76 research outputs found

    A universal context-free grammar

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    In this report we show that, for each alphabet Σ, there exists a context-free grammar G which satisfies the property that for each context-free language L ⊆ Σ* a regular control set C can be found such that LC(G) = L

    Space complexity in on-line computation

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    AbstractA technique is developed for determining space complexity in on-line computation. It is shown that each of the following functions requires linear space: (i) the conversion of binary numbers into ternary numbers, (ii) the multiplication of integers and (iii) the translation of arithmetic expressions in infix notation into Polish notation

    The Othello game on an n × n board is PSPACE-complete

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    AbstractGiven an arbitrary position of the Othello game played on an n × n board, the problem of determining the winner is shown to be PSPACE-complete. It can be reduced from generalized geography played on bipartite graphs with maximum degree 3

    Language development in Japanese children who receive cochlear implant and/or hearing aid

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    Objectives: This study aimed to investigate a wide variety of factors that influence auditory, speech, and language development following pediatric cochlear implantation (CI). Study design: Prospective collection of language tested data in profound hearing-impaired children. Hypothesis: Pediatric CI can potentially be effective to development of practical communication skills and early implantation is more effective. Methods: We proposed a set of language tests (assessment package of the language development for Japanese hearing-impaired children; ALADJIN) consisting of communication skills testing (test for question-answer interaction development; TQAID), comprehensive (Peabody Picture Vocabulary Test-Revised; PVT-R and Standardized Comprehension Test for Abstract Words; SCTAW) and productive vocabulary (Word Fluency Test; WFT), and comprehensive and productive syntax (Syntactic processing Test for Aphasia; STA). Of 638 hearing-impaired children recruited for this study, 282 (44.2%) with >70 dB hearing impairment had undergone CI. After excluding children with low birth weight (11 points on the Pervasive Developmental Disorder ASJ Rating Scale for the test of autistic tendency, and those <2 SD on Raven's Colored Progressive Matrices for the test of non-verbal intelligence, 190 children were subjected to this set of language tests. Results: Sixty children (31.6%) were unilateral CI-only users, 128 (67.4%) were CI-hearing aid (HA) users, and 2 (1.1%) were bilateral CI users. Hearing loss level of CI users was significantly (p < 0.01) worse than that of HA-only users. However, the threshold level, maximum speech discrimination score, and speech intelligibility rating in CI users were significantly (p < 0.01) better than those in HA-only users. The scores for PVT-R (p < 0.01), SCTAW, and WET in CI users were better than those in HA-only users. STA and TQAID scores in CI-HA users were significantly (p < 0.05) better than those in unilateral CI-only users. The high correlation (r = 0.52) has been found between the age of CI and maximum speech discrimination score. The scores of speech and language tests in the implanted children before 24 months of age have been better than those in the implanted children after 24 months of age. Conclusions: We could indicate that CI was effective for language development in Japanese hearing-impaired children and early CI was more effective for productive vocabulary and syntax.ArticleINTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGOLOGY. 76(3):433-438 (2012)journal articl

    Computational Approach to Dendritic Spine Taxonomy and Shape Transition Analysis

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    The common approach in morphological analysis of dendritic spines of mammalian neuronal cells is to categorize spines into subpopulations based on whether they are stubby, mushroom, thin, or filopodia shaped. The corresponding cellular models of synaptic plasticity, long-term potentiation, and long-term depression associate the synaptic strength with either spine enlargement or spine shrinkage. Although a variety of automatic spine segmentation and feature extraction methods were developed recently, no approaches allowing for an automatic and unbiased distinction between dendritic spine subpopulations and detailed computational models of spine behavior exist. We propose an automatic and statistically based method for the unsupervised construction of spine shape taxonomy based on arbitrary features. The taxonomy is then utilized in the newly introduced computational model of behavior, which relies on transitions between shapes. Models of different populations are compared using supplied bootstrap-based statistical tests. We compared two populations of spines at two time points. The first population was stimulated with long-term potentiation, and the other in the resting state was used as a control. The comparison of shape transition characteristics allowed us to identify the differences between population behaviors. Although some extreme changes were observed in the stimulated population, statistically significant differences were found only when whole models were compared. The source code of our software is freely available for non-commercial use1

    Methamphetamine-induced structural plasticity in the dorsal striatum

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    Repeated exposure to psychostimulant drugs produces long-lasting changes in dendritic structure, presumably reflecting a reorganization in patterns of synaptic connectivity, in brain regions that mediate the psychomotor activating and incentive motivational effects of these drugs, including the nucleus accumbens and prefrontal cortex. However, repeated exposure to psychostimulant drugs also facilitates a transition in the control of some behaviors from action–outcome associations to behavior controlled by stimulus–response (S–R) habits. This latter effect is thought to be due to increasing engagement and control over behavior by the dorsolateral (but not dorsomedial) striatum. We hypothesized therefore that repeated exposure to methamphetamine would differentially alter the density of dendritic spines on medium spiny neurons (MSNs) in the dorsolateral vs. dorsomedial striatum. Rats were treated with repeated injections of methamphetamine, and 3 months later dendrites were visualized using Sindbis virus-mediated green fluorescent protein (GFP) expression in vivo . We report that prior exposure to methamphetamine produced a significant increase in mushroom and thin spines on MSNs in the dorsolateral striatum, but a significant decrease in mushroom spines in the dorsomedial striatum. This may be due to changes in the glutamatergic innervation of these two subregions of the dorsal striatum. Thus, we speculate that exposure to psychostimulant drugs may facilitate the development of S–R habits because this reorganizes patterns of synaptic connectivity in the dorsal striatum in a way that increases control over behavior by the dorsolateral striatum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72347/1/j.1460-9568.2007.05316.x.pd

    Language development in Japanese children who receive cochlear implant and/or hearing aid

    Get PDF
    Objectives: This study aimed to investigate a wide variety of factors that influence auditory, speech, and language development following pediatric cochlear implantation (CI). Study design: Prospective collection of language tested data in profound hearing-impaired children. Hypothesis: Pediatric CI can potentially be effective to development of practical communication skills and early implantation is more effective. Methods: We proposed a set of language tests (assessment package of the language development for Japanese hearing-impaired children; ALADJIN) consisting of communication skills testing (test for question-answer interaction development; TQAID), comprehensive (Peabody Picture Vocabulary Test-Revised; PVT-R and Standardized Comprehension Test for Abstract Words; SCTAW) and productive vocabulary (Word Fluency Test; WFT), and comprehensive and productive syntax (Syntactic processing Test for Aphasia; STA). Of 638 hearing-impaired children recruited for this study, 282 (44.2%) with >70 dB hearing impairment had undergone CI. After excluding children with low birth weight (11 points on the Pervasive Developmental Disorder ASJ Rating Scale for the test of autistic tendency, and those <2 SD on Raven's Colored Progressive Matrices for the test of non-verbal intelligence, 190 children were subjected to this set of language tests. Results: Sixty children (31.6%) were unilateral CI-only users, 128 (67.4%) were CI-hearing aid (HA) users, and 2 (1.1%) were bilateral CI users. Hearing loss level of CI users was significantly (p < 0.01) worse than that of HA-only users. However, the threshold level, maximum speech discrimination score, and speech intelligibility rating in CI users were significantly (p < 0.01) better than those in HA-only users. The scores for PVT-R (p < 0.01), SCTAW, and WET in CI users were better than those in HA-only users. STA and TQAID scores in CI-HA users were significantly (p < 0.05) better than those in unilateral CI-only users. The high correlation (r = 0.52) has been found between the age of CI and maximum speech discrimination score. The scores of speech and language tests in the implanted children before 24 months of age have been better than those in the implanted children after 24 months of age. Conclusions: We could indicate that CI was effective for language development in Japanese hearing-impaired children and early CI was more effective for productive vocabulary and syntax.ArticleINTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGOLOGY. 76(3):433-438 (2012)journal articl

    タテープ チューリングキ ト ランダム アクセスキ ノ ケイサンリョウ ノ ヒカク

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    京都大学0048新制・論文博士理学博士乙第3265号論理博第563号新制||理||244(附属図書館)UT51-52-L82(主査)教授 高須 達, 教授 一松 信, 教授 伊藤 清学位規則第5条第2項該当Kyoto UniversityDFA
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