bluuebunny/crossref_metadata_2025_split huggingface dataset:
Octree-Based Automatic Mesh Generation for Non-Manifold Domains
Authors: Saxena M. , Finnigan P. M. , Graichen C. M. , Hathaway A. F. , Parthasarathy V. N. 
Published: April 2021

Abstract
Automatic mesh generation from solid models heretofore has been confined to manifold objects only. While manifold objects are the most commonly encountered domains in many applications, other applications such as those requiring multiple material models and mixed-model representations (combination of 1-D, 2-D and 3-D domains), fall beyond the realm of the existing automatic meshing procedures as they require a non-conventional modeling environment, namely the non-manifold topology (NMT) based environment. This paper focuses on automatic mesh generation issues in the context of two such applications: (i) finite element modeling for multiple material models and (ii) geometric abstractions requiring a mixed-model representation. Specifically, the paper describes a geometry utility system, built around a NMT data structure and geometry-based meshing algorithms that ensure the validity of the mesh for non-manifold domains.
Extra Drag Force on a Circular Cylinder Due to the Presence of Solid Particles in Subsonic Compressible Flow
Authors: Mellsen Stanley B. 
Published: April 2021

Abstract
The effect of particles, such as dust in air on aerodynamic drag of circular cylinders was calculated for compressible flow at critical Mach number and for incompressible flow. The effect of compressibility was found negligible for particles larger than about 10 μm, for which the air can be considered a continuum. Drag coefficient and collection efficiency are provided for a wide range of inertia parameters and Reynolds numbers for both compressible and incompressible flow.
Prediction of Jets and Flames in Co-Flowing Streams
Authors: Ha S. , Lilley David G. 
Published: April 2021

Abstract
The theoretical computation of jets and flames in co-flowing streams is of considerable interest in aerothermochemistry. Axisymmetric flowfields are considered with time-mean velocity, temperature and species concentrations (three components — fuel, oxygen, and products) being predicted via a version of the GENMIX computer code. It is equipped with the standard Prandtl mixing length model of turbulence and an Arrhenius-type reaction rate expression for kinetically-influenced turbulent flame simulation. The code solves the boundary layer equations using a fully-implicit forward-marching solution procedure.
A variety of production runs have been made to show parameter effects, and results are tabulated, graphed and discussed. Complexities include:
1. The jet and surroundings may have different densities.
2. The surroundings may be co-flowing with nonzero axial velocity.
3. Flame ignition is via an outer annular hot zone.
4. Flames with typical hydrocarbon fuels burning in air are considered, and dissociation effects are included in a simple manner.
Results confirm the previous experimental findings about jet development in co-flowing streams, and extend knowledge to more practical and burning situations.
Simulation Model for Helical Rotor Expanders
Authors: Simmons Larry D. 
Published: April 2021

Abstract
The objective of this project was to develop a computer model for the helical rotor expander which can be used to determine performance potential and to facilitate optimization of expander design. Testing has shown that this energy conversion device has substantial potential advantages over conventional turbines in very high temperature cycles and for two-phase flow. However, the tests have been limited to particular non-optimized designs, and a model is badly needed to assess viable design improvements and their effects on performance. A computer model was developed to simulate the geometric and thermal/fluid characteristics of the expander to give power output, mass flow rate, and efficiency versus rotational speed for any chosen design configuration. The model has been tested against experimental data from expanders running on nitrogen gas and two-phase steam with good agreement. It is now ready and available for use in developing and evaluating designs for new applications of the helical rotor expander.
Evaluation of Thermal Radiation Simulator Rectangular Pulse Characterization Methods
Authors: Loucks Richard B. 
Published: April 2021

Abstract
The thermal output of an aluminum powder/liquid oxygen Thermal Radiation Simulator (TRS) is approximated to that of a rectangular pulse. The output varies as a function of time. The rise and fall times are not relatively abrupt. The problem is how to quantify the thermal output of the TRS into terms of a rectangular pulse.
Within the nuclear weapons effects community, flux, or the transient intensity of thermal radiation energy onto a surface, and fluence, the total energy irradiated onto a surface over a given time, are the determining parameters for specifying or evaluating an article’s survivability in the thermal environment. Four methods are used to determine the TRS output for these two parameters, assuming the output to be a perfect rectangular pulse. It was essential to determine which of the four methods best quantified the thermal output average flux and fluence. The four methods were compared by a computational experiment run on a personal computer.
The experiment was a simulation of five actual TRS traces irradiated onto a fictitious aluminum plate. The temperature profile of the front surface was computed using a finite difference method calculation. The traces were evaluated using the four characterization methods, generating twenty ideal thermal pulses. The temperature profile of the plate was computed using the twenty ideal thermal pulses. The resulting profiles were compared to profiles generated by the actual data to determine which of the characterization methods best evaluated the TRS output.
Finite Element Method of Flexible Multibody Dynamics Based on a New Kind of Floating Frame
Authors: Lu You-Fang , Qi Zhao-Hui , Wang Bin , Feng Guan-Min 
Published: April 2021

Abstract
A new kind of floating frame whose parameters do not appear in equations of motion as additional unknowns is defined. Numerical analysis of flexible multibody dynamics is much facilitated by using finite-element iteration of the corresponding equations based on this concept.
Automatic Mesh Generation on Annular Profiles With Geometric Constraints
Authors: Sharma M. , Rodriguez J. , Langrana N. 
Published: April 2021

Abstract
The Finite Element Method (FEM) has been recognized as one of the most effective analysis method for complicated domains. Unfortunately, any practical application of FEM requires extensive amount of input data. General pre-processors usually require a large amount of user defined information. Therefore, in some particular applications, where more specific options are needed, a special mesh generator in required. In this paper we present an automatic mesh generator for annular models with inherent geometric constraints, such as fiber orientation in composite-like structures/systems. The developed generator is designed to generate 3-D meshes with minimal users’ input and effort, and it can be used in conjunction with almost any CAD system or FEM software. The code is particularly useful for efficient performance of numerical studies relating mesh density and convergence.
Innovative Approaches for Teaching Descriptive Geometry With CADD
Authors: Cherng John G. 
Published: April 2021

Abstract
This paper presents the innovative approaches that can be implemented in teaching descriptive geometry by using a Computer-Aided-Design-Drafting (CADD) software. Examples of line relations, line/surface relations, and plane/cylindrical solid intersections are given in the paper. The paper first discusses the principles of descriptive geometry, and then focuses on how these principles can be applied in a CADD environment. In addition, new methods that take advantage of CADD are also provided. The paper emphasizes creativity while solving descriptive problems by using a CADD software. Although all examples illustrated in CADKEY, the concepts revealed in this paper can be applied to other 3-D CADD software, such as AutoCAD 10 and will significantly improve the engineering student’s CADD skills.
Computerized Data Acquisition, Reduction and Analysis of a Solar Water Heating System
Authors: Dini Said , Davison Wellen G. , Vaccaro John 
Published: April 2021

Abstract
A computerized data acquisition system for the solar hot water heating system located in the School of Engineering at Western New England College was designed and implemented. The system consists of three flat plate collectors located on the roof of the building facing south and inclinded at an angle of 40° with the horizontal, a heat exchanger, a storage tank, and an AST computer for data reduction, storage and analysis. The data collection and processing of this system was automated by interfacing a DAS-8 board located in the AST computer and a Metrabyte Exp-16 multiplexer amplifier board with 12 thermocouples and a pyranometer. The data acquisition program was written using GWBASIC along with DAS-8 commands. A program was also written to run the boards and do performance calculations. The program provides the solar radiation data, temperature distribution into the flat plate collector, temperatures in and out of the collector, useful energy gain and the efficiency of the collectors.
Declarative Rule Based Programming for Solving Problems in Kinematics and Dynamics of Machines
Authors: Haque Imtiaz , Huey Cecil O. 
Published: April 2021

Abstract
The required, senior course in kinematics and dynamics of mechanisms at Clemson University is currently being taught using a declarative rule based program as a computational tool for all analytical tasks. This is because of the necessity of numerical techniques for the solution of mechanism problems and the difficulty and inefficiency of programming in Fortran or similar languages. Also, it is felt that introductory course work in any subject should not be tied to specific purpose applications software. The course has been successful in developing sound competency in analysis and design of mechanisms while relying only on a widely available, general purpose computational tool. The overall approach used in the course is described and examples of the work assigned to students are provided.
An Automatic Speech Recognition System for Bedside Data Entry in an Intensive Care Unit
Authors: Petroni M. , Collet C. , Fumai N. , Roger K. , Yien C. , Lam A. , Malowany A. S. , Carnevale F. A. , Gottesman R. D. 
Published: April 2021

Abstract
An automatic speech recognition system is being developed for a patient data management system (PDMS) for the pediatric intensive care unit (ICU) at the Montreal Children’s Hospital. Here, fourteen bedside monitors are linked by a local area network to a personal computer for real-time acquisition of vital sign data and the graphical display of trends. The PDMS also allows for the manual input of data, such as fluid balance data, by means of a keyboard and a pointing device. This paper presents a description of the multimodal human-computer interface of the bedside data entry system, focusing on the speech recognition and generation sub-systems and their integration in the OS/2 Presentation Manager environment.
Shape Interrogation by Medial Axis Transform
Authors: Patrikalakis N. M. , Gursoy H. N. 
Published: April 2021

Abstract
In this paper we develop a new interrogation method based on the medial axis transform to extract some important global shape characteristics from geometric representations. These shape characteristics include constrictions, maximum thickness points, and associated length scales; isolation of holes and their proximity information; and a set of topologically simple subdomains decomposing a complex domain. The algorithm we develop to compute the medial axis transform of planar multiply connected shapes with curved boundaries can automatically identify these characteristics. Higher level algorithms for generation of finite element meshes of planar multiply connected domains, adaptive triangulation and approximation of trimmed curved surface patches and other engineering applications using the medial axis transform are also discussed.
Probabilistic Optimal Design Using Successive Surrogate Probability Density Functions
Authors: Eggert R. J. , Mayne R. W. 
Published: April 2021

Abstract
Probabilistic optimization using the moment matching method and the simulation optimization method are discussed and compared to conventional deterministic optimization. A new approach based on successively approximating probability density functions, using recursive quadratic programming for the optimization process, is described. This approach incorporates the speed and robustness of analytical probability density functions and improves accuracy by considering simulation results. Theoretical considerations and an example problem illustrate the features of the approach. The paper closes with a discussion of an objective function formulation which includes the expected cost of design constraint failure.
Distance Calculations in Motion Planning Problems With Interference Situations
Authors: Liu C. Y. , Mayne R. W. 
Published: April 2021

Abstract
This paper discusses distance calculations for three dimensional polyhedra with the assumption of convex bodies. An n-surface convex polyhedron is viewed as the intersection of n half-spaces and is represented by n linear inequality equations while the square of the distance between two points is of a quadratic form in terms of two sets of x-y-z coordinates. The static distance-to-contact between two non-interfering convex polyhedral shapes is then directly solvable by quadratic programming. Based on the concept of distance-past-contact, distance calculations for situations with interference are presented and tested in optimization based robot path planning examples. The distance evaluation is further investigated for the dynamic situations by a swept volume computation strategy. The approach is illustrated in examples with a moving robot link and a fixed obstacle.
Maximum Intersection of Spherical Polygons and Workpiece Orientation for 4- and 5-Axis Machining
Authors: Tang Kai , Woo Tony , Gan Jacob 
Published: April 2021

Abstract
Orienting the workpiece in such a way as to minimize the number of setups in a 4-axis or a 5-axis Numerical Control (NC) machine is formulated as follows: Given a set of spherical polygons (that are representations of curved surfaces visible to a 3-axis NC machine), find a great circle (the 4th axis) or a band (the 4th and the 5th axes) containing a great circle that intersects the polygons maximally.
While there are potentially infinitely many solutions to this problem, a sphere is partitioned into O(N2) regions based on the N polygons. Within each of these regions, it is shown that it requires O(NlogN) time to determine maximum intersections and all the solutions are congruent. Central projection mapping is employed so as to present the algorithms in the plane.
General Tool Offset Curves and Surfaces
Authors: Brechner Eric L. 
Published: April 2021

Abstract
Offset curves and surfaces are often used to define two- and three-axis tool paths for circular and spherical cutting tools. This paper derives extensions of these curves and surfaces that can define tool paths for general cutting tool shapes. The general tool offsets are based on a study of mathematical envelopes of arbitrary smooth “structuring” surfaces centered on an arbitrary differentiable “foundation” surface. When a part is used for the foundation surface and a cutting tool is used for the structuring surface then the envelope forms a general tool offset. Explicit parameterizations are computed for these envelopes and for their tangents, normals, and curvature matrices in terms of the known respective quantities of the structuring and foundation surfaces.
Design Shell: A Framework for Interactive Parametric Design
Authors: Srinivasan Raman V. , Agrawal Rajiv , Kinzel Gary L. 
Published: April 2021

Abstract
This paper consists of a study of the mechanical engineering design methodology and the development of a computer-based framework for performing design. The framework, known as the Design Shell, provides the essential design tools, such as, constraint manager, nonlinear simultaneous equation solvers, optimizers, sensitivity analyzer, and graphics handler, in an interactive design environment. The design shell attempts to enhance the designer’s understanding of the relationships between the various design parameters and how these affect the overall design. As an illustration of the capabilities of the computer tool, the design of a torsion bar spring is presented in the paper.
Compatibility-Based Design for Contact Stress
Authors: Ishii K. , Klinger J. M. , Hamrock B. J. 
Published: April 2021

Abstract
This paper discusses the combined use of quantitative analysis equations and knowledge-based techniques in the design of machine elements. We introduce the method of design compatibility analysis to 1) guide the application of correct analysis equations, 2) interpret the results of analysis, and 3) suggest modifications to improve the design. As an example vehicle, this paper focuses on design issues related to contact stresses and lubrication between two surfaces. The compatibility approach covers not only quantitative performance measures, but also the qualitative design issues such as suitability of surface materials, machining methods, surface roughness, lubricants, etc. To verify the utility of this concept, we developed DECS (Design Expert for Contact Stress), a PC-based design-aid for contact stresses and lubrication. DECS uses Prolog for top-level management and inference, while C provides and efficient computation of the quantitative equations. DECS also utilizes some recent developments in the computations of contact stress and elastohydrodynamic lubrication. Our method would be useful in many other design applications.
Computational Implementation and Tests of a Sequential Linearization Algorithm for Mixed-Discrete Nonlinear Design Optimization
Authors: Loh Han Tong , Papalambros Panos Y. 
Published: April 2021

Abstract
A previous article gave the theoretical background and motivation for a new sequential linearization approach to the solution of mixed-discrete nonlinear optimal design problems. The present sequel article gives the implementation details of program MINSLIP based on this approach. Illustrative examples, modeling issues, and program parameter selection are discussed. A report on extensive computational results with test problems, as well as comparisons with other methods, shows advantages in both robustness and efficiency. Sample design applications are included.
A Deterministic Global Design Optimization Method for Nonconvex Generalized Polynomial Problems
Authors: Lo Chihsiung , Papalambros Panos Y. 
Published: April 2021

Abstract
A new design optimization method is described for finding global solutions of models with a nonconvex objective function and nonlinear constraints. All functions are assumed to be generalized polynomials. By introducing new variables, the original model is transformed into one with a linear objective function, one convex and one reversed convex constraint. A two-phase algorithm that includes global feasible searches and local optimal searches is used for globally optimizing the transformed model. Several examples illustrate the method.
Remarks on Conditions for the Validity of Parametric Decomposition in Optimal Design
Authors: Rao J. R. Jagannatha , Papalambros Panos Y. 
Published: April 2021

Abstract
Decomposition strategies are used in a variety of practical design optimization applications. Such decompositions are valid, if the solution of the decomposed problem is in fact also the solution to the original one. Conditions for such validity are not always obvious. In the present article, we develop conditions for two-level parametric decomposition under which: (1) isolated minima at the two levels imply an isolated minimum for the original problem; (2) necessary conditions at the two-levels are equivalent to the necessary conditions for the original problem; and, (3) a descent algorithm for computing Karush-Kuhn-Tucker points in decomposition formulations is globally convergent. Since no special problem structure is assumed, the results are general and could be used to evaluate the suitability of a variety of approaches and algorithms for decomposition strategies.
Optimization Formulations for Designs Posed in the Labeled Interval Calculus
Authors: Wilhelm Robert , Ward Allen 
Published: April 2021

Abstract
Optimization formulations are developed for design problems stated in the labeled interval calculus. The labeled interval calculus is discussed briefly and an example is shown where motors and transmissions must be selected to meet design requirements. Optimization formulations for selection over continuous and discrete ranges are shown. A transformation from the labeled interval calculus to an optimization formulation is then discussed.
Design of Control Systems for Performance: A Constraint Mapping Approach
Authors: Beyers Robert , Desa Subhas 
Published: April 2021

Abstract
This paper is the single-input, single-output frequency domain counterpart of a framework developed by the authors [7] for the design for performance of constrained controlled dynamic systems. Simple s-plane maps are used to graphically reveal interactions of performance requirements and constraints, thus permitting a control system designer to clearly understand performance trade-offs. Two important facts underlie our approach: (a) the dynamic performance of a closed-loop system is limited by certain constraints and (b) successful control system design must explicitly account for these constraints. The approach is applied to second-order linear systems which are the basis for much control system analysis and design of single-input, single-output linear systems.
An Optimization-Based Framework for Simultaneous Plant-Controller Redesign
Authors: Beyers Robert , Desa Subhas 
Published: April 2021

Abstract
In this paper we develop a framework for the redesign of computer-controlled, closed-loop, mechanical systems for improved dynamic performance. A central notion which underlies the redesign framework is that, in order to achieve the best possible performance from a constrained closed-loop system, the plant and controller should be designed simultaneously. The framework is presented as the formulation and solution of a progression of optimization problems which enable the designer to systematically establish the various redesign possibilities. An example clearly demonstrates the underlying ideas as well as the use of the redesign framework for performance improvement.
Dynamic Analysis of Mechanical Systems With Time-Varying Topologies: Part 2 — Global Analysis and Simulation Results
Authors: Wang Yu 
Published: April 2021

Abstract
The discrete time model developed in Part 1 has been applied to the determination of regions of stability. The backward mapping method is applied and the associated numerical properties are discussed. The model is combined with conventional numerical techniques to form a computer simulation system which is more reliable and accurate in handling the topological changes. The simulation results of an example system are presented.