bluuebunny/crossref_metadata_2025 huggingface dataset:
C2orf40 inhibits hepatocellular carcinoma through interaction with UBR5
Authors: Wu Yue , Xiang Qin , Lv Xiaoqin , Xiang Xia , Feng Zhihao , Tian Shaorong , Tang Jun , Xiang Tingxiu , Gong Jianping
Published: February 2021

Background and Aim

Hepatocellular carcinoma (HCC) urgently needs a marker for early diagnosis and targeted treatment. C2orf40 has been identified as a tumor suppressor gene in many cancers. However, the precise role and regulatory mechanism by C2orf40 contribute to HCC remain elusive and merit exploration.

Methods

Reverse‐transcription PCR, quantitative real‐time PCR, and methylation‐specific PCR were used to detect expression and methylation of C2orf40 in HCC cell lines or tissues. The effects of C2orf40 in liver cancer cells were examined via colony formation, CCK8, transwell, and flow cytometric assays. The effect of C2orf40 on tumorigenesis in vivo was determined by xenografts and immunohistochemical analysis. Western blot, indirect immunofluorescence, Co‐IP, and cycloheximide (CHX) were used to further investigate the potential mechanism of C2orf40.

Results

The down‐regulation of C2orf40 in hepatocellular cancer tissue samples is often related to the degree of methylation of its promoter CpG. The recovery of C2orf40 expression in HCC cell lines can induce G0/G1 phase arrest and apoptosis and also inhibit cell migration and invasion by reversing the epithelial–mesenchymal transition (EMT) process, both in vivo and in vitro. In addition, C2orf40 can increase the expression of p21 through interaction with UBR5.

Conclusions

Low expression levels of C2orf40 are related to the hypermethylation of its promoter. C2orf40 can inhibit HCC through UBR5‐dependent or p53‐independent mechanisms. C2orf40 may be a diagnostic biomarker and a potential therapeutic target in HCC.
Mavericks or misconstruction? A reply to Campbell and Allan
Authors: PALMER STEPHANIE , MARTIN STEVIE
Published: February 2021

In a jurisdiction without a codified constitution clearly demarcating the role of the courts, and given the centrality of the principle of parliamentary sovereignty to the United Kingdom's constitutional framework, criticism of the courts for overstepping the mark – particularly in politically contentious cases – is par for the course. In their 2019 article, Professors David Campbell and James Allan offer a criticism of the Supreme Court for what they describe as its surreptitious creation of judicial supremacy at the expense of parliamentary sovereignty. In support of their claim, the authors examine two particularly significant judgments: R (Miller and another) v. Secretary of State for Exiting the European Union and Re Northern Ireland Human Rights Commission's Application for Judicial Review. This reply discusses several problematic aspects of the authors’ critique of those judgments, demonstrating that, contrary to the authors’ claims, these cases do not provide evidence of a surreptitious attempt by the Supreme Court to expand its power.
Unsecured lending and the indigenous economy in Australia and South Africa
Authors: HUTCHISON ANDREW , ALLEN DOMINIQUE
Published: February 2021

Consumer credit is closely regulated in both Australia and South Africa. Nevertheless, unsecured lending often results in financial hardship in low‐income communities. One aspect of this picture is the impact of the consumer debt burden on the Indigenous economy, which is disproportionately affected by poverty in both countries. Here we juxtapose the comparative regulatory regimes and then contextualize the law using an inter‐disciplinary account of each Indigenous economy. We find through this law‐in‐context comparison that neither Australia nor South Africa has fully resolved the problem of Indigenous financial hardship. This mutual failure is confirmed by the recent Kobelt decision of the High Court of Australia and the drastic measures enacted in the South African National Credit Amendment Act 2019. One positive lesson that South Africa provides is that accommodating the Indigenous economy in financial regulation can promote and empower that sector.
Detection of an HLA‐C*08 variant, HLA‐C*08:01:31, in a Chinese individual
Authors: Liu Tong
Published: February 2021

HLA‐C*08:01:31 differs from C*08:01:01:01 by a single synonymous nucleotide substitution at position 642 in exon 4.
An Integrated Multi-Domain Analysis Environment for High Consequence Systems
Authors: Davis James , Scott Jason , Sztipanovits Janos , Karsai Gabor , Martinez Marcus
Published: February 2021

Modeling and analysis of high consequence, high assurance systems requires special modeling considerations. System safety and reliability information must be captured in the models. Previously, high consequence systems were modeled using separate, disjoint models for safety, reliability, and security. The MultiGraph Architecture facilitates the implementation of a model-integrated system for modeling and analysis of high assurance systems. Among the tools used for analyzing safety and reliability are a behavioral simulator and an automatic fault tree generation and analysis tool. Symbolic model checking techniques are used to efficiently investigate the system models. A method for converting finite state machine models to ordered binary decision diagrams allows the application of symbolic model checking routines to the system models. This integrated approach to modeling and analysis of high consequence systems ensures consistency between the models and the different analysis tools.
Retrofitting Industrial Manipulators for Study of Open Architecture Integration of Mechatronic Systems
Authors: Pannu Jat , Hu Xudong , Cheng Harry H.
Published: February 2021

We have developed a plug-and-play open architecture CH language environment for integration of mechatronic systems for network-based agile manufacturing (Cheng, 1993). For experimental verification of this language environment in real-time applications, the original controllers of two popular industrial robot manipulators Puma 560 and IBM 7575 have been completely retrofitted and integrated with a conveyer system to form a robot workcell. This robot workcell, bypassing their original controllers, can be programmed to run under the CH language environment. Details about retrofitting these two industrial manipulators with new servo control boards, A/D boards, and I/O boards running the CH language environment under a commercial real-time operating system will be described. The CH language environment is designed for open architecture integration of mechatronic systems. The user application program written in CH is computer platform independent, mechatronic device independent, and mechatronic system independent. A sample CH application program for simulated assembly operations of this robot workcell will be presented to demonstrate the underlying principles of open architecture integration of mechatronic systems under the programming paradigm of the CH language environment.
A Temporal Process Specification Language for Virtual Manufacturing Engineering
Authors: Lee David E. , Hahn H. Thomas
Published: February 2021

A process specification language is being developed for virtual manufacturing that provides a structured portable definition of a given manufacturing process as well as the ability to specify the temporal relationships between individual operation steps that compose a process. Based on the concepts embodied in markup languages such as HTML, SGML and XML, a portable process definition structure is defined. This structure provides a template from which virtual process specifications can be created. Subsequently, these structures can be exchanged between development environments for virtual process engineering and the actualized manufacturing facilities where processes are implemented. In addition, dependencies in time between the operation steps of a process such as common start times and operation serialization can be represented to allow for a complete specification of temporal behavior of a given manufacturing process. By providing this explicit mechanism for representing temporal constraints, a virtual manufacturing process can be viewed and utilized both in a localized application on a single virtual factory floor as well as distributed across multiple, interlinked virtual environments.
Features and Constraints in Architectural Design
Authors: De Vries Bauke , Jessurun Joran
Published: February 2021

The concepts of the experimental design system that are discussed are feature modeling and geometrical constraints. The main technique for creating the user environment is Virtual Reality. Feature modeling forms the basis for managing the design data. To start with, data storage is implemented in a Relational Data Base Management System. Along with this a (traditional) interface is developed for managing the data. Data management consists of feature type creation and feature type instancing. Features are used to define building elements, their relationships and additional constraints. Apart from the design data, geometrical data are stored. The system contains a library of parameterized geometrical objects which format is in coherence with the geometrical modeling environment (VR). Possible design solutions can be limited using geometrical constraints. Specifying connection types between building elements result in a set of solutions for the position of the bounding boxes of the building elements in space.
An Architecture for VR-Based Virtual Prototyping of Human-Operated Systems
Authors: Jayaram Sankar , Angster Scott R. , Gowda Sanjay , Jayaram Uma , Kreitzer Robert R.
Published: February 2021

Virtual prototyping is a relatively new field which is significantly changing the product development process. In many applications, virtual prototyping relies on virtual reality tools for analysis of designs. This paper presents an architecture for a virtual prototyping system which was created for the analysis of automotive interiors. This flexible and open architecture allows the integration of various virtual reality software and hardware tools with conventional state-of-the-art CAD/CAM tools to provide an integrated virtual prototyping environment. This architecture supports the automatic transfer of data from and to parametric CAD systems, human modeling for ergonomic evaluations (first person and third person perspectives), design modifications in the virtual environment, distributed evaluations of virtual prototypes, reverse transfer of design modifications to the CAD system, and preservation of design intent and assembly intent during modifications in the virtual environment.
Intelligent Scheduling for Product Distribution
Authors: Xue Deyi
Published: February 2021

A number of intelligent scheduling models for product distribution have been introduced in this research. The databases, representing scheduling requirements and results, are described using object oriented modeling approach. The optimal schedule for product distribution considering relevant constraints is identified using two optimization approaches: state space search and genetic algorithm. State space search is employed when search space is not large. Genetic algorithm, on the other hand, provides a robust mechanism for identifying the global optimal schedule when the search space is large. Different heuristic functions, considering traveling time and distance, have been developed to evaluate the schedules generated in the optimization. In addition to single-vehicle based scheduling, scheduling considering a number of vehicles has also been studied.
Intelligent Multi-Component Thermal Analysis
Authors: Holzhauer Douglas , Grosse Ian
Published: February 2021

This paper documents ongoing research into using Artificial Intelligence (AI) techniques to intelligently control finite element thermal analyses. These techniques are used to implement component level decomposition of the physical domain and to integrate domain information into the analysis process. Techniques developed by this research have been implemented into a new finite element program. This program uses a blackboard architecture to integrate the various numerical and symbolic knowledge sources. The blackboard architecture also supports the storage of all data in an object oriented form. A test problem involving transient thermal analysis of an integrated circuit package show significant decrease in the number of floating point operations when using this method.
Declarative User-Defined Feature Classes
Authors: Bidarra Rafael , Idri Abdelfettah , Noort Alex , Bronsvoort Willem F.
Published: February 2021

Designing mechanical parts using a feature vocabulary is a very effective and rich paradigm. Its expressive power, however, is severely limited if the set of feature types available in a feature library is fixed. It is, therefore, desirable to be able to extend and configure a feature library according to particular requirements, either of an end-user of a CAD system or of an application area. These requirements are not limited to topologic and parametric aspects of a generic feature definition, but include also validity conditions to be verified for each feature instance in a model.

This paper proposes a new declarative scheme for the definition of feature classes. This scheme provides a unified description of the shape and validity issues of a feature class, as well as a flexible configuration of the feature class interface. In the definition process, the various constraint classes available play a central role, whereas an inheritance mechanism structures the feature library hierarchy. At the end of the process, validation of the class is performed, in order to avoid over- and underconstrained specifications. A graphical user interface supports the whole feature class definition process. Once defined, a feature class is automatically made available for use in a feature library of the modeling system.
Maximum Mixing Times of Methane and Air Under Non-Reacting and Reacting Conditions
Authors: Brasoveanu Dan , Gupta Ashwani K.
Published: February 2021

Mixing times between methane and air under non-reacting or reacting conditions in the presence of rates of temperature and pressure and velocity gradients are examined using a mixing model based on the ideal gas law and the equation of continuity. The model is valid for low-pressure combustors under non-reacting conditions. The model is also valid under reacting conditions for the fresh mixture containing only trace amounts of combustion products. The effects of initial pressure, temperature and fluid composition on mixing time are also analyzed. In general, the exact mixing time has to be determined numerically. Nevertheless maximum values of mixing times can be determined analytically for a broad range of operational conditions. Results show that under both reacting and non-reacting conditions, the maximum mixing time is directly proportional to the initial pressure and temperature of mixture and inversely proportional to rates of pressure and temperature, and to velocity divergence. Mixing through fuel dispersion into the surrounding air is shown to be faster than via air penetration into the fuel flow. Rates of pressure of less than 1 atm/s acting alone provide a mixing time in excess of one second, which is unacceptably long for many applications, in particular gas turbine combustion. Rates of temperature produced by flame may provide mixing times shorter than 0.1 s. Mixing times of the order of a few milliseconds for efficient combustion and low emission, require high velocity gradients at the fuel-air boundary. Results show that enhanced mixing is achieved by combining temperature and velocity gradients. This analysis of mixing time is intended to provide important design guidelines for the development of high intensity, high efficiency and low emission combustors.
Applications of a Local Multigrid Approach to the Finite Element Analysis of a Crack-Microcrack Problem
Authors: Cardew G. E. , Seed G. M. , Koh W. K.
Published: February 2021

An established group of methods allows fine grid patches to overset their coarser surroundings by an arbitrary amount. These are the Domain Decomposition methods which offer a flexibility, in that finite element models may contain local refinements in the vicinity of significant features such as crack tips. The present application is based on a restricted form of Domain Decomposition using a Multigrid algorithm applied to a composite grid consisting of local refinement patches embedded within selected zones of an underlying finite element grid. Constructing a finite element grid with disjoint, overset refinement patches is significantly simpler than the conventional approach of designing a single, complex grid of strong connectivity, with increased refinements within crack tip regions. Furthermore, the overall size of a problem can be dramatically reduced by using the patch approach, resulting in lower computational effort.

Stress intensity factors are presented for the two-dimensional problem of a main crack with multiple, arbitrarily located and oriented microcracks in the vicinity of the main crack tip. The crack-microcrack interactions are further investigated with respect to crack tip shielding and amplification. Predictions of the stress intensity factors, based on the J conservation integral within the local patches, are shown to be in excellent agreement with stress intensity factors obtained on conventional grids and with known solutions.
Onvex Partitioning Approach for the Construction of Solid Model From Measured Point Data
Authors: Holla V. Devaraja , Krishnan S. S. , Gurumoorthy B.
Published: February 2021

This paper describes an algorithm for the construction of solid model from measured point data using Convex Partitioning approach. Convex Partitioning approach is based on the idea that any non-convex body can be viewed as a combination of several convex pieces. The input constitutes a set or cluster of points, measured on each face of the object, which is obtained by scanning the part. Points in each cluster are used to fit a plane or a non-planar surface depending upon the type of face. Partitioning is done along the planes till one gets all the convex pieces. The individual convex pieces are then combined together to get the final model of the object. The definition of convex partition is relaxed for objects having curved faces, to be an object with all its edges convex.

Apart from allowing the construction of solid model from measured point data, the output (convex pieces) obtained from this approach is useful in planning for rapid prototyping and feature suppression in finite element analysis.
Improved Trust Region Model Management for Approximate Optimization
Authors: Wujek Brett A. , Renaud John E.
Published: February 2021

Approximations play an important role in multidisciplinary design optimization (MDO) by offering system behavior information at a relatively low cost. Most approximate optimization strategies are sequential in which an optimization of an approximate problem subject to design variable move limits is iteratively repeated until convergence. The move limits are imposed to restrict the optimization to regions of the design space in which the approximations provide meaningful information. In order to insure convergence of the sequence of approximate optimizations to a Karush Kuhn Tucker solution a move limit management strategy is required. In this paper, issues of move-limit management are reviewed and a new adaptive strategy for move limit management is developed. With its basis in the provably convergent trust region methodology, the TRAM (Trust region Ratio Approximation Method) strategy utilizes available gradient information and employs a backtracking process using various two-point approximation techniques to provide a flexible move-limit adjustment factor. The new strategy is successfully implemented in application to a suite of multidisciplinary design optimization test problems. These implementation studies highlight the ability of the TRAM strategy to control the amount of approximation error and efficiently manage the convergence to a Karush Kuhn Tucker solution.
Towards Dynamic Tolerance Analysis Using Bond Graphs
Authors: Salomons Otto W. , Zijlstra Johan , van der Zwaag Johnny A. , van Houten Fred J. A. M.
Published: February 2021

A generic method is proposed by which the effect of tolerances in combination with physical effects such as wear can be analysed on the dynamic behavior of mechanisms. The method uses bond graphs in order to simulate the dynamic behavior under the influence of tolerances and other physical effects. The method has the potential to offer enhanced computer support in tolerance value specification as well as in robust design and model based maintenance. The method has partly been implemented using a combination of a geometric modeling system (FROOM) and a bond graph based physical modeling and simulation system (20-Sim).
Computer Simulation for Ergonomic Bus Operator Workstation Design With Validation
Authors: You H. , Oesterling B. , Lowe B. , Gilmore B. J. , Freivalds A.
Published: February 2021

Bus operator’s workstations neglecting ergonomic features can cause overall discomfort and injuries to the users. This paper presents use of JACK®, a human work simulation package, in designing and evaluating a bus operator workstation which can provide sufficient visibility, natural reach, and comfortable posture for operators who range from the 5th percentile female to the 95th percentile male as defined by SAE J833 (SAE, 1994). Three human models representing the two extremes and their medium size person were created and performed 15 bus operating tasks on the bus workstation implemented in JACK®. Kinematic constraints were defined between the human models and the workstation to simulate the tasks in a realistic manner. While the human models simulated the tasks, the body joints were monitored to determine if they exceeded their comfort ranges recommended by Diffrient et al. (1981) and the workstation was evaluated in terms of visibility, reach, comfort, and adjustability. After the workstation design was refined by iterative modifications and the required component adjustment ranges were determined, the workstation design was prototyped into an actual working bus. A jury of bus operators evaluated the workstation design by operating the prototype on a test track. The response from the operators indicated that the workstation would accommodate the intended population.
The Subcontractors Role in Computer Aided Tolerance Management
Authors: Söderberg Rikard , Wandebäck Fredrik , Wahlborg Per-Johan
Published: February 2021

As modern development process tends to be more and more intense, the time from idea to product on the market continues to shorten. Competitive pressure, shorter lead times and greater demands for quality and customization increase the need for computer aided geometrical product and process verification.

Computer Aided Tolerance Management, including all design, manufacture and inspection activities striving to minimize the effect of geometrical variation, is not fully supported today. To meet future industry demands for shorter lead times and lower cost with maintained or improved quality, the field of variation control must be broadened and the subcontractors role must be changed.

This paper discusses and identifies the future role of the subcontractor and the most critical factors for achieving an effective and consistent information flow for control of geometrical variation throughout the whole product and production development process.
Life Cycle Design With Green QFD-II
Authors: Zhang Yanping (Paul) , Wang H. P. (Ben) , Zhang Chun (Chuck)
Published: February 2021

Green Quality Function Deployment-II (GQFD-II), a new methodology for product development or improvement, is introduced in this paper. By integrating Life Cycle Costing (LCC) into QFD matrices and deploying quality, environmental and cost requirements throughout the entire product development process, GQFD-II elaborates the original GQFD, in which Life Cycle Assessment (LCA) and QFD are combined to evaluate different product concepts. GQFD-II includes three major phases. Phase I - Technical Requirement Identification. Quality house, green house and cost house are established in this phase, where customer, environmental and cost requirements are established and documented. Phase II - Product Concept Generation. A series of product concepts are generated to satisfy the requirements established in Phase I. These concepts can be evaluated with respect to quality, environment and cost. The best product concept is then selected. Phase III - Product/Process Design. In this phase, the requirements from previous phases are deployed into all product/ process design stages. In this paper, an illustrative example (light fixtures) is used to demonstrate the concept of GQFD-II.
Design of Virtual Objects for Exact Collision Detection in Virtual Reality Modeling of Manufacturing Processes
Authors: Tesic Rade , Banerjee Pat
Published: February 2021

Collision detection becomes a key issue when we want to model interactions between general, nonconvex objects in virtual reality applications which arise in manufacturing process domain. Despite significant progress which has been made in developing efficient, exact collision detection algorithms for convex objects, limited and slow progress has been reported in developing collision detection algorithms for general, nonconvex objects. To narrow this gap we introduce a concept of virtual objects which extends applicability of exact collision detection algorithms to nonconvex objects. This paper presents a methodology to encapsulate into virtual objects the surface patches of interest for collision detection as well as the automatic procedures for creation of virtual objects and for partitioning them into convex pieces.

The collision detection technique described in this paper is best suited for interactive simulation and animation applications where high accuracy of object contact modeling is required. Examples include virtual assembly; mobile robot simulation; and simulation of manufacturing processes where accurate modeling of near-miss detection is essential, e.g. robotic painting, robotic welding, and NC machining operations.
An Enhanced Axiomatic Design Process
Authors: Yu Hongqian , Shu Lily H. , Venter Ron
Published: February 2021

This paper describes an Axiomatic Design process enhanced by the House of Quality that combines the advantages of these two methods: 1) the House of Quality is used to translate customer needs into engineering specifications; 2) decomposition by theme is used to determine the Basic Functional Requirements; 3) engineering specifications are categorized into strategies, constraints, Quality Functional Requirements and possible Basic Functional Requirements; 4) Quality Functional Requirements are assigned to different Basic Functional Requirements; 5) Basic Design Matrix, Single Quality Design Matrix and Cross Quality Design Matrix are generated to study and evaluate design concepts from different aspects. By using this approach, it is possible that an improved understanding and higher efficiency of the design process may be achieved.
Understanding Product Similarity Using Customer Needs
Authors: McAdams Daniel A. , Stone Robert B. , Wood Kristin L.
Published: February 2021

In this paper, related product functions are determined for a group of approximately 70 consumer products. Using customer need data, a new matrix approach is introduced to identify these relationships. Techniques are then created for determining product similarity. These techniques are clarified and validated through three case studies, including beverage brewers and material-removal products. The results of these case studies are argued to have significant impact on design-by-analogy procedures, benchmarking methods, mass customization strategies, and modular design. The paper concludes with a discussion of applications and related procedures for product development.
Aggregation and Controlled Interaction: Automated Mechanisms for Managing Design Complexity
Authors: Jacobs Timothy M. , Cohen Elaine
Published: February 2021

Complexity in modern product design is manifest through large numbers of diverse parts, functions, and design disciplines that require an intricate web of synergistic relationships to link them together. It is extremely difficult for designers to assimilate or represent such complex designs in their totality.

In this research, we present a framework that utilizes the intricate relationships between design components to enhance the representational power of design models and to provide focal points for automating the management of design complexity. We introduce automated mechanisms, based on aggregation and interaction relationships between design components, that integrate model structure, a variety of conceptual and detailed design information, and product management controls into a single modeling framework. These mechanisms are easily incorporated into design models and they facilitate re-use and cooperative design by ensuring that related entities can be modified independently.
Vibration and Analysis of Multi-Disk Friction Systems
Authors: Larsson Henric , Farhang Kambiz
Published: February 2021

The paper presents a lumped parameter model of multiple disks in frictional contact. The contact elastic and dissipative characteristics are represented by equivalent stiffness and damping parameters in the axial as well as the torsional directions. The formulation accounts for the coupling betwen the axial and angular motions by viewing the contact normal force to be the result of axial behavior of the system. The frictional contact of two disks in contact is modeled in two dynamic states (i.e. sticking and slipping state) having individual lumped parameter models and the conditions that control the switching between the two states are established. The friction forces are represented by assuming the coefficient of friction to be a function of the sliding velocity, varying exponentially from its static value at zero relative velocity to its kinetic value at high velocities.

A computer simulation of an eight-rotor disk assembly is presented. The torsional vibration characteristics and how it is liked to the axial modes of vibration is analyzed. The vibration characteristics in the transient, steady-state and stick-slip region is compared. In the stick-slip region, the angular velocity of the interfaces in frictional contact is depicted and the sticking and slipping states are defined. It is shown that the duration of slip is approximately constant and the duration of stick increases almost exponentially until a final sticking is achieved.
Synchronization of Intermittently Activated Conveyor Belts by Adaptation of Multiple Geneva Wheels in Parallel: Part II — A Novel Application
Authors: Sepahpour Bijan , Fischer Ian S.
Published: February 2021

Synchronization of intermittently activated conveyor belts is achieved by the adaptation of the method of synchronization of multiple Geneva wheels in parallel. The correlation of the index and dwell time ratios is discussed and the method for control and selection of these ratios is presented. Modification of the drivers for maximizing the interaction of the synchronized dwell times is discussed. These modifications offer a wide variety of index and dwell time ratios to be utilized for the adjustment and control of the synchronized incremental movements. Comparison and advantages of the modified drivers and the applications of this method are presented through illustrative situations.
Feature-Recognition for MEMS Extraction
Authors: Baidya Bikram , Gupta Satyandra K. , Mukherjee Tamal
Published: February 2021

Microelectromechanical systems (MEMS) integrating multi-domain sensors and actuators with conventional microelectronic batch fabrication processes are becoming increasingly complex. In order to design systems with large numbers of multi-domain components, we need to use a hierarchical structured design approach, with design at the schematic level instead of the traditional layout representation used in MEMS design. However, since fabrication can only be done from a layout representation, an automatic or manual layout generation from schematic is necessary. It is essential to be able to translate from the layout representation back to the schematic to reason about layout correctness in meeting the schematic’s function as well as to extract geometric parameters for functional simulation. An extraction module is developed which reads in the geometric description of the layout structure and reconstructs the corresponding schematic. This schematic can then be fed to an ordinary differential equation solver or can be compared with the design schematic to validate the correctness of the designed layout. The extraction module also minimizes the number of nodes required to represent the schematic as a netlist. The results presented show the success of the module for some example MEMS designs.
Extensions to the Mass Moment Substitution Method for Complete Shaking Force Balancing of Spatial Linkages
Authors: Kong Xian-Wen , Yang Ting-Li
Published: February 2021

This paper aims at simplifying the derivation of conditions for complete shaking force balancing (CSFB) of spatial linkages. The formulation of conditions for CSFB of a spatial linkage is reduced to the mass moment substitution of binary links, ternary links, quaternary links, dyads and spatial serial open chains. The conditions and formulae for mass moment substitution of different types of ternary links and quaternary links are derived. From these conditions and formulae together with the conditions and formulae for mass moment substitution of binary links, dyads and spatial serial open chains presented in previous works, the conditions for CSFB of a spatial linkage can be written down directly instead of extracting them from the kinematic equations of the linkage. A general procedure to formulate the condition for CSFB is then proposed and an example is given to illustrate the application of the proposed approach.
A Time Finite Element Method for Dynamic Analysis of Elastic Mechanisms in Link Coordinate Systems
Authors: Wang Yu (Michael) , Wang Zaiping
Published: February 2021

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

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

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

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

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

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

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

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

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

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

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

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.