Data segment

In computing, a data segment (often denoted .data) is a portion of an object file or the corresponding virtual address space of a program that contains initialized static variables, that is, global variables and static local variables. The size of this segment is determined by the size of the values in the program's source code, and does not change at run time.

The data segment is read-write, since the values of variables can be altered at run time. This is in contrast to the read-only data segment (rodata segment or .rodata), which contains static constants rather than variables; it also contrasts to the code segment, also known as the text segment, which is read-only on many architectures. Uninitialized data, both variables and constants, is instead in the BSS segment.

Historically, to be able to support memory address spaces larger than the native size of the internal address register would allow, early CPUs implemented a system of segmentation whereby they would store a small set of indexes to use as offsets to certain areas. The Intel 8086 family of CPUs provided four segments: the code segment, the data segment, the stack segment and the extra segment. Each segment was placed at a specific location in memory by the software being executed and all instructions that operated on the data within those segments were performed relative to the start of that segment. This allowed a 16-bit address register, which would normally provide 64KiB (65536 bytes) of memory space, to access a 1MiB (1048576 bytes) address space.

Data (moth)

Data is a genus of moths of the Noctuidae family.

Species

References

Data (Star Trek)

Lieutenant Commander Data (/ˈdeɪtə/ DAY-tə) is a character in the fictional Star Trek universe portrayed by actor Brent Spiner. He appears in the television series Star Trek: The Next Generation and the feature films Star Trek Generations, Star Trek: First Contact, Star Trek: Insurrection and Star Trek: Nemesis.

An artificial intelligence and synthetic life form designed and built by Doctor Noonien Soong, Data is a self-aware, sapient, sentient, and anatomically fully functional android who serves as the second officer and chief operations officer aboard the Federation starships USS Enterprise-D and USS Enterprise-E. His positronic brain allows him impressive computational capabilities. Data experienced ongoing difficulties during the early years of his life with understanding various aspects of human behavior and was unable to feel emotion or understand certain human idiosyncrasies, inspiring him to strive for his own humanity. This goal eventually led to the addition of an "emotion chip", also created by Soong, to Data's positronic net. Although Data's endeavor to increase his humanity and desire for human emotional experience is a significant plot point (and source of humor) throughout the series, he consistently shows a nuanced sense of wisdom, sensitivity, and curiosity, garnering immense respect from his peers and colleagues.

Expansion

Expansion may refer to:

Physics

Computer programming

Mathematics

Economics

Music

Other uses

See also

Expansions (album)

Expansions is the tenth album by jazz pianist McCoy Tyner and his fourth released on the Blue Note label. It was recorded in August 1968 and features performances by Tyner with Woody Shaw, Gary Bartz, Wayne Shorter, Ron Carter, Herbie Lewis, and Freddie Waits.

Reception

The Allmusic review by Scott Yanow states "The stimulating music falls between advanced hard bop and the avant-garde, pushing and pulling at the boundaries of modern mainstream jazz".

Track listing

Personnel

References

Non-integer representation

A non-integer representation uses non-integer numbers as the radix, or bases, of a positional numbering system. For a non-integer radix β > 1, the value of

is

The numbers d_i are non-negative integers less than β. This is also known as a β-expansion, a notion introduced by Rényi (1957) and first studied in detail by Parry (1960). Every real number has at least one (possibly infinite) β-expansion.

There are applications of β-expansions in coding theory (Kautz 1965) and models of quasicrystals (Burdik et al. 1998).

Construction

β-expansions are a generalization of decimal expansions. While infinite decimal expansions are not unique (for example, 1.000... = 0.999...), all finite decimal expansions are unique. However, even finite β-expansions are not necessarily unique, for example φ + 1 = φ² for β = φ, the golden ratio. A canonical choice for the β-expansion of a given real number can be determined by the following greedy algorithm, essentially due to Rényi (1957) and formulated as given here by Frougny (1992).