Kilo = 10^3
Mega = 10^6
Giga = 10^9
I was fatuously believing this conversion rate is true.
But...I just found out that the story is a bit different in case of "byte".
When I was checking my data usage on verizon,
I noticed that the first few digits of GB, MB, and KB are different!
That can't be true if Kilo means 1000 and Mega means 1000,000.
Soon I found out the following fact.
1000 Bytes is not Equal to 1 Kilobyte.
1 Kilobyte is very close to 1000 bytes, but it is 1024 bytes in exact.
That makes sense as the computer data is in binary.
However when I checked about this with wikipedia, I found out that the story is not that simple.
It seems that both are in use...well who cares about it?
The difference between 1000 and 1024 is probably negligible.
But 1000^K and 1024^K's difference will become significant as K increases.
Going to Tera, Peta, and larger, the huge difference will be a problem, I believe.
....I think someone has to resolve this issue in near future.
Friday, July 5, 2013
Thursday, July 4, 2013
Harmonic Mean
In mathematics there are several ways to take the mean (average) value.
The most well known is the arithmetic mean, which is the just average we usually think about.
But today I would like to mention about "Harmonic Mean".
Harmonic Mean of two numbers X and Y is
2/(1/X + 1/Y)
I come up with an instance to use harmonic mean.
Suppose I live at the foot of a hill, my office is at the top of the hill, and
I drive a roundtrip between my home and my office.
Furthermore, suppose my MPG( millage per gallon) is 10 for upward and 40 for downward for sake of simplicity.
Then my MPG for the round trip must be computed as follow:
MPG = # miles driven/ # gallon consumed.
Let D be the # miles in one way.
So #miles driven for the round trip is 2D
then #gallon for up should be D/10, and
#gallon for down should be D/40.
So # gallon consumed for the round trip is the sum D/10 + D/40.
Hence, MPG = (2D) / (D/10 +D/40)
= 2/(1/10 + 1/40) = 80/5 = 16 mpg.
Notice that the distance D is irrelevant to find the average fuel consumption for the round trip.
The blue part (obtained from above line by dividing top and bottom of the expression by D.)
is exactly the harmonic mean of 10 and 40. So in this sense 16 is the average mpg of 10 and 40.
Now I want to improve my overall mpg by driving mildly.
Which strategy works better?
1. Improve only my uphill consumption rate from 10mpg to 20mpg.
2. Improve only my down consumption rate from 40mpg to 80mpg.
The first strategy will result to 26.666 mpg, pretty good.
But....
the second strategy will result to 17.777 mpg......Not much change!
Here is the lesson.
To improve the harmonic mean, one should consider improving the lower value.
Improving the lowest performer will result a better overall performance.
Help the most struggling worker will do better than help the talented one to go further.
Isn't it Harmonic??
Anyway, in reality, my commuting route has lots of short sloped roads, disgusting traffic lights,
and entrance to a freeway. If I can pass these mpg-killing points with mild loss of fuel, my over all mpg will improve a lot. In fact after I realized this, my MPG is improving from 39 to 46!
Thinking mathematically saves lots of fuels and money!
(I lied here, it doesn't save much money for me because I live close to my office.)
The most well known is the arithmetic mean, which is the just average we usually think about.
But today I would like to mention about "Harmonic Mean".
Harmonic Mean of two numbers X and Y is
2/(1/X + 1/Y)
I come up with an instance to use harmonic mean.
Suppose I live at the foot of a hill, my office is at the top of the hill, and
I drive a roundtrip between my home and my office.
Furthermore, suppose my MPG( millage per gallon) is 10 for upward and 40 for downward for sake of simplicity.
Then my MPG for the round trip must be computed as follow:
MPG = # miles driven/ # gallon consumed.
Let D be the # miles in one way.
So #miles driven for the round trip is 2D
then #gallon for up should be D/10, and
#gallon for down should be D/40.
So # gallon consumed for the round trip is the sum D/10 + D/40.
Hence, MPG = (2D) / (D/10 +D/40)
= 2/(1/10 + 1/40) = 80/5 = 16 mpg.
Notice that the distance D is irrelevant to find the average fuel consumption for the round trip.
The blue part (obtained from above line by dividing top and bottom of the expression by D.)
is exactly the harmonic mean of 10 and 40. So in this sense 16 is the average mpg of 10 and 40.
Now I want to improve my overall mpg by driving mildly.
Which strategy works better?
1. Improve only my uphill consumption rate from 10mpg to 20mpg.
2. Improve only my down consumption rate from 40mpg to 80mpg.
The first strategy will result to 26.666 mpg, pretty good.
But....
the second strategy will result to 17.777 mpg......Not much change!
Here is the lesson.
To improve the harmonic mean, one should consider improving the lower value.
Improving the lowest performer will result a better overall performance.
Help the most struggling worker will do better than help the talented one to go further.
Isn't it Harmonic??
Anyway, in reality, my commuting route has lots of short sloped roads, disgusting traffic lights,
and entrance to a freeway. If I can pass these mpg-killing points with mild loss of fuel, my over all mpg will improve a lot. In fact after I realized this, my MPG is improving from 39 to 46!
Thinking mathematically saves lots of fuels and money!
(I lied here, it doesn't save much money for me because I live close to my office.)
Tuesday, July 2, 2013
Give Up to Leave Fame!
After my little dinner, I noticed sound of
fireworks.
The loudness indicates that the fireworks were held nearby.
I expected to see it from here, so I went outside. T
here was a drizzling, but I found out a good view spot under a tree in front of my apartment.
A bit too far to feel the sonic vibration.
But I did enjoy the incessant sequence of fireworks for 10 minutes or so.
While watching the show, I felt how short the life of each one of fireworks’ bombs.
I don’t know how challenging to create an exquisite and enchanting bomb.
Anyway its life is so short, much shorter than cherry blossoms which are famous representation for a short lived life in Japanese culture.
Each bomb was glorious for a second and was already in oblivion in another second.
So sad isn’t it? What a pitiful life! Or Am I wrong!?
After all, human’s life is very short. It is as short as the fire bombs.
Yeah, I remember now that everything is in relative scale.
Each one of us is just like a single bomb in the sequence of the firework show.
Hey, don’t try to live for leaving fame!
If one bomb’s smoke remained in the air for long, people can’t enjoy the rest of the show.
Just exit the stage without hesitation!
Ok, I try to reset my mind and I’m not going to fear of a life like the bomb or the cherry blossoms.
Yes, spectators forget each one of the explosions but they feel something by seeing the fireworks and their hearts reshape by the end of the show. They forget all the details, but they gain something!
If a bomb can do it, I can live like that!
The loudness indicates that the fireworks were held nearby.
I expected to see it from here, so I went outside. T
here was a drizzling, but I found out a good view spot under a tree in front of my apartment.
A bit too far to feel the sonic vibration.
But I did enjoy the incessant sequence of fireworks for 10 minutes or so.
While watching the show, I felt how short the life of each one of fireworks’ bombs.
I don’t know how challenging to create an exquisite and enchanting bomb.
Anyway its life is so short, much shorter than cherry blossoms which are famous representation for a short lived life in Japanese culture.
Each bomb was glorious for a second and was already in oblivion in another second.
So sad isn’t it? What a pitiful life! Or Am I wrong!?
After all, human’s life is very short. It is as short as the fire bombs.
Yeah, I remember now that everything is in relative scale.
Each one of us is just like a single bomb in the sequence of the firework show.
Hey, don’t try to live for leaving fame!
If one bomb’s smoke remained in the air for long, people can’t enjoy the rest of the show.
Just exit the stage without hesitation!
Ok, I try to reset my mind and I’m not going to fear of a life like the bomb or the cherry blossoms.
Yes, spectators forget each one of the explosions but they feel something by seeing the fireworks and their hearts reshape by the end of the show. They forget all the details, but they gain something!
If a bomb can do it, I can live like that!
Monday, July 1, 2013
On Reading News Articles on Economy
These
days I push myself reading articles on economy. Today’s my choice was an article
on Chinese economy (please see the link below) based on PMI. I had no idea about PMI and I was actively
enough to do a little search for it. I learned that PMI stands for “Purchasing
Manager Index” and it is just a weighted average of +1 (as Improvement), 0.5
(as No Change), and 0 (as Deterioration) from answers of monthly surveys of
private sector companies. I don’t know how the surveys are conducted, but need
I know it? I learned that PMI (Purchasing Manager Index) is announced at the
beginning of each month and it has a strong positive correlation with GDP. No
wonder I found out this news article today! Since I haven’t seen China by
myself and haven’t thought about it much either, I can’t judge how reliable and
trustful this article is. Yet I found some yield from this reading experience.
First is the very fact that I clicked the
link to this article and read it. Unthinkable! What’s wrong with me! My
interest toward the world is getting wider and wider. In the last month I read
two books about future Chinese economy. One of the books was advertised in the
economic magazine I was reading. Then
why I gradually was drawn to reading economics?
It was simply because significant portion of my students were majoring
economics and business/commerce. So I wanted to find out how important
mathematics in these field.
Second was my activeness googling PMI and
understood the main logic behind this article. I was impressed to myself for
being able to read the economic article this clearly. I couldn’t do this at all
before!
The I want to gain more core knowledge in
various fields so I will be able to read many more quickly and deeply.
Wednesday, June 19, 2013
Scutaro is Back on Line Up!
I'm very excited to see him back in SF Line Up.
I wish his finger heals well.
I wish his finger heals well.
Tuesday, June 18, 2013
MPG Game (2)
It has been 5 months since I started driving the hybrid car.
I still can't ignore the mpg digital display on the dashboard.
Well thanks to the hybrid economic fuel efficiency (and thanks to myself for not driving a lot), I need to visit the gas station only once per month.
I keep track of my MPG at each refueling and here is the my record so far.
Look at the improvement in MPG column over the past 5 months!
I'm getting better at getting a higher MPG value since January.
Well the part of the reason could be the season. Expected MPG is lower in winter season.
But I think I'm driving more gently these days, avoiding sudden acceleration and frequent braking to improve MPG. I will visit the gas station soon, but I'm sure that I will get over 40.00 this time.
Currently the annoying digital display says 45.7 mpg!
I hope I can maintain this high standard.
I still can't ignore the mpg digital display on the dashboard.
Well thanks to the hybrid economic fuel efficiency (and thanks to myself for not driving a lot), I need to visit the gas station only once per month.
I keep track of my MPG at each refueling and here is the my record so far.
Look at the improvement in MPG column over the past 5 months!
I'm getting better at getting a higher MPG value since January.
Well the part of the reason could be the season. Expected MPG is lower in winter season.
But I think I'm driving more gently these days, avoiding sudden acceleration and frequent braking to improve MPG. I will visit the gas station soon, but I'm sure that I will get over 40.00 this time.
Currently the annoying digital display says 45.7 mpg!
I hope I can maintain this high standard.
| Miles | MPG | |
| 1/27/13 | ? | ? |
| 2/19/13 | 400 | 34.28 |
| 3/31/13 | 398.4 | 36.72 |
| 4/21/13 | 429.8 | 38.61 |
| 5/22/13 | 400.2 | 39.77 |
| 6/xx/13 | ? | ? |
Monday, June 17, 2013
To the Next Generation....
I tend to think of my life as mine.
Often I'm searching for the purpose of my life, and I couldn't think of the world after my death at all.
Sort of a self-contained life, I'm only visioning my life span.
Nothing in the past matters, and nothing in the future after my death matters....
Reading an aritcle "Crazy Far" in 125th Anniversary special edition of National Geographic magazine, I was quite amazed at the future visions that NASA technologists were seeing.
How human can go to Mars, moons of Saturn, out of Solar System....in 20 years, 100 years, or 500 years?????? They will never know that they can accomplish something in their life. But probably it doesn't matter to them. Look at the time scale of their future vision! Probably they are happy to be the part of the huge project that human is working on.
Look at me! I couldn't think that way. I want to complete something in my life. I don't want to be a mere particle in a huge stream of the history.
After reading "Crazy Far", I felt that I grasp some idea on life's purpose.
Often I'm searching for the purpose of my life, and I couldn't think of the world after my death at all.
Sort of a self-contained life, I'm only visioning my life span.
Nothing in the past matters, and nothing in the future after my death matters....
Reading an aritcle "Crazy Far" in 125th Anniversary special edition of National Geographic magazine, I was quite amazed at the future visions that NASA technologists were seeing.
How human can go to Mars, moons of Saturn, out of Solar System....in 20 years, 100 years, or 500 years?????? They will never know that they can accomplish something in their life. But probably it doesn't matter to them. Look at the time scale of their future vision! Probably they are happy to be the part of the huge project that human is working on.
Look at me! I couldn't think that way. I want to complete something in my life. I don't want to be a mere particle in a huge stream of the history.
After reading "Crazy Far", I felt that I grasp some idea on life's purpose.
Sunday, May 12, 2013
Traffic Ticket Spam.
I received the spam email which asks to pay for the traffic ticket for speeding.
I received this email on 5/6 for the speeding on 4/27 at 7:25AM in 55mph zone.
At the beginning, I thought I might be caught by the police.
But then I was thinking about where I drive with high speed on 4/27.
1. Since I changed my vehicle to the hybrid car, I rarely drive at very high speed.
I feel that the gas pedal is heavier than the car I used drive, and the instantaenous mpg displayer deters me pushing the car as well.
2. I felt very weird about this email because the body part of the message doesn't include any of my personal and my vehicle information. The message just says the open the attached document for payment instruction or whatever. Look at the sender's email. It's not from nys government. It was a gmail sender, so it could be from anyone. Furthermore that the attached file is a zipped file. Why not a single PDF file? So I felt strange and didn't want to open the attachment.
3. I tried to recollect where I drive on 4/27. 4/27 was Saturday. What!? Saturday?
Hmm but wait a minute, when I was caught speeding? 7:25AM?? AM!!
I didn't remember what I did on this Saturday. I'm absolutely positive that I was in my bed at 7:25AM of any Saturday! At this point I was sure that this email was the spam.
4. I searched online to see that whether this spam was alerted previously and I found it.
The following link shows the spam email that exactly as what I received.
Same time, same date, same speeding zone,.....
http://techhelplist.com/index.php/spam-list/216-uniform-traffic-ticket-virus
I must be really attentive when checking emails!
This is something I should avoid to do when I'm too tired!
I received this email on 5/6 for the speeding on 4/27 at 7:25AM in 55mph zone.
At the beginning, I thought I might be caught by the police.
But then I was thinking about where I drive with high speed on 4/27.
1. Since I changed my vehicle to the hybrid car, I rarely drive at very high speed.
I feel that the gas pedal is heavier than the car I used drive, and the instantaenous mpg displayer deters me pushing the car as well.
2. I felt very weird about this email because the body part of the message doesn't include any of my personal and my vehicle information. The message just says the open the attached document for payment instruction or whatever. Look at the sender's email. It's not from nys government. It was a gmail sender, so it could be from anyone. Furthermore that the attached file is a zipped file. Why not a single PDF file? So I felt strange and didn't want to open the attachment.
3. I tried to recollect where I drive on 4/27. 4/27 was Saturday. What!? Saturday?
Hmm but wait a minute, when I was caught speeding? 7:25AM?? AM!!
I didn't remember what I did on this Saturday. I'm absolutely positive that I was in my bed at 7:25AM of any Saturday! At this point I was sure that this email was the spam.
4. I searched online to see that whether this spam was alerted previously and I found it.
The following link shows the spam email that exactly as what I received.
Same time, same date, same speeding zone,.....
http://techhelplist.com/index.php/spam-list/216-uniform-traffic-ticket-virus
I must be really attentive when checking emails!
This is something I should avoid to do when I'm too tired!
Monday, February 25, 2013
Haagen Dazs, Gelato Line.
In my most recent shopping, I found a Gelato series of Haagen Dazs for the first time.
I haven't bought any icecream since the winter break, but I bought two flavors with no hesitation.
I bought "cappucino" and "vanilla bean".
I only tasted "cappucino" so far, but it is delicious.
You should try them right now!
http://www.haagendazs.com/Products/Gelato/
I haven't bought any icecream since the winter break, but I bought two flavors with no hesitation.
I bought "cappucino" and "vanilla bean".
I only tasted "cappucino" so far, but it is delicious.
You should try them right now!
http://www.haagendazs.com/Products/Gelato/
Friday, February 8, 2013
MPG game.
On January 27th, I purchased an used 2005 Civic Hybrid.
One thing I like about this car is that it has lots of meters in the instrumental panel.
There are a MPG for a current travel and current instantenous MPG are displayed.in digital format.
At first I liked it.
While driving, I'm in "playing a game" mode.
I'm trying to improve and maximize the MPG displayed in the panel.
I'm getting more sensitive when pushing pedals.
Should I brake really gently? Will it increase the amount of battery recharging?
It's a great pleasure to attain the MPG value higher than the value it is advertised.
But soon after I realized that this really distracts me.
My eyes are too frequent to look at the digital numbers keep changing.
I guess I shouldn't play this game too much. Instead, I should focus on road.
One thing I like about this car is that it has lots of meters in the instrumental panel.
There are a MPG for a current travel and current instantenous MPG are displayed.in digital format.
At first I liked it.
While driving, I'm in "playing a game" mode.
I'm trying to improve and maximize the MPG displayed in the panel.
I'm getting more sensitive when pushing pedals.
Should I brake really gently? Will it increase the amount of battery recharging?
It's a great pleasure to attain the MPG value higher than the value it is advertised.
But soon after I realized that this really distracts me.
My eyes are too frequent to look at the digital numbers keep changing.
I guess I shouldn't play this game too much. Instead, I should focus on road.
Wednesday, February 6, 2013
Breaking the Abstinence in a Day.
I was invited for the dinner this evening.
My host knew very well about my favorite.
After having a gorgous dinner, the dessert comes.
Fruits, cakes, ....and ice-creams!
I thought that it would be impolite to decline it!
What a fantastic excuse to break my abstinence from ice-cream!
Oh well, my abstinence lasts only one month and one day.
Very the next day from my previous post on "no ice-cream!"
My host knew very well about my favorite.
After having a gorgous dinner, the dessert comes.
Fruits, cakes, ....and ice-creams!
I thought that it would be impolite to decline it!
What a fantastic excuse to break my abstinence from ice-cream!
Oh well, my abstinence lasts only one month and one day.
Very the next day from my previous post on "no ice-cream!"
Tuesday, February 5, 2013
Abstinence from Ice-Cream.
I'm not having ice-creams for more than one month!
The last time I had ice-creams into my stomach is January 4th of 2013.
I was afraid of any kinds of syndrome for this abstinence.
So far I'm not looking for ice-cream eagerly.
Actually when I do shopping, I still always walk to and stop in front of ice-cream aisle.
I was thinking about buying several quarts of Hargen Datz this evening.
But my curiosity prevails my desire to have sweets.
I'm wondering how long I can survive without having any ice-cream.
The last time I had ice-creams into my stomach is January 4th of 2013.
I was afraid of any kinds of syndrome for this abstinence.
So far I'm not looking for ice-cream eagerly.
Actually when I do shopping, I still always walk to and stop in front of ice-cream aisle.
I was thinking about buying several quarts of Hargen Datz this evening.
But my curiosity prevails my desire to have sweets.
I'm wondering how long I can survive without having any ice-cream.
Saturday, January 26, 2013
"Take Five"
I like "Take Five" by Dave Brubeck Quartet so much.
This is one of pieces that I really want to be able to play on piano someday.
Recently I purchased the music book for beginner that include "Take Five".
This sheet is not satisfactory at all because it is too simplified and it is in different tonality.
But I think this is a good starting point for me.
It is good for me to learn melody and rhythms...and to practice reading the sheet.
After studying this "Take Five" for "beginner", I would like to try different versions.
But I think that I will need at least one month to be able to play it (for beginners) comfortably.
This is one of pieces that I really want to be able to play on piano someday.
Recently I purchased the music book for beginner that include "Take Five".
This sheet is not satisfactory at all because it is too simplified and it is in different tonality.
But I think this is a good starting point for me.
It is good for me to learn melody and rhythms...and to practice reading the sheet.
After studying this "Take Five" for "beginner", I would like to try different versions.
But I think that I will need at least one month to be able to play it (for beginners) comfortably.
Monday, January 7, 2013
Add Something into a Ricecooker.
I just have to mix it with rice into a ricecooker and just wait for 50 minutes or so.
Then I can enjoy flavored rice with mixtures such as mushrooms and crabs.
But I had never come up with idea of mixing something other than products on markets that is solely for mixing with rice.
When I was reading some article, I learned that some people add butter into the ricecooker to make the rice less sticky. I've never thought about adding butter into the ricecooker.
I thought that it would be fun to try adding various things into the ricecooker.
For my first challenge, I added several scoops of salmon flakes.
Well, it is not a big adventure yet it is a huge first step for me enjoying cooking.
This year, I would like to cook more by myself and train my taste sensation.
By the way, I liked the smell of salmon from the ricecooker.
But I thought that I should've add more when I was eating it. Too frugal am I?
Sunday, January 6, 2013
Journey to Find the Next Career.
I have to keep studying to improve myself, our community, and the world.
First I need to figure out the most effective way to use myself.
Is a high school math teacher the answer to it?
Right now I'm on the journey to find the answer to this question.
I know I should find the answer quickly because time I have is finite.
But please give me a year or two.
First I need to figure out the most effective way to use myself.
Is a high school math teacher the answer to it?
Right now I'm on the journey to find the answer to this question.
I know I should find the answer quickly because time I have is finite.
But please give me a year or two.
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