Balder W. Holst

Hello there!

My name is Balder and this is my personal website. Here i write down what i learn to maybe help others some day. For now i will just act like people are reading my articles, and make them for fun.

This website has three main sections:

I write these articles for fun, and even though i try to make sure that they are correct, i am not a perfect human and there are sure to be mistakes. Below is a list of most recent articles in all categories.

Recent Posts

Foldningssum
Foldningssum See slides. $h$-funktionen “spejles” med akse i $n$ ganges med $x$-funktionen. $$y(n) = x(n) \times h(n) = \sum_{m=0}^{n}x(m) \cdot h(n - m)$$
0001/01/01 · Notes
Fordampningsenergi
Fordampningsenergi Energien det tager at fordampe en væske måles i kJ/kg.
0001/01/01 · Notes
Fordoblings- og halveringkonstant
Fordoblingskonstanten Formelsamling.pdf>page=19 Viser hvor meget $x$ skal vokse før, $y$ fordobles. $$T_2= \frac{ln(2)}{ln(a)}$$ $a$ : $a$-værdien i den eksponentielle funktion. Halveringskonstanten Formelsamling.pdf>page=20 Viser hvor meget $x$ skal vokse før, $y$ halveres. $$T_2= \frac{ln(\frac{1}{2})}{ln(a)}$$ $a$ : $a$-værdien i den eksponentielle funktion.
0001/01/01 · Notes
Forward Kinematics
Forward Kinematics Forward kinematics describes how motion of the joints affects motion of the robot end-effector. There is no standard way to place frames. Placing Frames $$ >^0_3T =\ ^0_1T\ ^1_2T\ ^2_3T >$$
0001/01/01 · Notes
Forwarding Table
Forwarding Table The way routers determine where to send a request to an ip it does not host. If the router does not know which router to forward the request to, it sends an ARP Packet to find the destination. This route is recorded in the routers forwarding table.
0001/01/01 · Notes
Fotoelektrisk Effekt
Fotoelektrisk Effekt Fotoelektrisk effekt sker hvis dette er sandt $$A_L \le E_{\gamma}$$ $A_L$: Løsrivningsarbejde $E_{\gamma}$: Fotoner>Fotoners kinetiske energi Den samlede energi (Einsteins Fotoelektriske Lov) $$E_{samlet}=A_L+E_{kin}$$ Fotoelektronens energi $$E_{fotoelektron}=E_{foton} - E_{binding}$$ Sandsynligheden for at fotoelektrisk effekt forekommer $$\sigma_{F} \propto \frac{Z^n}{E^m}$$
0001/01/01 · Notes
Fotoner
Fotoner Fotoners kinetiske energi $$E_{\gamma} = h \cdot f = \frac{h \cdot c}{\lambda}$$ $h$: Planck konstanten $f$: Frekvensen Fotoners masse Fotoner har enlig ikke en masse når de står stille, for det kan et foton ikke, men forsøg har vist at en foton har en ækvivalent masse, der skan beregnes således (Orbit 3, s. 255): $$m_{foton} = \frac{E_{foton}}{c^2}$$ Fotoners bevægelsesmængde $$P_{foton} = m_{foton} \cdot c = \frac{h}{\lambda} \Arrows P_{foton} = \frac{h \cdot f}{c}$$
0001/01/01 · Notes
Fourier-transformation
Fourier-transformation See slides. Trigonometric approximations for aperiodic signals. Make the period of the signal, as large as the signal duration and use Fourieseries. $$L \to \infty$$ $$ X(\omega) = \int_{-\infty}^{\infty} x(t) e^{-j \omega t} \mathrm{dt} $$ $$ x(t) = \frac{1}{2\pi} \int_{-\infty}^{\infty} X(\omega) e^{j \omega t} \mathrm{d\omega} $$ Examples lektion1.pdf>page=2 lektion1.pdf>page=3 lektion1.pdf>page=4 Tables
0001/01/01 · Notes
Fourieseries
Fourieseries Se slides. Trigonometric approximations for periodic signals. (As opposed to Fourier-transformation) $$ f(x) = \frac{a_0}{2} + \sum^\infty_{n=1} \left( a_n \cos \left( \frac{n\pi x}{L} \right) + b_n \sin \left( \frac{n\pi x}{L} \right) \right) $$ $n$: A how many times of the base frequency. $L$: The half period. $$ \begin{align} a_n &= \frac{1}{L} \int^L_{-L} f(x) \cos \left( \frac{n\pi x}{L} \right) \dx, \s n \geq 0 \ \ b_n &= \frac{1}{L} \int^L_{-L} f(x) \sin \left( \frac{n\pi x}{L} \right) \dx, \s n > 0 \end{align} $$
0001/01/01 · Notes
Frames
Frames Frames are coordinate systems. Frames can be positions relative to each other. Kinematics is basically about describing these relationship.
0001/01/01 · Notes