William S.-Y. Wang

Paternal population history of East Asia : Sources, patterns, and microevolutionary processes

Asia has served as a focal point for human migration during much of the Late Pleistocene and Holocene. Clarification of East Asias role as a source and/or transit point for human dispersals requires that this regions own settlement history be understood. To this end, we examined variation at 52 polymorphic sites on the nonrecombining portion of the Y chromosome (NRY) in 1,383 unrelated males, representing 25 populations from southern East Asia (SEAS), northern East Asia (NEAS), and central Asia (CAS). The polymorphisms defined 45 global haplogroups, 28 of which were present in these three regions. Although heterozygosity levels were similar in all three regions, the average pairwise difference among haplogroups was noticeably smaller in SEAS. Multidimensional scaling analysis indicated a general separation of SEAS versus NEAS and CAS populations, and analysis of molecular variance produced very different values of Phi(ST) in NEAS and SEAS populations. In spatial autocorrelation analyses, the overall correlogram exhibited a clinal pattern; however, the NEAS populations showed evidence of both isolation by distance and ancient clines, whereas there was no evidence of structure in SEAS populations. Nested cladistic analysis demonstrated that population history events and ongoing demographic processes both contributed to the contrasting patterns of NRY variation in NEAS and SEAS. We conclude that the peopling of East Asia was more complex than earlier models had proposed-that is, a multilayered, multidirectional, and multidisciplinary framework is necessary. For instance, in addition to the previously recognized genetic and dental dispersal signals from SEAS to NEAS populations, CAS has made a significant contribution to the contemporary gene pool of NEAS, and the Sino-Tibetan expansion has left traces of a genetic trail from northern to southern China.

Chemical looping processes for CO2 capture and carbonaceous fuel conversion – prospect and opportunity

Chemical looping processes offer a compelling way for effective and viable carbonaceous fuel conversion into clean energy carriers. The uniqueness of chemical looping processes includes their capability of low cost in situ carbon capture, high efficiency energy conversion scheme, and advanced compatibility with state-of-the-art technologies. Based on the different functions of looping particles, two types of chemical looping technologies and associated processes have been developed. Type I chemical looping systems utilize oxygen carrier particles to perform the reduction–oxidation cycles, while Type II chemical looping systems utilize CO2 carrier particles to conduct carbonation–calcination cycles. The exergy analysis indicates that the chemical looping strategy has the potential to improve fossil fuel conversion schemes. Chemical looping particle performance and looping reactor engineering are the key drivers to the success of chemical looping process development. In this work, the desired particle characterization and recent progress in mechanism studies are generalized, which is followed by a discussion on the looping reactor design. This perspective also illustrates various chemical looping processes for combustion and gasification applications. It shows that both Type I and Type II looping processes have great potentials for flexible and efficient production of electricity, hydrogen and liquid fuels.

Phonological Features of Tone

1 Versions of this paper have been presented to the linguistic groups at Berkeley, UCLA, and Honolulu. Work discussed in this paper is supported in part by the Office of Naval Research. I am indebted to W. L. Ballard for his assistance in collecting and systematizing the basic data on tone systems upon which the present discussion is based, and for several profitable discussions on matters of interpretation.

When words collide: Orthographic and phonological interference during word processing☆

The interaction between orthographic and phonological information was studied in two experiments by requiring subjects to match visually presented word pairs on the basis of their visual or rhyming similarity. Word pairs either rhymed and looked alike, rhymed but did not look alike, looked alike but did not rhyme, or did not rhyme and did not look alike. In Experiment 1 under rhyme matching, reaction time (RT) was markedly increased whenever there was a conflict between orthographic and phonological cues. Under visual matching, overall RT was shorter than rhyme matching, with visually similar rhyming and non-rhyming pairs producing equally rapid and short responses compared to the non-rhyming but visually different word pairs. Most subjects also responded slower to rhyming and visually different stimuli compared to word pairs that did no look alike or rhyme. Experiment 2 sought to specify the processing locus of these effects by recording event-related brain potentials (ERPs) under task conditions similar to the first experiment. The RT data essentially replicated the effects found in Experiment 1 for both matching tasks. The ERP data viewed in the context of these results suggested that the interaction of the orthographic and phonological codes begins at least at the stimulus comparison processing stage, but that the conflict may also contribute to delays in response selection. The results are discussed in terms of several current models of word processing.

Cerebral lateralization of function and bilingual decision processes: Is thinking lateralized? ☆

Abstract Four experiments utilizing tachistoscopic presentation of verbal and spatial stimuli to visual half-fields are presented. Three experiments failed to find any cerebral lateralization effect of the type predicted from existing models of cerebral lateralization processes. One experiment found marked lateralization effects. Since the experiments differ only in the ratio of trials to experimental stimuli, it is argued that cerebral lateralization experiments are detecting only a memory process occurring after subjects have learned all the stimuli to be presented. When new stimuli are presented on each trial, no cerebral lateralization effects are found, suggesting that active ongoing cognitive processing is independent of lateralization.

Self‐organization and selection in the emergence of vocabulary

Human language may have started from a consistent set of mappings between meanings and signals. These mappings, referred to as the early vocabulary, are considered to be the results of conventions established among the agents of a population. In this study, we report simulation models for investigating how such conventions can be reached. We propose that convention is essentially the product of self-organization of the population through interactions among the agents and that cultural selection is another mechanism that speeds up the establishment of convention. Whereas earlier studies emphasize either one or the other of these two mechanisms, our focus is to integrate them into one hybrid model. The combination of these two complementary mechanisms, i.e., self-organization and cultural selection, provides a plausible explanation for cultural evolution, which progresses with high transmission rate. Furthermore, we observe that as the vocabulary tends to convergence there is a uniform tendency to exhibit a sharp phase transition.

TWO ASPECT MARKERS IN MANDARIN.

Introduction.l In this study I present the solution to a well-known problem of aspect markers in Mandarin. The problem involves several seeming irregularities in the formation of negative sentences and of the so-called A-not-A questions. Essentially, my solution of the problem consists of the identification of the morph -you (as in meiyou) and the aspect marker -le as suppletive alternants of the same morpheme. In the light of this identification, it will be seen that the relations among declarative, negative, and A-not-A sentences are both simple and regular. According to the theory of grammar2 which underlies the present study, the structural description (hereafter abbreviated SD) of a sentence is represented by a series of diagrams each of which is called a P-marker. Briefly, a P-marker consists of a tree graph3 whose nodes are labeled by a hierarchy of grammatical constituents; the top node is labeled S, i.e. sentence. A P-marker, then, is one of a series of statements about the relations among the postulated constituents of a sentence.

The influence of language experience on categorical perception of pitch contours

Previous research on categorical perception of pitch contours has mainly considered the contrast between tone language and non-tone language listeners. This study investigates not only the influence of tone language vs. non-tone language experience (German vs. Chinese), but also the influence of different tone inventories (Mandarin tones vs. Cantonese tones), on the categorical perception of pitch contours. The results show that the positions of the identification boundaries do not differ significantly across the 3 groups of listeners, i.e., Mandarin, Cantonese, and German, but that the boundary widths do differ significantly between tone language (Mandarin and Cantonese) listeners and non-tone language (German) listeners, with broader boundary widths for non-tone language listeners. In the discrimination tasks, the German listeners exhibit only psychophysical boundaries, whereas Chinese listeners exhibit linguistic boundaries, and these linguistic boundaries are further shaped by the different tone inventories.

Segmentation Techniques in Speech Synthesis

A basic method of speech synthesis is discussed in which segments of recorded utterances are joined together to produce continuous speech. The segments are characterized as (A) containing parts of two phones with their mutual influence in the middle of the segment, and (B) beginning and ending at the phonetically most stable position of each phone. All segments containing the same articulatory sequence have been defined as a dyad. The method of synthesis described involves not only the articulatory phones, but also the intonation, stress, and durational aspects of speech. Various techniques of obtaining the segments for speech synthesis are discussed. The method is limited to a specific dialect, and practically it is limited to a single speaker. A large number of segments is required to synthesize any arbitrarily selected utterance within these restrictions of dialect and speaker.

Tone recognition of continuous Cantonese speech based on support vector machines

Abstract Tone is an essential component for word formation in all tone languages. It plays a very important role in the transmission of information in speech communication. In this paper, we look at using support vector machines (SVMs) for automatic tone recognition in continuously spoken Cantonese, which is well known for its complex tone system. An adaptive log-scale 5-level F 0 normalization method is proposed to reduce the tone-irrelevant variation of F 0 values. Furthermore, an extended version of the above normalization method that considers intonation is also presented. A tone recognition accuracy of 71.50% has been obtained in a speaker-independent task. This result compares favorably with the results reported earlier for the same task. Considerable improvement has been achieved by adopting this tone recognition scheme in a speaker-independent Cantonese large vocabulary continuous speech recognition (LVCSR) task.