bluuebunny/crossref_metadata_2025 huggingface dataset:
Mixed Reality Tools for Playful Representation of Ideation, Conceptual Blending and Pastiche in Design and Engineering
Authors: Wendrich Robert E.
Published: January 2015

This paper describes the development and evaluation of mixed reality tools for the early stages of design and engineering processing. Externalization of ideal and real scenes, scripts, or frames are threads that stir the imaginative exploration of the mind to ideate, formulate, and represent ideas, fuzzy thoughts, notions, and/or dreams. The body in the mind, embodied imagination is more important than knowledge. Current computational tools and CAD systems are not equipped or fully adapted in the ability to intuitively convey creative thoughts, closely enact or connect with users in an effective, affective, or empathic way. Man-machine interactions are often tethered, encumbered by e.g. stupefying modalities, hidden functionalities, constraint interface designs and preprogrammed interaction routes. Design games, mixed reality, ‘new’ media, and playful tools have been suggested as ways to support and enhance individual and collaborative ideation and concept design by improving communication, performance, and generation. Gamification seems to be successful especially in framing and/or blending common ground for collaborative design and co-creation processes. Playing games with cross-disciplinary design teams and future users in conjunction with tools to create stories, narratives, role-play and visual representations can be used as abstract ideation and design material in an open-ended design process. In this paper we discuss mixed reality tools based on a holistic user-centered approach within playful stochastic environments. We present preliminary findings and studies from experimentation with robust tools, prototypes, and interfaces based on our empirical research and work in progress.
An Empirical Study of Information Exchange and Design Support in Product Family Development
Authors: Lundin Michael , Lejon Erik , Dagman Andreas , Näsström Mats , Jeppsson Peter
Published: January 2015

An investigation carried out at a Swedish manufacturing company has focused specifically on information exchange and design support in and between activities in the company’s product family development process. The process allows, within a defined product family, automated generation of 3D models, product specifications, and a complete foundation for subsequent manufacture and verification.

The core contributions of this paper are the investigation performed, a set of identified challenges which relate to the complexity of everyday decisions made in product family development, how these challenges can be approached and a set of tools exemplifying that approach.

The study indicates that there are limitations in terms of motivation, resources and support for insight, understanding and consequent consideration to downstream implications of design decisions made. The question is whether tools and methods, which are integral aspects of the process already, might serve to further illuminate the process, maximize purposeful support and thereby minimize the efforts required to better consider downstream implications of decisions made. It is the opinion of the authors that it can, and the set of tools for information exchange and design support presented in this paper serves to exemplify how.
An Approach Towards Generating Surrogate Models by Using RBFN With a Priori Bias
Authors: Amouzgar Kaveh , Stromberg Niclas
Published: January 2015

In this paper, an approach to generate surrogate models constructed by radial basis function networks (RBFN) with a priori bias is presented. RBFN as a weighted combination of radial basis functions only, might become singular and no interpolation is found. The standard approach to avoid this is to add a polynomial bias, where the bias is defined by imposing orthogonality conditions between the weights of the radial basis functions and the polynomial basis functions. Here, in the proposed a priori approach, the regression coefficients of the polynomial bias are simply calculated by using the normal equation without any need of the extra orthogonality prerequisite. In addition to the simplicity of this approach, the method has also proven to predict the actual functions more accurately compared to the RBFN with a posteriori bias. Several test functions, including Rosenbrock, Branin-Hoo, Goldstein-Price functions and two mathematical functions (one large scale), are used to evaluate the performance of the proposed method by conducting a comparison study and error analysis between the RBFN with a priori and a posteriori known biases. Furthermore, the aforementioned approaches are applied to an engineering design problem, that is modeling of the material properties of a three phase spherical graphite iron (SGI). The corresponding surrogate models are presented and compared.
Energy Optimization in Net-Zero Energy Building Clusters
Authors: Odonkor Philip , Lewis Kemper , Wen Jin , Wu Teresa
Published: January 2015

Traditionally viewed as mere energy consumers, buildings have in recent years adapted, capitalizing on smart grid technologies and distributed energy resources to not only efficiently use energy, but to also output energy. This has led to the development of net-zero energy buildings, a concept which encapsulates the synergy of energy efficient buildings, smart grids, and renewable energy utilization to reach a balanced energy budget over an annual cycle. This work looks to further expand on this idea, moving beyond just individual buildings and considering net-zero at a community scale. We hypothesize that applying net-zero concepts to building communities, also known as building clusters, instead of individual buildings will result in cost effective building systems which in turn will be resilient to power disruption. To this end, this paper develops an intelligent energy optimization algorithm for demand side energy management, taking into account a multitude of factors affecting cost including comfort, energy price, Heating, Ventilation, and Air Conditioning (HVAC) system, energy storage, weather, and on-site renewable resources. A bi-level operation decision framework is presented to study the energy tradeoffs within the building cluster, with individual building energy optimization on one level and an overall net-zero energy optimization handled on the next level. The experimental results demonstrate that the proposed approach is capable of significantly shifting demand, and when viable, reducing the total energy demand within net-zero building clusters. Furthermore, the optimization framework is capable of deriving Pareto solutions for the cluster which provide valuable insight for determining suitable energy strategies.
Efficient Large Deformation Simulations of Multi-Flexible-Body Systems Using Absolute Nodal Coordinate Beam and Plate Elements
Authors: Khan Imad M. , Anderson Kurt S.
Published: January 2015

In this paper, we investigate the absolute nodal coordinate finite element (FE) formulations for modeling multi-flexible-body systems in a divide-and-conquer framework. Large elastic deformations in the individual components (beams and plates) are modeled using the absolute nodal coordinate formulation (ANCF). The divide-and-conquer algorithm (DCA) is utilized to model the constraints arising due to kinematic joints between the flexible components. We develop necessary equations of the new algorithm and present numerical examples to test and validate the method.
Design and Analysis of New Large-Range XY Compliant Parallel Micromanipulators
Authors: Yu Jingjun , Li Zhenguo , Lu Dengfeng , Zong Guanghua , Hao Guangbo
Published: January 2015

The need for a compliant parallel micromanipulator (CPM) providing large motion range and high precision is increasing. Existing CPMs vary in constraint configurations and therefore it is necessary to verify/compare their characteristics. This paper compares three kinds of typical over-constrained CPMs, and derives their theoretical compliance matrix models pointing out constraint characteristics of the three kinematic configurations. Then the three CPMs are analyzed with FEA (finite element analysis), and results illustrate that the theoretical compliance matrix models are close to their FEA models. Moreover, cross-axis coupling along two motion axes (X&Y), parasitic motion and compliance fluctuation of motion stages are described in details. Through analyzing the FEA results, we present an improved CPM with a mirror-symmetry structure and redundant-constraint characteristic which can effectively constrain in-plane yaw and cross-axis coupling. It is shown that the improved CPM presented in this paper has a series of merits: large motion range up to 10mm×10mm in the dimension of 311mm×311mm×24mm, small compliance fluctuation (only 37.32% of that of the initial model), a smaller cross-axis coupling (only 24.39% of that of the initial model generated by a single-axis 5mm driving), a smaller in-plane parasitic yaw (only 53.57% of that of the initial model generated by double-axis 5mm driving).
Dynamic Modeling and Sliding Mode Control of a 2-DOF Spherical Parallel Mechanism With a Passive Branch
Authors: Chen Bin , Yu Jingjun , Zong Guanghua , Kuang Jing
Published: January 2015

This paper presents a dynamic analysis and a sliding mode control approach for high speed tracking control of a 2-DOF spherical parallel mechanism with a redundant branch. The kinematics of this mechanism is briefly introduced, two of three branches are actuated and the rest one is a passive branch. The dynamic model is built based on Lagrange method and simplified to develop a real-time controller. The control scheme is designed given that only the angle and angular velocity of actuators are measureable. First a Quasi-sliding mode control algorithm is proposed to compensate the parameter perturbation and reduce the chattering phenomenon, and then the trending law is introduced to decrease the regulation time of tracking control. Lyapunov theory is performed to guarantee that the controller design is stable. Finally, experiment based on a prototype of SPM is carried out to verify the effectiveness of the proposed method.
Effects of Prosthesis Mass on Hip Energetics, Prosthetic Knee Torque, and Prosthetic Knee Stiffness and Damping Parameters Required for Transfemoral Amputees to Walk With Normative Kinematics
Authors: Narang Yashraj S. , Winter Amos G.
Published: January 2015

We quantify how the hip energetics and knee torque required for an above-knee prosthesis user to walk with the kinematics of able-bodied humans vary with the inertial properties of the prosthesis. We also select and optimize passive mechanical components for a prosthetic knee to accurately reproduce the required knee torque.

Previous theoretical studies have typically investigated the effects of prosthesis inertial properties on energetic parameters by modifying both mass and mass distribution of the prosthesis and computing kinetic and energetic parameters only during swing. Using inverse dynamics, we determined the effects of independently modifying mass and mass distribution of the prosthesis, and we computed parameters during both stance and swing. Results showed that reducing prosthesis mass significantly affected hip energetics, whereas reducing mass distribution did not. Reducing prosthesis mass to 25% of the mass of a physiological leg decreased peak stance hip power by 26%, average swing hip power by 74%, and absolute hip work over the gait cycle by 22%.

Previous studies have also typically optimized prosthetic knee components to reproduce the knee torque generated by able-bodied humans walking with normative kinematics. However, because the prosthetic leg of an above-knee prosthesis user weighs significantly less than a physiological leg, the knee torque required for above-knee prosthesis users to walk with these kinematics may be significantly different. Again using inverse dynamics, it was found that changes in prosthesis mass and mass distribution significantly affected this required torque. Reducing the mass of the prosthesis to 25% of the mass of the physiological leg increased peak stance torque by 43% and decreased peak swing torque by 76%.

The knee power required for an above-knee prosthesis user to walk with the kinematics of able-bodied humans was analyzed to select passive mechanical components for the prosthetic knee. The coefficients of the components were then optimized to replicate the torque required to walk with the kinematics of able-bodied humans. A prosthetic knee containing a single linear spring and two constant-force dampers was found to accurately replicate the targeted torque (R2=0.90 for a typical prosthesis). Optimal spring coefficients were found to be relatively insensitive to mass alterations of the prosthetic leg, but optimal damping coefficients were sensitive. In particular, as the masses of the segments of the prosthetic leg were altered between 25% and 100% of able-bodied values, the optimal damping coefficient of the second damper varied by 330%, with foot mass alterations having the greatest effect on its value.
A New Design Tool for Tire Braking Performance Evaluations
Authors: Sivaramakrishnan Srikanth , Siramdasu Yaswanth , Taheri Saied
Published: January 2015

The objective of this study is to understand the influence of high frequency tire vibrations induced due to road disturbances and brake torque cycling due to ABS on braking performance. Under these conditions, transient dynamics of the tire play a crucial role in the generation of braking force. To implement this, a dynamic tire model was developed using a rigid ring tire and a tandem elliptical cam design for the enveloping model. This tire model is validated using experimental data obtained from high speed cleat tests on a fixed axle. The validated tire model is then integrated with a quarter vehicle and a commercial grade rule-based ABS model to evaluate braking performance with and without a road cleat, which can provide a high frequency disturbance. Simulation results show that the presence of a 1 cm cleat cause large variations in wheel slip, consequently increasing the braking distance. The developed tool will help both tire and vehicle manufactures for quick and early evaluation of braking performance without computationally intensive FEA tools.
Aerodynamic Design of Flat Delta Kite Based on Polhamus Concept of Leading Edge Suction Analogy
Authors: Madduri Bharath , Borazjani Iman
Published: January 2015

The primary objective of this paper is to design an aerodynamically efficient delta kite that can balance a given load when subjected to aerodynamic loads at a specific angle of attack (α) and altitude (h). The aerodynamic forces calculated based on the potential theory heavily underestimate the forces because of the formation of leading edge vortices on the delta shaped kite. The leading edge vortices are the flow separations caused at the sharp leading edge even for very small angles of attack, which remain attached to the leading edge while the kutta condition is still satisfied at the trailing edge.

Vortex lift and induced drag due to the leading edge vortices are calculated using the Polhamus method. Aerodynamic loads (L and D) have been computed by determining proportionality constants (kp, kv) using the standard Multhopp lifting surface theory (MLST). The variation of (CL) and (ΔCD) for delta kites with aspect ratio A=1, 1.5 and 2 has been examined and validated by comparing the computed CL and ΔCD values to experimental measurements. A set of vertical and horizontal loads (WT,HT) that can be balanced by delta kite at operational heights h=140, 150 and 160 m and α=8° has been successfully determined using this method. The method will be applied for the design and control of a delta kite, which will be used to harvest wind energy at high altitudes.
Solving Structure for Network-Decomposed Problems Optimized With Augmented Lagrangian Coordination
Authors: Xu Meng , Fadel Georges , Wiecek Margaret M.
Published: January 2015

The complexity of design and optimization tasks of modern products which cannot be carried out by a single expert or by a single design team motivated the development of the field of decomposition-based optimization. In general, the process of decomposition-based optimization consists of two procedures: (1) Partitioning the original problem into sub-problems according to the design disciplines, components or other aspects; and (2) Coordinating these sub-problems to guarantee that the aggregation of their optimal solutions results in a feasible and optimal solution for the original problem. Much current work focuses on alternative approaches for these two procedures.

For a decomposed problem with a hierarchical structure, the above two procedures work very well and the Analytical Target Cascading method tailored for this type of problems can be used as the coordination method. However, for a more generally decomposed problem with a non-hierarchical structure, there are several factors that might affect the performance of the optimization by decomposition besides the traditional two procedures. In this paper, these factors are identified as: (1) the number of Lagrangian multipliers; (2) the number of decomposition levels (3) the existence and the selection of the master sub-problem. These factors further characterize the structure to solve the decomposed problem: the Solving Structure for decomposition-based optimization. Both mathematical and engineering test problems are used to explore the role of the solving structure. The results show that under the same partition and using the same coordination method, the Augmented Lagrangian Coordination, the performance of the decomposition-based optimization may be largely different in terms of efficiency, accuracy and resource cost. The results highlight the importance of choosing an optimal solving structure after deciding on the procedures of partitioning and coordination. Based on these test results, several suggestions for guidelines on the selection of an optimal solving structure selection are proposed.
Design and Testing of an Automated Multi-Cell Nanoinjection System
Authors: Lindstrom Zachary K. , Gregory Nicholas , Jensen Brian D.
Published: January 2015

An automated nanoinjection system has been developed and tested for the delivery of propidium iodide into culture cells. Nanoinjection is the process by which molecules are delivered into living cells using a solid needle. Propidium iodide, a dye that fluoresces when bound to nucleic acids, was used as the injection molecule to monitor nanoinjection efficiency. The nanoinjection system uses a programmable microcontroller to manipulate a linear actuator, which presses a silicon lance array into thousands of living culture cells simultaneously. The lances penetrate cell membranes, allowing dye molecules to enter the cell through membrane pores opened by lances. The system was developed to apply the same injection force to each cell sample at the press of a button, eliminating any experimental variability in data due to the operator. Tests were performed at a dye concentration of 0.04 mg/mL for all experiments. Several forces were tested to determine the optimal nanoinjection force needed for maximum dye delivery. We found the optimal force range to be 8.8–14.7 N. The average PI uptake into cells at a force of 8.8 N and 14.7 N is 57.6±7.7% and 60.3±6.6%, respectively. Previous studies with a manual injection force have shown average propidium iodide uptake to be 60.4±18.0%. High cell viability is maintained with the automated nanoinjection system. At all forces applied in this experiment, an average of 78% or greater viability was observed. With the data gathered in this experiment, we conclude that the automated nanoinjection system eliminates much of the uptake efficiency variability inherent to nanoinjections performed with a manual injection force.
New Simplified Three-Spheres Intersection Algorithm for the Forward Pose Kinematics of Cable-Suspended Robots
Authors: Williams Robert L. , Needler Noah
Published: January 2015

A novel simplified analytical three-spheres intersection algorithm is presented for use with forward pose kinematics solutions of a four-cable-suspended robot (the method is applicable to various other cable-suspended robots with equal pole heights and three cables intersecting in one point). It is required that the vertical center heights of all three spheres are equal (otherwise one can use the existing more-complicated algorithm). We derive this new algorithm and show that the multiple solutions, algorithmic singularity, and imaginary solutions do not cause any trouble in practical implementation. The algorithmic singularity of the original three-spheres intersection algorithm regarding equal Z heights is eliminated with the new algorithm. The new algorithm requires significantly less computation compared with the original algorithm. Examples are presented to demonstrate the new three-spheres intersection algorithm for a 4-cable robot.
The Impact of Virtual Dissection on Engineering Student Learning and Self-Efficacy
Authors: Toh Christine A. , Disco Connor S. , Miller Scarlett R.
Published: January 2015

Product dissection activities are widely practiced in engineering education as a means of increasing student learning and understanding of core engineering concepts. While recent efforts in this area of research have sought to develop and utilize virtual dissection tools in order to reduce and mitigate the costs of physical dissection activities, little data exists on how virtual dissection impacts student learning and understanding. This lack of data makes it difficult to draw conclusions on the utility of virtual dissection tools for enhancing engineering instruction. In this paper we present the results of a controlled experiment conducted with first-year engineering students developed to examine the impact of virtual dissection on engineering student learning and self-efficacy. Our results revealed that student learning appeared to be unaffected through the use of virtual dissection environments. However, electro-mechanical self-efficacy gains were smaller for students who performed virtual dissection compared to students who performed physical dissection. These results add to our knowledge of the impact that virtual dissection tools can have on student learning and understanding and enable us to develop recommendations and guidelines for improving the effectiveness of these tools in engineering education.
Automated Generation of Linkage Loop Equations for Planar 1-DoF Linkages, Demonstrated up to 8-Bar
Authors: Parrish Brian E. , McCarthy J. Michael , Eppstein David
Published: January 2015

In this paper we present an algorithm that automatically creates the linkage loop equations for planar 1-DoF linkages of any topology with rotating joints, demonstrated up to 8-bars. The algorithm derives the linkage loop equations from the linkage graph by establishing a cycle basis through a single common edge. Divergent and convergent loops are identified and used to establish the fixed angles of the ternary and higher links.

Results demonstrate the automated generation of the linkage loop equations for the five distinct 6-bar mechanisms, Watt I-II and Stephenson I-III, as well as the seventy one distinct 8-bar mechanisms.

The resulting loop equations enable the automatic derivation of the Dixon determinant for linkage kinematic analysis of the position of every possible assembly configuration. The loop equations also enable the automatic derivation of the Jacobian for singularity evaluation and tracking of a particular assembly configuration over the desired range of input angles.

The methodology provides the foundation for the automated configuration analysis of every topology and every assembly configuration of 1-DoF linkages with rotating joints up to 8-bar. The methodology also provides a foundation for automated configuration analysis of 10-bar and higher linkages.
Integrated Decision Making in Electric Vehicle and Charging Station Location Network Design
Authors: Kang Namwoo , Feinberg Fred M. , Papalambros Panos Y.
Published: January 2015

A major barrier in consumer adoption of electric vehicles (EVs) is ‘range anxiety,’ the concern that the vehicle will run out of power at an inopportune time. Range anxiety is caused by the current relatively low electric-only operational range and sparse public charging station infrastructure. Range anxiety may be significantly mitigated if EV manufacturers and charging station operators work in partnership using a cooperative business model to balance EV performance and charging station coverage. This model is in contrast to a sequential decision making model where manufacturers bring new EVs to the market first and charging station operators decide on charging station deployment given EV specifications and market demand. This paper proposes an integrated decision making framework to assess profitability of a cooperative business models based on a multi-disciplinary optimization model that combines marketing, engineering, and operations. This model is demonstrated in a case study involving battery electric vehicle design and direct-current fast charging station location network in the State of Michigan. The expected benefits can motive both government and private enterprise actions.
Art Meets Engineering Design: An Approach for Reducing Sketch Inhibition in Engineers During the Design Process
Authors: Booth Joran W. , Bhasin Abhinav K. , Ramani Karthik
Published: January 2015

While much prior work has been done regarding sketching and its impact on design and a few on how to train engineers to sketch, there have been no prior studies in engineering to reduce inhibition to frequent sketching. This paper describes a sketching intervention developed from art teaching aimed at reducing inhibition to sketching and a study to evaluate its effectiveness. In the study, students (n = 55) were tested with pre-mid-post assessments consisting of a mechanical, organic, and design-oriented sketching task and a TLX survey measuring the level of difficulty. The study found that the students overwhelmingly reported their inhibition was lowered, but the short-term TLX data suggested inhibition was higher. However, the TLX data showed a longterm decrease in inhibition-related measures, perhaps suggesting that long-term encouragement to sketch is effective in reducing inhibition to sketch. These results tentatively suggest that sketch inhibition is reduced by actively promoting creativity and sketching, some use of the activities presented here, and by deemphasizing the importance of higher-level skills such as perspective drawing.
Towards Extracting Affordances From Online Consumer Product Reviews
Authors: Chou Amanda , Shu L. H.
Published: January 2015

We examined online product reviews as a source of novel affordances. Certain affordances may only be discovered through extended use across various environments. User-generated reviews may thus contain unique insights. We analyzed online consumer product reviews from Canadian Tire, one of Canada’s largest retailers. We determined properties of this collection of reviews and commonalities between valuable reviews. In addition to typical challenges associated with natural-language processing, e.g. word-sense disambiguation, we identify characteristics of online consumer reviews that create additional challenges. These challenges include the use of ‘wild English’ and sarcasm in online reviews.

We first present criteria to define and more objectively identify novel affordances from review content. Next, k-means clustering reveals that a combination of syntactical features and high frequency word percentages can separate descriptive from non-descriptive review content. Finally, we identified cue phrases that may indicate higher likelihood of affordance content in a review. Despite existing obstacles, the substantial volume of available online product reviews has potential to become a valuable source of affordances and feedback for designers and retailers alike.
Peg-in-Hole Revisited: A Generic Force Model for Haptic Assembly
Authors: Behandish Morad , Ilieş Horea T.
Published: January 2015

The development of a generic and effective force model for semi-automatic or manual virtual assembly with haptic support is not a trivial task, esp. when the assembly constraints involve complex features of arbitrary shape. The primary challenge lies in a proper formulation of the guidance forces that effectively assist the user in his/her exploration of the virtual environment, from repulsing collisions to attracting proper contact. The secondary difficulty is that of efficient implementation that maintains the standard 1 kHz haptic refresh rate. We propose a purely geometric model for an artificial energy field that favors spatial relations leading to proper assembly, differentiated to obtain forces and torques in a 6 DOF motion. The energy function is expressed in terms of a convolution of shape-dependent affinity fields, precomputed offline separately for each object. We test the effectiveness of the method using familiar peg-in-hole examples. We show that the proposed technique unifies collision detection and precision assembly modes into a single interaction, and provides a generic and automatic constraint model for the so-called virtual fixtures, with no restrictive assumptions on the types of the involved assembly features.
Effects of Abstraction on Selecting Relevant Biological Phenomena for Biomimetic Design
Authors: Feng Tao , Cheong Hyunmin , Shu L. H.
Published: January 2015

The natural-language approach to identifying biological analogies exploits the existing format of much biological knowledge, beyond databases created for biomimetic design. However, designers may need to select analogies from search results, during which biases may exist towards: specific words in descriptions of biological phenomena, familiar organisms and scales, and strategies that match preconceived solutions.

Therefore, we conducted two experiments to study the effect of abstraction on overcoming these biases and selecting biological phenomena based on analogical similarities. Abstraction in our experiments involved replacing biological nouns with hypernyms. The first experiment asked novice designers to choose between a phenomenon suggesting a highly useful strategy for solving a given problem, and another suggesting a less-useful strategy, but featuring bias elements. The second experiment asked novice designers to evaluate the relevance of two biological phenomena that suggest similarly useful strategies to solve a given problem.

Neither experiment demonstrated the anticipated benefits of abstraction. Instead, our abstraction led to: 1) novice designers associating non-abstracted words to design problems and 2) increased difficulty in understanding descriptions of biological phenomena. We recommend investigating other ways in which abstraction can be implemented when designing similar tools or techniques that aim to support biomimetic design and other design-by-analogy work.
Rigid Object Tracking Algorithms for Low-Cost AR Devices
Authors: Garrett Timothy , Debernardis Saverio , Radkowski Rafael , Chang Carl K. , Fiorentino Michele , Uva Antonio E. , Oliver James
Published: January 2015

Augmented reality (AR) applications rely on robust and efficient methods for tracking. Tracking methods use a computer-internal representation of the object to track, which can be either sparse or dense representations. Sparse representations use only a limited set of feature points to represent an object to track, whereas dense representations almost mimic the shape of an object. While algorithms performed on sparse representations are faster, dense representations can distinguish multiple objects. The research presented in this paper investigates the feasibility of a dense tracking method for rigid object tracking, which incorporates the both object identification and object tracking steps. We adopted a tracking method that has been developed for the Microsoft Kinect to support single object tracking. The paper describes this method and presents the results. We also compared two different methods for mesh reconstruction in this algorithm. Since meshes are more informative when identifying a rigid object, this comparison indicates which algorithm shows the best performance for this task and guides our future research efforts.
Comparison of Natural Feature Descriptors for Rigid-Object Tracking for Real-Time Augmented Reality
Authors: Bermudez Francely Franco , Diaz Christian Santana , Ward Sheneeka , Radkowski Rafael , Garrett Timothy , Oliver James
Published: January 2015

This paper presents a comparison of natural feature descriptors for rigid object tracking for augmented reality (AR) applications. AR relies on object tracking in order to identify a physical object and to superimpose virtual object on an object. Natural feature tracking (NFT) is one approach for computer vision-based object tracking. NFT utilizes interest points of a physcial object, represents them as descriptors, and matches the descriptors against reference descriptors in order to identify a phsical object to track. In this research, we investigate four different natural feature descriptors (SIFT, SURF, FREAK, ORB) and their capability to track rigid objects. Rigid objects need robust descriptors since they need to describe the objects in a 3D space. AR applications are also real-time application, thus, fast feature matching is mandatory. FREAK and ORB are binary descriptors, which promise a higher performance in comparison to SIFT and SURF. We deployed a test in which we match feature descriptors to artificial rigid objects. The results indicate that the SIFT descriptor is the most promising solution in our addressed domain, AR-based assembly training.
Development of a Design Tool for Flow Rate Optimization in the Tata Swach Water Filter
Authors: Ricks Sean T. , Lewandowski John R. , Lim Emmanuel G. , Wendell Dawn M. , Winter Amos G.
Published: January 2015

When developing a first-generation product, an iterative approach often yields the shortest time-to-market. In order to optimize its performance, however, a fundamental understanding of the theory governing its operation becomes necessary. This paper details the optimization of the Tata Swach, a consumer water purifier produced for India. The primary objective of the work was to increase flow rate while considering other factors such as cost, manufacturability, and efficacy. A mathematical model of the flow characteristics through the filter was developed. Based on this model, a design tool was created to allow designers to predict flow behavior without prototyping, significantly reducing the necessity of iteration. Sensitivity analysis was used to identify simple ways to increase flow rate as well as potential weak points in the design. Finally, it was demonstrated that maximum flow rate can be increased by 50% by increasing the diameter of a flow-restricting feature while simultaneously increasing the length of the active purification zone. This can be accomplished without significantly affecting cost, manufacturability, and efficacy.
User Research Methods for Development Engineering: A Study of Method Usage With IDEO’s HCD Connect
Authors: Fuge Mark , Agogino Alice
Published: January 2015

While there is increasing interest in designing for the developing world, one major challenge lies in understanding when to apply different design methods in unfamiliar contexts. This paper uses HCD Connect, an online design case study repository, to compare what types of methods people frequently apply to developing world problems. Specifically, it covers how the following factors correlate to method usage: application area (e.g., farming versus healthcare), affiliation of the person using the method (IDEO designer versus not), and stages of the user research process. We find that designers systematically use certain types of methods for certain types of problems, and that certain methods complement each other in practice. When compared with non-IDEO users, professional designers at IDEO use fewer methods per case and focus on earlier stages of the process that involve data gathering. Our results recommend certain kinds of user research methods for different developing world problems, as well as identifying which research methods complement each other. It also highlights that professionals designing for developing world contexts commit more time to earlier stage data-gathering efforts, rather than in concept generation or delivery, to better understand differences in needs and design contexts.
Analogy Seeded Mind-Maps: Testing of a New Design-by-Analogy Tool
Authors: Marshall K. Scott , Crawford Richard , Green Matthew , Jensen Daniel
Published: January 2015

Recent research has investigated methods based on design-by-analogy meant to enhance concept generation. This paper presents Analogy Seeded Mind-Maps, a new method to prompt generation of analogous solution principles drawn from multiple analogical domains.

The method was evaluated in two separate design studies using senior engineering students. The method begins with identifying a primary functional design requirement such as “eject part.” We used this functional requirement “seed” to generate a WordTree of grammatically analogical words for each design team. We randomly selected a set of words from each WordTree list with varying lexical “distances” from the seed word, and used them to populate the first-level nodes of a mind-map, with the functional requirement seed as the central hub. Design team members first used the word list to individually generate solutions and then performed team concept generation using the analogically seeded mind-map. Quantity and uniqueness of the resulting verbal solution principles were evaluated. The solution principles were further analyzed to determine if the lexical “distance” from the seed word had an effect on the evaluated design metrics. The results of this study show Analogy Seeded Mind-Maps to be useful tool in generating analogous solutions for engineering design problems.
On the Dynamic Response of Actuation Devices in Open and Closed-Loop Mechanisms With Nonlinear Dynamics
Authors: Rastegar Jahangir , Feng Dake
Published: January 2015

This paper presents a study of the dynamic response of actuation devices used in mechanical systems with open and closed-loop linkage mechanisms and highly nonlinear dynamics such as robot manipulators. The study shows that the actuation forces/torques provided by actuation devices can be divided into two basic groups. The first group corresponds to the components of each actuator force/torque that is “actuator motion independent”. The dynamic response of this group is relatively high and limited only by the dynamic response limitations — for the case of electrically driven actuation systems — of the driving power amplifiers, electronics, computational and signal processing devices and components. The second group corresponds to those components of the actuator forces/torques that is “actuator motion dependent”. The dynamic response of this group is relatively low and dependent on the actuator effective inertial load and actuation speed. In all mechanical systems that are properly designed, the dynamic response of the first group is significantly higher than those of the second group. By separating the required actuating forces/torques into the above two groups, the dynamic response of such nonlinear dynamics systems may be determined for a given synthesized trajectory. The information can also be used to significantly increase the performance of mechanical systems. When a feed-forward control signal is used, the performance of the system is shown to be significantly improved by generating each one of the group of actuation components separately considering the dynamic response of the actuation system to each group of components. A method for separating the actuation forces/torques into the said “actuator motion independent” and “actuator motion dependent” groups for mechanical systems with open-loop and closed-loop linkage mechanisms is provided. Provided examples include an open-loop manipulators with feed-forward trajectory control and a closed-loop mechanism, both with highly nonlinear dynamics. Practical methods for implementing the proposed feed-forward control for nonlinear dynamics systems are discussed.
Bi-Linear Shear Deformable ANCF Shell Element Using Continuum Mechanics Approach
Authors: Yamashita Hiroki , Valkeapää Antti I. , Jayakumar Paramsothy , Sugiyama Hiroyuki
Published: January 2015

In this investigation, a bi-linear shear deformable shell element is developed using the absolute nodal coordinate formulation for the large deformation analysis of multibody shell structures. The element consists of four nodes, each of which has the global position coordinates and the gradient coordinates along the thickness introduced for describing the orientation and deformation of the cross section of the shell element. The global position field on the mid-plane and the position vector gradient at a material point in the element are interpolated by bi-linear polynomials. The continuum mechanics approach is used to formulate the generalized elastic forces, allowing for the consideration of nonlinear constitutive models in a straightforward manner. The element locking exhibited in this type of element can be eliminated using the assumed natural strain (ANS) and enhanced assumed strain (EAS) approaches. In particular, the combined ANS and EAS approach is introduced to alleviate the thickness locking arising from the erroneous transverse normal strain distribution. Several numerical examples are presented in order to demonstrate the accuracy and the rate of convergence of numerical solutions obtained by the bi-linear shear deformable ANCF shell element proposed in this investigation.
Design and Testing of a Low-Cost and Low-Maintenance Drip Irrigation Filtration System for Micro-Irrigation in Developing Countries
Authors: Greenlee Alison , Murray Timothy , Lesniewski Victor , Jeunnette Mark , Winter Amos G.
Published: January 2015

The cylindrical filters presently used in <1000 m2 drip irrigation systems are frequently clogged, increasing pressure loss and lowering the flow rate through the filters. This work investigates the mechanisms for this clogging and proposes an alternative filtration design that would enable both more reliable and lower maintenance filtering. This proposed system is compatible with existing drip irrigation systems and could be made inexpensively with plastic bottle manufacturing equipment. To compare the proposed design to off-the-shelf options, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments confirmed that pleated cartridge filters, with high effective surface area, incurred lower pressure losses than cylindrical filters. These tests revealed that the greatest reason for clogged performance was that filtered particles (not the cartridge filter itself) eventually restricted the flow of water through the system. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improved the overall performance of the filtration system, reduced the maintenance requirement necessary from the user, and would enable inexpensive manufacturing via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.
Condition Monitoring and Diagnostics of Wind Turbines: A Survey
Authors: Pennacchi Paolo , Borghesani Pietro , Chatterton Steven , Gultekin Candas
Published: January 2015

Wind energy conversion is the fastest growing source of electricity generation in the world among the other renewable energy production technologies. Whereas investment costs have decreased over years, operational and maintenance costs of wind turbines are still high, thus attracting the focus of researchers and industrial operators.

Classical maintenance techniques, i.e.: run-to-failure and scheduled-preventive maintenance, are still dominant in this sector; however, condition monitoring has gained space in the wind turbine market and new diagnostic methods and techniques are continuously being proposed. Condition monitoring techniques seem the most effective tools to minimize operational and maintenance costs and reduce downtimes by early detection of faults.

This paper is aimed at reviewing the state of the art of condition monitoring for horizontal axis wind turbines. After a brief introduction presenting the current trends in the market of wind energy, the paper reviews the most common failure modes of wind turbines and the traditional approach to maintenance. The core of this study details the state of the art in the field of system architectures, sensors and signal processing techniques for the diagnostic of faults in wind turbine components. Finally, some general conclusions are drawn on the overall trends in the field of condition monitoring of wind turbines.
A Method for Determining Customer Needs in the Developing World
Authors: Wood Amy E. , Mattson Christopher A.
Published: January 2015

There are currently 1.4 billion people in the world living on less than $1.25 a day. Many engineers have designed products intended to alleviate the poverty faced by these individuals but most of these products have failed to have the desired impact. This is largely because we as engineers do not clearly understand the needs of people in poverty, which is understandable as it is particularly hard to determine needs in this context. This lack of understanding is usually because the engineer and the resource-poor individuals are from different cultures, because the engineer has no personal experience with life in poverty, and because the engineer has limited access to suitable market surrogates for testing and validation. This paper presents a method for determining the needs of resource-poor individuals in the developing world. The method presented here is organized into four steps to be completed within three different stages of need finding. Engineers and designers can follow these steps to more accurately determine the needs of resource-poor individuals as they design a product. The paper also includes examples of this method being used to determine customer needs for products in India and Peru.
Hopf Bifurcations in Two-Player Delayed Replicator Dynamics
Authors: Wesson Elizabeth , Rand Richard
Published: January 2015

We investigate the dynamics of two-strategy replicator equations in which competition between strategies is delayed by a given time interval T. Taking T as a bifurcation parameter, we demonstrate the existence of (non-degenerate) Hopf bifurcations in these systems, and present an analysis of the resulting limit cycles using Lindstedt’s method.
A Dynamic Model of Magneto-Active Elastomer Actuation of the Waterbomb Base
Authors: Bowen Landen , Frecker Mary , Simpson Timothy W. , von Lockette Paris
Published: January 2015

Of special interest in the growing field of origami engineering is self-folding, wherein a material is able to fold itself in response to an applied field. In order to simulate the effect of active materials on an origami-inspired design, a dynamic model is needed. Ideally, the model would be an aid in determining how much active material is needed and where it should be placed to actuate the model to the desired position. A dynamic model of the origami waterbomb base, a well-known and foundational origami structure, is developed using Adams, a commercial dynamics software package. Creases are approximated as torsion springs with stiffness and damping. The stiffness of an origami crease is calculated, and the dynamic model is verified using the bistability of the waterbomb. An approximation of the torque produced by magneto-active elastomers (MAE) is calculated and is used to simulate MAE-actuated self-folding of the waterbomb.