Cloud Computing for Mobile Users Can Offloading Computation Save Energy - Summary

介绍云计算的英语作文Cloud computing is a revolutionary concept that has transformed the way we access and process data. It refers to the delivery of computing services over the internet, which includes servers, storage, databases, networking, software, analytics, and intelligence. This essay will explore the fundamentals of cloud computing, its benefits, and itsvarious deployment models.Fundamentals of Cloud ComputingCloud computing operates on a simple principle: instead of having a physical server or a local storage device, users can access a shared pool of computing resources over the internet. This is similar to how electricity is provided as a utility, where you only pay for what you use. The infrastructure is maintained by a cloud provider, which handles everything from data storage to processing power.Benefits of Cloud Computing1. Cost Efficiency: One of the most significant advantages of cloud computing is cost savings. It eliminates the need for businesses to invest in expensive hardware and software, as they can rent these resources as needed.2. Scalability: Cloud services can be easily scaled up ordown based on the demand. This flexibility allows businessesto handle sudden spikes in traffic without worrying about infrastructure limitations.3. Accessibility: Data and applications are accessible from anywhere with an internet connection, which is particularly beneficial for remote teams and global enterprises.4. Reliability and Redundancy: Cloud providers typicallyoffer high levels of reliability and redundancy, ensuringthat your data is backed up and always available.5. Maintenance and Updates: Cloud providers are responsiblefor maintaining the servers and software, which means that users do not have to worry about updates and patches.Deployment ModelsThere are three primary deployment models for cloud computing:1. Public Cloud: This is the most common model where services are provided over the public internet. Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform are examples of public cloud providers.2. Private Cloud: In this model, the cloud infrastructure is operated solely for a single organization, which can be managed by the organization itself or a third-party service provider.3. Hybrid Cloud: This combines elements of both public and private clouds, allowing for greater flexibility and theability to move workloads between the two environments. ConclusionCloud computing has become an integral part of modern IT infrastructure. It offers a range of benefits that make it an attractive option for businesses of all sizes. As technology continues to evolve, the adoption of cloud computing is expected to grow, further expanding the capabilities and services available to users around the world.。

关于云计算的英语作文英文回答：Cloud computing has revolutionized the way businesses and individuals store, process, and access data and applications. As a result, there are multiple benefits of cloud computing, including improved flexibility, reduced costs, increased security, enhanced collaboration, and innovative services.Flexibility is one of the key advantages of cloud computing. It allows users to access their data and applications from anywhere with an internet connection. This makes it easier for businesses to operate remotely and for individuals to work from home.Reduced costs are another advantage of cloud computing. Businesses can avoid the upfront costs of purchasing and maintaining their own IT infrastructure. Instead, they can pay for cloud services on a pay-as-you-go basis.Increased security is another key benefit of cloud computing. Cloud providers have invested heavily insecurity measures to protect their customers' data. This makes cloud computing a more secure option than storingdata on-premises.Enhanced collaboration is another advantage of cloud computing. Cloud-based applications make it easier forteams to collaborate on projects. This is because cloud applications can be accessed from anywhere, and they allow users to share files and collaborate in real-time.Innovative services are another key benefit of cloud computing. Cloud providers are constantly developing new services, such as artificial intelligence, machine learning, and data analytics. These services can help businesses improve their operations and make better decisions.Overall, cloud computing offers a number of benefitsthat can help businesses and individuals improve their operations, reduce costs, and increase innovation.中文回答：云计算的优势。

我对云计算的看法英语作文Title: My View on Cloud ComputingCloud computing has revolutionized the way businesses and individuals store, manage, and access data. In recent years, it has become increasingly prevalent in various industries due to its numerous benefits and advantages. In this essay, I will discuss my perspective on cloud computing and its impact on our lives.One of the key advantages of cloud computing is its scalability. Businesses can easily scale their resources up or down based on their needs without having to invest in expensive infrastructure. This flexibility allows companies to adapt to changing market conditions quickly and efficiently. Moreover, cloud computing offers cost savings as companies do not have to purchase and maintain their own hardware and software. Instead, they can pay for the services they use on a subscription basis, reducing upfront costs and operational expenses.Another benefit of cloud computing is its accessibility. Users can access their data and applications from any device with an internet connection, making remote work and collaboration more convenient. This feature has become especially important in light of the COVID19 pandemic, as many organizations have shifted to remote work setups. Additionally, cloud computing enables realtime collaboration among teammembers located in different parts of the world, fostering innovation and productivity.Security is a critical aspect of cloud computing, and many providers invest heavily in maintaining the security and privacy of their users' data. By entrusting their data to reputable cloud service providers, businesses can benefit from advanced security measures and protocols that protect against cyber threats and data breaches. However, concerns about data privacy and compliance with regulations such as GDPR remain valid, and companies must carefully assess the security practices of their chosen cloud providers.Furthermore, cloud computing facilitates data backup and disaster recovery, ensuring that critical information is safe and accessible in the event of a system failure or natural disaster. The redundancy and geographically distributed nature of cloud data centers reduce the risk of data loss and downtime, enhancing business continuity and resilience.In conclusion, cloud computing has transformed the way we store, manage, and utilize data, offering scalability, cost savings, accessibility, security, and disaster recovery capabilities. As technology continues to advance, cloud computing will play an increasingly prominent role in shaping the future of businesses and society as a whole. Embracing cloud technologies can empower organizations to innovate, streamlineoperations, and stay competitive in a rapidly evolving digital landscape.。

Cloud Computing>Cloud Computing Essay: In today’s scientifically advanced and all IT dominated era, cloud computing is the term du jour. Cloud computing is computing in which large groups of remote servers are networked to allow the centralised data storage, and online access to computer services or resources. Clouds can be classified as public, private or hybrid.Long and Short Essays on Cloud Computing for Kids and Students in EnglishGiven below are two essays in English for students and children about the topic of ‘Cloud Computing’ in both long and short form. The first essay is a long essay on Cloud Computing of 400-500 words. This long essay about Cloud Computing is suitable for students of class 7, 8, 9 and 10, and also for competitive exam aspirants. The second essay is a short essay on Cloud Computing of 150-200 words. These are suitable for students and children in class 6 and below.Long Essay on Cloud Computing 500 Words in EnglishBelow we have given a long essay on Cloud Computing of 500 words is helpful for classes 7, 8, 9 and 10 and Competitive Exam Aspirants. This long essay on the topic is suitable for students of class 7 to class 10, and also for competitive exam aspirants.As a metaphor for the Internet, ‘the cloud’ is a familiar cliche, but when combined with ‘computing,’ the meaning gets bigger and fuzzier. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends IT’s existing capabilities. In a cloud computingsystem, there’s a significant workload shift. Local computers no longer have to do all the heavy lifting when it comes to running applications. The network of computers that make up the cloud handles them instead. Hardware and software demands on the user’s side decrease. The only thing the user’s computer needs to be able to run is the cloud computing system’s interface software, which can be as simple as a Web browser, and the cloud’s network takes care of the rest.Cloud computing is typically defined as a type of computing that relies on sharing computingresources rather than having local servers or personal devices to handle applications. In cloud computing, the word cloud (also phrased as ‘the cloud’) is used as a metaphor for ‘the Internet,’ so the phrase cloud computing means “a type of Internet-based computing,” where different services –such as servers, storage and applications –are delivered to an organisation’s computers and devices through the Internet.Cloud computing is comparable to grid computing, a type of computing where unused processing cycles of all computers in a networkare harnesses to solve problems too intensive for any stand-alone machine.The goal of cloud computing is to apply traditional supercomputing, or high-performance computing power, normally used by military and research facilities, to perform tens of trillions of computations per second, in consumer-oriented applications such as financial portfolios, to deliver personalised information, to provide data storage or to power large, immersive computer games.It relies on restricting sharing of resources to achieve coherence and economies of scale,similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services.To do this, cloud computing uses networks of large groups of servers typically running low-cost consumer PC technology with specialised connections to spread data-processing chores across them. This shared IT infrastructure contains large pools of systems that are linked together. Often, virtualisation techniques are used to maximise the power of cloud computing.Cloud computing will become even more prominent in the coming years, with the predicted rapid, continued growth of major global cloud data centres. Cloud computing has been around for quite some time, and goes as far back as the birth of email. But it’s only in recent years that companies have started renting servers and storage instead of purchasing hardware and running it at huge costs.And with more organisations – especially those that rely on India’s outsourcing infrastructure –transferring some of their IT work onto the cloud,companies such as Tata Consultancy Services (TCS), Infosys and Wipro have stepped up to facilitate that shift. They have positioned themselves as enablers between owners and renters.A report published by IT research and advisory firm Gartner estimates that in India alone the market for cloud-based services will rise by a third to $557 million this year-, and more than triple by 2018. India’s IT giants are becoming experts at going in early, at the planning stage, and defining what their corporate customers ought to be doing to take advantage of emergingtechnologies. “They are playing to their strengths, which is services. Even in the cloud, they are in the services area, specifically focussed on services brokerage,” says Arup Roy, research director at Gartner. They have the advantage of being experts at managing IT back-end for global customers, which will play a crucial role in the shift to the cloud.Short Essay on Cloud Computing 200 Words in EnglishBelow we have given a short essay on Cloud Computing is for Classes 1, 2, 3, 4, 5, and 6.This short essay on the topic is suitable for students of class 6 and below.Users access cloud computing using networked client devices, such as desktop computers, laptops, tablets and smartphones. Some of these devices –cloud clients –rely on cloud computing for all or a majority of their applications so as to be essentially useless without it. Examples are thin clients and the browser-based Chromebook. Many cloud applications do not require specific software on the client and instead use a web browser to interact with the cloud application. With Ajax andHTML5 these Web user interfaces can achieve a similar, or even better, look and feel to native applications. Some cloud applications, however, support specific client software dedicated to these applications (eg. virtual desktop clients and most email clients). Some legacy applications (line of business applications that until now have been prevalent in thin client computing) are delivered via a screen-sharing technology.According to Gartner’s Hype cycle, cloud computing has reached a maturity that leads it into a productive phase. This means that most ofthe main issues regarding cloud computing have been addressed to a degree that clouds have become interesting for full commercial exploitation. This however does not mean that all the problems listed above have actually been solved, only that the according risks can be tolerated to a certain degree. Cloud computing is therefore still as much a research topic, as it is a market offering. What is clear through the evolution of Cloud Computing services is that the full form of CTO is a major driving force behind Cloud adoption. The major Cloud technology developers continue to invest billions a year in Cloud R&D, in 2011 Microsoft forexample committed 90% of its $9.6bn R&D budget to Cloud.Cloud Computing Essay Word Meanings for Simple UnderstandingDu jour – of the day, currentMetaphor –a thing regarded as representative or symbolic of something elseCliche – something that is used very oftenEncompasses – includes comprehensivelyFuzzier – more difficult to perceive; indistinct or vagueHarnesses – controls and makes use of(natural resources), especially to produce energyLegacy –something left or handed down by a predecessorProminence –the state of being important, famous, or noticeableEvolution –the gradual development of something.。

Cloud ComputingWhat is Cloud Computing and What Does This Stupid Buzzword Mean?The other day a reader wrote in asking if cloud computing could help save his hard drive space, which made me realize that it’s time to talk about exactly what this moronic bu zzword really means.What is Cloud Computing?According to the National Institute of Standards and Technology, the definition for “Cloud Computing” is this incomprehensible piece of nonsense clearly written to be as confusing as possible:Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.So what’s a definition for real people?Cloud Computing = Web ApplicationsimageThat’s all there is to it. If you’re using a web or internet-based application from a major provider like Google or Microsoft, you’re using cloud c omputing. Congrats!Every web application that you’ve ever used, like Gmail, Google Calendar, Hotmail, SalesForce, Dropbox, and Google Docs, are based on “cloud computing”, because when you connect to one of these services, you’re really connecting to a ma ssive pool of servers somewhere out there on the internet. The client doesn’t need to be a web browser, but that’s the direction everything is heading.Think there’s more to it than that? Don’t believe me? Just listen to Larry Ellison, the CEO & co-founder of Oracle, talk about how moronic this term really is:So Why Cloud Computing?We’ve already established that it’s a pointless term that simply describes web applications, which have been around for a very long time—but in order to get businesses to start switching to web applications instead of self-hosted servers, the marketing types invented a new buzzword.The reason why they used the word “cloud” in the buzzword is simple: in network diagrams, the internet is usually represented with a cloud in the middle of the drawing. Those marketingdrones are inventive, aren’t they?So basically the term itself is just a way for consultants and companies to sell more services in a shiny new package. Here’s a good illustration of how this works:Comic by Geek and PokeHow Can Cloud Computing Help Me?Since businesses everywhere are moving their applications to the web and coming out with new and interesting features accessible through your web browser, you’ll soon be able to access virtually anything from any browser on any PC, and the lines will blur between desktop and the internet.Now that Microsoft has finally released the beta for Internet Explorer 9, which supports new web standards like HTML5 and uses hardware acceleration to make the whole experience speedy—every browser will finally be on the same footing. When Microsoft said that IE9 is going to change the web, they weren’t kidding—they were the only ones holding the web back with their anemic IE7 and IE8 browsers, not to mention the ancient IE6. And now the nightmare is finally almost over.It’ll get even more interesting whenever Chrome OS is finally released, which is basically an entire operating system built around a web browser as the primary interface, with all of your applications as web applications instead of local—hopefully it will support web integration like IE9 does with the Windows 7 taskbar.How Is Cloud Computing Different for Businesses?If you’re in the IT world you’re probably scratching your head at this point and thinking that I’m oversimplifying the idea behind cloud computing, so let’s explain the real difference from the more technical side of things.In the past, every company would run all of their applications on all of their own servers, hosted at their own location or data center. This obviously requires a lot of maintenance and money to keep everything running, upgraded, and secure.From a business perspective, businesses can now move much of their computing to cloud services, which provide the same applications that you would install on your own servers, but now they are accessible over the internet for any of their customers. Have you read about companies switching to Google Docs? That’s a perfect example of companies switching fromhosting their own local servers to using cloud computing instead.But what if your company provides a service to others? You can also take advantage of cloud computing by creating applications that don’t run on your own servers, but actually utilize server resources provided by one of the big providers—Google has App Engine, Microsoft has Windows Azure, and Amazon has their EC2 framework.Most of these services operate on a pay-for-resources basis—so your application only gets charged for the amount of CPU and network use that it actually uses—when your application is small and doesn’t have a lot of users, you don’t get charged much, but the benefit is that it can scale up to 10,000 users without any trouble (though you’ll be paying a lot more for the added CPU usage).Still need more? Here’s a video that explains it with… little fluffy clouds.Why Cloud Computing is the Future of Mobile?The term "cloud computing" is being bandied about a lot these days, mainly in the context of the "future of the web." But cloud computing's potential doesn't begin and end with the personal computer's transformation into a thin client - the mobile platform is going to be heavily impacted by this technology as well. At least that's the analysis being put forth by ABI Research. Their recent report, Mobile Cloud Computing, theorizes that the cloud will soon become a disruptive force in the mobile world, eventually becoming the dominant way in which mobile applications operate.You may be wondering: what does the term "mobile cloud computing" really mean? Basically, it refers to an infrastructure where both the data storage and the data processing happen outside of the mobile device. Today, there are already some good examples of mobile cloud computing applications including mobile Gmail, Google Maps, and some navigation apps. However, the majority of applications today still do most of the data storage and processing on the mobile devices themselves and not in the cloud. In a few years, that could change.Why Mobile Cloud Computing?With a Western-centric view of the world, it can sometimes be hard to remember that not everyone owns a smartphone. There are still a large number of markets worldwide where the dominant phone is a feature phone. While it's true that smartphones will grow in percentage and feature phones will become more sophisticated in time, these lower-end phones are not goingaway anytime soon. And it's their very existence which will help drive the mobile cloud computing trend.Not only is there a broader audience using feature phones in the world, there are also more web developers capable of building mobile web applications than there are developers for any other type of mobile device. Those factors, combined with the fact that feature phones themselves are becoming more capable with smarter built-in web browsers (and more alternative browsers available for download), will have an impact on mobile cloud computing's growth.How Will Mobile Cloud Computing Become a Disruptive Force?There are two primary reasons why ABI believes cloud computing will become a disruptive force in the mobile world. The first is simply the number of users the technology has the power to reach: far more than the number of smartphone users alone. The second reason has to do with how applications are distributed today. Currently, mobile applications are tied to a carrier. If you want an iPhone app, for example, you have to first have a relationship with the mobile operator who carries the iPhone. If you want a Blackberry app, the same rule applies. But with mobile clouding computing applications, as long as you have access to the web, you have access to the mobile application.Moves by PaaS Players Could Change EverythingWhen you think of Plaform-as-a-Service (PaaS), one of the first companies that springs to mind is probably Salesforce. With their platform, business applications can be built and run "in the cloud." But Salesforce is not the only major PaaS player out there today - Amazon Web Services (AWS) and Google's App Engine are also two platforms that could have a major impact on this trend.Currently, AWS is used by over half a million developers and Google's App Engine hosts 45,000 applications. Now imagine if those two companies along with all of a sudden started aggressively marketing their mobile capabilities. Today, neither AWS nor Google offers this, and Salesforce's mobile offering is limited to smartphones (Windows Mobile, Blackberry, and iPhone). But if the companies decided to make building for the mobile web as easy as building for the web, you could have a mobile revolution on your hands.But People Like Apps!Saying that "mobile cloud computing" is the future doesn't mean phones will be filled withlinks to websites that work in any browser instead of special, downloadable applications, some of which you can even purchase. Instead, mobile applications will exist in both formats. As for the downloadable applications themselves, they will still appear to be your typical mobile app - end users won't even notice a difference. However, there will be a difference - it will just be on the back-end. Mobile applications will begin to store your data in the cloud as opposed to on the mobile device, and the applications will become more powerful as processing power is also offloaded to the cloud.The first mobile apps powered by the cloud will likely be business-focused mobile productivity applications where collaboration, data sharing, multitasking, and scheduling are key factors. For consumers, though, navigation and mapping applications will be the most obvious examples of the trend. Plus, there are some specialty applications today which already function as mobile cloud apps - for example, Schlage offers a remote keyless entry system which lets you mobilely control your home from a distance. You can let someone into your house, manage your lights, your thermostat, your camera system, etc. There are also a few applications in the iPhone app store that let you remotely manage your PC and your DVR, too.Potential ProblemsOf course, there are some potential issues that could be barriers to this shift in mobile computing. The most notable problem is the lack of speedy mobile Internet access everywhere. Here in the US, for example, 3G coverage is spotty outside urban areas, leading to intermittent connection issues and slow speeds. Other markets may have it even worse.However, new technologies like HTML5, which does local caching, could help mobile cloud apps get past those sorts of issues. And there's even a chance that the browser could one day be replaced - at least in some markets - with another technology altogether which provides a better way to access the mobile web. ABI Research mentions initiatives like OMA's Smartcard Web Server, essentially a souped-up SIM card that connects directly with the carrier to push applications to mobile phones. There's also TokTok, a technology that allows access to web services like Gmail and Google Calendar by voice. With voice-enabled search like this, mobile apps could talk directly to the service itself which sits on the edge of the network, as opposed to needing the user to launch a web browser and navigate through the mobile web.When Will Mobile Cloud Computing Really Take Off?According to ABI, this change is only a few years away. By 2010, we'll see one or all of the major PaaS players marketing their mobile capabilities, they say. But first, API standards from open-source mobile collaboration group BONDI will go into effect. Later, in 2011, we'll see more of HTML5, and the OneAPI standard will come into play. (OneAPI involves standardized apps for networks allowing developers to consistently access parts of network providers' capabilities, such as location services). All these factors combined will help drive the move to the cloud.The changes will occur with differing speeds depending on the market. Markets with higher Internet participation will obviously lead the way, as will markets with higher subscriber penetration. That includes Western Europe, North America, and parts of Asia. Other markets will then follow. By 2014, mobile cloud computing will become the predominant application development strategy. By that time, our PCs will be more like thin client devices than they are today, and now it seems our phones will too.The Future of Cloud ComputingA solid majority of technology experts and stakeholders participating in the fourth Future of the Internet survey expect that by 2020 most people will access software applications online and share and access information through the use of remote server networks, rather than depending primarily on tools and information housed on their individual, personal computers. They say that cloud computing will become more dominant than the desktop in the next decade. In other words, most users will perform most computing and communicating activities through connections to servers operated by outside firms.Among the most popular cloud services now are social networking sites (the 500 million people using Facebook are being social in the cloud), webmail services like Hotmail and Yahoo mail, microblogging and blogging services such as Twitter and WordPress, video-sharing sites like YouTube, picture-sharing sites such as Flickr, document and applications sites like Google Docs, social-bookmarking sites like Delicious, business sites like eBay, and ranking, rating and commenting sites such as Yelp and TripAdvisor.This does not mean, however, that most of these experts think the desktop computer will disappear soon. The majority sees a hybrid life in the next decade, as some computing functions move towards the cloud and others remain based on personal computers.The highly engaged, diverse set of respondents to an online, opt-in survey included 895 technology stakeholders and critics. The study was fielded by the Pew Research Center's Internet & American Life Project and Elon University's Imagining the Internet Center. Some 71% agreed with the statement:"By 2020, most people won't do their work with software running on a general-purpose PC. Instead, they will work in Internet-based applications such as Google Docs, and in applications run from smartphones. Aspiring application developers will develop for smartphone vendors and companies that provide Internet-based applications, because most innovative work will be done in that domain, instead of designing applications that run on a PC operating system."Some 27% agreed with the opposite statement, which posited:"By 2020, most people will still do their work with software running on a general-purpose PC. Internet-based applications like Google Docs and applications run from smartphones will have some functionality, but the most innovative and important applications will run on (and spring from) a PC operating system. Aspiring application designers will write mostly for PCs."Most of those surveyed noted that cloud computing will continue to expand and come to dominate information transactions because it offers many advantages, allowing users to have easy, instant, and individualized access to tools and information they need wherever they are, locatable from any networked device. Some experts noted that people in technology-rich environments will have access to sophisticated-yet-affordable local networks that allow them to "have the cloud in their homes."Most of the experts noted that people want to be able to use many different devices to access data and applications, and - in addition to the many mentions of smartphones driving the move to the cloud - some referred to a future featuring many more different types of networked appliances. A few mentioned the "internet of things" - or a world in which everyday objects have their own IP addresses and can be tied together in the same way that people are now tied together by the internet. So, for instance, if you misplace your TV remote, you can find it because it is tagged and locatable through the internet.Some experts in this survey said that for many individuals the switch to mostly cloud-based work has already occurred, especially through the use of browsers and social networking applications. They point out that many people today are primarily using smartphones, laptops,and desktop computers to network with remote servers and carry out tasks such as working in Google Docs, following web-based RSS (really simple syndication) feeds, uploading photos to Flickr and videos to YouTube, doing remote banking, buying, selling and rating items at , visiting with friends on Facebook, updating their Twitter accounts and blogging on WordPress.Many of the people who agreed with the statement that cloud computing will expand as the internet evolves said the desktop will not die out but it will be used in new, improved ways in tandem with remote computing. Some survey participants said they expect that a more sophisticated desktop-cloud hybrid will be people's primary interface with information. They predicted the desktop and individual, private networks will be able to provide most of the same conveniences as the cloud but with better functionality, overall efficiency, and speed. Some noted that general-purpose in-home PC servers can do much of the work locally via a connection to the cloud to tap into resources for computing-intensive tasks.Among the defenses for a continuing domination of the desktop, many said that small, portable devices have limited appeal as a user interface and they are less than ideal for doing work. They also expressed concern about the security of information stored in the "cloud" (on other institutions' servers), the willingness of cloud operators to handle personal information in a trustworthy way, and other problems related to control over data when it is stored in the cloud, rather than on personally-controlled devices.Some respondents observed that putting all or most of faith in remotely accessible tools and data puts a lot of trust in the humans and devices controlling the clouds and exercising gatekeeping functions over access to that data. They expressed concerns that cloud dominance by a small number of large firms may constrict the internet's openness and its capacity to inspire innovation - that people are giving up some degree of choice and control in exchange for streamlined simplicity.A number of people said cloud computing presents difficult security problems and further exposes private information to governments, corporations, thieves, opportunists, and human and machine error.Survey participants noted that there are also quality of service and compatibility hurdles that must be crossed successfully before cloud computing gains more adopters. Among the otherlimiting factors the expert respondents mentioned were: the lack of broadband spectrum to handle the load if everyone is using the cloud; the variability of cost and access in different parts of the world and the difficulties that lie ahead before they can reach the ideal of affordable access anywhere, anytime; and complex legal issues, including cross-border intellectual property and privacy conflicts.Among the other observations made by those taking the survey were: large businesses are far less likely to put most of their work "in the cloud" anytime soon because of control and security issues; most people are not able to discern the difference between accessing data and applications on their desktop and in the cloud; low-income people in least-developed areas of the world are most likely to use the cloud, accessing it through connection by phone.The Three Layers of Cloud ComputingCloud computing is made up of a variety of layered elements, starting at the most basic physical layer of storage and server infrastructureCloud computing is made up of a variety of layered elements, starting at the most basic physical layer of storage and server infrastructure and working up through the application and network layers. The cloud can be further divided into different implementation models based on whether it's created internally, outsourced or a combination of the two.The three cloud layers are:•Infrastructure cloud: Abstracts applications from servers and servers from storage•Content cloud: Abstracts data from applicati ons•Information cloud: Abstracts access from clients to dataThe three cloud implementation models are:•Private cloud: Created and run internally by an organization or purchased and stored within the organization and run by a third party•Hybrid cloud: O utsources some but not all elements either internally or externally•Public cloud: No physical infrastructure locally, all access to data and applications is externalAn infrastructure cloud includes the physical components that run applications and store data. Virtual servers are created to run applications, and virtual storage pools are created to house new and existing data into dynamic tiers of storage based on performance and reliabilityrequirements. Virtual abstraction is employed so that servers and storage can be managed as logical rather than individual physical entities.The content cloud implements metadata and indexing services over the infrastructure cloud to provide abstracted data management for all content. The goal of a content cloud is to abstract the data from the applications so that different applications can be used to access the same data, and applications can be changed without worrying about data structure or type. The content cloud transforms data into objects so that the interface to the data is no longer tied to the actual access to the data, and the application that created the content in the first place can be long gone while the data itself is still available and searchable.The information cloud is the ultimate goal of cloud computing and the most common from a public perspective. The information cloud abstracts the client from the data. For example, a user can access data stored in a database in Singapore via a mobile phone in Atlanta, or watch a video located on a server in Japan from his a laptop in the U.S. The information cloud abstracts everything from everything. The Internet is an information cloud.Christopher Poelker is the author of Storage Area Networks for Dummies, the vice president of enterprise solutions at FalconStor Software, and deputy commissioner of the TechAmerica Foundation Commission on the Leadership Opportunity in U.S. Deployment of the Cloud (CLOUD²).Cloud Computing: What Does It Mean For User Experience? A Lot. And It’s All Good.Cloud computing is exactly what it sounds like: the usage of services like web servers, database servers and other applications so it’s transparent to the user and developer. The configuration and management is taken care of by a large company (in this case, a Microsoft and Amazon), and they provide all the software and services that are needed to run web applications without any of the maintenance.For the end user, what’s at the other end of the internet connection really doesn’t mean much. Users want the applications that work and are easy to use. Scallability, system architecture and configurations don’t mean much when all you want to do is buy a book.Cloud computing is the hot new topic that’s going to revolutionize how we look and implement applications. Because of this, the responsibilities of User Experence Architects and Information Architects is going to drastically change, and cloud computing services is likeWindows Azure are going to enable this revolution.The opportunity to develop new applications is going to explodeCloud computing has a completely different model than traditional hosting: pay for what you use. That means the cost of employing system administrators, buying servers, and all of the overhead associated with developing applications is gone; now developers can order a server to be spun up, and the service provider provides all the VPN interfaces to connect to the server.How quick is the setup? You could have a whole farm of servers ready to go in minutes, complete with database software installed. Complete scalability with a bit of architecture planning and a credit card.The choice of buy versus build is going to dramatically changeWith lower costs in one of area of software development, companies are going to look for other areas to optimize their technology spend, and so software platforms like SharePoint are going to get a second look, and a third look. And the job of the User Experience Architect to find the right tool for the job.No tool will fit your client’s needs 100 percent of the time, but most applications (like a Microsoft CRM or a Sales Force) will fit 80 percent of your client’s requirements, and many of these packages are also going to be easily available through the cloud.User Experience and Information Architects will be in the position of guiding the client or stackholder to a solution that not only fits most of the user needs, but saves time, money and fits within a platform.Think of it: your client wants an intranet, and instead of collecting requirements, you can get a test drive of an application in the cloud environment 30 minutes later. Within a day or two, you are doing interative development building applications they want or need.Custom development isn’t going to go away, but companies will look more to what’s already there versus what to build, or customizing platforms. This means that from a development standpoint, applications will be better tested and in the long run quicker to market. The hope is these applications also will have better usability based on industry standard design patterns, therefore supporting cloud computing even further.The pricing model for for these applications of going to be more palitable for a larger range of clientsThe massive licensing needs of an Oracle or SAP isn’t going to go away: those applications are mission critical that have extensive security and governance requirements. Companies that have those needs are going to keep the applications internal to their networks for business needs, mainly because exposing that data in a virtual cloud has all kinds of security consequences.What about that client that has extensive CRM needs, but only a company of ten people?The pay as you go pricing model is perfect for them: they are going to get the functionality they need to run their business at a higher level, but only pay for what they use. Gone are the days of having a huge IT department; here are the days of consultants that can drop in and provide expertise on meeting exactly the client needs. Providing more value without the overhead of re petitve tasks, the costs of this isn’t going to require 15 signatures just to get started.Think of it as instead of not needing a mechanic to ride with you at all times while driving, and only needing repair exactly when your car breaks down.It’s happening now with some open source applications, and it’s only going to accelerate with cloud computing.How long is this going to take?Like all marketing concepts (Web 2.0, Social Networking, etc.), it’ll take a while to take hold. But when you look at some o f the advantages, there’s never been a better time to be a User Experience Architect. This could be the one thing that enables the technology sector to survive this recession and even grow through it. Cloud computing provides real value with cutting costs, and that’s music to companies’ ears.Embrace change, because the future’s never been sunnier.云计算云计算，这个满天飞的口号到底是什么？最近云计算四处出没，非IT人士常常被搞得云里雾里，糊里糊涂。

英语作文介绍云计算Title: Exploring the World of Cloud Computing。

In today's digital era, cloud computing has emerged as a revolutionary technology, reshaping the way businesses operate and individuals access information. This essay delves into the concept of cloud computing, its significance, benefits, and implications.### What is Cloud Computing?Cloud computing refers to the delivery of computing services—including storage, processing power, and applications—over the internet. Unlike traditional computing, where data and applications are stored on physical hardware, cloud computing enables users to access resources remotely via the internet.### Key Components of Cloud Computing:1. Infrastructure as a Service (IaaS): IaaS provides virtualized computing resources over the internet. Users can rent servers, storage, and networking infrastructure on a pay-as-you-go basis, eliminating the need for physical hardware maintenance.2. Platform as a Service (PaaS): PaaS offers a platform allowing developers to build, deploy, and manage applications without the complexity of infrastructure management. It provides tools and frameworks forapplication development and deployment.3. Software as a Service (SaaS): SaaS delivers software applications over the internet on a subscription basis. Users can access applications hosted in the cloud without the need for installation or maintenance.### Significance of Cloud Computing:1. Scalability: Cloud computing allows businesses to scale resources up or down based on demand, ensuring optimal performance and cost-efficiency.2. Cost-Effectiveness: By eliminating the need for upfront infrastructure investment and reducing maintenance costs, cloud computing offers a cost-effective solution for businesses of all sizes.3. Flexibility: Cloud computing enables remote access to resources, allowing users to work from anywhere with an internet connection. This flexibility promotescollaboration and productivity.4. Innovation: Cloud computing fuels innovation by providing access to advanced technologies such asartificial intelligence, machine learning, and big data analytics, empowering businesses to stay competitive in a rapidly evolving market.### Benefits of Cloud Computing:1. Accessibility: Cloud computing enables ubiquitous access to data and applications, allowing users to access information from any device, anywhere in the world.2. Reliability: Cloud service providers offer robust infrastructure with built-in redundancy and disaster recovery mechanisms, ensuring high availability and reliability of services.3. Security: Cloud providers implement stringent security measures to protect data from unauthorized access, ensuring data confidentiality and integrity.4. Scalability: Cloud computing platforms allow businesses to scale resources dynamically to meet changing demand, ensuring optimal performance and cost-efficiency.### Implications of Cloud Computing:1. Data Privacy: Storing data in the cloud raises concerns about data privacy and compliance with regulatory requirements such as GDPR and HIPAA. Organizations must implement appropriate security measures and data governance policies to protect sensitive information.2. Vendor Lock-in: Dependence on a single cloud provider may lead to vendor lock-in, limiting flexibility and hindering migration to alternative platforms. Adopting a multi-cloud or hybrid cloud strategy can mitigate this risk.3. Internet Dependency: Cloud computing relies on internet connectivity, and disruptions in internet service can impact accessibility and productivity. Organizations should have contingency plans in place to mitigate the impact of internet outages.In conclusion, cloud computing represents a paradigm shift in the way computing resources are delivered and consumed. With its scalability, cost-effectiveness, and flexibility, cloud computing offers unprecedented opportunities for innovation and growth. However, organizations must address challenges related to security, data privacy, and vendor lock-in to fully harness the benefits of cloud computing.。

毕业设计说明书英文文献及中文翻译学生姓名：学号：计算机与控制工程学院：专指导教师：2017 年 6 月英文文献Cloud Computing1。

Cloud Computing at a Higher LevelIn many ways，cloud computing is simply a metaphor for the Internet, the increasing movement of compute and data resources onto the Web. But there's a difference: cloud computing represents a new tipping point for the value of network computing. It delivers higher efficiency, massive scalability, and faster，easier software development. It's about new programming models，new IT infrastructure, and the enabling of new business models。

For those developers and enterprises who want to embrace cloud computing, Sun is developing critical technologies to deliver enterprise scale and systemic qualities to this new paradigm:（1) Interoperability —while most current clouds offer closed platforms and vendor lock—in, developers clamor for interoperability。

Cloud computingDatabaseCloud computing metaphor:For a user,the network elements representing the provider-rendered services are invisible,as if ob-scured by a cloud.Cloud computing ,also known as 'on-demand comput-ing',is a kind of Internet-based computing,where shared resources,data and information are provided to comput-ers and other devices on-demand.It is a model for en-abling ubiquitous,on-demand access to a shared pool of configurable computing resources.[1][2]Cloud com-puting and storage solutions provide users and enter-prises with various capabilities to store and process their data in third-party data centers .[3]It relies on sharing of resources to achieve coherence and economies of scale ,similar to a utility (like the electricity grid )over a network.[4]At the foundation of cloud computing is the broader concept of converged infrastructure and shared services .Cloud computing is a model for enabling ubiquitous,convenient,on-demand network access to a shared pool of configurable computing resources (e.g.,networks,servers,storage,applications and services)that can be rapidly provisioned and released with minimal manage-ment effort.Cloud computing,or in simpler shorthand just “the cloud”,also focuses on maximizing the effectiveness of the shared resources.Cloud resources are usually not onlyshared by multiple users but are also dynamically reallo-cated per demand.This can work for allocating resourcesto users.For example,a cloud computer facility that serves European users during European business hourswith a specific application (e.g.,email)may reallocate the same resources to serve North American users during North America’s business hours with a different applica-tion (e.g.,a web server).This approach helps maximize the use of computing power while reducing the overall cost of resources by using less power,air conditioning,rack space,etc.to maintain the system.With cloud com-puting,multiple users can access a single server to re-trieve and update their data without purchasing licenses for different applications.The term “moving to cloud”also refers to an organiza-tion moving away from a traditional CAPEX model (buy the dedicated hardware and depreciate it over a period of time)to the OPEX model (use a shared cloud infrastruc-ture and pay as one uses it).Proponents claim that cloud computing allows compa-nies to avoid upfront infrastructure costs,and focus on projects that differentiate their businesses instead of on infrastructure.[5]Proponents also claim that cloud com-puting allows enterprises to get their applications up and running faster,with improved manageability and less maintenance,and enables IT to more rapidly adjust re-sources to meet fluctuating and unpredictable business demand.[5][6][7]Cloud providers typically use a “pay as you go”model.This can lead to unexpectedly high charges if administrators do not adapt to the cloud pricing model.[8]The present availability of high-capacity networks,low-cost computers and storage devices as well as the widespread adoption of hardware virtualization ,service-oriented architecture ,and autonomic and utility comput-ing have led to a growth in cloud computing.[9][10][11]Companies can scale up as computing needs increase and then scale down again as demands decrease.Cloud computing has now become a highly demanded service or utility due to the advantages of high computing power,cheap cost of services,high performance,scala-bility,accessibility as well as availability.Cloud vendors are experiencing growth rates of 50%per annum.[12]But due to being in a stage of infancy,it still has some pitfalls which need to be given proper attention to make cloud computing services more reliable and user friendly.[13][14]1History of cloud computing 1.1Origin of the term The origin of the term cloud computing is unclear.The word “cloud”is commonly used in science to describe a121HISTORY OF CLOUD COMPUTINGlarge agglomeration of objects that visually appear from a distance as a cloud and describes any set of things whose details are not inspected further in a given context.[15]An-other explanation is that the old programs that drew net-work schematics surrounded the icons for servers with a circle,and a cluster of servers in a network diagram had several overlapping circles,which resembled a cloud.[16] In analogy to above usage the word cloud was used as a metaphor for the Internet and a standardized cloud-like shape was used to denote a network on telephony schematics and later to depict the Internet in computer network diagrams.With this simplification,the implica-tion is that the specifics of how the end points of a network are connected are not relevant for the purposes of under-standing the diagram.The cloud symbol was used to rep-resent networks of computing equipment in the original ARPANET by as early as1977,[17]and the CSNET by 1981[18]—both predecessors to the Internet itself.The term cloud has been used to refer to platforms for distributed computing.In Wired’s April1994fea-ture“Bill and Andy’s Excellent Adventure II”on the Apple spin-offGeneral Magic,Andy Hertzfeld comments on General Magic’s distributed programming language Telescript that:[19]“The beauty of Telescript...is that now, instead of just having a device to program,wenow have the entire Cloud out there,where asingle program can go and travel to many dif-ferent sources of information and create sortof a virtual service.No one had conceived thatbefore.The example Jim White[the designerof Telescript,X.400and ASN.1]uses now is adate-arranging service where a software agentgoes to theflower store and ordersflowers andthen goes to the ticket shop and gets the ticketsfor the show,and everything is communicatedto both parties.”References to“cloud computing”in its modern sense ap-peared as early as1996,with the earliest known mention in a Compaq internal document.[20]The popularization of the term can be traced to2006 when introduced the Elastic Compute Cloud.[21]1.2The1970sDuring the mid-1970s,time-sharing was popularly known as RJE(Remote Job Entry);this terminology was mostly associated with large vendors such as IBM and DEC.IBM developed the VM Operating System(first released in1972)to provide time-sharing services via virtual machines.1.3The1990sIn the1990s,telecommunications companies,who previ-ously offered primarily dedicated point-to-point data cir-cuits,began offering virtual private network(VPN)ser-vices with comparable quality of service,but at a lower cost.By switching traffic as they sawfit to balance server use,they could use overall network bandwidth more ef-fectively.They began to use the cloud symbol to denote the demarcation point between what the provider was re-sponsible for and what users were responsible for.Cloud computing extends this boundary to cover all servers as well as the network infrastructure.[22]As computers became more prevalent,scientists and technologists explored ways to make large-scale com-puting power available to more users through time-sharing.They experimented with algorithms to optimize the infrastructure,platform,and applications to prioritize CPUs and increase efficiency for end users.[23]1.4The New Millennium:2000sSince2000,cloud computing has come into exis-tence.In early2008,NASA's OpenNebula,enhanced in the RESERVOIR European Commission-funded project, became thefirst open-source software for deploying private and hybrid clouds,and for the federation of clouds.[24]In the same year,efforts were focused on providing quality of service guarantees(as required by real-time interactive applications)to cloud-based in-frastructures,in the framework of the IRMOS Euro-pean Commission-funded project,resulting in a real-time cloud environment.[25][26]By mid-2008,Gartner saw an opportunity for cloud computing“to shape the relation-ship among consumers of IT services,those who use IT services and those who sell them”[27]and observed that “organizations are switching from company-owned hard-ware and software assets to per-use service-based mod-els”so that the“projected shift to computing...will result in dramatic growth in IT products in some areas and sig-nificant reductions in other areas.”[28]Microsoft Azure was announced as“Azure”in Octo-ber2008and released on1February2010as Windows Azure,before being renamed to Microsoft Azure on25 March2014.[29]In July2010,Rackspace Hosting and NASA jointly launched an open-source cloud-software initiative known as OpenStack.The OpenStack project intended to help organizations offer cloud-computing services running on standard hardware.The early code came from NASA’s Nebula platform as well as from Rackspace’s Cloud Files platform.On March1,2011,IBM announced the IBM SmartCloud framework to support Smarter Planet.[30]Among the var-ious components of the Smarter Computing foundation, cloud computing is a critical piece.3On June7,2012,Oracle announced the Oracle Cloud.[31] While aspects of the Oracle Cloud are still in develop-ment,this cloud offering is poised to be thefirst to pro-vide users with access to an integrated set of IT solutions, including the Applications(SaaS),Platform(PaaS),and Infrastructure(IaaS)layers.[32][33][34]2Similar conceptsCloud computing is the result of the evolution and adop-tion of existing technologies and paradigms.The goal of cloud computing is to allow users to take benefit from all of these technologies,without the need for deep knowl-edge about or expertise with each one of them.The cloud aims to cut costs,and helps the users focus on their core business instead of being impeded by IT obstacles.[35] The main enabling technology for cloud computing is virtualization.Virtualization software separates a phys-ical computing device into one or more“virtual”devices, each of which can be easily used and managed to per-form computing tasks.With operating system–level vir-tualization essentially creating a scalable system of mul-tiple independent computing devices,idle computing re-sources can be allocated and used more efficiently.Vir-tualization provides the agility required to speed up IT operations,and reduces cost by increasing infrastructure utilization.Autonomic computing automates the pro-cess through which the user can provision resources on-demand.By minimizing user involvement,automation speeds up the process,reduces labor costs and reduces the possibility of human errors.[35]Users routinely face difficult business problems.Cloud computing adopts concepts from Service-oriented Archi-tecture(SOA)that can help the user break these problems into services that can be integrated to provide a solution. Cloud computing provides all of its resources as services, and makes use of the well-established standards and best practices gained in the domain of SOA to allow global and easy access to cloud services in a standardized way. Cloud computing also leverages concepts from utility computing to provide metrics for the services used.Such metrics are at the core of the public cloud pay-per-use models.In addition,measured services are an essential part of the feedback loop in autonomic computing,allow-ing services to scale on-demand and to perform automatic failure recovery.Cloud computing is a kind of grid computing;it has evolved by addressing the QoS(quality of service)and reliability problems.Cloud computing provides the tools and technologies to build data/compute intensive parallel applications with much more affordable prices compared to traditional parallel computing techniques.[35]Cloud computing shares characteristics with:•Client–server model—Client–server computingrefers broadly to any distributed application that dis-tinguishes between service providers(servers)and service requestors(clients).[36]•Grid computing—“A form of distributed and par-allel computing,whereby a'super and virtual com-puter'is composed of a cluster of networked,loosely coupled computers acting in concert to perform very large tasks.”•Mainframe computer—Powerful computers used mainly by large organizations for critical applica-tions,typically bulk data processing such as:census;industry and consumer statistics;police and secret intelligence services;enterprise resource planning;andfinancial transaction processing.•Utility computing—The“packaging of computing resources,such as computation and storage,as a me-tered service similar to a traditional public utility, such as electricity.”[37][38]•Peer-to-peer—A distributed architecture without the need for central coordination.Participants are both suppliers and consumers of resources(in con-trast to the traditional client–server model).3CharacteristicsCloud computing exhibits the following key characteris-tics:•Agility improves with users’ability to re-provision technological infrastructure resources.[wtf?]•Cost reductions claimed by cloud providers.A public-cloud delivery model converts capital expen-diture to operational expenditure.[39]This purport-edly lowers barriers to entry,as infrastructure is typ-ically provided by a third party and does not need to be purchased for one-time or infrequent inten-sive computing tasks.Pricing on a utility computing basis isfine-grained,with usage-based options and fewer IT skills are required for implementation(in-house).[40]The e-FISCAL project’s state-of-the-art repository[41]contains several articles looking into cost aspects in more detail,most of them conclud-ing that costs savings depend on the type of activities supported and the type of infrastructure available in-house.•Device and location independence[42]enable users to access systems using a web browser regardless of their location or what device they use(e.g.,PC,mo-bile phone).As infrastructure is off-site(typically provided by a third-party)and accessed via the In-ternet,users can connect from anywhere.[40]44SERVICE MODELS•Maintenance of cloud computing applications is easier,because they do not need to be installed on each user’s computer and can be accessed from dif-ferent places.•Multitenancy enables sharing of resources and costs across a large pool of users thus allowing for:•centralization of infrastructure in locationswith lower costs(such as real estate,electric-ity,etc.)•peak-load capacity increases(users need notengineer for highest possible load-levels)•utilisation and efficiency improvementsfor systems that are often only10–20%utilised.[43][44]•Performance is monitored,and consistent and loosely coupled architectures are constructed using web services as the system interface.[40][45][46]•Productivity may be increased when multiple users can work on the same data simultaneously,rather than waiting for it to be saved and emailed.Time may be saved as information does not need to be re-entered whenfields are matched,nor do users need to install application software upgrades to their computer.[47]•Reliability improves with the use of multiple redun-dant sites,which makes well-designed cloud com-puting suitable for business continuity and disaster recovery.[48]•Scalability and elasticity via dynamic(“on-demand”)provisioning of resources on afine-grained,self-service basis in near real-time[49][50] (Note,the VM startup time varies by VM type,loca-tion,OS and cloud providers[49]),without users hav-ing to engineer for peak loads.[51][52][53]This gives the ability to scale up when the usage need increases or down if resources are not being used.[54]•Security can improve due to centralization of data, increased security-focused resources,etc.,but con-cerns can persist about loss of control over certain sensitive data,and the lack of security for stored kernels.Security is often as good as or better than other traditional systems,in part because providers are able to devote resources to solving security is-sues that many customers cannot afford to tackle.[55] However,the complexity of security is greatly in-creased when data is distributed over a wider area or over a greater number of devices,as well as in multi-tenant systems shared by unrelated users.In addition,user access to security audit logs may be difficult or impossible.Private cloud installations are in part motivated by users’desire to retain con-trol over the infrastructure and avoid losing control of information security.The National Institute of Standards and Technology's definition of cloud computing identifies“five essential characteristics":On-demand self-service.A consumer can unilaterally provision computing capabilities,such as server time and network storage,asneeded automatically without requiring humaninteraction with each service provider.Broad network access.Capabilities are available over the network and accessedthrough standard mechanisms that promoteuse by heterogeneous thin or thick client plat-forms(e.g.,mobile phones,tablets,laptops,and workstations).Resource pooling.The provider’s comput-ing resources are pooled to serve multiple con-sumers using a multi-tenant model,with differ-ent physical and virtual resources dynamicallyassigned and reassigned according to consumerdemand.Rapid elasticity.Capabilities can be elasti-cally provisioned and released,in some casesautomatically,to scale rapidly outward and in-ward commensurate with demand.To the con-sumer,the capabilities available for provision-ing often appear unlimited and can be appro-priated in any quantity at any time.Measured service.Cloud systems automat-ically control and optimize resource use byleveraging a metering capability at some levelof abstraction appropriate to the type of ser-vice(e.g.,storage,processing,bandwidth,andactive user accounts).Resource usage can bemonitored,controlled,and reported,provid-ing transparency for both the provider and con-sumer of the utilized service.—National Institute of Standards and Technology[4]4Service modelsThough service-oriented architecture advocates“every-thing as a service”(with the acronyms EaaS or XaaS or simply aas),[56]cloud-computing providers offer their “services”according to different models,[4][57]which happen to form a stack:infrastructure-,platform-and software-as-a-service.[58]4.1Infrastructure as a service(IaaS)See also:Category:Cloud infrastructureIn the most basic cloud-service model-and according to the IETF(Internet Engineering Task Force)-providers4.3Software as a service(SaaS)5Cloud-computing layers accessible within a stackof IaaS offer computers–physical or(more often)virtual machines–and other resources.IaaS refers to online ser-vices that abstract user from the detail of infrastructure like physical computing resources,location,data parti-tioning,scaling,security,backup etc.A hypervisor,such as Xen,Oracle VirtualBox,KVM,VMware ESX/ESXi, or Hyper-V runs the virtual machines as guests.Pools of hypervisors within the cloud operational system can support large numbers of virtual machines and the abil-ity to scale services up and down according to customers’varying requirements.IaaS clouds often offer addi-tional resources such as a virtual-machine disk-image li-brary,raw block storage,file or object storage,firewalls, load balancers,IP addresses,virtual local area networks (VLANs),and software bundles.[59]IaaS-cloud providers supply these resources on-demand from their large pools of equipment installed in data centers.For wide-area con-nectivity,customers can use either the Internet or carrier clouds(dedicated virtual private networks).To deploy their applications,cloud users install operating-system images and their application software on the cloud infrastructure.In this model,the cloud user patches and maintains the operating systems and the application soft-ware.Cloud providers typically bill IaaS services on a utility computing basis:cost reflects the amount of re-sources allocated and consumed.[60][61][62][63]4.2Platform as a service(PaaS)Main article:Platform as a serviceSee also:Category:Cloud platformsPaaS vendors offers a development environment to appli-cation developers.The provider typically develops toolkit and standards for development and channels for distribu-tion and payment.In the PaaS models,cloud providers deliver a computing platform,typically including oper-ating system,programming-language execution environ-ment,database,and web server.Application develop-ers can develop and run their software solutions on a cloud platform without the cost and complexity of buy-ing and managing the underlying hardware and software layers.With some PaaS offers like Microsoft Azure and Google App Engine,the underlying computer and stor-age resources scale automatically to match application demand so that the cloud user does not have to allocate resources manually.The latter has also been proposed by an architecture aiming to facilitate real-time in cloud environments.[64]Even more specific application types can be provided via PaaS,such as media encoding as pro-vided by services like [65]or media.io.[66] Some integration and data management providers have also embraced specialized applications of PaaS as deliv-ery models for data solutions.Examples include iPaaS and dPaaS.iPaaS(Integration Platform as a Service)en-ables customers to develop,execute and govern integra-tionflows.[67]Under the iPaaS integration model,cus-tomers drive the development and deployment of inte-grations without installing or managing any hardware or middleware.[68]dPaaS(Data Platform as a Service)de-livers integration—and data-management—products as a fully managed service.[69]Under the dPaaS model,the PaaS provider,not the customer,manages the develop-ment and execution of data solutions by building tai-lored data applications for the customer.dPaaS users retain transparency and control over data through data-visualization tools.[70]Platform as a Service(PaaS)the consumer does not man-age or control the underlying cloud infrastructure includ-ing network,servers,operating systems,or storage,but has control over the deployed applications and possibly configuration settings for the application-hosting environ-ment.4.3Software as a service(SaaS)Main article:Software as a serviceIn the software as a service(SaaS)model,users gain access to application software and databases.Cloud providers manage the infrastructure and platforms that run the applications.SaaS is sometimes referred to as “on-demand software”and is usually priced on a pay-per-use basis or using a subscription fee.In the SaaS model,cloud providers install and operate application software in the cloud and cloud users access the software from cloud clients.Cloud users do not man-age the cloud infrastructure and platform where the ap-plication runs.This eliminates the need to install and run the application on the cloud user’s own computers,which simplifies maintenance and support.Cloud applications differ from other applications in their scalability—which can be achieved by cloning tasks onto multiple virtual66DEPLOYMENT MODELSmachines at run-time to meet changing work demand.[71] Load balancers distribute the work over the set of virtual machines.This process is transparent to the cloud user, who sees only a single access-point.To accommodate a large number of cloud users,cloud applications can be multitenant,meaning that any machine may serve more than one cloud-user organization.The pricing model for SaaS applications is typically a monthly or yearlyflat fee per user,[72]so prices become scalable and adjustable if users are added or removed at any point.[73]Proponents claim that SaaS gives a business the poten-tial to reduce IT operational costs by outsourcing hard-ware and software maintenance and support to the cloud provider.This enables the business to reallocate IT oper-ations costs away from hardware/software spending and from personnel expenses,towards meeting other goals. In addition,with applications hosted centrally,updates can be released without the need for users to install new software.One drawback of SaaS comes with storing the users’data on the cloud provider’s server.As a result, there could be unauthorized access to the data.For this reason,users are increasingly adopting intelligent third-party key-management systems to help secure their data. Software as a Service(SaaS)known as on-demand soft-ware,it provides the software service to the consumer hosted on cloud.5Cloud clientsSee also:Category:Cloud clients and Cloud APIUsers access cloud computing using networked client de-vices,such as desktop computers,laptops,tablets and smartphones and any Ethernet enabled device such as Home Automation Gadgets.Some of these devices–cloud clients–rely on cloud computing for all or a ma-jority of their applications so as to be essentially useless without it.Examples are thin clients and the browser-based Chromebook.Many cloud applications do not re-quire specific software on the client and instead use a web browser to interact with the cloud application.With Ajax and HTML5these Web user interfaces can achieve a similar,or even better,look and feel to native appli-cations.Some cloud applications,however,support spe-cific client software dedicated to these applications(e.g., virtual desktop clients and most email clients).Some legacy applications(line of business applications that un-til now have been prevalent in thin client computing)are delivered via a screen-sharing technology.Cloud Computing T ypesCloud computing types6Deployment models6.1Private cloudPrivate cloud is cloud infrastructure operated solely for a single organization,whether managed internally or by a third-party,and hosted either internally or externally.[4] Undertaking a private cloud project requires a significant level and degree of engagement to virtualize the business environment,and requires the organization to reevaluate decisions about existing resources.When done right,it can improve business,but every step in the project raises security issues that must be addressed to prevent seri-ous vulnerabilities.Self-run data centers[74]are generally capital intensive.They have a significant physical foot-print,requiring allocations of space,hardware,and en-vironmental controls.These assets have to be refreshed periodically,resulting in additional capital expenditures. They have attracted criticism because users“still have to buy,build,and manage them”and thus do not benefit from less hands-on management,[75]essentially"[lacking] the economic model that makes cloud computing such an intriguing concept”.[76][77]6.2Public cloudA cloud is called a“public cloud”when the services are rendered over a network that is open for public use.Pub-lic cloud services may be free.[78]Technically there may be little or no difference between public and private cloud architecture,however,security consideration may be sub-stantially different for services(applications,storage,and other resources)that are made available by a service provider for a public audience and when communication is effected over a non-trusted network.Generally,public cloud service providers like Amazon AWS,Microsoft and Google own and operate the infrastructure at their data center and access is generally via the Internet.AWS and Microsoft also offer direct connect services called“AWS Direct Connect”and“Azure ExpressRoute”respectively, such connections require customers to purchase or lease a private connection to a peering point offered by the cloud provider.[40]6.4Others76.3Hybrid cloudHybrid cloud is a composition of two or more clouds(pri-vate,community or public)that remain distinct entities but are bound together,offering the benefits of multiple deployment models.Hybrid cloud can also mean the abil-ity to connect collocation,managed and/or dedicated ser-vices with cloud resources.[4]Gartner,Inc.defines a hybrid cloud service as a cloud computing service that is composed of some combina-tion of private,public and community cloud services, from different service providers.[79]A hybrid cloud ser-vice crosses isolation and provider boundaries so that it can't be simply put in one category of private,public,or community cloud service.It allows one to extend either the capacity or the capability of a cloud service,by aggre-gation,integration or customization with another cloud service.Varied use cases for hybrid cloud composition exist.For example,an organization may store sensitive client data in house on a private cloud application,but interconnect that application to a business intelligence application pro-vided on a public cloud as a software service.[80]This example of hybrid cloud extends the capabilities of the enterprise to deliver a specific business service through the addition of externally available public cloud services. Hybrid cloud adoption depends on a number of factors such as data security and compliance requirements,level of control needed over data,and the applications an or-ganization uses.[81]Another example of hybrid cloud is one where IT orga-nizations use public cloud computing resources to meet temporary capacity needs that can not be met by the pri-vate cloud.[82]This capability enables hybrid clouds to employ cloud bursting for scaling across clouds.[4]Cloud bursting is an application deployment model in which an application runs in a private cloud or data center and “bursts”to a public cloud when the demand for comput-ing capacity increases.A primary advantage of cloud bursting and a hybrid cloud model is that an organiza-tion only pays for extra compute resources when they are needed.[83]Cloud bursting enables data centers to cre-ate an in-house IT infrastructure that supports average workloads,and use cloud resources from public or pri-vate clouds,during spikes in processing demands.[84] The specialized model of hybrid cloud,which is built atop heterogeneous hardware,is called“Cross-platform Hy-brid Cloud”.A cross-platform hybrid cloud is usually powered by different CPU architectures,for example, x86-64and ARM,ers can transparently deploy and scale applications without knowledge of the cloud’s hardware diversity.[85]This kind of cloud emerges from the raise of ARM-based system-on-chip for server-class computing.6.4Others6.4.1Community cloudCommunity cloud shares infrastructure between sev-eral organizations from a specific community with com-mon concerns(security,compliance,jurisdiction,etc.), whether managed internally or by a third-party,and ei-ther hosted internally or externally.The costs are spread over fewer users than a public cloud(but more than a pri-vate cloud),so only some of the cost savings potential of cloud computing are realized.[4]6.4.2Distributed cloudA cloud computing platform can be assembled from a dis-tributed set of machines in different locations,connected to a single network or hub service.It is possible to dis-tinguish between two types of distributed clouds:public-resource computing and volunteer cloud.•Public-resource computing:This type of dis-tributed cloud results from an expansive defini-tion of cloud computing,because they are more akin to distributed computing than cloud comput-ing.Nonetheless,it is considered a sub-class of cloud computing,and some examples include dis-tributed computing platforms such as BOINC and Folding@Home.•Volunteer cloud:Volunteer cloud computing is characterized as the intersection of public-resource computing and cloud computing,where a cloud computing infrastructure is built using volunteered resources.Many challenges arise from this type of infrastructure,because of the volatility of the re-sources used to built it and the dynamic environ-ment it operates in.It can also be called peer-to-peer clouds,or ad-hoc clouds.An interest-ing effort in such direction is Cloud@Home,it aims to implement a cloud computing infrastructure using volunteered resources providing a business-model to incentivize contributions throughfinancial restitution[86]6.4.3IntercloudMain article:IntercloudThe Intercloud[87]is an interconnected global“cloud of clouds”[88][89]and an extension of the Internet“network of networks”on which it is based.The focus is on direct interoperability between public cloud service providers, more so than between providers and consumers(as is the case for hybrid-and multi-cloud).[90][91][92]。

英语云计算英语40题1. We use cloud computing to store our photos. Which of the following is NOT an advantage of cloud computing?A. Easy access from anywhereB. High securityC. Limited storage spaceD. Cost-effective答案：C。

本题考查云计算的基础知识。

选项A 表示可以从任何地方轻松访问，这是云计算的优点；选项B 高安全性也是其优点之一；选项 D 成本效益高符合云计算的特点。

选项 C 中说存储空间有限是错误的，云计算通常提供较大的存储空间。

2. In cloud computing, data is stored _____.A. on local computersB. on servers in the cloudC. only on personal devicesD. in physical hard drives答案：B。

此题主要关于云计算中数据的存储位置。

选项A 本地计算机不是云计算存储数据的地方；选项C 只在个人设备上不符合云计算的特点；选项 D 物理硬盘不是云计算存储数据的常见方式。

选项B 服务器在云中是云计算数据存储的正确位置。

3. Which of the following is a common application of cloud computing?A. Playing offline gamesB. Editing documents without an internet connectionC. Streaming moviesD. Printing documents directly from a USB drive答案：C。

本题考查云计算的常见应用。

选项A 离线游戏不是云计算的应用；选项B 没有网络连接编辑文档不是云计算的典型应用；选项D 从U 盘直接打印文档与云计算无关。