Digital twin system and blockchain
according to media reports, the people's Bank of China has completed a test on December 15, which shows how to conct transactions and clearing in the distributed ledger system
it is reported that this test was concted jointly with China's mainstream commercial banks, including ICBC, Bank of China and Weizhong bank< The report reads: "the people's Bank of China believes that digital currency can not only rece circulation costs, but also increase transparency, inhibit money laundering and tax evasion."
the report even suggests that Shanghai bill exchange pilot digital currency and set up a national bank bill transaction. At the same time, the people's Bank of China will also establish a digital currency Research Center, and is recruiting experts in big data, cryptography and blockchain technology< The report comes after Zhou Xiaochuan, the governor of the people's Bank of China, issued a statement in February in which he hinted that the people's Bank of China was considering using blockchain to issue digital currency
moreover, this test was concted at the time when the people's Bank of China launched an investigation into China's bitcoin exchange, which started early this month and has led to many changes in trading policies
as the world's first standard digital currency, Puyin takes 1 billion Tibetan tea as the primary standard asset, writes 1 billion Tibetan tea assets into the blockchain through digital encryption technology, and records the identification, evaluation and right confirmation of Tibetan tea.
blockchain refers to the technical solution of collective maintenance of a reliable database through centralization and distrust in the past, and it is a technical way for the whole people to participate in bookkeeping. Previous bookkeeping methods were all centralized and needed centralized intermediary, whether it was traditional government, financial institutions, notarization institutions or emerging e-commerce platform and online payment platform
in economic hypothesis, information is sufficient. In fact, it is precisely because of insufficient information that there are very large intermediaries. The existence of intermediaries increases the transaction cost and raises the transaction threshold. In essence, blockchain technology is a large-scale collaboration tool. It makes direct value transfer possible by using pure technology for the first time, and continues the trend of Internet decentralization and disintermediation. Disintermediated blockchain technology will greatly subvert the information intermediary instry
blockchain technology is the basic technology for building bitcoin data structure and encrypted transmission of transaction information, which realizes the issue and transaction of bitcoin. The core of blockchain technology is that all the current participating nodes jointly maintain the transaction and database, so that the transaction is based on the principle of cryptography rather than trust, so that any agreed parties can directly carry out payment transactions without the participation of a third party
technically, a block is a data structure for recording transactions, reflecting the capital flow of a transaction. In the system, the transaction blocks are connected to form a main chain, and all the nodes participating in the calculation record the main chain or part of the main chain
a block contains the following three parts: transaction information, hash formed by the previous block and random number. Transaction information is the task data carried by the block, including the private keys of both parties, the number of transactions, the digital signature of electronic currency, etc; The hash hash formed by the previous block is used to connect the blocks and realize the sequence of past transactions; Random number is the core of the transaction. All nodes compete to calculate the answer of the random number. The node that gets the answer the fastest generates a new block and broadcasts it to all nodes for updating, so as to complete a transaction.
The hottest things this year are "bitcoin", "Ethereum" and all kinds of cryptocurrencies, so hot that even aunts and uncles are about to start talking about them. It is no exaggeration to say that 2017 is the first year of the development of cryptocurrency and blockchain technology
as the underlying technology behind bitcoin, the concept of blockchain has only been mentioned in the past two or three years, although as early as 2009, "Nakamoto Tsung" released bitcoin. After this wave of digital currency boom, the concept of blockchain technology has really entered the eyes of all walks of life. I'm afraid it's too early to mention the wide application of blockchain technology, which is still in a very early stage of development. However, e to the arrival of the boom, many technicians and teams have contributed their efforts to build some blockchain concept projects“ Needless to say, as the first application of blockchain technology, bitcoin of "Zhongben cong" has realized the function of distributed ledger, which can realize the first decentralized value transmission of human beings. It can be said that it is "blockchain 1.0". Then Ethereum invented the smart contract, which extended the function of blockchain technology to build applications. It is well deserved to be defined as "blockchain 2.0". However, the blockchain concept projects that came out later did not realize this leap forward role, but only improved to a certain extent at the application level, so they can not be called "blockchain 3.0"
so what is "blockchain 3.0"? Maybe bitcoin OS is the answer: an operation system that is completely based on blockchain technology and follows the concept of blockchain technology. In the 1980s, before Microsoft released the windows operating system, personal computers and Internet technology were still in a non systematic state and could not be popularized. After the release, personal computers were allowed to enter ordinary people's homes, making PC and Internet universal application procts. Recently, bitcoin OS team announced the implementation of the bifurcations of bitcoin and Ethereum on Christmas day, so as to officially publish the plan of developing blockchain OS
anyone who knows a little bit about blockchain technology knows that bitcoin solves the problem of account book, while Ethereum is a smart contract to realize application expansion. Later, a team will launch a distributed storage project. But these systems with only a single functional mole are not "operating systems". The traditional definition of operating system is a huge management and control program, which includes five management functions: process and processor management, job management, storage management, device management and file management. In fact, the OS based on blockchain does not need to change all the five functional blocks into distributed ones, as long as the parts related to the external transmission of value and information can be decentralized and distributed. Therefore, the blockchain operating system should have at least three functions of "account system management, computing resource management and storage resource management", which can realize distributed ledger, edge computing and edge storage. Although it is still too early to define the instry standard in this way, bitcoin OS team is committed to realizing the blockchain OS possessed by these three functional blocks first, and then improving it through iteration
according to the bitcoin OS team, the name "bitcoin OS" is actually "blockchain OS", which is named after "bitcoin", which is also a tribute to the inventor "Satoshi Nakamoto". At present, from the technical details given by the bitcoin OS team, we may be able to see some aspects of this "blockchain 3.0" project
firstly, the management function of the account book system supports locating the ownership of resources according to the account ID, such as the private key; Computing resource management can obtain corresponding computing resources according to the demand, support edge computing, and share distributed computing power. In addition, storage resource management can use storage resources according to the demand, and support edge storage. Compared with bitcoin OS, Ethereum only supports account system and smart contract, which can not meet the distribution of distributed computing tasks. Ethereum only supports the fair execution of contract code, let alone the management of storage resources. So Ethereum is only a custom calculator
in addition, it is worth mentioning that bitcoin OS self customized enhanced smart contract. It supports two modes, which are more flexible and efficient
1. Central computing mode: the outgoing node is responsible for executing the smart contract, and both the incoming parameters and the output results support sipfs to be stored in the storage node
Distributed computing mode: ordinary nodes can claim computing tasks, input parameters and output results support sipfs storage to storage nodesfinally, we also need to mention the built-in sipfs super interstellar file system of bitcoin OS. Sipfs can realize the decentralized storage of technical input parameters and output parameters. At the same time, the file has a life cycle, and the DNA description of the file descriptor is recorded on the blockchain. The file descriptor of sipfs does not exist on the blockchain, but it will be stored in a separate file descriptor data file. After the end of the file life cycle, the blockchain will automatically delete the file descriptor, Realize the intelligent slimming of blockchain
"blockchain 3.0" is worth looking forward to, and bitcoin OS team, as the vanguard, is worth paying attention to and encouraging. We are looking forward to the real blockchain operating system
even though many enterprises have invested in the research of blockchain, there are few domestic projects of blockchain, so we should make a certain distinction. At present, there are few enterprises applying blockchain technology to develop digital currency system. For example, the digital currency system scheme developed by Yingtang Zhongchuang has many references. There are many systems developed by Yingtang Zhongchuang. You can have a look at them.
when installing an operating system, it often involves new installation, upgrade installation, windows installation, DOS installation and other installation methods. The meaning of various installation methods is as follows:
● new installation: installing an operating system in addition to the original operating system, which is commonly known as the coexistence of multiple operating systems. If you still want to use the previous operating system, or you are not so confident about the new version of windows system, but just want to try it for a period of time, then the "new installation" method is the most ideal choice. The advantage of this method is high security, the original system will not be damaged, common Windows 98 / 2000, Windows 98 / XP
● upgrade and installation: upgrade the original operating system, for example, from Windows 98 to Windows 2000 or Windows XP. The advantage of this method is that the original program, data and settings will not change, and there are few hardware compatibility problems. Of course, the disadvantage is that it is easy to upgrade and difficult to recover
● installation under Windows: This is the simplest installation method. Insert the installation CD into the windows desktop environment to run the installation program. The advantages are familiar interface and simple operation
● installation under DOS: This is the installation method only used by experts. It needs to be carried out under the dark DOS prompt, so it is generally experts who can master this installation method. Usually, we only need to set the CD-ROM boot in the BIOS, and then use the windows installation CD to start the system, and the installation program can run automatically; Alternatively, you can run setup.exe manually in windows
tip: if you are reloading the system under DOS, please back up and load smartdrv.exe (disk cache program) in advance, otherwise the installation speed will be surprisingly slow
because we are considering the system re installation, we naturally do not involve the upgrade and installation. Generally speaking, there are two cases:
passive re installation: e to various reasons, such as user misoperation or virus or Trojan program damage, the important files in the system are damaged, resulting in errors or even crashes, which can not be started. At this time, we naturally have to re install the system. Sometimes, although the system is running normally, there is an error from time to time. Instead of taking time and effort to find it, it is better to reload it
active reload: some DIY enthusiasts who like to fiddle with computers, even if the system runs normally, they will regularly reload the system, in order to lose weight on the bloated system and make the system work in the optimal state
tips: whether it's active or passive reload, it can be divided into overlay reload and brand new reload. The former is based on the original operating system, the advantage is that it can keep the original system settings, the disadvantage is that it can't completely solve the problems existing in the system, after all, it's not a cure for the symptoms; The latter is to reformat the partition where the operating system is located. Sometimes, for the sake of thoroughness, it may also be repartitioned. The operating system that is reloaded on this basis is almost completely new. This way of reloading is relatively thoroughgoing. It can not only solve the original errors in the system once and for all, but also completely kill the possible viruses, It is highly recommended to use this method of reassembly
preparation before system re installation
system re installation is a relatively large project. According to the author's experience, it will take at least 2-3 hours to partition, format, install the system and install the driver. If the system is configured a little less, it may take more time. Before reloading the system, the following preparations are essential:
● back up important data
although there is no great danger in upgrading the system, we should always be prepared. It is recommended that friends back up the important data in the system before upgrading, especially the account configuration / address book of e-mail, QQ friend list / chat record, MSN Messenger contact list, favorite list, cookies, and of course your personal documents
when you back up the above data, you can back up them manually or one by one by using third-party tool software. If you are using Windows XP system, you might as well use the built-in "file and Settings Transfer Wizard" of the system. This is a very good backup tool, which can be found in "start", "all programs", "accessories" and "system tools"
● export data
Figure 1
Step 1: as shown in Figure 1, since we are performing the operation of exporting data, we should select "old computer" here, and then click the "next" button. After a moment, we will see a dialog box that prompts you to select the transfer method, which lists the direct cable, home network or small office network For floppy disk drive, other removable media and other options, it is recommended to select the "other" option. In this way, files and settings can be saved to any disk or folder, such as floppy disk and USB flash disk. Users can choose more freely and more richly
Figure 2
Step 2: when you see the dialog box in Figure 2, you can freely choose to transfer items here according to your needs. You can transfer only settings or files, or transfer files and settings at the same time. These settings include ie settings, Microsoft Messenger, Microsoft NetMeeting, MSN explorer, Outlook Express, Windows Media Player Regional settings, taskbar options, display properties, shared documents, desktop, my documents, etc. Of course, you can also customize the file and setting list again. After clicking the "next" button, you can export it to the specified path
● import data
Figure 3
when you need to import data, you should select the "new computer" item in the window in Figure 1. When you see the window in Figure 3, please select it according to the actual situation. Because we selected the "other" item before, you should select the "I don't need the wizard disk, I have collected files and settings from the old computer" item here, Then select the "other" item, and then click the "next" button to import the data. The process is completely automatic. The only thing that needs manual intervention is to restart the system or log off the system after the import
backup drivers
after the system is reinstalled, the installation of drivers is also a big problem. Although there are many kinds of hardware that can be recognized by Windows XP, some newly launched hardware devices still need to install drivers manually. If you can find the corresponding driver CD / floppy disk on hand, it goes without saying, but what if the driver CD / floppy disk has been lost
● download from the Internet: save the corresponding driver downloaded from the Internet in advance on the USB disk or mobile hard disk, or burn it to the CD
● manual export: of course, it does not mean manual export after searching for the contents in *. INF file. We can use driver wizard 2004, driver wizard 2005 and other software to back up the driver (see Figure 4). The specific operation is not mentioned here
Figure 4
necessary tools
please prepare a super boot disk of Windows 98. Note that this is not a boot disk created by using the format a / s command in the command line mode of Windows 98, nor a floppy disk formatted from "Explorer", but a boot disk created ring the installation of Windows 98, Or the startup disk made in "control panel" add or delete program "startup disk" after installation. This is the so-called super boot disk. This floppy disk can load the CD-ROM drive, create a virtual disk, call external commands, etc
of course, if your computer supports CD-ROM boot, and you happen to have a genuine windows installation CD, you can save the steps of making a super boot disk. Just set the system to CD-ROM boot, and then boot the system with the installation CD<
quick reload system
the reload system generally includes the following steps:
Step 1: adjust the boot sequence of the system. Enter the BIOS Setup program and set the system boot order to CD-ROM priority or floppy priority
Step 2: repartition and formatting. In order to keep the system clean, it is strongly recommended that the hard disk be repartitioned and reformatted when the system is reinstalled. If you don't want to repartition, it's necessary to format the system partition. Just run the format C: command
Step3: install the operating system. Use windows to install the CD-ROM boot system, and then follow the instructions of the installation wizard
Step4: install the driver. In most cases, there are not many drivers that need to be installed manually, such as graphics card, sound card, modem, network card and so on. If the driver has been backed up with driver wizard 2005 and other software, you just need to restore it, or insert the driver disk and install it manually<
patch the newly installed system with security patches
although Microsoft regards security as a top priority, Windows XP, known as the "most secure operating system" in history, still exposes various vulnerabilities from time to time. Although Microsoft is busy releasing the corresponding patches and patches, it is still unable to prevent them. For example, the shock wave in 2003 and the shock wave in 2004 caused considerable losses to Windows users all over the world
how to ensure the security of Windows operating system when the system re installation has just been completed and the antivirus software and firewall software have not been installed<
installing patches after disconnection
the shock wave and concussion wave pose a great threat to Windows 2000 / XP. If you are using the always online community broadband, please disconnect the network (unplug the network cable) at the first start of the system re installation, and then manually install the Sp1 patch package; If you think it's too big, you can manually install kb823980, kb835732 and other update programs, which can remove the threat of shockwave and shockwave. Of course, these update programs need to be downloaded before the system is reinstalled
if you are using the Windows XP operating system, please do not forget to activate the built-in firewall function. Although the built-in firewall function can not be compared with professional firewall software, it is not a problem to close the fence door to prevent the attacks of pseudo hackers
install the update program
open IE and run the "Windows Update" command from the "tools" menu. At this time, it will automatically link to the microsoft update site http://windowsupdate.microsoft.com , click the "scan for updates" button in the welcome interface, and the update program will automatically search the available update data from windows update. next
high food is a famous school in Taiwan's catering instry. The smell course is very special and can be experienced. However, if the school has a full subsidy for tuition and miscellaneous fees, it's best, because it's expensive
the impression of mainland students on Taiwan's scenic spots, such as Sun Moon Lake, Alishan and the Forbidden City,
if they are afraid that the cost of each one-way trip is too high,
it is suggested that they buy a five-day ticket to Taiwan's Tiehuan island at the end of the semester (NT $599 / 130RMB)
concentrate on planning their five-day trip, The transportation cost is very low.
note: the ship cost of Sun Moon Lake is about 32RMB / the foreign students of the Forbidden City are 16RMB (discount)
the above are the ways I observe and suggest to save money when I get along with my mainland friends.
if you want to circle the island in the future, you are also welcome to ask TA for help, and I will answer for you wholeheartedly
1. Walk about 20m from the new Dakeng market to the new Dakeng market station
2. Take no.365, after 18 stops, to Huangge Cuiyuan station
3. Walk about 770m to Longgang District Hospital of traditional Chinese medicine
take bus m279 (or 862 Take bus no.m296 (take bus No.1) to Longdong community station, then transfer to Shenhui line 2 (take bus No.23) to overpass instrial and Commercial Bank of China (Danshui overpass)
note: you can also walk from Longgang central hospital to "Shuanglong subway station (bus station) and take bus No.2 of Shenhui line
bus information:
Shenhui line 2 (Huiyang bus terminal HuiLongPu bus terminal)
stations: Shuanglong subway station Longdong community xindakeng market Tongle Instrial Zone Tongle community Baolong intersection zhuyangkeng Baoshan police station Pingshan New District Management Committee songzikeng pangushi Laokeng Instrial Zone Kengzi bus station Longtian intersection Kengzi market Kengzi court intersection Baishi intersection Jinsha market Tianjiao village Shatian toll station huiyanghai Guan Zhonghui Hotel Huiyang procuratorate shijihuayuan overpass ICBC