bluuebunny/crossref_metadata_2025_split huggingface dataset:
Approximate Re-Analysis of Dynamic Systems
Authors: Cao Qiushi , Krishnaswami Prakash 
Published: March 2021

Abstract
Dynamic analysis of a mechanical system is extremely time consuming. It may be desirable for a designer to approximate the state variables at a new design if state and sensitivity information at previous designs are already available. In this paper, several approximate re-analysis schemes have been explored. These include Taylor’s series of first and second order, weighted sum of state variables and weighted sum of Taylor’s series. The results show that Taylor’s series of second order can predict state variables quite well if the perturbation in design is relatively small. Weighted sum approximation based on state variables can generally give acceptable results, while weighted Taylor’s series is generally unsatisfactory if the perturbation is large.
Solution of Load Distribution on the Contact Line of Helical Gears With EHL Theory
Authors: Tonghui Yu , Chenwen Chen , Liqin Wang 
Published: March 2021

Abstract
On the base of analysis of the effects of each term in Renolds equaiton on the lubrication state of helical gears, the three dimensional elastohydrodynamic lubrication (EHL) problem is discomposed into two dimensional problems to deal with. A special boundary condition for helical gear EHL problem is led in and applying multigrid method (MGM), numerical solutions for the helical gear EHL problem are accomplished along the contact line. Film shapes and pressure ditributions with typical EHL features are obtained at discreted points on the contact line. The procedure presented here to calculate the load distribution on the contact line can also be used to calculate the load shares among different contact lines.
Bilevel Models for Optimum Designs Which Are Insensitive to Perturbations in Variables and Parameters
Authors: Badhrinath Krishnakumar , Rao J. R. Jagannatha 
Published: March 2021

Abstract
Design models may be subject to a variety of perturbations or uncertainties, such as in variables, parameters and the constraint right-hand sides. In this paper, we study the specific cases of deterministic variations in the variables and the parameters. The goal is to obtain designs that not only reduce cost but which are also insensitive to such perturbations. We formulate bilevel models for this purpose and illustrate with examples the nature of insensitive designs, as well as the singularities that occur in such bilevel models.
Artificial Neural Network and the Taguchi Method Application for Robust Wheatstone Bridge Design
Authors: Hong Jung-eui , Dagli Cihan H. , Ragsdell Kenneth M. 
Published: March 2021

Abstract
The primary function of the Wheatstone bridge is to measure an unknown resistance. The elements of this well-known measurement circuit will take on different values depending upon the range and accuracy required for a particular application. The Taguchi approach to parameter design is used to select values for the measurement circuit elements so as to reduce measurement error. Next we introduce the use of an artificial neural network to extrapolate limited experimental results to predict system response over a wide range of applications. This approach can be employed for on-line quality control of the manufacture of such device.
Multicriterion Optimization: A Tool in Advanced Materials Technology
Authors: Wang Jianxiang , Thomsen Niels B. , Karihaloo Bhushan L. 
Published: March 2021

Abstract
This paper will demonstrate on two advanced materials — a fibre-reinforced composite laminate (FRC) and a transformation toughened ceramic (TTC) — the importance of multicriterion optimization in the production of useful advanced materials with enhanced mechanical properties. In a previous paper (Thomsen et al., 1994a), the authors have demonstrated the application of single-criterion optimization to these materials which are based on a brittle matrix and thus prone to cracking at very low applied stresses. The optimization process aims at altering their microstructure so that all their desirable mechanical properties are enhanced. Currently, the advanced materials technologists must take a heuristic approach to meeting the often competing requirements. The present paper will show how multicriterion optimization can come to the aid of the technologists and reduce their reliance on empirical approaches.
Power Converter Design With Coupled Thermal Analysis Using Multidisciplinary Design Optimization
Authors: Kott Gregory , Gabriele Gary A. , Korngold Jacob 
Published: March 2021

Abstract
This paper describes the application of multidisciplinary design optimization to the power stage design of a power converter. Multidisciplinary design is used to integrate the electrical, loss, and thermal analyses into one system problem. The Sequential Global Approximation method, a non-hierarchic algorithm, is used to optimize the power stage design problem. The code used for the thermal analysis, COSMOS/M, runs externally to the Sequential Global Approximation algorithm. A comparison of the results of the non-hierarchic formulation and the non-decomposed formulation shows a 67 percent decrease in total system iterations and a 12 percent decrease in total finite element analyses required.
Design System for Blow Moulded Products
Authors: Geilen Johannes , Fuchs Willi J. 
Published: March 2021

Abstract
In recent years the spectrum of applications for thermoplastics has experienced constant growth. They do not only exhibit good specific materials properties and lend themselves to costeffective processing, but it is also possible to manufacture products of great complexity. Numerous possibilities for structural configuration are thus presented, enabling product material and form to be adapted to specific requirements. Computer-aided simulation techniques are among the tools utilized in developing optimal components or products. This led to a design system which can accelerate the entire development process of a product or component. It starts from the idea and results in the production stage making use of multidisciplinary combination of C-technologies, structural analysis procedures, material data bases, production, inspection and testing.
The propagated concept is significantly furthered by the rapid development in the areas of hardware and software. A comparison of a traditional development process with the development process utilizing the design system illustrates the possibilities which exist to exploit simulation thechniques in every stage of product development in order to enhance quality and reduce costs.
Modeling of a Leg System to Illustrate the Feasibility of Energy Recovery in Walking Machines
Authors: Dhandapani Sivakumar , Ogot Madara M. 
Published: March 2021

Abstract
A key consideration in the design of walking machines is the minimization of energy consumption. Two main avenues of research have been pursued in the past (a) finding an optimal gait which reduces energy consumption or (b) the employment of energy storage devices to recover energy from one step to the next. This study follows the latter approach, which has hitherto concentrated on hopping machines. Several practical design considerations for energy recovery in multi-legged walking machines, where a stance phase prevents the immediate recovery of energy from one step to the next, are investigated. Two schemes, passive and active locking, are introduced. The simplified models presented serve to illustrate the feasibility of these schemes.
Isotropic Design of Spherical Parallel Manipulators
Authors: Mohammadi Daniali Hamid R. , Zsombor-Murray Paul J. , Angeles Jorge 
Published: March 2021

Abstract
Manipulator designs with isotropic architectures have a number of advantages, including good servo accuracy and low sensitivity to measuring and manufacturing errors. The isotropic design continua of two classes of spherical 3-dof parallel manipulators are found. These continua describe the complete set of isotropic design possibilities for the respective manipulator types.
Structural Analysis and Optimization of Pneumatic Components
Authors: Post Peter U. 
Published: March 2021

Abstract
Within the last few years engineering analysis and optimization methods became more and more reasonable in the development stage not only of specialised high-tech products but also of industrial standard components and systems. This trend is forced by establishing simultaneous engineering concepts in R&D-departments. Acceptance of these methods in industrial practice goes along with increasing power of solution procedures as well as reliability and ease-of-use of software implementations.
This paper shows practical applications on the development of pneumatic actuators and control-components. Optimal design of cylinder housings and profile shapes as well as structural analysis and optimization of rubber elements with their non-linear structural behaviour due to hyperelastic material law, contacting surfaces and friction are discussed.
Topological Characteristics and Automatic Generation of Structural Synthesis of Planar Mechanisms Based on the Ordered Single-Opened-Chains
Authors: Yang Ting-Li , Yao Fang-Hua 
Published: March 2021

Abstract
This paper presents a new viewpoint about structural composition of planar kinematic chains: single-opened-chains, which is composed of binary links, are regarded as basic structural units of mechanisms. The constraint characteristics (the constraint factors, Δj) of single opened chains and the constraint characteristics (the coupled degree κ and the κ-algorithm) of mechanical networks are presented. Thus a kinematic chain with v independent loops is regarded to be composed of one basic link and v single-opened-chains in regular sequence.
Based on the ordered single-opened-chains and the topological constraints characteristics of mechanisms, a powerful new method for structural synthesis of planar kinematic chains with plane and nonplane linear graphs has been developed. This permits the development of a highly efficient and completely automatic program for the computer-generated enumeration of structural types of mechanisms. The method is illustrated by applying to the case of kinematic chains with up to six independent loops on a personal computer.
The ordered single-opened-chains and the topological characteristics are used for setting up a new unified model for structics, kinematics and dynamics of planar mechanisms.
Kinematic Analysis of Skew Cardanic Motion and the Skew Swinging-Block Linkage
Authors: Freudenstein F. , Primrose E. J. F. , Chen Hong-Jen 
Published: March 2021

Abstract
The classical cardanic motion and the swinging-block linkage are basic planar mechanisms. In the following investigation, the objective is the analysis of their three-dimensional (and, hence, more versatile) counterparts: the skew slider-crank mechanism and the skew swinging-block linkage. These linkages as far as we are aware, have not yet been analyzed analytically. An analysis utilizing their algebraic geometry will be instructive in determining their displacements and derivatives in closed form. This, in turn, should be useful in facilitating three-dimensional applications.
With the ever-increasing sophistication in the area of mechanisms design and analysis, we believe that the time has come for the analysis of these linkages, including their algebraic geometry. This is the objective of this investigation.
On the Analysis and Synthesis of Type I Spatial 6R Overconstrained Mechanism
Authors: Lee Chung-Ching 
Published: March 2021

Abstract
Based on matrix algebra and its differentiation, we derive the general analytical kinematic solutions and simple stationary configurations of Type I spatial 6R overconstrained mechanism. This mechanism is a general form of Sarrus 6R mechanism. Its coupler point of a certain link has straight-line motion and this is used for the synthesis of straight-line mechanism by the optimization method. Moreover, a graphical synthesis technique with descriptive geometry is presented to design the linkage type of double-toggle mechanism for spatial clamping device. Two numerical examples are given for illustration and their results are verified by computer animation of motion.
Synthesis of Defect Free Six Bar Linkages for Body Guidance Through up to Six Finitely Separated Positions
Authors: Tylaska Timothy , Kazerounian Kazem 
Published: March 2021

Abstract
In the synthesis of watt I six bar linkage, for finitely separated design positions, or in higher order design, constraint equations become highly nonlinear and transcendental. This paper presents a method to decouple the synthesis problem to the synthesis of two path generator 4-bar linkages. Based on this decoupled system, an explicit design methodology is developed, enabling a three, four, five or six body guidance position Watt I linkage to be designed while the designer has choice of some body pivots and ground pivots. Numerical procedures for higher number of positions are also discussed. The methodology allows the designer to obtain an entire set of solutions to a particular design problem. As a spin off from this work, a methodology is also presented to obtain complete solution sets of four bar path generators capable of passing through up to seven precision points, with a procedure that can be eventually extended to eight and nine path points. Design considerations such as branching and transmission angles are also considered.
A Force Transmission Index for Planar Linkage Mechanisms
Authors: Holte Jennifer E. , Chase Thomas R. 
Published: March 2021

Abstract
A new transmission index based on a static force analysis, the joint-force index, is presented. The joint-force index is an improved transmission index for mechanisms which support external loads. No other transmission index in the literature predicts the effect of specific external loads on the force transmission, even though mechanisms that are subjected to external loads are very common. The joint-force index provides a meaningful transmission guideline regardless of the complexity of the mechanism. Planar four-bar linkages as well as complex planar linkages of six or more links may be evaluated using the joint-force index.
Velocity and Acceleration Analysis of Contact Between Three-Dimensional Rigid Bodies
Authors: Sarkar Nilanjan , Kumar Vijay , Yun Xiaoping 
Published: March 2021

Abstract
During manipulation and locomotion tasks encountered in robotics, it is often necessary to control the relative motion between two contacting rigid bodies. In this paper we obtain the equations relating the motion of the contact points on the pair of contacting bodies to the rigid body motions of the two bodies. The equations are developed up to the second order. The velocity and acceleration constraints for contact, for rolling, and for pure rolling are derived. These equations depend on the local surface properties of each contacting body. Several examples are presented to illustrate the nature of the equations.
A More Direct Method for Structural Synthesis of Simple-Jointed Planar Kinematic Chains
Authors: Dharanipragada Varada Raju , Yenugadhati Nagaraja Kumar , Rao A. C. 
Published: March 2021

Abstract
Structural synthesis of kinematic chains leans heavily on indirect methods, most of them based on Graph Theory, mainly because reliable isomorphism tests are not available. Recently however, the first and third authors have established the Secondary Hamming String of a kinematic chain as an excellent indicator of its isomorphism. In the present paper this Hamming String method was applied with slight modifications for synthesizing on a PC-386, distinct kinematic chains with given number of links and family description. The computer program, written in Pascal, generated both the six-bar and all 16 eight-bar chains as well as one sample family (2008) of ten-bar chains, verifying previously established results. Hence this paper presents a direct, quick and reliable method to synthesize planar simple-jointed chains, open or closed, with single- or multi-degree of freedom, containing any number of links. A spin-off of this paper is a simple, concise and unambiguous notation for representing a chain.
Dynamic Model of a Spur Gear System With Backlash and Friction Consideration
Authors: Shing T. K. , Tsai Lung-Wen , Krishnaprasad P. S. 
Published: March 2021

Abstract
A new model which accounts for both backlash and friction effects is proposed for the dynamics of a spur gear system. The model estimates average friction torque and uses it to replace the instantaneous friction torque to simplify the dynamical equations of motion. Two simulations, free oscillation and constant load operation, are performed to illustrate the effects of backlash and friction on gear dynamics. The results are compared with that of a previously established model which does not account for the friction. Finally, the effect of adding a damper on the driving shaft is also studied. This model is judged to be more realistic for real time control of electronmechanical systems to reduce gear noise and to achieve high precision.
Gerotor Configurations With Non-Uniform Cross Sections
Authors: Adams Glynn P. , Beard John E. 
Published: March 2021

Abstract
This study investigates the displacement, compression ratio and surface area to volume ratio of epitrochoidal gerotor mechanisms created with non-uniform cross sectional areas perpendicular to the rotor axis of rotation, skew gerotors. An algorithm is presented for modelling the gerotor mechanisms using a quadratic surface as the generating pin. The method used to model the skew gerotors consists of rotating the axis of the generating pin such that it is skewed relative to the rotor axis of rotation. The resulting effects on the displacement, compression ratio and surface area to volume ratio are presented for various configurations.
Design and Evaluation of Flexible Gas Fired Forging System
Authors: Clark R. K. , Avasarala Pantulu V. , Soni Athamaram H. 
Published: March 2021

Abstract
The advances in the furnace and high speed press technologies for forging applications necessitate the installation of automated material handling systems. In order to study the effect of integrating all these three new technologies, a simulation model of a flexible forging system (FFS) concept is developed. In this work a design procedure of the FFS is developed. A FFS is designed and evaluated. A simulation model of the FFS is developed on a computer using AutoMod simulation software. The developed model is simulated for various scenarios and the results are presented in this paper.
Identification of Dynamics Bodies From Part Mating Conditions
Authors: Fung-Ho Victor , Wu J. K. 
Published: March 2021

Abstract
A method to automatically identify bodies for Dynamics Analysis based on a given set of arbitrary parts and their mating conditions has been developed. The use of this method is considered within the context of Concurrent Engineering design of mechanical systems, where an entity translator from a shared global database to a Dynamics database is intended to automatically identify the bodies for rapid Dynamics model setup and simulation. A simplified formulation of the mating conditions that reduces the number of equations needed with respect to previous research is presented. The importance of detecting the equations associated with redundant constraints, in order to obtain the set of bodies, is presented. The method has been demonstrated by using some examples.
An Authorization Mechanism for a Document Database
Authors: Peltonen Hannu , Alho Kari , Männistö Tomi , Sulonen Reijo 
Published: March 2021

Abstract
A programmable authorization mechanism for an engineering document database is described. The database stores documents and their versions in a commercial relational database. Documents and other objects contain user-defined attributes. Release and approval procedures of the documents are described by means of state graphs that specify the possible states of a document and the transitions between them. The system consists of centralized server and client programs, which communicate with the server using a specific protocol.
The database administrator must be able to formulate rules that tell who is allowed to do particular database operations; rules that tell which operations are allowed in particular document states; and rules that describe consistency invariants between attributes.
These rules are expressed by means of authorization procedures written in a special language. Whenever the server receives an operation request, it executes the corresponding authorization procedure. The system can thus be easily adapted to an organization without actually modifying the client or server programs.
Using Critical Incident Technique to Investigate Anxiety in Physical Activity Settings
Authors: Dasinger Timothy M. , Solmon Melinda A. 
Published: March 2021

Physical activity participation is linked with many benefits including a reduction in anxiety; it is, however, also important to explore aspects of activity that incite anxiety. One way to investigate sources of anxiety in physical activity is to use the critical incident technique (CIT). The purpose of this study was to explore anxiety-inducing events in physical activity settings and to evaluate the impact on future behavior. A total of 122 participants (M = 21.23 ± 1.77 years) completed an online survey asking when a physical activity setting incited anxiety using the CIT. Four common sources of anxiety were evident in the responses: fragile self-beliefs, social interaction and the threat of negative social evaluation, competition, and a lack of knowledge or unfamiliarity with surroundings. Tenets from achievement goal theory can help to explain the incitement of anxiety and can help shape physical activity settings to be more inclusive and welcoming for all.
Optimization of (S)-3-Hydroxybutyric Acid Biosynthesis from Glucose through the Reversed Fatty Acid β-Oxidation Pathway by Recombinant Escherichia coli Strains
Authors: Gulevich A. Yu. , Skorokhodova A. Yu. , Debabov V. G. 
Published: March 2021

Abstract
The microaerobic synthesis of 3-hydroxybutyric acid by the Escherichia coli strain BOX3.1 ∆4 PL-atoB PL-tesB (MG1655 lacIQ, ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆fadE, PL-SDphi10-atoB, Ptrc-ideal-4-SDphi10-fadB, PL-SDphi10-tesB), which was previously directly engineered for the biosynthesis of the target compound from glucose through the reversed fatty acid β-oxidation pathway, was studied. A target product yield of 0.12 mol/mol was achieved. Inactivation of the nonspecific YciA thioesterase gene in the strain led to an increase in the yield of 3-hydroxybutyric acid to 0.15 mol/mol. For the optimization of biosynthesis of target product the strain MG∆4 PL-tesB (MG1655 ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, PL-SDphi10-tesB) was engineered, and the genes encoding key enzymes of fatty acid β-oxidation were overexpressed in the strain from the plasmid pMW118m-atoB-fadB. The level of microaerobic synthesis of 3-hydroxybutyric acid by the strain MG∆4 PL-tesB (pMW118m-atoB-fadB) achieved in primary evaluation conditions reached 0.35 mol/mol. Inactivation in the strain of the gene of nonspecific thioesterase YciA led to only minor decrease in acetate byproduction. Further inactivation in the strain of gene encoding nonspecific thioesterase YdiI had virtually no effect on the level of synthesis of side products. Cultivation of the constructed strain MG∆4 PL-tesB ∆yciA (pMW118m-atoB-fadB) in bioreactor under the controlled conditions ensured achievement of a yield of 3‑hydroxybutyric acid amounting to 0.75 mol/mol.