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Statics/Resultants of Force Systems (contents)

A force system is a collection of forces acting at specified locations (may also include couples). Thus the set of forces shown on any free body diagram make up a force system. Force system is simply a term used to describe a group of forces.

Resultants
When two or more forces or moments are combined, the combination is called a resultant. Any force system can be simplified about a point to a resultant consisting of one force and one couple (either or both of which may be zero). The force is applied to the point and is the vector sum of all of the forces in the system. The couple is the vector sum of all of the couples in the force system plus the vector sum of all of the moments about the point of all of the forces in the force system. One immediate consequence of this definition of resultant is that the resultant about any point of the external force system acting on any system in equilibrium must be zero. The statement that the sum of the external forces and the sum of the external moments acting on a system in equilibrium is zero is often replaced by the statement that the resultant acting on a system in equilibrium is zero. An important attribute of the resultant of a force system is that if you apply the resultant of a force system to a rigid body, the effect on that rigid body is exactly the same as the effect of the original force system. It is in this sense that the resultant is "equivalent" to the original force system. Thus as we study the behavior of rigid bodies under the action of forces, the resultant of the external force system will be of vital interest. Care must be taken in replacing force systems with their resultant when dealing with deformable bodies as the effects of the resultant acting on a non-rigid system will be different than the effects of the actual force system.

Equipollence
The "equivalence" of effect on a rigid body of a force system and its resultant is the motivation for the term equipollence. Two force systems are said to be equipollent if they have the same resultant about a point. Thus two equipollent force systems have the same effect on a rigid body. Thus the precise way to state what we have learned about the toe is that the upper clamping surface exerts a force system on the toe that is equipollent to a force of 540 lb in the -Y direction acting at a point at the top, middle of the toe. Typically we are not this precise and merely state that the clamping surface is exerting a force of 540 lb in the -Y direction on the top, middle point of the toe. It is important for you to recognize that when you hear such statements, what they mean is that the force system acting on the object is equipollent to the specified force and that the particular distribution or combination of forces involved may be quite complicated.


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Engineering Analysis/Arbitrary Basis Expansion

The classical Fourier series uses the following basis:

 * $$\phi(x) = {1, \sin(n\pi x), \cos(n \pi x)}, n = 1, 2, ...$$

However, we can generalize this concept to extend to any orthogonal basis set from the L2 space.

We can say that if we have our orthogonal basis set that is composed of an infinite set of arbitrary, orthogonal L2 functions:

 * $$\phi = {\phi_1, \phi_2, \cdots, }$$

We can define any L2 function f(x) in terms of this basis set:

 * $$f(x) = \sum_{n=1}^\infty a_n\phi_n(x)$$

Using the method from the previous chapter, we can solve for the coefficients as follows:

 * $$a_n = \frac{\langle f(x), \phi_n(x)\rangle}{\langle \phi_n(x), \phi_n(x)\rangle}$$

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Wikijunior:The Elements/Matter Is The Stuff Around You

What is Matter?

Matter is everything around you. Matter is everything made of atoms and molecules. Matter is anything that has a mass and occupies space, which means it can be weighed. However, some things that are matter can't be scooped up and weighed. For instance, matter is also related to light.

Even though matter can be found all over the universe, you usually find it in just a few forms. As of 1995, scientists have identified five states of matter. They may discover one more by the time you get old.

You should know about solids, liquids, and gases, because they are the states of matter you deal with every day. Ionized gases, or plasmas, are also a state of matter. In 1995 scientists first created a new state of matter called a Bose-Einstein condensate. The scientists who first made Bose-Einstein condensates received a Nobel Prize for their work in 2001.

But what makes a state of matter? It's all about what the smallest parts of matter, called molecules and atoms, are doing. They might be flying around really fast, like in a gas. Or they might be stuck together in a rigid form to make a solid. These are very different ways for molecules to behave, and they lead to very different properties, as we shall see later.

Elements and compounds can move from one state to another and not change. Nitrogen as a gas still has the same properties as liquid nitrogen. The liquid state is denser but the molecules are still the same. Water is another example. The compound water is made up of two hydrogen atoms and one oxygen atom. It has the same molecular structure whether it is a gas, liquid, or solid. Although its physical state may change, its chemical state remains the same.

So, you ask "What is a chemical state?" If the formula of water were to change, that would be a chemical change. If you added another oxygen atom, you would make hydrogen peroxide, a different molecule. Changing states of matter is about changing densities, pressures, and temperatures. If the basic chemical structure changes, that is a chemical change.


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Engineering Analysis/Bessel Equation and Parseval Theorem

Bessel's equation relates the original function to the fourier coefficients an:

 * $$\sum_{n=1}^\infty a_n^2 \le \|f(x)\|^2$$

If the basis set is infinitely orthogonal, and if an infinite sum of the basis functions perfectly reproduces the function f(x), then the above equation will be an equality, known as Parseval's Theorem:

 * $$\sum_{n=1}^\infty a_n^2 = \|f(x)\|^2$$

Engineers may recognize this as a relationship between the energy of the signal, as represented in the time and frequency domains. However, parseval's rule applies not only to the classical Fourier series coefficients, but also to the generalized series coefficients as well.


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Talk:Jeep Liberty/Transmissions

Merged
The content of this article is the result of merging multiple pages created by Jeepkj02 and Unixxx.

title: Talk:Jeep Liberty/Transmissions


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Talk:Jeep Liberty/Engines

Merged
The content of this article is the result of merging multiple pages created by Jeepkj02 and Unixxx.

title: Talk:Jeep Liberty/Engines


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Engineering Analysis/Banach and Hilbert Spaces

There are some special spaces known as Banach spaces, and Hilbert spaces.

Convergent Functions
Let's define the piece-wise function φ(x) as:

 * $$\phi_n(x) = \left\{\begin{matrix}0 & x \le 0 \\

nx & 0 < x \le \frac{1}{n} \\ 1 & \frac{1}{n} < x                           \end{matrix}\right. $$

We can see that as we set $$n \to \infty$$, this function becomes the unit step function. We can say that as n approaches infinity, that this function converges to the unit step function. Notice that this function only converges in the L2 space, because the unit step function does not exist in the C space (it is not continuous).

Convergence
We can say that a function φ converges to a function φ* if:

 * $$\lim_{n \to \infty}\|\phi_n - \phi^*\| = 0$$

We can call this sequences, and all such sequences that converge to a given function as n approaches infinity a cauchy sequence.

Complete Function Spaces
A function space is called complete if all sequences in that space converge to another function in that space.

Banach Space
A Banach Space is a complete normed function space.

Hilbert Space
A Hilbert Space is a Banach Space with respect to a norm induced by the scalar product. That is, if there is a scalar product in the space X, then we can say the norm is induced by the scalar product if we can write:

 * $$\|f\| = g(\langle f, f\rangle)$$

That is, that the norm can be written as a function of the scalar product. In the L2 space, we can define the norm as:

 * $$\|f\| = \sqrt{\langle f, f\rangle}$$

If the scalar product space is a Banach Space, if the norm space is also a Banach space.

In a Hilbert Space, the Parallelogram rule holds for all members f and g in the function space:

 * $$\|f + g\|^2 + \|f - g\|^2 = 2\|f\|^2 + 2\|g\|^2$$

The L2 space is a Hilbert Space. The C space, however, is not.


text: Category:Book:Engineering Analysis

title: Category:Book:Engineering Analysis


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Jeep Liberty/Transfer Cases

Transfer cases for the Jeep Liberty are built by New Venture Gear, hence the NV prefix. New Venture inherited New Process Gear from Chrysler, therefore the older transfer cases are prefixed with NP. Whether prefixed with NV or NP, parts are interchangeable between the same transfer case model.

Full-time 4WD can be used on pavement because it utilizes the differential in the transfer case. Part-time 4WD Lo and 4WD Hi can't be used on pavement because they lock the axles together in the transfer case. While the 2WD, full-time 4WD, and part-time 4WD Hi modes support the maximum vehicle speed, the part-time 4WD Lo mode does not. Part-time 4WD Hi should not be engaged over 55mph. Essentially, part-time 4WD should be used for off-road, full-time 4WD for maximum traction on-road, and 2WD for everything else.

NV231J
The NV231J, utilized in the Command-Trac system, is a mechanically shifted part-time transfer case. Its chain-driven aluminum construction makes it weaker than gear-driven iron transfer cases.

NV241J
The NV241J, also known as Command-Trac HD, is sometimes incorrectly referred to as an "NV231J-HD". It was available in the 2005-2007 Jeep Liberty (KJ) with the 6-spd transmission in any package. The transfer case is tagged "241J" in these applications and uses the same gear ratios as the NV231J. This is not the limited production NV241OR found in the Wrangler Rubicon models.

NV242
The NV242, also known as Select-Trac, is a mechanically shifted full time transfer case.

Slip Yoke Eliminator
A slip yoke eliminator replaces the slip yoke in the rear of the transfer case with a fixed yoke. Primarily this allows for the installation of double cardon joints and reduces the driveshaft angle by increasing the driveline length. These two changes help cut down on vibration caused by lifting the Jeep. As an added benefit, it prevents the transfer case from spilling fluid everywhere if the driveshaft gets pulled out. When installing a slip yoke eliminator, a drive shaft with an integrated slip yoke and double cardon joints must also be installed.

title: Jeep Liberty/Transfer Cases


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Wikijunior:The Elements/States Of Matter

= The States of Matter=

There are four main states of matter:

Each state is also known as a phase. Elements can change from one phase to another under certain physical conditions. These conditions are temperature and pressure. Temperature is related to the amount of heat a substance has, and pressure is the amount of force "squeezing" the substance. Deep underwater there is high pressure, and atop a mountain there is low pressure.

There is also another state of matter called plasma. It exists on the sun and in fluorescent lights. Plasma is basically a gas that has become electrified.

There are special names for the process of changing from one phase to another:

A substance can change from one phase to another, but still be the same substance. You can see water vapor over a boiling pot of water. That gas can condense and become a drop of water. If you put that drop in the freezer, it would become a solid. No matter what phase it is in, it is always the same chemical: water. It has the same chemical properties. In other words, ice is just solid water, and steam is just gaseous water.


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Automobile Repair/Honda

Models

 * Civic
 * /Accord/
 * /Odyssey/

title: Automobile Repair/Honda


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Cookbook:Whole Wheat Waffles

 * Breakfast Recipes | Bread

Ingredients

 * 1¼ cups whole wheat flour
 * 1 cup wheat germ
 * 2 tablespoons white granulated sugar
 * 1 tablespoon baking powder
 * 1 tablespoon nutmeg
 * 1 teaspoon salt
 * 2 cups milk
 * ½ cup vegetable oil
 * 2 eggs

Procedure

 * 1) Heat waffle iron according to the manufacturer's directions.
 * 2) Combine dry ingredients and mix well.
 * 3) Add milk, vegetable oil, and eggs, and mix until smooth.
 * 4) Pour 1 cup of batter onto the oiled waffle iron, and cook according to the manufacturer's directions.

Notes, tips and variations

 * Waffles are generally served with butter melted on top, then sweet syrup.
 * Fruit may be spread on top.

title: Cookbook:Whole Wheat Waffles


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Engineering Analysis/Matrices

Derivatives
Consider the following set of linear equations:

 * $$a = bx_1 + cx_2$$
 * $$d = ex_1 + fx_2$$

We can define the matrix A to represent the coefficients, the vector B as the results, and the vector x as the variables:

 * $$A = \begin{bmatrix}b & c \\ e & f\end{bmatrix}$$
 * $$B = \begin{bmatrix}a \\ d\end{bmatrix}$$
 * $$x = \begin{bmatrix}x_1 \\ x_2\end{bmatrix}$$

And rewriting the equation in terms of the matrices, we get:

 * $$B = Ax$$

Now, let's say we want the derivative of this equation with respect to the vector x:

 * $$\frac{d}{dx}B = \frac{d}{dx}Ax$$

We know that the first term is constant, so the derivative of the left-hand side of the equation is zero. Analyzing the right side shows us:

Pseudo-Inverses
There are special matrices known as pseudo-inverses, that satisfies some of the properties of an inverse, but not others. To recap, If we have two square matrices A and B, that are both n × n, then if the following equation is true, we say that A is the inverse of B, and B is the inverse of A:

 * $$AB = BA = I$$

Right Pseudo-Inverse
Consider the following matrix:

 * $$R = A^T[AA^T]^{-1}$$

We call this matrix R the right pseudo-inverse of A, because:

 * $$AR = I$$

but

 * $$RA \ne I$$

We will denote the right pseudo-inverse of A as $$A^\dagger$$

Left Pseudo-Inverse
Consider the following matrix:

 * $$L = [A^TA]^{-1}A^T$$

We call L the left pseudo-inverse of A because

 * $$LA = I$$

but

 * $$AL \ne I$$

We will denote the left pseudo-inverse of A as $$A^\ddagger$$

title: Engineering Analysis/Matrices


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Automobile Repair/Honda/Odyssey

see Odyssey

Model Years

 * /1998/
 * /1999/
 * /2000/
 * /2001/
 * /2002/

Maintenance Job How-Tos

 * /Oil Change/
 * /Radiator Flush and Fill/

title: Automobile Repair/Honda/Odyssey


text:
User talk:MuzikalProdigy

where are your multiple choice answers?

title: User talk:MuzikalProdigy


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Engineering Analysis/Eigenvalues and Eigenvectors

The Eigen Problem
This page is going to talk about the concept of Eigenvectors and Eigenvalues, which are important tools in linear algebra, and which play an important role in State-Space control systems. The "Eigen Problem" stated simply, is that given a square matrix A which is n × n, there exists a set of n scalar values λ and n corresponding non-trivial vectors v such that:

 * $$Av = \lambda v$$

We call λ the eigenvalues of A, and we call v the corresponding eigenvectors of A. We can rearrange this equation as:

 * $$(A - \lambda I)v = 0$$

For this equation to be satisfied so that v is non-trivial, the matrix (A - λI) must be singular. That is:

 * $$|A - \lambda I| = 0$$

Characteristic Equation
The characteristic equation of a square matrix A is given by:

 * $$|A - \lambda I| = 0$$

Where I is the identity matrix, and λ is the set of eigenvalues of matrix A. From this equation we can solve for the eigenvalues of A, and then using the equations discussed above, we can calculate the corresponding eigenvectors.

In general, we can expand the characteristic equation as:

 * $$|A - \lambda I| = (-1)^n(\lambda^n + c_{n-1}\lambda^{n-1} + \cdots + c_1\lambda^1 + c_0)$$

This equation satisfies the following properties:

 * $$|A| = (-1)^n c_0$$
 * 1) A is nonsingular if c0 is non-zero.

Example: 2 × 2 Matrix
Let's say that X is a square matrix of order 2, as such:

 * $$X = \begin{bmatrix}a & b \\c & d\end{bmatrix}$$

Then we can use this value in our characteristic equation:

 * $$\begin{vmatrix}a - \lambda & b \\ c & d- \lambda\end{vmatrix} = 0$$

 * $$(a - \lambda)(d - \lambda) - (b)(c) = 0$$

The roots to the above equation (the values for λ that satisfies the equality) are the eigenvalues of X.

Eigenvalues
The solutions, λ, of the characteristic equation for matrix X are known as the eigenvalues of the matrix X.

Eigenvalues satisfy the following properties:

 * 1) If λ is an eigenvalue of A, λn is an eigenvalue of An.
 * 2) If λ is a complex eigenvalue of A, then λ* (the complex conjugate) is also an eigenvalue of A.
 * 3) If any of the eigenvalues of A are zero, then A is singular. If A is non-singular, all the eigenvalues of A are nonzero.

Eigenvectors
The characteristic equation can be rewritten as such:

 * $$Xv = \lambda v$$

Where X is the matrix under consideration, and λ are the eigenvalues for matrix X. For every unique eigenvalue, there is a solution vector v to the above equation, known as an eigenvector. The above equation can also be rewritten as:

 * $$|X - \lambda I|v = 0$$

Where the resulting values of v for each eigenvalue λ is an eigenvector of X. There is a unique eigenvector for each unique eigenvalue of X. From this equation, we can see that the eigenvectors of A form the nullspace:

 * $$v = \mathcal{N}\{A - \lambda I\}$$

And therefore, we can find the eigenvectors through row-reduction of that matrix.

Eigenvectors satisfy the following properties:

 * 1) If v is a complex eigenvector of A, then v* (the complex conjugate) is also an eigenvector of A.
 * 2) Distinct eigenvectors of A are linearly independent.
 * 3) If A is n × n, and if there are n distinct eigenvectors, then the eigenvectors of A form a complete basis set for $$\mathcal{R}^n$$

Generalized Eigenvectors
Let's say that matrix A has the following characteristic polynomial:

 * $$(A - \lambda I) = (-1)^n(\lambda - \lambda_1)^{d_1}(\lambda - \lambda_2)^{d_2} \cdots (\lambda - \lambda_s)^{d_s}$$

Where d1, d2, ..., ds are known as the algebraic multiplicity of the eigenvalue λi. Also note that d1 + d2 + ... + ds = n, and s < n. In other words, the eigenvalues of A are repeated. Therefore, this matrix doesnt have n distinct eigenvectors. However, we can create vectors known as generalized eigenvectors to make up the missing eigenvectors by satisfying the following equations:

 * $$(A-\lambda I)^k v_k = 0$$
 * $$(A-\lambda I)^{k-1} v_k = 0$$

Right and Left Eigenvectors
The equation for determining eigenvectors is:

 * $$(A - \lambda I) v = 0$$

And because the eigenvector v is on the right, these are more appropriately called "right eigenvectors". However, if we rewrite the equation as follows:

 * $$u(A - \lambda I) = 0$$

The vectors u are called the "left eigenvectors" of matrix A.


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Automobile Repair/Honda/Odyssey/Oil Change

 * 1) Drive the vehicle on to a set of ramps
 * 2) Engage the parking brake. Place blocks behind the rear wheels.
 * 3) Place jack stands in a suitable location under the ramped vehicle. This minimizes another risk with ramps, that they can collapse. Possible locations for jack stands are the jack seam.
 * 4) Place drain pan under the vehicle and remove the drain plug with a socket.
 * 5) Place the drainung pan so that it collects the oil draining from the pan as well as covering the area under the filter.
 * 6) Remove the filter. The location varies depending on the year.
 * 7) Check that the filter gasket has been removed before installing a new filter. Lubricate the new filter before installation
 * 8) Install the drain pan
 * 9) Remove the filler plug. Add the recommended amount of oil. This is 4.3 litres of 5W-20. Secure the filler plug. Check the oil level with the dipstick. It should be close to right.
 * 10) Start the vehicle, remove it from the ramps, and place it on a level surface.
 * 11) Check the oil level and add as required.


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Control Systems/Standard Forms

Companion Form
A companion form contains the coefficients of a corresponding characteristic polynomial along one of its far rows or columns. For example, one companion form matrix is:

 * $$\begin{bmatrix} 0 & 0 & 0 & \cdots & 0 & -a_0 \\

1 & 0 & 0 & \cdots & 0 & -a_1 \\ 0 & 1 & 0 & \cdots & 0 & -a_2 \\ 0 & 0 & 1 & \cdots & 0 & -a_3 \\ \vdots & \vdots & \vdots &\ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & 1 & -a_{n-1} \end{bmatrix}$$

and another is:

 * $$\begin{bmatrix} -a_{n-1} & -a_{n-2} & -a_{n-3} & \cdots & -a_1 & -a_0 \\

1 & 0 & 0 & \cdots & 0 & 0 \\ 0 & 1 & 0 & \cdots & 0 & 0 \\ 0 & 0 & 1 & \cdots & 0 & 0 \\ \vdots & \vdots & \vdots &\ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & 1 & 0 \end{bmatrix}$$

Two companion forms are convenient to use in control theory, namely the observable canonical form and the controllable canonical form. These two forms are roughly transposes of each other (just as observability and controllability are dual ideas). When placed in one of these forms, the design of controllers or observers is simplified because the structure of the system is made apparent (and is easily modified with the desired control).

Observable Canonical Form
Observable-Canonical Form is helpful in several cases, especially for designing observers.

The observable-canonical form is as follows:

 * $$A = \begin{bmatrix} -a_1 & 1 & 0 & \cdots & 0 \\

-a_2 & 0 & 1 & \cdots & 0 \\ \vdots & \vdots & \vdots & \ddots & \vdots \\ -a_{n-1} & 0 & 0 & \cdots & 1 \\ -a_n & 0 & 0 & \cdots & 0 \end{bmatrix}$$

 * $$B = \begin{bmatrix} b_1 \\ b_2 \\ \vdots \\ b_n \end{bmatrix}$$

 * $$C = \begin{bmatrix} 1 & 0 & \cdots & 0 \end{bmatrix}$$

Controllable Canonical Form
Controllable-Canonical Form is helpful in many cases, especially for designing controllers when the full state of the system is known.

The controllable-canonical form is as follows:

 * $$A = \begin{bmatrix} -a_1 & -a_2 & -a_3 & \cdots & -a_{n-1} & -a_n \\

1 & 0 & 0 & \cdots & 0 & 0 \\ 0 & 1 & 0 & \cdots & 0 & 0 \\ 0 & 0 & 1 & \cdots & 0 & 0 \\ \vdots & \vdots & \vdots &\ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & 1 & 0 \end{bmatrix}$$

 * $$B = \begin{bmatrix} 1 \\ 0 \\ \vdots \\ 0 \end{bmatrix}$$

 * $$C = \begin{bmatrix} b_1 & b_2 & b_3 & \cdots & b_n \end{bmatrix}$$

 * $$D = \begin{bmatrix} b_0 \end{bmatrix}$$

If we have two spaces, space v which is the original space of the system (A, B, C, and D), then we can transform our system into the w space which is in controllable-canonical form (Aw, Bw, Cw, Dw) using a transformation matrix Tw. We define this transformation matrix as:

 * $$T = \zeta_v \zeta_w^{-1}$$

Where ζ is the controllability matrix.

Notice that we know beforehand Aw and Bw, since we know both the form of the matrices and the coefficients of the equation (e.g. a linear ODE with constant coefficients or a transfer function).

We can form ζw if we know these two matrices. We can then use this matrix to create our transformation matrix.

We will discuss the controllable canonical form later when discussing state feedback and closed-loop systems.

Phase Variable Form
The Phase Variable Form is obtained simply by renumbering the phase variables in the opposite order of the controllable canonical form. Thus:

 * $$A_c = \begin{bmatrix}

0 & 1 & \cdots & 0 & 0 & 0\\ \vdots & \vdots &\ddots & \vdots & \vdots & \vdots \\ 0 & 0 & \cdots & 1 & 0 & 0\\ 0 & 0 & \cdots & 0 & 1 & 0\\ 0 & 0 & \cdots & 0 & 0 & 1\\ -a_n & -a_{n-1} & -a_{n-2} & \cdots & -a_2 & -a_1 \end{bmatrix}$$

 * $$B_c = \begin{bmatrix} 0 \\ 0 \\ \vdots \\ 1 \end{bmatrix}$$

 * $$C_c = \begin{bmatrix} b_n & b_{n-1} & \cdots & b_2 & b_1 \end{bmatrix}$$

 * $$D_c = \begin{bmatrix} b_0 \end{bmatrix}$$

Modal Form
In this form, the state matrix is a diagonal matrix of its (non-repeated) eigenvalues. The control has a unitary influence on each eigenspace, and the output is a linear combination of the contributions from the eigenspaces (where the weights are the complex residuals at each pole).

 * $$A_m = \begin{bmatrix} -p_1 & 0 & 0 & \cdots & 0 & 0 \\

0 & -p_2 & 0 & \cdots & 0 & 0 \\ 0 & 0 & -p_3 & \cdots & 0 & 0 \\ \vdots & \vdots & \vdots &\ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & 0 & -p_n \end{bmatrix}$$

 * $$B_m = \begin{bmatrix} 1 \\ 1 \\ \vdots \\ 1 \end{bmatrix}$$

 * $$C_m = \begin{bmatrix} c_1 & c_2 & \cdots & c_n \end{bmatrix}$$

 * $$D_m = \begin{bmatrix} D_c \end{bmatrix}$$

Jordan Form
This "almost diagonal" form handles the case where eigenvalues are repeated. The repeated eigenvalues represent a multi-dimensional eigenspace, and so the control only enters the eigenspace once and it's integrated through the other states of that small subsystem.

 * $$A = \begin{bmatrix}

-p_1 & 1 & 0 & 0 & 0 & \cdots & 0 & 0 \\ 0 & -p_1 & 1 & 0 & 0 & \cdots & 0 & 0 \\ 0 & 0 & -p_1 & 0 & 0 & \cdots & 0 & 0 \\ 0 & 0 & 0 & -p_4 & 0 &\cdots & 0 & 0 \\ \vdots & \vdots & \vdots & \vdots & \vdots &\ddots & \vdots & \vdots \\ 0 & 0 & 0 & 0 & 0 & \cdots & 0 & -p_n \end{bmatrix}$$

 * $$B = \begin{bmatrix} 0 \\ 0 \\ 1 \\ 1 \\ \vdots \\ 1 \end{bmatrix}$$

 * $$C = \begin{bmatrix} c_1 & c_2 & \cdots & c_n \end{bmatrix}$$

Computing Standard Forms in MATLAB
MATLAB can convert a transfer function into a control canonical form by using the command tf2ss.

tf2ss(num, den); % num and den on the form: [x_0*s^n, x_1*s^n-1,..., x_n*s^n-n].

MATLAB contains a function for automatically transforming a state-space equation into a companion

(e.g., controllable or observable canonical form) form.

[Ap, Bp, Cp, Dp, P] = canon(A, B, C, D, 'companion');

Moving from one companion form to the other usually involves elementary operations on matrices and vectors (e.g., transposes or interchanging rows). Given a vector with the coefficients of a characteristic polynomial, MATLAB can compute a companion form with the coefficients in the top row (there are other 3 possible companion forms not generated by that function)

compan(P)

Given another vector with the coefficients of a transfer function's numerator polynomial, the canon command can do the same.

[Ap, Bp, Cp, Dp, P] = canon(tf(Pnum,Pden), 'companion');

The same command can be used to transform a state-space equation into a modal (e.g., diagonal) form.

[Ap, Bp, Cp, Dp, P] = canon(A, B, C, D, 'modal');

However, MATLAB also includes a command to compute the Jordan form of a matrix, a modified modal form suited for matrices with repeated eigenvalues.

jordan(A);

Control Canonical Form
We are given a system that is described by the transfer function:

 * $$ \frac{Y(s)}{U(s)} = \frac{s^2+6s+8}{s^3+9s^2+23s+15} $$

and are now tasked to obtain the state-space matrixes in control canonical form. We first note that the order of the numerator is 2, while the corresponding order is 3 in the denominator. This means that we will not have any feed-forward and thus, the scalar D is 0.

We now split the transfer function into two factors:

 * $$ \frac{Y(s)}{x_1(s)} \times \frac{x_1(s)}{U(s)} = \frac{s^2+6s+8}{1} \times \frac{1}{s^3+9s^2+23s+15}. $$

We then retrieve the time-domain description,

 * $$ Y(s) = (s^2+6s+8)x_1. $$

 * $$ Y(s) = s^{2} x_1+6s x_1 +8 x_1. $$

 * $$ y(t) = \ddot{x_1} + 6\dot{x_1} +8x_1. $$

We now create two new states that describe all these derivatives. Since the highest order of the system is 3 (in the denominator of TF), we must create 2 new states, so that we have 3 states in total.

 * $$ \dot{x_1} = x_2, \dot{x_2} = x_3 = \ddot{x_1}. $$

We substitute the new states into the equation above:

 * $$ y(t) = x_3 + 6x_2 + 8x_1. $$

Now we evaluate the input of the system in a similar manner:

 * $$ U(s) = (s^3+9s^2+23s+15)x_1. $$

 * $$ U(s) = s^3x_1+9s^2x_1+23sx_1+15x_1. $$

 * $$ u(t) = x_1^{(3)}+9\ddot{x_1}+23\dot{x_1}+15x_1. $$

Note that the first term is a third derivative. We can now insert our new states into the above equation:

 * $$ u(t) = \dot{x_3}+9x_3+23x_2+15x_1. $$

We move the derivative of the third state to the left side and get:

 * $$ \dot{x_3} = -15x_1 - 23x_2 -9x_3 + u. $$

We are now ready to rewrite these equations in the state-space form. We start by moving the input to the right side of the equation so that we have an expression for each state.

$$ \begin{bmatrix} \dot{x_1} \\ \dot{x_2} \\ \dot{x_3} \\ \end{bmatrix} = \begin{bmatrix} 0 & 1 & 0 \\        0 & 0 & 1 \\         -15 & 0-23 & -9 \\ \end{bmatrix} \times \begin{bmatrix} x_1 \\ x_2 \\ x_3 \\ \end{bmatrix} + \begin{bmatrix} 0 \\        0 \\         1 \\ \end{bmatrix} u $$

$$ y = \begin{bmatrix} 8 & 6 & 1 \\ \end{bmatrix} \times \begin{bmatrix} x_1 \\ x_2 \\ x_3 \\ \end{bmatrix} + \begin{bmatrix} 0 \\ \end{bmatrix} u $$

title: Control Systems/Standard Forms


text:
Ruby Programming/Strings

Like Python, Java, and the .NET Framework, Ruby has a built-in String class.

String literals
One way to create a String is to use single or double quotes inside a Ruby program to create what is called a string literal. We've already done this with our "hello world" program. A quick update to our code shows the use of both single and double quotes.

Being able to use either single or double quotes is similar to Perl, but different from languages such as C and Java, which use double quotes for string literals and single quotes for single characters.

So what difference is there between single quotes and double quotes in Ruby? In the above code, there's no difference. However, consider the following code:

Because " " contains an apostrophe, which is the same character as the single quote, in the second line we need to use a backslash to escape the apostrophe so that Ruby understands that the apostrophe is in the string literal instead of marking the end of the string literal. The backslash followed by the single quote is called an escape sequence.

Single quotes
Single quotes only support two escape sequences.

 * \' – single quote
 * \\ – single backslash

Except for these two escape sequences, everything else between single quotes is treated literally.

Double quotes
Double quotes allow for many more escape sequences than single quotes. They also allow you to embed variables or Ruby code inside of a string literal – this is commonly referred to as interpolation.

Escape sequences
Below are some of the more common escape sequences that can appear inside of double quotes.

 * \" – double quote
 * \\ – single backslash
 * \a – bell/alert
 * \b – backspace
 * \r – carriage return
 * \n – newline
 * <tt>\s </tt>– space
 * <tt>\t </tt>– tab

Try out this example code to better understand escape sequences.

The result:

$ double-quotes.rb Hello		world Goodbye world Start over world 1. Hello 2. World

Notice that the newline escape sequence (in the last line of code) simply starts a new line.

The bell character, produced by escape code, is considered a control character. It does not represent a letter of the alphabet, a punctuation mark, or any other written symbol. Instead, it instructs the terminal emulator (called a console on Microsoft Windows) to "alert" the user. It is up to the terminal emulator to determine the specifics of how to respond, although a beep is fairly standard. Some terminal emulators will flash briefly.

Run the following Ruby code to check out how your terminal emulator handles the bell character.

puts
We've been using the  function quite a bit to print out text. Whenever  prints out text, it automatically prints out a newline after the text. For example, try the following code.

The result:

$ hello-world.rb Say hello to the world

print
In contrast, Ruby's  function only prints out a newline if you specify one. For example, try out the following code. We include a newline at the end of 's argument list so that the shell prompt appears on a new line, after the text.

The result:

$ hello-world.rb Sayhellototheworld

The following code produces the same output, with all the words run together.

title: Ruby Programming/Strings


text:
Engineering Analysis/Diagonalization

Similarity
Matrices A and B are said to be similar to one another if there exists an invertable matrix T such that:

 * $$T^{-1}AT = B$$

If there exists such a matrix T, the matrices are similar. Similar matrices have the same eigenvalues. If A has eigenvectors v1, v2 ..., then B has eigenvectors u given by:

 * $$u_i = Tv_i$$

Matrix Diagonalization
Some matricies are similar to diagonal matrices using a transition matrix, T. We will say that matrix A is diagonalizable if the following equation can be satisfied:

 * $$T^{-1}AT = D$$

Where D is a diagonal matrix. An n × n square matrix is diagonalizable if and only if it has n linearly independent eigenvectors.

Transition Matrix
If an n × n square matrix has n distinct eigenvalues λ, and therefore n distinct eigenvectors v, we can create a transition matrix T as:

 * $$T = [v_1 v_2 ... v_n]$$

And transforming matrix X gives us:

 * $$T^{-1}AT = \begin{bmatrix}\lambda_1 & 0 & \cdots & 0 \\

0 & \lambda_2 & \cdots & 0 \\ \vdots & \vdots & \ddots & \vdots \\ 0 & 0 & \cdots & \lambda_n\end{bmatrix}$$

Therefore, if the matrix has n distinct eigenvalues, the matrix is diagonalizable, and the diagonal entries of the diagonal matrix are the corresponding eigenvalues of the matrix.

Complex Eigenvalues
Consider the situation where a matrix A has 1 or more complex conjugate eigenvalue pairs. The eigenvectors of A will also be complex. The resulting diagonal matrix D will have the complex eigenvalues as the diagonal entries. In engineering situations, it is often not a good idea to deal with complex matrices, so other matrix transformations can be used to create matrices that are "nearly diagonal".

Generalized Eigenvectors
If the matrix A does not have a complete set of eigenvectors, that is, that they have d eigenvectors and n - d generalized eigenvectors, then the matrix A is not diagonalizable. However, the next best thing is acheived, and matrix A can be transformed into a Jordan Cannonical Matrix. Each set of generalized eigenvectors that are formed from a single eigenvector basis will create a jordan block. All the distinct eigenvectors that do not spawn any generalized eigenvectors will form a diagonal block in the Jordan matrix.

title: Engineering Analysis/Diagonalization


text:
Wikijunior:The Elements/Stub Template

What does it look, feel, taste, or smell like?
Calcium is a soft gray alkaline metal. We often see it in impure forms and it looks like white powder. In its pure form it smells like oranges. It tastes mostly like chalk, because chalk is mainly made of calcium.

Where did its name come from?
 Did You Know?
 * First interesting fact.
 * Another interesting fact.
 * Yet another interesting fact.

title: Wikijunior:The Elements/Stub Template


text:
Automobile Repair/Honda/Odyssey/2002

Repairs

 * /Change engine oil and filter/
 * /Change Transmission Fluid/
 * /Change Cabin Filter/
 * /Repair/Replace Front Rotors/
 * /Replace Front Brake Pads/
 * /Lubricate sliding doors/

title: Automobile Repair/Honda/Odyssey/2002


text:
Automobile Repair/Honda/Odyssey/2002/Change engine oil and filter

Indications

 * Owners manual indicates every 6000 km or 12000 km depending upon service conditions.

Method 1 - Using Ramps

 * 1) Drive the vehicle on to a set of ramps.  One of the risks with this method is overshooting the ramps.  This happened to me once: the ramps, at 8 inches height skidded under the running boards but did no damage.
 * 2) Engage the parking brake. Place blocks behind the rear wheels.
 * 3) Place jack stands in a suitable location under the ramped vehicle. This minimizes another risk with ramps, that they can collapse.  Possible locations for jack stands are the jack seam.
 * 4) Place drain pan under the vehicle and remove the drain plug with a 14 mm socket.
 * 5) Place the drain pan so that it collects the oil draining from the pan as well as covering the area under the filter.
 * 6) Remove the filter.  Removing the filter on this vehicle will make quite a mess of the plastic shrouds in the passenger side fender.  You can clean it with rags or try to avoid some of the mess by placing old plastic bags over the filter when removing.  Good luck!
 * 7) Check that the filter gasket has been removed before installing a new filter.  Lubricate the new filter before installation
 * 8) Install the drain pan plug. Honda will provide a new washer for the drain plug.
 * 9) Remove the filler plug.  Add the recommended amount of oil.  This is 4.3 litres  of 5W-20. Secure the filler plug.  Check the oil level with the dipstick.  It should be close to right.
 * 10) Start the vehicle, remove it from the ramps, and place it on a level surface.
 * 11) Check the oil level and add as required.


text:
Engineering Analysis/Matrix Exponentials

Matrix Exponentials
If we have a matrix A, we can raise that matrix to a power of e as follows:

 * $$e^{A}$$

It is important to note that this is not necessarily (not usually) equal to each individual element of A being raised to a power of e. Using taylor-series expansion of exponentials, we can show that:

 * $$e^{A} = I + A + \frac{1}{2}A^2 + \frac{1}{6}A^3 + ... = \sum_{k=0}^\infty{1 \over k!}A^k$$.

In other words, the matrix exponential can be reduced to a sum of powers of the matrix. This follows from both the taylor series expansion of the exponential function, and the cayley-hamilton theorem discussed previously.

However, this infinite sum is expensive to compute, and because the sequence is infinite, there is no good cut-off point where we can stop computing terms and call the answer a "good approximation". To alleviate this point, we can turn to the Cayley-Hamilton Theorem. Solving the Theorem for An, we get:

 * $$A^n = -c_{n-1}A^{n-1} - c_{n-2}A^{n-2} - \cdots - c_1A - c_0I$$

Multiplying both sides of the equation by A, we get:

 * $$A^{n+1} = -c_{n-1}A^n - c_{n-2}A^{n-1} - \cdots - c_1A^2 - c_0A$$

We can substitute the first equation into the second equation, and the result will be An+1 in terms of the first n - 1 powers of A. In fact, we can repeat that process so that Am, for any arbitrary high power of m can be expressed as a linear combination of the first n - 1 powers of A. Applying this result to our exponential problem:

 * $$e^A = \alpha_0I + \alpha_1A + \cdots + \alpha_{n-1}A^{n-1}$$

Where we can solve for the α terms, and have a finite polynomial that expresses the exponential.

Inverse
The inverse of a matrix exponential is given by:

 * $$(e^{A})^{-1} = e^{-A}$$

Derivative
The derivative of a matrix exponential is:

 * $$\frac{d}{dx}e^{Ax} = Ae^{Ax} = e^{Ax}A$$

Notice that the exponential matrix is commutative with the matrix A. This is not the case with other functions, necessarily.

Sum of Matrices
If we have a sum of matrices in the exponent, we cannot separate them:

 * $$e^{(A+B)x} \ne e^{Ax}e^{Bx}$$

Differential Equations
If we have a first-degree differential equation of the following form:

 * $$x'(t) = Ax(t) + f(t)$$

With initial conditions

 * $$x(t_0) = c$$

Then the solution to that equation is given in terms of the matrix exponential:

 * $$x(t) = e^{A(t - t_0)}c + \int_{t_0}^t e^{A(t - \tau)}f(\tau)d\tau$$

This equation shows up frequently in control engineering.

Laplace Transform
As a matter of some interest, we will show the Laplace Transform of a matrix exponential function:

 * $$\mathcal{L}[e^{At}] = (sI - A)^{-1}$$

We will not use this result any further in this book, although other books on engineering might make use of it.


text:
Modern History/Vietnam War

 * /Battle of Khe Sanh/

title: Modern History/Vietnam War


text:
Automobile Repair/Honda/Odyssey/2002/Change Transmission Fluid

Indications

 * Honda recommends that the transmission fluid be changed at 48000km or 96000 km depending upon service conditions. This change is simply a drain and replace of the nominal 3.3 litres that drains.  Honda does not recommend a flush.  [2002 Owners Manual]

The drain/refill could be repeated after a short drive if one wished to replenish a greater fraction of the total 7.9 litres of fluid in the transmission, torque converter, and transmission cooler. This might be a good idea, given the reputation of this transmission.

Method 1 - Per manufacturers recommendation
Despite the low profile of this vehicle, since the drain plug is towards the front, it is just possible to do this replacement without jack stands or ramps.

 * 1) Place the vehicle on a level surface or slightly declined with the front lower than the back.  The drain plug is towards the front of the transmission and any incline that raises the front of the vehicle will result in incomplete fluid drainage.
 * Loosen the fill bolt before draining the tranny or you might be forced to fill it through the small tube which is a PITA***
 * 1) Place a drain pan under the vehicle and remove the transmission plug with a 3/8" ratchet end (square end).  The fluid ejects rather quickly toward the drivers side, so be ready.
 * 2) Clean the debris from the drain plug. Replace the drain plug gasket.  Available from Honda.  Reinstall the drain plug.
 * 3) discard of the old fluid, ideally in an old graduated container.  Note the amount removed.
 * 4) Add 3 litres or the amount removed, whichever is the lesser. Honda recommends their own ATF-Z1.  I used a small diameter (>8.5mm) plastic kitchen funnel to get the fluid into the dipstick tube.  This works fine. Alternatively, there is a 17mm  bolt on top of the transmission marked ATF - behind the dipstick towards the firewall - that is the transmission fill port.
 * 5)  With the vehicle on a level surface, check the fluid level with a dipstick.  If it's close, but a little low, that's fine
 * 6) Per honda's recommendation, run the vehicle to operating temperature.  Check the fluid level and adjust as required.
 * 7) Do not overfill


text:
Wikijunior talk:Alphabet

printable version?
I bet many educators or parents would like to be able to print this out to have a hard copy. Might we make a "print version" page with all of the letters below each other? --Sanitized (talk) 17:15, 5 September 2009 (UTC)

 * It might also be useful to make a version that prints nicely in black and white since not all schools or home schools can print in color, and some photographs need tweaking to read well in black and white. -- anon 19:02, 15 February 2012

 * Since then somebody has linked a "printable version" which links to Wikijunior:Alphabet/All_pages
 * Let's discuss printing issues further over at Wikijunior talk:Alphabet/All pages
 * -- Harry Wood (discuss • contribs) 22:36, 8 November 2015 (UTC)

Slideshow viewing
It really would be more effective if it could be viewed as a slideshow, one image and text-sentence per slide. Is there any software on wikipedia that would allow such viewing?

Also: there are many, many more possibilities for slideshows that could be useful for the classroom; for example, sets of rhyming words, lists of consonant-vowel-consonant words, groups of objects for counting practice, abc books with themes (animals, household items).... M Linley 03:37, 2 October 2006 (UTC)

 * Yeah I was thinking there could be '<<>>' buttons added as part of the navigation. Think that's do-able in a mediawiki template.
 * Another way to do a slideshow would be to launch a slideshow from a PDF document, if the printable version was better. It would need to have one picture per A4 page
 * -- Harry Wood (discuss • contribs) 22:43, 8 November 2015 (UTC)

Separation of letters.
I am proposing that each letter should be separated into individual pages to allow the reader (child) to receive the information slowly without consecutively attaining the knowledge. The current layout also poses a problem if it were to be published in paper form. --Herraotic 21:28, 3 December 2006 (UTC)

 * DONE by Xxagile back in 2008. The book used to be all on one page on this older revision -- Harry Wood (discuss • contribs) 22:46, 8 November 2015 (UTC)

Categories
It would be good to have, for each letter, one word from each of several categories, like Animals, Machines, Names, etcetera. Stalefries 21:15, 26 March 2007 (UTC)

Pictures
I am moving the pictures here so that i can try to develop the front page. If anyone thinks the pictures should be moved back to the front page, please contact me so that i can do so or you can change it yourself if you know how to. Xxagile (talk) 04:20, 14 August 2008 (UTC)

 * I'll blow those away from here now, because it's messing up this discussion page a bit. On a similar topic though, I think we should the following... -- Harry Wood (discuss • contribs) 23:20, 8 November 2015 (UTC)

General principles for pictures in this book
Some quality improvements or suggestions can be made in relation to individual pages, on their 'talk page. For example I have just improved the 'Xylophone' photo at Wikijunior:Alphabet/X, and made a comment at Wikijunior talk:Alphabet/X. I've also left a quick comment at Wikijunior talk:Alphabet/O about the photo. Please dive in and discuss individual images in that way!

Some general principles could be discussed here though.

--Harry Wood (discuss • contribs) 23:50, 8 November 2015 (UTC)

Photos vs Illustrations/Cartoons
I note that the majority of pictures are photos not cartoon illustrations. In a very young children's book one might expect colourful cartoons, but I can see it's going to be a lot easier to pick out photos from the commons collections. Illustrating this book with cartoons would be fun actually, but I have no idea how we might agree (or otherwise a achieve) a consistent illustrating style. If they are all photos, we should be consistent in that choice. Currently the fish cartoon on: Wikijunior:Alphabet/F seems inconsistent.

--Harry Wood (discuss • contribs) 23:50, 8 November 2015 (UTC)

Soon deleted image
I found that the image File:Lion zoo antwerp 1280.jpg, used for Wikijunior:Alphabet/L is about to get deleted. How about this one instead: File:Lion-1.jpg? /Skagedal (discuss • contribs) 14:48, 4 January 2012 (UTC)
 * Seems a fair choice. --Pi zero (discuss • contribs) 04:42, 8 January 2012 (UTC)

Audio recordings
I recorded some audio clips for each letter and added to each subpage (except B, which turned out wrong; I'll fix this later). I'm not a native English speaker so my pronounciation isn't perfect. Would love to get feedback on exactly how. :) Hope it adds some value anyway. I made this for an educational game I'm working on which will be free software and based on open content. I hope to record with a native English speaker at a later point, if somebody else would do it that would of course be awesome. /Skagedal (discuss • contribs) 23:27, 21 January 2012 (UTC)

 * Cool stuff!
 * Pronunciation is fine. I thought Xylophone sounded too much like an "S". That was my only quibble... that and of course Z is completely wrong, but that's because I'm english not american :-)
 * I guess if these were all in one track then it'd be like an audio book. Is there a standard approach for that in wikibooks?
 * We're missing 'B' and also 'D' too hey? To fill in the gaps... we'd need to User:Skagedal to come back and do those two, or somebody else re-record them all, or somebody fill in the gaps and we just live with some discontinuity of accents/recording style.
 * --Harry Wood (discuss • contribs) 23:58, 8 November 2015 (UTC)

Visit this relevant page on reading and writing letters
Wikijunior:Reading and writing Alphabet... though the work is in progress. Please suggest all possible improvements. Alternatively; that format could be merged with all other alphabet-learning pages. RIT RAJARSHI (discuss • contribs) 22:24, 12 July 2017 (UTC)

Next/prev button?
Could you please make a button to got to the next or previous letter because the letters don't fit into my screen and I have to scroll down every time unless I open it on fullscreen. --Red-back spider (discuss • contribs) 09:16, 21 April 2021 (UTC)

title: Wikijunior talk:Alphabet


text:
Modern History/Vietnam War/Battle of Khe Sanh

The Battle of Khe Sanh
The Khe Sanh base was established in 1964 as a small Special Forces camp near the border between North and South Vietnam. It was tucked away in a remote corner about eight miles from the border of Laos and near Route 9, the major road in that region. The reason the base was located here was to protect the area from North Vietnamese coming from Laos or North Vietnam to attack. This was a strategic location; Khe Sanh was the "gateway" into South Vietnam. Khe Sanh could also serve as an air base for operations into Laos, a supply base for overland units, and a wall against enemy infiltration, which it would soon become.

In mid-1966, a battalion of Marines was dispatched to the base to provide the Special Forces team reinforcement after numerous short battles with the North Vietnamese. The Marines stayed at Khe Sanh and continued to fight the North Vietnamese until 13 December 1967. On this date, they were ordered to relocate their combat base to a safer location. The new Khe Sanh Combat Base was located approximately two miles south of the old base, which had been just outside the town of Khe Sanh. Three weeks later, on 2 January 1968, six high ranking North Vietnamese officers were gunned down at the base perimeter of the new base. The reason that the north Vietnamese Army sent out six of their high ranking officers was to show that Khe Sanh was a priority target in their plan to enter South Vietnam. The actions of the North Vietnamese were quickly passed to the head of the operation and the American position was fortified.

To fortify Khe Sanh, the Marines dug trenches, some of which were over six feet deep; the perimeter was reinforced with land mines, barbed wire, German razor tape, and trip flares. The same reinforcement was done around the tactically crucial hills. Several hills were located around the base and became sub-bases with artillery and Marines stationed on each. This gave the Americans a strategic advantage in the area.

On 20 January 1968, a company of marines was investigating the site of a previous ambush when North Vietnamese soldiers attacked them. At first, this was a devastating loss by the Americans until shells from 155mm howitzers pulverized enemy positions. That same day, the Americans captured a North Vietnamese soldier near the airstrip. This soldier informed them that at midnight that night the North Vietnamese would storm the base. Trusting this information as truth, the American troops prepared for the surprise attack. That night at midnight, the North Vietnamese Army launched their attack on Khe Sanh, but was repelled by the Americans in the base. Extensive damage was sustained though, with the airstrip damaged, the munitions dump destroyed, the communications center down, and the control base bombed. A reason that the traitorous North Vietnamese soldier gave the information freely could have been because he was a conscripted soldier who wanted the war to end. Many soldiers in the North Vietnamese Army had been drafted to make such a large army possible.

Following the surprise attack on Khe Sanh on 20 January 1968, reinforcements were sent to join the troops already stationed there. This brought the total number of defenders to 6000 against the estimated 40,000 North Vietnamese soldiers attacking the base. Since the airstrip had been damaged during the surprise attack and Route 9 was cut off by the enemy, supplies could not be sent to Khe Sanh easily which is the reason that more soldiers were not sent as reinforcements.

At this time, another question arose for the president in Washington; should the base be held or evacuated? President Lyndon Johnson and his military advisor, General Maxwell Taylor, both suggested that a withdrawal should be considered. The advantages of a withdrawal would have been numerous, including saving lives, diverting the enemy, and avoiding the problems caused by the base's isolated location. The enemy struck the rest of South Vietnam before Johnson could decide, however, and the decision was made to hold the base at all costs. The reason for this decision was that the government had built up the Khe Sanh situation in the eyes of the public and it would have been difficult to explain that the battle of Khe Sanh was unimportant. For this reason, the battle continued at Khe Sanh for many more months.

Several quick, insignificant skirmishes took place over the next few weeks, but nothing serious occurred until the attack on Lang Vei, a Special Forces camp about four miles southwest of Khe Sanh. During the night of 7 February 1968, eleven tanks passed through the wire around Lang Vei's perimeter and bombarded the entire base. By morning, Lang Vei had been completely destroyed. The soldiers that had not escaped had been killed during the attack. The attack on Lang Vei was only a diversionary battle involving 400 North Vietnamese soldiers to lure soldiers away from Khe Sanh before a major battle there.

The major assault on Khe Sanh never occurred, though. By early April, all North Vietnamese soldiers had left the area unexpectedly. Perhaps North Vietnamese commanders believed that Khe Sanh was not worth the losses sustained by the North Vietnamese Army. Over 120,000 tons of bombs had been dropped on North Vietnamese positions during the battle for Khe Sanh. The loss for the North Vietnamese had been both physical and psychological. The Americans defending Khe Sanh withdrew shortly after the North Vietnamese withdrawal, to be replaced by fresh battalions.

Author
Dr. C. J. Stumph, D.D.


text:
Automobile Repair/Honda/Odyssey/2002/Repair/Replace Front Rotors

Indications

 * One indicator for repair or replacement of the rotors on this vehicle may be wobble or vibration that is felt in the steering wheel or the vehicle when the brakes are being used.  A warpage in the rotors will cause the vibration.

Method 1 - Using Jack Stands

 * 1) Place the vehicle on a level surface and engage the parking brake.
 * 2) Loosen the lug nuts on the front wheels.
 * 3) Place a floor jack with a piece of wood under the seam (below the running boards).  The seam on this vehicle is shrouded with the plastic running board cover.  However, by using a block of wood, the vehicle can be lifted without any damage to the plastic.
 * 4) Lift one wheel of the vehicle until it is off the ground.  Place a jack stand at the  reinforced jack stand point adjacent to this wheel.  Repeat for all wheels.
 * 5) I choose to jack stand all 4 wheels since the front wheels will need to be removed for this repair and I didn't want any risk of the vehicle rolling.
 * 6) Place extra jack stands under the control arms just in case, but not let them bear any significant weight.
 * 7) Remove front wheels.
 * 8) Using 19 mm socket, remove the bolts that secure the front caliper.
 * 9) Slid the front caliper off the rotor and suspend it, providing strain relief to the brake hose.  This can be done by wiring it to the mcpherson strut.
 * 10) The rotors on this vehicle are secured with #3 philips machine screws and they can be tight ones to remove.
 * 11) Remove rotors.  It may be necessary to employ a dead blow or rubber mallet to disengage the rotors.
 * 12) Have a reputable shop machine the rotors to remove any warp.  If the warp cannot be removed while still maintaining the minimum rotor thickness, the rotors will need to be replaced.
 * 13) Reinstall the rotors.
 * 14) Install the caliper and torque (spec?) the caliper bolts.
 * 15) Install the wheels.
 * 16) Remove the front jack stands and drop the front wheel with a floor jack until it bears enough weigh to allow the lug nuts to be tightened.
 * 17) Tighten lug nuts.
 * 18) Repeat on the other front wheel.
 * 19) remove jack stands from rear of vehicle.


text:
Wikijunior:The Elements/Aluminum

Aluminum, also known as aluminium, is a metal that is very light. Aluminum is used in many industries to make lots of things. It is very important to the world economy.

What does it look, feel, taste, and smell like?

Aluminum is a soft, lightweight metal which usually has a dull silvery appearance. This dull appearance is caused by a thin layer of oxidation that forms quickly when the metal is exposed to air. Without this layer of oxidation, aluminum has a bright and clear silvery appearance. It feels very soft and it is odorless.

Who discovered aluminum and how?
Sometimes there can be disagreement about who discovered something, even when all the facts are known. Friedrich Wöhler is credited with isolating aluminum in 1827 by mixing anhydrous aluminum chloride with potassium. The metal, however, had indeed been produced for the first time two years earlier — but in an impure form — by the Danish physicist and chemist Hans Christian Ørsted. Therefore, Ørsted can also be listed as the discoverer of the metal.

Where did its name come from?
In 1807, Sir Humphry Davy was trying to isolate aluminum from a mineral called alumina. He first called the metal alumium, but decided to call it aluminum in 1812.

 Did You Know?
 * Recycling aluminum requires one twentieth as much energy as producing aluminum from raw ore.
 * Aluminum is the most common metal in the earth's crust.
 * Aluminum and Aluminium are two different names for the same metal.

Where is it found?
Aluminum is the most abundant metal in the Earth's crust, and the third most abundant element overall, after oxygen and silicon. But it is not found free in nature. The Bayer process is used to refine aluminum from bauxite (aluminum oxide), an aluminum ore.

What are its uses?
Aluminum has many uses. It is light and strong. Aluminum helps us get from place to place since it's a part of cars, trucks, airplanes, bicycles, rockets, and more.

Every morning you wake up and look in a mirror, the reflective backing is likely made from aluminum. The pots and pans your family uses to cook dinner may be made with aluminum. The utensils you eat your dinner with could be made with aluminum, along with the kitchen aluminum foil used to wrap up leftover food. Soda cans are also made from aluminum.

When aluminum is combined with iron oxide (Fe2O3) in the right quantity, thermite can be made. Thermite burns very quickly and with extreme heat, which is why it's often used to cut or weld steel objects, such as railway tracks. Aluminum is one of the primary components of the fuel that propels rockets into space.

Is it dangerous?
Aluminum isn't dangerous. The metal is protected by a surface layer of aluminum oxide. This surface layer forms at once when the metal is exposed to air, and is very stable. So dishes, pots, and pans can be made of aluminum, and aluminum foil can be used for packing sensitive foods. However, acidic foods, such as tomatoes, can dissolve the surface oxide layer and some of the aluminum underneath. This isn't dangerous and doesn't compromise the strength of the aluminum object, but can lead to off tastes in the food, which is why it is usually not recommended to cook acidic foods in aluminum cookware.

title: Wikijunior:The Elements/Aluminum


text:
Meteorology

About the Book
Meteorology embraces the study of the physics, chemistry, and dynamics of the atmosphere of the earth, including the related effects at the air–earth boundary over both land and the oceans. Fundamental topics include the composition, structure, and motion of the atmosphere. Meteorologists aim to understand completely and predict accurately atmospheric phenomena. Weather describes the state of the atmosphere at a given time and place with respect to such variables as temperature, moisture, wind velocity, and barometric pressure. Determining future weather involves more than simply looking at some pictures.

Understanding meteorology requires understanding the atmosphere, some physics, and a lot of charts. Although this book may attempt to explain some mathematical concepts, many chapters simply require a preexisting considerable understanding of differential and integral calculus. Linear algebra, differential equations, and vector calculus also will aid the student greatly. Students also should possess some familiarity with physics, chemistry, computer information science (programming), statistics, and communication. <!-- Meteorology includes:

 * dynamic meteorology
 * kinematic structures
 * transport mechanisms
 * fluid mechanics
 * fluid dynamics
 * atmospheric dynamics
 * advanced dynamics
 * atmospheric wave phenomena
 * turbulence
 * boundary layers
 * boundary layer meteorology
 * computational fluid dynamics
 * processes governing the movement of atmospheric phenomena
 * coupling

 * atmospheric thermodynamics
 * advanced thermodynamics
 * energization

 * atmospheric physics
 * clouds
 * cloud physics
 * precipitation physics
 * atmospheric processes
 * processes governing the interactions of atmospheric phenomena
 * processes governing the behavior of atmospheric phenomena
 * atmospheric acoustics
 * atmospheric electricity
 * solar radiation
 * terrestrial radiation
 * solar radiation transfer

 * synoptic meteorology
 * general circulation patterns
 * large-scale phenomena
 * behavior of the atmospheric envelopes surrounding the earth
 * weather systems
 * operational weather analysis

 * mesoscale meteorology
 * tropical meteorology
 * mesoscale phenomena
 * storms
 * effect of the atmosphere of the earth on terrestrial weather
 * precipitation processes
 * precipitation patterns
 * weather phenomena
 * micrometeorology
 * introduction to numerical weather prediction
 * numerical analysis
 * statistical analysis
 * data analysis
 * numerical modeling
 * parameterization
 * weather simulation
 * prediction of atmospheric motion
 * atmospheric predictability
 * weather forecasting
 * forecasting techniques

 * atmospheric measurements
 * atmospheric measurement techniques
 * instrumentation
 * computer measurement
 * remote sensing
 * passive remote sensing
 * active remote sensing
 * satellite meteorology
 * radar meteorology
 * radar observations of meteorological phenomena

 * water-related topics
 * hydrology
 * hydrometeorology
 * oceanography
 * physical oceanography

 * chemistry-related topics
 * general chemistry
 * environmental chemistry
 * composition of the atmospheric envelopes surrounding the earth
 * atmospheric constituents
 * gases
 * trace gases
 * aerosols
 * aqueous phase chemistry
 * atmospheric reactions
 * atmospheric chemistry
 * sinks
 * ionization
 * recombination
 * phtoemission
 * plasma chemistry
 * natural plasma
 * dispersion analysis
 * air pollution meteorology
 * use of air quality models

 * climate-related topics
 * climatology
 * climate diagnosis
 * climate variability
 * applied climatology
 * agricultural meteorology
 * biometeorology
 * earth-system science
 * related problems of climate
 * climate change
 * paleoclimatology
 * climate modeling

-->
 * miscellaneous topics
 * aviation meteorology
 * aircraft instruments
 * aircraft systems
 * aircraft icing
 * broadcast meteorology
 * other environmental topics
 * Geographic Information Systems
 * weather information systems
 * related problems of environment
 * related terrestrial phenomena
 * related solar phenomena
 * solar wind
 * aeronomy
 * magnetospheric physics
 * geomagnetic storms
 * ionospheric environment

title: Meteorology


text:
Talk:Blender 3D: Noob to Pro/Archive 1

Tutorial Authors Wanted on Official Blender MediaWiki!
The main Blender documentation and tutorial authors are now working on the Official Blender MediaWiki. If you're considering helping write Blender tutorials or documentation, please consider helping us at the official wiki instead.--Popski 17:46, 18 July 2006 (UTC)
 * That's just silly, whichever set of documents is best is what everyone should be working on, link to each other instead of repeating efforts. --DuLithgow 14:14, 26 July 2006 (UTC)

Please, abandon this stupid nonsense, telling which keys to press, where a menu or other GUI element exists. Why do they exist? Because visual memory is quite rather effective than textual memory …

The GUI will tell, which key to press, once the user is interested in. Sometimes it is hard to find the according GUI-Elements. Plus, you can omit those ridiculous "Gnome-Users would press XXKEY, instead. Mac-Users would press YYKEY instead." For Mac-Users, CMD+LMB is identical to RMB.

Memorize: You're not a Pro, because you are the most hardly working vocabulary learner. You're a Pro, because you master more than one application. And as a Pro you would always adopt the keycodes exactly the way, you individually work most efficient. Blender is no commercial software. So, there is no need to compete about the knowledge of certain keycodes. --Bgks 10:11, 28 July 2006 (UTC)

 * I think the idea of merging has merit but I believed the original intent of the Docs and Noob to Pro to be different. The official docs are "official" whereas Noob to Pro is a collection of individual ideas originally planned to take a user through Blender via a series of specific hands-on tutorials.

 * What I'd really like to see is for someone to take down the OLD html docs (version 2.3x) as these often cause more trouble than they are worth as noobs spend hours looking for the subsurf button and wondering why they can't add an armature the way the docs describe. "Where has subsurf gone?" is without doubt the most asked question on the forums and 70-90% of the time it is asked because people are following an old doc tutorial --AndyD 18:13, 30 July 2006 (UTC)

Snapshot of the wikibook ?
I just wonder if we can made a snapshot of this wikibooks into PDF ? This should be possible and it would be better to learn with a printable version. I've started one, in order to see if it's easy to do, but i am afraid it's not (because of the perpetual evolution of the wb).

Printable versions
A printable version of this book - Such as a PDF or one really big HTML file; HTML file preferred - would be superb. It wouldn't be continuously evolving, but it'd be something I can save to a CD-RW and take home with me. ~ Eric Melech
 * The html version works fine as far as i can tell, and if it's been done right then it's generated when you ask for it, so it's always up-to-date with the latest changes. I have just made a pdf version and invited people to email me if they want it. If someone knows how to edit the front page appropriately we can upload the pdf for people to get directly. It's 3.1MB. Openoffice crashed every time I tried to paste from the HTML printable version into the Writer componant, so I downloaded it as webpage complete, edited it slightly in nvu to get rid of extra junk, and then printed it to a file as a Post Script (PS) file. On the command line (in Ubuntu Linux 6.06) I was then able to convert it from PS to PDF using ps2pdf13. The next problem is how to preserve the internal links, PDF can handle internal links but how to keep it in the conversion? --DuLithgow 14:22, 26 July 2006 (UTC)
 * I've just discovered that the print page doesn't actually have all the pages appearing on it. They are correctly listed, just not displayed - so this must be some internal resource-saving setting on the wikibook servers. We'll have to look at the best way to split the wikibook up into two or more sections. --DuLithgow 17:01, 16 August 2006 (UTC)

The order of chapters
Shouldn't Modeling/Rendering/Texturing/... Basics be taugth before attempting Quickie Model/Render/Texture/..? The current order of pages jumps right into the quickie-part. --ZeroOne 16:29, 30 Nov 2004 (UTC)

 * actually i intended the basics pages to be more in depth than the quickies. the quickies are just to help noobs get a quick & dirty first model down.  in the Modeling Basics tutorial I would like to teach the user extrusion, subdivide, and a lot of hotkeys.  to teach them this, I would actually like to have them build a simple model of something... maybe a simple person using mostly the extrusion tool.  then i will rename the page to modeling a simple human or something like that.

 * thanx for the input and for putting up pics. --spiderworm 14:54, 30 Nov 2004 (UTC)

 * OK... I'll try to follow your work and add some stuff like images when I have time to do that. Btw, please sign these talk-page comments of yours with --~, that will autocomplete as your name and signature. There's also a hotkey for that over this textbox. Also learn to use : as a way to indent your replies, like I have done here. :) But above all, keep up the good work. Blender is such a great program! --ZeroOne 20:18, 30 Nov 2004 (UTC)

 * Great, thanx for the insight! I'm kinda new at this whole thing, but I'm sure you've figured that out by now.  I'm trying to get more authors for it but it might just be mostly me... until I can get content and traffic up.  One idea I had was to create a 2nd versions of each tutorial written by a different author, I'll call it the Second Opinion or something like that.  The reason is so that if a reader doesnt understand or like one author's way of explaining something, they can switch to the Second Opinion.  It will be the same tutorial, they will need to follow the same steps, but it will be explained differently, probably with more detail.  This will also help out when the user didn't learn something they were supposed to learn from previous tutorials.  It's not something that will be done immediately, because hey, there's no First Opinions yet, but just an idea I had.  Good idea or a waste of time? --Spiderworm 20:41, 30 Nov 2004 (UTC)

freedom
btw, feel free to change anything, or discuss changing anything with me. i want to turn noobs into pros, teaching both mechanical and artistic techniques of everything, modeling to texturing to lighting to putting the camera in the right spot. this has to be a series of building tutorials. if you or anyone feels that the way the tutorials are being taught or the sequence of the tutorials is out of line with the stated goals of this book, please feel free to discuss it with me.

i need help with tutorial ideas and objectives. please entries on the main page with your ideas and what will be taught in each tute. then actually put together the tute if you can.

also needing screenshots.

this is going to be such a great book :D --spiderworm 16:48, 30 Nov 2004 (UTC)

Game Plan
OK, to anyone helping with this book, I've created the first 13 pages or so. Let's fill those up with content, screenshots, etc, before moving on. I'd like some feedback on my idea about a "Second Opinion" which I put earlier on this discussion page. Good idea or no? If this is a good idea, let's put this on our immediate to-do list as well. Anyone reading this, if you can recruit some help for this book, that'd be great. There's already a large number of Blender tutes web-wide, and if we can get permission from authors to include sometimes slightly modified versions of their tutes, that'd be great. --Spiderworm 15:44, 1 Dec 2004 (UTC)

 * I think the idea of a book of tutorials is a fantastic way to help user's learn blender, and more rewarding that just reading theory, etc. However one thing of note, in my opinion at least, is that the main focus of each tutorial should be on the tool/procedure than the end result. Providing more detail about why you're doing each step, and explaining the how and why of the command (such as the extrude tool), than simply providing the steps to accomplish the end results. The couple I've looked at thus far have all had the steps, but not much on the "theory". Lots on the "how", but not a lot of the "why". Perhaps this would be better suited to your "second opinion" idea. Or some other possible title for it. In either case I plan to provide some contributions to the book, as I think it definately has potential. --camel 16:44, May 8, 2005 (UTC)

 * Thanx for your input! Providing the why of everything, the theory of 3D modeling, is something that is going to be covered and covered very well in the Intermediate tutorials.  Feel free to chip in there!  --Spiderworm 00:40, 9 May 2005 (UTC)

 * an idea for the advanced section is some tutes on the theory of types of 3d models that are needed professionally. (have a page for animal theory, one for plant theory, one for buildings theory, one for vehicle theory).  if fact you could even break it down to smaller parts (in vehicles have "starships", "land vehicles", "water vehicles", "air vehicles" and one made on the theories on combining any of the above). --Matrim 21:46, Jun 5, 2005 (UTC)

 * Matrim, I absolutely agree. I've tried to start that up in the Intermediate Tutorials section, but no tutorials have popped up yet.  The problem is, I don't consider myself a good modeler at this point, so I'm not writing any tutorials for that section until I believe that I have something good to offer.  I hope some of those that are really Blender pros will help out here soon.  --Spiderworm 15:00, 6 Jun 2005 (UTC)

 * I'll try to spread the word at some of the forums i go to. not very many tho. Basically just blender battles and blenderwars.--Matrim 19:09, Jun 7, 2005 (UTC)

 * Well guys, i noticed this book a while ago whilst trawling the Elysiun forums, back then i didnt really take the the time to have a good look at it. I had a proper look yeterday and i think it is great. I have a few tutorials that i wrote for the Blenderman magazine which is dead now i think (RIP). I plan on contributing a lot to this book, as i think it has a lot of potential. I won't have much time to do anything this week, but next week i will crack on and try to understand how this Wiki structure works and hopefully get some good stuff contributed. If anyone i interested in modifying my tutorials to put them on here, before i get a chance, then they are welcome, just let me know and i will e-mail them to you. One last thing, i would love it if we could get some good in-depth information on the new features since about 2.35 becasue documentation seems to be lacking for them. Once ive sorted out my old tutorials then i think i may very well concentrate on this. leinad13_at_hotmail_._com --Leinad13

Logo Usage
I have removed the 'Blender icon' (Blender.png) image from this page. It is not the Blender icon or logo, and looks like it has been made by a third party. Unfortunately there's no logo pages on the blender website (there will be with the new site), but there's a brief history of the logo here, with some 'unofficial' usage guidelines: http://www.mopi.nl/blogo/

Artistic side of things getting lost?
The mechanics of Blender tutorials seem to be coming along nicely. I feel that this is a good time to ask what happened to the artistic component? Even if you knew Blender backwards, you would have trouble creating an appealing image if you knew nothing about art... there's a reason Blender users are called "artists" :)

The artistic side of things is touched on in the lighting section, but I feel that such an important subject is getting lost. --Jonon 15:40, 18 Jun 2005 (UTC)

 * Jonan, I absolutely agree. I really want to talk about the artistic side of the Blender, but I don't have good artistic skills with the Blender as of right now myself and am trying to get those with artistic skills from the community to pitch in.  I believe Popski has some artistic skills (from what I've seen of his stuff so far), maybe he could help out more with this.  --Spiderworm 17:50, 18 Jun 2005 (UTC)

Sounds like a good idea in theory, but I strongly advise against it. Humankind has been trying to define "art" for millenia. It is an instinctual thing; art cannot be taught with words, and even attempting would diminish its significance and its enigma. You either are an artist - being born with a creative mind deeply imbedded into the id - or not an artist and therefore should stay far from Blender, Photoshop, and their kin. It would save everyone a lot of frustration and arguments if we left such subjects for the philosophical geniuses to pick apart :) ~ Eric Melech

 * Eric, I must respectfully disagree. "Art" may not be definable in theory, but is is definable by example. "I cannot define it, but I know it when I see it." Go to elysium.com and look at the forums. Blender artists are true artists, working in a novel medium. The most renowned artists of the past (Da Vinci and Reubens come to mind) were also technological innovators in new media. So: even if we cannot ask artists to produce a "how to create art for the N00b," we can still ask artists to provide guidance on the techniques used to produce specific work that the community considers to be "artistic." Another way to look at this: not all competent technicians are great artists, but as a general rule great artists are competent technicians. Nacent artists can benefit by the technical insights of great artists.
 * A second point: Blender is useful to technicians even if they do not have the "artistic soul" you allude to. but even these benighted souls (such as myself) may benefit from the techniques used by "real" artists as we persue our more mundane technical craft. If I want to use blender to display my commercial procduct (a vacuum cleaner, say) against a really nice surreal background, the insights of a great artistic creator of surreal backgrounds are of great interest even if I am merely a marketing hack. arch_dude 25 June 2006

 * Jonan and Spiderworm. I have to agree that such a topic should be covered in depth. But it's another book, not this one. Perhaps you could start a book about 3D Digital Art. It doesn't belong in a book about Blender except where is needed in order to explain why or how to do something a certain way. --DuLithgow 14:26, 26 July 2006 (UTC)

 * DuLithgow,

 * The original design of this book was to teach artistic skills and techniques along with the dull how-tos. There were originally three major divisions: Beginner, Intermediate, and Advanced.  The beginner section was to teach every tool in Blender, which means, of course, that the beginner section was originally intended to be HUGE.  The second section, the intermediate tutorials, was intended to teach artistic use of these tools.  The advanced tutorials were going to teach primarily Python in Blender.  I thought I would bring that up so that you would understand my comment in context.  --Spiderworm 02:53, 16 August 2006 (UTC)

Intermediate animation
Added a couple of topics under Intermediate animation.. if you're not happy with them or their descriptions, feel free to modify them. --Jonon 08:06, 19 Jun 2005 (UTC)

Thanks to the editors
I really want to thank the editors of this tutorial for this amazing job they're doing. I'm a contributer to the Dutch Wikipedia and Wikibooks and while editing interwiki's here, I came to reverting some vandalist actions on this tutorial. That's how I came to this tutorial. I've had never heard about Blender before, but it surprises me what you can do with the program.

I already liked it to write, but now, I can also use work from others to learn something!

Editors of this tutorial, I'm really glad with this tutorial, thank you! Firefox 21:41, 29 Jun 2005 (UTC)

Links
Perhaps it would be a good idea to add further links to each lesson. I think someone who started as a "Noob" would like to stay at one lesson for a while and practice what he has learned. So it would be good for him to know where to find further examples.

Random observations
I've been watching this project for quite some time, so allow me to make a couple criticisms.

 * Some of these tutorials contain waaay too much text, for example Blender 3D: Noob to Pro/Putting Hat on Person.

 * "Simple Person" shouldn't be the first tutorial. It should be "screwdriver" or something. Therefore, the "person" model could be more detailed, and at a more advanced level.

—Snargle 23:19, 2 September 2005 (UTC)
 * Also, it might make sense to distribute the .blend files, so editors can make major changes. For instance, incorporating the face and edge select modes. For now, they could be hosted at http://blendermodels.katorlegaz.com

 * Also the Blender model of simple person detailing doesn't connect

Advanced Animation
Hi everyone. I added the Advanced Animation topic as placeholder. I will fill this as time pass by. Deadline is for mid november, so don't worry these sections will not remain empty. This is in fact a re-transcription of the presentation I did at the Montreal Blender conference. Most of the .Blend are ready and a rough text is already done. --Gabio 03:22, 28 October 2005 (UTC)

Die Another Way
It appears that someone recently added a page called "Die Another Way". This page is listed in the contents but is not part of the "Previous Page/Next Page" chain found on each page. Maybe it should be added to the chain? The page also doesn't appear to follow conventions of other pages (for example, keynames such as WKEY) and needs to be revised a little. I'm also not sure where it belongs (beginning, intermediate, etc). 68.126.1.251 20:29, 30 October 2005 (UTC)

Making the dice - Error???
I think I spottet an Error in this tutorial but 'cause im a Noob to Blender I first want to post ist here instead of changing the tutorial at once.

Step 8 says: Make sure these are the right ones by rotating your view with the middle mouse button. Now press x and select 'vertices'. This should leave only the top side of the die:

Don't I have to go to Select->Inverse (in the Menu on the bottom of the 3D Vieport) 'cause if I select all the Vertices of the top side of the dice an press x and select vertices so they are all gone and I have a Cube with one side open.

So far so good.

Muli

P.S.: Using Blender 2.4 on WinXP Pro

reviewed on website
I saw this and thought you might want to know about it: http://www.linux.com/article.pl?sid=06/01/30/2029223 its basicly a review of the book. It says some good things about it, and some bad things, but I thought it was a bit negative. Bawolff 00:00, 9 February 2006 (UTC)

Conversion into another format..?
Hi, I'm not sure if i have the right place here, so we will see what drops, and take it from there..

I'm using moodle, the open source elearning software, and am embarking on a project to put decent training "manuals" like this one into a moodle system, along with assignments relating to each stage. For an online training course project allowing users to easily find and particiape in training courses,

I would like to take this course, and put it into moodle, and amek this course available to people via the elarning system...

Can i do that? there is no charging for the courses.. All Authors will be acknowledged..

fieldyweb@gmail.com

 * Take a look at the license . I don't think there's any problem with doing what you want to do.  Thanks for your support of this book!  --Spiderworm 17:02, 13 February 2006 (UTC)

About the Review
Hi Im working in the translation of this book to spanish (my english is not good so you will understand). About that article and the "bad things" that u say i think is not that bad. I mean, the changing type of this book is not a bad thing, acctualy i think is one of the most interensting things of this system. These are the first objects of comon construction in a non-logical language. Of corse its not nice find an uncomplete ejercise but is part of the experimet. Im not sure that this book would be any better by editing it by a sngle person. I understand that the original autor of this book feel misunderstood when he find new improvments but, hey! Thats the problem at every level. We born in a individual world where personal growing is much more important than the colective stuff. What ever this is the way i see this book.

Reptiles Extintos

lunes, 13 de febrero 2006

Where are they?
Where are the advanced tutorials?

 * Someone is trying to remove them it seems, but they are back right now.. --62.46.146.222 21:09, 21 February 2006 (UTC)

Orphaned Modules

 * Blender 3D: Noob to Pro/Baking
 * Blender 3D: Noob to Pro/Box Modeling
 * Blender 3D: Noob to Pro/Human Body and Head Modelling
 * Blender 3D: Noob to Pro/Intermediate Modelling
 * Blender 3D: Noob to Pro/Mechanical Modeling
 * Blender 3D: Noob to Pro/Organic Modeling
 * Blender 3D: Noob to Pro/Poly by Poly Modeling
 * Blender 3D: Noob to Pro/Sequencer
 * Blender 3D: Noob to Pro/Sky materials
 * Blender 3D: Noob to Pro/Softbody functions
 * Blender 3D: Noob to Pro/Spiderworms Notebook
 * Blender 3D: Noob to Pro/Modeling Basics
 * Blender 3D: Noob to Pro/Render Size
 * Blender 3D: Noob to Pro/Turning your 2D logo into a slick 3D image

 * You can just ignore the 'Spiderworms Notebook' one... that is just a page I created as a place to hold my notes while I was writing the book.... I didn't know much about User namespaces at the time :) --Spiderworm 02:44, 16 August 2006 (UTC)

Screenshot on Index
Why is there a screenshot of Blender 2.36 on the index page? Why not upkeep a sreenshot of the latest version?

good idea

Why dont you load it. I dont think there would be any problem for any one. (Reptiles extintos 17:04, 10 April 2006 (UTC))

 * I can sort of see why this was book of the month for July. As long as all instructions are followed, the tutorial seems quite easy to understand and comprehensive. I've yet to find fault with the article {but I will be keeping an eye out ;) }. Dessydes 20:57, 28 April 2006 (UTC)

Missing advanced tutorials / joystick game
Seems that 84.176.249.244 is a bit of a joker - all of the links to the advanced tutorials were deleted and replaced with a link to a nonsense page about a "joystick game". I've put it back to how it was before, hopefully

 * That joystick game thing is up for VfD... but no-one there knows if it's a legitimate page or not. -- SB_Johnny | talk 12:20, 17 August 2006 (UTC)

Great!
Having great fun with this... thanks to everyone who made it!--72.146.129.200 23:05, 10 May 2006 (UTC)

Where did the modular version go?
Sorry for a n00b question, but I've just got to the end of the advanced tutorials and now there's only the massive printable version available. Where did the rest of it go?
 * it seems it got blanked by an IP Address 62.84.228.7 11:25, 24 May 2006 (UTC)

I see it's back. Cheers for the response.

Links to wrong section.
I recently added a tutorial on Lip-Sync using shape keys. I also noticed the shape key page was empty (as linked from the contents page) so I threw something in there too. However, when I set up the next/previous navigation and tested it out, I discovered a different Shape Key page did already exist.

What seems to have happened is the links on the noob-pro content page link to the tutorial section while the links from the vertex groups & constraints pages correctly link to the existing noob-pro page. I hadn't noticed this when I added the lip-sync page (which you might decide to move anyway?).

I'm happy for the link in the table of contents to be changed to link to the noob-pro shape key page if desired (my shape key page can disappear if it's not needed). I guess my Lip-Sync page should be added to the table of contents in the tutorials section???

I was going so well too! :( AndyD 11:43, 5 June 2006 (UTC)

 * I went ahead and changed the link on the contents page to point to the existing noob to pro Shape Key page (it doesn't look finished though) and I added my Shape Key walk-through to the end of that page. --AndyD 11:43, 5 June 2006 (UTC)

Images and Copyright
When an image is uploaded it recommends choosing a license type. I churned through a few of the existing (old) pages to see what others had used for Blender screenshots and they're all different. The wiki help pages are no help to those not trained in corporate law. Maybe a link should be added to the contents page showing contributors the correct license to use for Blender screenshots with suggestions for the most common license types likely to apply for Blender tutorials. --AndyD 11:43, 5 June 2006 (UTC)
 * I've been advised that Blender screenshots should use the GPL license graphic and it's been requested that existing images be changed to this license type. I'll change them as I find them but it would help if others did the same. Currently, many screenshot images have different licenses while some have none at all. Just click on an image, enter edit mode on its info page and put/replace GPL for the license.--AndyD 05:18, 7 June 2006 (UTC)

I read http://commons.wikimedia.org/wiki/Commons:Licensing#Screenshots and I think that the template should be added for every screenshot, in addtion to the template

We shoud add a for every screenshot too (and for blender render). Is it possible to create a unique template for blender screenshots that adds all this information?

--Argento 22:04, 15 September 2006 (UTC)

next step tutorials
The tutorials here only get someone so far, none of them go into the next step of giving an image/animation/whatever and telling the reader that it can be modeled using these tools, but the steps are not provided on purpose. This makes the reader solve real world problems and become a step closer to being a good 3d artist. --V2os 01:40, 2 August 2006 (UTC)

Urgent hosting needed for pdf version
I've been hosting the pdf version for download, but it's proven far too popular for my hosting plan to cope with. It's only the 9th of the month and I'm at 80% of my quota. It's had 5988 requests and 7550838 Kbs of traffic (97.01% of my traffic).

I don't think the wikimedia foundation should host this file, their servers are overstreached already. So please contact me if you can host it, otherwise I'll have to temporarily pull the plug on it. --DuLithgow 21:46, 9 August 2006 (UTC)

 * Hi DuLithgow, I'm glad to see my baby (this book) is growing up and becoming popular. Sorry about the effect that the PDF's having on your server :(

 * Two things... I do have some web space at tellim.com .... I'll look into how much traffic I am allowed, but I need to know the file size. How big is this thing?  Also, what script are you using to generate the PDF of the book?  Please point me to a website if there is one.

 * One thought, have you tried making a torrent of this?

 * Thanks a ton, and we'll try to relieve you of your burden a bit here! --Spiderworm 02:41, 16 August 2006 (UTC)

 * Why not use, for example, a coralcache link? Then the actual host's bandwidth use will be minimised.

Move to Wikiversity?
Should this be moved to Wikiversity? 67.181.61.13 06:22, 24 August 2006 (UTC)

external resources
I would like to do a big edit to the initial page, but I think it's better to discuss it before I do such big change. I would like to add an "external resources" part of the book between "Miscellaneous Tutorials" and the "Appendix". I would move the Blender 3D: Noob to Pro/Blueprint Links List page to external resources, together with Blueprints Materials Models Photos Textures of Blender_3D:_Tutorial_Links_List as separated pages.

This is the final structure for my external resources section proposal
 * Blender 3D: Noob to Pro/External Resources/Tutorials Links from Blender_3D:_Tutorial_Links_List
 * Blender 3D: Noob to Pro/External Resources/Blueprint Links (merge of Blender 3D: Noob to Pro/Blueprint Links List and Blender_3D:_Tutorial_Links_List blueprints section)
 * Blender 3D: Noob to Pro/External Resources/Materials Links from Blender_3D:_Tutorial_Links_List
 * Blender 3D: Noob to Pro/External Resources/Models Links from Blender_3D:_Tutorial_Links_List
 * Blender 3D: Noob to Pro/External Resources/Photos Links from Blender_3D:_Tutorial_Links_List
 * Blender 3D: Noob to Pro/External Resources/Textures Links from Blender_3D:_Tutorial_Links_List
 * Blender 3D: Noob to Pro/External Resources/Procedural Modelling Links new section (all the programs that generates models from parameters (humans, trees, textures...)

Note that the page Blender_3D:_Tutorial_Links_List is linked two times in the main page, one in the "Miscellaneous Tutorials" section and another in the "Appendix" section. I would remove both and leave only one in "external resources section". --Argento 16:27, 15 September 2006 (UTC)

Sorry I forgot my motivation, the page Blender_3D:_Tutorial_Links_List title only says tutorials, I'm not expected to find blueprints here when I click it, so I created lot of time ago the Blender 3D: Noob to Pro/Blueprint Links List page, I didn't know that blueprints were in the tutorials page, an "external resources" section is more appropriate in my opinion --Argento 16:27, 15 September 2006 (UTC)

We can also rename the page Blender_3D:_Tutorial_Links_List to Blender_3D:External Resoruces and keep all in a single page.--Argento 16:30, 15 September 2006 (UTC)

I just noticed that there is a section similiar to the proposed Blender 3D: Noob to Pro/External Resources/Procedural Modelling Links in Blender_3D:_Noob_to_Pro/Advanced_Tutorials/Python_Scripting/Procedural_object_creation--Argento 21:23, 15 September 2006 (UTC)

title: Talk:Blender 3D: Noob to Pro/Archive 1


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Talk:Muggles' Guide to Harry Potter/Books/Prisoner of Azkaban/Chapter 9

Unfortunately, the dates of the actual full moon in 1993/1994 do not seem to completely tally with the story. The full moon falls on October 30 and November 29 of 1993; internal evidence (Lupin looking healthy on October 31, Quidditch against Hufflepuff one to two weeks later, Lupin sick just before and possibly during the Quidditch match) would indicate the need for a full moon sometime around the second week in November. While there is a full moon on May 25 and June 23 1994, the episode in The Shrieking Shack falls immediately after Exams, which would place it most likely early in the second week of June. As the events in the story could, in both cases, be either one or two weeks off the dates of the full moon, we may simply assume that J. K. Rowling consulted a lunar phases chart for a different year than the one where story actually occurred... except that Lupin is apparently sick on Christmas, and there was a full moon on 28 December 1993.

I include this information because it nags at me; however, I don't believe that it belongs in the book proper. Chazz 07:18, 2 October 2006 (UTC)


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Muggles' Guide to Harry Potter/Characters/Madam Rosmerta

Overview
Madam Rosmerta is "a curvy sort of woman with a pretty face", the owner of The Three Broomsticks pub in Hogsmeade.

Prisoner of Azkaban
Madam Rosmerta is first mentioned by name when Harry escapes from Hogwarts to join Ron and Hermione in Hogsmeade. She serves Professor McGonagall, Professor Flitwick, Hagrid and Cornelius Fudge, and is invited to join them for a drink. She is unhappy that there are Dementors in Hogsmeade, as they have searched the pub twice and scared her customers away.

Rosmerta finds it difficult to believe that Sirius Black went over to the Dark side, as she knew Black when he was a boy. When Professor McGonagall asks her if she remembers Black's best friend, Madam Rosmerta remarks how you never saw one without the other, eventually revealing that Black's best friend was James Potter, Harry's father.

Goblet of Fire
Madam Rosmerta isn't impressed that Professor Moody insists on drinking from his hipflask whilst he visits the Three Broomsticks, instead of buying a drink from the pub, and glares at Moody as she collects glasses from the tables around him and Hagrid.

Order of the Phoenix
Perhaps curiously, we do not see Madam Rosmerta in the Three Broomsticks when Harry is there being interviewed by Rita Skeeter. As Harry is then banned from all further Hogsmeade weekends by Umbridge, we do not see Madam Rosmerta in this book.

Half-Blood Prince
Rosmerta greets Harry and Dumbledore when they secretly left Hogwarts to find Voldemort's Horcrux. On their return, she warns them of the Dark Mark above Hogwarts, and loans them brooms to speed their return to the school. At the school, Harry is present, though immobilized and concealed by his Invisibility Cloak, as Dumbledore engages Draco Malfoy in conversation to attempt to win his allegiance. In the course of conversation, Dumbledore wonders how Draco knew when they left the castle, and then realizes that Rosmerta, under the Imperius curse, had told him. This revelation also explains how Katie Bell came to be carrying the cursed necklace back to school after a Hogsmeade visit; Rosmerta, acting under Malfoy's curse, had met Katie in the toilets, placed her under the Imperius curse, and given her the necklace to deliver to Dumbledore.

Relationships with Other Characters
Ron seems to have a bit of a crush on Madam Rosmerta; perhaps he just likes her shape. He is well aware that she is literally old enough to be his mother; in fact, Madam Rosmerta was tending bar at the Three Broomsticks when Harry's father was at Hogwarts.

Analysis
In Harry Potter and the Prisoner of Azkaban, Madam Rosmerta's primary function is to be an excuse to tell the story of Sirius Black's supposed back story. The more mature reader might find this a little unlikely, as a barmaid or publican is likely to know all the news almost before the people it's happened to. This would not be obvious to the book's intended audience, however. Hagrid's unfamiliarity with the story might be reason enough to tell it, but Rosmerta has a vested interest - the Dementors stationed around the village are hurting her business, and the person ultimately responsible for their presence has just walked into her establishment; who better to explain why she has to take a hit in her profits?

One of the things that goes past without significant mention is that Rosmerta is quite literally old enough to be Ron's mother, and he would realize that if he ever thought about it. Rosmerta mentions that she had known Harry's father and the other Marauders, in Harry Potter and the Prisoner of Azkaban. It is unlikely she would remember them so well if she was significantly younger than them, so we can assume that she is roughly of an age, at least, as Harry's parents, or older if, as is suggested in the discussion with Fudge in the Three Broomsticks just before Christmas, she served them in the pub. Ron still seems to be angling for a glimpse of her in subsequent books, despite the conversation having happened in his hearing, and while he was paying attention to it.