219 research outputs found

    Towards A Computational Intelligence Framework in Steel Product Quality and Cost Control

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    Steel is a fundamental raw material for all industries. It can be widely used in vari-ous fields, including construction, bridges, ships, containers, medical devices and cars. However, the production process of iron and steel is very perplexing, which consists of four processes: ironmaking, steelmaking, continuous casting and rolling. It is also extremely complicated to control the quality of steel during the full manufacturing pro-cess. Therefore, the quality control of steel is considered as a huge challenge for the whole steel industry. This thesis studies the quality control, taking the case of Nanjing Iron and Steel Group, and then provides new approaches for quality analysis, manage-ment and control of the industry. At present, Nanjing Iron and Steel Group has established a quality management and control system, which oversees many systems involved in the steel manufacturing. It poses a high statistical requirement for business professionals, resulting in a limited use of the system. A lot of data of quality has been collected in each system. At present, all systems mainly pay attention to the processing and analysis of the data after the manufacturing process, and the quality problems of the products are mainly tested by sampling-experimental method. This method cannot detect product quality or predict in advance the hidden quality issues in a timely manner. In the quality control system, the responsibilities and functions of different information systems involved are intricate. Each information system is merely responsible for storing the data of its corresponding functions. Hence, the data in each information system is relatively isolated, forming a data island. The iron and steel production process belongs to the process industry. The data in multiple information systems can be combined to analyze and predict the quality of products in depth and provide an early warning alert. Therefore, it is necessary to introduce new product quality control methods in the steel industry. With the waves of industry 4.0 and intelligent manufacturing, intelligent technology has also been in-troduced in the field of quality control to improve the competitiveness of the iron and steel enterprises in the industry. Applying intelligent technology can generate accurate quality analysis and optimal prediction results based on the data distributed in the fac-tory and determine the online adjustment of the production process. This not only gives rise to the product quality control, but is also beneficial to in the reduction of product costs. Inspired from this, this paper provide in-depth discussion in three chapters: (1) For scrap steel to be used as raw material, how to use artificial intelligence algorithms to evaluate its quality grade is studied in chapter 3; (2) the probability that the longi-tudinal crack occurs on the surface of continuous casting slab is studied in chapter 4;(3) The prediction of mechanical properties of finished steel plate in chapter 5. All these 3 chapters will serve as the technical support of quality control in iron and steel production

    Deep neural networks for marine debris detection in sonar images

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    Garbage and waste disposal is one of the biggest challenges currently faced by mankind. Proper waste disposal and recycling is a must in any sustainable community, and in many coastal areas there is significant water pollution in the form of floating or submerged garbage. This is called marine debris. It is estimated that 6.4 million tonnes of marine debris enter water environments every year [McIlgorm et al. 2008, APEC Marine Resource Conservation WG], with 8 million items entering each day. An unknown fraction of this sinks to the bottom of water bodies. Submerged marine debris threatens marine life, and for shallow coastal areas, it can also threaten fishing vessels [Iñiguez et al. 2016, Renewable and Sustainable Energy Reviews]. Submerged marine debris typically stays in the environment for a long time (20+ years), and consists of materials that can be recycled, such as metals, plastics, glass, etc. Many of these items should not be disposed in water bodies as this has a negative effect in the environment and human health. Encouraged by the advances in Computer Vision from the use Deep Learning, we propose the use of Deep Neural Networks (DNNs) to survey and detect marine debris in the bottom of water bodies (seafloor, lake and river beds) from Forward-Looking Sonar (FLS) images. This thesis performs a comprehensive evaluation on the use of DNNs for the problem of marine debris detection in FLS images, as well as related problems such as image classification, matching, and detection proposals. We do this in a dataset of 2069 FLS images that we captured with an ARIS Explorer 3000 sensor on marine debris objects lying in the floor of a small water tank. We had issues with the sensor in a real world underwater environment that motivated the use of a water tank. The objects we used to produce this dataset contain typical household marine debris and distractor marine objects (tires, hooks, valves, etc), divided in 10 classes plus a background class. Our results show that for the evaluated tasks, DNNs area superior technique than the corresponding state of the art. There are large gains particularly for the matching and detection proposal tasks. We also study the effect of sample complexity and object size in many tasks, which is valuable information for practitioners. We expect that our results will advance the objective of using Autonomous Underwater Vehicles to automatically survey, detect and collect marine debris from underwater environments

    Plastics as a Materials System in a Circular Economy

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    Technical Design Report for the PANDA Micro Vertex Detector

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    This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is outlined

    Learning to segment in images and videos with different forms of supervision

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    Much progress has been made in image and video segmentation over the last years. To a large extent, the success can be attributed to the strong appearance models completely learned from data, in particular using deep learning methods. However, to perform best these methods require large representative datasets for training with expensive pixel-level annotations, which in case of videos are prohibitive to obtain. Therefore, there is a need to relax this constraint and to consider alternative forms of supervision, which are easier and cheaper to collect. In this thesis, we aim to develop algorithms for learning to segment in images and videos with different levels of supervision. First, we develop approaches for training convolutional networks with weaker forms of supervision, such as bounding boxes or image labels, for object boundary estimation and semantic/instance labelling tasks. We propose to generate pixel-level approximate groundtruth from these weaker forms of annotations to train a network, which allows to achieve high-quality results comparable to the full supervision quality without any modifications of the network architecture or the training procedure. Second, we address the problem of the excessive computational and memory costs inherent to solving video segmentation via graphs. We propose approaches to improve the runtime and memory efficiency as well as the output segmentation quality by learning from the available training data the best representation of the graph. In particular, we contribute with learning must-link constraints, the topology and edge weights of the graph as well as enhancing the graph nodes - superpixels - themselves. Third, we tackle the task of pixel-level object tracking and address the problem of the limited amount of densely annotated video data for training convolutional networks. We introduce an architecture which allows training with static images only and propose an elaborate data synthesis scheme which creates a large number of training examples close to the target domain from the given first frame mask. With the proposed techniques we show that densely annotated consequent video data is not necessary to achieve high-quality temporally coherent video segmentation results. In summary, this thesis advances the state of the art in weakly supervised image segmentation, graph-based video segmentation and pixel-level object tracking and contributes with the new ways of training convolutional networks with a limited amount of pixel-level annotated training data.In der Bild- und Video-Segmentierung wurden im Laufe der letzten Jahre große Fortschritte erzielt. Dieser Erfolg beruht weitgehend auf starken Appearance Models, die vollständig aus Daten gelernt werden, insbesondere mit Deep Learning Methoden. Für beste Performanz benötigen diese Methoden jedoch große repräsentative Datensätze für das Training mit teuren Annotationen auf Pixelebene, die bei Videos unerschwinglich sind. Deshalb ist es notwendig, diese Einschränkung zu überwinden und alternative Formen des überwachten Lernens in Erwägung zu ziehen, die einfacher und kostengünstiger zu sammeln sind. In dieser Arbeit wollen wir Algorithmen zur Segmentierung von Bildern und Videos mit verschiedenen Ebenen des überwachten Lernens entwickeln. Zunächst entwickeln wir Ansätze zum Training eines faltenden Netzwerkes (convolutional network) mit schwächeren Formen des überwachten Lernens, wie z.B. Begrenzungsrahmen oder Bildlabel, für Objektbegrenzungen und Semantik/Instanz- Klassifikationsaufgaben. Wir schlagen vor, aus diesen schwächeren Formen von Annotationen eine annähernde Ground Truth auf Pixelebene zu generieren, um ein Netzwerk zu trainieren, das hochwertige Ergebnisse ermöglicht, die qualitativ mit denen bei voll überwachtem Lernen vergleichbar sind, und dies ohne Änderung der Netzwerkarchitektur oder des Trainingsprozesses. Zweitens behandeln wir das Problem des beträchtlichen Rechenaufwands und Speicherbedarfs, das der Segmentierung von Videos mittels Graphen eigen ist. Wir schlagen Ansätze vor, um sowohl die Laufzeit und Speichereffizienz als auch die Qualität der Segmentierung zu verbessern, indem aus den verfügbaren Trainingsdaten die beste Darstellung des Graphen gelernt wird. Insbesondere leisten wir einen Beitrag zum Lernen mit must-link Bedingungen, zur Topologie und zu Kantengewichten des Graphen sowie zu verbesserten Superpixeln. Drittens gehen wir die Aufgabe des Objekt-Tracking auf Pixelebene an und befassen uns mit dem Problem der begrenzten Menge von dicht annotierten Videodaten zum Training eines faltenden Netzwerkes. Wir stellen eine Architektur vor, die das Training nur mit statischen Bildern ermöglicht, und schlagen ein aufwendiges Schema zur Datensynthese vor, das aus der gegebenen ersten Rahmenmaske eine große Anzahl von Trainingsbeispielen ähnlich der Zieldomäne schafft. Mit den vorgeschlagenen Techniken zeigen wir, dass dicht annotierte zusammenhängende Videodaten nicht erforderlich sind, um qualitativ hochwertige zeitlich kohärente Resultate der Segmentierung von Videos zu erhalten. Zusammenfassend lässt sich sagen, dass diese Arbeit den Stand der Technik in schwach überwachter Segmentierung von Bildern, graphenbasierter Segmentierung von Videos und Objekt-Tracking auf Pixelebene weiter entwickelt, und mit neuen Formen des Trainings faltender Netzwerke bei einer begrenzten Menge von annotierten Trainingsdaten auf Pixelebene einen Beitrag leistet

    Contributions for the automatic description of multimodal scenes

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    Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

    Low-power CMOS digital-pixel Imagers for high-speed uncooled PbSe IR applications

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    This PhD dissertation describes the research and development of a new low-cost medium wavelength infrared MWIR monolithic imager technology for high-speed uncooled industrial applications. It takes the baton on the latest technological advances in the field of vapour phase deposition (VPD) PbSe-based medium wavelength IR (MWIR) detection accomplished by the industrial partner NIT S.L., adding fundamental knowledge on the investigation of novel VLSI analog and mixed-signal design techniques at circuit and system levels for the development of the readout integrated device attached to the detector. The work supports on the hypothesis that, by the use of the preceding design techniques, current standard inexpensive CMOS technologies fulfill all operational requirements of the VPD PbSe detector in terms of connectivity, reliability, functionality and scalability to integrate the device. The resulting monolithic PbSe-CMOS camera must consume very low power, operate at kHz frequencies, exhibit good uniformity and fit the CMOS read-out active pixels in the compact pitch of the focal plane, all while addressing the particular characteristics of the MWIR detector: high dark-to-signal ratios, large input parasitic capacitance values and remarkable mismatching in PbSe integration. In order to achieve these demands, this thesis proposes null inter-pixel crosstalk vision sensor architectures based on a digital-only focal plane array (FPA) of configurable pixel sensors. Each digital pixel sensor (DPS) cell is equipped with fast communication modules, self-biasing, offset cancellation, analog-to-digital converter (ADC) and fixed pattern noise (FPN) correction. In-pixel power consumption is minimized by the use of comprehensive MOSFET subthreshold operation. The main aim is to potentiate the integration of PbSe-based infra-red (IR)-image sensing technologies so as to widen its use, not only in distinct scenarios, but also at different stages of PbSe-CMOS integration maturity. For this purpose, we posit to investigate a comprehensive set of functional blocks distributed in two parallel approaches: • Frame-based “Smart” MWIR imaging based on new DPS circuit topologies with gain and offset FPN correction capabilities. This research line exploits the detector pitch to offer fully-digital programmability at pixel level and complete functionality with input parasitic capacitance compensation and internal frame memory. • Frame-free “Compact”-pitch MWIR vision based on a novel DPS lossless analog integrator and configurable temporal difference, combined with asynchronous communication protocols inside the focal plane. This strategy is conceived to allow extensive pitch compaction and readout speed increase by the suppression of in-pixel digital filtering, and the use of dynamic bandwidth allocation in each pixel of the FPA. In order make the electrical validation of first prototypes independent of the expensive PbSe deposition processes at wafer level, investigation is extended as well to the development of affordable sensor emulation strategies and integrated test platforms specifically oriented to image read-out integrated circuits. DPS cells, imagers and test chips have been fabricated and characterized in standard 0.15μm 1P6M, 0.35μm 2P4M and 2.5μm 2P1M CMOS technologies, all as part of research projects with industrial partnership. The research has led to the first high-speed uncooled frame-based IR quantum imager monolithically fabricated in a standard VLSI CMOS technology, and has given rise to the Tachyon series [1], a new line of commercial IR cameras used in real-time industrial, environmental and transportation control systems. The frame-free architectures investigated in this work represent a firm step forward to push further pixel pitch and system bandwidth up to the limits imposed by the evolving PbSe detector in future generations of the device.La present tesi doctoral descriu la recerca i el desenvolupament d'una nova tecnologia monolítica d'imatgeria infraroja de longitud d'ona mitja (MWIR), no refrigerada i de baix cost, per a usos industrials d'alta velocitat. El treball pren el relleu dels últims avenços assolits pel soci industrial NIT S.L. en el camp dels detectors MWIR de PbSe depositats en fase vapor (VPD), afegint-hi coneixement fonamental en la investigació de noves tècniques de disseny de circuits VLSI analògics i mixtes pel desenvolupament del dispositiu integrat de lectura unit al detector pixelat. Es parteix de la hipòtesi que, mitjançant l'ús de les esmentades tècniques de disseny, les tecnologies CMOS estàndard satisfan tots els requeriments operacionals del detector VPD PbSe respecte a connectivitat, fiabilitat, funcionalitat i escalabilitat per integrar de forma econòmica el dispositiu. La càmera PbSe-CMOS resultant ha de consumir molt baixa potència, operar a freqüències de kHz, exhibir bona uniformitat, i encabir els píxels actius CMOS de lectura en el pitch compacte del pla focal de la imatge, tot atenent a les particulars característiques del detector: altes relacions de corrent d'obscuritat a senyal, elevats valors de capacitat paràsita a l'entrada i dispersions importants en el procés de fabricació. Amb la finalitat de complir amb els requisits previs, es proposen arquitectures de sensors de visió de molt baix acoblament interpíxel basades en l'ús d'una matriu de pla focal (FPA) de píxels actius exclusivament digitals. Cada píxel sensor digital (DPS) està equipat amb mòduls de comunicació d'alta velocitat, autopolarització, cancel·lació de l'offset, conversió analògica-digital (ADC) i correcció del soroll de patró fixe (FPN). El consum en cada cel·la es minimitza fent un ús exhaustiu del MOSFET operant en subllindar. L'objectiu últim és potenciar la integració de les tecnologies de sensat d'imatge infraroja (IR) basades en PbSe per expandir-ne el seu ús, no només a diferents escenaris, sinó també en diferents estadis de maduresa de la integració PbSe-CMOS. En aquest sentit, es proposa investigar un conjunt complet de blocs funcionals distribuïts en dos enfocs paral·lels: - Dispositius d'imatgeria MWIR "Smart" basats en frames utilitzant noves topologies de circuit DPS amb correcció de l'FPN en guany i offset. Aquesta línia de recerca exprimeix el pitch del detector per oferir una programabilitat completament digital a nivell de píxel i plena funcionalitat amb compensació de la capacitat paràsita d'entrada i memòria interna de fotograma. - Dispositius de visió MWIR "Compact"-pitch "frame-free" en base a un novedós esquema d'integració analògica en el DPS i diferenciació temporal configurable, combinats amb protocols de comunicació asíncrons dins del pla focal. Aquesta estratègia es concep per permetre una alta compactació del pitch i un increment de la velocitat de lectura, mitjançant la supressió del filtrat digital intern i l'assignació dinàmica de l'ample de banda a cada píxel de l'FPA. Per tal d'independitzar la validació elèctrica dels primers prototips respecte a costosos processos de deposició del PbSe sensor a nivell d'oblia, la recerca s'amplia també al desenvolupament de noves estratègies d'emulació del detector d'IR i plataformes de test integrades especialment orientades a circuits integrats de lectura d'imatge. Cel·les DPS, dispositius d'imatge i xips de test s'han fabricat i caracteritzat, respectivament, en tecnologies CMOS estàndard 0.15 micres 1P6M, 0.35 micres 2P4M i 2.5 micres 2P1M, tots dins el marc de projectes de recerca amb socis industrials. Aquest treball ha conduït a la fabricació del primer dispositiu quàntic d'imatgeria IR d'alta velocitat, no refrigerat, basat en frames, i monolíticament fabricat en tecnologia VLSI CMOS estàndard, i ha donat lloc a Tachyon, una nova línia de càmeres IR comercials emprades en sistemes de control industrial, mediambiental i de transport en temps real.Postprint (published version

    Aeronautical Engineering: A continuing bibliography with indexes (supplement 182)

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    This bibliography lists 475 reports, articles and other documents introduced into the NASA scientific and technical information system in December 1984

    Integrated methodology for analyzing highly enriched uranium production scenarios at gas centrifuge enrichment plants

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 399-417).The dramatic change in the international security environment after the collapse of the bipolar system has had a negative impact on the effectiveness of the existing nuclear non-proliferation regime. Furthermore, the success of the Pakistani Gas Centrifuge Enrichment Technology (GCET)- based nuclear weapons program has imposed a great challenge on the Nuclear Nonproliferation Treaty (NPT) regime. In this context, this study tried to answer two questions: (a) what is the probability of proliferators successfully producing Highly Enriched Uranium (HEU) at Gas Centrifuge Enrichment Plants (GCEPs) and (b) how effective is the current NPT regime in dealing with this issue. In order to tackle these two questions, an integrated methodology is used that reflects all factors affecting the nuclear proliferation on the front-end of the nuclear fuel cycle. A quantitative assessment of the proliferation risks of producing HEU for multiple scenarios is presented using success tree models, uncertainty analysis, sensitivity analysis, importance measures, and expert opinion. This assessment identifies the factors that can reduce the proliferators' success of producing HEU, which will be helpful in prioritizing the use of the IAEA's limited resources.(cont.) The study found that legal capabilities of the NPT regime are more problematic than technological capabilities in preventing proliferators from producing HEU at GCEPs, since the United Nations Security Council (UNSC) is the only NPT regime component that has compliance-enforcing resources. This study recommends three approaches as follows: First, the NPT regime should take a multi-faceted approach that incorporates all NPT regime components into each step of nuclear weapons program development. Second, the NPT regime should impose nuclear elements control via Multilateral Export Control Regimes (MECRs). Third, the NPT regime should develop an approach that challenges HEU production from both technological- and legal points of view. Since law governs technological capability, a multidimensional approach that includes this relationship would be more effective than an approach that focuses on either aspect individually.by Taeshin Kwak.Ph.D

    Tracking the Temporal-Evolution of Supernova Bubbles in Numerical Simulations

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    The study of low-dimensional, noisy manifolds embedded in a higher dimensional space has been extremely useful in many applications, from the chemical analysis of multi-phase flows to simulations of galactic mergers. Building a probabilistic model of the manifolds has helped in describing their essential properties and how they vary in space. However, when the manifold is evolving through time, a joint spatio-temporal modelling is needed, in order to fully comprehend its nature. We propose a first-order Markovian process that propagates the spatial probabilistic model of a manifold at fixed time, to its adjacent temporal stages. The proposed methodology is demonstrated using a particle simulation of an interacting dwarf galaxy to describe the evolution of a cavity generated by a Supernov
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