2900154
Learning simulation through team projects
For several years, team projects have been an integral part of the simulation course at the department of Industrial and Operations Engineering at the University of Michigan. We believe that team projects are an effective tool for learning how to perform simulation. In this paper, we present a brief summary of research on cooperative learning from the field of education research. Based on findings from that research, we present the procedure we follow in assigning, running, and evaluating team projects during an academic semester. We analyze students' responses to a survey on their preference and perceived value of the team project as conducted in this course. Two student papers, published in this conference, provide for examples of completed team projects.
490124
Modeling Psychological Refractory Period (PRP) and Practice Effect on PRP with Queuing Networks and Reinforcement Learning Algorithms
PRP (Psychological Refractory Period) is a basic but important form of human information processing in dual-task situations. This article describes a queuing network model of PRP that successfully modeled PRP without the need of setting up complex lock/unlock performance strategies employed in the EPIC model of PRP or drawing complex scheduling charts employed in the ACT-R/PM model of PRP. Further, by integrating queuing networks with reinforcement learning algorithms, the queuing network model successfully simulated practice effect on PRP, which has not been modeled in existing PRP models. The current research indicates that depending on an individual’s degree of practice, cognition can be either serial or parallel at the level of production or response selection. Extensions of queuing network model in modeling other tasks and its easiness in modeling concurrent tasks in practice are also discussed.
3236118
Human performance modeling in temporary segmentation Chinese character handwriting recognizers
Human performance in Chinese character handwriting recognizers is critical to the satisfaction and acceptance of their users. Based on Teal's [CHI'92 (1992) p. 295] interactive model, a static model describing the independent factors in determining the task completion time was set up with a simple mathematical inference; in addition, a dynamic model describing these factors' direct and indirect causal relationship was established by the path analytic method. Results in Experiment 1 indicated that both the static model and the dynamic model could fit observed task completion time satisfactorily with minor modifications. In addition, with users' average writing time around 1500 ms for each frequently used character, it was found that the user's performance was impaired significantly when segmentation time was longer than 1040 ms. An integrated model was devised after combining the static and dynamic models. Experiment 2 testified the integrated model in another handwriting recognizer and found that it could still fit human performance data with users in three different training conditions. Implications of the integrated model are that: (1) when recognition accuracy and number of inputting characters are constant, the weights of average writing time for each character, segmentation time, recognition time in determining task completion time are equal but bigger than the weight of the repairing time; (2) when the repairing time, average writing time for each character, segmentation time and recognition time are constant, there is an inverse model between task completion time and recognition accuracy; when recognition accuracy is from 50% to 93%, every 1% increase of recognition accuracy will reduce task completion time from 1989 to 1915 ms; when recognition accuracy increases from 94% to 100%, every 1% increase of recognition accuracy will reduce task completion time from 1895 to 1392 ms. Guidelines in designing these recognizers were given based on these implications.
41090415
Correlation immunity and resiliency of symmetric Boolean functions
Correlation immunity of symmetric Boolean functions is studied in this paper. Lower bounds on the number of constructible correlation immune symmetric functions are given. Constructions for such new balanced functions are presented. These functions are also known as 1-resilient functions. In 1985, Chor et al. conjectured that the only 1-resilient symmetric functions are the exclusive-or of all n variables and its negation. This conjecture, however, was disproved by Gopalakrishnan, Hoffman and Stinson in 1993 by giving a class of infinite counterexamples, and they noted that it does not seem to extend any further in an obvious way. In this paper two more infinite classes of such examples are presented for n being even and being odd, respectively, and consequently one of the two open problems proposed by Gopalakrishnan et al., is addressed by constructing new symmetric resilient functions.
27585937
Multi-modal Sign Icon Retrieval for Augmentative Communication
This paper addresses a multi-modal sign icon retrieval and prediction technology for generating sentences from ill-formed Taiwanese sign language (TSL) for people with speech or hearing impairments. The design and development of this PC-based TSL augmented and alternative communication (AAC) system aims to improve the input rate and accuracy of communication aids. This study focuses on 1) developing a effective TSL icon retrieval method, 2) investigating TSL prediction strategies for input rate enhancement, 3) using a predictive sentence template (PST) tree for sentence generation. The proposed system assists people with language disabilities in sentence formation. To evaluate the performance of our approach, a pilot study for clinical evaluation and education training was undertaken. The evaluation results show that the retrieval rate and subjective satistactory level for sentence generation was significantly improved.
15699236
Facial Phoneme Extraction for Taiwanese Sign Language Recognition
We have developed a system that recognizes the facial expressions in Taiwanese Sign Language (TSL) using a phoneme-based strategy. A facial expression is decomposed into three facial phonemes of eyebrow, eye, and mouth. A fast method is proposed for locating facial phonemes. The shapes of the phonemes were then matched by the deformable template method, giving feature points representing the corresponding phonemes. The trajectories of the feature points were tracked along the video image sequence and combined to recognize the type of facial expression. The tracking techniques and the feature points have been tailored for facial features in TSL. For example, the template matching methods have been simplified for tracking eyebrows and eyes. The mouth was tracked using the optical flow method, taking lips as homogeneous patches. The experiment has been conducted on 70 image sequences covering seven facial expressions. The average recognition rate is 83.3%.
31789422
Performance Analysis of Multistage Interconnection Network Configurations and Operations
A performance evaluation using both analytical and simulation models, of circuit-switching multistage interconnection networks in aspects of configurations and operations is presented. Two configurations of the networks, single and dual, are evaluated. Network operations considered include conflict resolution strategies and communication strategies. Two different conflict resolution strategies, drop and hold, are analyzed. New analyses using Markov chains, are given, and are verified by simulation results. In the single-network configuration, it is shown that the drop strategy is better than the hold strategy for randomly distributed traffic. In the dual network configuration, five different communication strategies are investigated, and the optimum performance level is shown to be dependent on the length of the data transfer time. >
15881866
Performance analysis of circuit switching, baseline interconnection networks
Performance evaluation, using both analytical and simulation models, of circuit switching baseline networks is presented. Two configurations of the baseline networks, single and dual, are evaluated. In each configuration, two different conflict resolution strategies, drop and hold, are tried to see the performance difference. Our analytical models are based on a more realistic assumption. New analyses are given and are verified by simulation results. In single network configuration, it is shown that the drop strategy is better than the hold strategy in the case that the data transfer time is longer than 10 cycles under a high request rate. In the dual network configuration, five different communication strategies are investigated and the optimum performance level is shown to be dependent on the length of the data transfer time.