40 research outputs found

    A note on compactly generated co-t-structures

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    The idea of a co-t-structure is almost "dual" to that of a t-structure, but with some important differences. This note establishes co-t-structure analogues of Beligiannis and Reiten's corresponding results on compactly generated t-structures.Comment: 10 pages; details added to proofs, small correction in the main resul

    Differential graded motives: weight complex, weight filtrations and spectral sequences for realizations; Voevodsky vs. Hanamura

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    We describe the Voevodsky's category DMgmeffDM^{eff}_{gm} of motives in terms of Suslin complexes of smooth projective varieties. This shows that Voeovodsky's DMgmDM_{gm} is anti-equivalent to Hanamura's one. We give a description of any triangulated subcategory of DMgmeffDM^{eff}_{gm} (including the category of effective mixed Tate motives). We descibe 'truncation' functors tNt_N for N>0N>0. t=t0t=t_0 generalizes the weight complex of Soule and Gillet; its target is Kb(Choweff)K^b(Chow_{eff}); it calculates K0(DMgmeff)K_0(DM^{eff}_{gm}), and checks whether a motive is a mixed Tate one. tNt_N give a weight filtration and a 'motivic descent spectral sequence' for a large class of realizations, including the 'standard' ones and motivic cohomology. This gives a new filtration for the motivic cohomology of a motif. For 'standard realizations' for l,s0l,s\ge 0 we have a nice description of Wl+sHi/Wl1Hi(X)W_{l+s}H^i/W_{l-1}H^i(X) in terms of ts(X)t_s(X). We define the 'length of a motif' that (modulo standard conjectures) coincides with the 'total' length of the weight filtration of singular cohomology. Over a finite field t0Qt_0Q is (modulo Beilinson-Parshin conjecture) an equivalence.Comment: Several linguistic corrections made; section 2.3 was corrected als

    Automatic recognition of schwa variants in spontaneous Hungarian speech

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    This paper analyzes the nature of the process involved in optional vowel reduction in Hungarian, and the acoustic structure of schwa variants in spontaneous speech. The study focuses on the acoustic patterns of both the basic realizations of Hungarian vowels and their realizations as neutral vowels (schwas), as well as on the design, implementation, and evaluation of a set of algorithms for the recognition of both types of realizations from the speech waveform. The authors address the question whether schwas form a unified group of vowels or they show some dependence on the originally intended articulation of the vowel they stand for. The acoustic study uses a database consisting of over 4,000 utterances extracted from continuous speech, and recorded from 19 speakers. The authors propose methods for the recognition of neutral vowels depending on the various vowels they replace in spontaneous speech. Mel-Frequency Cepstral Coefficients are calculated and used for the training of Hidden Markov Models. The recognition system was trained on 2,500 utterances and then tested on 1,500 utterances. The results show that a neutral vowel can be detected in 72% of all occurrences. Stressed and unstressed syllables can be distinguished in 92% of all cases. Neutralized vowels do not form a unified group of phoneme realizations. The pronunciation of schwa heavily depends on the original articulation configuration of the intended vowel

    Affective stimulus properties influence size perception and the Ebbinghaus illusion

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    In the New Look literature of the 1950s, it has been suggested that size judgments are dependent on the affective content of stimuli. This suggestion, however, has been ‘discredited’ due to contradictory findings and methodological problems. In the present study, we revisited this forgotten issue in two experiments. The first experiment investigated the influence of affective content on size perception by examining judgments of the size of target circles with and without affectively loaded (i.e., positive, neutral, and negative) pictures. Circles with a picture were estimated to be smaller than circles without a picture, and circles with a negative picture were estimated to be larger than circles with a positive or a neutral picture confirming the suggestion from the 1950s that size perception is influenced by affective content, an effect notably confined to negatively loaded stimuli. In a second experiment, we examined whether affective content influenced the Ebbinghaus illusion. Participants judged the size of a target circle whereby target and flanker circles differed in affective loading. The results replicated the first experiment. Additionally, the Ebbinghaus illusion was shown to be weakest for a negatively loaded target with positively loaded and blank flankers. A plausible explanation for both sets of experimental findings is that negatively loaded stimuli are more attention demanding than positively loaded or neutral stimuli

    Comparative constructions of similarity in Northern Samoyedic languages

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    The purpose of this paper is to analyze the suffixes which are used in Northern Samoyedic languages to build comparative constructions of equality. Depending on the language, the suffixes may perform three functions: word-building, form-building, and inflectional. When they mark the noun, they serve as simulative suffixes and are employed to build object comparison. In the inflectional function, these suffixes mark the verb and are a means of constructing situational comparison. In this case, they signal the formation of a special mood termed the Approximative. This paper provides a detailed description of the Approximative from paradigmatic and syntagmatic perspectives
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