bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Household Energy Challenges in Himalayan Communities Using Participatory Design Approaches
Authors: Tang Lisa , Patel Arnav , Sweeney Daniel J. , Banerjee Nilanjana , Thakur Amit K. , Chaudhari Pranava , Kumar Rahul , Joshi Jyeshtharaj 
Published: November 2021

Abstract
Traditional biomass-burning stoves are used for cooking and heating across the globe. These stoves generate smoke that results in household air pollution, which poses a significant risk to human health. In the past decades, there have been many efforts to promote the adoption of improved cookstove designs, but uptake of improved stoves is often slow due to high costs, inconsistent supply chains, and incompatibility with local cooking practices. This paper presents survey results from rural villages in Uttarakhand, India regarding routines and attitudes on cooking and space heating. Significant findings include the dual use of liquified petroleum gas and biomass fuels, the interconnected and seasonal nature of cooking and space heating, the cultural significance of traditional cookstoves, and the prominence of locally available materials in cookstove construction and maintenance. Comparisons of these surveys’ findings to previous investigations on energy use in the Himalayan region show many common trends, but also reveal regional differences. The paper concludes that due to the significance of culture and context in cookstove design, understanding user needs and behaviors and working with local communities are integral parts the design methodology for clean cookstoves. These results provide a case study which agrees with existing literature on the importance of participatory design in global development.
Sequentially Working Origami Multi-Physics Simulator (SWOMPS): A Versatile Implementation
Authors: Zhu Yi , Filipov Evgueni T. 
Published: November 2021

Abstract
This work presents the underlying implementation of a new origami simulator (SWOMPS) that allows for adaptability and versatility with sequential analyses and multi-physical behaviors of active origami systems. The implementation allows for easy updating of origami properties, realistic simulation with multi-physics based actuation, and versatile application of different loadings in arbitrary number and sequence. The presented simulator can capture coupling between multiple origami behaviors including electro-thermo-mechanical actuation, heat transfer, self-stress induced folding, inter panel contact, applied loading forces, and kinematic/mechanical deformations. The simulator contains five different solvers, including three for mechanical loading, one for self-folding, and one for thermal loading. The paper presents details of this code package and uses three practical examples to highlight the versatility and efficiency of the package. Because various loadings and different origami behaviors can be modeled simultaneously and/or sequentially, this simulator is well suited for capturing origami behaviors in practical real-world scenarios. Furthermore, the ability to apply an arbitrary number and sequence of loadings is useful for design, optimization, or system control studies where an unknown set of loads are needed to fold functional active origami. The coded implementation for this simulator and additional examples are made available to encourage future expansions of this work where new sequential and multi-physical behaviors in origami can be explored.
A Block-Based Arduino Programming Platform for Developing Computational Thinking Skills for K-12 Students
Authors: Qian Binsen , Cheng Harry H. 
Published: November 2021

Abstract
As a critical set of skills in the 21st century, computational thinking has attracted increasing attention in K-12 education. Microcontrollers, combined with LEDs, actuators, and a variety of sensors, provide students countless real-world projects, such as autonomous vehicles, smart homes, and robotics. By solving those projects through programming, students will not only learn computational skills but also benefit from the hands-on activities to get some experience on solving real-world problems. It makes microcontroller projects a perfect tool to develop the computational thinking skills of K-12 students. Our previous work has proposed a solution for higher graders to program Arduino through Ch, a C/C++ interpreter. It is necessary, however, to develop a platform for lower graders (K-6) since most of them do not have the ability to type through the keyboard. This paper extends our previous work such that students can program Arduino on RoboBlockly, a block-based programming platform. In the paper, we will present two case studies to demonstrate how to build blocks to control the Arduino board and what concepts students will learn from those projects. In addition, the proposed platform also provides an interactive way of transitioning students from the block-based program to a text-based program in Ch.
Singularity-Free Lie Group Integration of Multibody System Models Described in Absolute Coordinates
Authors: Müller Andreas 
Published: November 2021

Abstract
A classical approach to the modeling of multibody systems (MBS) is to use absolute coordinates, i.e. a set of (redundant) coordinates that describe the absolute position and orientation of the individual bodies w.r.t. to an inertial frame (IFR). A well-known problem for the time integration of the equations of motion (EOM) is the lack of a singularity-free parameterization of spatial motions, which is usually tackled by using unit quaternions. Lie group integration methods were proposed as alternative approach to the singularity-free time integration. Lie group methods are inherently coordinate free and thus incompatible with any absolute coordinate description. In this paper, an integration scheme is proposed that allows describing MBS in terms of arbitrary absolute coordinates and at the same using Lie group integration schemes, which allows for singularity-free time integration. Moreover, the direct product group SO (3) × ℝ3 as well as the semidirect product group SE (3) can be use for representing rigid body motions, which is beneficial for constraint satisfaction. The crucial step of this method, which renders the underlying Lie group integration scheme applicable to EOM in absolute coordinates, is the update of the (global) absolute coordinates in terms of the (local) coordinates on the Lie group by means of a local-global transitions (LGT) transition map. This LGT map depends on the used absolute coordinates and the local coordinates on the Lie group, but also on the Lie group itself used to represent rigid body configurations (respectively the deformation field of flexible bodies), i.e. the geometry of spatial frame motions. The Lie group formulation is thus embedded, which allows interfacing with standard vector space integration methods.
Viscous Friction Effect During the Process of Tightening and Loosening of Bolted Joints
Authors: Lin Qingyuan , Zhao Yong , Sun Qingchao , Chen Kunyong 
Published: November 2021

Abstract
Bolted connection is one of the most widely used mechanical connections because of its easiness of installation and disassembly. Research of bolted joints mainly focuses on two aspects: high precision tightening and improvement of anti-loosening performance. The under-head bearing friction coefficient and the thread friction coefficient are the two most important parameters that affect the tightening result of the bolted joint. They are also the most critical parameters that affect the anti-loosening performance of the bolted joint. Coulomb friction model is a commonly used model to describe under-head bearing friction and thread friction, which considers the friction coefficient as a constant independent of normal pressure and relative sliding velocity. In this paper, the viscous effect of the under-head bearing friction and thread friction is observed by measuring the friction coefficient of bolted joints. The value of the friction coefficient increases with the increase of the relative sliding velocity and the decrease of the normal pressure. It is found that the Coulomb viscous friction model can better describe the friction coefficient of bolted joints. Taking into account the dense friction effect, the loosening prediction model of bolted joints is modified. The experimental results show that the Coulomb viscous friction model can better describe the under-head bearing friction coefficient and thread friction coefficient. The model considering the dense effect can more accurately predict the loosening characteristics of bolted joints.
Finding Features of Positioning Error for Large Industrial Robots Based on Convolutional Neural Network
Authors: Kato Daiki , Yoshitugu Kenya , Maeda Naoki , Hirogaki Toshiki , Aoyama Eiichi , Takahashi Kenichi 
Published: November 2021

Abstract
Most industrial robots are taught using the teaching playback method; therefore, they are unsuitable for use in variable production systems. Although offline teaching methods have been developed, they have not been practiced because of the low accuracy of the position and posture of the end-effector. Therefore, many studies have attempted to calibrate the position and posture but have not reached a practical level, as such methods consider the joint angle when the robot is stationary rather than the features during robot motion. Currently, it is easy to obtain servo information under numerical control operations owing to the Internet of Things technologies. In this study, we propose a method for obtaining servo information during robot motion and converting it into images to find features using a convolutional neural network (CNN). Herein, a large industrial robot was used. The three-dimensional coordinates of the end-effector were obtained using a laser tracker. The positioning error of the robot was accurately learned by the CNN. We extracted the features of the points where the positioning error was extremely large. By extracting the features of the X-axis positioning error using the CNN, the joint 1 current is a feature. This indicates that the vibration current in joint 1 is a factor in the X-axis positioning error.
Tuning Motion of Musical Saw With a Humanoid Robot for Industrial Automation Based on a Sound Feed-Back Process
Authors: Hanai Hiroaki , Miura Atsuyuki , Hirogaki Toshiki , Aoyama Eiichi 
Published: November 2021

Abstract
In recent years, cooperative robots have been attracting attention for their ability to work with humans. The ability to share tools is an important factor in the development of collaborative robots. In this study, we investigated the methods necessary to realize a robot that can manipulate tools. To understand the characteristics of the tools, we modeled the target tools and performed finite element analysis. Based on the analysis results, we determined the initial command values to be given to the robot. Under the constraint of the robot’s range of motion, we created a hand jig and arranged the tools to expand the control sound range. The robot uses acoustic information to judge a situation and meets different demands with its two arms. The left hand controls the generated frequency by applying a forced displacement to the instrument. With the right hand, the robot focuses on the difference in sound pressure between the main and secondary frequencies and controls the position of the blow in the plane of the instrument to increase this difference. The introduction of this control based on acoustic recognition makes it possible to teach the musical saw performance posture in real time. Using this method, we were able to demonstrate the possibility that a tool manipulating robot can work in an environment where humans coexist.
Switched Fractional Order Model Reference Adaptive Control for an Automatic Voltage Regulator
Authors: Aguila-Camacho Norelys , García-Bustos Jorge E. , Castillo-López Eduardo I. 
Published: November 2021

Abstract
This paper presents the design and implementation of a Switched Fractional Order Model Reference Adaptive Controller (SFOMRAC) for an Automatic Voltage Regulator (AVR). The fractional orders, adaptive gains and switching times of the controller adaptive laws are tuned offline, using Particle Swarm Optimization (PSO). The functional to be optimized contains not only parameters of the AVR response but also the control energy. The obtained controllers are compared to non switched Integer Order Model Reference Adaptive Controller (IOMRAC) and non switched Fractional Order Model Reference Adaptive Controller (FOMRAC) proposed previously for this process, showing that the SFOMRAC can improve both, the system response and the control energy used.
Combined Coulomb and Viscous Damping Estimation Using Topological Signal Processing
Authors: Myers Audun , Khasawneh Firas A. 
Published: November 2021

Abstract
In this work we develop a novel time-domain approach for the simultaneous estimation of the damping parameters for a single degree of freedom oscillator with both viscous and coulomb damping. Our approach leverages zero-dimensional sublevel set persistence — a tool from Topological Signal Processing (TSP) — to analyze the ring down vibration of the signal. Sublevel set persistence is used as it alleviates the need for peak selection when analyzing the time-domain of the signal and provides an alternative noise-robust method for visualizing the damping envelope. We are able to successfully estimate the damping parameters using both a direct approach and a function fitting method. We show that the direct approach is only appropriate for low levels of additive noise, but allows for a less computationally demanding estimation of the parameters. Alternatively, the function fitting method provides accurate estimates for significantly higher levels of additive noise. The results are provided through a numerically simulated example with mixed coulomb and viscous damping. We demonstrate the robustness of our method for accurately estimating both damping parameters for various levels of additive noise, a wide range of sampling frequencies, and both high and low levels of damping. This analysis includes providing suggested limitations of the method when applied to real-world signals.
Sustainability and Design Education: The Current Status of Product Design Higher Education in the UK
Authors: Delaney Emelia , Liu Wei 
Published: November 2021

Abstract
The aim of sustainability is to fulfil the needs of current generations without compromising the needs of future generations. It is also a rising area of concern within industry, it is therefore important that graduate designers are equipped with the skills to accommodate sustainability issues as well as demands from industry. Additionally, the product design stage during New Product Development has been identified to have the greatest impact on the sustainability of the entire product, however how educated designers are on the topic of sustainability is unclear. An initial literature review has been conducted to investigate design education on sustainability as well as teaching styles. Following this the study identifies and reviews UK Product Design courses to establish the current status of sustainability integration in higher education. The exploration into university prospectuses has found that around half of UK universities implement sustainability in some way, however there are limited courses which dedicate specific modules to sustainability. Additionally, links with industry and accreditation organizations between UK product design courses have been confirmed, but there is no definite information to suggest that the universities use this to aid in the implementation sustainability education. From this review future research directions have been outlined.
Kinematic Synthesis of Gait Correction for a Rehabilitation Machine
Authors: Pusnik Zvonimir , Nelson Carl A. , Burnfield Judith M. , Buster Thad W. 
Published: November 2021

Abstract
This paper outlines the synthesis process for a redesign of the intelligently controlled assistive rehabilitation elliptical’s (ICARE) pedal system to enhance replication of gait-like movement patterns while training. The synthesized mechanism overcomes some limitations identified in certain ellipticals, specifically generation of taller, more rounded foot paths compared to over-ground gait. The proposed solution minimizes the position and angle difference curves between the ICARE foot motion and normal gait.
Direct Sensitivity Analysis of Spatial Multibody Systems With Joint Friction Using Index-1 Formulation
Authors: Verulkar Adwait , Sandu Corina , Dopico Daniel , Sandu Adrian 
Published: November 2021

Abstract
Sensitivity analysis is one of the most prominent gradient based optimization techniques for mechanical systems. Model sensitivities are the derivatives of the generalized coordinates defining the motion of the system in time with respect to the system design parameters. These sensitivities can be calculated using finite differences, but the accuracy and computational inefficiency of this method limits its use. Hence, the methodologies of direct and adjoint sensitivity analysis have gained prominence. Recent research has presented computationally efficient methodologies for both direct and adjoint sensitivity analysis of complex multibody dynamic systems. The contribution of this article is in the development of the mathematical framework for conducting the direct sensitivity analysis of multibody dynamic systems with joint friction using the index-1 formulation. For modeling friction in multibody systems, the Brown and McPhee friction model has been used. This model incorporates the effects of both static and dynamic friction on the model dynamics. A case study has been conducted on a spatial slider-crank mechanism to illustrate the application of this methodology to real-world systems. Using computer models, with and without joint friction, effect of friction on the dynamics and model sensitivities has been demonstrated. The sensitivities of slider velocity have been computed with respect to the design parameters of crank length, rod length, and the parameters defining the friction model. Due to the highly non-linear nature of friction, the model dynamics are more sensitive during the transition phases, where the friction coefficient changes from static to dynamic and vice versa.
A Pareto Front Mechanism Optimization for Controlling an Aircraft Using a Bio-Inspired Rotating Empennage
Authors: Myszka David H. , Joo James J. , Murray Andrew P. 
Published: November 2021

Abstract
This paper presents a mechanism design optimization for actuating the horizontal stabilizers of an aircraft using a rotating empennage without a vertical stabilizer. Birds do not have vertical stabilizers and rotate their tail feathers to control agile maneuvers. A rotating empennage concept will mimic this motion and enable the bio-inspired flight of a fixed wing aircraft. To maintain control, the bio-inspired rotating empennage (BIRE) will incorporate three degrees of freedom: independent rotation of each horizontal stabilizer and rotation of the empennage relative to the main axis of the fuselage. The primary benefits of an aircraft without a vertical stabilizer is reduced drag and weight, which in turn results in more efficient operation.
In order to reduce inertia of the rotating empennage, the linear actuators that position the horizontal stabilizers will be placed within the fuselage. Mechanisms that couple the linear translation of the actuators with the rotation of the horizontal stabilizers ideally require a low peak force and short stroke from the actuator. With two conflicting objectives, a Pareto front optimization was conducted to determine appropriate link lengths of candidate solutions and to understand the effectiveness of alternate mechanisms. The study considers a rack & pinon, scotch-yoke, slider-crank, inverted slider-crank, Watt, and Stephenson mechanisms.
An Algorithm for Partitioning Objects Into a Cube Skeleton and Segmented Shell Covers for Parallelized Additive Manufacturing
Authors: Li Wilson , Poozhikala Thomas , Dinar Mahmoud 
Published: November 2021

Abstract
Despite a growing application of additive manufacturing, build volume has limited the size of fabricated parts. Machines that can produce large-scale parts in whole have high costs and less commercially available. A workaround is to partition the desired part into smaller partitions which can be manufactured in parallel, with the added benefit of controlling process parameters for each partition independently and reducing manufacturing time. This paper proposes an approach that divides a part into a cube skeleton covered by shell segments where all components can be fabricated with smaller 3D printers. The proposed algorithm first hollows out the original fully dense part to a user-specified thickness, then partitions the part into 26 surrounding regions using the six faces of the maximally inscribed cube (or cuboid). Islands, i.e., small, disconnected partitions within each region, are combined with the smallest neighbor to create up to 26 connected partitions. To minimize the number of printed partitions, the connected partitions are ranked based on their volume and combined with their smallest neighbor in pairs in descending order, while ensuring each pair fits within a pre-selected build volume of available 3D printers. The final partitioned shell segments, the cube (or cuboid) center, and the secondary layer of cubes propagated from the face centers of the maximally inscribed cube are generated by the algorithm. Results of two cases are shown.
The Effect of Membrane Load on the Usage of Berger’s Model in Electrostatically Actuated Pre-Stressed Circular Curved Micro Plates
Authors: Medina Lior , Eliasi Rami , Gilat Rivka , Krylov Slava 
Published: November 2021

Abstract
The effect of membrane load on the behaviour of axisymmetric bistable circular curved microplates on Berger’s based axisymmetric reduced order (RO) model, incorporating radial prestress, is studied. The model is first validated for a “mechanical” load, against a Föppl-von-Kármán’s RO model with twenty degrees of freedom (DOF), a finite differences (FD) solution and a finite elements (FE) model, serving as the reference. All solutions implement the “Riks” method to track possible unstable branches, which can swerve in due to the presence of higher buckling modes. A convergence study is carried out for the snap-through location and load, as well as for the critical elevation and prestress required for bistability. Based on validated results of the analysis, the reliability of the model for predicting the effect of prestress on the plate behaviour under nonlinear electrostatic load is then investigated while using FD solutions as the reference. The study furnishes a reliable expended RO model, which includes prestress on the as-fabricated curved plate. The resulting model can further be used to estimate the value of residual prestress, present in an electrostatically actuated curved plate, based on its response.