bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the Oil Squeezing Power Losses of a Spur Gear Pair by Mean of CFD Simulations
Authors: Concli Franco , Gorla Carlo 
Published: December 2013

Efficiency is becoming more and more a main concern in the design of power transmissions and the demand for high efficiency gearboxes is continuously increasing. Also the new restrictive euro standards for the reduction of pollutant emissions from light vehicles impose to improve the efficiency of the engines but also of the gear transmissions. For this reason the resources dedicated to this goal are continuously increasing.
The first step to improve efficiency is to have appropriate models to compare different design solutions. Even if the efficiency of transmissions is quit high if compared to the efficiency of the engines and appropriate models to predict the power losses due to gear meshing, to bearings and to seals already exist, in order to have a further improvement, some aspects like the power losses related to the oil churning, oil squeezing and windage are still to be investigated. These losses rise from the interaction between the moving or rotating elements of the transmission and the lubricant. In previous papers [39, 40, 41 43, 44], the authors have investigated the churning losses of planetary speed reducers (in which there is a relative motion between the “planets + planet carrier” and the lubricant). This report is focused on the oil squeezing power losses. This kind of losses is associated with the pumping of the oil at the gear mesh, where there is a contraction of the volume between the mating gears due to the rotation of them and a consequent overpressure. This overpressure implies a fluid flow primarily in the axial direction and this, for viscous fluids, means additional power losses and a decrease of the efficiency. In this work this phenomena has been studied by means of some CFD (computational fluid dynamic) simulations with a VOF (volume of fluid) approach. The influence of some operating conditions like the rotational speed and the lubricant temperature have been studied.
The results of this study have been included in a model to predict the efficiency of the whole transmission.
Virtual Reality Interfaces Applied to Web-Based 3D E-Commerce
Authors: Elordi Unai , Segura Alvaro , Goenetxea Jon , Moreno Aitor , Arambarri Jon 
Published: December 2013

E-commerce is well established on today’s Internet and has created its own set of techniques for performing and optimizing sales. Traditional shops on the other hand provide a physical space in which decoration and space are relevant. In this paper we present innovative interfaces that join the concepts of real shops and on-line e-commerce in a Web-based virtual reality platform.
The idea involves making the e-shopping experience more intuitive, closer to the experience of visiting a real shop, and providing on-line 3D interfaces for the entire process from shop design and product placement to customer experience analysis. We researched traditional marketing and sales techniques and the way they can be transferred to 3D virtual reality environments. Web 3D technologies allow us to implement interactive virtual worlds on the Web, accessible for everyone over different platforms and without special applications or plug-ins.
Energy of Vibroacoustic Signal as Parameter of Logistics Model of the Tooth’s Crack Development
Authors: Radkowski Stanisław , Gumiński Robert 
Published: December 2013

The paper takes on the issue of uncertainty in statistical methods of cracks propagation. The goal of the paper was to develop a method, which would enable use of diagnostic information in assessment of fatigue damage process.
Particular attention was paid to the possibility of forecasting the occurrence of damage due to fatigue while relying on the analysis of the structure of a vibroacoustic signal. The difficulty in this case is that the set of parameters containing diagnostic information may change as defects develop. This fact confirms the necessity of examining the evolution of probability distribution and defining the periods of an object’s operation, carried out while taking into account the actual technical condition as well as the associated identification of defect development phases. The study presents the following issue: developing the method of diagnosing the early stages of defect development while analyzing energy of vibroacoustics signal as parameter of logistics model of cracks development.
A Real-Time Algorithm for Fault Detection in Construction Machinery
Authors: Cazzulani G. , Moschini S. , Ripamonti F. , Resta F. 
Published: December 2013

The laws concerning safety on worksite have become more strict year on year being that topic always more important. The main causes of injuries are workers unawareness and structural failures of machineries, i.e. cranes, or scaffolds. In order to prevent injuries, an accurate maintenance is mandatory. During the last years a new trend in maintenance has arisen in opposition to programmed maintenance. Monitoring the system, the condition based maintenance may prevent accidents avoiding unnecessary stops of the machineries and the corresponding reduced returns.
In this paper a health monitoring algorithm for a typology of construction machinery (the concrete displacing booms) is proposed. The proposed algorithm is based on the knowledge of geometrical and dynamical parameters of the boom, estimated through a stand-alone self-learning procedure. This feature makes the developed diagnostics system predisposed to be easily extended to other machineries or work fields. The common failure conditions, such as an overload or a crack propagation, are readily signaled.
The algorithm has been numerically and experimentally validated on a specific test rig which reproduces a reduced scale concrete displacing boom. The results, referred to the detection of two simulated common failure conditions, are presented and discussed.
Human Perceptions of Nonverbal Behavior Presented Using Synthetic Humans
Authors: Gallimore Jennie J. , Ward Blake , Johnson Adrian , Leard Bobbie , Lewis Jeremy , Preuss Kyle , Skipper Julie 
Published: December 2013

Synthetic humans are computer-generated characters that are designed to behave like humans for the purpose of training or entertainment. The purpose of this study was to evaluate the perceptions of subjects interacting with synthetic humans to determine their responses to nonverbal behaviors, realism, and character personality. This study was part of a research program to develop a virtual game to train awareness of nonverbal communication for cross-cultural competency (3C).
Three synthetic humans were created with different levels of realism with respect to their facial movements and skin textures. Low realism characters were defined as models purchased from the company Evolver, with additional facial action units (FAU) added to the character’s face. High realism characters were created based on a model of a real person’s head using 3D imaging cameras and a digital video camera. The same FAUs available in the Evolver characters were also coded into the high realism character as well as more realistic skin texture. During a virtual scenario the subject was asked to interview three characters in the U.S. Army. The subject interviewed each character one-on-one. The three computer characters included two white males, and one black female.
The results of this study showed that it is possible to create synthetic humans that include nonverbal behaviors and personalities that are perceived by subjects, and that the subject’s own personal lens affected how they perceive the character. For example, the character Brent was rated similarly by most subjects with respect to personality traits as defined by the Big Five Factor Model. However, half the subjects indicated they liked him (friendly and confident), while about half the subjects did not like him (too confident as to be arrogant).
Simulation Technology of Self-Induced Vibration in a Metal Pushing V-Belt CVT
Authors: Saito Toshihiro 
Published: December 2013

Noise and vibration are factors affecting the marketability of automobiles. It is required for the drivetain design not to transmit unpleasant noise and vibration to the passengers when driving. As for continuous variable transmission (CVT), noise that is considered to be generated from the metal pushing V-belt has been studied. A research project on this matter reported an estimated mechanism that attributes the noise to self-inducing vibration between the metal pushing V-belt and the pulleys. The self-induced vibration occurs when dynamic friction characteristics exhibit a negative gradient in relation to the sliding speed. However, the effect of the gradient on frequency spectrum of the noise has not been quantitatively elucidated in a consistent manner.
In this research, noise at the vehicle start-up phase was studied based on the already reported prediction technology for metal pushing V-belt behavior. In other words, this study focuses on the effect of the friction characteristic gradient between the metal pushing V-belt and the pulleys on each element’s behavior and frequency components of belt pushing force.
The results revealed that self-induced vibration on the element V-surface at the exit of the drive pulley excites high-order string vibration at the belt string, generating noise via the transmission case. In addition, it was also found that acoustic energy that excites the high-order string noise is affected by the change in belt pitch diameter at the exit of the pulley, and this determines the magnitude of frequency spectrum of the noise.
It was concluded from the above findings that the change in the pitch diameter can be suppressed by narrowing the radial clearance between the shaft and the movable pulley and this measure is effective in reducing noise.
A Tentative Model for Analysis of Human-Automation Interaction in Control Rooms
Authors: Andersson Jonas 
Published: December 2013

This paper describes a tentative model to analyze work in joint human-automation systems. The tentative model is used to represent known human-automation related problems in a unified way. The out-of-the-loop problem is used as an example in the paper.
The present paper has three main objectives; (I) present a tentative model that can characterize work in joint human-automation systems, (II) show how the tentative model can be used to describe examples of human-automation related problems (III) discuss how the tentative model can be used as a viable tool to understand human-automation interaction.
The paper reports an evaluation made by using empirical data from an interview study on turbine automation operation in the nuclear power domain where human-automation related problems were identified.
The evaluations show that the tentative model provide useful explanations to how specific automation related problems emerge. These explanations could potentially be generalized into human-automation interface design guidance. Further, it is discussed how the tentative model can be developed into a viable tool for industrial use where limited resources are available for extensive analysis of human-automation interaction.
Efficiency of Implicit Symplectic Finite-Difference Time-Domain Method for Near-Field Optics
Authors: Saitoh Ikuo , Naruse Makoto 
Published: December 2013

We proposed a new method, implicit symplectic finite difference time domain (FDTD) method) which inherits the good properties from the conventional FDTD method, simplecticity and the conservation of energy. The proposed method is free from the Courant-Friedrics-Lewy condition at the same time.
In this paper, we show our method is more efficient than the conventional FDTD method using a typical problem, a polarization control in optical near and far fields of the designing the shape of a metal nanostructure.
Experimental Analysis and Simulation of the Dynamic Response of a Propeller Pitch Change Actuator
Authors: Leclercq Maxime , Malburet François , Veron Philippe 
Published: December 2013

This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response.
The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities.
Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article.
Computational Models for Resistance Spot Welding
Authors: Mollicone Pierluigi , Muscat Martin , Said Matthew 
Published: December 2013

Spot welding is a very important joining process for many industries. Structural integrity of a spot welded joint is however compromised by the formation of residual stress fields, which arise due to the thermal loadings imposed on the material during this welding process. Experimental investigation of these effects is possible but often costly, especially in complex and large-scale applications. Computational models, through the application of advanced Finite Element Analysis (FEA) techniques, are hence of interest for the prediction, analysis and assessment of these effects. The computational modelling required to assess these effects is however relatively complex due to the interaction of thermal and structural solution fields. It follows that many decisions must be taken with regards to the modelling technique to adopt in these scenarios.
This work presents a modelling technique for the prediction of spot welding induced residual stresses, validated with experimental measurements for the temperature and residual stress fields. The simulations, carried out in ANSYS, are aimed at using a general-purpose solver to predict residual stresses whilst the validation is carried out through transient thermocouple measurements and residual stress measurements done using the hole drilling method. Comparison of experimental and FEA model results highlight which parts and assumptions of the computational model are to be considered valid and hence its boundary for use in industry.
Some New Theoretical Results for Orthotropic Inflatable Beams
Authors: Nguyen Quang Tung , Thomas Jean-Christophe , Le Van Anh 
Published: December 2013

A so-called inflatable beam is a membrane tube which gains its stiffness only by a prescribed internal pressure. Such lightweight structures are useful in inflatable buildings and particularly in space industry, whenever rapidly deployable and easily transportable structures are required.
An inflatable beam may look like a standard beam, but its mechanism is quite different and a specific mechanical study is necessary in order to establish its governing equations. The only way to correctly take account of the internal pressure — which is a follower load — is to carry out a complete nonlinear analysis before any possible linearization.
This work aims to extend the analytical results for isotropic inflatable beams to the practical situation when the beam is made of an orthotropic fabric. It will be shown that the Timoshenko beam model combined with the finite rotation kinematics enables one to correctly account for all the nonlinear terms in the governing equations. A linearization will then be performed to study deformations about the pre-stressed reference configuration. Furthermore, it will be shown how to precisely compute the radius and the length of the inflated tube in the reference state, a very significant issue which is overlooked so far in the literature. All the proposed analytical results will be compared with the numerical ones obtained from a nonlinear 3D finite element code.
Towards Delayed Teleoperation With Pneumatic Master and Slave for MRI
Authors: Leleve Arnaud , Pham Minh Tu , Tavakoli Mahdi , Moreau Richard 
Published: December 2013

Over the last 50 years, master-slave teleoperation has become a widespread and successful field of research. This discipline explores how to perform tasks using a robot on an environment with haptic feedback about robot-environment interaction being provided to the human operator. Most of the master and slave manipulators used in teleoperation are electrically actuated. However, in some particular applications such as inside an MRI for image-guided surgery, ferromagnetic materials including electrical wiring is prohibited. Thus, non-ferromagnetic actuators like pneumatic or hydraulic actuators are a solution to this problem. This specific application also requires teleoperation in the sense of “tele-actuation” because of the lack of space inside the MRI chamber to put the robot’s actuators and the presence of electrical components in pneumatic servovalves.
In this paper, we study the case of a teleoperation system composed of two identical pneumatic cylinders (as the master and the slave) equipped with servovalves, making a symmetric teleoperation system. This serves as a one-degree-of-freedom system to outline the design and analysis in terms of teleoperation transparency and stability. Simulation and experimental results check the validity of the theory without and with classical transmission delays.
Sensitivity Analysis of a Solar Cooling System
Authors: Letexier Blaise , Marc Olivier , Praene Jean-Philippe , Lucas Franck 
Published: December 2013

The aim of this paper is the optimization of Solar Absorption Cooling (SAC) system’s performances. Over the past decade the electricity consumption has significantly increased in Reunion Island during the summer months, which is mainly due to the use of standard air conditioning systems. SAC systems present a good alternative for reducing this consumption. Solar cooling systems are environmentally friendly as they use water and lithium bromide solution as the working fluid.
The purpose of this work is to undertake a sensitivity analysis to identify parameters which have a significant influence on the SAC systems performances. The sensitivity analysis has been carried out on numerical models developed at the PIMENT laboratory and validated using RAFSOL experimental data (experimental plant is set up at the IUT in St-Pierre). The results of the sensitivity analysis are used to establish the design and create the control rules to allow for the optimization and ensure the performance of future SAC systems.
Firstly, this paper presents the modelization of the SAC system and the sensitivity analysis method used. Secondly, it displays the results from the sensitivity analysis that has been applied to all main components of the plant separately (solar collector field, solar loop and absorption chiller) and to the entire system. Finally, the results are analyzed and discussed.
Two types of influential parameters have been distinguished: variables factors and geometrical properties of the plant. This study highlights that the compactness of the installation, the quality of the solar collector, and the control of the temperature at the output of the distribution loop are essential.
Enhancing the Performance of Photovoltaic Solar Modules by Active Thermal Management
Authors: Rodgers Peter , Eveloy Valerie , Bojanampati Shrinivas 
Published: December 2013

The electrical efficiency and reliability of photovoltaic (PV) modules are severely limited by elevated cell operating temperature in high solar irradiation and ambient air temperature environments, such as in the Middle East. In this study the potential of water-cooling to improve the electrical performance of stationary south facing and sun-tracked flat-type PV modules is experimentally investigated for application at oil and gas facilities in the Persian Gulf. The cooling design is based on gravity-assisted water trickling over the module active surface. In parallel with measurements of PV module electrical characteristics, global solar irradiation, ambient air and cooling water temperatures are also recorded.
From the results obtained, the following initial guidelines are derived for the operation of PV modules in late winter to early spring conditions (G ≈ 485–900 W/m2, T∞ ≈ 26–40°C) in the United Arab Emirates (24.43°N, 54.45°E), which would correspond to summer at for example mid European latitudes: i) vertical single-axis sun tracking improves module peak electrical power output by 6% to 10% compared to operation in stationary, geographical south facing orientation, for both passively- or water-cooled modules; ii) for cooling water temperatures ranging from 26 to 33°C, water-cooling enhances the power output of stationary south facing and sun-tracked modules for a significant portion of the day, up to 19.8 W (21%) at solar noon; iii) the integration of water-cooling and sun-tracking increases power output by 22 W (26%) at for example 10:30 a.m. relative to a stationary, passively-cooled module. For the latitude and seasonal conditions considered, water-cooling a stationary PV module is 9 to 15% more effective than sun-tracking a passively-cooled module in terms of peak power output. Higher performance improvements could be obtained using either chilled or underground water at a temperature below ambient air temperature, particularly in Middle East summer conditions.
Latent Heat Estimation of the Martensite Transformation Through Inverse Methods During the Hot Stamping Process
Authors: Blaise Alexandre , Bourouga Brahim , Abdulhay Bakri , Dessain Christine 
Published: December 2013

In the hot stamping process, the temperature evolution drives the metallurgy, as well as the metallurgical transformation influences the temperature evolution through the exothermic nature of the austenite to martensite transformation. This heat release has already been highlighted by previous experimental work. This heat release leads to a source term in the heat equation in the blank. This source term must be quantified in order to accurately predict blank temperature evolution. Moreover, the end of the heat release corresponds to the end of the metallurgical transformation. It allows the determination of the minimum quenching time, relevant information for industry to minimize the process time.
This paper presents a method to quantify the heat released by the metallurgical transformation during the hot stamping of Usibor 1500P® ArcelorMittal steel, solving inverse conduction problems. It allows the determination of this heat release as a function of temperature or time. Then, integrating it, the latent heat of the transformation can be estimated. This can be done for different contact pressures between tool and blank. Finally, it can be linked to the martensite proportion to estimate it as a function of time or temperature and determine the Koistinen-Marburger model parameters. These results should improve the accuracy of numerical simulations of the hot stamping process.