bluuebunny/crossref_metadata_2025 huggingface dataset:
Aircraft Detail Design Course at Embry-Riddle Aeronautical University
Authors: Gonzalez Luis
Published: January 2015

The capstone course in aircraft detail design at the Aerospace Engineering department of Embry-Riddle Aeronautical University will be presented. It is structured as a balanced mixture of lectures and a real-world project given by industry with some other activities carefully conceived to address specific deficiencies encountered in traditional engineering education; specifically, the dissociation in the students minds, or even practicing engineers, between abstract or numerical analysis and real-world design. In earlier semesters students tend to be exposed only to “clean” problems, where only one type of loading or deformation is considered or where certain aspects of the problem, such as attachments, are left out. Furthermore, in many cases these disciplines are taught in isolation, detached from their natural context. This results in students lacking a sense of feel and touch for structural analysis, something also observed for other engineering disciplines; capable of manipulating mathematical formulae but without understanding what the numbers they calculate really mean and therefore deprived of confidence about whether their design is sound or not. A special innovative learning experience at the beginning of the term has been implemented to deal with these problems, which consists, in essence, in a condensed version of the semester-long project.
Conception and Design of Mobile Driving Simulators
Authors: Wagner Paul , Betz Alexander , Winner Hermann
Published: January 2015

Driving simulators (DS) are an indispensable developmental tool in the automotive industry. Versatile areas of application all profit from the high degree of reproducibility and safety of DS. The upcoming demands for advanced driver assistance systems (ADAS) with respect to urban traffic situations result in increasing DS requirements in regard to motion envelope and system dynamics [1]. To fulfill those increased requirements, modern-day DS show up to 12 degrees of freedom (DOF) whilst comprising multiple drive mechanisms. These improvements come with the disadvantage of creating a complex system with increased moving mass of about 80 t. Thus, a link between moving mass and motion envelope is caused, limiting either motion envelope or system dynamics.

Mobile dynamic DS solve the core problem of the increased moving mass. The proposed design of a Wheeled Mobile Driving Simulators (WMDS) shows three self-propelled and active steerable wheels that allow translational motion and yaw [2]. The main idea is based on the assumption that a wheeled system, whose propulsion is limited by friction forces, is suitable to simulate dynamics of vehicles that are also limited by tire friction forces. An additional system provides cabin tilt. Avoiding the conventional rail systems, which mainly cause the moving mass increase, results in a light weight concept [3]. The design and construction of the WMDS are carried out at the Institute of Automotive Engineering (Fahrzeugtechnik Darmstadt: FZD), Germany since 2010.

This paper shows the evaluation of a suitable design — by the standards of modern product development — in general for mobile dynamic DS and specifically for WMDS. Furthermore, this paper shows the selection of the individual components and overall properties as well as limitations of the prototype.
Parallel Implementation of Periodic Boundary Conditions for a Curvilinear Immersed Boundary Method
Authors: Daghooghi Mohsen , Borazjani Iman
Published: January 2015

In this paper, a periodic boundary condition is implemented for 3D unsteady finite volume solver for incompressible Navier-Stokes equations on curvilinear structured grids containing moving immersed boundaries of arbitrary geometrical complexity. The governing equations are discretized with second-order accuracy on a hybrid staggered/non-staggered grid layout. The discrete equations are integrated in time via a second-order fractional step method. To resolve all the relevant scales in the flow accurately, a high-resolution curvilinear mesh is required, i.e., the simulations are computationally expensive. Therefore, high-performance parallel computing is essential to obtain results within reasonable time for practical applications. The main challenge with the implantation of the parallel periodic boundary condition is to update information at ghost nodes on different processors. An efficient parallel algorithm is implemented to update the ghost nodes for the periodic boundary condition. The parallel implementation is tested by comparing the results with analytical solutions, which are found to be in excellent agreement with each other. The parallel performance of the solver with the periodic boundary condition is also investigated for different cases.
A Novel Design Optimization Method for Obtaining Desired Deformation Behavior in Additively Manufactured Multi-Material Parts
Authors: Gopi Ranjit , Das Sonjoy , Rai Rahul
Published: January 2015

This paper introduces a novel design optimization method to optimize models with multiple material layers and complex cross-sections, for desired behavior. The developed optimization procedure utilizes an upscaling approach to approximate a full scale finite element (FE) model, by only analyzing a small material volume element. This approach requires less modeling efforts and is computationally less expensive than the full scale model. The developed method helps in building computationally efficient models for obtaining desired deformation behavior. The efficacy of the proposed method is illustrated through a couple of example design problems.
Simultaneous Resonances of Electrostatically Actuated MEMS Resonators
Authors: Caruntu Dumitru I. , Reyes Christian
Published: January 2015

This paper deals with simultaneous resonance of MEMS cantilever resonator sensors under double electrostatic actuation. The system consists of a MEMS cantilever between two parallel fixed plates. The two frequencies of actuation are one near natural frequency, and the other near half natural frequency. The frequency response of the structure is investigated, and parameter influences reported.
Optimal Damped Vibration Absorber: Including Multiple Modes and Excitation due to Rotating Unbalance
Authors: Sinha Alok
Published: January 2015

Optimal vibration absorbers are designed using the definition of H-infinity norm and numerical optimization. The cases of both constant amplitude excitation, and rotating unbalance excitation are considered. The design procedure is quite general, and can easily handle multiple modes of vibration. A general procedure to construct a root loci plot is also developed. Using a cantilever beam, numerical results are presented.
MBSVT: Software for Modeling, Sensitivity Analysis, and Optimization of Multibody Systems at Virginia Tech
Authors: Zhu Yitao , Dopico Daniel , Sandu Corina , Sandu Adrian
Published: January 2015

This paper introduces MBSVT (Multibody Systems at Virginia Tech), as a software library for the kinematic and dynamic simulation of multibody systems, with forward kinematics and dynamics, direct and adjoint sensitivity analysis, and optimization capabilities. The MBSVT software was developed in Fortran 2003 as a collection of Fortran modules and it was tested on several different platforms using multiple compilers. The kinematic library includes dot-1 constraint, revolute, spherical, Euler, and translational joints, as well as distance and coordinates driving constraints. The forward dynamics uses the penalty formulation to write the equations of motion and both explicit and implicit Runge-Kutta numerical integrators are implemented to integrate the equations. The library implements external forces, such as translational spring-damper-actuator, bump stop, linear normal contact, and basic tire force. Direct and adjoint sensitivity equations are implemented for the penalty formulation. The L-BFGS-B quasi-Newton optimization algorithm [1] is integrated with the library, to carry out the optimization tasks. MBSVT also provides a connection with Matlab by means of the Matlab engine. 3D rendering is available via the graphic library MBSVT-viz based on OpenSceneGraph. The collection of benchmark problems provided includes a crank-slider mechanism, 2D and 3D excavators models, a vehicle suspension, and full vehicle model. The distribution includes a Cmake list, gfortran make files, MSV2010 project files, and a collection of training problems. Detailed doxygen documentation for the MBSVT library is available in html and pdf formats.
Free Vibration Analysis of FG Skew Plates Based on Second Order Shear Deformation Theory
Authors: Bakhtiari-Nejad Firooz , Shamshirsaz Mahnaz , Mohammadzadeh Mohammad , Samie Sasan
Published: January 2015

In this paper free vibration analysis of skew plates with fully clamped boundary condition made of functionally graded materials is investigated. The study is based on the second order shear deformation plate theory (SSDT) using Generalized Differential Quadrature (GDQ) method. With a proper transformation, partial differential equations of a rectangular plate in Cartesian coordinates into skew coordinates are obtained; the governing differential equations are seven second order partial differential equations. The comparison of simulation results with those presented previously in the literature shows the accuracy of the proposed method. Also, fast rate of convergence is achieved by this method. Finally, the effects of angle of skew plate, power law index and plate geometrical parameters on the natural frequencies of the plate are also obtained and the related results are presented in this paper.
Nonlinear Analysis of a Z-Shaped Planar Beam
Authors: Zhang Wei , Hu Wenhua , Cao Dongxing , Yang Xiaofeng
Published: January 2015

In this paper, a z-shaped planar inextensible beam with harmonic foundation excitations is considered. The linear frequencies and modes of the beam with various folding angles are obtained through analytical formulations, and validated by numerical simulations. The continuous system is truncated into a system of ordinary differential equations with quadratic nonlinear terms by using the Galerkin method based on the modes obtained under a special folding angle, which may bring about modal interactions. The nonlinearities of the system are researched under the combined resonances, such as primary and internal resonances.
Energy and Resource Efficiency in the Abrasive Flow Machining Process: An Assessment of Environmental and Economic Viability Within a UK Precision Machining SME
Authors: Howard Mitchell J. , Cheng Kai
Published: January 2015

Environmental performance of the abrasive flow machining (AFM) process is currently not well understood. Its flexibility as a manufacturing process has only recently been realised in SMEs (Small to Medium Enterprise) as a feasible automated alternative to deburring and polishing of complex geometry by hand, and as an alternative to honing and grinding using semi-automated machinery. [1–3]

Economic benefit is still the main driver in the commercial uptake of environmentally-sustainable technologies [4, 5]; despite AFM’s known flexibility and capability, this paper presents systematic research by focusing on AFM including, 1) assessing and comparing the requirements of competing processes (values sourced from [6]), 2) their power consumption, 3) operating conditions, 4) cost of pre-requisite ancillary equipment and 5) embodied energy and recyclability of machine structures and consumables. Three workpiece scenarios are laid out (distinguished by feature-count, processing time, tolerance-demands and setup-count) for comparison purposes — the trade-off between environmental and economic cost is described with reference to industrially-significant quality measures such as repeatability, accuracy, precision and uniformity. Key findings in this research include the comparatively high energy demand from natural gas-fired warm air blow-heaters, a requirement for the heating of spaces for human labour activity. Performance is shown to be limited by design — the AFM machine in this study operates with only an additional 22% of current between idle mode and production mode [7] suggesting sub-assembly redesign may be of benefit. To conclude, the AFM process offers a clear route to sustainable part-finishing, low-maintenance and high potential for ‘greening’ considering factors in addition to running cost.
A Methodology for Addressing Defects in Transfer Moulding as an Encapsulating Technique for Semi-Conductors
Authors: Farrugia Philip , Vella Pierre , Kinsella Godwin Cutajar
Published: January 2015

One of the manufacturing steps involved in fabricating semiconductor devices is encapsulation, whose function is to protect the semiconductor device by sealing the package from environmental hazards such as heat, humidity and vibration. Transfer moulding, as an encapsulation technique, offers various advantages over other techniques such as injection moulding. In most cases it is difficult to foresee the effect of a design decision on a complex semiconductor process such as transfer moulding, since process robustness is rarely a function of a single property and is affected by several different parameters. A literature review reveals that whilst support has been developed to help relevant stakeholders to detect and rectify problems associated with fabrication of semiconductors, such as die design, photolithography and ion implantation, support aimed at guiding process engineers and other relevant stakeholders to rapidly deal with transfer moulding defects, are lacking. Within this context, the research reported in this paper is aimed at developing a methodology relevant to transfer moulding which guides stakeholders in identifying and rectifying mouldability problems concerning new semiconductor devices. The proposed methodology is aimed at capitalizing efforts on the production preparation phase of the Integrated Product Development model before problematic semiconductor products reach the execution phase. The methodology is the key contribution of this paper. The evaluation results collectively provide a degree of evidence that the developed methodology helps relevant stakeholders in this direction.
NREL Phase VI Wind Turbine Modeling Using an Unsteady Panel Method
Authors: Grigoriev Eugene , Borazjani Iman
Published: January 2015

Wind energy production has been increasing steadily in the past decade. The majority of wind power is generated by horizontal axis wind turbines (HAWT). We investigate the modeling of the HAWT using the vortex panel method, which is an inviscid, steady, computationally inexpensive method. Pressure coefficient profiles, calculated by the vortex panel method, were compared to NREL phase VI wind turbine experiments under two different flow conditions. We show that if the flow is not separated over the blade, the vortex panel method can capture the pressure profile on the blade. Furthermore, the panel method has been extended to handle unsteady inviscid flows to investigate the effect of blade oscillations on the power generation, which is not known. The unsteady behavior is modeled by accounting for the time rate of change of circulation. Unsteady effects due to heaving and pitching motion were quantified for different blade oscillation frequencies. It is estimated that the mean thrust coefficient with heaving and pitching motion can be higher than the thrust generated without blade motion in some cases assuming that the flow does not separate.
Evaluating the Effect of Interactions Between Appearance-Related Product Designs and Facial Characteristics on Social Affectivity
Authors: Lo Cheng-Hung , Chu Chih-Hsing , Huang Szu-Hao
Published: January 2015

For products that can improve the appearance of the user, such as facial accessories, both the characteristics of the product user and design features must be considered in design evaluation. This paper proposes an experimental evaluation scheme that investigates the interactions between the design features of 3D eyeglasses frames and user facial characteristics. Face models of users containing both geometric and image data were constructed using 3D scanning. A face deformation method was developed to manipulate individual facial features without changing the other features on the face models. In the evaluation scheme, participants judged synthetic faces, which had varied eye distances and orientations and were wearing factorized eyeglasses frames, according to three affective measures related to the personality attributes of confidence, friendliness, and attractiveness. The experimental results show that changing certain design features influences the impressions of the face models with varied facial characteristics. The proposed scheme facilitates designing products that strengthen the impression of specific personality traits by accommodating individual differences in facial features.
Safety and Usability Design Method Based on Gaps Between Designer and User
Authors: Murakami Tamotsu , Yasumi Takashi , Togo Naoyuki , Ueda Kazutaka , Sano Yasunobu
Published: January 2015

It is very important for designers to ensure the safety and usability of products. In this paper, a gap model between designers and users is first proposed as a framework to detect problems in safety and usability and to analyze the causes. Then methods to describe operations on a product, simulate its behavior as state transitions, and detect safety and effectiveness gaps based on temporal intervals and their qualitative relationships are proposed. The proposed methods are implemented in a gap analysis program (GAP), which is used to analyze the operations of a tractor by eight general participants and four employees of a tractor-manufacturer. As a result, potential safety and effectiveness gaps are correctly detected.
Power System Identification Through Simultaneous Model Selection and Bayesian Calibration
Authors: Viana Felipe A. C.
Published: January 2015

Computer models are very important to planning, operation, and control of power system. Although elements such as generators and transmission lines have been relatively well understood, developing a comprehensive power system model is a daunting task because challenges associated with loads modeling (they change all the time and utilities have very little control on). Unfortunately, inaccurate load models have serious implications such as unsafe operating conditions, power outages, under-utilization of system capacity, or inappropriate capital investment. This paper presents the use of state-of-the art Bayesian calibration framework for simultaneous load model selection and calibration. The approach aims at identifying configuration and reducing parameters uncertainty of the Western Electricity Coordinating Council’s (WECC) composite load model in the presence of measured field data. The success of the approach is illustrated with synthetic field data and a simplified model.
Modeling of Four-Bar Tensegrity-Membrane Systems
Authors: Yang Shu , Sultan Cornel
Published: January 2015

Tensegrity-membrane systems are lightweight and deployable structures that can be utilized in space applications such as solar sails and radar antennas. This work focuses on four-bar tensegrity-membrane systems. An energy-based method is used to determine the static configurations of four-bar tensegrity-membrane systems, and the explicit equilibrium conditions for the symmetric systems are derived. The system dynamics is studied based on the Lagrange’s method by appropriately choosing a floating reference frame for the attached membrane. The stress distribution in the membrane due to corner displacements and the free vibration modes of the membrane are determined by a polynomial series method, and are compared with the finite element results calculated by ANSYS. The linear and nonlinear simulation results of the system are presented and compared. The difference between linear and nonlinear simulation results is illustrated and discussed.
Enabling Improved Process Control Opportunities by Means of Logistics Control Towers and Vision-Based Monitoring
Authors: Alias Cyril , Kalkan Yakup , Koç Emre , Noche Bernd
Published: January 2015

Due to the lack of integration of existing IT solutions between the planning level and the execution level, many enterprises in the logistics sector are not able to achieve optimal process executions, particularly in cases of deviations and exceptions. Despite a greater supply of sensor devices over the past years, a wider spread of sensor devices has not yet taken place because the required information are either unavailable, unreliable or badly remunerative. Thereby, process control and deviation management often ends in mere troubleshooting rather than in searching for the optima in an organized manner. By adopting control towers at the interface between the two concerned levels and using low-cost cameras and image processing algorithms for the detection of objects, such lack of trust in the yielded information can be overcome. Such a vision-based monitoring tool is capable of supporting functions which are useful for the decision-making process on executional level. In the present paper, the different information which are provided by a vision-based monitoring tool are presented, followed by three application examples which show the different functionalities provided and the potential disclosed by the tool.
Active Front Steering LTV MPC for Varying Friction Conditions
Authors: De Val Nicola , Fuso Andrea , Braghin Francesco , Sabbioni Edoardo
Published: January 2015

The developed Active Front Steering (AFS) Linear Time Variant (LTV) Model Predictive Control (MPC) is a linear model predictive control based on linearization of the nonlinear vehicle model. A sensitivity analysis of the parameters of the controller is carried out on a simple path following test. Once the optimal parameters are found, both in terms of trajectory following and real-time performances, the LTV-MPC is used for determining the requirements for the necessary sensors (in terms of minimum obstacle distance detection) as a function of the vehicle speed. Then, the same analysis is carried out considering wet road conditions (i.e. the tyre-road friction coefficient is different from that accounted for by the controller).
Design and Fatigue Life Analysis of a Motorcycle Frame
Authors: Gobbi Massimiliano , Previati Giorgio , Mastinu Giampiero
Published: January 2015

An off-road motorcycle frame has been analyzed and modified to optimize its fatigue life. The fatigue life of the frame is very important to define the service life of the motorcycle.

The strain levels on key parts of the frame were collected during experimental tests. It has been possible to locate the areas where the maximum stress level is reached.

A finite element (FE) model of the frame has been developed and used for estimating its fatigue life. Static test bench results have been used to validate the FE model. The accuracy of the finite element model is good, the errors are always below 5% with respect to measured data.

The mission profile of the motorcycle is dominated by off-road use, with stress levels close to yield point, so a strain-life approach has been applied for estimating the fatigue life of the frame.

Particular attention has been paid to the analysis of the welded connections. A shell and a 3D FE model have been combined to simulate the stress histories at the welds. Two reference maneuvers have been considered as loading conditions. The computed stresses have been used to assess the life of the frame according to the notch stress approach (Radaj & Seeger). The method correlates the stress range in a idealized notch, characterized by a fictitious radius in the weld toe or root, to the fatigue life by using a single S-N curve.

New technical frame layouts have been proposed and verified by means of the developed finite element model.

The considered approach allows to speed up the design process and to reduce the testing phase.
A 3-D Pseudo-Rigid Body Model for Rectangular Cantilever Beams With an Arbitrary Force End-Load
Authors: Chimento Jairo , Lusk Craig , Alqasimi Ahmad
Published: January 2015

This paper presents the first three-dimensional pseudo-rigid body model (3-D PRBM) for straight cantilever beams with rectangular cross sections and spatial motion. Numerical integration of a system of differential equations yields approximate displacement and orientation of the beam’s neutral axis at the free-end, and curvatures of the neutral axis at the fixed-end. This data was used to develop the 3-D PRBM which consists of two torsional springs connecting two rigid links for a total of 2 degrees of freedom (DOF). The 3-D PRBM parameters that are comparable with existing 2-D model parameters are characteristic radius factor (means: γ = 0.8322), bending stiffness coefficient (means: KΘ = 2.5167) and parametric angle coefficient (means: cΘ = 1.2501). New parameters are introduced in the model in order to capture the spatial behavior of the deflected beam including two parametric angle coefficients (means: cΨ = 1.0714; cΦ = 1.0087).
A New Method for the Kinematic Synthesis of Parallel Platforms
Authors: Pérez-Soto G. I. , Rico J. M. , Cervantes-Sánchez J. J. , López-Custodio P. C. , Gallardo-Mosqueda L. A. , Camarillo-Gómez Karla A.
Published: January 2015

This contribution presents a novel theory for the kinematic synthesis of parallel platforms. The theory is based on the concepts of screw systems of locally constant rank and screw systems of locally constant rank when the sum of the joint coordinates of two or three revolutes or helical parallel pairs are equal to zero. The authors believe that the approach presented here has advantages with respect to previously presented methods.
A Hybrid Approach to Polygon Offsetting Using Winding Numbers and Partial Computation of the Voronoi Diagram
Authors: Burton Greg
Published: January 2015

In this paper we present a new, efficient algorithm for computing the “raw offset” curves of 2D polygons with holes. Prior approaches focus on (a) complete computation of the Voronoi Diagram, or (b) pair-wise techniques for generating a raw offset followed by removal of “invalid loops” using a sweepline algorithm. Both have drawbacks in practice. Robust implementation of Voronoi Diagram algorithms has proven complex. Sweeplines take O((n + k)log n) time and O(n + k) memory, where n is the number of vertices and k is the number of self-intersections of the raw offset curve. It has been shown that k can be O(n2) when the offset distance is greater than or equal to the local radius of curvature of the polygon, a regular occurrence in the creation of contour-parallel offset curves for NC pocket machining. Our O(n log n) recursive algorithm, derived from Voronoi diagram algorithms, computes the velocities of polygon vertices as a function of overall offset rate. By construction, our algorithm prunes a large proportion of locally invalid loops from the raw offset curve, eliminating all self-intersections in raw offsets of convex polygons and the “near-circular”, k proportional to O(n2) worst-case scenarios in non-convex polygons.
A Dissipative String Model for Human Tendons
Authors: Piovesan Davide , Panza Michael J.
Published: January 2015

This work presents an analytical modelling of a tendon driven system. We modelled the tendon as a continuum string using physiologically plausible value for the intrinsic characteristics of biological tissues to verify the system’s stability. We used Poincare’s sections to verify the types of attractors the system has and proved that the system is non-chaotic in a large range of physiologically plausible excitation frequencies. This work is relevant for understanding the control of force and movement as a function of the muscle contraction. Wide applications can also be found as a guideline for the design of artificial muscles and cable driven robots.
Tolerance Analysis for Validating Manufacturing Process Plans
Authors: Fu Wentao , Nelaturi Saigopal , Rangarajan Arvind , Kurtoglu Tolga
Published: January 2015

In manufacturing process planning, it is critical to ensure that the part generated from a process plan complies with tolerances specified by designers to meet engineering constraints. Manufacturing errors are stochastic in nature and are introduced at almost every stage of executing a plan, for example due to inaccuracy of tooling, misalignment of location, distortion of clamping etc. Furthermore, these errors accumulate or ‘stack-up’ as the manufacturing process progresses to inevitably produce a part that varies from the designed model. The resultant variation should be within prescribed design tolerances. In this work, we present a novel approach for validating process plans using 3D tolerance stack-up analysis by representing variations of nominal features in terms of extents of their degrees of freedom within design and manufacturing tolerance zones. We will show how the manufacturing error stack-up can be effectively represented by composition and intersection of these transformations. We demonstrate several examples with different tolerance specifications to show the applicability of our approach for process planning.
Ocean Wave Energy Harvester With a Novel Power Takeoff Mechanism
Authors: Ai Junxiao , Lee Hwan , Liang Changwei , Zuo Lei
Published: January 2015

The potential for electricity generation from ocean wave energy in the US is estimated to be 64% of the total electricity generated from all sources in 2010. Over 53% of the US population lives within 50 miles of the coast (NOAA), which means ocean waves offer ready opportunity for harvesting power. This paper will present a details progress of developing an innovative ocean wave energy harvester, with adopting an innovative power takeoff mechanism named mechanical motion rectifier (MMR), which will directly convert the irregular oscillatory wave motion into regular unidirectional rotation of the generator. It marries the advantages of the direct and indirect-drive power takeoff methods, with a much higher energy conversion efficiency and enhanced reliability and compactness. Experiment has been carried out and the results verify that the novel power take-off mechanism improved the performance of wave energy harvester.
1/F Noise-Fluctuated Cozy Lighting System for Concentration Improvement
Authors: Ito Teruaki , Honda Eiichi , Ichikawa Tetsuo , Kinouchi Yosuke , Akutagawa Masatake , Emoto Takahiro , Yoshida Midori
Published: January 2015

The power spectrum of human heart rate measured over 24 h exhibits “power-law” 1/f alpha-type spectral behavior with alpha approximately 1. This may be one of the reasons why 1/f noise help people make relaxed, or feel comfortable. As a result, people feel relaxed by looking at a candle light, listening to the sound of ocean wave, or feeling the breezing wind because all of these natural phenomenon is based on the 1/f noise fluctuation. Considering this feature, a technical approach of 1/f noise fluctuation has been applied to various industry products, ranging from light illumination, fan control, temperature control, etc. to implement cozy products. For example, one typical example would be a lighting product mimicking a candle light, which illuminate just like a true candle. A candle light provides a cozy atmosphere to relax our mind by forgetting severe business issues, which is because of the nature of 1/f noise fluctuation as mentioned above. However, it is not suitable to do something important by concentration under a candle light because of the changes of brightness and the blinking nature of candles. This study designs and develops 1/f noise-fluctuated cozy lighting system with stable brightness and chromaticity without blinking so that people unconsciously feel relaxed under this lighting system without noticing the 1/f noise fluctuation and concentrate on work or operation. In order to implement this lighting system, combination of two types of white LED lights were used. White LED lights are manufactured by the combination of different colors having different spectrum. For example, Blue with YAG fluorophore, Blue with RG fluorophore, UV with RGB fluorophore, etc. provide all white LED lights. This means that it is possible to make two different types of LED lights which have the same white color with different combination of spectrums. If the two white colors of the two LED are the same, nobody cannot notice when the two LEDs are switching over each other, periodically or randomly. People only think that the white color is constantly provided by the white LED light. However, if the switching is based on 1/f noise fluctuation, some positive effect can be expected under this lighting system. This paper shows the overview of the idea of 1/f noise-fluctuated cozy lighting system, and then presents the two basic challenges of the idea towards concentration improvement; Combination of two types of white LED and 1/f noise-fluctuated switching system. These two challenges are presented using a prototype lighting systems developed in this study.
Eco-Design Platform Within an Extended Enterprise: How to Implement It?
Authors: Germani Michele , Mandolini Marco , Marconi Marco , Morbidoni Alessandro , Rossi Marta
Published: January 2015

Nowadays, the environmental issue has become increasingly important and has taken a leading role in the product design process. The product sustainability pass through the use of specific software tools supporting the design phase. Their integration, to build up a platform, is a key aspect toward the implementation of an effective eco-design approach.

Even if the approaches presented in literature to create an eco-design platform aim to integrate environmental aspects during the design process, a proper tools integration is not existing.

To overcome these limitations, the paper presents an eco-design platform in which tools for the improvement of the product environmental characteristics are contained. The tools of the platform are used to calculate the environmental impact of a product for each product life cycle phase: manufacturing, transportation, use and End of Life. The platform is completed by a tool containing the eco-design guidelines, also specific for the industrial sector of the company, used to suggest the designers how to improve the product eco-sustainability.

The end users of the platform consist of designers from the design office but also from every department relevant for the project, mainly R&D, production, purchasing department, and quality. In particular, the following roles have been considered as users: designer, product manager, environmental manager and buyer.

Designers and company experts use the same workspace, made of different tools. They can detail all the product life cycle phases, quantify the product performances, modify its characteristics and verify the improvements obtained without change the traditional design process in a radical way.
Ontology-Based Design Rationale Retrieval Supporting Natural Language Query
Authors: Li Luye , Qin Feiwei , Gao Shuming , Qin Xiaolian
Published: January 2015

Design rationale is an important category of design knowledge. Effective reuse of design rationale depends on its successful retrieval. In this paper, an ontology-based design rationale retrieval approach is presented, based on which, users can input natural language questions to search what they want. First, a database of ontology-based design rationale is constructed, which supports SPARQL query. Then, several SPARQL templates are defined according to different knowledge query requirements in engineering design domain. Moreover, a SPARQL query generating method is proposed to generate SPARQL query from natural language query automatically through template matching and keywords extending. Finally, a design rationale retrieval prototype system is implemented, and the experimental results show the advantages of the proposed approach.
Design and Analysis of a Novel Articulated Drive Mechanism for Multifunctional NOTES Robot
Authors: Shen Tao , Warburton Kevin , Nelson Carl A. , Oleynikov Dmitry
Published: January 2015

This paper presents a novel articulated drive mechanism (ADM) for a multifunctional natural orifice transluminal endoscopic surgery (NOTES) robotic manipulator. It consists mainly of three major components including an articulated snake-like linkage, motor housing and an arm connector. The ADM contains two independent curvature sections which can articulate into complex S shapes for improved access to surgical targets. A connector between the bimanual arms and the ADM provides an efficient and convenient way to assemble and disassemble the system as necessary for insertion and removal of the robot. Four DC motors guide four pairs of cables with linear actuation to steer the robot. The workspace, cable displacement and force transmission relationships are derived. Experimental results give preliminary validation of the feasibility and capability of the ADM system.
Designing Optimal Origami Structures by Computational Evolutionary Embryogeny
Authors: Li Wei , McAdams Daniel A.
Published: January 2015

As the advantages of foldable or deployable structures are being discovered, research into origami engineering has attracted more focus from both artists and engineers. With the aid of modern computer techniques, some computational origami design methods have been developed. Most of these methods focus on the problem of origami crease pattern design — the problem of determining a crease pattern to realize a specified origami final shape, but don’t provide computational solutions to actually developing a shape that meets some design performance criteria. This paper presents a design method that includes the computational design of the finished shape as well as the crease pattern. The origami shape will be designed to satisfy geometric, functional, and foldability requirements. This design method is named computational evolutionary embryogeny for optimal origami design (CEEFOOD), which is an extension of the genetic algorithm (GA) and an original computational evolutionary embryogeny (CEE). Unlike existing origami crease pattern design methods that adopt deductive logic, CEEFOOD implements an abductive approach to progressively evolve an optimal design. This paper presents how CEEFOOD — as a member of the GA family — determines the genetic representation (genotype) of candidate solutions, the formulation of the objective function, and the design of evolutionary operators. This paper gives an origami design problem, which has requirements on the folded-state profile, position of center of mass, and number of creases. Several solutions derived by CEEFOOD are listed and compared to highlight the effectiveness of this abductive design method.
Investigation of Rocking Semicircular and Parabolic Disk Equilibria, Stability, and Natural Frequencies
Authors: Mazzoleni Michael J. , Krone Michael B. , Mann Brian P.
Published: January 2015

This paper performs a theoretical and experimental investigation of the natural frequency and stability of rocking semicircular and parabolic disks. Horace Lamb’s method for deriving the natural frequency of an arbitrary rocking disk is applied to two shapes with semicircular and parabolic cross sections, respectively. For the case of the semicircular disk, the system’s equation of motion is derived to verify Lamb’s method. Additionally, the rocking semicircular disk is found to always have one stable equilibrium position. For the case of the parabolic disk, this investigation unveils a super-critical pitchfork bifurcation for changes in a single geometric parameter which reveals that the system can exhibit bistable behavior. Rapid prototyping technology was used to manufacture sample disks across a wide range of parameters, and a laser tachometer was used to experimentally determine the natural frequency of each disk. Comparisons between experiment and theory show good agreement.
Creating Faultable Network Models of Complex Engineered Systems
Authors: Haley Brandon M. , Dong Andy , Tumer Irem Y.
Published: January 2015

This paper presents a new methodology for modeling complex engineered systems using complex networks for failure analysis. Many existing network-based modeling approaches for complex engineered systems “abstract away” the functional details to focus on the topological configuration of the system and thus do not provide adequate insight into system behavior. To model failures more adequately, we present two types of network representations of a complex engineered system: a uni-partite architectural network and a weighted bi-partite behavioral network. Whereas the architectural network describes physical inter-connectivity, the behavioral network represents the interaction between functions and variables in mathematical models of the system and its constituent components. The levels of abstraction for nodes in both network types affords the evaluation of failures involving morphology or behavior, respectively. The approach is shown with respect to a drivetrain model. Architectural and behavioral networks are compared with respect to the types of faults that can be described. We conclude with considerations that should be employed when modeling complex engineered systems as networks for the purpose of failure analysis.
3D Printing Technologies for Tissue Engineering
Authors: Lin Weibin , Peng Qingjin
Published: January 2015

Tissue engineering (TE) integrates methods of cells, engineering and materials to improve or replace biological functions of native tissues or organs. 3D printing technologies have been used in TE to produce different kinds of tissues. Human tissues have intricate structures with the distribution of a variety of cells. For this reason, existing methods in the construction of artificial tissues use universal 3D printing equipment or some simple devices, which is hard to meet requirements of the tissue structure in accuracy and diversity. Especially for soft tissue organs, a professional bio-3D printer is required for theoretical research and preliminary trial. Based on review of the exiting 3D printing technologies used in TE, special requirements of fabricating soft tissues are identified in this research. The need of a proposed bio-3D printer for producing artificial soft tissues is discussed. The bio-3D printer suggested consists of a pneumatic dispenser, a temperature controller and a multi-nozzle changing system.
A Pilot-Control Device Model for Helicopter Sensitivity to Collective Bounce
Authors: Zanlucchi Stefano , Masarati Pierangelo , Quaranta Giuseppe
Published: January 2015

This work presents a parametric dynamic model of a helicopter collective control inceptor that includes the biodynamics of the pilot. The biodynamic feedthrough and neuromuscular admittance of a helicopter pilot are characterized using a detailed multibody analysis of the pilot’s left arm holding the inceptor as a ‘virtual experiment’ to produce the results required to identify the parameters of the coupled system. The goal is to develop an analytical model of the dynamics of the coupled pilot-device system and gain insight into the effect of several design parameters on the characteristics of the coupled system. The effect of device inertia, damping, stiffness and friction on the stability margins of the coupled system with respect to the collective bounce instability phenomenon are analyzed and discussed. The analytical model is verified using it in place of the detailed multibody model of the pilot’s arm in the fully detailed multibody simulation of the coupled system. It is then used in linearized analysis of the complete system in support of the vehicle design.
On the Applicability of Analytical Supply Chain Disruption Models for Selecting the Optimum Contingency Strategies for Electronic Supply Chain Disruption Management: A Comparison With Simulation
Authors: Allison Hannah , Sandborn Peter , Eriksson Bo
Published: January 2015

Due to the nature of the manufacturing and support activities associated with long life cycle products, the parts that products required need to be dependably and consistently available. However, the parts that comprise long lifetime products are susceptible to a variety of supply chain disruptions. In order to minimize the impact of these unavoidable disruptions to production, manufacturers can implement proactive mitigation strategies. Two mitigation strategies in particular have been proven to decrease the penalty costs associated with disruptions: second sourcing and buffering. Second sourcing involves selecting two distinct suppliers from which to purchase parts over the life of the part’s use within a product or organization. Second sourcing reduces the probability of part unavailability (and its associated penalties), but at the expense of qualification and support costs for multiple suppliers. An alternative disruption mitigation strategy is buffering (also referred to as hoarding). Buffering involves stocking enough parts in inventory to satisfy the forecasted part demand (for both manufacturing and maintenance requirements) for a fixed future time period so as to offset the impact of disruptions. Careful selection of the mitigation strategy (second sourcing, buffering, or a combination of the two) is key, as it can dramatically impact a part’s total cost of ownership.

This paper studies the effectiveness of traditional analytical models compared to a simulation-based approach for the selection of an optimal disruption mitigation strategy. A verification case study was performed to check the accuracy and applicability of the simulation-based model. The case study results show that the simulation model is capable of replicating results from operations research models, and overcomes significant scenario restrictions that limit the usefulness of analytical models as decision-making tools. Four assumptions, in particular, severely limit the realism of most analytical models but do not constrain the simulation-based model. These limiting assumptions are: 1) no fixed costs associated with part orders, 2) infinite-horizon, 3) perfectly reliable backup supplier, and 4) disruptions lasting full ordering periods (as opposed to fractional periods).
Steering Feel Improvement for Different Driver Types Using Model-Based Control
Authors: Mehrabi Naser , McPhee John
Published: January 2015

A realistic driver model can support the development of new steering technologies by reducing the time-consuming trial and error process of designing products. A neuromuscular driver model, by offering physiologically realistic steering maneuvers can provide insights into the task performance and energy consumption of the driver, including fatigue and muscle co-contraction. Here, two muscles are used in a simplified neuromuscular driver model. To study the effect of driver’s characteristics such as age, gender and physical ability on steering, the muscle parameters are adjusted to represent a particular population. Then, this modified driver model is used to to tune the Electric Power Steering (EPS) assist curves for that particular population.