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BLL German/A1/Lesson 1

Goal
In this lesson you will learn how to introduce yourself in German. You need not have any previous knowledge of German or English grammar terms, however you should have consulted the page on pronunciation and memorised basic greetings from there.

Text
"Guten Tag! Ich heiße Lisa Müller. Ich wohne in Bern, aber ich komme aus Deutschland. Ich arbeite als Fremdenführerin." "Guten Tag! Ich heiße John Smith. Ich komme aus Manchester, aber ich arbeite in Bern."

Explanations

 * 1) You probably already noticed that there's an entry for e.g. "heißen" in the vocabulary list but not for "heiße". That is because "heiße" is a conjugated form, like "am called", whereas "heißen" is the infinitive "be called". You wouldn't say "I be called" either, would you? That's what "ich heißen" would sound like to a German. So take off the -n from all the verbs listed in the vocabulary or a dictionary in order to get the 1st person singular form (the one to be used with "I").
 * 2) Why is Fremdenführer just one (admittedly long) word? Germans don't like to put spaces in between nouns that obviously belong together, so in such cases you will often find them glued together while English uses two words to convey the same meaning. The words glued together here are: "Fremden"(strangers) and "Führer"(guide, leader). In your pronunciation you should always reflect that these are separate parts and pronounce it "Fremden-führer". If you pronounce it "Frem-denführer", people might have difficulties understanding you.
 * 3) Why is Fremdenführer spelled with a capital letter? This is not a typo. In German, you actually have to spell every noun with a capital letter. This may look strange to you at first, but it is very useful, because it makes the language less ambiguous, at least in writing.

Exercises

 * Use the words you have learned in this lesson as often as you can in the next few days. If you don't know any Germans or German-learning friends on whom you could try them out, at least call them up in your memory whenever you have a few minutes to spare and imagine how you would introduce yourself to somebody in Germany.

 * Choose the correct answer:

 * Which of the following German phrases is not said when greeting somebody?
 * A. Hallo!
 * B. Guten Tag!
 * C. Guten Abend!
 * D. Gute Nacht!

 * Which words require a capital letter in German?
 * A. The word at the beginning of a sentence, the word "Ich" and proper words like "Deutschland".
 * B. The word at the beginning of a sentence and all nouns, for example also words for professions.
 * C. Only the word at the beginning of a sentence.
 * D. The first word and then every third word following it.

 * Which of the following sentences contains a mistake?
 * A. Ich kommen aus London.
 * B. Ich heiße Lisa.
 * C. Ich arbeite als Putzfrau.
 * D. Ich wohne in Berlin.

 * Which of the following sentences contains a mistake?
 * A. Ich wohne in Deutschland.
 * B. Ich komme aus New York.
 * C. Ich heiße Thomas.
 * D. Ich arbeite als Fremden Führer.

Answer to this exercise 1D, 2B, 3A, 4D

 * Fill in the blanks with the following verbs: arbeiten, heißen, kommen, lernen (= to learn), lieben (= to love), sprechen (= to speak)
 * Hallo! Ich ___ Max Schmidt. Ich ___ als Kaufmann in Amerika, aber ich ___ aus Hamburg. Ich ___ Deutsch und Englisch. Ich ___ Spanisch. Ich ___ Spanisch.

Answer to this exercise heiße, arbeite, komme, spreche, lerne, liebe

 * How do you say...
 * that your name is Michael?
 * that you come from America?
 * that you live in Hamburg, not necessarily meaning that you were born there?

Answer to this exercise Ich heiße Michael. Ich komme aus Amerika. Ich wohne in Hamburg.

Extension
If you'd like to learn more words that you can use without having to study another lesson, use this section in order to find them. Feel free to learn selectively, picking out words you consider useful for your situation or interesting. If you don't have the time, you can just skip this section. You will not be required to know any of these words in the next lessons.

Additional expressions: "Ich spreche Englisch und Französisch. Ich lerne Deutsch." New words: sprechen (to speak), und (and), lernen (to learn) and language names from the list.

 * List of language names
 * List of professions

(a more complete list can be found here, but country names on that list that consist of more than one word might not fit seamlessly into the pattern "Ich komme aus ...")

Cultural information: Bern
Bern is the capital of Switzerland. Despite that, it's a comparatively small city with a population of about 130,000. It sits on a peninsula formed by the meandering turns of the river Aare. Bern's beautiful old town is part of the UNESCO World Heritage List and there are a lot of fascinating places to go, particularly if you are interested in history or art. Read more about Bern on Wikipedia.

title: BLL German/A1/Lesson 1


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User:Mjkaye

I am Michael Kaye, a computer programmer specializing in Object-Oriented Programming, and a believer in eXtreme Programming.

I am a Trekkie, and spend a lot of my Wikipedia time over on the Star Trek pages.

My largest contributions have been to the Wikipedia Paraty article, taking some of the statistical data from the Portuguese version of the page, and to the Portuguese Wikibook (specifically the new Brazilian Portuguese section).

I am a firm believer in Free Software (and Open Source). Hence, my commitment to using Wikipedia and Wikibooks as my primary sources of information. I run Linux at home, and have no reason to run Windows.

Templates
I have created the Language table template (suggestions for a better name are welcome). This is based on the German table template, which I think is an excellent piece of work. I made the Language table template to use in the Brazilian Portuguese section of the Portuguese Wikibook, but I hope it is general enough to be used in any language-teaching Wikibook. In fact, I hope that, in future, it can form a base for language-specific vocabulary/verb tables. See the discussion page for more on those plans.

A current problem with the Language table template is that if it is used over a number of languages, it could result in conflicting audio file names. I hope to resolve this soon.

There seem to be a great multitude of templates on Wikibooks, and it is not easy to find ones that are useful to you. There also seems to be a lot of duplicated effort, with copies made of templates for only small changes. I think that templates are a powerful aspect of Wikibooks (and other Wikimedias), and I hope they can be made easier to use. I think the duplication of effort can be minimised by using the equivalent of Object Composition to simulate inheritance. This should also result in smaller, simpler templates, which can be composed more easily into powerful templates.

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

title: User:Mjkaye


text:
Signals and Systems/Frequency Response

Frequency Response
Systems respond differently to inputs of different frequencies. Some systems may amplify components of certain frequencies, and attenuate components of other frequencies. The way that the system output is related to the system input for different frequencies is called the frequency response of the system.

The frequency response is the relationship between the system input and output in the Fourier Domain.

In this system, X(jω) is the system input, Y(jω) is the system output, and H(jω) is the frequency response. We can define the relationship between these functions as:

 * $$Y(j\omega) = H(j\omega)X(j\omega)$$

 * $$\frac{Y(j\omega)}{X(j\omega)} = H(j\omega)$$

The Frequency Response Functions
Since the frequency response is a complex function, we can convert it to polar notation in the complex plane. This will give us a magnitude and an angle. We call the angle the phase.

Amplitude Response
For each frequency, the magnitude represents the system's tendency to amplify or attenuate the input signal.

 * $$A\left( \omega \right) = \left| {H\left( {j\omega } \right)} \right|$$

Phase Response
The phase represents the system's tendency to modify the phase of the input sinusoids.
 * $$\phi \left( \omega \right) = \angle H\left( {j\omega } \right)$$.

The phase response, or its derivative the group delay, tells us how the system delays the input signal as a function of frequency.

Filters
An important concept to take away from these examples is that by desiging a proper system called a filter, we can selectively attenuate or amplify certain frequency ranges. This means that we can minimize certain unwanted frequency components (such as noise or competing data signals), and maximize our own data signal

We can define a "received signal" r as a combination of a data signal d and unwanted components v:

 * $$r(t) = d(t) + v(t)$$

We can take the energy spectral density of r to determine the frequency ranges of our data signal d. We can design a filter that will attempt to amplify these frequency ranges, and attenuate the frequency ranges of v. We will discuss this problem and filters in general in the next few chapters. More advanced discussions of this topic will be in the book on Signal Processing.

title: Signals and Systems/Frequency Response


text:
Portuguese/Contents/BPL1/Quarta lição

Verb "ter"/ Verbo ter
The verb to have is another important verb in Portuguese. It's an irregular verb:

See some examples:
 * Nós temos um cachorro. ("We have a dog.")
 * Eles têm uma bela casa. ("They have a beautiful house.")

The verb "ter" means "to have" in the sense of "possess", but, whenever followed by que or de, also can design some obligation, meaning "to have to" or "must". Frequently "ter que" means "to need to" as well.

See some examples:
 * Nós temos de ser amigos. ("We have to be friends.")
 * Eles têm que trabalhar? ("Do they need to work?")
 * Ele não tem que voltar para casa, mas eu tenho. ("He doesn't have to go back home, but I must.")

Past imperfect indicative of regular verbs/Pretérito imperfeito do indicativo de verbos regulares
Conjugation rules:
 * the second conjugation (er-verbs) is equals to the third conjugacion (ir-verbs), only changing the stem vowel e of er-verbs by i.
 * the first person singular (eu) is equals to the third person singular (ele/ela).
 * the second person singular (tu) is equals to the third person singular (ele/ela) plus -s.
 * the third person singular (ele/ela) takes the stem vowel plus -va in first conjugation (ar-verbs) and -a in third conjugation (er and ir-verbs), noting that er-verbs have the stem vowel replaced by -i.
 * the first person plural (nós) takes the stem vowel plus -vamos (ar-verbs) or -amos (er and ir-verbs). Don't forget the acute accent upon the stem vowels and to replace stem vowel in er-verbs by -i.
 * the second person plural (vós) takes the stem vowel plus -veis (ar-verbs) or -eis (er and ir-verbs). Don't forget the acute accent upon the stem vowels and to replace the stem vowel in er-verbs by -i.
 * the third person plural (eles/elas) is equals to the third person singular (ele/ela) plus -m.

There is a table with three examples below: "cantar" ("to sing"), "comer" ("to eat") and "partir" ("to leave").

title: Portuguese/Contents/BPL1/Quarta lição


text:
Signals and Systems/Filter Design

The Laplace transform allows analyzing the frequency response of circuits based on the differential equations of their capacitive and inductive components. Filter design starts with finding the proper transfer function in order to amplify selected parts of a signal and to damp other ones as a function of their frequency.

Choosing the proper filter structure and deriving the coefficient values is a further topic prensented in the wikibook Signal Processing which deals with the application of signal and systems.

Brick-wall filters
Separating signal from noise or different signals in the same transmission channel basing on their frequency content is best done with a brick-wall filter which shows full transmission in the passband and complete attenuation in the nearby stopbands, with abrupt transitions.

This can be done with the help of the Fourier transform which provides complete information of the frequency content of a given signal. Having calculated a Fourier transform, one can zero out unwanted frequency contents and calculate the inverse Fourier Transform, in order to provide the signal filtered with a brick-wall gauge.

The Fourier transform being given by:
 * $$\mathcal{F}(f(t)) = F(j\omega) = \int_{-\infty}^\infty f(t)e^{-j\omega t}dt$$

one finds out that the Fourier transform integral, with its infinite bounds, would have to be calculated from the day of the creation of our universe and all the way up to the day of its decay before the integral could have been fully calculated. And only then can the ideal brick-wall filtered signal be delivered.

In more technical terms, the ideal brick-wall filter suffers from an infinite latency.

Analog filters
The analysis of analog circuits shows that their outputs are related to their input by a set of differential equations. The Laplace transform rewrites these differential equations as a set of linear equations of the complex variable $$s$$. With this, a polynomial function multiplying the Laplace transform of the input signal can be equated to another polynomial function multiplying the Laplace transform of the ouput signal:
 * $$(b_m s^{m} + b_{m-1} s^{m-1} + \ldots + b_1 s + b_0) \cdot X(s) = (a_n s^{n} + a_{n-1} s^{n-1} + \ldots + a_1 s + a_0) \cdot Y(s)$$

Thus, the transfer function of a realizable analog filter can be written as the ratio of two polynomial functions of $$s$$:
 * $$H(s) = \frac{Y(s)}{X(s)} = \frac{b_m s^{m} + b_{m-1} s^{m-1} + \ldots + b_1 s + b_0}{a_n s^{n} + a_{n-1} s^{n-1} + \ldots + a_1 s + a_0}$$

Hence, the problem of analog filter design is to find a pair of polynomial functions which, put together, best approximate the ideal but not realizable brick-wall transfer function.

In the early days of electric signal processing, scientists have come up with filter functions which are still largely used today. The functions they have devised are all of lowpass type. Frequency transformation techniques allow to find polynomials for other filter types such as highpass and bandpass.

The Complex Plane
The transfer function of an analog filter is the ratio of two polynomial functions of $$s$$:
 * $$H(s) = \frac{Y(s)}{X(s)} = \frac{num(s)}{den(s)}$$

The variable $$s$$ is a complex number which can be written as $$s = \sigma + i \cdot \omega$$. The complex plane is a plane with the imaginary axis vertical and the horizontal axis as the real part.

The roots of the transfer function numerator polynom are called the transfer function zeroes. The roots of the transfer function denominator polynom are called the transfer function poles.

The transfer function can be written as a function of its zeroes $$z_i$$, its poles $$p_i$$ and an additional gain factor $$k$$ in the form:
 * $$H(s) = k \cdot \frac{\prod_{i=1}^M (s-z_i)}{\prod_{i=1}^N (s-p_i)}$$

The poles and the zeroes of a transfer function can be drawn in the complex plane. Their position provide information about the frequency response of the system. Indeed, the frequency response is equal to the transfer function taken for $$s = i \omega$$, which is along the imaginary axis.
 * $$\frac{Y(i \omega)}{X(i \omega)} = H(s = i \omega)$$

Effect of Poles
A stable LTI system has all its poles on the left side half plane of $$s$$.

If a pole would be located on the imaginary axis, at $$p = i \omega_p$$, then the factor $$1/{(s-p)}$$ of the transfer function would be infinite at the point $$s = i \omega_p$$ and so would the global frequency response $$H(s = i \omega_p)$$. A special case of this is the integrator: it has a pole at $$p = 0$$, and indeed has a long-term infinite output for a constant, non-zero, input.

For poles close to the imaginary axis, the frequency response takes a large amplitude for frequencies close to them. In other words, poles close to the imaginary axis indicate the passband.

Effect of Zeros
If a zero is located on the imaginary axis, at $$z = i \omega_z$$, then the factor $$(s-z)$$ of the transfer function is zero at the point $$s = i \omega_z$$ and so is the global frequency response $$H(s = i \omega_z)$$.

Zeroes on, or close to the imaginary axis indicate the stopband.

Designing Filters
Devising the proper transfer function for a given filter function goes through the following steps:
 * selecting a normalized filter function
 * transforming and scaling the function for the particular needs

The coefficients of the numerator and denominator coefficients are finally used to calculate the element values of a selected filter circuit.

Example: Lowpass Filter
A reduced version of CCITT G712 input filter specification, giving only the lowpass part, is shown in the plot on the side.

The passband goes up to $$3 kHz$$ and allows a maximal ripple of $$0.125 dB$$. The stopband requires an attenuation of $$14 dB$$ at $$4 kHz$$ and an attenuation of $$32 dB$$ above $$4.6 kHz$$.

Filter Function
As a first step, we have to choose a filter function.

Programs such as Octave or Matlab provide functions which allow to determine the minimal filter order required to fulfill a given specification. This is a good help when choosing from the possible functions.

Let's however here arbitrarily choose a Butterworth transfer function.

Normalized Filter Function
The following Octave script allows to plot the amplitudes of normalized Butterworth transfer functions from order 8 to 16.

#--- # fs = 40E3; fPass = 3000; rPass = 0.125; fStop1 = 4000; rStop1 = 14; fStop2 = 4600; rStop2 = 32; pointNb = 1000; AdbMin = 40; makeGraphics = 1; figureIndex = 0; # wLog = 2*pi*logspace(-1, 1, pointNb); fc = 0.87; Adb = []; for order = 8:16 [num, den] = butter(order, 2*pi, 's'); while ( length(num) < length(den) ) num = [0, num]; endwhile; Adb = [Adb; 20*log10(abs(freqs(num, den, wLog)))]; endfor Adb(Adb < -AdbMin) = -AdbMin; figureIndex = figureIndex+1; figure(figureIndex); semilogx(wLog/(2*pi), Adb); hold on; semilogx([wLog(1)/(2*pi), fc, fc], -[rPass, rPass, AdbMin], 'r'); semilogx([fStop1*fc/fPass, fStop1*fc/fPass, fStop2*fc/fPass, fStop2*fc/fPass, wLog(length(wLog))/(2*pi)], ...        -[0    , rStop1, rStop1, rStop2, rStop2            ], 'r'); hold off; axis([wLog(1)/(2*pi), wLog(length(wLog))/(2*pi), -AdbMin, 0]); grid; xlabel('frequency [Hz]'); ylabel('amplitude [dB]'); if (makeGraphics != 0) print -dsvg g712_butterworth_normalized.svg endif
 * 1) Specifications
 * 1) Normalized filter function
 * 1) Normalized filter function

The following figure shows the result: one needs at least a 13th order Butterworth filter to meet the specifications.

On the graph, one can note that all the amplitude responses go through the same point at -3 dB.

The specification frequencies have been scaled down to fit to the normalized cutoff frequency of 1 Hz. In the script, one might have noted an additional scaling factor of : this is due to the fact that the corner cutoff amplitude is -0.125 dB and not -3 dB. That value has been adjusted by hand for this example. Again, Octave or Matlab scripts automate this task.

Denormalized Filter Function
The frequency scaling of the normalized transfer function is done by replacing

$$s \to f_c \cdot s $$

The following Octave script does this by multiplying the numerator and denominator coefficients by the appropriate power of $$f_c$$.

#--- # order = 13; wLog = 2*pi*logspace(2, 5, pointNb); fc = 0.87; [num, den] = butter(order, 2*pi, 's'); while ( length(num) < length(den) ) num = [0, num]; endwhile; for index = 1:order+1 num(index) = num(index) * (fPass/fc)^(index-1); den(index) = den(index) * (fPass/fc)^(index-1); endfor Adb = 20*log10(abs(freqs(num, den, wLog))); Adb(Adb < -AdbMin) = -AdbMin; figureIndex = figureIndex+1; figure(figureIndex); semilogx(wLog/(2*pi), Adb); hold on; semilogx([wLog(1)/(2*pi), fPass, fPass], -[rPass, rPass, AdbMin], 'r'); semilogx([fStop1, fStop1, fStop2, fStop2, wLog(length(wLog))/(2*pi)], ...        -[0    , rStop1, rStop1, rStop2, rStop2            ], 'r'); hold off; axis([wLog(1)/(2*pi), wLog(length(wLog))/(2*pi), -AdbMin, 0]); grid; xlabel('frequency [Hz]'); ylabel('amplitude [dB]'); if (makeGraphics != 0) print -dsvg g712_butterworth.svg endif
 * 1) Denormalized filter function

The coefficients of the numerator and denominator coefficients are now ready to be used to calculate the element values of a selected filter circuit.

title: Signals and Systems/Filter Design


text:
Neapolitan/weather

'O tiempo
The South of Italy experiences all the seasons with all of their accompanying weather patterns. It is hot in the summer and usually cold and rainy in the winter with snow in the mountains and occasionally down below.

Phrases
Some useful weather related phrases.

title: Neapolitan/weather


title: User:Alessandro57


text:
Control Systems/Matrix Operations

Laws of Matrix Algebra
Matrices must be compatible sizes in order for an operation to be valid:

 * Addition:Matrices must have the same dimensions (same number of rows, same number of columns). Matrix addition is commutative:
 * $$A + B = B + A$$

 * Multiplication:Matrices must have the same inner dimensions (the number of columns of the first matrix must equal the number of rows in the second matrix). For instance, if matrix A is n × m, and matrix B is m × k, then we can multiply:
 * $$AB = C$$
 * Where C is an n × k matrix. Matrix multiplication is not commutative:
 * $$AB \ne BA $$
 * Because it is not commutative, the differentiation must be made between "multiplication on the left", and "multiplication on the right".

 * Division:There is no such thing as division in matrix algebra, although multiplication of the matrix inverse performs the same basic function. To find an inverse, a matrix must be nonsingular, and must have a non-zero determinant.

Transpose Matrix
The transpose of a matrix, denoted by:

 * $$X^T$$

is the matrix where the rows and columns of X are interchanged. In some instances, the transpose of a matrix is denoted by:

 * $$X'$$

This shorthand notation is used when the superscript T applied to a large number of matrices in a single equation, and the notation would become too crowded otherwise. When this notation is used in the book, derivatives will be denoted explicitly with:

 * $$\frac{d}{dt}X(t)$$

Determinant
The determinant of a matrix it is a scalar value. It is denoted similarly to absolute-value in scalars:

 * $$|X|$$

A matrix has an inverse if the matrix is square, and if the determinant of the matrix is non-zero.

Inverse
The inverse of a matrix A, which we will denote here by "B" is any matrix that satisfies the following equation:

 * $$AB = BA = I$$

Matrices that have such a companion are known as "invertible" matrices, or "non-singular" matrices. Matrices which do not have an inverse that satisfies this equation are called "singular" or "non-invertable".

An inverse can be computed in a number of different ways:

 * 1) Append the matrix A with the Identity matrix of the same size. Use row-reductions to make the left side of the matrice an identity. The right side of the appended matrix will then be the inverse:
 * $$[A|I] \to [I|B]$$
 * 1) The inverse matrix is given by the adjoint matrix divided by the determinant. The adjoint matrix is the transpose of the cofactor matrix.
 * $$A^{-1} = \frac{\operatorname{adj}(A)}{|A|}$$
 * 1) The inverse can be calculated from the Cayley-Hamilton Theorem.

Eigenvalues
The eigenvalues of a matrix, denoted by the Greek letter lambda λ, are the solutions to the characteristic equation of the matrix:

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

Eigenvalues only exist for square matrices. Non-square matrices do not have eigenvalues. If the matrix X is a real matrix, the eigenvalues will either be all real, or else there will be complex conjugate pairs.

Eigenvectors
The eigenvectors of a matrix are the nullspace solutions of the characteristic equation:

 * $$(X - \lambda_i I)v_i = 0$$

There is at least one distinct eigenvector for every distinct eigenvalue. Multiples of an eigenvector are also themselves eigenvectors. However, eigenvalues that are not linearly independent are called "non-distinct" eigenvectors, and can be ignored.

Left-Eigenvectors
Left Eigenvectors are the right-hand nullspace solutions to the characteristic equation:

 * $$w_i(A - \lambda_i I) = 0$$

These are also the rows of the inverse transition matrix.

Generalized Eigenvectors
In the case of repeated eigenvalues, there may not be a complete set of n distinct eigenvectors (right or left eigenvectors) associated with those eigenvalues. Generalized eigenvectors can be generated as follows:

 * $$(A -\lambda I)v_{n+1} = v_n$$

Because generalized eigenvectors are formed in relation to another eigenvector or generalize eigenvectors, they constitute an ordered set, and should not be used outside of this order.

Transformation Matrix
The transformation matrix is the matrix of all the eigenvectors, or the ordered sets of generalized eigenvectors:

 * $$T = [v_1 v_2 \cdots v_n]$$

The inverse transition matrix is the matrix of the left-eigenvectors:

 * $$T^{-1} = \begin{bmatrix}w_1' \\ w_2' \\ \cdots \\ w_n'\end{bmatrix}$$

A matrix can be diagonalized by multiplying by the transition matrix:

 * $$A = TDT^{-1}$$

Or:

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

If the matrix has an incomplete set of eigenvectors, and therefore a set of generalized eigenvectors, the matrix cannot be diagonalized, but can be converted into Jordan canonical form:

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

MATLAB
The MATLAB programming environment was specially designed for matrix algebra and manipulation. The following is a brief refresher about how to manipulate matrices in MATLAB:

C = A + B; C = A * B;
 * Addition:To add two matrices together, use a plus sign ("+"):
 * Multiplication:To multiply two matrices together use an asterisk ("*"):
 * If your matrices are not the correct dimensions, MATLAB will issue an error.

C = A'; d = det(A); C = inv(A); [E, V] = eig(A);
 * Transpose:To find the transpose of a matrix, use the apostrophe (" ' "):
 * Determinant:To find the determinant, use the det function:
 * Inverse:To find the inverse of a matrix, use the function inv:
 * Eigenvalues and Eigenvectors:To find the eigenvalues and eigenvectors of a matrix, use the eig command:
 * Where E is a square matrix with the eigenvalues of A in the diagonal entries, and V is the matrix comprised of the corresponding eigenvectors. If the eigenvalues are not distinct, the eigenvectors will be repeated. MATLAB will not calculate the generalized eigenvectors.

[E, V] = eig(A); C = inv(V); The rows of C will be the left-eigenvectors of the matrix A.
 * Left Eigenvectors:To find the left eigenvectors, assuming there is a complete set of distinct right-eigenvectors, we can take the inverse of the eigenvector matrix:

For more information about MATLAB, see the wikibook MATLAB Programming.

title: Control Systems/Matrix Operations


text:
Neapolitan/interrogatives

'Nterrogative/Interrogatives
Napoletano/Interrogativi

title: Neapolitan/interrogatives


text:
Control Systems/State-Space Stability

State-Space Stability
If a system is represented in the state-space domain, it doesn't make sense to convert that system to a transfer function representation (or even a transfer matrix representation) in an attempt to use any of the previous stability methods. Luckily, there are other analysis methods that can be used with the state-space representation to determine if a system is stable or not. First, let us first introduce the notion of unstability:

Also, a key concept when we are talking about stability of systems is the concept of an equilibrium point:

The definitions below typically require that the equilibrium point be zero. If we have an equilibrium point xe = a, then we can use the following change of variables to make the equilibrium point zero:

 * $$\bar{x} = x_e - a = 0$$

We will also see below that a system's stability is defined in terms of an equilibrium point. Related to the concept of an equilibrium point is the notion of a zero point:

Stability Definitions
The equilibrium x = 0 of the system is stable if and only if the solutions of the zero-input state equation are bounded. Equivalently, x = 0 is a stable equilibrium if and only if for every initial time t0, there exists an associated finite constant k(t0) such that:

 * $$\operatorname{sup}_{t \ge t_0}\|\phi(t, t_0)\| = k(t_0) < \infty$$

Where sup is the supremum, or "maximum" value of the equation. The maximum value of this equation must never exceed the arbitrary finite constant k (and therefore it may not be infinite at any point).

Uniform stability is a more general, and more powerful form of stability than was previously provided.

A time-invariant system is asymptotically stable if all the eigenvalues of the system matrix A have negative real parts. If a system is asymptotically stable, it is also BIBO stable. However the inverse is not true: A system that is BIBO stable might not be asymptotically stable.

For linear systems, uniform asymptotic stability is the same as exponential stability. This is not the case with non-linear systems.

Marginal Stability
Here we will discuss some rules concerning systems that are marginally stable. Because we are discussing eigenvalues and eigenvectors, these theorems only apply to time-invariant systems.

 * 1) A time-invariant system is marginally stable if and only if all the eigenvalues of the system matrix A are zero or have negative real parts, and those with zero real parts are simple roots of the minimal polynomial of A.
 * 2) The equilibrium x = 0 of the state equation is uniformly stable if all eigenvalues of A have non-positive real parts, and there is a complete set of distinct eigenvectors associated with the eigenvalues with zero real parts.
 * 3) The equilibrium x = 0  of the state equation is exponentially stable if and only if all eigenvalues of the system matrix A have negative real parts.

Eigenvalues and Poles
A Linearly Time Invariant (LTI) system is stable (asymptotically stable, see above) if all the eigenvalues of A have negative real parts. Consider the following state equation:

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

We can take the Laplace Transform of both sides of this equation, using initial conditions of x0 = 0:

 * $$sX(s) = AX(s) + BU(s)$$

Subtract AX(s) from both sides:

 * $$sX(s) - AX(s) = BU(s)$$
 * $$(sI - A)X(s) = BU(s)$$

Assuming (sI - A) is nonsingular, we can multiply both sides by the inverse:

 * $$X(s) = (sI - A)^{-1}BU(s)$$

Now, if we remember our formula for finding the matrix inverse from the adjoint matrix:

 * $$A^{-1} = \frac{\operatorname{adj}(A)}{|A|}$$

We can use that definition here:

 * $$X(s) = \frac{\operatorname{adj}(sI - A)BU(s)}{|(sI - A)|}$$

Let's look at the denominator (which we will now call D(s)) more closely. To be stable, the following condition must be true:

 * $$D(s) = |(sI - A)| = 0$$

And if we substitute λ for s, we see that this is actually the characteristic equation of matrix A! This means that the values for s that satisfy the equation (the poles of our transfer function) are precisely the eigenvalues of matrix A. In the S domain, it is required that all the poles of the system be located in the left-half plane, and therefore all the eigenvalues of A must have negative real parts.

Impulse Response Matrix
We can define the Impulse response matrix, G(t, τ) in order to define further tests for stability:

 * $$ G(t, \tau) = \left\{\begin{matrix}C(t)\phi(t, \tau)B(\tau) & \mbox{ if } t \ge \tau \\0 & \mbox{ if } t < \tau\end{matrix}\right.$$

The system is uniformly stable if and only if there exists a finite positive constant L such that for all time t and all initial conditions t0 with $$t \ge t_0$$ the following integral is satisfied:

 * $$\int_0^t \|G(t, \tau)\|d\tau \le L$$

In other words, the above integral must have a finite value, or the system is not uniformly stable.

In the time-invariant case, the impulse response matrix reduces to:

 * $$ G(t) = \left\{\begin{matrix}Ce^{At}B & \mbox{ if } t \ge 0 \\0 & \mbox{ if } t < 0\end{matrix}\right.$$

In a time-invariant system, we can use the impulse response matrix to determine if the system is uniformly BIBO stable by taking a similar integral:

 * $$\int_0^\infty \|G(t)\|dt \le L$$

Where L is a finite constant.

Positive Definiteness
These terms are important, and will be used in further discussions on this topic.

 * f(x) is positive definite if f(x) > 0 for all x.
 * f(x) is positive semi-definite if $$f(x) \ge 0$$ for all x, and f(x) = 0 only if x = 0.
 * f(x) is negative definite if f(x) < 0 for all x.
 * f(x) is negative semi-definite if $$f(x) \le 0$$ for all x, and f(x) = 0 only if x = 0.

A Hermitian matrix X is positive definite if all its principle minors are positive. Also, a matrix X is positive definite if all its eigenvalues have positive real parts. These two methods may be used interchangeably.

Positive definiteness is a very important concept. So much so that the Lyapunov stability test depends on it. The other categorizations are not as important, but are included here for completeness.

Lyapunov's Equation
For linear systems, we can use the Lyapunov Equation, below, to determine if a system is stable. We will state the Lyapunov Equation first, and then state the Lyapunov Stability Theorem.

 * $$MA + A^TM = -N$$

Where A is the system matrix, and M and N are p × p square matrices.

Notice that for the Lyapunov Equation to be satisfied, the matrices must be compatible sizes. In fact, matrices A, M, and N must all be square matrices of equal size. Alternatively, we can write:

If the matrix M can be calculated in this manner, the system is asymptotically stable.

title: Control Systems/State-Space Stability


text:
Programmable Logic/VHDL Data Types

This page is going to discuss some of the basic data types of VHDL.

Bit
0 and 1

Boolean
Boolean is another predefined type that has value FALSE and TRUE.

Integer
This integer values varies from -2147483648 to 2147483648.

Real
Real numbers ranging from �1.0E38 to þ1.0E38. Not synthesizable

Character
Single ASCII character or a string of such characters. Not synthesizable.

Physical
Used to inform physical quantities, like time, voltage, etc. Useful in simulations. Not synthesizable

Arrays
Arrays allow many identical data types to be created. These data types are accessed using a number called an index. An example array declaration is as follows:

type tIntegerArray is array ( 7 downto 0 ) of integer;

This declaration will create a new data type that is an array. This array will contain 8 integers with indexes of the numbers 7, 6, 5, ... 1, 0.

Once declared, an array can be used as any data type would: signal sBunchOfInts: tIntegerArray;

A individual element of an array can then be accessed with using : sBunchOfInts(2) <= 4;

Many newer synthesis tools will expand arrays into many signals with the array appended on the end of the signal name as a suffix. This helps organize repetitive VHDL code and allows std_logic_vectors to be used in for generate and for loops in VHDL code. This reduces the lines of code, and helps organize the code and make it more maintainable.

Records
Records allow one to group related data types together. It is analogous to a "struct" in C programming. Although records do not add any additional functionality to a module, they do assist in organizing code and making it more maintainable. Here is an example declaration of a record:

type rStatus is record read_failure: std_logic; write_failure: std_logic; failure_count: std_logic_vector( 7 downto 0 ); end record;

Once the record is declared, a port, signal, or variable can then be declared using the record as a type:

decoder_status : in rStatus;

signal sStatus:     rStatus; signal sStatus_next: rStatus;

variable vStatus: rStatus;

The record type can then be accessed using the ".": sStatus_next.failure_count <= sStatus.failure_count + x"01";

Although they used to be limited to test benches and other simulation only VHDL modules, many of the newer synthesis tools will correctly expand record types out into their individual parts. This allows the organizational and maintainability benefits of record types to be used in RTL and other synthesizable code.

ieee.std_logic_1164
The ieee.std_logic_1164 library was created to give a standard representation of digital circuit logic values. It defines the type std_logic and the various manipulations of std_logic (and, or, not, etc...). When writing VHDL for a synthesizable circuit, this is usually a required library.

ieee.numeric_std
ieee.numeric_std defines signed and unsigned types with their arithmetic. It is based on std_logic_vector, so it differs from integer.

ieee.std_logic_arith
this is not a standard library, despite being in the "ieee" library. Always use numeric_std instead.

More details here

title: Programmable Logic/VHDL Data Types


text:
Programmable Logic/VHDL Operators

 * < Programmable Logic/VHDL

This page is going to discuss VHDL Operators.

Some abbreviations used in this text:
 * int - integer, a data type
 * sl - std_logic, a data type (in most cases replacable with bit)
 * slv - std_logic_vector, a data type (in most cases replacable with bit_vector)
 * slu - std_logic_unsigned - a part of library ieee.
 * sls - std_logic_signed - a part of library ieee.
 * iff - "if and only if"

Logical Operators
This list is far from complete.

Sign Operators
Sign operators are unary operators, i.e. have only one, right operand, which must be of a numeric type. The result of the expression evaluation is of the same type as the operand. There are two sign operators (Table 12).

Table 12 : Sign operators :

When ( + ) sign operator is used, the operand is returned unchanged, but In case of ( - ) sign operator the value of operand with the negated sign is returned. Because of the lower priority, the sign operator in the expression cannot be directly preceded by the multiplication operator, the exponentiation operator (**) or the abs and not operators. When these operators are used then sign operator and its operand should be enclosed in parentheses (Example 7).

Multiplying Operators
The multiplication and division operators are predefined for all integers, floating point numbers. Under certain conditions, they may be used for operations on physical type objects as well. The mod and rem operators, on the other hand, are defined only for the integers. When mod and rem operators are used, then both the operands and the result are of the same integer type. The multiplying operators are shown in the Table 13.

Table 13. Multiplying operators

Miscellaneous operators
The two miscellaneous operators are shown in the Table 14.

Table 14. Miscellaneous operators The abs operator has only one operand. It allows defining the operand's absolute value. The result is of the same type as the operand. The exponentiation operator has two operands. This operator is defined for any integer or floating point number. The right operand (exponent) must be of integer type. When the exponent is the positive integer, then the left operand is repeatedly multiplied by itself. When the exponent is the negative number, then the result is a reverse of exponentiation with the exponent equal to the absolute value of the right operand (Example 9). If the exponent is equal to 0 the result will be 1.

Example 1
The multiplication y*x is carried out first, then a is added to the result of multiplication. This is because the multiplication operator has higher level of priority than the adding operator.

Example 2
For the initial value of the variables We1, We2, We3 equal to '1', the result is assigned to the variable Wy and is equal to '0'.

Example 7
The same expressions without parentheses would be illegal.

Important Notes

 * All predefined operators for standard types are declared in the package STANDARD.
 * The operator not is classified as a miscellaneous operator only for the purpose of defining precedence. Otherwise, it is classified as a logical operator.

title: Programmable Logic/VHDL Operators


text:
Programmable Logic/VHDL Module Structure

Module Structure Overview
There are two methods of creating a model: top-down and bottom-up. A model can also be defined to varying levels of detail.

Being a modeling language, VHDL supplies a rich variety of constructs to fit the various methods and level of details used in modeling. Amongst these are: Entities, Architectures, Packages, and Libraries.

Signals
Here signals are used for propagating the data through the different stages of the implementation. Sometimes these signals are used to instantiation of the components which we are using in our design. These behave like a road map for propagating the data.

Syntax
variable variable_name : type; variable variable_name : type := initial_value;

Rules and Examples
A variable may be given an explicit initial value when it is declared. If a variable is not given an explicit value, its default value will be the leftmost value of its declared type.

Variables within subprograms (functions and procedures) are initialised each time the subprogram is called:

Variables in processes, except for "FOR LOOP" variables, receive their initial values at the start of the simulation time (time = 0 ns)

Generics
SFC

Entity
An entity is used to describe the interface of the VHDL module to other modules. All signals entering or exiting a vhdl module must be declared in the entity declaration. An example of an entity describing the interface for a two input AND gate can be found below:

Inside the entity a port declaration can be found. There are the following kinds of ports:

Architecture
An architecture in VHDL describes how functionality of the module is implemented. Below is the architecture for a two input and gate:

Types of Architecture Implementation
An architecture can be implemented in different ways depending on its purpose.

Structural
A structural implementation connects and instantiates other modules. It serves to organize and connect modules together. A strict structural implementation contains only other instantiated blocks wired together using port maps.

Behavioral
A behavioral implementation describes how a modules should function using the full array of VHDL constructs available. Behaviorally designed modules are not necessarily synthesizable, but are useful for modeling and testing synthesizable modules.

Register Transfer
A register transfer implementation describes the functionality of a module in terms of registers and the transformation of the data that flows between the registers. Register transfer implementations are commonly used to describe modules that are to be synthesized on actual devices.

Package
A VHDL package is used to contain a group of reusable data types, functions, procedures, and other VHDL constructs. The basic syntax for a package is as follows:

The package header is for the declaration of VHDL constructs. The package body is for their implementation. Not all constructs (such as data types) need an entry in the body. The body is commonly used for function and procedure implementation.

Libraries
A library establishes a namespace for the modules to exist in. When compiled by a simulator or synthesis tool, every package and entity is compiled into a library. There is no way for a VHDL file to specify which library it is compiled into. This is determined by the tool used to compile the VHDL code. The default library that tools compile VHDL objects into is called work. This means the following statement is assumed when creating VHDL models:

VHDL models can use the library keyword to make libraries visible to a module and use objects from them. This is needed to include packages from other libraries and to directly instantiate entities from other libraries.

The library keyword makes a library visible to a VHDL design. After the library is made visible, packages inside the library can be used. The next line states to make everything declared in the ieee.std_logic_1164 namespace declared in the current namespace. For example, this allows us to use the statement: instead of

Instantiation of a VHDL Module
There are two ways a VHDL modules can be instantiated. The original way, specified in VHDL '87, uses a component, port map, and corresponding entity declaration. The newer way, specified in VHDL '93, uses just the port map and corresponding entity declaration. Each one is useful under certain circumstances. For each method the following entity will be instantiated:

Without Components
Not using a component shortens the syntax quite a bit. To instantiate D_FF above, the following code is used:

As long as the tools used support this syntax, not using a component is recommended because it improves code maintainability. When signals are added/removed and removed from entities, they only need to be added or removed from the entity declaration and the port map. Components are useful when what is being instantiated does not have a VHDL module. When instantiating Verilog designs in VHDL or using IP cores, this is sometimes necessary. This allows the VHDL compiler to create a "black box" when compiling the VHDL and connect the actual model to the black box later.


text:
Programmable Logic/VHDL Procedures

procedure
empty

title: Programmable Logic/VHDL Procedures


text:
Programmable Logic/Verilog Tasks

"task"
A task is enabled from a statement that defines the argument values to be passed to the task and the variables that will receive the results. Control is passed back to the enabling process after the task has completed. Thus, if a task has timing controls inside it, then the time of enabling can be different from the time at which control is returned. A task can enable other tasks, which in turn can enable still other tasks—with no limit on the number of tasks enabled. Regardless of how many tasks have been enabled, control does not return until all enabled tasks have completed.

Using Tasks
[Task_name]([variable list]);

Calling Tasks
Defining a T ask The following is the syntax for defining tasks: Syntax 9-1: Syntax for Task and function declarations specify the following: local variables I/O ports registers times integers real events These declarations all have the same syntax as for the corresponding declarations in a module definition. If there is more than one output, input, and inout port declared in a task these must be enclosed within a block.
 * = task  ;

*  endtask
 * =

 * =

 * =
 * =
 * =
 * =
 * =
 * =
 * =
 * =

title: Programmable Logic/Verilog Tasks


text: Programmable Logic/Data-Flow Descriptions


text: Programmable Logic/Behavioral Descriptions


text: Programmable Logic/Structural Descriptions


text: Programmable Logic/Switch-Level Descriptions


text:
Template:Systems Theory/Page

 Systems Theory

title: Template:Systems Theory/Page


text:
Talk:Systems Theory

Page Header Template
I've created the following template for use as a general page-header in the Systems Theory book:

 * Template:Systems Theory Page

--Whiteknight (talk) (projects) 18:12, 12 May 2006 (UTC)

System dynamics
The section on system dynamics is a gross over-simplification (and also a misnomer). Please see resources at http://www.albany.edu/cpr/sds/.

 * Thanks for the input! This book is in a very bad state right now, and since I don't know the material whatsoever, I have assumed the role of "caretaker" for this book. The last meaningful edits to this book occured back in February of 2005, and since then, no knowledgable contributors have added content to this book in any way shape or form. I have other projects of my own to work on, and I do not have the time to learn this subject, find new resources, and contribute to this book. However, if you (or somebody you know) is willing to adopt this book and help it along, I would be more then happy to assist you. --Whiteknight (talk) (projects) 13:24, 7 August 2006 (UTC)

title: Talk:Systems Theory


text:
Understanding C++/Optimization

Optimization
Modern compilers generally have settings to automate the most common optimizations during the compiling process, often greatly reducing the number of optimizations that programmers might need to consider. Modern compilers commonly take advantage of knowledge about a specific system and architecture in the optimization process, as well as years of optimization research results, to further improve performance and minimize resource usage. Such optimizations are best left to the compiler since bloat or performance costs could result when done by hand.

When faced with a problem you try to find solutions that solve the problem. Sometimes the solution is straightforward and at other times the possible solutions aren't as straightforward and may require planning and deciding what steps to take. Algorithms are the detailed steps which form the solution to a problem for programmers. Algorithm research continue to find simpler and faster ways to solve problems, reconsider and reduce problems, and divide problems into easier to manage problems. Optimization is very important in algorithmic programming, but not all algorithms may benefit from optimization.

Problems like searching for names in a list or sorting them are solved with algorithms. Sorting algorithms for example, have been developed since the 1950s and new solutions are still being found. The choice of what algorithm to use depends on what is more important time or space. If it is more important that a program be fast than conserve memory usage, often values can be stored ahead of time that will allow for less computation later on. Similarly, an algorithm can use far less space if it is given the time to re-compute all values.

Often, a program can be optimized by simply realizing that it is doing more than it has to. As there are many ways of solving problems, one solution may work but be grossly inefficient when compared with other methods, as was the case with the first sorting algorithm, the bubble sort. Problems that involve searching through lists or binary trees may be exponentially slower than they need to be if a naive approach is used. If a part of the program is too slow to perform reliably, researching the problem at hand for a faster method may be worthwhile.

Redundancies
Redundancies can increase the size and time needed to solve problems. Modern compilers can usually eliminate some redundancies, such as, variables, functions, values and statements never used and constant variables, values and computational results. However, the complexity of algorithms can reduce the effectiveness of eliminating redundancies by the optimization process of compilers.

 * Example of redundancies

Common strategy for programmers to decrease or eliminate redundancies:
 * when creating small functions assume a valid state.
 * limit validating tests to events outside your control such as user input, computer resources and external functions.

Code reuse
Optimization is also reflected on the effectiveness of a code. If you can use an already existing code base/framework that a considerable number of programmers have access to, you can expect it to be less buggy and optimized to solve your particular need.

Some of these code repositories are available to C++ programmers as libraries. Be careful to consider dependencies and check how implementation is done: if used without considerations this can also lead to code bloat and increased memory footprint, as well as decrease the portability of the code. We will take a close look at some of them in the Standard Libraries section of the book.

title: Understanding C++/Optimization


text:
Talk:Statics/Quizzes and Tests (contents)

For quizes and tests with answers, the page provides a link to a page that requires a username and password to gain access. We should develop some quizes that are a part of the Wikibooks document itself.


text:
WebObjects/Web Applications/Deployment/ModRewrite

Some clients prefer to have human readable URLs for their WebObjects applications. There are a number of emails on the mailing lists that give specific rewrite rules for WebObjects applications, which I will dig up and add later. In the meantime, here is another approach by the folks at Jewelry Luv:

Jewelry Luv ModRewriteWOHyperlink article


text:
Template:Blender 3D: HotKeys/3D View/Multiple Modes/CTRL-SHIFT-AKEY

CTRL+SHIFT+AKEY - prompts to convert dupliverted objects to real objects.


text:
User:Geekygator~enwikibooks

Hi. Im geek.

Wikipedia: Geekygator

title: User:Geekygator~enwikibooks


text:
OpenCanvas

OpenCanvas is a dedicated 2D drawing and painting program by Portal Graphics, which is a subsidiary of System Products. The program features a simple tool set that is well suited for quick sketches via a tablet such as those made using a Wacom tablet. Also note that there are multiple versions of this program, and some of the older ones are freely available. Features and tools available in each are listed below. Also note that tools and features that carry over from previous versions do not need to be described in detail.

OpenCanvas 1.1
This is the version that can be found on the public domain. Be careful and make sure that you go to a reputable source if you download this version. There are a few miscreants out there who have used this application as a carrier to spread viruses and trojans. It's a good program, but make sure you get a clean copy that will not ruin your experience. The program has a good set of features including layers, event recording, networked drawing, and simple yet robust drawing tools. Also be aware that the translation to English from Japanese is incomplete for this old unsupported version, so that some notices or errors will not display correctly. Don't let this annoyance keep you from using it though, as it is pretty easy to figure out. Also sometimes this program defaults to Japanese, to get English menus go to the rightmost selection (Help) on the program title bar.

Toolbox
This features a basic set of tools. They will be listed left-to-right from top-to-bottom.
 * Drawing mode: Allows you to draw on the canvas. For more details see brush window.
 * Move current layer: Allows you to drag the current layer around the canvas. Be cautious with this, as dragging any part of a layer off the canvas erases it.
 * Color picker: makes any color from the canvas the current active color. This is the same as right clicking the canvas while in brush mode.
 * Draw line: Draw a simple two point line.
 * Create solid box: Create a box with current active color.
 * Erase solid box: Erases current layer by drawing a box.
 * Create filled polygon: Creates a polygon with active color. Double-clicking finishes drawing.
 * Erase via polygon: Works like the filled polygon, but erases current layer instead.
 * Move around canvas: Allows you to navigate around the canvas. Same as holding the space bar and left-click dragging while in drawing mode.
 * Rotate the canvas: This feature allows you to rotate the canvas without actually affecting the image. It is very useful when the artist has to draw long lines as the artist can rotate the canvas so that it is easier to follow his or her natural drawing arch.
 * Zoom in: Zooms in further into the picture.
 * Zoom out: Zooms out of the picture.

Layers
This feature allows you to work on multiple layers. This version has three types of layers: multiply, add, and subtract. The layers window features toggles for visibility, type, and transparency.

Layer Types:
 * Multiply: This is the default layer mode. The colors of this layer are multiplied with any of those below. It is similar to the CMYK color model.
 * Add: This layer mode adds to that below it. In this case lighter colors have more prominence as opposed to multiply. Using black on an add layer is akin to erasing.
 * Subtract: This mode subtracts from that below. Note that darker colors have a weaker effect, and lighter colors are subtracted more. Like the add layer, using full black is similar to erasing from this layer.

Color Palette
The window for the color palette has 4 active areas on it, 3 of which can be selected by the user.
 * Color preset: (left side) Various boxes for color presets. Left clicking uses the preset. Right clicking stores the current color in the preset.
 * Current color: (left bottom corner) This just shows the current color in use.
 * Color gradient: (middle) This is a color gradient of all shades and tints for the current hue.
 * Hue slider: (right) This is a slider that allows you to chose the hue of the desired color.

Brush
The brush window provides a variety of controls that influence the behavior of the brush. It is mainly intended to be used with the drawing tool, but it can also be used to set width when drawing lines. This window features two sets of tabs, one going down the left side for the drawing mode and another set of tabs going across for presets. Note that each drawing mode has its own set of presets.

Drawing modes: Presets: The five tabs across the top are used to store presets consisting of various settings for each particular drawing mode. The floppy disk icon in the upper far right of the brush window is used to save presets. When starting out, all presets are set to the program default for each drawing mode. Also note that once set, the presets are stored even after quitting the program.
 * Pencil/Pen: This mode makes the brush act like a pencil or pen. Which one it acts like is dependent on how the control settings are set. The default setting is akin to a thin-line pencil.
 * Watercolor: This mode makes the brush behave like a "watercolor" brush, this is good for blending colors. This mode has 3 adjustments that control it's blending and color behavior.
 * Blur mode: This one allows for blurring. If you click and hold, there's a second blur mode. Both seem to be rather weak in regards to the effect produced.
 * Eraser: This is used to erase from the current working layer. It too can be modified by setting the controls.

Controls/adjusters: Each one of these has a particular effect on how the brush behaves for a given drawing mode. They also enhance how a brush responds to a given input via the tablet.
 * Brush size indicator: A big square box that shows the brush size relative to a given zoom level.
 * Toggles: To the right of the size indicator, and below the save preset button.
 * Enable/disable size: controls whether stylus pressure effects size.
 * Enable/disable transparency: controls whether stylus pressure effects transparency. Turning this off makes strokes behave like a pen/marker. Turning it on makes it behave like a pencil.
 * Enable/disable edge smooth: Available for watercolor & eraser only. Produces a smooth blended transition along the edge of the brushstroke.
 * Watercolor adjusters: These are below the toggles. They affect watercolor behavior only. Nor do they store with the other presets.
 * Effect:
 * Env Effect:
 * Penetrate:
 * Minimum size: Sets the minimum size for a given brush. This is a percentage of the brush width.
 * Brush width: Sets the size in pixels. This is the with used if size toggle is disabled. Using a large brush width with a small minimum size can be used to create dynamic and expressive strokes.
 * Pressure correct: This controls how sensitive a given brush is for a given stylus input. The default is a flat diagonal line, but it can be set to a bias (curve) that alters sensitivity. X (horizontal) is stylus pressure, and Y (vertical) is effect strength.

Preview Window
This window works akin to the navigator window in PhotoShop. It shows the area being viewed in relation to the whole available canvas. You can also drag the selection box inside it around to quickly navigate the entire canvas.

Session Recording
This program by its very nature records the process of every drawing. The normal "session" mode that it saves under (.wps) doesn't show this. However, you can share your drawing technique by exporting an "event" file. This will save as a .wpe. If a .wpe is opened with OpenCanvas, it will replay all the actions used to produce a given drawing/painting. There is also a setting in the show pulldown called "event playint with weight". Weighted playback shows the strokes being made at their normal speed. Default playback gives each stroke the same amount of time, a bit like fast forwarding through a drawing session.

Networking
This is a neat feature that lets you share a canvas with up to 3 other people online in real-time (or close to it, depending on connection speed). Thus you can collaborate or "duel" with your artwork. Some folks consider this the greatest feature of this program, but other drawbacks or lack of interest caused it to be removed from later versions. Clicking on the "Show networking window" pulldown actually brings up two windows.

 * Chat window: The chat window allows you to communicate with other session participants in real time. For the most part, it works similar to an IRC chat. Note that typing a single character in the chat may close a networking session. (seems to be a bug)
 * Networking window: This window has three tabs that configure a networking session.
 * Server tab: Set your name, and server password. If you're hosting this is where you go to start. (standby)
 * Client tab: You can also set your name here, but now you can direct the computer to what IP you wish to join if someone else is hosting. If they set a password on their server, it's also where you enter it. If you're joining someone who has the port other than default, type it in after the IP like this: xxx.x.x.x:#### (x's are IP, & #'s are port number)
 * Network Preference tab: This is where the canvas size and number of available layers is set for a networked session. This also sets the number of users (including the host) from 1-4 for a given session. You can also set the port from here. (The default is 9001)

There is also a nifty Java based network client called Warpaint that makes it possible to host or join a networked session via a server list. It also includes a safe copy of OpenCanvas 1.1. By using Warpaint you can find and join a session by simply using your web browser. Note that it also uses the default port of 9001 unless specified otherwise, if you have problems you may need to change the port used or adjust settings on your router and/or firewall.
 * note-as of June 5th, 2006, the Warpaint server has been down due to lack of project development. There are individuals trying to get a server up and running currently, check back often for updates.
 * note- on February the 21st, 2007, the Warpaint server list went online again.

title: OpenCanvas


text:
A-level English/Wise Children/Plot Summary

Chapter 1
We are introduced to Dora (the narrator) and Nora (her twin sister). It becomes clear that Dora is writing her memoirs, and that this story is based on them. We learn about their famous Shakespearean actor of a father, Melchior Hazard, and that they are his illegitimate children. Melchior has for years disregarded Dora and Nora, claiming that they are his twin brother Perry's children. We learn that Melchior slept with the chamber maid "Pretty Kitty" during the first world war. Kitty then died giving birth to Dora and Nora whilst the "zeppelins were falling". Her landlady "Grandma" Chance took the children in as her own (there is some debate as to whether she is in actual fact the mother and Kitty was just a fabrication).

We learn of Ranulph and Estella Hazard (Dora and Nora's Grandparents), and how Estella has an affair with Cassius Booth. Ranulph, ultimately, murders Cassius, Estella and then himself. Melchior and Perry then departed on their separate lives. Melchior came to England and lived with an elderly relative before running away. Perry remained a wanderer - both hold rivalries between each other.

We then get the drama of the chapter. Tristram (son of Melchior by his third marriage) arrives and tells Dora and Nora that his girlfriend, Tiffany (Dora and Nora's godchild) has gone missing after she appeared on his trashy television show "Lashings of Lolly" in a delusional state. Her delirium was due to the fact that she was pregnant with Tristram's child, but he was unwilling to commit to her. A body is later found in a river, and the police believe it to be Tiffany.

Chapter 2
This chapter begins with Dora and Nora's seventh birthday, Grandma chance takes them to the theatre to see a "nayce musical comedy". This begins Nora and Dora's infatuation with low brow entertainment/culture. The show leaves the girls with "stars in their eyes" and they decide there and then that it will be the "damascus road" for the both of them. While at the theatre, Grandma spots Melchior, the girls biological father and points him out to the twins. The girls immediately form a crush on Melchior Hazard and thus begins their inappropriate and unconventional relationship with their father.

After the theatre, the girls return home to find a package from their uncle Perry. Inside is a present - a toy theatre that the girls learn to "treasure". The next important scene is set in Brighton, where Perry brings the girls for a family day out. This is a strange scene as it brings Perry's character into question. There is a hint that he may have had a sexual relationship with Dora ("I thought, I must have had it off with Perry"). This is a disturbing thought as not only is Dora just thirteen, but Perry is also her uncle. During the trip, the girls take a stop off at a seedy back theatre and they are introduced to Gorgeous George. Carter satirises the British public's view on empire through George, and the whole idea of low culture and bawdy humour is expressed through him (for instance, "he had a face as long as a..."). The tattoo on his chest is symbolic of the British Empire and its growth at the time (to be made ironic later on). After the show, the girls are walking with Perry when they see posters of Melchior acting in a show nearby. Their eyes swell up with tears and Perry eventually brings them into their father's dressing room. It is in this scene that the girls' fascination with Melchior becomes apparent ("i did piss myself when i saw him..."). This unexpected reaction shows how unconventional their relationship is and highlights the theme of female prevalence through the absence of father throughout the novel. Melchior completely disregards the girls and through this the girls fabricate fake memories in order to deal with the heartache of this rejection. The memory is of Peregrine lifting both girls up and performing "[a] back-flip out of the window". This is an example of magical realism that is evident throughout Carter's novel but also reminds the reader that the narrative is not all strictly true due to Dora's memory age.

The rest of the chapter is based around the girls growing up and coming of age ("We knew we were shedding our childhoods along with those ringlets, and we were pleased as punch"). Peregrine loses his money in the Wall Street Crash of 1929 and the girls are forced to earn their money by dancing in the music halls. As the girls age they become interested in the facts of life, Nora especially wants to find out about all of life's "dirty little secrets". She loses her virginity to the goose from her play in an alley. The girls eventually change their physical appearances and dye their hair black. "it looked like bath night at the minstrel show". This is an example of "carnivalesque" language. On Dora and Nora's 17th birthday, Dora asks Nora for her "fella for a birthday present". This is a good example of doubles as the twins swap identities in order to share the boy. For their birthday, Melchior acknowledges the girls and gives them a "special present" which was to star in his Shakespearian play. Dora even dances with her father on this night which is odd as they have never had a proper father-daughter relationship.

This leads on to the next important aspect of chapter two, the Lynde house party for the Shakespearian play. This continues the previous idea of mistaken identities as Nora's boyfriend still mistakes Dora for Nora. He is doubling as a waiter which also adds to the theme of doubles in the chapter. The two get re-acquainted and slip upstairs to have sex for the second time while Nora flirts with an American film producer (no formal name is given but he is referred to as Genghis Khan throughout the book). Genghis Khan leaves his cigar on the table in order to dance with Nora, causing the tablecloth to catch fire. With no waiter to notice the fire, the house sets alight and everyone is forced to run outside. Dora and the boy escape from the window, naked, and continue to have sex even while the house burns down around them. This is another example of carnival, as it incorporates many of the main themes such as the celebration of the body and also chaotic situations. The idea of the pretentious upper class is satirised here also as the high cultured people in question are pictured engaging in inappropriate sexual acts.

The end of this chapter depicts Melchior mourning the loss of a paper crown (once owned by his famous father Ranulph, made by Estella his mother), "a flimsy bit of make believe" instead of all the valuables that were burnt down, however Perry saves both Nora and the paper crown from the burning wreck. It is suggested here by Carter that Perry slept with Nora on this night because was it just by chance that she was with him barely dressed? The theme of Carnivalesque is also continued here as the chaos and celebration of body parts is continued.

Chapter 3
Chapter 3 describes the filming of 'A Midsummer Night's Dream'. This chapter is a very outrageous and chaotic chapter, just like the middle of a Shakespeare play. Melchior falls in love with Genghis Khan's wife, Delia Delaney aka Daisy Duck, a very flirtatious woman- whom at the beginning of the chapter was flirting with Perry. Genghis Khan is outraged by this and decides that he wants Nora to have his child but she is in love with Tony, a young Italian, and so he gets Dora to marry Genghis in her place. There is to be a triple wedding; Nora to Tony, Dora to Genghis and Melchior to Daisy Duck. This triple wedding is again an allusion to Shakespeare as in some Shakespeare plays there are prominent triple weddings. Genghis' ex-wife, who has been stalking Genghis for quite some time, turns up having had a face lift to look like Dora because she is desperate to re-marry Genghis and will do anything to please Genghis - even change her appearance and this shows she is a woman who has bowed to the patriarchal society. She marries Genghis instead of Dora, who hides at the wedding by wearing a big Donkey mask from Bottom in 'A Midsummer Night's Dream'. Tony's mother decided that Nora is not good enough for her son and so she empties a huge vat of marinara sauce onto Nora and this marriage is called off. Although Dora does not dwell on this, later in the book we see that Nora is perhaps more upset by this than you may first imagine. The Dream ends and the girls return home with Grandma Chance who arrives to rescue them.

We are also introduced properly to Irish, another of Dora's lovers, and, perhaps the one that she values most. Irish, a writer/playwright holds much similarity to Oscar Wilde. Irish seems to value Dora more than she does him as she is also sleeping with her German teacher at this time. Irish is an alcoholic. Dora seems to use Irish for an education she has never really properly had.

Chapter 4
Chapter 4 describes Dora and Nora alone after the death of Grandma Chance and how Grandma Chance was their "shelter and breast." This is also when Perry comes to Saskia's and Imogen's birthday baring gifts from his travels, two new types of butterflies he named after them, which the two sisters hate. Also Melchoir announces he is going to marry Saskia's friend Cordelia (a reference to King Lear, Shakespeare). The two sisters then throw a massive strop and smash plates at trees and destroy the so called party. Melchoir slaps Saskia and says he will no longer give them any pocket money. Poor old Perry is left heart broken because he has been totally rejected, and has his presents thrown back at him. This again is where Perry vanishes on one of his own quests.

It is later that night that Lady Atalanta is found at the bottom of the staircase of her home, followed by Saskia's and Imogen's sudden departure, having made their mother sign off the home and the last of her money to them. It is never told whether Lady Atalanta fell or was pushed, yet the end result is her being in a wheelchair and living with Dora and Nora in the basement room of 49 Bard Road.

Chapter 5
Dora, Nora and the Lady Atlanta depart to their father, Melchior's, 100th birthday party. Along the way, Dora meets Gorgeous George from Chapter 2, except he's now an old homeless tramp begging for money off the rich party-goers. Dora gives him £20 (a note with the face of Shakespeare on the reverse) and tells him to spend it all on booze.

At the party, Melchior finally acknowledges them as his children, but Dora and Nora are unsure of his sincerity as there are cameras and news crews everywhere - but they take Melchior's apologies with great pleasure and they both melt into the child versions of themselves whereby they saw great admiration and love toward this mysterious man.

A few things become apparent and some characters unexpectedly arrive with extravagant, carnivalesque entrances. Daisy Duck is the first, entering with a battalion of trumpet players and Gambian dancers (with Puck). Saskia's cake is then brought in. Before Melchior can cut the cake, there is a knocking at the door. Perry arrives in a magical, mystical way - not forgetting that he is presumed dead - and is described as "larger the life" in both persona and fat ("...was as large as a warehouse..."). Perry then releases butterflies, a butterfly for every person at the party, and produces a long box. Opening it, the lovely Tiffany steps out. She too is presumed dead (from chapter one), so her appearance strikes tears. Tristram begs for Tiffany to give him a second chance, but Tiffany completely disregards him, much to Dora and Nora's pleasure.

It is then discovered that Saskia, who baked the cake, had slipped poison into it - to try and murder her father as she tried to murder Lady Atalanta. Truths are shared relating to Saskia, Melchior and Lady A (in her speech)- whose presence is exemplified by Perry.

This is when Dora and Perry run off to the master bedroom and have sex, where Dora fantasises about "bringing the house down". Dora questions him, asking if he is her father. Perry replies, no - but he believes that Dora's mother isn't who Grandma said she was... The point of incest here is toned down, and also the desperation of the pair is denied, and the entire affair is seen as an act of equal compassion. The themes of Magic Realism and Carnivalesque are continued here as how many centenarians and 75 year olds have sex?

With this done, they find the Cardboard crown and present it to Melchior (as it had been discovered that Melchior has been feeling useless in his age) and Melchior sees this as a peace offering. Perry then gives Dora and Nora two twin 'babies' (which are described as similar to kittens) from his coat pocket, stating that they belong to Gareth (Tristram's twin) who had been in South America.

For once, there is a truce between the Hazards and the Chances, representing a truce between legitimacy and illegitimacy. Dora and Nora walk back to their houses with the two babies, and break into song and dance in the middle of the street.

The novel ends with the important motif, "What a joy it is to dance and sing!"


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Template:Blender 3D: HotKeys/3D View/Multiple Modes/.KEY

 * .KEY (on the alphanumeric pad) - changes the pivot point to the 3D cursor. The pivot point is the point where all things meet when scaled to 0, and the point of 0 translation during a rotation transformation. See the menu on the 3D view header, located immediately to the right of the Viewport Shading menu.
 * CTRL+.KEY - changes the pivot point to individual origins.
 * ALT+.KEY - changes the pivot point to active element.


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Template:Blender 3D: HotKeys/Multiple Windows/Multiple Modes/,KEY

 * ,KEY - changes the pivot point to the bounding box center.
 * CTRL+,KEY - changes the pivot point to median point.
 * ALT+,KEY - toggles manipulation of centre points (object and pose mode only).


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Talk:OpenCanvas

A bit of info explaining the nice drawing/painting app called OpenCanvas. I put what I know of the old public domain (afaik) version (1.1). It gives a nice text overview explaining the program. Feel free to revise, add pictures, and info on later versions. Pauljs75 21:38, 12 May 2006 (UTC)

title: Talk:OpenCanvas


text:
Blender 3D: HotKeys/Key/PeriodKey

The Period Key

title: Blender 3D: HotKeys/Key/PeriodKey


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Blender 3D: HotKeys/Key/CommaKey

The Comma Key

title: Blender 3D: HotKeys/Key/CommaKey


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User talk:74.131.204.115

Sorry for block, it was my mistake. --Derbeth talk 23:12, 12 May 2006 (UTC)

title: User talk:74.131.204.115


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Template:German/Level II/Header

! align="center" |  Lessons ! align="center" | Level II
 * [[File:00%.svg]] 2.00 Introduction
 * align="center" | S2.01 ~ Salzburg, Austria
 * [[Image:50%.svg]] 2.01 Ernährung (T·TA)
 * [[File:00%.svg]] 2.02 Tiere (T·TA)
 * [[File:00%.svg]] 2.03 Kommunikation (T·TA)
 * [[File:00%.svg]] Wiederholung 2.01
 * align="center" | S2.02 ~ Zürich, Switzerland
 * [[File:00%.svg]] 2.04 Kultur (T·TA)
 * [[File:00%.svg]] 2.05 Nein (T·TA)
 * [[File:00%.svg]] 2.06 Gesundheit (T·TA)
 * [[File:00%.svg]] Wiederholung 2.02
 * align="center" | S2.03 ~ Hannover, Germany
 * [[File:00%.svg]] 2.07 Die Welt (T·TA)
 * [[File:00%.svg]] 2.08 Ein Reise (T·TA)
 * [[File:00%.svg]] 2.09 Kunst (T·TA)
 * [[File:00%.svg]] Wiederholung 2.03
 * align="center" | S2.04 ~ Dresden, Germany
 * [[File:00%.svg]] 2.10 Schule (T·TA)
 * [[File:00%.svg]] 2.11 Bewölkt, Stürmisch, Gefährlich (T·TA)
 * [[File:00%.svg]] 2.12 Naturwissenschaft (T·TA)
 * [[File:00%.svg]] Wiederholung 2.04
 * align="center" | talk : page • level two
 * align="center" | edit : page • template
 * }
 * [[File:00%.svg]] 2.07 Die Welt (T·TA)
 * [[File:00%.svg]] 2.08 Ein Reise (T·TA)
 * [[File:00%.svg]] 2.09 Kunst (T·TA)
 * [[File:00%.svg]] Wiederholung 2.03
 * align="center" | S2.04 ~ Dresden, Germany
 * [[File:00%.svg]] 2.10 Schule (T·TA)
 * [[File:00%.svg]] 2.11 Bewölkt, Stürmisch, Gefährlich (T·TA)
 * [[File:00%.svg]] 2.12 Naturwissenschaft (T·TA)
 * [[File:00%.svg]] Wiederholung 2.04
 * align="center" | talk : page • level two
 * align="center" | edit : page • template
 * }
 * [[File:00%.svg]] 2.11 Bewölkt, Stürmisch, Gefährlich (T·TA)
 * [[File:00%.svg]] 2.12 Naturwissenschaft (T·TA)
 * [[File:00%.svg]] Wiederholung 2.04
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Template:German/Level II/Footer

II.0 Introduction Section II.A: II.1 Einfache Gespräche • II.2 Fremde und Freunde II.3 Die Zahlen • II.4 Zürich • II.5 Wiederholung Section II.B: II.6 Die Wohnung • II.7 Mathematik • II.8 Mein, Dein, Sein • II.9 Einkaufen gehen • II.10 Wiederholung Section II.C: II.11 Verbtempus und Wortstellung • II.12 Fragewörter • II.13 Mein Arm schmerzt • II.14 Tiergarten • II.15 Wiederholung
 * align="left"|
 * align="center" | [[Image:50%.svg]] Level II Lessons
 * align="right"| (discussion)
 * align="left" colspan=3|
 * align="left" colspan=3|
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 * align="left" colspan=3|
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 * }

title: Template:German/Level II/Footer


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Cookbook:Potage Parmentier

| Cuisine of France | Soup

There are few things more versatile or more satisfying than potage parmentier (leek and potato soup) or one of its myriad variations. It’s good freshly-made and better the next day. Hot or cold, it makes a lovely start to dinner; served with some left-over meat, a great lunch. It's a great mid-afternoon pick-me-up, either straight out of the fridge or zapped in the microwave.

As delicious as is basic leek-and-potato soup, you can also include other vegetables or herbs, such as broccoli stems, asparagus stalks, a large handful of parsley or cress, etc—the variations are endless. This is one of the classic ways the French utilize left-over or less-than-perfect vegetables bought cheap from the market, a principle of both taste and economy that all would do well to adopt.

You shouldn't be a stickler about using leeks, either—while they have a more subtle flavor than onions, they can be expensive and/or difficult to source out of season. Feel free to use regular onions (the milder yellow/Spanish varieties are best) or use a couple of bunches of scallions (spring onions). The only rub comes when it’s time to purée the soup. While it can be done in a blender, it’s much better to use a food mill. Blenders tend to make the potato starches glue-like and pulverize the woody parts of the other vegetables. The food mill doesn’t change the texture of the potato starch and strains out the vegetable pulp. It takes a little extra muscle, but it’s well worth the effort. Using the chopping blade in a food processor (Cuisinart) will also puree the soup without the potato separating provided the action is pulsed and not overdone, however the mixture should be sieved if woody-cored root vegetables such as turnips or parsnips are used. Some recipes suggest using a potato ricer (masher) which may work quite as well, since the potato and the leeks are very soft; and the result is a nicely textured soup.

This recipe makes two quarts of soup, though it's worthwhile to double or triple it; left-overs easily last 7–10 days in the refrigerator, though you’ll probably eat them long before that time.

Ingredients

 * 3–4 cups (~1 lb / 450 g) sliced leeks or onions
 * 3–4 cups (700–900 g / 2 lb) floury potatoes (e.g. Idaho, Maris Piper), peeled and thickly sliced
 * 2 quarts (2 L) water
 * 2 tbsp table salt or 1 tbsp sea/rock salt
 * White pepper, freshly ground, to taste
 * 4–6 tbsp heavy (double) cream
 * 1–2 cups (up to 450 g / 1 lb) vegetables (optional), thinly sliced
 * 1–2 handfuls flat-leaf parsley or watercress (optional), rough chopped

Procedure

 * 1) If using leeks, remove the roots and dark green leaves; wash twice as long as you think necessary to remove the grit.
 * 2) Place the vegetables, water and salt in a pot and bring to a boil. Lower the heat and gently simmer (partially covered) for 45–50 minutes. The soup is done when you can easily mash the vegetables against the side of the pot.
 * 3) Puree the soup using a food mill fitted with the fine disc. Optionally, pulse it in a blender just until smooth and pass through a fine sieve.
 * 4) Chill the soup if it is to be served cold, or gently reheat it to a simmer. Refrigerate any left-overs. It will keep for days if refrigerated in a covered container as soon as it cools.
 * 5) Add 1½–2 tsp cream (or whole milk) per portion just before serving. You’ll need more cream if you’re serving the soup hot or if it’s a bit watery; the idea is to create a smooth, silky puree, but you don’t want the taste or mouth feel of the cream to predominate. Taste and adjust for salt and pepper.

Notes, tips, and variations

 * After cooking the soup, leave it to cool in the refrigerator for 1–2 hours. It will taste better when heated up to serve!
 * Raw vegetables should be added to the soup at the beginning of the cooking time; if using left-over vegetables or herbs, add them after the soup has been cooking for 30–40 minutes, so they cook just long enough to completely warm through.
 * If using "regular" table salt instead of kosher salt, reduce the amount of salt to 1–1½ tbsp. A chilled soup usually requires slightly more seasoning than that added to a hot serving; this can be added individually to taste.
 * A combination of young buttery parsnips and a couple of punnets of mustard-and-cress makes the classic French puree pasternak. A teaspoon of potato, rice, or corn starch should be used to stabilise the puree, which should be milled or sieved.
 * Using white pepper is preferable for color. Use fresh-ground black pepper otherwise.
 * A proportion of light chicken or vegetable stock may be used instead of the water.
 * Snipped chives are the classic garnish for leek-and-potato soup. When including asparagus, you can use steamed asparagus tips as a garnish; with broccoli, use steamed broccoli florets—you get the idea. Of course, if you’re just pouring a mid-afternoon mug for yourself, who cares how it looks?

title: Cookbook:Potage Parmentier


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Wikibooks talk:Law bookshelf

As of 5/11/06
I reorganized this bookshelf, deleting unused catagories, uniforming the list, etc...

the "European Law" section seems to be operating as a "European Union Law" section, keep in mind these are not necessarily the same thing, as not all european countries are EU member states.

Basejumper123 02:20, 13 May 2006 (UTC)

Criminal Law
The Criminal Law book seems further than 25% complete. I recommend upgrading to 50%.

title: Wikibooks talk:Law bookshelf


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Harmonica/Basic Maintainence and Care

If you actually know your stuff, you will know that a good quality harmonica is gonna cost way more than a few dollars... especially a chromatic, which is $100 or more. Even though most harmonicas have good manufacturing, proper maintenance and preventative measures are still needed. Aside from the cost of repairs, you might have difficulty finding someone skilled enough to repair your harmonica, especially if you are not good at repairing!

 * 1) Always store your harmonica in a case. A hard case would be the best, but even a leather bag that fits the harmonica snugly is good to protect your harmonica from dust. A hard harmonica case also protects your harmonica from any minor impacts. If you need to carry numerous harmonicas, you may want to consider a harmonica briefcase, which usually can store all 12-key diatonic, plus one or two 16-hole chromatic, and maybe your microphone too.
 * A very good homemade case can be made by the Pelican waterproof cases. Note that Microcase usually do not come with the lining.
 * microcase 1040/1050 is good for 12-hole chromatic
 * microcase 1060 is good for 16-hole chromatics

 * 1) Avoid extreme temperatures. While your plastic comb should be somewhat tolerant to temperature, your wood comb definitely isn't; since it's already subjected to swelling and shrinking at room temperature, don't even encourage it more by using those.
 * 2) Avoid dust and other particles. Dust will interfere with the movements of the reed, making it sound weird. Of course, make sure there are no food particles in your mouth either.
 * 3) Avoid excess moisture. Obvious for wood comb (it swell and shrink), but all chromatics are affected, as they have windsavers. Thus, never dunk your harmonica into water/beer/liquid etc. Even if it's a plastic-comb harp with no windsavers, the reedplate, reed, bolt and/or screws may rust.
 * 4) Clear any moisture if possible. Most of the moisture actually comes from your mouth. After playing, shake the harmonica a little bit,, pat it against your palm softly, and wipe it clean with a cloth.
 * 5) Avoid the beach if possible. The salty air can cause the reeds to rust rapidly.

Routine cleaning

 * After playing, shake the harmonica a little bit, pat it against your palm softly, and wipe it clean with a cloth.
 * Once in a while, use alcohol and cotton balls to clean the mouthpiece and cover.

Cleaning the mouthpiece/slide package
Unless we all decided to use Tombo's S-50, the slide package is a blessing and curse at the same time. When it works, it's a blessing, as we can do quick chromatic runs and slide-based effects. when it doesn't... well, no amount of musicianship can save you as your slide move slowly, or even worse, stopped completely!

Thus, we all have to take it apart, from time to time.

Warnings

 * 1) Slide packages ARE made up of a few tiny but crucial pieces. Do it on a flat table with ample lighting.
 * 2) Slide packages are just as fragile if not more fragile than the reed plates. Always prepare your work surface before you do anything.

Tools needed

 * 1) Screwdriver. Preferably a precision version.
 * 2) Microfiber cloth
 * 3) Rubbing Alcohol To clean off any old grime
 * 4) Lubricant The lubricant has a twofold purpose. Obviously, it is supposed to make your slide slide easier, but it also does some sealing, which helps maintain your slide. Franz Chmel recommended paraffin oil, but I personally use Vaseline mainly because it's safer.

title: Harmonica/Basic Maintainence and Care


text:
Orthopaedic Surgery/Distal Radius Fractures

A fracture of the distal radius is the most common fracture referred for orthopedic consultation from the emergency room. While classification systems abound and eponyms linger in common parlance, neither descriptive system really provides suitable common ground for communication as to the particulars of these fractures. Communication typically over the phone or otherwise without the films available for review should at least convey enough information to allow a preliminary decision as to what treatment is required be it a splint and follow-up for a cast within a week, or a prompt reduction either closed or with internal fixation.

Tenting of the skin due to severe deformity, or neurovascular compromise, or an open injury should all warrant prompt attention to at least achieve a provisional reduction and an initial formal irrigation of the fracture site in the case of an open injury if definitive treatment needs to be put off.

The degree of energy imparted to create the fracture may be gleaned in part by the fracture pattern and in part by the mechanism of injury. The likely stability of the fracture with simple closed reduction will be a function of the amount of energy imparted and the baseline strength of the bone, thus a fall in a 60 year old woman may be more likely to collapse after an initial reduction than will a fracture sustained in a fall from a height in a 20 year old. The fracture pattern may be the same in each and the degree of comminution may be the same. The better bone stock of the younger patient may improve the prospect for closed treatment, on the other hand the long term impact of slight residual step off and a stiffer wrist due to prolonged immobilization might tend to favor plating of such a fracture. Thus the decision making is complex and not especially amenable to a well defined protocol or algorithm. It is typical that a secondary procedure will be required in 15% of cases when initial closed management is pursued with the expectation of that being the definitive treatment. Fortunately there is little lost if an initial effort at closed reduction and then early follow-up with radiographs which will be telling of the inherent stability of the reduction. Indeed the feel of the reduction how readily it tends to slip back, how much of a mold or how awkward a wrist position is needed to maintain a reduction will predict its behavior and the patient may be counseled accordingly as to the likely need for secondary surgery once the swelling has subsided. If the fracture seems to require longitudinal traction to maintain reduction without a splint on, then the something close to the initial position in the original unreduced film is the likely outcome with closed treatment. It is not unusual to be surprised however when the follow-up film at one week looks anatomic but if the initial impression is unfavorable it is prudent to see the patient back at three weeks as a loss of reduction may yet occur readily in this time frame. Even beyond that point, late loss of reduction leading to malunion remains a risk with closed management. The occurrence of the nascent malunion treated at 6 weeks after an extended effort at closed management, is a salvagable situation but not ideal, as the patient is already pretty stiff, and their hopes of avoiding surgery are dashed and now surgery is added with a more difficult dissection effectively losing ground on the healing biology as it is necessary to take the fracture down to affect reduction.

Making the correct choice the first time then has its merits, and the ever improving technology for internal fixation of this fracture makes the surgical option more appealing still.

Through the late 80's until the mid 90's external fixation, then augmented external fixation with k wires of even a plate was the typical default treatment when closed management was not suitable. The initial hypothesis of ligamentotaxis alone maintaining a reduction with an external fixator alone proved problematic especially from the standpoint of finger stiffness. Augmented external fixation relies of the ligamentotaxis to achieve reduction but then the distraction is relaxed once k wires were placed retaining the fixator as a neutralization device, and positioning the wrist ideally in slight extension to facilitate rehabilitation of the fingers. Observing a lack of distraction at the midcarpal joint is a good indicator that there is no undue amount of distraction. The placement of k wires percutaneously is risky recognizing that it is indeed feasible to transfix a tendon or nerve with this technique. A nerve pierced may produce a dysfunction long after the fracture is expertly healed. Instead the skin is incised a hemostat is used to spread down to bone, a drill guide is used and the k wire is placed using it as a joy stick to refine the reduction if needed. If feasible leaving the pins cut off below the skin is more comfortable and lessens the risk of pin tract infection, but may require an anesthetic to remove the pins at 6 to 8 weeks. Generally if the pins can be removed at 4 weeks as for a relatively stable fracture, then leaving the pins out works fine. Beyond 4 weeks this approach seems more problematic. When the buried pins are to be removed they should be directly visualized again to avoid inadvertent injury to closely adjacent nerves which may be injured by blindly placed needle drivers seeking out the pin.

Augmented external fixation may yet be the best option in high energy fractures with lots of comminution. Adding a forearm neutral sugar tong splint may avoid difficulties with the distal radio-ulnar joint which can at times be unstable in pronation, especially when the weight of the fixator tends to direct the forearm into pronation. Elbow motion to full extension in such a splint is feasible by cutting a smile out of the back of the sugar tong splint.


text: Template:Learning the vi Editor/Fn

title: Template:Learning the vi Editor/Fn


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Talk:NVIDIA/Introduction

Well done for getting the old gpmf.de content, I was 'richie' on gpmf.de and I wrote most of the TwinView and Stereo pages, have you got a copy of any of the other old gmpf pages, in particular the Stereo one? I cant find any of them in the google cache or on the waybackengine. Rythie 08:40, 13 May 2006 (UTC)

don't worry i've found it now Rythie 09:17, 13 May 2006 (UTC)

title: Talk:NVIDIA/Introduction


text:
User:ComSpex~enwikibooks

ComSpex

title: User:ComSpex~enwikibooks