Reflection – Is Privacy A Past Thing?

(“Facebook’s Acquisition of Instagram Just Another Question Mark for Internet Privacy”)

Today, we discussed about an ethical topic in our CS class: “Is privacy a past thing?” Mr. Lin first lead our discussion by stating a phenomenon: Some online services and social networks, which are so popular and convenient that we cannot give up using, may store and sell our private information to gain profit, but we may never know that. Sometimes we receive advertising calls from people who know our name and even our age. Where do their information comes from? Definitely, they bought from some services that we are using. Those companies may sell our private information without our permission. And our information in the company’s database may be stolen by hackers. It’s almost true that if we use the services on the internet, we will have the possibility to lose our privacy.

Mr. Pete made a very good point that we should try to choose the services provided by good companies that we trust. And when we want to use a new service that we don’t know its credibility, we should always read the “terms of use” before clicking on the check box. In addition, we should pay attention to the news to know if the services we are using have bad reputation about customers’ privacy. It is actually a skill that we can distinguish the good and bad companies by carefully investigating and judging.

Base on the fact that there is no 100% privacy on the internet, we should learn how much we should put our personal information on the internet. We should be aware of the danger to post our personal information – location, email-address, phone number, or passwords – on the social network. We should also be careful when a website or an app asks us to type in our private information mentioned previously.

Furthermore, Lin thinks that the government have the absolute power to access some of our private information. He asks us if that is a good thing. Personally speaking, I think the government is protecting us through monitoring people’s behaviors on the internet. By doing so, it will be much easier for the government to prevent crimes and ensure national security. All of our class agree this idea, and we choose to believe that the government is doing the right thing.

Coming back to the topic: Is privacy a past thing? To answering this question, we should know what privacy means. David and I hold the same opinion that privacy’s definition is changing over the time. Some information that we used to think is private now become “public” information that is exposed to everyone on the internet. I don’t think privacy is a past thing, because there is never absolute privacy and we will never be totally transparent. The point is that our ways of communicating is changing, and our privacy is getting easier to be accessed by others. What we should do is to be aware of this fact and be more cautious when we share our information on the internet.

Work Cited

Facebook’s Acquisition of Instagram Just Another Question Mark for Internet Privacy. AppAdvice, 10 Apr. 2012, http://appadvice.com/appnn/2012/04/facebooks-acquisition-of-instagram-just-another-question-mark-for-internet-privacy. Accessed 24 Sept. 2016.

Reflection – How Computers Add Numbers

Constructing Gates – Transistors

Transistor: A device that acts either as a wire or a resistor, depending on the
voltage level of an input signal.

(Pyae)

A transistor has three terminals

• A source
• A base
• An emitter (connected to a ground wire)

By combining transistors in different ways, we can simulate all the gates we have leant. Isn’t that amazing?
Semiconductor: Material such as silicon that is neither a good conductor nor a
good insulator.

When electric current passes through the semiconductor, the semiconductor, which is made up of silicon, becomes conductive. Thus, one transistor can affect the others’ conductivity, resulting a “on” or “off”, which can present binary numbers.

 

Here is an example of how gates are constructed by transistors.

(Pyae)

Now we know that gates can be made by transistors, then how do we use gates to perform calculation? In fact, the process is not such difficult. Let’s use adder as an example.

Adder is “an electronic circuit that performs an addition operation on binary values” (Dale). Under the concept of adder, there is half adder, which computes the two bits(inputs) to get a sum and a carry bit. For example, if we use a half adder to process 1 and 0, the sum will be one and the carry bit will be 0; If the inputs are 1 and 1, the sum will be 0 and the carry bit will be 1. However, half adder does not count the carry-in bit. So there is full adder, which takes the two inputs, and the previous carry-in bit into account. If the input is 1 and 1, and the carry-in is also 1, the output will be 1 and 1.

The half adder produces the sum and the carry value. How does it work? Here are the equations.

sum = A⊕B
carry = AB

By using XOR gates and AND gates, computers can yield sum and carry bits.

(Pyae)

Look at the graph, the full adder consists of two identical half adder so that the adder can count the carry-in bit into account. And before the carry-out there is an OR gate, producing the appropriate carry bit. Therefore, if we combine many full adders together, connecting the carry-in and carry-out together, we can add very big numbers in binary.

 

Circuits as Memory

Here I am going to introduce one type of memory circuits: S-R latch. S-R latch can store 1 bit of information (Dale).

It is designed that X and Y are always complementary. And X represent the value this S-R latch is storing (Dale).

Now suppose that X = 1 and S and R are 1. Because the two gates are NAND gates, the X will be 1 and Y will be 0. This state will not change so that this unit can store the value 1. When X is set to be 0, and both S and R are still 1, the X will keep its value, which is 0. Thus, by momentarily setting the X’s value, we can store 1 or 0 in this S-R latch. (Dale)

(Pyae)

Works Cited

Dale, Nell, and John Lewis. Computer Science Illuminated. Jones & Bartlett Learning, 2016.

Pyae, Sone Kyaw. “Data Representation”. BNDS IB program, 21 Sept. 2016. BNDS, Beijing. Keynote Address

 

 

 

Reflection – Logic Gates

(Pyae 1)

Today I have learned the Logic Gates, which is one of the most foundamental knowledge about computers. I am going to use charts to reflect upon what I have learnt in today’s class.

Boolean Algebra

Introduced by George Boole.

In Boolean algebra, there are only two values, True and False, which can be applied to binary number system – expressing values in 1 and 0.

Basics Gates (True = 1, False = 0)

Gates/Boolean Expressoin	Logic Diagram Symbol	Explanation (If there is two or less inputs)
NOT A = A’		Only accepts one input, and the output will be the inverted value
AND X = A * B		Only if the two or more inputs are all True, the output will be True
OR X = A + B		If there is at least one input is True, the output will be True
NAND X = (A * B)’		Invert the output of the AND gate
NOR X = (A + B)’		Invert the output of the OR gate
XOR X = A ⊕ B		Only when there is one True input, the output will be True

 

Truth Tables

NOT:

A	B
0	1
1	0

AND:

A	B	X
0	0	0
0	1	0
1	0	0
1	1	1

OR:

A	B	X
0	0	0
0	1	1
1	0	1
1	1	1

NAND:

A	B	X
0	0	1
0	1	1
1	0	1
1	1	0

NOR:

A	B	X
0	0	1
0	1	0
1	0	0
1	1	0

XOR:

A	B	X
0	0	0
0	1	1
1	0	1
1	1	0

Logic Gate Puzzler – Khan Academy

Method 1

Method 2 (simplified)

These two pictures are screenshots of the game Logic Gate Puzzler. They are actually the same level, but I used different way to build the XOR gate using the other four gates. I realized that it”s very important to try to find the simpliest way of doing this because, in real life, resources are limited. However, this process might be very difficult. We should learn to think a problem in different perspectives so that we may find out all the possible solutions.

 

Works Cited

Pyae, Sone Kyaw. “Data Representation”. BNDS IB program, 19 Sept. 2016. BNDS, Beijing. Keynote Address.

Christensen, Cameron. “Logic Gate Puzzler.” Computer Programming, Puzzle-Game Challenge, Khan Academy, 2014, https://www.khanacademy.org/computer-programming/logic-gate-puzzler/1522357785. Accessed 19 Sept. 2016.

 

Reflection – Date Representation

Computers are finite but the world is infinite, so it’s impossible to put all the information in the real life into computers. In the real world, the information is usually presented by analog data – data in continuous form. However, there is infinite information in the analog data, thus the computers put the information they receive into digital data – a process called digitizing. To digitize data is to “break data into pieces and representing those pieces separately” – from infinite to finite. Digitized data are actually binary numbers in the computers’ processors. They can store, present, and enable us to modify various types of information, including numbers, text, audio, images and graphics, and video. Therefore, computers are called “multimedia devices.” (Pyae 4).

(Pyae 9)

This picture shows the difference between analog and digital data. The analog signal is continuous, whereas the digital signal is not. After degradation, both signal lose their original accuracy, but, for the digital signal, the data received do not change because it is hard for the degraded signal to cross over the threshold.

Using digital data, computers can present different information. By using the same Character Set, computers can present and modify text data beyond platforms. Character set is created by assigning each character a binary string. (Unicode) ASCII, which is American Standard Code for Information Interchange, used to present each character with 7 bits. Then, because of the increasing need, ASCII was extended to 8 bits per character. However, this was still not enough for international use. Unicode then appeared, aiming to give every character in the world one unique binary number. Unicode uses 16 bits to represent each words so that there will be enough space for new characters or special characters. (“What Is Unicode”)

Besides, there are others methods to encode images. There are two types of images: Vectors or bitmaps. Bitmap images are made of pixels, which are small basic units of color or light. If you zoom in the bitmap images, you can see the blocks of color. Each pixel is presented by a fix amount of bits. The more the bits are, the better quality the image has, and the larger the file is. Vectors, however, are made by using geometry and coordinates. They can be reloaded when you zoom in so that you will always see them clearly. They are stored in the mathematical equations, which are transformed into binary data. (“Encoding Images”)

Bitmap

Vector

(“Encoding Images”)

Digital audios are broken down to “thousands of samples per second.” Each sample is processed as binary digitals. There are several factors that do with the audio’s quality.

sample rate – the number of audio samples captured every second

bit depth – the number of bits available for each clip

bit rate – the number of bits used per second of audio (“Encoding Audio and Video”).

Videos are made by displaying static images in a very high frequency, plus the audio part. Each static image is call a frame. Thus, one of the factor that affect the quality of a video is its frame rate per second (fps). HD films are usually 50-60 fps. There is also bit rate for measuring the total image and audio data processed per second. (“Encoding Audio and Video).

 

To reduce file size and make the process more efficient, images, audio, and video are usually compressed. There are lossy and lossless compress. Through lossy compression, the quality of the file is usually damaged. But lossless compression does not alter the quality of the file. (“Encoding Images”). For example, PNG is a kind of lossless compressing file. Contrarily, JPG is a type of lossy compression.

 

Works Cited

BBC. “Encoding Audio and Video.” Bitesize, 2016, http://www.bbc.co.uk/education/guides/z7vc7ty/revision/1. Accessed 16 Sept. 2016.

BBC. “Encoding Images.” Bitesize, 2016, http://www.bbc.co.uk/education/guides/zqyrq6f/revision/1. Accessed 16 Sept. 2016.

Pyae, Sone Kyaw. “Data Representation”. BNDS IB program, 14 Sept. 2016. BNDS, Beijing. Keynote Address.

“What Is Unicode?” Unicode, 2 Dec. 2015, http://unicode.org/standard/WhatIsUnicode.html. Accessed 16 Sept. 2016.

 

 

 

 

Reflection – Bit, Byte, Binary and Hexadecimal

 

At the begining of the class, we reviewed the classification of numbers:

• Natural number – including 0, 1, 2, 3, 100, 10000, …
• Negative numbers – numbers with negative signs (zero is not a negative number)
• Integers – natural numbers + negative numbers. Without decimal places
• Rational number – all numbers that can be represented in the form of fraction.

(Pyae 5)

Then we learned a essential concept about numbers: Positional notation. Positional notation is a method of representing numbers by using the same number on different places.

Here’s the formula:

(Pyae 8)

For example,

in base ten: 24 = 2×10¹ + 2×10¹;

in base two: 1011 = 1×2³ + 0×2² + 1×2¹ + 1×2⁰.

Because of the positional notation depends on different base, there are binary numbers (base 2), octal numbers (base 8), decimal numbers (base 10), and hexadecimal numbers (base 16).

By using the formula of positional notation, we can easily convert binary numbers, decimal numbers and hexadecimal numbers to each other.

In computer science, because of the nature of computers’ hardware, data are stored and processed by bits (b), which is also call binary digits. Each 8 bits is called one byte (B). Here is a list of common measurement of data.

8b = 1B

1024B = 1 KB

1024KB = 1 MB

1024MB = 1 GB

1024GB = 1 TB

1024TB = 1 PB

(Pyae 1)

Also, one digit of a base 16 number can be presented by 4 bits (16 = 2⁴); an octal number can be presented by 3 bits (8 = 2³).

 

In addition, there is a concept called word length. The word length of the computer is determined by the numbers of bits in a word. It is usually a multiple of 8. Now the computers we use are usually 32-bits or 64-bits.

Works Cited

Pyae, Sone Kyaw. “Bit, Byte, Binary, And Hexadecimal”. BNDS IB program, 13 Sept. 2016.

BNDS, Beijing. Keynote Address.

Possible Future of Computing

(Glenn J. Asakawa)

With the increasing needs for computing power, people are urged to develop new types of computing hardware that has faster speed and more powerful computing. There are two types of computers that are just theoretically and cannot be applied to mass production, but they may be the future of computing device.

Quantum Computers

As Moore’s Law states, the number of transistors on microprocessors doubles approximately every 18 months, and now this time interval is getting even smaller. The microprocessors will continue to be smaller and more energy-efficient. However, in the near future, the development of microprocessor may slow down. The Intel has already launched its smallest transistor which is 14 nano-meters, but it will take longer time for Intel to develop the next generation Scientists are seeking for new ways to create smaller units of computing. (Simonite) Then the quantum computers came to our sights. Theoretically, quantum computers make use of the quantum-mechanical phenomena to operate information. The data will no longer store in binary digital digits, but in qubits, which can show both 0 and 1 simultaneously. Because of the characteristic of quantum physics, it is hard to measure the qubit without destroying it. Physicists from Yale University have created a non-destructive measurement system which successfully measured one qubit, but it’s still a difficult task for them to control one or many qubits in the near future. (Gershon)

Optoelectronic Computers

Besides the theoretical quantum computers, there are optoelectronic computers which is more practical now. The computers now use electrons to transfer information. If we want to speed up the computing, we need to increase the bandwidth, which will consume much more energy. Optoelectronic computers use photon to transfer information. The energy used will only increase a little when the bandwidth is increased. (Hardesty). Therefore, optoelectronic computing technology save energy and increase the computing speed. Computer scientists from MIT has produced an optoelectronic chip which can work well just as a microprocessor. Although the computing process is still done by electricity, using light to move data is definitely more energy-efficient. The chip has 70 million transistors and 850 optical components, which has less than the number of transistors in a typical microprocessor. (Hardesty). Scientists still need more time to make the production of large-scale chips possible, but this prototype will be a good start of the realization of optical computing.

 

Works Cited

Asakawa, Glenn J. “Optoelectronic Microprocessors Built Using Existing Chip                                        Manufacturing.” MIT News, MIT News, 23 Dec. 2015, http://news.mit.edu/sites/mit.edu.newsoffice/files/styles/news_article_image_top_slideshow/public/images/2015/MIT-Painless-Opto-1_0.jpg?itok=joIVR6J5. Accessed 8 Sept.                        2016.

Gershon, Eric. “New Qubit Control Bodes Well for Future of Quantum Computing.” Phys, 13           Jan. 2013, http://phys.org/news/2013-01-qubit-bodes-future-quantum.html.                         Accessed 8 Sept. 2016.

Hardesty, Larry. “Microchips’ optical future.” MIT News, MIT News, 15 Feb. 2012,                              http://news.mit.edu/2012/manufacturing-optical-chips-0215. Accessed 8 Sept. 2016.

Hardesty, Larry. “Optoelectronic Microprocessors Built Using Existing Chip                                        Manufacturing.” MIT News, MIT News, 23 Dec. 2015, http://news.mit.edu/2015/optoelectronic-microprocessors-chip-manufacturing-1223.                  Accessed 8 Sept. 2016.

Simonite, Tom. “Intel Is Putting the Brakes on Moore’s Law.” MIT Technology Review, MIT            Technology Review, 15 Aug. 2016, https://www.technologyreview.com/s/601102/intel-          puts-the-brakes-on-moores-law/. Accessed 8 Sept. 2016.

Layers of Computing System – Reflection

Today we learned the layers of computing system. At the same time, we have a general idea about what CS is about.

Before talking about the layers of computing system, we discussed three key words: Observation, investigating and problem solving. We can ask ourselves: What do we see? Why I see what I see? How I can use what I observed and investigated to solve problems?

(A picture from Mr. Pete’s presentation)

Beginning with the information section, which is the core of computing system, we learned that information is different from data. Data are the facts and details that may not mean anything sometimes. Information is derived from the data and can be understood by people. Through some processes, data can be organized and summarized into information.

The information is like our memory, and what about hardware? Hardware is like the brain and body that carry our memory. For computer, hardware is all the physical devices which are components of a computer.

Programming is the layer outside the hardware. Now we have brain and memory, what can we do? We can think by processing our memories which is carried by our brain. The way of programming is the way we deal with the data. We think through Chinese language, and the computer “thinks” though different programming languages.

The next layer is operating system. It is used to use the computer’s resource effectively. This is more difficult to do the analogy with human. It is like the framework of thinking. When people perceive information, they inevitably disregard some useless information so that we can think logically and reasonably. Similar to our thinking process, the computer needs an OS to manage its limited resource to do the maximum tasks.

Laying outside the operating system layer, application is known by most of the user of computers. It is the part in which resources are used to perform specific tasks. It’s like our hands, and mouths, which are used to solve problems. Applications in computer can used for solving problems, analyzing data, and entertainment.

The last layer is communication. I think communication is so important that it can be the source of information, which is the central layer. It is like the mouths and ears which we used to spread and perceive information. Communication is usually done through connecting the World Wide Web. By communication, computers are connected together to solve bigger problems collectively. Although communication is placed at the last layer, it is the function that enables people from all over the world to share information and to work together in a effective and efficient way.

 

Work Cited

Pyae Sone Kyaw. “Layers of Computing System.” BNDS, 6 September 2016, Yuquan Road,           Beijing. Powerpoint Address.

Command Terms – Reflection

(The picture is the logo of IB diploma programme. To see the source of this picture, you can visit the official website of the International Baccalaureate)

Blogging is a smart way to record my learning process and to reflect on how I learned and what I learned. As the first reflection I posted in my blog, this reflection is about my first assignment, which is highlighting the key words in the definitions of IB command terms. In order to know how to answer the questions from both the teacher and the exams, it is crucially important to perceive and interpret the teacher’s and exam’s instructions correctly. As we read and understand the IB definitions of the command terms, we learn the question types that we are going to be tested by as well as the methods we are going to apply to get the right answer. If we don’t know meaning of the command terms, we may not recognize what the question asks us to do, thus is hard for us to get the answers correct. In this case, even if we know the answer to the question, we still make mistakes because we don’t know what parts of answers should be written down.

Let me provide some examples of other cases. If the question is like this: “Please state the factors that influence the outcome of this experiment.” “State” here is a command term. It basically means that you just give the answer to the question without explanations. If you are not sure whether you should write down the explanations which, you think, are very important, you may write down all the explanations. If you do so, you will waste plenty of time doing the meaningless work. Besides, “to what extant” is asking the students to present the merits and otherwise of an argument by showing the appropriate evidence and sound explanation. If we don’t know the meaning of “to what extant”, we may only write only from one perspective.

Fortunately, most command terms are easy to be understood so we don’t have to put much effort in memorizing them. We just need to understand them and recall their meanings when we have a test.

Works Cited

“International education.” International Baccalaureate. International Baccalaureate, 7 Sept.         2016. Web. 8 Sept. 2016.

“ Computer Science Guide.” International Baccalaureate. International Baccalaureate, 7                 Sept. 2016. Web. 8 Sept. 2016.

 

Hello world, my name is Justin. This is the first blog in my website, so I am going to introduce myself briefly.

I am now a senior high school student in the IB program. I am proud of being an IB student and I feel excited about the courses I chose for this semester.

I have a strong interest in STEM subjects. Currently, I’ve just started to take Physics, Mathematics, and Computer Science HL courses. I think I love creating my world using codes but I have not tried yet. I am looking forward to the CS course in theses two years.

I love studying, and I have a lot of hobbies as well. I love travelling. This holiday I went to Shandong Province and Inner Mongolia. I have been to these places for several times, so this time I did not went to the famous resorts. Here are two pictures I took in both places.

(A small mountain in Shandong)

(Taken on the way home)

Besides traveling, I like skating, cycling, playing table tennis and drawing. I also love music – both listening to music, playing music by guitar and piano, and singing. Recently, I have been listening to Eminem’s songs, and I think I have fallen in love with the rap. In my spare time, if I want to exercise, I would like to play basketball since it is one of my favorite sports.

This blog will be primarily used for recording my weekly progress in my IB Computer Science class. In addition, I will regularly share some news about cool techs, my views about some CS related ethical issues, etc. I hope this post will be a good start.

So…

Hello, world!