This is the fift reflection. The term is about to finished.  In this reflection, I am going to mention following things.

1. Hierarchy of Software
2. System Software 
3. Application Software
4. Flowchart poster picture and my experience from the project

The hierarchy of software 

Software are generally classified as system software and application software. 

The system software 

It is a software designed to operate the computer hardware and to provide a platform for running application software. Programming language translators, utility programs, library programs, and operating systems are four category under system software.

Operating Systems are a collection of programs that make the computer hardware conveniently available to the user. It hides the complexities of the computer’s operation. It is an interface between the application software and computer. OS interprets commands issued by application. software. Without the operating system, the application programs would be unable to communicate with the computer.

 

Library program is a collection of compiled routines/functions that other programs can use.

It contains code and data that provide services to other programs such as interface, printing, network code, the graphic engines of computer games. All Microsoft Office programs have the same look and feel because they are using the same graphical user interface libraries. Computer game developers often buy graphical libraries to speed up development. This will allow them to quickly develop a good looking game that runs on the desired hardware. For example Battlefield 3 and Need for Speed both use the same Frostbite engine. For example: game engine and code. 

Utilities are programs that perform a very specific task related to working with computers. They are small, powerful programs with a limited capability. They are usually operated by the user to maintain a smooth running of the computer system 

Translator  software is a software that allows new programs to be written and run on computers, by converting source code into machine code. In the class, Mr. Pete showed a video to us, which explained how translator works. There are three main kinds of translator assemblers, compiler, and interpreter. Assembler is a program that translates an assembly language program into machine code. Compiler is a program that takes a program in a high-level language, the source code, and translates it into object code all at once. Interpreter analyses and executes each line of a high-level language program one line at a time. Generally, complier works more efficiently, but all  the works done by compiler would be ruined, if it makes even a small mistake. Although interpreter works every slow, but people would soon find out the mistake and correct it when mistake is made, which would not ruined every work we did. However, this video teach me more than just computer knowledge about translator, but also life experience: Shadow always exist with sunshine. Good sides and bad sides of one thing would always exist——good or bad sides could not exist lonely. 

Application software

It allows users to perform non-computer tasks. It is a software designed to help the user to perform specific tasks, such as writing a letter or processing orders. It is designed for end users to perform tasks that they consider useful. Three categories of application software are presented: General purpose application software, special purpose application software, and Bespoken application software.

General-purpose software is a type of software that can be used for many different tasks.It is not limited to one particular function.  

Special purpose application software is a type of software that created to execute one specific  task. 

Bespoke software is tailor made for a specific user and purpose.

Flow chart

This week, we had a group activity called flow chart which is the general structure of how the computer works. I and Hania were in a group. Our topic is to classifying 16 personalities.  MBTI theory believes that a person’s personality can be analyzed from four angles, with the letters representing the following:

1. Source of driving force: outgoing E—inward I

2. Ways of accepting information: feeling S—intuition N

3. The way of decision making: thinking T—emotion F

4. Attitude towards uncertainty: judging J—perception P

Two or two combinations can be combined into 16 personality types.  So our flow chart is about classifying each of the four dimension and combine those result. To form 16 kinds of basic personalities. In the very beginning of the flow chart, we design a loop: if you are going to do the test? If no, then try again, if yes, then welcome to the test.  After that loop , the main part of the flow chart is. consisted of four parallel group of questions. The “yes’ or “ No” would lead the user to different next step. I learn a lot from the activity.  First, teamwork is really important, because I made good teamwork with Hania. The devision of work is clear so we did not waste any time. Second, I should try my best to increase  the efficiency of the work. In the activities, I spent about 6 hour writing the Pseudocode, but most of the work is repetitional. If I use abstraction, I would finish the work in 1 hour.  

This is the fifth reflection I wrote. I learned the definition and properties of algorithm. And there were algorithm magic shows and role playing activities during the class. I am going to talk about following things in my reflection.

1. the definition and properties of algorithm.
2. Expressions for an algorithm
3. Designing an Algorithm and understanding the Problem
4. Explain 3 algorithms that I learned from the video “The Secret Rules of Modern Living: Algorithms”
5. How I would improve and apply the knowledge with computation thinking

Firstly, algorithm is a step by step clear instructions to solve a problem. The algorithms detail the specific instructions a computer should perform to carry out a specific work.Because the algorithm is precise, the order of computation is always critical to the functioning of algorithm. The algorithm has several properties, which are finiteness, definiteness, input, output, effectiveness.

Secondly, the expression of algorithm are consisted of Natural language, flow chart, pseudocode, and programming Language. Natural language is simple English. Flow chart is formalized graphic representation. Pseudocode is generic artificial language. Programming language is artificial language to communicate with computer system.

Designing an algorithm has two main things to look at. One is the big picture, what is the final goal. The other is the individual stages, what barriers need to be overcome on the way. Before an algorithm can be designed, it is important to check if the problem is well understood. We need to ask ourself some questions checking if we understand the problem. Those questions include:

1. What are the inputs into the problem?
2. What will be the outputs of the problem?
3. In what order do instructions need to be carry out?
4. What decisions need to be made in the problem?
5. Are any area of problem repeated?

“The Secret Rules of Modern Living: Algorithms” introduces us several amazing algorithms that benefits us in our daily life. I would explain three of those amazing algorithms.

1. Face detection
2. a mathematical game with a jar full of chocolates and one red hot chilli 
3.  Euclidean greatest common divisor

Face detection belongs to the category of computer vision. In the early days, people’s main research direction was face recognition, which means that the identity of a person is recognized according to the face. Later, the face detection needs in complex backgrounds are getting bigger and bigger, and face detection is gradually increasing. Developed as a separate research direction.

“The knowledge-based approach mainly uses prior knowledge to treat faces as a combination of organ features, detecting faces based on the characteristics of organs such as eyes, eyebrows, mouth, nose, and geometric positions. The statistical method is based on Think of the face as a holistic model—a two-dimensional pixel matrix. From a statistical point of view, the face pattern space is constructed by a large number of face image samples, and the presence of the face is judged according to the similarity measure. Under these two frameworks, A number of methods have been developed. At present, with the continuous introduction of various methods and changes in application conditions, a comprehensive system combining knowledge models with statistical models will become a future research trend.” (From the paper “Adaboost-based face detection method” And eye localization algorithm research)

There is a math game with a jar full of chocolates and one red hot chilli. Two people play the game, each person can take out 1 or 2 or 3 chocolates from each time, the pepper can only be taken at the end, whoever has to take the pepper will have to eat her, and lose.

The strategy is, if the number of the chocolate could be divisible by 4, the other people take the chocolate first and he can take 1 or 2 or 3 chocolate. Then you take the chocolate in the next, you take the number of chocolate that equals 4 minus the number that the other people just take. If the number of the chocolate could not be divisible by 4, you take the chocolate first. After you take the chocolate, the number of the chocolate is always divisible to 4.

In short,

The algorithm is to find a balance point.If the initial state is balanced, then the other party will come first, let him break the balance, and then he will maintain balance again.If the initial state is not balanced, then you should come first, maintain balance, then let the other party break, and then maintain balance yourself.

The Euclidean algorithm is the greatest common divisor used to calculate two positive integers a, b.

This is because The greatest common divisor of two integers is equal to the greatest common divisor of the smaller integer and the division remainder of the two integer.

This week, we had several activities in the class. The first one is role play. Lucybillact as a blind robot that need to catch a bottle in the desk. Kingsly was the person who gave order to Lucybilly teaching telling her how to get the bottle. They did catch the bottle. I learn from this activity that order need to be specific, or the order would fail the whole process.

The second activity is guided tour city tube map. We need to find a route that goes through all the tourist attraction without repeating journey. Such activity benefits me in the real life. Because when I visit a city, I can plan a route pass through every site that I hope to visit without repeating journey. I would save the time and cost of the transportation as the high efficiency of the route.

We designed several algorithm this week. The most impressive one is about recognizing parity. It can determine the parity of the numbers that if the numbers are divisible to 2. It can determine the parity of the numbers that if the last digit of the numbers is”1″in binary system. The reasons why this algorithm impressed me is the involvement of two solutions other than one solution. I learned that everything could be. solved in more than one ways.

Magic show this week took a lot of time of us. We prepared it until the dawn is coming. The magic has four step:

1. rank the card from 1 to 54. The card has individual serial number 
2. remember the content of the card 16. The card is in 16th of those 54 cards
3. dividing those 54 card into two group. Each group should have number between 16 to 32 due to the position of card we just remember.(all card are facing up)
4. we pick the group of card that contain the 16th card.
5. we process those card. one card face down, next one face up in another group. ( process 1)Repeating step 4 and 5 until there is only one card. ( so we might have process it for 4 to 5And that card is the card we pick in step2

We might wonder, why 16. 2 to the power of 4. Step 4: one card face down, next one face up in another group. we process those card. one card face down, next one face up in another group. ( process 1) if we do it again, we call it process2 or 3 or 4 or5 and so onThis magic is a classification system. The number are classified by their divisor of 2. We say 1 to 54. Those are the serial number of the card.1 equals 2 to the power of 0, so it is classified as those humber that have no divisor to 2. Which this process are done in the process 1 in which you just manipulated the card for once. 16 is classified as those number whose divisor of 2 have the power of 4. So the system works as classification system.

We could say the magic classify the card due to order of the card in  binary system as well. I mean the classification system has nothing to do with the content of the card, just relate to its serial number. So we translate the serial number of the card from 1 to 54, in binary system. During the process 1, if the binary number has 1 in this line, it is classified Into one category, as we make it facing down and discard it later. And in second process, we do this again, card that are not discarded in the process one, whose serial number  could be exact divided by two, are manipulate similarly. Serial number that has 1 in this line, are classified as another category, which is discarded. So 16 would not be discarded for a long time. After process 4, all the card that can not be exact divided by 16 is discarded or we could say have already classified into other category. So only serial number 16 is left. 

I was in charge of explaining the logic of this magic show. So I have a deep understanding of this magic show. Therefore my skills of computational thinking is developed. I used decomposition to give each card a serial number. I used abstraction to group those card by their serial number. I used pattern recognition to estimate the attribution of the card. I used algorithm to figure out which card is survived. Using computational thinking to solve and study real life problem makes my computational thinking skills to be more proficient, and I benefit from that.

In conclusion, this week, CS class pushes the gate of algorithm for me. Therefore, my skills of computational thinking improved that I could tackle with real life problem by using computational thinking skills, which benefits me a lot.

Hello, guys. This is the third blogs I ever write. This blog is different from any other blogs because I have gone through so much. I would explain that later.

1. My personal experience and thought.
2. The knowledge I learn about computer out of the class.
3. The knowledge I learn from the class and group activity.

My personal experience this week is full of pain, but joviality is accompanied, which is like the Oreo in the milkshakes. On April 2, I should be playing basketball happily in the basketball court, but I fell down when I was trying to catch the ball. I accidentally use my hand to push the ground when I just “touch” it. Pain engulfed my mind before I realized what is happening. The consequence is obvious that my hand fractures, right hand, the hand I used to write, to grab the chopsticks, to brush my teeth, to play basketball. I can no longer do that in the next 3 to 4 month due to the slow recovering rate of the type of bones that fractured. I started to wonder what to do in the next 3 to 4 month because I am an IB student, I have to study and I have a bunch of homework waiting for me as well as test and quiz. Pain came from my mind even exceeds the the physical pain as I did not see the bright side of the future.

However, my dad said, life is life, broken hand is broken hand, you can do nothing about it. So you just follow it, just like function change direction would follow the gradient direction if the function wanna increase in maximum rate. Therefore, I accepted the fact that I would minimally use my right hand, try to do everything in my left hand. It is such a transformation that I took a few days to adapt to it. However I appreciate the what have been gone through on me. I gain skills that I could write by my left hand. I gain friendship when people help me and I say thanks. I gain faith that I would not give up but fighting against the plight. I gain confidence that whatever problems I meet, I would solve it. Those are the joviality I gained.

During this week, I learned what is float operation. it is addition, subtraction, multiplication and division of decimals.
There is no decimal point in the hardware of the computer. The things that cpu can handle are all. Therefore, decimals are expressed in a way similar to scientific notation. Such as 1.234 in the computer, can be understood as using 1234 and -3 two integers to represent 1234 * 10 -3 power, such numbers are called floating point numbers. Due to the limitations and complexity of this representation. Real numbers in computers are limited by precision. For example, it can only be accurate to 20 decimal places. Moreover, cpu requires a much more complicated circuit design than integer arithmetic when dealing with such numbers, and the speed is much slower than integer arithmetic.

I have a deeper understanding about computer during the class.

Binary system is the basis of computer. Data and information are based on it. So it can represent everything. it has multiple patterns of representing the information or data. In the class time, we had a group activity that we would translate number from 0 to 63 into the language of computer, BINARY.

EG: There are two levels of high level and low level in the computer. For example, the high level is 3.3v and the low level is 0v.The high level represents 1 and the low level represents 0. Such a combination of high level and low level is a binary number such as 10101101.So the computer stores information in binary. Other hexadecimal numbers are also converted from binary.In addition, the picture you are talking about uses the principle of binary. First, the picture is composed of many pixels. Each pixel is described by three numbers. For example, a pixel value (255, 111, 222) represents the three primary color values ​​of the pixel. Values ​​are converted to binary storage.

Transformation: binary to decimal and decimal to binary

m×10^n : m indicates the value of the current bit, and n indicates that there are n numbers to the right of the current bit.
For example, the understanding of the hundred digits 6×10^2 means that the current digit value m is 6, and the index 2 indicates that there are still two numbers on the right side of the current hundred digits. Decimal is the base 10 index. Similarly, the binary difference is the base 2 index. The binary representation is as follows:

m×2^n : m indicates the value of the current bit, and n indicates that there are n numbers to the right of the current bit.
According to the above formula, we can try to convert a binary value: 11011 =1×2^4 1×2^3 0×2^2 1×2^1 1×2^0 =2^4 2^3 2^1 2^0 =16 8 2 1 =27 From the above calculation we can see that the binary only has 0 and 1, so we generally consider that there are 1 bits in the calculation, and then we can sum them.

After that, we were provided with another example. The example that tells us real life application of binary. The light up or not is a representation of ”1″ and”0″ in binary system. In this example, light up or not are reflected to binary'”1″ or “0”. “1” or “0” are reflected to numbers. Number are reflected to letters. Letters make the sentence.

The function of CPU

1. processing the instruction
2. perform an action
3. Control time
4. process data

The function of CU

Direct computer components to work automatically and consistently

1. Buffering of data
2. Error control
3. Data exchange
4. Stating thee statues
5. receive and recognize the order

The function of ALU

The ALU arithmetic logic unit is the execution unit of the central processing unit (CPU). It is the core component of all central processing units. The arithmetic logic unit consists of “And Gate” and “Or Gate”. The main function is to perform two-bit arithmetic operations, such as addition, subtraction, and multiplication (excluding integer division).

The function of Register

Cache is to solve the speed difference between CPU speed and memory speed
The most frequently accessed data and instructions in the memory are copied into the cache in the CPU, so that the CPU can not fetch data into the slow memory like “snail”. The CPU only needs to go to the cache to fetch it. And the cache is much faster than the memory.

Cache is to solve the speed difference between CPU speed and memory speed
The most frequently accessed data and instructions in the memory are copied into the cache in the CPU, so that the CPU can not fetch data into the slow memory like “snail”. The CPU only needs to go to the cache to fetch it. And the cache is much faster than the memory.

The function of Bus

It is to perform hardware communication and data transmission between hardware\

How does CPU work?

The first step: fetch instructions, cpu controller reads an instruction into the instruction register.

The second step: instruction decoding, decoding the instruction in the instruction register, determining the operation of the instruction, and the operand address.

The third step: execute the instruction, use the operand address to find the operand, and perform the operation.

ASCII and UNICODE

ASCII:It is a computerized coding system based on the Latin alphabet, mainly used to display modern English and other Western European languages. It is the most versatile single-byte encoding system available today and is equivalent to the international standard ISO/IEC 646.

UNICODE:It is an industry standard in the field of computer science, including character sets and coding schemes. Unicode is created to address the limitations of traditional character encoding schemes. It sets a uniform and unique binary encoding for each character in each language to meet cross-language, cross-platform text conversion and processing requirements.

Role play activity

In order to better understand the patterns that the computer works, 6 people in a group would act all 5 component of the computer, which are CPU, ALU, Bus, Register, Display, CPU clock. I act as a CPU clock. My job is to record the times that CPU works. My job is repeating and boring. I learn that If the CPU is multi-threaded, my workload will increase a lot. However, in role play, CPU is not multi-threaded.

Thanks for joining me!

Good company in a journey makes the way seem shorter. — Izaak Walton