Flow Experience and Challenge-Skill Balance in E-Learning

Flow is an optimal experience resulting in intense engagement in the activity. People achieved flow state when they perceived balance between challenge of the activity and their skill to the activity. The concept of flow can be used to explore students’ learning performance in e-learning environment. The current research aims to empirically explore the influence of challenge-skill balance on the flow experience and the influence of flow experience on learning satisfaction and learning performance in e-learning environment. The current research conducted a quasi-experimental design with questionnaire survey and carried out an electroencephalography (EEG) analysis, a psychophysiological method. The empirical survey results have shown that challenge-skill balance is an antecedent factor affecting learners’ flow experience. Once learners reach flow experience, their learning performance and learning satisfaction would get improved. Besides, the current research also found that flow experience is relative with learners’ attention measured by EEG brainwave signal. Learners’ perception of challenge-skill balance would influence their attention in e- learning activities. The current research is also in the pioneering position that using non-medical purpose EEG device in e-learning research

Eye-of-the-Tiger sign is not Pathognomonic of Pantothenate Kinase-Associated Neurodegeneration in Adult Cases

An eye-of-the-tiger sign is previously known to have one-to-one correlation with pantothenate kinase-associated neurodegeneration (PKAN). Reviewing the literature on this subject, the correlation between eye-of-the-tiger sign and PKAN seems to show an interesting hypothesis that differs from conventional conclusion. We analyze the published papers in an attempt to reflect this trend and illustrate our points with findings in a 39-year-old man. His brain magnetic resonance imaging study shows typical eye-of-the-tiger sign suggestive of PKAN. Genetic analyses revealed no mutations in pantothenate kinase 2

A Fringe Center Detection Technique Based on a Sub-Pixel Resolution, and Its Applications Using Sinusoidal Gratings

A common problem in optical profilometry is the accuracy in locating fringe centers. This paper presents an accurate fringe center detection technique based on sub-pixel resolution using the fringe projection method. An optimum reconstruction filter is developed which has low sensitivity to noise. In fringe center detection, computer simulation results of using one-pixel and sub-pixel resolutions are compared. The detection technique is then applied to radius measurement of cylindrical objects and surface profile measurement of diffuse objects. The experimental results thus obtained through the proposed optimum reconstruction filter show significant improvement in measurement accuracy

Micro data flow processor design

Computer has evolved rapidly during the past several decades in terms of its implementation technology; it's architecture, however, has not changed dramatically since the von Neumann computer(control flow) model emerged in the 1940s. One main reason is that the performance for this kind of computers was able to satisfy the requirement of most users. Another reason maybe that the engineers who designed them are more familiar with this model. However, recent solutions to the problem of parallelizing sequential nature instructions on a von Neumann machine complicate both the compiler and the controller design. Therefore, another computer model, namely the data flow model, has regained attention since this model of computation exposes parallelism inherent in the program naturally. In terms of implementation methodology, we currently use synchronous sequential logic, which is clock controlled for synchronization within circuits. This design philosophy becomes hard to follow due to the occurrence of clock skew as the clock frequency goes higher and higher. One way to eliminate these clock related problems is to use the self-timed(asynchronous) implementation methodology. It features advantages such as free of clock-skew, low power consumption, composibility and so forth. Since data flow(data driven) computation model provides the execution of instructions asynchronously, it is natural to implement a data flow processor using self-timed circuits. In this thesis, micro pipelines, one of the self-timed implementation methodology, is used to implement a preliminary version of general purpose static data flow processor. Some interesting observations will be addressed in this thesis. An example program of general difference recursive equation is given to test the correctness and performance of this processor. We hope to gain more insight on how to design and implement self-timed systems in the future

A Fringe Center Detection Technique Based on a Sub-Pixel Resolution, and Its Applications Using Sinusoidal Gratings

A common problem in optical profilometry is the accuracy in locating fringe centers. This paper presents an accurate fringe center detection technique based on sub-pixel resolution using the fringe projection method. An optimum reconstruction filter is developed which has low sensitivity to noise. In fringe center detection, computer simulation results of using one-pixel and sub-pixel resolutions are compared. The detection technique is then applied to radius measurement of cylindrical objects and surface profile measurement of diffuse objects. The experimental results thus obtained through the proposed optimum reconstruction filter show significant improvement in measurement accuracy

Design of High Efficiency Illumination for LED Lighting

A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against device difference. Finally, a prototype circuit for driving 112 W LEDs in total was built and tested to verify the theoretical analysis