Thursday, August 29, 2013

Windows XP (IT)

Windows XP
Windows XP was originally released in year 2001. It included improved graphics, and a more user-friendly environment. Windows XP was built on the core of Windows 2000 but adds greater stability for most desktop users plus a fancier graphical user interface. Although the goal of perfect security continues to elude the OS, Service Pack 2 (SP2) improves matters over the original release and rolls up enhancements added between release and mid-2004.
Operating System Design
The Windows XP kernel is considered a modified-microkernel, and is also sometimes called a macro kernel. Although most system components run in the same address space, some subsystems run as user-mode server processes and many of the design objectives are the same as Mach.
A hardware abstraction layer (HAL) is an abstraction layer, implemented in software, between the physical hardware of a computer and the software that runs on that computer. Its function is to hide differences in hardware from most of the operating system kernel, so that most of the kernel-mode code does not need to be changed to run on systems with different hardware. On a PC, HAL can basically be considered to be the driver for the motherboard and allows instructions from higher level computer languages to communicate with lower level components, such as directly with hardware.
A microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, thread management, and inter-process communication (IPC). If the hardware provides multiple rings or CPU modes, the microkernel is the only software executing at the most privileged level (generally referred to as supervisor or kernel mode) Traditional operating system functions, such as device drivers, protocol stacks and file systems, are removed from the microkernel to run in user space

The monolithic approach is to defines a high-level virtual interface over the hardware, with a set of primitives or system calls to implement operating system services such as process management, concurrency, and memory management in several modules that run in supervisor mode. Even if every module servicing these operations is separate from the whole, the code integration is very tight and difficult to do correctly, and, since all the modules run in the same address space, a bug in one module can bring down the whole system
Device Drivers
Device drivers frequently perform direct memory access (DMA), and therefore can write to arbitrary locations of physical memory, including over kernel data structures. Such drivers must therefore be trusted. It is a common misconception that this means that they must be part of the kernel. In fact, a driver is not inherently more or less trustworthy by being part of the kernel.
While running a device driver in user space does not necessarily reduce the damage a misbehaving driver can cause, in practice it is beneficial for system stability in the presence of buggy (rather than malicious) drivers: memory-access violations by the driver code itself (as opposed to the device) may still be caught by the memory-management hardware. Furthermore, many devices are not DMA-capable, their drivers can be made untrusted by running them in user space
Executive
The Windows Executive services make up the low-level kernel-mode portion. It deals with I/O, object management, security and process management. These are divided into several subsystems, among which are Cache Manager, Configuration Manager, I/O Manager, Local Procedure Call (LPC), Memory Manager, Object Manager, Process Structureand Security Reference Monitor (SRM). Grouped together, the components can be called Executive services (internal name Ex). System Services (internal name Nt), i.e., system calls, are implemented at this level, too, except very few that call directly into the kernel layer for better performance. Diagram : Windows XP system architecture

Object Manager
The Object Manager (internal name Ob) is an executive subsystem that all other executive subsystems, especially system calls, must pass through to gain access to Windows NT resources—essentially making it a resource management infrastructure service. The object manager is used to reduce the duplication of object resource management functionality in other executive subsystems, which could potentially lead to bugs and make development of Windows NT harder. To the object manager, each resource is an object, whether that resource is a physical resource (such as a file system or peripheral) or a logical resource (such as a file). Each object has a structure or object type that the object manager must know about.
Cache Controller
Closely coordinates with the Memory Manager, I/O Manager and I/O drivers to provide a common cache for regular file I/O. Uniquely, the Windows Cache Manager operates on file blocks (rather than device blocks), for consistent operation between local and remote files, and ensures a certain degree of coherency with memory-mapped views of files, since cache blocks are a special case of memory-mapped views and cache misses a special case of page faults.
Configuration Manager
Implements the Windows registry.
I/O Manager
Allows devices to communicate with user-mode subsystems. It translates user-mode read and write commands into read or write IRPs which it passes to device drivers. It accepts file system I/O requests and translates them into device specific calls, and can incorporate low-level device drivers that directly manipulate hardware to either read input or write output. It also includes a cache manager to improve disk performance by caching read requests and write to the disk in the background.
Local Procedure Call (LPC)
Provides inter-process communication ports with connection semantics. LPC ports are used by user-mode subsystems to communicate with their clients, by Executive subsystems to communicate with user-mode subsystems, and as the basis for the local transport for MSRPC.
Memory Manager
Manages virtual memory, controlling memory protection and the paging of memory in and out of physical memory to secondary storage, and implements a general-purpose allocator of physical memory. It also implements a parser of PE executables that lets an executable be mapped or unmapped in a single, atomic step.
Starting from Windows NT Server 4.0, Terminal Server Edition, the memory manager implements a so-called session space, a range of kernel-mode memory that is subject to context switching just like user-mode memory. This lets multiple instances of the kernel-mode Win32 subsystem and GDI drivers run side-by-side, despite shortcomings in their initial design. Each session space is shared by several processes, collectively referred to as a "session".
PnP Manager
Handles Plug and Play and supports device detection and installation at boot time. It also has the responsibility to stop and start devices on demand—this can happen when a bus (such as USB orFireWire) gains a new device and needs to have a device driver loaded to support it. Its bulk is actually implemented in user mode, in the Plug and Play Service, which handles the often complex tasks of installing the appropriate drivers, notifying services and applications of the arrival of new devices, and displaying GUI to the user.
Power Manager
Deals with power events (power-off, stand-by, hibernate, etc.) and notifies affected drivers with special IRPs (Power IRPs).
Security Reference Monitor (SRM)
The primary authority for enforcing the security rules of the security integral subsystem. It determines whether an object or resource can be accessed, via the use of access control lists (ACLs), which are themselves made up of access control entries (ACEs). ACEs contain a security identifier (SID) and a list of operations that the ACE gives a select group of trustees—a user account, group account, or login session--permission (allow, deny, or audit) to that resource.
Environment Subsystem
The environment subsystem was designed to run applications written for many different types of operating systems. None of the environment subsystems can directly access hardware, and must request access to memory resources through the Virtual Memory Manager that runs in kernel mode. Also, applications run at a lower priority than kernel mode processes.
There are three main environment subsystems: the Win32 subsystem, an OS/2 subsystem and a POSIX subsystem.
The Win32 environment subsystem can run 32-bit Windows applications. It contains the console as well as text window support, shutdown and hard-error handling for all other environment subsystems. It also supports Virtual DOS Machines (VDMs), which allow MS-DOS and 16-bit Windows (Win16) applications to run on Windows NT.
The ANSI/POSIX Environment (APE) is a compatibility subsystem that implements an interface close to ANSI C and POSIX, with some common extensions. It also includes a POSIX-compatible shell.
DLL (Dynamic-link library)
DLLs provide a mechanism for shared code and data, allowing a developer of shared code/data to upgrade functionality without requiring applications to be re-linked or re-compiled. From the application development point of view Windows and OS/2 can be thought of as a collection of DLLs that are upgraded, allowing applications for one version of the OS to work in a later one, provided that the OS vendor has ensured that the interfaces and functionality are compatible.
DLLs execute in the memory space of the calling process and with the same access permissions which means there is little overhead in their use but also that there is no protection for the calling EXE if the DLL has any sort of bug.

Friday, August 23, 2013

Exams Not Canceled

Monday, August 19, 2013

University Examination Time Table

Electronic Book

Friday, August 16, 2013

Value Education Poems Meaning

Ozymandias

Summary

The speaker recalls having met a traveler “from an antique land,” who told him a story about the ruins of a statue in the desert of his native country. Two vast legs of stone stand without a body, and near them a massive, crumbling stone head lies “half sunk” in the sand. The traveler told the speaker that the frown and “sneer of cold command” on the statue’s face indicate that the sculptor understood well the emotions (or "passions") of the statue’s subject. The memory of those emotions survives "stamped" on the lifeless statue, even though both the sculptor and his subject are both now dead. On the pedestal of the statue appear the words, “My name is Ozymandias, king of kings: / Look on my works, ye Mighty, and despair!” But around the decaying ruin of the statue, nothing remains, only the “lone and level sands,” which stretch out around it.

Form

“Ozymandias” is a sonnet, a fourteen-line poem metered in iambic pentameter. The rhyme scheme is somewhat unusual for a sonnet of this era; it does not fit a conventional Petrarchan pattern, but instead interlinks the octave (a term for the first eight lines of a sonnet) with the sestet (a term for the last six lines), by gradually replacing old rhymes with new ones in the form ABABACDCEDEFEF.

Commentary

This sonnet from 1817 is probably Shelley’s most famous and most anthologized poem—which is somewhat strange, considering that it is in many ways an atypical poem for Shelley, and that it touches little upon the most important themes in his oeuvre at large (beauty, expression, love, imagination). Still, “Ozymandias” is a masterful sonnet. Essentially it is devoted to a single metaphor: the shattered, ruined statue in the desert wasteland, with its arrogant, passionate face and monomaniacal inscription (“Look on my works, ye Mighty, and despair!”). The once-great king’s proud boast has been ironically disproved; Ozymandias’s works have crumbled and disappeared, his civilization is gone, all has been turned to dust by the impersonal, indiscriminate, destructive power of history. The ruined statue is now merely a monument to one man’s hubris, and a powerful statement about the insignificance of human beings to the passage of time. Ozymandias is first and foremost a metaphor for the ephemeral nature of political power, and in that sense the poem is Shelley’s most outstanding political sonnet, trading the specific rage of a poem like “England in 1819” for the crushing impersonal metaphor of the statue. But Ozymandias symbolizes not only political power—the statue can be a metaphor for the pride and hubris of all of humanity, in any of its manifestations. It is significant that all that remains of Ozymandias is a work of art and a group of words; as Shakespeare does in the sonnets, Shelley demonstrates that art and language long outlast the other legacies of power.

Of course, it is Shelley’s brilliant poetic rendering of the story, and not the subject of the story itself, which makes the poem so memorable. Framing the sonnet as a story told to the speaker by “a traveller from an antique land” enables Shelley to add another level of obscurity to Ozymandias’s position with regard to the reader—rather than seeing the statue with our own eyes, so to speak, we hear about it from someone who heard about it from someone who has seen it. Thus the ancient king is rendered even less commanding; the distancing of the narrative serves to undermine his power over us just as completely as has the passage of time. Shelley’s description of the statue works to reconstruct, gradually, the figure of the “king of kings”: first we see merely the “shattered visage,” then the face itself, with its “frown / And wrinkled lip and sneer of cold command”; then we are introduced to the figure of the sculptor, and are able to imagine the living man sculpting the living king, whose face wore the expression of the passions now inferable; then we are introduced to the king’s people in the line, “the hand that mocked them and the heart that fed.” The kingdom is now imaginatively complete, and we are introduced to the extraordinary, prideful boast of the king: “Look on my works, ye Mighty, and despair!” With that, the poet demolishes our imaginary picture of the king, and interposes centuries of ruin between it and us: “ ‘Look on my works, ye Mighty, and despair!’ / Nothing beside remains. Round the decay / Of that colossal wreck, boundless and bare, / The lone and level sands stretch far away.”

Ozymandias

This article is about Shelley's poem. For other uses, see Ozymandias (disambiguation).

Ozymandias

I met a traveller from an antique land
Who said: Two vast and trunkless legs of stone
Stand in the desart. Near them, on the sand,
Half sunk, a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them and the heart that fed:
And on the pedestal these words appear:
"My name is Ozymandias, king of kings:
Look on my works, ye Mighty, and despair!"
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare
The lone and level sands stretch far away.^[1]

"Ozymandias" (/ˌ ɒ z i ˈ m æ n d i ə s /,^[2] also pronounced with four syllables in order to fit the poem's meter) is a sonnet by Percy Bysshe Shelley, published in 1818 in the 11 January issue of The Examiner in London. It is frequently anthologised and is probably Shelley's most famous short poem. It was written in competition with his friend Horace Smith, who wrote another sonnet titled "Ozymandias" seen below.
In addition to the power of its themes and imagery, the poem is notable for its virtuosic diction. The rhyme scheme of the sonnet is unusual and creates a sinuous and interwoven effect.^[3]
The central theme of "Ozymandias" is the inevitable decline of all leaders, and of the empires they build, however mighty in their own time.^[4]

Ozymandias represents a transliteration into Greek of a part of Ramesses' throne name, User-maat-re Setep-en-re. The sonnet paraphrases the inscription on the base of the statue, given by Diodorus Siculus in his Bibliotheca historica, as "King of Kings am I, Osymandias. If anyone would know how great I am and where I lie, let him surpass one of my works."^[5]^[6]
Shelley's poem is often said to have been inspired by the 1821 arrival in London of a colossal statue of Ramesses II, acquired for the British Museum by the Italian adventurer Giovanni Belzoni in 1816.^[7] Rodenbeck and Chaney, however,^[8] point out that the poem was written and published before the statue arrived in Britain, and thus that Shelley could not have seen it. Its repute in Western Europe preceded its actual arrival in Britain (Napoleon had previously made an unsuccessful attempt to acquire it for France, for example), and thus it may have been its repute or news of its imminent arrival rather than seeing the statue itself which provided the inspiration.
The 2008 edition of the travel guide Lonely Planet's guide to Egypt says that the poem was inspired by the fallen statue of Ramesses II at the Ramesseum, a memorial temple built by Ramesses at Thebes, near Luxor in Upper Egypt.^[9] This statue, however, does not have "two vast and trunkless legs of stone", nor does it have a "shattered visage" with a "frown / And wrinkled lip, and sneer of cold command." Nor does the base of the statue at Thebes have any inscription, although Ramesses's cartouche is inscribed on the statue itself.
Among the earlier senses of the verb "to mock" is "to fashion an imitation of reality" (as in "a mock-up"),^[10] but by Shelley's day the current sense "to ridicule" (especially by mimicking) had come to the fore.
This sonnet is often incorrectly quoted or reproduced.^[11] The most common misquotation – "Look upon my works, ye Mighty, and despair!" – replaces the correct "on" with "upon".^[12]

Publication history[edit source | edit]

Both Percy Bysshe Shelley and Horace Smith submitted a sonnet on the subject to The Examiner published by Leigh Hunt in London. Shelley's was published on January 11, 1818 under the pen name Glirastes, appearing on page 24 under Original Poetry. Smith's was published, with the initials H.S., on February 1, 1818. Shelley's poem was later republished under the title "Sonnet. Ozymandias" in his 1819 collection Rosalind and Helen, A Modern Eclogue; with Other Poems by Charles and James Ollier and in the 1826 Miscellaneous and Posthumous Poems of Percy Bysshe Shelley by William Benbow, both in London.
Percy Bysshe Shelley wrote this poem in competition with his friend Horace Smith, who published his sonnet a month after Shelley's in the same magazine.^[14] It takes the same subject, tells the same story, and makes a similar moral point, but one related more directly to modernity, ending by imagining a hunter of the future looking in wonder on the ruins of an annihilated London. It was originally published under the same title as Shelley's verse; but in later collections Smith retitled it "On A Stupendous Leg of Granite, Discovered Standing by Itself in the Deserts of Egypt, with the Inscription Inserted Below".^[15]

Cultural influence[edit source | edit]

The poem has made numerous appearances in popular culture, and has significantly influenced the production of new creative works. For example, Terry Carr's science fiction short story "Ozymandias" was inspired by the poem, as was the song "Ozymandias" by Jean-Jacques Burnel. Edward Elgar began setting the poem to music, but never finished it. The best-known setting appears to be that in Russian for baritone by the Ukrainian composer Borys Lyatoshynsky. On television, Monty Python's Flying Circus featured a humorous parody named "Ozymandias, King of Ants", and the Beauty and the Beast episode titled "Ozymandias" included a reading of the entire poem. Writer Alan Moore named a superhero in the comic book miniseries Watchmen after Ozymandias, and overtly quoted the poem. Short excerpts of the poem, or references to its title, have appeared in a variety of other contexts including the closing ceremony of the 2012 Summer Olympics. In July 2013, the popular American television series Breaking Bad debuted a trailer that featured Bryan Cranston reading the entire poem.^[16] The fourteenth episode of the fifth season is entitled Ozymandias.^[17] Top of Form

Where The Mind is without Fear

This poem in this selection has been taken from his English ‘Gitanjali’. Tagore had a very deep religious caste of mind and profound humanism. He was both a patriot and an internationalist. In the poem, ‘Where The Mind Is Without Fear’, Tagore sketches a moving picture of the nation he would like India to be. Where everyone within the fold of the brotherhood is free to hold up one’s head high and one’s voice to be heard without having any tension of fear of oppression or forced compulsion. Where the knowledge is not restricted by narrow ideas and loyalties. The British rule had robbed India of its pride and dignity by reducing it to a subject nation.
The India of Tagore’s dream is a country where her people hold their heads high with their pride in knowledge and strength born of that knowledge. Where all countrymen must come out the aged-old world of people who have lost the vision of one humanity by the narrow loyalties of caste creed and religion. Prejudice and superstitious which narrow the mind and divide people would be a thing of the past. Where the words of truth come out from the depths of the heart and are spoken out courageously in the open for the world to hear. People would work for perfections in the clear light of reason leaving aside all superstitious rituals.

Where everyone is free to toil and work hard for anything they desire either for their own or for the good of the nation. Everyone is encouraged to strive tirelessly till they attain full satisfaction in reaching their goals and perfection. Where blind superstitious habits of thought and action have not put out the light of reason. Where people’s mind should not dwell in the mistakes of the past nor be possessed by it. On the other hand they should be led by the power of reasoning to be focused on the future by applying scientific thought and action. Tagore’s only prayer to the Supreme Ultimate is leading the nation to such an ideal state of heaven. It is only by the universality of outlook and an abiding passion for the realization of great human ideals that India will achieve her true freedom. This way alone she will realize her destiny.