-A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length. Cartesian coordinate system is a way of locating objects in either two- or three-dimensional space by specifying their X(horizontal) position, Y (vertical) position and Z (through) position. It is used in graphics and in positioning text on documents.

-Algebraic equations involving the coordinates of the points lying on the shape. For example, a circle o f radius 2 may be described as the set of all points whose coordinates x and y satisfy the equation x2 + y2 = 4.

A system or two or three mutually perpendicular axes along which any point can be precisely located with reference to any other point, often referred to as x, y and z coordinates. Relative measure of distance, area and direction are constant throughout the system. The Cartesian coordinate system is named after René Descartes.

The idea of this system was developed in 1637 in two writings by Descartes and independently by Pierre de Fermat, although Fermat used three dimensions, and did not publish the discovery.
Two dimensions

In two dimensions the position of a point P in a plane can be specified by it's distance from two lines intersecting at right angles, called axes. For instance, in Figure 1 two lines intersect each other at right angles in the point 0, the origin. One axis is the line O-X, the other O-Y and any point in the plane can be denoted by two numbers giving it's perpendicular distances from O-X and from O-Y.

A general point P can reached by traveling a distance x along a line O-X, and then a distance y along a line parallel to O-Y. O-X is called the x-axis, O-Y the y-axis, and the point P is said to have Cartesian coordinates (x, y). In the coordinate system shown, as is indicated in the diagram, the...

...History:
The Cartesiancoordinatesystem is named after René Descartes(1596-1650), the noted French mathematician and philosopher, who was among the first to describe its properties. However, historical evidence shows that Pierre de Fermat (1601-1665), also a French mathematician and scholar, did more to develop the Cartesiansystem than did Descartes.
The development of the Cartesiancoordinatesystem enabled the development of perspective and projective geometry. It would later play an intrinsic role in the development of calculus by Isaac Newton andGottfried Wilhelm Leibniz.[3]
Nicole Oresme, a French philosopher of the 14th Century, used constructions similar to Cartesiancoordinates well before the time of Descartes.
Many other coordinatesystems have been developed since Descartes, such as the polar coordinates for the plane, and the spherical and cylindrical coordinates for three-dimensional space.
Cartesiancoordinatesystem:
A Cartesiancoordinatesystem specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length.
Each reference...

...Homogeneous Coordinates and Matrix Representation
Homogeneous Coordinates
Homogenous coordinates utilize a mathematical trick to embed three-dimensional coordinates and transformations into a four-dimensional matrix format. As a result, inversions or combinations of linear transformations are simplified to inversion or multiplication of the corresponding matrices. Homogenous coordinates also make it possible to define perspective transformations.
Homogenous coordinates allow each point (x, y, z) to be represented by any of an infinite number of four dimensional vectors:
The three-dimensional vector corresponding to any four-dimensional vector can be computed by dividing the first three elements by the fourth, and a four-dimensional vector corresponding to any three-dimensional vector can be created by simply adding a fourth element and setting it equal to one.
* CoordinateSystem
We need a coordinatesystem to describe an image, the coordinatesystem used to place elements in relation to each other is called user space, since this is the coordinates the user uses to define elements and position them in relation to each other.
The coordinatesystem has the origin in the upper left, with the x axis extending to the right and y axis extending...

...INDEXING SPATIAL DATA IN P2P SYSTEMS
ABSTRACT:
The peer-to-peer (P2P) paradigm has become very popular for storing and sharing information in a totally decentralized manner. At first, research focused on P2P systems that host 1D data. Nowadays, the need for P2P applications with multidimensional data has emerged, motivating research on P2P systems that manage such data. The majority of the proposed techniques are based either on the distribution of centralized indexes or on the reduction of multidimensional data to one dimension. Our goal is to create from scratch a technique that is inherently distributed and also maintains the multidimensionality of data. Our focus is on structured P2P systems that share spatial information. We present SPATIALP2P, a totally decentralized indexing and searching framework that is suitable for spatial data. SPATIALP2P supports P2P applications in which spatial information of various sizes can be dynamically inserted or deleted, and peers can join or leave. The proposed technique preserves well locality and directionality of space.
EXISTING SYSTEM:
THE peer-to-peer (P2P) paradigm has become very popular for storing and sharing information in a totally decentralized manner. Typically, a P2P system is a distributed environment formed by autonomous peers that operate in an independent manner. Each peer stores a part of the available...

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A) Quadrant I B) Quadrant II C) Quadrant III D) Quadrant IV
Ans: B Section: 2.1
2. Plot the points in a rectangular coordinatesystem.
(5, –2), (–4, 1), (3, 4), (–2, –4)
Ans:
Section: 2.1
Use the following to answer questions 3-7:
3. Find the coordinates of points A, B, C, and D.
Ans: A = (1, 5), B = (–5, 0), C = (–4, –3), D = (2, –1)
Section: 2.1
4. Reflect A, B, C, and D through the y-axis and give the coordinates of the reflected points, A , B , C , and D .
Ans: A = (–1, 5), B = (5, 0), C = (4, –3), and D = (–2, –1)
Section: 2.1
5. Reflect A, B, C, and D through the x-axis and give the coordinates of the reflected points, A , B , C , and D .
Ans: A = (1, –5), B = (–5, 0), C = (–4, 3), and D = (2, 1)
Section: 2.1
6. Reflect A, B, C, and D through the origin and give the coordinates of the reflected points, A , B , C , and D .
Ans: A = (–1, –5), B = (5, 0), C = (4, 3), and D = (–2, 1)
Section: 2.1
7. Reflect A, B, C, and D through the x axis and then through the y-axis and give the coordinates of the reflected points, A , B , C , and D .
Ans: A = (–1, –5), B = (5, 0), C = (4, 3), and D = (–2, 1)
Section: 2.1
Use the following to answer questions 8-12:
8. Find the coordinates of points A, B, C, and D....

...General CoordinateSystems
For identifying each position in space uniquely, three numbers are required, as space is three-dimensional (these numbers correspond to length, width, and height, for example, as they teach you in school).
If the numbers are assigned in such a way that neighboring positions are assigned with neighboring numbers (what mathematicians call "continuously") and in a unique way (i.e., each set of numbers corresponds to exactly one position in space), this system of assigned numbers is called a coordinatesystem. From what is stated, it is obvious that there is an infinite number of possibilities to introduce a coordinatesystem in space. In practice, however, astronomy and other sciences prefer to deal with certain specific systems, which have been described above. The numbers assigned to a position, or point, are called the coordinates of that point (in the coordinatesystem under consideration).
In physical laboratories, and sometimes for everyday purpose, it is convenient to use cartesiancoordinates, i.e., just length, width and height measured from a reference point (the origin of the system) in three mutually othogonal (or perpendicular) directions, i.e., three straight lines called axes of the coordinatesystem, which have...

...A new generalized three-dimensional analytical solution is developed for a partially-penetrating vertical rectangular parallelepiped well screen in a confined aquifer by solving the three-dimensional transient ground water flow differential equation in x-y-z Cartesiancoordinatessystem for drawdown by taking into account the three principal hydraulic conductivities (K _x, K _y, and K _z) along the x-y-z coordinate directions. The fully penetrating screen case becomes equivalent to the single vertical fracture case of Gringarten and Ramey (1973). It is shown that the new solution and Gringarten and Ramey solution (1973) match very well. Similarly, it is shown that this new solution for a horizontally tiny fully penetrating parallelepiped rectangular parallelepiped screen case match very well with Theis (1935) solution. Moreover, it is also shown that the horizontally tiny partially-penetrating parallelepiped rectangular well screen case of this new solution match very well with Hantush (1964) solution. This new analytical solution can also cover a partially-penetrating horizontal well by representing its screen interval with vertically tiny rectangular parallelepiped. Also the solution takes into account both the vertical anisotropy (a _(zx)=K _z/K _x) as well as the horizontal anisotropy (a _(yx)=K _y/K _x) and has potential application areas to analyze pumping test drawdown data from partially-penetrating vertical...

...Enhancement Segmentation Technique for Iris Recognition System Based on Daugman’s Integro-Differential Operator
Asama Kuder Nsaef
Institute of Visual Informatics (IVI) Universiti Kebangsaan Malaysia Bangi, Selangor, Malaysia osama_ftsm@yahoo.com
Azizah Jaafar
Institute of Visual Informatics (IVI) Universiti Kebangsaan Malaysia Bangi, Selangor, Malaysia aj@ftsm.ukm.my
Khider Nassif Jassim Faculty of Management and Economics Department of Statistics University of Wasit Al-Kut, Iraq khider_st@yahoo.com
Abstract—In spite of having been highly recognized as one of the critical steps in recognizing and determining the accuracy of iris matching, segmentation process of Iris is still encountered with few problematic challenges, especially in the process of separating the iris from the eye image and eyelids and eyelashes as it leads to reduction of the accuracy. To enhance the accuracy of iris segmentation, therefore, this study was carried-out using Integro-differential Operator approach in the segmentation process with the aim of locating the iris region of eye image, by employing one centre of the iris and pupil. This approach is found more effective in emphasizing the accuracy of iris segmentation. The evaluation was carried-out at the end of the study using CASIA-IrisV3-Intervals Database. The results of the experimental evaluation showed that the accuracy of the iris recognition increased, and the speed was acceptable. Keywords-Enhancement...

...Understanding the AutoCAD Windows requirements
4. Using Button Functions of a Mouse
5. Understanding Toolbars, Function Keys, Status Bar
Know the following:
Hardware and Software Requirements
Default Windows Screen
How to OPEN a program (from Desktop)
Opening file or folder
Navigating Active Windows
Copying, Deleting and Renaming a file or folder
Starting AutoCAD
Open a drawing
Understanding the AutoCAD User’s Interface
Lecture-discussion
Demonstration
Drill and Practice
Hands On
3
Autodesk Mannual
Internet
AutoCAD or User’s CoordinateSystem
1. Absolute Coordinate
2. Relative CartesianCoordinates
3. Relative Polar Coordinate
4. Direct Distance Entry
5. Polar Tracking and Snap
6. Dynamic Input
Templates ( Free Hand and Automated)
Manipulate AutoCAD coordinate commands:
Absolute Coordinate command
CartesianCoordinate command
Polar Coordinate command
Direct Distance Entry command
Snap and Polar Tracking command
Dynamic Input command
Lecture-discussion
Demonstration
Drill and Practice
Hands On
12
Autodesk Mannual
Internet
Draw Command Tools
Drawing and Labeling
Bullets and Numbering
Editing Text
Templates ( Free Hand and Automated)
Learn to apply the following draw command tools:
Linear...