bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid Streaming in Micro/Minibifurcating Networks
Authors: Zhang Z. , Fadl A. , Liu C. , Meyer D. M. L. , Krafczyk M.
Published: July 2009

In this study, we investigate the phenomena of flow streaming in micro-/minichannel networks of symmetrical bifurcations using computer simulations with analytical validation. The phenomena of the flow streaming can be found in zero-mean velocity oscillating flows in a wide range of channel geometries. Although there is no net mass flow (zero-mean velocity) passing through the channels, the discrepancy in velocity profiles between the forward flow and backward flow causes fluid particles near the walls to drift toward one end while particles near the centerline to drift toward the opposite end. The unique characteristics of flow streaming could be used for various applications. The advantages include enhanced mixing, pumpless fluid propulsion, multichannel fluid distribution, easy system integration, and cost-effective operation. The results of computer simulations showed that oscillation amplitude is the dominant effect on streaming velocity in channel networks. Streaming velocity was directly proportional to the oscillation frequency and can be used as a cost-effective and reliable convective transport means when the particle diffusivity is less than the fluid kinematic viscosity. A considerable amount of work is needed to further study and understand the flow streaming phenomenon.
Biomimetic Treatments on Dental Implants for Immediate Loading Applications
Authors: Aparicio C. , Salvagni E. , Werner M. , Engel E. , Pegueroles M. , Rodriguez-Cabello C. , Munoz F. , Planell J. A. , Gil J.
Published: July 2009

Commercially pure titanium (cp Ti) dental implants have been widely and successfully used with high rates of clinical success in normal situations. However, there is still a lack of reliable synthetic materials to be used either a) when immediate loading of the implant is desired or b) when bone presents compromised conditions due to trauma, infection, systemic disease and/or lack of significant bone volume. Our group has aimed the development of biomimetic strategies of surface modification to obtain metallic implants with osteostimulative capabilities. These surface modifications will provide implants with a rapid rate of newly-formed bone growth and with ossecoalescence, i.e., direct chemical contact with the surrounding tissues. Consequently, the biomimetically-modified implants will be reliably used on those more demanding clinical situations. cp Ti surfaces treated to obtain a combination of an optimal random surface topography (in the micro and nanolevels) with a chemical modification of the naturally-formed titania layer have been proved bioactive. These rough and bioactive surfaces nucleate and grow a homogeneous hydroxyapatite layer both in vitro and in vivo. They stimulate the osteoblasts differentiation and trigger a rapid bone formation that mechanically fixes implants under immediate-loading conditions. A simple process using silane chemistry has been proved specific, rapid, and reliable to covalently immobilize biomolecules on c.p. Ti surfaces. This methodology can be used to develop biofunctionalized implant surfaces with different or combined bioactivities. The biofunctional molecules can be biopolymers, proteins, growth factors, and synthetic peptides specifically designed to be attached to the surface. The bioactive properties of the molecules designed and used can be mineral growing and nucleation, osteoblast differentiation (bone regeneration), fibroblasts differentiation (biological sealing), antibiotic,… Specifically, we have obtained mechanically and thermochemically stable coatings made of recombinant elastin-like biopolymers. The biopolymers bear either a) the RGDS peptide, which is a highly-specific cell-adhesion motif present in proteins of the extracellular matrix for different tissues including bone, or b) an acidic peptide sequence derived from statherin, a protein present in saliva with high affinity for calcium-phosphates and with a leading role in the remineralization processes of the hard tissues forming our teeth. Two different biomimetic strategies have been successfully developed combining topographical modification, inorganic treatments and/or biofunctionalization for improving bioactive integrative properties of c.p. Ti implants.
Generation and Sketching of Generalized Kinematic Chains
Authors: Hsieh Chiu-Fan , Hwang Yii-Wen , Yan Hong-Sen
Published: July 2009

An algorithm of generalized kinematic chains and its computer program are developed in this paper. By this program, users can give the number of links and joints and then the link assortments and contracted link assortments can be calculated. The synthesis of multiple link adjacency matrix (MLAM) and the cut-link diagnosis are proposed to produce effectively the generalized kinematic chains. The algorithm can automatically determine the feature of a chain, which is connected, closed, non-isomorphism, without any cut-link (or cut-joint), and with simple joint only. Then, it can be called a generalized kinematic chain. Finally, various given number of links and joints, the nice looking atlas of generalized kinematic chains can also be generated. The developed computer program could help designers to be able to study and compare different devices in a very basic way.
Application of Artificial Neural Networks (ANN) Based Model for Monitoring of Vehicle Longitudinal Dynamic Performance
Authors: Albers Albert , Wang Jiangang , Ott Sascha , Du¨ser Tobias , Lerspalungsanti Sarawut
Published: July 2009

Nowadays, with the integration of diverse driver assistance systems the vehicle has become a complex mechatronic system. The goal of this improvement is to help a driver to manage his vehicle and to perceive his environment. The functional capability of these driver assistance systems is mostly influenced by the functionality of mechanical and/or hydraulic components in the vehicle and the sensors, which are essential elements for the estimation of external and internal state of the vehicle. To ensure the reliability of the vehicle there is a great need to develop a monitoring system to meet the new requirements. In a complex mechatronic system the functionality and reliability of the whole system depend not only on those of the subsystems. To monitor the functionality of a system, it is necessary to understand how the system works. Thus it becomes more difficult for the driver to monitor the functionality and the working state of modern vehicle. In order to help a driver to monitor the performance of his/her vehicle, an appropriate condition monitoring system is required. This paper outlines an approach to estimate the vehicle longitudinal performance for the purpose of developing a fault monitoring system based on simulation technique. Firstly, the necessity of this monitoring system is expounded. After introduction of diverse methods for the analysis of the system safety, structure of this monitoring system is introduced. The kernel of this system is a vehicle model and an observer model. Regarding the requirements of a real-time operating system, the vehicle model in this work is built by applying an artificial neural network (ANN). The achieved structure of the network and simulation results are presented in this paper. Furthermore the real-time capability of the networks is verified within this work.
Evaluation and Representation of the Orientation Workspace of the Gough-Stewart Platform
Authors: Jiang Qimi , Gosselin Cle´ment M.
Published: July 2009

The evaluation and representation of the orientation workspace of robotic manipulators is a challenging task. This work focuses on the determination of the orientation workspace of the Gough-Stewart platform with given leg length ranges [ρimin, ρimax]. By use of the Roll–Pitch–Yaw angles (φ, θ, ψ), the orientation workspace at a prescribed position can be defined by 12 workspace surfaces. The obtained orientation workspace is a region in the 3D Cartesian orientation space O φ θ ψ. As all rotations R(x, φ), R(y, θ) and R(z, ψ) take place with respect to the fixed frame, any point of the orientation workspace provides a clear measure for the platform to respectively rotate in order around the (x, y, z) axes of the fixed frame. Also, as the shape of the 3D orientation workspace is very complex, a numerical algorithm is presented to compute its volume.
The Control of a Long-Range Single-Axis Nanometer Positioning System
Authors: Chen J. L. , Wijaya M. T.
Published: July 2009

This paper is focusing on the control strategy design of a long-range single-axis positioning system [1], which has a travel range of 100 mm. The positioning system was constructed by a linear guide, a feeding mechanism and three stacked piezoelectric actuators. The stacked piezoelectric actuators were used to drive the feeding mechanism with a circular movement, which will feed the linear guide by friction force. Through continuous feeding, an unlimited travel range positioning system can be achieved. Two-stage control strategy was introduced for the positioning control, i.e. coarse motion control and fine motion control. At coarse motion stage, impact-drive motion combined with fuzzy control was used to accelerate the linear guide to approach the target position. At fine motion stage, stick-drive motion combined with classical feedback–feedforward control can provide a nanometer positioning accuracy. The control algorithm was implemented on TMS320F240 DSP-based control board, and the experimental results show that the proposed feeding mechanism system with two-stage control strategy can achieve a travel range more than 90 mm with maximum velocity of 5.8 mm/s, average velocity 1 mm/s, steady state error is less than 20 nm, positioning bias is less than 0.5 nm and standard deviation is less than 7 nm.
Issues in the Design of Electromagnetic Actuators Using Circuit Models and Hysteresis Simulation
Authors: Rosenbaum So¨ren , Radler Oliver , Hu¨fner Thorsten , Stro¨hla Tom
Published: July 2009

This paper shows modeling approaches and methods for the fully dynamic optimization of electromagnets in the design process. The used circuit models are characterized by sustainable calculation times and good accuracy and thus allow quickly to determine the design with the best properties (e.g. the shortest actuation times or the lowest power consumption) within a given range. Besides that, a method to simulate hysteresis effects during the actuator design is pointed out. An automated process to identify Jiles-Atherton model parameters from measured characteristics will be shown. The presented method allows the designers of solenoids a fast and reliable design process and thus matching the increasing demands on functionality.
Conceptual Design of Fixed Center Steering Wheels
Authors: Guo Fang-Fu , Yan Hong-Sen , Lan Chao-Chieh , Huang Shin-Tsung
Published: July 2009

Various patents relating fixed center steering wheels are studied. The corresponding topological characteristics, design specifications, and design requirements and constraints of mechanisms are concluded. A methodology for the creative design of mechanisms is applied to generate all possible design concepts of mechanisms subjected to the concluded design requirements and constraints. In conclusion, 29 new design concepts of fixed center steering wheels are synthesized.
Conceptual Design Using Generic Object Inheritance
Authors: Johansson Olof , Andersson Henric , Krus Petter
Published: July 2009

Conceptual design for complex products like aircraft and power plants requires a considerable effort since the product models become very large if they are to cover all important aspects for different stakeholders. To cope with this overall effort, designers have to rely on legacy designs and reuse, and improve the product concepts incrementally between product generations. This paper describes a generalized inheritance mechanism we call generic object inheritance that enables quick reuse and modification of conceptual product models at any level in their hierarchical break down structures. By facilitating reuse of conceptual models of previously well studied products, more time can be spent on developing the parts that contain the edge of a new product generation. This enables keeping the modified concepts in context of a complete analyzable product model where the impact of changes can be studied without having to maintain multiple copies of the same object structures. The paper describes how generic object inheritance is used for developing the next version of a conceptual product model of a small business jet, while reusing the essential parts of the previous version with minor modifications to design parameters and substructures. The design and core mechanisms of generic object inheritance are briefly described, and illustrated with examples from the case study.
Radial Basis Function Based Simplified Trapping Probability Models for Optical Tweezers
Authors: Banerjee Ashis G. , Balijepalli Arvind , Gupta Satyandra K. , LeBrun Thomas W.
Published: July 2009

In order to automatically manipulate microspheres using optical tweezers in real-time, it is essential to efficiently compute an estimate of the probability with which they will be trapped by a moving laser beam in a spatial region close to its focus. This paper presents a radial basis function approach to generate simplified models for estimating trapping probability from the offline simulation data. The difference form of Langevin’s equation is used to perform offline particle motion simulation for estimating probabilities at discrete points. Gaussian radial basis functions combined with kd-tree based partitioning of the parameter space are then used to generate simplified models. We show that the proposed approach is computationally efficient in estimating the trapping probability. We also show that the estimated probability using the simplified models is sufficiently close to the probability estimated from the offline simulation data.
Comparison and Application of Metrics That Define the Components Modularity in Complex Products
Authors: Van Eikema Hommes Qi D.
Published: July 2009

As the content and variety of technology increases in automobiles, the complexity of the system increases as well. Decomposing systems into modules is one of the ways to manage and reduce system complexity. This paper surveys and compares a number of state-of-art components modularity metrics, using 8 sample test systems. The metrics include Whitney Index (WI), Change Cost (CC), Singular value Modularity Index (SMI), Visibility-Dependency (VD) plot, and social network centrality measures (degree, distance, bridging). The investigation reveals that WI and CC form a good pair of metrics that can be used to assess component modularity of a system. The social network centrality metrics are useful in identifying areas of architecture improvements for a system. These metrics were further applied to two actual vehicle embedded software systems. The first system is going through an architecture transformation. The metrics from the old system revealed the need for the improvements. The second system was recently architected, and the metrics values showed the quality of the architecture as well as areas for further improvements.
Diverse Shape Generation for Digital Style Design
Authors: Ujiie Yoshiki , Matsuoka Yoshiyuki
Published: July 2009

A method for style design support, which strives to extend design candidates by combining computer images of the designer’s ideas with engineering techniques, is used to generate diverse design candidates. This paper considers the problems, “What are diverse design candidates?” and “Which design candidates reflect a designer’s image?” Moreover, this paper introduces a diverse curved profiles generation method to manipulate designer’s image and its application in vehicle design as an example of style design support by diverse shape generation.
Provision of Basis for a New Snake-Like Reconnaissance Robot for Disaster Situations
Authors: Welp Ewald G. , Labenda Patrick , Neumann Marc , Jansen Sebastian
Published: July 2009

It frequently comes to building collapses all over the world. Often people are buried alive. They must be rescued and saved by rescue teams. It depends on the time that passes during a rescue whether a person can still be rescued alive. Especially the information which is available about the exact position of a person buried alive is decisive for a fast accomplishment of rescue actions. Accordingly the exact localization of victims buried alive is of primary importance. It is the only way, a fast rescue and salvation can be started. However, biological and technical locating equipment available today shows numerous weak points. This refers particularly to the precision of position determination of the victims. But the essential disadvantage of the utilizable technologies is that a collapsed building cannot be entered actively. There is no equipment available that enables a deep penetration into ruins for inspection and exploration tasks, without the necessity of using heavy machines. In a research project currently funded in Germany these difficulties shall be encountered by a part autonomous, energy self-sufficient and remotely controlled reconnaissance robot. It will become a motion system, which orientates its design and behavior at the biological archetype snake. The paper at hand introduces the state-of-the-art of technology and research in the fields of locating, reconnaissance robots as well as snake robots. Originating from a multifunctional locomotion system that has been already implemented successfully, elements for a robot system to be newly developed are introduced and discussed.
Exploiting the Features of ISO GPS Standards to Enhance a Knowledge-Based Method for Product Redesign and Process Reconfiguration
Authors: Cristofolini Ilaria , Filippi Stefano
Published: July 2009

Previous work developed a knowledge-based method named Design GuideLines Collaborative Framework (DGLs-CF), adopted during product redesign and process reconfiguration and aimed at dealing and matching with particular manufacturing and verification technologies, according to ISO GPS concepts. Aim of present work is improving the role of the ISO GPS within the DGLs-CF, not only to raise coherence in terms of concepts, but to gain some important internal and external improvements for the DGLs-CF. The main activity toward achieving this goal is the formalization of DGLs-CF product features by means of the ISO GPS features. The procedure is proposed and the consequences of its application on the elements of the DGLs-CF are evaluated. A case of study as an example of application is also presented. A significant improvement in the DGLs-CF is realized, both in terms of knowledge structure and organization, and in terms of the possibility of interfacing it with other methodologies, tools, and environments.
General and Partial Shape Matching Approaches on Feature-Based CAD Models to Support Efficient Part Retrieval
Authors: Li Min , Fuh J. Y. H. , Zhang Y. F. , Qiu Z. M.
Published: July 2009

Presently, mechanical design activities are almost fully digitalized and a large percentage of CAD models that are digitally created can be reused to facilitate new designs. Conventional alphanumeric-based part retrieval methods are error-prone. In order to support users to efficiently locate desirable parts to reuse, two novel knowledge-based approaches for feature-based model retrieval are proposed in the paper, namely general shape matching and partial shape matching, to assess CAD models by measuring their overall similarity without details and local similarity of sub-parts, respectively. The first approach simplifies feature-based CAD models from fully detailed to less detailed, and progressively simplified shapes are characterized by general shape descriptors. When a 3D query model that represents the general shape of a desired part is sketched, the approach compares the query model against pre-generated general shape descriptors so that all parts similar to the 3D query in overall shapes are retrieved; therefore the general shape matching is achieved. The second approach extracts reusable sub-parts from feature-based CAD models in an unsupervised way and indexes them using partial shape descriptors. Based on the partial shape descriptors indexed, designers could retrieve all existing parts sharing a desirable sub-part by sketching the shape of the sub-part; the partial shape matching is thereby realized to facilitate the part retrieval on local similarity. The approaches proposed in this paper are implemented on a prototype system and tested by hundreds of mechanical parts. The preliminary results show that the proposed approaches are feasible and promising.
Optimal Product Design Under Price Competition
Authors: Shiau Ching-Shin , Michalek Jeremy J.
Published: July 2009

Engineering optimization methods for new product development model consumer demand as a function of product attributes and price in order to identify designs that maximize expected profit. However, prior approaches have ignored the ability of competitors to react to a new product entrant; thus these methods can overestimate expected profit and select suboptimal designs that perform poorly in a competitive market. We propose an efficient approach to new product design accounting for competitor pricing reactions by imposing Nash and Stackelberg conditions as constraints, and we test the method on three product design case studies from the marketing and engineering design literature. We find that a Stackelberg leader strategy generates higher profit than a Nash strategy. Both strategies are superior to ignoring competitor reactions: In our case studies, ignoring price competition results in overestimation of profits by 12%–79%, and accounting for price competition increases realized profits by up to 3.4%. The efficiency, convergence stability, and ease of implementation of the proposed approach enables practical implementation for new product design problems in competitive markets.
MEMS Passive Latching Mechanical Shock Sensor
Authors: Wittwer Jonathan W. , Baker Michael S. , Epp David S. , Mitchell John A.
Published: July 2009

This paper presents a novel micro-scale passive-latching mechanical shock sensor with reset capability. The device integrates a compliant bistable mechanism, designed to have a high contact force and low actuation force, with metal-to-metal electrical contacts that provide a means for interrogating the switch state. No electrical power is required during storage or sensing. Electrical power is only required to initialize, reset, self-test, or interrogate the device, allowing the mechanism to be used in low-power and long shelf-life applications. The sensor has a footprint of about 1 mm2, allowing multiple devices to be integrated on a single chip for arrays of acceleration thresholds, redundancy, and/or multiple sense directions. Modeling and experimental results for a few devices with different thresholds in the 100g to 400g range are given. Centrifuge test results show that the accelerations required to toggle the switches are higher than current model predictions. Resonant frequency measurements suggest that the springs may be stiffer than predicted. Hammer-strike tests demonstrate the feasibility of using the devices as sensors for actual mechanical shock events.
Simulation and Application of Fuzzy Theory for Supercritical Carbon Dioxide Extraction of Green Tea
Authors: Sheu Shane-Rong , Jang Ming-Jyi , Wang Cheng-Chi , Tsai Chih-Ho , Hsueh Yao-Ching
Published: July 2009

This study performs a series of experimental investigations to determine the temperature and pressure conditions which maximize the quantities of caffeine and EGCG extracted from green tea using a supercritical fluid extraction process with a carbon dioxide solvent. The experimental data are then used to construct a fuzzy model for predicting the extractant quantities given the temperature and pressure conditions of the extraction process. The average discrepancy between the experimental results and the predicted results for the quantities of caffeine and EGCG extracted at temperatures of 40°C, 50°C and 60°C, respectively, is found to be just 7.38%, thus confirming the viability of the fuzzy model as a predictive tool. Overall, the results reveal that a temperature of 40°C and a pressure of 2500 psi represent the optimum extraction conditions for both caffeine and EGCG.
Mathematical Imbalance Determination From Vibrational Measurements and Industrial Applications
Authors: Niebsch Jenny , Ramlau Ronny
Published: July 2009

The paper focuses on the identification of imbalances from vibrational measurements in rotating machinery and its application to industrial problems. Since it is an ill-posed inverse problem the reconstruction is based on regularization techniques. To handle the direct problem, a model of the rotor under consideration has to be provided. We have employed the imbalance reconstruction principle to several industrial applications of linear and nonlinear nature.
Agent Based Modelling to Improve Comfort and Save Energy in the Built Environment
Authors: Zeiler Wim , Boxem Gert , van Houten Rinus , van der Velden Joep , Wortel Willem , Kamphuis Rene
Published: July 2009

In Europe comfort in buildings needs 40% of the total energy. With effects of Global warming becoming more and more apparent there is a need to reduce this energy demand by comfort within the built environment. In comfort control strategy there is an exciting development based on inclusive design: the user’s preferences and their behaviour have become central in the building services control strategy. Synergy between end-user and building is the ultimate in the intelligent comfort control concept. This new comfort control technology is based on the use of agent technology and can further reduce energy consumption of buildings while at the same time improve individual comfort. The TU/e (Technische Universiteit Eindhoven) together with Kropman and ECN (Energy research Centre Netherlands) work together in the research for user based preference indoor climate control technology. Central in this approach is the user focus of the whole building design process which makes it possible to reduce energy consumption by tuning demand and supply of the energy needed to fulfill the comfort demand of the occupants building.
Artificial Neural Networks for Solving of Optics Inverse and Direct Problems
Authors: Abrukov Victor S.
Published: July 2009

Possibilities of artificial neural networks (ANN) to solve problems of determination of local characteristics (an inner structure of an object) and integral characteristic (estimation of an object as a whole) in a case of incomplete information about object image (or an object signal) are presented. It is very important when an object cannot be visualized (registered) as a whole as well as in a number of other cases when ordinary methods of solution of inverse problems and direct tasks can not be used. Possibilities of using of the only one (one-point measurement) or two (two-point measurement) values of a signal distribution function in a plane of the registration in order to determine a full distribution of local characteristics in an object with a cylindrical symmetry as well as its integral characteristics are shown. In a case of homogeneous object, ANN allow to define a form, size and orientation of an object. In prospects, ANN can be used for creation of automated systems for diagnostics, testing and control in various fields of scientific and applied research as well as in industry.
A Structure-Based Approach to Measuring Adaptability of Product Design
Authors: Shao X. Y. , Cheng Q. , Zhang G. J. , Li P. G. , Gu P. H.
Published: July 2009

Adaptable design aims to extend the utilities of designs and products. Adaptability is classified into product and design adaptabilities. Product adaptability indicates that functionality and life can be extended for both economical and environmental benefits. Design adaptability improves design reuse by using existing designs to develop new designs more efficiently. To evaluate adaptable design, it is necessary to develop a method for quantitative measurement of the adaptability of products. A new method has been developed that first analyzes the independencies of functions and functional modules and then evaluates the adaptability of interfaces with two indices, as well as the performances of adaptive requirements. The effectiveness of the proposed method is demonstrated by an illustrative example of personal computer motherboards. The results show that the method can evaluate and reveal product adaptability for improving design and providing innovative design.
Kinematic Analysis and Parameter Sensitivity to Hard Points of Five-Link Rear Suspension Mechanism of Passenger Car
Authors: Balike Krishna Prasad , Rakheja S. , Stiharu Ion
Published: July 2009

An existing kinematic model is discussed in this paper for its suitability for the kinematic analysis and synthesis of five-link rear suspension mechanism of a passenger car. The formulations for the trajectory of wheel center and contact patch along with other basic suspension kinematic parameters, as a function of wheel jounce and rebound are discussed and simulated. A model of the suspension is built in Multi-body Dynamics software ADAMS/view to validate the discussed model. The simulation results of kinematic model are found to be influenced by magnitude of the assumed velocity component of wheel center, however when a small magnitude of velocity is assumed as the input to the model the results match with the ADAMS model. A sensitivity analysis method is discussed in this paper which reveals the influence of suspension joint locations on the wheel center trajectory and other kinematic parameters. The information obtained from the sensitivity analysis can be effectively used for tuning of the hard points to obtain desired kinematic parameters. Using the results of sensitivity analysis, two of the hard points of an existing suspension are relocated and was verified by kinematic analysis of the modified suspension that the modification had resulted in an improved camber variation with a slight compromise on ride height.
Design for Manufacturing (DFM) Methodology to Implement Friction Stir Welding (FSW) for Automobile Chassis Fabrication
Authors: Bagaitkar Harish , Allada Venkat
Published: July 2009

The manufacturing functional feasibility of implementing Friction Stir Welding (FSW) for automobile chassis fabrication is discussed using a case study. In the case study, the Design for Manufacturing (DFM) principles are applied to manufacture an aluminum automobile chassis. Various DFM issues are addressed while proposing the FSW technique as an alternative to laser welding and metal inert gas welding techniques. DFM guidelines involving joint design change, component geometries, and component elimination are discussed in this paper. By making appropriate changes in the component geometries and joint designs and eliminating some components, more than 50% of the joints in the example case study could be welded using the FSW technique.
General Polyhedral Finite Elements for Rapid Nonlinear Analysis
Authors: Rashid Mark M. , Selimotic Mili , Dinar Tarig
Published: July 2009

An analysis system for solid mechanics applications is described in which a new finite element method that can accommodate general polyhedral elements is exploited. The essence of the method is direct polynomial approximation of the shape functions on the physical element, without transformation to a canonical element. The main motive is elimination of the requirement that all elements be similar to a canonical element via the usual isoparametric mapping. It is this topological restriction that largely drives the design of mesh-generation algorithms, and ultimately leads to the considerable human effort required to perform complex analyses. An integrated analysis system is described in which the flexibility of the polyhedral element method is leveraged via a robust computational geometry processor. The role of the latter is to perform rapid Boolean intersection operations between hex meshes and surface representations of the body to be analyzed. A typical procedure is to create a space-filling structured hex mesh that contains the body, and then extract a polyhedral mesh of the body by intersecting the hex mesh and the body’s surface. The result is a mesh that is directly usable in the polyhedral finite element method. Some example applications are: 1) simulation on very complex geometries; 2) rapid geometry modification and re-analysis; and 3) analysis of material-removal process steps following deformation processing. This last class of problems is particularly challenging for the conventional FE methodology, because the element boundaries are, in general, not aligned with the cutting geometry following the deformation (e.g. forging) step.
Overcoming Blocks in Conceptual Design: The Effects of Open Goals and Analogical Similarity on Idea Generation
Authors: Tseng Ian , Moss Jarrod , Cagan Jonathan , Kotovsky Kenneth
Published: July 2009

Designers have been known to seek analogical inspiration during design ideation. This paper presents an experiment that studies the types of analogies that most impact design creativity, as well as the time during problem solving when it is most effective to seek such analogical stimulation. This experiment showed that new information that was highly similar to the problem affected problem solving even if the information was given before problem solving began. On the other hand, new information that was distantly related to the problem only affected problem solving when it was presented during a break after problem solving had already begun. These results support the idea that open goals increase the likelihood that distantly related information become incorporated into problem solving. Functional principles found in the problem-relevant information given were also found to prime solutions in corresponding categories.
Use of Analogies by Novice and Experienced Design Engineers
Authors: Ahmed Saeema , Christensen Bo T.
Published: July 2009

This paper describes a study to understand the use of analogies by design engineers with different levels of experience. Protocol analyses of twelve design engineers have been analysed to understand the functions and reasoning of the analogies. The protocols are real world data from the aerospace industry. The findings indicate a significant difference in both the functions and reasoning by novices and experienced designers. Novices were found to predominantly transfer information without explicit reference to design issues, whereas experienced designers tended to either solve or identify problems. Experienced designers were found to reason about the function of a component and to some degree the predicted behaviour of the component, whereas the novices seem to lack such reasoning processes.
Closed Form Dimensional Synthesis of a High-Accuracy Four-Position Tilt Mechanism
Authors: Tahmasebi Farhad
Published: July 2009

The conceptual and closed-form dimensional synthesis of a high-accuracy four-position tilt mechanism is discussed in detail. The mechanism, which consists of a customized five-bar linkage, is capable of accurately rotating an optical bench, which supports an object such as a space instrument, or another type of similar platform to four required and discrete angular postures. The mechanism is driven by two stepper motors. Due to the special characteristics of the five-bar linkage, even relatively large stepper motor errors produce very minor errors in the four desired angular postures of the optical bench. The dimensional synthesis of the mechanism involves solving a system of four non-linear equations in four unknowns. A methodology is introduced for reducing this system of non-linear equations to a closed-form quadratic equation in one unknown. A numerical example of the closed-form dimensional synthesis methodology is also presented.
Quantifying Aesthetic Form Preference in a Utility Function
Authors: Orsborn Seth , Cagan Jonathan , Boatwright Peter
Published: July 2009

One of the greatest challenges in product development is creating a form that is attractive to an intended market audience. Functional product features are easier to test and verify through user surveys and consumer interactions. But, aesthetic preferences are as varied as the people that respond to these products. Currently, there is no technique that clearly and concisely quantifies aesthetic preference. The common methods use semantics like “strong” and “sexy”. A designer then needs to take the consumer’s desire for a certain aesthetic and translate that into a form that the consumer will find desirable. This translation is a gap in understanding that often is not crossed successfully, such as in the creation of the Pontiac Aztek. By providing the designer with a method for understanding and quantifying a consumer’s aesthetic preference for a product’s form, this gap can be closed. The designer would have concrete directions to use as a foundation for development of the product form. Additionally, the quantification of the aesthetics could be used by the designer as leverage when engineering and manufacturing decisions are made that might adversely affect the product form. This paper demonstrates how a qualitative attribute, like form, can be represented quantitatively. This quantification can be molded into a utility function which through design of experiments can be used to capture an individual’s preference for the indicated attributes. Once preference is summarized in the utility function, the utility function can be used as the basis for form generation and modification or design verification.
The Design of New Type Multipoint Mortise Locks
Authors: Huang Hsing-Hui , Yan Hong-Sen , Lin Yi-Ming
Published: July 2009

Locks are important safety devices in our daily lives. The purpose of this study is to design new mechanisms of multipoint mortise locks based on a systematic approach. Firstly, the classification and advantages of mechanical locks are introduced, and the definitions and the development of mortise locks are described. Then, the multipoint mortise locks are decomposed into four sub-parts by the different functions, including the latch bolt lock, the dead bolt lock, the dead-latch bolt lock, and the connecting mechanism. The four sub-parts are further analyzed to conclude their structural characteristics as well as design requirements and constraints. Based on Yan’s creative mechanism design methodology, the concepts and the atlas of designs are synthesized systematically. One feasible mechanism is further chosen for detail design. Finally, a computer program for simulation is developed and prototypes are built for verifying the design results. The results of this study provide a valuable reference for designing multipoint mortise locks and for the analysis of mechanism characteristics of mortise locks.
Conceptual Stress and Conceptual Strength for Functional Design-for-Reliability
Authors: Huang Zhaofeng , Jin Yan
Published: July 2009

Stress and Strength Interference Theory (SSIT) is a fundamental theory for reliability assessment. It has been widely used as a foundation for design-for-reliability (DFR). However, SSIT and associated methodology and tools, that require detailed definitions of constructional and form structure, are only applicable to an embodiment design. As many researchers have attempted to push DFR upfront to a conceptual and functional design stage, SSIT loses its usefulness, while other equivalent theory and tools for conceptual and functional design-for-reliability do not exist. Therefore, DFR for conceptual and function design becomes ad-hoc that lacks a systematic approach and parametric reliability quantification. In this paper, we first review the literature on stress and strength interference, and then extend the concepts of stress and strength to conceptual stress and conceptual strength that are relevant to conceptual and functional designs. Based on the conceptual stress and conceptual strength, we introduce a Conceptual Stress and Conceptual Strength Interference Theory (CSCSIT) and discuss how it can be applied to support conceptual and function design-for-reliability. We illustrate our theoretical work with a conceptual and function design example. We conclude the paper with a discussion of the future research to further define and substantiate the CSCSIT work.
Description Logic for Product Information Models
Authors: Fiorentini X. , Rachuri S. , Mahesh M. , Fenves S. , Sriram Ram D.
Published: July 2009

The languages and logical formalisms developed by information scientists and logicians concentrate on the theory of languages and logical theorem proving. These languages, when used by domain experts to represent their domain of discourse, most often have issues related to the level of expressiveness of the languages and need specific extensions. In this paper we analyze the levels of logical formalisms and expressivity requirements for the development of ontologies for manufacturing products. We first discuss why the representation of a product model is inherently complex and prone to inconsistencies. We then explore how these issues can be overcome through a structured knowledge representation model. We report our evaluation of OWL-DL in terms of expressivity and of the use of SWRL for representing domainspecific rules. We present a case study of product assembly to document this evaluation and further show how the OWL-DL reasoner together with the rule engine can enable reasoning of the product ontology.
Comparing Component Functional Template Modeling Experimental Results in an Undergraduate Level Engineering Design Course
Authors: Abbott Daniel , Grantham Lough Katie
Published: July 2009

Component functional templates are a foundational tool, for the functional modeling method, that novice users can implement to develop functional modeling skills and produce better results by not requiring the modeler to have extensive background knowledge in the method. The templates provide common function layouts of ordinary electromechanical components that are based on historic data collected from design information on a wide range of consumer products. A previous experiment has been performed on a sophomore level design class to assess the change in quality between functional modeling results with and without the use of component functional templates. To address further evaluation of the usefulness the templates, another experiment was performed on multiple sections of an undergraduate engineering design course, controlling the amount of time that the students are exposed to the templates, in order to eliminate any extended exposure biases in the models using the templates. Quality and accuracy of the resulting models were gauged using a metric consisting of function structure, number of functions, flow representation through a chain, and product representation (the same metric used in the previous experiment). The results show that the students using the component functional templates consistently made fewer mistakes in their models in all categories than those that did not use them and thus, produced better models in terms of quality and accuracy.
Teaching Multinational, Multidisciplinary Sustainable Product Development
Authors: Agogino Alice M. , Beckman Sara L. , Borja Vicente , Lo´pez Marcelo , Shedroff Nathan , Rami´rez Alejandro C.
Published: July 2009

This paper describes a multinational program aimed at teaching processes and methods for sustainable product development using multidisciplinary project-based teams. The foundation course teaches processes for designing sustainable products and services, metrics and evaluation methods through a combination of lectures, project work, and examination of actual business cases. It is to be followed by courses on green manufacturing and pre-commercialization planning. The program features bi-national collaboration between the U.S. and Mexico, motivated by our shared vision for the development of sustainable solutions in a global context. The exploratory foundation course of the program, Design for Sustainability, was taught in Fall 2007 at the University of California at Berkeley with students and faculty members from 14 disciplines and three institutions: University of California at Berkeley (UCB), the California College of the Arts (CCA) in San Francisco, and the National University of Mexico (UNAM) in Mexico City. This paper describes the course content, project experiences, faculty evaluation and student lessons learned from the foundation course as well as a proposed three-phase strategy for future program development.
Double Pendulum Balanced by Counter-Rotary Counter-Masses as Useful Element for Synthesis of Dynamically Balanced Mechanisms
Authors: Van der Wijk Volkert , Herder Just L.
Published: July 2009

Complete dynamic balancing principles still cannot avoid a substantial increase of mass and inertia. In addition, the conditions for dynamic balance and the inertia equations can be complicated to derive. This article shows how a double pendulum can be fully dynamically balanced by using counter-rotary counter-masses (CRCMs) for reduced additional mass and inertia. New CRCM-configurations were derived that have a low inertia, a single CRCM or have all CRCMs near the base. This article also shows how a CRCM-balanced double pendulum can be used as building element in the synthesis of balanced mechanisms for which the balancing conditions and inertia equations can be written down quickly. For constrained mechanisms the procedure is to first write down the known balancing conditions and inertia equations for the balanced double pendula and subsequently substitute the kinematic relations.
Laser Beam Trajectory Generation for Micro-Manufacturing With a Two-Photon Polymerization Technique
Authors: Liao Chao-Yaug , Le´on Jean-Claude , Masclet Ce´dric , Bouriau Michel , Baldeck Patrice L. , Chung Tien-Tung
Published: July 2009

Micro-manufacturing with a Two-Photon Polymerization (TPP) technique is an emerging manufacturing technique to produce small objects of tens of μm size. Combined with three axes numerically controlled equipment, it becomes possible to produce a wide diversity of product shapes. As a result, controlling this equipment while taking into account the manufacturing constraints raises the problem of trajectory generation. It is the purpose of this paper to show how this trajectory generation process can take advantage of the three numerically controlled axes to produce complex-shaped objects. Here, it is shown how the concept of layered manufacturing commonly used in rapid prototyping can be superseded by a combination of different path planning strategies, much in the same way free-form surfaces or complex shapes can be produced with classical milling machines. Through the proposed process, the boundary decomposition process applied to an object reduces to a set of sub-domains where groups of parallel trajectories are generated. The proposed trajectory generation process takes also into account the manufacturing constraints specific to TPP to produce microstructures of high quality. Examples of products illustrate the proposed approach and demonstrate its capabilities.
A Review of Recent Phase Transition Simulation Methods: Transition Path Search
Authors: Lasrado Vernet , Alhat Devendra , Wang Yan
Published: July 2009

In this paper, we give a review of recent transition path search methods for nanoscale phase transition simulation A potential energy surface (PES) characterizes detailed information about phase transitions where the transition path is related to a minimum energy path on the PES. The minimum energy path connects reactant to product via saddle point(s) on the PES. Once the minimum energy path is generated, the activation energy required for transitions can be determined. Using transition state theory, one can estimate the rate constant of the transition. The rate constant is critical to accurately simulate the transition process with sampling algorithms such as kinetic Monte Carlo.