VISUALIZING ORIENTATION USING QUATERNIONS

INTRODUCTION: Visualization of 3D kinematic data presents special challenges, not only in terms of hardware requirements, but also in terms of the mathematics used to describe it. The ISB Standardization and Technology Committee has been working to standardize methods for representing kinematic data, particularly in the definition of coordinate systems and the representation of spatial orientations. In this presentation we will show that, although the ISB’s recommendation to regard a segment’s orientation as an ordered series of rotations may be useful for reporting and comparing results, it is not particularly suitable for 3D animation. The fundamental problems in ordered series of rotations will be briefly summarized. We will contrast this with the algebraic elegance of the quaternion and its usefulness as a rotation operator. The advantages of quaternions will be visually demonstrated by showing them “in action” in examples of real-time key frame animations

An Assessment of Young Cattle Behaviour and Welfare in a Virtual Fencing System

Virtual fencing is a novel technology which uses a combination of audio and electrical stimuli to contain grazing livestock within a GPS boundary. There are however some concerns around the use of such a technology and its potential effects on the behaviour and welfare of animals. To investigate this, 64 dairy-origin calves were assigned to one of two treatments in a randomised complete block design, with 4 groups of 8 calves per treatment. The two treatments were virtual fencing (VF) and electric fencing (EF). The experimental period lasted 31 days in total, consisting of a 10 day training period and a 21 day grazing period. Welfare and behaviour of the animals was measured using faecal cortisol metabolites, activity pedometers, and behavioural recordings. Virtual fence data denoting the number of audio and electrical stimuli delivered for each animal were also recorded. Results show that there was no significant difference in animal welfare and behaviour between EF and VF in the current study. Additionally, there was no significant difference in daily liveweight gain between treatments. In the VF animals the rate of electric pulses declined after an initial learning period however there was a significant degree of variation in the rate of learning between animals. Virtual fencing could therefore offer an alternative to physical fencing for grazing young cattle without negatively impacting animal behaviour or welfare. The individual animal variation in VF systems however warrants further study

An interface to retrieve personal memories using an iconic visual language

Relevant past events can be remembered when visualizing related pictures. The main difficulty is how to find these photos in a large personal collection. Query definition and image annotation are key issues to overcome this problem. The former is relevant due to the diversity of the clues provided by our memory when recovering a past moment and the later because images need to be annotated with information regarding those clues to be retrieved. Consequently, tools to recover past memories should deal carefully with these two tasks. This paper describes a user interface designed to explore pictures from personal memories. Users can query the media collection in several ways and for this reason an iconic visual language to define queries is proposed. Automatic and semi-automatic annotation is also performed using the image content and the audio information obtained when users show their images to others. The paper also presents the user interface evaluation based on tests with 58 participants

Unfolding-Based Process Discovery

This paper presents a novel technique for process discovery. In contrast to the current trend, which only considers an event log for discovering a process model, we assume two additional inputs: an independence relation on the set of logged activities, and a collection of negative traces. After deriving an intermediate net unfolding from them, we perform a controlled folding giving rise to a Petri net which contains both the input log and all independence-equivalent traces arising from it. Remarkably, the derived Petri net cannot execute any trace from the negative collection. The entire chain of transformations is fully automated. A tool has been developed and experimental results are provided that witness the significance of the contribution of this paper.Comment: This is the unabridged version of a paper with the same title appearead at the proceedings of ATVA 201

A Web-Based Serious Game on Delirium as an Educational Intervention for Medical Students:Randomized Controlled Trial

BACKGROUND: Adequate delirium recognition and management are important to reduce the incidence and severity of delirium. To improve delirium recognition and management, training of medical staff and students is needed. OBJECTIVE: In this study, we aimed to gain insight into whether the serious game, Delirium Experience, is suited as an educational intervention. METHODS: We conducted a three-arm randomized controlled trial. We enrolled 156 students in the third year of their Bachelor of Medical Sciences degree at the University Medical Centre Groningen. The Game group of this study played Delirium Experience. The Control D group watched a video with explanations on delirium and a patient's experience of delirious episodes. The Control A group watched a video on healthy aging. To investigate students' skills, we used a video of a delirious patient for which students had to give care recommendations and complete the Delirium Observations Screening Scale and Delirium Rating Scale R-98. Furthermore, students completed the Delirium Attitude Scale, the Learning Motivation and Engagement Questionnaire, and self-reported knowledge on delirium. RESULTS: In total, 156 students participated in this study (Game group, n=51; Control D group, n=51; Control A group, n=55). The Game group scored higher with a median (interquartile range) of 6 (4-8) for given recommendations and learning motivation and engagement compared with the Control D (1, 1-4) and A (0, 0-3) groups (P<.001). Furthermore, the Game group scored higher (7, 6-8) on self-reported knowledge compared with the Control A group (6, 5-6; P<.001). We did not find differences between the groups regarding delirium screening (P=.07) and rating (P=.45) skills or attitude toward delirious patients (P=.55). CONCLUSIONS: The serious game, Delirium Experience, is suitable as an educational intervention to teach delirium care to medical students and has added value in addition to a lecture

Reasons to Engage in and Learning Experiences From Different Play Strategies in a Web-Based Serious Game on Delirium for Medical Students:Mixed Methods Design

BACKGROUND: Although many studies have recently been published on the value of serious games for medical education, little attention has been given to the role of dark play (choosing unacceptable actions in games). OBJECTIVE: This study aimed to investigate potential differences in the characteristics of medical students who have the opportunity to choose normal or dark play in a serious game. This study also aimed to compare their reasons for choosing a play strategy and their perceptions of what they learned from their game play. METHODS: We asked undergraduate medical students to play a serious game in which they had to take care of a patient with delirium (The Delirium Experience). After getting acquainted with the game, students could opt for normal or dark play. Student characteristics (age, gender, experience with caring for older or delirious patients, and number of completed clerkships) were collected, and the Delirium Attitude Scale and Learning Motivation and Engagement Questionnaire were administered. Reasons for choosing normal or dark play were evaluated with an open-ended question. Information on lessons they had learned from the game was collected using an open-ended question and self-reported knowledge on delirium. RESULTS: This study had 160 participants (89 normal play, 71 dark play). Male students (26/160, 56.5%) chose dark play significantly more often than female students (45/160, 39.5%; P=.049). We did not find significant differences in student characteristics or measurement outcomes between play strategies. Participants' main reason for choosing normal play was to learn how to provide care to delirious patients, and the main reason for dark play was to gain insight into what a delirious patient has to endure during delirious episodes. All participants learned what to do when taking care of a delirious patient and gained insight into how a patient experiences delirium. We found no differences in self-reported knowledge. CONCLUSIONS: When medical students have the opportunity to choose dark play in a serious game, half of them will probably choose this play strategy. Male students will more likely opt for dark play than female students. Choice of play strategy is not affected by any other student characteristic or measurement outcome. All students learned the same lessons from playing the game, irrespective of their learning strategy

Synthesis and photophysical properties of benzotriazole-derived unnatural &#945; -amino acids

The synthesis of a new class of benzotriazole-derived α-amino acid is described using a highly efficient nucleophilic aromatic substitution of ortho-fluoronitrobenzenes with l-3-aminoalanine and a polymer-supported nitrite reagent-mediated diazotization and cyclization of the subsequent 1,2-aryldiamines as the key steps. Further functionalization of the benzotriazole unit by preparation of halogenated analogues and Suzuki–Miyaura cross-coupling with aryl boronic acids allowed the synthesis of α-amino acids with conjugated side chains. Analysis of the photophysical properties of these α-amino acids revealed that incorporation of electron-rich substituents results in charge-transfer-based, fluorescent compounds with MegaStokes shifts

Preservation of lagging strand integrity at sites of stalled replication by pol α-primase and 9-1-1 complex

Plant science