Practice and application of baas platform based on cloud chain and blockchain service

InfoQ 2021-05-06 07:04:41 阅读数:356

practice application baas platform based
{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" For most companies that focus on Application Development , There is no need to have an in-depth understanding of the underlying technology of blockchain 、 There is no need to invest too much resources in the underlying technology “ Repeat the wheel ”, use BaaS service , And building business applications on it is the ideal choice for enterprises ."},{"type":"text","marks":[{"type":"strong"}],"text":" Tencent cloud blockchain service platform TBaaS"},{"type":"text","text":", On 2017 It was officially launched and commercialized in , So far, many application cases have been implemented , Won many professional certification and awards in the industry ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Cloud computing , More than ten years ago, it was a term in the stage of concept popularization , Enterprises are trying to do business in the cloud , To prove that it can reduce costs , Can we get greater productivity improvement . In the early stages of development , Enterprises spend a lot of time trying and adapting gradually . This is similar to the early development stage of blockchain , Until today, , Cloud has been widely recognized and applied by all walks of life . Enter the era of digital economy , The cloud has become one of the most important infrastructures of the digital economy . Cloud has become an enterprise in the era of digital economy IT The most important part of infrastructure ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Following 2019 year 10 month 24 General secretary Xi Jinping stressed the eighteenth collective learning of the Political Bureau of the CPC Central Committee :“ We should take blockchain as an important breakthrough for independent innovation of core technology ”,2020 year 4 month , The national development and Reform Commission has incorporated blockchain into “ New infrastructure ” Range , Same as cloud computing 、 AI is listed as a new technology infrastructure ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/\/infoq\/89\/89e3b13acd3d4bb0863bf77017616a8d.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Blockchain , As a connector of cross industry digital ecology ,"},{"type":"text","marks":[{"type":"strong"}],"text":" It's another important infrastructure in the era of digital economy "},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Compared with cloud computing technology , Cloud computing provides convenient digital transformation technology for enterprises , And blockchain provides enterprises with inter enterprise cooperation , Information infrastructure for trusted data exchange . As a kind of technology, blockchain can effectively link the information systems between enterprises reliably and reliably , Will play an extremely important role in the era of digital economy , In particular, blockchain has the ability to digitize assets ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Of course , Blockchain technology itself needs to be applied together with other technologies , Because blockchain has its limitations , Blockchain alone, in many cases , It's hard to complete a complete business , Blockchain needs to be combined with a lot of other technologies on the cloud , To solve user problems ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" therefore , We put forward a very important idea ——“"},{"type":"text","marks":[{"type":"strong"}],"text":" Cloud chain combination "},{"type":"text","text":"”, Put a lot of tools on the cloud 、 A lot of capabilities like IoT, big data , Artificial intelligence and so on give blockchain , Combined with blockchain , To really solve users' problems , At the same time, it also reduces the cost for users to use blockchain , Improve development efficiency ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"“ Cloud chain combination ” Typical service of , Blockchain BaaS(Blockchain as a Service) service ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" In the world , from 2015 To begin to 2018 year , Microsoft ,IBM,AWS And other Internet giants have successively released blockchain basic service platforms based on cloud services BaaS Type a products , At the same time , In China , Including Tencent , Ali , Huawei has also released BaaS service . With BaaS Industry international \/ The formation of domestic standards , Big blockchain Services BaaS Platforms have become a trend ,BaaS The platform can help multiple enterprises quickly build enterprise level alliance chain network , Enterprises can interact directly on the chain , Become the cornerstone of the digital economy era ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Tencent cloud blockchain team is 2017 Introduced in the BaaS Platform products ——TBaaS(Tencent Blockchain as a Service).TBaaS The platform enables enterprises to link at a lower cost , Realize the rapid construction of blockchain network and application ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Tencent cloud blockchain service TBaaS At the beginning of platform promotion , The clear purpose is to provide   Efficient 、 Easy to use 、 Security 、 Flexible blockchain Services ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Building TBaaS In the process of , We have overcome a number of technical difficulties , Including trading performance 、 Network size and so on . meanwhile , We also explore ideas from multiple dimensions , From the scene 、 programme 、 Contract development , Innovation in operation management and other aspects ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/\/infoq\/1e\/1e5a49cfafdc38c7b51621da32446c5d.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The above is Tencent cloud blockchain service TBaaS Panorama of platform product capabilities . The bottom layer is Tencent's cloud infrastructure layer , Including cloud servers 、 The Internet 、 Storage 、 Resources and services including cluster management and automatic operation and maintenance ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" In the middle is TBaaS The core function of the service platform , Including the blockchain underlying chain engine , Such as Hyperledger Fabric Tencent cloud enhanced engine , The whole life cycle management of blockchain network , It embodies the hierarchical governance model , Such as alliance management ( Alliance Governance )、 Blockchain network management ( Network governance layer based on different underlying engine encapsulation ) And single chain management ( The management of sub chain in network ), as well as TBaaS Supporting services 、 Operation monitoring and development support, etc ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" For example, in terms of smart contracts ,TBaaS The service platform provides developers with an online smart contract editor , On-line IDE It provides a smart contract template for developers based on simple business scenarios , Make developers better understand smart contracts , stay IDE More convenient debugging in 、 compile 、 Executing smart contracts ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The top level is based on TBaaS Industry application of blockchain infrastructure practice , Including credible deposit ( To the letter chain )、 Electronic bills ( Financial instruments )、 Supply chain finance ( Easy financing )、 Smart city construction ( Bidding platform )、 Intelligent building ( Concrete blockchain platform )、 A series of industry application directions such as public welfare and charity ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" As enterprises gradually embrace blockchain Technology ,BaaS How can the service platform further serve the enterprises , How to apply BaaS The service platform ?"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" From the perspective of technical service providers ,BaaS The service platform is to provide enterprises with a network of rapidly forming alliance chain 、 Platform tools for management chain . You can see , At present, the major cloud service providers provide BaaS service , They all take advantage of the deployment and management advantages of cloud service infrastructure , Convenient for developers 、 High performance blockchain network examples and ecological supporting services , Support developers based on BaaS Service development, business development and operation support ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Another angle , From the perspective of a single enterprise , That is, each participant holding the node , What enterprises care more about ?"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Companies may be involved in multiple businesses ( That is, in multiple blockchains ), It holds different nodes to participate in different businesses , From a corporate perspective , Enterprises are more concerned about how to manage the nodes they hold , High availability , High security , Flexible enough , Whether it is possible to achieve cross regional, cross cloud and even cross chain interconnection between the holding nodes and other organization nodes , Achieve greater collaboration between enterprises ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Here is a revelation to us :"},{"type":"text","marks":[{"type":"strong"}],"text":"BaaS The service platform needs to be flexible enough , Let the enterprises holding nodes manage nodes better , More flexible networking with other enterprise organizations , Node interconnection "},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Based on this revelation , Tencent cloud blockchain TBaaS The service platform , Design and implement the flexible interconnection of nodes among multiple enterprises , Make multiple sets TBaaS The console is connected across cloud and domain , Finally, enterprises holding nodes can flexibly connect with other organizations . meanwhile , To break the isolation of blockchain , Achieve greater collaboration between enterprises , Tencent cloud blockchain cross chain communication scheme has also been realized ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/\/infoq\/0f\/0f0203b680960bf828b0f258d9874406.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" For most enterprises that focus on application layer development ,BaaS Service launch , No doubt it's a very good signal , You can see , Tencent's cloud TBaaS In the platform soil , It has also produced a lot of enterprise application flowers ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" In many blockchain application cases , Share an interesting innovative case : Using blockchain to register and finance chattel pledge . Let's see , In traditional industries , How enterprises apply blockchain BaaS Serving and producing value , meanwhile , From such a case , I hope you can find the value generated by the full combination of blockchain technology and other technologies ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/\/infoq\/6d\/6d359930885e38b8e966657b87c29c21.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The figure above shows the core process of warehouse receipt pledge financing business scenario , Warehouse receipt pledge financing refers to , In trade finance or supply chain finance , Trading enterprises pledge warehouse receipts to financial institutions , Access to financing services ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The above financing scenarios exist in the real financial business , But the actual problems are also exposed : Because financial institutions rely on the risk logic of enterprise credit financing , In the supply chain , Small and medium-sized enterprises due to the lack of natural subject credit qualification ( This includes, for example, excellent group strong credit guarantee , Good financial statements , Real estate mortgage, etc ), They are faced with the problem of difficult and expensive financing ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" How to break the situation , Solve the problem of insufficient credit qualification ? For SMEs , It needs to be based on “ Cargo control “ Form a complete set of financing solutions , What I'm talking about here “ Cargo control ” Small and medium-sized enterprises pledge goods , Real things , But in real production activities , The lack of trusted facilities at the bottom of movable property leads to frequent risk events ( Such as “ One thing is worth more ” Phenomena, etc ), It makes the small and medium-sized enterprises have an urgent demand for real estate financing , How can financial institutions trust SMEs , How to guarantee the authenticity of pledged goods and trade has become a top priority ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" You can see , In the context of chattel mortgage financing , The issues involved here include : The confirmation of chattel registration , The uniqueness and traceability of chattel pledge registration , And warehouse credit and so on . In such a warehouse receipt pledge financing business scenario , We can see that all parties have different concerns :"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Financial institutions are concerned about the risks of financing and lending , The security and authenticity of the pledged goods ;"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Enterprises are concerned about the cost and efficiency of pledge financing ;"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The warehouse is concerned about the safety and compliance of the pledged goods ."}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" So based on the concerns of all parties , As well as the circulation convenience of the core asset certificate warehouse receipt 、 Security considerations , Let it play the role of financial derivatives . We've integrated blockchain Technology , Provide blockchain BaaS Service to enterprises 、 Financial institutions and warehousing units ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" In this application , Blockchain provides electronic warehouse receipts 、 The ability to digitize assets , By transforming the traditional paper warehouse receipt into electronic voucher , In other words, it is a way of general evidence , The identity of participants based on blockchain is trusted 、 Privacy security 、 Multi party sharing, etc , We allow businesses and financial institutions to easily transfer warehouse receipts , And then realize the transfer of goods right , Facilitate financing business ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Blockchain, because of its inherent distributed ledger features , It can prevent double blossom of warehouse receipt , That is, the phenomenon of one thing more than one , But is there real goods behind the blockchain warehouse receipt , This is difficult to solve with abstract blockchain technology , So we introduced technologies like the Internet of things and artificial intelligence , Let the highly abstract blockchain technology be grounded ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Through IOT sensors , Real time access to various sensor information of the collateral in the warehouse , And the cameras in the warehouse , Combined with AI video analysis technology , It's like sending a warehouse supervisor for a financial institution , Help financial institutions to do post loan risk control ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Final , We have built such a blockchain with our partners BaaS service , A combination of technologies "},{"type":"text","marks":[{"type":"strong"}],"text":" Supply chain finance movable property pledge blockchain registration system "},{"type":"text","text":"."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The enterprise is located in Foshan , from 2019 year 3 Month to 2020 year 11 End of month , Cumulative realization of 85,000 Pledge supervision of tons of stainless steel coil . The new pledge regulatory demand is close to 75 home , The amount of supply chain financial services increased compared with the same period last year 50%, The total amount of financing exceeds 30 One hundred million yuan ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/\/infoq\/28\/283b667fb3a14c075c35451a2c8c809b.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Through the Internet of things + Artificial intelligence + Blockchain approach , Easy financing - The chattel pledge blockchain registration system establishes a one-to-one mapping relationship between assets in the digital world and assets in the real world , Financial institutions use this function , Ensure the security and authenticity of the pledged goods , Reduced post loan risk , And then provide financing services for the real economy with low cost and high efficiency ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" As can be seen from this example , A blockchain system integrating many technologies , Can provide more powerful capabilities , Serving the economy , To serve people's lives ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The blockchain technology has been upgraded to the national strategy , Under the macro environment of the new infrastructure , Enterprises in the pursuit of digital transformation process , Blockchain BaaS The basic service platform enables enterprises to link at a lower cost , Realize blockchain +, Finally realize the digital transformation of enterprises , To be more open , Interconnected and trusted digital ecosystem ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Cloud chain combination , Let technology help upgrade traditional industries , Reinvent trust , From this we can see that , Blockchain BaaS Service has become the cornerstone of digital ecology of industrial blockchain . future , We are looking forward to BaaS There are more applications on top ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"“ chain ” To the future , The future has to ."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"horizontalrule"},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" The first figure :Unsplash"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" author : Wu Nan "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" original text :https:\/\/\/s\/cIao3WNo5woCLxxOEN4AYQ"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" original text : Cloud chain combination , Blockchain Services BaaS Platform practice and application "}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" source : Cloud and community - WeChat official account [ID:QcloudCommunity]"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" Reprint : The copyright belongs to the author . Commercial reprint please contact the author for authorization , Non-commercial reprint please indicate the source ."}]}]}