bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete Solutions for the Approximate Synthesis of Spherical Four-Bar Function Generators
Authors: O’Connor Sam , Plecnik Mark , Baskar Aravind , Joo James 
Published: November 2023

Abstract
Kinematic synthesis to meet an approximate motion specification naturally forms a constrained optimization problem. In this work, we conduct global design searches by direct computation of all critical points through stationarity conditions. The idea is not new, but performed at scale is only possible through modern polynomial homotopy continuation solvers. Such a complete computation finds all minima, including the global, serving as a powerful design exploration technique. We form equality constrained objective functions that pertain to the synthesis of spherical four-bar linkages for approximate function generation. For each problem considered, Lagrangian stationarity conditions set up a square system of polynomials. We consider the most general case where all mechanism dimensions may vary, and a more specific case that enables the placement of ground pivots. The former optimization problem is shown to permit an estimated maximum of 268 sets of critical points, and the latter permits 61 sets. Critical points are classified as saddles or minima through a post-process eigenanalysis of the projected Hessian. Approximate motion is specified as discretized points from a desired input-output angle function. The coefficients of the stationarity polynomials can be expressed as summations of symmetric matrices indexed by the discretization points. We take the sums themselves to parameterize these polynomials rather than constituent terms (the discrete data). In this way, the algebraic structure of the synthesis equations remains invariant to the number of discretization points chosen. The results of our computational work were used to design a mechanism that coordinates the unfolding of wings for a deployable aircraft.
Concurrent Probabilistic Control Co-Design and Layout Optimization of Wave Energy Converter Farms Using Surrogate Modeling
Authors: Azad Saeed , Herber Daniel R. 
Published: November 2023

Abstract
Wave energy converters (WECs) are a promising candidate for meeting the increasing energy demands of today’s society. It is known that the sizing and power take-off (PTO) control of WEC devices have a major impact on their performance. In addition, to improve power generation, WECs must be optimally deployed within a farm. While such individual aspects have been investigated for various WECs, potential improvements may be attained by leveraging an integrated, system-level design approach that considers all of these aspects. However, the computational complexity of estimating the hydrodynamic interaction effects significantly increases for large numbers of WECs. In this article, we undertake this challenge by developing data-driven surrogate models using artificial neural networks and the principles of many-body expansion. The effectiveness of this approach is demonstrated by solving a concurrent plant (i.e., sizing), control (i.e., PTO parameters), and layout optimization of heaving cylinder WEC devices. WEC dynamics were modeled in the frequency domain, subject to probabilistic incident waves with farms of 3, 5, 7, and 10 WECs. The results indicate promising directions toward a practical framework for array design investigations with more tractable computational demands.
Roll Center and Centrodes of an Eight-Bar Suspension System
Authors: Lanni Chiara , Figliolini Giorgio , Tomassi Luciano 
Published: November 2023

Abstract
This paper deals with the roll motion analysis of vehicles which are provided of two double wishbone independent suspension mechanisms on the front side. According to a planar car model and supposing that both front wheels are rotating about their fixed revolute joints, the position analysis of an eight-bar mechanism is formulated, in order to determine the position of the roll center, along with the fixed and moving centrodes.
In particular, all instantaneous centers of rotations have been determined by devoting particular attention to the roll center and to those of each wheel with respect to the vehicle chassis, according to the kinematic characteristics of the double wishbone independent suspension mechanism. Moreover, a suitable mechanism with 18 members and 1 d.o.f. is proposed to generate mechanically or by using any CAD-software, both centrodes, according to the direct and inverse planar motion of the chassis with respect to the ground and vice versa. Finally, a first curvature analysis is carried out by using the Euler-Savary equation and the inflection circle, in order to determine the center of curvature of the mass center trajectory for the chassis roll motion. The proposed formulation has been implemented in a Matlab program and several examples allowed its validation in different mechanism configurations.
On the Effects of Inertia Force on the Actual Motion of a Special-Case Grashof Linkage at its Singular Points
Authors: Xie Jin , Liu Zhaohui 
Published: November 2023

Abstract
A special-case Grashof linkage has two singular point at which the linkage may changes from parallelogram form into antiparallelogram form or vice versa. Whereas, at the singular points, the linkage is underactuated and its analysis of dynamics is complicated issue because that the actual motion is dependent upon not only the usual forces but also the inertial forces. Based on Gauss’s principle in which the inertial forces are expressed as a scalar quantity, known as acceleration energy, a method to predict the actual motion of the special-case Grashof linkage is proposed in this paper. The method models the issue into an unconstrained optimization. With the outcomes of optimization, the actual form the linkage taking can be determined by the signs of angular velocities of the two links pivoted to frame. The effectiveness of the method is demonstrated by numerical examples.
An Experimental Study on the Accuracy of Cumulative Damage Models in Gear Tooth Bending Fatigue
Authors: Anichowski Gabriel , Damm Riley , Kahraman Ahmet , Hong Isaac 
Published: November 2023

Abstract
Tooth bending fatigue failure is a primary design concern for gear designers in power transmission applications. Fracture of a gear tooth in operation results in overload conditions to adjacent teeth which cascades into potential failure. Total loss of power transmission usually occurs within seconds of the primary failure. While standard constant stress amplitude fatigue evaluations are common to experimentally determine probabilistic stress life (PSN) relationships, they do not directly measure the fatigue lives under complex, non-constant amplitude loading scenarios applied to gears in most applications. Various cumulative damage models exist to estimate fatigue life under duty cycle loading but their accuracy is both material and stress state dependent. Most models are validated under only uniaxial stress states and for limited materials. There is a void of experimental data that would enable the evaluation of the accuracy of cumulative damage models for gear tooth bending fatigue in typical case carburized gear steels. This research study conducts a standard fatigue evaluation along with two sets of dual stress amplitude single tooth bending fatigue tests to empirically determine the effects of multi-stage loading. Various cumulative damage fatigue models are then employed to estimate the fatigue lives of the dual stress amplitude specimens and the accuracy of each model is assessed.
Towards Quantifying Interviews: Comparing Techniques to Evaluate the Quality of Design Interviews
Authors: Grover Micki , Wright Natasha C. , Lauff Carlye A. 
Published: November 2023

Abstract
Exploratory interviewing for front-end design research is a widely used practice, but unstandardized process. There are documented best practices for conducting “good” interviews, and these skills can be used to develop metrics to evaluate interview quality. A standard practice for verifying interview quality would increase confidence in studies that utilize student or novice interviewers, who often have less interviewing experience than expert researchers. Additionally, metrics to evaluate interviews could be used for individualized feedback to help novices improve over time, and feel confident and ready to complete field interviews for design and research projects. In this study, 12 undergraduate students were trained in design ethnography techniques and participated in field interviewing for a design project related to developing a service model for dialysis treatment in End Stage Kidney Disease in Zimbabwe. The quality of the students’ practice interviews from training and from field interviews during the design project were measured using a calculated scoring method that was developed based on interviewing best practices. To test the validity of the scoring method, this study compared the method to two accepted practices for evaluating interview quality: experts and information gained from interviews. The scoring method was found to not have a strong relationship to either accepted practice. Therefore, the metrics and formula used in the calculated scoring method were reexamined in light of the findings from the practice and field interviews to produce recommendations for future iterations.
Protocol Study: Patterns of Designer Behaviors When Describing Engineering Problem Domains Through Concept Maps
Authors: Kochenberger John , Sen Chiradeep 
Published: November 2023

Abstract
This paper presents a pilot protocol study that examines the behavioral patterns in human designers when they describe a problem domain of engineering interest through constructing concept maps. Ten voluntary participants were assigned a choice of three problem domains and asked to construct concept maps for any one of them. The data was encoded into four elements of the map — nodes, edges, node labels, and edge labels. The data generated was encoded using eleven activity codes and four element codes at a one-second interval. In addition, patterns of forming crosslinks, temporal grouping, and clustering of the elements in the map were examined. The results shed light on the relative difficulty of conceiving and naming the concepts, relations, and distant relations between the concepts, and the patterns of information generation across and within element clusters and temporal groups.
Fixed-Time Learning for Optimal Feedback Control
Authors: Kokolakis Nick-Marios T. , Vamvoudakis Kyriakos G. , Haddad Wassim M. 
Published: November 2023

Abstract
In this paper, we introduce the problem of fixed-time optimal stabilization to construct feedback controllers that guarantee closed-loop system fixed-time stability while optimizing a given performance measure. Specifically, fixed-time stability of the closed-loop system is established via a Lyapunov function satisfying a differential inequality while simultaneously serving as a solution to the steady-state Hamilton-Jacobi-Bellman equation ensuring optimality. Given that the Hamilton-Jacobi-Bellman equation is generally difficult to solve, we develop a critic-only reinforcement learning-based algorithm for learning the solution to the steady-state Hamilton-Jacobi-Bellman equation in fixed-time. In particular, a non-Lipschitz experience replay-based learning law utilizing recorded and current data is introduced for updating the critic weights to learn the value function. The non-Lipschitz property of the dynamics gives rise to fixed-time stability, while the experience replay-based approach eliminates the need to satisfy the persistence of excitation condition as long as the recorded data is sufficiently rich. Simulation results demonstrate the efficacy of the proposed approach.
“LEVER” - Low-Cost Electric Vehicle Charging Robot: Development and Testing
Authors: Cochran Bryan , Zaidi Zulfiqar , Bras Bert 
Published: November 2023

Abstract
This article describes the design and development of an autonomous Electric Vehicle (EV) charging system. An autonomous EV charger can extend the effective range of autonomous EVs by enabling them to recharge without human intervention. The motivation behind the development of the system was to reduce costs compared to other autonomous EV chargers. As such, the system was developed using consumer grade IoT hardware instead of commercial robotic systems and controllers. The system employs a decentralized control architecture with Robot Operation System (ROS) as its backbone. This control architecture utilizes a Raspberry Pi single-board computer as the primary controller, a series of Arduino microcontrollers to interface with motion control, and a Nvidia Jetson vision processors to execute the necessary computation to allow the entire system to operate without the need of a dedicated computer or PLC. The control algorithm utilizes vision feedback and compliant mechanisms to compensate for the limited computational capabilities of the individual microcontrollers. The system was developed in a laboratory environment and once the system operated as intended, the system was tested on a production Plug-in Hybrid Electric Vehicle (PHEV). Experiments were conducted to improve the control algorithm accuracy and decrease operating time. Overall, the system demonstrates the feasibility of using low-cost IoT hardware to develop an autonomous EV charging system, reducing the barrier to entry for the widespread adoption of autonomous EVs. The system represents an important step towards the goal of achieving sustainable and efficient transportation and opens up new possibilities for the future of electric vehicles.
Integrated Sustainable Product Design With Warranty and End-of-Use Considerations
Authors: Liu Xinyang , Wang Pingfeng 
Published: November 2023

Abstract
The idea of integrated sustainable product design has been recently proposed to integrate downstream lifecycle performance into the initial product design to better achieve sustainability. Various sustainable product design tools based on life-cycle assessment or quality function deployment have been established while the influence of reliability in the circular practice has not been investigated much. Realizing that product reliability plays a critical role in determining post-design performance, this paper develops a product design optimization model that considers the warranty performance and the effect of end-of-use options. The effect of uncertain operating conditions on product reliability is incorporated into the model. Two optimization goals including the minimization of expected unit lifecycle cost and environmental impact are achieved by the model. Then, the model has been applied to an electric motor design problem to illustrate the benefit of the integrated approach. Results show that the component selection and reliability design will be adjusted when integrating the end-of-use options in the early design phase. Furthermore, lifecycle cost savings and environmental impact reductions can be achieved through the circular usage of used products. Finally, the effects of operating conditions, warranty policy, and take-back price for used products on the design decisions are analyzed to provide insights for product designers.
Model Validation Based on Value-of-Information Theory
Authors: Hazelrigg George A. 
Published: November 2023

Abstract
The modeling and simulation community has devoted considerable attention to the question of model validity. Their work has focused on the concept of “accuracy,” loosely defined as the difference between a model-computed result and a real-world result. This paper makes use of an example case that results in a paradox to illustrate weaknesses in an accuracy-focused approach, and proposes in its stead a value-focused approach based on classical decision theory. Instead of advocating the use of a model based on its accuracy, this work advocates using a model if it adds value to the overall application thus relating validation directly to system performance. The approach fills significant gaps in the current theory, notably providing a clearly defined validity metric and a fundamental rationale for the use of this metric.
Uncertainty Quantification on Mechanical Behavior of Corroded Plate With Statistical Shape Modeling
Authors: Wu Hao , Bansal Parth , Liu Zheng , Li Yumeng , Wang Pingfeng 
Published: November 2023

Abstract
Corrosion is a process of uncertain nature considering the randomness associated with corrosion initiation and growth, therefore estimating the stochastic behavior of a corroded structure therefore quantifying of system performance uncertainties would be very important for a wide range of engineering systems such as the shipment structure to ensure structural safety and reliability. In the presented study, we have focused on estimating uncertainty on plate mechanical behaviors due to the impact of the corrosion, such as the shape and depth. Considering the limitation of small quantity of corroded plate samples, we firstly regenerate simulated images based on the statistical shape modeling method. Secondly, these simulated images are imported into a multiphysics-based corrosion simulation platform to reconstruct the shape of corroded plate and the mechanical behavior of the plate with different severity levels of corrosions can be obtained through finite element analysis. Thirdly, uncertainty quantification study is then conducted to understand the statistical characteristic of stochastic behavior of corroded plates from simulated and origin image data. The case study results showed that the statistical characteristic of mechnical behavior from both source data are similar, and the statistical shape modeling method could be useful in situations where there is insufficient sample data for uncertainty quantification.
Linear Electrostatic Oscillator With Viscous Damping
Authors: Coonley Kip D. , Humber Hammond , Mann Brian P. 
Published: November 2023

Abstract
Experimental analysis of a translating spring-mass system with a constant electrostatic force in the presence of viscous damping is presented. The challenge in this effort has been to develop an analytical model for the electrostatic system and experimentally extract numerical values for viscous damping and the very small electrostatic force. The system has dynamical equations of motion similar to that of a homogeneous spring-mass system with no external force in the presence of viscous damping. The electrostatic parallel plate system includes the addition of a conservative electrostatic potential energy term corresponding to an electrostatic restoring force. The electrostatic force is conservative and opposes the direction of motion when the position of the oscillating mass being acted upon is greater than or less than zero. Another, similar system comparison can be made between the electrostatic one and that of a translating system acted upon by friction alone. However, the frictional force, unlike the electrostatic one presented here, is non-conservative and, also unlike the electrostatic force, opposes the direction of velocity when the oscillating mass being acted upon is greater than or less than zero. From empirical data, parameters of the translating electrostatic system are determined and cross-verified by more than one method. A state-space model is developed using the Lagranian formalism which includes a dissipative viscous damping term. Results are simulated in Matlab numerically. These simulated results are compared to measured data. Applications of the electrostatic force in a translating set-up are discussed and concluded.
Optimal Swing Assistance Using a Hip Exoskeleton: Comparing Simulations With Hardware Implementation
Authors: Echeveste Salvador , Hernandez Hinojosa Ernesto 
Published: November 2023

Abstract
Despite tremendous potential, predictive simulations for exoskeleton control tend to overpromise the performance of assistance on walking. The transition from simulation to hardware faces several hurdles such as difficulty representing human-machine interface, an overreliance on intuition, and a lack of exploration in assistive strategies. This work presents a simulation-to-hardware strategy that creates optimized assistance profiles to implement on a hip exoskeleton to assist leg swinging as an intermediary step to improve control strategies for walking. By simplifying the activity we were able to observe a smaller disconnect between simulation and hardware. In addition, the comparison provided insight on the differences between the effectiveness of assistance on frequency of the activity and type of work.
Neurocognition of New Ideas During Engineering Design
Authors: Walker Emma , Shealy Tripp , Gero John 
Published: November 2023

Abstract
The research presented in this paper investigated the changes that occur in the prefrontal cortex (PFC) when new ideas are introduced during engineering design. Undergraduate and graduate engineering students (n = 25) were outfitted with a functional near-infrared spectroscopy (fNIRS) headband. Students were asked to design a personal entertainment system while thinking aloud. New ideas were timestamped with the fNIRS data across 48 channels grouped into eight regions within the PFC. The data were preprocessed using temporal derivative distribution repair motion correction, finite impulse response bandpass filter, and the modified beer-lambert law to convert optical density into hemoglobin concentration. Baseline neurocognitive activation and physiological noise were removed. The study found a significant decrease in oxygenated hemoglobin in the left dorsolateral prefrontal cortex and a subregion of the left ventrolateral prefrontal cortex when new ideas were introduced during design. This finding begins to provide a neurocognitive signature of what a new idea looks like as it arises in the brain. This could be used to develop tools and techniques to inhibit this brain region or use this insight to predict when designers will experience a new idea based on their neural activation.
A Unified Real-Time Motion Generation Algorithm for Approximate Position Analysis of Planar N-Bar Mechanisms
Authors: Lyu Zhijie , Liao Wei , Purwar Anurag 
Published: November 2023

Abstract
This paper introduces a novel real-time motion simulation algorithm that enables approximate position analysis of planar N-bar linkage mechanisms of arbitrary complexity. The algorithm was designed specifically for implementation in a web-based software platform, although not exclusively, with the aim of facilitating the simulation and design of mechanisms incorporating revolute and prismatic joints, for both students and industry practitioners. To ensure the efficient computation of positions, all geometric and actuation constraints of links in a mechanism were reduced to the same form, enabling the use of a unified approach. A key aspect of the algorithm is the use of a reinterpretation trick to convert all prismatic elements into a combination of links with only revolute joints. This simplification requires only two solvers while providing motion output within a desired degree of error. Furthermore, the proposed algorithm employs a solving path-finding procedure based on mobility analysis to further reduce simulation time. The resulting algorithm offers the ability to simulate serial, parallel, and hybrid mechanisms with any degree-of-freedom. Additionally, the time estimation for the simulation process and the estimation expression of a mechanism’s structural complexity are provided. To demonstrate the practical utility of the proposed method, the algorithm is applied to several mechanisms as examples.