Regular Monomorphisms of Hausdorff Frames

Regular monomorphisms in the category of Hausdorff frames are characterized by means of a naturally defined closure operator; this is used also to characterize the epimorphisms. Further it is shown that for spatial (strongly) Hausdorff frames the regular monomorphisms do not generally coincide with the quotients, and do not generally compose. Also, an additional property (under which regular monomorphisms do compose) is briefly studied.     

Investigation of vocal fold impact stress in human subjects

The primary purpose of the study was to explore a methodology for measuring vocal fold impact stress (SI) in awake humans, and to provide information about the general magnitude of SIs that may occur at the midpoint of the membranous vocal folds during phonation. A secondary purpose was to examine the potential use of the electroglottographic closed quotient (EGG CQ) to indirectly reflect SI. Seven male and 13 female adults were enrolled as subjects, of whom 18 had normal larynges and normal voices, 1 had nodules, and 1 had vocal fold paresis and bowing. Subjects attempted to produce 3 different voice types (pressed, normal, breathy), at 3 different pitches (low, medium, high) and 3 different loudness levels (quiet, medium, loud). For a first set of trials, only EGG data were collected. For a second set, a sensor was also introduced to the midmembranous glottis for the collection of SI data. The primary findings were that (1) endolaryngeal sensor placement was achieved during phonation trials for 17 of 20 subjects; however, grossly consistent anteroposterior positioning was accomplished, and analyzable data were obtained, for only 7 subjects; (2) SIs ranged from less than 1 kPa to about 3 kPa for those 7 subjects; and (3) no relation was detected between simultaneous CQs and SIs for individual data, although a relation was reported in a prior canine study. One possible reason for the failure to show such a relation in the present study was subtle variations in vertical as well as anteroposterior positioning of the sensor during the trials. Future studies should focus on developing a methodology for ensuring invariant 3-dimensional sensor positioning between the membranous folds, so that the stability of both SI and simultaneous CQ data can be improved.     

Free vibration of membrane/bounded incompressible fluid

Vibration of a circular membrane in contact with a fluid has extensive applications in industry.The natural vibration frequencies for the asymmetric free vibration of a circular membrane in contact with a bounded incompressible fluid are derived in this paper.Considering small oscillations induced by the membrane vibration in an incompressible and inviscid fluid,the velocity potential function is used to describe the fluid field.Two approaches are used to derive the free vibration frequencies of the system,which include a variational formulation and an approximate solution employing the Rayleigh quotient method.A good correlation is found between free vibration frequencies evaluated by these methods.Finally,the effects of the fluid depth,the mass density,and the radial tension on the free vibration frequencies of the coupled system are investigated.     

等价关系和距离的提升与超拓扑,商拓扑,拓扑熵间的关系

给出由等价关系的提升确定的商拓扑与超拓扑,距离拓扑之间的相等或同胚的新结果,建立了映射与其提升在拓扑熵方面的联系,关于连续映射的提升本文减弱了文「６」中相应定理的条件。     

幂环

提出幂环概念,使环的提升更趋合理,建立了幂环的结构定理,并得到了某种条件下幂环同商环的关系。     

Quasilinear elliptic problems with multivalued terms

We study the quasilinear elliptic problem with multivalued terms.We consider the Dirichlet problem with a multivalued term appearing in the equation and a problem of Neumann type with a multivalued term appearing in the boundary condition. Our approach is based on Szulkin's critical point theory for lower semicontinuous energy functionals.     

Vocal Intensity Characteristics inNormal and Elderly Speakers

The relationship of lung pressure, fundamental frequency, peak airflow, open quotient, and maximal flow declination rate to vocal intensity for a normal speaking, young male control group and an elderly male group was investigated. The control group consisted of 17 healthy male subjects with a mean age of 30 years and the elderly group consisted of 11 healthy male subjects with a mean age of 77 years. Data were collected at three levels of vocal intensity: soft, comfortable, and loud, corresponding to 25%, 50%, and 75% of dynamic range, respectively. Phonational threshold pressure and lung pressure were obtained using the intraoral technique. The oral airflow waveform was inverse filtered to provide an approximation to the glottal airflow waveform from which measures of fundamental frequency, peak airflow, open quotient, and maximal flow declination rate were determined. Excess lung pressure was calculated as lung pressure minus estimated phonational threshold pressure. The results show for both groups an increase in sound pressure level across the conditions, with corresponding increases in lung pressure, excess lung pressure, fundamental frequency, peak airflow, and maximal flow declination rate. Open quotient decreased with increasing vocal intensity. Lung pressure, sound pressure level, and peak airflow were all found to be significantly greater for the control group than for the elderly group at each condition. Open quotient was found to be significantly lower in the control group than in the elderly group at each condition. No significant difference was observed for excess lung pressure, phonational threshold pressure, fundamental frequency, or maximal flow declination rate between the two groups. These results show that a difference in vocal intensity does exist between young and elderly voices and that this difference is the result of differences in lung pressure, peak airflow, and open quotient.     

Estimating perceived phonatory pressedness in singing from flow glottograms

The normalized amplitude quotient (NAQ), defined as the ratio between the peak-to-peak amplitude of the flow pulse and the negative peak amplitude of the differentiated flow glottogram and normalized with respect to period time, has been shown to be related to glottal adduction. Glottal adduction, in turn, affects mode of phonation and hence perceived phonatory pressedness. The relationship between NAQ and perceived phonatory pressedness was analyzed in a material collected from a professional female singer and singing teacher who sang a triad pattern in breathy, flow, neutral, and pressed phonation in three different loudness conditions (soft, middle, loud). In addition, she also sang the same triad pattern in four different styles of singing, classical, pop, jazz, and blues, in the same three loudness conditions. A panel of experts rated the degree of perceived phonatory press along visual analogue scales. Comparing the obtained mean rated pressedness ratings with the mean NAQ values for the various triads showed that about 73% of the variation in perceived pressedness could be accounted for by variations of NAQ.     

Moment Maps and Equivariant Volumes

The study of the volume of big line bundles on a complex projective manifold M has been one of the main veins in the recent interest in the asymptotic properties of linear series. In this article, we consider an equivariant version of this problem, in the presence of a linear action of a reductive group on M.     

关于BCK-代数中对偶理想的一个定理

证明文[3]中的若干定理的交换性要求可以去掉.主要结论是:若X是有界BCK代数,D是X的对偶理想,一定存在从DI(X,D)到DI(XD)的一一对应