bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term course of oxaliplatin‐induced polyneuropathy: a prospective 2‐year follow‐up study
Authors: Briani Chiara , Argyriou Andreas A. , Izquierdo Cristina , Velasco Roser , Campagnolo Marta , Alberti Paola , Frigeni Barbara , Cacciavillani Mario , Bergamo Francesca , Cortinovis Diego , Cazzaniga Marina , Bruna Jordi , Cavaletti Guido , Kalofonos Haralabos P.
Published: January 2015

This prospective study sought to identify the potential reversibility of oxaliplatin‐induced peripheral neuropathy (OXAIPN) by following‐up its long‐term course 2 years after discontinuation of oxaliplatin (OXA)‐based chemotherapy. Participants were 91 colorectal cancer patients treated with OXA‐based chemotherapy. Neurological assessment, clinical Total Neuropathy Score© (TNSc©) and nerve conduction studies were performed at baseline (T0), the end of chemotherapy (T1) and 2 years (T2) after discontinuation of chemotherapy. A total of 73 of 91 (80%) patients experienced OXAIPN at T1. At a median follow‐up of 25 months, persistence of chronic OXAIPN was present in 61 of 73 patients (84%) and complete resolution was present in 12 patients (17%). Longitudinal comparison of TNSc© values between T1 and T2 revealed that the overall severity of OXAIPN in those 61 patients significantly decreased over time. Median TNSc© values were nine (range: 2–15) at T1 vs. four (range: 2–12) at T2 (P < 0.001). Likewise, sensory nerve conduction measures at T2 significantly improved in all sensory nerves tested, compared with T1. Severity of OXAIPN at T2 was significantly associated (P < 0.001) with high severity of OXAIPN at T1. In conclusion, persistence of OXAIPN beyond 2 years after finishing chemotherapy is common. Clinical and neurophysiological improvement is observed, although recovery is often incomplete.
Nebulised adrenaline to manage a life‐threatening complication in a pug with trismus
Authors: Leece E. , Cherubini G.
Published: January 2015

A 13‐month‐old pug with severe trismus because of suspected masticatory muscle myositis underwent anaesthesia for magnetic resonance imaging. When regurgitation occurred, the tongue was pulled from the mouth to enable suctioning but could not be repositioned into the oral cavity as it was not possible to open the mouth. Swelling due to venous congestion and a bite wound were treated using nebulised adrenaline and resolved within 2 hours allowing retraction of the tongue. The use of nebulised adrenaline offers a non‐invasive method of managing this potentially life‐threatening complication.
Involvement of the H1 Histamine Receptor, p38 MAP Kinase, Myosin Light Chains Kinase, and Rho/ROCK in Histamine‐Induced Endothelial Barrier Dysfunction
Authors: Adderley Shaquria P. , Zhang Xun E. , Breslin Jerome W.
Published: January 2015

Objective

The mechanisms by which histamine increases microvascular permeability remain poorly understood. We tested the hypothesis that H1 receptor activation disrupts the endothelial barrier and investigated potential downstream signals.

Methods

We used confluent EC monolayers, assessing TER as an index of barrier function. HUVEC, HCMEC, and HDMEC were compared. Receptor expression was investigated using Western blotting, IF confocal microscopy and RT‐PCR. Receptor function and downstream signaling pathways were tested using pharmacologic antagonists and inhibitors, respectively.

Results

We identified H1–H4 receptors on all three EC types. H1 antagonists did not affect basal TER but prevented the histamine‐induced decrease in TER. Blockade of H2 or H3 attenuated the histamine response only in HDMEC, while inhibition of H4 attenuated the response only in HUVEC. Combined inhibition of both PKC and PI3K caused exaggerated histamine‐induced barrier dysfunction in HDMEC, whereas inhibition of p38 MAP kinase attenuated the histamine response in all three EC types. Inhibition of RhoA, ROCK, or MLCK also prevented the histamine‐induced decrease in TER in HDMEC.

Conclusion

The data suggest that multiple signaling pathways contribute to histamine‐induced endothelial barrier dysfunction via the H1 receptor.
Transcriptome analysis of cyclic AMP‐dependent protein kinase A–regulated genes reveals the production of the novel natural compound fumipyrrole by Aspergillus fumigatus
Authors: Macheleidt Juliane , Scherlach Kirstin , Neuwirth Toni , Schmidt‐Heck Wolfgang , Straßburger Maria , Spraker Joseph , Baccile Joshua A. , Schroeder Frank C. , Keller Nancy P. , Hertweck Christian , Heinekamp Thorsten , Brakhage Axel A.
Published: January 2015

Aspergillus fumigatus is an opportunistic human pathogenic fungus causing life‐threatening infections in immunocompromised patients. Adaptation to different habitats and also virulence of the fungus depends on signal perception and transduction by modules such as the cyclic AMP‐dependent protein kinase A (PKA) pathway. Here, by transcriptome analysis, 632 differentially regulated genes of this important signaling cascade were identified, including 23 putative transcriptional regulators. The highest upregulated transcription factor gene was located in a previously unknown secondary metabolite gene cluster, which we named fmp, encoding an incomplete non‐ribosomal peptide synthetase, FmpE. Overexpression of the regulatory gene fmpR using the TetOn system led to the specific expression of the other six genes of the fmp cluster. Metabolic profiling of wild type and fmpR overexpressing strain by HPLC‐DAD and HPLC‐HRESI‐MS and structure elucidation by NMR led to identification of 5‐benzyl‐1H‐pyrrole‐2‐carboxylic acid, which we named fumipyrrole. Fumipyrrole was not described as natural product yet. Chemical synthesis of fumipyrrole confirmed its structure. Interestingly, deletion of fmpR or fmpE led to reduced growth and sporulation of the mutant strains. Although fmp cluster genes were transcribed in infected mouse lungs, deletion of fmpR resulted in wild‐type virulence in a murine infection model.
The Campylobacter jejuni CprRS two‐component regulatory system regulates aspects of the cell envelope
Authors: Svensson Sarah L. , Hyunh Steven , Parker Craig T. , Gaynor Erin C.
Published: January 2015

Campylobacter jejuni is a leading cause of food‐borne gastroenteritis in humans. It lives commensally in the gastrointestinal tract of animals, and tolerates variable conditions during transit/colonization of susceptible hosts. The C. jejuni CprRS two‐component system contains an essential response regulator (CprR), and deletion of the cprS sensor kinase enhances biofilms. We sought to identify CprRS‐regulated genes and better understand how the system affects survival. Expression from the cprR promoter was highest during logarithmic growth and dependent on CprS. CprRD52A did not support viability, indicating that CprR phosphorylation is essential despite the dispensability of CprS. We identified a GTAAAC consensus bound by the CprR C‐terminus; the Asp52 residue of full‐length CprR was required for binding, suggesting phosphorylation is required. Transcripts differing in expression in ΔcprS compared with wildtype (WT) contained a putative CprR binding site upstream of their promoter region and encoded htrA (periplasmic protease upstream of cprRS) and peb4 (SurA‐like chaperone). Consistent with direct regulation, the CprR consensus in the htrA promoter was bound by CprRCTD. Finally, ΔhtrA formed enhanced biofilms, and ΔcprS biofilms were suppressed by Mg2+. CprRS is the first C. jejuni regulatory system shown to control genes related to the cell envelope, the first line of interaction between pathogen and changing environments.
The signalling mucin Msb2 regulates surface sensing and host penetration via BMP1 MAP kinase signalling in Botrytis cinerea
Authors: Leroch Michaela , Mueller Nathalie , Hinsenkamp Isabel , Hahn Matthias
Published: January 2015

Botrytis cinerea is a necrotrophic fungus that infects a wide range of fruit, vegetable and flower crops. Penetration of the host cuticle occurs via infection structures that are formed in response to appropriate plant surface signals. The differentiation of these structures requires a highly conserved mitogen‐activated protein (MAP) kinase cascade including the MAP kinase BMP1. In yeast and several plant‐pathogenic fungi, the signalling mucin Msb2 has been shown to be involved in surface recognition and MAP kinase activation. In this study, a B. cinerea msb2 mutant was generated and characterized. The mutant showed normal growth, sporulation, sclerotia formation and stress resistance. In the absence of nutrients, abnormal germination with multiple germ tubes was observed. In the presence of sugars, normal germination occurred, but msb2 germlings were almost unable to form appressoria or infection cushions on hard surfaces. Nevertheless, the msb2 mutant showed only a moderate delay in lesion formation on different host plants, and formed expanding lesions similar to the wild‐type. Although the wild‐type showed increasing BMP1 phosphorylation during the first hours of germination on hard surfaces, the phosphorylation levels in the msb2 mutant were strongly reduced. Several genes encoding secreted proteins were found to be co‐regulated by BMP1 and Msb2 during germination. Taken together, B. cinerea Msb2 is likely to represent a hard surface sensor of germlings and hyphae that triggers infection structure formation via the activation of the BMP1 MAP kinase pathway.
MoTup1 is required for growth, conidiogenesis and pathogenicity of Magnaporthe oryzae
Authors: Chen Yue , Zhai Su , Sun Yi , Li Mengying , Dong Yanhan , Wang Xiaoli , Zhang Haifeng , Zheng Xiaobo , Wang Ping , Zhang Zhengguang
Published: January 2015

The general transcriptional repressor Tup1 proteins play important regulatory roles in the growth and development of fungi. In this report, we characterized MoTup1, a protein homologous to Tup1 of Saccharomyces cerevisiae, from M. oryzae. Disruption of MoTUP1 resulted in severe mycelial growth reduction and a defect in conidiogenesis. We found that MoTup1 is required for the maintenance of cell wall integrity by regulating the expression of the genes involved in cell wall biosynthesis. Pathogenicity assays indicated that the ΔMotup1 mutants lost the ability to invade both rice and barley hosts. Moreover, observation of rice epidermis penetration showed that the hyphal tips of the mutants could still form appressorium‐like structures, but were unable to invade host cells. Taken together, our results demonstrate that M. oryzae MoTup1 is an important regulatory factor in fungal growth, development and pathogenesis on hosts.
Pericardial Effusion Following Drain Removal after Percutaneous Epicardial Access for an Electrophysiology Procedure
Authors: KILLU AMMAR M. , WAN SIU‐HIN , MUNGER THOMAS M. , HODGE DAVID O. , MULPURU SIVA , PACKER DOUGLAS L. , ASIRVATHAM SAMUEL J. , FRIEDMAN PAUL A.
Published: January 2015

Objectives

To determine the frequency and predictors of pericardial effusion following epicardial sheath removal.

Background

Pericardial effusion can occur following cardiac surgical or interventional procedures including percutaneous epicardial access (EpiAcc), which is increasingly used as part of electrophysiology ablation procedures.

Methods

A retrospective analysis of the Mayo Clinic comprehensive electronic medical record was performed from all patients who underwent planned EpiAcc as part of an electrophysiology ablation procedure between January 1, 2004 and June 30, 2013.

Results

Of 144 patients (mean age 51.3 ± 15.5 years, 68% male) who underwent planned EpiAcc as part of an electrophysiology ablation (95.8% pericardial access success rate), seven (4.9%) developed a postoperative pericardial effusion requiring repeat EpiAcc. Inferior access was utilized in 74 (51.4%) patients. Patients with pericardial effusion tended to be younger (41.1 years vs 51.8 years, P = 0.08) and were more likely to have undergone inferior approach access (85.7% vs 49.6%, P = 0.06) than those who did not develop postoperative pericardial effusion. Seventy‐one percent of patients with postoperative pericardial effusion versus 32.1% of patients without postoperative pericardial effusion had a preprocedure ejection fraction ≥55% (P = 0.03). There were no procedural‐related deaths, and no difference in mortality between groups.

Conclusions

Postoperative pericardial effusion requiring repeat access/drainage was relatively infrequent, occurring in 4.9% of patients shortly after epicardial procedures. While the majority occur early and therefore require close observation, some patients may present in a delayed manner.
Blood flow in internal carotid and vertebral arteries during graded lower body negative pressure in humans
Authors: Ogoh Shigehiko , Sato Kohei , Okazaki Kazunobu , Miyamoto Tadayoshi , Hirasawa Ai , Sadamoto Tomoko , Shibasaki Manabu
Published: January 2015

New Findings

What is the central question of this study?

Recently, the heterogeneity of the cerebral arterial circulation has been argued. Orthostatic tolerance may be associated with an orthostatic stress‐induced change in blood flow in vertebral arteries rather than in internal carotid arteries, because vertebral arteries supply blood to the medulla oblongata, which is the location of important cardiac, vasomotor and respiratory control centres.

What is the main finding and its importance?

The effect of graded orthostatic stress on vertebral artery blood flow is different from that on internal carotid artery blood flow. This response allows for the possibility that orthostatic tolerance may be associated with haemodynamic changes in posterior rather than anterior cerebral blood flow.

Recently, the heterogeneity of the cerebral arterial circulation has been argued, but the characteristics of vertebral artery (VA) and internal carotid artery (ICA) blood flow during graded orthostatic stress remain unknown. We hypothesized that the change in blood flow in VA is not similar to that in ICA blood flow during graded orthostatic stress. We measured blood flows in both ICA and VA during graded lower body negative pressure (LBNP; −20, −35 and −50 mmHg) by using two colour‐coded ultrasound systems. The effect of graded orthostatic stress on the VA blood flow was different from that on the ICA blood flow (LBNP × artery, P = 0.006). The change in ICA blood flow was associated with the level of LBNP (r = 0.287, P = 0.029), and a reduction in ICA blood flow from pre‐LBNP was observed during −50 mmHg LBNP (from 411 ± 35 to 311 ± 40 ml min−1, P = 0.044) without symptoms of presyncope. In contrast, VA blood flow was unchanged during graded LBNP compared with the baseline (P = 0.597) relative to the reduction in ICA blood flow and thus there was no relationship between VA blood flow and the level of LBNP (r = 0.167, P = 0.219). These findings suggest that the change in ICA blood flow is due to the level of LBNP during graded orthostatic stress, but the change in VA blood flow is different from that in ICA blood flow across the different levels of LBNP. These findings provide the possibility that posterior cerebral blood flow decreases only during severe orthostatic stress and is therefore more likely to be linked with orthostatic tolerance.
Elastodynamic Modeling and Simulation of the AIRBUS A380 Wing
Authors: Ghaith Fadi A. , Haque MD F.
Published: January 2015

This paper addresses the dynamic modeling and simulation of the AIRBUS A380 wing. The governing equations of motion which describe the vibrational motion of the wing were derived using the extended Hamilton’s principle. The elastic wing structure is assumed to follow a Bernoulli-Euler cantilever beam clamped on the moving fuselage and carrying two Trent-900 engines on its span which were treated as lumped masses. The obtained equations of motion of the wing model were analyzed by means of the unconstrained modal analysis and the system natural frequencies were estimated. In order to verify the obtained results, the dynamic response was simulated using the Finite Element (FE) computational software by which the vibrational response was generated under several types of excitation. The obtained results showed good match between the natural frequencies extracted from the mathematical model and the corresponding ones generated by FE simulation. Also the developed computational model in this investigation was found successful in capturing the vibrational motions of a wide spectrum of relevant aerodynamic and unbalance loading conditions.
Non-Linear Dynamics of Gear Pair With Combined Internal and External Periodic Excitations
Authors: Li Yinggang , Chen Tianning , Wang Xiaopeng
Published: January 2015

In this paper, we theoretically investigate the nonlinear dynamic characteristics of gear pair system under combined internal and external periodic excitations. The dynamic model of a viscously damped gear pair model with periodic time-varying stiffness, backlash, static transmission error and external periodic excitation is established. The incremental harmonic balance method (IHBM) is applied to analyze the frequency response characteristics as well as the effects of the periodic time-varying stiffness, excitation force amplitude and viscous damping ratio on the dynamic characteristics. Results show that, under combined internal and external periodic excitations, the multi-valued properties and jump phenomena occur not only in primary resonance frequency but also in super harmonic frequency, the excitation force amplitude has less influence on the nonlinear dynamic characteristics and the increase of the excitation force amplitude could no longer control the nonlinear vibration of gear system, which are different from the dynamic characteristics under internal periodic excitations.
A Generalized “Max-Min” Sample for Reliability Assessment With Dependent Variables
Authors: Lacaze Sylvain , Missoum Samy
Published: January 2015

This paper introduces a novel approach for reliability assessment with dependent variables. In this work, the boundary of the failure domain, for a computational problem with expensive function evaluations, is approximated using a Support Vector Machine and an adaptive sampling scheme. The approximation is sequentially refined using a new adaptive sampling scheme referred to as generalized “max-min”. This technique efficiently targets high probability density regions of the random space. This is achieved by modifying an adaptive sampling scheme originally tailored for deterministic spaces (Explicit Space Design Decomposition). In particular, the approach can handle any joint probability density function, even if the variables are dependent. In the latter case, the joint distribution might be obtained from copula. In addition, uncertainty on the probability of failure estimate are estimated using bootstrapping. A bootstrapped coefficient of variation of the probability of failure is used as an estimate of the true error to determine convergence. The proposed method is then applied to analytical examples and a beam bending reliability assessment using copulas.
Hopf Bifurcations, Quasi-Periodic Oscillations and Frequency Locking Zones in a Self-Excited System Driven by Parametric and External Excitations
Authors: Warminski Jerzy , Warminska Anna
Published: January 2015

Vibrations of a nonlinear self-excited system driven by parametric and/or external excitations are studied in the paper. The model is composed of a self-excitation term represented by a nonlinear van der Pol function, periodically varied stiffness which represents parametric excitation and external harmonic force. Interactions between self and parametric or/and external force lead to complex behaviours observed by quasi-periodic or chaotic motions but under specific conditions, near resonance zones the response is harmonic. The transition from quasi-periodicity to periodic oscillations is caused by so called the frequency locking phenomenon which in fact corresponds to the second kind Hopf bifurcation (Neimark-Sacker bifurcation). The periodic resonances can be determined analytically, quasi-periodic oscillations however are investigated mainly numerically. The goal of this paper is to determine quasi-periodic dynamics and Hopf bifurcations analytically by using the multiple time scale method (MSM) in two steps: (1) to determine periodic solutions of the fast flow by the first order MSM and (2) to determine periodic solutions of the slow–flow by the second order MSM. The analytical solutions obtained in both scales allow determining bifurcation points of the system.
Experimental Research of Tire Elastomer-Surface Tribological Properties
Authors: Kupreyanov Andrei A. , Morozov Mikhail V. , Belousov Boris N. , Ksenevich Tatiana I. , Vantsevich Vladimir V.
Published: January 2015

This paper presents a new experimental test rig and experimental findings on tire elastomer-surface friction characteristics that are necessary for modeling tire thermodynamic characteristics and then tire characteristics, including the μ-curve in the driving and braking modes of operation.

Unlike common approaches, the paper offers experimental procedures and test results on both steady and non-steady friction process by introducing (i) velocity factor, (ii) normal pressure distribution, and (iii) a temperature factor in the elastomer-surface contact. The group of (i), (ii), and (iii)-listed factors, taken together, represents the key elements by means of which tribological properties of the tire-road interaction, i.e., an elastomer-surface friction pair, impact the μ-curve.
Five Steps for Crafting a Doctoral Research Proposal in Engineering Design
Authors: Khosrojerdi Amirhossein , Rezapour Shabnam , Allen Janet K. , Mistree Farrokh
Published: January 2015

Doctoral students are required to prepare and defend a research proposal. In this paper, we present five steps for doctoral students to identify the questions that are worthy of investigation and thence to develop a research plan and proposal. Our method involves five steps, namely,

Step 1: Frame the problem

Step 2: Develop a research plan

Step 3: Verification and validation

Step 4: Proposal template

Step 5: Proposal outline

We illustrate the method using the sustainable design of plug-in-electric vehicle charging stations as an example.
Using Assistive Device Design to Implement Cornerstone Design in a Junior Level Machine Design II Course
Authors: Reffeor Wendy S.
Published: January 2015

Assistive device design was used in a Junior level Machine Design II course to reinforce design concepts while increasing student awareness of the specialized needs of individual product users. Since these projects addressed the needs of specific users and/or a group of specific users, they were externally funded. This provided an incentive for student groups to accomplish the task assigned with a greater level of attention to detail and need to satisfy the design constraints. In all cases, student teams provided a useable, deliverable device to the customer at the end of the semester. A survey of the customers was completed at the end of the semester to determine customer satisfaction with the process. Overall, customers were highly satisfied with the results, although many expressed frustration due to the project timeline being too long.

In all cases, a useable product was delivered at the end of the project. However, improvements were also possible in all cases and further work will be done on the products to better align them with user needs.

Student response to the project was as expected. The students felt this project was a very valuable learning experience and reinforced not only the course material, but also forced them to learn about technologies not discussed in class. However, many commented that the time required to complete the project as well as the traditional course work was far greater than the time required of their peers taking the course with a “paper” project.
Performance Barriers for Single-Degree-of-Freedom Energy Harvesters Under Generic Stochastic Excitation
Authors: Joo Han Kyul , Sapsis Themistoklis P.
Published: January 2015

We develop performance criteria for the objective comparison of different classes of single-degree-of-freedom oscillators under stochastic excitation. For each family of oscillators, these objective criteria take into account the maximum possible energy harvested for a given response level, which is a quantity that is directly connected to the size of the harvesting configuration. We prove that the derived criteria are invariant with respect to magnitude or temporal rescaling of the input spectrum and they depend only on the relative distribution of energy across different harmonics of the excitation. We then compare three different classes of linear and nonlinear oscillators and using stochastic analysis tools we illustrate that in all cases of excitation spectra (monochromatic, broadband, white-noise) the optimal performance of all designs cannot exceed the performance of the linear design.
Application of HDQM for the Analysis of Two-Dimensional Nonlinear Dynamics of Axially Accelerating Beam
Authors: Wang Dong-Mei , Zhang Wei , Li Mu-Rong , Wang Qian
Published: January 2015

In this paper, the two-dimensional nonlinear dynamics are investigated for the nonplanar nonlinear vibrations of an axially accelerating moving viscoelastic beam with in-plane and out-of-plane vibrations by the harmonic differential quadrature method (HDQM). The coupled nonlinear partial differential equations for the two-dimensional nonplanar nonlinear vibrations are discretized in space and time domains using HDQM and Runge-Kutta-Fehlberg methods respectively. Based on the numerical solutions, the nonlinear dynamical behaviors such as bifurcations and chaotic motions of the nonlinear system are investigated by using of the phase portrait and the bifurcation diagrams. The bifurcation diagrams for the in-plane and out-of-plane displacements via the mean axial velocity and the amplitude of velocity fluctuation are respectively presented while other parameters are fixed.
Origami Folding and Bar Frameworks
Authors: Diaz Alejandro R.
Published: January 2015

One of the more computationally demanding tasks in a process of synthesizing “from scratch” origami crease patterns designed for a given purpose involve a simulation capability to track the progression of the folding process as the pattern folds. This work presents an approach to simulate origami folding based on bar frameworks. The work is related to joint frameworks and projected polyhedral, as they apply to folding. The analysis starts from a representation of a crease pattern as an undirected graph G(E,V) formed by edges E and vertices V. A framework G(p) is an instance of G where the vertex locations are assigned positions according to a vector valued function p(t), where t marks the folding progression and t=0 represents the initial, flat configuration. The strategy presented is based on finding a sequence of instances {p(1), p(2), …} corresponding to an analytic flex p, i.e., functions such that edges in all G(p(t)) have the same length. The method is based on using a finite element description of a bar framework corresponding to a truss-like structure congruent with G(p). Solutions to an eigenvalue problem associated with this structure provide the means to update from p(t) to p(t+1). Two simple (purely geometric) optimization problems adjust the update to compensate for higher order effects, guaranteeing that the length of the edges remain constant. The methodology can be used to achieve configurations close to “flat folding”, provided that no interference of the faces occurs along the way. We expected that physically-motivated constraints (stresses, deformations, etc.) and sensitivity analysis computations will be more easily represented in this framework and therefore this formulation will have an advantage over more standard “origami mathematics” approaches. The approach is illustrated with an example of folding a simple 10-crease pattern.
Off-Vehicle Tire Traction and Endurance Testing System: System Upgrade Design
Authors: Satterfield Zachary T. , O’Shields Steven T. , Moylan Justin T. , Smentek Brett T. , Gendreau Elizabeth J. , Heustess Coleman M. , Addis Rachael E. , Reynolds William A. , Scott Hannah J. , Summers Joshua D.
Published: January 2015

A system was created for sand traction performance testing of tire prototypes for extraterrestrial use by NASA. The system consists of a suspended sand-filled trough that rotates when driven by the prototype. Sensors are used to determine traction slippage of prototypes, providing a quantitative measure of relative prototype performance. This paper describes system improvements to better simulate extraterrestrial environments and more accurately measure prototype performance. A tire prototype hard stop was designed and built to prevent damage associated with the tire assembly resting in the trough. A rock obstacle was created to simulate rough terrain. A sensor system was designed to more accurately determine tire velocity. Various concepts were developed and prototyped to groom the sand during testing. Computational hardware and software upgrades were made to better facilitate the data acquisition processes. An instructional video was created to explain operational procedures. The sensor system will be integrated with the software and a sand grooming concept will be implemented.
Robotic Hopper Using Phase Oscillator Controller
Authors: New Philip , Wheeler Chase , Sugar Thomas G.
Published: January 2015

The work presented in this paper describes a robotic hopper that uses a bounded energy, phase oscillator controller. It exhibits exceptional stability when given disturbances. The controller uses a phase angle to regulate the forcing function, creating a parametric oscillator. In this paper we include simulated and experimental data for analysis of the hopper.
On the Complete Synthesis of Finite Positions With Constraint Decomposition via Kinematic Mapping
Authors: Zhao Ping , Ge Q. J. , Purwar Anurag
Published: January 2015

In this paper, we revisit the classical Burmester problem of the exact synthesis of a planar four-bar mechanism with up to five task positions. A novel algorithm is presented that uses prescribed task positions to obtain “candidate” manifolds and then find feasible constraint manifolds among them. The first part is solved by null space analysis, and the second part is reduced to finding the solution of two quadratic equations. Five-position synthesis could be solved exactly with up to four resulting dyads. For four-position synthesis, a limited number of solutions could be selected from the ∞1 many through adding an additional linear constraint equation without increasing the computational complexity. This linear constraint equation could be obtained either by defining one of the coordinates of the center/circle points, by picking the ground line/coupler line, or by adding one additional task position, all of which are proved to be able to convert into the same form as in (23). For three-position synthesis, two additional constraints could be imposed in the same way to select from the ∞2 many solutions. The result is a novel algorithm that is simple and efficient, which allows for task driven design of four-bar linkages with both revolute and prismatic joints, as well as handling of different kinds of additional constraint conditions in the same way.
Kinematics Meets Crystallography: The Concept of a Motion Space
Authors: Chirikjian Gregory S.
Published: January 2015

In this paper, it is shown how rigid-body kinematics can be used to assist in determining the atomic structure of proteins and nucleic acids when using x-ray crystallography, which is a powerful method for structure determination. The importance of determining molecular structures for understanding biological processes and for the design of new drugs is well known. Phasing is a necessary step in determining the three-dimensional structure of molecules from x-ray diffraction patterns. A computational approach called molecular replacement (MR) is a well-established method for phasing of x-ray diffraction patterns for crystals composed of biological macromolecules. In MR, a search is performed over positions and orientations of a known biomolecular structure within a model of the crystallographic asymmetric unit, or, equivalently, multiple symmetry-related molecules in the crystallographic unit cell. Unlike the discrete space groups known to crystallographers and the continuous rigid-body motions known to kinematicians, the set of motions over which molecular replacement searches are performed does not form a group. Rather, it is a coset space of the group of continuous rigid-body motions, SE(3), with respect to the crystallographic space group of the crystal, which is a discrete sub-group of SE(3). Properties of these ‘motion spaces’ (which are compact manifolds) are investigated here.
Decision Topology Assessment in Engineering Design Under Uncertainty
Authors: Pandey Vijitashwa , Mourelatos Zissimos P. , Castanier Matthew P.
Published: January 2015

The implications of decision analysis (DA) on engineering design are well known. Recently, the authors proposed decision topologies (DT) as a visual method for making design decisions and proved that they are consistent with normative decision analysis. This paper addresses the practical issue of assessing DTs for a decision maker (DM) using their responses, particularly under uncertainty. This is critical to encoding decision maker preferences so that further analysis and mathematical optimization can be performed using the correct set of preferences. We show how multiattribute DTs can be directly assessed from DM responses. Four methods are shown to evolutionarily assess DTs among which one that requires the DM to rank alternatives and another where a utility function is first assessed. It is also shown that preferences under uncertainty can be easily incorporated. In addition, we show that topologies can be constructed using single attribute topologies similarly to multi-linear functions in utility analysis. This incremental construction simplifies the process of topology construction. The reverse problem of inferring single attribute DTs is also presented. The proposed assessment methods are used on a design decision making problem of a welded beam.
Compensating for Operational Uncertainty in Man-Machine Systems: A Case Study on Intelligent Vehicle Parking Assist
Authors: Su Dale , Chan Kuei-Yuan
Published: January 2015

Successful executions of man-machine systems require consistent human operations and reliable machine performances. Compared with the abundant resources on machine reliability improvements, human-related operational uncertainty that has direct impacts on man-machine systems received little attention. Most studies and formal documentations only provide suggestions to alleviate human uncertainty instead of providing specific methods to ensure operation accuracy in real time. In this paper we present a general framework of a reliable system that compensates for human operating uncertainty in realtime. This system learns the response of an operator, constructs the user’s behavior pattern, and then develop new compensated instructions to ensure the completion of the desired tasks, hereby improve the reliability of the entire man-machine systems. The effectiveness of the proposed framework is demonstrated via the development of an intelligent vehicle parking assist. Existing parking assist systems do not account for drivers’ error; neither do these systems consider realistic urban parking spaces with obstacles. Our proposed system computes a theoretical path once a parking space is identified. Audio commands are then sent to the driver with realtime compensation for a minimal deviations from the path. When an operation is too far away from the desired path to be compensated, new set of instructions will be recomputed with the collected uncertainty. Various real-world urban parking scenarios are used to demonstrate the effectiveness of the proposed method. Our system is able to park a vehicle with a space that is as small as 1.07 times the vehicle length with up to 30% uncertainty. Results also show that the compensation scheme not only allows more diverse operators to achieve a desired goal, but also ensures a higher reliability of meeting such goals.
Improve System Reliability and Robustness Using Axiomatic Design and Fault Tree Analysis
Authors: Wang Jing , Li Mian
Published: January 2015

The reliability and robustness are critical aspects for engineering systems. In a complex system, usually multiple functions need to be achieved. In such cases, there exist optimal mappings between functions and physical components. In this paper, a new approach, Axiomatic Fault Tree Analysis (AFTA), is proposed to improve the system reliability and robustness simultaneously. In AFTA, system robustness is improved by using Axiomatic Design (AD) to decouple the system to an extent where a group of functions have a corresponding relationship with only one physical component. Moreover, Fault Tree Analysis and Axiomatic Design have been integrated in AFTA by using two new indices indicating the importance degrees of functions and physical components in a reliability sense, which provides a guideline for reliability improvement. A case study of a complex system is used to illustrate the procedure and applicability of AFTA. Theoretical calculations are used to verify AFTA for non-repairable systems, and multi-agent based simulations are for repairable systems. Both the theoretical and simulated results show that the system reliability has been improved significantly without large additional cost.
Mode Saturation, Mode Coupling and Energy Harvesting From Ambient Vibration in a Portal Frame Structure
Authors: Balthazar J. M. , Rocha R. T. , Brasil R. M. F. L. , Tusset A. M. , de Pontes B. R. , Silveira M.
Published: January 2015

There has been much recent interest in the concepts of electro-mechanical systems that are able to scavenge, or harvest energy from their operating environment. Here, we present the extraction of energy from a simple portal frame structure excited via its second (first symmetric) mode. As 2:1 internal resonance is present between that mode and the first (sway) mode, the phenomenon of mode saturation and energy exchange (modal coupling) occurs. Energy pumped into the system through the second (vertical) mode is partially transferred to the horizontal (sway) mode. This paper presents results of numerical simulations of these phenomena and energy harvesting using a nonlinear piezoelectric material as a means of energy transduction. An evaluation of the energy available for harvesting in each of the considered modes is computed.
Improvement Design for Rollover Accidents Involving Large Passenger Vehicles
Authors: Zhang Xiaoyun , Du Xiaoping , Wang Rui
Published: January 2015

Public transportation provides a crucial solution to economic, energy, and environmental challenges. Large passenger vehicles in public transportation, however, often cause more serious accidents than passenger cars. It is therefore critical to improve both the designs of large passenger vehicles and road safety facilities. This work develops a design methodology to minimize the accident damage of large passenger vehicle rollover against guardrails. The design improvement is based on the finite element analysis (FEA) that reconstructs the common accident — bus rollover against guardrail on the road side. For the vehicle design, the FEA simulation reveals that strengthening side window pillars is effective, and the side window pillars are therefore improved by selecting proper parameters of material and thickness. The study also shows that the design of guardrail could be improved with an optimal size through uniform design (a methodology of Design of Experiments). The research results not only benefit the design improvement of large passenger vehicles and guardrails, but also provide useful information to the policy makers of safety regulations.
Expanding VRPN to Tasks in Virtual Engineering
Authors: Stelzer Ralph , Steindecker Erik , Arndt Stephan , Steger Wolfgang
Published: January 2015

A high variety of peripherals for the interaction between human and computer is available (e.g. Mouse, Touch and Camera). Therefore the peripherals communicate in different ways with the computer and its applications. The library VRPN is a common, generalized interface between peripherals and VR applications to reduce the development effort. Its main advantages are the system independent client-server architecture with real-time capability and the easy implementation of new peripheral devices.

The proposed paper describes the adaption and extension of the VRPN concept to address the challenges of engineering like modeling, evaluation, simulation and modification. Innovative interaction devices have the capability to enhance engineering applications with comparatively small effort but great benefit. As an example a VRPN client is implemented into the CAD application SolidWorks. This enables the use of any interaction device which is supported by VRPN. For example, the designer can control the model view by human movement via tracking device like the Microsoft Kinect or the Geomagic Touch.

The data transfer can be either established in a synchronous or in an asynchronous manner. Regarding synchronous transfer, the server-client architecture was implemented in different applications (e.g. CAD, VR). In order to realize a time shifted asynchronous transfer a recorder-player middleware was developed.
Upgrade Planning of Used Products Considering Uncertainty in Market Demand, Quantity and Variability in Quality of Returns
Authors: Mashhadi Ardeshir Raihanian , Behdad Sara
Published: January 2015

Remanufacturing is becoming an important business as market demand for remanufactured products increases and environmental legislation puts further enforcement on Original Equipment Manufacturers (OEMs). However, profitability of salvaging operations is still a challenge in remanufacturing industry. Several factors influence the cost effectiveness of remanufacturing operations, including variability in the quality of received used items and uncertainty in the quantity of return flows and the market demand for those products. Remanufacturing companies need to handle these sources of uncertainties in order to improve their profitability. The current paper develops a Stochastic Optimization method to model these sources of uncertainties in take-back and inventory planning systems. The main purpose of the model is to determine the best upgrade level for a received product with certain quality level with the aim of profit maximization. An example of personal computer is provided to show the application of the method.
Recent Experience in “Flipping” the Kinematics Classroom
Authors: Nelson Carl A.
Published: January 2015

In teaching kinematic analysis of mechanisms, there are few formulas but much that can be called “process.” To convey process in a static set of lecture notes can be very difficult. Therefore, in this paper, a more dynamic method of kinematics education is presented, which involves using screen-capture software to record the audio and visual process of the instruction as it takes place on a touch-enabled or tablet computer. This allows dynamic instruction to be asynchronous; it can occur in class, be archived for after class, and be prerecorded for so-called “flipping” of the classroom. Recent experiences using this method to flip the kinematics classroom are presented and preliminary outcomes summarized.
Policy and Demand as Drivers for Product Quality and Sustainability: A Market Systems Approach
Authors: Hoffenson Steven , Söderberg Rikard
Published: January 2015

The market is a complex system with many different stakeholders and interactions. A number of decisions within this system affect the design of new products, not only from design teams but also from consumers, producers, and policy-makers. Market systems studies have shown how profit-optimal producer decisions regarding product design and pricing can influence a number of different factors including the quality, environmental impact, production costs, and ultimately consumer demand for the product. This study models the ways that policies and consumer demand combine in a market systems framework to influence optimal product design and, in particular, product quality and environmental sustainability. Implementing this model for the design of a mobile phone case shows how different environmental impact assessment methods, levels of taxation, and factors introduced to the consumer decision-making process will influence producer profits and overall environmental impacts. This demonstrates how different types of policies might be evaluated for their effectiveness in achieving economic success for the producer and reduced environmental impacts for society, and a “win-win” scenario was uncovered in the case of the mobile phone.
Vibration Analysis and Control of a Bridge Under Vehicular Random Excitation
Authors: Bakhtiari-Nejad Firooz , Hosseyni Seyyed Mahdi Ostad , Shamshirsaz Mahnaz , Bakhtiarinejad Mahsan
Published: January 2015

In this paper, vibration response of a bridge under vehicular loads has been analyzed and consequently been controlled by two actuators using active Neural Network (NN) control strategy. The bridge and the vehicles are modeled as a simply-supported Euler Bernoulli beam possessing a simple support precisely located at the middle and one-DOF vehicles respectively. With that goal, equations of the coupled system of the bridge and the vehicles are derived using Hamilton’s principle, and then randomness of vibrations transferred to the bridge due to the alternative velocities of the vehicles added, latterly controlled by the designed NN control algorithm. The randomness includes 10 percent of vehicle initial speed. Deflection of the first quarter-span is considered as the output of the system and tried to be controlled by two symmetric forces whose desirable positions are determined by recent studies. Furthermore the sensitivity of the system response has been investigated by applying the different conditions in which the number of the moving vehicles varies. It is shown that the increment in the number of moving vehicles has led to unsolicited deflection specifically when two or more cars moves concurrently, whereas the NN algorithm could either perfectly or effectively get over the issue.
Dynamics Modeling to Inform Design Optimization
Authors: Foglesong Tim , Stone Rob , Parmigiani John
Published: January 2015

This paper presents the methods employed in modeling a vibratory conveyor for use in model-based design optimization. The conveyor, essentially a large table whose top oscillates at an angle off of horizontal, uses springs between the drive mechanism and the tabletop to directly apply a sinusoidal excitation. These springs prevent the system from losing response amplitude as load is increased. The manufacturer is having difficulty optimizing performance and reliability in newer designs, and has requested a model-based approach to the design optimization. This study discusses the initial steps taken in modeling the original mechanism design, specifically the dynamic model and experimental determination of the necessary spring constants. The first full iteration of the model starts with low detail and simplified geometry, with a plan to add complexity as needed to improve accuracy. In the initial model, the parallel springs in the tabletop suspension are combined, bypassing the spring mounting geometry, and tested as one large spring. The drive mechanism springs, bars of fiber reinforced plastic (FRP), are more meticulously tested in a tensile testing machine. The resulting spring constants are used in the initial model to calculate the sinusoidal response of the tabletop at any given input frequency. The deflection response per time of the tabletop is then measured and compared to the model. Conclusions detail the initial model’s accuracy and Future Work examines how to bring it in closer agreement with the real machine’s sinusoidal response.