1,062 research outputs found

    A Learning Science Foundation for Project-Based Learning in Engineering

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    ABSTRACT Seeking to connect the cognitive sciences and teaching faculty, Susan Ambrose and her coauthors recently published, How Learning Works: 7 Research Based Principles for Smart Teaching. [1] Ambrose and her co-authors observed that cognitive and educational psychology was making great strides advancing the science of learning, but little of this science was impacting college classrooms. Ambrose et al. sought to connect effective teaching practices and cognitive psychology's advances in our understanding of learning and bring that science of learning into others' classrooms. Their book distills seven principles from the learning sciences, and then instantiates those principles with concrete teaching practices. We find in Ambrose's work a substantiation of project-based learning in engineering, providing a foundation for understanding why this pedagogy works. Specifically, problembased learning works because it naturally embodies all seven research-based principles of effective teaching and learning outlined by Ambrose and her co-authors. Appropriately executed, project-based learning implicitly complies with our students' ability to learn. We elaborate on four of Ambrose's seven findings and describe how the documented practices of emerging from the CDIO initiative instantiate those principles. Furthermore, Ambrose's principles suggest criteria by which we might justifiably identify best practices in projectbased learning. This assessment may help promote and facilitate adoption of fine-tuned educational strategies within the CDIO framework. Furthermore, this will shift the arguments for project-based learning from appeals to intuition and trial-and-error to a more rigorous foundation built from the teaching and learning sciences

    Differential Random Fault Attacks on certain CAESAR Stream Ciphers (Supplementary Material)

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    This document contains supplementary material to the paper with the same title available from the proceedings of the International Conference on Information Security and Cryptology (ICISC) 2019. In this supplementary material, we demonstrate that the random fault attack strategy described in the full paper can be applied to ciphers in the MORUS family, resulting in partial state recovery for these ciphers

    State convergence and keyspace reduction of the Mixer stream cipher

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    This paper presents an analysis of the stream cipher Mixer, a bit-based cipher with structural components similar to the well-known Grain cipher and the LILI family of keystream generators. Mixer uses a 128-bit key and 64-bit IV to initialise a 217-bit internal state. The analysis is focused on the initialisation function of Mixer and shows that there exist multiple key-IV pairs which, after initialisation, produce the same initial state, and consequently will generate the same keystream. Furthermore, if the number of iterations of the state update function performed during initialisation is increased, then the number of distinct initial states that can be obtained decreases. It is also shown that there exist some distinct initial states which produce the same keystream, resulting in a further reduction of the effective key space

    Participatory design in the development of the wheelchair convoy system

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    <p>Abstract</p> <p>Background</p> <p>In long-term care environments, residents who have severe mobility deficits are typically transported by having another person push the individual in a manual wheelchair. This practice is inefficient and encourages staff to hurry to complete the process, thereby setting the stage for unsafe practices. Furthermore, the time involved in assembling multiple individuals with disabilities often deters their participation in group activities.</p> <p>Methods</p> <p>The Wheelchair Convoy System (WCS) is being developed to allow a single caregiver to move multiple individuals without removing them from their wheelchairs. The WCS will consist of a processor, and a flexible cord linking each wheelchair to the wheelchair in front of it. A Participatory Design approach – in which several iterations of design, fabrication and evaluation are used to elicit feedback from users – was used.</p> <p>Results</p> <p>An iterative cycle of development and evaluation was followed through five prototypes of the device. The third and fourth prototypes were evaluated in unmanned field trials at J. Iverson Riddle Development Center. The prototypes were used to form a convoy of three wheelchairs that successfully completed a series of navigation tasks.</p> <p>Conclusion</p> <p>A Participatory Design approach to the project allowed the design of the WCS to quickly evolve towards a viable solution. The design that emerged by the end of the fifth development cycle bore little resemblance to the initial design, but successfully met the project's design criteria. Additional development and testing is planned to further refine the system.</p

    The osteology of ‘Periptychus carinidens’: a robust, ungulate-like placental mammal (Mammalia: Periptychidae) from the Paleocene of North America

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    Periptychus is the archetypal genus of Periptychidae, a clade of prolific Paleocene 'condylarth' mammals from North America that were among the first placental mammals to radiate after the end-Cretaceous extinction, remarkable for their distinctive dental anatomy. A comprehensive understanding of the anatomy of Periptychus has been hindered by a lack of cranial and postcranial material and only cursory description of existing material. We comprehensively describe the cranial, dental and postcranial anatomy of Periptychus carinidens based on new fossil material from the early Paleocene (Torrejonian) of New Mexico, USA. The cranial anatomy of Periptychus is broadly concurrent with the inferred plesiomorphic eutherian condition, albeit more robust in overall construction. The rostrum is moderately elongate with no constriction, the facial region is broad, and the braincase is small with a well-exposed mastoid on the posterolateral corner and tall sagittal and nuchal crests. The dentition of Periptychus is characterized by strongly crenulated enamel, enlarged upper and lower premolars with a tall centralised paracone/protoconid. The postcranial skeleton of Periptychus is that of a robust, medium-sized (~20 Kg) stout-limbed animal that was incipiently mediportal and adopted a plantigrade stance. The structure of the fore- and hindlimb of Periptychus corresponds to that of a typically terrestrial mammal, while morphological features of the forelimb such as the low tubercles of the humerus, long and prominent deltopectoral crest, pronounced medial epicondyle, and hemispherical capitulum indicate some scansorial and/or fossorial ability. Most striking is the strongly dorsoplantarly compressed astragalus of Periptychus, which in combination with the distal crus and calcaneal morphology indicates a moderately mobile cruropedal joint. The anatomy of Periptychus is unique and lacks any extant analogue; it combines a basic early placental body plan with numerous unique specializations in its dental, cranial and postcranial anatomy that exemplify the ability of mammals to adapt and evolve following catastrophic environmental upheaval

    Tweaking Generic OTR to Avoid Forgery Attacks

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    This paper considers the security of the Offset Two-Round (OTR) authenticated encryption mode \cite{cryptoeprint:2013:628} with respect to forgery attacks. The current version of OTR gives a security proof for specific choices of the block size (n)(n) and the primitive polynomial used to construct the finite field F2n\mathbb{F}_{2^n}. Although the OTR construction is generic, the security proof is not. For every choice of finite field the distinctness of masking coefficients must be verified to ensure security. In this paper, we show that some primitive polynomials result in collisions among the masking coefficients used in the current instantiation, from which forgeries can be constructed. We propose a new way to instantiate OTR so that the masking coefficients are distinct in every finite field F2n\mathbb{F}_{2^n}, thus generalising OTR without reducing the security of OTR
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