expand for answer

Buffer

A temporary storage area, usually in RAM. The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device. Because the processes of reading and writing data to a disk are relatively slow, many programs keep track of data changes in a buffer and then copy the buffer to a disk. For example, word processors employ a buffer to keep track of changes to files. Then when you save the file, the word processor updates the disk file with the contents of the buffer. This is much more efficient than accessing the file on the disk each time you make a change to the file. Note that because your changes are initially stored in a buffer, not on the disk, all of them will be lost if the computer fails during an editing session. For this reason, it is a good idea to save your file periodically. Most word processors automatically save files at regular intervals. Another common use of buffers is for printing documents. When you enter a PRINT command, the operating system copies your document to a print buffer (a free area in memory or on a disk) from which the printer can draw characters at its own pace. This frees the computer to perform other tasks while the printer is running in the background. Print buffering is called spooling. Most keyboard drivers also contain a buffer so that you can edit typing mistakes before sending your command to a program. Many operating systems, including DOS, also use a disk buffer to temporarily hold data that they have read from a disk. The disk buffer is really a cache.


Similar items:
<strong>Maturity Level Details:</strong><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Maturity levels consist of a predefined set of process areas. The maturity levels are measured by the achievement of the&nbsp;specific&nbsp;and&nbsp;generic goals&nbsp;that apply to each predefined set of process areas. The following sections describe the characteristics of each maturity level in detail.</p><strong>Maturity Level 1 - Initial</strong><br>At maturity level 1, processes are usually ad hoc and chaotic. The organization usually does not provide a stable environment. Success in these organizations depends on the competence and heroics of the people in the organization and not on the use of proven processes.<p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Maturity level 1 organizations often produce products and services that work; however, they frequently exceed the budget and schedule of their projects.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Maturity level 1 organizations are characterized by a tendency to over commit, abandon processes in the time of crisis, and not be able to repeat their past successes.</p><strong>Maturity Level 2 - Managed</strong><br>At maturity level 2, an organization has achieved all the&nbsp;specific&nbsp;and&nbsp;generic goals&nbsp;of the maturity level 2 process areas. In other words, the projects of the organization have ensured that requirements are managed and that processes are planned, performed, measured, and controlled.<p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">The process discipline reflected by maturity level 2 helps to ensure that existing practices are retained during times of stress. When these practices are in place, projects are performed and managed according to their documented plans.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">At maturity level 2, requirements, processes, work products, and services are managed. The status of the work products and the delivery of services are visible to management at defined points.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Commitments are established among relevant stakeholders and are revised as needed. Work products are reviewed with stakeholders and are controlled.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">The work products and services satisfy their specified requirements, standards, and objectives.</p><strong>Maturity Level 3 - Defined</strong><br>At maturity level 3, an organization has achieved all the&nbsp;specific&nbsp;and&nbsp;generic goals&nbsp;of the process areas assigned to maturity levels 2 and 3.<p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">At maturity level 3, processes are well characterized and understood, and are described in standards, procedures, tools, and methods.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">A critical distinction between maturity level 2 and maturity level 3 is the scope of standards, process descriptions, and procedures. At maturity level 2, the standards, process descriptions, and procedures may be quite different in each specific instance of the process (for example, on a particular project). At maturity level 3, the standards, process descriptions, and procedures for a project are tailored from the organization's set of standard processes to suit a particular project or organizational unit. The organization's set of standard processes includes the processes addressed at maturity level 2 and maturity level 3. As a result, the processes that are performed across the organization are consistent except for the differences allowed by the tailoring guidelines.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Another critical distinction is that at maturity level 3, processes are typically described in more detail and more rigorously than at maturity level 2. At maturity level 3, processes are managed more proactively using an understanding of the interrelationships of the process activities and detailed measures of the process, its work products, and its services.</p><strong>Maturity Level 4 - Quantitatively Managed</strong><br>At maturity level 4, an organization has achieved all the&nbsp;specific goals&nbsp;of the process areas assigned to maturity levels 2, 3, and 4 and the&nbsp;generic goals&nbsp;assigned to maturity levels 2 and 3.<p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">At maturity level 4 Subprocesses are selected that significantly contribute to overall process performance. These selected subprocesses are controlled using statistical and other quantitative techniques.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Quantitative objectives for quality and process performance are established and used as criteria in managing processes. Quantitative objectives are based on the needs of the customer, end users, organization, and process implementers. Quality and process performance are understood in statistical terms and are managed throughout the life of the processes.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">For these processes, detailed measures of process performance are collected and statistically analyzed. Special causes of process variation are identified and, where appropriate, the sources of special causes are corrected to prevent future occurrences.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Quality and process performance measures are incorporated into the organization.s measurement repository to support fact-based decision making in the future.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">A critical distinction between maturity level 3 and maturity level 4 is the predictability of process performance. At maturity level 4, the performance of processes is controlled using statistical and other quantitative techniques, and is quantitatively predictable. At maturity level 3, processes are only qualitatively predictable.</p><strong>Maturity Level 5 - Optimizing</strong><br>At maturity level 5, an organization has achieved all the&nbsp;specific goals&nbsp;of the process areas assigned to maturity levels 2, 3, 4, and 5 and the&nbsp;generic goals&nbsp;assigned to maturity levels 2 and 3.<p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Processes are continually improved based on a quantitative understanding of the common causes of variation inherent in processes.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Maturity level 5 focuses on continually improving process performance through both incremental and innovative technological improvements.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Quantitative process-improvement objectives for the organization are established, continually revised to reflect changing business objectives, and used as criteria in managing process improvement.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">The effects of deployed process improvements are measured and evaluated against the quantitative process-improvement objectives. Both the defined processes and the organization's set of standard processes are targets of measurable improvement activities.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">Optimizing processes that are agile and innovative depends on the participation of an empowered workforce aligned with the business values and objectives of the organization. The organization's ability to rapidly respond to changes and opportunities is enhanced by finding ways to accelerate and share learning. Improvement of the processes is inherently part of everybody's role, resulting in a cycle of continual improvement.</p><p style="margin: 0.8em 0px 1em; padding: 0px; text-align: justify; color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12px;">A critical distinction between maturity level 4 and maturity level 5 is the type of process variation addressed. At maturity level 4, processes are concerned with addressing special causes of process variation and providing statistical predictability of the results. Though processes may produce predictable results, the results may be insufficient to achieve the established objectives. At maturity level 5, processes are concerned with addressing common causes of process variation and changing the process (that is, shifting the mean of the process performance) to improve process performance (while maintaining statistical predictability) to achieve the established quantitative process-improvement objectives.</p>
[view]
Pronounced cash, a special highspeed storage mechanism. It can be either a reserved section of main memory or an independent highspeed storage device. Two types of caching are commonly used in personal computers: memory caching and disk caching. A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of highspeed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. Disk caching works under the same principle as memory caching, but instead of using highspeed SRAM, a disk cache uses conventional main memory. When data is found in the cache, it is called a cache hit, and the effectiveness of a cache is judged by its hit rate.
[view]
A type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such as printers. There are two basic types of RAM: dynamic RAM (DRAM) and static RAM (SRAM).
[view]
A channel that conveys information by writing data to a common storage area where another process can read it. A covert channel that involves the direct or indirect writing of a storage location by one process and the direct or indirect reading of the storage location by another process. Covert storage channels typically involve a finite resource that is shared by two subjects at different security levels. Covert channel involving the direct or indirect writing to a storage location by one process and the direct or indirect reading of the storage location by another process. Covert storage channels typically involve a finite resource (e. g. , sectors on a disk) that is shared by two subjects at different security levels.
[view]
The area in a computer that serves as temporary storage for programs and data during program execution. The main memory resources directly available to a system’s CPU. Primary memory normally consists of volatile random access memory (RAM) and is a high- performance storage resource available to a system.
[view]


There are no comments yet.

Authentication required

You must log in to post a comment.

Log in