bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of Non-Manifold Topology
Authors: Charlesworth William W. , Anderson David C. 
Published: March 2021

Abstract
It is widely recognized that a solid model based on a non-manifold boundary representation can have a more complicated surface topology than one based on a manifold boundary representation, but non-manifold topology has other capabilities that may be more valuable to the application developer. Non-manifold topology can be put to use in existing application areas in ways that differ significantly from the techniques developed for manifold modeling and it can be put to use in new applications that have not been satisfactorily solved by manifold topology. Several applications of non-manifold topology that would be difficult or impossible to implement using a purely manifold geometric modeler are illustrated: automatic formulation of finite element analyses from solid models, automatic generation of machining tool paths for 2½-dimensional pockets, and construction of geometric models using topological constraints. These applications demonstrate how a non-manifold model partitions the entire space in which an object is embedded, preserves elements of the model that would be discarded by conventional schemes, and permits the implementation of a common merge operation. All three applications have been implemented using a two dimensional non-manifold (non-1-manifold) geometric modeler.
Superior Mesh Quality With Automatic Node Mergers
Authors: Gutfinger Ron S. 
Published: March 2021

Abstract
Automatic surface meshers have been designed with the intent to eliminate the manual effort involved in creating a finite element model. Naturally, the quality of the mesh must be such that the solver will yield accurate results. For geometries having boundaries with short edges relative to the rest of the geometry, the existing meshers yield poor quality meshes. Hence, the stress analyst must manually attain reasonable mesh quality. This manual effort is very tedious and time consuming. Mesh quality improvement techniques such as smoothing, fail to improve the mesh quality. In this work, a new technique is introduced, which improves the initial boundary node loop quality, and in turn yields high quality meshes. Examples show marked improvement in quality, and the meshes are comprised of fewer elements.
Stress Analysis of the Target Enclosure at the R14B Firing Range
Authors: Gupta Aaron D. 
Published: March 2021

Abstract
A stress analysis of the target enclosure structure at the R14B firing range at Aberdeen Proving Ground (APG), MD, subjected to an internal blast and worst-case fragment impact was conducted to assure structural integrity and safe operation of the structure during tests. The reflected dynamic pressure loads due to explosive blast were estimated from the CONWEP explosion effects code developed by the U.S. Army Waterways Experiment Station and were modeled as exponentially decaying pressure pulses which could be approximated as triangular loads with equivalent impulses. Fragment impact loads are approximated from a momentum-impulse balance formulation as step loading functions. A closed-form solution of the equation of motion of a sidewall of the structure subjected to a triangular blast load was obtained and verified by a three-dimensional (3-D) finite element model.
A Boundary Element Method for Multi-Body Contact Problems and its Application to the Analysis of a Huge Excavator
Authors: Liu Chong-De , Yu Jiyuan , Wang Xiaoming 
Published: March 2021

Abstract
The derivation of a boundary integral formulation and discretization technique in terms of boundary elements for the solution of multi-body contact problems has been carried out. A FORTRAN program has been developed based on this boundary element formulation and has been applied to the stress analysis of a huge caterpillar excavator woth 16 m3 bucket capacity.
REFINED: A Computer Code for

R

eacting

E

lliptic

F

lows

in

E

xpansion

D

omains
Authors: Dong M. , Lilley D. G. 
Published: March 2021

Abstract
REFINED (acronym for Reacting Elliptic Flows inExpansion Domains) is a general computer code that has been developed for turbulent swirling reacting flow predictions. A variety of user choices, such as inlet velocity profiles, inlet flow parameters, chemical reaction schemes from user-oriented accuracy and complexity requirements, and interaction with flowfield color graphic display utility are included. Development of the computer code is documented, with emphasis on the theory and application of the methodology.
Development of Interactive Tutorials to Aid in Teaching of a Rapid Design Prototyping Laboratory Course
Authors: Biswas Arunava , Kinzel Gary L. 
Published: March 2021

Abstract
A rapid design prototyping facility comprising of table top CNC milling machines, CNC lathes, CAD/CAM workstations and an injection molding machine has been established at the Ohio State University. Interactive tutorials have been developed for helping the users to learn the details of the machines and the software programs. The tutorials have successfully improved the learning efficiencies of the students and reduced the training costs for instructors. This paper presents an overview of the tutorials.
Computer Graphics Modeling of Anatomy: From 2D Data Acquisition to 3D Sculpting
Authors: Alciatore David G. 
Published: March 2021

Abstract
This paper describes a process which is used to generate three-dimensional computer graphics surface models of gross anatomical structures. Key steps in the generation of these models include acquiring 2D cross-sectional data from macrocryotome slicing, generating 2D cross section contours from edge detection and region segmentation, generating a polygonal mesh surface model by triangulating between the 2D contours, and interactive sculpting of the 3D surface for editing and changing the appearance of the model. The algorithms and development involved with these steps are briefly described here and several images resulting from the process are presented. The main purpose of the paper is not to present the details of implementation of the various algorithms, but rather to present the overall methodology and illustrate the results. Implementation details can be found in other papers referenced here. The most recent results of our efforts, which are presented here, are 3D surface models of the complete human thorax. These models have numerous applications in anatomy and biomechanics visualization and teaching.
On Developing User’s M Files for MATLAB in Engineering Applications
Authors: Pao Y. C. 
Published: March 2021

Abstract
This paper presents a collection of M files created for applications of MATLAB software in graduate and undergraduate engineering classes. Starting with the simple need of printing a difference table, presented in order of increasing difficulty of numerical procedural setup and programming arrangement are M files for volume integration, animation of a rotating block, Runge-Kutta solution of a nonlinear oscillation problem, and solution of a warping function governed by Laplace equation using the relaxation method. Threading through these M files are the demonstrative applications of MATLAB’s own M files and its graphics commands and vector operations.
Integration of CAD to CAM Through Feature Recognition Based Solid Modeling
Authors: Jha Prabhudutt 
Published: March 2021

Abstract
This paper deals with the development of a system to convert a general positive-based solid geometry data set into one more suitable for process planning. The basic software used is IDEAS for solid modeling on IBM/RS 6000 workstation.
The objective is to capture design and manufacturing knowledge in existing engineering drawings of CAD/CAM databases and then convert the captured design features into workable products through feature recognition techniques.
The paper presents an approach of converting CSG geometry representation to a DSG (Destructive Solid Geometry) form and then results are written to I-DEAS program file. The user can examine the excess materials for removal from model file, where it is stored. The program is written in FORTRAN 77.
Unified Feature Definition for Feature Based Design and Feature Based Manufacturing
Authors: Geelink Reinholt , Salomons Otto W. , van Slooten Fjodor , van Houten Fred J. A. M. , Kals Huub J. J. 
Published: March 2021

Abstract
In this paper, interactive “constraint based feature definition” is used to drive both feature based design and feature recognition. At present, hardly any feature based CAD or CAPP system does offer adequate facilities to easily define application specific features. Feature definition by means of programming is an error prone and difficult task. The definition of new features has to be performed by domain experts in the fields of design and manufacturing. In general they will not be programming experts. This paper elaborates on interactive feature definition, aiming at facilitating the definition of features by non-programming experts. The interactive feature definition functionality is implemented in a re-design support system called FROOM. It supports feature based design. Feature definition is also used in a Computer Aided Process Planning system, called PART, for the definition of features to be recognized. Conceptual graphs are used as an aid in the definition of features and for the representation of the features. The conceptual graphs are automatically transformed into feature recognition algorithms. Degrees of freedom (DOF) analysis is used for support during feature definition and for solving geometric constraints related to the feature to be defined.
Features: Semantic Objects for the Integration of Tasks in the Product Development Process
Authors: Krause F.-L. , Ciesla M. , Rieger E. , Stephan M. , Ulbrich A. 
Published: March 2021

Abstract
For the integration of the tasks to be mastered within the development process it is necessary to take account of non-geometrical information, from product design to manufacturing process, alongside geometrical design shape. The introduction of objects as carriers of semantic information leads to the use of features. In the present contribution, a concept and its realization are described that facilitate a flexible definition and computer-internal representation as well as the interpretation of features as semantically endowed objects. Based on the feature model, approaches are introduced for the support of product development with the partial tasks conception, design, integrated planning of manufacture and quality assurance.
An Efficient System for Geometric Assembly Sequence Generation and Evaluation
Authors: Romney Bruce , Godard Cyprien , Goldwasser Michael , Ramkumar G. 
Published: March 2021

Abstract
In this paper, we present a software system which can automatically determine how to assemble a product from its parts, given only a geometric description of the assembly. Incorporated into a larger CAD tool, this system, the Stanford Assembly Analysis Tool (STAAT), could thus provide immediate feedback to a team of product designers about the complexity of assembling the product being designed. This would be particularly useful in complex assemblies where each designer may not be fully aware of the impact of his design changes on the assemblability of the product as a whole. STAAT’s underlying data structure is an efficient version of the non-directional blocking graph (NDBG), a compact representation of the blocking relationships in an assembly. STAAT implements several techniques using this structure, under a unified approach in which the same software “machinery” can analyze the product under different assembly constraints. In initial experiments conducted on relatively small polyhedral assemblies of 20 to 40 parts and 500 to 1500 faces, using one-step translational motions, STAAT generated assembly sequences much more quickly than did previous NDBG-based systems. We are working now on extending both these results and the underlying theory to more sophisticated cases.
Geometric Reasoning for the Coding of CAD Models
Authors: Qamhiyah A. Z. , Benhabib B. , Venter R. D. 
Published: March 2021

Abstract
Many of today’s concurrent product-development cycles depend on the utilization of intelligent Computer-Aided Design (CAD) systems. Thus, it would be essential to provide CAD users with effective means for interacting with the CAD system and its database. This paper addresses the development of a boundary-based coding procedure for CAD models. Coding the geometric and processing characteristics of objects, based on their CAD model representation, has been long recognized as an effective approach that allows convenient design retrieval on the one hand and process-planning automation on the other. Our work is based on the assumption that form features are recognizable and extractable from the CAD model by current feature-recognition, feature extraction and feature-based-design approaches. The coding procedure is applicable to the boundary representation of the object and its extracted form features.
Extension of Feature-Based CAD Systems Using TAE Structures to Support Integrated Rapid Prototyping
Authors: Otto Harald E. , Kimura Fumihiko , Mandorli Ferruccio , Cugini Umberto 
Published: March 2021

Abstract
Due to life cycles of artifacts, which become shorter, rapid prototyping development and tight feedback among product requirements, design, and manufacturing are gaining increasing importance. Classical rapid prototyping technologies such as computer-numerically-controlled (CNC) machinery, which remain still time consuming and expensive, are getting superseded by a growing propensity to apply new solid freeform fabrication (SFF) technologies, which became commercially available since 1987.
Although, being on the market for only less than a decade, remarkable progress in various directions such as accuracy, used materials, through-put, and equipment costs, has been achieved in SFF technologies.
However, there are still several technological as well as methodological problems left. Within given scope, we would like to tackle some, taken from the methodological field, which seems still weakly developed compared to existing technology. Within our approach we apply feature-based models and techniques, realized within typed attributed entity (TAE) structures. In particular, we are interested in the handling of additional fabrication relevant form structures and the automatic determination of fabrication parameters.
To verify developed methodologies and to demonstrate the applicability of our taken approach, several selected parts, taken from precision machinery engineering and aerospace engineering were modeled and processed. An implemented prototype environment and a stereolithography apparatus (SLA) were used for integrated knowledge handling, computation and SFF fabrication.
Part Selection From a Federated Catalog
Authors: Jiang Ling , Brown Don R. , Hwang Kuo-Yen 
Published: March 2021

Abstract
This paper discusses issues related to a network-based catalog part selection system. Some of the key issues are: the optimal search problem, the burden imposed on the server of a network-based catalog or the time spent in data retrieval, identical parts in different vendor catalogs, and the excessive amount of data in a database of component information. The paper addresses the problem of network “burden,” the problem of identical parts, and the excessive data problem. The authors employ a “Configuration-decomposition” strategy in the approach to the excessive data problem. As an example of applying this approach, the implementation of the authors’ experimental system for part selection is discussed.
Geometric Improvement on Ribbed Globoidal Cams for Unsymmetrical Motion Controls
Authors: Tsay Der Min , Lin Bor Jeng 
Published: March 2021

Abstract
A procedure with design and machining considerations is developed to define unsymmetrical turret motions of ribbed globoidal cams. Adjusting the parameters of rational B-splines to interpolate required angular motion constraints, one can refine the turret motion that is superior to those obtained by other traditional methods. To judge the geometric performance of the spatial cam surface corresponding to its turret motion, the envelope theory is applied to derive the analytical description of the cam surface. As a result, the pressure angle and the curvature of the cam surface can be investigated. A real example is illustrated to show the effectiveness of the procedure and the favorable results compared to those obtained by other means.
Computer Prototyping of Moving Mechanical Parts
Authors: Pai Uday N. , Liou F. W. 
Published: March 2021

Abstract
In this paper computer implementation of automated simulation of rigid bodies in collision is presented. It can be used for automatic simulation of unconstrained and/or constrained mechanical systems. The key tasks include feature extraction, collision detection, constraint identification, collision response, and simulation. Feature extraction includes volumetric feature extraction such as mass, volume, density and moment of inertia, and planar geometric feature extraction like the faces, edges, vertices and their inter-relationships. Collision detection is a kinematic problem involving the positional relationships of rigid bodies in space, while collision response is a dynamic problem involving the prediction of rigid body behavior according to physical laws. Case studies are used to explain the behavior of a typical system comprising of two rigid bodies to explain the underlying principles.
A Method for Embedding Human Expert Knowledge Into a Fuzzy Logic Controller
Authors: Canning John R. , Edwards Dean B. 
Published: March 2021

Abstract
This paper presents a method for embedding human expert knowledge into a fuzzy logic controller. The method was developed while designing a fuzzy logic control system for an autonomous vehicle that utilized sparse sensor data for terrain classification. We will discuss the design for the fuzzy logic terrain classification system and use it as an example for explaining the embedding method.
In the example, a human expert classified terrain features from sensor data provided by a two-dimensional computer simulation. From the information derived from the expert, we developed both a classification system for the terrain features and a fuzzy logic rule base for the controller. The simulation, along with an optimization algorithm, was then used to train the fuzzy logic controller to match the human responses.
A Hybrid Fuzzy Controller for Industrial Power Plants
Authors: de Sam Lazaro A. , Steffenhagan W. 
Published: March 2021

Abstract
The automation of the control to a power plant is indeed a challenge mainly because of the occurrences of random and unpredictable variations in output demands as well as because of highly non-linear behavior of the system itself [1]. It is sometimes argued that the ‘best’ control for a power plant is the operators themselves. Experienced operators are capable of taking decisions on the basis of incomplete and imprecise information. The extent to which these decisions are correct is a matter of speculation. Erroneous conclusions, established post facto, are chalked up to the learning process and in fact, contribute to the forming of a good, experienced control team. The need to automate the control process for a plant is even more acutely felt when considering the complexity of the plants themselves and the volume of data that would have to be processed before a control decision can be taken. Factored into this decision would also be several governing parameters such as costs, reliability, other constraints and their interdependancy, as well as planned and unscheduled outages for maintenance and so on. In this paper, however, only one facet of a power plant operation is considered. It is intended to demonstrate that thermal efficiency may be improved by better techniques for automated control of throttle valves in the steam turbine of the plant. One of these options, fuzzy logic, is selected, and defended, as being the more effective than current techniques. A comparative analysis is conducted of control techniques for plant operations followed by a brief overview of fuzzy control and its application to control of non-linear systems. A method of applying this ‘new’ computer-based technique to control of non-linear, somewhat erratic plants is presented and discussed.
Design of a Flexible Data Acquisition and Control System
Authors: Yip T. Gary , Loh Dennis 
Published: March 2021

Abstract
Automatic data acquisition and control have become an indispensable part of engineering but many data acquisition and control equipments remain relatively inflexible and cumbersome for most engineering applications. Hence, engineers often need to custom design and build their data acquisition and control system to support their in-house automatic testing and monitoring equipment.
This project investigates the design fundamentals and guidelines in setting up a flexible data acquisition and control system. A flexible data acquisition and control system (FDACS) is defined as one which possesses such characteristics as the ease of implementation, the ease of upgrading system’s capability (e.g. data volume and control channels) and the ability for information sharing. An experimental data acquisition system is used as the platform to facilitate the study. It consists of an IBM compatible personal computer, a remote host microprocessor and seven signal processors. Using this implementation, the system is able to provide up to 28 digital I/O lines, 28 analog input lines, 42 digital output lines and an average execution time per instruction of 1 ms.
A Prototype Multimedia Auto Broker
Authors: Birkes Angela Y. , Hsiung Chien H. , Cohen Tal , Fulton Robert E. 
Published: March 2021

Abstract
Intelligent, easy to use, and entertaining multimedia information brokers are vital to the explosive role of information technology. With the advent of interactive television and the information superhighway in the near future, information management systems (information brokers) for consumer services and products will be necessary.
This paper describes the application requirements process and subsequent prototyping efforts for a multimedia auto broker. The research activity presented has distinct phases which overlap and take place concurrently in some instances. The phases include a knowledge acquisition phase, applications requirements definition phase, and testing and validation phase. The details of each of these phases which led to the prototype multimedia auto broker are characterized, followed by a brief introduction of effort underway for the system architecture, and recommendations for generalizing the multimedia information broker to other applications.