This metaphor is credited to David Hoffman, a General Magic communications employee, based on its long-standing use in networking and telecom. The use of the "cloud" metaphor to denote virtualized services traces back to 1994, when it was used by General Magic to describe the universe of "places" that mobile agents in the Telescript environment could go. This was a time of exploration and experimentation with ways to make large-scale computing power available to more users through time-sharing, optimizing the infrastructure, platform, and applications, and increasing efficiency for end users. The "data center" model, where users submitted jobs to operators to run on mainframes, was predominantly used during this era. Ĭloud computing has a rich history that extends back to the 1960s, with the initial concepts of time-sharing becoming popularized via Remote Job Entry (RJE). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). To the consumer, the capabilities available for provisioning often appear unlimited and can be appropriated in any quantity at any time. Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. The provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations). A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider. The United States National Institute of Standards and Technology's definition of cloud computing identifies "five essential characteristics": Cloud computing relies on sharing of resources to achieve coherence and typically uses a pay-as-you-go model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users. Large clouds often have functions distributed over multiple locations, each of which is a data center. For the horse, see Cloud Computing (horse).Ĭloud computing metaphor: the group of networked elements providing services does not need to be addressed or managed individually by users instead, the entire provider-managed suite of hardware and software can be thought of as an amorphous cloud.Ĭloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. The polygon has touched just 5 points (see map of Convex hull below) but normally it should pass on 20 points (all points of the contour).Įach point has a pixel, actually the outline should not touch the points but it must pass through the outer limit of these pixels."Cloud Computing" redirects here. With the tool suggested by I can only draw a polygon with the outer points that are more extreme. I know there is Points2One plugin, but it makes an outline with all points, even with the data found in the middle of the point cloud. I want to know if there is a plugin in QGIS, which will allow me to draw the outline a point cloud.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |