Pit tools

After the computing power of the whole network has been improved to a certain extent, the probability of getting rewards is too low, so that some geeks on "bitcoin talk" can develop a method that can combine a small amount of computing power and operate jointly, and use this method to build websites

in this mechanism, no matter how much computing power an indivial miner can use, as long as he participates in mining activities by joining the mine pool, no matter whether he has successfully mined effective data blocks, he can get a small amount of bitcoin reward through his contribution to the mine pool, that is to say, many people cooperate in mining, and the bitcoin reward is shared by many people according to their contribution

as of January 2019, the top five bitcoin pools in global computing power are btc.com, pool, antpool, flush pool, and f2pool. At present, about 70% of global computing power is in the hands of Chinese miners

extended data:

handling charge:

bitcoin miners will charge a small amount of fees for most transactions, the main purpose of which is to prevent people from sending a large number of boring small transactions and wasting network resources. At present, most of the handling charges for each transaction are & T 3647; 0.0001/kb (0.0001btc / KB). In fact, after 0.9.0, the default handling charge will be reced to & 3647; 0.00001/KB(0.00001 btc/KB)

because the amount of data occupied by most transactions is less than 1 kilobyte, generally speaking, the amount of data is less than 3647; 0.00001 (0.00001 BTC / KB) is enough. At the same time, in the future, when the bitcoin block rewards are less, the service charge will become the main source of miners' income, and the service charge of bitcoin will be related to the number of bytes occupied by the transaction

at present, the calculation standard of service charge in bitcoin system is not mandatory, so users can not give any service charge when the transaction is in progress

however, most miners usually give priority to the transaction with higher handling charges when building data blocks, so that they can get higher remuneration when mining is successful. Therefore, the transaction without any handling charges may take a long time to be processed and incorporated into the blockchain

in addition, e to the block capacity limit of 1MB and the recent increase in bitcoin transaction volume, the handling charges have increased significantly, and the waiting time for the transaction to be confirmed has also become much longer

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

< 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 = 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:

< EM >
< / EM >

How to dig bitcoin:

The Casar class, which takes air defense as its main task, must be equipped with high-power air defense radar, air defense combat system and heavy area air defense missile launching system. Both the equipment weight and the occupied deck space are further increased, which makes the basic design of f-70 general purpose destroyer face the high tension of space and weight; For this reason, Kasar level has to make some sacrifices. First of all, the original design of Casar class was finalized in 1977, and the superstructure was made of aluminum alloy; Later, based on the lessons of the 1982 Falklands war, most of the surface ships built by various countries used steel to replace the flammable and fusible aluminum alloy materials
after the Falklands war in 1982, the French Navy modified the design of three unfinished destroyers of George Legge class, and adopted steel superstructure instead; However, the first Casar class warship, which was built after the end of the Falklands war, had to continue to use the lighter aluminum alloy as the building material of the superstructure e to its complicated equipment (the weight of the whole ship's weapon system, ammunition and oil has exceeded 1 / 3 of the ship's displacement) and saturated load. In order to make up for the inherent limitation of low anti damage ability of building materials, Casar class is equipped with precise and perfect damage control fire fighting system and nuclear and biochemical protection equipment (including spray cleaning device) to make up for it
the surface of the superstructure of Casar stage is inclined and smooth, which can partly rece the RCS. In order to increase the downward firing angle of the bow main gun, the bow of Casar class is cut down by 5 degrees to present a negative saddle arc. On the central axis of the second deck of the ship, there is a passage through the whole ship. The personnel on board can use this passage to move quickly on the ship and reach the battle position. In the nuclear and biochemical environment, the whole ship can maintain a sealed operation state for 24 hours. Compared with the French ships in the past, the Casar class has better habitability. The soldier cabin is one for every six people, and the military / Sergeant cabin is different according to class and seniority. The highest level is one for two people. Besides, there are more spaces in the living service cabin areas such as restaurants, kitchens, warehouses and medical treatment. Kasar has 225 personnel (19 officers) and 251 berths. The spare space can accommodate the relevant personnel of Marine Corps, special forces or headquarters. The over weight also occurs in the power system. The George Legge class originally used the composite gas turbine or diesel engine power system (CODOG) which is in line with the current trend. The gas turbine has the advantages of fast start, fast acceleration, light weight and high thrust to weight ratio, which is the mainstream power of the new generation of surface warships; However, in order to cooperate with the gas turbine, a large air inlet needs to be set up on the surface of the ship, and a space in front of the air inlet is needed as a buffer. Nothing can be installed so that the gas turbine can absorb enough and stable air flow, which will occupy valuable space on the surface of the ship. In order to save space for air intake, Casar class abandoned high-performance gas turbine and adopted composite diesel engine and diesel power system (CODAD), becoming the first surface combat ship of French navy to use all diesel power< The main engine of Casar class is four SEMT 18 cylinder PA6 V 280 BTC diesel engines, which are propelled by two fixed pitch propellers. The main engine operates at 1050 rpm and has a total power of 43200 HP. It is divided into two completely independent engine rooms (40 m of the ship's length). The probability of the two cabins breaking into water at the same time is extremely low, which can increase the survival rate; The ship's power is provided by three sets of diesel generators with a power of 3400kw. The maximum speed of Casar class reached 29 knots, while the de Gaulle nuclear powered aircraft carrier planned by France was only 27 knots at that time, so the matching was not a problem at all. Under the speed of 24 knots, the enrance of Casar class reaches 4800 nautical miles. If it sails at the speed of 17 knots, the enrance is 8200 nautical miles, which can last for 30 days at sea. At first, the ship was equipped with a Thompson CSF Jupiter 2D long range air search radar and a drbv-15 sea tiger plane search radar; Drbv-15 should be only a temporary equipment, which was replaced by the new drbj-11 Abel 3D multi-function phased array radar in 1992. Arabel radar uses X-band, although the use of a short range, but high accuracy, and its high speed (60 rpm) is also concive to accurate tracking of approaching targets. This ship is equipped with two Racal drbn-34a (i.e. 1229 type) I-frequency navigation radars, one of which is set in the front of the ship, mainly for navigation, and the other is set in the rear of the ship, mainly for helicopter control
the ship is equipped with two American made an / spg-51 lighting radars to guide the standard sm-1mr air defense missile to engage. In addition, there are also DCN's CTMS optical / Radar launch control system (including IBC 1A piranha II TV / infrared tracking system, Sagem dibv-1a infrared target tracking system integrated with search radar, and DCN's CTMS optical / Radar launch control system) Thomson drbc-32 / 33 I-frequency shipborne gun fire control radar and CSEE najir optical command system are used to guide and control shipborne gun. The EW system of the warship includes the arbb-33 electronic countermeasure system (H / I / J frequency) of Dassault (Thales optrosys now), the arbr-17b electronic support system (dr-3000s French version) of Thomson CSF (Thales now), the ambl-1b dagaie jamming wire device of two csees (EADS now) and the ten joint jamming bomb launcher of two SAGAIE ambl-2a, In addition, there is an American made an / slq-25 torpedo countermeasure system. The most important air defense weapon of Casar class is an American made mk-13 single arm missile launching system, which is located between the hangar and the lighting radar. This equipment is transplanted from four air defense 47 destroyers. However, the air defense missiles are replaced by the more advanced standard SM-1 from the original tartar, with a ammunition capacity of 40. The installation position of this device is sandwiched between the front and rear superstructure, so the shooting angle is limited greatly, which is not ideal. The first two Casals adopted mk-13, while the French Navy initially planned to replace the latter two Casals with vertical launched aster series air defense missiles, but the construction plan of these two vessels was cancelled
in the aspect of near air defense, there are six legal units (syst) on both sides of the Casar hangar è me d' Auto-d é fense Rapproch é e Anti-a é rienne L é (g) air defense missile device, which intercepts approaching enemy aircraft and enemy missiles with the sea derivative of army northwest wind missile; Each sadral is equipped with about 13 spare missiles in addition to six spare missiles. In general, the sadral system is under the command of the combat system, and it is fully automatic. If necessary, it can be changed to manual operation. During the test in October 1990, Casar's sadral air defense missile system successfully launched two northwest wind air defense missiles and shot down a sea skimming flight target
the Casar bow is equipped with a model 1968 cadam 100 mm 55 diameter high level al-purpose automatic naval gun with a firing rate of 78 rounds / min, which has both air defense and anti surface capabilities. Other weapons on the ship include eight MM-40 anti-ship missiles (replaced with new MM-40 block3 since 2006), two Oerlikon 20 mm machine guns (firing rate 720 rounds / min, range 10 km) on both sides of 02 deck of superstructure, two 12.7 mm machine guns, two kd-59e fixed light torpedoes (equipped with ten ECAN L5 mod 4 light anti submarine torpedoes, with a range of 10 km), Equipped with active / passive sonar seeker, the speed is 35 knots, the maximum range is 10km, it can attack targets within 550m in depth, and the warhead has 150kg high explosive warhead)