bluuebunny/crossref_metadata_2025 huggingface dataset:
The Contribution of the Creative Economy to the Resilience of Rural Communities: Exploring Cultural and Digital Capital
Authors: Roberts Elisabeth , Townsend Leanne
Published: January 2015

This article develops understanding of cultural and digital capital in order to evaluate the contribution of creative practitioners to rural community resilience. Online practices today impact on creative work in rural locales in a number of ways. However, exactly how they extend ‘reach’ and contribute to rural creativity deserves greater attention. We examine how broadband Internet access and online practices impact on rural creative work and, in turn, how this enables creatives to participate at different levels in their rural communities, thus contributing to research into both rural community resilience and rural creative economies by providing in‐depth qualitative analysis. Through interviews undertaken in rural Scotland, the article outlines the implications of poor rural Internet connectivity for creative economies and explores the impact of this on the role of creatives in their rural communities and their ‘community‐focused’ creative activities. Our findings suggest creative practitioners are using digital technologies and adaptive approaches to overcome barriers to connectivity and to remain in rural locations. Creatives are invested in their communities and their rurality on a number of levels, contributing to community resilience through building cultural capital in diverse ways, and to ‘ripple effects’ from online activities.
Presentation and management of mycotic pseudoaneurysm after kidney transplantation
Authors: Patrono D. , Verhelst R. , Buemi A. , Darius T. , Godefroid N. , Mourad M.
Published: January 2015

Pseudoaneurysms (PAs) developing at the site of vascular anastomosis after organ transplantation are a rare but serious complication. We report a series of 3 cases of PA observed in a single center over a period of 18 years. The mode of presentation was acute bleeding in 2 cases. In the third patient, who underwent combined kidney and pancreas transplantation, the PA on the renal graft was discovered by chance. Graft removal associated with iliac artery ligation and extra‐anatomic femoro‐femoral bypass represents the standard treatment. However, interposition of a venous homograft may allow preservation of inferior limb perfusion and possibly graft salvage.
Conversion to a sirolimus‐based regimen is associated with lower incidence of BK viremia in low‐risk kidney transplant recipients
Authors: Tohme F.A. , Kalil R.S. , Thomas C.P.
Published: January 2015

Background

BK viral nephropathy is an increasingly recognized cause of early allograft loss in kidney transplantation. This study aimed to determine whether a sirolimus (Sir)‐based calcineurin inhibitor‐sparing regimen is associated with a lower incidence of BK viremia.

Methods

This was a single‐center retrospective study. Patients were either on tacrolimus (Tac)‐based or on Sir‐based immunosuppression. Conversion from Tac to Sir occurred at or after 3 months if patients were <62 years of age, had calculated panel reactive antibodies of <20%, and did not have acute early rejection.

Results

Incidence of clinically significant BK viremia was 17.9% in the Tac group and 4.3% in the Sir group. Cox regression multivariate analysis showed that male gender (hazard ratio [HR] = 2.87) and switch to Sir (HR = 0.333) impacted the incidence of BK viremia. Kaplan–Meier analysis showed a higher BK‐free survival in the Sir group. A trend was seen toward shorter time to resolution of BK viremia and lower peak viremia in the Sir group. Patients on Sir had a higher estimated glomerular filtration rate at each time point; 34% of patients discontinued Sir because of side effects.

Conclusion

Conversion to Sir‐based maintenance immunosuppression at or about 3 months after kidney transplantation correlates with a lower incidence of BK viremia.
Treatment of uncomplicated malaria with artesunate plus sulfadoxine–pyrimethamine is failing in Somalia: evidence from therapeutic efficacy studies and Pfdhfr and Pfdhps mutant alleles
Authors: Warsame Marian , Hassan Abdillahi Mohamed , Barrette Amy , Jibril Ali Mohamed , Elmi Husein Haji , Arale Abdulkadir Mohamed , Mohammady Hanan El , Nada Rania A. , Amran Jamal Ghilan Hefzullah , Muse Abdikarim , Yusuf Fahmi Essa , Omar Abdiqani Sheikh
Published: January 2015

Objective

Artesunate plus sulfadoxine–pyrimethamine (AS + SP) has been Somalia's national treatment policy since 2006. Routine monitoring of first‐line malaria treatment is needed to ensure appropriate national malaria treatment policy and early detection of drug resistance. For this purpose, we conducted therapeutic efficacy studies of AS + SP for the treatment of uncomplicated malaria in Somalia in 2011.

Methods

Studies were conducted in three sentinel sites. Eligible patients were evaluated for clinical and parasitological outcomes according to the WHO standard protocol. Molecular surveillance was conducted on resistance conferring mutations in the P.falciparum dihydrofolate reductase (dfhr) and dihydropteroate synthase (dhps) genes.

Results

The proportion of PCR‐corrected treatment failures was high in Jamame (22%, 95% CI: 13.7–32.8%) and low (<5%) in Janale and Jowhar. All patients cleared parasites by day 3. Molecular markers associated with SP resistance were detected in all three sites. Treatment failure was associated with the presence of the double mutant dhps A437G/K540E (OR = 22.4, 95% CI: 5.1–98.1), quadruple mutant dhfr N51I/S108N+dhps A437G/K540E (OR = 5.5, 95% CI: 2.3–13.6), quintuple mutant dhfr N51I/C59R/S108N+dhps A437G/K540E (OR = 3.5, 95% CI: 1.4–8.8) and younger age (OR=0.86, 95% CI: 0.76–0.96).

Conclusions

The high treatment failure rate observed in Jamame, together with the presence of molecular mutations associated with SP resistance, indicates P. falciparum resistance to SP. In Jowhar, high treatment failure rates were absent despite the presence of molecular mutations; signs of resistance in vivo may have been masked by the stronger immunity of the older study population. The study underscores the need to update Somalia's national malaria treatment policy.
Antimicrobial use in critically ill horses
Authors: Dunkel Bettina , Johns Imogen C.
Published: January 2015

Objective

To discuss controversies surrounding antimicrobial use in critically ill horses.

Data Sources

PubMed searches from 1970‐present for terms including, but not limited to: “horse,” “foal,” “antimicrobial,” “prophylaxis,” “infection,” “surgery,” “sepsis,” and “antimicrobial resistance.”

Human Data Synthesis

Increasing bacterial antimicrobial resistance has changed first‐line antimicrobial choices and prompted shortening of the duration of prophylactic and therapeutic treatment. The need to decrease bacterial resistance development to critically important antimicrobials has been highlighted.

Veterinary Data Synthesis

Veterinary medicine has followed a similar trend but often without a high‐level evidence. Common dilemmas include diseases in which the theoretically most effective drug is a reserved antimicrobial, the inability to differentiate infectious from noninfectious disease, the duration and necessity of prophylactic antimicrobials and use of antimicrobials in primary gastrointestinal disease. These problems are illustrated using examples of purulent infections, neonatal sepsis, colic surgery, and treatment of colitis. Although enrofloxacin, cephalosporins, and doxycycline, in contrast to gentamicin, reach therapeutic concentrations within the lungs of healthy horses, the first two should not be used as first line treatment due to their reserved status. Due to the high risk of bacterial sepsis, antimicrobial treatment remains indispensable in compromised neonatal foals but shortening the length of antimicrobial treatment might be prudent. One prospective randomized study demonstrated no difference between 3 and 5 days of perioperative antimicrobial treatment in colic surgery but shorter durations were not evaluated. High‐level evidence to recommend antimicrobial treatment of adult horses with undifferentiated diarrhea does not exist.

Conclusions

Few evidence‐based recommendations can be made. Commonly used antimicrobial combinations remain the mainstay for treating purulent infections. Antimicrobial treatment for compromised foals should not extend beyond recovery. Continuation of prophylactic antimicrobials >3 days is likely unnecessary after colic surgery; shorter durations might be equally effective. Antimicrobial prophylaxis in adult horses with diarrhea is unlikely to be beneficial.
The -adic -functions of evil Eisenstein series
Authors: Bellaïche Joël , Dasgupta Samit
Published: January 2015

We compute the $p$-adic $L$-functions of evil Eisenstein series, showing that they factor as products of two Kubota–Leopoldt $p$-adic $L$-functions times a logarithmic term. This proves in particular a conjecture of Glenn Stevens.
Research on the Wet Clutch Engagement Torque
Authors: Zhang Yingying , Xiang Changle
Published: January 2015

The driving performance of the vehicle with automatic transmission is influenced by the performance of the wet clutch directly. But at present it is still a challenge to build a reliable predictable model for the torque of the engagement process of the wet clutch. Focusing on the wet clutch of vehicle, this paper starts from mechanism analysis, and a modified Reynolds equation with the consideration of the centrifugal force of the squeeze-film is established. In the model, we can consider the speeds of the friction and separator plates independently. At the same time, flow factors have been used to research the impacts of rough surface on the flow of the lubrication oil. In the three-dimensional solution domain, the circumferential pressure gradient of lubrication oil is considered. The model is solved with the finite volume method. The simulation of the torque of the asperity contact calculates the real contact area changed with the engagement process, and the microscopic texture direction of rough surface is considered. Subsequently, the squeeze-film flow model is combined with the asperity contact model to create an integrated clutch engagement model. Finally, the influence of applied force, viscosity of lubrication oil, friction material, the depth of grooves and the width of the grooves are investigated. Based on the comparison with the experimental data, the performance of the proposed model is found satisfactory. Because in this model more detail properties of material and geometric features of the friction plate are include, the wet clutch model developed in this research can become a baseline model for the prediction of the engagement behavior of a real wet clutch. The present model may become an efficient alternative to laboratory testing and lead to designs that can not be envisioned by other approaches.
Testing and Validation of a Series PHEV Control System
Authors: Golecki Christopher J. , Monaco Christopher D. , Sattler Benjamin J.
Published: January 2015

EcoCAR 2: Plugging into the Future is an Advanced Vehicle Technology Competition managed by the U.S. Department of Energy at Argonne National Laboratory. The competition challenges 15 universities across North America to reduce the environmental impact of a production vehicle without compromising performance, safety and consumer acceptability. To meet this goal, the Pennsylvania State University Advanced Vehicle Team has designed a series plug-in hybrid electric vehicle (PHEV) capable of achieving a 40 mile all-electric range. An auxiliary power unit (750 cc two-cylinder engine converted to run on E85 fuel) provides extended range greater than 200 miles. A rigorous development process has been followed to provide a control system that meets the safety, performance and fuel economy targets, including fault mitigation.

This paper summarizes the control system development strategy, starting with vehicle component selection. The strategies used to develop a control algorithm and plant model in parallel are described. Extensive testing is performed throughout the vehicle development process, including both software-in-the-loop (SiL), hardware-in-the-loop (HiL), and in-vehicle testing. In addition, it will be shown how pertinent testing data plays a crucial role in further plant model developments.
Optimization Under Uncertainty of Nonlinear Energy Sinks
Authors: Boroson Ethan , Missoum Samy , Mattei Pierre-Olivier , Vergez Christophe
Published: January 2015

Nonlinear Energy Sinks (NES) are used to passively reduce the amplitude of vibrations. This reduction is made possible by introducing a nonlinearly stiffening behavior in the NES, which might lead to an irreversible transfer of energy between the main system (e.g., a building) and the NES. However, this irreversible transfer, and therefore the efficiency of the NES, is strongly dependent on the design parameters of the NES. In fact, the efficiency of the NES might be so sensitive to changes in design parameters and other factors (e.g., initial conditions) that it is discontinuous, switching from efficiency to inefficiency for a small perturbation of parameters. For this reason, this work introduces a novel technique for the optimization under uncertainty of NES. The approach is based on a support vector machine classifier, which is insensitive to discontinuities and allows one to efficiently propagate uncertainties. This enables one to efficiently solve an optimization under uncertainty problem. The various techniques presented in this paper are applied to an analytical NES example.
Analysis of Planar Reconfigurable Motion Generators
Authors: Venkataramanujam Venkatesh , Larochelle Pierre
Published: January 2015

This article presents the kinematic analysis of a new class of mechanical devices called planar Reconfigurable Motion Generators (RMGs) for multi-phase motion generation tasks having only a slight change in the desired motion. The concepts of configuration matrices and state vectors are introduced as a novel way to represent planar RMGs. The kinematic analysis of a planar RMG in it’s initial configuration to determine the associated adjustable link lengths and angles is discussed. The adjustable link lengths are used to determine the link vector and state vector of a RMG. Future work will involve the application of configuration matrices and state vectors to aid in both systematic analysis and synthesis of RMGs.
Uncertainty Propagation in a Supply Chain / Network With Uncertain Facility Performance
Authors: Rezapour Shabnam , Allen Janet K. , Mistree Farrokh
Published: January 2015

Decentralized production systems in supply chains / networks makes them more profitable and agile than traditional enterprises with centralized production systems. However, this decentralization makes supply chains / networks more vulnerable respect to uncertainties which are unavoidable. Today’s supply chains / networks producing and supplying their products to markets are characterized by uncertain demands (called demand-side uncertainty) and uncertainties associated with the performances of their constituent production facilities (called supply-side uncertainty). Supply-side uncertainty is due to the fact that there is not any perfect production system. Sparse literature of supply-side uncertainty management in supply chains / networks is only restricted to supply chains / networks with single-echelon supply processes. However most of the real case supply chains / networks have longer production processes involving suppliers of suppliers, suppliers, component manufacturers, assemblers, etc. In this paper we fill this gap of the literature by considering a supply chain/network with multi-echelon supply process including unreliable production facilities working in markets with uncertain demands. We show that in such a complex production process in addition to investigating the local effects of the uncertainties in the performances of their corresponding facilities, it is necessary to consider their global and cumulative effect on the performance of the entire supply chain/networks by following the propagation of these uncertainties in the flow of the material and product. Not only we introduce and describe the salient features of uncertainty propagation phenomenon in supply chains/networks, but also we demonstrate its quantification approach. Finally we propose mathematical models and solution approaches that can provide robust production plans for the supply chain/network that are protected against all demand and supply side uncertainties and their propagated effects. Performances of the proposed models and solution approaches are tested with test problems and a real case problem from automotive industry.
A Random Process Metamodel for Time-Dependent Reliability of Dynamic Systems
Authors: Drignei Dorin , Baseski Igor , Mourelatos Zissimos P. , Pandey Vijitashwa
Published: January 2015

A new metamodeling approach is proposed to characterize the output (response) random process of a dynamic system with random variables, excited by input random processes. The metamodel is then used to efficiently estimate the time-dependent reliability. The input random processes are decomposed using principal components or wavelets and a few simulations are used to estimate the distributions of the decomposition coefficients. A similar decomposition is performed on the output random process. A Kriging model is then built between the input and output decomposition coefficients and is used subsequently to quantify the output random process corresponding to a realization of the input random variables and random processes. In our approach, the system input is not deterministic but random. We establish therefore, a surrogate model between the input and output random processes. The quantified output random process is finally used to estimate the time-dependent reliability or probability of failure using the total probability theorem. The proposed method is illustrated with a corroding beam example.
Application of Origami in the Starshade Spacecraft Blanket Design
Authors: Sigel Deborah , Trease Brian P. , Thomson Mark W. , Webb David R. , Willis Paul , Lisman P. Doug
Published: January 2015

A Starshade is a large deployable structure and sole payload of an external occulter. At 34m in diameter or more, starshades are designed to block most of the light from a nearby star so that a small orbiting space telescope can image and characterize the Earth-like exoplanets in orbit around it. The starshade resembles a sunflower with a circular central disk supporting petals that are arrayed around its periphery. The petal edges are precisely shaped to match an optical profile that prevents diffraction. The area circumscribed by the edges must be completely opaque, black, and non-reflective. The petals and ring structure are covered by specially designed deployable blankets that must remain completely opaque even if they become perforated by micrometeorites. The blankets must also not cause any significant on-orbit thermoelastic loads on the lightweight supporting ring and petal structures despite very large differential thermal strains that are developed between these Kapton blankets and the thermally stable composite ring and petal structures. There are two types of blankets: one for the deployable petals and one for the central support disc that is formed by a lightweight deployable ring truss structure.

The starshade blankets cover such a large area that they must be unusually lightweight compared to conventional multi-layer insulated (MLI) spacecraft blankets. The blankets must also stow around the central hub of the spacecraft with the deployable ring and petal structures in a highly repeatable fashion. This makes them ideal candidates for origami folding schemes. Based on prior studies of large deployable rigid arrays, we began with variants on the origami flasher to fold the central ring blanket, which is a minimum of 20m in diameter. We looked at the simplest methods for integrating this large blanket with a mechanical ring truss while providing ample optical baffling and little to no thermally induced loads on the structure. Petal blankets were also developed using deployable softgoods with pseudo-mechanical and shingled designs with optically blocking folds for deployment. The design was developed iteratively utilizing a variety of prototypes to explore and demonstrate the interaction between the softgoods and rigid elements.
Single and Multi-Objective Optimization Issues and Analysis of a 3UPU Parallel Manipulator
Authors: Zhang Dan , Wei Bin
Published: January 2015

Differential evolution (DE) and Pareto front theory are used to optimize stiffness in three directions and workspace of a 3UPU manipulator. Stiffness of the mechanism in each direction is analyzed, and it comes to the fact when stiffness in x and y directions increase, stiffness in z direction will decrease and therefore, the sum of stiffness in x and y and stiffness in z are optimized simultaneously by applying DE, but those two objectives are not in the same scale, a normalization of objectives is therefore considered. Furthermore, workspace volume of the mechanism is analyzed and optimized by using DE. By comparing landscapes of stiffness and workspace volume, one finds stiffness in z has same trend with workspace volume whereas stiffness in x and y and workspace volume conflicts. By employing Pareto front theory and DE, the sum of stiffness in x and y and workspace volume are optimized simultaneously.
Vibration Suppression of Wind Turbine Blades Using Tuned Mass Dampers
Authors: Ikeda Takashi , Harata Yuji , Sasagawa Yusuke , Ishida Yukio
Published: January 2015

Passive control of flapwise vibrations of a wind turbine blade is investigated when a single tuned mass damper (TMD) is attached to the blade. The blade is subjected to a wind pressure which changes linearly with height from the ground level due to the wind shear. The vibrations of the wind turbine blade are theoretically and numerically analyzed to determine the natural frequency diagrams, frequency responses, stationary time histories and their FFT results. It is found that several peaks appear near the specific rotational speeds in the response curves for the blade because of both the wind pressure and the parametric excitation terms. It is also demonstrated that the optimal single TMD can suppress the resonance peaks if the fixed point theorem is used to determine the optimal values of the parameters of the TMD. The influences of the mass and install position of the TMD on its performance are also examined.
Emotional Break-In of Products
Authors: Fukuda Shuichi
Published: January 2015

Although break-in is important in products, only the aspect of run-in is considered in mechanical products. But we feel happy when our shoes come to fit us. We feel happy, too, if our products come to fit us in our operating conditions and work very well as we expect and meet not only our needs but also our preferences.

Further, if our products come to fit us very well, we feel attached to them and will use them longer. Such emotional break-in has seldom been considered in mechanical design.

If a product or a machine degrades and does not satisfy its design requirements, it will be restored to its original design level. This is considered to be the most important task of maintenance.

But break-in is associated with the phenomenon of degradation. If we can manage our degradation more intelligently, we would feel happier because we feel the product or the machine is breaking in to our needs and to our preferences.

This is a position paper to discuss this issue.
2D Shape and Force Tracking in Rehabilitation Therapy of Upper Extremities Through a Multimodal Guidance System
Authors: Covarrubias Mario , Mansutti Alessandro , Bordegoni Monica , Cugini Umberto
Published: January 2015

This paper describes a shape and force tracking approach aimed for the assessment and training of patients’ upper extremities functionalities, while performing 2D tasks in a post-stroke rehabilitation program. The 2D tasks are assisted by a Multimodal Guidance System (MGS), which consists in a combination of visual, haptic and sound interaction. The device enables users to haptically interact with a virtual template, which acts as a virtual tool path taking advantage of its force feedback capabilities while the patient performs a 2D task, as sketching and hatching operations. Furthermore, the patient receives sound information, which provides audio feedback related to the hand velocity. By tracking the shape and the forces required to complete the tasks according to the visual feedback provided on the computer screen, the system can inform about quantitative measurement of a patients progress. The paper concludes by presenting a preliminary test using the device for sketching and hatching operations.
Biased Information Passing Between Subsystems Over Time in Complex System Design
Authors: Austin-Breneman Jesse , Yu Bo Yang , Yang Maria C.
Published: January 2015

The early stage design of large-scale engineering systems challenges design teams to balance a complex set of considerations. Established structured approaches for optimizing complex system designs offer strategies for achieving optimal solutions, but in practice sub-optimal system-level results are often reached due to factors such as satisficing, ill-defined problems or other project constraints. Twelve sub-system and system-level practitioners at a large aerospace organization were interviewed to understand the ways in which they integrate sub-systems. Responses showed sub-system team members often presented conservative, worst-case scenarios to other sub-systems when negotiating a trade-off as a way of hedging their own future needs. This practice of biased information passing, referred to informally by the practitioners as adding “margins,” is modeled with a series of optimization simulations. Three “bias” conditions were tested: no bias, a constant bias and a bias which decreases with time. Results from the simulations show that biased information passing negatively affects both the number of iterations needed to reach and the Pareto optimality of system-level solutions. Results are also compared to the interview responses and highlight several themes with respect to complex system design practice.
Wheel Dynamics Fundamentals for Agile Tire Slippage Modeling and Control
Authors: Vantsevich Vladimir V.
Published: January 2015

One of the technical problems in wheel dynamics is to establish and control the relationship between the tire kinematic and force characteristics related to tire slippage and thus to tire-soil power losses and wheel mobility estimation. This problem has been attracting a lot attention from the research community for decades. The electronization of modern vehicles can enhance their performance in complex and severe vehicle-road/terrain environments by implementing agile control decision within the scale of milliseconds. Thus, agility requires new approaches when considering and analyzing the tire slippage process.

This paper presents an analysis of the tire slippage process in stochastic terrain conditions for the purpose of agile tire slip modeling, estimation and control. Based on the introduced relations between the rolling radii of the tire, circumferential wheel force/wheel torque, wheel kinematic parameters and tire slippage, a set of agile tire-terrain characteristics is offered in the paper. The proposed characteristics take in consideration the rate of change of the listed parameters and thus allow a user to estimate the agile dynamics of the tire slip and evidence the closeness to the peak friction coefficient and hence estimate potential mobility loss. The characteristics establish relationships between the stochastic peak friction coefficient, rolling resistance coefficient, and wheel kinematic/force parameters. The characteristics are illustrated by computer simulation results in several terrain conditions.
A Full Disturbance Model for Reaction Wheels
Authors: Le M. P. , Ellenbroek M. H. M. , Seiler R. , van Put P. , Cottaar E. J. E.
Published: January 2015

Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for reaction wheels was developed at Moog Bradford by combining empirical and theoretical models. The empirical data is obtained from a highly accurate reaction wheel characterization test setup from the European Space Agency and includes disturbance signals of ball bearings transmitted through the structures of the reaction wheel assembly. The theoretical model is derived from the equation of motion of a rigid rotor and a disc supported by two ball bearings including static, dynamic unbalances, structural modes and gyroscopic effects of the wheel rotor. To fully model the disturbance signature of the wheel, the bearing stiffness is formulated as a function of ball pass frequency and the flexibility of the supporting structural items like the reaction wheels housing are included. Finally, the empirical model is added into the theoretical model as excitations to form a full disturbance model for reaction wheels. The resulting combined model is then validated by tests on different types of Moog Bradford reaction wheels. The validated disturbance model is used to evaluate the pointing performance of spacecraft as well as to predict micro-disturbance performance for future reaction wheel designs.
Experimental Analysis of a Model Based Crack Identification Approach for Rotating Machines
Authors: Cavalini Aldemir Ap , Sanches Leonardo , Steffen Valder
Published: January 2015

In this paper an experimental application of a crack identification methodology based on combinational resonances is proposed. The technique uses external applied diagnostic forces at combinational frequencies, together with a pseudorandom optimization code, Differential Evolution, in order to characterize the signatures of the crack in the spectral responses of the flexible rotor. A finite element model is used to obtain the dynamic responses of the rotating machine. In this system, the additional excitations are applied by means an electrodynamic shaker. The method of multiple scales is used to determine the frequency of the excitation force under which combinational resonances appear. The breathing crack is simulated according to the Mayes model, in which the crack transition from fully opened to fully closed is described by a cosine function. The additional flexibility introduced by the crack is calculated by using the linear fracture mechanics theory. The results show that the methodology is a promising tool for estimates the crack location and depth.
Development of Recreating Space Technology for Pipe Joint Manufacturing System With a Dual Industrial Robot
Authors: Kuroyanagi Sosuke , Hirogaki Toshiki , Aoyama Eiichi , Omori Shinya , Mori Koichi , Takahashi Kenichi , Furuta Masaki
Published: January 2015

A technology has been developed for recreating in a pipe joint manufacturing plant the measurement space in the field. A dual industrial robot system checks whether each manufactured joint matches the measured positions and orientations of the two pipes to be connected before the joint is sent for installation. The accuracy of robot motion is estimated using off-line robot teaching control provided by a program based on computer-aided design data. A double ball bar (DBB) method is used to frequently check the accuracy of machine tool motion. Testing showed that the developed technology is sufficiently accurate once the positions used in the off-line teaching mode are revised on the basis of the errors in motion obtained with the DBB method.
Explicit Communication of Geometric Design Intent in CAD: Evaluating Annotated Models in the Context of Reusability
Authors: Camba Jorge , Contero Manuel , Otey Jeffrey , Company Pedro
Published: January 2015

CAD model reusability is largely determined by a proper communication of design intent, which is usually expressed implicitly within the model. Recent studies have suggested the use of 3D annotations as a method to embed design information in the model’s geometry and make part of the design knowledge explicitly available. In this paper, we evaluate the effectiveness of this method and analyze its impact in model alteration tasks. Our goal is to determine whether annotated models provide significant benefits when performing activities that require a direct manipulation of the geometry. We present the results of a study that measured user performance in two scenarios. First, we tested whether annotations are helpful when inadequate modeling assumptions can be made by designers. Second, we evaluated annotations as tools to communicate design decisions to select the most appropriate solution to a challenge when multiple options are available. In both cases, results show statistically significant benefits of annotated models, suggesting the use of this technique as a valuable approach to improve design intent communication.
A Software Tool for Unit Process-Based Sustainable Manufacturing Assessment of Metal Components and Assemblies
Authors: Garretson Ian C. , Eastwood Christopher J. , Eastwood Michael D. , Haapala Karl R.
Published: January 2015

While environmental impact analysis is standard in accordance with ISO 14040:2006 using life cycle assessment software, such as GaBi and SimaPro, software tools supporting broader sustainability assessment are limited. Recent research has developed methods for sustainable manufacturing assessment and has led to unit manufacturing process models that can be used to quantify sustainability metrics. In spite of these advances, engineering designers must apply such methods in an ad hoc manner, which increases engineering analysis time and limits the utility of sustainability assessment in early design. Thus, manufacturing process models and supporting software tool are developed to assist design for manufacturing efforts pursuing sustainability performance improvement. The software is constructed using Visual Basic to create a graphical user interface for an MS Excel calculation engine. Using unit manufacturing process models, a product sustainability assessment can be generated by chaining together a sequential manufacturing process flow. In this way, cradle-to-gate assessments can support decisions made during product, process, and supply chain design. The method combines upstream inventory analysis and in-house unit process modeling to perform cradle-to-gate sustainability assessment. The utility of the approach is demonstrated for the assessment of an aircraft-like metal product assembly.
A Machine Learning-Based Design Representation Method for Designing Heterogeneous Microstructures
Authors: Xu Hongyi , Liu Ruoqian , Choudhary Alok , Chen Wei
Published: January 2015

In designing microstructural materials systems, one of the key research questions is how to represent the microstructural design space quantitatively using a descriptor set that is sufficient yet small enough to be tractable. Existing approaches describe complex microstructures either using a small set of descriptors that lack sufficient level of details, or using generic high order microstructure functions of infinite dimensionality without explicit physical meanings. We propose a new machine learning-based method for identifying the key microstructure descriptors from vast candidates as potential microstructural design variables. With a large number of candidate microstructure descriptors collected from literature covering a wide range of microstructural material systems, a 4-step machine learning-based method is developed to eliminate redundant microstructure descriptors via image analyses, to identify key microstructure descriptors based on structure-property data, and to determine the microstructure design variables. The training criteria of the supervised learning process include both microstructure correlation functions and material properties. The proposed methodology effectively reduces the infinite dimension of the microstructure design space to a small set of descriptors without a significant information loss. The benefits are demonstrated by an example of polymer nanocomposites optimization. We compare designs using key microstructure descriptors versus using empirically-chosen microstructure descriptors to validate the proposed method.
Reconstructing the Designers Intention for Reusing Failure Information
Authors: Iino Kenji , Nakao Masayuki , Ota Michelle Lovella M.
Published: January 2015

The function-structure (F-S) Map expresses the high-level structure of a design. It is often used in the early stage of conceptual design and serves as the starting point for a number of design tools like quality function deployment, failure mode and effects analysis, and more. On the other hand, in designing risk products whose failure can result in serious damage to the quality of human health or the society, the designer often uses tools like failure mode and effect analysis or fault tree analysis to detect weaknesses in design before the products are shaped. Failures, nonetheless, take place and cause negative impact to the society. It is then that the designer or other experts review the design to find flaws in the failure analysis tree or find elements or links in the graph that the designer overlooked. In other words, pre-production failure analysis is limited to the designer’s knowledge and insight. This paper proposes a way to make use of failure knowledge with past accident cases by constructing the F-S Map for the failed products and storing the information in a failure database. Designers can then compare the F-S Map for new products with linked representation of past failure cases and realize scenarios of failure he did not recognize or have to design carefully.
Multi-Objective Selection of Cutting Conditions in Advanced Machining Processes via an Efficient Global Optimization Approach
Authors: Aly Mohamed , Hamza Karim , Tauhiduzzaman Mohammed , Meshreki Mouhab , Nassef Ashraf O. , Veldhuis Stephen , Attia Helmi
Published: January 2015

Optimum selection of cutting conditions in high-speed and ultra-precision machining processes often poses a challenging task due to several reasons; such as the need for costly experimental setup and the limitation on the number of experiments that can be performed before tool degradation starts becoming a source of noise in the readings. Moreover, oftentimes there are several objectives to consider, some of which may be conflicting, while others may be somewhat correlated. Pareto-optimality analysis is needed for conflicting objectives; however the existence of several objectives (high-dimension Pareto space) makes the generation and interpretation of Pareto solutions difficult. The approach adopted in this paper is a modified multi-objective efficient global optimization (m-EGO). In m-EGO, sample data points from experiments are used to construct Kriging meta-models, which act as predictors for the performance objectives. Evolutionary multi-objective optimization is then conducted to spread a population of new candidate experiments towards the zones of search space that are predicted by the Kriging models to have favorable performance, as well as zones that are under-explored. New experiments are then used to update the Kriging models, and the process is repeated until termination criteria are met. Handling a large number of objectives is improved via a special selection operator based on principle component analysis (PCA) within the evolutionary optimization. PCA is used to automatically detect correlations among objectives and perform the selection within a reduced space in order to achieve a better distribution of experimental sample points on the Pareto frontier. Case studies show favorable results in ultra-precision diamond turning of Aluminum alloy as well as high-speed drilling of woven composites.
The Duality Between the Singularity of Bricard Mechanism and the Singularity of Stewart Platform
Authors: Slavutin Michael , Shai Offer , Müller Andreas
Published: January 2015

The duality (known also as symmetry) between serial chain manipulators and fully parallel mechanisms is well known in the literature. This paper takes this idea one step further, by introducing a systematic method that transforms mechanical systems into other and different mechanical systems so that the wrench screws in the original system gives rise to the relative twist screws in the second system. The mathematical foundation of this work relies on using the BB graph, a variant of graph representation widely used in mechanisms, possessing both the topology and geometry of the original system. From the dual graph of the latter it is possible to construct the dual system at a specific configuration. Relying on the equivalence between the dual systems, it is proved that if the screw system of a mechanism is at the singular position, so is that of its dual. This idea is demonstrated by showing the dual system of a Bricard mechanism, which is a 6/6 Stewart Platform in the singular position. The paper also shows that the cyclohexane molecule is dual to the 6/3 Stewart platform at the singular position, providing another perspective of the known mobility of this molecule.
Quantitative Comparison of High- and Low-Performing Teams in a Design Task Subject to Drastic Changes
Authors: McComb Christopher , Cagan Jonathan , Kotovsky Kenneth
Published: January 2015

Many design tasks are subject to changes in goals or constraints. For instance, a client might modify specifications after design has commenced, or a competitor may introduce a new technology or feature. A design team often cannot anticipate such changes, yet they pose a considerable challenge. This paper presents a study where engineering teams sought to solve a design task that was subject to two large, unexpected changes in problem formulation that occurred during problem solving. Continuous design data was collected to observe how the designers responded to the changes. We show that high- and low-performing teams demonstrated very different approaches to solving the problem and overcoming the changes. In particular, high-performing teams achieved simple designs and extensively explored small portions of the design space; low-performing teams explored complex designs with little exploration around a target area of the design space. These strategic differences are interpreted with respect to cognitive load theory and goal theory. The results raise questions as to the relationship between characteristics of design problems and solution strategies. In addition, an attempt at increasing the teams’ resilience in the face of unexpected changes is introduced by encouraging early divergent search.
Value Creation in Collaborative Analysis Model Development Processes
Authors: Sirin Göknur , Welo Torgeir , Yannou Bernard , Landel Eric
Published: January 2015

Integration and coordination of engineering analysis model is a vast development field in the context of complex product development. Engineers’ siloed way of working in combination with lack of efficiency in current model development process may cause inconsistency based on model interfaces, human errors, miscommunication between teams and misinterpretations. In lean terms, this may create multiple wastes, including waiting, overproduction leading to excess inventory, unnecessary processing and may be the most harmful: defects (e.g., incorrect models) with rework consequences. Hence, product manufacturing companies must establish effective processes to add value throughout the multidisciplinary distributed modeling environment. The goal of this paper is to propose a pull-control model development process, providing model architecture integration and coherent control in early design phase. This paper proposes also an appropriate reuse strategy; this allows for utilizing plug-and-play type modular product models managed through a single-source of authority concept. A pull-control development process helps prevent potential rework arising from inconsistencies related to definitions, know-how and stakeholders communication at an early stage of the design process. Also, the proposed black box models reuse strategy helps reduce human-related error such as lack of domain knowledge, experience and misinterpretations. The proposed method is used to identify and visualize potential improvement in terms of increased model transparency and reuse when transforming from the present to the suggested future modeling strategy. The research has been conducted by synthesizing findings from a literature review, in combination with observations and analysis of current analysis model development practices within the automotive OEM Renault in France.
Information Modeling for Sustainable Manufacturing Assessment
Authors: Wang Haoqi , Zhang Xu , Liang Chao , Zhang Qing
Published: January 2015

For sustainable manufacturing, energy consumption, air and waste emission, and environmental impact of product and process are analyzed in product and process development. The sustainability assessment is realized based on complete, structured information models of product, process and manufacturing resources, which are proposed in this paper. After analyzing the process of unit assembly and machining, two information models of unit assembly operation and unit machining process are given in UML representation. Besides the basic process parameters, the sustainable manufacturing related information such material consumption, energy usage, wastes and greenhouse air emission are also considered in the models. The manufacturing resource mode is core model to relate process and sustainability indicators. The resource information model of machining tool is proposed with process parameters and unit data of indictors. A sustainability assessment process is given in the end.
Quantifying the Price and Demand of Subassemblies in the End of Life Strategy of Product Resynthesis
Authors: John Suja Rose , Tucker Conrad S.
Published: January 2015

In the United States alone, millions of tons of waste are generated every year, highlighting the urgency for innovative solutions for waste management. Traditional strategies of reducing the amount of End-of-Life (EOL) products include reuse, recycle, remanufacture and disposal. Recently, resynthesis has been proposed in the design community as an alternate approach that aims to combine assemblies/subassemblies of EOL products from multiple domains to create a ‘new’ product, distinct from its parent products. The original work on resynthesis assumes that there is an equal demand for ‘resynthesized products’ based on the available supply of EOL components that the resynthesized products are composed of. Furthermore, the price was assumed to be equal to the price of similar products on the market. However, such an assumption may underestimate or overestimate the value of resynthesized products, which in turn impacts the demand of these products. Recent research has shown that customer reviews express customers’ true opinion and value for specific products or product features. The authors of this paper propose a data mining methodology to quantify the price and demand for resynthesized products by mining user-generated reviews of products publicly available on the internet. A case study involving a resynthesized electronic mouse and white board eraser is presented to demonstrate the feasibility of the proposed methodology.