131 research outputs found
Machining GLARE fibre metal laminates: a comparative study on drilling effect between conventional and ultrasonic-assisted drilling
No full textGLARE laminates are multi-layered metal-composite materials created from bonding sheets of metallic alloys with carbon or glass fibre layers. The application of hybrid-conventional machining processes such as ultrasonic-assisted drilling (UAD) is becoming of great interest to the aerospace industry due to its capability in reducing the cutting forces and tool wear which are directly responsible for drilling-induced delamination. There is rich literature on the conventional drilling (CD) of GLARE, but no work reported using UAD process. This study will fill this gap and investigate the UAD of GLARE laminates using an indigenously developed UAD system. The influence of spindle speed and feed rate on thrust force and surface roughness metrics (Ra and Rz) were investigated under CD and UAD regimes. The quality of the borehole and damage mechanisms in the laminate constituents was examined using scanning electron microscopy (SEM). The contribution of the drilling parameters on the measured outputs was further evaluated using the analysis of variance (ANOVA) statistical analysis. It was found that UAD resulted in a significant reduction in thrust force by up to 65% while surface roughness metrics Ra and Rz were unaffected by the type of drilling process used. SEM analysis showed irregular and fuzzier surfaces in glass fibre layers in holes machined using UAD due to the longitudinal vibration of the tool.Aerospace Manufacturing Technologie
Multiscale modelling and experimental analysis of ultrasonic-assisted drilling of GLARE fibre metal laminates
No full textThis study aims to evaluate the effectiveness of Ultrasonic-assisted drilling (UAD) of Glass laminate aluminium reinforced epoxy (GLARE) at high cutting speeds (Spindle speeds: 3000–7500 rpm; feed rates 300–750 mm/min) by analysing the thrust force and hole quality metrics (surface roughness, hole size, and burr formations. The research also presents numerical modelling of FMLs under conventional and UAD regimes to predict thrust force using ABAQUS/SIMULIA. The thrust force and exit burrs were reduced by up to 40.83 % and 80 %, respectively. The surface roughness metrics (Ra and Rz) were slightly higher using UAD but remained within the desirable limits of surface roughness for machined aeronautical structures. The discrepancy between the simulation and experimental results was adequate and did not exceed 15 %. The current study shows that it is feasible to drill holes in GLARE using higher cutting parameters and maintain excellent hole quality, which means increased productivity and reduced costs.Group Sink
PERANCANGAN DAN IMPLEMENTASI PAPERLESS OFFICE BERBASIS WORDPRESS DI ITTC UAD
No full textPerlu dilakukan satu upaya untuk mengurangi limbah kertas yang dihasilkan oleh
perkantoran. Era kemajuan teknologi informasi dan komunikasi memiliki peluang
dikembangkannya komunikasi secara online melalui jaringan komputer, sehingga dapat
mengurangi penggunaan kertas untuk surat menyurat dan pembuatan dokumen. Untuk
keperluan administrasi perkantoran dapat dilakukan dengan cara menerapkan paperless office
system. Tujuan penelitian ini adalah merancang suatu sistem paperless office berbasis
WordPress yang dapat diterapkan dalam lingkup perkantoran, khususnya di ITTC UAD.
Penelitian ini mengambil subjek tentang sistem pengelolaan dokumen elektronik berbasis
WordPress yang menyediakan sarana pengelolaan dokumen dalam format digital, sehingga
diharapkan dapat mengurangi pemakaian kertas. Beberapa plug in ditambahkan seperti
themes, bookmark, dan pengamanan pada situs, yaitu: Post Protect Quiet, dan Password
Protect WordPress Blog. Selain admin, ada beberapa level user yang memiliki wewenang yang
berbeda-beda pada sistem ini, yaitu: author, editor, dan contributor. Dokumen digital yang
dikelola dalam sistem ini adalah surat-menyurat, informasi pelatihan, tutorial, dan Surat
Keputusan (SK), yang dapat didistribusikan melalui media e-mail maupun jejaring sosial.
Sistem diuji untuk setiap level user. Hasil pengujian menunjukkan bahwa semua
fitur/menu pada sistem dapat berjalan dengan baik. Hasil rata-rata persentase dari pengujian
diperoleh responden yang menyatakan sangat setuju = 26,5%, setuju = 71%, kurang setuju =
2,5%, dan tidak setuju = 0%
Upscaling circularity in urban area development: A qualitative study in ‘Circular Buiksloterham’
No full textThe city of Amsterdam is following the ambitions of the National Government to operate a fully circular economy in 2050. To do so, circular urban area development (UAD) must become standard. As a start, Buiksloterham is declared as a circular urban area development project by over twenty participating parties including the municipality of Amsterdam. This master thesis aims to give recommendations about upscaling circularity in UAD. The research question that is answered is: How can the municipality of Amsterdam scale up circular urban area development by learning from projects with high circular ambitions in Buiksloterham? The answers to this question take two main issues into account. A practical issue on the implementation and possibilities for circularity and a management issue for the municipality on how they should operate in projects with high circular ambitions. The practical issue is in this research substantiated with a literature study in circular strategies for urban area development. A framework of circular strategies is realised, to indicate, structure, and reflect upon circularity in the built environment. A case study in the urban area development Buiksloterham answers the question for the municipality. Upscaling circularity in UAD requires a combination of good policy and management from the municipality. Key elements are: provide clear image and information of the plans. Explain the different roles of the municipality. Learn from the implemented circular strategies and aim for implementing the strategies on a larger scale. Upscaling requires attention to the barriers experienced by the developers. Involve the developers in both the development of the public space as with the new developers, because they have intrinsic motivation, professional knowledge and much experience
Urban Development Trust: Possibilities & limitations for Dutch Urban Area Development
No full textThe Dutch UAD-practice finds itself in a new era full of challenges and opportunities. Urban development projects are struggling to achieve successes. New revenue models, like the Urban Development Trust (UDT), have been discussed rather extensively by many academics & practitioners. Nonetheless, remarkably little theoretical & empirical knowledge is available about how UDTs work and what the effects of UDTs are on their overall business model. This research provides an answer to the following research question: 'To what extent will the revenue model Urban Development Trust be able to facilitate the business model for successful urban development projects?Urban Area DevelopmentReal Estate & HousingArchitecture and The Built Environmen
De herontwikkeling van het DSM terrein; naar een strategisch advies voor de ontwikkeling van het DSM terrein te Delft
No full textHet doel van het onderzoek is het traceren van het (bewust of onbewust) gevolgde strategisch proces voor de herontwikkeling van het DSM terrein te Delft, en vervolgens het vormen van een strategisch advies voor de belanghebbende ‘Triple Helix’ actoren. Hiertoe wordt de kern van het onderzoek opgedeeld in het terugblikken op de DSM casus en vervolgens vooruit kijken (en tot een strategisch advies komen). De centrale vraag in dit onderzoek is Op welke wijze kan de strategie voor de herontwikkeling van het DSM terrein worden verbeterd?Urban Area Development (UAD)Real Estate & HousingArchitectur
Multiscale modelling and experimental analysis of ultrasonic-assisted drilling of GLARE fibre metal laminates
No full textWOS:001147541000001This study aims to evaluate the effectiveness of Ultrasonic-assisted drilling (UAD) of Glass laminate aluminium reinforced epoxy (GLARE) at high cutting speeds (Spindle speeds: 3000–7500 rpm; feed rates 300–750 mm/min) by analysing the thrust force and hole quality metrics (surface roughness, hole size, and burr formations. The research also presents numerical modelling of FMLs under conventional and UAD regimes to predict thrust force using ABAQUS/SIMULIA. The thrust force and exit burrs were reduced by up to 40.83 % and 80 %, respectively. The surface roughness metrics (Ra and Rz) were slightly higher using UAD but remained within the desirable limits of surface roughness for machined aeronautical structures. The discrepancy between the simulation and experimental results was adequate and did not exceed 15 %. The current study shows that it is feasible to drill holes in GLARE using higher cutting parameters and maintain excellent hole quality, which means increased productivity and reduced costs. © 2023 The Author(s)Ministry of Education of the People's Republic of China, MOE: 2018GXZ017923; China Scholarship Council, CSC; Beijing Institute of Technology, BITThe first author would like to thank the China Scholarship Council (Chinese Ministry of Education) for the PhD scholarship (2018GXZ017923) at Beijing Institute of Technology
Unsupervised Anomaly Detection in Stream Data with Online Evolving Spiking Neural Networks
No full textPublisher Copyright: © 2021 The Author(s)Unsupervised anomaly discovery in stream data is a research topic with many practical applications. However, in many cases, it is not easy to collect enough training data with labeled anomalies for supervised learning of an anomaly detector in order to deploy it later for identification of real anomalies in streaming data. It is thus important to design anomalies detectors that can correctly detect anomalies without access to labeled training data. Our idea is to adapt the Online evolving Spiking Neural Network (OeSNN) classifier to the anomaly detection task. As a result, we offer an Online evolving Spiking Neural Network for Unsupervised Anomaly Detection algorithm (OeSNN-UAD), which, unlike OeSNN, works in an unsupervised way and does not separate output neurons into disjoint decision classes. OeSNN-UAD uses our proposed new two-step anomaly detection method. Also, we derive new theoretical properties of neuronal model and input layer encoding of OeSNN, which enable more effective and efficient detection of anomalies in our OeSNN-UAD approach. The proposed OeSNN-UAD detector was experimentally compared with state-of-the-art unsupervised and semi-supervised detectors of anomalies in stream data from the Numenta Anomaly Benchmark and Yahoo Anomaly Datasets repositories. Our approach outperforms the other solutions provided in the literature in the case of data streams from the Numenta Anomaly Benchmark repository. Also, in the case of real data files of the Yahoo Anomaly Benchmark repository, OeSNN-UAD outperforms other selected algorithms, whereas in the case of Yahoo Anomaly Benchmark synthetic data files, it provides competitive results to the results recently reported in the literature.Peer reviewe
Elaboration of the Dutch Olympic approach: Design of decision support instruments for multiple Olympic urban decision arenas
No full textIn this report the traditional top-down approach for spatial planning in the Netherlands has been brought up for discussion. On the basis of the decision-making process concerning the organization of the Dutch Olympic Games of 2028, the foundations for a new way of spatial planning is elaborated. That new way of spatial planning is termed the Dutch Olympic approach, wherein both national (top-down) as urban interests (bottom-up) are considered simultaneously. With the elaboration of the Dutch Olympic approach, the improvement and acceleration of the decision-making process in the initiative phase of the Dutch Olympic UAD process has been purposed, which should be facilitated through the design of decision support instruments for multiple Olympic urban decision arenas.Urban Area DevelopmentReal Estate & HousingArchitectur
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