I am more than half way through Steins Gate. Apparently, it will become one of my all time favorite. Okay, there will be spoilers here. For those who didn’t watch it, go watch it now! It doesn’t matter if you are an anime fan or not. This one will definitely change your attitude towards anime…
Here are some notes of TF-IDF as a measure for identifying keywords in a document. To efficiently indexing documents for future search, it is important to identify the keywords in a document. For a word $latex w$ to be a good keyword, first, it should be relatively rare. This can be measured by the inverse document frequency…
I am studying an online class on Web Intelligence and Big Data. Dr. Shroff described a very nice example of LSH. Below are some quick notes. The idea of LSH is essentially the same as dimension reduction. We have some data vector $latex x$ that can be in very high dimension. By processing hash data…
Here is some personal notes on Bernstein-Vazirani algorithm. Assume that we have a black box that does nothing but compute $latex u \cdot x$, where $latex x$ is an input binary vector and $latex u$ is another binary vector that we don’t know its value. Note that all operation is bit-wise and so the output…
The effect of applying Hadamard gates to multiple qubits is rather subtle and is used in many quantum algorithms. Consider $latex n$ input qubits, $latex |u_1 u_2 u_3 \cdots u_n\rangle$. What will be the output if we apply the Hadamard gate to each of the qubit? Note that a Hadamard gate maps $latex |0\rangle$ to…
It appears that YouTube occasionally hiccups on some ogv files and produces green screen. The following may not be the best solution. But it almost always solves the problem by first transcoding the video to avi. In linux, it can be done by mencoder as follows mencoder input.ogg -ovc xvid -oac mp3lame -xvidencopts pass=1 -o…
Let say Alice wants to pass her qubit to Bob. By no cloning theorem, we know that Alice cannot duplicate her qubit to Bob. However, she can “teleport” her qubit to Bob if they share a Bell state . First, Alice will apply CNOT gate from to her qubit in the shared Bell state. This…
I’m still studying the online course on quantum computing where Prof. Vazirani went through the no cloning theorem. It is very interesting to see that something that can lead to some very subtle consequence can also have a very simple proof. Below is a summary. Basically, the theorem states that no quantum state can be…
I have a JVC HD camcorder to video tape some presentations. The webcam is not bad but the AC in our room is just too noisy. As I mentioned in a previous post, one can easily remove noise using Audacity. However, the video from the my camcorder has the annoying MTS format. It took me…
I am studying the online class on quantum computing (coursera). I did a quantum mechanic course more than a decade ago but I didn’t go into the detail of the Bell’s experiment then. The explanation from Prof. Vazirani is great and I feel that I finally understand the setup after all these years! Here, I…