Ahmad, A & Waldron, KJ 1979, 'Synthesis of adjustable planar 4-bar mechanisms', Mechanism and Machine Theory, vol. 14, no. 6, pp. 405-411.
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The ability of planar 4-bar mechanism, to generate various kinds of motion, can be greatly enhanced if it is made adjustable. With a simple adjustment of the position of the driven crank fixed pivot(s), a variety of outputs can be obtained with the same set of hardware. This paper outlines synthesis techniques for 4-bar linkages, having adjustable driven crank pivots, for different motion generation problems. For a 4-bar mechanism, no more than five design positions can be specified. All the possible maximal motion specifications for the two "phases", consisting of different combination of the five positions, are enumerated. This leads to four classes of motion generation problems. Synthesis procedure for each class is presented. An example of the P1-P2-P3:P1-P4-P5 case is solved. The method of solution is analytical in nature, and, therefore well suited for use on a digital computer. © 1979.
Churches, AE, Howlett, CR, Waldron, KJ & Ward, GW 1979, 'The response of living bone to controlled time-varying loading: Method and preliminary results', Journal of Biomechanics, vol. 12, no. 1, pp. 35-45.
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This paper describes a method and equipment for applying controlled sinusoidally-varying axial compressive loading to a typical animal long bone - the ovine metacarpus. The loading is generated hydraulically and applied to the bone through stainless steel bone-pins surgically inserted in the metaphyses. For the ovine metacarpus, the mid-diaphyseal cross-section is well removed from the sites of surgical trauma and from the points of load application. Preliminary results show that the bones responded by adaptive remodelling in the mid-diaphyseal region. The maximum increase in cross-sectional area during a 28-day test period was approximately 17% when the nominal compressive stress was 8.8 MPa. Although a uniform stress field on the mid-diaphyseal region is theoretically possible, it has been found that significant stress non-uniformity may occur due to slight eccentricity of loading. © 1979.
Heiman, JL, Bakoss, SL, Burfitt, AJ & Cridland, L 1979, 'MEASURED AND PREDICTED AXIAL STRAINS AND DEFORMATIONS IN A COLUMN OF A TALL REINFORCED CONCRETE BUILDING.', National Conference Publication - Institution of Engineers, Australia, no. 79 /9, pp. 44-51.
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A site investigation was carried out to determine the axial deformations of a column in a tall reinforced concrete building. Strains were measured in the column concrete using vibrating wire gauges and the column deformations were measured by precise levelling. In addition to strain measurements on standard laboratory shrinkage and creep specimens, strain data was obtained from tests that related more closely to the site conditions. Appreciable differences occurred between shrinkage and creep strains measured in the laboratory and some of those obtained by methods given in codes. Shortcomings were found in some of the equations used to predict long-term creep strains from laboratory data and a hyperbolic equation was developed that enabled more accurate predictions to be made. Measured strains in the column were compared with predicted values obtained by two calculation methods and good agreement was obtained.
Hung, N & Anderson, B 1979, 'Triangularization technique for the design of multivariable control systems', IEEE Transactions on Automatic Control, vol. 24, no. 3, pp. 455-460.
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Kumar, A & Waldron, KJ 1979, 'NUMERICAL PLOTTING OF SURFACES OF POSITIONING ACCURACY OF MANIPULATORS.', Proceedings - OSU Applied Mechanisms Conference (Oklahoma State University).
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A mathematical model has been developed to calculate the expected errors of position and orientation of the hand at any point in workspace, given the expected error of positioning the individual joints of manipulator. The model is used to derive equations, which can be used to plot the contours of expected errors in positioning the hand either in a specified direction or regardless of direction. Because of the highly non-linear characteristics of the equations, they are solved numerically to plot the contours. The parameter perturbation method left bracket 2 right bracket is used in conjunction with the Newton Raphson method to solve the simultaneous non-linear equations.
Shannon, AG 1979, 'Letters: Individual Differences and Instructional Inequalities', Educational Researcher, vol. 8, no. 10, pp. NP-NP.
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SHANNON, AG & CLARK, BE 1979, 'MATHEMATICAL ATTITUDES OF SOME POLYTECHNIC STUDENTS', BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, vol. 10, no. 1, pp. 59-60.
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This is an investigation in which semantic differentials are used to study differences in attitudes of some first‐year polytechnic students towards ways of learning mathematics according to the field of study or level of ability of the students. Of particular interest to educational technologists are the attitudes towards audio‐visual aids and individualized instruction. Irrespective of the generalizability of the results, the research is seen as suggesting a methodology for partial course evaluation with minimum interference in the instructional process. Copyright © 1979, Wiley Blackwell. All rights reserved
Shannon†, AG 1979, 'Mathematical attitudes and semantic differentials', International Journal of Mathematical Education in Science and Technology, vol. 10, no. 4, pp. 497-507.
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The semantic differential-one approach to attitude measurement- basically records a combination of a person's associations with a particular concept with a scaling procedure. This paper considers the implications of such a device for teachers of mathematics. © Taylor & Francis Group, LLC.
Strong, RT & Waldron, KJ 1979, 'Joint Displacements in Linkage Synthesis Solutions', Journal of Mechanical Design, vol. 101, no. 3, pp. 477-487.
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A comprehensive and unified treatment of the relationship between the displacements, about the joints of a four-bar linkage as it moves through specified design positions is given. The behavior of joint displacements is characteristic of Grashof type, and can be used to help locate solutions of a given type.
Thanh, NC, Vigneswaran, S & Polprasert, C 1979, 'OPTIMIZATION OF DUAL‐MEDIA FILTER PERFORMANCE1', JAWRA Journal of the American Water Resources Association, vol. 15, no. 5, pp. 1459-1465.
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ABSTRACT: Rapid‐rate filter with sand or anthracite as filter media was studied at filtration rates of 4.5 and 9.0 m3/m2‐h. Different parameters were evaluated by adopting a proposed simplified model. A suitable combination of anthracite‐sand as filter media was given by using corresponding filter parameters of single‐medium filters and break‐even optimization technique.
Waldron, KJ & Stevensen, EN 1979, 'Elimination of Branch, Grashof, and Order Defects in Path-Angle Generation and Function Generation Synthesis', Journal of Mechanical Design, vol. 101, no. 3, pp. 428-437.
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Path-Angle Generation and Function Generation synthesis problems are restated as Plane-Position (or Motion Generation) problems, enabling the use of the classical Burmester technique and recent extensions that permit the avoidance of Branch, Grashof, and Order defects. An example of the solution of a Path-Angle Generation problem is given.
Waldron, KJ & Sun, JWH 1979, 'CONTROL OF ANGULAR DISPLACEMENT IN BURMESTER SYNTHESIS PROBLEMS.', Urban Systems, vol. 1, pp. 38-41.
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Methods of imposing inequality, or partial equality, constraints on the relative angular displacements of links of planar four-bar linkages synthesized using Burmester's technique have recently been developed as a result of the work of Filemon and of Waldron on the elimination of solutions requiring a change of branch. However, control of these relative displacements has many applications beyond elimination of branch change. The ability to impose inequality constraints on the angular displacements of any joint, or joints, opens a whole new class of synthesis problems. In this paper, a unified theory of the application of inequality constraints on joint angles is presented and illustrated with examples.
