bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of Thermoforming Process Parameters to Increase Quality of Surfaces Using Pin-Based Tooling
Authors: Sreedhara Vijay Sarthy Mysore , Mocko Gregory
Published: January 2016

Tooling is a significant time and cost investment in manufacturing processes that include casting, injection molding, sheet metal forming, and plastic thermo-forming. These tooling investments are often justified for large production volumes. However, for small volume, prototyping, and custom manufacturing, the tooling investments are hard to justify. To meet the needs of smaller volume production, several adaptable tooling technologies has been developed. One solution, pin-based tooling enables adaptable surfaces for use in plastic thermoforming and composites. However, a key challenge in pin-based tooling is achieving accurate high quality surfaces. The objective in this research is to study the effects of process parameters on surface quality using pin-based tooling. Specifically, in this research polymer surfaces are manufactured without the use of an interpolating layer. A set of experiments was conducted by keeping the shape constant, with and without an interpolator, and varying the process parameters to check the feasibility of producing smooth surfaces. It was observed that smooth, shape-specific surfaces can be produced by optimizing the process parameters. The parameters thus optimized would be shape-specific and optimizing the process parameters for surfaces having complex shapes is a new research challenge that comes out of this work. Future work involves continuing the experiments, measuring the resulting parts and controlling process parameters to increase surface quality.
Integrating Gamification in Mechanical Engineering Systems to Support Knowledge Processes
Authors: Baalsrud Hauge Jannicke M. , Stănescu Ioana Andreea , Carvalho Maira B. , Stefan Antoniu , Banica Marian , Lim Theodore
Published: January 2016

Rapid technological changes have a large influence in the field of engineering systems. However, just being fast is not sufficient; additionally, the system has to be user-friendly, flexible and cost effective. Serious Games (SG), as fast-paced, immersive, interactive media, have not only become popular in various learning and training environments, including engineering, but there are also several examples on how game-based mechanisms can be used to enhance User Experience (UX) and performance. So far, gamification of Mechanical Engineering Systems (MES) have not reached their full potential, due to the fact that gamification efforts are costly, time consuming to develop, and require the constant involvement of MES developers even for small changes. Furthermore, its adaption to MES requires specific knowledge in game design and development. Thus, as demand for user friendlier, intuitive interfaces increases, there is also a need for support tools that enable access to design and development of gamification mechanisms for non-SG professionals. In this context, the authors discuss the creation of a library of User Interface (UI) automation tools that enables gamification and through which tutors can create interactive learning scenarios to guide users through the functionalities of engineering systems. Such tools have the potential to support knowledge processes, respectively knowledge experiencing, conceptualizing, analyzing and applying, in engineering environments.
In Search of Effective Design Problems for Design Research
Authors: Durand Fabien , Helms Michael E. , Tsenn Joanna , McAdams Daniel A. , Linsey Julie S.
Published: January 2016

Much design theory research seeks to create, evaluate, improve or optimize design methods. Whether that research focuses on design thinking, tools, methods, or education, short design problems are often provided to participants in order to evaluate the effects of the variables being tested. When designing and creating such problems, certain characteristics may influence design outcomes: experience and exposure to the design problems vary between participants, and each problem may be more or less favorable to the controlled variable.

In this paper we conjecture a small set of design problem characteristics that may influence experimental outcomes, and we discuss two experiments targeted at uncovering this influence. In our first experiment we examine differences in evaluation metrics between two design problems. In a follow up experiment we correlate the hypothesized characteristics to the variances in experiment outcome. These early results assist to further compare and contrast the empirical differences in common evaluation metrics, as well as show how familiarity and extent of the subjects’ knowledge of a design problem influence these metrics. We also expose the potential for interaction between the design method and the design problem.
An Interactive Virtual Environment for Programming Modular Robots
Authors: Gucwa Kevin J. , Cheng Harry H.
Published: January 2016

The design of RoboSim, a virtual environment for modular robots which controls simulated robots with code written for the hardware robots without modification, is described in detail in this paper along with its applications in educational environments. RoboSim integrates into the Ch programming environment, a C/C++ interpreter, that provides the ability to remotely control robots through interpreted C/C++ code allowing users to alternate between hardware and virtual robots without modifying the code. Open source software projects Open Dynamics Engine, OpenSceneGraph, and Qt are employed to produce the virtual environment and user interface which provide the capability of running on all major software platforms. The design of the software includes multiple library modules each specific to a particular task; therefore the simulation library and Graphical User Interface (GUI) can link against only the necessary libraries. The GUI links against the graphical library and XML library to give an interactive view of the RoboSim Scene as users are adding robots and obstacles into both the GUI and simulation. Execution of Ch code generates a new RoboSim Scene window which has the entire simulation that utilizes the simulation, graphical, xml, and callback libraries, in addition to the identical Scene from the GUI. It generates its own window for the user to view and interact with the progress of the simulation.
Utilization of Nonlinear Resonance of Vessels for Ocean Wave Power Generation
Authors: Yerrapragada Karthik , Karami M. Amin
Published: January 2016

This paper presents a method to utilize the pitch-roll nonlinear energy transfer phenomenon in vessels for off-shore wave power generation. This paper builds on an existing design where the power generator is a horizontal pendulum on board a vessel. The surface waves result in rocking of the ship, which in turn results in rotation of the pendulum. The pendulum is connected to a DC generator to produce power. The coupled electro-mechanical system is modeled using energy methods. The design in this paper utilizes the nonlinear coupling between the roll and pitch motions of the generator vessel. The natural frequency of the roll motion of the vessel is tuned to be twice the fundamental frequency of the pitch motion. In this specific condition when the vessel is excited in the pitch direction, the energy is nonlinearly transferred to the roll mode and the vessel oscillates in the roll direction. It is shown that the combination of the pitch as well as roll motion is far superior to the pitch motion since the combination results in full rotations of pendulum. A pendulum in full rotations generates orders of magnitude more power compared to a locally oscillating pendulum.
Investigating Spontaneous Flexibility in Concept Generation
Authors: Johnson Tyler A. , Caldwell Benjamin W. , Green Matthew G.
Published: January 2016

Guilford’s Alternate Uses Test (ALTU) measures a person’s spontaneous flexibility, a propensity for generating many varied responses to a situation, by requiring them to list six possible uses for a given object. Shah’s metrics of ideation effectiveness measure the innovative qualities of engineering concepts with similar scales. The study presented in this paper explores the relationship between spontaneous flexibility and engineering concept generation through a research study. Fifty-two participants generated ideas for three items on a spontaneous flexibility test (SFT) and three problems on an engineering ideation test (EIT). The participants’ responses were analyzed for fluency and flexibility. Correlations between the SFT and EIT were identified in order to better understand the role of spontaneity and divergent thinking in an engineering environment. It was found that both fluency and flexibility of responses were strongly correlated between the two test types. It is hypothesized that the EIT complements the SFT in measuring spontaneous flexibility in engineering design.
Design and Calibration of a 3D High-Resolution Surface Profiling System Using Photometric Stereo
Authors: Li Boren , Furukawa Tomonari
Published: January 2016

This paper presents the design and calibration of a 3D high-resolution surface profiling system using photometric stereo (PS). This system is mainly composed of a high resolution DSLR camera with a macro lens facing perpendicularly to the target surface, and several LEDs tilting towards the surface constrained by a light fixture. With each LED turned on at a time to create one lighting direction, the camera fixed at the same position captures an image. PS with surface normal integration (SNI) are then performed to reconstruct the surface in 3D. Methods of four calibrations for the developed system are proposed to achieve better accuracy, which are the camera radiometric calibration, the camera geometric calibration, the light direction calibration and the light intensity calibration. Experiments have demonstrated that the developed system with the calibration processes could achieve the accuracy in the order of 10 microns.
Can Micro-Chiral Cellular Structures Be Auxetic?
Authors: Samadikhah Kaveh , Lanzara Giulia
Published: January 2016

Auxetic materials with negative Poisson’s ratio have recently attracted the interest of the scientific community. This is because these materials have the potential to deliver specific functions thanks to a discretization of their constitutive matter that is intended as an aggregation of macro-scaled cellular structures characterized by specific geometries. Many auxetic structures with different geometries and auxetic response have been proposed. Downscaling the cellular structures (e.g. microscale) has the potential to improve the overall auxetic properties of the material, yet there is not enough research on the behavior of these structures at the microscale. This paper studies the auxetic behavior of a modified hexachiral structure formed by microscale elements. First an optimization study was performed to define the most appropriate geometrical dimensions. Then the auxeticity of the proposed cell was assessed carefully introducing a new Coefficient of Auxeticity which allowed to capture complex mechanical responses (e.g. including cellular rotations) as those faced with the proposed design. The proposed miniaturized design shows an outstanding stable auxetic response up to 20% strain of the micro-cell. It is believed that this study has the potential to pave the way to a new class of auxetic materials.
Informing Early Design via Crowd-Based Co-Creation
Authors: Ramanujan Devarajan , Vinayak  , Nawal Yash , Reid Tahira , Ramani Karthik
Published: January 2016

Customer inputs in the early stages of design can potentially lead to completely new outlooks in concept generation. We propose crowd-based co-creation as a means to this end. Our main idea is to think of the customer as a source of initial design concepts rather than a means for obtaining preferences towards designer-generated concepts. For analyzing a large collection of customer-created prototypes, we develop a framework that focuses on generating hypotheses related to customer perception of design attributes. We demonstrate our approach through a web interface to gather design requirements for a computer mouse, a bicycle seat, a pen holder, and a cola bottle. This interface was used in a crowdsourcing study with 253 users who represented potential end users for these products. Results from this study show that web-based co-creation allows designers to capture a variety of form and function-related design requirements from user-created virtual prototypes. We also found that such studies can be instrumental in identifying innovative product concepts, and gaining insights about how user perception correlates with product form. Therefore, we make the case that customer creation through distributed co-creation platforms can reinforce concept exploration in future early design processes.
A Point Cloud-Based Method for Object Alignment Verification for Augmented Reality Applications
Authors: Radkowski Rafael
Published: January 2016

The paper introduces a method for an augmented reality (AR) assembly assistance application that allows one to quantify the alignment of two parts. Point cloud-based tracking is one method to recognize and to track physical parts. However, the correct fitting of two parts cannot be determined with high fidelity from point cloud tracking data due to occlusion and other challenges. A Maximum Likelihood Estimate (MLE) of an error model is suggested to quantify the probability that two parts are correctly aligned. An initial solution was investigated. The results of an offline-simulation with point cloud data are promising and indicate the efficacy of the suggested method.
Experimental Characterization of a Meso-Scale Combustion Driven Actuator Designed for High Efficiency
Authors: Bélanger Desbiens Alexandre , Plante Jean-Sébastien , Masson Patrice
Published: January 2016

Meso-scale power systems (10 W to 1000 W) are needed to power untethered mobile robots and assisting devices such as powered exoskeletons. Air-breathing combustion driven actuators, used in a direct acting manner, can be used for such applications and take advantage of the high power density of fluidic actuators and the high energy density of chemical fuels. However, fuel-to-mechanical energy conversion efficiency is critical to make such chemical systems viable over electrical systems. This paper presents the efficiency-based design and experimental characterization of two combustion driven actuators intended to reach high specific power and specific energy. First, efficiency oriented design principles are derived from internal combustion engine theory: (1) an ideal-cycle thermodynamic model of a generic constant volume combustion system suggests that compression ratio and the expansion/compression ratio should both be maximized, and (2) the practical effects of heat, mass and friction losses as well as fuel choice in a small scale combustion chamber context are discussed. Second, two simplified prototypes are built and tested. The first prototype uses a rolling diaphragm seal to limit the effect of mass and friction losses. The second prototype consists of a standard air cylinder that minimizes heat losses by reducing the surface-to-volume ratio of the combustion chamber. Hydrogen is selected as fuel because it allows lean combustion which limits the effect of heat loss with low combustion temperatures. Compression ratio and equivalence ratio are varied experimentally to evaluate their effect on efficiency. Experimental results demonstrate an energy conversion efficiency of 15.3% at a compression ratio of 4.15 and a low equivalence ratio of 0.3. Ragone analysis of relevant meso-scale power systems for mobile robotic suggest that, with proper optimization and system integration, combustion driven power systems can become a viable solution for lightweight and long range meso-scale robotic applications.
Understanding the Role of Time-Delay on Maintaining Upright Stance on Rotational Balance Boards
Authors: Chagdes James R. , Haddad Jeffrey M. , Rietdyk Shirley , Zelaznik Howard N. , Raman Arvind
Published: January 2016

Mathematical models of human posture on a rigid surface predict two types of balance instabilities — a static tipping instability and a dynamic instability leading to large oscillations. Although a common technique to improve balance performance is placing patients on balance boards, little research has modeled bipedal posture on rotational boards to better understand the mechanisms underlying improvement. In this study we present a mathematical model of human stance on a single-degree-of-freedom balance board with controllable torsional stiffness and delayed feedback. Through a bifurcation analysis we find that the standard manipulation of decreasing board stiffness can lead to very different instabilities depending on an individual’s neuromuscular time-delay. This dependency limits the ability to use traditional boards for training and identification of balance deficits. We show that implementing a controllable time-delay may be more beneficial and allow for the customization of treatment plans for individual with very different characteristics.
ChMindstorms for Controlling Multi-Robot Systems
Authors: Qian Binsen , Cheng Harry H.
Published: January 2016

This article describes the design and mechanism of ChMindstorms, a cross-platform multi-robot controller, for controlling and programming Lego Mindstorms robots, NXT and EV3, with C/C++ code. Heterogeneous multi-robot systems are facing unique control and programming challenges due to cooperation between different types of robots. ChMindstorms not only has a Graphic Users Interface (GUI) for controller each robot, but also provides Application Programming Interfaces (APIs) integrated with Ch, a C/C++ interpreter, so that robots can be controlled remotely by C/C++ code without compilation. In addition, different types of robots can cooperate with each other effectively, such as sharing sensing abilities. Debugging process is also simplified since a debugger is implemented in Ch so that even beginners can also easily program Lego robots.
Empirical Studies of Functional Decomposition in Early Design
Authors: Booth Joran W. , Bhasin Abhinav K. , Reid Tahira N. , Ramani Karthik
Published: January 2016

This paper explores functional decomposition in early design. In the first part of this study, we explore how the three most common methods (top-down, energy-flow, enumeration) affect concept generation for novice design teams (n=25). We found that nearly all the features in the final concept could be mapped to the function diagram, though not all the functions mapped to the actual concept. This suggests that there is not much change in system functionality between these two phases, despite being separated by a few weeks. We also found that teams who used top-down and energy-flow performed nearly the same, and teams who used enumeration performed worse than those who used energy-flow. Based on these results, we recommend using either top-down or energy-flow, but not enumeration in early design. We also observed that teams used the diagramming process to reach a consensus and support team communication. The second part of this study evaluates design reports (n=78) from industry engineers taking a distance learning design course. Even though roughly half of the reports used functional decomposition, there was no correlation between using functional decomposition and final design quality as measured by various grade components. We also observed that half of the function diagrams were tree diagrams. This supports prior findings that a top-down, tree-based approach is more intuitive for engineers. Together, these results suggest that functional decomposition is helpful for team communication, but show no direct correlation with design outcome. We also recommend training strategies for teaching decomposition based on differences between the two datasets.
Mirror Integration Process for High Precision, Lightweight X-Ray Optics
Authors: Biskach Michael , Saha Timo , Zhang William , Mazzarella James , McClelland Ryan , Niemeyer Jason , Schofield Mark , Chan Kai
Published: January 2016

Next generation X-ray telescopes in the coming decades require optics with high angular resolution and large collecting area at a fixed cost and budget. X-ray optics, unlike traditional normal incidence optics in optical and infrared telescopes, require many times the polished surface area to obtain an equivalent collecting area due to the nature of glancing incidence optics necessary to reflect higher energy X-ray photons. The Next Generation X-ray Optics (NGXO) group at NASA Goddard Space Flight Center (GSFC) is developing a manufacturing process capable of producing sub 5 arc-second half-power diameter (HPD) angular resolution optics in the near term, with the long term goal of producing optics for an X-ray telescope in the next 10 years with sub 1 arc-second HPD angular resolution. By parallelizing the production, integration, and testing of X-ray mirrors in separate modules, thousands of precisely formed X-ray mirror segments are assembled into one Mirror Assembly (MA), lowering the cost per collecting area by orders of magnitude compared to previous X-ray telescopes with similar resolution like the Chandra X-ray Observatory. Novel uses of kinematic mounts, precision actuators, and epoxy fixes each X-ray mirror segment to the submicron level with the sufficient strength to survive rocket launch.
Optimal Manual Control for Heart Rate Tracking During Treadmill Exercises
Authors: Karimi Mahmood , Rao Ramesh R.
Published: January 2016

Recently, a nonlinear dynamic system has been presented to model the heart rate (HR) response during and after treadmill exercise. The parameters of the model can be estimated and individualized. Based on the nonlinear model, several control techniques for the regulation of HR during treadmill exercise have been proposed. But commercial treadmills may not have equipments to be computer-controlled. In this paper, an optimal manual method is presented to track a predefined HR trajectory. A piecewise constant speed profile is considered as the input to the system and computed by an optimization procedure offline. The objective function is constituted in term of heart rate deviation from its desired. The subject must change manually the speed of the treadmill according to the optimal protocol periodically. The time interval between two speed changes should be long enough so that the subject is able to change the speed. Also, the proposed method is such that, limited attention for control is needed and the controller is not always active.
Balancing Design Freedom and Brand Recognition in the Evolution of Automotive Brand Styling
Authors: Burnap Alex , Hartley Jeffrey , Pan Yanxin , Gonzalez Richard , Papalambros Panos Y.
Published: January 2016

Designers faced with the task of developing the next model of a brand must balance several considerations. The design must be novel and express attributes important to the customers, while also recognizable as a representative of the brand. This balancing is left to the intuition of the designers, who must anticipate how all customers will perceive the new design. Oftentimes, the design freedom used to meet a styling attribute such as aggressiveness can compromise the recognition of the product as a member of the brand. In this paper, an experiment is conducted measuring change in ten styling attributes common to both design freedom and brand recognition for automotive designs, using customer responses to vehicle designs created interactively. Results show that, while brand recognition is highly dependent on the particular manufacturer, tradeoffs between design freedom and brand recognition may be measured using predictive models to inform strategic design decisions.
Operation Modes and Singularities of 3-PRS Parallel Manipulators With Different Arrangements of P-Joints
Authors: Nurahmi Latifah , Caro Stéphane , Wenger Philippe
Published: January 2016

The subject of this paper is about the study of the operation modes and the singularity conditions of the 3-PRS parallel manipulator with different arrangements of prismatic joints. The three prismatic joints of the PRS legs are attached to the base with an angle α between the horizontal plane of the base and their directions.

By using an algebraic approach, namely the Study kinematic mapping of the Euclidean group SE(3), the mechanisms are described by a set of eight constraint equations. A primary decomposition is computed over a set of eight constraint equations and reveals that the 3-PRS manipulators with different arrangements of prismatic joints have identical operation modes, namely x0 = 0 and x3 = 0. Both operation modes are analysed.

The singularity conditions are obtained by deriving the determinant of the Jacobian matrix of the eight constraint equations. All the singular configurations are mapped onto the joint space and are geometrically interpreted. The singularity loci of the 3-PRS parallel manipulators are also traced in its orientation workspace for different values of angle α.
Topological Optimization of Coronary Stents
Authors: Zhao Shijia , Gu Linxia
Published: January 2016

The structural topological optimization method is an effective way to find the optimal topology of stents, which could be tailored for targeted stent performance, such as scaffolding ability, foreshortening, potential restenosis rate, etc. The radial stiffness is one of the major characteristics about stent performance. In this work, the homogenization method was utilized for the optimization of stent designs with the objective of maximizing the scaffolding ability of stent, i.e. its radial stiffness. A few design choices were presented by changing the number and distribution of strut connectors while keeping the void volume as 80%. The obtained optimal topology illustrated that the material distribution was mainly determined by the radial stress applied onto the stent. The optimal topology design in this work paves the way for the following dimension design, which can be targeted to the customized stent design for patient-specific lesions.
Wearable Upper Body Suit for Assisting Human Load Carriage
Authors: Park Joon-Hyuk , Stegall Paul , Agrawal Sunil K. , Yarlagadda Shridhar , Tierney John , Sharma Shashank , Gillespie John
Published: January 2016

This paper presents a wearable upper body suit designed to assist in human load carriage. The two functions of the suit are: (i) load distribution between the shoulders and the waist, and (ii) reduction of the dynamic load on the waist during walking. These are achieved through two cable driven modules — passive and active — within a custom fitted shirt integrated with motion/force sensors, actuators, and a real time controller. The load distribution between the shoulders and the waist is achieved through the load bearing columns connecting the shoulder pads and the waist belt whose load bearing capacity is modulated by a nominal cable tension in the passive module via a ratchet mechanism. The dynamic load is reduced in addition in the active module by modulating the cable tension via external actuator. Mathematical model of the system is presented and a state feedback controller is designed. Simulation study was performed to investigate the system response under different disturbance conditions as a result of vertical motion of the waist during human walking. Experiment evaluation of the suit was performed with a subject walking on a treadmill while carrying a backpack load. The results show that the developed suit can transfer the load from the shoulders to the waist as well as reduce the dynamic load induced during human walking. This can potentially reduce the energy expenditure and the risk of musculoskeletal injuries associated with human load carriage.
The Potential Usages of Interactive Tabletops and Surfaces in Product Design
Authors: Sadeghi Samira , Hayes Caroline
Published: January 2016

This is a “concept” paper. It explores the potential usages of interactive tabletops and surfaces in product design. Interactive tabletops and surfaces are a family of display technologies coupled with sensors that enable a more natural approach for interacting with computers. Previous research demonstrates the many possible uses for interactive tabletops and surfaces in design domain through several applications. This paper explores the potential of this technology to enhance the performance of designers and design groups. This paper highlights the benefits of interactive tabletops and surfaces in design through discussion of different potential applications and their possible advantages. The methodological approach for developing interactive tabletops and surfaces application for design has been presented and supported through a case study. Through the proposed approach we aim to gain a better understanding of practical challenges that need to be considered when integrating interactive tabletops and surfaces technology into a design office.
Transmission Efficiency Research of Multi-Range Hydro-Mechanical CVT
Authors: Mingzhu Zhang , Zhili Zhou , Liyou Xu
Published: January 2016

The transmission efficiency of a multi-range hydro-mechanical continuously variable transmission (HMCVT) is researched, which considered the factors of the power cycle and the efficiency variation of hydraulic units with their input power and speed. An efficiency algorithm of the closed pump-motor system is given, which is relative to the speed, pressure and displacement of hydraulic units. Efficiency formulas of typical structures of HMCVT are derived by meshing power method. The efficiency of a multi-range HMCVT is calculated. The calculated efficiency is consistency with the measured efficiency. The result shows that the average efficiency of HMCVT is reasonably higher than the peak efficiency of pure hydraulic transmission, although the efficiency varies obviously with the transmission ratio, the input power or torque. When the output torque of engine is smaller, the efficiency of HMCVT is lower. However, the speed change of engine has a less influence on the efficiency of HMCVT.
Design of Solid Rocket Engine
Authors: Amano Ryoichi S. , Yen Yi-Hsin
Published: January 2016

This paper presents both experiment and simulation of alumina molten flow in a solid rocket motor (SRM), when the propellant combusts, the aluminum is oxidized into alumina (Al2O3) which, under the right flow conditions, tends to agglomerate into molten droplets, impinge on the chamber walls, and then flow along the nozzle wall. Such agglomerates can cause erosive damage. The goal of the present study is to characterize the agglomerate flow within the nozzle section by studying the breakup process of a liquid film that flows along the wall of a straight channel while a high-speed gas moves over it. We have used an unsteady-flow Reynolds-Averaged Navier-Stokes code (URANS) to investigate the interaction of the liquid film flow with the gas flow, and analyzed the breakup process for different flow conditions. The rate of the wave breakup was characterized by introducing a breakup-length-scale for various flow conditions based on the Volume Fraction (VF) of the liquid, which is an indicator of a two-phase flow liquid breakup level. A smaller breakup-length-scale means that smaller drops have been created during the breakup process. The study covers the breakup and fluid behaviors based on different gas-liquid momentum flux ratios, different surface tension and viscosity settings, different Ohnesorge numbers (Oh), and different Weber numbers. Both water and molten aluminum flows were considered in the simulation studies. The analysis demonstrates an effective method of correlating the liquid breakup with the main flow conditions in the nozzle channel path.
Bifurcation Trees of Period-1 Motion to Chaos in a Duffing Oscillator With Double-Well Potential
Authors: Guo Yu , Luo Albert C. J.
Published: January 2016

In this paper, periodic motions of a periodically forced Duffing oscillator with double-well potential are analytically predicted through implicit discrete mappings. The implicit discrete maps are obtained from discretization of differential equation of the Duffing oscillator. From mapping structures, bifurcation trees of periodic motions are predicted analytically, and the corresponding stability and bifurcation analysis are carried out through eigenvalue analysis. From the analytical prediction, numerical results of periodic motions are performed to verify the analytical prediction.
Products’ Shared Visual Features Do Not Cancel in Consumer Decisions
Authors: Du Ping , MacDonald Erin F.
Published: January 2016

Consumers’ product purchase decisions typically involve comparing competing products’ visual features and functional attributes. Companies strive for “product differentiation” [1–5], which makes consumers’ product comparisons fruitful but also sometimes challenging. Psychologists that study decision-making have created models of choice such as the cancellation-and-focus (C&F) model. C&F explains and predicts how people decide between choice alternatives with both shared and unique attributes: the shared attributes are “cancelled” (ignored) while the unique ones have greater weight in decisions. However, this behavior has only been tested with text descriptions of choice alternatives. To be useful to designers, C&F must be tested with product visuals. This study tests C&F under six conditions defined by: the representation mode (text-only, image-only, and image-with-text) and presentation (sequentially, or side-by-side) of choice alternatives. For the products tested, C&F holds for only limited situations. Survey and eye-tracking data suggest different cognitive responses to shared text attributes vs. shared image features: in text-only, an attribute’s repetition cancels its importance in decisions, while in images, repetition of a feature reinforces its importance. Generally, product differences prove to attract more attention than commonalities, demonstrating product differentiation’s importance in forming consumer preferences.
Interaction of ice binding proteins with ice, water and ions
Authors: Oude Vrielink Anneloes S. , Aloi Antonio , Olijve Luuk L. C. , Voets Ilja K.
Published: January 2016

Ice binding proteins (IBPs) are produced by various cold-adapted organisms to protect their body tissues against freeze damage. First discovered in Antarctic fish living in shallow waters, IBPs were later found in insects, microorganisms, and plants. Despite great structural diversity, all IBPs adhere to growing ice crystals, which is essential for their extensive repertoire of biological functions. Some IBPs maintain liquid inclusions within ice or inhibit recrystallization of ice, while other types suppress freezing by blocking further ice growth. In contrast, ice nucleating proteins stimulate ice nucleation just below 0 °C. Despite huge commercial interest and major scientific breakthroughs, the precise working mechanism of IBPs has not yet been unraveled. In this review, the authors outline the state-of-the-art in experimental and theoretical IBP research and discuss future scientific challenges. The interaction of IBPs with ice, water and ions is examined, focusing in particular on ice growth inhibition mechanisms.
Zero added oxygen for high quality sputtered ITO: A data science investigation of reduced Sn-content and added Zr
Authors: Peshek Timothy J. , Burst James M. , Coutts Timothy J. , Gessert Timothy A.
Published: January 2016

The authors demonstrate mobilities of >45 cm2/V s for sputtered tin-doped indium oxide (ITO) films at zero added oxygen. All films were deposited with 5 wt. % SnO2, instead of the more conventional 8–10 wt. %, and had varying ZrO2 content from 0 to 3 wt. %, with a subsequent reduction in In2O3 content. These films were deposited by radio-frequency magnetron sputtering from nominally stoichiometric targets with varying oxygen partial pressure in the sputter ambient. Anomalous behavior was discovered for films with no Zr-added, where a bimodality of high and low mobilities was discovered for nominally similar growth conditions. However, all films showed the lowest resistivity and highest mobilities when the oxygen partial pressure in the sputter ambient was zero. This result is contrasted with several other reports of ITO transport performance having a maximum for small but nonzero oxygen partial pressure. This result is attributed to the reduced concentration of SnO2. The addition of ZrO2 yielded the highest mobilities at >55 cm2/V s and the films showed a modest increase in optical transmission with increasing Zr-content.
Physical basis of energy per cluster atom in the universal concept of sputtering
Authors: Paruch Robert J. , Postawa Zbigniew , Garrison Barbara J.
Published: January 2016

The interpretation of the variables, scaled by the number of projectile cluster atoms n, in the universal relation of the sputtering yield Y versus incident energy E, that is, Y/n vs E/n, is not necessarily obvious. Following on previous works, the objective of this study is to elucidate the physical basis of the energy per atom variable E/n. The authors employ molecular dynamics simulations of Arn cluster bombardment of Ag(111) metal samples for this study. The authors find that the energy per cluster atom quantity E/n is responsible for the fraction of the initial energy that is deposited in the solid, rather than energy per cluster mass E/m. The results show that even though there is an average loss of the energy for a cluster, each cluster atom loses a different fraction of its initial energy, thus yielding a distribution of energy loss by individual atoms. The analysis of these distributions indicates that the energy deposition process is more effective for clusters with higher E/n when compared to the clusters with lower E/n. This conclusion is supported by a visual analysis of the cluster bombardment event. The cluster atoms that lose most of their initial energy are those which split off from the cluster and penetrate into the bulk of the solid. Conversely, the atoms of the clusters with low E/n keep together during the interaction with the solid, and eventually reflect into the vacuum taking away a portion of the initial kinetic energy. In addition, the simulations indicate that the clusters of different sizes have the same distribution of energy loss for individual atoms if they have the same E/n, in other words, if the initial energy E is proportional to the cluster size n.
ACOUSTICAL STANDARDS NEWS
Authors: Blaeser Susan B. , Struck Christopher J.
Published: January 2016

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Susan B. Blaeser.

Comments are welcomed on all material in Acoustical Standards News.

This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org.
Agreement of BMI-Based Equations and DXA in Determining Body-Fat Percentage in Adults With Down Syndrome
Authors: Esco Michael R. , Nickerson Brett S. , Bicard Sara C. , Russell Angela R. , Bishop Phillip A.
Published: January 2016

The purpose of this investigation was to evaluate measurements of body-fat percentage (BF%) in 4 body-mass-index- (BMI) -based equations and dual-energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). Ten male and 10 female adults with DS volunteered for this study. Four regression equations for estimating BF% based on BMI previously developed by Deurenberg et al. (DEBMI-BF%), Gallagher et al. (GABMI-BF%), Womersley & Durnin (WOBMI-BF%), and Jackson et al. (JABMI-BF%) were compared with DXA. There was no significant difference (p = .659) in mean BF% values between JABMI-BF% (BF% = 40.80% ± 6.3%) and DXA (39.90% ± 11.1%), while DEBMI-BF% (34.40% ± 9.0%), WOBMI-BF% (35.10% ± 9.4%), and GABMI-BF% (35.10% ± 9.4%) were significantly (p < .001) lower. The limits of agreement (1.96 SD of the constant error) varied from 9.80% to 16.20%. Therefore, BMI-based BF% equations should not be used in individuals with DS.
“I Don’t Have Time”: Barriers and Facilitators to Physical Activity for Adults With Intellectual Disabilities
Authors: Taliaferro Andrea R. , Hammond Lindsay
Published: January 2016

Individuals with intellectual disabilities (ID) tend to have low rates of participation in voluntary or prescribed physical activity. The purpose of this study, therefore, was to identify the barriers, facilitators, and needs influencing physical activity participation of adults with ID within the framework of a social ecological model. A qualitative approach consisted of data collected from surveys and guided focus groups. Participants included adults with ID (n = 6) and their primary caregiver (n = 6). Barriers were categorized under three themes: organizational barriers, individual constraints, and external influences. Examples of subthemes included information dissemination, reliance on others, and caregiver considerations. Facilitators included primary caregivers as champions and camaraderie. Needs centered on family program involvement, improved programmatic structure, and programmatic support. Results indicate the need for community programs to examine barriers and facilitators applicable to their unique setting and population across all levels of a social ecological model.
SerpinB1 improves insulin sensitivity
Authors: VanHook Annalisa M.
Published: January 2016

A protease inhibitor secreted by the liver enables pancreatic β cells to compensate for reduced insulin sensitivity.
First Description of Two Sequence Type 2 Acinetobacter baumannii Isolates Carrying OXA-23 Carbapenemase in Pagellus acarne Fished from the Mediterranean Sea near Bejaia, Algeria
Authors: Brahmi Soumia , Touati Abdelaziz , Cadière Axelle , Djahmi Nassima , Pantel Alix , Sotto Albert , Lavigne Jean-Philippe , Dunyach-Remy Catherine
Published: January 2016

To determine the occurrence of carbapenem-resistant
Acinetobacter baumannii
in fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producing
A. baumannii
strains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [
aac(6
′
)
-Ib and
aac(3
′
)
-I genes].
Visualization of Periplasmic and Cytoplasmic Proteins with a Self-Labeling Protein Tag
Authors: Ke Na , Landgraf Dirk , Paulsson Johan , Berkmen Mehmet
Published: January 2016

The use of fluorescent and luminescent proteins in visualizing proteins has become a powerful tool in understanding molecular and cellular processes within living organisms. This success has resulted in an ever-increasing demand for new and more versatile protein-labeling tools that permit light-based detection of proteins within living cells. In this report, we present data supporting the use of the self-labeling HaloTag protein as a light-emitting reporter for protein fusions within the model prokaryote
Escherichia coli
. We show that functional protein fusions of the HaloTag can be detected both
in vivo
and
in vitro
when expressed within the cytoplasmic or periplasmic compartments of
E. coli
. The capacity to visually detect proteins localized in various prokaryotic compartments expands today's molecular biologist toolbox and paves the path to new applications.

IMPORTANCE
Visualizing proteins microscopically within living cells is important for understanding both the biology of cells and the role of proteins within living cells. Currently, the most common tool is green fluorescent protein (GFP). However, fluorescent proteins such as GFP have many limitations; therefore, the field of molecular biology is always in need of new tools to visualize proteins. In this paper, we demonstrate, for the first time, the use of HaloTag to visualize proteins in two different compartments within the model prokaryote
Escherichia coli
. The use of HaloTag as an additional tool to visualize proteins within prokaryotes increases our capacity to ask about and understand the role of proteins within living cells.
Venous thromboembolism occurring during adolescence
Authors: Biss Tina , Alikhan Raza , Payne Jeanette , Alamelu Jayanthi , Williams Michael , Richards Michael , Mathias Mary , Tunstall Oliver , Chalmers Elizabeth
Published: January 2016

Objective

Risk assessment for venous thromboembolism (VTE) and thromboprophylaxis in those with risk factors is established in adult practice. Evidence to support efficacy and safety of this approach in adolescents is lacking. We aimed to describe thrombotic risk factors and to determine the proportion of potentially preventable events in a retrospective cohort study of adolescents with VTE.

Design, setting and patients

Data were collected between 2008 and 2014 from eight tertiary UK centres. Qualifying events were radiologically confirmed VTE in subjects aged 12–17 years. Central venous line-related upper venous system events were excluded.

Results

76 cases were identified, 41 males, median age 15 years. Frequent risk factors were: reduced mobility, 45%; thrombophilia, 24%; malignancy, 20%; surgery, 18%; combined oral contraceptive pill, 12%; congenital venous anomaly, 5%. 28 (37%) had no significant underlying diagnosis and no provoking event/hospitalisation, presenting as outpatients with VTE which was considered ‘unpreventable’. Of 48 where there had been opportunity for risk assessment, chemical thromboprophylaxis was not indicated in 26 and was contraindicated in 8. 14/76 (18%) had an indication to consider thromboprophylaxis and no contraindication. Of these, four had cerebral palsy, five malignancy and two inflammatory bowel disease. All had reduced mobility with recent surgery in eight. Four received chemical thromboprophylaxis prior to presentation.

Conclusions

Among a cohort of adolescents with VTE, a small proportion (13%) had an indication to consider chemical thromboprophylaxis but did not receive it. VTE risk assessment and prevention should focus on adolescents with immobility or surgery, particularly in those with malignancy.
Under pressure: progressively enlarging facial mass following high-pressure paint injection injury
Authors: Mushtaq Jameel , Walker Abigail , Hunter Ben
Published: January 2016

High-pressure paint injection injuries are relatively rare industrial accidents and almost exclusively occur on the non-dominant hand. A rarely documented complication of these injuries is the formation of a foreign body granuloma. We report a case of a 33-year-old man presenting with extensive facial scarring and progressive right paranasal swelling 7 years after a high-pressure paint injury. After imaging investigations, an excision of the mass and revision of scarring was performed. Access to the mass was gained indirectly through existing scarring over the nose to ensure an aesthetic result. Histological analysis revealed a florid granulomatous foreign body reaction to retained paint. To the best of our knowledge, this is the first reported case of a facial high-pressure paint injury with consequent formation of a foreign body granuloma.