The three age system has been difficult to apply fully outside Europe. Some societies skipped some of the stages or never developed them when their societies didn't need them. Amazonian tribes in South America remain in the Neolithic for example, while there was no Bronze Age south of the Sahara; techonological innovation progressed from stone to iron working. It also soon became apparent that the switches from one age to another did not happen quickly or decisively. Flint tools remained in use in a limited fashion into the Iron Age in Europe and early metal items often ap ...

See also:

Three-age system, Three-age system - Origin, Three-age system - Divisions, Three-age system - Dating, Three-age system - Difficulties

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See also:

Three-age system, Three-age system - Origin, Three-age system - Divisions, Three-age system - Dating, Three-age system - Difficulties

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Later, the Stone Age was divided into the Palaeolithic and the Neolithic and further subdivisions were introduced to divide all the ages into early, mid or late (or lower, middle and upper in the case of the Palaeolithic) sections. There are also the Mesolithic and Epipaleolithic periods between the Palaeolithic and Neolithic. In some cultures, archaeological evidence has made it necessary to add a Copper Age period between the Neolithic and the Bronze Age. The term Megalithic does not refer to a period of time and merely describes the use of la ...

See also:

Three-age system, Three-age system - Origin, Three-age system - Divisions, Three-age system - Dating, Three-age system - Difficulties

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Cartesian means relating to the French mathematician and philosopher Descartes, who, among other things, worked to merge algebra and Euclidean geometry. This work was influential in the development of analytic geometry, calculus, and cartography. The idea of this system was developed in 1637 in two writings by Descartes. In Discourse on Method, in part two, he introduces the new idea of specifying the position of a point or object on a surface, using two intersecting axes as measuring guides. In La Géométrie, he furthe ...

Including:

• Cartesian coordinate system - Two-dimensional coordinate system
• Cartesian coordinate system - Three-dimensional coordinate system
• Cartesian coordinate system - Orientation and handedness
• Cartesian coordinate system - Further notes

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Separation of powers (or trias politica, a term coined by Montesquieu) is a model of democracy that involves the separation of political power between three branches of the state: The Executive, the Legislature, and the Judiciary. In the "separation of powers" model, each branch is prevented from exerting power in the field of responsibility of another branch. Nonetheless each branch of the state may be empowered to exert checks on the actions of the other branches. Separation of powers - Checks and balances. < ...

Including:

• Separation of powers - Checks and balances
• Separation of powers - The three-branch system
• Separation of powers - Case study: The United States
• Separation of powers - Three-branch systems around the world
• Separation of powers - Parliamentary systems
• Separation of powers - Case study: United Kingdom
• Separation of powers - Taiwan Republic of China : Five branches
• Separation of powers - The press around the world
• Separation of powers - Criticisms
• Separation of powers - Related restraint-of-power concepts

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Computer software (or simply software) is that part of a computer system that consists of encoded information (or computer instructions), as opposed to the physical computer equipment (hardware) which is used to store and process this information. The term is roughly synonymous with computer program but is more generic in scope. The term "software" was first used in this sense by John W. Tukey in 1957. In computer science and software engineering, computer software is all information processed by computer systems, ...

Including:

• Computer software - Relationship to hardware
• Computer software - Relationship to data
• Computer software - System application and programming software
• Computer software - Software program and library
• Computer software - Users see three layers of software
• Computer software - Software creation
• Computer software - Software operation
• Computer software - Software quality and reliability
• Computer software - Software patents

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A Chuck is a specialised type of clamp used to hold rotating tools or materials. Chuck engineering - Collet. A collet is a sleeve with a (normally) cylindrical inside and a conical outside. The collet has kerf cuts along its length to allow it to expand and contract. A threaded section at the rear of the collet is used to pull it into a matching conical socket. As the collet is pulled into the socket, the collet will contract - gripping the contents of the inner cylinder. Collets are most commonly found on ...

Including:

• Chuck engineering - Collet
• Chuck engineering - Drill
• Chuck engineering - Special Direct System SDS
• Chuck engineering - Three-jaw
• Chuck engineering - Four-jaw
• Chuck engineering - Multi jaw
• Chuck engineering - Self-centering four jaw
• Chuck engineering - Magnetic

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Collaborative software, also known as groupware, is application software that integrates work on a single project by several concurrent users at separated workstations (see also computer supported cooperative work). In its modern form, it was pioneered by Lotus Software with the popular Lotus Notes application running in connection with a Lotus Domino server; some historians argue that groupware was anticipated by earlier monolithic systems such as NLS. The wiki software upon which Wikipedia runs evolved from a free software ph ...

Including:

• Collaborative software - Overview
• Collaborative software - Three levels of collaboration
• Collaborative software - Implementation
• Collaborative software - Voting methods
• Collaborative software - Examples of collaborative software

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Sometime in the early 19th century the third dimension of measurement was added, using the z-axis. The coordinates in a three dimensional system are of the form (x,y,z). An example of two points plotted in this system are in the picture above, points P(3,0,5) and Q(−5,−5,7). Notice that the axes are depicted in a world-coordinates orientation with the z-axis pointing up. The x-, y-, and z-coordinates of a point (say P) can also be taken as the distances from the yz-plane, xz-plane, and xy-p ...

See also:

Cartesian coordinate system, Cartesian coordinate system - Two-dimensional coordinate system, Cartesian coordinate system - Three-dimensional coordinate system, Cartesian coordinate system - Orientation and handedness, Cartesian coordinate system - Further notes

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A key advantage for three-rail track is reverse loops, where a train enters a loop through a turnout and then exits through the same turnout in order to change the train's direction. With two-rail track, when the track reverses on itself, this causes a short circuit. With three-rail track, because the center rail remains constant and the outer rails are electrically identical, this causes no problems. The third rail has also been used to automate and animate layouts. An accessory, such as a railway signal, can be wired to a section of ...

See also:

Third rail model railroading, Third rail model railroading - Two-rail versus three-rail system, Third rail model railroading - Three-rail system

Read more here: » Third rail model railroading: Encyclopedia II - Third rail model railroading - Three-rail system

Separation of powers - The United States. Main article: Separation of powers under the United States Constitution In drafting the United States Constitution, the framers are believed to have included the best features of many concepts including the then-new concept of the separation of powers. The concept is also prominent in the state governments of the United States; as colonies of Britain, the founding fathers felt that the American states had suffered an abuse of the broad power of the monarchy. ...

See also:

Separation of powers, Separation of powers - Checks and balances, Separation of powers - The three-branch system, Separation of powers - The United States, Separation of powers - Two-Branch systems, Separation of powers - Three-branch systems around the world, Separation of powers - Parliamentary systems, Separation of powers - Case study: United Kingdom, Separation of powers - Taiwan Republic of China : Five branches, Separation of powers - The press around the world, Separation of powers - Criticisms, Separation of powers - Related restraint-of-power concepts

Read more here: » Separation of powers: Encyclopedia II - Separation of powers - The three-branch system

Separation of powers - Case study: The United States. Main article: Separation of powers under the United States Constitution Famously, the framers of the United States Constitution are said to have taken the best of many concepts including the then-new concept of the separation of powers in drafting the constitution. The concept is also prominent in the state governments of the United States; as colonies of Britain, the founding fathers felt that the American states had suffered an abuse of the bro ...

See also:

Separation of powers, Separation of powers - Checks and balances, Separation of powers - The three-branch system, Separation of powers - Case study: The United States, Separation of powers - Two-Branch systems, Separation of powers - Three-branch systems around the world, Separation of powers - Parliamentary systems, Separation of powers - Case study: United Kingdom, Separation of powers - Taiwan Republic of China : Five branches, Separation of powers - The press around the world, Separation of powers - Criticisms, Separation of powers - Related restraint-of-power concepts

Read more here: » Separation of powers: Encyclopedia II - Separation of powers - The three-branch system

Separation of powers - Case study: The United States. Main article: Separation of powers under the United States Constitution Famously, the framers of the United States Constitution are said to have taken the best of many concepts including the then-new concept of the separation of powers in drafting the constitution. The concept is also prominent in the state governments of the United States; as colonies of Britain, the founding fathers felt that the American states had suffered an abuse of the bro ...

See also:

Separation of powers, Separation of powers - Checks and balances, Separation of powers - The three-branch system, Separation of powers - Case study: The United States, Separation of powers - Three-branch systems around the world, Separation of powers - Parliamentary systems, Separation of powers - Case study: United Kingdom, Separation of powers - Taiwan Republic of China : Five branches, Separation of powers - The press around the world, Separation of powers - Criticisms, Separation of powers - Related restraint-of-power concepts

Read more here: » Separation of powers: Encyclopedia II - Separation of powers - The three-branch system

Generally, in electric power systems the load is distributed as evenly as practical between the phases. It is usual practice to discuss a balanced system first and then describe the effects of unbalanced systems as deviations from the elementary case. To keep the calculations simple we shall normalise A and R to 1 for the remainder of these calculations Three-phase - Star connected systems with neutral. An important property of three-phase power is that the power available to ...

See also:

Three-phase, Three-phase - Variable setup and basic definitions, Three-phase - Balanced loads, Three-phase - Star connected systems with neutral, Three-phase - Star connected systems without neutral, Three-phase - Unbalanced systems, Three-phase - Revolving magnetic field, Three-phase - Conversion to other phase systems, Three-phase - Patents

Read more here: » Three-phase: Encyclopedia II - Three-phase - Balanced loads

Let where t is time and f is frequency. Using x = ft the waveforms for the three phases are where A is the peak voltage and the voltages on L1, L2 and L3 are measured relative to the neutral. ...

See also:

Three-phase, Three-phase - Variable setup and basic definitions, Three-phase - Balanced loads, Three-phase - Star connected systems with neutral, Three-phase - Star connected systems without neutral, Three-phase - Unbalanced systems, Three-phase - Revolving magnetic field, Three-phase - Conversion to other phase systems, Three-phase - Patents

Read more here: » Three-phase: Encyclopedia II - Three-phase - Variable setup and basic definitions

Let where t is time and f is freqency. Using x the waveforms for the three phases are where A is the peak voltage and the voltages on L1 L2 and L3 are measured relative to the neutral. ...

See also:

Three-phase, Three-phase - Variable setup and basic definitions, Three-phase - Balanced loads, Three-phase - Star connected systems with neutral, Three-phase - Star connected systems without neutral, Three-phase - Revolving Magnetic Field, Three-phase - Conversion to other phase systems, Three-phase - Patents

Read more here: » Three-phase: Encyclopedia II - Three-phase - Variable setup and basic definitions

Generally, in electric power systems the load is distributed as evenly as practical between the phases. It is usual practice to discuss a balanced system first and then describe the effects of unbalanced systems as deviations from the elementary case. To keep the calculations simple we shall normalise A and R to 1 for the remainder of these calculations Three-phase - Star connected systems with neutral. Using R=1 See also:

Three-phase, Three-phase - Variable setup and basic definitions, Three-phase - Balanced loads, Three-phase - Star connected systems with neutral, Three-phase - Star connected systems without neutral, Three-phase - Revolving Magnetic Field, Three-phase - Conversion to other phase systems, Three-phase - Patents

Read more here: » Three-phase: Encyclopedia II - Three-phase - Balanced loads

The modern Cartesian coordinate system in two dimensions (also called a rectangular coordinate system) is commonly defined by two axes, at right angles to each other, forming a plane (an xy-plane). The horizontal axis is labeled x, and the vertical axis is labeled y. In a three dimensional coordinate system, another axis, normally labeled z, is added, providing a sense of a third dimension of space measurement. The axes are commonly defined as mutually orthogonal to each other (each at a right angle to the ...

See also:

Cartesian coordinate system, Cartesian coordinate system - Two-dimensional coordinate system, Cartesian coordinate system - Three-dimensional coordinate system, Cartesian coordinate system - Orientation and handedness, Cartesian coordinate system - Further notes

Read more here: » Cartesian coordinate system: Encyclopedia II - Cartesian coordinate system - Two-dimensional coordinate system

Single-phase loads may be connected to a three-phase system, either by connecting across two live conductors (a phase-to-phase connection), or by connecting between a phase conductor and the system neutral, which is either connected to the center of the Y (star) secondary winding of the supply transformer, or is connected to the center one winding of a delta transformer (Highleg Delta system). Single-phase loads should be distributed evenly between the phases of the three-phase system f ...

See also:

Three-phase electric power, Three-phase electric power - Color Codes, Three-phase electric power - Circuit Numbering, Three-phase electric power - Generation and distribution, Three-phase electric power - Single phase loads, Three-phase electric power - Connecting phase-phase, Three-phase electric power - Three phase loads, Three-phase electric power - Phase converters, Three-phase electric power - Alternatives to three-phase

Read more here: » Three-phase electric power: Encyclopedia II - Three-phase electric power - Single phase loads

In analytic geometry the Cartesian coordinate system is the foundation for the algebraic manipulation of geometrical shapes. Many other coordinate systems have been developed since Descartes. One common set of systems use polar coordinates; astronomers often use spherical coordinates, a type of polar coordinate system. In different branches of mathematics coordinate systems can be transformed, translated, rotated, and re-defined ...

See also:

Cartesian coordinate system, Cartesian coordinate system - Two-dimensional coordinate system, Cartesian coordinate system - Three-dimensional coordinate system, Cartesian coordinate system - Orientation and handedness, Cartesian coordinate system - Further notes

Read more here: » Cartesian coordinate system: Encyclopedia II - Cartesian coordinate system - Further notes