This paper proposes a new approach for functional analysis of cardiac images. A generic heart model is coupled with finite element methods to assess global and regional function from tagged magnetic resonance images. A model including both the left ventricle (LV) and right ventricle (RV) up to the basal area is needed for comprehensive understanding of cardiac physiology and anatomy. Most existing techniques can only handle the LV. Although some have attempted modeling the whole heart, these models have no geometric reference frame, so that it is difficult to compare different heart shapes and their motion. This paper uses a generic bi-ventricular heart model for functional analysis of heart motion. Three orthogonal tagging directions provide temporal correspondence of material points and enable tracking material points over time. The generic finite element model deforms due to forces exerted from material points by solving governing equations based on physical laws. The resulting model parameters can be used to characterize myocardial motion and deformation, including the basal area. We discuss the possibility of classifying parameters associated with normal and pathological hearts.

We present an automatic and robust technique for creating non-photorealistic rendering (NPR) and animation, starting from a video that depicts the shape details and follows the motion of underlying objects. We generate NPR from the initial frame of the source video using a greedy algorithm for stroke placements and models, in combination with a saliency map and a flow-guided difference-of-Gaussian filter. Our stroke model uses a set of triangles whose vertices are particles and whose edges are springs. Using a physicsbased framework, the generated and rendered strokes are translated, rotated and deformed by forces exerted from the sequential frames. External forces acting on strokes are calculated according to temporally and spatially smoothed per-pixel optical flow vectors. After simulating each frame, we delete unnecessary strokes and add new strokes for disappearing and appearing objects, but only if necessary to avoid popping and scintillation. Our framework automatically generates the coherent animation of rendered strokes, preserving the appearance details and animating strokes along with the underlying objects. This had been difficult to achieve with previous user-guided methods and automatic but limited transformations methods.

We present a simple and real-time technique for animating giant realistic looking soap bubbles. Unlike small spherical soap bubbles, giant soap bubbles stretch significantly and undergo globally varying and locally consistent deformations because of time-varying surface tensions. For physically plausible surface tensions, we introduce and combine a variable-length mass spring system and Gibbs elasticity and Marangoni elasticity. Using a proposed framework, we deform our models because of general forces from surface tensions, winds, and excessive pressures. Our framework effectively generates a physically plausible animation of giant soap bubbles, differing in shape according to the user's design; generates capillary waves and vibrations while floating in the air; and shows vivid iridescent colors corresponding to the deformations, all of which have been difficult to achieve using previous soap bubble animation methods.

Heart disease is the leading cause of death in the Western world and consequently the study of normal and pathological heart behavior is an active research area. In particular, the study of the shape and motion of the heart is important because many heart diseases are strongly correlated to these two factors. The human heart is composed of two separate pumps: a right heart that pumps the blood through the lungs and a left heart that pumps the blood through the peripheral organs. In turn, each of these "hearts" is a two-chamber pump composed of an atrium and a ventricle. Special mechanisms in the heart provide cardiac rhythm and transmit action potentials throughout the heart muscle to cause the heart's rhythmic relaxation (diastole) and contraction (systole).

The main purpose of virtual reality (VR) is to enhance realism and the player experience. To do this, we focus on VR interaction design methods, analyze the existing interaction solutions including both accurate and rough interaction methods, and propose a new method for creating stable and realistic player interactions in a first-person shooter (FPS) game prototype. In this research, we design and modify the existing mapping methods between physical and virtual worlds, and create interfaces such that physical devices correspond to shooting tools in virtual reality. Moreover, we propose and design prototypes of universal interactions that can be implemented in a simple and straightforward way. Proposed interactions allow the player to perform actions similar to those of real shooting, using both hands such as firing, reloading, attaching and grabbing objects. In addition, we develop a gun template with haptic feedback, and a visual collision guide that can optionally be enabled. Then, we evaluate and compare our methods with the existing solutions. We then use these in a VR FPS game prototype and conduct a user study with participants, and the resulting user study proves that the proposed method is more stable, player-friendly and realistic. INDEX TERMS Virtual reality, player interfaces, human computer interaction, interaction design, first-person shooting game. KYOUNGJU PARK received the B.E. degree in computer engineering from Ewha Woman's University, in 1997, and the M.S. and Ph.D. degrees in computer and information science from the University of Pennsylvania, in 2000 and 2005, respectively. After receiving her Ph.D., she was with Rutgers University, as a Research Professor, and with Samsung Electronics, as a Senior Engineer. In 2007, she joined Chung-Ang University, Seoul, South Korea, as a Faculty Member. Her research interests include virtual reality, and computer graphics and interaction.