bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Nonlinear Constraint Formulation for Direct and Inverse Vehicle Dynamics Modelling
Authors: Jarzębowska Elżbieta M. , Vantsevich Vladimir V. 
Published: January 2015

The paper presents an analysis of holonomic and non-holonomic material/non-material constrains that may be used in wheeled vehicle dynamics. Based on this analysis, a modified approach to the formulation of vehicle motion constraints is proposed. Specifically, a non-material constraint that limits vehicle kinematic parameters to a required motion, i.e. to a programmable motion that corresponds to required vehicle operational properties including turnability and stability of motion, is introduced.
The new concept of constraints put upon wheeled vehicle dynamics makes the resulting direct and inverse dynamic models more oriented towards required vehicle performance and facilitate the control design. The new constraint concept is illustrated by an example of a required vehicle acceleration performance.
Analysis of Optimal Cable Configurations in the Design of a 3-DOF Cable-Driven Robot Leg
Authors: Bryson Joshua T. , Agrawal Sunil K. 
Published: January 2015

The operational workspace of a cable-driven serial robot is largely dictated by the choice of cable placement and routing. As robot complexity increases with additional cables and degrees of freedom, the problem of designing a cable architecture can quickly become challenging.
This paper builds upon a previously described methodology to identify and analyze optimal cable configurations, expanding the approach to a 3-DoF robot leg driven by four cables. The methodology is used to analyze configuration trends in the routing and placement of the cables which achieve the desired range of motion for the robot. The results of the analysis are used to inform the design of a cable architecture which is shown to be capable of controlling the robot through the desired task.
Concept for an Integrated Workflow Planning of Dental Products Based on Federative Data Management
Authors: Heister Reinhard , Anderl Reiner 
Published: January 2015

Workflows to produce dental products by using CAD/CAM technology are very complex. Each patient needs an individual restoration. The challenge is to provide a patient individual production aiming at a price of mass production. But every single job has to run through an individual development as well manufacturing process. Typically, three stakeholders are involved in the workflow. The dentist performs the treatment and defines requirements for restoration. The dental laboratory plans the workflow and designs the reconstruction by using a dental CAD system. Subsequently, a milling center produces the restoration. Because of these highly heterogeneous workflows, diverse data streams and incompatibilities result. Often improper partners and resources are involved in the workflow. This fact is a significant source for errors. An additional complication is that errors are often discovered in late phases of the workflow.
To avoid high costs and unacceptable delivery times, the aim is to develop a new concept for integrated workflow planning. The concept depends on three parts: Federative dental data management (FDDM) as a basic approach, including anticipated logic and structured activities. The federative data management provides a loosely coupling of heterogeneous systems crossing enterprise borders by using web technology. The FDDM service depends on APP technology. Each participant applies its specialized APP: FDDMz (dentist), FDDMd (dental laboratory) and FDDMf (milling center). FDDM services enable a continuously integrated workflow throughout the whole process of a patient individual production. Each participating enterprise is able to register its available processes and resources. Information about resources like 3D dental scanner or milling machines are able to add, according to a global data model schema. This schema depends on an integrated information model with eight partial models: Collaboration, resource, process, workflow, requirements, product, work preparation and production model. This integrated information model provides dental information including interlinked objects. Through a proper anticipation logic, conclusions about later phases can be anticipated already at early phases. The last conceptual part is workflow management on frame of structured activities. By combining the information network with the anticipation logic, filtering of appropriate partners, processes, resources and sequences is supported. Next, a prototypical implementation is demonstrated exemplarily. This concept delivers an important contribution to increase process reliability and quality as well as to reduce delivery times and costs for digital dental workflows.
Vibrations of an Axial Bar Experiencing Periodic Unilateral Contact Using the Wavelet Balance Method
Authors: Jones Simon , Legrand Mathias 
Published: January 2015

Efficiently predicting the vibratory responses of flexible structures which experience unilateral contact is becoming of high engineering importance. An example of such a system is a rotor blade within a turbine engine; small operating clearances and varying loading conditions often result in contact between the blade and the casing.
The method of weighted residuals is a effective approach to simulating such behaviour as it can efficiently enforce time-periodic solutions of lightly damped, flexible structures experiencing unilateral contact. The Harmonic Balance Method (HBM) based on Fourier expansion of the sought solution is a common formulation, though it is hypothesized wavelet bases that can sparsely define nonsmooth solutions may be superior. This is investigated herein using an axially vibrating rod with unilateral contact conditions. A distributional formulation in time is introduced allowing periodic, square-integrable trial functions to approximate the second-order equations. The mixed wavelet Petrov-Galerkin solutions are found to yield consistent or better results than HBM, with similar convergence rates and seemingly more accurate contact force prediction.
Experimental and Numerical Analysis of the Effect of Segmentation on Modal Loss Factor of Constrained Layer Damped Beam
Authors: Hujare Pravin P. , Sahasrabudhe Anil D. , Chinchawade Sanket D. 
Published: January 2015

This paper presents experimental investigation on the damping effects of constrained layer treatment by cutting the constraining layer and constrained layer of viscoelastic material (VEM). The constraining layer causes shear in the damping material as the structure deforms. The shear deformation occurring in the viscoelastic core is mainly responsible for the dissipation of energy.
The shear deformation in the VEM is not significant in regions where the bending moment is maximal. Mostly only extensional deformation occurs in the damping layer. The local high-shear deformation in the damping material is produced by placing a cut at the region of highest curvature. Cutting both the constraining and the constrained layer, which leads to segmentation, increases the shear deformation at that position. This appropriate position of high bending moment for segmentation is obtained by MATLAB program.
The modal loss factor of constrained layer damped (CLD) beam is obtained by half-power bandwidth method using FFT analyzer. The CLD beams are prepared as per ASTM Standard E 756-05. Extensive experiments are conducted by making number of separate segmented CLD beams of different viscoelastic damping materials.
A three dimensional model of cantilever CLD beam has been used for numerical analysis. In this work, finite element commercial software MSC/NASTRAN is used to simulate the dynamic response of a CLD beam. The modal loss factor of constrained layer damped (CLD) beam is measured by Modal Strain Energy (MSE) Method.
This is a new method for enhancement of damping capabilities of constrained layer damping. It is found that the performance of segmented CLD beam using passive treatment shows significant improvement in modal loss factor which leads to vibration attenuation of beam. The numerical results are corroborated with experimental data obtained for segmented CLD beam. The analyzed finite element models are found to provide reliable results and compared very well with experimentally acquired data.
The Role of the Orthogonal Helicoid in the Generation of the Tooth Flanks of Involute-Gear Pairs With Skew Axes
Authors: Figliolini Giorgio , Stachel Hellmuth , Angeles Jorge 
Published: January 2015

Camus’ concept of Auxiliary Surface (AS) is extended to the case of involute gears with skew axes. In the case at hand, we show that the AS is an orthogonal helicoid whose axis a) lies in the cylindroid and b) is normal to the instant screw axis of one gear with respect to its meshing counterpart; in general, the helicoid axis is skew with respect to the latter. According to the spatial version of Camus’ Theorem, any line attached to the AS, in particular any generator g of AS itself, can be chosen to generate a pair of conjugate flanks with line contact.
While the pair of conjugate flanks is geometrically feasible, as they always share a line of contact and the tangent plane at each point of this line, there are poses where the flanks even have a common Disteli axis. Then there is a G2-contact at the striction point and the two surfaces penetrate each other.
The outcome is that the surfaces are not realizable as tooth flanks. Nevertheless, this is a fundamental step towards the synthesis of the flanks of involute gears with skew axes.
The Y-Prize Competition: An Inverted X-Prize Competition for Commercializing University Research
Authors: Hayward Rebecca , Eckert Michelle , Thomas Justin , Whitzer Mickey , Chaudhuri Saikat , Fitzsimons Tom , Hsu David , Yim Mark , Kumar Vijay 
Published: January 2015

We have seen an increase in engineering competitions for high school and collegiate students ranging from concrete canoes [1] to human powered vehicles [2], FIRST Robotics [3] to iGem [4], and hackathons to business plan competitions. Each of these efforts challenges students to develop new ideas, methodologies, technologies, and designs to solve problems. Indeed, on a larger scale, X-Prize competitions foster innovation by getting top inventors to compete against one another to create solution methodologies in specific problem domains (e.g., automotive, space, or genomics).
We have developed the Y-Prize competition that flips the X-Prize structure by challenging students to innovate in the problem space instead of the solution space. In the problem space, students compete to develop the best applications for technological solutions that have been developed in university research laboratories. The three goals of the Y-Prize competition are: a) Expose a wide range of students in and outside engineering to emerging technology and to shine the spotlight on the opportunities in research labs on campus; b) Educate university students on the challenges inherent with technology transfer in research laboratories and engage them in technological innovation; and c) Develop and evaluate a new methodology for innovation based on cutting-edge university research which dramatically increases the number of students engaged in technology transfer.
A Novel Pressure Compensating Valve for Low-Cost Drip Irrigation
Authors: Wiens A. Josh , Winter Amos G. 
Published: January 2015

This paper presents a novel pressure-compensating flow restrictor for low-cost/low-pressure drip irrigation systems. There are nearly one billion subsistence farmers in the developing world who lack the resources and opportunities to rise out of poverty. Irrigation is an effective development strategy for this population, enabling farmers to increase crop yields and grow more lucrative plant varieties. Unfortunately, as a large fraction of subsistence farmers live off the electrical grid, the capital cost of solar or diesel powered irrigation systems makes them unobtainable. This cost could be drastically reduced by altering drip irrigation systems to operate at a decreased pressure such that lower pumping power is required. The work presented here aims to accomplish this by designing a drip emitter that operates at 0.1 bar, 1/10 the pressure of current products, while also providing pressure-compensation to uniformly distribute flow over a field.
Our proposed pressure compensating solution is inspired by the resonating nozzle of a deflating balloon. First, a reduced order model is developed to understand the physical principles which drive the cyclic collapse of the balloon nozzle. We then apply this understanding to propose a pressure compensating emitter consisting of compliant tube in series with a rigid diffuser. A scaling analysis is performed to determine the ideal geometry of the system and the reduced order model is applied to demonstrate that the proposed design is capable of pressure compensation in the required operation range. Preliminary experiments demonstrating the collapse effect are presented, along with initial work to translate the concept to a robust physical device.
Energy Harvesting From Controlled Buckling of a Horizontal Piezoelectric Beam
Authors: Ansari M. H. , Karami M. Amin 
Published: January 2015

A piezoelectric vibration energy harvester is designed to generate electricity under the weight of passing crowds. The piezoelectric beam buckles to a controlled extent when the device is stepped on. The device is a seven bar mechanism. The upper and lower bars as well as the lateral links are rigid. The middle horizontal beam is a bimorph piezoelectric beam. Damages to the piezoelectric beam are avoided by constraining its axial deformation. This constrain is implemented by limiting squeezing of the mechanism. When a person moves over the mechanism or steps off the devices it causes the bimorph to buckle or return to the unbuckled condition. The transitions result in vibrations of the piezoelectric beam and thus generate energy.
In this paper, the energy harvester is analytically modeled. The electro-mechanical coupling and the geometric nonlinearities have been included in the model for the piezoelectric beam. The design criteria for the device are discussed. It is demonstrated that the device can be realized with commonly used piezoelectric patches and can generate hundreds of milliwatts of power. A three part beam is also investigated. The effect of design parameters on the generated power and required tolerances are illustrated.
The proposed device could be implemented in the sidewalks producing energy from the weight of people passing over it. Other possible applications are portable smart phones chargers and shoe hill energy harvesting. Dance floor of a club is another applicable example for using this harvester. The main advantage of using horizontal configuration instead of a vertical arrangement is the ease of placement in the pavements.
Kinematic Analysis of the 3-RPS Cube Parallel Manipulator
Authors: Nurahmi Latifah , Schadlbauer Josef , Husty Manfred , Wenger Philippe , Caro Stéphane 
Published: January 2015

The 3-RPS Cube parallel manipulator, a three-degree-of-freedom parallel manipulator initially proposed by Huang et al. in 1995, is analysed in this paper with an algebraic approach, namely Study kinematic mapping of the Euclidean group SE(3) and is described by a set of eight constraint equations.
A primary decomposition is computed over the set of eight constraint equations and reveals that the manipulator has only one operation mode. Inside this operation mode, it turns out that the direct kinematics of the manipulator with arbitrary values of design parameters and joint variables, has sixteen solutions in the complex space. A geometric interpretation of the real solutions is given.
The singularity conditions are obtained by deriving the determinant of the Jacobian matrix of the eight constraint equations. All the singular poses are mapped onto the joint space and are geometrically interpreted. By parametrizing the set of constraint equations under the singularity conditions, it is shown that the manipulator is in actuation singularity. The uncontrolled motion gained by the platform is also provided.
Graph Based Representation and Analyses for Conceptual Stages
Authors: Coatanéa Eric , Nonsiri Sarayut , Christophe Francois , Mokammel Faisal 
Published: January 2015

What is the fundamental similarity between investing in stock of a company, because you like the products of this company, and selecting a design concept, because you have been impressed by the esthetic quality of the presentation made by the team developing the concept?
Except that both decisions are based on a surface analysis of the situations, they both reflect a fundamental human’s cognitive feature. Human brain is profoundly trying to minimize the efforts required to solve a cognitive task and is using when possible an automatic mode relying on recognition, memory, and causality. This mode is even used in some occasion without the engineer being conscious of it. Such type of tendencies are naturally pushing engineers to rush into known solutions, to avoid analyzing the context of a design problem, to avoid modelling design problems and to take decision based on isolated evidences. Those behaviors are familiar to experience teachers and engineers. This tendency is magnified by the time pressure imposed to the engineering design process. Early phases in particular have to be kept short despite the large impact of decisions taken at this stage. Few support tools are capable of supporting a deep analysis of the early design conditions and problems regarding the fuzziness and complexity of the early stage. The present article is hypothesizing that the natural ability of humans to deal with cause-effects relations push toward the massive usage of causal graphs analysis during the design process and specifically during the early phases. A global framework based on graphs is presented in this paper to efficiently support the early stages. The approach used to generate graphs, to analyze them and to support creativity based on the analysis is forming the central contribution of this paper.
MyD88-Dependent Signaling Drives Host Survival and Early Cytokine Production during Histoplasma capsulatum Infection
Authors: Coady Alison , Sil Anita 
Published: January 2015

ABSTRACTThe ability of the innate immune system to trigger an adaptive T cell response is critical to resolution of infection with the fungal pathogenHistoplasma capsulatum. However, the signaling pathways and cell types involved in the recognition of and response to this respiratory pathogen remain poorly defined. Here, we show that MyD88, an adaptor protein vital to multiple innate immune pathways, is critically required for the host response toHistoplasma. MyD88-deficient (MyD88−/−) mice are unable to control the fungal burden and are more sensitive toHistoplasmainfection than wild-type, Dectin-1−/−, or interleukin 1 receptor-deficient (IL-1R−/−) mice. We found that MyD88 is necessary for the production of key early inflammatory cytokines and the subsequent recruitment of inflammatory monocytes to the lung. In both ourin vitroandex vivoanalyses, MyD88 was intrinsically required in dendritic cells and alveolar macrophages for initial cytokine production. Additionally, MyD88-deficient bone marrow-derived dendritic cells fail to efficiently control fungal growth when cocultured with primed splenic T cells. Surprisingly, mice that lack MyD88 only in dendritic cells and alveolar macrophages are competent for early cytokine production and normal survival, indicating the presence of compensatory and redundant MyD88 signaling in other cell types during infection. Ultimately, global MyD88 deficiency prevents proper T cell activation and gamma interferon (IFN-γ) production, which are critical for infection resolution. Collectively, this work reveals a central role for MyD88 in coordinating the innate and adaptive immune responses to infection with this ubiquitous fungal pathogen of humans.
Small-Molecule Inhibitors of Gram-Negative Lipoprotein Trafficking Discovered by Phenotypic Screening
Authors: McLeod Sarah M. , Fleming Paul R. , MacCormack Kathleen , McLaughlin Robert E. , Whiteaker James D. , Narita Shin-ichiro , Mori Makiko , Tokuda Hajime , Miller Alita A. 
Published: January 2015

ABSTRACT

In Gram-negative bacteria, lipoproteins are transported to the outer membrane by the Lol system. In this process, lipoproteins are released from the inner membrane by the ABC transporter LolCDE and passed to LolA, a diffusible periplasmic molecular chaperone. Lipoproteins are then transferred to the outer membrane receptor protein, LolB, for insertion in the outer membrane. Here we describe the discovery and characterization of novel pyridineimidazole compounds that inhibit this process.
Escherichia coli
mutants resistant to the pyridineimidazoles show no cross-resistance to other classes of antibiotics and map to either the LolC or LolE protein of the LolCDE transporter complex. The pyridineimidazoles were shown to inhibit the LolA-dependent release of the lipoprotein Lpp from
E. coli
spheroplasts. These results combined with bacterial cytological profiling are consistent with LolCDE-mediated disruption of lipoprotein targeting to the outer membrane as the mode of action of these pyridineimidazoles. The pyridineimidazoles are the first reported inhibitors of the LolCDE complex, a target which has never been exploited for therapeutic intervention. These compounds open the door to further interrogation of the outer membrane lipoprotein transport pathway as a target for antimicrobial therapy.
The Formation of Streptococcus mutans Persisters Induced by the Quorum-Sensing Peptide Pheromone Is Affected by the LexA Regulator
Authors: Leung Vincent , Ajdic Dragana , Koyanagi Stephanie , Lévesque Céline M. 
Published: January 2015

ABSTRACT

The presence of multidrug-tolerant persister cells within microbial populations has been implicated in the resiliency of bacterial survival against antibiotic treatments and is a major contributing factor in chronic infections. The mechanisms by which these phenotypic variants are formed have been linked to stress response pathways in various bacterial species, but many of these mechanisms remain unclear. We have previously shown that in the cariogenic organism
Streptococcus mutans
, the quorum-sensing peptide CSP (competence-stimulating peptide) pheromone was a stress-inducible alarmone that triggered an increased formation of multidrug-tolerant persisters. In this study, we characterized SMU.2027, a CSP-inducible gene encoding a LexA ortholog. We showed that in addition to exogenous CSP exposure, stressors, including heat shock, oxidative stress, and ofloxacin antibiotic, were capable of triggering expression of
lexA
in an autoregulatory manner akin to that of LexA-like transcriptional regulators. We demonstrated the role of LexA and its importance in regulating tolerance toward DNA damage in a noncanonical SOS mechanism. We showed its involvement and regulatory role in the formation of persisters induced by the CSP-ComDE quorum-sensing regulatory system. We further identified key genes involved in sugar and amino acid metabolism, the clustered regularly interspaced short palindromic repeat (CRISPR) system, and autolysin from transcriptomic analyses that contribute to the formation of quorum-sensing-induced persister cells.