bluuebunny/crossref_metadata_2025 huggingface dataset:
What Is your PhD Worth? The Value of a PhD for Finding Employment outside of Academia
Authors: Canolle Fabien , Vinot Didier
Published: December 2020

This research investigates the value of a PhD for employment outside academia by showing how PhD holders create it through the help of intermediations during their thesis preparation. We analyse scientific practice through the use of Cultural Historical Activity Theory (CHAT) to better understand PhDs' employment outside academia. With CHAT, intermediation on labour markets is seen via the lens of activity. Using a qualitative methodology, we interviewed 20 students who completed PhDs at the University of Lyon in France and who now work for private companies. Our findings show how the value of these PhDs is shaped both by what they do during thesis and by what they seek to become in their professional careers. We contribute to the literature by providing a new theoretical stance on intermediation in labour markets, and offer reflections for universities across Europe to tailor their PhD programmes.
Imaging the future: the emerging era of single‐cell spatial proteomics
Authors: Paul Indranil , White Carl , Turcinovic Isabella , Emili Andrew
Published: December 2020

The proteome of a human cell is partitioned within organelles, such as the nucleus, and other subcellular compartments, such as the cytoplasm, forming a myriad of membrane‐bound and membrane‐free ultrastructures. This compartmentalization allows discrete biochemical processes to occur efficiently in isolation, with relevant proteins localized to appropriate niches to fulfill their biological function(s). Proper delivery and dynamic exchange of proteins between compartments underlie the regulation of many cellular processes, such as cell signaling, division, and programmed cell death. To this end, cells deploy dedicated trafficking mechanisms to ensure correct protein localization, as mis‐localization can result in pathology. In addition to trafficking, variation in the expression, modification, and physical associations of proteins within and between cells can result in biological heterogeneity, motivating the need for single‐cell measurements. In this review, we introduce diverse platform technologies developed for subcellular proteomics and high‐throughput systems biology, with the aim of providing mechanistic insights into fundamental cell biological processes underlying healthy and diseased states, and valuable public data resources. In contrast to the rapidly advancing field of single‐cell genomics, the single‐cell spatial proteomics toolbox remains in its infancy, but is poised to make considerable advances in the coming years.
The impact of climate change and climate extremes on sugarcane production
Authors: Flack‐Prain Sophie , Shi Liangsheng , Zhu Penghui , da Rocha Humberto R. , Cabral Osvaldo , Hu Shun , Williams Mathew
Published: December 2020

Sugarcane production supports the livelihoods of millions of small‐scale farmers in developing countries, and the bioenergy needs of millions of consumers. Yet, future sugarcane yields remain uncertain due to differences in climate projections, and because the sensitivity of sugarcane ecophysiology to individual climate drivers (i.e. temperature, precipitation, shortwave radiation, VPD and CO2) and their interactions is largely unresolved. Here we ask: how sensitive is sugarcane yield to future climate change, including climate extremes, and what are its key climate drivers? We combine the Soil‐Plant‐Atmosphere model with detailed time‐series measurements from experimental plots in Guangxi, China, and São Paulo State, Brazil. We first calibrated and validated modelled carbon and water cycling against field flux and biometric data. Second, we simulated sugarcane growth under the historical climate (1980–2018), and six future climate projections (2015–2100). We computed the ‘yield‐effect’ of each climate driver by generating synthetic climate forcings in which the driver time series was alternated to that of the historical median. In Guangxi, median yield and yield lows (i.e. lower decile) were relatively insensitive to forecast climate change. In São Paulo, median yield and yield lows decreased under all future climates projections ( = −4% and −12% respectively). At Guangxi, where moisture stress was low, radiation was the principal driver of yield variability (yield‐effect  = −1.2%). Conversely, high moisture stress at São Paulo raised yield sensitivity to temperature (yield‐effect  = −7.9%). In contrast, a number of other modelling studies report a positive effect of increased temperatures on sugarcane yield. We ascribe the disparity between model predictions to the representation of key phenological processes, including the link between leaf ageing and thermal time, and the role of ageing in driving leaf senescence. We highlight climate sensitivity of phenological processes as a key focus for future research efforts.
Factors associated with utilisation of dental services by the elders from São Paulo, Brazil
Authors: Soares Gustavo Hermes , Ortiz‐Rosa Ezequiel , Alves Caroline Paula , Paz Dayanne , An Ki Sung , Pereira Antonio Carlos , Biazevic Maria Gabriela Haye , Frias Antônio Carlos , Michel‐Crosato Edgard
Published: December 2020

Background

Population ageing in Brazil is rapid and is likely to place additional pressure over the Brazilian public health system.

Objective

This study aims to examine the factors associated with utilisation of dental services in the previous year among a representative sample of older adults from São Paulo, Brazil.

Methods

The sample included 5951 older adults who participated in the SBSP‐15 study, an epidemiological survey conducted in 2015 in the State of São Paulo, Brazil. The outcome “utilisation of dental services” was defined as having visited a dentist in the previous year. Chi‐square tests were employed in the bivariate analyses and Poisson regressions with robust variance in the multilevel analysis.

Results

Only 30.5% of the participants had their last dental appointment within the previous year. Number of teeth and dental pain presented the strongest effects on the investigated outcome. Education, income, age, ethnicity, living alone, higher Family Health Strategy coverage and the Metropolitan area were associated with having visited a dentist in the previous year. Older adults who rated their oral health as positive did not report treatment need nor prosthodontic need, presented negative oral health‐related quality of life, had their last dental appointment in the public health system and sought treatment due to pain or extraction also were more likely to report the utilisation of dental services in the previous year.

Conclusion

Regional, sociodemographic and subjective factors are associated with utilisation of dental services in the previous year among the elders from the State of São Paulo, Brazil.
Accessible and affordable healthcare? Views of Australians with and without chronic conditions
Authors: Zurynski Yvonne , Ansell James , Ellis Louise A , Pomare Chiara , Smith Carolynn L , Holt Joanna , Root Jo , Gillespie James , Wells Leanne , Braithwaite Jeffrey
Published: December 2020

Background

With 50% of Australians having chronic disease, health consumer views are an important barometer of the ‘health’ of the healthcare system for system improvement and sustainability.

Aims

To describe the views of Australian health consumers with and without chronic conditions when accessing healthcare.

Methods

A survey of a representative sample of 1024 Australians aged over 18 years, distributed electronically and incorporating standardised questions and questions co‐designed with consumers.

Results

Respondents were aged 18–88 years (432 males, 592 females) representing all states and territories, and rural and urban locations. General practices (84.6%), pharmacies (62.1%) and public hospitals (32.9%) were the most frequently accessed services. Most care was received through face‐to‐face consultations; only 16.5% of respondents accessed care via telehealth. The 605 (59.0%) respondents with chronic conditions were less likely to have private health insurance (50.3% vs 57.9%), more likely to skip doses of prescribed medicines (53.6% vs 28.6%), and miss appointments with doctors (15.3% vs 10.1%) or dentists (52.8% vs 40.4%) because of cost. Among 480 respondents without private health insurance, unaffordability (73.5%) or poor value for money (35.3%) were the most common reasons. Most respondents (87.7%) were confident that they would receive high quality and safe care. However, only 57% of people with chronic conditions were confident that they could afford needed healthcare compared with 71.3% without.

Conclusions

Health consumers, especially those with chronic conditions, identified significant cost barriers to access of healthcare. Equitable access to healthcare must be at the centre of health reform.
Post acne scars treatment ‐ do picosecond lasers offer a superior non‐ablative modality?
Authors: Lepidoth M. , Levi A.
Published: December 2020

Linked article: H.H. Kwon et al. J Eur Acad Dermatol Venereol 2020; 34: 2907–2913. https://doi.org/10.1111/jdv.16643.
Extensive fluid–rock interaction and pressure solution in a UHP fluid pathway recorded by garnetite, Lago di Cignana, Western Alps
Authors: van Schrojenstein Lantman Hugo W. , Scambelluri Marco , Gilio Mattia , Wallis David , Alvaro Matteo
Published: December 2020

This study combines the microstructural and petrological analysis of garnet and its inclusions in quartzite‐hosted garnetite from the ultrahigh‐pressure Lago di Cignana metaophiolite (Western Alps). We present a comprehensive record of metamorphism, compaction, and the state of stress during interaction between oceanic metasediments and infiltrating fluids along a major open‐system fluid pathway. The arrangement of garnet into garnetite layers is attributed to concomitant compaction and dissolution that resulted in the formation of a garnet stylolite. The fluid pulses that were accommodated by this pathway subsequently resulted in several stages of garnet deformation, dissolution, local reprecipitation, and recrystallization. Abundant evidence for pressure solution in garnet, alongside near‐hydrostatic to hydrostatic conditions indicated by elastic strains of quartz inclusions in garnet obtained through Raman spectroscopy, support low differential stresses during fluid–rock interaction. The high degree of dissolution recorded by the garnetite showcases the strong potential for compaction by fluid‐assisted volume loss and mass transfer. Dehydration of subducting rocks with subsequent migration of resulting fluids through the slab provides a mechanism of mass transfer and has the potential to drive compaction and exert control on differential stress along fluid pathways.
The impact of critical incidents on nurses and midwives: A systematic review
Authors: Buhlmann Melanie , Ewens Beverley , Rashidi Amineh
Published: December 2020

Aims

To synthesise the existing literature, which focuses on the impact of critical incidents on nurses and midwives, and to explore their experiences related to the support they received in the current healthcare environment to move on from the event.

Design

Systematic review and qualitative synthesis.

Data sources

The electronic databases CINAHL, MEDLINE, PsycINFO, PubMed, Embase and Nursing and Allied Health (ProQuest) were systematically searched from 2013–2018, and core authors and journals identified in the literature were manually investigated.

Review methods

Qualitative studies of all research design types written in English were included according to the PRISMA reporting guidelines. The methodological quality of included studies was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Qualitative Research.

Results

A total of 7,520 potential publications were identified. After removal of duplicate citations, study selection and appraisal process, 11 qualitative primary research papers progressed to the meta‐synthesis by meta‐aggregation. The 179 findings and sub‐findings from the included studies were extracted, combined and synthesised into three statements addressing three different aspects within the context of critical incidents: the experiences of the impact, the perceptions of support and the ability to move on.

Conclusion

This review illuminated that moving‐on after critical incidents is a complex and wearisome journey for nurses and midwives. More attention should to be drawn to second victims within general nursing and midwifery practice to strengthen their ability to navigate the aftermath of critical incidents and reclaim the professional confidence indispensable to remain in the workforce.
Detection of Cortical and Deep Gray Matter Lesions in Multiple Sclerosis Using DIR and FLAIR at 3T
Authors: Park Charlie C. , Thongkham Dean W. , Sadigh Gelareh , Saindane Amit M. , Chu Renxin , Bakshi Rohit , Allen Jason W. , Hu Ranliang
Published: December 2020

BACKGROUND AND PURPOSE

The comparative detection rates of deep gray matter (GM) multiple sclerosis (MS) lesions using double inversion recovery (DIR) and fluid‐attenuated inversion‐recovery (FLAIR) on 3T MR imaging remain unknown. We aimed to assess the detectability of cortical and deep GM MS lesions using DIR and FLAIR on 3T clinical exams and evaluate the relationship between deep GM lesions and brain atrophy.

METHODS

One hundred fifty consecutive MS patients underwent routine brain MRI that included 3D DIR and 2D T2 FLAIR on the same 3T scanner. Three neuroradiologists independently reviewed all exams for cortical and deep GM lesions. Statistical parametric mapping (SPM) and FMRIB software library (FSL)‐FIRST pipelines were used to determine normalized whole brain and deep GM volumes.

RESULTS

A total of 65 cortical and 98 deep lesions were detected on DIR versus 24 and 20, respectively, on FLAIR. Among all 150 patients, the number and percentage of patients with GM lesions on DIR and FLAIR were as follows: cortical 43 (28.7%) versus 24 (16.0%) (P < .001), thalamus 47 (31.3%) versus 20 (13.3%) (P < .001), putamen 10 (6.7%) versus 3 (2.0%) (P = .02), globus pallidus 9 (6.0%) versus 3 (1.3%) (P = .02), and caudate 5 (3.3%) versus 1 (0.7%) (P = .125). Presence of deep GM lesions weakly correlated with deep GM volume fractions.

CONCLUSION

Deep GM MS lesions can be detected using routine clinical brain MRI including DIR and FLAIR at 3T. Future studies to optimize these sequences may improve the detection rates of cortical and deep GM lesions. The presence of GM lesions showed weak correlation with GM atrophy.
The gastro‐sphincteric pressure gradient: A new parameter to diagnose a rumination episode
Authors: Geysen Hannelore , Michielsen Siebe , Rommel Nathalie , Vanuytsel Tim , Tack Jan , Pauwels Ans
Published: December 2020

Background

Rumination is defined as the repetitive, effortless regurgitation of recently ingested food into the mouth. These episodes are preceded by a rise in intragastric pressure (IGP) and mainly occur postprandially. IGP peaks >30 mmHg have been proposed as a cutoff to differentiate rumination from reflux events. In clinical practice, we observed that this cutoff, which does not consider esophagogastric junction (EGJ) resistance, is not always reached.

Methods

We studied 27 patients with rumination syndrome [age: 43.6, 59% female] and 28 gastro‐esophageal reflux disease patients [age: 45.9, 54% female]. For each rumination episode, reflux event, transient lower esophageal sphincter relaxation (TLESR), or straining without regurgitation, the following parameters were registered: maximal IGP, IGP, and EGJ pressure preceding the respective episodes. We also quantified the gastro‐sphincteric pressure gradient (GSPG) prior to the respective episodes.

Key Results

Five reflux episodes were characterized by a maximal IGP >30 mmHg. In 28% of the rumination episodes, the IGP peak did not exceed 30 mmHg. Median GSPG was positive for rumination episodes and significantly higher compared with TLESRs, reflux episodes, and straining without regurgitation (7 [3–13] vs. 0 [−1–0] vs. 0 [−1–0] vs. −9 [−13–−2]; p < 0.0001).

Conclusions & Interferences

Applying the proposed cutoff of 30 mmHg, 28% of the rumination episodes were missed. We found that the GSPG differentiates between rumination (positive GSPG), TLESRs and reflux events (GSPG around 0), and straining without regurgitation (negative GSPG). We propose a GSPG value ≥2 mmHg to distinguish rumination from reflux episodes, TLESRs, and straining without regurgitation.
Association between Helicobacter pylori antibody‐positive status and extragastric diseases in Japanese junior high school students
Authors: Abe Yuriko , Kusano Chika , Takano Chika , Morioka Ichiro , Gotoda Takuji
Published: December 2020

Background

Helicobacter pylori (H. pylori) infection causes various extragastric diseases. Its transmission route has still not been clarified. However, no large‐scale studies have examined the extragastric diseases caused by H. pylori in adolescents. This study aimed to examine the association of H. pylori infection with anemia, serum cholesterol levels, physique, and birth delivery method (vaginal or cesarean) in a large number of Japanese adolescents.

Methods

From 2016 to 2018, we screened 2,399 adolescents (aged 13–15 years) in their second and third years of junior high school using an enzyme‐linked immunosorbent assay‐based antibody test. Red blood cells, hemoglobin, hematocrit, total cholesterol, high‐density lipoprotein (HDL) cholesterol, and serum antibody levels were measured.

Results

Hemoglobin and hematocrit levels were significantly lower in the H. pylori antibody‐positive group than in the H. pylori antibody‐negative group in both sexes (boys: P = 0.0004 and 0.0022; girls: P = 0.0019 and 0.0005, respectively). Total cholesterol and non‐HDL cholesterol levels were significantly higher in the H. pylori‐positive group than in the H. pylori‐negative group among boys (P = 0.0370 and 0.0293 respectively). There was no significant difference in body mass index percentile and birth delivery method between the H. pylori‐positive and H. pylori‐negative groups in both boys and girls.

Conclusions

Among Japanese junior high school students, H. pylori antibody‐positive status was associated with anemia in both sexes while total cholesterol and non‐HDL cholesterol levels were associated among boys. There was no association between H. pylori antibody status, body mass index percentile, and birth‐delivery method.
A population‐based study of concurrent prescriptions of opioid analgesic and selective serotonin reuptake inhibitor medications during pregnancy and risk for adverse birth outcomes
Authors: Sujan Ayesha C. , Rickert Martin E. , Quinn Patrick D. , Ludema Christina , Wiggs Kelsey K. , Larsson Henrik , Lichtenstein Paul , Almqvist Catarina , Öberg Anna Sara , D'Onofrio Brian M.
Published: December 2020

Background

Pregnant women with painful conditions often have mental health problems, including depression and anxiety. Co‐morbid conditions may cause pregnant women to use multiple medications, although safety of such practice is poorly understood.

Objectives

We investigated the influence of combined prescriptions of opioid analgesics and selective serotonin reuptake inhibitors (SSRIs) during pregnancy on two adverse birth outcomes.

Methods

We analysed Swedish population‐based births (n = 688 914) between 2007 and 2013. Using national registers, we obtained data on filled medication prescriptions, birth outcomes, and a wide range of parental characteristics. We estimated preterm birth and small‐for‐gestational‐age risk following independent or combined prescriptions of the two medications compared with no filled prescriptions for either medication. We adjusted for confounders using inverse probability of treatment weights.

Results

After adjusting for confounders, preterm birth risk was higher among women with opioid analgesic prescriptions only (5.9%; risk ratio [RR] 1.27, 95% confidence interval [CI] 1.22, 1.33), SSRIs only (6.2%; RR 1.34, 95% CI 1.27, 1.42), and both medications (7.8%; RR 1.70, 95% CI 1.47, 1.96) compared with unexposed women (4.6%). The interaction between the medications on preterm birth was small (risk difference [RD] 0.4%, 95% CI −0.8%, 1.6%); relative excess risk due to interaction [RERI] 0.09, 95% CI −0.17, 0.34; RR 1.00, 95% CI 0.85, 1.17). For small for gestational age, risk was approximately 2% across all groups, and there was no interaction between the medications (RD 0.3%, 95% CI −0.4%, 1.1%); RERI 0.15, 95% CI −0.16, 0.47; RR 1.15, 95% CI 0.87, 1.52).

Conclusions

Compared with unexposed pregnancies, those with either medication alone had a small increased risk for preterm birth but no increased risk for small for gestational age. The magnitude of associations with combined exposure to both medications were not greater than the sum of the associations with each medication considered individually.
Compilation of antiviral treatments and strategies to fight fish viruses
Authors: Pereiro Patricia , Figueras Antonio , Novoa Beatriz
Published: December 2020

The implementation of antiviral treatments and prophylaxis strategies in fish aquaculture needs to be established. The absence of commercial vaccines for most viral diseases affecting economically relevant fish species, and the total lack of treatments to fight these diseases once they have emerged in a fish farm remains one of the main bottlenecks in fish aquaculture production. However, although no antivirals are currently applied on farms, a great number of investigations have been conducted to assess the potential use of antiviral treatments against several fish viruses. Although most of these works were based on in vitro approaches, some included in vivo experiments to demonstrate the potential applicability of these treatments. This review summarizes the investigations conducted both in vitro and in vivo in the field of antiviral treatments against fish viruses. The highlighted works include those using piscine and non‐piscine proteins with antimicrobial functions, metabolites, chemical compounds (some of which are used in medicine to treat human viruses), bioactive compounds mainly isolated from plants and bacteria, and emerging DNA‐ and RNA‐based therapeutics. This information can be used for developing both specific and broad‐spectrum antiviral strategies to be further used in the aquaculture industry, and it may even provide interesting indications for biomedical research.
Seven‐week asynchronous twins in a buffalo heifer (Bubalus bubalis) associated with superfetation – A case report
Authors: Penchev Pencho , Ilieva Yordanka , Nenova Radena
Published: December 2020

A female buffalo (Bubalus bubalis) of the Bulgarian Murrah breed aged 1,090 days was observed to give birth to a second newborn (normally developed male) after she had calved (normal female) 49 days earlier. This phenomenon is highly associated with her melatonin treatment within a trial for induction of puberty, the last ear implants being placed approximately 50 days before the assumed date of first mating, to which point the level of progesterone had increased dramatically. Despite none of the matings of the dam was visually witnessed to prove ovulation over an existing gestation, we take the liberty to qualify this phenomenon as superfetation, ruling out the other possible phenomena, namely embryonic diapause as it is highly unlikely to occur in any livestock species, and differentiated development of twin foetuses as it is associated with foetal malformation, which was not observed in this case.
Tonalité grégorienne: Musica recta as Prescriptive Harmony
Authors: Lam Nathan L.
Published: December 2020

Late nineteenth-century organist-composers wrote liturgical music dans la tonalité grégorienne based on Niedermeyer and d'Ortigue's chant-accompaniment treatise Traité théorique et pratique de l'accompagnement du plain-chant (1857). The resulting
music contained no musica ficta —, especially not raised leading tones in minor—a watershed moment in the nineteenth-century re-emergence of diatonic modality. Focusing on modes 1 and 2 (the Dorian modes) as a case study, part 1 of the essay discusses the historical background
of Niedermeyer's treatise, part 2 examines features and theoretical implications therein, part 3 details large modal collections such as Guilmant's Soixante interludes dans la tonalité grégorienne, and part 4 analyses two Dorian marches: one from Guilmant's L'Organiste
pratique and one from Gigout's Cent pièces brèves dans la tonalité du plain-chant.
The Development of Augmented Reality Environment: A Case Study on the Parts Feeding Systems
Authors: Huang C. P. , Agarwal S. , Liou F. W.
Published: December 2020

Due to the advances in computer engineering technologies, currently much effort has been devoted to simulate the real world in a computer generated environment. However, there are always differences between a virtual environment and the real world, and those variations can be from the complexities and the uncertainties of initial conditions, contributing parameters and the models employed. Before a virtual environment is put into work for design and development, some way of quantifying possible errors or uncertainties in the computer model is needed so that a robust and reliable system can be achieved. The aim of this paper is to present a current case study on an augmented reality environment with 3-D tracking and dynamic simulation technologies for the parts feeding systems, so that engineers can run high-fidelity simulation to test new materials, components, and systems before investing valuable resources in construction.
Construction and Functions of Self-Study System for Power Plant Operation
Authors: Tang Shengli , He Zuwei , Chang Tao , Xuan Liming
Published: December 2020

In this paper, the Construction and functions of the self-study system for power plant operation is introduced. As a self-study system, it consists of two parts, a simulator and knowledge base. The knowledge base has been built by the combination of expert system and artificial neural network, which supports the system with practical experience and theoretic knowledge. The trainees’ knowledge can be improved by using the system. The realization of the intelligent training function, applications of expert system and artificial neural network are mainly introduced in this paper.
Modeling Collaborative Engineering Design Process Using Petri-Net
Authors: Zhao Li , Jin Yan
Published: December 2020

Collaborative engineering involves multiple engineers and managers working together to develop engineering products. As the engineering problems become more and more complicated, new technologies are required to achieve better effectiveness and efficiency. While process models management and technologies have been developed to support engineering design, most of them apply only to routine design tasks and do not explicitly deal with the change of processes during execution. Our research proposes a process-driven framework to support collaborative engineering. The framework is composed of a process model that captures both high level and low level activity dependencies, an agent network that monitors process execution and facilitates coordination among engineers, and a Petri-net based modeling tool to represent and analyze process features and predict the performance of engineering processes. In this paper, we first describe a simple collaborative design problem and our proposed ActivePROCESS collaborative engineering framework. After that we present our Petri-net based analytical model of collaborative design process and discuss the model along with a case example.
Extending Express-G to Model Fuzzy Information in Product Data Model
Authors: Ma Z. M. , Zhang W. J. , Ma W. Y. , Chen G. Q.
Published: December 2020

Information with uncertainty and imprecision is inherently presented in engineering design and manufacturing. The nature of uncertainty and imprecision is incompleteness. The incompleteness is a typical feature in earlier product design phases. Product design is essentially viewed as a process of reducing the incompleteness in the description of conceptual design. Some methods and strategies for the preliminary engineering design, calculation, and modeling in relational database systems have been proposed to process imprecise and uncertain information. Product data model, being a core of intelligent manufacturing system, consists of all concerned data in the product life cycle. EXPRESS-G is a powerful tool to develop a product data model. This paper extends the EXPRESS-G to make it possible to represent information with uncertainty and imprecision.
Synthesis of Cutting Tool Placement, Orientation and Motion Based on Surface Analysis
Authors: Jensen C. G. , Hill J. K. , White K. A.
Published: December 2020

Engineers and designers use a wide variety of curve and surface formulations to describe products. The process of producing the physical shape of these products has remained essentially unchanged for many years. Traditionally, the process of finish surface machining has been error prone and inefficient due in large part to the mathematical basis used to control the positioning, orientation and movement of cutting tools in five-axis machining centers. This paper presents swept silhouette curvature matching algorithms for positioning and orienting a cutter such that tool and surface curvatures match. Formulations are given for both flat and filleted end mill cutters. The benefits of curvature matching are: reduction of local machining errors, reduction or elimination of grinding of the finished machined surface, and the improvement of machine tool efficiency. Examples are given that compare curvature matching to traditional machining methods. The paper concludes by discussing current research into a priori gouge detection methods based on intersection contact between the cutting tool and the design surface or the lower tolerance-bound offset surface to the design surface. An a priori gouge detection algorithm is necessary for the development of optimal tool motion and the reduction of time spent in tool path editing and verification. Techniques involving collinear normals, Bézier clipping, triangulation, normal intersection and swept volumes are suggested as techniques for examining the positional and translational tool gouge problem.
Fitting Freeform Shape Patterns to Scanned 3D Objects
Authors: Vergeest Joris S. M. , Spanjaard Sander , Horváth Imre , Jelier Jos J. O.
Published: December 2020

This paper describes a new approach to identify freeform shape patterns in measured point data, to extract them and to fit their parameters. The method is based on direct matching of parameterized shape templates to digitized points. For a given class of feature, the optimal pose and the optimal intrinsic feature parameters are determined relative to the point data at hand. Although this principle has been used in digital image processing and also for fitting of prismatic features, it has rarely been applied in 3D to freeform features. Yet, several engineering applications may profit from improved feature fitting. The motivation of our investigation is the supporting of shape modeling using precedent designs available in the form of physical parts. We aim at an extension to what is generally known as reverse engineering. However, the proposed technique can also be used to extract feature parameters from imported CAD models. This paper addresses computational aspects of the method and presents the algorithms, implementation tests and numerical results.
A GUI-Based Computer Model for Simulation of Vibration in Automotive Caliper-Disc Brakes
Authors: Meinhardt Glenn , Farhang Kambiz
Published: December 2020

Two computer models are presented that simulate the vibration response of an automotive caliper-disc brake system during braking. The computer programs, each represented by simulation block diagrams, are designed to solve a set of seven ordinary second order coupled differential equations. The first program analyzes the equations using a constant stiffness value for all structural components. The second program allows the user to modify the polynomials describing the contact normal and shear stiffnesses of both brake pads independently. The programs are modified and executed using a graphical user interface (GUI), which allows the user to modify all parameters of the simulation. This includes energy input, caliper and pad dimensional and material properties, and plot (output) parameters.
Nonstationary Random Response Analysis of Spatially Stochastic Structures Without Applying Probabilistic Finite Elements
Authors: To C. W. S.
Published: December 2020

A procedure based on the stochastic central difference method that was presented earlier by the author has been extended to cases involving with spatially and temporally stochastic structural systems that are approximated by the versatile finite element method. It is believed that for the first time nonstationary random responses of this class of systems are considered. The procedure eliminates the limitations associated with those employing the so-called stochastic or probabilistic finite element methods. Owing to its simplicity, the proposed method can easily be incorporated into many commercially available finite element packages.
Distributed Database and Knowledge Base Modeling for Concurrent Design
Authors: Zhang F. , Xue D.
Published: December 2020

This research introduces a new distributed database and knowledge base modeling approach for concurrent design. The data of product life-cycle aspects are modeled by primitives called features. The knowledge for developing products is described by collections of rules called rule-bases. Databases and knowledge bases at different locations for modeling different life-cycle aspects of the same product are associated by Internet. In addition, mechanisms for maintaining dependency relations of the product data at different locations and reasoning using the knowledge at different locations are also developed.
Decomposition-Based Assembly Synthesis Based on Structural Considerations
Authors: Yetis F. Arkin , Saitou Kazuhiro
Published: December 2020

This paper presents a method for decomposition of structural products in order to provide the product designer with choices for feasible assemblies. The synthesis of assemblies is done by decomposing a complex structure obtained via structural topology optimization into an assembly of multiple structural members with simpler geometries. The aim is at providing a systematic approach to explore a large number of decompositions prior to the detailed component design phase. Initially, the structure, which is represented as a bitmap image, is transformed to a graph with equivalent topology through application of image processing algorithms. Then, the obtained graph is decomposed by a genetic algorithm into subgraphs using strength-based criteria. Results for an example structure are given to clarify and discuss the method.
Modular Platform-Based Product Family Design
Authors: Gonzalez-Zugasti Javier P. , Otto Kevin N.
Published: December 2020

In this paper we present a method for designing families of products built onto modular platforms. A product platform is the set of components and subsystems shared across multiple products offered by a firm. A modular platform is one that allows for swapping of modules to configure multiple products in a family. The problem of designing a family of products based on such a platform is formulated as an optimization exercise, from which an implementation is derived. The method allows for the design of the modules that are shared across multiple members of the family, or the platform, as well as the portions of the products that are individually designed, or the variants. The result is a candidate design for the product family: both the combination of which modules should be shared and across which of the products, and the desired settings for the shared modules and the individual portions of each variant. The procedure is illustrated by an example of the telecommunications subsystem design for a set of spacecraft. The optimum degree of commonality for the set of products is found, as well as optimum settings for the common modules.
Performance Estimation and Robust Design Decisions
Authors: Tang Xiao , Krishnamurty Sundar
Published: December 2020

This paper deals with two major issues critical to the development and implementation of a decision-based robust design, namely, representation of design performance under conditions of uncertainty and the development of a robust design decision model. Specifically, this paper presents a computationally efficient procedure for accurate estimation of performance variance using a novel Surround Point Method (SPM) and discusses its incorporation into a decision-based robust design framework. Results indicate that by mimicking effects from Monte-Carlo Simulation (MCS), SPM-based uncertainty estimation method appears to offer the best promise in achieving an optimal balance between computational complexity and design-scenario independence. It can be expected to be a viable and applicable probability estimation tool in generic engineering design, and particularly useful in highly nonlinear configuration design with many design variables. Furthermore, to explicitly incorporate robustness criteria, this paper introduces the concept of design evaluation level as a means for decision-making in an evolving design process. Using this concept, this paper introduces a robust decision-based design methodology that can methodically handle multiple performance attributes, system constraints, and robustness issues in engineering design. These issues are discussed in the context of engineering design decision-making with the aid of a simple case study and the results are discussed.
On Improving the Accuracy of Lattice Models in Crashworthiness Analysis
Authors: Ignatovich Cori L. , Diaz Alejandro R. , Soto Ciro A.
Published: December 2020

Lattice models are used to represent the behavior of a complex structure in an impact event. An optimization problem is proposed to “tune” the model to capture the relevant behavior of the structure. Wavelet transforms are used to identify the systematic component of a signal characterizing the structural behavior from its random component.
Part to Art: Basis for a Systematic Geometric Design Tool for Surface Micromachined MEMS
Authors: Venkataraman Venkat A. , Sarma Radha , Ananthasuresh Suresh G. K.
Published: December 2020

Currently most MEMS designers begin the geometric design of a new device by creating the masks that would lead to a geometric model. At the macro level, this is analogous to generating a geometric model from the tool paths, which would be a very difficult task. In contrast to MEMS designers, designers of macro devices have the advantage of starting with a geometric model and being able to directly visualize or manipulate their designs. The geometric model is then queried to generate the process specific data. In the case of MEMS, there is no systematic means to generate the mask data after the geometric model of a MEMS device has been refined through behavioral simulations.

This paper focuses on automatically generating masks, given a geometric model of the MEMS device and the process sequence (referred to here as the inverse problem). This necessitates the systematic solution of the forward problem, which involves automatically generating a geometric model of the MEMS device given the masks. A systematic and implementation-independent framework for the geometric modeling of MEMS is presented in order to solve the forward and inverse problems for general surface-micro-machined devices. However, all implementations and examples are two-dimensional, i.e., they do not deal with complexity in the third dimension.
Development of an Image-Based CAD Using Wavelet Transform
Authors: Yim Soonkyu , Gea Hae Chang
Published: December 2020

Traditionally, designers describe features of objects from various geometric modeling tools. However, a geometry-based system requires complex mathematical formulations and data structures that make it very cumbersome to manipulate. Furthermore, Layered Manufacturing (LM) has become a prominent manufacturing technology in recent years. To support LM under geometry based CAD systems, users have to slice the model into layers. It is obvious that geometric characteristics of the geometry-based CAD models are destroyed during these conversions, at the same time, additional efforts and costs will be accumulated. To bridge the gap between CAD and LM, an image-based data format instead of a geometry based data format is proposed to serve as the foundation of CAD systems in this paper. A wavelet transform is used to reduce the file size and produce multi-resolution image map. To further increase the computational efficiency of the algorithm, we developed the Reduced Haar Wavelet transform and a bit-remainder index.
A Computational Design Framework for a Rapid Solid Freeform Fabrication Process
Authors: Khandelwal Deepesh , Kesavadas T.
Published: December 2020

Solid Freeform Fabrication (SFF) techniques in recent years have shown tremendous promise in reducing the design time of products. This technique enables designers to get three-dimensional physical prototypes from 3D CAD models. Although SFF has gained popularity, the manufacturing time and cost have limited its use to small and medium sized parts. In this paper we have proposed a novel concept for rapidly building SFF parts by inserting prefabricated inserts into the fabricated part. A computational algorithm was developed for determining ideal placement of inserts/cores in the CAD model of the part being prototyped using a heuristic optimization technique called Simulated Annealing.

This approach will also allow the designers to build multi-material prototypes using the Rapid Prototyping (RP) technique. By using cheaper pre-fabricates instead of costly photopolymers, the production cost of the SFFs can be reduced. Additionally it will also reduce build time, resulting in efficient machine utilization.
Design Decision Templates and Their Implementation for Distributed Design and Solid Freeform Fabrication
Authors: Rosen David , Chen Yong , Gerhard Jonathan , Allen Janet , Mistree Farrokh
Published: December 2020

In this paper, we describe issues arising in distributed design and fabrication, where fabrication of prototypes is performed by Solid Freeform Fabrication (SFF) technologies. The focus is on a design-manufacture collaboration problem, namely the transfer of design information from the design organization to a manufacturing organization. In other research, this has been called the need for a “clean digital interface.” In the context of designing and fabricating a prototype, we explore two factors: the types of design and product information to be transferred from design to manufacturing, and which types of decisions can be made by the manufacturer regarding the prototype. As a representative product design process, we focus on three main activities, including material and SFF process selection, geometric tailoring (detailed design for manufacture modifications), and process planning. Further we investigate three interfaces between design and manufacturing organizations, one interface before each main activity. We demonstrate that a series of design decision templates can be used to transfer design information between the design and manufacturing organizations in support of the main activities. Furthermore, we demonstrate the implementation of these decision templates in a distributed design and fabrication environment called the Rapid Tooling TestBed. An example scenario is explored to illustrate the usage of two of the decision templates. Results show that, for the decision templates utilized, the templates are sufficient to specify design freedom to the manufacturer, enabling the manufacturer to assume more decision-making responsibility during the development of prototypes.
Determination of Optimum Sensor Positions for Defect Detection on Revolving Machines by a Finite Element Vibration Analysis
Authors: Bogard F. , Debray K. , Guo Y. Q. , Pavan A.
Published: December 2020

The vibration monitoring is largely used to detect the defects in the revolving machines. The determination of the best sensor positions is one of main research goals in the domain of the conditional maintenance. This paper proposes a numerical methodology based on a finite element model and a spectral analysis in order to find optimum sensor positions. The bearing is considered as a key component in vibration propagation from the moving parts to static ones. In this paper, we use an analytical bearing model and its numerical implementation in a FE code. The tangent stiffness matrix of the bearing element is calculated by the Newton-Raphson method and then introduced into the modal and spectral analysis. The technique of “Mode Shape Summation Plot” (MSSP) is adopted to find the most sensitive zones to usual defects. The proposed numerical approach gives good agreements with the experimental results. A real grinder modeling shows its interesting industrial applications.
An Approach to a 2D/3D Geometric Constraint Solver
Authors: Liping Chen , Xiaobo Peng , Boxing Wang , Fanli Zhou
Published: December 2020

With the Euler parameter expression in multi-body system, component expressions of constraint relations are presented. Based on directed graph representation of geometry constraint system and decomposition technology of sparse algebraic structure, a modeling method of 2D/3D geometric constraints is advanced. Finally, an optimal decomposition of general underconstrained geometric system which is common especially in primary design phase is realized.
www.wapip.com: A Special-Purpose Search Engine for

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Authors: Huang G. Q. , Shen B. , Mak K. L.
Published: December 2020

There have been widespread interests in the development and application of World Wide Web (WWW) to support decision-making activities in product design and manufacture. An increasing number of web applications are emerging and a large number of practitioners are keen on trying these web-based decision support systems. In the meanwhile, it becomes increasingly difficult to surf for appropriate web applications on the Internet with general-purpose search engines. This paper describes a web site, WAPIP, that has been developed specifically to support new product introduction activities. It provides databases for software vendors and researchers to register their web applications with the “wapip” search engine. It also provides facilities to support practitioners in product design and manufacture to search rapidly for the right web applications suitable for solving their problems. This paper discusses the various issues regarding the design, development and operation of this “wapip” search engine.
Preliminary Design Support System Based on a Generic Under-Constraint Solving Technique
Authors: Sawada Hiroyuki , Yan Xiu-Tian
Published: December 2020

Engineering design is an intensive decision making process. A designer with an informative and insightful decision making support can usually produce high quality product design solutions with less or no rework. However, with current support designers very often face challenge or even difficulties as more and more design parameters come into design decision making process when a design progresses. This paper proposes a novel approach to providing designers with such a decision support by using under-constraint design problem solver. It is argued that design requirements represented in the form of Product Design Specifications (PDSs) can be converted into a set of related constraint expressions. These PDS constraint sets, which are usually incomplete, i.e., under-constrained, can then be solved by the solver to provide a designer with guided solutions for each design parameter, thus support a designer to make an informative and insightful design decision. A case study is finally presented in the paper to demonstrate how this approach is used to solve a real engineering design problem — a robotic finger system design.