omega_{\mathrm{o}}$ is the frequency (angular velocity) which relates the angle to time and $\phi$ is a constant that will accommodate the incorporation of initial conditions (see Sect. 2.1.1) or the phase between the driving stimulus and the system’s response (see Sect. 2.5). As the angle, $\theta$, increases with time, the projection of the uniformly rotating vector, $\vec{x}=|\vec{x}| e^{j \omega_o t+j \phi t} \equiv \widehat{\mathbf{x}} e^{j \omega_{\omega_o} t}$, traces out a sinusoidal time dependence on either axis. This choice is also known as phasor notation. In this case, the phasor is designated $\widehat{\mathbf{x}}$, where the “hat” reminds us that it is a phasor and its representation in bold font reminds us that the phasor is a complex number.
$$\widehat{\mathbf{x}}=|\widehat{\mathbf{x}}| e^{j \theta}$$
Although the projection on either the real or imaginary axis generates the time-harmonic behavior, the traditional choice is to let the real component (i.e., the projection on the real axis) represents the physical behavior of the system. For example, $x(t) \equiv \Re e\left[\widehat{\mathbf{x}} e^{j \omega_o t}\right]$.

## 物理代写|声学代写声学代考|阿根平面上的几何解释

$$\mathbf{z}=x+j y=|\mathbf{z}|(\cos \theta+j \sin \theta)=|\mathbf{z}| e^{j \theta}$$

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|声学代写Acoustics代考|Equilibrium, Stability, and Hooke’s Law

Pause for a moment as you are reading and look around. Close your eyes, count to ten, and then open your eyes. Probably not much has changed. This is because most of the material we observe visually is in a state of stable equilibrium. ${ }^4$ For an object to be in equilibrium, the vector sum of all the forces acting on that body (i.e., the net force) must be zero, and the first derivative of the object’s potential energy with respect to its position must be zero. For that equilibrium state to be stable, the second derivative of the object’s potential energy must be positive.

Figure $1.2$ illustrates three possible equilibrium conditions based on the rate of change of a body’s potential energy with position. For this illustration, let us assume that the solid curve represents the height, $z$, above some reference height, $z_0$, in a uniform gravitational field. The (gravitational) potential energy, $P E(z)$, of each of the three balls shown in Fig. $1.2$ is therefore proportional to their height, $z$, where the mass of each ball is $m$ and $g$ is the acceleration due to gravity that is assumed to be independent of $z: P E(z)=m g\left(z-z_o\right)$.

The three balls in Fig. $1.2$ each respond to a small displacement from their equilibrium positions differently. We can think of the solid curve as representing a flat surface on the left, two peaks at the center and the right, and a valley between two peaks. All three balls are in a state of mechanical equilibrium because the vector sum of the force of gravity (down) and of the surface (up) is zero. In all three cases, the first derivative of the potential energy vanishes at all three locations: $d(P E) / d x=0$. The ball on the left is in a state of neutral equilibrium because it can be moved to the left or to the right by a small distance and it will still be at equilibrium, even at its displaced position. The curve at that location is flat and horizontal.

## 物理代写|声学代写Acoustics代考|Potentials and Forces

The relationship between forces and potential energy can be extended beyond our simple stability example. In general, the net (vector) force, $\vec{F}{\text {net, }}$, is the negative of the gradient of the (scalar) potential energy: $\vec{\nabla}(P E)=-\vec{F}{\text {net. }}{ }^6$ This is consistent with the definitions of work and energy.
$$W_{1,2} \equiv \int_1^2 \vec{F} \cdot d \vec{x}=(P E)1-(P E)_2=-\Delta(P E)$$ The right-hand side assumes that $\vec{F}$ is a conservative force ${ }^7$ and the work, $W{1,2}$, done in moving an object from position 1 to position 2, over some distance along the direction of the force (indicated by the “dot product” under the integral), leads to a change in potential energy, $-\Delta(P E)$. Again, application of the Fundamental Theorem of Calculus leads to the desired relationship between the gradients of the potential energy and the net force: $\vec{\nabla}(P E)=-\vec{F}_{\text {net }}$.

If we limit ourselves to the current example of a ball in the valley, we can expand the potential energy about the stable equilibrium position that is identified as $x_o$.

$$P E\left(x_o+d x\right)=P E\left(x_o\right)+\left.\frac{d^2(P E)}{d x^2}\right|{x_o} \frac{(d x)^2}{2}+\left.\frac{d^3(P E)}{d x^3}\right|{x_o} \frac{(d x)^3}{6}+\ldots$$
Note that the first derivative of $P E$ is missing from Eq. (1.23) because it is zero if $x_o$ is the equilibrium position. ${ }^8$ The term proportional to $(d x)^3$ corresponds to the contribution to the difference between the actual curve and the dashed parabola in Fig. 1.2. If the deviation between the two curves is symmetric, then the leading correction term would be proportional to $(d x)^4$. If the deviation is not symmetric, the leading correction term will be proportional to $(d x)^3$.

In our one-dimensional example, the gradient of the potential energy will simply be the derivative of Eq. (1.23) with respect to $x$.
$$F_{n e t}(d x)=-\frac{d(P E)}{d x}=-\left.\frac{d^2(P E)}{d x^2}\right|{x_o}(d x)-\left.\frac{d^3(P E)}{d x^3}\right|{x_o} \frac{(d x)^2}{2}-\cdots$$
For sufficiently small displacements from equilibrium, the parabolic approximation to the potential energy curve (i.e., the dashed parabola in Fig. 1.2) provides an adequate representation, and therefore the series of Eq. (1.24) that describes the force can be truncated after the first term.
$$F_{n e t}(d x) \cong-\left.\frac{d^2(P E)}{d x^2}\right|_{x_o}(d x) \equiv-\mathrm{K}(d x)$$

## 物理代写|声学代写声学代考|电位和力

$$W_{1,2} \equiv \int_1^2 \vec{F} \cdot d \vec{x}=(P E)1-(P E)2=-\Delta(P E)$$右边假设$\vec{F}$是一个保守力${ }^7$，将一个物体从位置1移动到位置2所做的功$W{1,2}$，沿力的方向移动了一段距离(用积分下面的“点积”表示)，导致势能$-\Delta(P E)$的变化。同样，应用微积分基本定理得到了势能梯度和合力之间的期望关系:$\vec{\nabla}(P E)=-\vec{F}{\text {net }}$ .

$$P E\left(x_o+d x\right)=P E\left(x_o\right)+\left.\frac{d^2(P E)}{d x^2}\right|{x_o} \frac{(d x)^2}{2}+\left.\frac{d^3(P E)}{d x^3}\right|{x_o} \frac{(d x)^3}{6}+\ldots$$注意。的一阶导数 $P E$ 在式(1.23)中缺失，因为如果 $x_o$ 是平衡位置。 ${ }^8$ 这一项与 $(d x)^3$ 对应于图1.2中实际曲线与虚线抛物线之差的贡献。如果两条曲线之间的偏差是对称的，那么前导修正项将成比例 $(d x)^4$。如果偏差不对称，前导修正项将成正比 $(d x)^3$.

$$F_{n e t}(d x)=-\frac{d(P E)}{d x}=-\left.\frac{d^2(P E)}{d x^2}\right|{x_o}(d x)-\left.\frac{d^3(P E)}{d x^3}\right|{x_o} \frac{(d x)^2}{2}-\cdots$$

$$F_{n e t}(d x) \cong-\left.\frac{d^2(P E)}{d x^2}\right|_{x_o}(d x) \equiv-\mathrm{K}(d x)$$

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|运动学代写Kinesiology代考|ENSURE THAT THE TESTERS ARE TRAINED

Some testing protocols require training and practice. Testing is itself a skill. Even basic measures such as height and weight can be inaccurate if performed incorrectly. Usually, participants should stand with feet together when height is measured, and should be asked to take in and hold a deep breath while the measure is being taken. For more complicated testing skills, extensive training may be required. Instruction manuals and training videos can help with training. For novice testers, it may be helpful to check their accuracy against an experienced tester. Even for experienced testers it is advisable to conduct occasional quality control to ensure that their skills have not drifted. Observational skills can be validated using videos of performance or behavior. For example, Senne et al. (2009) used videos of physical education lessons to train and check the observational accuracy for using the System for Observing Fitness Instruction Time (SOFIT). If more than one person will conduct testing and the test requires skill using the equipment or expert subjective judgment of a performance, it may be useful to check interrater objectivity before testing.

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|运动学代写Kinesiology代考|Introduction to Testing

Almost everyone has been tested at some point in their lives. Within minutes of being born, many of us were given a numeric score. The APGAR (Appearance, Pulse, Grimace, Activity, Respiration) assessment is used to provide a numeric score that is evaluated against a set of criterion-referenced standards for determining the health of newborns. Throughout our early months, measurements are taken of our height and weight and other body dimensions, such as head circumference, in order to monitor our growth and development. This is done by comparing our scores against norm-referenced standards from other children of a similar age and sex. We continue to be tested throughout our school years, most notably on our learning and knowledge, and testing continues throughout the rest of our lives. Information from tests is used to make important decisions about us; admission to college, job offers, promotions, and other important life events hang on the outcomes of testing situations. We therefore have plenty of experience with tests from the perspective of a test-taker, and of having decisions made about us by others, based on our test scores. In this chapter, we provide insight into testing from the perspective of the test user or administrator.

Testing has several functions, or purposes, and is important for societal reasons with regards to health, fitness, and education. Kinesiology covers a broad range of disciplines and professions, such as exercise science, physical education, physical therapy, coaching, and sport management. Within these subdisciplines of kinesiology there is an array of different types of tests to choose from, but the principles of testing remain broadly the same regardless of the type of test you are using. Testing situations can vary from individual testing that takes up to 1 or 2 hours to accomplish (e.g., a maximal treadmill exercise test given to a single client or clinical patient) to mass testing, in which several people are tested simultaneously over a relatively short period (such as a PACER test given to a whole class). In some situations, the testing is performed by a professional, such as a physical education teacher or clinical exercise physiologist; in other situations, we may need to rely on the participant or co-participant to conduct the test. An example of the latter would be a participant submitting pedometer scores via an online survey or pairs of students in a class counting each other’s push-ups. Within kinesiology, therefore, the nature of the testing situation varies considerably. In this chapter, we will guide you through the factors you should consider and help you to decide which factors are the most important in any given testing situation. Throughout, practical examples will be used to illustrate the concepts, so that when you meet terms such as reliability, validity, and evaluation in your studies and research you will understand them in the context of how you will apply them in practical testing situations in kinesiology.

## 物理代写|运动学代写Kinesiology代考|The Nature and Purpose of Testing

When you hear the word test, what comes to mind? For most people, a test was something they took at school (also called an exam), requiring them to respond to a set of questions in order to assess their level of learning and knowledge. Much of measurement theory and practice in kinesiology evolved from educational testing, and it is sometimes useful to think of a test in this way. Drawing on personal experiences can be helpful in understanding the relevant principles of testing. However, tests, or measurement instruments, in kinesiology take many more shapes and forms than a paper-and-pencil exam and can pose some unique challenges to the tester. Table $2.1$ lists several examples of types of tests used in kinesiology. It lists the tests by category and describes the construct measured by each test.

The construct is the underlying characteristic we wish to assess. Although some constructs in kinesiology are very tangible and concrete, such as height or strength, others are more abstract and less directly observable. For psychological constructs such as motivation or attitude, we have to use an indirect measure (such as by asking participants to respond to questions that aim to tap into their underlying thoughts and emotions). The Behavioral Regulations in Exercise Questionnaire (BREQ; Mullan, Markland, \& Ingledew, 1997) poses a series of statements such as “It’s important to me to exercise regularly” and “I value the benefits of exercise” in order to measure motivation. Participants respond on a numeric scale ranging from 0 (“Not true for me”) to 4 (“Very true for me”). Their responses are indicative of their underlying level of motivation for exercise. Even quite straightforward constructs such as body fatness often require indirect methods of measurement, because much of our body fat is hidden deep within our body, around our organs. The body plethysmograph (or Bod Pod) measures body fatness by enclosing the body in an airtight box and measuring air displacement. It thus allows us to estimate the body’s volume, from which we can calculate body density, and, using assumptions about the density of fat and fat-free tissue, we then estimate the percent of body weight that is body fat. This is quite indirect!

.

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。

Posted on Categories:Kinesiology, 物理代写, 运动学

## avatest™帮您通过考试

avatest™的各个学科专家已帮了学生顺利通过达上千场考试。我们保证您快速准时完成各时长和类型的考试，包括in class、take home、online、proctor。写手整理各样的资源来或按照您学校的资料教您，创造模拟试题，提供所有的问题例子，以保证您在真实考试中取得的通过率是85%以上。如果您有即将到来的每周、季考、期中或期末考试，我们都能帮助您！

•最快12小时交付

•200+ 英语母语导师

•70分以下全额退款

## 物理代写|运动学代写Kinesiology代考|DETERMINING ACCURACY OF CRITERION-REFERENCED STANDARDS

Unlike norm-referenced standards, which use continuous variables, criterion-referenced standards create categories into which participants are classified. These categories are often dichotomies (a dichotomy is a division into two parts). Terms such as pass-fail, fit-not fit, healthy-needs improvement, masterynonmastery, or proficient-nonproficient are used to describe the dichotomy. The validity of the criterionreferenced standard can be examined by using a $2 \times 2$ contingency table. The accuracy of the criterionreferenced standard is analyzed by comparing how a participant scored relative to the criterion-referenced standard and a criterion measure that represents the person’s true state. This creates four possible options, which are illustrated in Figure 1.1. Methods are available to determine the quality of a criterion-referenced standard by estimating its reliability and validity.

Criterion-referenced test reliability examines the consistency of classification-the percentage of people consistently classified as passing or failing a test that has been administered two times. Criterion-referenced test validity refers to the accuracy of classification-the percentage of participants correctly classified by the test as passing or failing compared to their true state.

When using the type of $2 \times 2$ table in Figure 1.1, a positive test indicates the presence of whatever is being tested. In a clinical setting, a positive test for heart disease indicates the presence of heart disease. In a fitness test setting, a positive test for fitness indicates the presence of adequate fitness levels.

A negative test indicates the absence of the entity being tested. In a clinical setting, a negative test for heart disease indicates the absence of heart disease. In a fitness test setting, a negative test for fitness indicates inadequate fitness levels.

For youth fitness testing, a true positive occurs when a participant’s performance on the fitness test achieves the criterion-referenced standard and that participant’s true fitness is considered adequate for health purposes. A true negative results when a person’s performance on the fitness test does not reach the criterionreferenced standard and his or her true fitness is below a level adequate for health promotion.

## 物理代写|运动学代写Kinesiology代考|DEVELOPMENT OF HEALTH-RELATED CRITERION-REFERENCED STANDARDS

The main challenge of the criterion-referenced approach is the setting of an appropriate standard. It is often not possible to find a criterion that explicitly defines mastery. Assume, for example, that a physical education teacher wants a criterion for the mastering of volleyball skills. Tests of mastery of complex motor skills are typically not readily available. However, other situations exist where criterion-referenced standards can be easily set. For example, some skills, such as beginning swimming, lend themselves to the criterion-referenced approach. The successful execution of these defined skills can be clearly determined and judged. Within the field of kinesiology, the setting of criterion-referenced standards for health-related youth fitness tests has received substantial attention.

The FITNESSGRAM” health-related youth fitness test provides criterion-referenced standards for aerobic fitness and body composition. These standards were validated by comparison with the prevalence of metabolic syndrome. A health outcome-centered method was used to set the criterion-referenced standards (Zhu, Welk, Going, \& Cureton, 2011). The key steps of the health outcome-centered method are:

1. Determine the components of health-related fitness.
2. Select field tests and criterion measures of the components of health-related fitness.
3. Determine the relationships between the criterion measure of health-related fitness and appropriate health outcomes.
4. Set criterion-referenced standards (also called cut-off scores) based on the relationship between the criterion measures of health-related fitness and the health outcomes.
5. Cross-validate the criterion-referenced standards.
The following section summarizes this approach applied to aerobic fitness tests of the FITNESSGRAM**.

## 物理代写|运动学代写运动学代考|健康相关评价参考标准的制定

1. 确定健康相关健身的组成部分。
2. 选择与健康相关的适应性成分的现场测试和标准测量。
3. 确定与健康相关的适宜性标准度量与适当的健康结果之间的关系。根据与健康有关的健康状况的标准措施与健康结果之间的关系，设置标准参考标准(也称为截止分数)。
4. 交叉验证标准参考。

. .

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。