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.
10305231
The Protein Information Resource: an integrated public resource of functional annotation of proteins
The Protein Information Resource (PIR) serves as an integrated public resource of functional annotation of protein data to support genomic/proteomic research and scientific discovery. The PIR, in collaboration with the Munich Information Center for Protein Sequences (MIPS) and the Japan International Protein Information Database (JIPID), produces the PIR-International Protein Sequence Database (PSD), the major annotated protein sequence database in the public domain, containing about 250 000 proteins. To improve protein annotation and the coverage of experimentally validated data, a bibliography submission system is developed for scientists to submit, categorize and retrieve literature information. Comprehensive protein information is available from iProClass, which includes family classification at the superfamily, domain and motif levels, structural and functional features of proteins, as well as cross-references to over 40 biological databases. To provide timely and comprehensive protein data with source attribution, we have introduced a non-redundant reference protein database, PIR-NREF. The database consists of about 800 000 proteins collected from PIR-PSD, SWISS-PROT, TrEMBL, GenPept, RefSeq and PDB, with composite protein names and literature data. To promote database interoperability, we provide XML data distribution and open database schema, and adopt common ontologies. The PIR web site (http://pir.georgetown.edu/) features data mining and sequence analysis tools for information retrieval and functional identification of proteins based on both sequence and annotation information. The PIR databases and other files are also available by FTP (ftp://nbrfa.georgetown.edu/pir_databases).
15660415
On-the-fly sharing for streamed aggregation
Data streaming systems are becoming essential for monitoring applications such as financial analysis and network intrusion detection. These systems often have to process many similar but different queries over common data. Since executing each query separately can lead to significant scalability and performance problems, it is vital to share resources by exploiting similarities in the queries. In this paper we present ways to efficiently share streaming aggregate queries with differing periodic windows and arbitrary selection predicates. A major contribution is our sharing technique that does not require any up-front multiple query optimization. This is a significant departure from existing techniques that rely on complex static analyses of fixed query workloads. Our approach is particularly vital in streaming systems where queries can join and leave the system at any point. We present a detailed performance study that evaluates our strategies with an implementation and real data. In these experiments, our approach gives us as much as an order of magnitude performance improvement over the state of the art.
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.
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. >
6331913
Speech content integrity verification integrated with ITU G.723.1 speech coding
A speech content integrity verification scheme integrated with ITU G.723.1 speech coding to minimize the total computational cost is proposed in this research. Speech features relevant to the semantic meaning are extracted, encrypted and attached as the header information. This scheme is not only much faster than cryptographic bitstream integrity algorithms, but also more compatible with a variable of applications. The speech signal could go through recompression, amplification, transcoding, re-sampling, D/A and A/D conversion and minor white noise pollution without triggering the verification alarm.