document_title: Huckleberry Finn

question_text: who is the character huck finn based on

question_tokens: who is the character huck finn based on

text: Huckleberry Finn

text: Characterization[edit]

text: Huckleberry "Huck" Finn is the son of the town's vagrant drunkard, "Pap" Finn. Sleeping on doorsteps when the weather is fair, in empty hogsheads during storms, and living off of what he receives from others, Huck lives the life of a destitute vagabond. The author metaphorically names him "the juvenile pariah of the village" and describes Huck as "idle, and lawless, and vulgar, and bad," qualities for which he was admired by all the children in the village, although their mothers "cordially hated and dreaded" him.

text: Huck is an archetypal innocent, able to discover the "right" thing to do despite the prevailing theology and prejudiced mentality of the South of that era. The best example of this is his decision to help Jim escape slavery, even though he believes he will go to hell for it (see Christian views on slavery).

text: His appearance is described in The Adventures of Tom Sawyer. He wears the clothes of full-grown men which he probably received as charity, and as Twain describes him, "he was fluttering with rags." He has a torn broken hat and his trousers are supported with only one suspender.

text: Tom's Aunt Polly calls Huck a "poor motherless thing." Huck confesses to Tom in The Adventures of Tom Sawyer that he remembers his mother and his parents' relentless fighting that only abated with her death.

text: Huck has a carefree life free from societal norms or rules, stealing watermelons and chickens and "borrowing" boats and cigars. Due to his unconventional childhood, Huck has received almost no education. At the end of The Adventures of Tom Sawyer, Huck is adopted by the Widow Douglas, who sends him to school in return for his saving her life. In the course of The Adventures of Huckleberry Finn he learns enough to be literate and even reads books for entertainment when there isn't anything else to do. His knowledge of history as related to Jim is wildly inaccurate, but it is not specified if he is being wrong on purpose as a joke on Jim.

text: In Adventures of Huckleberry Finn, the sequel to The Adventures of Tom Sawyer, the Widow attempts to "sivilize" (sic) the newly wealthy Huck. Huck's father takes him from her, but Huck manages to fake his own death and escape to Jackson's Island, where he coincidentally meets up with Jim, a slave who was owned by the Widow Douglas' sister, Miss Watson.

text: Jim is running away because he overheard Miss Watson planning to "sell him South" for eight hundred dollars. Jim wants to escape to Ohio, where he can find work to eventually buy his family's freedom. Huck and Jim take a raft down the Mississippi River in hopes of finding freedom from slavery for Jim and freedom from Pap for Huck. Their adventures together, along with Huck's solo adventures, comprise the core of the book.

text: In the end, however, Jim gains his freedom through Miss Watson's death, as she freed him in her will. Pap, it is revealed, has died in Huck's absence, and although he could safely return to St. Petersburg, Huck plans to flee west to Indian Territory.

text: In Tom Sawyer Abroad and Tom Sawyer, Detective, the sequels to Huck Finn, however, Huck is living in St. Petersburg again after the events of his eponymous novel. In Abroad, Huck joins Tom and Jim for a wild, fanciful balloon ride that takes them overseas. In Detective, which occurs about a year after the events of Huck Finn, Huck helps Tom solve a murder mystery.

text: Relationships[edit]

text: Huck is Tom Sawyer's closest friend. Their friendship is partially rooted in Sawyer's emulation of Huck's freedom and ability to do what he wants, like swearing and smoking when he feels like it. In one moment in the novel, he openly brags to his teacher that he was late for school because he stopped to talk with Huck Finn and enjoyed it, something for which he knew he would (and did) receive a whipping. Nonetheless, Tom remains a devoted friend to Huck in all of the novels they appear in. In Huckleberry Finn, it's revealed that Huck also considers Tom to be his best friend. At various times in the novel, Huck mentions that Tom would put more "style" in Jim and his adventure.

text: Jim, a runaway slave whom Huck befriends, is another dominant force in Huck's life. He is the symbol for the moral awakening Huck undergoes throughout Adventures of Huckleberry Finn. This is seen when Huck considers sending a letter to Ms. Watson telling her where Jim is but ultimately chooses to rip it up despite the idea in the south that one who tries helping a slave escape will be sent to eternal punishment.

text: Pap Finn is Huck's abusive, drunken father who shows up at the beginning of Adventures of Huckleberry Finn and forcibly takes his son to live with him. Pap's only method of parenting is physical abuse. Although he seems derisive of education and civilized living, Pap seems to be jealous of Huck and is infuriated that his son would try to amount to more, and live in better conditions than he did. Despite this, early in the novel Huck uses his father's method of "borrowing" though he later feels sorry and stops.

text: Inspiration[edit]

text: The character of Huck Finn is based on Tom Blankenship, the real-life son of a sawmill laborer and sometime drunkard named Woodson Blankenship, who lived in a "ramshackle" house near the Mississippi River behind the house where the author grew up in Hannibal, Missouri.[1] The father of Huck, called "Pap" Finn, may be based on Jimmy Finn, a full-blown alcoholic who lived on the streets, and it is only through Twain's remembrances that Woodson is characterized as a drunkard. Twain left Hannibal and his boyhood at an early age and his memories of these people are colored by what he could have known and understood at the time, as a boy of less than 14 years old. Twain's friend Tom Blankenship didn't attend school because there were no public schools at the time, and his family was too poor to send him to a private school. Left at loose ends in a busy household with six sisters and lacking a mother who seems to have died when he was young, this Tom was indeed "at liberty" most of the time.[citation needed]

text: Twain mentions his childhood friend Tom Blankenship as the inspiration for creating Huckleberry Finn in his autobiography: "In Huckleberry Finn I have drawn Tom Blankenship exactly as he was. He was ignorant, unwashed, insufficiently fed; but he had as good a heart as ever any boy had. His liberties were totally unrestricted. He was the only really independent person—boy or man—in the community, and by consequence he was tranquilly and continuously happy and envied by the rest of us. And as his society was forbidden us by our parents the prohibition trebled and quadrupled its value, and therefore we sought and got more of his society than any other boy's." – Mark Twain's Autobiography.

text: Appearances[edit]

text:
The Adventures of Tom Sawyer (1876)
Adventures of Huckleberry Finn (1884)
Tom Sawyer, Detective (1896)
Tom Sawyer Abroad (1894)
"Schoolhouse Hill" (1898) – unfinished
Huck Finn and Tom Sawyer among the Indians – unfinished
Tom Sawyer's Conspiracy – unfinished

tag: ol

text: Since Mark Twain's death, Huck Finn has also appeared in a number of novels, plays, and stories written by various authors that purport to tell the latter adventures of Huck and his friends.

text: Portrayals[edit]

text: Actors who have portrayed Huckleberry Finn in movies and TV:

text:
Lewis Sargent (1920)
Junior Durkin (1930 and 1931)
Jackie Moran (1938)
Donald O'Connor (1938)
Mickey Rooney (1939)
Eddie Hodges (1960)
Michael Shea (1968 in the tv series The New Adventures of Huckleberry Finn)
Roman Madyanov (1973 in Hopelessly Lost)
Jeff Tyler (1973 in Huckleberry Finn)
Jeff East (1973 and 1974)
Steve Stark (1979)
Ron Howard (1975)
Ian Tracey
Gary Krug (1985 in The Adventures of Mark Twain)
Patrick Day (1986)
Mitchell Anderson (1990 in Back to Hannibal: The Return of Tom Sawyer and Huckleberry Finn)
Elijah Wood (1993)
Brad Renfro (1995)
Mark Wills (voice)
Evan Wang (2011)
Leon Seidel (2011, German Version of The Adventures of Tom Sawyer)
Leon Seidel (2012, German Version of The Adventures of Huckleberry Finn)
Jake T. Austin (2013)
Kyle Gallner (2015)


document_title: Buffer overflow

question_text: by manipulating a buffer overflow an attacker can jump

root

text: Buffer overflow

text: Technical description[edit]

text: A buffer overflow occurs when data written to a buffer also corrupts data values in memory addresses adjacent to the destination buffer due to insufficient bounds checking. This can occur when copying data from one buffer to another without first checking that the data fits within the destination buffer.

tag: p

text: Example[edit]

text: In the following example expressed in C, a program has two variables which are adjacent in memory: an 8-byte-long string buffer, A, and a two-byte big-endian integer, B.

text: Initially, A contains nothing but zero bytes, and B contains the number 1979.

text:
variable name

A

B

value

[null string]

1979

hex value

00
00
00
00

00
00
00
00

07
BB

tag: table

text: Now, the program attempts to store the null-terminated string "excessive" with ASCII encoding in the A buffer.

text: "excessive" is 9 characters long and encodes to 10 bytes including the null terminator, but A can take only 8 bytes. By failing to check the length of the string, it also overwrites the value of B:

text:
variable name

A

B

value

'e'
'x'
'c'
'e'

's'
's'
'i'
'v'

25856

hex

65
78
63
65

73
73
69
76

65
00

text: B's value has now been inadvertently replaced by a number formed from part of the character string. In this example "e" followed by a zero byte would become 25856.

text: Writing data past the end of allocated memory can sometimes be detected by the operating system to generate a segmentation fault error that terminates the process.

text: To prevent the buffer overflow from happening in this example, the call to strcpy could be replaced with strncpy, which takes the maximum capacity of A as an additional parameter and ensures that no more than this amount of data is written to A:

text: Note that the above code is not free from problems either; while a buffer overrun has been prevented this time, the strncpy library function does not null-terminate the destination buffer if the source string's length is greater than or equal to the size of the buffer (the third argument passed to the function), therefore A is, in this case, not null-terminated and cannot be treated as a valid C-style string.

text: Exploitation[edit]

text: The techniques to exploit a buffer overflow vulnerability vary by architecture, by operating system and by memory region. For example, exploitation on the heap (used for dynamically allocated memory), differs markedly from exploitation on the call stack.

text: Stack-based exploitation[edit]

text: A technically inclined user may exploit stack-based buffer overflows to manipulate the program to their advantage in one of several ways:

text:
By overwriting a local variable that is located near the vulnerable buffer on the stack, in order to change the behavior of the program
By overwriting the return address in a stack frame. Once the function returns, execution will resume at the return address as specified by the attacker - usually a user-input filled buffer
By overwriting a function pointer[1] or exception handler, which is subsequently executed
By overwriting a local variable (or pointer) of a different stack frame, which will be used by the function which owns that frame later.[2]

tag: ul

text: If the address of the user-supplied data used to affect the stack buffer overflow is unpredictable, exploiting a stack buffer overflow to cause remote code execution becomes much more difficult.  One technique that can be used to exploit such a buffer overflow is called "trampolining".  In that technique, an attacker will find a pointer to the vulnerable stack buffer, and compute the location of their shellcode relative to that pointer.  Then, they will use the overwrite to jump to an instruction already in memory which will make a second jump, this time relative to the pointer; that second jump will branch execution into the shellcode.  Suitable instructions are often present in large code.  The Metasploit Project, for example, maintains a database of suitable opcodes, though it lists only those found in the Windows operating system.[3]

text: Heap-based exploitation[edit]

text: A buffer overflow occurring in the heap data area is referred to as a heap overflow and is exploitable in a manner different from that of stack-based overflows.  Memory on the heap is dynamically allocated by the application at run-time and typically contains program data.  Exploitation is performed by corrupting this data in specific ways to cause the application to overwrite internal structures such as linked list pointers.  The canonical heap overflow technique overwrites dynamic memory allocation linkage (such as malloc meta data) and uses the resulting pointer exchange to overwrite a program function pointer.

text: Microsoft's GDI+ vulnerability in handling JPEGs is an example of the danger a heap overflow can present.[4]

text: Barriers to exploitation[edit]

text: Manipulation of the buffer, which occurs before it is read or executed, may lead to the failure of an exploitation attempt. These manipulations can mitigate the threat of exploitation, but may not make it impossible. Manipulations could include conversion to upper or lower case, removal of metacharacters and filtering out of non-alphanumeric strings. However, techniques exist to bypass these filters and manipulations; alphanumeric code, polymorphic code, self-modifying code and return-to-libc attacks. The same methods can be used to avoid detection by intrusion detection systems. In some cases, including where code is converted into Unicode,[5] the threat of the vulnerability has been misrepresented by the disclosers as only Denial of Service when in fact the remote execution of arbitrary code is possible.

text: Practicalities of exploitation[edit]

text: In real-world exploits there are a variety of challenges which need to be overcome for exploits to operate reliably. These factors include null bytes in addresses, variability in the location of shellcode, differences between environments and various counter-measures in operation.

text: NOP sled technique[edit]

text: A NOP-sled is the oldest and most widely known technique for successfully exploiting a stack buffer overflow.[6] It solves the problem of finding the exact address of the buffer by effectively increasing the size of the target area. To do this, much larger sections of the stack are corrupted with the no-op machine instruction. At the end of the attacker-supplied data, after the no-op instructions, the attacker places an instruction to perform a relative jump to the top of the buffer where the shellcode is located. This collection of no-ops is referred to as the "NOP-sled" because if the return address is overwritten with any address within the no-op region of the buffer, the execution will "slide" down the no-ops until it is redirected to the actual malicious code by the jump at the end. This technique requires the attacker to guess where on the stack the NOP-sled is instead of the comparatively small shellcode.[7]

text: Because of the popularity of this technique, many vendors of intrusion prevention systems will search for this pattern of no-op machine instructions in an attempt to detect shellcode in use. It is important to note that a NOP-sled does not necessarily contain only traditional no-op machine instructions; any instruction that does not corrupt the machine state to a point where the shellcode will not run can be used in place of the hardware assisted no-op. As a result, it has become common practice for exploit writers to compose the no-op sled with randomly chosen instructions which will have no real effect on the shellcode execution.[8]

text: While this method greatly improves the chances that an attack will be successful, it is not without problems. Exploits using this technique still must rely on some amount of luck that they will guess offsets on the stack that are within the NOP-sled region.[9] An incorrect guess will usually result in the target program crashing and could alert the system administrator to the attacker's activities. Another problem is that the NOP-sled requires a much larger amount of memory in which to hold a NOP-sled large enough to be of any use. This can be a problem when the allocated size of the affected buffer is too small and the current depth of the stack is shallow (i.e. there is not much space from the end of the current stack frame to the start of the stack). Despite its problems, the NOP-sled is often the only method that will work for a given platform, environment, or situation; as such it is still an important technique.

text: The jump to address stored in a register technique[edit]

text: The "jump to register" technique allows for reliable exploitation of stack buffer overflows without the need for extra room for a NOP-sled and without having to guess stack offsets. The strategy is to overwrite the return pointer with something that will cause the program to jump to a known pointer stored within a register which points to the controlled buffer and thus the shellcode. For example, if register A contains a pointer to the start of a buffer then any jump or call taking that register as an operand can be used to gain control of the flow of execution.[10]

text: In practice a program may not intentionally contain instructions to jump to a particular register. The traditional solution is to find an unintentional instance of a suitable opcode at a fixed location somewhere within the program memory. In figure E on the left you can see an example of such an unintentional instance of the i386 jmp esp instruction. The opcode for this instruction is FF E4.[11] This two-byte sequence can be found at a one-byte offset from the start of the instruction call DbgPrint at address 0x7C941EED. If an attacker overwrites the program return address with this address the program will first jump to 0x7C941EED, interpret the opcode FF E4 as the jmp esp instruction, and will then jump to the top of the stack and execute the attacker's code.[12]

text: When this technique is possible the severity of the vulnerability increases considerably. This is because exploitation will work reliably enough to automate an attack with a virtual guarantee of success when it is run. For this reason, this is the technique most commonly used in Internet worms that exploit stack buffer overflow vulnerabilities.[13]

text: This method also allows shellcode to be placed after the overwritten return address on the Windows platform. Since executables are mostly based at address 0x00400000 and x86 is a Little Endian architecture, the last byte of the return address must be a null, which terminates the buffer copy and nothing is written beyond that. This limits the size of the shellcode to the size of the buffer, which may be overly restrictive. DLLs are located in high memory (above 0x01000000) and so have addresses containing no null bytes, so this method can remove null bytes (or other disallowed characters) from the overwritten return address. Used in this way, the method is often referred to as "DLL Trampolining".

text: Protective countermeasures[edit]

text: Various techniques have been used to detect or prevent buffer overflows, with various tradeoffs. The most reliable way to avoid or prevent buffer overflows is to use automatic protection at the language level. This sort of protection, however, cannot be applied to legacy code, and often technical, business, or cultural constraints call for a vulnerable language. The following sections describe the choices and implementations available.

text: Choice of programming language[edit]

text: Assembly and C/C++ are popular programming languages that are vulnerable to buffer overflow, in part because they allow direct access to memory and are not strongly typed.[14] C provides no built-in protection against accessing or overwriting data in any part of memory; more specifically, it does not check that data written to a buffer is within the boundaries of that buffer. The standard C++ libraries provide many ways of safely buffering data, and C++'s Standard Template Library (STL) provides containers that can optionally perform bounds checking if the programmer explicitly calls for checks while accessing data. For example, a vector's member function at() performs a bounds check and throws an out_of_range exception if the bounds check fails.[15] However, C++ behaves just like C if the bounds check is not explicitly called. Techniques to avoid buffer overflows also exist for C.

text: Languages that are strongly typed and don't allow direct memory access, such as COBOL, Java, Python, and others, prevent buffer overflow from occurring in most cases.[14] Many programming languages other than C/C++ provide runtime checking and in some cases even compile-time checking which might send a warning or raise an exception when C or C++ would overwrite data and continue to execute further instructions until erroneous results are obtained which might or might not cause the program to crash.  Examples of such languages include Ada, Eiffel, Lisp, Modula-2, Smalltalk, OCaml and such C-derivatives as Cyclone, Rust and D. The Java and .NET Framework bytecode environments also require bounds checking on all arrays. Nearly every interpreted language will protect against buffer overflows, signaling a well-defined error condition. Often where a language provides enough type information to do bounds checking an option is provided to enable or disable it. Static code analysis can remove many dynamic bound and type checks, but poor implementations and awkward cases can significantly decrease performance. Software engineers must carefully consider the tradeoffs of safety versus performance costs when deciding which language and compiler setting to use.

text: Use of safe libraries[edit]

text: The problem of buffer overflows is common in the C and C++ languages because they expose low level representational details of buffers as containers for data types.  Buffer overflows must thus be avoided by maintaining a high degree of correctness in code which performs buffer management. It has also long been recommended to avoid standard library functions which are not bounds checked, such as gets, scanf and strcpy. The Morris worm exploited a gets call in fingerd.[16]

text: Well-written and tested abstract data type libraries which centralize and automatically perform buffer management, including bounds checking, can reduce the occurrence and impact of buffer overflows.  The two main building-block data types in these languages in which buffer overflows commonly occur are strings and arrays; thus, libraries preventing buffer overflows in these data types can provide the vast majority of the necessary coverage.  Still, failure to use these safe libraries correctly can result in buffer overflows and other vulnerabilities; and naturally, any bug in the library itself is a potential vulnerability. "Safe" library implementations include "The Better String Library",[17] Vstr[18]  and Erwin.[19] The OpenBSD operating system's C library provides the strlcpy and strlcat functions, but these are more limited than full safe library implementations.

text: In September 2007, Technical Report 24731, prepared by the C standards committee, was published;[20] it specifies a set of functions which are based on the standard C library's string and I/O functions, with additional buffer-size parameters.  However, the efficacy of these functions for the purpose of reducing buffer overflows is disputable; it requires programmer intervention on a per function call basis that is equivalent to intervention that could make the analogous older standard library functions buffer overflow safe.[21]

text: Buffer overflow protection[edit]

text: Buffer overflow protection is used to detect the most common buffer overflows by checking that the stack has not been altered when a function returns.  If it has been altered, the program exits with a segmentation fault. Three such systems are Libsafe,[22] and the StackGuard[23] and ProPolice[24] gcc patches.

text: Microsoft's implementation of Data Execution Prevention (DEP) mode explicitly protects the pointer to the Structured Exception Handler (SEH) from being overwritten.[25]

text: Stronger stack protection is possible by splitting the stack in two: one for data and one for function returns.  This split is present in the Forth language, though it was not a security-based design decision.  Regardless, this is not a complete solution to buffer overflows, as sensitive data other than the return address may still be overwritten.

text: Pointer protection[edit]

text: Buffer overflows work by manipulating pointers (including stored addresses).  PointGuard was proposed as a compiler-extension to prevent attackers from being able to reliably manipulate pointers and addresses.[26]  The approach works by having the compiler add code to automatically XOR-encode pointers before and after they are used.  Because the attacker (theoretically) does not know what value will be used to encode/decode the pointer, he cannot predict what it will point to if he overwrites it with a new value.  PointGuard was never released, but Microsoft implemented a similar approach beginning in Windows XP SP2 and Windows Server 2003 SP1.[27]  Rather than implement pointer protection as an automatic feature, Microsoft added an API routine that can be called at the discretion of the programmer.  This allows for better performance (because it is not used all of the time), but places the burden on the programmer to know when it is necessary.

text: Because XOR is linear, an attacker may be able to manipulate an encoded pointer by overwriting only the lower bytes of an address.  This can allow an attack to succeed if the attacker is able to attempt the exploit multiple times or is able to complete an attack by causing a pointer to point to one of several locations (such as any location within a NOP sled).[28]  Microsoft added a random rotation to their encoding scheme to address this weakness to partial overwrites.[29]

text: Executable space protection[edit]

text: Executable space protection is an approach to buffer overflow protection which prevents execution of code on the stack or the heap. An attacker may use buffer overflows to insert arbitrary code into the memory of a program, but with executable space protection, any attempt to execute that code will cause an exception.

text: Some CPUs support a feature called NX ("No eXecute") or XD ("eXecute Disabled") bit, which in conjunction with software, can be used to mark pages of data (such as those containing the stack and the heap) as readable and writable but not executable.

text: Some Unix operating systems (e.g. OpenBSD, macOS) ship with executable space protection (e.g. W^X). Some optional packages include:

text:
PaX[30]
Exec Shield[31]
Openwall[32]

text: Newer variants of Microsoft Windows also support executable space protection, called Data Execution Prevention.[33] Proprietary add-ons include:

text:
BufferShield[34]
StackDefender[35]

text: Executable space protection does not generally protect against return-to-libc attacks, or any other attack which does not rely on the execution of the attackers code. However, on 64-bit systems using ASLR, as described below, executable space protection makes it far more difficult to execute such attacks.

text: Address space layout randomization[edit]

text: Address space layout randomization (ASLR) is a computer security feature which involves arranging the positions of key data areas, usually including the base of the executable and position of libraries, heap, and stack, randomly in a process' address space.

text: Randomization of the virtual memory addresses at which functions and variables can be found can make exploitation of a buffer overflow more difficult, but not impossible. It also forces the attacker to tailor the exploitation attempt to the individual system, which foils the attempts of internet worms.[36] A similar but less effective method is to rebase processes and libraries in the virtual address space.

text: Deep packet inspection[edit]

text: The use of deep packet inspection (DPI) can detect, at the network perimeter, very basic remote attempts to exploit buffer overflows by use of attack signatures and heuristics. These are able to block packets which have the signature of a known attack, or if a long series of No-Operation instructions (known as a NOP-sled) is detected, these were once used when the location of the exploit's payload is slightly variable.

text: Packet scanning is not an effective method since it can only prevent known attacks and there are many ways that a NOP-sled can be encoded. Shellcode used by attackers can be made alphanumeric, metamorphic, or self-modifying to evade detection by heuristic packet scanners and intrusion detection systems.

text: Testing[edit]

text: Checking for buffer overflows and patching the bugs that cause them naturally helps prevent buffer overflows.  One common automated technique for discovering them is fuzzing.[37]  Edge case testing can also uncover buffer overflows, as can static analysis.[38]  Once a potential buffer overflow is detected, it must be patched; this makes the testing approach useful for software that is in development, but less useful for legacy software that is no longer maintained or supported.

text: History[edit]

text: Buffer overflows were understood and partially publicly documented as early as 1972, when the Computer Security Technology Planning Study laid out the technique: "The code performing this function does not check the source and destination addresses properly, permitting portions of the monitor to be overlaid by the user. This can be used to inject code into the monitor that will permit the user to seize control of the machine." (Page 61)[39] Today, the monitor would be referred to as the kernel.

text: The earliest documented hostile exploitation of a buffer overflow was in 1988. It was one of several exploits  used by the Morris worm to propagate itself over the Internet. The program exploited was a service on Unix called finger.[40] Later, in 1995, Thomas Lopatic independently rediscovered the buffer overflow and published his findings on the Bugtraq security mailing list.[41] A year later, in 1996, Elias Levy (also known as Aleph One) published in Phrack magazine the paper "Smashing the Stack for Fun and Profit",[42] a step-by-step introduction to exploiting stack-based buffer overflow vulnerabilities.

text: Since then, at least two major internet worms have exploited buffer overflows to compromise a large number of systems. In 2001, the Code Red worm exploited a buffer overflow in Microsoft's Internet Information Services (IIS) 5.0[43] and in 2003 the SQL Slammer worm compromised machines running Microsoft SQL Server 2000.[44]

text: In 2003, buffer overflows present in licensed Xbox games have been exploited to allow unlicensed software, including homebrew games, to run on the console without the need for hardware modifications, known as modchips.[45] The PS2 Independence Exploit also used a buffer overflow to achieve the same for the PlayStation 2. The Twilight hack accomplished the same with the Wii, using a buffer overflow in The Legend of Zelda: Twilight Princess.


document_title: Oil burner

question_text: what is the typical pressure at which an oil burner operates

text: Oil burner

text: Fuel injection[edit]

text: Fuel is injected into the combustion chamber by a spray nozzle.

text: The nozzles are usually supplied with high pressure oil. Because erosion from friction with the oil, and possible blockage due to lumps in it, they need replacement when worn. Fuel nozzles are usually rated in fuel volume flow per unit time e.g. USGal/h (U.S. Gallons per hour).

text: A fuel nozzle is characterized by three features:

text:
Flow at 100psi pump pressure (e.g. 0.65 USGal/h)
Spray characteristic (e.g. "S")
Spray angle (e.g. 60 °)

text: Alternatively fuel may be passed over a tiny orifice fed with compressed air. This arrangement is referred to as Babington atomiser/nozzle, named after its inventor Robert Babington.[3] As the oil flows over the nozzle, the fuel needn't be under any great pressure. If the pump can handle such the oil may even contain lumps such as scraps of food. Because it is only compressed air that passes through the orifice hole, such nozzles do not suffer much from erosion.

text: Oil pump[edit]

text: A gear pump of two parts:

text: Gear pump assembly[edit]

text: This pumps the oil in and increases the pressure in the nozzles to 15 bar maximum (217.5 psi). Usually a gerotor of the sickle type is used. Gear pumps are used frequently in oil burners because of their simplicity, stability and low price.

text: Pressure regulator[edit]

text: To set the heat output of the burner, the rate of fuel delivery via the nozzle must be adjustable. This is often achieved by an adjustable pressure relief valve between the pump and the nozzle. When the set pressure is reached (usually 100psi), this valve opens and allows excess oil to flow through a bypass back to the fuel tank or the pump suction side.

text: Electromagnetic valve[edit]

text: This allows fuel to be shut off from the sprayer by electrical control. It helps avoid drips when the valve is closed. It also eases the purging of the burner (and any boiler) of fuel mist during start up, or while restarting after a misfire. If the burner were not purged the oil/air mixture could explode dangerously.

text: Fan[edit]

text: The fan blows air into the combustion chamber. The rotor of the fan is powered by an electric motor.

text: Igniters[edit]

text: Some oil burners use glow bars which operate much like the glow plugs of a diesel engine.

text: Many use high voltage generated by a voltage-step up transformer to create a spark for ignition, somewhat similar to a spark plug.

text: Original oil burner transformers were copper wire conductors wrapped around an iron core. A standard type of transformer to this day. In the mid 90s electronic igniters replaced the copper and iron transformer,solving many problems related to the old style transformer. This new technology in igniters would soon replace all old style transformers throughout the oil burner industry. The new igniters would run cooler so the output voltage could be increased from 10,000 to 20,000 VAC.

text: This increase of voltage would be more reliable, reduce delayed ignition, run cooler and all while using less energy. The voltage is high, but a standard igniter will only pull around 35 milliamp.

text: Safety control[edit]

text: Oil-fired burners are fitted with a safety mechanism for determining if the fuel has ignited and a flame present. The terms "primary control", "safety control", "cad cell control", "master control", and "fire-eye control" are variously used to describe a light dependent electrical resistor (LDR) which detects the flame whose value changes by the amount of light it is exposed to. The resistance decreases as the LDR is exposed to more light. The material is usually cadmium sulfide, hence the name "cad cell" for this component. In darkness the resistance is around 1 MΩ, while when exposed to light from a properly ignited flame the resistance is significantly lower, around 75-300 Ω.

text: Older oil burners were equipped with a primary control installed on the exhaust stack with a bimetallic heat sensing element protruding into the stack, such a control was referred to as a "stack relay" or a "stack control". It performed the same function as the newer cad-cell control but instead of sensing light from the burner flame it sensed heat from the flame exhaust gases to prove that ignition took place.

text: Capacitor start motor[edit]

text: The motor which drives the fan and the oil pump is usually a capacitor start motor. It is a vortex shortage tank motor because it also contains a short cage or cage holds. The difference with a three-phase motor is in the stator. Where the vortex power motor has three coils aligned at 120° in the stator, the capacitor start motor holds one main winding and one auxiliary winding aligned at 90°. The phase shift of 90° between the main winding and the auxiliary winding is achieved by a connected capacitor which feeds the auxiliary winding and is connected on the single-phase AC mains. The capacitor will achieve a phase shift of 90° between the main and the auxiliary winding, producing an acceptable initial torque. This motor is intended for continuous operation.


document_title: List of NCAA Division I men's basketball champions

question_text: who won the national championship in men's basketball last year

question_tokens: who won the national championship in men 's basketball last year

text: Championship games[edit]

text:
Legend for "Championship games" table below

Indicator
Meaning

*
Game was decided in an overtime period

Game was decided in a third overtime period

Score
Each score is linked to an article about that particular championship game, when available

Year
Each year is linked to an article about that particular NCAA Tournament

text:
Championship games, by year, showing winners and losers, final scores and venues

Year
Winning team
Winning head coach
Score
Losing team
Losing head coach
Venue
City
Ref.

1939
Oregon
Hobson, HowardHoward Hobson
046.3 !46–33
Ohio State
Olsen, HaroldHarold Olsen
Patten Gymnasium
Evanston, Illinois
[17]

1940
Indiana
McCracken, BranchBranch McCracken
060.3 !60–42
Kansas
Allen, PhogPhog Allen
Municipal Auditorium
Kansas City, Missouri
[18]

1941
Wisconsin
Foster, BudBud Foster
039 !39–34
Washington State
Friel, JackJack Friel
Municipal Auditorium
Kansas City, Missouri
[19]

1942
Stanford
Dean, EverettEverett Dean
053.2 !53–38
Dartmouth
Cowles, O. B.O. B. Cowles
Municipal Auditorium
Kansas City, Missouri
[20]

1943
Wyoming
Shelton, EverettEverett Shelton
046.2 !46–34
Georgetown
Ripley, ElmerElmer Ripley
Madison Square Garden
New York City, New York
[21]

1944
Utah
Peterson, VadalVadal Peterson
042 !42–40*
Dartmouth
Brown, EarlEarl Brown
Madison Square Garden
New York City, New York
[22][23]

1945
Oklahoma A&M
Iba, HenryHenry Iba
049 !49–45
NYU
Cann, HowardHoward Cann
Madison Square Garden
New York City, New York
[24]

1946
Oklahoma A&M
Iba, HenryHenry Iba
043 !43–40
North Carolina
Carnevale, BenBen Carnevale
Madison Square Garden
New York City, New York
[25]

1947
Holy Cross
Julian, DoggieDoggie Julian
058.1 !58–47
Oklahoma
Drake, BruceBruce Drake
Madison Square Garden
New York City, New York
[26]

1948
Kentucky
Rupp, AdolphAdolph Rupp
058.2 !58–42
Baylor
Henderson, BillBill Henderson
Madison Square Garden
New York City, New York
[27]

1949
Kentucky
Rupp, AdolphAdolph Rupp
046.1 !46–36
Oklahoma A&M
Iba, HenryHenry Iba
Hec Edmundson Pavilion
Seattle, Washington
[28]

1950
CCNY
Holman, NatNat Holman
071.2 !71–68
Bradley
Anderson, ForddyForddy Anderson
Madison Square Garden
New York City, New York
[29]

1951
Kentucky
Rupp, AdolphAdolph Rupp
068.3 !68–58
Kansas State
Gardner, JackJack Gardner
Williams Arena
Minneapolis, Minnesota
[30]

1952
Kansas
Allen, PhogPhog Allen
080.3 !80–63
St. John's
McGuire, FrankFrank McGuire
Hec Edmundson Pavilion
Seattle, Washington
[31]

1953
Indiana
McCracken, BranchBranch McCracken
069 !69–68
Kansas
Allen, PhogPhog Allen
Municipal Auditorium
Kansas City, Missouri
[32]

1954
La Salle
Loeffler, KenKen Loeffler
092.2 !92–76
Bradley
Anderson, ForddyForddy Anderson
Municipal Auditorium
Kansas City, Missouri
[33]

1955
San Francisco
Woolpert, PhilPhil Woolpert
077.3 !77–63
La Salle
Loeffler, KenKen Loeffler
Municipal Auditorium
Kansas City, Missouri
[34]

1956
San Francisco
Woolpert, PhilPhil Woolpert
083.2 !83–71
Iowa
O'Connor, BuckyBucky O'Connor
McGaw Hall
Evanston, Illinois
[35]

1957
North Carolina
McGuire, FrankFrank McGuire
054.1 !54–53
Kansas
Harp, DickDick Harp
Municipal Auditorium
Kansas City, Missouri
[36]

1958
Kentucky
Rupp, AdolphAdolph Rupp
084.3 !84–72
Seattle
Castellani, JohnJohn Castellani
Freedom Hall
Louisville, Kentucky
[37]

1959
California
Newell, PetePete Newell
071.1 !71–70
West Virginia
Schaus, FredFred Schaus
Freedom Hall
Louisville, Kentucky
[38]

1960
Ohio State
Taylor, FredFred Taylor
075.4 !75–55
California
Newell, PetePete Newell
Cow Palace
Daly City, California
[39][40]

1961
Cincinnati
Jucker, EdEd Jucker
070 !70–65*
Ohio State
Taylor, FredFred Taylor
Municipal Auditorium
Kansas City, Missouri
[41]

1962
Cincinnati
Jucker, EdEd Jucker
071.4 !71–59
Ohio State
Taylor, FredFred Taylor
Freedom Hall
Louisville, Kentucky
[42]

1963
Loyola Chicago
Ireland, GeorgeGeorge Ireland
060.1 !60–58*
Cincinnati
Jucker, EdEd Jucker
Freedom Hall
Louisville, Kentucky
[43]

1964
UCLA
Wooden, JohnJohn Wooden
098 !98–83
Duke
Bubas, VicVic Bubas
Municipal Auditorium
Kansas City, Missouri
[44]

1965
UCLA
Wooden, JohnJohn Wooden
091 !91–80
Michigan
Strack, DaveDave Strack
Memorial Coliseum
Portland, Oregon
[45]

1966
Texas Western
Haskins, DonDon Haskins
072.2 !72–65
Kentucky
Rupp, AdolphAdolph Rupp
Cole Field House
College Park, Maryland
[46]

1967
UCLA
Wooden, JohnJohn Wooden
079 !79–64
Dayton
Donoher, DonDon Donoher
Freedom Hall
Louisville, Kentucky
[47]

1968
UCLA
Wooden, JohnJohn Wooden
078.2 !78–55
North Carolina
Smith, DeanDean Smith
Sports Arena
Los Angeles, California
[48]

1969
UCLA
Wooden, JohnJohn Wooden
092.3 !92–72
Purdue
King, GeorgeGeorge King
Freedom Hall
Louisville, Kentucky
[49]

1970
UCLA
Wooden, JohnJohn Wooden
080.2 !80–69
Jacksonville
Williams, JoeJoe Williams
Cole Field House
College Park, Maryland
[50]

1971
UCLA
Wooden, JohnJohn Wooden
068.2 !68–62
Villanova[a]
Kraft, JackJack Kraft
Astrodome
Houston, Texas
[51]

1972
UCLA
Wooden, JohnJohn Wooden
081.2 !81–76
Florida State
Durham, HughHugh Durham
Memorial Sports Arena
Los Angeles, California
[52]

1973
UCLA
Wooden, JohnJohn Wooden
087 !87–66
Memphis State
Bartow, GeneGene Bartow
St. Louis Arena
St. Louis, Missouri
[53]

1974
North Carolina State
Sloan, NormNorm Sloan
076.3 !76–64
Marquette
McGuire, AlAl McGuire
Greensboro Coliseum
Greensboro, North Carolina
[54]

1975
UCLA
Wooden, JohnJohn Wooden
092.1 !92–85
Kentucky
Hall, Joe B.Joe B. Hall
San Diego Sports Arena
San Diego, California
[55]

1976
Indiana
Knight, BobBob Knight
086 !86–68
Michigan
Orr, JohnnyJohnny Orr
Spectrum
Philadelphia, Pennsylvania
[56]

1977
Marquette
McGuire, AlAl McGuire
067 !67–59
North Carolina
Smith, DeanDean Smith
Omni Coliseum
Atlanta, Georgia
[57]

1978
Kentucky
Hall, Joe B.Joe B. Hall
094 !94–88
Duke
Foster, BillBill Foster
The Checkerdome
St. Louis, Missouri
[58]

1979
Michigan State
Heathcote, JudJud Heathcote
075.3 !75–64
Indiana State
Hodges, BillBill Hodges
Special Events Center
Salt Lake City, Utah
[59]

1980
Louisville
Crum, DennyDenny Crum
059 !59–54
UCLA[a]
Brown, LarryLarry Brown
Market Square Arena
Indianapolis, Indiana
[60]

1981
Indiana
Knight, BobBob Knight
063.2 !63–50
North Carolina
Smith, DeanDean Smith
Spectrum
Philadelphia, Pennsylvania
[61]

1982
North Carolina
Smith, DeanDean Smith
063.1 !63–62
Georgetown
Thompson, JohnJohn Thompson
Louisiana Superdome
New Orleans, Louisiana
[62]

1983
North Carolina State
Valvano, JimJim Valvano
054.2 !54–52
Houston
Lewis, GuyGuy Lewis
University Arena
Albuquerque, New Mexico
[63]

1984
Georgetown
Thompson, JohnJohn Thompson
084.2 !84–75
Houston
Lewis, GuyGuy Lewis
Kingdome
Seattle, Washington
[64]

1985
Villanova
Massimino, RollieRollie Massimino
066 !66–64
Georgetown
Thompson, JohnJohn Thompson
Rupp Arena
Lexington, Kentucky
[65]

1986
Louisville
Crum, DennyDenny Crum
072.1 !72–69
Duke
Krzyzewski, MikeMike Krzyzewski
Reunion Arena
Dallas, Texas
[66]

1987
Indiana
Knight, BobBob Knight
074 !74–73
Syracuse
Boeheim, JimJim Boeheim
Louisiana Superdome
New Orleans, Louisiana
[67]

1988
Kansas
Brown, LarryLarry Brown
083.1 !83–79
Oklahoma
Tubbs, BillyBilly Tubbs
Kemper Arena
Kansas City, Missouri
[68]

1989
Michigan
Fisher, SteveSteve Fisher
080.1 !80–79*
Seton Hall
Carlesimo, P. J.P. J. Carlesimo
Kingdome
Seattle, Washington
[69]

1990
UNLV
Tarkanian, JerryJerry Tarkanian
103 !103–73
Duke
Krzyzewski, MikeMike Krzyzewski
McNichols Sports Arena
Denver, Colorado
[70]

1991
Duke
Krzyzewski, MikeMike Krzyzewski
072.2 !72–65
Kansas
Williams, RoyRoy Williams
Hoosier Dome
Indianapolis, Indiana
[71]

1992
Duke
Krzyzewski, MikeMike Krzyzewski
071.5 !71–51
Michigan[a]
Fisher, SteveSteve Fisher
Metrodome
Minneapolis, Minnesota
[72]

1993
North Carolina
Smith, DeanDean Smith
077.2 !77–71
Michigan[a]
Fisher, SteveSteve Fisher
Louisiana Superdome
New Orleans, Louisiana
[73]

1994
Arkansas
Richardson, NolanNolan Richardson
076.1 !76–72
Duke
Krzyzewski, MikeMike Krzyzewski
Charlotte Coliseum
Charlotte, North Carolina
[74]

1995
UCLA
Harrick, JimJim Harrick
089.1 !89–78
Arkansas
Richardson, NolanNolan Richardson
Kingdome
Seattle, Washington
[75]

1996
Kentucky
Pitino, RickRick Pitino
076.2 !76–67
Syracuse
Boeheim, JimJim Boeheim
Continental Airlines Arena
East Rutherford, New Jersey
[76]

1997
Arizona
Olson, LuteLute Olson
084.1 !84–79*
Kentucky
Pitino, RickRick Pitino
RCA Dome
Indianapolis, Indiana
[77]

1998
Kentucky
Smith, TubbyTubby Smith
078.1 !78–69
Utah
Majerus, RickRick Majerus
Alamodome
San Antonio, Texas
[78]

1999
Connecticut
Calhoun, JimJim Calhoun
077.1 !77–74
Duke
Krzyzewski, MikeMike Krzyzewski
Tropicana Field
St. Petersburg, Florida
[79]

2000
Michigan State
Izzo, TomTom Izzo
089.2 !89–76
Florida
Donovan, BillyBilly Donovan
RCA Dome
Indianapolis, Indiana
[80]

2001
Duke
Krzyzewski, MikeMike Krzyzewski
082.3 !82–72
Arizona
Olson, LuteLute Olson
Metrodome
Minneapolis, Minnesota
[81]

2002
Maryland
Williams, GaryGary Williams
064 !64–52
Indiana
Davis, MikeMike Davis
Georgia Dome
Atlanta, Georgia
[82]

2003
Syracuse
Boeheim, JimJim Boeheim
081.1 !81–78
Kansas
Williams, RoyRoy Williams
Louisiana Superdome
New Orleans, Louisiana
[83]

2004
Connecticut
Calhoun, JimJim Calhoun
082.2 !82–73
Georgia Tech
Hewitt, PaulPaul Hewitt
Alamodome
San Antonio, Texas
[84]

2005
North Carolina
Williams, RoyRoy Williams
075.1 !75–70
Illinois
Weber, BruceBruce Weber
Edward Jones Dome
St. Louis, Missouri
[85]

2006
Florida
Donovan, BillyBilly Donovan
073 !73–57
UCLA
Howland, BenBen Howland
RCA Dome
Indianapolis, Indiana
[86]

2007
Florida
Donovan, BillyBilly Donovan
084.2 !84–75
Ohio State
Matta, ThadThad Matta
Georgia Dome
Atlanta, Georgia
[87]

2008
Kansas
Self, BillBill Self
075.2 !75–68*
Memphis[a]
Calipari, JohnJohn Calipari
Alamodome
San Antonio, Texas
[88]

2009
North Carolina
Williams, RoyRoy Williams
089.3 !89–72
Michigan State
Izzo, TomTom Izzo
Ford Field
Detroit, Michigan
[89]

2010
Duke
Krzyzewski, MikeMike Krzyzewski
061 !61–59
Butler
Stevens, BradBrad Stevens
Lucas Oil Stadium
Indianapolis, Indiana
[90]

2011
Connecticut
Calhoun, JimJim Calhoun
053.1 !53–41
Butler
Stevens, BradBrad Stevens
Reliant Stadium
Houston, Texas
[91]

2012
Kentucky
Calipari, JohnJohn Calipari
067.1 !67–59
Kansas
Self, BillBill Self
Mercedes-Benz Superdome
New Orleans, Louisiana
[92]

2013
Louisville[a]
Pitino, RickRick Pitino
067.1 !82–76
Michigan
Beilein, JohnJohn Beilein
Georgia Dome
Atlanta, Georgia
[93]

2014
Connecticut
Ollie, KevinKevin Ollie
060.2 !60–54
Kentucky
Calipari, JohnJohn Calipari
AT&T Stadium
Arlington, Texas
[94]

2015
Duke
Krzyzewski, MikeMike Krzyzewski
068.1 !68–63
Wisconsin
Ryan, BoBo Ryan
Lucas Oil Stadium
Indianapolis, Indiana
[95]

2016
Villanova
Jay Wright
077.1 !77–74
North Carolina
Williams, RoyRoy Williams
NRG Stadium
Houston, Texas
[96]

2017
North Carolina
Roy Williams
071.3 !71–65
Gonzaga
Mark Few
University of Phoenix Stadium
Glendale, Arizona
[97]

2018
Villanova
Jay Wright
077.1 !79–62
Michigan
Beilein, JohnJohn Beilein
Alamodome
San Antonio, Texas
[98]

text: Multiple champions[edit]

text:
Teams with multiple championships

Team
Wins
Years won

UCLA
11
1964, 1965, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1975, 1995

Kentucky
8
1948, 1949, 1951, 1958, 1978, 1996, 1998, 2012

North Carolina
6
1957, 1982, 1993, 2005, 2009, 2017

Duke
5
1991, 1992, 2001, 2010, 2015

Indiana
5
1940, 1953, 1976, 1981, 1987

Connecticut
4
1999, 2004, 2011, 2014

Kansas
3
1952, 1988, 2008

Villanova
3
1985, 2016, 2018

Louisville
2
1980, 1986, 2013[c]

Michigan State
2
1979, 2000

Cincinnati
2
1961, 1962

Florida
2
2006, 2007

North Carolina State
2
1974, 1983

Oklahoma State[b]
2
1945, 1946

San Francisco
2
1955, 1956

text:
Coaches with multiple championships

Team
Wins
Years won

Wooden, JohnJohn Wooden
10
1964, 1965, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1975

Krzyzewski, MikeMike Krzyzewski
5
1991, 1992, 2001, 2010, 2015

Rupp, AdolphAdolph Rupp
4
1948, 1949, 1951, 1958

Calhoun, JimJim Calhoun
3
1999, 2004, 2011

Knight, BobBob Knight
3
1976, 1981, 1987

Williams, RoyRoy Williams
3
2005, 2009, 2017

Crum, DennyDenny Crum
2
1980, 1986

Donovan, BillyBilly Donovan
2
2006, 2007

Iba, HenryHenry Iba
2
1945, 1946

Jucker, EdEd Jucker
2
1961, 1962

McCracken, BranchBranch McCracken
2
1940, 1953

Smith, DeanDean Smith
2
1982, 1993

Woolpert, PhilPhil Woolpert
2
1955, 1956

Wright, JayJay Wright
2
2016, 2018

text: Champions by conference status[edit]

text: Champions by conference at the time of tournaments[edit]

text:
Championships by conference membership at the time of tournaments

Conference
Wins
Years won
Ref(s)

Pac-12 Conference !Pac-12 Conference (1915–current)
15
1939, 1942, 1959, 1964, 1965, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1975, 1995, 1997
[17][38][99][100][101]

Atlantic Coast Conference !Atlantic Coast Conference (1953–current)
14
1957, 1974, 1982, 1983, 1991, 1992, 1993, 2001, 2002, 2005, 2009, 2010, 2015, 2017
[102][103][104][105][106]

Southeastern Conference !Southeastern Conference (1932–current)
11
1948, 1949, 1951, 1958, 1978, 1994, 1996, 1998, 2006, 2007, 2012
[107][108][109][110][111][112][113][114][115][116][117]

Big Ten Conference !Big Ten Conference (1896–current)
10
1940, 1941, 1953, 1960, 1976, 1979, 1981, 1987, 1989, 2000
[118]

Big East Conference !Big East Conference (1979–current)
8
1984, 1985, 1999, 2003, 2004, 2011, 2013,[c] 2016, 2018
[93][119][120][121][122]

Independents
6
1944, 1947, 1954, 1963, 1966, 1977
[46][123][124][125][126][127]

Missouri Valley Conference !Missouri Valley Conference (1907–current)
4
1945, 1946, 1961, 1962
[128][129][130][131]

Big Eight Conference !Big 8 Conference (1907–1996)
2
1952, 1988
[31][68]

Metro Conference !Metro Conference (1975–1995)
2
1980, 1986
[132]

West Coast Conference !West Coast Conference (1952–current)
2
1955, 1956
[133]

American Athletic Conference !American Athletic Conference (2014–current)
1
2014
[94]

Big Twelve Conference !Big 12 Conference (1994–current)
1
2008
[134]

Big West Conference !Big West Conference (1969–current)
1
1990
[135]

Metropolitan New York Conference !Metropolitan New York Conference (1933–1963)
1
1950
[136]

Mountain States Conference !Mountain States Conference (1938–1962)
1
1943
[137]

text: Championships by current conference membership[edit]

text:
Championships by current conference membership

Conference
Wins
Years won
Ref(s)

Atlantic Coast Conference !Atlantic Coast Conference
16
1957, 1974, 1980, 1982, 1983, 1986, 1991, 1992, 1993, 2001, 2003, 2005, 2009, 2010, 2013,[c] 2015, 2017
[138][139]

Pac-12 Conference !Pac-12 Conference
16
1939, 1942, 1944, 1959, 1964, 1965, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1975, 1995, 1997
[140][141]

Southeastern Conference !Southeastern Conference
11
1948, 1949, 1951, 1958, 1978, 1994, 1996, 1998, 2006, 2007, 2012
[142]

Big Ten Conference !Big Ten Conference
11
1940, 1941, 1953, 1960, 1976, 1979, 1981, 1987, 1989, 2000, 2002
[143]

American Athletic Conference
6
1961, 1962, 1999, 2004, 2011, 2014
[144][145][146]

Big Twelve Conference !Big 12 Conference
5
1945, 1946, 1952, 1988, 2008
[147][148][149]

Big East Conference
5
1977, 1984, 1985, 2016, 2018
[122][150][151]

Mountain West Conference !Mountain West Conference
2
1943, 1990
[152][153]

West Coast Conference !West Coast Conference
2
1955, 1956
[154]

Atlantic 10 Conference !Atlantic 10 Conference
1
1954
[155]

City University of New York Athletic Conference !City University of New York Athletic Conference
1
1950
[156]

Conference USA !Conference USA
1
1966
[157]

Missouri Valley Conference !Missouri Valley Conference
1
1963
[158]

Patriot League !Patriot League
1
1947
[159]

text: Championships by state[edit]

text:
Championships by state

State
Wins
Years won

California
15
1942, 1955, 1956, 1959, 1964, 1965, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1975, 1995

North Carolina
13
1957, 1974, 1982, 1983, 1991, 1992, 1993, 2001, 2005, 2009, 2010, 2015, 2017

Kentucky
10
1948, 1949, 1951, 1958, 1978, 1980, 1986, 1996, 1998, 2012, 2013[c]

Indiana
5
1940, 1953, 1976, 1981, 1987

Connecticut
4
1999, 2004, 2011, 2014

Pennsylvania
4
1954, 1985, 2016, 2018

Ohio
3
1960, 1961, 1962

Kansas
3
1952, 1988, 2008

Michigan
3
1979, 1989, 2000

Oklahoma
2
1945, 1946

Wisconsin
2
1941, 1977

New York
2
1950, 2003

Florida
2
2006, 2007

Oregon
1
1939

Wyoming
1
1943

Utah
1
1944

Massachusetts
1
1947

Illinois
1
1963

Texas
1
1966

Washington, D.C.
1
1984

Nevada
1
1990

Arkansas
1
1994

Arizona
1
1997

Maryland
1
2002

text: Indicates vacated by NCAA


document_title: Cave painting

question_text: the most ancient examples of art found in caves throughout europe served to

text: Cave painting

text: Dating[edit]

text: Nearly 340 caves have now been discovered in France and Spain that contain art from prehistoric times. Initially, the age of the paintings had been a contentious issue, since methods like radiocarbon dating can produce misleading results if contaminated by samples of older or newer material,[4] and caves and rocky overhangs (where parietal art is found) are typically littered with debris from many time periods. But subsequent technology has made it possible to date the paintings by sampling the pigment itself, torch marks on the walls,[5] or the formation of carbonate deposits on top of the paintings.[6] The subject matter can also indicate chronology: for instance, the reindeer depicted in the Spanish cave of Cueva de las Monedas places the drawings in the last Ice Age.

text:
The oldest known cave painting is a red hand stencil in Maltravieso cave, Cáceres, Spain. It has been dated using the uranium-thorium method[6] to older than 64,000 years
and was made by a Neanderthal.[3]
The oldest date given to an animal cave painting is now a pig with a minimum age of 35,400 years, at Timpuseng cave in Sulawesi,  Indonesia.[2]

text:
The earliest known European figurative cave paintings are those of Chauvet Cave in France. These paintings date to earlier than 30,000 BCE (Upper Paleolithic) according to radiocarbon dating.[7] Some researchers believe the drawings are too advanced for this era and question this age.[8] However, more than 80 radiocarbon dates had been obtained by 2011, with samples taken from torch marks and from the paintings themselves, as well as from animal bones and charcoal found on the cave floor. The radiocarbon dates from these samples show that there were two periods of creation in Chauvet: 35,000 years ago and 30,000 years ago. One of the surprises was that many of the paintings were modified repeatedly over thousands of years, possibly explaining the confusion about finer paintings  that seemed to date earlier than cruder ones.[9]
In 2009, cavers discovered drawings in Coliboaia Cave in Romania, stylistically comparable to those at Chauvet.[10] An initial dating puts the age of an image in the same range as Chauvet: about 32,000 years old.[11]

text: In Australia, cave paintings have been found on the Arnhem Land plateau showing megafauna which are thought to have been extinct for over 40,000 years, making this site another candidate for oldest known painting; however, the proposed age is dependent on the estimate of the extinction of the species seemingly depicted.[12]  Another Australian site, Nawarla Gabarnmang, has charcoal drawings that have been radiocarbon-dated to 28,000 years, making it the oldest site in Australia and among the oldest in the world for which reliable date evidence has been obtained.[13]

text: Other examples may date as late as the Early Bronze Age, but the well-known Magdalenian style seen at Lascaux in France (c. 15,000 BCE) and Altamira in Spain died out about 10,000 BCE, coinciding with the advent of the Neolithic period.  Some caves probably continued to be painted over a period of several thousands of years.[14]

text: The next phase of surviving European prehistoric painting, the rock art of the Iberian Mediterranean Basin, was very different, concentrating on large assemblies of smaller and much less detailed figures, with at least as many humans as animals.  This was created roughly between 10,000 and 5,500 years ago, and painted in rock shelters under cliffs or shallow caves, in contrast to the recesses of deep caves used in the earlier (and much colder) period.  Although individual figures are less naturalistic, they are grouped in coherent grouped compositions to a much greater degree.

text: Subjects, themes, and patterns[edit]

text:
The most common subjects in cave paintings are large wild animals, such as bison, horses, aurochs, and deer, and tracings of human hands as well as abstract patterns, called finger flutings. The species found most often were suitable for hunting by humans, but were not necessarily the actual typical prey found in associated deposits of bones; for example, the painters of Lascaux have mainly left reindeer bones, but this species does not appear at all in the cave paintings, where equine species are the most common.  Drawings of humans were rare and are usually schematic as opposed to the more detailed and naturalistic images of animal subjects. One explanation for this may be that realistically painting the human form was "forbidden by a powerful religious taboo."[15] Kieran D. O'Hara, geologist, suggests in his book Cave Art and Climate Change that climate controlled the themes depicted.[16]
Pigments used include red and yellow ochre, hematite, manganese oxide and charcoal. Sometimes the silhouette of the animal was incised in the rock first, and in some caves all or many of the images are only engraved in this fashion, taking them somewhat out of a strict definition of "cave painting".

text: Similarly, large animals are also the most common subjects in the many small carved and engraved bone or ivory (less often stone) pieces dating from the same periods.  But these include the group of Venus figurines, which have no real equivalent in cave paintings.[citation needed]

text: Hand stencils, made by placing a hand on the wall and blowing pigment at it (probably through a pipe of some kind), form a characteristic image of a roughly round area of solid pigment with the uncoloured shape of the hand in the centre, which may then be decorated with lines or dashes.  These are often found in the same caves as other paintings, or may be the only form of painting in a location. Some walls contain many hand stencils.  Similar hands are also painted in the usual fashion. A number of hands show a finger wholly or partly missing, for which a number of explanations have been given.  Hand images are found in similar forms in Europe, Eastern Asia and South America.[17]

text: Theories and interpretations[edit]

text: Henri Breuil interpreted the paintings as hunting magic to increase the abundance of prey.

text: Another theory, developed by David Lewis-Williams and broadly based on ethnographic studies of contemporary hunter-gatherer societies, is that the paintings were made by paleolithic shamans.[18] The shaman would retreat into the darkness of the caves, enter into a trance state, then paint images of his or her visions, perhaps with some notion of drawing out power from the cave walls themselves.

text: R. Dale Guthrie, who has studied both highly artistic and lower quality art and figurines, identifies a wide range of skill and age among the artists. He hypothesizes that the main themes in the paintings and other artifacts (powerful beasts, risky hunting scenes and the representation of women in the Venus figurines) are the work of adolescent males, who constituted a large part of the human population at the time.[19][verification needed] However, in analyzing hand prints and stencils in French and Spanish caves, Dean Snow of Pennsylvania State University has proposed that a proportion of them, including those around the spotted horses in Pech Merle, were of female hands.[20]

text: Paleolithic cave art by region[edit]

text: Europe[edit]

text: Well-known cave paintings include those of:

text:
Cave of El Castillo, Spain (~40.000 y.o.)
Chauvet Cave, near Vallon-Pont-d'Arc, France (~35,000 y.o.)
Cave of La Pasiega, Cuevas de El Castillo, Cantabria, Spain (~30,000 y.o.?)
Caves of Arcy-sur-Cure, France (~28,200 y.o.)
Cosquer Cave, with an entrance below sea level near Marseille, France (~27,000 y.o.)
Caves of Gargas, France (~27,000 y.o.)
Grotte de Cussac, France (~25,000 y.o.)
Pech Merle, near Cabrerets, France (25,000 y.o.)
Lascaux, France (~17,000 y.o.)
Cave of Niaux, France (~17,000 y.o.)
Font-de-Gaume, in the Dordogne Valley, France (~17,000 y.o.)
Cave of Altamira, near Santillana del Mar, Cantabria, Spain (~15,500 y.o.)
La Marche, in Lussac-les-Châteaux,  France (~15,000 y.o.)
Les Combarelles, in Les Eyzies de Tayac, Dordogne, France (~13,600 y.o.)
Magura Cave, Bulgaria (~10,000 y.o.)

text: Other sites include Creswell Crags, Nottinghamshire, England (~14,500 ys old cave etchings and bas-reliefs discovered in 2003), Peștera Coliboaia in Romania (~29,000 y.o. art?),[21] and Kapova Cave in Russia (~16,000 y.o. art).

text: Rock painting was also performed on cliff faces; but fewer of those have survived because of erosion. One example is the rock paintings of Astuvansalmi (3000–2500 BC) in the Saimaa area of Finland.

text: When Marcelino Sanz de Sautuola first encountered the Magdalenian paintings of the Altamira cave, Cantabria, Spain in 1879, the academics of the time considered them hoaxes. Recent reappraisals and numerous additional discoveries have since demonstrated their authenticity, while at the same time stimulating interest in the artistry of Upper Palaeolithic peoples.

text: East and Southeast Asia[edit]

text: Originating in the Paleolithic period, the rock art found in Khoit Tsenkher Cave, Mongolia, includes symbols and animal forms painted from the walls up to the ceiling.[23] Stags, buffalo, oxen, ibex, lions, Argali sheep, antelopes, camels, elephants, ostriches, and other animal pictorials are present, often forming a palimpsest of overlapping images. The paintings appear brown or red in color, and are stylistically similar to other Paleolithic rock art from around the world but are unlike any other examples in Mongolia.

text:
In Indonesia the caves in the district of Maros in Sulawesi are famous for their hand prints.
About 1,500 negative handprints have also been found in 30 painted caves in the Sangkulirang area of Kalimantan; preliminary dating analysis as of 2005 put their age in the range of 10,000 years old.[24]
A 2014 study  based on uranium–thorium dating dated a Maros hand stencil to a minimum age  of 39,900 years.
A painting of a babirusa was dated to at least 35.4 ka, placing it among the oldest known figurative depictions worldwide.
[2]

text: The Padah-Lin Caves of Burma contain 11,000-year-old paintings and many rock tools.

text: India[edit]

text:
The Bhimbetka rock shelters exhibit the earliest traces of human life in India.
The earliest paintings on the cave walls are believed to date to about 30,000 years ago. The most recent painting, consisting of geometric figures, date to the medieval period.
Executed mainly in red and white with the occasional use of green and yellow, the paintings depict the lives and times of the people who lived in the caves, including scenes of childbirth, communal dancing and drinking, religious rites and burials, as well as indigenous animals.[25]

text: Southern Africa[edit]

text: Cave paintings found at the Apollo 11 Cave in Namibia are estimated to date from approximately 25,500–27,500 years ago.[26]

text: In 2011, archaeologists found a small rock fragment at Blombos Cave, about 300 km (190 mi) east of Cape Town on the southern cape coastline in South Africa, among spear points and other excavated material. After extensive testing for seven years, it was revealed that the lines drawn on the rock were handmade and from an ochre crayon dating back 73,000 years. This makes it the oldest known rock drawing.[27][28]

text: Australia[edit]

text: Significant early cave paintings, executed in ochre, have been found in Kakadu, Australia. Ochre is not an organic material, so carbon dating of these pictures is often impossible. Sometimes the approximate date, or at least, an epoch, can be surmised from the painting content, contextual artifacts, or organic material intentionally or inadvertently mixed with the inorganic ochre paint, including torch soot.[5]

text: A red ochre painting, discovered at the centre of the Arnhem Land Plateau, depicts two emu-like birds with their necks outstretched. They have been identified by a palaeontologist as depicting the megafauna species Genyornis, giant birds thought to have become extinct more than 40,000 years ago; however, this evidence is inconclusive for dating.  It may merely suggest that Genyornis became extinct at a later date than previously determined.[12]

text: Hook Island in the Whitsunday Islands is also home to a number of cave paintings created by the seafaring Ngaro people.[29]

text: Holocene cave art[edit]

text:
The following sections present notable examples of prehistorc cave art dated to after the end of the Upper Paleolithic
(to the Holocene, after c. 11,500 years ago).

text: Asia[edit]

text: In the Philippines at Tabon Caves the oldest artwork may be a relief of a shark above the cave entrance. It was partially disfigured by a later jar burial scene.[citation needed]

text: The Edakkal Caves of Kerala, India, contain drawings that range over periods from the Neolithic] as early as 5,000 BC to 1,000 BCE.[30][31][32]

text: Horn of Africa[edit]

text: In 2002, a French archaeological team discovered the Laas Geel cave paintings on the outskirts of Hargeisa in the northwestern region of Somaliland. Dating back around 5,000 years, the paintings depict both wild animals and decorated cows. They also feature herders, who are believed to be the creators of the rock art.[33] In 2008, Somali archaeologists announced the discovery of other cave paintings in Dhambalin region, which the researchers suggest includes one of the earliest known depictions of a hunter on horseback. The rock art is in the Ethiopian-Arabian style, dated to 1000 to 3000 BCE.[34][35]

text: Additionally, between the towns of Las Khorey and El Ayo in Karinhegane is a site of numerous cave paintings of real and mythical animals. Each painting has an inscription below it, which collectively have been estimated to be around 2,500 years old.[36][37] Karihegane's rock art is in the same distinctive Ethiopian-Arabian style as the Laas Geel and Dhambalin cave paintings.[38][39] Around 25 miles from Las Khorey is found Gelweita, another key rock art site.[37]

text: In Djibouti, rock art of what appear to be antelopes and a giraffe are also found at Dorra and Balho.[40]

text: North Africa[edit]

text: Many cave paintings are found in the Tassili n'Ajjer mountains in southeast Algeria. A UNESCO World Heritage Site, the rock art was first discovered in 1933 and has since yielded 15,000 engravings and drawings that keep a record of the various animal migrations, climatic shifts, and change in human inhabitation patterns in this part of the Sahara from 6000 BCE to the late classical period.[41] Other cave paintings are also found at the Akakus, Mesak Settafet and Tadrart in Libya and other Sahara regions including: Ayr mountains, Niger and Tibesti, Chad.

text: The Cave of Swimmers and the Cave of Beasts in southwest Egypt, near the border with Libya, in the mountainous Gilf Kebir region of the Sahara Desert. The Cave of Swimmers was discovered in October 1933 by the Hungarian explorer László Almásy. The site contains rock painting images of people swimming, which are estimated to have been created 10,000 years ago during the time of the most recent Ice Age.

text: Southern Africa[edit]

text: At uKhahlamba / Drakensberg Park, South Africa, now thought to be some 3,000 years old, the paintings by the San people who settled in the area some 8,000 years ago depict animals and humans, and are thought to represent religious beliefs. Human figures are much more common in the rock art of Africa than in Europe.[42]

text: North America[edit]

text: Distinctive monochrome and polychrome cave paintings and murals exist in the mid-peninsula regions of southern Baja California and northern Baja California Sur, consisting of Pre-Columbian paintings of humans, land animals, sea creatures, and abstract designs. These paintings are mostly confined to the sierras of this region, but can also be found in outlying mesas and rock shelters. According to recent radiocarbon studies of the area, of materials recovered from archaeological deposits in the rock shelters and on materials in the paintings themselves, suggest that the Great Murals may have a time range extending as far back as 7,500 years ago.[43]

text: Native artists in the Chumash tribes created cave paintings that are located in present-day Santa Barbara, Ventura, and San Luis Obispo Counties in Southern California. They include well executed examples at Burro Flats Painted Cave and Chumash Painted Cave State Historic Park.

text: There are also Native American pictogram examples in caves of the Southwestern United States.  Cave art that is 6,000 years old was found in the Cumberland Plateau region of Tennessee.[44]

text: South America[edit]

text: Serra da Capivara National Park is a national park in the north east of Brazil with many prehistoric paintings; the park was created to protect the prehistoric artifacts and paintings found there. It became a World Heritage Site in 1991. Its best known archaeological site is Pedra Furada.

text: It is located in northeast state of Piauí, between latitudes 8° 26' 50" and 8° 54' 23" south and longitudes 42° 19' 47" and 42° 45' 51" west. It falls within the municipal areas of São Raimundo Nonato, São João do Piauí, Coronel José Dias and Canto do Buriti. It has an area of 1291.4 square kilometres (319,000 acres). The area has the largest concentration of prehistoric small farms on the American continents. Scientific studies confirm that the Capivara mountain range was densely populated in prehistoric periods.

text: Cueva de las Manos (Spanish for "Cave of the Hands") is a cave located in the province of Santa Cruz, Argentina, 163 km (101 mi) south of the town of Perito Moreno, within the borders of the Francisco P. Moreno National Park, which includes many sites of archaeological and paleontological importance.

text: The hand images are often negative (stencilled). Besides these there are also depictions of human beings, guanacos, rheas, felines and other animals, as well as geometric shapes, zigzag patterns, representations of the sun, and hunting scenes. Similar paintings, though in smaller numbers, can be found in nearby caves. There are also red dots on the ceilings, probably made by submerging their hunting bolas in ink, and then throwing them up. The colours of the paintings vary from red (made from hematite) to white, black or yellow. The negative hand impressions date to around 550 BCE, the positive impressions from 180 BCE, while the hunting drawings are calculated to more than 10,000 years old.[45]  Most of the hands are left hands, which suggests that painters held the spraying pipe with their right hand.[citation needed]

text: Southeast Asia[edit]

text: There are rock paintings in caves in Thailand, Malaysia, Indonesia, and Burma. In Thailand, caves and scarps along the Thai-Burmese border, in the Petchabun Range of Central Thailand, and overlooking the Mekong River in Nakorn Sawan Province, all contain galleries of rock paintings. In Malaysia the oldest paintings are at Gua Tambun in Perak, dated at 2000 years, and those in the Painted Cave at Niah Caves National Park are 1200 years old. The anthropologist Ivor Hugh Norman Evans visited Malaysia in the early 1920s and found that some of the tribes (especially Negritos) were still producing cave paintings and had added depictions of modern objects including what are believed to be cars.[46] (See prehistoric Malaysia.)