Inelastic uniform torsion of steel members

This paper develops a mitre model for the shear strain distribution in steel members under uniform torsion. The mitre model provides reasonable approximations for the shear stress distributions, except near re-entrant corners, and accurate predictions of the fully plastic uniform torque. The elastic torque-twist relationship is predicted with high accuracy, and the inelastic relationship with reasonable accuracy. The mitre model uses a simple approximation to the shear strain distribution caused by uniform torsion. It can be expected to provide a relatively simple method of predicting the inelastic behaviour of steel members when uniform torsion acts in combination with axial force and bending moment.     

Contamination from 131I, 103Ru, and 239Np in the eluate of 99Mo-99mTc generators loaded with (n, gamma)-produced 99Mo

Iodine-131, ruthenium-103, and neptunium-239 are present as contaminants in the eluate of 99Mo-99mTc generators loaded with 99Mo prepared by thermal-neutron irradiation of enriched 98Mo. The elution pattern of each of these contaminants is determined, together with the amounts found in the eluate of all generators tested over a 7-month period.     

Shape recognition and pose estimation for mobile Augmented Reality

Nestor is a real-time recognition and camera pose estimation system for planar shapes. The system allows shapes that carry contextual meanings for humans to be used as Augmented Reality (AR) tracking targets. The user can teach the system new shapes in real time. New shapes can be shown to the system frontally, or they can be automatically rectified according to previously learned shapes. Shapes can be automatically assigned virtual content by classification according to a shape class library. Nestor performs shape recognition by analyzing contour structures and generating projective-invariant signatures from their concavities. The concavities are further used to extract features for pose estimation and tracking. Pose refinement is carried out by minimizing the reprojection error between sample points on each image contour and its library counterpart. Sample points are matched by evolving an active contour in real time. Our experiments show that the system provides stable and accurate registration, and runs at interactive frame rates on a Nokia N95 mobile phone.     

NapWell: An EOG-based Sleep Assistant Exploring the Effects of Virtual Reality on Sleep Onset

Virtual Reality - We present NapWell, a Sleep Assistant using virtual reality (VR) to decrease sleep onset latency by providing a realistic imagery distraction prior to sleep onset. Our proposed...     

Wearable devices: new ways to manage information

Although the Information Age has many upsides, one of its major downsides is information overload. Indeed, the amount of information easily pushes the limit of what people can manage. This conflict drives research to seek a solution to humanity's information woes. As computers have shrunk from room size to palm size, so they have also moved from being passive accessories, such as laptops and personal digital assistants, to wearable appliances that form an integral part of our personal space. Wearable computers are always on and accessible. As the computer moves from desktop to coat pocket to the human body, its ability to help manage, sort, and filter information will become more intimately connected to our daily lives. The paper discusses the principles of wearable computers     

Touch-Space: Mixed Reality Game Space Based on Ubiquitous, Tangible, and Social Computing

This paper presents a novel computer entertainment system which recaptures human touch and physical interaction with the real-world environment as essential elements of the game play, whilst also maintaining the exciting fantasy features of traditional computer entertainment. Our system called ‘Touch-Space’ is an embodied (ubiquitous, tangible, and social) computing based Mixed Reality (MR) game space which regains the physical and social aspects of traditional game play. In this novel game space, the real-world environment is an essential and intrinsic game element, and the human’s physical context influences the game play. It also provides the full spectrum of game interaction experience ranging from the real physical environment (human to human and human to physical world interaction), to augmented reality, to the virtual environment. It allows tangible interactions between players and virtual objects, and collaborations between players in different levels of reality. Thus, the system re-invigorates computer entertainment systems with social human-to-human and human-to-physical touch interactions. Correspondence to: Professor A. Cheok, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. Email: adriancheok@nus.edu.sg     

Pressure-sketch: a tablet-based design system in immersive VR

Virtual Reality - Sketch design is generally a feasible concept within virtual reality (VR). However, VR controllers suffer from a fundamental problem that limits operability and immersion, which...     

Egocentric Object Manipulation in Virtual Environments: Empirical Evaluation of Interaction Techniques

The acceptance of virtual environment (VE) technology requires scrupulous optimization of the most basic interactions in order to maximize user performance and provide efficient and enjoyable virtual interfaces. Motivated by insufficient understanding of the human factors design implications of interaction techniques and tools for virtual interfaces, this paper presents results of a formal study that compared two basic interaction metaphors for egocentric direct manipulation in VEs, virtual hand and virtual pointer, in object selection and positioning experiments. The goals of the study were to explore immersive direct manipulation interfaces, compare performance characteristics of interaction techniques based on the metaphors of interest, understand their relative strengths and weaknesses, and derive design guidelines for practical development of VE applications.