Visual Attention and Eye Gaze During Multiparty Conversations with Distractions

Our objective is to develop a computational model to predict visual attention behavior for an embodied conversational agent. During interpersonal interaction, gaze provides signal feedback and directs conversation flow. Simultaneously, in a dynamic environment, gaze also directs attention to peripheral movements. An embodied conversational agent should therefore employ social gaze not only for interpersonal interaction but also to possess human attention attributes so that its eyes and facial expression portray and convey appropriate distraction and engagement behaviors

Generating Sequence of Eye Fixations Using Decision-theoretic Attention Model

Human eyes scan images with serial eye fixations. We proposed a novel attention selectivity model for the automatic generation of eye fixations on 2D static scenes. An activation map was first computed by extracting primary visual features and detecting meaningful objects from the scene. An adaptable retinal filter was applied on this map to generate Regions of Interest (ROIs), whose locations corresponded to those of activation peaks and whose sizes were estimated by an iterative adjustment algorithm. The focus of attention was moved serially over the detected ROIs by a decision-theoretic mechanism. The generated sequence of eye fixations was determined from the perceptual benefit function based on perceptual costs and rewards, while the time distribution of different ROIs was estimated by a memory learning and decaying model. Finally, to demonstrate the effectiveness of the proposed attention model, the gaze tracking results of different human subjects and the simulated eye fixation shifting were compared

Control of edge bulge evolution during photoresist reflow and it's application to diamond micro-lens fabrication

We present an empirical study of profile evolution of lithographically defined photoresist (PR) patterns during thermal reflow and apply the findings to diamond micro-lens fabrication. During PR reflow, a bulge forms at the edge of the PR pattern and propagates inwards as the temperature and PR thickness are increased. An empirical relationship for this propagation is derived. Furthermore, it was found that at a certain reflow temperature and a limited pattern size, there is a minimum initial thickness of the PR pattern for forming spherical lens profiles. Based on these findings, diamond micro-lenses with a diameter of 400 µm and a previously unachieved radius of curvature of over 13 mm were fabricated. This is underpinned by forming PR micro-lens patterns with a large radius of curvature and transferring the PR patterns through low-selectivity Ar/Cl2 inductively coupled plasma etching

Evaluating American Sign Language Generation Through the Participation of Native ASL Signers

We discuss important factors in the design of evaluation studies for systems that generate animations of American Sign Language (ASL) sentences. In particular, we outline how some cultural and linguistic characteristics of members of the American Deaf community must be taken into account so as to ensure the accuracy of evaluations involving these users. Finally, we describe our implementation and user-based evaluation (by native ASL signers) of a prototype ASL generator to produce sentences containing classifier predicates, frequent and complex spatial phenomena that previous ASL generators have not produced

Concept of a GaN-LED-based positioning system using structured illumination

Accurate self-orientation within a space can be achieved using only a simple photodetector and a remote Gallium Nitride micro-light-emitting diode array, emitting a time series of varying spatial illumination patterns onto the scene

Positioning and space-division multiple access enabled by structured illumination with light-emitting diodes

Self-location of devices in an illuminated area can be realized using light-emitting diode array luminaires with integrated electronic smart control. These smart lighting sources project a rapidly displayed time sequence of spatial illumination patterns onto the scene, which enables positioning on a millisecond timescale. We demonstrate a prototype system based on a CMOS-driven 16×16 array of GaN light-emitting diodes and its application to space-division multiple access in a Gb/s optical wireless network

Experimental study on microlaser fluorescence spectrometer

This paper presents a kind of miniature handheld laser fluorescence spectrometer, which integrates a laser emission system, a spectroscopic system, and a detection system into a volume of 100 × 50 × 20 mm3. A universal serial bus interface is connected to PC for data processing and spectrum display. The emitted laser wavelength is 405 nm. A spectral range is 400 to 760 nm and 2-nm optical resolution has been achieved. This spectrometer has the advantages of compact structure, small volume, high sensitivity, and low cost. 1.Introductio

Integrating diamond with GaN photonic device

The nitrogen vacancy is a photostable emitter in diamond which is optically accessible at room temperature and a potential candidate for quantum information processing as a spin register. The challenge facing research today is the efficient collection and manipulation of the NV’s emissions, such as enhancing the zero phonon line transitions for a coherent spin-photon interface. This project focuses on integrating ultra-thin diamond membranes with established photonic devices. By bonding the diamond to GaN, for example, mode simulations show that light can be coupled significantly into and out of the defect allowing processing across large area PICs

Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5kAcm−2

The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm−2 for emerging microLED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC