STRUCTURE is an arrangement and organization of interrelated elements in a material object or system , or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as biological organisms , minerals and chemicals . Abstract structures include data structures in computer science and musical form . Types of structure include a hierarchy (a cascade of one-to-many relationships), a network featuring many-to-many links , or a lattice featuring connections between components that are neighbors in space.
* 1 Load-bearing * 2 Biological * 3 Chemical * 4 Mathematical * 5 Musical * 6 Social * 7 Data * 8 Software * 9 Logical * 10 See also * 11 References * 12 Further reading * 13 External links
A traditional Sami food storage structure Gothic quadripartite cross-ribbed vaults of the Saint-Séverin church in Paris
Buildings, aircraft, skeletons, anthills, beaver dams and salt domes are all examples of load -bearing structures. The results of construction are divided into buildings and non-building structures , and make up the infrastructure of a human society. Built structures are broadly divided by their varying design approaches and standards, into categories including building structures, architectural structures , civil engineering structures and mechanical structures.
The effects of loads on physical structures are determined through
structural analysis , which is one of the tasks of structural
engineering . The structural elements can be classified as
one-dimensional (ropes , struts , beams , arches ), two-dimensional
(membranes , plates, slab , shells , vaults ), or three-dimensional
(solid masses). :2 The latter was the main option available to early
structures such as
The structure elements are combined in structural systems. The majority of everyday load-bearing structures are section-active structures like frames, which are primarily composed of one-dimensional (bending) structures. Other types are Vector-active structures such as trusses , surface-active structures such as shells and folded plates, form-active structures such as cable or membrane structures, and hybrid structures. :134–136
Load-bearing biological structures such as bones, teeth, shells, and tendons derive their strength from a multilevel hierarchy of structures employing biominerals and proteins , at the bottom of which are collagen fibrils .
Ribbon schematic of the 3D structure of the protein
triosephosphate isomerase . The brown spirals are α-helices and the
green arrows are β strands, the components of β-pleated sheets.
In biology , structures exist at all levels of organization, ranging hierarchically from the atomic and molecular to the cellular , tissue , organ , organismic , population and ecosystem level. Usually, a higher-level structure is composed of multiple copies of a lower-level structure.
Structural biology is concerned with the biomolecular structure of macromolecules , particularly proteins and nucleic acids . The function of these molecules is determined by their shape as well as their composition, and their structure has multiple levels. Protein structure has a four-level hierarchy. The primary structure is the sequence of amino acids that make it up. It has a peptide backbone made up of a repeated sequence of a nitrogen and two carbon atoms. The secondary structure consists of repeated patterns determined by hydrogen bonding . The two basic types are the α-helix and the β-pleated sheet . The tertiary structure is a back and forth bending of the polypeptide chain, and the quaternary structure is the way that tertiary units come together and interact.
Main article: Chemical structure A skeletal formula for dopamine
Chemical structure refers to both molecular geometry and electronic structure. The structure can be represented by a variety of diagrams called structural formulas . Lewis structures use a dot notation to represent the valence electrons for an atom; these are the electrons that determine the role of the atom in chemical reactions. :71–72 Bonds between atoms can be represented by lines with one line for each pair of electrons that is shared. In a simplified version of such a diagram, called a skeletal formula , only carbon-carbon bonds and functional groups are shown.
Atoms in a crystal have a structure that involves repetition of a basic unit called a unit cell. The atoms can be modeled as points on a lattice , and one can explore the effect of symmetry operations that include rotations about a point, reflections about a symmetry planes, and translations (movements of all the points by the same amount). Each crystal has a finite group, called the space group , of such operations that map it onto itself; there are 230 possible space groups. :125–126 By Neumann\'s law , the symmetry of a crystal determines what physical properties, including piezoelectricity and ferromagnetism , the crystal can have. :34–36,91–92,168–169
Main article: Mathematical structure
See also: Musical form A motif from the Preludes by Chopin , Op. 28 no.6, bars 1–3
A large part of numerical analysis involves identifying and
interpreting the structure of musical works.
In analogy to linguistic terminology, motifs and phrases can be combined to make complete musical ideas such as sentences and phrases . A larger form is known as the period . One such form that was widely used between 1600 and 1900 has two phrases, an antecedent and a consequent, with a half cadence in the middle and a full cadence at the end providing punctuation. :38–39 On a larger scale are single-movement forms such as the sonata form and the contrapuntal form , and multi-movement forms such as the symphony .
A social structure is a pattern of relationships. They are social
organizations of individuals in various life situations. Structures
are applicable to people in how a society is as a system organized by
a characteristic pattern of relationships. This is known as the social
organization of the group. Sociologists have studied the changing
structure of these groups.
Structure and agency
Main article: Data structure In a singly linked list, each element has a data value and a pointer to the next element.
In computer science , a data structure is a way of organizing information in a computer so that it can be used efficiently. Data structures are built out of two basic types: An array has an index that can be used for immediate access to any data item, but its size must be specified when it is initialized . A linked list can be reorganized, grown or shrunk, but its elements must be accessed with a pointer that links them together in a particular order. :156 Out of these any number of other data structures can be created such as stacks , queues , trees and hash tables .
In solving a problem, a data structure is generally an integral part of the algorithm . :5 In modern programming style, algorithms and data structures are encapsulated together in an abstract data type . :ix
In software architecture, the structure of software is the way in which it is partitioned into interrelated components. A key structural issue is minimizing dependencies between these components. This makes it possible to change one component without requiring changes in others. :3 The structure can be represented in diagrams such as the Control Structure Diagram and the Nassi–Shneiderman diagram . Structural elements reflect the requirements of the application: for example, if the system requires a high fault tolerance, then a redundant structure is needed so that if a component fails it has backups. A high redundancy is an essential part of the design of several systems in the Space Shuttle .
As a branch of philosophy, logic is concerned with distinguishing good arguments from poor ones. A chief concern is with the structure of arguments. An argument consists of one or more premises from which a conclusion is inferred . The steps in this inference can be expressed in a formal way and their structure analyzed. Two basic types of inference are deduction and induction . In a valid deduction, the conclusion necessarily follows from the premises, regardless of whether they are true or not. An invalid deduction contains some error in the analysis. An inductive argument claims that if the premises are true, the conclusion is likely.
* ^ "structure, n.". Oxford English Dictionary (Online ed.).
Retrieved 1 October 2015.
* ^ A B Carpinteri, Alberto (2002). Structural Mechanics: A unified
approach. CRC Press. ISBN 9780203474952 .
* ^ Knippers, Jan; Cremers, Jan; Gabler, Markus; Lienhard, Julian
* Carpi, A.; Brebbia, C.A. (2010). Design & nature V : comparing design in nature with science and engineering. Southampton: WIT. ISBN 9781845644543 . * Pullan, Wendy (2000). Structure. Cambridge: Cambridge University Press. ISBN 0-521-78258-9 . * Rottenberg, Annette T.; Winchell, Donna Haisty (2012). The structure of argument (7th ed.). Boston: Bedford/St. Martins. ISBN 9780312650698 . * Schlesinger, Izchak M.; Keren-Portnoy, Tamar; Parush, Tamar (2001). The structure of arguments. Amsterdam: J. Benjamins. ISBN 9789027223593 .
* Wüthrich, Christian.