H. Abelson and A. diSessa. Turtle Geometry. MIT Press, Cambridge, MA, 1980.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....is increased by one unit length while turning a constant direction. To complete a closed spirolateral, it is necessary to only repeat this procedure until the starting point is reached. The first apparent reference to this geometric figure was by Odds [4] Further information was found at Abelson [5] and Gardner [6] In addition to the property of closure, spirolaterals need not always turn the same direction. The direction can be reversed at any turn, which makes the total number of possible spirolateral unknown. Figure 1 displays the systematic generation of an order 3 spirolateral; one ....

Abelson, Harold, diSessa, Andera, 1968, Turtle Geometry, MIT Press, pp.37-39, 120-122

....realism in the pictures, we added external forces, which interact with the L structures and allow physical modeling. External forces can also have an important impact in the evolution of objects. L systems are in general interpreted using a turtle geometry as described by Abelson and diSessa [1]. These authors describe an innovative program of mathematical discovery that demonstrates how the effective use of personal computers can profoundly change the nature of a students contact with mathematics. The book proceeds from a novel procedural view of the elements of plane geometry to such ....

....The second example treats random motion of an actor with reaction to tactile collision detection. For simplicity, we only mention L system parameters and growth function of the symbols when it is necessary for the comprehension. 4. 1 Escaping from a maze based on vision The Pledge algorithm [1] describes a sure method for finding the exit of maze. 1. Select an arbitrary initial direction, call it north and face that way. 2. Walk straight northward until you hit an obstacle. 3. Turn left until that obstacle is on your right. 4. Follow the obstacle around, keeping it on your ....

H. Abelson, A.A. diSessa, Turtle Geometry, The MIT Press, 1984

.... family of plane figures can be generated easily with the turtle graphics (see [ 14 ] and the references therein) A very simple graphical interface is based on Seymour Papert s concept of turtle graphics as a part of the LOGO language for teaching children some elements of geometry and programming [15]. The notion of turtle is similar to a turtle facing in a certain direction and migrating over the page. It leaves a trace on the paper. To control the turtle we need four methods (see, for example, 14] the turnTo( method, which turns the turtle to face the given direction; the turn( ....

H. Abelson and A.A. Siessa, Turtle Geometry, Cambridge, MA, MIT Press, 1981.

....relegating textual programs to the status currently occupied by assembly language a necessary, but low level construct. Many languages targeted at novices [25] are model based. The Logo language [26] was one of the first languages based on the idea of programming through the use of a turtle [27, 28] capable of carrying out a set of simple instructions, with graphical feedback for output. Karel the Robot [29] has similar aims with a robot replacing the turtle and by extending the functionality of the moving agent with respect to its interaction environment. Methods of programming by ....

Harold Abelson and Andrea diSessa. Turtle Geometry. MIT Press, 1980.

....resolution (typically 840x840) bit map images. Like the majority of children, Rose creates line drawings. Each perceived volume is represented in the drawing by a single form which is a continuous pen stroke usually approximating an elliptical shape. Rose employs a turtle like drawing method [13] in which the pen is advanced in small steps of constant length and varying angle. The drawing in progress is stored as a series of linked lists of points, one for each form depicted. A reasonably complex drawing takes typically five seconds to be drawn. To reflect the physical nature of the ....

Abelson, H & diSessa, A. Turtle Geometry. MIT Press. Cambridge. Massachusetts. 1982.

....[122] and extended by Prusinkiewicz [90,91] and Hanan [41,42] is representative of this approach. The summary below is based on [54,91,99] The interpreted string is scanned sequentially from left to right, and its consecutive symbols are interpreted as commands that maneuver a LOGOstyle turtle [1,88] in three dimensions. The turtle is represented byitsstate, which consists of turtle position and orientation in the Cartesian coordinate system, as well as additional attributes, suchascurrent color and line width. The position is defined byavector P, and the orientation is defined by three ....

H. Abelson and A. A. diSessa. Turtle geometry. M.I.T. Press, Cambridge, 1982.

....the turtle to draw in this way providesaneasyintroduction to computing for young children, but LOGO is equally suitable for older students. Many sophisticated areas of mathematics (including topology, relativity and differential geometry) can be explored through the use of turtle graphics (see [1]) The system under development at Cardiff is specifically designed for exploring nonEuclidean geometry. Euclidean geometry is the kind taught in schools. Most students will be familiar with the properties of Euclidean parallel lines; given a straight line, L, and a point, P, not on the line, we ....

H Abelson and A diSessa, Turtle Geometry, MIT Press, (1980)

.... is included in [6] and subsequent results are presented in [5] The summary below is based on [6,31,34,36] After a string has been generated by an L system, it is scanned sequentially from left to right, and the consecutive symbols are interpreted as commands that maneuver a LOGO style turtle [37,38] in three dimensions. The turtle is represented by its state, which consists of turtle position and orientation in the Cartesian coordinate system, as well as various attribute values, such as current color and line width. The position is defined by a vector P , and the orientation is defined by ....

H. Abelson and A. A. diSessa. Turtle geometry. M.I.T. Press, Cambridge, 1982.

....are connected by either xed or actuated joints. The construction module builds creatures by processing a sequence of construction commands that specify how, and where, to attach bars to the existing design. This sequence of commands is based on the instruction language for a LOGO style turtle [1]. As the turtle moves it creates bars, and commands in the language specify whether subsequent bars are to be attached with a xed or actuated joint. The turtle command language is similar to the L system languages for creating plants [22] Push and pop operators, and ] are used to store ....

H. Abelson and A. A. deSessa. Turtle Geometry. M.I.T. Press, 1982.

....[11] II) Sensor System: There are two different varieties of sensors, namely touch and vision, that have been studied in literature. 4 Class Subclassification Representative References Class A maze searching Shannon s mouse [79] Tarry and Tremaux [57] Fraenkel [27] Pledge algorithm [1] touch sensor Lumelsky [45] Cox and Yap [18] Sankaranarayanan and Vidyasagar [73] continuous vision Sutherland [79] Lumelsky et al. [50] Lumelsky and Skewis [51] discrete vision Rao [61] Choo et al. [15] Foux et al. 26] Class B searching in plane Baeza Yates [3] Kao et al. [38] figure ....

....navigation algorithms. A) Touch Sensors: Typically a touch sensor detects when the robot touches an obstacle. Several algorithms based on such sensors have been extensively studied by Lumelsky [45] and by many other researchers. Early use of touch sensors goes back to the Pledge algorithm [1]. Some of the more recent works based on these sensors are due to Cox and Yap [18] and Sankaranarayanan and Vidyasagar [72, 71, 73] B) Vision Sensors: A vision sensor typically provides the information visible to the robot; there are two basic characterizations of a vision sensor: continuous ....

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H. Abelson and A. diSessa. Turtle Geometry. MIT Press, Cambridge, MA, 1980. pp. 191-198.

....increased by one unit length while turning to a constant angle. To complete a closed spirolateral, it is necessary to only repeat this procedure until the starting point is reached. The first apparent reference to this geometric figure was by Odds [8] Further information can be found at Abelson [1] and Gardner [3] In addition to the property of closure, spirolaterals need not always turn the same direction. The direction can be reversed at any turn, which makes the total number of possible spirolateral unknown. 2 45 4 60 4 120 Figure 1: Closed spirolaterals In this series of ....

Abelson, Harold, diSessa, Andera, 1968, Turtle Geometry, MIT Press, pp.37-39, 120-122

....are usually considered quite different, more or less applicative, activities belonging to partially related subdomains of Computing. Several scholars have attempted to use one or another of those activities to show that they were useful for learning. The outstanding example is Papert s LOGO [20] [2]: the conjecture to support being that programming in LOGO would be useful for children to develop (a) programming skills (in a functional programming language rich of abstractions) b) domain dependent skills (e.g: in Geometry, if the programs constructed were about how to draw figures with ....

H. Abelson and A. DiSessa. Turtle geometry. The MIT Press series in artificial intelligence. The MIT Press, Cambridge, Mass. - London, England, 1984.

....the evolutionary algorithm and the physics and network simulator. 2. 1 MORPHOLOGY CONSTRUCTOR The morphology constructor and simulator is a 3D extension of the 2D work in [Hornby et al. 2001] The morphology constructor builds a model from a string of build commands to a LOGO style turtle [Abelson deSessa, 1982] using a command language similar to that of L system languages for creating plants [Prusinkiewicz Lindenmayer, 1990] As the turtle moves, bars are created and these become the morphology of the creature. The commands instruct the turtle to move forward or backward and to change orientation, ....

Abelson, H. & deSessa, A. A. (1982). Turtle Geometry. M.I.T. Press.

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H. Abelson and A. diSessa. Turtle Geometry. MIT Press, Cambridge, MA, 1980.

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H. Abelson and A. di Sessa, Turtle Geometry, MIT Press, 1980.

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H. Abelson and A. A. diSessa. Turtle Geometry. MIT Press, Cambridge, 1980.

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H. Abelson and A. A. diSessa. Turtle Geometry. MIT Press, Cambridge, 1980.

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H. Abelson and A. A. diSessa. Turtle Geometry. M.I.T. Press, 1982.

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Abelson, H., & DiSessa, A. (1980). Turtle Geometry. Cambridge, MA: MIT Press.

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H. Abelson, A. A. Disessa, Turtle Geometry, MIT Press, 1986.

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H. Abelson and A. A. diSessa. Turtle Geometry. MIT Press, Cambridge, 1982.

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H. Abelson and A. A. diSessa. Turtle Geometry. M.I.T. Press, Cambridge, 1982.

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Abelson, H. and diSessa, A. Turtle Geometry. MIT Press, Cambridge, MA 1980.

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Abelson, H. and diSessa, A. Turtle Geometry. MIT Press, Cambridge, MA 1980.

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Abelson, H. & A. A. diSessa (1982), Turtle Geometry, MIT Press.

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