bluuebunny/crossref_metadata_2025 huggingface dataset:
Orchestrating cradle‐to‐cradle innovation across the value chain: Overcoming barriers through innovation communities, collaboration mechanisms, and intermediation
Authors: Hansen Erik G. , Schmitt Julia C.
Published: November 2020

The circular economy (CE) aims at cycling products and materials in closed technical and biological loops. Cradle to cradle (C2C) operationalizes the CE with a product design concept rooted in the circulation of “healthy” materials because contamination of materials with substances of concern hampers cycling and may pose risks to people in contact with them. Extant research shows that barriers often hinder organizations from successfully pursuing cradle‐to‐cradle product innovation (CPI). Innovation community theory helps to explain how to overcome barriers and further the innovation process by taking a microlevel perspective on intra‐ and interorganizational collaboration of individual promotors (or champions). We elaborate innovation community theory with a longitudinal embedded case study of a C2C frontrunner company with the goal to get a precise understanding of how promotors collaborate in the CPI process. Our contribution is threefold: We identify eight collaboration mechanisms used between promotors to sequentially overcome a hub firm's individual, organizational, value chain, and institutional level barriers to circularity. Second, we differentiate these mechanisms according to their cooperative and coordinative facets and put emphasis on the coordinative functions of those mechanisms linked to the C2C standard. Third, we highlight the importance of promotors at the linking level who facilitate the CPI process as intermediaries.
Evaluation of cochlear involvement and hearing function in lipoid proteinosis patients
Authors: Yukkaldıran Ahmet , An İsa , Erdoğan Osman
Published: November 2020

Background

Lipoid proteinosis (LP) is a rare genodermatosis involving amorphous hyaline accumulation in the skin, oral mucosa, larynx, mucous membranes, and viscera.

Aims

In this study, we aimed to investigate the effects of hyaline accumulation on cochlear function and hearing in LP patients.

Patients/Methods

In this prospective study, 20 patients who were followed up with a diagnosis of LP between October 2016 and April 2020 in our clinic and 20 healthy individuals of the same age and gender, as a control group, were included. Pure‐tone audiometry, tympanometry, and distortion‐product otoacoustic emission tests of the patient and control groups were performed. The audiological results of the LP and control groups were compared statistically.

Results

In the comparison of air‐conduction thresholds between groups in pure‐tone audiometry, hearing thresholds in the patient group were found to be higher than the control group at frequencies of 250, 4000, 6000, and 8000 Hz for the right ear, and 500 and 4000 Hz for the left ear. In the comparison of signal‐noise responses between groups in distortion‐product otoacoustic emission (DP‐OAE) test, signal‐noise responses in the right and left ear at frequencies of 1000, 2000, 4000, and 6000 Hz were lower in the patient group than in the control group.

Conclusion

We found that the cochlear functions of patients with LP were affected due to the increase in hearing thresholds and decreased signal‐noise responses. We think that LP patients are candidates for hearing loss in their later life.
Liquidity Supply in the Corporate Bond Market
Authors: GOLDBERG JONATHAN , NOZAWA YOSHIO
Published: November 2020

This paper examines dealer inventory capacity, or liquidity supply, as a driver of liquidity and expected returns in the corporate bond market. We identify shocks to aggregate liquidity supply using data on corporate bond yields and dealer positions. Liquidity supply shocks lead to persistent changes in market liquidity, are correlated with proxies for dealer financial constraints, and have significant explanatory power for cross‐sectional and time‐series variation in expected returns, beyond standard risk factors. Our findings point to liquidity supply by financially constrained intermediaries as a main driver of market liquidity and asset prices.
Plastid Engineering of a Marine Alga, Nannochloropsisgaditana, for Co‐Expression of Two Recombinant Peptides
Authors: Cui Yulin , Wang Kang , Xu Wenxin , Wang Yinchu , Gao Zhengquan , Cui Hongli , Meng Chunxiao , Qin Song
Published: November 2020

The purpose of this study was to establish a plastid transformation system for expressing recombinant proteins in Nannochloropsis gaditana. On the basis of the sequenced plastid genome, the homologous flanking region, 16S‐trnI/trnA‐23S, and the endogenous regulatory fragments containing the psbA promoter, rbcL promoter, rbcL terminator, and psbA terminator were amplified from N. gaditana as elements of a plastid transformation vector. Then, the herbicide‐resistant gene (bar) was used as a selectable marker, regulated by the psbA promoter and rbcL terminator. Finally, two codon‐optimized antimicrobial peptide‐coding genes linked by endogenous ribosome binding site (RBS) in a polycistron were inserted into the constructed vector under the regulation of the rbcL promoter and psbA terminator. After microparticle bombardment, the positive clones were detected using polymerase chain reaction (PCR), and Southern and Western blotting were used to assess the co‐expression of the two antimicrobial peptides from the plastid. Nannochloropsis gaditana showed the potential to express recombinant proteins for biotechnological applications, for example, for the development of oral vaccines in aquaculture.
Reply to Timothy Hinton on Gareth Moore's Philosophy of God
Authors: Robinson Howard
Published: November 2020

Hinton's defence of Gareth's philosophy is welcome - but I don't think it works. This is because he does not show how, on Gareth's theory, ‘God’ can be referential, and, if it is not referential, then ‘belief in God’ cannot be taken in any literal sense. Sadly, I stand by my original claim that the radical, Phillipsian Wittgensteinianism that Gareth adopts is a form of informal positivism that only allows an expressivist sense to religious, and, indeed, all metaphysical language.
Association between pain sensitivity and gray matter properties in the sensorimotor network in women with irritable bowel syndrome
Authors: Grinsvall Cecilia , Ryu Hyo Jin , Van Oudenhove Lukas , Labus Jennifer S. , Gupta Arpana , Ljungberg Maria , Törnblom Hans , Mayer Emeran A. , Simrén Magnus
Published: November 2020

Background

Enhanced perception of visceral stimuli is an important feature of Irritable Bowel Syndrome (IBS), but it is not known whether visceral sensitivity is associated with regional structural brain properties in IBS.

Methods

Structural brain magnetic resonance imaging data from 216 women with IBS and 138 healthy women were parcellated with FreeSurfer to define regional gray matter morphometry (volume, cortical thickness, surface area and mean curvature) in the sensorimotor network. General linear models were used to detect group differences between IBS and health. In a second set of 48 female IBS patients, pain threshold, pain intensity ratings during rectal balloon distension, and reported levels of abdominal pain and bloating were correlated with brain regions that showed differences between IBS and health in the first data set.

Key Results

Several statistically significant differences between IBS patients and healthy controls were found, mainly higher gray matter volume and cortical thickness in primary somatosensory cortex, secondary somatosensory cortex, and subcortical regions, and lesser gray matter volume, surface area and cortical thickness in posterior insula and superior frontal gyrus. Pain intensity ratings during rectal distension were associated with left primary somatosensory cortical thickness, and pain threshold was associated with right nucleus accumbens volume.

Conclusions and Inferences

Regional gray matter differences in sensorimotor network are associated with visceral sensitivity and may represent neuroplastic changes in female IBS patients.
Dermatofibrosarcoma protuberans (DFSP) in children: A combined multidisciplinary approach
Authors: Sleiwah Aseel , Psomadakis Cristina , Craythorne Emma , Stefanato Catherine M. , Rickaby William , Robson Alistair , Mellerio Jemima E. , Greig Aina
Published: November 2020

Dermatofibrosarcoma protuberans (DFSP) is rare, comprising (1%‐6%) of all sarcomas. The incidence is less than one per million before the age of 20. It is a locally aggressive tumor with a low risk of metastasis. We share our experience in the management of three pediatric patients with complex cases of DFSP in a combined surgical approach involving plastic and dermatologic surgery, using the slow Mohs micrographic surgery technique.
TiO2 Synthesis by the Pechini’s Method and Application for Diclofenac Photodegradation†
Authors: Souza Danilo R. , Neves João Vitor S. , França Yago K.S. , Malheiro Wellington C.
Published: November 2020

In this work, the effect of the calcination temperature on the TiO2 synthesis using Pechini’s method was reported. The adopted calcination temperatures were 500, 600, and 700°C. XRD measurements indicated the composition of crystalline phases, and from there, the conversion of the anatase phase to rutile. TiO2 Evonik® was used as a reference standard and sodium diclofenac as a standard for photodegradation assessment. The average crystalline size increased. In both cases, this trend accompanied the increase in calcination temperature. The optical properties were performed using diffuse UV‐Vis reflectance. Results obtained indicated maximum absorption wavelength values more intense and displaced to the visible region. Also, the estimated band gap energy values decreased. The photocatalytic performance of TiO2 samples was superior to the reference catalyst (TiO2 Evonik®). Especially in the first 10 minutes, the comparative photodegradation was up to approximately 58% higher. The photodegradation kinetic constants were also higher, and by comparison, up to approximately 73% higher. Toxicity measurements, using Artemias salina, also indicated similar decay behavior in the first 10 minutes, with a performance of up to approximately 60%.
The Return of Ethnocentrism
Authors: Bizumic Boris , Monaghan Conal , Priest Daniel
Published: November 2020

The concept of ethnocentrism was introduced by Gumplowicz in the 1870s, popularized by Sumner in the 1900s, and first investigated psychometrically by Adorno and colleagues in the 1940s. It has become a fundamental concept in the social sciences, but over the last several decades, its popularity and usage in political and social psychology have decreased. Recent events, such as the growing popularity of ethno‐nationalist and populist leaders and policies, show that ethnocentrism as a phenomenon has been resurging around the world. In addition, given its important explanatory power, an increasing number of political psychologists have started again to use the concept. This article presents an analysis of ethnocentrism reconceptualized as a hierarchical construct emanating from a strong sense of ethnic group self‐centeredness and self‐importance. It discusses the prevalence of ethnocentrism around the world, its conceptualization and measurement, and its theoretical underpinnings, supporting them with novel empirical research conducted with two abbreviated measures of ethnocentrism. The article argues that ethnocentrism ultimately stems from the need to strengthen one's own ethnic group at the expense of anyone who and anything that can weaken it.
Transcript abundance of anti‐Mullérian hormone and follicle‐stimulating hormone receptor predicted superstimulatory response in embryo donor Holstein cows
Authors: Abdel Aziz Rabie L. , Abdel‐Wahab Ahmed , Ibrahim Marwa A. , Kasimanickam Ramanathan K.
Published: November 2020

The goal was to investigate the relationship among mRNA expressions of anti‐Mullérian hormone (AMH), follicle‐stimulating hormone receptor (FSHR) and responses to superovulation (SO) in embryo donor dairy cows. Holstein cows (n = 19) were submitted to a standard SO protocol, with twice daily FSH treatments, and artificially inseminated. Prior to SO (Day 0), relative mRNA expressions of AMH and FSHR in blood were determined for all cows. Day 7 embryos were collected and were graded to determine superovulatory response for each donor. Results showed that relative mRNA expressions of AMH and FSHR were positively correlated (R2 = 0.94). Relative mRNA expressions of both AMH and FSHR were positively correlated with total embryos (R2 = 0.68 and 0.69, respectively), total transferable embryos (R2 = 0.92 and 0.97, respectively) and total grade 1 embryos (R2 = 0.54 and 0.59, respectively). Further, transcript abundances of AMH and FSHR positively associated with milk production of donor cows, and meanwhile, they were negatively associated with days in milk (DIM) at submission of cows to SO (p < .05) protocol. The relative mRNA expression of AMH was higher (p < .05) in donor cows <5 years of age. However, age of donor at superovulation did not influence mRNA expression of FSHR. Collectively, we infer that the mRNA expressions of AMH and FSHR prior to superovulation can predict donor cows’ positive response to superovulation.
Did Mali benefit from joining the CFA zone? An analysis using the synthetic control method
Authors: Strong Christine O.
Published: November 2020

This article examines the benefits of CFA zone membership by estimating the effects of joining the CFA zone on short‐run business cycle indicators such as income per capita and inflation as well as long‐term economic indicators such as trade relations with France and foreign direct investment (FDI) in Mali. Using the synthetic control method, we show that Mali’s CFA membership has a positive effect on its income, inflation, and FDI but no discernible effect on trade relations with France. We conclude that joining the CFA zone can generate potential economic gains for countries seeking membership by fostering growth and providing price stability but does not necessarily increase trade relations with France even though the CFA is a former French colonial currency.
Nonparametric extreme conditional expectile estimation
Authors: Girard Stéphane , Stupfler Gilles , Usseglio‐Carleve Antoine
Published: November 2020

Expectiles and quantiles can both be defined as the solution of minimization problems. Contrary to quantiles though, expectiles are determined by tail expectations rather than tail probabilities, and define a coherent risk measure. For these two reasons in particular, expectiles have recently started to be considered as serious candidates to become standard tools in actuarial and financial risk management. However, expectiles and their sample versions do not benefit from a simple explicit form, making their analysis significantly harder than that of quantiles and order statistics. This difficulty is compounded when one wishes to integrate auxiliary information about the phenomenon of interest through a finite‐dimensional covariate, in which case the problem becomes the estimation of conditional expectiles. In this paper, we exploit the fact that the expectiles of a distribution F are in fact the quantiles of another distribution E explicitly linked to F, in order to construct nonparametric kernel estimators of extreme conditional expectiles. We analyze the asymptotic properties of our estimators in the context of conditional heavy‐tailed distributions. Applications to simulated data and real insurance data are provided.
A Boy’s Journey and the Journey to Freedom*
Authors: Zussman Robert
Published: November 2020

The journey to freedom is a literary genre that involves a realization of oppression, a decision to leave, a journey that is both physical and moral, a wilderness experience, a self‐reinvention, and, most importantly, a first person testimonial to the reality of oppression.
Interrogating a measurement conjecture to introduce the concept of statistical association in upper elementary education
Authors: Hourigan Mairéad , Leavy Aisling M.
Published: November 2020

The association or relationship between two variables, also known as covariation, has been identified as one of the fundamental statistical concepts. This article details a statistical investigation that was used to informally introduce Grade 6 students to this concept.
Morphology of the cisterna chyli in nine dogs with idiopathic chylothorax and in six healthy dogs assessed by computed tomographic lymphangiography
Authors: Rengert Roger , Wilkinson Tom , Singh Ameet , Brisson Brigitte A. , Fransson Boel
Published: November 2020

Objective

To describe the morphology of the lymphatics in the region of the cisterna chyli in healthy dogs and in dogs with idiopathic chylothorax by using computed tomographic lymphangiography.

Study Design

Retrospective study.

Animals

Nine dogs with idiopathic chylothorax and six healthy dogs.

Methods

Computed tomographic lymphangiograms were reviewed to evaluate the number of cisterna chyli branches, total cross‐sectional area of the branches normalized to the cross‐sectional area of the aorta, number of branches with cross‐sectional area greater than 25% of the aorta cross‐sectional area, and ratio of the total perimeter to the total cross‐sectional area of the branches. Data (mean ± SD) were compared between unaffected dogs and dogs with idiopathic chylothorax.

Results

The cisterna chyli included more branches in dogs with chylothorax (4.30 ± 1.57) than in unaffected dogs (1.67 ± 0.56, P = .02), occupying a relative perimeter approximately double that in unaffected dogs (P < .001). The relative cross‐sectional area of the cisterna chyli was approximately twofold smaller in affected (0.73 ± 0.35) than in unaffected (1.63 ± 0.91, P = .02) dogs. The fraction of dogs with branches greater than 25% of the cross‐sectional area of the aorta tended to be larger in unaffected dogs (P = .07). Most larger branches were located dorsal or to the right of the aorta.

Conclusion

The cisterna chyli of dogs with idiopathic chylothorax contained smaller and more numerous branches compared with that of unaffected dogs.

Clinical significance

Altered cisterna chyli morphology may impact the surgical approach for cisterna chyli ablation in dogs with idiopathic chylothorax.
Nonlinear Dynamics and Stability of Shallow Spherical Caps Under Pressure Loading
Authors: Iarriccio Giovanni , Pellicano Francesco
Published: November 2020

The post-buckling and nonlinear dynamic response of shallow spherical caps subjected to external pressure is analyzed. The Novozhilov's nonlinear thin shell theory is used to express the strain–displacement relations. Following the Rayleigh-Ritz method, the displacement fields are expanded using a mixed series: Legendre polynomials in the meridional direction, harmonic functions in the circumferential direction. Once the linear analysis is completed, the displacement fields are re-expanded and the nonlinear dynamic model is obtained by using the Lagrange equations. The response of clamped caps, made of isotropic and homogeneous material, is investigated. The bifurcation analyses of equilibrium points and periodic orbits are presented by using continuation techniques. Benchmark results are provided in terms of natural frequencies and critical buckling loads. The dynamic effects due to the interaction between static and dynamic pressure are investigated. Numerical results pointed out that, under particular load conditions, dynamic bifurcation results in nonnegligible asymmetric states activation in the response of the structure.
Product Life-Cycle Management and the Virtual Enterprise
Authors: Parr Richard H.
Published: November 2020

This paper presents an approach to provide a complete Product Life-Cycle Management architecture across a virtual enterprise. Today’s worldwide marketplace requires; Teaming arrangements, Collaboration across multiple continents and time zones, Protection of corporate assets and Configuration Management of the team’s product. Each of the key building blocks will be reviewed:

• Infrastructure

• Legacy data

• Collaboration

• Product Data Management

• Configuration Management

• Support Management

• Data Storage
Where Interoperability Ends
Authors: Vergeest Joris S. M. , Horváth Imre
Published: November 2020

The shared usage of computer tools among members of a design team heavily relies on the interoperability of the systems involved. Interoperability is an outstanding issue in engineering information management science for more than twenty years, and is held responsible for a multi-billion economical loss yearly in industry. Efforts (STEP, IGES) by standardization bodies and by the software industry, which now deliver web-based platforms such as Corba and Java, can only superficially address the interoperability problem. Most of the solutions come down to giving clients long fingers to remotely control a centralized model. It is generally recognized that such a centralized approach is far from efficient. However, when the design tasks are really distributed among the team members, a rock bottom limitation invariably emerges, thus canceling most of the potential gain in efficiency. In this paper the interoperability is formally defined. It is then shown why and under which conditions interoperability is deemed to fail. The prime purpose of the paper is to promote awareness about this issue among researchers and infrastructure designers. Once being aware of the fundamental constraints of interoperability, compromise solutions may be intentionally developed, rather than to implement ad hoc work-around procedures (which are responsible the bulk of the financial loss mentioned). We present an approach to systematically analyze and model the requirements of a shared infrastructure, and to anticipate the feasibility of interoperability.
An Architecture for Virtual Prototyping of Complex Systems
Authors: Chadha Bipin , Welsh John
Published: November 2020

Virtual prototyping has emerged as a significant enabler for cost effective management of complex products over their lifecycle. The virtual prototypes play an important role through all life-cycle phases of products. Due to the breadth of impact, significant challenges arise in developing virtual prototypes. This paper describes the issues and tradeoffs that are important for implementing virtual prototypes. A detailed architecture is described that has been used to implement a successful virtual prototype for a complex DoD (Department of Defense) program. The paper discusses key properties of an architecture and strategies to enable its evolution over large timescales. The paper then describes the benefits of this approach.
Comparing Different Fitting Strategies for Matching Two 3D Point Sets Using a Multivariable Minimizer
Authors: Spanjaard Sander , Vergeest Joris S. M.
Published: November 2020

Finding the best match of two geometric entities in 3D space is a key stage for purposes such as object recognition and reverse engineering. The reuse of existing freeform shapes during conceptual design is also an application. In this paper we compare different fitting strategies for matching two 3D point sets using a multivariable minimizer. The strategies are evaluated against speed, robustness and correctness of result. The fitting process aims at matching two point sets, a source point set and a template point set. The template point set is translated, rotated but also deformed during the fit, such that it gets placed into the neighborhood of the source point set and gets aligned to it as good as possible. The deformation of the template shape is controlled by shape parameters, which are varied to enhance the match. The engine behind the process is a multivariable function’s global minimum finder. Its objective is to minimize the Mean Directed Hausdorff Distance (MDHD) between the two point sets by altering the parameters of the template point set. One research question was whether or not a fully automated fitting process is feasible with our method. We performed numerical experiments with 3D scan data and a shape template defined by up to 8 free parameters. Four different strategies where used to do the fitting with one of them allowing user intervention. Comparing the strategies on total fit time, minimum MDHD and correctness of result a conclusion is drawn which strategy gives the highest chance on the best results. The relevance of the technology for shape reuse in conceptual design is also discussed.
Integration of Requirement Management and Product Data Management Systems
Authors: Svensson Daniel , Malmqvist Johan
Published: November 2020

Various database systems are used during the product development process to store and retrieve data about products. For example product data management (PDM), enterprise resource planning (ERP) and requirement management (RM) systems. All those might be needed to support the product development process. Earlier research has investigated the co-existence of PDM and ERP systems. This paper extends this question and takes a look on how requirement management systems fit into the picture and how these systems can be used together in order to support the product development process.

A comparison of functionality and product models of RM and PDM systems is made. A requirements driven product model of a car cockpit implemented in a RM tool is used as a theoretical reference. The actual situation at the company developing the cockpit is then described. Based on the comparison of the functionality and the product models, three strategies for how the systems could cooperate are presented. The strategies are discussed from both a theoretical and a practical point of view. The conclusions are that RM systems has functionalities for requirements management that do not exist in a PDM system, which calls for the use of both systems. This results in problems with traceability and duplicate data. A certain degree of requirements traceability can be achieved between the systems by applying the strategies presented, but this is not a trivial task.
Integrating Design Process Knowledge With CAD Models
Authors: Hayes Erik E. , Regli William C.
Published: November 2020

Solid models are static entities, often defined by boundary representation models as sets of enclosing surfaces. Constructive Solid Geometry and feature-based computer-aided design environments create procedural descriptions of 3D objects in forms of history or CSG trees. These representations are temporally fixed, i.e., they describe the state of an object at a point in time.

This paper describes a method to represent and capture temporal evolution of solid models — what we call model process history. We define process history to be all states of a model — the search space of design process. This paper presents a representational formalism we call model process graphs (MPGs). We use MPGs to integrate a model’s description with a model of temporal changes that occur during the design process. We believe that MPG representations can have valuable application for many design and manufacturing problems. The paper describes our preliminary results to use MPGs to (1) create a record of design process; (2) store process-based design rationale; (3) represent in-process shapes for machined artifacts. We anticipate that similar structures will find application in other design and manufacturing problems where important process knowledge is embodied by temporal changes occurring in model evolution.
Hybrid Strain Based Finite Element Modeling of Laminated Plates With Distributed Piezoelectric Components
Authors: To C. W. S. , Liu Wei
Published: November 2020

A layerwise hybrid strain based lower order flat triangular laminated composite shell finite element with piezoelectric effects has been developed and reported in this paper. This layerwise three-node triangular shell element is formed by stacking a lower-order flat triangular shell element with piezoelectric effects. In every node there are seven degrees of freedom (dof). These include three translational dof, three rotational dof, and one electric potential dof. The important drilling dof (ddof) is included in every node. The degenerated three dimensional solid assumption and the first order shear deformation theory (FSDT) were adopted. Consequently, shear and membrane lockings are eliminated. This feature is superior to those elements based on the displacement formulation. Explicit expressions for the consistent element mass and stiffness matrices were obtained by using the symbolic algebraic package, MAPLE V. Thus, it reduces considerably the computational time as opposed to those applying numerical matrix inversion and numerical integration for the derivation of element matrices.
Affordable Space Systems Manufacturing: Intelligent Synthesis Technology, Process Planning, and Production Scheduling
Authors: Herrmann Jeffrey W. , Fleischer Mark , Lin Edward , Mathur Vidit , Glasser Jim
Published: November 2020

Low volume production associated with space systems manufacturing is inherently expensive, time-consuming, and risk-laden. At the root of this problem is an inability to adequately predict, monitor, and control the product development and sustainment process. This paper describes the ASSIST system, an intelligent knowledge management system designed to address inefficient information management processes and improve space system affordability. ASSIST is designed for collaborative engineering, manufacturing, and testing within a company, between companies, and between local and remote individuals. ASSIST uses web-based standards (including HTTP and XML) as the common message approach connecting its components. Automated process planning and production scheduling is a key component of ASSIST. This paper describes an integrated process planning and production scheduling problem and discusses the solution approach.
Collaborative Modeling With Features
Authors: Bidarra Rafael , van den Berg Eelco , Bronsvoort Willem F.
Published: November 2020

Collaborative systems are distributed multiple-user systems that are both concurrent and synchronized. An interesting research challenge is to develop a collaborative modeling system that offers all facilities of advanced modeling systems to its users, while at the same time providing them with the necessary coordination mechanisms that guarantee an effective collaboration.

To achieve this, a web-based collaborative feature modeling system, webSPIFF, has been developed. It has a client-server architecture, with an advanced feature modeling system as a basis for the server, providing feature validation, multiple views and sophisticated visualization facilities.

A good distribution of the functionality between the server and the clients has resulted in a well-balanced system. On the one hand, the server offers all the functionality of the original feature modeling system. On the other hand, all desirable interactive modeling functionality is offered by the clients, ranging from display of sophisticated feature model images to interactive model specification facilities.

The architecture of webSPIFF, the distribution of model data, the functionality of the server and the clients, and the communication mechanisms are described. It is shown that a good compromise between interactivity and network load has been achieved, and that indeed advanced modeling with a collaborative system is feasible.
Design for Facility Over the Internet: A Case Study With Automotive Connecting Rod Designs
Authors: Qureshi Khurshid A. , Saitou Kazuhiro
Published: November 2020

This paper introduces a new methodology called ‘Design for Facility over Internet (DFF)’. This methodology provides an Internet-based environment for designers to perform manufacturability analysis of product designs with respect to the capabilities of existing manufacturing facilities, upfront into the design process. In the current work, only fixturing (machining datums) capabilities of a manufacturing facility are considered. A prototype DFF system for an automotive connecting rod, is developed. The system enables the designers to design the connecting rods by considering the fixturing (datums) capabilities of existing manufacturing facilities upfront at the concept design stage. The complete system implementation will also enable the manufacturers of connecting rods to create and update the database of their capabilities over the Internet. The DFF system analyzes the parametric design with respect to the fixturing capabilities and generates suggestions for a designer, to modify his design if required, to fit the capabilities of specified facilities.
Exploration of a Multi-User Collaborative Assembly Environment on the Internet: A Case Study
Authors: Chen Li , Song Zhijie , Liavas Billy
Published: November 2020

Real-time collaboration systems, in which participants share product data and applications in real time, have been a subject of interest for many years. Nowadays, a rapid development of Internet-based technologies with steadily increasing easiness in accessing any kind of information through the World Wide Web (WWW) would offer the possibility of developing a real-time collaborative system over the Internet.

Two strategies are required to create such a system. One strategy is finding effective methods for communicating and sharing distributed product information, especially those related to design and manufacturing. Another strategy is developing Web-based approaches that support real-time sharing of platform-independent applications.

In this paper, a concept for a multi-user collaborative assembly environment on the Internet is presented. The Client/Server structure of the environment, and the four main functional modules including: 1) integration and sharing of distributed product data through a STEP server; 2) session management including team management, user management and access control; 3) sharing of multimedia data (e.g. text, audio and video); 4) 3D collaborative assembly, are described. Finally, a scenario has been designed to demonstrate the effectiveness of the environment to support distributed collaborative assembly design.
Communication Model for the User Interface of a Shape Conceptualization System
Authors: Kuczogi György , Horváth Imre , Vergeest Joris S. M. , Rusák Zoltán
Published: November 2020

It is commonly recognized that the user interfaces of recent CAD systems do not effectively support creative man-machine communication in the conceptual phase of the design process. At the same time, speech, hand sketching, claying, etc. are appropriate tools for communicating ideas among designers. The inherent vagueness of verbalism and hand movement is both tolerable and requested for the human-computer interaction, as well. However, the natural format of communication may also permit unnecessary uncertainty, which can easily lead to significant failures in the understanding.

The aim of the paper is to investigate how we can find those particular formats of natural communication that offer the benefit of communication of vague concepts and help to prevent failures of understanding. We have decided to use a simplified model of Gitt’s [5] information theory. We have selected three evaluation criteria (i.e., effectiveness, efficiency, and comfort) to facilitate the ranking of different ways of communication for a particular purpose. As a future work, we intend to accomplish the evaluation prove the evaluation by pilot implementation.
Minimum Torque Placement of a Kinematic Structure
Authors: Yu Wei , Yang Jingzhou , Abdel-Malek Karim
Published: November 2020

A general formulation for calculating where a kinematic structure must be positioned (and oriented) is presented. This study is applicable to both humans; to place a human in a working environment while minimizing stress on extremity joints, or for robot manipulators. In recent years, there has been focused interest on ergonomics and ergonomic design with emphasis on the disposition of a worker while performing tasks at prolonged periods of time and where repetitive motions are exerted. To a great extent, the effect of stress on a joint is major factor leading to potential injuries. We believe there is a unique opportunity for the mechanical engineering community to make a significant contribution to this field. Furthermore, because the ergonomic design process encompasses many parameters, it is evident that it must be formulated using optimization methods where the best possible solution is calculated from an infinite number of solutions. This study presents a rigorous formulation for placement of a worker based on minimizing the torque (as a cost function) induced at a joint, whereby satisfying constraints imposed by the given task. The reverse of this problem is the calculation of the coordinates of a number of target points in the reachable space of a fixed kinematic structure, which is also addressed. Both problems are mathematically formulated and numerically solved. Examples are illustrated.
Analysis of Finite Self Motion and Finite Dwell in Closed-Loop Mechanisms and Parallel Manipulators
Authors: Bandyopadhyay Sandipan , Ghosal Ashitava
Published: November 2020

In this paper, we present the necessary and sufficient criteria for finite self motion and finite dwell of the passive links of a parallel manipulator or a closed-loop mechanism. We study the first order properties of the constraint equations associated with the kinematic constraints inherent in a closed-loop mechanism or a parallel manipulator, and arrive at the criteria for the mechanism to gain a degree-of-freedom at a singular point of its workspace. By analyzing the second order properties of the constraint equations, we show that the gain of degree-of-freedom may lead to finite self motion of the passive links if certain configurational and architectural criteria are met. Special configurations and architecture may also lead to finite dwell of the passive links, and the criteria for the same has been derived. The results are illustrated with the help of several closed-loop mechanisms.
The Design of Parallel Manipulators of Star Topology Under Isotropic Constraint
Authors: Baron Luc , Bernier Ghislain
Published: November 2020

This paper proposes a necessary and sufficient number of 18 geometrical parameters allowing to describe the design manifold of the Star topological class, i.e., all geometries of manipulators having the same topology and mobility as the Y-Star parallel manipulator. The isotropic constraints are then applied on this manifold in order to define the constraint manifold of isotropic designs, i.e., those having isotropic Jacobian matrices at their home position. This constraint manifold is of dimension 11 and greatly facilitates the design of isotropic manipulators in this topological class.
CAD/FEM Analysis of Teeth Contact Stress and Load Share in Face Gears
Authors: Barone Sandro , Forte Paola , Borgianni Leonardo
Published: November 2020

Face gear drives have many advantageous characteristics compared to other angular transmissions but their complex geometry makes their design difficult with common approaches. This work is aimed at investigating the stress state of the teeth of a face gear and the mating pinion by integrating a 3D CAD system and a FEA code, and by simulating the meshing of a pinion and gear three teeth sector using contact elements and an automated contact algorithm. The procedures followed to create the 3D models of teeth in mesh are described and finite element analysis results are discussed.
Structural Optimization of a Spherical Parallel Manipulator Using a Two-Level Approach
Authors: Bidault Florence , Teng Chin-Pun , Angeles Jorge
Published: November 2020

The Agile Wrist, a spherical wrist with a parallel, isotropic architecture for highest orientational accuracy, is being designed as a module of an 11-degree-of-freedom (dof) robot.

The wrist consists of two main elements, the base and the moving plates. The two plates are coupled by means of three identical legs, each of these composed of two links, proximal and distal, coupled to each other by a revolute joint. Each leg, in turn, is coupled to its proximal plate via revolute joints. Moreover, the three axes of the leg-revolute joints are concurrent at the center of the wrist, each axis making an angle of 90° with its neighbor. Direct-drive DC motors are used to rotate the wrist proximal links and electrical brakes and optical encoders are located on each of the motor shafts for control purposes.

In this paper we introduce a two-level approach to the optimum design of the proximal link of the Agile Wrist. First, the shape of the midcurve producing minimum stress concentrations is obtained by means of the concept of curve synthesis using cubic splines. At the second level, the optimum cross-section along the midcurve producing a link of minimum weight is determined.
An Intelligent System for Spur Gear Design and Analysis
Authors: Aziz El-Sayed , Chassapis C.
Published: November 2020

A methodology for the analysis of load distribution and contact stress on gear teeth, which utilizes a combination of closed form solutions and two-dimensional finite element methods, within a constraint-based knowledge-based environment, is presented. Once the design parameters are specified, the complete process of generating the analysis model, starting from the determination of the coordinates of the tooth profile, the creation of a sector of the mating gear teeth, automatic mesh generation, boundary conditions and loading, is totally automated and transparent to the designer. The effects of non-standard geometry, load sharing on the contact zone, friction and root stresses are easily included in the model. The Finite Element Method (FEM) based results compare favorably with those obtained from closed form solutions (AGMA equations and classical Hertzian contact solution).

The advantage of the approach rests in the ability to modify any of the gear design parameters such as diametral pitch, tooth profile modification etc., in an automated manner along with obtaining a better estimation of the risks of failure of the gear design on hand. The procedure may be easily extended to other types of gearing systems.
Product Variety Optimization: Simultaneous Optimization of Module Combination and Module Attributes
Authors: Fujita Kikuo , Yoshida Hiroko
Published: November 2020

This paper proposes a simultaneous optimization method for both module combination and module attributes of multiple products. As manufacturing competition has become restricted with high profitability and external constraints, simultaneous design of multiple products, which is called product variety design etc., becomes an important strategy. System-based optimal design paradigm is expected to be essential to rationalize such practices, since design for product variety is more complicated than one for a single product. Toward such a direction, we configure an optimization method for both module combination and module attributes across multiple products. The optimization method hybridizes a genetic algorithm, a mixed-integer programming method with a branch-and-bound technique, and a constrained nonlinear programming method, i.e., a successive quadratic programming method. In its optimization process, the first optimizes the combinatorial pattern of module commonality and similarity among different products, the second optimizes the directions of similarity on scale-based variety, and the third optimizes the continuous module attributes under the others. Finally it is applied to the simultaneous design problem of multiple airplanes to demonstrate its validity and effectiveness.
Automatic Geometry Adaptive Quadrilateral Mesh Generation Using Medial Axis Transform
Authors: Quadros W. R. , Ramaswami K. , Prinz F. B. , Gurumoorthy B.
Published: November 2020

The medial axis transform (MAT) has been used in meshing algorithms for decomposition (Tam 1991; Price 1995; Price 1997) and for decomposition and termination (Quadros 2000: Quadros Thesis 2000). This paper describes an algorithm that uses the MAT for quad meshing that is adapted to the variation of geometric feature size in the domain. The algorithm is a modification of Lay Tracks, an automatic quad meshing algorithm that uses the MAT for both subdividing the domain and for terminating the advancing front of the mesh. The modification involves the adaptive placing of nodes inside the subdivided regions and makes use of the radius function available in the MAT to identify feature size and adapt the node spacing and mesh size to it. The algorithm has been implemented and tested on some typical geometries. Results on the quality of the mesh obtained are presented.
A Quadratic Form-Based Approach to Identification of Kinematic Chains in Structural Analysis and Synthesis of Mechanisms
Authors: He Peiren , Zhang Wenjun , Li Qing
Published: November 2020

Identification of kinematic chains is needed when studying in structural analysis and synthesis of mechanisms. Research on detection of isomorphism in graphs/kinematic chains has a long history. Many algorithms or methods have been proposed. However, these methods have only achieved success in restricted conditions. This paper proposes a new approach using the concept of quadratic form. Graphs/kinematic chains are first represented by their adjacency matrices, the eigenvalues and their eigenvectors corresponding to these adjacency matrices are then calculated. Two graphs are represented by two quadratic expressions. The comparison of two graphs reduces to the comparison of two quadratic expressions. Quadratic expressions are characterized by the eigenvalues and eigenvectors. An algorithm is developed to compare, correspondingly, eigenvalues and eigenvectors of two graphs, known test cases are used to verify the effectiveness of the approach.
Screw Theory Based Metrology for Design and Error Compensation of Machine Tools
Authors: Moon Sang-Ku , Moon Yong-Mo , Kota Sridhar , Landers Robert G.
Published: November 2020

The paper presents a generalized mathematical framework for computation and compensation of tool tip errors in multi-axis machine tools using screw theory. In contrast to conventional Denavit–Hartenberg notation, Screw theory offers several advantages including: (i) modeling of complex machine tool configurations with rotational axes, (ii) tractability of error propagation which simplifies solution of inverse kinematics and subsequent error-compensation procedures, and (iii) functional representation of error screws in a global reference frame rather than cumbersome coordinate transformations of local reference frames. Kinestatic filtering technique [11,12] is adopted for evaluating the compensatability of errors and the Jacobian is used for error compensation. The methodology is illustrated using a five-axis machine tool with two rotational axes.
Tuning a Hybrid Optimization Algorithm by Determining the Modality of the Design Space
Authors: Hacker Kurt , Eddy John , Lewis Kemper
Published: November 2020

In this paper we present an approach for increasing the efficiency of a hybrid Genetic/Sequential Linear Programming algorithm. We introduce two metrics for evaluating the modality of the design space and then use this information to efficiently switch between the Genetic Algorithm and SLP algorithm. The motivation for this study is an effort to reduce the computational expense associated with the use of a Genetic Algorithm by reducing the number of function evaluations needed to find good solutions. In the paper the two metrics used to evaluate the modality of the design space are the variance in fitness of the population of the designs in the Genetic Algorithm and the error associated with fitting a response surface to the designs evaluates by the Genetic Algorithm. The effectiveness of this approach is demonstrated by considering a highly multimodal Genetic Algorithm benchmarking problem.