Top PDF Conference on Thermal Issues in Machine Tools: Proceedings

Conference on Thermal Issues in Machine Tools: Proceedings

Conference on Thermal Issues in Machine Tools: Proceedings

The quality of workpiece is depends on by the thermo-elastic behavior of the machine tool during the production process. Machine tool deformations occur due to waste heat from motors and frictional heat from guides, joints and the tool, while coolants act to reduce this influx of heat. Additional thermal influ- ences come from the machine tool’s environment and foundation. This leads to inhomogeneous, transient temperature fields inside the machine tool which dis- place the tool center point (TCP) and thus reduce production accuracy and finally the product quality [1]. Next to approximation strategies such as characteristic diagram based correction as in [8] and structure model based correction shown in [4], the most reliable way to predict the TCP displacement is via structure-me- chanical finite element (FE) simulation. A CAD model of a given machine tool serves as the basis for this approach. On it a FE mesh is created. After establishing the partial differential equations (PDEs) describing the heat transfer within the machine tool and with its surroundings, FE simulations are run in order to obtain the temperature fields of the machine tool for specified load regimes. Using lin- ear thermo-elastic expansion, the deformation can then be calculated from each temperature field and the displacement of the TCP read from this deformation field, see [6]. The accuracy of this latter approach depends on the correct mod- elling of the heat flux within the machine tool and the exchange with its sur- roundings. In order to calculate the correct amount of heat being exchanged with the environment, one may use known parameters from well-established tables. However, if the surrounding air is in motion or otherwise changing, computa- tional fluid dynamics (CFD) simulations are required to accurately determine these transient parameters. This two-step approach makes realistic thermo-elas- tic simulations particularly complicated and time-consuming. Negative aspect of this approach is the very computing time intensive CFD simulation. Some meth- ods aiming at real-time thermo-elastic simulations based on model order reduc- tion must therefore rely on the inaccurate predetermined parameter sets [5]. This could be supported if all the necessary CFD simulations could be run in ad- vance and supplied to the thermo-elastic models when they are needed. Nevertheless, the whole output of this CFD simulations is too much amount of data for an effective computation of the correction steps. Therefore, a reduction of this data is desirable wherefore the ideas of this paper comes up.
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Irish Machine Vision and Image Processing Conference Proceedings 2018

Irish Machine Vision and Image Processing Conference Proceedings 2018

The movement of cells, known as cell migration, is among the vital processes that could benefit from au- tomated extraction and analysis. It is a driving force behind many biological mechanisms, including immune response and wound healing, and its improper functioning can trigger life-threatening issues, such as tumors and autoimmune diseases [Etienne-Manneville, 2008]. Subcellular multi-protein structures called focal adhe- sions (FAs) mechanically attach the actin cytoskeleton of the cell to the extracellular matrix components, thus playing an essential role in cell migration [Strzyz, 2016]. New FAs are formed at the front of the migrating cell as new connections are established there; they grow in size, reach maturation, and then shrink, to finally disappear as the cell severs old connections with the matrix. This explains why FAs can display a multiplicity of complex behaviours, including changing shape, assembling, disassembling or sliding, thus making their track- ing a challenging task. This variety in behaviour and appearance as well as the difficulty to reliably segment them call for the use of one or several carefully chosen motion models to effectively extract their trajectory.
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IRISH MACHINE VISION & IMAGE PROCESSING
Conference proceedings 2015

IRISH MACHINE VISION & IMAGE PROCESSING Conference proceedings 2015

CityEngine is effective in situations where a “good enough” output is acceptable, such as stylised video games. One problem with this approach, however, is that the indirect nature of L-system descriptions makes them difficult to adjust, especially as they increase in size to deal with detailed map features. Lechner et al. [Lechner et al., 2003] proposed an alternative agent-based approach that helps overcome these issues. Their technique delegates the handling of road and building placement to agents that follow specific rules, similar to those used by city planners. Different agent types are assigned specific tasks, such as extending roads into unexplored terrain, connecting existing roads to create shortcuts, and searching for available land on which to construct buildings. Building construction is based on the type of zone being built and the estimated land value. Lechner’s approach requires less user input than CityEngine, needing only one image. It also has the advantage of allowing the user to set global parameters to fine tune the appearance of the generated city. In later work, the authors combined their system with the SimCity engine for more aesthetically pleasing output [Lechner et al., 2004]. There are, however, two limitations with an agent-based approach. One is that basing generation on the emergent results of a set of heuristics limits the control over the resulting city appearance. The second is that generation speed is relatively slow.
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Conference proceedings 2006

Conference proceedings 2006

Specific methodological problems of experimentation in the social and behavioural sciences, are those of standardisation and operationalisation. Standardised measures are not any more valid than other research tools because, as we have argued before, there is nothing to be measured as a result of the unique relationship all of us have with our own realities. Constructed scales and their subsequent validation lead to denaturalisation, encapsulation and objectification of meaning (Burnard and Hannigan 2000; Massé 2000). Thus, approaches that draw on standardisation inherently ontologise social reality. As has been shown before, such is impossible in the field of child protection, as well as most aspects of the social sciences in general. For example, child neglect can have an entirely different meaning to one person than it has to the other. Whereas one might have experienced child neglect as a completely negative situation, another might think of it with mixed feelings, as a lack of parental interest in the child also renders it a sense of freedom. An abstract concept, such as ‘neglect’ cannot be observed. Because of this, attempts to come to know to what extent a child is neglected are made by operationalising the concept by formulating parameters of abuse and neglect and the gravity of these phenomena (Baeten and Willems 2004). The researcher constructs these parameters, and subjects are then asked to report where they would place themselves or others at such a parameter. Alternatively, a practitioner might ‘score’ the situation of a family on a decision-aid, which is inherently a value-judgment on the basis of an inference made on the basis of incomplete, contradictory, ambiguous information. Thus, the designer of the research instrument frames the answer beforehand by superimposing a certain definition and parameters of neglect. Furthermore, the problem with self-reported behaviour is that it is prone to a multitude of biases. Because quantification can only take place through inference instead of direct observation, we might be able to roughly approach a socially constructed measure of neglect by quantitative means, but we will never be able to measure it as exactly as we would determine the weight of a bag of sugar. Methods are nothing more than a means by which we can improve our knowledge and all methods have to deal with issues of validity and reliability, which is something quite different from objectivity (Humphries 2003; Oakley 2000). Contrary to most parts of medicine, in the social sciences quantification and measurement are not the same. Quantification in the social sciences consists of value judgments expressed in a number. Because they are expressed in a number, it does not make them more objective.
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Traceable Measurements on Machine Tools - Thermal Influences on Machine Tool Structure and Measurement Uncertainty

Traceable Measurements on Machine Tools - Thermal Influences on Machine Tool Structure and Measurement Uncertainty

There are some main differences between a MT and a CMM. The geometric errors of the MT kinematic for example influence the manufacturing result and prevent if not known a traceable measurement on the MT. The knowledge of these errors is the basis for the uncertainty determination. Beneath these systematic errors, the environment of the shop floor means the biggest challenge to a traceable measurement as the manufacturing of large-scale devices in most instances cannot take place in expensive controlled environments. The dominant uncertainty source for the measurement of large scale devices are in time and space varying thermal effects of the environment and the gravitational distortion of both measuring instrument and measured part. Issues such as gravitational sag, thermal expansion, thermal diffusity and thermal effects on instruments and parts have to be tackled by using multidisciplinary approaches involving dimensional and thermal metrology and state-of-the-art modeling.[7][8][9] The presented concept can be seen as a first step in the chain for an process integrated quality inspection for large scale parts. The model based approach for the user friendly determination of the measurement uncertainty combines methods from the coordinate metrology field with research results in the field of MTs and precision engineering.
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Irish Machine Vision and Image Processing (IMVIP) 2014 conference proceedings

Irish Machine Vision and Image Processing (IMVIP) 2014 conference proceedings

The European Project GRAISearch (Use of Graphics Rendering and Artificial Intelligence for Improved Mobile Search Capabilities, http://tapastreet.com/GRAISearch, FP7- PEOPLE-2013-IAPP (612334), 2014-18) is a research collaboration between two universities (Trinity College Dublin, Ireland, and INSA Lyon, France) and the company Tapastreet Ltd (see mobile app at http://tapastreet.com/). It aims at providing enhanced visuali- sation tools for visual content available on social media and an architecture for social media summarisation. Tapastreet has a location based social media search engine platform that, in its current form, returns geo-located video and image media from major social networks for any location and any topic (#hashtags) anywhere in the world. The current platform deals well with images on social media but videos are yet not well tackled. Several challenges exist for videos on social platforms. First, they are too large to all be downloaded when browsing on mobile devices and therefore need to be summarised very efficiently. Second, media on social platforms consist mainly of very diverse amateur recordings with little or no editing rules that also contain many artefacts that alter their quality, such as low lights and motion shakiness when the recording device is hand-held.
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Proceedings of the SIGDIAL 2013 Conference

Proceedings of the SIGDIAL 2013 Conference

conference reception and dinner, and best paper awards. We gratefully acknowledge the support of our sponsors, including Amazon, Apple, AT&T, Heidelberg Institute for Theoretical Studies (HITS), Honda Research Institute (HRI), La R´egion Lorraine, Microsoft, Nuance, Samsung, and SUPELEC. We also thank Priscilla Rasmussen at the ACL for handling the financial aspects of sponsorship for SIGDIAL 2013.

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TCC 2015 Conference Proceedings

TCC 2015 Conference Proceedings

research PLCs (Feger & Arruda, 2008), determining which type of instructional strategies could be incorporated to ensure meaningful, relevant, and long lasting PLCs for online instructors. In addition, it is important to model and encourage teachers to incorporate PLCs with their students, similar to how one teacher felt confident her learners would experience the same sense of community she experienced in the OITI. Fourthly, based upon some teacher responses during the interview sharing not being as comfortable addressing special needs students in an online environment, it would be beneficial to incorporate universal design learning (UDL) in future training curriculum, a framework that assists teachers in creating curricula that addresses the needs of all learners (National Center on UDL, 2014). Lastly, there is a lot of content to cover to ensure teachers gain skills essential for online teaching. Teachers from the study indicated increase in technological skills through exploration of technology tools. The recommendation is to be selective of tools introduced during training that would address foundational skills, easy to learn, and serve multiple purposes in engaging students and increasing student impact and achievement.
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Influence of external heat sources on volumetric thermal errors of precision machine tools

Influence of external heat sources on volumetric thermal errors of precision machine tools

EHS mainly include ambient temperature, lamp, electronic control cabinet (ECC), hydraulic pump station (HPS), etc. Different from IHSs, EHSs affect machine tool temperature through convection and thermal radiation. Some researchers investigated the impacts of environment temperature perturbation on machine tools and established some thermal characteristic models. Zhang [9] proposed analytical approaches of time domain and frequency domain to analyze the influence of time-varying environment temperature on machine tool thermal error. For simplicity, author decomposed the machine tool into several units composed of relatively simple structures, then calculated the overall thermal error transfer function. However, thermal gradients result in machine tool non-linear structure deformation. Hence, the simplification in this paper is not suitable for precision machine tool thermal error modeling. Finite element analysis (FEA) is an efficient calculation method which is widely used in machine tool temperature and deformation prediction. Mian [10] studied the effect of ambiance temperature swings on machine tool deformation by FEA. The presented modeling methodology observably reduced the machine downtime required to establish the thermal response. Regrettably, other EHSs which affect machine tool through thermal radiation were leave out of the consideration. Tan [11] further studied the environment thermal hysteresis effects and brought up a time-varying analytical model between environment temperature and thermal error of large machine tools using Fourier synthesis, time series and the Newton cooling law. Further, the experiment verifies that the ambient temperature has a significant influence on heavy-duty machine tool. However, other EHSs impacts such as lamps, ECC, HPS have not been discussed. Based on fiber Bragg grating sensing technology, Huang [12] measured real-time temperature and deformation filed of a heavy-duty machine tool. Experiments results indicated that the surface temperature and spindle thermal error have a similar change trend following the ambient temperature. Since this paper is focused on measurement methodology, thermal error prediction method has not been presented. Glänzel [13] proposed a novel method to provide the heat transfer parameters quickly and efficiently for transient environmental conditions. Furthermore, the temperature and heat transfer coefficient of column and the velocity and temperature of surrounding air were simulated. However, the deformations of machine tool have not been calculated. In general, the impacts of ambient temperature on machine tools have been investigated in previous studies while other EHSs convection and thermal radiation effects on machine tools still lack of systematic studies.
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Proceedings of the SIGDIAL 2010 Conference

Proceedings of the SIGDIAL 2010 Conference

For the first time, this year a local organizing committee was formed. Our thanks go to its members who worked very hard on the local arrangements such as deciding the venue, maintaining the conference web site, handling registrations, managing the conference bank account, printing proceedings, and arranging the conference lunches and dinner.

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Proceedings of the SIGDIAL 2011 Conference

Proceedings of the SIGDIAL 2011 Conference

advice, and responses to our questions. We thank last year’s General co-chair Mikio Nakano for updates to the conference chair kit, and much helpful advice. Thanks also go to Kazunori Komatani and Guodong Zhou for answering our questions related to assembling the conference proceedings. We would like to thank Priscilla Rasmussen at ACL for handling the financial transactions, including advance registration. We would also like to thank Drago Radev, ACL Secretary, for helpful advice. Thanks to SoftConf for use of the START conference management systems as well as helpful responses on its use. Thanks also to the SIGDIAL board, in particular Tim Paek, Amanda Stent, and Kristiina Jokinen, for their advice and support in all matters.
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REPORT OF THE CONFERENCE PROCEEDINGS AND RESOLUTIONS

REPORT OF THE CONFERENCE PROCEEDINGS AND RESOLUTIONS

102. H.E. Tumusiime thanked the guest speakers and all the participants who contributed to drafting the resolutions which would lead to the improvement of the livestock sector in Africa. She recalled the theme of the conference “Improving access to markets for African animal resources to significantly contribute to economic growth and reduction of poverty” and noted that a key challenge to practitioners in the livestock domain was to assist and empower poor African poor farmers to fully benefit from the huge opportunities offered by the rapidly expanding demand for products of animal origin. She reminded the participants of the key highlights of the discussions during the conference including the following:
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Application of thermal error in machine tools based on Dynamic Bayesian Network

Application of thermal error in machine tools based on Dynamic Bayesian Network

Dynamic Bayesian Network (DBN) is a type of BN that can model time-series data to capture the fact that time flows forward, which coupled with the time constraints on the properties of the original network structure. It has the advantage both of model-based and data-based methods. And with the introduction of time factor, the data on the state of the formation of different time, reflects the development change rule represented by the variable, and its intuitive, high precision and adaptive for thermal error modeling of machine tools.

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Compensation of Thermal Effects on Machine Tools using a FDEM Simulation Approach

Compensation of Thermal Effects on Machine Tools using a FDEM Simulation Approach

A hybrid model of a high-speed precision machining centres headstock based on the two computational methods FEM and FDM was developed to determine its optimal operating characteristics in detail. The simulation allows to evaluate thermal and structural properties of a machine model [11]. Other authors developed a modified lumped capacitance method (MLCM) to model the heat flux in CNC (computer numerical control) machine tools feed drive systems, solving with FEM [9,12].

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Sborník příspěvků Conference Proceedings

Sborník příspěvků Conference Proceedings

Seniori spokojní so svojim zdravotným stavom majú vyššiu mieru celkovej anticipovanej sociálnej opory a vyššie skórujú v subškále chápajúca autorita, v životnej spokojnosti vyšši[r]

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Sborník příspěvků Conference Proceedings

Sborník příspěvků Conference Proceedings

Výsledky v tabuľke prezentujú, že existujú rozdiely v miere anticipovanej sociálnej opory a životnej spokojnosti podľa spokojnosti so zdravotným stavom. Pri signifikantných škálach majú[r]

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[J100.Ebook] Free PDF Thermal Deformation In Machine Tools By Yoshimi Ito.pdf

[J100.Ebook] Free PDF Thermal Deformation In Machine Tools By Yoshimi Ito.pdf

Often, reviewing Thermal Deformation In Machine Tools By Yoshimi Ito is really boring and it will take very long time starting from getting the book and also begin reviewing. Nevertheless, in contemporary period, you can take the developing technology by utilizing the net. By internet, you could visit this page and begin to look for the book Thermal Deformation In Machine Tools By Yoshimi Ito that is required. Wondering this Thermal Deformation In Machine Tools By Yoshimi Ito is the one that you need, you can go for downloading and install. Have you understood ways to get it?
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Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)

Proceedings of the Fourth Conference on Machine Translation (Volume 2: Shared Task Papers, Day 1)

Loïc Barrault, Ondˇrej Bojar, Marta R. Costa-jussà, Christian Federmann, Mark Fishel, Yvette Gra- ham, Barry Haddow, Matthias Huck, Philipp Koehn, Shervin Malmasi, Christof Monz, Mathias Müller, Santanu Pal, Matt Post and Marcos Zampieri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Results of the WMT19 Metrics Shared Task: Segment-Level and Strong MT Systems Pose Big Challenges Qingsong Ma, Johnny Wei, Ondˇrej Bojar and Yvette Graham . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Findings of the First Shared Task on Machine Translation Robustness
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The modelling and correction of ball screw geometric, thermal and load errors on CNC machine tools

The modelling and correction of ball screw geometric, thermal and load errors on CNC machine tools

White et al [38] described a combined thermal and geometric error compensation system with a flexible structure that is general purpose in its application to any machine tool. The system can accept input from any number of temperature sensors. Using data from a single test on the machine, a novel Matlab model can be programmed in such a way that it estimates its thermal movement. The program then directs error values to a number of outputs which are used by the machine controller to effect compensation by axis position modification. The entire compensation system can be applied either in a stand-alone computer that accepts a wide range of feedback signal types, or integrated into an open architecture machine controller. The system allows the management of temporary or permanent input failures and displays every thermal error component as an aid to fault diagnosis. Both position independent and position dependent thermal errors can be reduced through compensation. The system has been applied to several machine tools, and has shown itself capable of reducing thermal movements between the tool and the workpiece by over 6 times when using a quick heating and cooling test for calibration.
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Application of GNNMCI(1, N) to environmental thermal error modelling of CNC machine tools

Application of GNNMCI(1, N) to environmental thermal error modelling of CNC machine tools

The process was repeated to create a GNNMCI (1, 5) model for the Y-axis direction. To validate the robustness of these proposed models on non-training data, a normal environmental simulation was run using the temperature data presented in Fig. 3. The measured and simulated profile results were plotted for the Z-axis and Y-axis. Compared to the measured results, the correlations were 97% for the Z displacement profiles Fig. 5, and 98% for the Y displacement profiles Fig. 6. The residual errors were less than ± 10 μm for the Z axis and less than ± 6 μm for the Y axis even when considering the rapid changes due to the opened workshop door. Under more predictable conditions, which could be achieved by better management of the environment, ±3µm would be achieved in each axis. Thus, the proposed GNNMCI (1, 5) model can predict the normal daily cyclic error accurately and also can track sudden changes of thermal error from a relatively small training sample.
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