251 research outputs found
A Survey of Artificial Intelligence Techniques Employed for Adaptive Educational Systems within E-Learning Platforms
Abstract
The adaptive educational systems within e-learning platforms are built in response to the fact that the learning process is different for each and every learner. In order to provide adaptive e-learning services and study materials that are tailor-made for adaptive learning, this type of educational approach seeks to combine the ability to comprehend and detect a personâs specific needs in the context of learning with the expertise required to use appropriate learning pedagogy and enhance the learning process. Thus, it is critical to create accurate student profiles and models based upon analysis of their affective states, knowledge level, and their individual personality traits and skills. The acquired data can then be efficiently used and exploited to develop an adaptive learning environment. Once acquired, these learner models can be used in two ways. The first is to inform the pedagogy proposed by the experts and designers of the adaptive educational system. The second is to give the system dynamic self-learning capabilities from the behaviors exhibited by the teachers and students to create the appropriate pedagogy and automatically adjust the e-learning environments to suit the pedagogies. In this respect, artificial intelligence techniques may be useful for several reasons, including their ability to develop and imitate human reasoning and decision-making processes (learning-teaching model) and minimize the sources of uncertainty to achieve an effective learning-teaching context. These learning capabilities ensure both learner and system improvement over the lifelong learning mechanism. In this paper, we present a survey of raised and related topics to the field of artificial intelligence techniques employed for adaptive educational systems within e-learning, their advantages and disadvantages, and a discussion of the importance of using those techniques to achieve more intelligent and adaptive e-learning environments.</jats:p
Real-time and Freehand Multimodal Imaging: Combining White Light Endoscopy with All-Optical Ultrasound
Minimally invasive surgery offers significant benefits
over open surgery in terms of patient recovery, complication
rates, and cost. Accurate visualisation is key for successful interventions; however, no single imaging modality offers sufficient
resolution, penetration, and soft-tissue contrast to adequately
monitor interventional treatment. Consequently, multimodal interventional imaging is intensively investigated. All-optical ultrasound (AOUS) imaging is an emerging modality where light is
used to both generate and detect ultrasound. Using fibre-optics,
highly miniaturised imaging probes can be fabricated that yield
high-quality pulse-echo images and are readily integrated into
minimally invasive interventional instruments. In this work, we
present the integration of a miniature (diameter: 800 Âľm), highly
directional AOUS imaging probe into a commercially available
white light urethroscope, and demonstrate the first real-time, 3D
multimodal imaging combining AOUS and white light endoscopy.
Through the addition of an electromagnetic tracker, the position
and pose of the instrument could be continuously recorded.
This facilitated accurate real-time registration of the imaging
modalities, as well as freehand operation of the instrument. In addition, the freehand imaging paradigm allowed for âpiece-wiseâ
scanning where the instrument was retracted and repositioned
without recalibration. The presented imaging probe and system
could significantly improve the quality of image guidance during
interventional surgery
Robot-assisted Optical Ultrasound Scanning
Optical ultrasound, where ultrasound is both generated and received using light, can be integrated in very small diameter instruments making it ideally suited to minimally invasive interventions. One-dimensional information can be obtained using a single pair of optical fibres comprising of a source and detector but this can be difficult to interpret clinically. In this paper, we present a robotic-assisted scanning solution where a concentric tube robot manipulates an optical ultrasound probe along a consistent trajectory. A torque coil is utilised as a buffer between the curved nitinol tube and the probe to prevent torsion on the probe and maintain the axial orientation of the probe while the tube is rotating. The design and control of the scanning mechanism are presented along with the integration of the mechanism with a fibre-based imaging probe. Trajectory repeatability is assessed using electromagnetic tracking and a technique to calibrate the transformation between imaging and robot coordinates using a known model is presented. Finally, we show example images of 3D printed phantoms generated by collecting multiple OpUS A-scans within the same 3D scene to illustrate how robot-assisted scanning can expand the field of view
Minerals of Jenolan Caves, New South Wales, Australia: Geological and Biological Interactions
Geological and biological processes in the Jenolan Caves have formed a range of mineral species spanning several chemical groups. So far 25 mineral species have been either conďŹrmed, or identiďŹed for the ďŹrst time at Jenolan. Their chemical groups include carbonates: (calcite, aragonite, hydromagnesite, huntite, dolomite, ankerite); silicates: (kaolinite, K-deďŹcient muscovite (âilliteâ), montmorillonite clays); phosphates, (ardealite, hydroxylapatite, taranakite, leucophosphite, variscite, crandallite, montgomeryite, kingsmountite); sulfate: (gypsum); oxides: (quartz, cristobalite, amorphous silica, hematite, romanèchite); hydroxide: (goethite); nitrate: (niter); and chloride: (sylvite). Dolomitised limestone bedrock and ankerite veins can be recognised as a magnesium source of some magnesium carbonate minerals, as well as supplying a calcite inhibitor favouring aragonite formation. The cave clays have diverse origins. Some are recent sedimentary detritus. Older clays of Carboniferous age contain components of reworked altered volcaniclastics washed or blown into the caves, so these clays may represent argillic alteration of volcanic products. Some of the clays may have formed as alteration products of ascending hydrothermal ďŹuids. The phosphates and some gypsum formed when bat guano reacted chemically with limestone and cave clays. Gypsum has also been formed from the breakdown of pyrite in altered bedrock or dolomitic palaeokarst. The niter and sylvite have crystalized from breakdown products of mainly wallaby guano
Measurement of Liver Blood Flow: A Review
The study of hepatic haemodynamics is of importance in understanding both hepatic physiology and
disease processes as well as assessing the effects of portosystemic shunting and liver transplantation. The
liver has the most complicated circulation of any organ and many physiological and pathological
processes can affect it1,2. This review surveys the methods available for assessing liver blood flow,
examines the different parameters being measured and outlines problems of applicability and interpretation
for each technique
Environmental and ecological citizenship in civil society
Drawing from the work of Andrew Dobson, two notions of citizenship in civil society can be distinguished: environmental citizenship, which focuses on environmental rights and seeks to redefine the relationship between the state and the citizen; and ecological citizenship, which goes beyond a rights-based notion of citizenship to advocate the fair usage of ecological space across international borders. Using civil society initiatives to conserve forests, this article argues that these two notions of citizenship should be seen as overlapping in that civil society groups seek to work through national and international law to reduce the ecological footprint of some countries on others. The article concludes by drawing a distinction between the environmental state and the ecological state
Counterparts: Clothing, value and the sites of otherness in Panapompom ethnographic encounters
This is an Author's Accepted Manuscript of an article published in Anthropological Forum, 18(1), 17-35,
2008 [copyright Taylor & Francis], available online at:
http://www.tandfonline.com/10.1080/00664670701858927.Panapompom people living in the western Louisiade Archipelago of Milne Bay Province, Papua New Guinea, see their clothes as indices of their perceived poverty. âDevelopmentâ as a valued form of social life appears as images that attach only loosely to the people employing them. They nevertheless hold Panapompom people to account as subjects to a voice and gaze that is located in the imagery they strive to present: their clothes. This predicament strains anthropological approaches to the study of Melanesia that subsist on strict alterity, because native selfâjudgments are located âat homeâ for the ethnographer. In this article, I develop the notion of the counterpart as a means to explore these forms of postcolonial oppression and their implications for the ethnographic encounter
Ultrasensitive plano-concave optical microresonators for ultrasound sensing
Highly sensitive broadband ultrasound detectors are needed to expand the capabilities of biomedical ultrasound, photoacoustic imaging and industrial ultrasonic non-destructive testing techniques. Here, a generic optical ultrasound sensing concept based on a novel plano-concave polymer microresonator is described. This achieves strong optical confinement (Q-factors > 105) resulting in very high sensitivity with excellent broadband acoustic frequency response and wide directivity. The concept is highly scalable in terms of bandwidth and sensitivity. To illustrate this, a family of microresonator sensors with broadband acoustic responses up to 40âMHz and noise-equivalent pressures as low as 1.6âmPa per âHz have been fabricated and comprehensively characterized in terms of their acoustic performance. In addition, their practical application to high-resolution photoacoustic and ultrasound imaging is demonstrated. The favourable acoustic performance and design flexibility of the technology offers new opportunities to advance biomedical and industrial ultrasound-based techniques
Haptic Guidance Based on All-Optical Ultrasound Distance Sensing for Safer Minimally Invasive Fetal Surgery
By intervening during the early stage of gestation, fetal surgeons aim to correct or minimize the effects of congenital disorders. As compared to postnatal treatment of these disorders, such early interventions can often actually save the life of the fetus and also improve the quality of life of the newborn. However, fetal surgery is considered one of the most challenging disciplines within Minimally Invasive Surgery (MIS), owing to factors such as the fragility of the anatomic features, poor visibility, limited manoeuvrability, and extreme requirements in terms of instrument handling with precise positioning. This work is centered on a fetal laser surgery procedure treating placental disorders. It proposes the use of haptic guidance to enhance the overall safety of this procedure and to simplify instrument handling. A method is described that provides effective guidance by installing a forbidden region virtual fixture over the placenta, thereby safeguarding adequate clearance between the instrument tip and the placenta. With a novel application of all-optical ultrasound distance sensing in which transmission and reception are performed with fibre optics, this method can be used with a sole reliance on intraoperatively acquired data. The added value of the guidance approach, in terms of safety and performance, is demonstrated in a series of experiments with a robotic platform
Exclusion and reappropriation: Experiences of contemporary enclosure among children in three East Anglian schools
Transformations of the landscapes which children inhabit have significant impacts on their lives; yet, due to the limited economic visibility of childrenâs relationships with place, they have little stake in those transformations. Their experience, therefore, illustrates in an acute way the experience of contemporary enclosure as a mode of subordination. Following fieldwork in three primary schools in South Cambridgeshire, UK, we offer an ethnographic account of childrenâs experiences of socio-spatial exclusion. Yet, we suggest that such exclusion is by no means an end-point in childrenâs relationships with place. Challenging assumptions that children are disconnected from nature, we argue that through play and imaginative exploration of their environments, children find ways to rebuild relationships with places from which they find themselves excluded. This is the author accepted manuscript. The final version is available from SAGE via http://dx.doi.org/10.1177/026377581664194
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