bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Time Finite Element Method for Dynamic Analysis of Elastic Mechanisms in Link Coordinate Systems
Authors: Wang Yu (Michael) , Wang Zaiping 
Published: February 2021

Abstract
A time finite element method is developed for the steady-state solutions of vibrating elastic mechanisms. The governing equations of motion for each individual link are described in a link (local) coordinate system with constant coefficients. The set of second order differential equations for all links are then coupled by a set of constitutive equations of elastic joint models describing the link interconnections. In utilizing time finite elements which discretize the forcing time period into a number of time intervals, the elastic motion is approximated by a set of temporal nodes of all spatial degrees of freedom of the mechanism system. The result is a set of linear algebraic system with a sparse structure and that can be solved effectively. A scotch york mechanism and a four-bar linkage are included as examples to illustrate the modeling and solution procedures applied.
Optimal Motion Patterns for Golf Swings
Authors: Yuan L. , Rastegar J. , Pollo F. 
Published: February 2021

Abstract
Due to the dynamic response and maximum output force (torque) limitations of their actuating motors, computer controlled machines such as robot manipulators can only have a limited performance in terms of the time to complete a specified motion and other similar measures of operating speed. For example, a robot manipulator arm with limited joint motion can only reach a maximum end-effector speed due to the aforementioned limitations of its actuating torque. The dynamic response limitations of the actuators dictate that for high speed motions, the robot arm should be required to follow trajectories for which the required actuating torques do not contain harmonics with frequencies beyond the “bandwidth” of its actuators. For systems with nonlinear dynamics such as robot arms with revolute joints operating at high speeds, the higher harmonics of the actuating torques are the harmonics of the joint trajectories that are generated due to the nonlinear dynamics of the system. During sport activities, the muscle forces and the resulting limb motions can also be expected to be subject to similar dynamic response limitations. The present study examines such a hypothesis. The measured motion at the shoulder and the wrist of an experienced golfer during downswing is measured and together with the required muscle generated actuating torques are analyzed for their harmonic content. Similar analysis is also performed for published motion data for expert golfers. The results confirm the hypothesis that optimal golf swing motions consist almost entirely of low harmonic patterns that are synthesized to require joint torques with negligible high harmonic content.
Forcing the Burmester Curves Into Desired Regions Using Position Tolerances
Authors: Niyogi Siddhartha , Kinzel Gary L. 
Published: February 2021

Abstract
This paper develops a method for forcing the Burmester curves to pass through desired regions, specifically, points. Numerical optimization with constraints is used. Some, or all, of the design positions are considered to have small tolerances associated with them. Those positions that have tolerances are then considered to be the variables used in the optimization and a set of positions is found such that it is as close as possible to a desired nominal set.
A New Method of Dimensional Synthesis of Function Generator for Planar 4-BAR Linkage Based on Wavelet Characteristic Parameters
Authors: Xin Wu , Jinkui Chu , Weiqing Cao 
Published: February 2021

Abstract
The wavelet description of output function of planar 4-bar linkage is presented in the light of wavelet transform theory. By the aid of Daubechies orthogonal wavelet to transform and analyze the linkage’s output function, a new conception of Wavelet Characteristic Parameters (in short WCP) about output function is originated. Based on this conception, a resolution to function synthesis of planar linkage is provided according to WCP with fuzzy identification method employed. It helps to synthesize function generator that will approximately realize “infinite points” of the output function specially for output requirement with given range. Two examples will illustrate the efficiency and advantages of this method.
Multiply Separated Synthesis of Six-Link Mechanisms Using Parallel Homotopy With M-Homogenization
Authors: Dhingra A. K. , Zhang M. 
Published: February 2021

Abstract
This paper presents complete solutions to the function generation problem of six-link Watt and Stephenson mechanisms, with multiply separated precision positions (PP), using homotopy methods with m-homogenization. It is seen that using the matrix method for synthesis, applying m-homogeneous group theory and by defining auxiliary equations in addition to the synthesis equations, the number of homotopy paths to be tracked in obtaining all possible solutions to the synthesis problem can be drastically reduced. Numerical work dealing with the synthesis of Watt and Stephenson mechanisms for 6 and 9 multiply separated precision points is presented. For both mechanisms, it is seen that complete solutions for 6 and 9 precision points can be obtained by tracking 640 and 286,720 paths, respectively. A parallel implementation of homotopy methods on the Connection Machine on which several thousand homotopy paths can be tracked concurrently is also discussed.
Generation of Singular 6-SPS Parallel Manipulators
Authors: Kong Xian-Wen 
Published: February 2021

Abstract
A singular 6-SPS parallel manipulator is a 6-SPS parallel manipulator with architecture singularities spanning over the whole workspace. It should be abandoned in the design process. This paper presents a component method for generation of singular 6-SPS parallel manipulators. The proposed method is based on that a 6-SPS parallel manipulator with one or more over-actuated components or singular components must be a singular 6-SPS parallel manipulator. Some classes of singular 6-SPS parallel manipulators can be generated from the generation of over-actuated components or singular components for 6-SPS parallel manipulators. All the over-actuated components for 6-SPS parallel manipulators are generated. The singular LL component is generated after an alternative approach to the configuration analysis of LL component is proposed. At last, new classes of singular 6-SPS parallel manipulators in addition to those already known are generated.
Forward Displacement Analysis of Three New Classes of Analytic Spherical Parallel Manipulators
Authors: Kong Xian-Wen 
Published: February 2021

Abstract
The analytic manipulator is a manipulator the characteristic polynomial of which is of fourth degree or lower. Three new classes of analytic spherical parallel manipulators with prismatic actuators are proposed. The first is the spherical parallel manipulator with non-similar planar platforms, the second is the spherical parallel manipulator with similar planar platforms, and the third is the spherical parallel manipulator with orthogonal platforms. The forward displacement analysis of these new classes of spherical parallel manipulators is investigated in sequence. Polynomials of degree 4, 2 and 2 in one unknown respectively can be obtained to inscribe this problem. Due to dual solutions of other unknowns, a maximum of eight solutions might be possible for each of the new analytic spherical parallel manipulators.
Analysis and Design of a Spatial Five-Degree-of-Freedom Hybrid Manipulator for Underwater Applications
Authors: Gagné Martin , Gosselin Clément M. 
Published: February 2021

Abstract
This paper presents the analysis and design of a spatial five-degree-of-freedom hybrid manipulator to be mounted on a submarine. The main concern of this new design is to provide a cheaper alternative to the six-degree-of-freedom serial manipulator currently used. The architecture is chosen from several hybrid architectures using simplicity and stiffness as the principal selection criteria. The direct and inverse kinematics are then developed based on a general form of the hybrid architecture, the velocity equations are obtained and the singularity loci are determined. Thereafter, the architecture parameters of the manipulator are optimized in order to provide optimum workspace. Finally, a specific architecture that uses the optimum parameters is provided and a workspace without singularities is presented.
Synthesis of Multi-Degree-of-Freedom Force-Generating Linkages
Authors: Soper R. Randall , Reinholtz Charles F. , Canfield Stephen L. 
Published: February 2021

Abstract
This paper presents the conceptual foundation and analytical techniques for the design of multiple-degree-of-freedom force-generating linkages. Force-generating mechanisms produce a specified quasi-static force or torque as a function of input position with resisting energy supplied to the mechanism from an external energy-storage device, such as a spring or load weight. Multiple-degree-of-freedom force-generating mechanisms provide the tailored resistance force along a design path while incorporating additional mobility, which allows the mechanism to deviate from the path within a local workspace. Although many potential applications for these mechanisms exist, the focus of this research has been on the design of weight-loaded machines for personal strength training, where the additional freedom of motion is valuable for reasons of ergonomic and exercise efficiency. A variety of open- and closed-chain mechanisms are considered as potential candidates for design. Techniques are developed for the closed-form synthesis of simple, two link, open loop chains that are able to produce a specified force component along a prescribed path. This result provides a foundation for designing more useful mechanisms, including doubly weighted symmetric and singly weighted asymmetric 5R linkages. In all cases, closed-form solutions are developed using Burmester-type synthesis procedures and equations of static equilibrium.
A Motion Analysis for one D.O.F. Anthropomorphic Finger Mechanism
Authors: Figliolini Giorgio , Ceccarelli Marco 
Published: February 2021

Abstract
A novel kinematic structure of a tendon-driven mechanism is proposed for an anthropomorphic finger mechanism of artificial hands. The kinematic structure is composed by three links as the three phalanges of a human finger and they are moved independently by means of suitable endless tendons. The three d.o.f.s of the proposed open-loop kinematic chain have been appropriately reduced to only one in order to simplify the actuation and control of the finger mechanism. A motion analysis has been carried out by using the polode method to obtain a suitable algorithm for computer simulation. The grasp performances of the proposed new anthropomorphic finger mechanism have been investigated and some design considerations have been pointed out.
Design and Analysis of a Camera and Sensor Positioning Mechanism for ARIES: An Autonomous Mobile Robot
Authors: Rocheleau David N. , Moore Matthew M. 
Published: February 2021

Abstract
ARIES (Autonomous Robotic Inspection Experimental System) is a program for the Department of Energy (DOE) that was charged with the mission of surveying and inspecting drums containing low-level radioactive waste stored in warehouses at DOE facilities. This paper reports on the final development of the ARIES project, and focuses on the mechanical design and analysis of three mechanisms that position a camera and sensor package that sits atop a Cybermotion K3A mobile robotic platform.
The ARIES project was executed through a joint effort of three parties: University of South Carolina (USC), Clemson University, and Cybermotion, Inc., of Salem, Virginia. The goal of the project was to develop an autonomous mobile robot that positions a data acquisition package (DAP) which surveys drums containing hazardous materials in Department of Energy (DOE) warehouses. The unique mechanical design of the positioning system is comprised of three distinct components: a lift mechanism, a fourbar mechanism, and a camera panning mechanism. The components are integrated in a manner that allows the DAP to be positioned from 0 to 16 feet off the ground while the robot maneuvers through aisles of drums in a warehouse. The three mechanisms, and the integration thereof, are reported in this paper.
Dynamic Analysis of High Speed Hypoid Gears With Emphasis on Automotive Axle Noise Problem
Authors: Cheng Yuping , Lim Teik C. 
Published: February 2021

Abstract
Hypoid gear whine problems in right-angle driveline components mainly used in rear and all-wheel drive vehicles have frequently posed major concerns in automotive industry. Narrow frequency-band response peaks from the rear axle component at mesh frequency and its harmonics tend to generate high-cost warranty issue and consumer dissatisfaction. In order to develop low noise and vibration geared rotor system, one must have better understanding of the dynamic behavior of these high speed non-parallel precision gears. Hence, it is the objective of this paper to develop a 3-dimensional coupled torsional and translational vibratory model of a generic hypoid gear pair by also taking into account the effect of global driveline system dynamics. In this analytical model, the effective mesh point is assumed to be at the theoretical mean pitch location. Its coordinate and corresponding tooth contact normal vector are determined analytically by applying the theory of hypoid gear kinematics. The resultant formulations for the mesh point and line of action are then incorporated into a dynamic model for a right-angle geared rotor system assuming time-invariant mesh stiffness. The proposed model is used to predict the system modal characteristics and dynamic response due to transmission error excitation for various boundary and operating conditions. A limited set of parametric design studies is also performed to analyze the effects of pinion offset, spiral angle and pinion shaft compliance on torsional and translational vibration response.
Quantitative systems pharmacology model predictions for efficacy of atezolizumab and nab-paclitaxel in triple-negative breast cancer
Authors: Wang Hanwen , Ma Huilin , Sové Richard J , Emens Leisha A , Popel Aleksander S 
Published: February 2021

BackgroundImmune checkpoint blockade therapy has clearly shown clinical activity in patients with triple-negative breast cancer, but less than half of the patients benefit from the treatments. While a number of ongoing clinical trials are investigating different combinations of checkpoint inhibitors and chemotherapeutic agents, predictive biomarkers that identify patients most likely to benefit remains one of the major challenges. Here we present a modular quantitative systems pharmacology (QSP) platform for immuno-oncology that incorporates detailed mechanisms of immune–cancer cell interactions to make efficacy predictions and identify predictive biomarkers for treatments using atezolizumab and nab-paclitaxel.MethodsA QSP model was developed based on published data of triple-negative breast cancer. With the model, we generated a virtual patient cohort to conduct in silico virtual clinical trials and make retrospective analyses of the pivotal IMpassion130 trial that led to the accelerated approval of atezolizumab and nab-paclitaxel for patients with programmed death-ligand 1 (PD-L1) positive triple-negative breast cancer. Available data from clinical trials were used for model calibration and validation.ResultsWith the calibrated virtual patient cohort based on clinical data from the placebo comparator arm of the IMpassion130 trial, we made efficacy predictions and identified potential predictive biomarkers for the experimental arm of the trial using the proposed QSP model. The model predictions are consistent with clinically reported efficacy endpoints and correlated immune biomarkers. We further performed a series of virtual clinical trials to compare different doses and schedules of the two drugs for simulated therapeutic optimization.ConclusionsThis study provides a QSP platform, which can be used to generate virtual patient cohorts and conduct virtual clinical trials. Our findings demonstrate its potential for making efficacy predictions for immunotherapies and chemotherapies, identifying predictive biomarkers, and guiding future clinical trial designs.
Foraging modes and movements of Oncorhynchus mykiss as flow and invertebrate drift recede in a California stream
Authors: Rossi Gabriel J. , Power Mary E. , Pneh Shelley , Neuswanger Jason R. , Caldwell Timothy J. 
Published: February 2021

Salmonids frequently adapt their feeding and movement strategies to cope with seasonally fluctuating stream environments. Oncorhynchus mykiss tend to drift-forage in higher velocity habitat than other salmonids, yet their presence in streams with seasonally low velocity and drift suggests behavioral flexibility. We combined 3D videogrammetry with measurements of invertebrate drift and stream hydraulics to investigate the drivers of O. mykiss foraging mode and movement during the seasonal recession in a California stream. From May to July (2016), foraging movement rate increased as prey concentration and velocity declined; however, movement decreased in August as pools became low and still. In May, 80% of O. mykiss were drift-foraging, while by July, over 70% used search or benthic-foraging modes. Velocity and riffle crest depth were significant predictors of foraging mode, while drift concentration was a poor univariate predictor. However, top-ranked additive models included both hydraulic variables and drift concentration. A drift-foraging bioenergetic model was a poor predictor of foraging mode. We suggest that infall and benthic prey, as well as risk aversion, may influence late-summer foraging decisions.
The Bohras as Neo-Fāṭimids: Documentary Remains of a Fāṭimid Past in Gujarat
Authors: Akkerman Olly 
Published: February 2021

Abstract
This article traces the remains of Fāṭimid chancery documents, and the writing practices that surround them, among the Bohras of Gujarat. As Shiʿi Ismaʿilis, the Bohras consider themselves heirs of the Fāṭimid Imāmate (909–1171). Whereas other Ismaʿili communities, such as the Nizārīs, claim their genealogical link to the Fāṭimids through the presence of a living Imam, the Bohras legitimize their “Neo-Fāṭimid” identity through a living Arabic Ismaʿili manuscript culture. While the philological link between the Bohras and the Fāṭimids has hitherto been acknowledged through the mobility and preservation of these manuscripts, their use of documents, however, and its potential Fāṭimid influences, has remained unexplored. Based on ethnographic observations and archival research among the ʿAlawi Bohras of Baroda, I suggest that practices from the Fāṭimid chancery continued in Yemen and Gujarat in the post-Fāṭimid world, and continue to survive today in the Bohra community’s documentary culture.
Postural sway in young female artistic and acrobatic gymnasts according to training experience and anthropometric characteristics
Authors: Opala-Berdzik Agnieszka , Głowacka Magdalena , Juras Grzegorz 
Published: February 2021

AbstractBackgroundGymnastics training enhances the development of postural control in children and adolescents. In competitive gymnastics, the training regimen is specific to the given gymnastic discipline and is usually followed from the early years of practicing. This study aimed to determine whether postural steadiness differed between young gymnasts practicing two distinct disciplines, and whether it was related to the duration of their training experience, age, and their anthropometric characteristics.MethodsThirty 10–13-year-old females ̶ ten artistic gymnasts, ten acrobatic gymnasts (training as “tops”), and ten non-athletes ̶ were examined during 60-s quiet standing trials on a force platform with the eyes open and closed. Their postural sway was represented by directional components of centre of foot pressure mean velocity. Mann-Whitney U, Wilcoxon and Spearman’s ρ tests were used for analyses.ResultsAnterior-posterior and medial-lateral centre of foot pressure mean velocities were not different between the artistic and acrobatic gymnasts (p > 0.05). In the artistic gymnasts, the duration of training experience, age, body height, body mass, and maturity offset were negatively correlated with the anterior-posterior centre of foot pressure mean velocity under eyes-open conditions. The acrobatic gymnasts’ body mass and BMI percentiles were negatively correlated with their anterior-posterior and medial-lateral centre of foot pressure mean velocities under both visual conditions (rranged from − 0.64 to − 0.93;p < 0.05). The non-athletes’ centre of foot pressure mean velocities were non-significantly correlated with their age and anthropometric measures under both visual conditions (p > 0.05).ConclusionsThe artistic gymnasts’ longer training experience, greater age, body height, body mass, and biological maturity were associated with better anterior-posterior postural steadiness when vision was available; the acrobatic gymnasts’ greater body mass and BMI percentiles were associated with better overall postural steadiness regardless of visual conditions. Relationships were observed between postural steadiness and discipline-specific training experience and anthropometric characteristics; however, causes and effects were not proven.
Local low-rank approach to nonlinear matrix completion
Authors: Sasaki Ryohei , Konishi Katsumi , Takahashi Tomohiro , Furukawa Toshihiro 
Published: February 2021

AbstractThis paper deals with a problem of matrix completion in which each column vector of the matrix belongs to a low-dimensional differentiable manifold (LDDM), with the target matrix being high or full rank. To solve this problem, algorithms based on polynomial mapping and matrix-rank minimization (MRM) have been proposed; such methods assume that each column vector of the target matrix is generated as a vector in a low-dimensional linear subspace (LDLS) and mapped to a pth order polynomial and that the rank of a matrix whose column vectors are dth monomial features of target column vectors is deficient. However, a large number of columns and observed values are needed to strictly solve the MRM problem using this method when p is large; therefore, this paper proposes a new method for obtaining the solution by minimizing the rank of the submatrix without transforming the target matrix, so as to obtain high estimation accuracy even when the number of columns is small. This method is based on the assumption that an LDDM can be approximated locally as an LDLS to achieve high completion accuracy without transforming the target matrix. Numerical examples show that the proposed method has a higher accuracy than other low-rank approaches.