text:
Signals and Systems/Time Domain Analysis

There are many tools available to analyze a system in the time domain, although many of these tools are very complicated and involved. Nonetheless, these tools are invaluable for use in the study of linear signals and systems, so they will be covered here.

Linear Time-Invariant (LTI) Systems
This page will contain the definition of a LTI system and this will be used to motivate the definition of convolution as the output of a LTI system in the next section. To begin with a system has to be defined and the LTI properties have to be listed. Then, for a given input it can be shown (in this section or the following) that the output of a LTI system is a convolution of the input and the system's impulse response, thus motivating the definition of convolution.

Consider a system for which an input of xi(t) results in an output of yi(t) respectively for i = 1, 2.

Linearity
There are 2 requirements for linearity. A function must satisfy both to be called "linear".

 * 1) Additivity: An input of $$x_3(t) = x_1(t) + x_2(t)$$ results in an output of $$y_3(t) = y_1(t) + y_2(t)$$.
 * 2) Homogeneity: An input of $$ax_1$$ results in an output of $$ay_1$$

Being linear is also known in the literature as "satisfying the principle of superposition". Superposition is a fancy term for saying that the system is additive and homogeneous. The terms linearity and superposition can be used interchangeably, but in this book we will prefer to use the term linearity exclusively.

We can combine the two requirements into a single equation: In a linear system, an input of $$a_1x_1(t)+a_2x_2(t)$$ results in an output of $$a_1y_1(t)+a_2y_2(t)$$.

Additivity
A system is said to be additive if a sum of inputs results in a sum of outputs. To test for additivity, we need to create two arbitrary inputs, x1(t) and x2(t). We then use these inputs to produce two respective outputs:

 * $$y_1(t) = f(x_1(t))$$
 * $$y_2(t) = f(x_2(t))$$

Now, we need to take a sum of inputs, and prove that the system output is a sum of the previous outputs:

 * $$y_1(t) + y_2(t) = f(x_1(t)) + f(x_2(t))$$

If this final relationship is not satisfied for all possible inputs, then the system is not additive.

Homogeneity
Similar to additivity, a system is homogeneous if a scaled input (multiplied by a constant) results in a scaled output. If we have two inputs to a system:

 * $$y_1(t) = f(x_1(t))$$
 * $$y_2(t) = f(x_2(t))$$

Where

 * $$x_1(t) = cx_2(t)$$

Where c is an arbitrary constant. If this is the case then the system is homogeneous if

 * $$y_1(t) = cy_2(t)$$

for any arbitrary c.

Time Invariance
If the input signal x(t) produces an output y(t) then any time shifted input, x(t + δ), results in a time-shifted output y(t + δ).

This property can be satisfied if the transfer function of the system is not a function of time except expressed by the input and output.

Linear Time Invariant (LTI) Systems
The system is linear time-invariant (LTI) if it satisfies both the property of linearity and time-invariance. This book will study LTI systems almost exclusively, because they are the easiest systems to work with, and they are ideal to analyze and design.

Other Function Properties
Besides being linear, or time-invariant, there are a number of other properties that we can identify in a function:

Memory
A system is said to have memory if the output from the system is dependent on past inputs (or future inputs) to the system. A system is called memoryless if the output is only dependent on the current input. Memoryless systems are easier to work with, but systems with memory are more common in digital signal processing applications.

Causality
Causality is a property that is very similar to memory. A system is called causal if it is only dependent on past or current inputs. A system is called non-causal if the output of the system is dependent on future inputs. Most of the practical systems are causal.

Stability
Stability is a very important concept in systems, but it is also one of the hardest function properties to prove. There are several different criteria for system stability, but the most common requirement is that the system must produce a finite output when subjected to a finite input. For instance, if we apply 5 volts to the input terminals of a given circuit, we would like it if the circuit output didn't approach infinity, and the circuit itself didn't melt or explode. This type of stability is often known as "Bounded Input, Bounded Output" stability, or BIBO.

Studying BIBO stability is a relatively complicated course of study, and later books on the Electrical Engineering bookshelf will attempt to cover the topic.

Linear Operators
Mathematical operators that satisfy the property of linearity are known as linear operators. Here are some common linear operators:

 * 1) Derivative
 * 2) Integral
 * 3) Fourier Transform

Impulse Response
Impulse response tells us how a system reacts when we hit it with an impulse signal (also called as dirac delta function). This impulse response is very important term in analyzing the behaviour of systems.

Zero-Input Response

 * $$x(t)=u(t)$$
 * $$h(t)=e^{-x}u(t)$$

Zero-State Response
zero state response means steady state or forced response. This is the system response y(t) to an input f(t) when the system is in zero state; that is, when all initial conditions are zero.

Second-Order Solution

 * Example. Finding the total response of a driven RLC circuit.

Convolution
Convolution (folding together) is a complicated operation involving integrating, multiplying, adding, and time-shifting two signals together.

The convolution a * b of two functions a and b is defined as the function:

 * $$(a*b)(t) = \int_{-\infty}^\infty a(\tau)b(t - \tau)d\tau$$

The Greek letter τ (tau) is used as the integration variable, because the letter t is already in use. τ is used as a "dummy variable" because we use it merely to calculate the integral.

In the convolution integral, all references to t are replaced with τ, except for the -t in the argument to the function b. Function b is time inverted by changing τ to -τ. Graphically, this process moves everything from the right-side of the y axis to the left side and vice-versa. Time inversion turns the function into a mirror image of itself.

Next, function b is time-shifted by the variable t. Remember, once we replace everything with τ, we are now computing in the tau domain, and not in the time domain like we were previously. Because of this, t can be used as a shift parameter.

We multiply the two functions together, time shifting along the way, and we take the area under the resulting curve at each point. Two functions overlap in increasing amounts until some "watershed" after which the two functions overlap less and less. Where the two functions overlap in the t domain, there is a value for the convolution. If one (or both) of the functions do not exist over any given range, the value of the convolution operation at that range will be zero.

After the integration, the definite integral plugs the variable t back in for remaining references of the variable τ, and we have a function of t again. It is important to remember that the resulting function will be a combination of the two input functions, and will share some properties of both.

Properties of Convolution
The convolution function satisfies certain conditions:

 * Commutativity:
 * $$f * g = g * f \,$$

 * Associativity:
 * $$f * (g  * h) = (f  * g)  * h \,$$

 * Distributivity:
 * $$f * (g + h) = (f  * g) + (f  * h) \,$$

 * Associativity With Scalar Multiplication:
 * $$a (f * g) = (a f)  * g = f  * (a g) \,$$

for any real (or complex) number a.

 * Differentiation Rule
 * $$(f * g)' = f' * g = f * g' \,$$

Correlation
Akin to Convolution is a technique called "Correlation" that combines two functions in the time domain into a single resultant function in the time domain. Correlation is not as important to our study as convolution is, but it has a number of properties that will be useful nonetheless.

The correlation of two functions, g(t) and h(t) is defined as such:

 * $$R_{gh}(t) = \int_{-\infty}^\infty g(\tau)h(t + \tau) d\tau$$

Where the capital R is the Correlation Operator, and the subscripts to R are the arguments to the correlation operation.

We notice immediately that correlation is similar to convolution, except that we don't time-invert the second argument before we shift and integrate. Because of this, we can define correlation in terms of convolution, as such:

 * $$R_{gh}(t) = g(t) * h(-t)$$

Uses of Correlation
Correlation is used in many places because it demonstrates one important fact: Correlation determines how much similarity there is between the two argument functions. The more the area under the correlation curve, the more is the similarity between the two signals.

Autocorrelation
The term "autocorrelation" is the name of the operation when a function is correlated with itself. The autocorrelation is denoted when both of the subscripts to the Correlation operator are the same:

 * $$R_{xx}(t) = x(t) * x(-t)$$

While it might seem ridiculous to correlate a function with itself, there are a number of uses for autocorrelation that will be discussed later. Autocorrelation satisfies several important properties:

 * 1) The maximum value of the autocorrelation always occurs at t = 0. The function always decreases, stays constant, or fluctuates (if the signal is periodic) as t approaches infinity.
 * 2) Autocorrelation is symmetric about the x axis.

Crosscorrelation
Cross correlation is every instance of correlation that is not considered "autocorrelation". In general, crosscorrelation occurs when the function arguments to the correlation are not equal. Crosscorrelation is used to find the similarity between two signals.

 * $$R_{gh}(t) = \int_{-\infty}^\infty g(\tau)h(t + \tau) d\tau$$


text: User talk:71.57.133.162

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

title: User talk:71.57.133.162


text:
Signals and Systems/Noise

Noise is an unfortunate phenomenon that is the greatest single enemy of an electrical engineer. Without noise, digital communication rates would increase almost to the infinity

White Noise (Gaussian Noise)
White Noise, or Gaussian Noise is called white because it affects all the frequency components of a signal equally. This noise can be modeled as a Gaussian noise process. Gaussian processes are stochastic processes for which the random variables are jointly Gaussian. We don't talk about Frequency Domain analysis till a later chapter, but it is important to know this terminology now.

Colored Noise
Colored noise is different from white noise in that it affects different frequency components differently. For example, Pink Noise is random noise with an equal amount of power in each frequency octave band.

White Noise and Autocorrelation
White Noise is completely random, so it would make intuitive sense to think that White Noise has zero autocorrelation. As the noise signal is time shifted, there is no correlation between the values. In fact, there is no correlation at all until the point where t = 0, and the noise signal perfectly overlaps itself. At this point, the correlation spikes upward. In other words, the autocorrelation of noise is an Impulse Function centered at the point t = 0.

 * $$\mathcal{C}[n(t), n(t)] = \delta(t)$$

Where n(t) is the noise signal.

Noise Power
Noise signals have a certain amount of energy associated with them. The more energy and transmitted power that a noise signal has, the more interference the noise can cause in a transmitted data signal. We will talk more about the power associated with noise in later chapters.

Thermal Noise
Thermal noise is a fact of life in electronic components. As components heat up, the resistance of resistors change, and even the capacitance and inductance of energy storage elements can be affected. This change amounts to noise in the circuit output. In this chapter, we will study the effects of thermal noise.

The thermal noise which is an example of white noise is the random noise which is generated in a resistor or the resistive component of a complex impedance due to rapid and random motion of the molecules, atoms and electrons. According to the kinetic theory of thermodynamics, the temperature of a particle denotes its internal kinetic energy. This means that the temperature of a body expresses the rms value of the velocity of motion of the particles in a body. As per this kinetic theory, the kinetic energy of these particles becomes approximately zero (i.e. zero velocity) at absolute zero. Therefore, the noise power produced in a resistor is proportional to its absolute temperature. Also the noise power is proportional to the bandwidth over which the noise is measured. Therefore the expression for maximum noise power output of a resistor may be given as:
 * $$ Vn^2=k \cdot T \cdot R \cdot B $$

where
 * k is Boltzmann's constant
 * T is the absolute temperature, in Kelvin degrees
 * B is the bandwidth of interest, in Hertz.
 * R is the thermal resistance

Disclaimer: The above section contains significant errors. The noise power equation is wrong. The physical reasons given for Johnson noise are wrong. Do not use this source of information.

title: Signals and Systems/Noise


text:
Signals and Systems/Periodic Signals

Periodic Signals
A signal is a periodic signal if it completes a pattern within a measurable time frame, called a period and repeats that pattern over identical subsequent periods. The completion of a full pattern is called a cycle. A period is defined as the amount of time (expressed in seconds) required to complete one full cycle. The duration of a period represented by T, may be different for each signal but it is constant for any given periodic signal.

Terminology
We will discuss here some of the common terminology that pertains to a periodic function. Let g(t) be a periodic function satisfying g(t + T) = g(t) for all t.

Period
The period is the smallest value of T satisfying g(t + T) = g(t) for all t. The period is defined so because if g(t + T) = g(t) for all t, it can be verified that g(t + T') = g(t) for all t where T' = 2T, 3T, 4T, ... In essence, it's the smallest amount of time it takes for the function to repeat itself. If the period of a function is finite, the function is called "periodic". Functions that never repeat themselves have an infinite period, and are known as "aperiodic functions".

The period of a periodic waveform will be denoted with a capital T. The period is measured in seconds.

Frequency
The frequency of a periodic function is the number of complete cycles that can occur per second. Frequency is denoted with a lower-case f. It is defined in terms of the period, as follows:

 * $$f = \frac{1}{T}$$

Frequency has units of hertz or cycle per second.

Radial Frequency
The radial frequency is the frequency in terms of radians. It is defined as follows:

 * $$\omega = 2 \pi f$$

Amplitude
The amplitude of a given wave is the value of the wave at that point. Amplitude is also known as the "Magnitude" of the wave at that particular point. There is no particular variable that is used with amplitude, although capital A, capital M and capital R are common.

The amplitude can be measured in different units, depending on the signal we are studying. In an electric signal the amplitude will typically be measured in volts. In a building or other such structure, the amplitude of a vibration could be measured in meters.

Continuous Signal
A continuous signal is a "smooth" signal, where the signal is defined over a certain range. For example, a sine function is a continuous signal, as is an exponential function or a constant function. A portion of a sine signal over a range of time 0 to 6 seconds is also continuous. Examples of functions that are not continuous would be any discrete signal, where the value of the signal is only defined at certain intervals.

DC Offset
A DC Offset is an amount by which the average value of the periodic function is not centered around the x-axis.

A periodic signal has a DC offset component if it is not centered about the x-axis. In general, the DC value is the amount that must be subtracted from the signal to center it on the x-axis. by definition:

 * $$A_0 = (1/T)*\int_{-T/2}^{T/2} f(x)dx$$

With A0 being the DC offset. If A0 = 0, the function is centered and has no offset.

Half-wave Symmetry
To determine if a signal with period 2L has half-wave symmetry, we need to examine a single period of the signal. If, when shifted by half the period, the signal is found to be the negative of the original signal, then the signal has half-wave symmetry. That is, the following property is satisfied:

 * $$f (t-L) = - f (t)\,$$

Half-wave symmetry implies that the second half of the wave is exactly opposite to the first half. A function with half-wave symmetry does not have to be even or odd, as this property requires only that the shifted signal is opposite, and this can occur for any temporal offset. However, it does require that the DC offset is zero, as one half must exactly cancel out the other. If the whole signal has a DC offset, this cannot occur, as when one half is added to the other, the offsets will add, not cancel.

Note that if a signal is symmetric about the half-period point, it is not necessarily half-wave symmetric. An example of this is the function t3, periodic on [-1,1), which has no DC offset and odd symmetry about t=0. However, when shifted by 1, the signal is not opposite to the original signal.

Half Wave Symmetric signals don't have even "sine and cosine" harmonics.

Quarter-Wave Symmetry
If a signal has the following properties, it is said to quarter-wave symmetric:
 * It is half-wave symmetric.
 * It has symmetry (odd or even) about the quarter-period point (i.e. at a distance of L/2 from an end or the centre).

Any quarter-wave symmetric signal can be made even or odd by shifting it up or down the time axis. A signal does not have to be odd or even to be quarter-wave symmetric, but in order to find the quarter-period point, the signal will need to be shifted up or down to make it so. Below is an example of a quarter-wave symmetric signal (red) that does not show this property without first being shifted along the time axis (green, dashed):

An equivalent operation is shifting the interval the function is defined in. This may be easier to reconcile with the formulae for Fourier series. In this case, the function would be redefined to be periodic on (-L+Δ,L+Δ), where Δ is the shift distance.

Discontinuities
Discontinuities are an artifact of some signals that make them difficult to manipulate for a variety of reasons.

In a graphical sense, a periodic signal has discontinuities whenever there is a vertical line connecting two adjacent values of the signal. In a more mathematical sense, a periodic signal has discontinuities anywhere that the function has an undefined (or an infinite) derivative. These are also places where the function does not have a limit, because the values of the limit from both directions are not equal.

Common Periodic Signals
There are some common periodic signals that are given names of their own. We will list those signals here, and discuss them.

Sinusoidal wave
The quintessential periodic waveform. These can be either Sine functions, or Cosine Function.

$$ V_{p} \, \sin ( 2 \pi f \, t ) $$

Square Wave
The square wave is exactly what it sounds like: a series of rectangular pulses spaced equidistant from each other, each with the same amplitude.

Triangle Wave
The triangle wave is also exactly what it sounds like: a series of triangles. These triangles may touch each other, or there may be some space in between each wavelength.

Classifications
Periodic functions can be classified in a number of ways. one of the ways that they can be classified is according to their symmetry. A function may be Odd, Even, or Neither Even nor Odd. All periodic functions can be classified in this way.

Even
Functions are even if they are symmetrical about the y-axis.

 * $$f(-x) = f(x)$$

For instance, a cosine function is an even function.

Odd
A function is odd if it is inversely symmetrical about the y-axis.

 * $$f(-x) = -f(x)$$

The Sine function is an odd function.

Neither Even nor Odd
Some functions are neither even nor odd. However, such functions can be written as a sum of even and odd functions. Any function f(x) can be expressed as a sum of an odd function and an even function: $ f(x) = f_{even}(x) + f_{odd}(x) $  (Note that the first term is zero for odd functions and that the second term is zero for even functions.)

Using the above mentioned equations for even and odd signals in $$ f(-x) $$ we get: $$ f(-x) = f_{even}(-x) + f_{odd}(-x) = f_{even}(x) - f_{odd}(x) $$

 * Hence, $$ f_{even}(x)= \frac{f(x)+f(-x)}{2}

$$   and    $$ f_{odd}(x)= \frac{f(x)-f(-x)}{2} $$

title: Signals and Systems/Periodic Signals


text:
Poker/Omaha8

Omaha is often played high-low split. The player may use any combination of exactly two holecards and exactly three boardcards for the high hand and another (or the same) combination of exactly two holecards and exactly three boardcards for the low hand.

Rules

 * 1) All the rules of Omaha apply to Omaha high-low split except as below.
 * 2) A qualifier of 8-or-better for low is used. This means to win the low half of the pot, a player’s hand at the showdown must have five cards of different ranks that are an eight or lower in rank. (An ace is the highest card and also the lowest card.) If there is no qualifying hand for low, the best high hand wins the whole pot.

title: Poker/Omaha8


text:
User talk:Kernigh

 * /Archive 1 November to December 2005

pipe trick
I discovered a little trick. Stop me if you've heard this one before.

Often "normal" links to an article (putting square brackets around the article name) don't look quite right in normal running text. The article name includes extra disambiguation stuff before the colon, or inside parentheses, that's a bit jarring.

Adding a single pipe character to the link strips out that extra stuff, leaving the "normal" name, which is very often exactly what we wanted.

2 examples:

 * 1) Acoustic:Boundary Conditions and Wave Properties Acoustic:Boundary Conditions and Wave Properties
 * 2) Boundary Conditions and Wave Properties Boundary Conditions and Wave Properties
 * 3) Boundary Conditions and Wave Properties Acoustic:Boundary Conditions and Wave Properties

 * 1) Hyperion (moon) Hyperion (moon)
 * 2) Hyperion Hyperion (what people write when they don't know the pipe trick)
 * 3) Hyperion Hyperion (moon) (what people write when they do know the pipe trick)

(I wouldn't bother converting from the 2nd form to the more compact 3rd form, since they both look identical to readers, unless I was editing the link anyway.)

Keep on making those good wikibook edits.

--DavidCary 05:26, 4 January 2006 (UTC)

Messageboxes
Hey, Kernigh, why are you changing site-wide templates without asking anyone for opinion?

BTW, you are doing strange things, like replacing CSS classes: "notice" and "metadata" (preventing template from being printed) by noneixisting class "top". --Derbeth talk 00:02, 11 January 2006 (UTC)

 * I did this test, which suggests that "top" works and "notice metadata" does not.

top notice metadata notice metadata

 * I thought I was making only minor changes to the templates (though I think that I changed the width of some of them). Was I more "bold" then I should be? --Kernigh 00:07, 11 January 2006 (UTC)

 * I don't see any change made by "top". When it comes to templates design, your changes are not bad, but I don't understand why you made subst: to Message box. Take this example - you have to insert "metadata" to large number of templates now, if you had used Message box, you would have to insert it only once. --Derbeth talk 00:17, 11 January 2006 (UTC)

 * When I use "printable version" from "toolbox", "top" disappears for me in Konqueror browser, the other three do not. So I tried Firefox browser, where I was not logged in; again "top" disappears but the others do not.

 * Should I set class="top notice metadata"? --Kernigh 00:27, 11 January 2006 (UTC)

 * That's strange. I checked this page on three browsers: Opera, Firefox and Internet Explorer. All of them displayed only "notice". I'm sure "metadata" won't be printed, because it is mentioned in MediaWiki:Monobook.css. I'm only suprised that "top" is not printed, because I can't find it in Monobook and MediaWiki:Common.css. Nonetheless, because of semantic meaning "metadata" should be used and I don't see any reason for using "top". --Derbeth talk 00:42, 11 January 2006 (UTC)

 * I just noticed that class="top" is working in the User namespace, but not in the Template namespace. Further, class="metadata" only disappears for me if I actually print the page (using print preview), not if I use the "printable versions" link. So it seems that only class="metadata" will work from templates. I will go change the templates. --Kernigh 00:47, 11 January 2006 (UTC)

Test using "center" instead of "div" element: --Kernigh 01:04, 11 January 2006 (UTC)

top notice metadata  notice metadata

So class="top" works on "div", but not on "center". --Kernigh 01:06, 11 January 2006 (UTC)

Speedy Delete
Is there really any discussion page for SD, nothing has ever been discussed on the candidates listing page. You have tagged Christianity/Christianity and the world's religions for SD. What about the other 19 blank pages on the Main page outline? The outline did not originate with me, but I completed Chapter 1 as I had extra time from working on the Appendix. Christianity took 2000 years to develop and this hefty overview might take a while. The "no wiki page for this" was just some digital gladiator taking potshots at Christianity, never to return. - Athrash | T a l k 22:31, 13 January 2006 (UTC)

 * Are you familiar with the Project:Deletion policy? One can speedily delete "a page with no meaningful content". If there are "other 19 blank pages", then I missed them because I encountered Christianity/Christianity and the world's religions by chance.

 * If you want to discuss the page, you can list it at Project:Votes for deletion. --Kernigh 01:25, 14 January 2006 (UTC)

meta
Kernigh, I left a message at your meta talk page. Thanks, Chick Bowen 21:13, 16 January 2006 (UTC)

Adminship
I'm wondering why you still haven't requested for adminship here and noone has nominated you. IMO you're doing lots of cleanup work here and such permissions would allow to make many things easier and faster. You are doing good nominations for speedy deletion, revert vandalism quite often and clean up old pages. It will be your fourth month here. Looking at your contributions, you are a reasonable person so, all in all, I think you are good material for a sysop. --Derbeth talk 18:37, 24 January 2006 (UTC)

 * At 28 December 2005, I created 4414. I had lost the ability to view deleted edit histories. The bug closed with "Please discuss the issue with the enwikibooks community," at which point I understood that it was not a bug, it was a decision by developers to delegate decisions to communities.

 * In January, I started thinking that it would be convenient if I could delete certain pages instead of using delete. A request for adminship at WB:RFA is a way for me to ask Wikibookians whether they would let me delete pages and read their histories. I will do a request for adminship when I have time. --Kernigh 02:58, 2 February 2006 (UTC)

Elements of Style on WS
A message awaits you! Kind regards 213.120.56.41 20:33, 24 January 2006 (UTC) AKA Apwoolrich on WS

Message
Check your Wiktionary talk page. I left a message for you there. Happy editing! --Cromwellt 00:32, 27 January 2006 (UTC)

Nomination for Adminship
Just an FYI, but you have been nominated for adminship here on Wikibooks, thanks in large part due to your contributions. We certainly can use a few more admins here, and I would ask you to accept this nomination if you are interested. --Rob Horning 02:29, 3 February 2006 (UTC)

thanks
Thanks for your help with deleting the pages I'd merged -- much appreciated! Sorry for the hassle; I should have been more careful.--Bcrowell 03:27, 4 February 2006 (UTC)

 * BTW, Kernigh, I hope you know who Bcrowell is likely to be.... Dr. Ben Crowell who wrote the Physics textbook that can be found at http://www.lightandmatter.com/. If he is contributing to Wikibooks I am incredibly impressed.  I hope this is not a userper of the name but the actual guy.  I hope we can encourage him to continue on Wikibooks but not overwhelm him.  --Rob Horning 14:58, 5 February 2006 (UTC)

m:Transwiki:Wikimania05
I got a major complaint today about the transwiki of this Wikibook to Meta, and the user is so pissed that he invoked Jimbo. I basically replied "bring it on! I'd love to see Jimbo try to defend this Wikibook."

I sorta doubt that Jimbo is going to be so forceful, but I finished off the transwiki yesterday with deleting all of the Wikimania content. I suggested that he put up a proposal on Votes for undeletion if he really is that pissed over the whole thing. This is an FYI because your name is attached to a part of the transwiki to Meta.

I knew I was stepping on some "powerful" toes by doing a transwiki of this content, and I'll see just how independent we as a Wikibooks community really are going to be with this transfer. This book should not have been here in the first place, and I did complain about it back elsewhen. I think I have a stronger backbone on this now, and am willing to even go against board members (who BTW encouraged the Wikimania content to be added in the first place to Wikibooks). --Rob Horning 01:05, 10 February 2006 (UTC)
 * This was a fair bit of work. I don't see this as stepping on toes so much as being courteous to current users of the content; replacing this page with a stub that points visitors to the right place (and protecting it), &c.
 * Meta is a fine place to have the proceedings end up. I am not sure which board members you feel encouraged the proceedings to be added to Wikibooks last summer; I seem to recall it being the book-like nature of traditional conference proceedings that suggested using WB in the first place. Sj 07:10, 11 February 2006 (UTC)

 * The board members who encouraged this to be on Wikibooks were Anthere and Angela. Both contributed to it here on Wikibooks, and certainly did not raise any objection to it, dispite a strong protest by Aya at the time.  I didn't know that at the time, but after I was about half way through the process of deleting the content did I notice both names on the edit history log of many of the pages, as I noticed yours as well, SJ.  --Rob Horning 10:02, 18 February 2006 (UTC)

---

BTW, I guess I need to thank you at least partically for your defense of my removal of this content. There are more pages that Brion restored that need to be deleted as well, but you provided a good start. And thanks for the redirects as well. I've been a stick in the mud about the redirects mainly because of the "demands" that I perform the action instead of one of the Wikimania participants stepping in and doing it themselves. It didn't require sysop privileges to add the redirects. Thanks anyway, and I hope this whole thing quiets down real soon. --Rob Horning 10:02, 18 February 2006 (UTC)

Congratulations
Congrats, Kernigh, you are a sysop now. Make good use of your admin tools. --Derbeth talk 02:22, 12 February 2006 (UTC)

 * I normally edit with Konqueror, but some of my Firefox windows were too narrow to hold all of those new tabs. --Kernigh 00:50, 14 February 2006 (UTC)

 * Congrats tambien. Don't be afraid to ask for help with admin tools if you are unsure about something. -- LV (Dark Mark) 02:38, 17 February 2006 (UTC)

My RFA
Kernigh. I thought I would write you concerning my RFA. I thought I would ask (and hope) that you would reconsider your vote of Oppose. While I know my contributions weighs heavy to my own project, if you look closely you will see where I have contributed to other projects (primarily with suggestions and comments.) I have taken your advice and began watching the locations you have suggested. I will admit I am not a die hard vandal hunter, I feel I can be an asset in taking what I've learned from Wikibooks and help others to improve their materials. I guess I could become a major vandal hunter if that's what it takes to help others with development, but I feel that my assistance in the area of development would be my strength. I completely understand if you choose not to, but I thought I would at least ask for your consideration. Thanks.--Mfinney 10:00, 1 March 2006 (UTC)

Deleting Things On Wikipedia
Over there, the tag for speedies is csd and has to meet certain requirements, some of which are fairly contreversial and undefined. If it doesn't meet speedy requirements, it goes into a certain area (Articles For Deletion, Redirects For Deletion, Stubs For Deletion, Miscellaneous For Deletion, Templates For Deletion, etc.), although that varies from place to place and depending on who closes the debate, unfortunately. Karmafist 03:49, 7 March 2006 (UTC)

Thanks for the tips!
I will ask the site admin. Thanks a million! Renmiri 14:56, 12 March 2006 (UTC)

THINKSTARSHIP
hey, interested graphic you left for me. And an interesting trail. as long as we are playing with useful graphics, maybe you could try the "This module is under Construction" kind until I let you know things have changed? I'm only two weeks into this? Actually a little less. Give me like a month or two to get it together and then come knocking? k? Prometheuspan 23:51, 13 March 2006 (UTC)

http://en.wikibooks.org/wiki/Talk:THINKSTARSHIP

i hope you don't mind, i moved your graphic to the talk page and put up a copy of the template but with something that doesn't give me anxiety to read, or make me have to scroll down every time i go to the main page. Prometheuspan 04:54, 15 March 2006 (UTC)

Lord of the Flies and failed Google test
I've gone through the history of the content for this Wikibook, and I am convinced that the bundle of other web pages are all copies of the content that was originally developed here on Wikibooks. The first edit was done back in April 2004 (almost two years ago) and subsequent additions of content was very piecemeal with almost 300 different unique edits to this page. While there may have been some recent additions that did copy from perhaps previous copyrighted material, this Wikibook doesn't seem to be the problem here. Instead, I think these other websites are violating our copyright at Wikibooks, for failure to disclose the GFDL and acknowledging that Wikibooks is the source of this material.

I'd like to dig up some more information about this, but I think you found a really good copyright violation I'd like to hand over to the Wikimedia legal team. I'm sure a couple of appropriate letters sent to a couple of website owners about misuse of Wikibooks content.... --Rob Horning 03:05, 29 March 2006 (UTC)

As requested in #wikimedia-irc
"I am IRC Kernigh" Kernigh 03:49, 29 March 2006 (UTC)

Thanks
Thanks for your help. I could have figured much of it out by reading the guidelines forever, but you definitely saved me a bunch of time. - Taxman 06:34, 3 April 2006 (UTC)

Hi, this is Martha Whittington
You wrote a note on the page I so 'bolded' created. If my comments don't fit this wonderful site then go ahead and delete it. I meant no harm.

Thanks for explaining what Wikibooks can do.

Thanks for your time, take care.

MW

Novial book
I'm changing the naming convention for the pages to conform to the agreed standard. Old pages will become redirects to new copies. I'm the only person working on this book so there shouldn't be confusion. I won't finish it all in one day either. Novialiste 00:19, 4 April 2006 (UTC)

On the front page of the Novial book I have indicated which old pages can be deleted. Could you or another administrator delete those? Thanks. Novialiste 11:05, 8 April 2006 (UTC)

RuneScape Cheats
Hey man. In votes for deletion, you said this about the RuneScape Cheats article.

The bot community is trying to make contractually illegal the informing of JAGex or the public about bots; maybe we should mention that somewhere in the book.

I don't fully understand what you're saying there. Can you go further into detail please?? Richard 01:37, 5 April 2006 (UTC)

 * To write a Wikibook module about RuneScape cheating robots, or to verify that the mentioned bots actually exist, one would need to research them. However at this time I guess that JAGeX has suppressed most cheating bots, and their remaining users are hiding behind forums such as aryanrune, and applying terms of use that impede anyone from describing these bots in public.

 * The most problematic part of their terms reads, In these Terms and Conditions "images" refers to the images used by the domain and host of AryanRune.com. To view any image on fagex.net or its server that it is hosted on, you must not be in any way affiliated with Jagex Ltd you must not be affiliated with RuneScape and/or Employed by either. / Viewing the images on the site means you are in no way trying to report, send, capture or scan this sites server or images.

 * For now, I ignore the difference between AryanRune.com and fagex.net. These terms not only bar JAGeX/RuneScape from accessing the "images", they also bar third parties – such as Wikibook authors – from describing ("report") the contents of the images.

 * However, it is also possible that I only misinterpreted the terms. --Kernigh 03:07, 6 April 2006 (UTC)

K but I got another question for you.

A user made an Experience Table for RuneScape. I was wondering, if its possible, can you please rename it to RuneScape/Skills/Experience Table? Richard 20:32, 6 April 2006 (UTC)

 * I took care of this one, thanks for making the request though Richard. --Rob Horning 04:34, 7 April 2006 (UTC)

Coq au vin
Thanks. A book could be written about this dish, but I'm just trying to add my recipe to the Cookbook. I started this tonight after a good meal, using methods I learned on WP, so I think I'll come back here tomorrow and pick up the technical stuff.--Shtove 23:56, 7 April 2006 (UTC)

Meta on Cabalism
Great, that sounds like a good option. I'll focus on it there instead of here if I build it up again. Thank you for your kind and considerate input there. Karmafist 17:40, 9 April 2006 (UTC)

Mythology/Greek Mythology and Greek Mythology
Hi, back in February, you expressed a desire to merge these two books together. I merged the two on Greek Mythology because it has considerably more pages than Mythology/Greek Mythology, and changed the latter's pages to redirects. The only pages that still need to be merged are Talk:Mythology/Greek Mythology and Talk:Greek Mythology. Now the only issue that remains is whether the book should be part of Mythology or stand on its own. I'll leave that up to you to decide. Cheers! --Hagindaz 05:50, 11 April 2006 (UTC)

Lolo 2 (Japanese) info
Hello. I saw your message and see how the format works. I'm doing well so far, I believe. I had 6 of the 17 levels pre-written, which is why progress was so fast. I intend to reword some things to make them not be first person.

I also wanted to ask you a question with the way my guides are structured: Is my use of images for each level acceptable? I'd like to think that it is, but if you have any recommendations I would like to hear them. If you wish to see what I mean, please use this link for a quick demonstration. Thanks for your help at the beginning. --Sivak 05:55, 13 April 2006 (UTC)

RuneScape/Popular item price guide
Man, I need some help with this page. It gets vandilized every fricken day. Retards remove whole sections and put swears all over it. I'm really angry, REALLY angry over what people are doing and I'm deciding on deleting it to avoid the problem. But before this, I was wondering if maybe you could do something about, like make it on a 'high risk for vandilism' or something that can keep it watched often. It's just so annoying to see everyday that someone messed up the page. Thanks for the help you've done before, and maybe you could do this last thing.

Oh, and can it be renamed to RuneScape/Guides/Item Price Guide? Thanks. Richard 12:58, 13 April 2006 (UTC)

 * Current location is RuneScape/Guides/Item Price. --Kernigh 17:48, 15 April 2006 (UTC)

Page moves
What is it with these odd page-moves?? --TurretTower 15:18, 15 April 2006 (UTC)

 * Vandalism. If you see any more vandal page-moves, you can report them to Vandalism in progress. --Kernigh 17:48, 15 April 2006 (UTC)

Vandalism attack on our user pages
I just reverted some vandalism by an idiot who moved both of our user pages and user talk pages. I put them back, but I also added move protection, and even edit protection on the main user page. You are certainly welcome to reverse that for your own page, but I felt that would be a good general protection to you in this situation, especially since you have admin authority anyway to do what you want on these pages. I want to nail this idiot, and I want to thank you for bringing up the current discussion on Foundation-l. --Rob Horning 13:37, 16 April 2006 (UTC)

I share my IP address with these vandals. Ignore them... they'll get bored like most Wiki-vandals do! --TurretTower 14:55, 16 April 2006 (UTC)

DickyRobert?
On my talk page, I got a DickyRobert template. What the heck is it? Can it be removed? --Richard 00:28, 17 April 2006 (UTC)

 * It was vandalism; you can revert it. It looks like User:Robert Horning already reverted the template and blocked that vandal. --Kernigh 16:32, 17 April 2006 (UTC)

Wikibooks Embassy and technical help
Kernigh,

I started an English Embassy page, which is pretty much a copy of the english wikipedia's embassy page. I was wondering, if it should be English Embassy instead, or anything like that. Also, I would like to ask people who speak other languages if they would like to list themselves on the page, to be available for any non-english speaking people who would need help- I was wondering, should I look at the different language categories and ask people on their personal page, or just post on the staff lounge?(I don't want to keep posting stuff there every day if it isn't appropriate)

Also, I have been preparing to contribute to the Russian Language wikibook, but don't know much about using templates and making boxes(you know, the things that make wikibooks look pretty). I was wondering, are there people out there who can make a bland wikibook look better as content is being added, based on the needs of the wikibook? Maybe I should ask about it in the staff lounge too, I don't know. I basically am asking you this because you seem to know what you're doing more than anyone else here. Thanks in advance, DettoAltrimenti 19:58, 17 April 2006 (UTC)

Image:Wikiversity-logo-zs.png
I clarified the legalities of the licensing issue at Wikipedia commons for. I hope this helps.

Basically, the licensing is the only thing that matters. The owner can grant as many licenses to use his image as he wants. Each license can have its own stipulations. He granted one license to the world under the GNU FDL and another license to me to make the logo. The logo license was issued separately and directly from the owner, and is therefore not subject to the GNU FDL. For that reason, I can grant propriety rights to the logo to the Wikimedia foundation. --Zephram Stark 16:49, 19 April 2006 (UTC)

Videogame transwikiing method
In various postings you've mentioned your search for a transwikiing aid. MWDumper seems to be the answer. It can search an archive and extract pages based on a filter list, so all you need is a full dump. I've been testing its accuracy and so far I haven't come across any problems.

This is the tool StrategyWiki is going to use, and I've already begun creating automated filters for it to aid transwikiing. These are written in a compatible raw format; they can be pasted straight into a .txt for MWDumper's consumption. GarrettTalk 12:08, 24 April 2006 (UTC)
 * Actually, what I am interested in is a way to remove guides from this wiki, Wikibooks, after transwiki. Currently, if we move a guide to Strategy Wiki or elsewhere, then it is a fork; a copy remains at Wikibooks. I would like to have a Wikibooks policy that allows us to delete these guides.
 * Deletion policy already allows us to use transwiki to delete stuff, but that only applies for transwikis to other Wikimedia projects. However, if most Wikibookians support it, then we can change the deletion policy to let us delete moved computer and video game guides. --Kernigh 18:51, 24 April 2006 (UTC)
 * Oh, now I get what you're talking about! Well, I can't see anything like that being passed through any time soon what with all this chaos. In the meantime you could list them on Vfd. Since they now breach WB:WIW (or at least Jimbo's revision of it) the lack of a matching clause in the deletion policy is immaterial. GarrettTalk 03:10, 25 April 2006 (UTC)

Bureaucrats can now set, unset 'bot' flags
Yes, I did, and even changed information at WB:RFA in section about bots. --Derbeth talk 23:19, 26 April 2006 (UTC)

Policy review
Policy is not the most exciting subject at Wikibooks but we do have some major unresolved issues.

The most important issue, in my opinion, is Dispute resolution which starts by declaring that:

"Currently there is no official organized process to resolve disputes between users"

The suggested remedy for this is: Ad hoc administration committee which puts into place the absolute minimum in terms of an enforcement apparatus.

The second most important is No personal attacks where a vote has recommended the policy be enforced but it still languishes as "proposed".

The third policy that is needed and which will prevent edit disputes from getting out of hand is Editing disputes policy.

Other policies that need consideration are at: Policies and guidelines.

Please spare a minute or two to peruse these issues and add a comment and/or a vote. RobinH 12:35, 28 April 2006 (UTC)

empty pages
well, to tell the truth, i didnt understand anything you said, sorry. but i didnt create empty pages.... if you go to edit, youll see that stuff is there, i just havent added all the data yet, so i hid the stuff with  so that it would be easier to add all the data later.... but thanks for deleting them without talking to me first... thatll be a biiiigg help... -Xornok 13:11, 5 May 2006 (UTC)

Reply from Yunzhong Hou
Thanks for replying to the discussion page on the StarCraft Wikibook. You are the first person since my series of revisions to leave a comment, and I was becoming desperate.

I would like to point out to you that my High Templar page on Wikipedia is more than a 'poorly written article'; it survived the Deletion proposal by overwhelming votes, and many of the voters agreed with me that the StarCraft articles should be transferred to Wikibooks because doing so will make the subject's various pages more coherent. Although the task is daunting, I have already transwikified my High Templar page and many others.

However, I do agree with you that some components of the page are a bit irrelevant or crude, in which case I would be happy to make any changes that you deem important. If you can, please find people who may be interested in editing the StarCraft Wikibook. I know only a few Wikipedes. Thanks! --Yunzhong Hou 02:40, 7 May 2006 (UTC)

Templates vs. screenshots
Hello there. You were the one who initially spoke to me about the Adventures of Lolo 2 (Japanese) book and ways to go about doing it. I've done some more work on it and I wanted to ask you: I've come up with a new template to assist in the guide. What I was doing before was posting screenshots, but using the template I can lay out things and hopefully eliminate screenshots. My question is: What is better? The template of the screenshots? The template could be applied to future books, though the screenshots are quick and simple.

 * One page that is using the new template is This one
 * One page that is using the screenshot system is This one

I would like to hear from you about your opinion as you are an administrator and I don't want to get ahead of myself. Thank you. --Sivak 05:42, 12 May 2006 (UTC)

 * Replied at User talk:Sivak. --Kernigh 19:22, 13 May 2006 (UTC)

Vicious circle
I noticed that on No personal attacks you seemed to support enforcement. There is a vicious circle occurring in Wikibooks Policies where the absence of an accepted policy on voting (see General voting rules) can be used to prevent votes from becoming enforced. It seems to me that unless we get General voting rules enforced we cannot get any other policy enforced. This is fine for the moment but I have looked over the wall at Wikipedia.... RobinH 10:20, 14 May 2006 (UTC)

 * I commented on Wikibooks talk:No personal attacks, where I wrote, "I prefer that we have only one policy to deal with user behaviour (limiting insults against users, implementing consistent voting rules, resolving various disputes) instead of creating so many pages." --Kernigh 01:27, 15 May 2006 (UTC)

"accredited institution"
You might want to read the comments I left for Rob at Votes_for_deletion. It seems WMF is not internally consistent about its mission for WB. Jimbo obviously has a particular view and could likely make that WMF policy, but it is definitely not 100% clear. I assume you've also read w:User_talk:Jimbo_Wales. Kellen T 00:47, 16 May 2006 (UTC)

No personal attacks Change of text
You voted for enforcement of No personal attacks. The text of this policy has been changed by Jguk during the vote, I have further modified these changes to restore some of the original "bite". This is highly unusual but without these changes Jguk is unwilling to allow the policy to move to enforced. I am happy that the changes are not sufficiently substantial to undermine the policy, if you disagree then please make your views known. Changes to text during a vote could be construed as a delaying tactic so I have proposed a move to "enforced" status by 1st June. RobinH 10:05, 20 May 2006 (UTC)

Could you update the CSS files?
See http://en.wikibooks.org/w/index.php?limit=500&title=Special%3ARecentchanges&namespace=9. Thanks, hagindaz 17:04, 11 June 2006 (UTC)

votes for deletion
Kernigh, could you look at Votes_for_deletion and Votes_for_deletion, I'd really like to clean up the Business and economics bookshelf. DettoAltrimenti 22:12, 11 June 2006 (UTC)

XML/Firefox
Thanks for answering my question at the help desk. Your second idea sounds viable, but once I get the page, I have no idea how to selectively take out say the premieres for October 25th or something (or to make it easier, the first five lines). And none of the tutorials I read help me. They all assume the site has an RSS feed or are already written in XML in which case isolating information is a breeze, just include one link in your code. How do you import selected text from HTML sources into a firefox extension? - 131.211.210.16 07:54, 21 June 2006 (UTC) P.S. You can answer at w:User talk:MacGyverMagic. - 131.211.210.16 07:55, 21 June 2006 (UTC)

Blender Dokumentation seems to use non-GFDL license
Hallo Kernigh, I've written a comment on http://de.wikibooks.org/wiki/Benutzer_Diskussion:Kernigh regarding the topic. In short: no, http://de.wikibooks.org/wiki/Blender_Dokumentation is not a copy of http://mediawiki.blender.org/index.php/Manual.de/Handbuch, but I've written text as well for de.wikibooks.org as for mediawiki.blender.org. http://de.wikibooks.org/wiki/Benutzer:Soylentgreen

General voting rules/Proposal
I want to call the attention of all wikibookians, especially active admins to the discussion about the new voting policy. Wikibooks currently does not have a concrete voting policy in effect, so the adaptation of this policy will potentially create immediate differences in the way business is conducted here. Due to large amounts of discussion, changes, and dissention, there are several versions of this policy being considered:

 * Version 1 Written by User:Whiteknight
 * Version 2 Written by User:Jguk
 * Version 3 User:RobinH's revision of Jguk's version
 * Version 4 Written by User:Kellen
 * Version 5 Whiteknight's Revision of Kellen's Version.

Also, there are additional issues being discussed, such as the inclusion of a "minimum contributions" clause, that will limit users with less then 20 votes from editing. Also, there is a proposed clause that would allow this 20 vote minimum to be raised in response to abuse.

I am sending this same message to all currently active admins. I hope you are able to come in and give your opinions on this matter. --Whiteknight (talk) (projects) 20:48, 11 August 2006 (UTC)

Your De-Adminship
Hello. I would like to inform you that you will have your sysop rights removed here on 8 Oct 2007 due to inactivity. If you would like to discuss the matter, please see WB:RFA. You can re-apply for adminship at a later date if you wish. Thanks. -within focus 01:06, 8 September 2007 (UTC)
 * Hi, Kernigh,
 * After a request on meta I have removed your adminship on this wiki, according to local removal policy. Effeietsanders 14:49, 11 October 2007 (UTC)

title: User talk:Kernigh


text:
Apache Ant/Build File Structure

Here is the structure of a typical build.xml file:

  Running target init  Running target MyTarget

Here are a few things to note:

 * 1) The Begin and End tags for project ( and ) MUST start and end the file.
 * 2) The Begin MUST have an attribute called default which is the name of one of the targets.
 * 3) Each build file must have at least one target.
 * 4) The Begin and End tags for and must also match EXACTLY.
 * 5) Each target MUST have a name.
 * 6) Targets depend only on other targets and reference them by their target name.  Targets NEVER depend on projects or tasks.
 * 7) Target depends are optional.
 * 8) Anything between and tags is outputted to the console if the surrounding target is called.
 * 9) Every task has to be in a target.

You can execute this from a DOS or UNIX command prompt by creating a file called build.xml and typing:

ant

Ant will search for the build file in the current directory and run the build.xml file.

Here is a sample output of this build:

Buildfile: C:\AntClass\Lab01\build.xml init: [echo] Running target init MyTarget: [echo] Running target MyTarget BUILD SUCCESSFUL Total time: 188 milliseconds

Optionally you can also pass ant the name of the target to run as a command line argument

ant init

Which triggers only the init target

Buildfile: C:\AntClass\Lab01\build.xml init: [echo] Running target init BUILD SUCCESSFUL Total time: 188 milliseconds

Next Chapter

title: Apache Ant/Build File Structure


text:
Wikijunior talk:Introduction to History

Where to go from here.

I am trying to rethink how children learn history. Instead of taking the easy way out, and following chronology, I am trying to think about what is really important.

I've written so far about the big changes in history. I think the next thing to write about is the Twentieth Century. I remember taking "modern history" in college, and being disappointed because we never got to the Twentieth Century. For a long time, I knew more about ancient Babylon than I knew about World War I. I think kids want to know (and need to know) about the history their fathers and mothers and grandparents lived through. Rick Norwood 20:25, 17 October 2005 (UTC)

Hi, I stumbled across this page and I think it was done very well! The only thing was that the format was a little bit intimidating, so I broke it down into smaller bits to make it easier to read. If there is any problem with how I edited things feel free to revert it. --Sanitized (talk) 19:13, 15 July 2008 (UTC)

I would like to re-start this project. I am thinking of adding broad topics first (i.e. methods and uses of history research, philosophy of history and history of human society). Focusing, like the original author of the project, on the non-linear presentation of history.

2011, now 2019!
Well, this looks abandoned(like REALLY) because the only edit that changed the content was in 2011 (more recent one by Pi Zero was not a content change). Therefore, I will try to turn this a new way. Qwerty number1 (discuss • contribs) 22:27, 22 February 2019 (UTC)

title: Wikijunior talk:Introduction to History


text:
Talk:Visual Basic/Object Oriented Programming

The discussion of user defined types should come before that of using classes and objects, as they are conceptually and programmatically much simpler to use.

There should primarily be discussion of the 'dot' notation, perhaps even before anything else, as the notation is used without explanation in previous pages. In fact the dot notation can be used to identify both UDTs and Objects in VB.

It should also be shown what Object type variables actually are: that is, pointers to memory. This will help explain how Objects are passed by reference (or by value) to functions and what happens when you assign one object to another.

Examples of some common VB objects you might use in a program (such as the Debug object or Controls on a Form or Collections), should be given.

How to write a class from scratch should then be discussed; and how these objects can be instantiated and how object lifetimes (reference counting) works in practice. This will include such areas as the prefered use of the New keyword and what happens when Object variables go out of scope and with circular references.

Lastly the use of visibility of functions (methods) and variables or properties (properties), and the difference between Private, Public and Friend keywords.

Some advanced topics (maybe for other sections) should include authoring DLLs, COM objects (and GUIDs), default methods (and the use of the 'bang' ! operator) and enumerators (for use in For Each loops).

I shall write some of this perhaps, when I have some time...

First Person
This section over-uses the first-person perspective, which goes against Wiki standards and makes it awkward to edit.


text:
Talk:Visual Basic/Snippets

For reversing a string, very slightly optimized version from that given would be:

Private Function ReverseStr(ByVal IPStr As String) As String Dim i As Integer For i = 1 To Len(IPStr) ReverseStr = Mid$(IPStr, i, 1) & ReverseStr Next End Function

The changes are that the index (i) goes forward instead of backwards. But the characters are added backwards instead of forwards.

If you really want to optimize it, create the string once with the proper length, so it is only allocated once. The above code would mean one (behind-the-scenes) call to SysReAllocString per loop iteration. Like this...

Private Function ReverseStr(ByVal IPStr As String) As String Dim i As Long, j As Long, n As Long n = Len(IPStr) j = n  ReverseStr = Space$(n) For i = 1 To Len(IPStr) Mid$(ReverseStr, i, 1) = Mid$(IPStr, j, 1) j = j - 1 Next End Function

need for help
Hello Sir Since you are in contact with experts in computer programming, I kindly ask you for TWO favors: FIRST: I want to build an application having a command button that can connect me through my modem to my ISP: IDM. Please, can you tell me what are the instructions that must be put in the code of the cmd if I am using Visual Basic 6.0???

SECOND: If I want to load the Dial-up connection in the Network Connections folder, I cannot construct the path that I should include in the "Shell" instruction. What is the path to the Dial-up connection? Your help is highly appreciated and I thank you in advance. Best Regards Please e-mail me the answer if you don't mind

magids18@inco.com.lb

Majid

title: Talk:Visual Basic/Snippets


text:
User talk:Sfarsaii~enwikibooks

Copyright problem with Image:StudentsIrvingISD.jpg
--Derbeth 20:50, 17 October 2005 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Sfarsaii. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Sfarsaii~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:44, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:28, 19 April 2015 (UTC)

title: User talk:Sfarsaii~enwikibooks


text:
User:Sfarsaii~enwikibooks

Sam Farsaii Director of Instructional Technology sfarsaii@irvingisd.net http://www.irvingisd.net Tel. 972-215-5255

title: User:Sfarsaii~enwikibooks


text:
Bookbinding

Table of contents

 * 1) /Introduction/
 * 2) /Motivation/
 * 3) Content of self-bound books
 * 4) * Printing free material
 * 5) ** Wikibooks and Wikipedia
 * 6) ** Other sources
 * 7) * Preservation & restoration of existing books
 * 8) * Blank books: notebooks, photo albums, scrap books, planners, sketch books, etc.
 * 9) * Self-publishing
 * 10) Types of binding
 * 11) * Adhesive
 * 12) ** /Perfect binding/
 * 13) ** Fan binding
 * 14) * Stiff leaf
 * 15) * Side stitch[[File:50%.svg]]
 * 16) ** Stapled side stitch
 * 17) ** Coptic
 * 18) ** Japanese side stitch (Stab Binding)
 * 19) * /Saddle stitch/
 * 20) * /Long stitch/
 * 21) * Sewn book
 * 22) * Case binding
 * 23) * Traditional hardcover
 * 24) * Box making- slip case, drop-spine boxes
 * 25) /Equipment/
 * 26) * Press
 * 27) * Brush
 * 28) * /Bone folder/
 * 29) * /Paperknife/
 * 30) * Awl & needle
 * 31) * /Plane/ or guillotine
 * 32) /Materials/
 * 33) * Paper
 * 34) ** PH
 * 35) ** Grain
 * 36) * Adhesive
 * 37) ** Contact/rubber cement
 * 38) ** PVA homopolymer vs. copolymer
 * 39) * Spine
 * 40) ** Super
 * 41) ** /Thread/
 * 42) ** Stiff materials
 * 43) * Cover
 * 44) ** Letter size card stock
 * 45) ** /Museum board/
 * 46) ** Clear adhesive vinyl
 * Damaging effect on toner
 * 1) ** Re-used materials
 * 2) ** Binder's board & buckram

title: Bookbinding


text: User talk:213.93.216.48

title: User talk:213.93.216.48


text:
Blender 3D: HotKeys/Key/A

A

title: Blender 3D: HotKeys/Key/A


text:
Formal Logic/Sentential Logic/Subderivations and Discharge Rules

= Subderivations and Discharge Rules =

As already seen, we need three more inference rules, Conditional Introduction (CI), Negation Introduction (NI), and Negation Elimination (NE). These require subderivations.

Example derivation
We begin with an example derivation which illustrates Conditional Introduction, then follow with an explanation. A derivation for the argument
 * $$\mathrm{Q} \land \mathrm{R} \!$$ ∴  $$\mathrm{P} \rightarrow \mathrm{Q}$$

is as follows:

Lines 2 and 3 constitute a subderivation. It starts by assuming desired formula's antecedent and ends by deriving the desired formula's consequent. There are two vertical fences between the line numbers and the formulae to set it off from the rest of the derivation and to indicate its subordinate status. Line 2 has a horizontal fence under it to separate the assumption from the rest of the subderivation. Line 4 is the application of Conditional Introduction. It follows not from one or two individual lines but from the entire subderivation (lines 2–3) as a whole.

Conditional Introduction is a discharge rule. It discharges (makes inactive) that assumption and indeed makes the entire subderivation inactive. Once we apply a discharge rule, no line from the subderivation (here, lines 2 and 3) can be further used in the derivation.

The Conditional Introduction rule
To derive a formula $$(\varphi \rightarrow \psi)\,\!$$, the rule of Conditional Introduction (CI) is applied by first assuming in a subderivation that the antecedent $$\varphi$$ is true, then deriving $$\psi$$ as the conclusion of the subderivation. Symbolically, CI is written as
 * $$\underline{\text{Assume }\varphi \text{, derive } \psi}$$
 * $$(\varphi \rightarrow \psi)\,\!$$

Here, the consequent line is not inferred from one or more antecedent lines, but from a subderivation as a whole. The annotation is the range of lines occupied by the subderivation and the abbreviation CI. Unlike previously introduced inference rules, Conditional Introduction cannot be justified by a truth table. Rather it is justified by the Deduction Principle introduced at Properties of Sentential Connectives. The intuition behind why we assume $$\varphi$$ in order to derive $$(\varphi \rightarrow \psi)\,\!$$, however, is that $$(\varphi \rightarrow \psi)\,\!$$ is true by definition if $$\varphi$$ is false. Thus, if we show $$ \psi$$ is true whenever $$\varphi$$ happens to be true, then $$(\varphi \rightarrow \psi)\,\!$$ must be true.

Note that the antecedent subderivation can consist of a single line serving both as the assumed $$\varphi\,\!$$ and the derived $$\psi\,\!$$, as in the following derivation of

 * ∴  $$\mathrm{P} \rightarrow \mathrm{P},$$

Example derivation
To illustrate Negation Introduction, we will provide a derivation for the argument

 * $$\lnot (\mathrm{P} \rightarrow \mathrm{Q}) \rightarrow \mathrm{R},\ \mathrm{P} \land \lnot \mathrm{Q}\!$$ ∴  $$\mathrm{Q} \lor \mathrm{R}\,\!$$

Lines 3 through 6 constitute a subderivation. It starts by assuming the desired formula's opposite and ends by assuming a contradiction (a formula and its negation). As before, there are two vertical fences between the line numbers and the formulae to set it off from the rest of the derivation and to indicate its subordinate status. And the horizontal fence under line 3 again separates the assumption from the rest of the subderivation. Line 7, which follows from the entire subderivation, is the application of Negation Introduction.

At line 9, note that the annotation '5 DI' would be incorrect. Although inferring $$\mathrm{Q} \lor \mathrm{R}\,\!$$ from $$\mathrm{Q}\,\!$$ is valid by DI, line 5 is no longer active when we get to line 9. Thus we are not allowed to derive anything from line 5 at that point.

The Negation Introduction rule
Negation Introduction (NI)
 * $$\underline{\text{Assume }\varphi \text{, derive } \psi \text{ and } \lnot \psi}

$$
 * $$\lnot \varphi\,\!$$

The consequent line is inferred from the whole subderivation. The annotation is the range of lines occupied by the subderivation and the abbreviation is NI. Negation Introduction sometimes goes by the Latin name Reductio ad Absurdum or sometimes by Proof by Contradiction.

Like Conditional Introduction, Negation Introduction cannot be justified by a truth table. Rather it is justified by the Reductio Principle introduced at Properties of Sentential Connectives.

Another example derivation
To illustrate Negation Elimination, we will provide a derivation for the argument

 * $$\lnot( \lnot \mathrm{P} \lor \lnot \mathrm{Q}) \land \mathrm{R}\!$$ ∴  $$\mathrm{P}\,\!$$

Lines 2 through 4 constitute a subderivation. As in the previous example, it starts by assuming the desired formula's opposite and ends by assuming a contradiction (a formula and its negation). Line 5, which follows from the entire subderivation, is the application of Negation Elimination.

The Negation Elimination rule
Negation Elimination (NE)
 * $$\underline{\text{Assume }\lnot\varphi \text{, derive } \psi \text{ and } \lnot \psi }

$$
 * $$\varphi\,\!$$

The consequent line is inferred from the whole subderivation. The annotation is the range of lines occupied by the subderivation and the abbreviation is NE. Like Negation Introduction, Negation Elimination sometimes goes by the Latin name Reductio ad Absurdum or sometimes by Proof by Contradiction.

Like Negation Introduction, Negation Elimination is justified by the Reductio Principle introduced at Properties of Sentential Connectives. This rule's place in the Introduction/Elimination naming convention is somewhat more awkward than for the other rules. Unlike the other elimination rules, the negation that gets eliminated by this rule does not occur in an already derived line. Rather the eliminated negation occurs in the assumption of the subderivation.

Terminology
The inference rules introduced in this module, Conditional Introduction and Negation Introduction, are discharge rules. For lack of a better term, we can call the inference rules introduced in Inference Rules 'standard rules'. A standard rule is an inference rule whose antecedent is a set of lines. A discharge rule is an inference rule whose antecedent is a subderivation.

The depth of a line in a derivation is the number of fences standing between the line number and the formula. All lines of a derivation have a depth of at least one. Each temporary assumption increases the depth by one. Each discharge rule decreases the depth by one.

An active line is a line that is available for use as an antecedent line for a standard inference rule. In particular, it is a line whose depth is less than or equal to the depth of the current line. An inactive line is a line that is not active.

A discharge rule is said to discharge an assumption. It makes all lines in its antecedent subderivation inactive.


text:
User talk:69.169.245.195

— Laura Scudder | Talk 00:04, 18 October 2005 (UTC)

title: User talk:69.169.245.195


text:
Software Engineers Handbook/Language Dictionary/COBOL

COBOL
COBOL is a computer programming language whose name is an acronym for "COmmon Business-Oriented Language". It is widely used in the financial services industry typically for mainframe based applications. It has been used extensively since the 1960s. COBOL was designed for use in business applications and consequently it was implemented with fixed-point arithmetic support. This is one of the advantages of COBOL as it allows complete and accurate computation of financial values without the possibility of rounding errors.

Type
COBOL is a full procedural language.

Execution Entry Point
A COBOL program is split into four divisions, all four divisions must be present in every program in this sequence: Identification; Environment; Data and Procedure. Each division contains a number of mandatory and optional sections and paragraphs.

The Identification Division contains information about the program, including its name, author, date of compilation, etc. It must contain the  paragraph that uniquely names the program. All other paragraphs are optional.

The Environment Division describes the environment in which the program will execute. For example, it includes details of input and output files and the target execution platform. The division contains two sections: the Configuration Section and the Input-Output section.

The Data Division contains the File Section, which fully describes the record layout of each input and output file, and the Working-Storage Section where variables are declared. It also contains the Linkage Section that describes data that will be passed between programs that call each other.

The Procedure Division contains the executable program instructions. The execution entry point is the first statement in the division.

General Syntax
It would be very difficult to give an overview of COBOL's general syntax, since the language has over 500 reserved words. Moreover, the syntax (like other early languages, including FORTRAN) is not designed to follow a formal grammar; for this reason COBOL and FORTRAN parsers are rarely implemented using automatic code generators.

Here are some sample assignment statements:

While many sites still use all uppercase characters, modern COBOL compilers are case-insensitive. The following two statements are absolutely equivalent:

Character case is respected for quoted literals (character strings).

Comments
Normally the only way to specify a comment is by putting an asterisk in the indicator-area (column 7). The entire line is a comment. Block comments must have * in column 7 of every line. There is a 2002 standard that allows part of a line to be a comment:

Variable Declarations
There are a few variables of a type known as special registers that do not need to be defined, but generally all variables must be defined in COBOL, unlike interpreted BASIC.

COBOL has a number of data types, but the most common are numeric (with specifiers for internal format), numeric edited data, alphanumeric data, and records (similar to structs in C):

Your simple example, declaring an integer, might look something like this:

COBOL also supports redefinition, which is somewhat similar to union in C.

Method Declaration/Implementation
Object-oriented extensions are available to COBOL, but the vast majority of COBOL programmers do not make use of them, and see no need for them.

However, if a COBOL programer wants to create a class, it is quite easy. For example, here is a HelloWorld class with an instanceMethod

Scope
All data contained in the working-storage section of the COBOL program is global. Some data items may be defined as external, and visible to other programs in a load module. The data items in a COBOL subprogram are global to the subprogram, but local since the caller cannot see them. Typically, data is "passed" from a COBOL main program to a subprogram by reference. There are alternatives of "by content" or "by value", but they are typically only used to call subprograms written in C or other languages that do not normally use call by reference.

Some vendors provide extensions, such as thread-local-storage section and local-storage section. These extensions allow data to be scoped as either thread-local or temporary to the program.

Conditional statements
There are a lot of them. Here are some examples:

Looping Statements
There are several of those too:

Output Statements
Here are several examples.

For key-sequenced files, there is support for,  ,  ,  , and.

Containers
Not applicable to COBOL.

Algorithms
Recursion is not generally supported, although it can be simulated by iteration.

Garbage collection
Memory allocated dynamically via system APIs such as malloc should be free'ed with the appriopiate call to "free".

COBOL programs that uses CLASS'es may need to invoke the "finalize" method to release the object. For example:

If the COBOL application is executing under a VM such as a Java VMs or Microsoft's CLR, standard garbage collection rules apply.

Otherwise..

COBOL programmers do not normally know or care what garbage collection is. They rarely have to allocate memory or clean it up afterwards.

Physical Structure
A COBOL source file may have (but need not have) copybooks, somewhat similar to .h files in C. The compiled program generally makes use of a COBOL runtime library of service routines that are dynamically loaded. The COBOL source file itself consists of four divisions: ,  ,  , and.

Tips

Web references

 * COBOL FAQ (as .DOC)
 * GnuCOBOL FAQ and How-To
 * GnuCOBOL Manuals and Guides
 * COBOL User Groups (COBUG) (site offline, archive from 2013)
 * cob-rte
 * svalgard
 * swbell page
 * dissert
 * csis.ul.ie page
 * infogoal page
 * COBOL Blog

Books and articles

Back to the title page

Tools

 * Cobos Project The Open Source Cobol / Mainframe / CICS / DB2 Integrated Development Environment (within Eclipse)

Programmation Cobol Programmeren in COBOL


text: User:Eredian

title: User:Eredian


text:
User:Bertmung

I'm a mental health counselor working in a group practice in Essex Junction, Vermont. I work with a variety of clients including those with depression and anxiety, and substance use disorders. My practice includes work with clients with Borderline Personality which I hope to bring closer to standard DBT over time.

title: User:Bertmung


text:
Dialectical Behavioral Therapy/Distress Tolerance Skills/Willingness

Willingness is an active form of acceptance. It is accepting the need for action and taking that action. It is not necessarily going along with whatever the therapist or skills trainer thinks is best. Willingness does not demand that reality be something other than what it is. On the other hand willingness does not give up and refuse to take action that could change reality for the better in the future.


text:
File talk:XRS.jpg

God is not a God of letters
Grammatically speaking   - Athrash |  ( T a l k )  03:27, 18 October 2005 (UTC)

title: File talk:XRS.jpg


text:
Dog Care/Training/Obedience

Dominance training is a controversial method of training dogs. While it has many proponents, it is often considered outdated and potentially harmful by many dog behaviorists and trainers. It is a theory that believes that the key to a well behaved dog is to be in charge of them, and not the other way around. The practice tries to emulate the way another dog would do it, mostly through body language -- not speech as most people use. Dogs rarely bark at each other to show dominance, they bark when excited, afraid, or angry. But the way we control dogs is primarily by "barking" orders to them using complex language, which they don't understand as readily and therefore don't accept our dominance as readily. Those who practice dominance training think using mostly body language is a much more direct and native language for dogs to understand.

Dominance training theory holds that dominance training should be done on all dogs, regardless of their breed because it can be used to treat all kinds of behavior problems. Those who oppose dominance training theory hold that dominance tactics are often harmful, that dominance tactics can make an aggressive dog more aggressive and a fearful dog more fearful, and that other techniques have been shown to be more effective for basic training in any dog, for correcting bad behavior in any dog, and for rehabilitating problem dogs.

The following is a list of methods or desired behaviors embraced by dominance theory proponents, some of which are considered effective and some of which are considered harmful under other theories of dog behavior and training:

 * have them allow you to take food or toys away from them; you give them back, but they should accept your taking them and not growl

 * you should walk through doors first

 * you should always eat before your dog; let them smell that you are eating, but do not share (do not tease either of course)

 * you can nuzzle your dog's nose, head, neck, body, in almost grooming motions, much like a parent dog would do to their puppy to clean them

 * you can kiss your dog all over

 * petting your dog on the top of their head (they generally don't like that)

 * playing with and gently pulling your dogs ears

 * playing with their feet

 * when your dog is standing or sitting, put your hand over your dog's paw so you are standing on it (but not putting pressure on it of course, just the act of covering it)

 * when your dog is standing on all fours, stand behind your dog with your hands on their hips, and your legs against the back of their legs; when they accept that, then add a repeating knee bend, vaguely simulating the motion that another dog who mounted this dog would be doing

 * gently bite your dog's neck, arms, and legs

 * nibble on your dogs fur as if a parent dog picking out bugs or ticks; watch your dog nibble on their own fur to observe the motion

 * open your mouth wide and put it over the top of your dog's lengthwise (not front on) nose (again, just like another dog would)

 * when your dog is standing, stand to the side of your dog, kneel down, and grab the bottom of the further two legs away from you and pull them towards you; the dog will gently tip over and be forced to lay down in a submissive position; continue to hold the front and back legs that you grabbed; make sure it is a soft surface like grass or carpet so the dog does not get hurt when falling, and perform gently

 * put your dog belly up and sit on them straddled; their back legs should be behind you, not under or in front of you, and you should not allow them to kick you

 * when straddling your dog, expose their neck fully. to do this, tip the bottom of their mouth up so that their forehead is pressing against the floor and their entire neck is exposed and stretched out and available to you, facing up; they should hold that position

 * growl at your dog, especially if they approach you while you are eating or beg (dominant dogs will not let other dogs get too close to them when they are eating)

 * use a gentle leader leash, which simulates another dog putting their mouth over your dog's mouth

 * put your hand(s) over the top of your dog's mouth like a muzzle

title: Dog Care/Training/Obedience


text: User talk:65.33.196.163

title: User talk:65.33.196.163


text: User talk:24.34.94.4

title: User talk:24.34.94.4


text: User talk:24.19.240.139

title: User talk:24.19.240.139


text:
User talk:Danny Wilde~enwikibooks

Hello. Welcome to Wikibooks (と, ぼくが言うのは変かもしれませんが...).

Why don't you take a look at Japanese? We're currently working on New Lesson Thread. If you're interested in, please join the mailing list since most of the discussions are held there. Best regards, Marsian / talk 09:40, 18 October 2005 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Danny Wilde. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Danny Wilde~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:07, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 04:51, 19 April 2015 (UTC)

title: User talk:Danny Wilde~enwikibooks


text: User talk:210.211.231.200

title: User talk:210.211.231.200


text:
Talk:Visual Basic/Jarithmetic Round Two Implementation

Literate Programming?
With a small application it should be possible to download code written on the Wiki and automatically transform it into VB source code ready to compile. Perhaps this could be a general purpose way of presenting code on the Wiki. --kwhitefoot 10:41, 18 October 2005 (UTC)

To do
Explain more about how error handling is implemented in this application.


text:
Movie Making Manual/HDV

WikiPedia article on HDV

HDV vs DVCproHD
DVCproHD will probably produce better results than HDV. DVCproHD uses a chroma subsampling of 4:2:2 (i.e. it records a full-resolution lumanance image and a half-resolution colour image) whilst HDV uses 4:2:0.

DVCproHD also uses a much higher bitrate (100Mbps) than HDV (25Mbps). But that doesn't mean that DVCproHD will be 4 times "better" than HDV. HDV is a more efficient codec than DVCproHD. And, if you're shooting at 24fps then you actually throw away a lot of DVCproHD's data.

There's an interesting discussion of HDV in comparison to other HD formats on episode 2 of the recent Creative Cow podcasts:

http://www.creativecowcast.net

/Cinematography /Formats

title: Movie Making Manual/HDV


text:
Circuit Theory/Analysis Methods

Analysis Methods
When circuits get large and complicated, it is useful to have various methods for simplifying and analyzing the circuit. There is no perfect formula for solving a circuit. Depending on the type of circuit, there are different methods that can be employed to solve the circuit. Some methods might not work, and some methods may be very difficult in terms of long math problems. Two of the most important methods for solving circuits are Nodal Analysis, and Mesh Current Analysis. These will be explained below.

Superposition
One of the most important principals in the field of circuit analysis is the principal of superposition. It is valid only in linear circuits.

What does this mean? In plain English, it means that if we have a circuit with multiple sources, we can "turn off" all but one source at a time, and then investigate the circuit with only one source active at a time. We do this with every source, in turn, and then add together the effects of each source to get the total effect. Before we put this principle to use, we must be aware of the underlying mathematics.

Necessary Conditions
Superposition can only be applied to linear circuits; that is, all of a circuit's sources hold a linear relationship with the circuit's responses. Using only a few algebraic rules, we can build a mathematical understanding of superposition. If f is taken to be the response, and a and b are constant, then:

 * $$f(ax_1+bx_2)= f(ax_1) + f(bx_2) \,$$

In terms of a circuit, it clearly explains the concept of superposition; each input can be considered individually and then summed to obtain the output. With just a few more algebraic properties, we can see that superposition cannot be applied to non-linear circuits. In this example, the response y is equal to the square of the input x, i.e. y=x2. If a and b are constant, then:

 * $$y=(ax_1+bx_2)^2 \ne (ax_1)^2 + (bx_2)^2 = y_1+y_2\,$$

Note that this is only one of an infinite number of counter-examples...

Step by Step
Using superposition to find a given output can be broken down into four steps:

 * 1) Isolate a source - Select a source, and set all of the remaining sources to zero. The consequences of "turning off" these sources are explained in Open and Closed Circuits.  In summary, turning off a voltage source results in a short circuit, and turning off a current source results in an open circuit. (Reasoning - no current can flow through a open circuit and there can be no voltage drop across a short circuit.)
 * 2) Find the output from the isolated source - Once a source has been isolated, the response from the source in question can be found using any of the techniques we've learned thus far.
 * 3) Repeat steps 1 and 2 for each source - Continue to choose a source, set the remaining sources to zero, and find the response. Repeat this procedure until every source has been accounted for.
 * 4) Sum the Outputs - Once the output due to each source has been found, add them together to find the total response.

Impulse Response
An impulse response of a circuit can be used to determine the output of the circuit:

The output y is the convolution h * x of the input x and the impulse response:

 * $$y(t) = (h*x)(t) = \int_{-\infty}^{+\infty} h(t-s)x(s)ds$$.

If the input, x(t), was an impulse ($$\delta(t)$$), the output y(t) would be equal to h(t).

By knowing the impulse response of a circuit, any source can be plugged-in to the circuit, and the output can be calculated by convolution.

Convolution
The convolution operation is a very difficult, involved operation that combines two equations into a single resulting equation. Convolution is defined in terms of a definite integral, and as such, solving convolution equations will require knowledge of integral calculus. This wikibook will not require a prior knowledge of integral calculus, and therefore will not go into more depth on this subject then a simple definition, and some light explanation.

Definition
The convolution a * b of two functions a and b is defined as:

 * $$(a * b)(t) = \int_{-\infty}^\infty a(\tau)b(t - \tau)d\tau$$

The asterisk operator is used to denote convolution. Many computer systems, and people who frequently write mathematics on a computer will often use an asterisk to denote simple multiplication (the asterisk is the multiplication operator in many programming languages), however an important distinction must be made here: The asterisk operator means convolution.

Properties
Convolution is commutative, in the sense that $$a * b = b * a$$. Convolution is also distributive over addition, i.e. $$a * (b + c) = a * b + a * c$$, and associative, i.e. $$a * (b * c) = (a * b) * c$$.

Systems, and convolution
Let us say that we have the following block-diagram system:

Where x(t) is the input to the circuit, h(t) is the circuit's impulse response, and y(t) is the output. Here, we can find the output by convoluting the impulse response with the input to the circuit. Hence we see that the impulse response of a circuit is not just the ratio of the output over the input. In the frequency domain however, component in the output with frequency ω is the product of the input component with the same frequency and the transition function at that frequency. The moral of the story is this: the output to a circuit is the input convolved with the impulse response.

title: Circuit Theory/Analysis Methods


text:
Talk:CISCO Certification/Contents

I am to assume that the author that started this book is wanting to start off by covering the CCNA course first, then moving onto CCNP etc. Keeping each course clearly defined as they do lead into each other.

It clearly needs some more organization if it's for all Cisco certifications. Maybe the CISCO_Certification page should be a portal to the different ones. — Icez 01:42, 24 July 2006 (UTC)

title: Talk:CISCO Certification/Contents


text:
Circuit Theory/Terminology

Basic Terminology
There are a few key terms that need to be understood at the beginning of this book, before we can continue. This is only a partial list of all terms that will be used throughout this book, but these key words are important to know before we begin the main narrative of this text.

 * Time domain : The time domain is described by graphs of power, voltage and current that depend upon time. This is simply another way of saying that our circuits change with time, and that the major variable used to describe the system is time. Another name is "temporal".

 * Frequency domain: The frequency domain are graphs of power, voltage and/or current that depend upon frequency such as Bode plots. Variable frequencies in wireless communication can represent changing channels or data on a channel. Another name is the "Fourier domain". Other domains that an engineer might encounter are the "Laplace domain" (or the "s domain" or "complex frequency domain"), and the "Z domain". When combined with the time, it is called a "spectral" or "waterfall."

 * Circuit response : Circuits generally have inputs and outputs. In fact, it is safe to say that a circuit isn't useful if it doesn't have one or the other (usually both). Circuit response is the relationship between the circuit's input to the circuit's output. The circuit response may be a measure of either current or voltage.

 * Non-homogeneous : Circuits are described by equations that capture the component characteristics and how they are wired together. These equations are non-homogeneous in nature. Solving these equations requires splitting the single problem into two problems: a steady-state solution (particular solution) and a transient solution (homogeneous solution).

 * Steady-state solution : The final value, when all circuit elements have a constant or periodic behavior, is also known as the steady-state value of the circuit. The circuit response at steady-state (when voltages and currents have stopped changing due to a disturbance) is also known as the "steady-state response". The steady-state solution to the particular integral is called the particular solution.

 * Transient : A transient event is a short-lived burst of energy in a system caused by a sudden change of state.

 * Transient means momentary, or a short period of time. Transient means that the energy in a circuit suddenly changes which causes the energy storage elements to react. The circuit's energy state is forced to change. When a car goes over a bump, it can fly apart, feel like a rock, or cushion the impact in a designed manner. The goal of most circuit design is to plan for transients, whether intended or not.

 * Transient solutions are determined by assuming the driving function(s) is zero which creates a homogeneous equation, which has a homogeneous solution.

Summary
When something changes in a circuit, there is a certain transition period before a circuit "settles down", and reaches its final value. The response that a circuit has before settling into its steady-state response is known as the transient response. Using Euler's formula, complex numbers, phasors and the s-plane, a homogeneous solution technique will be developed that captures the transient response by assuming the final state has no energy. In addition, a particular solution technique will be developed that finds the final energy state. Added together, they predict the circuit response.

The related Differential equation development of homogeneous and particular solutions will be avoided.

title: Circuit Theory/Terminology


text:
User:David Kernow~enwikibooks

Wikijunior

NPOV disputes ... Cleanup

Editing help

title: User:David Kernow~enwikibooks


text:
Cookbook talk:Deep-fried Mars bar

Please don't. This stuff just isn't healthy. Really.

title: Cookbook talk:Deep-fried Mars bar


text:
Talk:Circuit Theory/Circuit Basics/Active vs. Passive Elements

I feel like the current incarnation of this page gets a little bit off topic. I don't think there is any sense confusing the subject when we can simply distill out all the information that isn't immediately important. Why do we need to blur the line between different types of sources, or even differentiate between different sources, when the only thing we need to mention is what each little symbol does on a circuit diagram. I'll leave this the way it is for now, but i think we will probably need to fix this later. --Whiteknight 13:53, 18 October 2005 (UTC)


text:
Talk:Circuit Theory/Circuit Basics/Ohm's Law

I think perhaps that this page might be better served if we merged it with the "resistors" page. that might make the information harder to find, however. --Whiteknight 13:56, 18 October 2005 (UTC)


text:
SPM/Installation on Windows

Preamble
Installing SPM on Windows 32 bit (XP, Vista, 7) should be relatively straightforward. Common pitfalls can be found in the description of the 64bit Windows installation.

Installation
>> addpath C:\Users\login\Documents\MATLAB\spm12 in MATLAB's workspace. >> spm
 * Download spm12.zip.
 * Unzip spm12.zip in a folder of your choice, such as C:\Users\login\Documents\MATLAB\spm12).
 * Start MATLAB and add SPM into your path, either using File > Set Path > Add Folder... or typing
 * Launch SPM by typing

You might have to install the VC++ 2005 and 2008 Redistributable Packages (vcredist_x86.exe) from Microsoft:
 * http://support.microsoft.com/kb/2019667

Update
If you have just downloaded the spm12.zip archive, it already contains the latest set of updates. To update SPM when a new version is released: Alternatively, you can use the spm_update.m function: >> spm_update If a new version is available, it can be applied to your local installation by typing: >> spm_update update
 * Download spm12_updates_rxxxx.zip
 * Unzip spm12_updates_rxxxx.zip on top of the folder containing your SPM installation so that newer files overwrite existing files.

Compilation
Precompiled MEX files (*.mexw32) are provided with SPM12 and you shouldn't need to recompile them by yourself.

Installation
>> addpath C:\spm\spm8 in MATLAB's workspace. >> spm
 * Download spm8.zip and its updates spm8_updates_rxxxx.zip
 * Unzip spm8.zip in a folder of your choice, such as C:\spm\spm8, and unzip spm8_updates_rxxxx.zip on top of it so that newer files overwrite existing files.
 * Start MATLAB and add SPM into your path, either using File > Set Path > Add Folder... or typing
 * Launch SPM by typing

Compilation
Precompiled MEX files (*.mexw32) are provided with SPM8 and you shouldn't need to recompile them by yourself.

See Compilation of SPM8 MEX files on Windows if needed.

Installation
>> addpath C:\spm\spm5 in MATLAB's workspace. >> spm
 * Download spm5.zip.
 * Unzip spm5.zip in a folder of your choice, such as C:\spm\spm5.
 * Start MATLAB and add SPM into your path, either using File > Set Path > Add Folder... or typing
 * Launch SPM by typing

Compilation
Precompiled MEX files (*.mexw32) are provided with SPM5 and you shouldn't need to recompile them by yourself.

See Compilation of SPM5 MEX files on Windows if needed.

Installation
>> addpath C:\spm\spm2 in MATLAB's workspace. >> spm
 * Download spm2.tar.gz and its updated MEX files SPM2_R2007a_XP_MEX.zip
 * Unzip spm2.tar.gz in a folder of your choice, such as C:\spm\spm2, and unzip SPM2_R2007a_XP_MEX.zip on top of it so that newer files overwrite existing files.
 * Start MATLAB and add SPM into your path, either using File > Set Path > Add Folder... or typing
 * Launch SPM by typing

Compilation
Precompiled MEX files (*.mexw32) are provided with SPM2 and you shouldn't need to recompile them by yourself.

See Compilation of SPM2 MEX files on Windows.

title: SPM/Installation on Windows