What is "kernel"

Kernel \Ker"nel\, v. i. [imp. & p. p. Kerneledor Kernelled; p. pr. & vb. n. Kerneling or Kernelling.] To harden or ripen into kernels; to produce kernels.

Kernel \Ker"nel\, n. [OE. kernel, kirnel, curnel, AS. cyrnel, fr. corn grain. See Corn, and cf. Kern to harden.]

1. The essential part of a seed; all that is within the seed walls; the edible substance contained in the shell of a nut; hence, anything included in a shell, husk, or integument; as, the kernel of a nut. See Illust. of Endocarp.

   'A were as good crack a fusty nut with no kernel
   --Shak.

2. A single seed or grain; as, a kernel of corn.

3. A small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh.

4. The central, substantial or essential part of anything; the gist; the core; as, the kernel of an argument.

Old English cyrnel "seed, kernel, pip," from Proto-Germanic *kurnilo- (cognates: Middle High German kornel, Middle Dutch cornel), from the root of corn "seed, grain" (see corn (n.1)) + -el, diminutive suffix. Figurative sense of "core or central part of anything" is from 1550s.

n. 1 The core, center, or essence of an object or system. 2 The central (usually edible) part of a nut, especially once the hard shell has been removed. 3 A single seed or grain, especially of corn or wheat. 4 (context US English) The stone of certain fruits, such as peaches or plums. 5 A small mass around which other matter is concreted; a nucleus; a concretion or hard lump in the flesh. 6 (context computing English) The central part of many computer operating systems which manages the system's resources and the communication between hardware and software components. 7 (context calculus English) A function used to define an integral transform. 8 (context mathematics English) A set of pairs of a mapping's domain which are mapped to the same value. 9 (context mathematics algebra English) Those elements, in the domain of a function, which the function maps to zero. 10 (context mathematics fuzzy set theory English) The set of members of a fuzzy set that are fully included (i.e., whose grade of membership is 1). 11 (context slang English) The human clitoris.

1. n. the inner and usually edible part of a seed or grain or nut or fruit stone; "black walnut kernels are difficult to get out of the shell" [syn: meat]

2. a single whole grain of a cereal; "a kernel of corn"

3. the choicest or most essential or most vital part of some idea or experience; "the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story" [syn: substance, core, center, essence, gist, heart, heart and soul, inwardness, marrow, meat, nub, pith, sum, nitty-gritty]

4. [also: kernelling, kernelled]

Kernel may refer to:

In the various branches of mathematics that fall under the heading of abstract algebra, the kernel of a homomorphism measures the degree to which the homomorphism fails to be injective. An important special case is the kernel of a linear map. The kernel of a matrix, also called the null space, is the kernel of the linear map defined by the matrix.

The definition of kernel takes various forms in various contexts. But in all of them, the kernel of a homomorphism is trivial (in a sense relevant to that context) if and only if the homomorphism is injective. The fundamental theorem on homomorphisms (or first isomorphism theorem) is a theorem, again taking various forms, that applies to the quotient algebra defined by the kernel.

In this article, we first survey kernels for some important types of algebraic structures; then we give general definitions from universal algebra for generic algebraic structures.

In set theory, the kernel of a function f may be taken to be either

• the equivalence relation on the function's domain that roughly expresses the idea of "equivalent as far as the function f can tell", or
• the corresponding partition of the domain.

In mathematics, and more specifically in linear algebra and functional analysis, the kernel (also known as null space or nullspace) of a linear map between two vector spaces V and W, is the set of all elements v of V for which , where 0 denotes the zero vector in W. That is, in set-builder notation,

ker(L) = {v ∈ V∣L(v) = 0}.

The term kernel has several distinct meanings in statistics.

In image processing, a kernel, convolution matrix, or mask is a small matrix useful for blurring, sharpening, embossing, edge detection, and more. This is accomplished by means of convolution between a kernel and an image.

In category theory and its applications to other branches of mathematics, kernels are a generalization of the kernels of group homomorphisms, the kernels of module homomorphisms and certain other kernels from algebra. Intuitively, the kernel of the morphism f : X → Y is the "most general" morphism k : K → X that yields zero when composed with (followed by) f.

Note that kernel pairs and difference kernels (aka binary equalisers) sometimes go by the name "kernel"; while related, these aren't quite the same thing and are not discussed in this article.

The kernel (also called nucleus) is a computer program that constitutes the central core of a computer's operating system. It has complete control over everything that occurs in the system. As such, it is the first program loaded on startup, and then manages the remainder of the startup, as well as input/output requests from software, translating them into data processing instructions for the central processing unit. It is also responsible for managing memory, and for managing and communicating with computing peripherals, like printers, speakers, etc. The kernel is a fundamental part of a modern computer's operating system.

The critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by other, less frequently used parts of the operating system or by applications. The kernel performs its tasks, such as executing processes and handling interrupts, in kernel space, whereas everything a user normally does, such as writing text in a text editor or running programs in a GUI (graphical user interface), is done in user space. This separation prevents user data and kernel data from interfering with each other and thereby diminishing performance or causing the system to become unstable (and possibly crashing).

When a process makes requests of the kernel, the request is called a system call. Various kernel designs differ in how they manage system calls and resources. For example, a monolithic kernel executes all the operating system instructions in the same address space in order to improve the performance of the system. A microkernel runs most of the operating system's background processes in user space, to make the operating system more modular and, therefore, easier to maintain.

The kernel's interface is a low-level abstraction layer.

Kernel is an EP by indie rock band Seam. It was released in February 15, 1993 through Touch and Go Records. It contains two new song, an alternate take of Shame and a cover of Breaking Circus.

Kernel is a corporation in the United States that sells goods and services relating to feature films, television programs, e-sports, video games, and related content including digital home entertainment, and VIP experiences over the Internet.