User:Jessica1088
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Profile
Name: Jessica Kwong
Age: 18
Birthplace: Orange County, NY
Profession: Student / Level 8631 Ninja-Rogue-Hwarang
Major: Biomedical Engineering
Blood Type: O
Horoscope: Scorpio
Hobbies/Obsessions
I enjoy doing typical things, like listening to music. My favorite bands include Gazette, DBSK, Koyote, NRG, Alice Nine and T.M. Revolution. I also like watching Asian dramas and movies, such as ‘Hana Yori Dango,’ ‘Gokusen,’ and ‘My Boss, My Hero.’ My favorite actor is currently Oguri Shun, who plays Hanazawa Rui in Hana Yori Dango, and Uchiyama Haruhiko in Gokusen. I like making web layouts featuring people I like, which usually include my favorite bands or other cute people. I like cute games and MMORPGs, such as Monato Esprit and World of Warcraft. I have a level 21 Blood Elf Hunter in WoW, but the max level is 70 and I am far from reaching that goal. In Monato, I have a Hwarang, a Mage, and a really, really weak Cleric >_< . Sims 2 is another favorite game of mine, probably because I get to tell people what to do and control every aspect of their lives =). I also like to draw, mostly anime/jrock-like people, but I am not very good at it.
Future/Goals
I am not sure of what I want to do exactly, but I would either work within the Biotech industry or go to Med-school and become a physician. Another thing I wish to accomplish is to be very proficient in web design and Photoshop, because I want layout designing to be something I continue to do in the future along with my career.
Links
Radio Signal Entries | Session II
22 February 2007
Today, we learned about the objectives of this lab and the equipment they use. They study cosmic rays by analyzing the radio signals that are produced from the rays, but these cosmic rays occur randomly so the lab creates a simulation of these rays. Also, noise from planes or other signal producing objects interfere with the radio signals and mess up data. The lab uses antennnas to pick up signals and these signals travel through wires and the radio reciever to the computer.
27 February 2007
We learned out to set up the computer to analyze radio waves. The antenna is connected to the reciever, which is then connected to the sound card of the computer, and the speakers are also connnected to the computer to output the sound. We used the program WinRadio to analyze the radio waves the antenna was recieving. We explored the features of this program and I learned that AM waves are of a lower frequency than FM waves and TV signals.
1 March 2007
Today, we learned about the program MATLAB and how to use programming with it. We learned how to input matrices. We also learned how to graph functions and control how the graph looked.
6 March 2007
We learned more about Matlab and how to graph sinusoidal functions. If the frequency of the function is increased, then the sampling period must be decreased in order to correctly show graph. We also learned how to output sound from Matlab. The amplitude controls the volume of the sound, i.e. a small amplitude makes the sound softer while a large amplitude makes the sound louder. Also, the frequency controls the pitch of the noise. A small frequency creates a low pitched sound while a large frequency creates a high pitched sound.
8 March 2007
We continued working with the program MATLAB and we learned how to save sounds we've created as wav files and how to upload sounds back into MATLAB. In real life data, there is always noise, things that we don't want in our data, so we learned how to add noise to our sounds to mimic real signals. MATLAB randomly generates a matrix and uses that as the noise. We then combined a pure sound with the noise and then listened to it.
13 March 2007
We learned how to add noise to real signals through MATLAB. First, we recorded 10 seconds from WCBS radio using WinRadio and uploaded the file to MATLAB. We then created a matrix of random numbers which we used as our noise. We played the files separately and then together. We then generated graphs of both noises, 2 of the full graph and 2 of a 0.1 sec segment of each. The top 2 graphs represent the pure sound from the WCBS radio signal and the bottom 2 graphs are the sounds after we added the noise. As you can see, the amplitude of the graph increased when noise was added.
15 March 2007
In this lab session, we learned about the a program created through Matlab that was a GUI, a graphical user interface. GUIs are much simplier and easier to use than Matlab because users do not need to know the commands of Matlab in order to use the GUI, whose interface includes easy input and output. Basically, we loaded wav files into the GUI and played with the controls, mainly with the frequency control. Also, we plotted the signals of these files. We then loaded melodies into the GUI and changed the sampling frequency of them, resulting in a low-pitched melody that lasted longer, and a high-pitched melody that was short.
Overall Experience
In this lab, we've learned about radio signals and how to process them. We used programs like WinRadio and MatLab to recieve signals and process them. First, signals are received with an antenna and then sent through wires to a reciever. Then, the signal goes through the sound card and to the computer. We used WinRadio to listen to these signals, such the WCBS radio station signal. Through MatLab, we can find the frequency of this signal and manipulate it, such as changing the amplitude and adding noise. We could also plot the signal with this program. Through MatLab, there was a GUI program that was created that could easily manipulate the signal. It could change the frequency, which would automatically change the number of steps between the start and the stop, and it could easily graph the signal. We then learned about carrier signals, which are used to transmitt information to radio receivers. With 2 function generators and an oscillioscope, we saw how one signal can act as a carrier signal for another.
Cosmic Rays Entries | Session III
22 March 2007
On the first day, we learned about cosmic rays. They are particles that come from space, probably from stars and other materials in space. Cosmic Rays are constantly falling to the earth, but what reaches the surface of the earth is not as harmful as the particles that first hit the earth's atmosphere. There are machines that can detect these particles, such as geiger counters and scintillators. Scintillators are enclosed in a black case and can detect particles as they pass through the scintillators, but they can only detect charged particles. Also, it is not known if the particles that pass through the scintillators are cosmic rays or noise from other materials on the earth. We used an oscilloscope to read the signals from the scintillators and also used a device to count how many particles were going through the scintillators.
27 March 2007
We measured the number of charged particles that passed through the scintillators with a counter and calculated the rate of coincidences between one scintillator and another one beneath it. First, we connected the wires so that the counter would count the number of charged particles that hit both scintillators at the same time. We then calculated the rate of coincidences over a 20-second interval and then for a 120-second interval. The rate was about 21 counts/sec and it seems that the longer the interval, the more accurate each trial was. We then measured the rate but with voltage as a variable. There is a correlation that as voltage increases, the rate of coincidences as increase, but it does not look like a perfect linear relationship. On the other hand, the rate at which particles would pass through the scintillators increased exopentially as the voltage increased.
29 March 2007
Instead of timing the counters to observe conincidence rates, we used a machine that did the work for us. A special program was made to use the hardware and make it do what we needed it to do. Using this machine, we looked at the reliability of the middle scintillator as a means of finding the coincidence points. We measured the coincidence between the top two scintillators, and then through all of them, to see how many of the charged particles that are detected by the middle scintillator actually go through all three scintillators.
To devise an experiment, we all met to dicuss possible questions that we could answer. We liked the idea of testing to see if cosmic rays can pass throrugh all materials, or if some materials can block CRs more easily than others. We wanted to test materials like water, fabric, sheets of metal (possibly), and other stuff, using air as a control. We also want to test the rate of CRs in the light and dark, seeing how there are more CRs at night.
10 April 2007
Today, we started the first part of our experiment, we hypothesized that the rate of CRs are dependent on the amount of light in the enivronment. Our data was:
Next for our experiments, we plan on placing several different materials in between the scintillators to see if certain materials can prohibit the passage of cosmic rays. We plan using materials such as water, the building, the tin roof and air as a control. We hypothesized that water and a mirror may bend the path of cosmic rays. By taking three 3-min trials of each material, we hope to see a correlation between the rate of CRs and the materials they pass through.
12 April 2004
17 April 2007
Today, we did a series of experiments to see from what direction cosmic rays come from. One group of two counted the rate of coincidences between 2 scintillators in different positions relative to the ground. The idea was that as the scintillators are further apart, the angle at which CR can hit both is reduced. By comparing values of rates taken from when the scintillators are in the vertical, horizontal and diagonal positions, we can see how CRs hit the scintillators.
Another group tested to see the rate of CRs vs height difference.
It seems that as the distance between the scintillators increase, the number of CRs decrease, which shows that CRs not only come directly down. Analyzing both sets of data, CRs can also come down at an angle, because when the scintillators were diagonal to each other, the rate did reduce, but not as much as when they were in the horizontal position.
19 April 2007
With two scintillators, we measured the approximate speed of the CRs. By measuring the height between two scintillators and the time difference between the pulses, and measuring another height difference with another time difference, we used v = d/t to find that the speed of the CR is 3.33*10^8 m/s, but this value has huge error because this experiment was not accurate enough to precisely measure the speed.
Reflection
First, I would like to correct myself in mis-analyzing the data. For the rate of the CRs while the scintillators are 30 in apart was not 11, but 3 CRs/sec, so the rate decreased.
Working in this lab was fun. I enjoyed being able to think about possible experiments and trying to prove them right. Also, cosmic rays are an interesting phenomenon so learning about them was fun, too. I wish I had more time to investigate their properties more, and I would love to elaborate on the materials experiment too.
