bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Condition Number of a FRF Matrix in Mechanical Parameter Identification
Authors: Wang Jhy-Horng , Liou Chen-Sung 
Published: March 2021

Abstract
A new identification algorithm is proposed in this work to identify the parameters of mechanical joints. The method considers the whole structure as two substructures which are connected by the joints to be identified. The frequency response functions of the whole structure and substructures are used to extract the joint parameters. In contrast to the traditional methods, only a FRF matrix is needed to inverse in the proposed method. Therefore, it is possible to calculate the condition number of the FRF matrix before the identification. The condition number is defined as the ratio of the maximum singular value divided by the minimum one of a matrix. The condition number of noise contaminated FRF matrix can be used to indicate the sensitivity of the FRF matrix to measurement noise. Therefore, the condition number can be used to avoid the ill-conditioned problem by eliminating the ill-conditioned FRF in some frequency ranges before identification. The simulated results show that the proposed method can significantly improve the accuracy of identification.
Prediction of the Frequency and Time Responses of Composite Structures: Application to Skis
Authors: Ulrich C. , Ferraris G. , Lalanne M. , Lacroix J. 
Published: March 2021

Abstract
The prediction of the dynamic behavior of composite structures composed of several viscoelastic materials is investigated. The material characteristics are a function of frequency and temperature which here will be kept constant and some material may be orthotropic. The method proposed is an extension of the pseudo-modal method presented previously Improvements have been obtained in the prediction of the natural frequencies and of the damping factors. Time response has also been developed. The pseudo-modal method uses a very low number of modes and thus allows a drastic reduction of the degrees of freedom, from several thousands to tens. The equations obtained are very efficient in predicting the frequency response and the time response.
The applications presented concern measurements and predictions using a finite element computer program. The initial test was based on a relatively simple example: a layered damped beam. Then an alpine ski was studied. Prediction and measurement correspond well.
Concurrent Optimization of Product Design and Manufacturing Coping With Demand Variability
Authors: Yoshimura Masataka , Takeuchi Atsushi 
Published: March 2021

Abstract
A user-oriented product design methodology for integrating design, manufacturing and marketing is proposed and the practical design optimization procedures are constructed and presented. First, market demand analyses are conducted by dividing users into groups based on similarities of users’ needs. The product satisfaction level of each group is formulated using the users’ satisfaction levels for product attributes. Next, in order to obtain optimum design solutions effectively in the integrated decision making processes of design, manufacturing and marketing (which include an enormous number of decision variables), multiphase procedures of design optimization are constructed according to simplicity levels of shape modelings with structural characteristics and manufacturing costs which can be evaluated. Then, practical design decision making procedures from the extraction of design alternatives through the determination of detailed decision variables are described corresponding to multiphase modeling starting with simplified models and advancing to detailed models. Here, the objective function of decision making is to maximize the satisfaction level of product user. Finally, the proposed integrated design optimization method is applied to industrial robots for demonstrating the effectiveness of the method.
An Area Preserving Transformation Algorithm for Press Forming Blank Development
Authors: Nair Nirmal K. , Oliver James H. 
Published: March 2021

Abstract
An efficient algorithm is presented to determine the blank shape necessary to manufacture a surface by press forming. The technique is independent of material properties and instead uses surface geometry and an area conservation constraint to generate a geometrically feasible blank shape. The algorithm is formulated as an approximate geometric interpretation of the reversal of the forming process. The primary applications for this technique are in preliminary surface design, assessment of manufacturability, and location of binder wrap. Since the algorithm exhibits linear time complexity, it is amenable to implementation as an interactive design aid. The algorithm is applied to two example surfaces and the results are discussed.
Simultaneous Kinematic and Dynamic Synthesis in the Preliminary Design of a Linkage
Authors: Krishnamachari Ramprasad , Vadde Srinivas , Allen Janet K. , Mistree Farrokh 
Published: March 2021

Abstract
In the early stages of project initiation, all aspects of system design may not be clearly defined. Some information might be uncertain (imprecise or vague). However, important design decisions need to be made in these stages in the presence of uncertainty. Fuzzy sets offer a useful method to represent the imprecision in such situations. Fuzzy compromise Decision Support Problems (DSPs) involving fuzzy membership functions are found to be effective in modeling this uncertainty and making decisions in such situations. A hat-shaped, piecewise linear membership function is introduced which is especially useful when the design space is not well understood. The use of a fuzzy compromise Decision Support Problem in the preliminary design synthesis of mechanical systems is illustrated using a case study involving the synthesis of a four-bar linkage.
An Efficient Technique for Computing the Sensitivities of Reciprocating Engine Dynamics to Dimensional Tolerances
Authors: Sinha A. , Gilmore B. J. , Kohli V. 
Published: March 2021

Abstract
An efficient method has been developed to determine the steady state response of an internal combustion engine, which is governed by a nonlinear differential equation with discontinuous forcing function due to the nature of the pressure-volume (P-V) diagram. Unlike previously reported methods for dynamically driven mechanical systems, this approach can accurately and efficiently predict the sensitivities of an engine’s output to dimensional tolerances. Hence, this technique is well suited for the development of an optimal tolerance allocation scheme based on nonlinear programming. The validity of this method which is based on the alternating frequency/time (AFT) domain technique has been established by comparison with results from numerical integration of differential equation of motion. This method directly yields the mean crank speed and Fourier coefficients of temporal variations in engine’s outputs such as crank’s speed and the driving torque.
XBB: A Blackboard System for Vehicle Suspension Tuning
Authors: Wang Nanxin , Fagan Daniel J. , Staley Scott M. 
Published: March 2021

Abstract
A design problem-solving system which uses Blackboard technology to couple previously independent application software packages into a common control and database structure is described. One application that has been investigated is the suspension tuning process. The process of suspension tuning is currently manpower intensive and involves trade-offs between desirable handling characteristics, noise, vibration and harshness (NVH) and packaging constraints. This paper reviews general blackboard concepts and presents an application of blackboard systems to the suspension tuning process. An application is described which couples the generic blackboard architecture with the symbolic dynamics package to help the engineer specify performance measures and constraints, and control the overall analysis process.
Using Engineering Models to Control Variability: Feasibility Robustness for Worst-Case Tolerances
Authors: Emch Gary , Parkinson Alan 
Published: March 2021

Abstract
Engineering models can and should be used to understand the effects of variability on a design. When variability is ignored, brittle designs can result that fail in service. By contrast, robust designs function properly even when subjected to off-nominal conditions. There is a need for better analytical tools to help engineers develop robust designs.
In this paper we present a general method for developing designs that are robust to variability induced by worst-case tolerances. The method adapts nonlinear programming techniques in order to determine how a design should be modified to account for variability. We show how this can be done with second order, or even exact, worst-case tolerance models. Results are given for 13 test cases that span a variety of problems. The method enables a designer to understand and account for the effects of worst-case tolerances, making it possible to build robustness into an engineering design.
Five-Axis Constrained and Optimal Orientation Planning
Authors: Haghpassand Khorssand 
Published: March 2021

Abstract
The five-axis constrained and optimal orientation planning is formulated as a design optimization problem that incorporates the process machine’s kinematic constraints with the workpiece and tool geometry, to obtain a constrained setup orientation which exploits the maximum capabilities of existing machines. This work will introduce this problem, and will obtain the setup orientation for two different types of rotation structures, i.e., tool rotation and table rotation in O(N) time. Further, the obtained constrained setup orientation, will be augmented to incorporate the workpiece surface magnitude, along with different machine rotation structures, to obtain an optimal setup orientation for different machine rotation structures. The drilling process is also introduced and formulated as additional constraints to the optimization problem.
The primary application of the introduced algorithms, is the machining process, where, they can efficiently reduce the number of tool motions and surface finishing processes. However, the solution is very suitable for many manufacturing applications, such as inspection, assembly, robotics, painting, welding, aerospace, electronic surface mount technology, and etc.
Hybrid Approach for Optimal Nesting Using a Genetic Algorithm and a Local Minimization Algorithm
Authors: Fujita Kikuo , Akagi Shinsuke , Hirokawa Noriyasu 
Published: March 2021

Abstract
In layout design problems including blank nesting, the positions and directions of layout elements must be determined so as to minimize the total space. It is difficult and computationally time-consuming to find the optimal solution for such layout problems, because they include a lot of underlying combinational conditions. In this paper, we present an approach for optimal nesting by combining a genetic algorithm and a local minimization algorithm. In the approach, the genetic algorithm is used for handling the combinations which are represented in the string, and the local minimization algorithm is used for determining the embodiment layout under the fixed combinations so as to minimize the scrap volume which is corresponding to the fitness value in the genetic algorithm. And we present an example for showing the effective nesting result produced by this approach.
Computer Aided Product Structure Modeling Using a DBMS
Authors: Johannesson H. L. 
Published: March 2021

Abstract
In the present paper a computer based method for top-down structure modeling of products is presented. A general hierarchical DBMS-based tree structure model is used. It is designed so that it can be connected to separately designed part product models, containing geometric models and references to standard component data bases and manufacturing documents. Together the presented product structure model and the part product models become a complete product model containing structural as well as geometric information.
The structure modeling is meant to be carried out as a first step during the embodiment design phase, before the parts are designed and the standard components are selected. Thus the geometric information is incomplete during the structure modeling phase.
A computer program for product structure modeling has been developed. It allows the number of hierarchical structure levels, as well as the number of objects on each level, to be chosen arbitrarily by the user. The data base management system TORNADO is used by the modeling program for building the structure model data bases. A structure modeling example is given in order to demonstrate the structure modeling procedure and the capabilities of the program.
Profile Determination and Analysis of Cylindrical Cams With Oscillating Roller-Followers
Authors: Tsay Der Min , Wei Hsien Min 
Published: March 2021

Abstract
A simple, integrated procedure for the profile determination and kinematic analysis of cylindrical cams with oscillating conical roller-followers is presented. Based on the theory of envelopes for a one-parameter family of surfaces, the new method can be easily utilized to determine cylindrical cam profiles once the appropriate follower motion curves are given. In addition, the kinematic characteristics such as the contact lines between the cam and the roller surfaces, the pressure angles, and the principal curvatures of the cam surface are analyzed in the design process. To illustrate the accuracy and effectiveness of the proposed design tool, the analytical expressions derived in this study are compared to those obtained by using the principle of contact point. Numerical examples are also given to show the application of this integrated approach.
NURBS Surface Reconstruction From a Large Set of Image and World Data Points
Authors: Theodoracatos Vassilios E. , Bobba Vasudeva 
Published: March 2021

Abstract
In this paper an approach is presented for the generation of a NURBS (Non-Uniform Rational B-splines) surface from a large set of 3D data points. The main advantage of NURBS surface representation is the ability to analytically describe both, precise quadratic primitives and free-form curves and surfaces. An existing three dimensional laser-based vision system is used to obtain the spatial point coordinates of an object surface with respect to a global coordinate system. The least-squares approximation technique is applied in both the image and world space of the digitized physical object to calculate the homogeneous vector and the control net of the NURBS surface. A new non-uniform knot vectorization process is developed based on five data parametrization techniques including four existing techniques, viz., uniform, chord length, centripetal, and affine invariant angle and a new technique based on surface area developed in this study. Least-squares error distribution and surface interrogation are used to evaluate the quality of surface fairness for a minimum number of NURBS control points.
Computations of Dual Numbers in the Extended Finite Dual Plane
Authors: Cheng Harry H. 
Published: March 2021

Abstract
The numerical computational aspects of dual numbers in the CH programming language are presented in this paper. Dual is a built-in data type in CH. Dual numbers and dual metanumbers are described in the extended dual plane and extended finite dual plane. The arithmetic and relational operations, and built-in mathematical functions are defined for both dual numbers and dual metanumbers of DualZero, DualInf, and DualNaN. Due to polymorphism, the syntax of dual arithmetic and relational operations, and built-in dual functions are the same as those for real and complex numbers in the CH programming language. The linguistic features and handling of user’s dual functions and dual arrays, as well as applications of dual numbers in robotics and spatial mechanisms in the CH programming language can be found in (Cheng, 1993c).
A Geometrical Solution for the Inverse Kinematics of Three Revolute Manipulators
Authors: Fichter Eugene F. 
Published: March 2021

Abstract
Points of intersection of a circle and a torus are used to find a solution to the inverse kinematics problem for a three revolute manipulator. Both geometrical and algebraic solution procedures are discussed. The algebraic procedure begins with a third order equation instead of the usual fourth order equation. Since the procedure is basically geometrical it lends itself to a computer implementation which graphically displays each steps in the solution procedure. The potential of this approach for both design and pedagogy is discussed.
Optimal Tolerance Allocation for Tolerance Stack-Ups
Authors: Dresner Thomas L. , Barkan Philip 
Published: March 2021

Abstract
The allocation of individual tolerances that form critical stack-ups is an important task in mechanical design. It is desirable, but difficult in practice, to allocate tolerances to obtain all required stack-ups at minimum cost. A minimum-cost allocation method is proposed here that works for both a single tolerance stack-up and for multiple tolerance stack-ups that share one or more individual tolerances. Tolerances can be optimally allocated for both worst case and a variety of 6σ statistical cases. The method is applicable to one-dimensional stack-ups and to multi-dimensional stack-ups with known sensitivity functions. It is a numerical Lagrange multiplier method that is more general than the Lagrange multiplier methods that have often been proposed. The basic method will almost always provide the lowest cost result when the manufacturing process to produce each toleranced dimension has been firmly established in advance. An exact method for efficiently extending the basic method to determine the lowest cost process for producing each dimension is also introduced.
Approximating Eigenvalues and Eigenvectors Using Padé Approximants
Authors: Vance Judy M. , Bernard James E. 
Published: March 2021

Abstract
Design optimization of finite element-based structures can be very compute intensive thus inhibiting interactive design. The research presented here outlines a fast method for approximating eigenvalues and eigenvectors across a wide range of design changes. An optimization scheme is described that combines Padé Approximants with curve-fitting techniques to achieve good approximations for large design changes.
On the Semantics of Generative Geometry Representations
Authors: Hoffmann Christoph M. 
Published: March 2021

Abstract
We argue that geometry constructs and solid operations currently emerging in commercial, feature-based CAD systems are without an appropriate semantic foundation, and that a rigorous semantics poses significant research problems. In particular, we argue that a formalization of feature attachment and other generative constructs in the presence of geometric constraints cannot be based solely on conventional boundary representation or on current geometry standards.
A Weighted Algorithm for Sculptured Surface Design
Authors: Wang Qifu , Gao Shande , Zhou Ji , Yu Jun 
Published: March 2021

Abstract
A new algorithm for constructing sculptured surfaces is presented in this paper. The basic idea of the algorithm is to control the shape of a surface by changing the weight values of the drive curves and the generator curves. With this algorithm, the shape of the surface can be designed conveniently. So far this algorithm has been practically used in a modeling system developed by the author, and proven to be flexible and efficient.
Data Probe: A Tool for EXPRESS-Based Data
Authors: Morris K. C. 
Published: March 2021

Abstract
The problem of sharing data has many facets. The need to share data across multiple enterprises, different hardware platforms, different data storage paradigms and systems, and a variety of network architectures is growing. The emerging Standard for The Exchange of Product Model Data (STEP), being developed in the International Organization for Standardization (ISO), addresses this need by providing information models, called application protocols, which clearly and unambiguously describe data. The validity of these information models is essential for success in sharing data in a highly automated engineering environment.
This paper describes the Data Probe: a tool for examining, editing, and managing EXPRESS-based data. The Data Probe tool supports the validation of STEP application protocols. The paper includes a description of the software architecture, the initial implementation, and plans for future enhancements. The software is designed as independent components which can be incorporated into other STEP-related systems or software requiring general purpose editing tools for structured information.
The initial version of the Data Probe tool is based on two implementation mechanisms defined within STEP: the conceptual modeling language EXPRESS and the STEP exchange file format. Future work will focus on integrating a database system into the software. The software architecture and the use of object-oriented techniques enables code reusability and system extensibility and has been instrumental for a phased implementation.
The software is under development at the National Institute of Standards and Technology and is in the public-domain. The software supports the Validation Testing System, part of the Application Protocol Development Environment, at the CALS-sponsored National PDES Testbed. (PDES, Product Data Exchange using STEP, is the U.S. effort in support of the international standard.)
The Effects of Combined Balance and Complex Training Versus Complex Training Only on Measures of Physical Fitness in Young Female Handball Players
Authors: Chaabene Helmi , Negra Yassine , Sammoud Senda , Moran Jason , Ramirez-Campillo Rodrigo , Granacher Urs , Prieske Olaf 
Published: March 2021

Purpose: To examine the effects of balance exercises conducted prior to complex training (bCT) versus complex training (CT) only on measures of physical fitness in young female elite handball players. Methods: Participants aged 17 years were randomly assigned to bCT (n = 11) or CT (n = 12). The 2 training interventions lasted 8 weeks with 2 sessions per week in replacement of some technical/tactical handball exercises and were matched for total training volume. Before and after training, tests were performed for the evaluation of proxies of muscle power (countermovement jump height, standing long-jump distance, and reactive strength index), muscle strength (back half-squat 1-repetition maximum), dynamic balance (Y-balance test), linear sprint speed (20-m sprint test), and change-of-direction speed (T test). Results: Two-factor repeated-measures analysis of variance revealed significant group × time interactions for the reactive strength index (d = 0.99, P = .03) and Y-balance test score (d = 1.32, P < .01). Post hoc analysis indicated significant pre–post reactive strength index improvements in CT (d = 0.69, P = .04) only. For the Y-balance test, significant pre–post increases were found in bCT (d = 0.71, P = .04) with no significant changes in CT (d = 0.61, P = .07). In addition, significant main effects of time were observed for half-squat 1-repetition maximum, countermovement jump, standing long jump, and T test performance (d = 1.50 to 3.10, P < .05). Conclusions: Both bCT and CT interventions were effective in improving specific measures of physical fitness in young elite female handball players. If the training goal is to improve balance in addition, balance exercises can be conducted within a CT training session and prior to CT exercises.