Cluster mining
CPU mining → GPU mining → FPGA mining → ASIC mining → large-scale cluster mining
while mining chips are updated, The change of mining speed is:
CPU (20mhash / s) → GPU (400mhash / s) → FPGA (25ghash / s) → ASIC (3.5thash / s) → large scale cluster mining (3.5thash / s * x)
mining speed, which is called computing power in professional terms, is the ability of computer to generate hash collisions per second. In other words, how many hash collisions can our miner do per second is the calculation force. Computing power is the ability to dig bitcoin. The higher the computing power, the more bitcoin you dig, the higher the return
in the world of bitcoin, a data block is recorded about every 10 minutes. All mining computers are trying to package the data block and submit it, and the person who successfully generates the data block will get a bitcoin reward. Initially, bitcoin rewards of 50 bitcoins could be generated about every 10 minutes. But the payment is halved every four years, and now the bitcoin network can generate 25 bitcoins every 10 minutes
in order to successfully generate data blocks, miners need to find the effective hash value. To get the correct hash value, there is no shortcut. They have to guess. The process of guessing is the process of computer random hash collision. If you guess correctly, you will get bitcoin
so far, the highest 1btc price in bitcoin history is about $20000, with a market value of more than $60 billion.
Online mining is real, that is, traffic mining
1、 Mining principle
at the beginning, we could dig bitcoin with the computer CPU. The founder of bitcoin, Nakamoto Tsung, g out the world's first creation block with his computer CPU. However, the era of CPU mining has long passed, and now bitcoin mining is the era of ASIC mining and large-scale cluster mining
looking back on the mining history, bitcoin mining has gone through the following five times: CPU mining → GPU mining → FPGA mining → ASIC mining → large-scale cluster mining, The mining speed changes are as follows:
CPU (20mhash / s) → GPU (400mhash / s) → FPGA (25ghash / s) → ASIC (3.5tash / s) → large scale cluster mining (3.5tash / s * x)
mining speed, which is called computing power in professional terms, that is, the ability of computer to generate hash collisions per second. In other words, how many hash collisions can our miner do per second is the calculation force. Computing power is the ability to dig bitcoin. The higher the computing power, the more bitcoin you dig, the higher the return
in the world of bitcoin, a data block is recorded about every 10 minutes. All mining computers are trying to package the data block and submit it, and the person who successfully generates the data block will get a bitcoin reward. Initially, bitcoin rewards of 50 bitcoins could be generated about every 10 minutes. But the payment is halved every four years, and now the bitcoin network can generate 25 bitcoins every 10 minutes
to successfully generate data blocks, miners need to find the effective hash value. To get the correct hash value, there is no shortcut. You can only guess. The process of guessing is the process of computer random hash collision. If you guess correctly, you will get bitcoin
Mining method: from a miner to a large-scale mine, you need to prepare a miner, a computer that can connect to the Internet, an AUC, a raspberry pie, power supply and all kinds of connecting lines, etc. The connection order of various devices is network cable - & gt; Raspberry pie - & gt; Microusb cable - & gt; AUC-> 4Pin cable - & gt; Mining machine and power supply
< EM > Figure 3: Mine Map (scale of tens of thousands of mining machines) < / EM >
nowadays, the profit space of small and medium-sized absenteeism who take one mining machine home or deploy a small family workshop (dozens of mining machines) is very limited, and the mining instry is graally concentrating on enterprises and teams with low-cost power resources and professional deployment ability
there are many factors that affect the mining revenue, such as the performance and power consumption of mining machinery, the computing power and difficulty of the whole network, the deployment and operation and maintenance capacity of the mine, the availability of low-cost electricity resources, and the currency price and policy guidance, etc. At present, excellent mining enterprises have the ability of chip research and development, a lot of computing power, professional mine deployment and operation experience, etc. in the future, resources and computing power will be more and more concentrated in these mining enterprises
2. Mine pool
in addition to the above equipment, you also need a necessary tool - mine pool. The function of the mine pool is to gather a large amount of mineral computing power, increase your probability of getting bitcoin, and at the same time, distribute your future bitcoin income to your account in advance
the simple explanation is as follows: now the bitcoin network generates a block every 10 minutes, which contains 25 bitcoins. Suppose there are 1W people in the world participating in mining, then in these 10 minutes, only one lucky person has taken these 25 bitcoins, and the others have nothing. The principle of the mine pool is that everyone mines in teams and distributes according to the agreed distribution method, so that the income of the miners' bitcoin tends to be stable and the risks of the miners are reced. Let's take the most common PPS allocation method as an example. Suppose that your computing power is 10t, and the computing power of the whole mine pool is 100t. Your computing power accounts for 1 / 10 of the total computing power of the mine pool. Suppose that the mine pool can generate 10 bitcoins a day, then you can get 1 bitcoin a day
3. Cloud computing power
in reality, the supply of mining machines often exceeds the demand, and at the same time, the delivery of mining machines needs a long waiting period. Miner installation, commissioning, maintenance and other processes are very complex, which requires a lot of energy. Miners have to enre the noise and heat of miner. For miners, the biggest cost is not these, but the high electricity charges consumed by mining. The profit space of small and medium-sized miners is getting smaller and smaller, even negative
Mining income and risk mining income can be calculated by the following formula:Mining income = generated bitcoin * currency price - mining machinery cost - electricity fee - custody fee
if you are just a small miner, generally you only need to dect mining machinery cost and electricity fee
Mining risks are as follows:
< UL >at present, the number of bitcoin is less than 4.5 million. If we do not issue additional bitcoin, the price of bitcoin will fluctuate, and the price callback will lead to the extension of the payback cycle
mining difficulty improvement at present, our machines can meet the market demand
the risk of power outage
< EM >
< / EM >
1. Cultivating students' computational ability is an important task of primary school mathematics teaching and an important foundation for students to learn mathematics in the future. According to the quality analysis of usual testing and final examination, students' computing ability is generally low, which undoubtedly causes great obstacles to students' learning and development. In order to quickly and effectively improve students' computing ability, better develop students' thinking, and improve the quality of mathematics teaching in a large area, it is necessary to strengthen the teaching of calculation as a breakthrough in primary school mathematics teaching
2. Through the research of this topic, we should strive to improve students' computing ability, cultivate their oral, mental and written abilities, and encourage students to graally like mathematics and become interested in calculation in lively and relaxed learning. So as to improve students' academic performance and lay a solid foundation for students' future study< Second, the goal of the research is to find out the reasons for the slow speed and low accuracy of students' mathematical calculation< Looking for teaching breakthrough and teaching training methods that can improve students' mathematical calculation speed and accuracy: (1) strengthen students' oral calculation training by taking oral calculation ability training as a breakthrough 2) Control a certain amount of training to cultivate students' sense of number 3) While paying attention to the training of students' thinking ability, we should pay attention to the training of students' mathematical calculation, grasp the basis, highlight the pertinence, find the regularity, and properly integrate< Third, research measures
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"in order to cultivate students' computational ability, we should pay attention to the basic training of oral arithmetic, insist on regular practice, and graally achieve proficiency." This is the requirement of mathematics curriculum standard. In the process of teaching, we should organize teaching and training in a planned, step-by-step and purposeful way, such as listening to arithmetic, reading cards and oral arithmetic, reading questions and calculating silently, and repeatedly emphasize that the first is correct and then fast
2. Strengthen basic knowledge and improve written calculation ability
in calculation teaching, oral calculation is the basis of written calculation, while written calculation is the key. Written calculation plays an extremely important role in primary school mathematics teaching. No matter how advanced the technology is in the future, the ability of written calculation is always a necessary ability for primary school students
(1) to enable students to understand the basic knowledge of mathematics and master skills is the primary condition for the formation of computational ability
each calculation is based on the corresponding concepts, rules, properties, formulas and other basic knowledge. If students don't understand these basic knowledge correctly and master them thoroughly, they can't calculate. Only after students understand and master the relevant operation properties, laws and skills, can they apply these knowledge in specific calculation to seek simple and reasonable methods, improve the accuracy of calculation and speed up calculation
(2) strengthening practice and skill training is the key to the formation of students' computing ability
for example, in the calculation of four items of scores, some students often encounter the situation that the calculation method is correct but the calculation result is wrong. The reason for the error lies in the basic skills such as score rection, general score or mutualization; Another example is the division of decimals, especially when the divisor is a decimal. The mistake is that when the divisor becomes an integer, the divisor does not expand the same multiple at the same time, resulting in a wrong quotient. So we should strengthen the training of basic calculation skills in calculation practice
(3) memorize common data to improve the calculation speed
in the four arithmetic operations, if students memorize some common data, it will not only help students to achieve the requirements of "correct and rapid", but also help them master the skills of calculation. For example: special data with sum and proct of whole hundred and thousand (for example: 75 + 25 = 100 + 25) × 4=100 125 × 8=1000 The proct of the approximate value of PI 3.14 with one digit and the proct with several common numbers 12, 15, 16, 25 and 36; The denominator is the decimal value of the simplest fraction of 2, 4, 5, 8, 10, 16, 20 and 25, that is, the interaction of these fractions and decimals
the results of the above numbers, whether in daily work or in real life, are used very frequently. After mastering and remembering them, they can be transformed into abilities and proce high efficiency in calculation
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after mastering the calculation method, students tend to deal with the boring calculation, resulting in more calculation errors. At this time, the proper development of some computing competition activities, often can better mobilize the students' learning initiative, improve the interest in computing, and achieve the purpose of improving the accuracy of computing. This semester, I plan to carry out two calculation competitions in the class, in order to improve the students' interest in calculation and improve the accuracy of calculation. After the competition, pay attention to sort out the students' mistakes, analyze and classify them, and then make targeted remedies, so as to clear the obstacles for improving the students' computing ability
4. Encourage students to have a pleasant learning experience
teachers should encourage students to make mistakes e to carelessness. In the usual homework correction, we should affirm its strengths, enhance self-confidence, put forward ardent hope, and urge it to correct its shortcomings< 5. Expected effect
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2. Cultivate students to participate in the derivation of rules and formulas, and truly clarify the calculation
3. Help students memorize common data and improve the calculation speed
4. Pay attention to the analysis of wrong cases and suit the right medicine to the case
5. Cultivate students' habit of checking calculation consciously and correcting mistakes independently
6. Cultivate students' habit of summarizing and reflecting< 6. Research steps of the project
the project started in February 2014 and ended in June 2014
the first stage is to formulate the implementation plan of the research project and write the experimental plan of the project
the second stage: implementation stage (February 2014 to June 2014)
the third stage: writing the final Research Report of this topic. In short, in the process of research, I will strive to make plans, implementation, feedback and summary, so as to ensure the smooth progress of the research and receive actual results.