Browsing by Author "Chen, Sheng-Chang"

Now showing 1 - 11 of 11

A Fuzzy Cache Lifetime Determination Scheme for LISP Mapping Systems
(2013)
Chen, Sheng-Chang
;
Chang, Chung-Ju
;
Chu, Yu-Huang
;
電機工程學系
;
Department of Electrical and Computer Engineering
Locator/ID Separation Protocol (LISP) is a simple and network-based architecture that can be used to address the scalability problem in the future Internet. The key function of LISP is the mapping system, which is responsible to map ID to locator. Usually, the cache table is used to store the queried mapping information. However, if the mapping information is changed, how to efficiently update and refresh the mapping information in the cache table is a very important issue. In this paper, we propose a fuzzy cache lifetime determination (FCLD) scheme for the LISP mapping system. This FCLD scheme adopts the fuzzy logic theory to generate and adjust cache lifetime of mapping information. It considers the update and lookup frequency, and lookup latency of mapping information as input linguistic variables to adjust the cache lifetime. In the high update and lookup frequency, the cache lifetime will be decreased to increase the accuracy of mapping information. In high lookup latency, the cache lifetime will be increased to reduce the overhead of inquiring mapping information. Simulation results show that the FCLD scheme has lower average packet delay by 10.78% and lower packet loss ratio by 2.1% than the solicit map request (SMR) scheme.
A human visual model for color break-up artifact in design field-sequential color LCDs
(2007)
Chen, Sheng-Chang
;
Yan, Shu-Ping
;
Cheng, Yu-Kuo
;
Lin, Fang-Cheng
;
Wei, Ching-Ming
A model to evaluate the color break-up (CBU) of field-sequential color liquid crystal display (FSC-LCD) had been successfully established. In order to quantify the CBU, "Color Break-Up Angle (CBUA)" was proposed as the evaluation index. From the psychophysical experiments, the CBUA=0.26 degrees was reported as the averaged threshold value for indistinguished color break-up. Consequently, the minimum frame rate could be derived from the model to suppress CBU in the various FSC-LCDs.
A method for estimating subject-specific body segment inertial parameters in human movement analysis
(2011-04-01)
Chen, Sheng-Chang
;
Hsieh, Hong-Jung
;
Lu, Tung-Wu
;
Tseng, Ching-Huan
;
機械工程學系
An optimization-based, non-invasive, radiation-free method was developed for estimating subject-specific body segment inertial properties (BSIPs) using a motion capture system and two forceplates. The method works with accurate descriptions of the geometry of the body segments, subject-specific center of pressure (COP) and kinematic data captured during stationary standing, and an optimization procedure. Twelve healthy subjects performed stationary standing in different postures, level walking and squatting while kinematic and forceplate data were measured. The performance of the current method was compared to three commonly used predictive methods in terms of the errors of the calculated ground reaction force, COP and joint moments using the corresponding predicted BSIPs. The current method was found to be capable of producing estimates of subject-specific BSIPs that predicted accurately the important variables in human motion analysis during static and dynamic activities. With the differences in the BSIPs from the current method, the mean COP errors were less than 5 mm during stationary standing postures, while those from the existing comparative methods ranged from 11 to 25 mm. During dynamic activities, the existing methods gave COP errors three times as large as the proposed method, with up to 2.5 times RMSE in joint moments during walking. Being non-invasive and using standard motion laboratory equipment, the current method will be useful for routine clinical gait analysis and relevant clinical applications, particularly in patient populations that are not targeted by the existing predictive methods. (C) 2011 Elsevier B.V. All rights reserved.
A new device for in situ static and dynamic calibration of force platforms
(2011-04-01)
Hsieh, Hong-Jung
;
Lu, Tung-Wu
;
Chen, Sheng-Chang
;
Chang, Chia-Min
;
Hung, Chinghua
In human motion analysis, in situ calibration of the force plate is necessary to improve the accuracy of the measured ground reaction force (GRF) and center of pressure (COP). Few existing devices are capable of both static and dynamic calibration of the usually non-linear GRF and COP errors, while are also easy to move and/or set up without damaging the building. The current study developed a small device (160 cm x 88 cm x 43 cm) with a mass of 50 kg, equipped with auxiliary wheels and fixing suction pads for rapid deployment and easy set-up. A PC-based controller enabled quick movement and accurate positioning of the applied force to the calibration point. Static calibration at 100 validation points and dynamic calibration of a force plate were performed using the device. After correction by an artificial neural network (ANN) trained with the static data from another 121 points, the mean errors for the GRF were all reduced from a maximum of 0.64% to less than 0.01%, while those for the COP were all reduced from a maximum of about 1.37 mm to less than 0.04 mm. For dynamic calibration, the mean errors for the GRF were reduced from a maximum of 0.46% to less than 0.28%, while those for the COP were reduced from a maximum of 0.95 mm to less than 0.11 mm. The results suggest that the calibration device with the ANN method will be useful for obtaining more accurate GRF and COP measurements in human motion analysis. (C) 2011 Elsevier B.V. All rights reserved.
Effects of Analogical Learning Approaches and Presentation Modalities on Ninth Graders' Learning Outcome and Eye Movements: a Preliminary Study
(1970-01-01)
Chen, Sheng-Chang
;
She, Hsiao-Ching
;
教育研究所
;
Institute of Education
This study analyzed the impact of different analogical learning approaches (analogies or metaphors) integrated with different presentation modalities (pictures or texts) on middle school students' learning performance of electricity with supporting evidence from their eye movement behaviors. Eighty ninth-grade middle school students were randomly assigned into four groups to receive four different versions of an online electricity learning program, including pictorial analogies, textual analogies, pictorial metaphors, and textual metaphors. Data regarding students' eye movement behaviors were collected simultaneously during their online learning. All the students took a pre-test, post-test, and retention test covering their comprehension of electricity concepts. Our results revealed that the analogy group provided more mapping and integration behaviors between the analog and target concepts about electricity, resulting in gaining better performance than the metaphor group. Additionally, students receiving pictorial modality generated more mapping and integration behaviors between the analog and target concepts, resulting in a better understanding of electricity concepts than students learning with textual modality. The associated implications for analogical learning approaches and presentation modalities concerning science learning and eye movement behaviors are also discussed in the paper.
Encoding of Physics Concepts: Concreteness and Presentation Modality Reflected by Human Brain Dynamics
(2012-07-27)
Lai, Kevin
;
She, Hsiao-Ching
;
Chen, Sheng-Chang
;
Chou, Wen-Chi
;
Huang, Li-Yu
Previous research into working memory has focused on activations in different brain areas accompanying either different presentation modalities (verbal vs. non-verbal) or concreteness (abstract vs. concrete) of non-science concepts. Less research has been conducted investigating how scientific concepts are learned and further processed in working memory. To bridge this gap, the present study investigated human brain dynamics associated with encoding of physics concepts, taking both presentation modality and concreteness into account. Results of this study revealed greater theta and low-beta synchronization in the anterior cingulate cortex (ACC) during encoding of concrete pictures as compared to the encoding of both high and low imageable words. In visual brain areas, greater theta activity accompanying stimulus onsets was observed for words as compared to pictures while stronger alpha suppression was observed in responses to pictures as compared to words. In general, the EEG oscillation patterns for encoding words of different levels of abstractness were comparable but differed significantly from encoding of pictures. These results provide insights into the effects of modality of presentation on human encoding of scientific concepts and thus might help in developing new ways to better teach scientific concepts in class.
Eye fixation-related fronto-parietal neural network correlates of memory retrieval
(2019-04-01)
Tsai, Pei-Yi
;
She, Hsiao-Ching
;
Chen, Sheng-Chang
;
Huang, Li-Yu
;
Chou, Wen-Chi
Eye movements are considered to be informative with regard to the underlying cognitive processes of human beings. Previous studies have reported that eye movements are associated with which scientific concepts are retrieved correctly. Moreover, other studies have also suggested that eye movements involve the cooperative activity of the human brain's fronto-parietal circuits. Less research has been conducted to investigate whether fronto-parietal EEG oscillations are associated with the retrieval processing of scientific concepts. Our findings in this study demonstrated that the fronto-parietal network is indeed crucial for successful memory retrieval. In short, significantly lower theta augmentation in the frontal midline and lower alpha suppression in the right parietal region were observed at the 5th eye fixation for physics concepts that were correctly retrieved than for those that were incorrectly retrieved. Moreover, the visual cortex in the occipital lobe exhibits a significantly greater theta augmentation followed by an alpha suppression following each eye fixation, while a right frontoparietal asymmetry was also found for the successful retrieval of presentations of physics concepts. In particular, the study results showed that eye fixation-related frontal midline theta power and right parietal alpha power at the 5th eye fixation have the greatest predictive power regarding the correctness of the retrieval of physics concepts.
Eye movements predict students' computer-based assessment performance of physics concepts in different presentation modalities
(2014-05-01)
Chen, Sheng-Chang
;
She, Hsiao-Ching
;
Chuang, Ming-Hua
;
Wu, Jiun-Yu
;
Tsai, Jie-Li
Despite decades of studies on the link between eye movements and human cognitive processes, the exact nature of the link between eye movements and computer-based assessment performance still remains unknown. To bridge this gap, the present study investigates whether human eye movement dynamics can predict computer-based assessment performance (accuracy of response) in different presentation modalities (picture vs. text). Eye-tracking system was employed to collect 63 college students' eye movement behaviors while they are engaging in the computer-based physics concept questions presented as either pictures or text. Students' responses were collected immediately after the picture or text presentations in order to determine the accuracy of responses. The results demonstrated that students' eye movement behavior can successfully predict their computer-based assessment performance. Remarkably, the mean fixation duration has the greatest power to predict the likelihood of responding the correct physics concepts successfully, followed by re-reading time in proportion. Additionally, the mean saccade distance has the least and negative power to predict the likelihood of responding the physics concepts correctly in the picture presentation. Interestingly, pictorial presentations appear to convey physics concepts more quickly and efficiently than do textual presentations. This study adds empirical evidence of a prediction model between eye movement behaviors and successful cognitive performance. Moreover, it provides insight into the modality effects on students' computer-based assessment performance through the use of eye movement behavior evidence. (C) 2014 Elsevier Ltd. All rights reserved.
Leveraging College Students' Scientific Evidence-Based Reasoning Performance with Eye-Tracking-Supported Metacognition
(2019-12-01)
Tsai, Pei-Yi
;
Yang, Ting-Ting
;
She, Hsiao-Ching
;
Chen, Sheng-Chang
;
教育研究所
This study specifically focuses on examining whether the eye-tracking-supported metacognition would benefit science majors' and nonscience majors' scientific evidence-based reasoning performance. Thirty-nine science majors and forty-one nonscience majors were recruited to participate in an online scientific evidence-based reasoning task. Data regarding the students' online learning process and eye movement behaviors were simultaneously collected. The results indicated that the science majors not only significantly outperformed the nonscience majors in terms of reasoning performance but also allocated significantly greater eye movements during their first time of processing scientific evidence-based reasoning task. Immediately after the task, the eye-tracking-supported metacognition provided each student with individualized feedback regarding their eye movement behaviors, such as their eye fixation sequence, durations, and locations. With such immediate feedback, the students were provided an opportunity to engage in self-monitoring, evaluating, and calibrating their approaches in order to revise their final answers. After the application of this eye-tracking-supported metacognition, both the science majors and the nonscience majors all made significant improvements in their scientific evidence-based reasoning performance. However, no statistically significant differences in the reasoning performance or visual attention of the science majors and nonscience majors were found. This study demonstrated that the use of eye-tracking-supported metacognition was not only able to maximize the performance of both the science majors and nonscience majors but that it also bridged the gap in performance between the two groups.
The effects of static versus dynamic 3D representations on 10th grade students' atomic orbital mental model construction: Evidence from eye movement behaviors
(2015-12-01)
Chen, Sheng-Chang
;
Hsiao, Mi-Shan
;
She, Hsiao-Ching
;
教育研究所
;
Institute of Education
This study examined the effectiveness of the different spatial abilities of high school students who constructed their understanding of the atomic orbital concepts and mental models after learning with multimedia learning materials presented in static and dynamic modes of 3D representation. A total of 60 high school students participated in this study and were randomly assigned into static and dynamic 3D representation groups. The dependent variables included a pre-test and post-test on atomic orbital concepts, an atomic orbital mental model construction test, and students\' eye-movement behaviors. Results showed that students who learned with dynamic 3D representation allocated a significantly greater amount of attention, exhibited better performance on the mental model test, and constructed more sophisticated 3D hybridizations of the orbital mental model than the students in the static 3D group. The logistic regression result indicated that the dynamic 3D representation group students\' number of saccades and number of re-readings were positive predictors, while the number of fixations was the negative predictor, for developing the students\' 3D mental models of an atomic orbital. High-spatial-ability students outperformed the low-spatial-ability students on the atomic orbital conceptual test and mental model construction, while both types of students allocated similar amounts of attention to the 3D representations. Our results demonstrated that low-spatial-ability students\' eye movement behaviors positively correlate with their performance on the atomic orbital concept test and the mental model construction. (C) 2015 Elsevier Ltd. All rights reserved.
Using Eye-tracking to investigate the different 3D representation on students\' mental model construction
(2015)
Chen, Sheng-Chang
;
She, Hsiao-Ching
;
Hsiao, Mi-Shan
;
教育研究所
;
Institute of Education
To alleviate these difficulties of students learning atomic orbital concepts, this study developed different 3D animations to foster students to generate better learning performance and their sophisticated mental models. The study also explored students\' eye movement behaviors. All 60 high school students received the pre- and post-test of atomic orbital concept test and mental model test before and immediately after learning from either static or dynamic 3D animations. The results indicated that the performances of students\' mental models are influenced by different 3D animations mode. With respect to eye movements, students who received dynamic 3D animations allocated greater number of fixation, number of saccade, and longer total inspection time as well as saccade distance than those who received static 3D animations. These findings have implications for how to develop welld-dsigned instruction to foster students\' learning performance and for the relationship between eye movement behaviors with learning performance.