A Bijection between Atomic Partitions and Unsplitable Partitions

In the study of the algebra $\mathrm{NCSym}$ of symmetric functions in noncommutative variables, Bergeron and Zabrocki found a free generating set consisting of power sum symmetric functions indexed by atomic partitions. On the other hand, Bergeron, Reutenauer, Rosas, and Zabrocki studied another free generating set of $\mathrm{NCSym}$ consisting of monomial symmetric functions indexed by unsplitable partitions. Can and Sagan raised the question of finding a bijection between atomic partitions and unsplitable partitions. In this paper, we provide such a bijection.Comment: 6 page

Distinct roles of delta- and theta-band neural tracking for sharpening and predictive coding of multi-level speech features during spoken language processing

The brain tracks and encodes multi‐level speech features during spoken language processing. It is evident that this speech tracking is dominant at low frequencies (<8 Hz) including delta and theta bands. Recent research has demonstrated distinctions between delta‐ and theta‐band tracking but has not elucidated how they differentially encode speech across linguistic levels. Here, we hypothesised that delta‐band tracking encodes prediction errors (enhanced processing of unexpected features) while theta‐band tracking encodes neural sharpening (enhanced processing of expected features) when people perceive speech with different linguistic contents. EEG responses were recorded when normal‐hearing participants attended to continuous auditory stimuli that contained different phonological/morphological and semantic contents: (1) real‐words, (2) pseudo‐words and (3) time‐reversed speech. We employed multivariate temporal response functions to measure EEG reconstruction accuracies in response to acoustic (spectrogram), phonetic and phonemic features with the partialling procedure that singles out unique contributions of individual features. We found higher delta‐band accuracies for pseudo‐words than real‐words and time‐reversed speech, especially during encoding of phonetic features. Notably, individual time‐lag analyses showed that significantly higher accuracies for pseudo‐words than real‐words started at early processing stages for phonetic encoding (<100 ms post‐feature) and later stages for acoustic and phonemic encoding (>200 and 400 ms post‐feature, respectively). Theta‐band accuracies, on the other hand, were higher when stimuli had richer linguistic content (real‐words > pseudo‐words > time‐reversed speech). Such effects also started at early stages (<100 ms post‐feature) during encoding of all individual features or when all features were combined. We argue these results indicate that delta‐band tracking may play a role in predictive coding leading to greater tracking of pseudo‐words due to the presence of unexpected/unpredicted semantic information, while theta‐band tracking encodes sharpened signals caused by more expected phonological/morphological and semantic contents. Early presence of these effects reflects rapid computations of sharpening and prediction errors. Moreover, by measuring changes in EEG alpha power, we did not find evidence that the observed effects can be solitarily explained by attentional demands or listening efforts. Finally, we used directed information analyses to illustrate feedforward and feedback information transfers between prediction errors and sharpening across linguistic levels, showcasing how our results fit with the hierarchical Predictive Coding framework. Together, we suggest the distinct roles of delta and theta neural tracking for sharpening and predictive coding of multi‐level speech features during spoken language processing

Ambiguity and language evolution: Evolution of homophones and syllable number of words

We investigate the evolution of homophones and its relation to the evolution of syllable number of words, based on the quantitative analysis on the historical data and simulation. We suggest that homophones are the outcome of arranging form-meaning associations according to Zipf’s law to maximize the referential power under effort for the speaker constraints. We also discuss the neural bases of ambiguity and the relation between ambiguity and robustness in language evolution. Furthermore, we show that homophones are stable and cumulate with the times. To avoid creating homophones, syllable number of words increases, with more recent entry dates of words associated with more syllables. We also explore stability of homophones and instability of synonyms in children’s acquisition process. The mechanism of the evolution of homophones and syllable length of words works cross-linguistically from the emergence of language and goes on at present

Controller design with regional pole constraints - Hyperbolic and horizontal strip regions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76652/1/AIAA-1992-4401-149.pd

Robust Strong Stabilization via Modified Popov Controller Synthesis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57860/1/StrongStabPopovTAC1994.pd

IT Governance For Systems Support And Maintenance – Views From CIOS In Multinational Enterprises

This paper explores IS governance as it relates to systems support and maintenance (SS&M). We argue, that can be critically supportive of business operations, decision making, innovation and knowledge management strategies. Based on interviews with high level IS practitioners from large IT companies, we find that the value of SS&M as a potential link between the IT side and the business side of the organization, while recognized is still under-utilized. We enumerate and discuss a number of reasons for this situation from an IT governance perspective and call for a comprehensive research agenda to develop an integrated approach to link SS&M more closely

H2-suboptimal stable stabilization,

In this paper we present two approaches for designing H2-suboptimal stable controllers. Both full-order and reduced-order controllers are considered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31240/1/0000146.pd

Oligorotaxane radicals under orders

A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components-namely oligoviologens-in which different numbers of 4,4'-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY(\u2022+) radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne-azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers