bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of Upright Posture on an Active Balance Board With Tunable Time-Delay and Stiffness
Authors: Cruise Denise R. , Chagdes James R. , Raman Arvind
Published: December 2016

Neurological disorders, a concussion, or aging can extend the time-delay in the human neuromuscular balance system; this time-delay increase has been shown [5] to be an important factor contributing to the loss of balance. However, commercial balance boards used to help improve individual’s balance deficiencies do not utilize time-delay as a tunable parameter. In order to systematically study stiffness and time-delay induced instabilities in standing posture, we developed an active balance board system with controllable torsional board stiffness, as well as an added controllable feedback time-delay of the torsional board. Using this dynamical system we confirmed the presence of two distinct mechanisms of instability: insufficient stiffness leading to tipping posture and excessive time-delays leading to limit cycle oscillations. We expect that this active balance board will allow for the early identification of an increased fall-risk, especially for subjects with extended time-delays and could help provide insights into how the human postural system adapts to various environments.
Remarks on Parameter Calibration and Model Validation Based on Sensitivity
Authors: Qiu Na , Kim Nam Ho , Gao Yunkai
Published: December 2016

In this paper, different approaches to parameter calibration and model validation were compared to understand the accuracy and robustness, especially when only a small number of data are available. Conventional one-point calibration, two-point calibration, sensitivity-based calibration, discrepancy-based calibration methods are compared when the number of data is less than three. An analytical example as well as a cantilever beam model are used to demonstrate the performance and accuracy of different methods. Numerical examples indicate that the conventional calibration method that does not account for the discrepancy function may lead to biased parameter and prediction models. It also can be seen that accurate parameter can be identified only when the form of discrepancy function is accurate.
Problem Exploration With Many-Objective Visual Analytics
Authors: Woodruff Matthew , Simpson Timothy W.
Published: December 2016

This paper discusses problem exploration using Many-Objective Visual Analytics (MOVA). It describes an electric motor product family design problem, including previous attempts at optimized product family designs. The study undertaken in this study shows how MOVA can be used to progressively expose the structure of a problem and develop new design strategies in response. This study presents new designs for the electric motor product family that have superior commonality to any reported in the literature, with equivalent or superior performance for the individual motors.
A Real Options Approach to Hybrid Electric Vehicle Architecture Design for Flexibility
Authors: Kang Namwoo , Bayrak Alparslan Emrah , Papalambros Panos Y.
Published: December 2016

Manufacturers launch new product models at various time increments to meet changing market requirements over time. At each design period, product design and price may change. While price decisions can be made at product launching time, redesign decisions must be made in advance. Real options theory addresses such time gap decisions. This paper presents a real options approach with a binomial lattice model to determine optimal design and price decisions for hybrid electric vehicles (HEVs) that maximize expanded net present value of profit under gas price uncertainty over time. Results confirm that we can obtain changing vehicle attributes by changing gear ratios rather than the architectures themselves due to high cost of redesigning. A parametric study examines the impact of gas price volatility on option decisions and shows that larger volatility of gas price causes the change option to be selected more frequently.
Dynamic Instabilities Induced Through Altered Visual Cues and Their Relationship to Postural Response Latencies
Authors: Chagdes James R. , Liddy Joshua J. , Huber Jessica E. , Zelaznik Howard N. , Rietdyk Shirley , Raman Arvind , Haddad Jeffrey M.
Published: December 2016

Mathematical models predict limit cycle oscillations (LCOs) in postural sway when the combination of neuromuscular time-delay and feedback gains are excessively large. LCOs have been observed in the standing posture of various populations known to have longer time-delays including concussed young adults and adults with neuromuscular impairment such as multiple sclerosis (MS) and Parkinsons disease (PD) but not healthy controls. However, the relationship between feedback gain and time-delay that leads to these LCOs has yet to be explored experimentally. In this study, we examine the relationship between the time-delay of healthy adults and the onset of LCOs under altered visual feedback. We find that there is an inversely proportional correlation between feedback gain and intrinsic neuromuscular time-delay for which LCOs arise. This finding has implications for the assessment and diagnosis of neuromuscular related balance issues through a simple and invasive protocol similar to that used in this study.
Analysis and Characterization of Piezoelectric Energy Harvesting From Galloping and Base Excitations With Complex Electrical Circuitry
Authors: Abdelmoula Hichem , Abdelkefi Abdessattar
Published: December 2016

The characteristics and performance of piezoelectric energy harvesters concurrently subjected to galloping and base excitations when using a complex electrical circuit are studied. The considered energy harvester is composed of a bilayered cantilever beam with a square cylindrical structure at its tip. Euler-Bernoulli beam theory, nonlinear quasi-steady hypothesis, and Galerkin method are used to develop a reduced order model of this system. The electrical circuitry of the harvester consists of a load resistance, a capacitance, and an inductance. The impacts of the electrical components of the harvester’s circuitry, the wind speed, and the base excitation frequency and acceleration on the broadband characteristics of the harvester, quenching phenomenon, and appearance of new nonlinear behaviors are deeply investigated and discussed. When both coupled frequencies of electrical and mechanical types exists and are far from each other, it is shown that the quenching phenomenon is only related to the coupled frequency of mechanical type. Unlike the existence of the quenching phenomenon, the results show that the beating phenomenon takes place for different excitation frequencies when they are close to the coupled frequencies of electrical and mechanical types.
Computational Local Mobility Analysis of Mechanisms With Higher Kinematic Pairs
Authors: Müller Andreas
Published: December 2016

The finite mobility of a mechanism is reflected by its configuration space (c-space), and the mobility analysis aims at determining this c-space. Crucial for the computational mobility analysis is an adequate formulation of the constraints. For lower pair linkages an analytic formulation is the product-of-exponential (POE) formula in terms of the screw systems of the lower pair joints. In other words, the screw coordinates of a lower pair joint serve as canonical coordinates on the corresponding motion subgroup. For such linkages, a computational approach to the local mobility analysis has been reported recently. The approach is applicable to general multi-loop linkages. Higher pairs do not generate motion subgroups so that their motion cannot be expressed in terms of screw coordinates. Hence their kinematics cannot be expressed in terms of a POE, and there is no efficient and generally applicable computational method for the mobility analysis. In this paper a formulation of higher-order constraints for mechanisms with higher pair joints is proposed making use of the result for lower pair linkages. The method is applicable to mechanisms where each fundamental loop comprises no more than one higher pair, which covers the majority of mechanisms. Based on this, a computational algorithm is introduced that allows mobility determination. As for lower pair linkages, this algorithm only requires simple algebraic operations.
Characterizing the Influence of Abstraction in Full-Scale Wind Turbine Nacelle Testing
Authors: Schkoda Ryan , Bibo Amin , Guo Yi , Lambert Scott , Wallen Robb
Published: December 2016

In recent years, there has been a growing interest in full-scale wind turbine nacelle testing to complement individual component testing. As a result, several wind turbine nacelle test benches have been built to perform such testing with the intent of loading the integrated components as they are in the field. However, when mounted on a test bench the nacelle is not on the top of a tower and does not have blades attached to it — this is a form of abstraction. This paper aims to quantify the influence of such an abstraction on the dynamic response of the nacelle through a series of simulation case studies. The responses of several nacelle components are studied including the main bearing, main shaft, gearbox supports, generator, and yaw bearing interface. Results are presented to highlight the differences in the dynamic response of the nacelle caused by the abstraction. Additionally, the authors provide recommendations for mitigating the effects of the abstraction.
An Accurate Singularity-Free Formulation of a Three-Dimensional Curved Euler-Bernoulli Beam for Flexible Multibody Dynamic Analysis
Authors: Fan W. , Zhu W. D.
Published: December 2016

An accurate singularity-free formulation of a three-dimensional curved Euler-Bernoulli beam with large deformations and large rotations is developed for flexible multibody dynamic analysis. Euler parameters are used to characterize orientations of cross-sections of the beam, which can resolve the singularity problem caused by Euler angles. The position of the centroid line of the beam is integrated from its slope, and position vectors of nodes of beam elements are no longer used as generalized coordinates. Hence, the number of generalized coordinates for each node is minimized. Euler parameters instead of position vectors are interpolated in the current formulation, and a new C1-continuous interpolation function is developed, which can greatly reduce the number of elements. Governing equations of the beam and constraint equations are derived using Lagrange’s equations for systems with constraints, which are solved by the generalized-α method for resulting differential-algebraic equations. The current formulation can be used to calculate static and dynamic problems of straight and curved Euler-Bernoulli beams under arbitrary concentrated and distributed forces. The stiffness matrix and generalized force in the current formulation are much simpler than those in the geometrically exact beam formulation (GEBF) and absolute node coordinate formulation (ANCF), which makes it more suitable for static equilibrium problems. Numerical simulations show that the current formulation can achieve the same accuracy as the GEBF and ANCF with much fewer elements and generalized coordinates.
Analysis of Aerodynamic Drag on Cycling Based on Complementary Numerical and Experimental Studies
Authors: Roa Sergio D. , Ferreira Diego A. , Muñoz Luis E. , López Omar D.
Published: December 2016

Aerodynamic drag is the main opposing force that a cyclist has to overcome when cycling on level ground at moderate-to-high speeds. Therefore, the aerodynamic study of the bike-cyclist set has been identified as a key factor for the analysis and improvement of performance. Although there are many reference aerodynamic studies, for the specific analysis of a bike-cyclist set it is necessary to take into account the particular influence of the cyclist’s body shape, cyclist position and cycling equipment on aerodynamic drag. In addition, there are quantitative studies focused on analyzing aerodynamic drag using numerical and experimental methodologies; nonetheless, these studies are generally not complementary or comparative. The aim of this paper is to present the first stage of a current work that seeks to develop a complementary methodology for the aerodynamic drag analysis using numerical and experimental studies. In this stage, a numerical study based on Computational Fluid Dynamics (CFD) is presented. A digitalized cyclist body model is analyzed while the mesh characteristics and the results of the CFD simulations are addressed. On the other hand, field experimental tests were carried out by the same cyclist to determine the power demand at two cyclist’s body positions. A method for monitoring the cyclist’s body position in order to achieve repeatable positions during experimental trials is presented. Complementary information for the aerodynamic evaluation is obtained through the numerical and experimental studies, and the aerodynamic drag area results from both approaches is compared.
Evaluations That Matter: Customer Preferences Using Industry-Based Evaluations and Eye-Gaze Data
Authors: Seshadri Priya , Bi Youyi , Bhatia Jaykishan , Simons Ross , Hartley Jeffrey , Reid Tahira
Published: December 2016

This study is the first stage of a research program aimed at understanding differences in how people process 2D and 3D automotive stimuli, using psychophysiological tools such as galvanic skin response (GSR), eye tracking, electroencephalography (EEG), and facial expressions coding, along with respondent ratings. The current study uses just one measure, eye tracking, and one stimulus format, 2D realistic renderings of vehicles, to reveal where people expect to find information about brand and other industry-relevant topics, such as sportiness. The eye-gaze data showed differences in the percentage of fixation time that people spent on different views of cars while evaluating the “Brand” and the degree to which they looked “Sporty/Conservative”, “Calm/Exciting”, and “Basic/Luxurious”. The results of this work can give designers insights on where they can invest their design efforts when considering brand and styling cues.
Design, Fabrication, and Modeling of an Electric-Magnetic Self-Folding Sheet
Authors: Bowen Landen , Springsteen Kara , Ahmed Saad , Arrojado Erika , Frecker Mary , Simpson Timothy W.
Published: December 2016

A concept recently proposed by the authors is that of a multi-field sheet that folds into several distinct shapes based on the applied field, be it magnetic, electric, or thermal. In this paper the design, fabrication, and modeling of a multi-field bifold is presented that utilizes magneto-active elastomer (MAE) to fold along one axis and P(VDF-TrFE-CTFE) terpolymer to fold along the other axis.

In prior work a dynamic model of self-folding origami was developed which simulated the effect of magneto-active materials on origami-inspired designs. This dynamic model is extended to include the effect of electroactive polymers (EAP) by approximating them as combinations of torques. The accuracy of this approximation is validated using experimental data from a terpolymer-actuated design known as the barking dog. After adjusting crease stiffness within the dynamic model, it shows good correlation with experimental data, indicating that the developed EAP approximation is accurate.

With the capabilities of the dynamic model improved by the EAP approximation method and a refined MAE approximation, the multi-field bifold can be accurately modeled. The model is compared to experimental data obtained from the fabricated multi-field bifold, and is found to predict well the fold angles of the sample. This validation is a first step to the simulation, design, and fabrication of more complicated multi-field sheets.
Modelling One-Dimensional Fractional Impact Using Basic Fractional Viscoelastic Models
Authors: Dabiri Arman , Butcher Eric A. , Nazari Morad
Published: December 2016

Viscoelastic materials can be mathematically represented using integer- or order models. It has been shown in different studies that modeling a viscoelastic material usually requires an enormous number of parameters. Fractional viscoelastic models have been shown to be advantageous over integer viscoelastic models in the representation of viscoelastic materials, specifically when the system has memory or hereditary property. However, to the authors’ knowledge, no study has yet been done about fractional impact models. Thus, in this paper, fractional modified Kelvin-Voigt model and fractional Maxwell model are introduced as one-dimensional fractional impact models for basic fractional viscoelastic materials. The force-displacement hysteresis curves are obtained by using the fractional Chebyshev collocation method and the gradient of impact force, penetration depth, separation depth, and the coefficient of restitution are studies. It is shown numerically that fractional viscoelastic models behave more realistic than their integer counterparts in one-dimensional impact problems.
Feature-Based Computer Modeling and Reasoning on Mechanical Functions
Authors: Sen Chiradeep
Published: December 2016

This paper presents an approach for feature-based computer-aided modeling of functions. Features are used in geometric CAD as a means to encapsulate primitive entities and operations into more complex forms that have engineering significance, which also allows faster modeling, uniformity of data sets between similar features, and reasoning support at the features-level. In a recent research, a formal language for functions has been proposed that ensures consistency of function models against physics, esp. the balance laws of mass and energy. The language is implemented in a software tool to support physics-based reasoning. In this paper, the primitive entities and relations of this language and tool are encapsulated to define more complex function features that have engineering significance. To demonstrate the approach and its benefits, three common functions from the Functional Basis vocabulary are defined as features and used in models, which are then used to show the reasoning potential of this approach.
Exploring the Use of Reverse Engineering as a Means to Introduce Engineering to Middle School Students
Authors: Paquette Gerid D. , Patel Deep N. , Bessette Amanda , Morkos Beshoy W.
Published: December 2016

Many K-12 students, and perhaps even some of their teachers, lack clear understanding of the significance or roles of an engineer [4, 13]. With the ever-growing integration of technology in our society, there is a need to establish a stronger foundation of STEM education, specifically ‘E’: engineering. Several research groups believe and have published data supporting the idea that minimal exposure of engineering at a young age may lead to the absence of motivation by students to consider engineering as a future career [14, 15]. In contrast, studies have also shown that exposing students to engineering concepts early in their academic careers could influence them to seriously consider engineering [28]. In this study, hands-on outreach events were held for students at local K-12 schools to expose and share knowledge about the importance of engineering, careers engineers enter into, and examples of problems engineers work to solve daily. Students were given the opportunity to reverse engineer various small home appliances to learn about the components and how those components collectively help complete a system function. These appliances were gender neutral, and included power drills, hair dryers, coffee makers and more. To engage their minds further, students were tasked with redesigning the product with proposed improvements to increase the product’s overall functionality and/or efficiency. The students were surveyed with a questionnaire to gauge their interest in engineering. This data was analyzed and it was found that though the students viewed engineering as fun and exciting, it did not correlate to their desire to pursue it as a career. Additionally, the known gender gap that exists in engineering today was reconfirmed with this study.
Let’s Get Physical? The Impact of Dissection Modality on Engineering Student Design Learning
Authors: Starkey Elizabeth M. , McKay Alexander S. , Hunter Samuel T. , Miller Scarlett R.
Published: December 2016

Product dissection, or the systematic disassembly of design products, has been utilized in engineering education in order to better prepare students for industry. Despite the common use of product dissection in engineering classrooms, knowledge is lacking about how effective different methods of dissection are for encouraging learning and student engineering self-efficacy. This is problematic because without this knowledge, we do not know what components of product dissection impact (positively or negatively) learning. Therefore, the purpose of this study was to identify the impact of dissection virtuality (physical and virtual), product power source (electrical and manual), and product complexity (simple and complex) on efficiency, learning, and engineering self-efficacy through a factorial experiment with 30 engineering students. The results of the study show that virtual dissection is more efficient than its physical counterpart and also maintains the same learning benefits as physical practices. These results are used to develop recommendations for the use of product dissection in education and propel future research that investigates relationships between example-based design practices and student learning outcomes.
Implementation of MTConnect for Open Source 3D Printers in Cyber Physical Manufacturing Cloud
Authors: Liu Xiaoqing Frank , Sunny S. M. Nahian Al , Shahriar Md Rakib , Leu Ming C. , Cheng Maggie , Hu Liwen
Published: December 2016

MTConnect is becoming a widely accepted Internet communication standard for factory automation. It is being used for collecting and analyzing data of manufacturing machines and monitoring them over the Internet. This paper describes an implementation of MTConnect RESTful protocol for monitoring networked open-source RepRap based 3D printers in a Cyber Physical Manufacturing Cloud. The open source RepRap based 3D printers are gaining popularity over past few years because of cheaper price, easy-to-use and self-replicating features. The implementation includes establishing communication with the 3D printer, collecting and transmitting status data using MTConnect Adapter developed in a Raspberry Pi and publishing the data in a standard XML format via MTConnect Agent over the Internet. We also describe detailed design of appropriate MTConnect standard dataitems and discuss how to use them to implement probe, current and sample operations of MTConnect Internet communication protocol for factory automation. The performance of the implemented system is evaluated and the results demonstrate excellent feasibility of real-time manufacturing process monitoring of networked open-source 3D printers with MTConnect over the Internet in a Cyber Physical Manufacturing Cloud.
Using a Large 2 Degree of Freedom Tail for Autonomous Aerobatics on a Flapping Wing Unmanned Aerial Vehicle
Authors: Roberts Luke , Bruck Hugh , Gupta S. K.
Published: December 2016

Flapping wing unmanned aerial vehicles (FWUAVs) provide an alternative to traditional platforms because they are more maneuverable than fixed wing platforms while being faster, quieter, and more natural looking than rotary wing platforms. While real birds are able to execute complex and highly controlled aerobatic maneuvers, executing FWUAV aerobatics presents unique challenges due to difficulty in execution of controlled quick orientation change. This paper demonstrates a simple method for using a large 2 degree of freedom tail for quick orientation changes and flight control, enabling execution of a pre-programmed backflip maneuver on the Robo Raven V, a hybrid FWUAV. The platform reached angular velocities of up to 420° per second during the maneuver.
TrackingExpert: A Versatile Tracking Toolbox for Augmented Reality
Authors: Radkowski Rafael , Garrett Timothy , Ingebrand Jarid , Wehr David
Published: December 2016

This paper presents a toolbox for rigid object tracking with a focus on augmented reality applications. Augmented reality relies on tracking to superimpose virtual objects on physical objects. Object tracking is usually based on registration and pose estimation techniques. Many different approaches have already been introduced. Our research focuses on tracking for application areas such as assembly assistance and the most promising candidate is rigid object tracking based on point cloud registration. Our work advances the robustness of point cloud-based tracking as well as the performance. One product of our research is our tracking tool TrackingExpert, which integrates all our research outcomes into one versatile software package. This paper introduces TrackingExpert covering functional areas such as the registration, visualizations, and experiment support. We also highlight several aspects which facilitate data analysis and ease our research.
The Design for Additive Manufacturing Worksheet
Authors: Booth Joran W. , Alperovich Jeffrey , Reid Tahira N. , Ramani Karthik
Published: December 2016

Additive manufacturing (AM) technologies have become integral to the modern manufacturing process. These roles are filled both in prototyping and production. Many studies have been conducted and lists been written on guidelines for AM. While these lists are useful, virtually none are written in a way that is accessible to novice users of AM, such as Makers. Most guidelines assume the user has extensive prior knowledge of the process, apply to only a few AM technologies, or describe benefits of the technology that novices already know. In this paper, we present a short, visual design-for-additive-manufacturing worksheet for novice and intermittent users. It addresses common mistakes and problems as identified by various expert machinists and additive manufacturing facilities. The worksheet helps designers accurately assess the potential quality of a part that is to be made using an AM process by giving intuitive feedback and indirectly suggest changes to improve a design. The immediate benefit of this worksheet is that it can help to streamline designs and reduce manufacturing errors. We validated it in a high-volume 3D-printing facility (Boilermaker Lab) where users are predominantly novice or intermittent. After the worksheet was implemented in the Boilermaker Lab, both the rate of print failures and reprinted parts fell roughly 40%.
Design of a 3D Wing Honeycomb Core Based on Origami Techniques
Authors: Saito Kazuya , Fujimoto Akinobu , Okabe Yoji
Published: December 2016

Honeycomb cores, which offer substantial weight reductions in design, are used in various engineering fields. For antenna reflector and rotor blade designs, Three-dimensional (3D) honeycomb cores are in considerable demand. 3D honeycombs are typically manufactured by curving or carving flat honeycombs. High associated manufacturing costs have limited their application. The authors of this paper investigated a new honeycomb design and manufacturing method called “kirigami honeycomb.” Resembling origami, kirigami honeycomb allows a single flat sheet of material with periodic slits to be folded into a honeycomb shape. Previous studies have reported successful use of this method to create various honeycomb shapes, changing only the folding line diagrams (FLDs). These previous studies have, however, considered only one-directional cross-section modifications; the core thickness and curvature changed in only the W-direction. This study proposes a new method that will support complex 3D double-curved honeycomb designs made from single flat sheets. A newly defined crease pattern conversion method provides arbitrary scaling of the honeycomb shape in the L-direction. The combined FLD and pattern conversion design methods encourage the cost-effective manufacture of 3D wing shaped honeycombs from single flat paper sheets. Wind or tidal power generation industries that use rotor blades could benefit from this design.
Design of Highly Reliable Infrastructural Traffic Monitoring Using Laser and Vision Sensors
Authors: Liu Hangxin , Tian Yi , Furukawa Tomonari
Published: December 2016

This paper presents a novel design of infrastructural traffic monitoring that performs vehicle counts, speed estimation, and vehicles classification by deploying three different approaches using two types of sensor, infrared (IR) cameras and laser range finders (LRFs). The first approach identifies passing vehicles by using LRFs and measuring the time-of-flight to the ground, which changes when vehicles pass. In the second approach, LRFs are used only to project a dotted line onto ground, and an IR camera identifies passing vehicles by recognizing the change of location of these laser dots in its images. The third approach utilizes an IR camera only and recognizes passing vehicles in each frame using background subtraction and edge detection algorithms. The design achieves high reliability because each approach has different strengths. A prototype system has been built and the field tests at a public road show promising results by achieving high reliability by having 95% accuracy in traffic counting and speed estimation.
Frictional Damping of Flutter: Microslip Versus Macroslip
Authors: Hudson Robert B. , Sinha Alok
Published: December 2016

Friction dampers are utilized in turbomachinery to reduce blade vibrations resulting from aeroelastic interactions. In this paper, the microslip friction model is applied to a blade with blade to ground damper and subjected to negative damping. Analysis using the describing function method, also known as the method of harmonic balance, is used to identify the behavior of the system and the maximum negative damping that can be stabilized by such a damper. These results are compared to those for the macroslip friction model.
Finding Only Finite Roots to Large Kinematic Synthesis Systems
Authors: Plecnik Mark M. , Fearing Ronald S.
Published: December 2016

In this work, a new method is introduced for solving large polynomial systems for the kinematic synthesis of linkages. The method is designed for solving systems with degrees beyond 100,000, which often are found to possess a number of finite roots that is orders of magnitude smaller. Current root-finding methods for large polynomial systems discover both finite and infinite roots, although only finite roots have meaning for engineering purposes. Our method demonstrates how all infinite roots can be avoided in order to obtain substantial computational savings. Infinite roots are avoided by generating random linkage dimensions to construct start-points and start-systems for homotopy continuation paths. The method is benchmarked with a four-bar path synthesis problem.
Spike Sorting via Multi Cluster Feature Selection
Authors: Dinparastdjadid Azadeh , Esfahani Ehsan T.
Published: December 2016

Having the ability to study the activity of single neurons will facilitate studies in many areas including cognitive sciences and brain computer interface applications. Due to the fact that every neuron has it’s own unique spike waveform, by applying spike-sorting methods, one can separate neurons based on their associated spike. Spike sorting is an unsupervised learning problem in the realm of data mining and machine learning. In this study, a new method that will improve the accuracy of spike sorting in comparison to existing methods has been introduced. This method, which is named Multi Cluster Feature Selection (MCFS), will designate a reduced number of features from the original data set that will best differentiate the existing clusters through solving a Lasso optimization problem. MCFS, was also applied to data obtained from multi-channel recordings on a rat’s brain. With MCFS, each channel was studied and neurons in each channel were sorted with an improved rate in comparison to conventional methods such as PCA.
Study on UGNX-LCA Integration for Sustainable Product Development
Authors: Tao Jing , Chen Zhaorui , Yu Suiran , Peng Qingjin
Published: December 2016

It is beneficial to conduct LCA(Life Cycle Assessment) during early stages of product development, as the earlier the environmental problems associated with the product life cycle are discovered, the less costly and more effective the preventing measures are. However, due to the lack of data communication tools between CAD and LCA systems, life cycle data collection during design stage is difficult. This paper presents a feature-based method of UGNX-LCA integration for sustainable product development. A feature-based multi-view life cycle model for integrating product-process-LCI (Life Cycle Inventory) data is developed based on mapping mechanism between engineering domains of product design, process planning and LCA. Data migration from UGNX models to LCA, including UG modeling feature identification, UG-LC(Life Cycle) feature transformation and LC feature model output are realized by embedded integrator. A case study of data migration from UGNX to LCA is presented to demonstrate the proposed approach.
A Network Based Modelling Approach Using the Dimensional Analysis Conceptual Modeling (DACM) Framework for Additive Manufacturing Technologies
Authors: Mokhtarian Hossein , Coatanéa Eric , Paris Henri , Ritola Tuomas , Ellman Asko , Vihinen Jorma , Koskinen Kari , Ikkala Kimmo
Published: December 2016

The application of additive manufacturing technologies in the industry is growing fast. This leads to an increasing need for reliable modeling techniques in the field of additive manufacturing. A methodology is proposed to systematically assess the influence of process parameters on the final characteristics of additively manufactured parts. The current study aims at presenting a theoretical framework dedicated to the modeling of the additive manufacturing technology. More specifically, the framework is used in the context of the study to plan and optimize the experimental process to minimize the amount of experiments required to populate the model. The framework presented is based on the Dimensional Analysis Conceptual Modelling framework (DACM). DACM is an approach supporting the production of models. This approach is designing networks representing a system architecture and behavior using an approach sharing similarities with neural networks. Based on the proposed approach, it is possible to detect where supplementary experimental data have to be collected to complete the model generated by the DACM approach. The modeling of the Direct Material Deposition process is conducted as an illustrative case study. The scope of the approach is vast and supported by validated scientific methods combined to form the core of the DACM method. The DACM framework is step by step extracting information from a description of the system architecture to create semi-automatically a model that can be simulated and used for multiple types of analyses associated for example with innovation and design improvement. The current paper will focus on the usage of the DACM framework, recently developed in a project, in the field of additive manufacturing.
Similarity of Engineering Design Problems to Enable Reuse in Design Research Experiments
Authors: Kumar Varun , Mocko Gregory
Published: December 2016

The objective of this research is to evaluate the similarity of design problems used in research experiments based on their representation. Design problems form an essential component of experiments in creativity research. However, the formulation of a design problem for an experiment is still a challenging task. An opportunity for the design community is leverage existing design problems to reduce a source of difference between experiments and increase the validity of new method and tools. To answer this question, fifty-five design problems, published over the past fifteen years, were collected and analyzed using two approaches. First, the information content of the design problems was assessed based on five structural elements. A protocol study was developed with four independent evaluators, who were asked to identify the five elements in a set of design problems. A high correlation was observed for the characteristics: goal of a problem, functional requirements, non-functional requirement and reference to an existing product. A low correlation was observed for the characteristics information about end user. The results suggest that this approach could serve as a useful tool in comparing and selecting problems with a desired number of elements. In the second approach, latent semantic analysis was used to compare the design problems. Latent semantic analysis enables design problem similarity to be computed prior to solving the problem. However, this method cannot identify the nuances in problem representations, which could potentially affect solution development. The paper concludes with an appeal to research community of using similar or benchmarked design problems, and postulate other means to enable comparison or development of problems in creativity research.
Nonlinear Thermally Buckled Piezoelectric Energy Harvester
Authors: Ansari M. H. , Karami M. Amin
Published: December 2016

A thermally buckled piezoelectric energy harvester is designed to power biomedical devices inside the body. The energy harvester (EN) uses the vibrations inside the body to generate the electricity needed for powering biomedical sensors and devices. The piezoelectric beam consists of a brass substrate and two piezoelectric patches attached to the top and the bottom of the substrate. The bimorph beam is inside a rigid frame. The bimorph beam is buckled due to the difference in the coefficient of the thermal expansion of the beam and the frame.

Inside the body, most of the energy content come from the low-frequency vibrations (less than 50 Hz). Having high natural frequency is a major problem in Microelectromechanical systems (MEMS) energy harvesters. Considering the small size of the EN, 1 cm3, the natural frequency is expected to be high. In our design, the natural frequency is lowered significantly by using a buckled beam. A mass is also used in the middle of the beam to decrease the natural frequency even more. Since the beam is buckled, the design is bistable and nonlinear which increases the output power.

In this paper, the natural frequencies and mode shapes of the EN are analytically derived. The geometric nonlinearities are included in the electromechanical coupled governing equations. The governing equations are solved and it is shown that the device generates sufficient electricity to power biomedical sensors and devices inside the human body.
An Experimentally-Validated Distributed-Parameters Model of a Ferrofluid Based Energy Harvester
Authors: Alazmi Saad , Xu Yawen , Daqaq Mohammed F.
Published: December 2016

This paper develops a distributed-parameters nonlinear model, which governs the electro-magneto-hydrodynamics of an electromagnetic ferrofluid-based energy harvester. An approximate analytical solution of the model is then obtained using per-turbation methods and the results are compared to experimental findings illustrating good qualitative agreement.
Feature Based Search of 3D Databases
Authors: Paterson Duncan , Corney Johnathan
Published: December 2016

This paper presents a novel algorithm “Twig Match” for feature based shape retrieval systems. The algorithm exploits recent advances in computational methods for subgraph isomorphism, in order to enable databases containing many thousands of components to be searched in less than a second. A face adjacency graph representation is created from a B-Rep model, allowing model comparison to be treated as a labelled subgraph isomorphism problem. This paper describes an experimental implementation which allows interactive specification of a target “feature”. By selectively including geometric filters, on faces and relations between neighbouring faces, the algorithm can ensure that matching topology is not incorrectly identified as matching geometry, while also offering users the ability to improve the precision of both query and results. Experimental results show that Twig Match accurately retrieves matching and similar sub-parts from collections at speeds suitable for interactive applications.
The Application of Retrospective Customer Needs Cultural Risk Indicator Method to Soap Dispenser Design for Children in Ethiopia
Authors: Igleski Joseph R. , Van Bossuyt Douglas L. , Reid Tahira
Published: December 2016

We present here the design and analysis of a cost-effective soap dispenser that prevents bar soap theft in schools in developing countries. The intended region of deployment is within Ethiopia and surrounding areas. Lack of public hygiene is attributed to 1.4 million global deaths annually due to preventable diarrheal diseases. Using soap while washing hands is estimated to decreases death due to diarrheal diseases by half. Theft of soap from public wash stations, such as those found in schools, is believed to contribute to the spread of diarrheal diseases. Currently there exists no adequate cost-effective solutions to protect bar soap from theft although there appears to be a demand and there is a need for such a device.

An undergraduate student mechanical design team in a sophomore design course at Purdue University was tasked with developing a soap dispenser that prevents theft of bar soap. The project prompt was provided by Purdue Global Engineering Programs’ Innovation to International Development (I2D) Lab. Students were instructed to complete the first step (Product Concept) of the Lean Design for the Developing World (LDW) method to develop a Minimum Viable Product (MVP). The team then completed a retrospective analysis of the MVP using the Customer Needs Cultural Risk Indicator (CNCRI) method to determine potential shortcomings that may be identified in the second step (Validated Learning) of the LDW method. Several customer needs and their component and design solutions that need close monitoring during the second step of the LDW method were identified. The highest risk customer needs included: culturally appropriate design, aesthetic appeal, security, and durability.

Based on the experiences of the design team, several important lessons were learned that can both be applied to improving the secure bar soap dispenser product and to the broader field of product design for the developing world. These lessons include: Customers in the developing world may be more concerned with cost than durability, cultural appeal of a device is highly dependent on first -hand experience and can easily be misunderstood or misrepresented, the LDW method is an invaluable tool in identifying customer needs that may be overlooked due to cultural and socio-economic differences. The use of the LDW framework and the CNCRI method in an undergraduate design group was found to be useful, viable, and valuable to both the undergraduate student learning outcomes and the development of a product that can be deployed to its intended market. Further development of an end-to-end tool chain is needed to better integrate product development for the developing world into mainstream engineering curriculum.
Product Submanifold Based Analysis of Kinematic Chains and a 3-PUP Parallel Mechanism
Authors: Zhang Xinsheng , Dai Jian S.
Published: December 2016

The five types of kinematic chains that generate the planar motion group SE(2) of dimension three, with the prismatic-joint direction always perpendicular with the revolute-joint axis in each chain, have shown their effectiveness and manifested the charm in type synthesis and mechanism analysis in parallel mechanisms. This paper extends the traditional PRP kinematic chain generating the planar motion group SE(2) to a relatively general case, in which one of the prismatic joint-direction is not necessarily perpendicular with the revolute-joint axis, leading to the discovery of a screw motion with a variable pitch in this kinematic chain. Following the extraction of a screw motion from this particular PRP kinematic chain, this paper presents the bifurcated motion in a 3-PUP parallel mechanism by changing the active geometrical constraint in its configuration space, with a Lie group approach and interpretation. The constraint-singularity configuration sets for bifurcation of the 3-PUP parallel mechanism. The paper hence provides a Lie group representation and geometry interpretation for the kinematic equivalence of serial chains and the bifurcated motion of a parallel mechanism.
Soft Spherical Tensegrity Robot Design Using Rod-Centered Actuation and Control
Authors: Chen Lee-Huang , Kim Kyunam , Tang Ellande , Li Kevin , House Richard , Agogino Alice M. , Agogino Adrian , Sunspiral Vytas , Jung Erik
Published: December 2016

This paper presents the design, analysis and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees of freedom in movement and flexible design. However to fully take advantage of these properties a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable and power routing systems and increased design difficulty. Here we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture.

This paper presents the novel mechanism design, architecture and simulations of TT-3, the first untethered, fully actuated cable-driven six-bar tensegrity spherical robot ever built and tested for mobility. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system’s behavior and performance.
Modal Analysis of Bandgap Formation for Vibration Attenuation in Locally Resonant Finite Beams
Authors: Sugino Christopher , Leadenham Stephen , Ruzzene Massimo , Erturk Alper
Published: December 2016

Metamaterials made from locally resonating arrays can exhibit attenuation bandgaps at wavelengths much longer than the lattice size, enabling low-frequency vibration attenuation. For an effective use of such locally resonant metamaterial concepts, it is required to bridge the gap between the dispersion characteristics and modal behavior of the host structure with its resonators. To this end, we develop a novel argument for bandgap formation in finite-length beams, relying on modal analysis and the assumption of infinitely many resonators. This assumption is analogous to the wave assumption of an infinitely long beam composed of unit cells, but gives additional analytical insight into the bandgap, and yields a simple formula for the frequency range of the bandgap. We present a design guideline to place the bandgap for a finite beam with arbitrary boundary conditions in a desired frequency range that depends only on the total mass ratio and natural frequency of the resonators. For a beam with a finite number of resonators and specified boundary conditions, we suggest a method for choosing the optimal number of resonators. We validate the model with both finite-element simulations and a simple experiment, and draw conclusions.