bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intelligent Scheduling for Product Distribution
Authors: Xue Deyi 
Published: February 2021

Abstract
A number of intelligent scheduling models for product distribution have been introduced in this research. The databases, representing scheduling requirements and results, are described using object oriented modeling approach. The optimal schedule for product distribution considering relevant constraints is identified using two optimization approaches: state space search and genetic algorithm. State space search is employed when search space is not large. Genetic algorithm, on the other hand, provides a robust mechanism for identifying the global optimal schedule when the search space is large. Different heuristic functions, considering traveling time and distance, have been developed to evaluate the schedules generated in the optimization. In addition to single-vehicle based scheduling, scheduling considering a number of vehicles has also been studied.
Intelligent Multi-Component Thermal Analysis
Authors: Holzhauer Douglas , Grosse Ian 
Published: February 2021

Abstract
This paper documents ongoing research into using Artificial Intelligence (AI) techniques to intelligently control finite element thermal analyses. These techniques are used to implement component level decomposition of the physical domain and to integrate domain information into the analysis process. Techniques developed by this research have been implemented into a new finite element program. This program uses a blackboard architecture to integrate the various numerical and symbolic knowledge sources. The blackboard architecture also supports the storage of all data in an object oriented form. A test problem involving transient thermal analysis of an integrated circuit package show significant decrease in the number of floating point operations when using this method.
Declarative User-Defined Feature Classes
Authors: Bidarra Rafael , Idri Abdelfettah , Noort Alex , Bronsvoort Willem F. 
Published: February 2021

Abstract
Designing mechanical parts using a feature vocabulary is a very effective and rich paradigm. Its expressive power, however, is severely limited if the set of feature types available in a feature library is fixed. It is, therefore, desirable to be able to extend and configure a feature library according to particular requirements, either of an end-user of a CAD system or of an application area. These requirements are not limited to topologic and parametric aspects of a generic feature definition, but include also validity conditions to be verified for each feature instance in a model.
This paper proposes a new declarative scheme for the definition of feature classes. This scheme provides a unified description of the shape and validity issues of a feature class, as well as a flexible configuration of the feature class interface. In the definition process, the various constraint classes available play a central role, whereas an inheritance mechanism structures the feature library hierarchy. At the end of the process, validation of the class is performed, in order to avoid over- and underconstrained specifications. A graphical user interface supports the whole feature class definition process. Once defined, a feature class is automatically made available for use in a feature library of the modeling system.
Maximum Mixing Times of Methane and Air Under Non-Reacting and Reacting Conditions
Authors: Brasoveanu Dan , Gupta Ashwani K. 
Published: February 2021

Abstract
Mixing times between methane and air under non-reacting or reacting conditions in the presence of rates of temperature and pressure and velocity gradients are examined using a mixing model based on the ideal gas law and the equation of continuity. The model is valid for low-pressure combustors under non-reacting conditions. The model is also valid under reacting conditions for the fresh mixture containing only trace amounts of combustion products. The effects of initial pressure, temperature and fluid composition on mixing time are also analyzed. In general, the exact mixing time has to be determined numerically. Nevertheless maximum values of mixing times can be determined analytically for a broad range of operational conditions. Results show that under both reacting and non-reacting conditions, the maximum mixing time is directly proportional to the initial pressure and temperature of mixture and inversely proportional to rates of pressure and temperature, and to velocity divergence. Mixing through fuel dispersion into the surrounding air is shown to be faster than via air penetration into the fuel flow. Rates of pressure of less than 1 atm/s acting alone provide a mixing time in excess of one second, which is unacceptably long for many applications, in particular gas turbine combustion. Rates of temperature produced by flame may provide mixing times shorter than 0.1 s. Mixing times of the order of a few milliseconds for efficient combustion and low emission, require high velocity gradients at the fuel-air boundary. Results show that enhanced mixing is achieved by combining temperature and velocity gradients. This analysis of mixing time is intended to provide important design guidelines for the development of high intensity, high efficiency and low emission combustors.
Applications of a Local Multigrid Approach to the Finite Element Analysis of a Crack-Microcrack Problem
Authors: Cardew G. E. , Seed G. M. , Koh W. K. 
Published: February 2021

Abstract
An established group of methods allows fine grid patches to overset their coarser surroundings by an arbitrary amount. These are the Domain Decomposition methods which offer a flexibility, in that finite element models may contain local refinements in the vicinity of significant features such as crack tips. The present application is based on a restricted form of Domain Decomposition using a Multigrid algorithm applied to a composite grid consisting of local refinement patches embedded within selected zones of an underlying finite element grid. Constructing a finite element grid with disjoint, overset refinement patches is significantly simpler than the conventional approach of designing a single, complex grid of strong connectivity, with increased refinements within crack tip regions. Furthermore, the overall size of a problem can be dramatically reduced by using the patch approach, resulting in lower computational effort.
Stress intensity factors are presented for the two-dimensional problem of a main crack with multiple, arbitrarily located and oriented microcracks in the vicinity of the main crack tip. The crack-microcrack interactions are further investigated with respect to crack tip shielding and amplification. Predictions of the stress intensity factors, based on the J conservation integral within the local patches, are shown to be in excellent agreement with stress intensity factors obtained on conventional grids and with known solutions.
Onvex Partitioning Approach for the Construction of Solid Model From Measured Point Data
Authors: Holla V. Devaraja , Krishnan S. S. , Gurumoorthy B. 
Published: February 2021

Abstract
This paper describes an algorithm for the construction of solid model from measured point data using Convex Partitioning approach. Convex Partitioning approach is based on the idea that any non-convex body can be viewed as a combination of several convex pieces. The input constitutes a set or cluster of points, measured on each face of the object, which is obtained by scanning the part. Points in each cluster are used to fit a plane or a non-planar surface depending upon the type of face. Partitioning is done along the planes till one gets all the convex pieces. The individual convex pieces are then combined together to get the final model of the object. The definition of convex partition is relaxed for objects having curved faces, to be an object with all its edges convex.
Apart from allowing the construction of solid model from measured point data, the output (convex pieces) obtained from this approach is useful in planning for rapid prototyping and feature suppression in finite element analysis.
Improved Trust Region Model Management for Approximate Optimization
Authors: Wujek Brett A. , Renaud John E. 
Published: February 2021

Abstract
Approximations play an important role in multidisciplinary design optimization (MDO) by offering system behavior information at a relatively low cost. Most approximate optimization strategies are sequential in which an optimization of an approximate problem subject to design variable move limits is iteratively repeated until convergence. The move limits are imposed to restrict the optimization to regions of the design space in which the approximations provide meaningful information. In order to insure convergence of the sequence of approximate optimizations to a Karush Kuhn Tucker solution a move limit management strategy is required. In this paper, issues of move-limit management are reviewed and a new adaptive strategy for move limit management is developed. With its basis in the provably convergent trust region methodology, the TRAM (Trust region Ratio Approximation Method) strategy utilizes available gradient information and employs a backtracking process using various two-point approximation techniques to provide a flexible move-limit adjustment factor. The new strategy is successfully implemented in application to a suite of multidisciplinary design optimization test problems. These implementation studies highlight the ability of the TRAM strategy to control the amount of approximation error and efficiently manage the convergence to a Karush Kuhn Tucker solution.
Towards Dynamic Tolerance Analysis Using Bond Graphs
Authors: Salomons Otto W. , Zijlstra Johan , van der Zwaag Johnny A. , van Houten Fred J. A. M. 
Published: February 2021

Abstract
A generic method is proposed by which the effect of tolerances in combination with physical effects such as wear can be analysed on the dynamic behavior of mechanisms. The method uses bond graphs in order to simulate the dynamic behavior under the influence of tolerances and other physical effects. The method has the potential to offer enhanced computer support in tolerance value specification as well as in robust design and model based maintenance. The method has partly been implemented using a combination of a geometric modeling system (FROOM) and a bond graph based physical modeling and simulation system (20-Sim).
Computer Simulation for Ergonomic Bus Operator Workstation Design With Validation
Authors: You H. , Oesterling B. , Lowe B. , Gilmore B. J. , Freivalds A. 
Published: February 2021

Abstract
Bus operator’s workstations neglecting ergonomic features can cause overall discomfort and injuries to the users. This paper presents use of JACK®, a human work simulation package, in designing and evaluating a bus operator workstation which can provide sufficient visibility, natural reach, and comfortable posture for operators who range from the 5th percentile female to the 95th percentile male as defined by SAE J833 (SAE, 1994). Three human models representing the two extremes and their medium size person were created and performed 15 bus operating tasks on the bus workstation implemented in JACK®. Kinematic constraints were defined between the human models and the workstation to simulate the tasks in a realistic manner. While the human models simulated the tasks, the body joints were monitored to determine if they exceeded their comfort ranges recommended by Diffrient et al. (1981) and the workstation was evaluated in terms of visibility, reach, comfort, and adjustability. After the workstation design was refined by iterative modifications and the required component adjustment ranges were determined, the workstation design was prototyped into an actual working bus. A jury of bus operators evaluated the workstation design by operating the prototype on a test track. The response from the operators indicated that the workstation would accommodate the intended population.
The Subcontractors Role in Computer Aided Tolerance Management
Authors: Söderberg Rikard , Wandebäck Fredrik , Wahlborg Per-Johan 
Published: February 2021

Abstract
As modern development process tends to be more and more intense, the time from idea to product on the market continues to shorten. Competitive pressure, shorter lead times and greater demands for quality and customization increase the need for computer aided geometrical product and process verification.
Computer Aided Tolerance Management, including all design, manufacture and inspection activities striving to minimize the effect of geometrical variation, is not fully supported today. To meet future industry demands for shorter lead times and lower cost with maintained or improved quality, the field of variation control must be broadened and the subcontractors role must be changed.
This paper discusses and identifies the future role of the subcontractor and the most critical factors for achieving an effective and consistent information flow for control of geometrical variation throughout the whole product and production development process.
Life Cycle Design With Green QFD-II
Authors: Zhang Yanping (Paul) , Wang H. P. (Ben) , Zhang Chun (Chuck) 
Published: February 2021

Abstract
Green Quality Function Deployment-II (GQFD-II), a new methodology for product development or improvement, is introduced in this paper. By integrating Life Cycle Costing (LCC) into QFD matrices and deploying quality, environmental and cost requirements throughout the entire product development process, GQFD-II elaborates the original GQFD, in which Life Cycle Assessment (LCA) and QFD are combined to evaluate different product concepts. GQFD-II includes three major phases. Phase I - Technical Requirement Identification. Quality house, green house and cost house are established in this phase, where customer, environmental and cost requirements are established and documented. Phase II - Product Concept Generation. A series of product concepts are generated to satisfy the requirements established in Phase I. These concepts can be evaluated with respect to quality, environment and cost. The best product concept is then selected. Phase III - Product/Process Design. In this phase, the requirements from previous phases are deployed into all product/ process design stages. In this paper, an illustrative example (light fixtures) is used to demonstrate the concept of GQFD-II.
Design of Virtual Objects for Exact Collision Detection in Virtual Reality Modeling of Manufacturing Processes
Authors: Tesic Rade , Banerjee Pat 
Published: February 2021

Abstract
Collision detection becomes a key issue when we want to model interactions between general, nonconvex objects in virtual reality applications which arise in manufacturing process domain. Despite significant progress which has been made in developing efficient, exact collision detection algorithms for convex objects, limited and slow progress has been reported in developing collision detection algorithms for general, nonconvex objects. To narrow this gap we introduce a concept of virtual objects which extends applicability of exact collision detection algorithms to nonconvex objects. This paper presents a methodology to encapsulate into virtual objects the surface patches of interest for collision detection as well as the automatic procedures for creation of virtual objects and for partitioning them into convex pieces.
The collision detection technique described in this paper is best suited for interactive simulation and animation applications where high accuracy of object contact modeling is required. Examples include virtual assembly; mobile robot simulation; and simulation of manufacturing processes where accurate modeling of near-miss detection is essential, e.g. robotic painting, robotic welding, and NC machining operations.
An Enhanced Axiomatic Design Process
Authors: Yu Hongqian , Shu Lily H. , Venter Ron 
Published: February 2021

Abstract
This paper describes an Axiomatic Design process enhanced by the House of Quality that combines the advantages of these two methods: 1) the House of Quality is used to translate customer needs into engineering specifications; 2) decomposition by theme is used to determine the Basic Functional Requirements; 3) engineering specifications are categorized into strategies, constraints, Quality Functional Requirements and possible Basic Functional Requirements; 4) Quality Functional Requirements are assigned to different Basic Functional Requirements; 5) Basic Design Matrix, Single Quality Design Matrix and Cross Quality Design Matrix are generated to study and evaluate design concepts from different aspects. By using this approach, it is possible that an improved understanding and higher efficiency of the design process may be achieved.
Understanding Product Similarity Using Customer Needs
Authors: McAdams Daniel A. , Stone Robert B. , Wood Kristin L. 
Published: February 2021

Abstract
In this paper, related product functions are determined for a group of approximately 70 consumer products. Using customer need data, a new matrix approach is introduced to identify these relationships. Techniques are then created for determining product similarity. These techniques are clarified and validated through three case studies, including beverage brewers and material-removal products. The results of these case studies are argued to have significant impact on design-by-analogy procedures, benchmarking methods, mass customization strategies, and modular design. The paper concludes with a discussion of applications and related procedures for product development.
Aggregation and Controlled Interaction: Automated Mechanisms for Managing Design Complexity
Authors: Jacobs Timothy M. , Cohen Elaine 
Published: February 2021

Abstract
Complexity in modern product design is manifest through large numbers of diverse parts, functions, and design disciplines that require an intricate web of synergistic relationships to link them together. It is extremely difficult for designers to assimilate or represent such complex designs in their totality.
In this research, we present a framework that utilizes the intricate relationships between design components to enhance the representational power of design models and to provide focal points for automating the management of design complexity. We introduce automated mechanisms, based on aggregation and interaction relationships between design components, that integrate model structure, a variety of conceptual and detailed design information, and product management controls into a single modeling framework. These mechanisms are easily incorporated into design models and they facilitate re-use and cooperative design by ensuring that related entities can be modified independently.
Vibration and Analysis of Multi-Disk Friction Systems
Authors: Larsson Henric , Farhang Kambiz 
Published: February 2021

Abstract
The paper presents a lumped parameter model of multiple disks in frictional contact. The contact elastic and dissipative characteristics are represented by equivalent stiffness and damping parameters in the axial as well as the torsional directions. The formulation accounts for the coupling betwen the axial and angular motions by viewing the contact normal force to be the result of axial behavior of the system. The frictional contact of two disks in contact is modeled in two dynamic states (i.e. sticking and slipping state) having individual lumped parameter models and the conditions that control the switching between the two states are established. The friction forces are represented by assuming the coefficient of friction to be a function of the sliding velocity, varying exponentially from its static value at zero relative velocity to its kinetic value at high velocities.
A computer simulation of an eight-rotor disk assembly is presented. The torsional vibration characteristics and how it is liked to the axial modes of vibration is analyzed. The vibration characteristics in the transient, steady-state and stick-slip region is compared. In the stick-slip region, the angular velocity of the interfaces in frictional contact is depicted and the sticking and slipping states are defined. It is shown that the duration of slip is approximately constant and the duration of stick increases almost exponentially until a final sticking is achieved.
Synchronization of Intermittently Activated Conveyor Belts by Adaptation of Multiple Geneva Wheels in Parallel: Part II — A Novel Application
Authors: Sepahpour Bijan , Fischer Ian S. 
Published: February 2021

Abstract
Synchronization of intermittently activated conveyor belts is achieved by the adaptation of the method of synchronization of multiple Geneva wheels in parallel. The correlation of the index and dwell time ratios is discussed and the method for control and selection of these ratios is presented. Modification of the drivers for maximizing the interaction of the synchronized dwell times is discussed. These modifications offer a wide variety of index and dwell time ratios to be utilized for the adjustment and control of the synchronized incremental movements. Comparison and advantages of the modified drivers and the applications of this method are presented through illustrative situations.
Feature-Recognition for MEMS Extraction
Authors: Baidya Bikram , Gupta Satyandra K. , Mukherjee Tamal 
Published: February 2021

Abstract
Microelectromechanical systems (MEMS) integrating multi-domain sensors and actuators with conventional microelectronic batch fabrication processes are becoming increasingly complex. In order to design systems with large numbers of multi-domain components, we need to use a hierarchical structured design approach, with design at the schematic level instead of the traditional layout representation used in MEMS design. However, since fabrication can only be done from a layout representation, an automatic or manual layout generation from schematic is necessary. It is essential to be able to translate from the layout representation back to the schematic to reason about layout correctness in meeting the schematic’s function as well as to extract geometric parameters for functional simulation. An extraction module is developed which reads in the geometric description of the layout structure and reconstructs the corresponding schematic. This schematic can then be fed to an ordinary differential equation solver or can be compared with the design schematic to validate the correctness of the designed layout. The extraction module also minimizes the number of nodes required to represent the schematic as a netlist. The results presented show the success of the module for some example MEMS designs.
Extensions to the Mass Moment Substitution Method for Complete Shaking Force Balancing of Spatial Linkages
Authors: Kong Xian-Wen , Yang Ting-Li 
Published: February 2021

Abstract
This paper aims at simplifying the derivation of conditions for complete shaking force balancing (CSFB) of spatial linkages. The formulation of conditions for CSFB of a spatial linkage is reduced to the mass moment substitution of binary links, ternary links, quaternary links, dyads and spatial serial open chains. The conditions and formulae for mass moment substitution of different types of ternary links and quaternary links are derived. From these conditions and formulae together with the conditions and formulae for mass moment substitution of binary links, dyads and spatial serial open chains presented in previous works, the conditions for CSFB of a spatial linkage can be written down directly instead of extracting them from the kinematic equations of the linkage. A general procedure to formulate the condition for CSFB is then proposed and an example is given to illustrate the application of the proposed approach.