bluuebunny/crossref_metadata_2025 huggingface dataset:
Operating Characteristics of Statistical Methods for Detecting Gene-by-Measured Environment Interaction in the Presence of Gene-Environment Correlation under Violations of Distributional Assumptions
Authors: Van Hulle Carol A. , Rathouz Paul J.
Published: January 2015

Accurately identifying interactions between genetic vulnerabilities and environmental factors is of critical importance for genetic research on health and behavior. In the previous work of Van Hulle et al. (Behavior Genetics, Vol. 43, 2013, pp. 71–84), we explored the operating characteristics for a set of biometric (e.g., twin) models of Rathouz et al. (Behavior Genetics, Vol. 38, 2008, pp. 301–315), for testing gene-by-measured environment interaction (GxM) in the presence of gene-by-measured environment correlation (rGM) where data followed the assumed distributional structure. Here we explore the effects that violating distributional assumptions have on the operating characteristics of these same models even when structural model assumptions are correct. We simulated N = 2,000 replicates of n = 1,000 twin pairs under a number of conditions. Non-normality was imposed on either the putative moderator or on the ultimate outcome by ordinalizing or censoring the data. We examined the empirical Type I error rates and compared Bayesian information criterion (BIC) values. In general, non-normality in the putative moderator had little impact on the Type I error rates or BIC comparisons. In contrast, non-normality in the outcome was often mistaken for or masked GxM, especially when the outcome data were censored.
Kardiologische Aspekte in der Musikermedizin
Authors: Schuppert Maria , Kerber Sebastian
Published: January 2015

Instrumentalspiel und Gesang gehen mit physiologischen Reaktionen und einer konditionellen Beanspruchung einher, die auch für das Herz-Kreislaufsystem relevant sind. Kardiologische Aspekte in der Musikermedizin sind bislang vergleichsweise wenig untersucht und werden in ihrer klinischen Bedeutung oft unterschätzt. Für Musiker mit gesundem Herz-Kreislaufsystem liegen die Effekte im Allgemeinen im physiologischen, belastungsabhängigen Bereich. Doch bei Vorliegen kardiovaskulärer Grunderkrankungen können während des Musizierens Herz-Kreislaufsymptome auftreten, die einer kardiologischen Diagnostik und Therapie unter Einbeziehung musikerbezogener Faktoren bedürfen. Eine besondere Rolle spielen bei Musikern in diesem Zusammenhang Stressfaktoren im spezifischen beruflichen Kontext. Bei der Betreuung von Instrumentalisten und Sängern mit kardiologischen Fragestellungen sind multidisziplinäre und multimodale Ansätze erforderlich, um den komplexen Wechselwirkungen von physischen, psychischen und musizierbezogenen Parametern gerecht zu werden.
Recoverable plasticity in penta-twinned metallic nanowires governed by dislocation nucleation and retraction
Authors: Qin Qingquan , Yin Sheng , Cheng Guangming , Li Xiaoyan , Chang Tzu-Hsuan , Richter Gunther , Zhu Yong , Gao Huajian
Published: January 2015

There has been relatively little study on time-dependent mechanical properties of nanowires, in spite of their importance for the design, fabrication and operation of nanoscale devices. Here we report a dislocation-mediated, time-dependent and fully reversible plastic behaviour in penta-twinned silver nanowires. In situ tensile experiments inside scanning and transmission electron microscopes show that penta-twinned silver nanowires undergo stress relaxation on loading and complete plastic strain recovery on unloading, while the same experiments on single-crystalline silver nanowires do not exhibit such a behaviour. Molecular dynamics simulations reveal that the observed behaviour in penta-twinned nanowires originates from the surface nucleation, propagation and retraction of partial dislocations. More specifically, vacancies reduce dislocation nucleation barrier, facilitating stress relaxation, while the twin boundaries and their intrinsic stress field promote retraction of partial dislocations, resulting in full strain recovery.
Plasma lipidomics analysis finds long chain cholesteryl esters to be associated with Alzheimer’s disease
Authors: Proitsi P , Kim M , Whiley L , Pritchard M , Leung R , Soininen H , Kloszewska I , Mecocci P , Tsolaki M , Vellas B , Sham P , Lovestone S , Powell J F , Dobson R J B , Legido-Quigley C
Published: January 2015

There is an urgent need for the identification of Alzheimer’s disease (AD) biomarkers. Studies have now suggested the promising use of associations with blood metabolites as functional intermediate phenotypes in biomedical and pharmaceutical research. The aim of this study was to use lipidomics to identify a battery of plasma metabolite molecules that could predict AD patients from controls. We performed a comprehensive untargeted lipidomic analysis, using ultra-performance liquid chromatography/mass spectrometry on plasma samples from 35 AD patients, 40 elderly controls and 48 individuals with mild cognitive impairment (MCI) and used multivariate analysis methods to identify metabolites associated with AD status. A combination of 10 metabolites could discriminate AD patients from controls with 79.2% accuracy (81.8% sensitivity, 76.9% specificity and an area under curve of 0.792) in a novel test set. Six of the metabolites were identified as long chain cholesteryl esters (ChEs) and were reduced in AD (ChE 32:0, odds ratio (OR)=0.237, 95% confidence interval (CI)=0.10–0.48, P=4.19E−04; ChE 34:0, OR=0.152, 95% CI=0.05–0.37, P=2.90E−04; ChE 34:6, OR=0.126, 95% CI=0.03–0.35, P=5.40E−04; ChE 32:4, OR=0.056, 95% CI=0.01–0.24, P=6.56E−04 and ChE 33:6, OR=0.205, 95% CI=0.06–0.50, P=2.21E−03, per (log2) metabolite unit). The levels of these metabolites followed the trend control>MCI>AD. We, additionally, found no association between cholesterol, the precursor of ChE and AD. This study identified new ChE molecules, involved in cholesterol metabolism, implicated in AD, which may help identify new therapeutic targets; although, these findings need to be replicated in larger well-phenotyped cohorts.
Mineralized collagen scaffolds induce hMSC osteogenesis and matrix remodeling
Authors: Weisgerber Daniel W. , Caliari Steven R. , Harley Brendan A. C.
Published: January 2015

Incorporating calcium phosphate nanocrystallites into a collagen biomaterial promotes mesenchymal stem cell (MSC) osteogenic differentiation in the absence of conventional growth factor supplements. Mineralized collagen scaffolds also support MSC proliferation and new matrix biosynthesis.
Superior electrocatalytic activity from nanodendritic structure consisting of a PtFe bimetallic core and Pt shell
Authors: Zhu Jianbing , Xiao Meiling , Li Kui , Liu Changpeng , Xing Wei
Published: January 2015

A novel PtFe@Pt core–shell nanostructure with a PtFe bimetallic core and a nanodendrite Pt shell was fabricated through a facile aqueous reduction process.
Infection and immunity on a chip: a compartmentalised microfluidic platform to monitor immune cell behaviour in real time
Authors: Gopalakrishnan N. , Hannam R. , Casoni G. P. , Barriet D. , Ribe J. M. , Haug M. , Halaas Ø.
Published: January 2015

Immunity on a chip: modeling and designing immune reactionsin vitroto study immune responses on a chip as well as unraveling physiological processes under a microscope.
Theranostic potentials of multifunctional chitosan–silver–phycoerythrin nanocomposites against triple negative breast cancer cells
Authors: Thangam Ramar , Sundarraj Shenbagamoorthy , Vivek Raju , Suresh Veeraperumal , Sivasubramanian Srinivasan , Paulpandi Manickam , Karthick S. Vignesh , Ragavi A. Sri , Kannan Soundarapandian
Published: January 2015

Study focused to the applications of nanocomposites with therapeutic and imaging functions against TNBC cells. The developed multifunctional nanocomposites exhibited cell imaging, cytotoxicity with apoptosis induction against cancer cells.
Mutational landscape of gastric adenocarcinoma in Chinese: Implications for prognosis and therapy
Authors: Chen Kexin , Yang Da , Li Xiangchun , Sun Baocun , Song Fengju , Cao Wenfeng , Brat Daniel J. , Gao Zhibo , Li Haixin , Liang Han , Zhao Yanrui , Zheng Hong , Li Miao , Buckner Jan , Patterson Scott D. , Ye Xiang , Reinhard Christoph , Bhathena Anahita , Joshi Deepa , Mischel Paul S. , Croce Carlo M. , Wang Yi Michael , Raghavakaimal Sreekumar , Li Hui , Lu Xin , Pan Yang , Chang Han , Ba Sujuan , Luo Longhai , Cavenee Webster K. , Zhang Wei , Hao Xishan
Published: January 2015

Significance

We have identified a lethal subtype of gastric cancer (GC) that is characterized by high levels of clonal heterogeneity and
TP53
(tumor protein P53) mutation. We have also uncovered key novel mutations in the targetable
NRG1
(neuregulin-1) and
ERBB4
(V-Erb-B2 avian erythroblastic leukemia viral oncogene homolog 4) ligand-receptor pair and identified
BRCA2
(breast cancer 2, early onset) mutations as new genetic markers to predict better survival for GC. Our study represents a novel approach for GC personalized medicine and identified novel clinical actionable therapies for GC therapy.
PASPA: a web server for mRNA poly(A) site predictions in plants and algae
Authors: Ji Guoli , Li Lei , Li Qingshun Q. , Wu Xiangdong , Fu Jingyi , Chen Gong , Wu Xiaohui
Published: January 2015

Motivation: Polyadenylation is an essential process during eukaryotic gene expression. Prediction of poly(A) sites helps to define the 3′ end of genes, which is important for gene annotation and elucidating gene regulation mechanisms. However, due to limited knowledge of poly(A) signals, it is still challenging to predict poly(A) sites in plants and algae. PASPA is a web server for poly(A) site prediction in plants and algae, which integrates many in-house tools as add-ons to facilitate poly(A) site prediction, visualization and mining. This server can predict poly(A) sites for ten species, including seven previously poly(A) signal non-characterized species, with sensitivity and specificity in a range between 0.80 and 0.95.

Availability and implementation:  http://bmi.xmu.edu.cn/paspa

Contact: xhuister@xmu.edu.cn

Supplementary information: Supplementary data are available at Bioinformatics online.
The knowledge of Italian wines on export markets
Authors: Barisan Luigino , Boatto Vasco , Rossetto Luca , Salmaso Luigi
Published: January 2015

Purpose

– The European Union (EU) has strongly rearranged the management of EU wine policy by introducing actions for promoting wine in third countries. The purpose of this paper is to evaluate factors affecting the knowledge of Italian wines in foreign consumers, i.e., to what extend wine promotion actions can improve the consumer’s awareness or the reputation of Italian wines. As a consequence, these activities may increase the wine consumption as well as wine exports in emerging markets.

Design/methodology/approach

– Data have been collected through survey questionnaires where information about wine tasting, sensory satisfaction and preferences about Italian wines have been collected. The sample survey collects preferences of wine market operators in both EU and third countries. The survey, carried out from 2009 to 2011, includes 3,579 interviews classified according to four promotion actions: press conference, wine tasting, tasting course, knowledge of Italian wines. Data have been analyzed through a nonparametric combination (NPC) of dependent permutation tests to evaluate differences between and within country groups and to assess the consumer perception about Italian wines through the Keller’s model.

Findings

– So far, Italian wine promotion activities, supported by EU wine policy, are fragmented among in many small and sometimes low effective actions. Research results may be helpful in designing more effective promotional strategies on third countries. In particular, promotional activities which should be focussed on consumer’s appreciation of Italian wines as a brand instead of promoting specific wines or wineries.

Research limitations/implications

– The NPC method is a nonparametric tool which does not measure the structure of consumer’s preferences, i.e, it does give any measure of relationships among consumer’s utility and factors affecting it as it happens when a modeling approach is applied.

Practical implications

– Targeted promotion and information actions strongly focussed internal and external wine attributes can increase the level of knowledge in foreign consumers. It can make more efficient the marketing activity oriented to the export market.

Originality/value

– The NPC method offers an innovative, flexible and well-tested approach for the analysis of multivariate hypothesis when we are dealing with complex problems in wine market.
Legislation, standards and diagnostics as a backbone of food safety assurance in Serbia
Authors: Smigic Nada , Rajkovic Andreja , Djekic Ilija , Tomic Nikola
Published: January 2015

Purpose

– The purpose of this paper is to analyze the current situation of multidimensional food safety assurance in Serbia, as an official candidate for European Union (EU) membership, in relation to its EU food law harmonization efforts.

Design/methodology/approach

– Serbian assurance scheme was covered in this paper included food safety legislation, control and standards.

Findings

– The food safety system in Serbia needs improvements in the area of effectiveness and efficiency of food safety control and inspection services, knowledge and expertise of state inspectors, governmental officials, food safety consultants and auditors. Additionally, problems related to the overlapping responsibilities of various legal authorities and inspection services have to be solved, with an improved transparency and communication between legal authorities, customers, consumers and food business operators.

Originality/value

– An overview of current situation in food safety assurance in Serbia is shown.
Critical success factors examined in ISO 9001:2008-certified Greek companies using multidimensional statistics
Authors: Ismyrlis Vasileios , Moschidis Odysseas , Tsiotras George
Published: January 2015

Purpose

– The purpose of this paper is to examine the level of the importance and implementation of the critical success factors (CSFs) required for the appropriate function of a quality management system (QMS) in ISO 9001:2008-certified companies and the differences between the CSFs and the demographic variables of the companies.

Design/methodology/approach

– A research project was carried out in Greek companies from all business sectors using the questionnaire technique. The selected companies all implement a QMS in accordance with the ISO 9001:2008 standard. Correspondence analysis, a methodology from the multidimensional statistics field, was also used to identify significant differences between the importance and implementation levels of the CSFs of the QMS.

Findings

– The importance that quality assurance managers attribute to these CSFs was high enough in most categories, but there was a significant difference in the implementation level, which displayed much lower scores. The most important factors seem to be management commitment, education, and communication, while the least important were the availability of data and use of statistics. Differences between categories of demographic variables were present only for the firm size variable.

Research limitations/implications

– The study was based on the perception (i.e. subjective data) of only one quality manager/representative of each company.

Practical implications

– The paper provides information to certified companies in Greece on the differences in the importance and implementation levels of quality management practices (especially for hard factors) and motivation to investigate possible causes. Moreover, the most important factors for the successful implementation of ISO 9001 are presented.

Originality/value

– This paper describes the implementation and given importance of the CSFs in companies with experience of the ISO 9001:2008 standard and for the analysis of the data a methodology from the multidimensional field is applied, with the complementary use of some special tables of coincidences.
Autonomous evolution of service system in cluster supply chain
Authors: Xue Xiao , Wang Shufang , Chao Hao
Published: January 2015

Purpose

– The purpose of this paper is to provide strong theoretical and technical support for the dynamic evolution of service system in “Cluster Supply Chain”(CSC), which can deal with two kinds of context changes: the internal service component changes and the external customer requirement changes.

Design/methodology/approach

– A “feedback-based” evolution mechanism of service system for CSC is proposed in this study. By means of the feedback update of enterprise service’s Quality of Service (QoS) attribute and the adjustment of the assumed QoS evaluation model, the evolution of service system can be achieved to suit the dynamic market demands.

Findings

– Results of the study suggest: by means of the “feed-back” evolution mechanism of service system, the enterprises in CSC can handle the context changes effectively to maintain the optimized operation status.

Practical implications

– The implementation of evolution mechanism in service system can keep the effectiveness of enterprise service composition to face the frequent service component changes and the unpredictable market turbulence.

Originality/value

– This paper proposes a method to realize the autonomous evolution of service system in CSC, which can support the flexibility and adaptability of enterprise service composition in the changing environment.
Fuzzy trust evaluation based on consistency intensity for cloud services
Authors: Huo Ying , Zhuang Yi , Ni Siru
Published: January 2015

Purpose

– The purpose of this paper is to define an evaluation model for cloud services to deal with the fuzzy information and propose a novel fuzzy evaluation method based on consistency intensity to analyze the quantitative value from the fuzzy information.

Design/methodology/approach

– The cloud service evaluation framework is constructed, and different trusted indicators for the infrastructure services and the application services are designed, respectively. In the novel fuzzy evaluation method, the interval values can be aggregated by the Dempster-Shafer Theory and be transformed into the certain value by linguistic discount factor. The consistency intensity is proposed to determine the value of the linguistic discount factor, which can reflect the mainstream opinions in the assessment.

Findings

– The proposed method can solve the problem on the analysis and synthesis of the fuzzy evaluation information. An instance of trust evaluation of cloud storage service is illustrated to verify that the proposed method can express the opinions of all evaluators more adequately.

Practical implications

– A serial of experiments are carried out on NetLogo, and the results show that the proposed method is practical and efficient.

Originality/value

– Instead of obtaining only the qualitative results by the multi-attribute decision-making method, the fuzzy evaluation method based on consistency intensity can obtain the quantitative results from the fuzzy information according to linguistic discount factor and consistency intensity.
The Role of Macrophages in Promoting and Maintaining Homeostasis at the Fetal–Maternal Interface
Authors: Svensson‐Arvelund Judit , Ernerudh Jan
Published: January 2015

A successful pregnancy requires that the maternal immune system adapts properly to avoid rejection of the semi‐allogeneic fetus without compromising the ability to protect the mother and the fetus against infections. In this review, we describe the role of decidual macrophages in creating a homeostatic environment at the fetal–maternal interface. We also discuss their role in pregnancy complications as well as future possibilities to modulate macrophage function therapeutically. Decidual macrophages are enriched at the fetal–maternal interface and play a major role in the regulation of inflammatory responses and the maintenance of a tolerant environment. Their function is, however, not restricted to immune tolerance, but extends to include functions such as the recognition and clearance of infections, the clearance of apoptotic debris, and tissue remodeling. Decidual macrophages seem to largely function as tissue‐resident macrophages that are crucial for maintaining homeostasis and reproductive success.
Latent class analysis of need descriptors within an Irish youth mental health early intervention program toward a typology of need
Authors: Peiper Nicholas , Illback Robert J. , O'Reilly Aileen , Clayton Richard
Published: January 2015

Aim

Significant overlap and comorbidity has been demonstrated among young people with mental health problems. This paper examined demographic characteristics, heterogeneity of need descriptors and services provided among young people (12–25 years) engaging in brief interventions at Jigsaw in the Republic of Ireland.

Method

Between 1 January 2013 and 31 December 2013, a total of 2571 young people sought help from 1 of 10 Jigsaw sites. Of these, 1247 engaged in goal‐focused brief interventions, typically consisting of one to six face‐to‐face sessions. Descriptive statistics were used to summarize social and demographic factors. Latent class analysis was used to cluster young people into relevant typologies of presenting issues. Multinomial logistic regression was then performed to determine significant predictors of class membership.

Results

The most common age of young people was 16. More women (59.6%) than men engaged in brief interventions, 56% attended school, 74% lived with their family of origin or with one parent, and 54.2% came from families where parents were married. Using established fit criteria, four relevant typologies emerged: Developmental (26.8%), Comorbid (15.8%), Anxious (42.7%) and Externalising (14.6%). Predictors varied by class membership, but general family problems and lack of adult support emerged as the strongest predictors for all classes.

Conclusion

This study demonstrated that the mental health needs of young people in Ireland are significant and diverse. Because Jigsaw favours a more descriptive approach to problem identification, the four typologies suggest a need to determine program capacity in engaging youth with heterogeneous presenting issues and to tailor brief interventions to each group's clinical profiles.
Natalizumab analogon therapy is effective in a B cell‐dependent multiple sclerosis model
Authors: Häusler Darius , Nessler Stefan , Kruse Niels , Brück Wolfgang , Metz Imke
Published: January 2015

Aims

Natalizumab is a humanized monoclonal antibody specific for CD49d receptors of integrins. It inhibits the entry of inflammatory cells into the central nervous system and is approved for the treatment of relapsing‐remitting multiple sclerosis (MS). Several lines of evidence indicate an involvement of B cells and plasma cells in MS pathogenesis. However, treatment with the natalizumab analogon PS/2 immunoglobulin G (IgG) has so far only been investigated in T cell‐mediated animal models of MS. Due to the importance of B lineage cells in the pathogenesis of MS, the objective of the present study has thus been to analyse the effects of PS/2 IgG in a mouse model of MS with T and B cell cooperation (OSE mice).

Methods

OSE mice were treated with the natalizumab analogon PS/2 IgG either at disease onset or after peak of disease. Treatment was also performed with PS/2 F(ab′)2 fragments.

Results

PS/2 IgG treatment improved the clinical outcome and decreased spinal cord demyelination and immune cell infiltration if given early in the disease course. Treatment increased blood leukocytes and resulted in a partial internalization of CD49d in T and B cells. The therapeutic effects of PS/2 IgG injections were independent of the Fc fragment as F(ab′)2 injections were equally beneficial. In contrast, PS/2 IgG was not effective when given late in the disease course.

Conclusions

Results indicate that natalizumab may also be beneficial in MS with B cell‐driven immunopathogenesis.
The role of shock index as a predictor of multiple‐trauma patients' pathways
Authors: Toccaceli Andrea , Giampaoletti Andrea , Dignani Lucia , Lucertini Carla , Petrucci Cristina , Lancia Loreto
Published: January 2015

Objectives

This research was conducted with the aim of investigating the accuracy of the shock index (SI) in distinguishing which multiple‐trauma patients should be admitted to an intensive care unit (ICU) after treatment in an emergency room (ER).

Background

The SI is an easily obtained indicator, as it corresponds to an arithmetic ratio between the two parameters that are always measured during the first‐aid treatment of multiple‐trauma patients: heart rate (HR) and systolic blood pressure (SBP). There are many studies examining the SI in the multiple‐trauma patients as a possible predictor of the destination unit. The SI is evaluated both at the trauma scene (pre‐hospital SI‐pH) and in the emergency room (SI‐ER).

Design and methods

An observational study with a retrospective approach was conducted on 158 adult patients with multiple trauma.

Results

The mean SI‐pH and SI‐ER values were higher in ICU patients than in‐patients discharged or admitted to a normal ward, but the difference between these two patient groups was significant only for the SI‐ER. Analysis of the receiver operating characteristic (ROC) curves confirmed that only the SI‐ER is significant as a reliable indicator for ICU admission with a best cut‐off of 1·05. However, a threshold value of 0·75 was still able to establish the correct type of destination for multiple‐trauma patients, with a sensitivity of 57·3% and a specificity of 62·5%.

Conclusions

This research showed that the SI‐pH and SI‐ER values are correlated, but only the SI‐ER has shown statistical significance in terms of distinguishing the type of destination of multiple‐trauma patient (ICU, ordinary ward or discharge) after initial treatment in the ER.

Relevance to clinical practice

The results of this study suggest the possibility of using SI in multiple‐trauma patients as a triage indicator to assess the patients' care complexity and to guide the choice of proper clinical paths.
Staphylococcus aureus sporotrichoid lymphangitis without bacteremia in a transplant recipient
Authors: Rotemberg V. , Valins W. , Husan S. , Grossman M.
Published: January 2015

Pyogenic sporotrichoid infections are rare. There are only 4 reports in the literature of Staphylococcus aureus presenting as sporotrichoid lymphangitis (also known as lymphocutaneous syndrome or nodular lymphangitis). We report the first case, to our knowledge, of S. aureus sporotrichoid infection without bacteremia in an immunocompromised organ transplant recipient.
Use of Wavelets for Mixed-Mode Damage Diagnostics in Warren Truss Structures
Authors: Altammar Hussain , Dhingra Anoop , Kaul Sudhir
Published: January 2015

The use of the wavelet transform has been gaining widespread acceptance over the last decade as a valuable tool for damage detection. This paper investigates the use of wavelets for detecting mixed-mode, also known as combined mode, cracks in truss structures. The propagation of an open, mixed-mode crack is simulated by using a macroscopic model of damage that is combined with a finite element model of the Warren truss. The natural modes of the truss with varying levels of damage are then used to determine crack location on a specific member of the truss. A damage detection algorithm is developed and the influence of multiple parameters such as truss geometry, crack geometry, number of truss members, etc. is investigated. A direct correlation between damage severity and the magnitude of wavelet coefficients is found for a predefined damage location. It is observed that the proposed damage detection algorithm can be used to successfully detect mixed-mode cracks even in the presence of noise, and even when a relatively coarse sampling of natural modes is used. Multiple simulations are presented and some shortcomings of the proposed algorithm are also discussed in detail.
A Modal Approach for the Study of the Transient Behavior of Motorcycle and Scooter Tires
Authors: Doria Alberto , Taraborrelli Luca , Urbani Marco
Published: January 2015

Stability of two-wheeled vehicles is influenced by the transient properties of tires, which are described in terms of the relaxation length, which is the distance that the vehicle travels before tire forces reach the steady state values. Relaxation length is often studied by means of rigid ring models, in which the belt of the tire is modeled as a rigid ring elastically connected to the rim and the contact patch is connected to the belt by means of residual springs. Actually these models are able to take into account the lateral and the diametrical modes of vibration of the rigid belt with respect to the rim and to represent in a simplified way the modes with belt deformation by means of the residual stiffness. Experimental tests are needed to find the parameters of the models and to validate results. This research focuses on the relaxation length of side-slip force and aims to improve knowledge in this field, since there is no consolidated method for deriving the parameters of rigid ring models and, especially in two-wheeled vehicles, the relevance of rigid belt and deformable belt modes is not well known. Experimental tests are performed on a rotating disk machine developed for testing tires of two-wheeled vehicles, two motorcycle and two scooter tires are considered. Transient properties are studied by carrying out tests with harmonic variations of side-slip angle, since in the frequency domain the relaxation length corresponds to a phase lag between the input and tire force. Phase lags are measured and relaxation lengths are identified for a wide range of inflation pressures. Then each tire is modally tested and natural frequencies, dampings and vibration modes are found, the stiffnesses associated to the lateral and diametrical modes are identified. Finally a comparison is made between the identified relaxation length and the prediction given by a model based on the identified tire modes. The relevance of deformable belt modes is analyzed and their influence on relaxation length is discussed.
Template Driven Conceptual Design of High Speed Trains
Authors: Gopinath Varun , Tarkian Mehdi , Ölvander Johan , Gaziza William
Published: January 2015

Conceptual design of multidisciplinary systems begins with a description of requirements and proceeds with a solution at a high abstraction level. A systematic and rigorous approach is required to evaluate complex systems and can be achieved by mapping the interactions between disciplines. Research has shown that the use of geometry in the early stages act as enablers for high fidelity analyses as required information can be extracted from the model. In the paper, Knowledge Based Engineering is used with the aim of managing the added complexity as it supports design automation and reuse. This article describes a configuration tool, which allows for quick generation of train geometry using High Level CAD Templates. The tool was created as part of a research project, with the primary objective of the development of a robust framework for a Multidisciplinary Design Optimization process which can support design of high-speed trains.
Planar Linkage Synthesis for Coupler Point Path Guidance Using Poles and Rotation Angles
Authors: Zimmerman Ronald A.
Published: January 2015

Coupler point path guidance is a long standing linkage design problem. It is possible to design a four bar linkage with a coupler point that will pass through up to nine specified points. This paper discloses a new graphical solution to this problem. The approach is to consider the constraints imposed by the target points on the linkage through the poles and rotation angles. This approach enables the designer to explore the range of possible solutions when fewer than nine points are specified by dragging a fixed or moving pivot in the plane. The selection of free choices is made at the end of the process and the complete mechanism is visible when the choices are made. The constraints only need to be made once which eliminates the repetitive construction required by previous methods to consider multiple pivot locations. Since it is so easy to consider multiple pivot locations and the solution mechanism is always visible, the required design time is greatly reduced. A corresponding analytical solution is also developed and solved based on the same constraints. The analytical solution is defined by a system of 28 nonlinear equations with 28 unknowns.
Materials Follow Form and Function: Probabilistic Factor Graph Approach for Automatic Material Assignments to 3D Objects
Authors: Zhang Binbin , Rai Rahul
Published: January 2015

There are strong co-relations between material assignment, shape, and functionality of a part in overall product/assembly. However, these strong co-relations are rarely exploited for automated material assignment. We present a probabilistic graphical model-based approach to automatically assign materials to the parts (components) of a 3D object (assembly). The presented model performs material assignment by identifying the relations between shape, functionality, and materials of parts in the existing database objects. By learning the context dependent correlation without supervision from a set of objects and their segmented parts, the learned model can be used to assign proper real materials to the parts of a query object. Our primary contributions are: a) the real materials definition and assignment and b) assigning materials based on the functionality and form of the parts in the object. The performance of proposed computational approach is demonstrated by results of material assignment on various query objects without pre-specified material definitions.
Shock Mitigation by Energy Reversal to the High Frequency Modes
Authors: AL-Shudeifat Mohammad A. , Vakakis Alexander F. , Bergman Lawrence A.
Published: January 2015

In this computational study, a light-weight dynamic device is investigated for passive energy reversal from the lowest frequency mode to the high frequency modes of a large-scale frame structure for rapid shock mitigation. The device is based on the single-sided vibro-impact mechanism. It has two functions for passive energy transfer: a nonlinear energy sink (NES) for local energy dissipation and an energy pump to high frequency modes where a significant amount of the shock energy is rapidly dissipated. As a result, a significant portion of the shock energy induced into the linear dynamic structure can be passively reversed from the lowest frequency mode to the high frequency modes and rapidly dissipated by their modal damping. The amount of the energy dissipated by the modal damping of the high frequency modes can be controlled by the amount of inherent damping in the device. Ideally, the device can passively reverse up to 80% of the input shock energy from the lowest frequency mode to the high frequency modes when its damping is assumed to be zero and its impact coefficient of restitution is equal to unity. The shock energy redistribution between this device and the high frequency modes is found to be efficient for rapid shock mitigation in the considered 9-story dynamic structure.
System Theoretic Approach for Determining Causal Factors of Quality Loss in Complex System Design
Authors: Goerges Stephanie L. , Hommes Qi D. Van Eikema
Published: January 2015

Identifying the factors that could lead to the loss of quality is difficult for large complex product systems. Traditional design methods such as Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA), and Robust Design have been proven effective at identifying component failures, but are less effective for causes of quality loss that involve interactions between components, software flaws, or external noises. This research applied System Theoretic Process Analysis (STPA) to a case study at Cummins, Inc. The case study was a technology change to a subsystem in a new product development project. The intent of this case was to determine if STPA, developed for safety engineering and hazard analysis, would be effective in identifying causes of quality losses. The results of the case study were compared to the traditional design methods. STPA allowed design teams to identify more causal factors for quality losses than FMEA or FTA, especially those involving component interactions, software flaws, and external noises. STPA was also found to be complementary to Robust Design methods.
Integrated Multiscale Robust Design Considering Microstructure Evolution and Material Properties in the Hot Rolling Process
Authors: Goh Chung-Hyun , Ahmed Salman , Dachowicz Adam P. , Allen Janet K. , Mistree Farrokh
Published: January 2015

A transmission gear is generally produced by a sequence of several processes from steelmaking to final machining and surface treatment. The intermediate processes such as hot rolling induce microstructure evolution and phase transformation which play a significant role in determining the mechanical properties and fatigue strength of gears. Therefore, these intermediate processes should be carefully considered in determining the performance and properties of the end product.

In this paper, an integrated multiscale robust design approach using the Inductive Design Exploration Method (IDEM) is implemented to improve robustness in the presence of uncertainty by exploring the solution space in order to find feasible solutions to satisfy technical requirements and/or customer aspirations. Four pass roll design with oval and round grooves is used to simulate the hot bar rolling process. The microstructure evolution, flow stress, and wear prediction models are implemented in the analysis model to account for the process-structure relationship in each roll pass. Surrogate models for some parameters such as ultimate tensile strength are then developed based on the analysis results. Using the relationship of processing-structure-property-performance, the integrated realization of engineered materials and products (IREMP) can be accomplished over multiple length scales. In IDEM, the range of the property-performance relationship is first evaluated by the requirements for the end product. Subsequently, the austenite and ferrite grain sizes and material properties are inductively determined by exploring the design space. Consequently roll pass design including the rolling conditions and the microstructure of billets are customized by the exploration of design variables based on IDEM.
A Dynamic Model of Friction Draft Gear
Authors: Wu Qing , Spiryagin Maksym , Cole Colin
Published: January 2015

Friction draft gears are the most widely used draft gears. Modeling and prediction of their dynamic behavior are of significant assistance in addressing various concerns. Longer, heavier and faster heavy haul trains mean larger in-train forces and more complicated force patterns, which require further improvements of dynamic modeling of friction draft gears to assess the longitudinal train dynamics. In this paper a force-displacement characteristics model named “base model” was described. The base model was simulated after the analyses of a set of field-test data. Approaches to improve the base model to a full advanced draft gear model were discussed; preliminary simulation results of an advanced draft gear model were also presented.
A Case Study of Configuration Management Methods in a Major Automotive OEM
Authors: Phelan Keith , Wilson Crystal , Summers Joshua D. , Kurz Mary E.
Published: January 2015

To compete in the global market, many manufacturers are moving towards mass customization of products. This allows the manufacturer to take advantage of the high volumes found in mass production while still manufacturing products that fit the needs of individual customers. In order to effectively implement mass customization principles in production, the manufacturers must rely on some form of configuration management to keep track of the large amount of domain knowledge that is involved. The purpose of this paper is to present a review of existing configuration management practices and why they are necessary in today’s economy. This includes a case study of the configuration management and configuration change practices of a major automotive OEM. Based on the results of the case study, the authors present a series of recommendations to increase the effectiveness of the OEM’s change management practices.
Contact Status Optimization of Multibody Dynamic Systems Using Dual Variable Transformation
Authors: Mummolo Carlotta , Mangialardi Luigi , Kim Joo H.
Published: January 2015

Generating the motion of redundant systems under general constraints within an optimization framework is a problem not yet solved, as there is, so far, a lack of completely predictive methods that concurrently solve for the optimal trajectory and the contact status induced by the given constraints. A novel approach for optimal motion planning of multibody systems with contacts is developed, based on a Sequential Quadratic Programming (SQP) algorithm for Nonlinear Programming (NLP). The objective is to detect and optimize the contact status and the relative contact force within the optimization sequential problem, while simultaneously optimizing a trajectory. The novelty is to seek for the contact information within the iterative solution of the SQP algorithm and use this information to sequentially update the resulting contact force in the system’s dynamic model. This is possible by looking at the analytical relationship between the dual variables resulting from the constrained NLP and the Lagrange multipliers that represent the contact forces in the classical formulation of constrained dynamic systems. This approach will result in a fully predictive algorithm that doesn’t require any a priori knowledge on the contact status (e.g., time of contact, point of contact, etc.) or contact force magnitude. A preliminary formulation is presented, as well as numerical experiments on simple planar manipulators, as demonstration of concepts.
Inverse Design of Manufacturing Process Chains
Authors: Kulkarni Nagesh , Gupta Rahul , Khan Danish , Gautham B. P. , Allen Janet K. , Panchal Jitesh , Mistree Farrokh
Published: January 2015

Finding the input specifications to obtain the specified performance of a component being designed is an essential activity of a designer. However, obtaining solutions for this inverse problem is a complex task; especially when there are multiple steps with many-to-one mappings at each step in the forward problem. This complexity is further augmented in the presence of uncertainty of the parameters and models used.

The typical heat treatment process involves multiple steps and the same outcome can possibly be achieved through multiple routes. Obtaining suitable process parameters for desired final properties such as the hardness profile is a requirement of the process design. In this work an error metric called the Hyper Dimensional Error Margin Index (HD_EMI) is used for inverse process chain design where the objective is to obtain the process set points in a sequence of heat treatment operations involving carburization, quenching and tempering processes. We have validated the solution of inverse problem by solving the detailed forward problem. The application procedure used in this study to solve inverse problem is simple and results obtained are encouraging for further exploration of HD_EMI.
Inverse Dynamics of a 6-DOF Decoupling Manipulator
Authors: Liu Taoran , Gao Feng , Zhao Xianchao , Qi Chenkun
Published: January 2015

In this paper, the kinematics and inverse dynamics of a 6-dof full decoupling parallel manipulator is presented. The forward and inverse kinematics solution can be easily obtained and simplify the real-time control due to 6 dof motion full decoupling. Three motors are embedded into the moving platform to realize rotational motion, simple kinematics and isotropic configurations due to the motors and speed reducers have a lower weight. An effective inverse dynamics of the manipulator is derived by the principle of virtual work. The existence of speed reducer for motors have advantages of decreasing mechanical couplings between axes and the full varying inertias are not directly onto each motor output shaft. Since the presence of speed reducer and in order to improve dynamic model accuracy, the inertia of motor rotor-reducer should be computed. Finally, numerical simulation of the inverse dynamics provides that the actuating torques created by gravity, velocity, acceleration and decoupling torque, coupling torque have been computed.
Singularity Analysis of Planar Multiple-DOF Linkages
Authors: Wang Jun , Nie Liangyi , Wang Quan , Sun Jinfeng , You Ying , Zhao Daxing , Ting Kwun-Lon
Published: January 2015

Singularity analysis of multi-DOF (multiple-degree-of-freedom) multiloop planar linkages is much more complicated than the single-DOF planar linkages. This paper offers a degeneration method to analyze the singularity (dead center position) of multi-DOF multiloop planar linkages. The proposed method is based on the singularity analysis results of single-DOF planar linkages and the less-DOF linkages. For an N-DOF (N>1) planar linkage, it generally requires N inputs for a constrained motion. By fixing M (M<N) input joints or links, the N-DOF planar linkage degenerates an (N-M)-DOF linkage. If any one of the degenerated linkages is at the dead center position, the whole N-DOF linkage must be also at the position of singularity. With the proposed method, one may find out that it is easy to obtain the singular configurations of a multiple-DOF multiloop linkage. The proposed method is a general concept in sense that it can be systematically applied to analyze the singularity for any multiple-DOF planar linkage regardless of the number of kinematic loop or the types of joints. The velocity method for singularity analysis is also used to verify the results. The proposed method offers simple explanation and straightforward geometric insights for the singularity identification of multiple-DOF multiloop planar linkages. Examples are also employed to demonstrate the proposed method.
Simulation-Based Unassisted Sit-to-Stand Motion Prediction for Healthy Young Individuals
Authors: Ozsoy Burak , Yang James
Published: January 2015

Sit-to-stand (STS) is a common activity in daily lives which requires relatively high joint torques and a robust coordination of lower and upper extremities with postural stability. Many elderly, people with lower limb injuries, and patients with neurological disorders or musculoskeletal abnormalities have difficulties in accomplishing this task. In contrast to the literature on numerous experimental studies of STS, there are limited studies that were carried out through simulations. In literature, mostly bilateral symmetry was assumed for STS tasks, however even for healthy people, it is more difficult to perform STS tasks with a perfect bilateral symmetry. The goal of this research is to develop a three-dimensional unassisted STS motion prediction formulation for healthy young individuals. Predicted results will be compared with experimental results found in literature for the validation of the proposed formulation.