Showing papers on "Tree (data structure) published in 1971"

Experiments in mixed-integer linear programming

Abstract: This paper presents a “branch and bound” method for solving mixed integer linear programming problems. After briefly discussing the bases of the method, new concepts called pseudo-costs and estimations are introduced. Then, the heuristic rules for generating the tree, which are the main features of the method, are presented. Numerous parameters allow the user for adjusting the search strategy to a given problem.

Representation of a protein molecule as a tree and application to modular computer programs which calculate and modify atomic coordinates.

Abstract: The concept and representation of a logical tree as defined in computer science is applied to obtain a suitable representation of protein molecules in computer programs which handle or calculate atomic coordinates of protein molecules. On the basis of this analysis and of the analysis of the calculation and modification of the structure of a protein from bond lengths, bond angles, and dihedral angles, which is reproduced in an appendix, program modules which accomplish the various required computations are described. Three such modules are given in Iverson notation; in fact, it is hoped that this article will serve as a reasonably complete basis for the preparation of machine programs by moderately proficient programmers.

A Computing Machine Based on Tree Structures

Abstract: The expenditure of resources to provide via software more structure and more function in conventional machines has become excessive. The answer to this problem may consist in providing more structure and more function in hardware. With respect to structure, we describe 1) the binary tree as basic data and control structure, 2) the implementation of a binary tree by a conventional memory, and 3) the associated hardware. The most important enhancement with respect to function, the newly introduced unit of action, deals with the handling of variables and substitution.

Christmas tree packaging means

Abstract: A specially constructed Christmas tree package or bagging means for enclosing the tree after usage thereof.

Storage optimization of tree structured files representing descriptor sets

Abstract: It is shown that the total node requirements for tree structured files can be minimized without significantly affecting the search time. However, search times are determined primarily by type of use, and the particular implementation of tree structured files.In this paper theoretical results are reported for full and sparse files, and empirical techniques for minimizing total node requirements of tree structured files are given.

Portable tree stand

Abstract: A portable tree stand for hunters use formed of a plurality of sections detachably secured together to support a seat section extending horizontally from the top of the erected sections to engage a tree. A chain and turnbuckle system encompasses the tree and draws a spike carrying bar into engagement with the tree with the spikes embedded in the tree.

Tree felling machine

Abstract: A tractor mounted tree felling machine having a pair of hydraulically actuated chain saws with the inner saw slidably mounted on a frame and the outer saw pivotally mounted on a frame to cut the tree from opposite sides thereof. The frame is adjustable in height and rotatable about a longitudinal axis for cutting trees at an angle. A pusher is mounted on the tractor and hydraulically actuated for pushing the tree over as it is being cut in a direction away from the tractor.

Reliability and Fault Tree Applications at the NRTS

Abstract: Fault tree methods and reliability engineering techniques are used at the National Reactor Testing Station (NRTS) principally to evaluate reactor protective and safeguard systems. The particular analytical technique called "Kinetic Tree Theory", with the associated computer programs, is used to obtain quantitative probabilistic characteristics regarding the safety and reliability of these systems. Once the fault tree or block diagram is drawn, the Kinetic Tree Theory technique automatically yields detailed time-dependent information forevery component, for every minimal cut set (critical path) and for the system itself. The computer time needed for this detailed analysis is negligible. In actual application, the fault tree and reliability engineering techniques, with the quantitative evaluations by Kinetic Tree Theory, have yielded results which verify the practical value of these types of safety and reliability analyses.

Bibliography of the tree shrews 1780–1969

Abstract: GENERAL The affiliations of tree shrews will not be debated here. I am among those who believe that the classification of mammals should be left to those such as SIMVSON (1945), whose interests and abilities permit them to give a thorough treatment of the complete Class Mammalia, viewing each creature from the perspective of all other species. I follow this line of reasoning here and accept the Tupaiidae as primates, according to SIMPSON (1945), until he or someone else has published a similarly complete analysis which indicates otherwise. This introduction is a vignette of the banquet of information available in this compilation of sources.

Apparatus for felling trees

Abstract: An apparatus for felling trees has an elongated beam carrying a saw-blade, a means for moving the beam back and forth with respect to the tree, and a counter-piece adapted to be moved to compress a tree trunk between it and the saw-blade

Tree Properties and Tree Scenes in Elizabethan Theater

Abstract: Theater us aware historians of the considerable and literary xtent critics to alike which have meaningful increasingly visual made and \"emblematic\" elements must have contributed to dramatic performances on the Elizabethan public stage.1 In this general context it seems useful to reconsider the dramaturgic function of large stage properties. The present essay, which concentrates on trees in particular, is an attempt to point out the use to which a constantly recurring type of property was put in an important phase of the history of the theater. It is also intended to plead for a combined consideration of the physical presence of these properties on the stage on the one hand, and of their part in the dramatists' scenic vision on the other. For even if it were possible to determine definitely how, when, and in what shape tree (or any other) properties were practicable on Elizabethan stages and there is a considerable lack of certainty in these matters such information would not tell us much

Harvesting system using tree frame

Abstract: The present invention relates to a harvesting method and apparatus for harvesting fruit, and the like, from trees. It includes a frame connected between limbs of a tree in a manner that shaking the frame shakes all of the limbs connected thereto and means for gripping the frame and shaking it. The frame is permanently installed in the tree at predetermined points on the limbs of the tree, so that shaking one point of the frame will shake all of the limbs at predetermined points for loosening the fruit located in the tree. A method is also provided for attaching the frame in the trees either by drilling holes in the limbs or placing a clamp around the limbs at predetermined points and connecting frame arms with bolts either extending through the holes drilled in the tree or through clamps around the limbs.

Generalized data structures in Madcap VI

Abstract: The data structures proposed for the Madcap VI programming language are described. The declaration, value specification, and referencing of these structures are defined formally and their implementation using "codewords" is discussed. A structure declaration has the form of a directed tree, and a structure itself, since it can contain references to other structures, including itself, has the form of a directed graph. Levels of the tree may be ordered or unordered. Variables of primitive data-type (real, complex, etc.) are naturally considered as empty structures. The possibility for both multi-and fractional-word representation of structures is evident, but, of course the language itself is implementation independent. Thus a field is equivalent to a sub-structure. The Madcap VI generalized data structures are compared to data structure concepts in PL/1.