bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic markers for Teratosphaeria destructans and closely related species
Authors: Havenga Minette , Wingfield Brenda D. , Wingfield Michael J. , Dreyer Léanne L. , Roets Francois , Aylward Janneke
Published: December 2020

Teratosphaeria foliar pathogens cause leaf and shoot blight on Eucalyptus trees in many parts of the world. Among them, T. destructans is one of the most aggressive pathogens causing defoliation of young Eucalyptus trees in tropic regions. Identification of T. destructans to species level is currently not possible based solely on morphological characteristics or ITS sequence data. The aim of this study was to assess T. destructans microsatellites and a newly developed T. epicoccoides microsatellite as a diagnostic tool to differentiate among T. destructans and several closely related foliar pathogens. Based on the number of markers that amplified, the T. destructans microsatellites allowed for the differentiation of T. destructans, T. epicoccoides,T. eucalypti,T. nubilosa,T. pseudoeucalypti and T. viscidus. These microsatellites provide a rapid and cost‐effective diagnostic tool that will enable the identification of a large number of isolates important in disease surveys and inoculation trials.
A critical appraisal on the recurrence of sandalwood spike disease and its management practices
Authors: Mondal Soma , Sundararaj Ramachandran , Yashavantha Rao H. C.
Published: December 2020

Sandal (Santalum album) is an important forest tree that has been utilized for centuries, valued for its wood and scented essential oil derived from the heartwood. Sandalwood spike disease (SSD) is one of the most destructive problems that affect Indian sandalwood. In 1969, three research groups confirmed that the causal agent of SSD was a phytoplasma. Although research literature on sandalwood spike disease has been published for over a century, many earlier publications reported only primarily descriptive macro‐morphological data. Identification of the causal agent was confirmed only recently, using nested PCR of 16S rRNA‐encoding gene sequences and restriction fragment length polymorphism (RFLP) analysis. The identified phytoplasma exhibited high sequence similarity to the aster yellows subgroup 16SrI‐B in NCBI BLAST search. The use of tissue culture in transgenic and disease‐free cloning strategies to produce disease‐resistant sandalwood tress might be the most realistic solution for SSD. The aim of this review is to increase understanding of SSD among phytopathologists in order to encourage research on SSD to discover best management practices. The increased cultivation of sandalwood plantations has significant importance, and it is essential to review the status of SSD.
L2 learners' language attitudes and their assessment
Authors: Artamonova Tatiana
Published: December 2020

This article describes the development of a new questionnaire for assessing L2 learners' language attitudes. Drawing on theoretical work in the fields of social psychology and applied linguistics, the author reviewed the concept of (language) attitudes and contrasted them with the concept of (language) motivation. This thorough literature review, including an examination of the currently available instruments, resulted in the generation of question items for the new questionnaire. The empirical part of the project consisted of data collection and analyses to establish the internal structure of the proposed instrument and to assess its reliability. The new Language Attitudes Questionnaire for Language Learners was found psychometrically sound and easily interpretable.
Non‐KIR NK cell receptors: Role in transplantation of allogeneic haematopoietic stem cells
Authors: Bogunia‐Kubik Katarzyna , Łacina Piotr
Published: December 2020

Natural killer (NK) cells are of major significance in patients after allogeneic haematopoietic stem cell transplantation (HSCT). They are the first subset of lymphocytes to appear in peripheral blood after transplantation and play an important role in the immune responses against cancer and viral infections. The function of NK cells is controlled by various surface receptors, of which type I integral proteins with immunoglobulin‐like domains (killer‐cell immunoglobulin‐like receptors, KIRs) have been the most extensively studied. The present review focuses on less studied NK cell receptors, such as type II integral proteins with lectin‐like domains (CD94/NKG2, NKG2D), natural cytotoxicity receptors (NCRs), immunoglobulin‐like transcripts (ILTs) and their ligands. Their potential role in patients with haematological disorders subjected to HSC transplant procedure in the context of post‐transplant complications such as viral reactivation and acute graft‐versus‐host disease (GvHD) will be presented and discussed.
Parkinson’s disease and skin cancer in Korean patients
Authors: Cardoso J.C.
Published: December 2020

Linked article: H.J. Ryu et al. J Eur Acad Dermatol Venereol 2020; 34: 2775–2780. https://doi.org/10.1111/jdv.16462.
Psychotrauma and the skin
Authors: Szabó C.
Published: December 2020

Linked article: S. Gielen et al. J Eur Acad Dermatol Venereol 2020; 34: 2877–2883. https://doi.org/10.1111/jdv.16828
Regional high‐T/low‐P metamorphism of the Kemum Basement High, Bird’s Head, West Papua, Indonesia
Authors: Jost Benjamin M. , Webb Max , White Lloyd T. , Tiranda Herwin
Published: December 2020

The northernmost part of the Australian continent is exposed in a basement high in the Bird's Head Peninsula at the NW tip of New Guinea. This basement consists of Silurian–Devonian turbidites that were regionally metamorphosed in the lower greenschist facies. Along its eastern margin, the basement high is intruded by numerous granitoid bodies and records a second, higher‐grade metamorphic overprint. We present the first detailed study of metamorphic rocks from this eastern part of the basement high, supported by field and petrographic observations, bulk rock and mineral chemistry, and phase equilibria modelling. Lower‐grade basement rocks include chlorite‐mica schists, slates, silt‐, and sandstones, which give way to andalusite‐ and cordierite‐bearing pelites and psammites, interspersed with layers of quartzite. The dominating pelitic phase assemblage is biotite+white mica±andalusite±cordierite+plagioclase+quartz+ilmenite; incipient sillimanite (fibrolite) is present in some rocks and replaces andalusite in baked margins around the numerous dykes and sills. Other rock types include metasedimentary migmatites, metacarbonates and calcsilicate concretions, rare metavolcanics, and kyanite‐bearing segregation veins. Metamorphism is of regional extent and often unrelated to granitoid intrusions. Our observations support the previous notion of an increase in peak metamorphic temperature from west to east. Microstructural relations suggest two phases of metamorphism, which are tentatively correlated with two phases of magmatic activity in the Devonian–Carboniferous and the Permian–Triassic. Based on petrographic observations and phase equilibria modelling, we propose that during the Permian–Triassic, metamorphism proceeded under high temperature/low pressure (HT/LP) or Abukuma‐type conditions along a narrow, counter‐clockwise P–T–t path with peak metamorphic conditions of the amphibolite facies (~520–650°C and ~2–4 kbar), potentially in an active continental margin setting. While much less evidence is available, similar metamorphic conditions are proposed for the Devonian–Carboniferous metamorphic event.
Contrasting trends in gray seal (Halichoerus grypus) pup production throughout the increasing northwest Atlantic metapopulation
Authors: den Heyer Cornelia E. , Bowen W. Don , Dale Julian , Gosselin Jean‐François , Hammill Michael O. , Johnston David W. , Lang Shelley L. C. , Murray Kimberly T. , Stenson Garry B. , Wood Stephanie A.
Published: December 2020

The northwest Atlantic subspecies of gray seal (Halicheorus grypus grypus) has been increasing for more than a half century and has reestablished breeding colonies in Canadian and US waters. In 2016, visual, oblique, and vertical large‐format digital photographic surveys were conducted at all known breeding colonies in the northwest Atlantic. Total pup production in the northwest Atlantic was estimated to be 109,000 (SE= 17,500) pups. At 87,500 (SE= 15,100) pups, Sable Island accounts for 80% of total pup production. Regional differences in pup production trends are evident. Pup production in the Gulf of St. Lawrence and along the eastern shore of Nova Scotia has been relatively stable. Since 2004, the rate of increase in pup production at Sable Island has slowed to about 5%–7% per year, while the newer colonies in southwest Nova Scotia and the northeastern United States are increasing rapidly. In 2016, the Muskeget Island (MA) breeding colony produced 3,900 (SE= 200) pups, making it the third largest breeding colony in the northwest Atlantic. This southward shift in production may reflect climate‐mediated changes in population growth as well as reestablishment of colonies throughout the former range associated with increased protection.
Short‐term efficacy of vacuum‐formed maintainer for deciduous second molar space maintenance in the mixed dentition: A single‐centre, randomized controlled clinical trial
Authors: Barros Sérgio Estelita , Siqueira Simone Pinheiro , Janson Guilherme , Chiqueto Kelly
Published: December 2020

Objective

To compare the efficacy of vacuum‐formed and banded space maintainers for deciduous second molar space maintenance during the mixed dentition.

Setting and Sample Population

The study sample comprised thirty children in the mixed dentition (age range, 5.9 to 9.8 years) with early loss of at least one deciduous second molar.

Methods

This was a parallel‐group, randomized, active‐controlled clinical trial. Patients were randomly allocated to space maintenance performed with vacuum‐formed or banded space maintainers with a 1:1 allocation ratio. The main outcome was any change in mesiodistal width of the extraction space. Secondary outcomes included the lingual rolling or axial rotation of the permanent first molar adjacent to the extraction site and extrusion of the antagonist tooth. Dental casts were obtained before appliance installation (T0), after 3 months (T1) and after 6 months (T2). Digital dental casts were measured using Dolphin 3D software. Chi‐square, t test or Mann‐Whitney and ANOVA or Friedman test were used for intra‐ and intergroup comparisons (P < .05).

Results

Baseline characteristics were similar between groups except for chronological age. Statistically, but not clinically significant space loss (mean, 0.32 mm; SD, ± 0.39) occurred with the vacuum‐formed space maintainer only at the first trimester (T0‐T1). Lingual rolling and axial rotation of the first permanent molar were not significant, as well as extrusion of the antagonist tooth.

Conclusions

The results of this study suggested that both tested devices were effective in maintaining space after early extraction of the deciduous second molar over a period of 6 months.
Up‐regulation of hsa‐miR‐221‐3p induced by UVB affects proliferation and apoptosis of keratinocytes via Bcl‐xL/Bax pathway
Authors: Tu Yunhua , Wu Wenjuan , Guo Yanni , Lu Fengyan , Li Xing , Xu Dan , Zou Dandan , Tu Ying , Chai Yanjie , He Li
Published: December 2020

Background

Chronic actinic dermatitis (CAD) is a photoallergic skin disease with abnormal hyperplasia. At present, the mechanism of abnormal proliferation is not clear.

Objective

To explore possible mechanism of CAD proliferative lesions.

Methods

Immunohistochemistry (IHC) assay and small RNA sequencing were carried out. Quantitative real‐time PCR (qRT‐PCR) analysis was performed to evaluate expression levels of hsa‐miR‐221‐3p and FOS. The interaction between hsa‐miR‐221‐3p and FOS was identified by dual‐luciferase reporter assay. Expression of hsa‐miR‐221‐3p also was detected by qRT‐PCR after UVB irradiation. Influences of hsa‐miR‐221‐3p and FOS on cell viability and apoptosis were assessed through a series of functional experiments and rescue experiments. Western blot analysis was used to detect protein expression of fos, Bax, Bcl‐xL, and caspase‐3.

Results

Patients with CAD had marked epidermal hyperplasia. The expression of hsa‐miR‐221‐3p was up‐regulated in CAD while FOS was significantly down‐regulated. Dual‐luciferase reporter assay confirmed that hsa‐miR‐221‐3p targeted FOS 3'UTR. Hsa‐miR‐221‐3p induced by UVB ranged from 0 to 30 mJ. Moreover, hsa‐miR‐221‐3p overexpression or FOS knockdown promoted cell proliferation and reduced cell apoptosis. Western blot showed that hsa‐miR‐221‐3p negatively regulated fos, which regulated Bcl‐xL/Bax. Cell proliferation caused by hsa‐miR‐221‐3p overexpression or FOS knockdown could be reversed by Bcl‐xL inhibitor.

Conclusion

Hsa‐miR‐221‐3p induced by UVB targeted FOS 3′UTR, which played an important role in regulating proliferation and apoptosis of keratinocytes via Bcl‐xL/Bax pathway; this may provide a new insight for CAD proliferative lesions.
Savor the moment: Willful increase in positive emotion and the persistence of this effect across time
Authors: Wilson Kayla A. , MacNamara Annmarie
Published: December 2020

Savoring is an emotion regulation technique that aims to increase, sustain, and deepen positive emotion. It has been incorporated into several novel, “positive affect” interventions for anxiety, depression, and chronic pain, but has not been studied in a laboratory setting. As such, it is unknown whether savoring can modulate subjective and neural correlates of emotion‐processing and whether savoring might exert a persistent effect on stimulus processing (i.e., modulating response at subsequent encounter). Here, 49 participants savored or viewed positive and neutral pictures, before seeing the same pictures again approximately 20 min later without instructions to savor (or view) pictures. Subjective valence and arousal ratings and the picture‐elicited late positive potential (LPP) were assessed during both tasks. Results showed that savoring increased participant ratings of picture pleasantness and arousal as well as a picture‐elicited LPP. Moreover, pictures that had previously been savored continued to elicit higher ratings during the subsequent picture viewing task. A larger LPP was observed for previously savored positive and neutral pictures during an early portion of picture viewing; later on during picture viewing, this effect was limited to positive pictures only (i.e., it was not evident for neutral pictures). Results validate savoring as an effective and durable means of increasing positive emotion and are discussed in the context of a broader emotion regulation literature, which has primarily examined the downregulation of negative picture processing.
Closing the Gap or Widening the Divide: The Impacts of Technology‐Enabled Coproduction on Equity in Public Service Delivery
Authors: Xu Corey Kewei , Tang Tian
Published: December 2020

This article investigates how 311 systems affect distributional equity in public service delivery. Many local governments in the United States have adopted interactive 311 platforms to engage citizens in coproduction. Using a novel household‐level data set on 311 service requests and power service restoration in the City of Tallahassee, Florida, after Hurricane Michael in 2018, the authors examine possible disparities between racial minority groups and nonminorities in making power service restoration requests via 311. The article further analyzes how coproduction participation through 311 affects distributional equity in power restoration. The findings show that minority groups are more likely to utilize these smart technologies to submit requests for essential services after disasters, as they may have greater needs but less political capital to reach out to the government. Their utilization of e‐governance technologies has helped them gain more attention from the government, which narrows the equity gap in service delivery.
The silence of the donkeys: Sensorial entanglements between people and animals at Willowra and beyond
Authors: Vaarzon‐Morel Petronella
Published: December 2020

An indelible memory of visitors to Willowra Aboriginal community in Central Australia is the sound of donkeys braying as they roam the village in search of sustenance and are chased by barking dogs. While Warlpiri people view donkeys as an integral part of their sonic landscape, outsiders typically perceive the animals as a noisy, land‐management ‘pest’ and want them removed. Recently, the arrival of a stranger in a truck towing a donkey trailer provoked concerned discussion. Talk intensified when, for a few days, the donkeys disappeared, and the silence of the donkeys echoed throughout the community. Tracing emergent social relations and mimetic connections that entangle donkeys and people in the Willowra region, this paper explores why donkeys matter to local Warlpiri, sensorially and otherwise. I contrast Warlpiri coexistence with donkeys to the treatment of donkeys by conservationists as feral animal and by capitalists as commodity. Linking the silence of donkeys at Willowra to the global trade in ejiao, a glue made from donkey hides used in Chinese medicine and cosmetics, I engage with Michael Taussig's (2019) ‘The cry of the burro [donkey]’ to examine differing senses of being and predicaments that the sound of donkeys evoke cross‐culturally. I conclude with a call to listen differently to other‐than‐human beings when considering multispecies assemblages. Attending to the sonic range of donkeys as an expression of their agency, I suggest that we learn from Warlpiri and heed the cries of donkeys and their global silencing if we are to ensure our mutual survival.
Implementation of VRML/Java Web-Based Animation and Communications for the Next Generation Inspection System (NGIS) Real-Time Controller
Authors: Shackleford William , Stouffer Keith
Published: December 2020

The Next Generation Inspection System (NGIS) project is a testbed that consists of a Cordax Coordinate Measuring Machine (CMM), advanced sensors, and the National Institute of Standards and Technology (NIST) Real-Time Control System (RCS) open architecture controller. The RCS controller permits real-time processing of sensor data for feedback control of the inspection probe. The open architecture controller permits external access to internal data, such as the current position of the probe. A remote access web site was developed to access this data to drive a Virtual Reality Modeling Language (VRML) * model of the Cordax CMM. The remote access web site contains a client-controlled pan/tilt/zoom camera which sends video to the client as well as the VRML 3D model of the CMM that is controlled by the NGIS controller located at NIST. This remote access web site allows a client to monitor a remote inspection with a PC and an internet connection.
XML Based Markup Languages for Knowledge Management in Manufacturing Companies
Authors: Veeramani Dharmaraj , Garikapati Ramarao
Published: December 2020

The manufacturing industry is facing many new challenges including redefined customer expectations in the E-Commerce era. The consumer is now better informed, more demanding and has higher expectations in terms of product features, product performance and service. To respond to these expectations companies are seeking to leverage the collective experience of the organization and the consequent knowledge gained to deliver improved performance in product and service. However, some fundamental issues pertaining to formal and unambiguous definition of terms and semantics of the information to be stored and retrieved need to be addressed in the manufacturing industry to fully leverage Intranet enabled knowledge management. The formalization of such unambiguous vocabularies can be achieved through the construction of Industry Specific Markup Languages (ISMLs). In this paper, we present XML based ISMLs, Machining Markup Language (MML) and Foundry Markup Language (FML) for the machining and foundry industries respectively and illustrate proof-of-concept knowledge management applications or TOMEs (Treasury for manufacturing Experience) that use the ISMLs as the underlying data models.
Mapping the Product Development Process to Information Technology Solutions Through Use Models
Authors: Whitney Daniel E. , Patil Samir
Published: December 2020

Product development, especially the design of large complex systems, is a special type of business process. What makes it special is the highly coupled nature of design decisions and the large size of product development teams. It is not unusual to have several hundred multi-disciplinary members taking millions of design decisions over the life of the project. From the Information Technology (IT) perspective, the special nature of design presents a challenge of coordinating the interdependent tasks of the team and integrating them. This paper explores the role of IT, specifically software tools, in improving the product development process through a framework that better represents and captures design knowledge. In order to overcome the limitations of the current implementations, the concept of “Use models” is developed. A use model consists of the methods, tools, and a map of the design process. This map is in the form of a design structure matrix (DSM) that represents tasks and relationship knowledge at a system level. By combining a detailed process view with tools and methods, the Use model creates a better IT representation of the product development process.
Product Model Definition Support for Knowledge Aided Engineering Applications Development
Authors: Ferruccio Mandorli , Monica Bordegoni
Published: December 2020

This paper addresses applications developed for supporting design/production activities that are tailored on a specific product. Currently, these applications are developed coding the engineer’s knowledge captured by the system developer into the product model. Minimizing the programming skill required in current systems for knowledge capturing would allow the designers themselves to directly insert knowledge into the system. In order to allow that, we see two ways: providing “design by example” systems, or providing appropriate graphical user interfaces for the systems. The objective of this work is to demonstrate that visual user interfaces can be used as the key to integrate and customize knowledge aided engineering (KAE) applications.

In order to demonstrate this idea we have developed a prototype of an interactive visual interface integrated within a KAE system. The approach has proved to be efficient for the development of product dependent systems and for engineers’ knowledge capture, in respect to systems based on programming languages.
A Fuzzy-Based Optimal Delivery Scheduling Approach
Authors: Wang H. , Xue D. , Norrie D. H.
Published: December 2020

A fuzzy-based optimal delivery scheduling approach is introduced in this research. In this approach, optimal delivery scheduling is conducted at three different levels considering (1) one driver and one load, (2) one driver and multiple loads, and, (3) multiple drivers and multiple loads. Fuzzy-based clustering methods are employed to classify delivery tasks into driver groups, load groups, and location groups. The optimal sequence and timing parameters of the delivery tasks are identified using the fuzzy-based clustering results and state-space search. The intelligent optimal delivery scheduling system was implemented using Smalltalk.
Modeling Concurrent Product and Process Design Using a Game Theoretic Team Approach
Authors: Chen Li , Li Simon
Published: December 2020

A satisfaction-driven game theoretic approach is developed with application to team-based concurrent product and process design (CPPD). This team approach for CPPD is based upon optimization formalism in which the design team is responsible to optimize overall product functionality (or performance) and the manufacture team pursues to minimize total manufacturing cost. This dual-team model characterizes the respective aspects of product design and process design. In particular, the preference of each team against a design configuration is characterized through the application of fuzzy set theory, whereby the method of Design for Satisfaction (DfS) can be applied to seek the most favorite design that best fulfills the team goal. Based on the strategic team paradigms derived from game theory, fuzzy set operators are used to aggregate satisfaction metrics of two teams. As a result, three team design models plus related algorithms are developed to reveal typical team interactions in the context of design computations. An illustrative example is worked out to demonstrate the satisfaction-driven team design models.
Exploring the Effectiveness of Various Patterns in an Extended Pattern Search Layout Algorithm
Authors: Yin Su , Cagan Jonathan
Published: December 2020

Automated synthesis of product layout has the potential of substantially reducing design cycle time while allowing for quick check of interference, clearance, scale and fit prior to the building of physical prototypes. The search for optimal positions and orientations of parts in the layout typically requires a huge number of iterations. An extended pattern search layout algorithm based on coordinate search was introduced in an earlier paper and shown one-to-two orders of magnitude improvement in speed over a robust simulated annealing-based layout algorithm. Coordinate search is a simple and straightforward way of implementing the pattern search method in the layout problem. However, it is not taking advantage of the wide variety of heuristics admissible in pattern search methods for identifying promising search directions. By introducing various search patterns and exploring their effectiveness in the layout problem, we will address the question of whether complex tactics can do better than the basic coordinate pattern search. We present in this paper four different heuristics for generating pattern directions in the extended pattern search layout algorithm: the conjugate direction method, the modified gradient method, the rank ordering method, and the simplex method. These heuristics are utilized to identify promising search directions and update the set of pattern directions used in the algorithm over iterations. The performance of the different heuristics is compared to that of the basic coordinate pattern search layout approach.
A Most Probable Point Based Method for Uncertainty Analysis
Authors: Du Xiaoping , Chen Wei
Published: December 2020

Uncertainty is inevitable at every stage of the life cycle development of a product. To make use of probabilistic information and to make reliable decisions by incorporating decision maker’s risk attitude under uncertainty, methods for propagating the effect of uncertainty are therefore needed. When designing complex systems, the efficiency of methods for uncertainty analysis becomes critical. In this paper, a most probable point (MPP) based uncertainty analysis (MPPUA) method is proposed. The concept of the MPP is utilized to generate the cumulative distribution function (CDF) of a system output by evaluating the probability estimates at a serial of limit states. To improve the efficiency of locating the MPP, a novel MPP search algorithm is presented that employs a set of searching strategies, including evaluating derivatives to direct a search, tracing the MPP locus, and predicting the initial point for MPP search. A mathematical example and the Pratt & Whitney (PW) engine design are used to verify the effectiveness of the proposed method. With the MPPUA method, the probabilistic distribution of a system output can be generated across the whole range of its performance.
Topology Optimization of Structures With Geometrical Nonlinearities
Authors: Luo Jian Hui , Gea Hae Chang
Published: December 2020

In this paper, the stiffness optimization problem is investigated for structures with geometrical nonlinearities. The mean compliance of the structure is chosen as the objective function and its sensitivities are derived using the adjoint method. The optimal problem is formulated using a microstructure-based design domain method and is solved iteratively by a sequential convex approximation method. Three numerical examples are presented to show the applications of the proposed method and the results demonstrate that the geometrically nonlinear finite element analysis is indispensable to the optimization process of large displacement structures.
A Real-Time, Interactive Method for Fast Modification of Large-Scale CAE Mesh Models
Authors: Chen Yifan , Stewart Paul , Buttolo Pietro , Ren Feng
Published: December 2020

An interactive mesh manipulation method is presented. Utilizing a Direct Surface Manipulation technique, the tool allows the user to define a specific region on an existing mesh model and modify the vertices within this region. Specific mathematical functions are applied to allow direct, precise, and coordinated modification of the vertices. The method was implemented on a prototype interactive graphics system and has demonstrated the capability to allow quick modification of large-scale automotive CAE models. One important benefit of the tool is to significantly shorten the time needed to perform CAE-based Design of Experiments (DoE), where a series of slightly different CAE mesh models must be generated in search for optimum design parameters.
Tube Production and Assembly Systems: The Impact of Compliance and Variability on Yield
Authors: Wei Yu-Feng , Thornton Anna C.
Published: December 2020

Variation modeling is used in design to predict and diagnose potential quality problems. Most variation modeling assumes the parts are rigidly assembled. However, in some cases, this assumption is invalid. For example, when hydraulic tubes are assembled into aircraft structures, the compliance of the tube facilitates assembly. If the tubes were rigid, they cannot be assembled, i.e., the variations of the tubes and structures are too great. Despite the importance of compliance in assembly, it is typically not explicitly modeled during design. This paper proposes a new method to directly predict the assemblability of any tube design with minimal dependence CAD/FEM modeling and simulation. The model includes a variation model for the tubes and aircraft, compliance model and assembly model. It can be used during design to improve yields.
Algorithms for Design and Interrogation of Functionally Gradient Material Objects
Authors: Liu Hongye , Cho Wonjoon , Jackson Todd R. , Patrikalakis Nicholas M. , Sachs Emanuel M.
Published: December 2020

Solid Freeform Fabrication (SFF) processes have demonstrated the ability to produce parts with locally controlled composition. In the limit, processes such as Three-Dimensional Printing(3DP) can create parts with composition to the length scale of 100 μm. To exploit this potential, new methods for automatic design of Functionally Gradient Material (FGM) parts need to be developed. This paper presents an efficient method for design and composition interrogation of FGM solids. The design tool based on the distance function from the surface of the part requires enhanced efficiency, and so does the interrogation of the part. The approach for improving efficiency includes preprocessing the model with bucket sorting and 3D digital distance transform, and an efficient point classification algorithm. Based on these tools, an efficient algorithm for distance function computation is developed for the design of FGM through distance to the surface of the part or distance to an .STL surface boundary. An efficient algorithm to evaluate composition at a point, along a ray or on a plane is also presented.
A Hybrid Genetic-Direct Search Algorithm for the Shape Optimization of Solid C-Frame Cross-Sections
Authors: Nassef Ashraf O. , Hegazi Hesham A. , Metwalli Sayed M.
Published: December 2020

The hybridization of different optimization methods have been used to find the optimum solution of design problems. While random search techniques, such as genetic algorithms and simulated annealing, have a high probability of achieving global optimality, they usually arrive at a near optimal solution due to their random nature. On the other hand direct search methods are efficient optimization techniques but linger in local minima if the objective function is multi-modal. This paper presents the optimization of C-frame cross-section using a hybrid optimization algorithm. Real coded genetic algorithms are used as a random search method, while Nelder-Mead is used as a direct search method, where the result of the genetic algorithm search is used as the starting point of direct search. Traditionally, the cross-section of C-frame belonged to a set of primitive shapes, which included I, T, trapezoidal, circular and rectangular sections. The cross-sectional shape is represented by a non-uniform rational B-Splines (NURBS) in order to give it a kind of shape flexibility. The results showed that the use of Nelder-Mead with Real coded Genetic Algorithms has been very significant in improving the optimum shape of a solid C-frame cross-section subjected to a combined tension and bending stresses. The hybrid optimization method could be extended to more complex shape optimization problems.
Surface Registration and Integration in a Reverse Engineering System for Rapid Manufacturing
Authors: Li L. , Schemenauer N. , Peng X. , Zeng Y. , Gu P.
Published: December 2020

Three-dimensional data acquisition, surface registration and integration as well as subsequent rapid manufacturing are important processes in reverse engineering. This paper describes a reverse engineering system for rapid manufacturing of complex objects. The system consists of a three-dimensional digitizer (3D Optical Digitizing System), surface reconstruction software and a rapid prototyping machine. The surface reconstruction software has three major components: 1) range view registration by an iterative closed-form solution, which uses Binary Space Partitioning (BSP) tree to accelerate computation; 2) range surface integration by reconstructing an implicit function to update the volumetric grid; and 3) iso-surface extraction by a Marching Cubes algorithm. The surface reconstruction software exports models in STL format for rapid prototyping. A FDM 2000 machine is used to manufacture products. Examples are included to illustrate the systems and the methods.
“Intelligent” Optimal Design of Woven Composites
Authors: Zarka Joseph , Doux Thierry
Published: December 2020

By the coupling of the existing knowledge of experts, the numerical results and the experimental data with the help of some special automatic learning and optimization techniques, it is now possible to propose a very simple tool to design materials. The purpose of this paper is to show its particular application to the very difficult design of woven composites where it is necessary to adjust the mechanical properties, the electromagnetic properties and taking care of the price too.
Intelligent Optimal Design of a Beam During the Crash
Authors: Zarka Joseph , Navidi Pirouz
Published: December 2020

We consider the optimal design of a beam. To improve the safety of a car during the crash, it is needed to dissipate the maximum of energy within a limited displacement but with a limited acceleration at the level of the driver/passengers. The beam may have different complex cells linked with continuous or spot solders. In a special office, they have to design a beam. In Germany, in United Kingdom, and also inside all the automotive industries, dedicated centers to test such beams were created. Other centers have developped numerical simulations. Usually, for each family of beams, a Design of Experiments is performed.

It is necessary to find its optimal design. Until now, this was not possible, as the CRASH is a very complex problem and the tests or numerical simulations are too expensive to allow the succssive iterations.
Design Synthesis of Path Generating Compliant Mechanisms by Evolutionary Optimization of Topology and Shape
Authors: Tai Kang , Cui Guang Yu , Ray Tapabrata
Published: December 2020

This work demonstrates the successful synthesis of path generating compliant mechanisms by the process of topology and shape design optimization. As geometric topology variation of continuum structures is difficult to treat and analysis of the displacement path or trajectory of such structures is computationally intensive, a highly effective and efficient optimization methodology is needed. This paper describes the use of a recently developed morphological geometric representation scheme coupled with an evolutionary algorithm to synthesize the mechanism. The scheme uses arrangements of skeleton and ‘flesh’ to define structural geometry, which facilitates transmission of topological/shape characteristics across generations in the evolutionary process and will not render any geometrically invalid designs. The evolutionary algorithm solves the problem as a discrete optimization problem, with a proficient constraint handling capability.
Edge Detection in Reverse Engineering Using a Virtual CMM
Authors: Schreve K. , Basson A. H.
Published: December 2020

This paper describes a method to reconstruct edges, i.e. the intersection curves of adjacent non-tangent surfaces, from point clouds. The method is quick, easy to use and provides accurate results. It does not rely on extending surface patches that were individually fitted to the segments of the point data. Only edges of C1 discontinuity and C0 continuity are considered. The method samples the point cloud by simulating a co-ordinate measurement machine (CMM). The edge detection procedure is semi-automatic and only requires a few simple inputs from the user. The technique can also be implemented as a measurement strategy on a CMM.
Evaluating Manufacturing and Assembly Errors in Rotating Machinery to Enhance Component Performance
Authors: Tumer Irem Y. , Huff Edward M.
Published: December 2020

Manufacturing and assembly phases play a crucial role in providing products that meet the strict functional specifications associated with rotating machinery components. The errors resulting during the production of such components are correlated with the vibration and noise emanating from the final system during its operational lifetime. Vibration and noise are especially unacceptable elements in high-risk systems such as helicopters, resulting in premature component degradation and an unsafe flying environment. In such applications, individual components often are subject to 100% inspection following production, as well as during operation through rigorous maintenance, resulting in increased product development cycles and high production and operation costs. In this work, we focus on providing designers and manufacturing engineers with a technique to evaluate vibration modes and levels for each component or subsystem prior to putting them into operation. This paper presents a preliminary investigation of the correlation between manufacturing and assembly errors and vibrations, using an experimental test rig. A factorial design is used to study the effects of: 1) different manufacturing instances; 2) different assembly instances; and, 3) varying shaft speeds. The results indicate a correlation between manufacturing or assembly errors and vibrations measured from accelerometers. Challenges in developing a tool for design and manufacturing engineers are identified, followed by a discussion of future work.
Flexible Design Methodology
Authors: Roser Christoph , Kazmer David
Published: December 2020

A flexible design methodology is developed to minimize the effect of uncontrolled variation by modeling potential design and manufacturing corrections in the product development process. Using this flexibility methodology, the different defect modes and the likelihood of these defects occurring is evaluated. For every defect mode, all design change options are investigated including the cost and probability of selection. The expected cost of the initial design including design changes is determined, thus allowing development of improved, more flexible designs. The theoretical method is demonstrated using an example. The results indicate that small changes in design variables may reduce the likelihood and cost of future design changes, yet provide opportunity for downstream cost minimization.
Computing Exact Global Accessibility Cones for Polyhedral Objects
Authors: Dhaliwal Savinder , Gupta Satyandra K. , Huang Jim
Published: December 2020

This paper describes an algorithm for computing exact global accessibility cones for various faces (i.e., the set of directions from which various faces are accessible) of a polyhedral object. In contrast to previously published algorithms that compute approximate global accessibility cones for a face by sampling a set of discrete points from the face, the algorithm presented in this paper computes the exact global accessibility cones. In this paper, we describe exact mathematical conditions and the associated procedure for determining the set of directions from which a planar face with triangular boundary is inaccessible due to another face in the object. By utilizing the procedure to compute the exact inaccessibility region for a face, we present an algorithm for computing global accessibility cones for various faces in the object. These global accessibility cones are represented in a convenient matrix and can be used to support a wide variety of accessibility queries for the object.
Do-It-Right-First-Time (DRFT) Approach to Design Structure Matrix (DSM) Restructuring
Authors: Yassine Ali A. , Whitney Daniel E. , Lavine Jerry , Zambito Tony
Published: December 2020

This paper argues, using two real-world applications from the automotive industry, that the biggest benefit of a Design Structure Matrix (DSM) model may come not from resequencing and partitioning, but rather from “rewiring” the process/blocks. “Rewiring” means redefining relationships among elements and/or inserting new elements into the matrix. This requires intimate understanding of the process and cannot be done with application of context-free partitioning algorithms.

The Do-it-Right-First-Time (DRFT) approach to DSM restructuring is another way to look at a DSM by inspecting the sources of iteration within a block and reversing it through inserting a DRFT activity at the beginning of the block. In this way, the traditional Design-Build-Test “Cycle” is reversed into a DRFT-Design-Build “Sequence”. That is, the “wiring diagram” of a process or system overpowers the behavior of the individual nodes, so changing the system requires changing the wiring.
Using Indifference Points in Engineering Decisions
Authors: Scott Michael J. , Antonsson Erik K.
Published: December 2020

Multi-criteria decision support methods are common in engineering design. These methods typically rely on the specification of importance weights to accomplish trade-offs among competing objectives. Such methods can have difficulties, however: they may not be able to select all possible Pareto optima, and the direct specification of importance weights can be arbitrary and ad hoc. The inability to reach all Pareto optima is shown to be surmountable by the consideration of trade-off strategy as an additional parameter of a decision. The use of indifference points to select a best solution, as an alternative to direct specification of importance weights, is presented, and a simple truss design example is used to illustrate the concepts.
Closed Form Solutions for Connectivity and Connectivity of Motion in Mechanisms
Authors: Kohli D. , Razmara N. , Dhingra A. K.
Published: December 2020

This paper presents a closed form solution for determining connectivity between any two links in mechanism. The formulation is based on graph theory and its modification. The proposed approach could be applied to both planar and spatial mechanisms including combined planar-spatial mechanisms. Further, the mechanism may have multiple closed loops and/or open-chain substructures. A new concept of Connectivity of Motion has been introduced to determine the connectivity between any two links when the mechanism under consideration has special arrangement of adjacent joints such as joints with parallel and/or intersecting axes. Four examples are presented to illustrate connectivity calculations in spatial mechanisms.
Application of Instantaneous Invariants to the Synthesis of Linkages
Authors: Shyu Jenq-Huey
Published: December 2020

This paper presents the development of an efficient synthesis technique to synthesize planar triads and six-link mechanisms satisfying the prescribed instantaneous motions, by using the method of instantaneous invariants. The application of planar path curvature theory is extended to the synthesis of planar triads. A complete classification of planar triads is presented. Different synthesis applications of planar six-link mechanisms are discussed, and their design procedures are stated in detail.
Kinematic Synthesis of Binary Actuated Mechanisms for Rigid Body Guidance
Authors: Hanchak Michael S. , Murray Andrew P.
Published: December 2020

This paper presents a method for designing mechanisms composed of Revolute-Binary state prismatic-Revolute (RBR) chains for rigid body guidance. Where a prismatic joint allows for any distance between two revolute joints, a binary state prismatic joint reaches two distances precisely. A single RBR chain can be designed to reach six positions. A parallel arrangement of three RBR chains can be assembled at the six positions but, in general, is not a viable kinematic solution. By requiring the arrangement of three RBR chains to share specific fixed and moving pivots, called an N-type arrangement, four positions are reachable. Further, the design space is quickly searchable for singularity-free solutions. Examples illustrate a solution to a four position synthesis problem and a ten position problem using a serial assembly of these mechanisms.
Dynamics of a Piezoelectrically Actuated Vibratory Feeder
Authors: Chang Shuo Hung , Yang T. W.
Published: December 2020

This paper presents the development of a vibratory parts feeder driven by piezoelectric bimorph actuators. Mathematical models to describe dynamic behaviors of the piezoelectric bimorph actuator, vibratory parts feeder, and kinematics of the moving parts are formulated and numerically solved. Design factors such as the vibration amplitude, vibration frequency and vibration angle that affect the performance of the parts feeder is quantitatively investigated. Operating at the resonant vibration, the developed vibratory parts feeder achieves a high operating frequency and fine feed steps.
The Optimum Quality Index for a Spatial Redundant 8-8 In-Parallel Manipulator
Authors: Zhang Yu , Duffy Joseph , Crane Carl D.
Published: December 2020

The quality index for a redundant 4-4 in-parallel manipulator with a square platform and a square base was obtained in [1]. Following this, the quality index for a redundant 4-8 manipulator with a square platform and an octagonal base was determined in [2]. In this paper the optimal quality index for a redundant 8-8 manipulator is determined. The device has an octagonal platform and a similar octagonal base connected by eight legs. The quality index is defined as a dimensionless ratio which takes a maximum value of 1 at a central symmetrical configuration that is shown to correspond to the maximum value of the square root of the determinant of the product of the manipulator Jacobian by its transpose. The Jacobian matrix is none other than the normalized coordinates of the eight leg lines. It is shown that the quality index can be used as a constructive measure of not only acceptable and optimum design proportions but also an acceptable operating workspace (in the static stability sense). The analysis of the redundant 8-8 manipulator described here can be used to model and design a self-deployable space structure that has a pair of flexible octagonal antenna platforms in the base and top platform.