6,067 research outputs found
Leading Undergraduate Students to Big Data Generation
People are facing a flood of data today. Data are being collected at
unprecedented scale in many areas, such as networking, image processing,
virtualization, scientific computation, and algorithms. The huge data nowadays
are called Big Data. Big data is an all encompassing term for any collection of
data sets so large and complex that it becomes difficult to process them using
traditional data processing applications. In this article, the authors present
a unique way which uses network simulator and tools of image processing to
train students abilities to learn, analyze, manipulate, and apply Big Data.
Thus they develop students handson abilities on Big Data and their critical
thinking abilities. The authors used novel image based rendering algorithm with
user intervention to generate realistic 3D virtual world. The learning outcomes
are significant
Conductance modulation in spin field-efect transistors under finite bias voltages
The conductance modulations in spin field-effect transistors under finite
bias voltages were studied. It was shown that when a finite bias voltage is
applied between two terminals of a spin field-effect transistor, the spin
precession states of injected spin-polarized electrons in the semiconductor
channel of the device will depend not only the gate-voltage controlled Rashba
spin-orbit coupling but also depend on the bias voltage and, hence, the
conductance modulation in the device due to Rashba spin-orbit coupling may also
depend sensitively on the bias voltage.Comment: 7 pages, 3 figures, to appear in Physical Review B, (April, 2004
Computational Multimedia for Video Self Modeling
Video self modeling (VSM) is a behavioral intervention technique in which a learner models a target behavior by watching a video of oneself. This is the idea behind the psychological theory of self-efficacy - you can learn or model to perform certain tasks because you see yourself doing it, which provides the most ideal form of behavior modeling. The effectiveness of VSM has been demonstrated for many different types of disabilities and behavioral problems ranging from stuttering, inappropriate social behaviors, autism, selective mutism to sports training. However, there is an inherent difficulty associated with the production of VSM material. Prolonged and persistent video recording is required to capture the rare, if not existed at all, snippets that can be used to string together in forming novel video sequences of the target skill. To solve this problem, in this dissertation, we use computational multimedia techniques to facilitate the creation of synthetic visual content for self-modeling that can be used by a learner and his/her therapist with a minimum amount of training data. There are three major technical contributions in my research. First, I developed an Adaptive Video Re-sampling algorithm to synthesize realistic lip-synchronized video with minimal motion jitter. Second, to denoise and complete the depth map captured by structure-light sensing systems, I introduced a layer based probabilistic model to account for various types of uncertainties in the depth measurement. Third, I developed a simple and robust bundle-adjustment based framework for calibrating a network of multiple wide baseline RGB and depth cameras
An Immersive Telepresence System using RGB-D Sensors and Head Mounted Display
We present a tele-immersive system that enables people to interact with each
other in a virtual world using body gestures in addition to verbal
communication. Beyond the obvious applications, including general online
conversations and gaming, we hypothesize that our proposed system would be
particularly beneficial to education by offering rich visual contents and
interactivity. One distinct feature is the integration of egocentric pose
recognition that allows participants to use their gestures to demonstrate and
manipulate virtual objects simultaneously. This functionality enables the
instructor to ef- fectively and efficiently explain and illustrate complex
concepts or sophisticated problems in an intuitive manner. The highly
interactive and flexible environment can capture and sustain more student
attention than the traditional classroom setting and, thus, delivers a
compelling experience to the students. Our main focus here is to investigate
possible solutions for the system design and implementation and devise
strategies for fast, efficient computation suitable for visual data processing
and network transmission. We describe the technique and experiments in details
and provide quantitative performance results, demonstrating our system can be
run comfortably and reliably for different application scenarios. Our
preliminary results are promising and demonstrate the potential for more
compelling directions in cyberlearning.Comment: IEEE International Symposium on Multimedia 201
Effects of spin imbalance on the electric-field driven quantum dissipationless spin current in -doped Semiconductors
It was proposed recently by Murakami et al. [Science \textbf{301},
1348(2003)] that in a large class of -doped semiconductors, an applied
electric field can drive a quantum dissipationless spin current in the
direction perpendicular to the electric field. In this paper we investigate the
effects of spin imbalance on this intrinsic Hall effect. We show that in
a real sample with boundaries, due to the presence of spin imbalance near the
edges of the sample, the spin Hall conductivity is not a constant but a
sensitively - quantity, and due to this fact, in order to
take the effects of spin imbalance properly into account, a microscopic
calculation of both the quantum dissipationless spin Hall current and the spin
accumulation on an equal footing is thus required. Based on such a microscopic
calculation, a detailed discussion of the effects of spin imbalance on the
intrinsic spin Hall effect in thin slabs of -doped semiconductors are
presented.Comment: 8 pages, 2 figures, An extended version with detailed calculations To
appear in Phys. Rev.
- …