906 resultados para machine-tool industry
Resumo:
The ability to accurately predict the remaining useful life of machine components is critical for machine continuous operation, and can also improve productivity and enhance system safety. In condition-based maintenance (CBM), maintenance is performed based on information collected through condition monitoring and an assessment of the machine health. Effective diagnostics and prognostics are important aspects of CBM for maintenance engineers to schedule a repair and to acquire replacement components before the components actually fail. All machine components are subjected to degradation processes in real environments and they have certain failure characteristics which can be related to the operating conditions. This paper describes a technique for accurate assessment of the remnant life of machines based on health state probability estimation and involving historical knowledge embedded in the closed loop diagnostics and prognostics systems. The technique uses a Support Vector Machine (SVM) classifier as a tool for estimating health state probability of machine degradation, which can affect the accuracy of prediction. To validate the feasibility of the proposed model, real life historical data from bearings of High Pressure Liquefied Natural Gas (HP-LNG) pumps were analysed and used to obtain the optimal prediction of remaining useful life. The results obtained were very encouraging and showed that the proposed prognostic system based on health state probability estimation has the potential to be used as an estimation tool for remnant life prediction in industrial machinery.
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This chapter is a tutorial that teaches you how to design extended finite state machine (EFSM) test models for a system that you want to test. EFSM models are more powerful and expressive than simple finite state machine (FSM) models, and are one of the most commonly used styles of models for model-based testing, especially for embedded systems. There are many languages and notations in use for writing EFSM models, but in this tutorial we write our EFSM models in the familiar Java programming language. To generate tests from these EFSM models we use ModelJUnit, which is an open-source tool that supports several stochastic test generation algorithms, and we also show how to write your own model-based testing tool. We show how EFSM models can be used for unit testing and system testing of embedded systems, and for offline testing as well as online testing.
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Effective research partnerships, both intra- and interdisciplinary, as well as academy-industry partnerships, rely on shared understandings of particular aspects of the research endeavour. Research partnerships are essentially learning partnerships, if we accept the argument that research may be seen as learning at the collective level. This paper establishes the need to investigate information technology (IT) researchers' varying ways of seeing certain aspects of their research world, in order to assist the process of forging effective research partnerships. We analyse the importance of facilitating effective partnerships in IT research, discuss our plan for investigating the collective consciousness of IT researchers, and explain some of the strategies to be used in the investigation.
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The ability to identify and assess user engagement with transmedia productions is vital to the success of individual projects and the sustainability of this mode of media production as a whole. It is essential that industry players have access to tools and methodologies that offer the most complete and accurate picture of how audiences/users engage with their productions and which assets generate the most valuable returns of investment. Drawing upon research conducted with Hoodlum Entertainment, a Brisbane-based transmedia producer, this project involved an initial assessment of the way engagement tends to be understood, why standard web analytics tools are ill-suited to measuring it, how a customised tool could offer solutions, and why this question of measuring engagement is so vital to the future of transmedia as a sustainable industry. Working with data provided by Hoodlum Entertainment and Foxtel Marketing, the outcome of the study was a prototype for a custom data visualisation tool that allowed access, manipulation and presentation of user engagement data, both historic and predictive. The prototyped interfaces demonstrate how the visualization tool would collect and organise data specific to multiplatform projects by aggregating data across a number of platform reporting tools. Such a tool is designed to encompass not only platforms developed by the transmedia producer but also sites developed by fans. This visualisation tool accounted for multiplatform experience projects whose top level is comprised of people, platforms and content. People include characters, actors, audience, distributors and creators. Platforms include television, Facebook and other relevant social networks, literature, cinema and other media that might be included in the multiplatform experience. Content refers to discreet media texts employed within the platform, such as tweet, a You Tube video, a Facebook post, an email, a television episode, etc. Core content is produced by the creators’ multiplatform experiences to advance the narrative, while complimentary content generated by audience members offers further contributions to the experience. Equally important is the timing with which the components of the experience are introduced and how they interact with and impact upon each other. Being able to combine, filter and sort these elements in multiple ways we can better understand the value of certain components of a project. It also offers insights into the relationship between the timing of the release of components and user activity associated with them, which further highlights the efficacy (or, indeed, failure) of assets as catalysts for engagement. In collaboration with Hoodlum we have developed a number of design scenarios experimenting with the ways in which data can be visualised and manipulated to tell a more refined story about the value of user engagement with certain project components and activities. This experimentation will serve as the basis for future research.
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Current governance challenges facing the global games industry are heavily dominated by online games. Whilst much academic and industry attention has been afforded to Virtual Worlds, the more pressing contemporary challenges may arise in casual games, especially when found on social networks. As authorities are faced with an increasing volume of disputes between participants and platform operators, the likelihood of external regulation increases, and the role that such regulation would have on the industry – both internationally and within specific regions – is unclear. Kelly (2010) argues that “when you strip away the graphics of these [social] games, what you are left with is simply a button [...] You push it and then the game returns a value of either Win or Lose”. He notes that while “every game developer wants their game to be played, preferably addictively, because it’s so awesome”, these mechanics lead not to “addiction of engagement through awesomeness” but “the addiction of compulsiveness”, surmising that “the reality is that they’ve actually sort-of kind-of half-intentionally built a virtual slot machine industry”. If such core elements of social game design are questioned, this gives cause to question the real-money options to circumvent them. With players able to purchase virtual currency and speed the completion of tasks, the money invested by the 20% purchasing in-game benefits (Zainwinger, 2012) may well be the result of compulsion. The decision by the Japanese Consumer Affairs agency to investigate the ‘Kompu Gacha’ mechanic (in which players are rewarded for completing a set of items obtained through purchasing virtual goods such as mystery boxes), and the resultant verdict that such mechanics should be regulated through gambling legislation, demonstrates that politicians are beginning to look at the mechanics deployed in these environments. Purewal (2012) states that “there’s a reasonable argument that complete gacha would be regulated under gambling law under at least some (if not most) Western jurisdictions”. This paper explores the governance challenged within these games and platforms, their role in the global industry, and current practice amongst developers in the Australian and United States to address such challenges.
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Due to the health impacts caused by exposures to air pollutants in urban areas, monitoring and forecasting of air quality parameters have become popular as an important topic in atmospheric and environmental research today. The knowledge on the dynamics and complexity of air pollutants behavior has made artificial intelligence models as a useful tool for a more accurate pollutant concentration prediction. This paper focuses on an innovative method of daily air pollution prediction using combination of Support Vector Machine (SVM) as predictor and Partial Least Square (PLS) as a data selection tool based on the measured values of CO concentrations. The CO concentrations of Rey monitoring station in the south of Tehran, from Jan. 2007 to Feb. 2011, have been used to test the effectiveness of this method. The hourly CO concentrations have been predicted using the SVM and the hybrid PLS–SVM models. Similarly, daily CO concentrations have been predicted based on the aforementioned four years measured data. Results demonstrated that both models have good prediction ability; however the hybrid PLS–SVM has better accuracy. In the analysis presented in this paper, statistic estimators including relative mean errors, root mean squared errors and the mean absolute relative error have been employed to compare performances of the models. It has been concluded that the errors decrease after size reduction and coefficients of determination increase from 56 to 81% for SVM model to 65–85% for hybrid PLS–SVM model respectively. Also it was found that the hybrid PLS–SVM model required lower computational time than SVM model as expected, hence supporting the more accurate and faster prediction ability of hybrid PLS–SVM model.
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Australia’s building stock includes many older commercial buildings with numerous factors that impact energy performance and indoor environment quality. The built environment industry has generally focused heavily on improving physical building design elements for greater energy efficiency (such as retrofits and environmental upgrades), however there are noticeable ‘upper limits’ to performance improvements in these areas. To achieve a stepchange improvement in building performance, the authors propose that additional components need to be addressed in a whole of building approach, including the way building design elements are managed and the level of stakeholder engagement between owners, tenants and building managers. This paper focuses on the opportunities provided by this whole-of-building approach, presenting the findings of a research project undertaken through the Sustainable Built Environment National Research Centre (SBEnrc) in Australia. Researchers worked with a number of industry partners over two years to investigate issues facing stakeholders at base building and tenancy levels, and the barriers to improving building performance. Through a mixed-method, industry-led research approach, five ‘nodes’ were identified in whole-of-building performance evaluation, each with interlinking and overlapping complexities that can influence performance. The nodes cover building management, occupant experience, indoor environment quality, agreements and culture, and design elements. This paper outlines the development and testing of these nodes and their interactions, and the resultant multi-nodal tool, called the ‘Performance Nexus’ tool. The tool is intended to be of most benefit in evaluating opportunities for performance improvement in the vast number of existing low-performing building stock.
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This study presents an acoustic emission (AE) based fault diagnosis for low speed bearing using multi-class relevance vector machine (RVM). A low speed test rig was developed to simulate the various defects with shaft speeds as low as 10 rpm under several loading conditions. The data was acquired using anAEsensor with the test bearing operating at a constant loading (5 kN) andwith a speed range from20 to 80 rpm. This study is aimed at finding a reliable method/tool for low speed machines fault diagnosis based on AE signal. In the present study, component analysis was performed to extract the bearing feature and to reduce the dimensionality of original data feature. The result shows that multi-class RVM offers a promising approach for fault diagnosis of low speed machines.
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Smartphone technology provides free or inexpensive access to mental health and wellbeing resources. As a result the use of mobile applications for these purposes has increased significantly in recent years. Yet, there is currently no app quality assessment alternative to the popular ‘star’-ratings, which are often unreliable. This presentation describes the development of the Mobile Application Rating Scale (MARS) a new measure for classifying and rating the quality of mobile applications. A review of existing literature on app and web quality identified 25 published papers, conference proceedings, and online resources (published since 1999), which identified 372 explicit quality criteria. Qualitative analysis identified five broad categories of app quality rating criteria: engagement, functionality, aesthetics, information quality, and overall satisfaction, which were refined into the 23-item MARS. Independent ratings of 50 randomly selected mental health and wellbeing mobile apps indicated the MARS had excellent levels of internal consistency (α = 0.92) and inter-rater reliability (ICC = 0.85). The MARS provides practitioners and researchers with an easy-to-use, simple, objective and reliable tool for assessing mobile app quality. It also provides mHealth professionals with a checklist for the design and development of high quality apps.
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If there is a silver lining to the adversarial, dispute-prone nature of the building and construction industry, it can be found in the concomitant rise of innovative dispute resolution mechanisms. Time, cost and relationship concerns have meant that the formal adversarial system holds little appeal for disputing parties. As these alternative forms of dispute avoidance/resolution have matured in Australia over the last 20 years, attention has turned to the key characteristics of each process and their suitability to the building and construction industry. This article considers the role of dispute review boards (DRBs) and mediation as two alternative methods for avoiding/resolving disputes in the construction industry. Criteria are established for evaluating the efficacy of these procedures and their sensitivity to the needs of construction industry disputants. The ultimate conclusion reached is that DRBs represent a powerful, yet underutilised dispute resolution tool in Australia, and possess many industry-specific advantages that more traditional forms of alternative dispute resolution (particularly mediation) do not provide.
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Building Information Modelling (BIM) has been regarded as a one stop shop capable of addressing the ills of the construction industry. Yet, while some firms have accepted BIM as a new way to work and gone on to record success, others (which have not so done) have raised such questions as: ‘How is BIM defined? Is it a tool or a process? Which kinds and sizes of organisations stand to benefit from BIM?’ These questions form the basis of this research. Hence, having explored the relevant body of literature, this research investigates three organisations within the UK – described as the earliest adopters of BIM – and considers how they have fared in terms of project performance in the years since adopting BIM; focusing on project cost, delivery time and quality achievement. This investigation also probed two of the leading voices in BIM in the UK in search of the much needed answers. The findings of the research show that successful projects executed in the organisations that have used BIM is predicated on its adoption as a process, rather than as a tool of technology; a process that changes the way work in the construction industry is typically done. Moreover, the successes recorded in the firms researched give credence to project success consequent upon adopting BIM. Nevertheless, the findings of this research show that the cornerstone of this success is leadership-driven innovation.
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Poor mine water management can lead to corporate, environmental and social risks. These risks become more pronounced as mining operations move into areas of water scarcity and/or increase climatic variability while also managing increased demand, lower ore grades and increased strip ratios. Therefore, it is vital that mine sites better understand these risks in order to implement management practices to address them. Systems models provide an effective approach to understand complex networks, particularly across multiple scales. Previous work has represented mine water interactions using systems model on a mine site scale. Here, we expand on that work by present an integrated tool that uses a systems modeling approach to represent mine water interactions on a site and regional scale and then analyses the risks associated with events stemming from those interactions. A case study is presented to represent three indicative corporate, environmental and social risks associated with a mine site that exists in a water scarce region. The tool is generic and flexible, and can be used in many scenarios to provide significant potential utility to the mining industry.
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Heart rate variability (HRV) refers to the regulation of the sinoatrial node, the natural pacemaker of the heart by the sympathetic and parasympathetic branches of the autonomic nervous system. HRV analysis is an important tool to observe the heart’s ability to respond to normal regulatory impulses that affect its rhythm. Like many bio-signals, HRV signals are non-linear in nature. Higher order spectral analysis (HOS) is known to be a good tool for the analysis of non-linear systems and provides good noise immunity. A computer-based arrhythmia detection system of cardiac states is very useful in diagnostics and disease management. In this work, we studied the identification of the HRV signals using features derived from HOS. These features were fed to the support vector machine (SVM) for classification. Our proposed system can classify the normal and other four classes of arrhythmia with an average accuracy of more than 85%.
Resumo:
The Hong Kong construction industry is currently facing ageing problem and labour shortage. There are opportunities for employing ethnic minority construction workers to join this hazardous industry. These ethnic minority workers are prone to accidents due to communication barriers. Safety communication is playing an important role for avoiding the accidents on construction sites. However, the ethnic minority workers are not very fluent in the local language and facing safety communication problems while working with local workers. Social network analysis (SNA), being an effective tool to identify the safety communication flow on the construction site, is used to attain the measures of safety communication like centrality, density and betweenness within the ethnic minorities and local workers, and to generate sociograms that visually represent communication pattern within the effective and ineffective safety networks. The aim of this paper is to present the application of SNA for improving the safety communication of ethnic minorities in the construction industry of Hong Kong. The paper provides the theoretical background of SNA approaches for the data collection and analysis using the software UCINET and NetDraw, to determine the predominant safety communication network structure and pattern of ethnic minorities on site.
Resumo:
The definition of tourism “is the travel for recreational, leisure, family or business purposes, usually of a limited duration. Tourism is commonly associated with trans-national travel, but may also refer to travel to another location within the same country”. Tourism as an industry, in today’s modern language is a means of global communication between nations and travelers of all countries, introducing them to the various cultures and societies abroad, as well there history, ancient, historical sites, and languages. Hence, advertising overall has become a tool of necessity in this ever-growing global industry. Given that, tourism is a part of the infrastructure of any country’s economy the growth and development of tourism is of great importance. Advertising plays a vital and is a crucial tool in developing the countries tourism by attractively presenting the nations points-of-interests, historical and cultural. Advertising has a central role in expanding this industry, generating economic growth in this area, as well as creating direct and indirect employment, but most importantly a creative innovating competition in the national and international travel industry. Importantly, to achieve a successful tourist industry, the Travel Agencies and governmental offices of the Ministry’s of Tourism and Business must work hand-in-hand to attain these goals. This article shows the impact of the various media and advertising methods used in tourism, which assisted in identifying the correct tool for expanding the country’s industry of tourism. The results of this study illustrated that the appropriate tools for promotional strategies to attract domestic and foreign traveler’s, found to be the most effective were, handbook, internet advertising, TV, brochures, newspapers