16,235 research outputs found
sj-docx-1-pec-10.1177_03010066221135472 - Supplemental material for You are how you speak: The roles of vocal pitch and semantic cues in shaping social perceptions
No full textSupplemental material, sj-docx-1-pec-10.1177_03010066221135472 for You are how you speak: The roles of vocal pitch and semantic cues in shaping social perceptions by Hannah Xiaohan Wu, Yuanhua Li, Boby Ho-Hong Ching and Tiffany Ting Chen in Perception</p
Control and Filtering for Discrete Linear Repetitive Processes with H infty and ell 2--ell infty Performance
No full textRepetitive processes are characterized by a series of sweeps, termed passes, through a set of dynamics defined over a finite duration known as the pass length. On each pass an output, termed the pass profile, is produced which acts as a forcing function on, and hence contributes to, the dynamics of the next pass profile. This can lead to oscillations which increase in amplitude in the pass to pass direction and cannot be controlled by standard control laws. Here we give new results on the design of physically based control laws for the sub-class of so-called discrete linear repetitive processes which arise in applications areas such as iterative learning control. The main contribution is to show how control law design can be undertaken within the framework of a general robust filtering problem with guaranteed levels of performance. In particular, we develop algorithms for the design of an H? and dynamic output feedback controller and filter which guarantees that the resulting controlled (filtering error) process, respectively, is stable along the pass and has prescribed disturbance attenuation performance as measured by and – norms
Acoustic radiation due to scattering of T-S wave by the mean-flow distortion induced by steady local suction
No full textSubstantial sound waves can be generated by boundary-layer instability modes when the latter are scattered by a rapid mean-flow distortion. This is a rather generic mechanism and operates when an oncoming T-S wave is scattered by a steady local suction slot. This paper focuses on this problem by extending a recently developed Local Scattering Theory (Wu & Dong, J. Fluid Mech. submitted), where a so-called transmission coefficient, defined as the ratio of the T-S wave amplitude downstream of the scatter to that upstream, is introduced to characterize the effect of a local scatter on boundary-layer instability and transition. As in the earlier work, the mathematical formulation is based on triple-deck formulism, but in order to accommodate the acoustic far field, which was not considered in the paper mentioned, the unsteady terms in the upper deck, which play a leading-order role in radiation, are retained, and the influence of the radiated sound on the near-wall perturbation is included. The upper deck equation for the pressure is the Helmholtz equation rather than the Laplace equation. This leads to a modified pressure-displacement relation, which is coupled with the linearized boundary-layer equations in the lower deck. Discretization of the whole system formulates a generalized eigenvalue problem, which is solved numerically. It is found that suction suppresses oncoming T-S waves, and this effect increases with the suction velocity and the slot width. The directivity is ndependent of the flow parameters only when the Mach number is low. The intensity of the radiated sound in general increases with the frequency, the suction velocity and the width of the suction slot. Interestingly, for O(1) suction velocities, the radiated sound is very weak, indicating that the gain of stabilizing effect does not cause aeroacoustic penalty
Being present: Witnessing landmark historical events boosts meaning in life
No full textAlthough not everyone shapes history, everyone is present as it unfolds. Recognizing oneself as a witness to history may become especially important in an era marked by frequent landmark events. In this research, we locate individuals in the ongoing process of history and examine its existential benefits. Specifically, we hypothesize that witnessing history (i.e., the subjective sense of witnessing or being present as history unfolds) enhances meaning in life, both in terms of the presence of meaning and the search for meaning. Through five investigations, using a multi-method approach that includes large-scale field data from Weibo (2,317,527 posts) alongside experimental and field studies (N = 1,945), we found that witnessing history contributes to or increases presence of and search for meaning. Further, connectedness to history mediates the effect of witnessing history on the presence of meaning, and a broadened perspective mediates its effect on the search for meaning. Our research provides a novel insight into how situating individuals within the ongoing progress of history can benefit their meaningful existence, and highlights the importance of cultivating a historical awareness and preserving historical heritage
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Tim Wu & “The Curse of Bigness”
No full textHost Nicholas Lemann sits down with Tim Wu, author of The Curse of Bigness, to discuss the politics of Louis Brandeis and Theodore Roosevelt as antitrust has reemerged this year as a major issue in the run-up to the 2020 U.S. Presidential Election.
Imprints of temperature fluctuations on the z ∼ 5 Lyman-α forest: a view from radiation-hydrodynamic simulations of reionization
No full textReionization leads to large spatial fluctuations in the intergalactic temperature that can persist well after its completion. We study the imprints of such fluctuations on the z similar to 5 Ly alpha forest flux power spectrum using a set of radiation-hydrodynamic simulations that model different reionization scenarios. We find that large-scale coherent temperature fluctuations bring similar to 20-60 per cent extra power at k similar to 0.002 s km(-1), with the largest enhancements in the models where reionization is extended or ends the latest. On smaller scales (k greater than or similar to 0.1 s km(-1)), we find that temperature fluctuations suppress power by less than or similar to 10 per cent. We find that the shape of the power spectrum is mostly sensitive to the reionization mid-point rather than temperature fluctuations from reionization's patchiness. However, for all of our models with reionization mid-points of z <= 8 (z <= 12), the shape differences are <= 20 per cent (<= 40 per cent) because of a surprisingly well-matched cancellation between thermal broadening and pressure smoothing that occurs for realistic thermal histories. We also consider fluctuations in the ultraviolet background, finding their impact on the power spectrum to be much smaller than temperature fluctuations at k >= 0.01 s km(-1). Furthermore, we compare our models to power spectrum measurements, finding that none of our models with reionization mid-points of z < 8 is strongly preferred over another and that all of our models with mid-points of z >= 8 are excluded at 2.5 sigma. Future measurements may be able to distinguish between viable reionization models if they can be performed at lower k or, alternatively, if the error bars on the high-k power can be reduced by a factor of 1.5
Evaluate the Validity of Two Popular Food Oxidation Markers (Hexanal & Limonene Oxide) in the Dry State
No full textUniversity of Minnesota M.S. thesis. January 2024. Major: Food Science. Advisor: Gary Reineccius. 1 computer file (PDF); viii, 64 pages.In research, it is common to use chemical indicators of oxidation to determine the oxidative state of a food. For example, hexanal formation/content is used to determine if lipids are oxidizing and limonene oxide (LO) serves a similar purpose in monitoring the oxidation of citrus oils. Recent research has shown that hexanal readily reacts with proteins and unpublished work suggests that limonene oxide also may react with proteins. Thus, these traditional indicators of oxidation may be inaccurate for foods that have higher protein levels or very reactive protein. β-Lactoglobulin (BLG) is a major whey protein in bovine milk and is also a prominent protein utilized in the food industry. Additionally, the structure and amino acid sequence of BLG is well characterized, and its molecular weight is appropriate for intact protein analysis. Therefore, BLG was selected as the model protein for this work. This research studied the covalent reactions between BLG and the two popular oxidation markers (hexanal and LO) in the dry state by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and to determine the influence of temperature, pH, and water activity on the reactions. Results show that limonene oxide could form covalent bonds with the BLG. Moreover, the reaction rate increases with the increase of storage time, which could make limonene oxide inaccurate as an oxidation marker in food containing high levels of proteins. For hexanal, the increase of the protein adduct is not very significant during storage. Therefore, hexanal still can be considered as a usable oxidation marker for dry foods.This research can help the food industry understand the validity of the two popular oxidation markers, choose better methods for food oxidation analysis, and improve their quality control system.Wu, Xiaohan. (2024). Evaluate the Validity of Two Popular Food Oxidation Markers (Hexanal & Limonene Oxide) in the Dry State. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/264276
Simulating the effect of photoheating feedback during reionization
No full textWe present self-consistent radiation hydrodynamic simulations of hydrogen reionization performed with AREPO-RT complemented by a state-of-the-art galaxy formation model. We examine how photoheating feedback, due to reionization, shapes the galaxies properties. Our fiducial model completes reionization by z≈6 and matches observations of the Lyαforest, the cosmic microwave background electron scattering optical depth, the high-redshift ultraviolet(UV) luminosity function, and stellar mass function. Contrary to previous works, photoheating suppresses star formation rates by more than 50 per cent only in haloes less massive than∼10^8.4 M_Sun (∼10^8.8 M_Sun) at z=6 (z=5), suggesting inefficient photoheating feedback from photons within galaxies. The use of a uniform UV background that heats up the gas at z≈10.7 generates an earlier onset of suppression of star formation compared to our fiducial model.This discrepancy can be mitigated by adopting a UV background model with a more realistic reionization history. In the absence of stellar feedback, photoheating alone is only able to quench haloes less massive than ∼ 10^9 M_Sun at z>~5, implying that photoheating feedback is sub-dominant in regulating star formation. In addition, stellar feedback, implemented as a non-local galactic wind scheme in the simulations, weakens the strength of photoheating feedback by reducing the amount of stellar sources. Most importantly, photoheating does not leave observable imprints in the UV luminosity function, stellar mass function, or the cosmic star formation rate density. The feasibility of using these observables to detect imprints of reionization therefore requires further investigation
Measurement of dwell times of spin polarized rubidium atoms on octadecyltrichlorosilane- and paraffin-coated surfaces
No full textWe report the measurement of dwell times of spin polarized Rb atoms on octadecyltrichlorosilane OTS- and paraffin-coated surfaces. We find that at a cell temperature of 72 °C the dwell times for OTS- and paraffin-coated surfaces are 0.9+-0.1 microsecond and 1.8 +-0.2 microsecond , respectively. Since the relaxation probability on paraffin is almost one order of magnitude smaller than that on OTS, the longer dwell time for paraffin indicates that the average strength of the interactions experienced by Rb atoms while they are inside paraffin is much weaker than while they are inside OTS.Peer reviewe
Éléments de continuité entre les écrits mathématiques des dynasties des Song-Yuan (XIIIe-XIVe siècles) et de la dynastie des Ming (XVe siècle) : Comparaison des Méthodes mathématiques (1261) de Yang Hui et du Grand Compendium (1450) de Wu Jing
No full textLe discours qui insiste sur une « rupture » entre les mathématiques de la période Song-Yuan et celles de la période Ming est très répandu dans les écrits historiques consacrés aux mathématiques en Chine. Cette thèse analyse le processus et les raisons de l’apparition de ce genre de discours, et montre que la représentation en forme de « rupture » ne se présente que lorsque les observateurs examinent les mathématiques depuis certaines perspectives. Cette thèse est consacrée à la recherche d'éléments de continuité entre les mathématiques des Ming et celles des Song et des Yuan. Les Neuf chapitres sur les procédures mathématiques (ci-après, Les Neuf chapitres) ont représenté un ouvrage très important au cours de l’ensemble de ces périodes. L'achèvement des Neuf chapitres, tel que transmis par la tradition écrite, date de quelque part entre le premier siècle avant notre ère et le premier siècle après notre ère. Les Méthodes mathématiques (1261) de Yang Hui et le Grand Compendium (1450) de Wu Jing sont de précieux écrits mathématiques rédigés au cours des deux périodes examinées. Ils sont basés sur Les Neuf chapitres et leurs commentaires antérieurs. Pour ce qui concerne la question de la continuité entre textes mathématiques, ma thèse propose des études de cas comparant ces deux livres, qui montrent que Wu Jing a systématiquement repris des parties du texte des Méthodes mathématiques pour compiler le Grand Compendium. La manière selon laquelle Wu Jing a extrait des passages dans chaque chapitre de Yang Hui pourrait être utilisée pour récupérer en partie le texte de Yang Hui. En ce qui concerne la continuité des idées mathématiques, tout d’abord, l’organisation et l’ordre des problèmes du texte ancien tel que revus par Yang Hui sont des résultats essentiels du traitement des Neuf chapitres par l’érudit des Song. Wu Jing les a repris lorsqu'il a organisé les problèmes du Grand Compendium. Par ailleurs, Yang Hui a beaucoup insisté sur les « méthodes mathématiques ». Il en a ajouté de nouvelles et en a modifié d’autres qui provenaient des Neuf chapitres. Wu Jing a compris ces modifications et les a adoptées dans son Grand Compendium. En même temps, certains concepts et termes mathématiques, ainsi que l’utilisation de diagrammes, relatifs aux méthodes mathématiques qu’avait introduits l’érudit des Song, ont également été intégrés dans le Grand Compendium. Toutes ces découvertes montrent que Les Neuf chapitres qui ont circulé sous la dynastie des Ming avaient largement intégrés les réflexions et le travail de l’érudit des Song.The discourse of “break” between the mathematics of the Song-Yuan period and that of the Ming period is quite widespread in the historical writings dealing with mathematics in China. This thesis analyzes the process and the reasons of the shaping of this kind of discourse and suggests that discourses that insisted on a “break” only appeared when observers looked at mathematics from certain viewpoints. This thesis is devoted to finding elements of continuity between the mathematics of the Ming dynasty and that of the Song-Yuan time period. The Nine Chapters on Mathematical Procedures (thereafter, The Nine Chapters) represented a very important book during these two periods. The completion date of The Nine Chapters in the form that was handed down is placed somewhere between the first century B.C.E. and the first century C.E. Yang Hui’s Mathematical Methods (1261 C.E.) and Wu Jing’s Great Compendium (1450 C.E.) are extant and precious mathematical writings from the two periods considered, which were based precisely on The Nine Chapters and its ancient commentaries. With respect to the continuity of mathematical text between these two books, my dissertation offers case studies that show that Wu Jing systematically took parts of the text of Mathematical Methods to compile Great Compendium. The rule by which text was extracted from each chapter could be used to partly recover Yang Hui’s text. With respect to the continuity of mathematical ideas, firstly, the arrangement and the order of problems are essential results of the Song scholar’s treatment of The Nine Chapters. They were taken up by Wu Jing when he arranged problems in Great Compendium. Secondly, Yang Hui laid a great emphasis on “mathematical methods”. He added some new mathematical methods and also changed some methods in The Nine Chapters. Wu Jing understood these changes and adopted them in his Great Compendium. Meanwhile, some mathematical concepts and terms, and the use of diagrams, relating to these mathematical methods that the Song scholar introduced, were also absorbed into Great Compendium. All these findings prove that The Nine Chapters that circulated in the Ming dynasty had been largely permeated by the thoughts of the Song scholar
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