bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous Type and Dimensional Synthesis of Mechanisms by Genetic Algorithms
Authors: Fang W. Eugene 
Published: March 2021

Abstract
Based on global search/optimization techniques called genetic algorithms, a new approach to the conceptual design of mechanisms is proposed. Emulating “natural” genetics and selection, competing types of mechanisms are treated as species and different dimensions are evaluated for each type simultaneously. The problem formulation is straight-forward, similar to an optimization problem. The result may be a spectrum of similar or different mechanisms, depending on whether multiple optimal solutions exist. The computational power required to utilize this approach is acceptable for most conceptual design problems.
Modular Third-Order Analysis of Planar Linkages With Applications
Authors: Pennestrí Ettore , Belfiore Nicola Pio 
Published: March 2021

Abstract
This paper reports analysis equations for the computerized third-order analysis of dyads. Such equations are an extension of those reported by C.H. Suh and C.W. Radcliffe.
Examples of tracing cubic of stationary curvature and quartic of derivative curvature for multiloop linkages are herein described.
Kinematic Design of a Large-Angular-Motion Constant-Velocity Coupling
Authors: Canfield Stephen L. , Salerno Robert J. , Reinholtz Charles F. 
Published: March 2021

Abstract
This paper describes a new type of constant-velocity coupling capable of producing solid joint angles greater than 180 degrees. Analytical expressions describing the range of motion are developed based on the kinematic closure equations of an equivalent spatial mechanism. This mathematical description is then used as a tool in the kinematic design and analysis of a constant-velocity coupling capable of producing a 240 degree solid angle output motion.
Quasi-Precision Position Synthesis of Four-Bar Linkages
Authors: Mirth John A. 
Published: March 2021

Abstract
Quasi positions describe portions of a mechanism’s motion that do not require an exact position. Quasi positions are combined with three exact positions to define a two-dimensional design plane for the synthesis of planar linkages. Quasi-precision position synthesis is based on precision position techniques. The method preserves the computational advantages of precision position synthesis with the added advantage of being able to specify a much greater number of design positions.
Designing Planar Mechanisms Using a Bi-Invariant Metric in the Image Space of SO (3)
Authors: Larochelle Pierre , McCarthy J. Michael 
Published: March 2021

Abstract
In this paper we present a technique for using a bi-invariant metric in the image space of spherical displacements for designing planar mechanisms for n (&gt; 5) position rigid body guidance. The goal is to perform the dimensional synthesis of the mechanism such that the distance between the position and orientation of the guided body to each of the n goal positions is minimized. Rather than measure these distances in the plane, we introduce an approximating sphere and identify rotations which are equivalent to the planar displacements to a specified tolerance. We then measure distances between the rigid body and the goal positions using a bi-invariant metric on the image space of SO(3). The optimal linkage is obtained by minimizing this distance over all of the n goal positions.
The paper proceeds as follows. First, we approximate planar rigid body displacements with spherical displacements and show that the error induced by such an approximation is of order 1/R2, where R is the radius of the approximating sphere. Second, we use a bi-invariant metric in the image space of spherical displacements to synthesize an optimal spherical 4R mechanism. Finally, we identify the planar 4R mechanism associated with the optimal spherical solution. The result is a planar 4R mechanism that has been optimized for n position rigid body guidance using an approximate bi-invariant metric with an error dependent only upon the radius of the approximating sphere. Numerical results for ten position synthesis of a planar 4R mechanism are presented.
Stephenson Chain Branch Analysis: Four Generic Stationary Configurations and One New Linkage Polynomial
Authors: Davis Henry P. , Chase Thomas R. 
Published: March 2021

Abstract
The stationary configurations of the Stephenson linkages have been defined in the literature. All stationary configurations of the Stephenson six-bars are mapped to the Stephenson III linkage inversion and represented as four ‘generic’ stationary configurations. A graphical interpretation of these stationary configurations is presented. It may be used to determine these stationary configurations. Analytical solutions of the first two generic stationary configurations are referenced. A twentieth order polynomial, whose roots correspond to the third generic stationary configuration, is derived and discussed.
Evaluation of Equivalent Spring Stiffness for Use in a Pseudo-Rigid-Body Model of Large-Deflection Compliant Mechanisms
Authors: Howell Larry L. , Midha Ashok 
Published: March 2021

Abstract
Compliant mechanisms gain some or all of their mobility from the flexibility of their members rather than from rigid-body joints only. More efficient and usable analysis and design techniques are needed before the advantages of compliant mechanisms can be fully utilized. In an earlier work, a pseudo-rigid-body model concept, corresponding to an end-loaded geometrically nonlinear, large-deflection beam, was developed to help fulfill this need. In this paper, the pseudo-rigid-body equivalent spring stiffness is investigated and new modeling equations are proposed. The result is a simplified method of modeling the force/deflection relationships of large-deflection members in compliant mechanisms. Flexible segments which maintain a constant end angle are discussed, and an example mechanism is analyzed. The resulting models are valuable in the visualization of the motion of large-deflection systems, as well as the quick and efficient evaluation and optimization of compliant mechanism designs.
On the Matrix Algebra Realization of the Theory of Biquaternions
Authors: Ge Q. J. 
Published: March 2021

Abstract
This paper describes a matrix algebra presentation of Clifford’s theory of biquaternions. We examine 4 × 4 skew-symmetric matrices and use their exponentials to relate quaternions to equal-angle double rotations in Euclidean four-space E4. We show how double rotations in E4 expressed in terms of plane coordinates lead to elliptic biquaternions in both Plücker and Study forms and present the fundamental Plücker and Study conditions that govern the biquaternions. Finally, we show that a spatial displacement in E3 in terms of parabolic biquaternions (or dual quaternions) is a limiting case of a double rotation in E4 in terms of elliptic biquaternions.
Motion Synthesis of Mechanisms Using Constraint Manifolds
Authors: Wu Y. K. , Fischer Ian S. 
Published: March 2021

Abstract
The motion synthesis of a mechanism is obtained by curve fitting the intersection of the constraint manifolds representing each leg of the linkage in an image space to points obtained by the kinematic mapping of the prescribed positions and orientations. The dimensions of the mechanism can be found by using optimization algorithms to minimize the normal distance between all the desired image points and image curve of the tracer frame. The theory is illustrated by numerical examples.
Multiple-Mode Input Shaping Sequences for Reducing Residual Vibrations
Authors: Rappole B. Whitney , Singer Neil C. , Seering Warren P. 
Published: March 2021

Abstract
A closed-form method of calculating Input Shaping sequences for two modes of vibration is presented. The new method eliminates the optimization routines previously required to find the same solutions. Input Shaping is a feed forward method of reducing residual vibrations in flexible structures by convolving an Input Shaping sequence with a command profile. The two-mode sequences are installed on a four-axis robot used in the manufacture of silicon wafers — the Cassette Management System. The new sequences are found to significantly improve the performance of the system. In standard throughput tests, speed increases of 15%–25% were obtained on each axis while vibrations were simultaneously reduced by 20%–90%.
On the Surface Geometry of Variable Pitch Cylindrical Cams With Hyperboloidical Meshing Elements
Authors: Kang Yaw-Hong , Wu Feng-Chi , Cheng Hong-Yih , Yan Hong-Sen 
Published: March 2021

Abstract
The hyperpoloid of revolution is a kind of skew surface that has engineering applications. Based on differential geometry, theory of gearing, and coordinate transformation, this paper derive mathematical equations of the geometric profiles of a double threaded variable pitch cylindrical cams with four hyperboloidical meshing elements. And based on the developed surface equations, we develope a computer program for solid modeling to simulate the surface geometry. Two examples are given to prove the derived equations.
Dynamics of Mechanical Systems Solved by Quadratic Programming
Authors: Wang Deshi , Chen Xin , Chen Xindu , Yu Jun , Zhou Ji 
Published: March 2021

Abstract
A new method for dynamics of mechanical systems has been established and the new use of the optimum software has been shown in this paper. Gauss’ principle in the theory of mechanics has been employed to transform the dynamical control and simulation into the quadratic programming problems, which makes it possible that the optimum software developed in CAD systems is applied to obtain the dynamics of mechanical systems. Such a method is significant for systems which contain complex motion and constraints, since there is no longer necessity of reducing the analytical dynamic models, which are tedious and even impossible to obtain. Morever, it gives a new way of applying the optimum software package. The dynamics of a robot with sliding and revolving joints has been demonstrated in detail.
Flow Rate Regularity in Rotary Trochoidal-Lobe Pumps
Authors: Mimmi G. , Pennacchi P. 
Published: March 2021

Abstract
This paper analyses a particular type of rotary positive-displacement pumps with lobes having epitrochoidal flanks, whose distinctive feature is that of providing a strictly constant geometric instantaneous flow rate. The pump design is analysed from geometric and kinematical points of view. Then the behavior of this type of lobe pump is compared with that of involute gear pumps.
Dynamic Analysis of Mechanical Systems With Elastic Telescopic Members
Authors: Al-Bedoor B. O. , Khulief Y. A. 
Published: March 2021

Abstract
A dynamic model for the vibrational motion of an elastic beam-like telescopic member is presented. In addition to translation, the elastic member is allowed to execute large reference rotation. The Lagrangian approach in conjunction with the assumed modes technique are employed in deriving the equations of motion. The developed model accounts for all the dynamic coupling terms, as well as the stiffening effect due to the beam reference rotation. The tip mass dynamics is included together with the associated dynamic coupling between the modal degrees of freedom. In addition, the devised dynamic model takes into account the gravitational effects, thus permitting motions in either vertical or horizontal planes. Numerical simulation of a mechanical system with an elastic telescopic member is presented.
Application of Threshold Logic to the Design and Analysis of Latching Systems in Deployers of Deployable-Retractable Structures
Authors: Chew M. , Ho M. T. 
Published: March 2021

Abstract
To erect deployable structures from a compact folded state, a supplemental mechanism called a deployer is used. Many latches are present in the deployer and these are coordinated in some logical and systematic manner to bring about the deployment. This article presents an investigation into analyzing the logic behavior of a deployer and design such latching systems in deployers in a more systematic manner; the logic functions used are based on modifications of the Mechanical Threshold Logic approach.
Dynamic Response to Mass Reduction in Flexible Mechanisms
Authors: Yu Yue-Qing , Smith M. R. 
Published: March 2021

Abstract
A new investigation into the kineto-elastodynamic (KED) behaviour of flexible mechanisms is presented. The characteristic response of inertia forces, such as the shaking force and moment, input torque and bearing reaction, in addition to dynamic stress and energy are studied as the mass of a planar four-bar linkage is reduced.
Fuzzy Logic in Hole Drilling of Composites
Authors: Thadani Aditya , Soni Athamaram H. 
Published: March 2021

Abstract
Experimental and theoretical research data was utilized in building a Fuzzy Logic Controller model applied to simulate the drilling process of composite materials. The objective is to have a better understanding and control of delamination of composites during the drilling process and at the same time to improve the hole finish by controlling fraying and splintering. By controlling the main issues in the drilling process such as feed rate, cutting speed, thrust force, and torque generated in addition to the tool geometry, it is possible to optimize the drilling process avoiding the conventionally encountered problems.
Approximate Degree Reduction of NURBS Curves and Surfaces: An Integrated Approach
Authors: Varanasi Srinivasa P. , Soni Athamaram H. 
Published: March 2021

Abstract
Data exchange between different CAD systems usually requires conversion between different representations of free-form curves and surfaces. Also, trimmed surfaces give rise to high degree boundary curves. Accurate conversion of these forms becomes necessary for reliable data transfer. Also important is the issue of shape control, specially in the aircraft industry. The objective of this paper is to investigate conversion methods and effect of shape control on the design and choice of such methods.
Research and Development Needs for Flexible Forging Systems
Authors: Clark R. K. , Avasarala Pantulu V. , Soni Athamaram H. 
Published: March 2021

Abstract
In recent years there has been considerable advances in the furnace technology in the form of rapid heating furnace. This new technology is not well known to the forging industry or very skeptical about its performance. To prove its usefulness, and to identify the future research issues it is necessary to identify the current industrial practices and sate of the art technology used by the forging industries. A forging industry survey is conducted to find the current industrial practices and a three furnace forging simulation model is developed to prove the usefulness of rapid heating furnace. The results of the survey and simulation model are discussed in this paper.
Quasi-Static Modelling and Computer Simulation of Hanging Cables on Robots
Authors: Yang Li-Ping , Song Shin-Min 
Published: March 2021

Abstract
This paper presents a computer method to simulate the quasi-static motion of hanging cables on robots. The shape of the flexible cable is changing during motion and the finite segment method is applied to determine its configuration. The cable is modeled as a series of rigid segments segments connected together through revolute joints in 2-D case and spherical joints in 3-D case. The elasticity of cable is represented by torsional springs at the joints. In both cases, a set of highly nonlinear equations are derived based on force equilibrium and the Newton-Raphson method is applied to calculate the solution. In order to assure convergence and improve computational efficiency, the parameter perturbation method is applied together with the Newton-Raphson method. Also, some computational strategies are developed to simplify the three dimensional problem. Finally, the developed methods are demonstrated in displaying the motion of a hanging cable which is attached to a revolute joint, a prismatic joint and a three degrees of freedom robot.
Force-Based Reasoning in Assembly Planning
Authors: Lee Sukhan , Yi Chunsik 
Published: March 2021

Abstract
A new approach to assembly planning based on force-based reasoning of decomposable subassemblies is presented. By decomposable subassemblies, we mean those clusters of parts that are naturally broken apart from an assembly by decomposition forces. The key feature of the proposed approach is that decomposable subassemblies can be identified from the minimal cut-sets of force-flow networks constructed by assigning bidirectional flow capacity to individual part mating. The flow capacity between two mating parts is defined here as the maximum amount as force that one can exert against its mating part (hypothesized fixed in space) in a chosen direction. Finally, the assemblability of decomposable subassemblies is verified by testing, through force-flow networks, whether the decomposed subassemblies can be reassembled by the mating forces opposite to the decomposition forces. The proposed force-based approach is advantageous due to the polynomial time complexity of a max-flow/min-cut algorithm, as well real-world application.
Characterization of Process Constraints and Exceptions in a Manufacturing Environment
Authors: Chadha Bipin , Fulton Robert E. 
Published: March 2021

Abstract
Constraints and exceptions form an integral part of information integration. In the absence of constraint and exception integration the shared data can lose consistency and will often raise exceptions that cannot be efficiently handled. In this paper the IDEF0 methodology is used to capture the process constraints (workflows) and a specification language is provided to map the IDEF0 models to a control network of process constraints suitable for knowledge based implementation. Semantics of ECA (Event Condition Action) rules is extended to support these constraints. IDEF0 methodology has been extended to model exceptions in the process. A specification language is provided to describe the semantics of exceptions, and an information model has been developed to support the specification language. The languages developed provide a mechanism for providing constraint and exception management in an integrated environment and for providing optimization and analysis capabilities for the manufacturing process. Such capabilities are critical for continuous process improvement initiatives.
A Critique of Conceptual Data Modelling Notions Relative to the Machine Design Domain
Authors: Zhang W. J. , van der Werff K. 
Published: March 2021

Abstract
In the development of a software environment for integrated design and manufacturing of machines, the relevance of conceptual data modelling becomes apparent. This paper presents an analysis of the applicability of some notions of conceptual data modelling in the current literature, based on our experience in modelling for CAD of machines. The notions to be examined are: object relativity, object reliability, object convertibility, Functional dependency, derived attribute and composite object. Some notes and proposals for extending those notions to meet new requirements from engineering design are also presented. To stimulate the application of database technology in engineering the examples have been taken from the machine design domain as much as possible. The paper may also provide some guidelines For conceptual data modelling.
Immunoreactive Proteins of Dormant Mycobacterium tuberculosis Cells
Authors: Trutneva K. A. , Avdienko V. G. , Demina G. R. , Shleeva M. O. , Shumkov M. S. , Salina E. G. , Kaprelyants A. S. 
Published: March 2021

Abstract
The protein profile of dormant Mtb obtained after the gradual acidification of Mtb culture was studied to find antigenic proteins for humans that are expressed by M. tuberculosis (Mtb) cells in vitro under conditions close to the situation of persistence in vivo. According to 2D electrophoresis, a significant diversity of proteins in dormant cells was found. However, the representation of individual proteins in dormant versus active cells differed substantially. Immunoblotting in different protein fractions of dormant cells revealed ten proteins that are able to bind antibodies in pooled sera of TB patients. Two proteins (Rv2018 and Rv0341) are new immunogenics that were not previously found in other studies. Four proteins (Rv0341, Rv2018, Rv1509, Rv2986) with the maximal structural specificity for Mtb due to their unique extended domains were selected for further analysis. These proteins were expressed in E. coli cells and studied via enzyme-linked immunosorbent assay (ELISA) for the immunogenicity of individual sera of TB patients and healthy donors. All proteins were found to have the ability to react with individual sera of TB patients. In TB patients, 5–45% (depending on the particulate protein) have a titer that is higher than the average titers of healthy donors +SD; the most immunogenic was protein Rv2986. Thus, the application of phenotypically changed (dormant) Mtb cells makes it possible to identify a specific repertoire of immunodominant proteins that could be used in the construction of polypeptides that are useful for the serodiagnosis of active/latent TB.
Dobutamine stress testing for the evaluation of atrial and diastolic ventricular function in Fontan patients
Authors: van der Ven Jelle P G , Bossers Sjoerd S M , van den Bosch Eva , Dam Niels , Kuipers Irene M , van Iperen Gabrielle G , Kroft Lucia J M , Kapusta Livia , ten Harkel Arend D J , Helbing Willem A 
Published: March 2021

ObjectiveTo assess the atrial and ventricular diastolic function response to dobutamine stress in Fontan patients, and to relate these measurements to exercise capacity and events during the follow-up.MethodsWe performed a secondary analysis of a cross-sectional multicentre study of Fontan patients with intra-atrial lateral tunnel (ILT) or extracardiac conduit (ECC) modification. Subjects underwent cardiac MRI during rest and low-dose dobutamine stress, and cardiopulmonary exercise testing. Atrial and diastolic ventricular function parameters were derived from volume-time curves.Medical records were abstracted for a composite end-point of death, listing for transplant, arrhythmia and reintervention. Spearman’s r correlation tests and Cox proportional hazards models were used to assess the relation between the dobutamine response for atrial and diastolic ventricular function and outcomes, including exercise capacity.ResultsWe included 57 patients (26 ECC; 31 ILT) aged 12.8 (IQR (10.3–15.5)) years. During dobutamine stress atrial cyclic volume change increased (3.0 (0.4–5.9) mL/m2, p<0.001), as did early (1.9 (−1.6 to 3.6) mL/m2, p=0.001) and late emptying volume (2.2 (0.2–4.4) mL/m2, p<0.001).Ventricular early filling decreased (−1.6 (−5.7 to 0.7) mL/m2,p=0.046) and ventricular late filling increased (1.0 (−0.4 to 3.4) mL/m2,p<0.001) while stroke volume remained similar.Only for patients with the ECC modification, atrial early emptying volume increase correlated with peak oxygen uptake (ρ=0.66,p=0.002). No other parameter related to exercise capacity.During a median 7.1-year follow-up, 22 patients reached the composite endpoint. No parameter predicted events during the follow-up.ConclusionsDobutamine stress augmented atrial reservoir and pump function for Fontan patients. Atrial early emptying reserve related to exercise capacity in ECC patients. No other atrial or diastolic ventricular function parameter related to outcomes.