bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of DNA Encapsulation on Buckling Instability of Carbon Nanotube Based on Nonlocal Elasticity Theory
Authors: Rafati Jacob , Asghari Mohsen , Goyal Sachin
Published: January 2015

Carbon nanotubes (CNTs) are capable to absorb and encapsulate some molecules to create new hybrid nano-structures providing a variety of functionally useful properties. CNTs functionalized by encapsulaitng single-stranded deoxy-ribonucleic acid (ssDNA) promise great potentials for applications in nanotechnology and nano-biotechnology. In this paper, buckling instability of ssDNA@CNT i.e. hybrid nano-structure composed of ssDNA encapsulated inside CNT has been investigated using the nonlocal elasticity theory. The nonlocal elasticity theory is capable to capture the small scale effects due to the discontinuity of nano-structures at atomic scales. The nonlocal elastic rod and shell equations are derived for modeling ssDNA and CNT respectively. Providing numerical examples, it is predicted that, ssDNA@(10,10) CNT is more resistant than the pristine (10,10) CNT against the buckling instability under radial pressure due to the inter-atomic van der Waals interactions between DNA and CNT. Furthermore, nonlocal elasticity theory predicts lower critical buckling pressure than does the local elasticity theory.
The Effect of Product Representation in Visual Conjoint Analysis
Authors: Sylcott Brian , Orsborn Seth , Cagan Jonathan
Published: January 2015

When most designers set out to develop a new product they solicit feedback from potential consumers. These data are incorporated into the design process in an effort to more effectively meet customer requirements. Often these data are used to construct a model of consumer preference capable of evaluating candidate designs. Although the mechanics of these models have been extensively studied there are still some open questions, particularly with respect to models of aesthetic preference. When constructing preference models, simplistic product representations are often favored over high fidelity product models in order to save time and expense. This work investigates how choice of product representation can affect model performance in visual conjoint analysis. Preference models for a single product, a table knife, are derived using three different representation schemes; simple sketches, solid models, and 3D printed models. Each of these representations is used in a separate conjoint analysis survey. The results from this study showed that consumer responses were inconsistent and potentially contradictory between different representations. Consequently, when using conjoint analysis for product innovation, obtaining a true understanding of consumer preference requires selecting representations based on how accurately they convey the product details in question.
A Novel Force Sensitive Resistor Wheatstone Bridge for Prosthesis Control
Authors: Schroeder Kyle A. , De La Fuente Juan , Sugar Thomas G. , Flaven Thierry
Published: January 2015

Control of prosthetic devices should be robust and intuitive. In this work a simple, robust, and intuitive method for opening and closing a prosthetic hand for transradial amputations is proposed. The method utilizes force sensitive resistors (FSR) in a sleeve around the residual forearm. Contracting the muscles to open or close the hand changes the shape of the forearm and the force on the FSR sensors. A novel Wheatstone bridge configuration of the sensors simplifies and expediates the calibration. Using all four FSRs as the resistors of the Wheatstone bridge, the system is relatively insensitive to sensor location. To calibrate the sensor, the user opens and closes the hand a few times. The method was demonstrated in simulation on two unamputated individuals opening and closing the hand. To demonstrate the robustness of the method, the sleeve was removed and replaced so that the FSR locations and the calibration is different, but the system is still functional.
Localization Phenomena in Pendulum Arrays Subjected to Vertical Excitation
Authors: Ikeda Takashi , Harata Yuji , Shi Chongyue , Nishimura Keisuke
Published: January 2015

Localization phenomena, also referred to as intrinsic localized modes (ILMs), are investigated in an N-pendulum array subjected to vertical harmonic excitation. The pendula behave nonlinearly and are connected with each other by weak linear springs. In the theoretical analysis, van der Pol’s method is employed to determine the expressions for frequency response curves for the principal parametric resonances, considering the nonlinear restoring moment of the pendula. In the numerical results, frequency response curves for N=2 and 3 are shown to examine the patterns of ILMs, and the influences of the connecting spring constants and the imperfections of the pendula. Bifurcation sets are also calculated to show the excitation frequency range and the conditions for the occurrence of ILMs. Increasing the connecting spring constant results in the appearance of Hopf bifurcation. The numerical simulations reveal the occurrence of ILMs with amplitude modulated motions (AMMs) including chaotic motions. ILMs were observed in experiments, and the experimental data were compared with the theoretical results. The validity of the theoretical analysis was confirmed by the experimental data.
Impact Task Model and Acoustic Recognition System With a Humanoid Robot for an Automation of Hammering Test
Authors: Hayashi Kento , Hirogaki Toshiki , Aoyama Eiichi , Sugiura Yoshihisa
Published: January 2015

The purpose of this study is to automate the hammering tests by using a humanoid robot. Therefore, this report discusses the impact of the task model using the robot and a new acoustic recognition system. This study also deals with the study of the robot playing the glockenspiel. We proposed a flexible rubber stick for the humanoid robot in order to control the impact task. The robot hits the glockenspiel using the vibrations of a flexible rubber stick. The results showed that the robot achieved high accuracy impact with the stick. Also, the robot could move both arms efficiently. Regarding the acoustic recognition, we focused on the frequency and the sound pressure generated from objects. The results showed that the acoustic recognition system detected the sounds. This system also recognized the sound of every object. Moreover, on the basis of the impact task model and acoustic recognition system, we developed a hit sound feedback system. This system achieved efficient results in the case study. Therefore, the proposed approach demonstrated the efficiency of using a humanoid robot in an automated hammering test.
Dynamics Based Time-Optimal Path Navigation for a Skid-Steer Robot
Authors: Kumar Suren , Krovi Venkat N.
Published: January 2015

We use dynamics formulation of skid-steer robot with an arc-length parametrized path description for path navigation of the robot in least possible time. We use Lagrangian formulation to derive dynamics of the robot and add the kinematic constraint to the dynamics using a parameter corresponding to internal force. This necessary conditions for the trajectory are established in terms of the path variable. The proposed methodology is experimentally evaluated for a circular and a custom trajectory. For the circular trajectory, it is demonstrated that the constraint can be removed by the choice of parameters. Moreover, the nature of the enforced constraint is demonstrated for the custom trajectory.
Compliant Mechanism Synthesis Using Degree of Genus and Variable Width Curves
Authors: Zhou Hong , Mohammed Azher Hussain Naser
Published: January 2015

Compliant mechanisms (CMs) utilize elastic deformations for mechanism functions. Their merits primarily come from jointless structures. The structure of a fully CM is a piece of elastic material and is defined by its topology, shape and size. Topology is the overarching material layout of a CM while shape and size are on its structural details, but topology is entangled with shape and size in the synthesis process of a CM because its elastic deformation is from the joint effect of topology, shape and size. Degree of freedom (DOF) and number of links used in rigid mechanism synthesis are not effective to guide the synthesis of CMs since any point of a fully CM can deform and its whole structure forms a single piece. Without effective synthesis guidance, the structural complexity of a synthesized CM can be undesirably high. In this paper, degree of genus (DOG) is introduced for topology guidance of CM synthesis. DOG of a CM is the number of holes and is actively controlled during its synthesis process. With DOG guidance, a synthesized CM will not have overcomplicated topology. Variable width curves (VWCs) are introduced in this paper for shape and size description. Any connection in a CM is defined as a VWC and the entire CM is modeled as a network of VWCs. With VWC description, a synthesized CM will not have unsmooth connection. Under DOG and VWC strategies, CM synthesis is systematized as optimizing control parameters of networks of VWCs. The proposed CM synthesis using DOG and VWC strategies is demonstrated by synthesizing shape morphing compliant mechanisms.
Gate-to-Gate Sustainability Assessment for Small-Scale Manufacturing Businesses: Caddisfly Jewelry Production
Authors: Armstrong Jessica L. , Garretson Ian C. , Haapala Karl R.
Published: January 2015

Recent manufacturing research has focused attention on methods for improving the sustainability performance of high-volume manufacturing. Most manufacturing businesses operate at the small to medium scale, however, and would benefit from the transfer of knowledge gained from this work to lower volume production. To demonstrate an example of this knowledge transfer, the sustainability performance of two manufacturing strategies is investigated for small-scale caddisfly jewelry production. Control over the aesthetics of the end product is an important feature of jewelry manufacturing. In this case, however, increasing product quality control can have life cycle impacts which are unaccounted for in typical decision making. To make a decision between two caddisfly jewelry manufacturing strategies, a comparative gate-to-gate sustainability assessment was performed. The method combines life cycle inventory analysis, life cycle costing, and worker injury risk assessment to develop a holistic comparison encompassing the three pillars of sustainability. The assessment revealed tradeoffs between environmental impacts, costs, and social impacts for the two scenarios. Thus, hierarchical importance of the three sustainability pillars is needed to make stakeholder decisions. In this small-scale manufacturing case, such decision-making is found to be primarily driven by the personal values of the business owners.
Multi-Objective Mechanism Design Using a Bi-Level Game Theoretic Formulation
Authors: Ghotbi Ehsan
Published: January 2015

This paper considers the design of a high speed mechanism as a multi objective optimization problem wherein the kinematic and dynamic criteria are optimized simultaneously. The kinematic criteria include minimization of the structural error and a minimization of deviation of the transmission angle from its ideal value. The dynamic criterion used is minimization of the peak torque required to drive the input link over a cycle. A Stackelberg (leader-follower) game theoretic approach is proposed to solve the multiobjective problem. Three variants, wherein both the kinematic and the dynamic criteria are treated as the leader, are considered. The design variables are the mechanism dimensions. A computational procedure using sensitivity information is proposed for approximating rational reaction sets needed for capturing exchange of information between the leader and the follower problems. A numerical example dealing with the design of a path generating 4-bar mechanism is presented. It is shown that significant improvement in both kinematic and dynamic performance measures is simultaneously achieved using the proposed approach.
Motion Analysis as an Evaluation Framework for Eye-Hand Coordination: A Case Study in Ultrasound-Guided Catheter Insertion
Authors: Kim Inki , Miller Scarlett R. , Freivalds Andris
Published: January 2015

Helping resident surgeons quickly and accurately develop expertise in clinical skills is crucial for improving patient safety and care. Because most surgical skills require visually aided device manipulations, developing effective eye-hand coordination is a crucial component of most surgical training. While eye-hand coordination has typically been evaluated on the basis of time to complete a task and number of errors, growing evidence suggests that task performance can be distinguished by detecting eye gaze patterns and movement planning. However, few studies have explored methods for collecting and evaluating gaze patterns without significantly impeding the user (e.g. goggle eye trackers), reducing the utility of this approach. Therefore, the current study was developed to propose and test a framework for evaluating the quality of eye-hand coordination using a novel motion analysis technique. To validate the framework, three expert and three novice resident surgeons were video-taped during ultrasound-guided central-venous catheter insertion procedures and compared. Our method was able to show that experts demonstrate distinguished patterns in adjusted accuracy, movement trajectories and time allocation. The results also showed that expert performance in eye-hand coordination appears to be characterized by goal-oriented adjustment. This research framework can be used to characterize individual differences and improve surgical residence training and can also be applied in other domains where eye-hand coordination needs to be studied without impeding user performance.
Independence of Irrelevant Alternatives in Engineering Design
Authors: Li Simon
Published: January 2015

When discussing Arrow’s Impossibility Theorem (AIT) in engineering design, we find that one condition, Independence of Irrelevant Alternatives (IIA), has been misunderstood generally. In this paper, two types of IIA are distinguished. One is based on Kenneth Arrow (IIA-A) that concerns the rationality condition of a collective choice rule (CCR). Another one is based on Amartya Sen (IIA-S) that is a condition for a choice function (CF). Through the analysis of IIA-A, this paper revisits three decision methods (i.e., Pugh matrix, Borda count and Quality Function Deployment) that have been criticized for their failures in some situations. It is argued that the violation of IIA-A does not immediately imply irrationality in engineering design, and more detailed analysis should be applied to examine the meaning of “irrelevant information”. Alternatively, IIA-S is concerned with the transitivity of CF, and it is associated with contraction consistency (Property α) and expansion consistency (Property β). It is shown that IIA-A and IIA-S are technically distinct and should not be confused in the rationality arguments. Other versions of IIA-A are also introduced to emphasize the significance of mathematical clarity in the discussion of AIT-related issues.
Regular Folding Pattern Generation for Deployable Non-Axisymmetric Tubes
Authors: Ishida Sachiko , Nojima Taketoshi , Hagiwara Ichiro
Published: January 2015

This paper presents two modeling techniques to design folding patterns for deployable non-axisymmetric tubes, with regular arrangement of fold lines based on three fundamental folding designs; Miura folding, bellows folding, and folding with six fold lines at each node. The first technique is conducted by allowing cutting and removing unnecessary parts from the original folding pattern — one of the corresponding straight cylinder. The next technique is to design additional fold lines on unnecessary parts to fold them up into the tube, without cutting the surface. Consequently, applicability and constraints of each folding design and modeling techniques are discussed and summarized.
Confidence-Based Method for Reliability-Based Design Optimization
Authors: Cho Hyunkyoo , Choi K. K. , Lamb David
Published: January 2015

An accurate input probabilistic model is necessary to obtain a trustworthy result in the reliability analysis and the reliability-based design optimization (RBDO). However, the accurate input probabilistic model is not always available. Very often only insufficient input data are available in practical engineering problems. When only the limited input data are provided, uncertainty is induced in the input probabilistic model and this uncertainty propagates to the reliability output which is defined as the probability of failure. Then, the confidence level of the reliability output will decrease. To resolve this problem, the reliability output is considered to have a probability distribution in this paper. The probability of the reliability output is obtained as a combination of consecutive conditional probabilities of input distribution type and parameters using Bayesian approach. The conditional probabilities that are obtained under certain assumptions and Monte Carlo simulation (MCS) method is used to calculate the probability of the reliability output. Using the probability of the reliability output as constraint, a confidence-based RBDO (C-RBDO) problem is formulated. In the new probabilistic constraint of the C-RBDO formulation, two threshold values of the target reliability output and the target confidence level are used. For effective C-RBDO process, the design sensitivity of the new probabilistic constraint is derived. The C-RBDO is performed for a mathematical problem with different numbers of input data and the result shows that C-RBDO optimum designs incorporate appropriate conservativeness according to the given input data.
Stiffness and Stability Characteristics of Small Satellite Deployables With Integrated Tape-Spring Booms
Authors: Wiens Gloria J. , Hansoge Amrith N.
Published: January 2015

Currently, the small satellite mechanisms that are used to deploy sensors and antennae in space have been restricted to simple one arm pin jointed members or telescopic mechanisms. This means, to deploy multiple sensors, multiple actuators and controllers are required. However, simple rigid link mechanisms, like the 6-bar hexagonal mechanism described in this paper, give the freedom to incorporate a greater number of sensor platforms in one deployable structure and also helps reduce the number of actuators. In fact, by the use of boom technology, the entire mechanism can be deployed by a single tape-spring boom. Further, to make these structures more robust and stiffer at the joints, rotational springs can be used. In this paper, an attempt is made to study the stiffness and stability of such mechanisms at their equilibrium points. Also since the positions and orientations of the sensor platforms are critical, it is shown through a few examples how these parameters can be adjusted just by tweaking the preloads of the rotational springs. The tape-spring boom — which is bi-stable in nature — offers further stiffness to the structure in its deployed state. It is well known now and also well established by the theory of mechanics of materials that by arranging multiple tape springs in certain orientations within the boom; a boom can be obtained with significant axial and flexural stiffness in its deployed state. Through modal analyses at equilibrium and by looking at the characteristics of the Hessian of the potential energy function, it is also shown how this significantly rigid boom affects the stiffness and stability of the structure. Herein, the force method of matrix analysis for deployable structures is used for analyses. This paper also discusses the possibilities of the system failing due to insufficient actuation force by the boom — the condition where the boom does not reach its second stable position.
Determination of Process Parameter for Twin-Wire Weld-Deposition Based Additive Manufacturing
Authors: Adinarayanappa Somashekara Makireddypalli , Simhambhatla Suryakumar
Published: January 2015

Various energy sources are available for sintering and/or depositing the material in additive manufacturing for metallic objects. These can be mainly categorized as laser based, electron beam based and arc based. While laser and electron offer better surface finish, it is possible to achieve high deposition rates in arc based weld-deposition. The inferior surface finish can be compensated by going for a hybrid system, combining deposition and machining. Twin-wire based weld-deposition, used in the present work, makes it possible to even realize functionally gradient material matrix; the use of two different filler materials into a single weld-pool makes this possible. Wire speed, torch speed and filler material are important factors that effect the composition of the deposited volume. Determination of the operating range and effect of these process parameters therefore is important to control the properties of the weld-deposited gradient objects. The current work presents the material composition of two filler materials ER70S6 and ER110SG with different wire speed and torch speed. Deposited material elemental compositions were analyzed using ED-XRF machine.
A Horseshoe Crab Inspired Surf Zone Robot With Righting Capabilities
Authors: Krummel Gregory , Kaipa Krishnanand N. , Gupta Satyandra K.
Published: January 2015

In this paper, we present the design of RoboCrab, an amphibious robot capable of traversing moderate surf zone environments. By taking inspiration from the morphology, locomotion, and righting behaviors of a horseshoe crab, the robot is designed for traversal and righting on granular terrain, open water, and turbulent surf zones. We present the details of the crab’s morphology that informed the design of our robot. Next, we present the mechanical design, material selection, and manufacturing of the various parts of the robot. We report the results from the computational fluid dynamics simulations used to characterize the robot shell performance. Finally, we present demonstrations of the physical robot walking and righting in a granular environment.
A Framework of CAD/CAE Integration System and its Implementation for Container Crane
Authors: Chen Xi , Li Hua , You Lin , Wang Chonghua
Published: January 2015

A framework of CAD/CAE integration system and its implementation for dockside container crane are proposed in this paper. First, the system framework based on web technology, software design pattern and service-oriented architecture (SOA) is introduced. Then, requirement input interfaces of Customer-Designer-Interaction (CDI) module are built based on ASP.NET multiple-layer Browser/Server (B/S) architecture, core design patterns and .NET WCF Services, and customers can provide specifications of the cranes to designers. Next, CAD and CAE modules are accomplished using multiple-layer architecture, and designers can parametrically create 3D models of the crane structures and conduct explicit dynamic Finite Element Analysis (FEA) on the designed crane structures. SOA based Design-Analysis-Integration (DAI) is developed to maintain consistence between CAD and CAE models by using .Net WCF Service. Last, system management functions such as user interaction, user account and file management are described. Since all the operations are conducted in Web and SOA context, customers and designers are able to participate in the design process at different geographical locations.
On Some Problems With Modeling of Coulomb Friction in Self-Locking Speed Reducers
Authors: Wojtyra Marek
Published: January 2015

A simple mathematical model of friction in speed reducers is presented and discussed. A rigid body approach, typical for multibody simulations, is adopted. The model is based on the Coulomb friction law and exploits the analogy between reducers and wedge mechanisms.

The first version of the model is purely rigid, i.e. no deflections of the mechanism bodies are allowed. Constraints are introduced to maintain the ratio between input and output velocity. It is shown that when friction is above the self-locking limit, paradoxical situations may be observed when kinetic friction is investigated. For some sets of parameters of the mechanism (gearing ratio, coefficient of friction and inertial parameters) two distinct solutions of normal and friction forces can be found. Moreover, for some combinations of external loads, a solution that satisfies equations of motion, constraints and Coulomb friction law does not exist. Furthermore, for appropriately chosen loads and parameters of the mechanism, infinitely many feasible sets of normal and friction forces can be found. Examples of all indicated paradoxical situations are provided and discussed.

The second version of the model allows deflection of the frictional contact surface, and forces proportional to this deflection are applied to contacting bodies (no constraints to maintain the input-output velocity ratio are introduced). In non-paradoxical situations the obtained results are closely similar to those predicted by the rigid body model. In previously paradoxical situations no multiple solutions of friction force are found, however, the amended model does not solve all problems. It is shown that in regions for which the paradoxes were observed only unstable solutions are available. Numerical examples showing behavior of the model are provided and analyzed.
Predictive Usage Mining for Sustainability of Complex Systems Design
Authors: Ma Jungmok , Kim Harrison M.
Published: January 2015

A new perspective of dynamic LCA (life cycle assessment) is proposed with the predictive usage mining for sustainability (PUMS) algorithm. By defining usage patterns as trend, seasonality, and level from a time series of usage information, predictive LCA can be conducted in a real time horizon. Large-scale sensor data of product operation is analyzed in order to mine usage patterns and build a usage model for LCA. The PUMS algorithm consists of handling missing and abnormal values, seasonal period analysis, segmentation analysis, time series analysis, and predictive LCA. A newly developed segmentation algorithm can distinguish low activity periods and help to capture patterns more clearly. Furthermore, a predictive LCA method is formulated using a time series usage model. Finally, generated data is used to do predictive LCA of agricultural machinery as a case study.
Tunable-Volume Handheld Pipette Utilizing a Pneumatic De-Amplification Mechanism
Authors: Beroz Justin , Jiang Sheng , Lewandowski John , Hart A. John
Published: January 2015

We present the design, analysis, and validation of a tunable-volume handheld pipette that enables precise drawing and dispensing of ml and μl liquid volumes. The design builds upon the standard mechanism of a handheld micropipette by incorporating an elastic diaphragm that de-amplifies the volume displacement of the internal piston via compression of an entrapped air volume. The degree of de-amplification is determined by the stiffness of the elastic diaphragm and the amount of entrapped air. An analytical model of the diaphragm mechanism is derived, which guides how to achieve linear de-amplification over an extended range where leading-order nonlinear contributions are significant. In particular, nonlinearities inherent in the mechanical behavior of the diaphragm and entrapped air volume may exactly cancel one another by careful design of the pipette’s parameter constants. This linearity is a key attribute for enabling the pipette’s tunable volumetric range, as this allows diaphragms with different stiffnesses to be selectively used with a conventional linear-stepping piston mechanism. Design considerations regarding the range, accuracy, and precision of the proposed pipette are detailed based on the model. Additionally, we have constructed a handheld prototype that uses a planar latex sheet as the diaphragm. Our pipetting experiments validate the derived model and exhibit linearity between the piston stroke and drawn liquid volume. We propose that this design enables a single handheld mechanical pipette to achieve drawing and dispensing of liquids over a 1μl-10ml range (i.e., the range of the entire micropipette suite), with volumetric resolution and precision comparable to commercially available counterparts.
Discovering Next Generation Product Innovations by Identifying Lead User Preferences Expressed Through Large Scale Social Media Data
Authors: Tuarob Suppawong , Tucker Conrad S.
Published: January 2015

An innovative consumer (a.k.a. a lead user) is a consumer of a product that faces needs unknown to the public. Innovative consumers play important roles in the product development process as their ideas tend to be innovatively unique and can be potentially useful for development of next generation, innovative products that better satisfy the market needs. Oftentimes, consumers portray their usage experience and opinions about products and product features through social networks such as Twitter and Facebook, making social media a viable, rich in information, and large-scale source for mining product related information. The authors of this work propose a data mining methodology to automatically identify innovative consumers from a heterogeneous pool of social media users. Specifically, a mathematical model is proposed to identify latent features (product features unknown to the public) from social media data. These latent features then serve as the key to discover innovative users from the ever increasing pool of social media users. A real-world case study, which identifies smartphone lead users in the pool of Twitter users, illustrates promising success of the proposed models.
An Optimized Kinematic Mobility Analysis of Protein Molecules
Authors: Demirtas Ahmet , Shahbazi Zahra
Published: January 2015

Understanding the 3D structure and consequently the motion of protein molecules contributes to simulate their function. Modeling protein molecules as kinematic chains has been used to predict protein molecules flexible and rigid regions as well as their degrees of freedom to predict their mobility. However, high computational cost for relatively large molecules is one of the major challenges in this field.

In this paper we have combined our previously developed rigidity analysis (ProtoFold) with pebble game thus improving computational cost of our simulation. Here, we have determined the required time for all steps of ProtoFold and subsequently the most time consuming step. Results have shown that finding rigid loops inside the protein structure using graph theory and Grübler-Kutzbach criterion is the slowest part of the procedure, taking an average of 75% of the time required for the rigidity analysis. Therefore we have replaced this step with pebble game. The modified method has been applied to a random group of protein molecules and its efficiency in significantly improving the simulation speed has been verified.
Enhanced Adaptive Choice-Based Conjoint Analysis Incorporating Engineering Knowledge
Authors: Ren Yi , Papalambros Panos Y.
Published: January 2015

Conjoint analysis from marketing has been successfully integrated with engineering analysis in design for market systems. The long questionnaires needed for conjoint analysis in relatively complex design decisions can become cumbersome to the human respondents. This paper presents an adaptive questionnaire generation strategy that uses active learning and allows incorporation of engineering knowledge in order to identify efficiently designs with high probability to be optimal. The strategy is based on viewing optimal design as a group identification problem. A running example demonstrates that a good estimation of consumer preference is not always necessary for finding the optimal design and that conjoint analysis could be configured more effectively for the specific purpose of design optimization. Extending the proposed method beyond a homogeneous preference model and noiseless user responses is also discussed.
Using Human Computation to Assist Biologically Inspired Design: Evaluating a Game-With-a-Purpose
Authors: Arlitt Ryan , Berthelsdorf Friederich , Immel Sebastian , Stone Robert
Published: January 2015

Locating relevant biological analogies is a challenge that lies at the heart of practicing biologically inspired design. One promising solution involves computationally providing relevant inspiration to the designer. This paper presents a novel human computation game for collecting computable descriptions of biological strategies, an assessment of the quality of these descriptions gathered from experimental data, and an evaluation of the game’s user experience. This human computation approach to collecting and organizing biological phenomena improves upon the breadth of curated database approaches without sacrificing the accuracy afforded by human reasoning skills. The Biology Phenomenon Categorizer (BioP-C); a cooperative, asymmetric, online game; was deployed in a small engineering graduate class in order to collect assertions about the biological phenomenon of cell division. Through the course of playing, the students formed assertions describing key concepts in the passage. These assertions are assessed for their factual correctness, and these correctness ratings are used to identify directly measurable indicators of assertion truth. Areas for improved game design are also identified.
Adaptive Segmentation for Air Gestures Identification
Authors: Ghobadi Mostafa , Esfahani Ehsan T.
Published: January 2015

Having a user-friendly Human-CAD interaction with high speed and accuracy plays a key role in development of future intelligent modeling environments. A major part of this puzzle is sketch identification using either 2D gestures — which is commonly recorded from mouse, light pen and touchpad — or air gestures captured from some newly emerged devices such as Leap Motion and Soft-Kinect. To this end, we present a leaning based technique for segmentation of air gestures. The proposed technique can detect the separation points of any single-stroke air gesture using specific motion features such as speed, curvature and center of curvature. Two types of separation points are considered: 1) rough separation points or simply corner points and 2) soft separation points such as inflection points. The segmentation is performed in two steps: Support Vector Machine (SVM) is used to adaptively differentiate the corner points from regular points. A soft segmentation method is then implemented to further break the rough segments into a set of smaller arcs and lines based on sudden change in the center of curvature. The experimental validation shows robust performance of the proposed method and low computation expenses.
Computational and Experimental Approach to Understanding Legged Mobility in Micro Ground Vehicles
Authors: Mukherjee Rudranarayan , Moreland Scott , Kim Isaac , Lele Nikhil , Goodwin Stephen , Houlihan Ryan , Parness Aaron , Wu Alice , Cutkosky Mark
Published: January 2015

The army has a vision for using autonomous micro ground vehicles (MGV) for soldier support in the last 100 meters of operations in urban and natural environments. These MGVs are expected to typically fit in a human palm and weigh in the order of 30–50 grams. Robust mobility is a necessary condition to ensure operations. Given the severe challenge of size, weight and power (SWAP) of the MGVs, significant uncertainties currently remain in quantifying micro ground vehicle mobility. In this paper we describe a research methodology and representative results for understanding legged MGV mobility in different types of terrain. Our methodology is based on a synergy of novel experimental setup and high-fidelity computational methods. We report the use of a novel “single-leg” test rig that uses tactile sensors to measure ground interaction loads. We also report the use of high speed imaging and use of particle image velocimetry to understand soil deformation during legged interactions with terrain. Finally, we report on the use of multibody dynamics and High Performance Computing (HPC) based granular media simulations. This conference paper emphases more on the overall approach based on synergistic use of high fidelity modeling and experimental methods supported by representative results rather than presenting a detailed analyses of the results.
Statistical Health Diagnostics for Water-Cooled Power Generator Stator Winding Against Water Absorption
Authors: Park Kyung Min , Youn Byeng D. , Yoon Joung Taek , Kim Hee Soo , Jang Beom Chan
Published: January 2015

One of most important components in power generator is a stator winding since an unexpected failure of the water absorbed-winding leads to plant shut-down and substantial loss. Typically the stator winding is maintained with a time- or usage-based strategy, which could result in substantial waste of remaining life, high maintenance cost and low plant availability. Recently, the field of prognostics and health management offers general diagnostic and prognostic techniques to precisely assess the health condition and robustly predict the remaining useful life of an engineered system, with an aim to address the aforementioned deficiencies. This research aims at developing health reasoning system of power generator stator winding with physical and statistical analysis against water absorption. And it is based upon the capacitance measurements on winding insulations. In particular, a new health measure, Directional Mahalanobis Distance (DMD), is proposed to quantify the health condition. In addition, the empirical health grade system based upon the proposed technique, DMD, is carried out with the maintenance history. The smart health reasoning system is validated using eight years’ field data from eight generators, each of which contains forty two windings.
Design of the Deployable Mechanisms Based on the Cardanic Motion of Planar Four-Bar Linkage
Authors: Shieh Win-Bin
Published: January 2015

A deployable mechanism is a mechanism that is designed to be repeatedly expanded and contracted without failure. Most deployable mechanisms are over-constrained mechanisms with a mobility of one. Although many deployable mechanisms had been proposed and employed in application in the past decades, few generalized methodologies for the synthesis of both planar and spatial deployable mechanisms are available. In this paper, a systematic methodology, based on the Cardanic motion of planar linkage, for the synthesis of both the spatial and planar deployable mechanisms is presented. By using the characteristics that some of the coupler points of Cardanic linkages are able to move along a straight line, a building unit mechanism that utilizes such a linkage can be extended or retracted as desired. Once the boundary conditions of the building unit mechanisms are obtained, design of an entire deployable mechanism, planar or spatial, can be fulfilled. After the design is achieved, motion of the synthesized mechanism is simulated in Pro/Engineer, and the prototype of a planar model is manufactured for the justification of this method.
Restart Strategies for Constraint-Handling in Generative Design Systems
Authors: Nordin Axel
Published: January 2015

Product alternatives suggested by a generative design system often need to be evaluated on qualitative criteria. This evaluation necessitates that several feasible solutions which fulfill all technical constraints can be proposed to the user of the system. Also, as concept development is an iterative process, it is important that these solutions are generated quickly; i.e., the system must have a low convergence time. A problem, however, is that stochastic constraint-handling techniques can have highly unpredictable convergence times, spanning several orders of magnitude, and might sometimes not converge at all. A possible solution to avoid the lengthy runs is to restart the search after a certain time, with the hope that a new starting point will lead to a lower overall convergence time, but selecting an optimal restart-time is not trivial. In this paper, two strategies are investigated for such selection, and their performance is evaluated on two constraint-handling techniques for a product design problem. The results show that both restart strategies can greatly reduce the overall convergence time. Moreover, it is shown that one of the restart strategies can be applied to a wide range of constraint-handling techniques and problems, without requiring any fine-tuning of problem-specific parameters.
Development of a Test Bench for the Subjective and Objective Evaluation of the Vibrational Comfort of Bicycle Components
Authors: Petrone Nicola , Trabacchin Francesco
Published: January 2015

Vibrational comfort is one of the most important parameters evaluated by cyclists and it is correlated to the response of bicycle components in combination with the cyclist’s characteristics.

Vibration transmissibility of wheels and saddles had been recently studied during lab tests using a wooden dummy bottom resting on the saddle and in road tests on an instrumented racing bicycle at different speeds on different surfaces.

In this study, a test bench was developed in order to simulate different vibrational inputs to the seatpost from the road surface on a group of real cyclists during steady cycling. The bench is composed by a racing bicycle without wheels, hinged at the front fork axle and sustained by an hydraulic actuator connected to the seatpost. The bicycle is equipped with pedals and chain wheel and a long chain drives another rear wheel fixed to the bench and connected to brake rollers.

Three racing bicycle saddles were evaluated by a group of five cyclists after the application of vibrational spectra corresponding to PSDs recorded in the field tests: the magnitude of the transfer function H between the input vertical acceleration at the seatpost and the output acceleration at the pelvis was obtained by two accelerometers. The cyclists were in the meantime asked to fill a questionnaire regarding the perceived comfort of the three saddles during the tests.

Initial results showed an encouraging correlation of the subjective ranking of saddles with the corresponding Index of Transmissibility derived from the transfer function H.
Decision Support Systems Design for Data-Driven Management
Authors: Lei Ningrong , Moon Seung Ki
Published: January 2015

This article discusses a design methodology for a Decision Support System (DSS) in the area of Data-Driven Management (DDM). We partition the DSS into an offline and an online system. Through rigorous testing, the offline system finds the best combination of Data Mining (DM) and Artificial Intelligence (AI) algorithms. Only the best algorithms are used in the online system to extract information from data and to make sense of this information by providing an objective second opinion on a decision result. To support the proposed design methodology, we construct a DSS that uses DM methods for market segmentation and AI methods for product positioning. As part of the offline system construction, we evaluate four intrinsic dimension estimation, three dimension reduction and four clustering algorithms. The performance is evaluated with statistical methods, silhouette mean and 10-fold stratified cross validated classification accuracy. We find that every DSS problem requires us to search a suitable algorithm structure, because different algorithms, for the same task, have different merits and shortcomings and it is impossible to know a priory which combination of algorithms gives the best results. Therefore, to select the best algorithms is empirical science where the possible combinations are tested. With this study, we deliver a blueprint on how to construct a DSS for product positioning. The proposed design methodology can be easily adopted to serve in a wide range of DDM problems.
Design and Performance Evaluation of Soft Morphing Car-Spoiler
Authors: Han Min-Woo , Rodrigue Hugo , Cho Seunghyun , Song Sung-Hyuk , Chu Won-Shik , Choi Haecheon , Ahn Sung-Hoon
Published: January 2015

Automotive wings are considered to be aerodynamic devices which have a significant effect on the driving, braking and cornering performances by influencing the flow of fluids around the vehicle without changing the weight of the vehicle. The wings have developed from having a fixed shape to multi-sectional wings in order to amplify the advantages of their aerodynamic effect in specific situations such as cornering and braking. However, the multi-sectional wings based on flaps, ailerons, and slats have to modify their surface or camber using hinged parts. These discrete sections create aerodynamic losses during shape changes. In this paper, a morphing car-spoiler based on a reinforced elastomer capable of continuous self-actuation throughout its surface was applied to a small-scale vehicle without slotted parts or mechanical elements. The designed morphing car-spoiler consists of a woven type Smart Soft Composite (SSC) which was made by weaving Shape Memory Alloy (SMA) wires and glass fibers embedded in a polydimethylsiloxane (PDMS) polymeric soft matrix. The phase transformation from martensite to austenite of the SMA wires creates an axial load in the longitudinal direction resulting in symmetric bending of the spoiler. Using an open-blowing type wind tunnel, tests were conducted on the stand-alone spoiler to verify its aerodynamic effects. Furthermore, to evaluate its performance in practice, the morphing car-spoiler was mounted on a small-scale vehicle and tested in a closed-type wind tunnel. Results show that the morphing car-spoiler generates a downforce which increases the normal tire adhesion and that it is possible to adapt its shape for various situations such as cornering and braking.
Simple Fall Criteria for MEMS Sensors: Data Analysis and Sensor Concept
Authors: Ibrahim Alwathiqbellah I. , Younis Mohammad I.
Published: January 2015

This paper presents a new and simple fall detection concept based on detailed experimental data of human falling and Activities of Daily Living (ADL). Establishing appropriate fall algorithms compatible with MEMS sensors requires detailed data on falls and ADL that indicate clearly the variations of the kinematics at the possible sensor node location on the human body, such as hip, head, and chest. Currently, there is a lack of data on the exact direction and magnitude of each acceleration component associated with these node locations. This is crucial for MEMS structures, which have inertia elements very close to the substrate and are capacitively biased, and hence, are very sensitive to the direction of motion whether it is toward or away from the substrate. This work presents detailed data of the acceleration components on various locations on the human body during various kinds of falls and ADL. An algorithm for fall detection based on MEMS switches is then established. A new sensing concept based on the algorithm is proposed. The concept is based on employing several inertia sensors, which are triggered simultaneously, as electrical switches connected in series, upon receiving a true fall signal. In the case of everyday life activities, some or no switches will be triggered resulting in an open circuit configuration, thereby preventing false positive. Lumped-parameter model is presented for the device and preliminary simulation results are presented illustrating the new device concept.
Synthesis of a Reconfigurable Four-Bar Mechanism With Variable Joints
Authors: Slaboch Brian J. , Voglewede Philip A.
Published: January 2015

This article introduces a reconfigurable four-bar mechanism. The mechanism uses a rotational-translational variable joint to switch between a RRRR four-bar and a RRRP1 four-bar. The ability to transition between two types of four-bar mechanisms allows the reconfigurable four-bar mechanism to complete a rigid body guidance task not possible by either a RRRR four-bar mechanism or a RRRP four-bar mechanism. The reconfigurable mechanism reduces the number of required actuators in the mechanism.