measurement of body segment parameters using dual energy x ray absorptiometry and three dimensional geometry an application in gait analysis abstract body segment parameters bsp are essential input for the computations in kinetics of motion applied in the field of biomechanics these data are usually obtained from population specific predictive equations which present limitations in being representative of the population under study more recently medical imaging techniques have been adopted but are limited to two dimensional 2 d measurements or required extensive tomographic images for three dimensional 3 d reconstruction we proposed an in vivo method to measure 3 d bsp using x ray imaging and 3 d exterior geometry criterion values of the bsp were determined using magnetic resonance imaging mri which has previously been validated errors for all bsp values were less than 2 when values derived from our method were compared to the criterion values we found no significant difference between our method and four selected bsp models in both stance and swing phase significant phase effects were observed for our method and other bsp models between stance and swing phase significant differences p

contravariantly finite subcategories closed under predecessors abstract let a be an artin algebra and moda be the category of finitely generated right a modules we prove that an additive full subcategory c of moda closed under predecessors is contravariantly finite if and only if its right ext orthogonal is covariantly finite or if and only if the ext injectives in c define a cotilting module over the support algebra of c or equivalently if and only if c is the support of the representable functors given by the ext injectives

measuring decision weights in recognition experiments with multiple response alternatives comparing the correlation and multinomial logistic regression methods psychophysical reverse correlation methods allow researchers to gain insight into the perceptual representations and decision weighting strategies of individual subjects in perceptual tasks although these methods have gained momentum until recently their development was limited to experiments involving only two response categories recently two approaches for estimating decision weights in m alternative experiments have been put forward one approach extends the two category correlation method to m 2 alternatives the second uses multinomial logistic regression mlr in this article the relative merits of the two methods are discussed and the issues of convergence and statistical efficiency of the methods are evaluated quantitatively using monte carlo simulations the results indicate that for a range of values of the number of trials the estimated weighting patterns are closer to their asymptotic values for the correlation method than for the mlr method moreover for the mlr method weight estimates for different stimulus components can exhibit strong correlations making the analysis and interpretation of measured weighting patterns less straightforward than for the correlation method these and other advantages of the correlation method which include computational simplicity and a close relationship to other well established psychophysical reverse correlation methods make it an attractive tool to uncover decision strategies in m alternative experiments

spectral weights for overall level discrimination in listeners with sensorineural hearing loss a conditional on a single stimulus coss analysis procedure b g berg j acoust soc am 86 1743 1746 1989 was used to measure the weight or relative reliance that normal hearing and hearing impaired listeners give to different frequencies in the discrimination of the overall level of a multitone complex on each trial two multitone tone complexes comprised of six octave frequencies from 250 to 8000 hz were presented to subjects the levels of the frequencies for each complex were randomly varied the listeners task was to identify the complex with the higher overall intensity level normal hearing listeners used a variety of listening strategies to perform the task showing no general preference to weight one component over another hearing impaired listeners however showed a general tendency to give greatest weight to the spectral information in the region of their hearing loss thirteen of the 14 hearing impaired listeners all of whom had a high frequency sensorineural hearing loss weighted one or more of the high frequency components in the complex the greatest

on the representation dimension of tilted and laura algebras abstract we prove that the representation dimension of a tilted or of a strict laura algebra is at most three

mri derived body segment parameters of children differ from age based estimates derived using photogrammetry abstract body segment parameters are required when researching joint kinetics using inverse dynamics models however the only regression equations for estimating pediatric body segment parameters across a wide age range were developed using photogrammetry based on 12 boys and have not been validated to date jensen r k 1986 body segment mass radius and radius of gyration proportions of children journal of biomechanics 19 359 368 to assess whether these equations could validly be applied to girls we asked whether body segment parameters estimated by the equations differ from parameters measured using a validated magnetic resonance imaging mri method if so do the differences cause significant differences in joint kinetics during normal gait body segment parameters were estimated from axial mris of the left thigh and shank of 10 healthy girls 9 6 0 9 years and compared to those from jensen s equations kinematics and kinetics were collected for 10 walking trials extrema in hip and knee moments and powers were compared between the two sets of body segment parameters with the exception of the shank mass center and radius of gyration body segment parameters measured using mri were significantly different from those estimated using regression equations these systematic differences in body segment parameters resulted in significant differences in sagittal plane joint moments and powers during gait nevertheless it is doubtful that even the greatest differences in kinetics are practically meaningful 0 3 bw ht and 0 7 bw ht s for moments and power at the hip respectively therefore body segment parameters estimated using jensen s regression equations are a suitable substitute for more detailed anatomical imaging of 8 10 year old girls when quantifying joint kinetics during gait

two sided gluings of tilted algebras we study the class of algebras a satisfying the property all but at most finitely many non isomorphic indecomposable a modules are such that all their predecessors have projective dimension at most one or all their successors have injective dimension at most one such a class includes the tilted algebras d happel c ringel trans amer math soc 274 1982 399 443 the quasi tilted algebras d happel i reiten s smalo mem am math soc 120 1996 575 the shod algebras f u coelho m lanzilotta manuscripta mathematica 100 1999 1 11 the weakly shod f u coelho m lanzilotta preprint 2001 and the left and right glued algebras i assem f u coelho j pure appl algebra 96 3 1994 225 243

frequency weighting functions for broadband speech as estimated by a correlational method the relative contributions of various regions of the frequency spectrum to speech recognition were assessed with a correlational method k a doherty and c w turner j acoust soc am 100 3769 3773 1996 the speech materials employed were the 258 item set of the nonsense syllable test the speech was filtered into four frequency bands and a random level of noise was added to each band on each trial a point biserial correlation was computed between the signal to noise ratio in each band on the trials and the listener s responses and these correlations were then taken as estimates of the relative weights for each frequency band when the four bands were presented separately the correlations for each band were approximately equal however when the four bands were presented in combination the correlations were quite different from one another implying that in the broadband case listeners relied much more on some bands than on others it is hypothesized that these differences reflect the way in which listeners combine and attend to speech information across various frequency regions the frequency weighting functions as determined by this method were highly similar across all subjects suggesting that normal hearing listeners use similar frequency weighting strategies in recognizing speech

almost split sequences in subcategories let r be a commutative artin ring and let i be an r algebra which is a finitely generated r module in 5 auslander and reiten introduced the notion of an almost split sequence in mod a the category of finitely generated modules over a and the existence and uniqueness of such short exact sequences were established there the theory of almost split sequences developed further and similar results for certain subcategories of mod i were proved by bautista and martinez 8 and roggenkamp 9 the main purpose of this paper is to develop a more general theory for subcategories of mod i having almost split sequences which has the previous examples as special cases notions closely related to that of almost split sequences are those of minimal left and right almost split morphisms these notions were introduced in 61 for mod i and further developed in 7 for subcategories of mod ii this paper is based upon 7 and we therefore use the same notations and conventions as used there we now give some definitions and then proceed to describe the content of the paper section by section let c be a subcategory of mod ii then a morphism g b c in c is said to be a right almost split morphism in c if i g is not a splittable epimorphism and ii whenever there is a nonsplittable epimorphism h c c in c there exists an h c b such that gh h dually a morphismfi a f b in c is said to be left almost split if i f is not a splittable monomorphism and ii whenever there is a nonsplittable monomorphism h a a there exists an h b a such that h f h we say that c has right almost split morphisms if for all indecomposable objects

a 3d reconstruction method of the body envelope from biplanar x rays evaluation of its accuracy and reliability the aim of this study was to propose a novel method for reconstructing the external body envelope from the low dose biplanar x rays of a person the 3d body envelope was obtained by deforming a template to match the surface profiles in two x rays images in three successive steps global morphing to adopt the position of a person and scale the template s body segments followed by a gross deformation and a fine deformation using two sets of pre defined control points to evaluate the method a biplanar x ray acquisition was obtained from head to foot for 12 volunteers in a standing posture up to 172 radio opaque skin markers were attached to the body surface and used as reference positions each envelope was reconstructed three times by three operators results showed a bias lower than 7 mm and a confidence interval 95 of reproducibility lower than 6 mm for all body parts comparable to other existing methods matching a template onto stereographic photographs the proposed method offers the possibility of reconstructing body shape in addition to the skeleton using a low dose biplanar x rays system

integration across frequency bands for consonant identification a comparison of the predictions of models of integration to data on the reception of consonants filtered into a variety of frequency bands is reported new data on the consonant identification are presented three experiments were conducted testing the following bands experiment i 0 2100 hz and 2100 4500 hz experiment ii 0 700 hz combined with 700 1400 1400 2100 2100 2800 and 2800 4500 hz experiment iii all combinations of 700 1400 1400 2100 2100 2800 and 2800 4500 hz the predictions of four models fletcher s speech and hearing in communication van nostrand new york 1950 independent errors model massaro s fuzzy logical model of perception proc int congress of phonetic sciences stockholm vol 3 pp 106 113 1987 and braida s pre labelling and post labelling models of integration q j exp psychol a 43 647 677 1991 were compared in terms of their ability to predict combined band scores at least two models were capable of predicting performance for each combined band condition for experiment i all models were able to make satisfactory predictions for experiment ii a variant of the pre labelling model was able to make satisfactory predictions for experiment iii no model was able to make satisfactory predictions but the fuzzy logical model of perception and a variant of the pre labelling model made relatively good predictions thus the ability of the models to predict performance depended more on whether the condition included the lowest frequency band than on the adjacency or frequency separation

spectral weighting strategies for hearing impaired listeners measured using a correlational method spectral weighting strategies using a correlational method r a lutfi j acoust soc am 97 1333 1334 1995 v m richards and s zhu j acoust soc am 95 423 424 1994 were measured in ten listeners with sensorineural hearing loss on a sentence recognition task sentences and a spectrally matched noise were filtered into five separate adjacent spectral bands and presented to listeners at various signal to noise ratios snrs five point biserial correlations were computed between the listeners response correct or incorrect on the task and the snr in each band the stronger the correlation between performance and snr the greater that given band was weighted by the listener listeners were tested with and without hearing aids on all listeners were experienced hearing aid users results indicated that the highest spectral band 2800 11000hz received the greatest weight in both listening conditions however the weight on the highest spectral band was less when listeners performed the tas

frequency selectivity and consonant recognition for hearing impaired and normal hearing listeners with equivalent masked thresholds thresholds in notched noise maskers nn and narrow band maskers nb were measured for normal hearing and hearing impaired subject pairs who were listening in a background of spectrally shaped broadband noise ssbb consonant recognition was also measured in ssbb ssbb was adjusted so that thresholds in that noise for each normal hearing hearing impaired subject pair were equal threshold and signal level differences between subject pairs were minimized with the addition of threshold elevating ssbb and the presence of a noise background for both groups provided a comparable listening environment for all subjects at signal frequencies outside masker passbands thresholds in nn and nb for hearing impaired subjects were higher than for normal hearing subjects although threshold differences were much smaller than observed between normal hearing and hearing impaired subjects without ssbb no consistent differences in consonant recognition measured in ssbb were observed between groups the pattern of results is comparable to that observed in a previous experiment dubno and schaefer j acoust soc am 91 2110 2121 1992 in which thresholds in nn and nb and consonant recognition for hearing impaired listeners were compared to results obtained for normal hearing subjects but only normal hearing subjects listened in ssbb using a modified power law model of masking additivity thresholds in combined masker conditions were estimated masking effects for spectrally overlapping maskers were similar for normal hearing and hearing impaired listeners and suggest that residual differences between subject groups are not due to the presence of an additional background noise

on the number of channels needed to understand speech recent studies have shown that high levels of speech understanding could be achieved when the speech spectrum was divided into four channels and then reconstructed as a sum of four noise bands or sine waves with frequencies equal to the center frequencies of the channels in these studies speech understanding was assessed using sentences produced by a single male talker the aim of experiment 1 was to assess the number of channels necessary for a high level of speech understanding when sentences were produced by multiple talkers in experiment 1 sentences produced by 135 different talkers were processed through n 2 n 16 number of channels synthesized as a sum of n sine waves with frequencies equal to the center frequencies of the filters and presented to normal hearing listeners for identification a minimum of five channels was needed to achieve a high level 90 of speech understanding asymptotic performance was achieved with eight channels at least for the speech material used in this study the outcome of experiment 1 demonstrated that the number of channels needed to reach asymptotic performance varies as a function of the recognition task and or need for listeners to attend to fine phonetic detail in experiment 2 sentences were processed through 6 and 16 channels and quantized into a small number of steps the purpose of this experiment was to investigate whether listeners use across channel differences in amplitude to code frequency information particularly when speech is processed through a small number of channels for sentences processed through six channels there was a significant reduction in speech understanding when the spectral amplitudes were quantized into a small number 8 of steps high levels 92 of speech understanding were maintained for sentences processed through 16 channels and quantized into only 2 steps the findings of experiment 2 suggest an inverse relationship between the importance of spectral amplitude resolution number of steps and spectral resolution number of channels

fuzzy information transmission analysis for continuous speech features feature information transmission analysis fita estimates information transmitted by an acoustic feature by assigning tokens to categories according to the feature under investigation and comparing within category to between category confusions fita was initially developed for categorical features e g voicing for which the category assignments arise from the feature definition when used with continuous features e g formants it may happen that pairs of tokens in different categories are more similar than pairs of tokens in the same category the estimated transmitted information may be sensitive to category boundary location and the selected number of categories this paper proposes a fuzzy approach to fita that provides a smoother transition between categories and compares its sensitivity to grouping parameters with that of the traditional approach the fuzzy fita was found to be sufficiently robust to boundary location to allow automation of category boundary selection traditional and fuzzy fita were found to be sensitive to the number of categories this is inherent to the mechanism of isolating a feature by dividing tokens into categories so that transmitted information values calculated using different numbers of categories should not be compared four categories are recommended for continuous features when twelve tokens are used

individualized estimation of the speech intelligibility index for short sentences test retest reliability the speech intelligibility index sii model was modified to allow individualized parameters these parameters included the relative weights of speech cues in five octave frequency bands ranging from 0 25 to 4 khz i e the band importance function and the transfer function that allows the sii to generate predictions on speech recognition scores a bayesian adaptive procedure the quick band importance function qbif procedure was utilized to enable efficient estimation of the sii parameters from individual listeners in two experiments the sii parameters were estimated for 30 normal hearing adults using institute of electrical and electronics engineers ieee sentences at speech levels of 55 65 and 75 db sound pressure level in experiment i and for 15 hearing impaired hi adult listeners using amplified ieee or azbio sentences in experiment ii in both experiments even without prior training the estimated model parameters showed satisfactory reliability between two runs of the qbif procedure at least one week apart for the hi listeners inter listener variability in most estimated sii parameters was larger than intra listener variability of the qbif procedure

the importance of temporal fine structure information in speech at different spectral regions for normal hearing and hearing impaired subjects speech reception thresholds srts were measured for target and competing speech signals processed to contain variable amounts of temporal fine structure tfs information signals were filtered into 30 1 erb n wide channels where erb n refers to the bandwidth of normal auditory filters which were either tone vocoded preserving temporal envelope information extracted using the hilbert transform or left unprocessed containing both tfs and envelope information improvements in srt were compared when tfs was progressively introduced starting with the high or low frequency channels the results suggest some redundancy in the tfs information across frequency regions in a second experiment the signal was divided into five 6 erb n wide spectral regions four of which were tone vocoded the remaining region was either absent creating a spectral notch or was present and unprocessed srts were measured for normal hearing and hearing impaired subjects conditions where all channels were vocoded or unprocessed were also included normal hearing subjects benefited similarly when tfs information was added to each region suggesting that tfs information is important over a wide frequency range hearing impaired subjects benefited less although the benefit varied across subjects benefit from tfs information in speech was correlated with a psychophysical measure of tfs sensitivity obtained at two center frequencies

correlation coefficients and correlation ratios as estimates of observer weights in multiple observation tasks advantages of correlational methods are described for estimating the relative reliance or weight observers give to different elements of a complex display when performing auditory or visual discriminations correlational methods differ from other such methods by providing a least squares estimate of weights rather than a maximum likelihood estimate based on a presumed model the main benefit is that these methods can be generally applied in cases where the statistical properties of elements are unknown where correlations exist between elements or where it is necessary to evaluate decision models that are inherently nonlinear

use of a compound approach to derive auditory filter wide frequency importance functions for vowels and consonants speech recognition in noise presumably relies on the number and spectral location of available auditory filter outputs containing a relatively undistorted view of local target signal properties the purpose of the present study was to estimate the relative weight of each of the 30 auditory filter wide bands between 80 and 7563 hz because previous approaches were not compatible with this goal a technique was developed similar to the hole approach the weight of a given band was assessed by comparing intelligibility in two conditions differing in only one aspect the presence or absence of the band of interest in contrast to the hole approach however random gaps were also created in the spectrum these gaps were introduced to render the auditory system more sensitive to the removal of a single band and their location was randomized to provide a general view of the weight of each band i e irrespective of the location of information elsewhere in the spectrum frequency weighting functions derived using this technique confirmed the main contribution of the 400 2500 hz frequency region however they revealed a complex microstructure contrasting with the bell curve shape typically reported

relative estimates of combination weights decision criteria and internal noise based on correlation coefficients a means by which relative combination weights may be determined is described for a signal detection model in which the decision variable is a weighted linear combination of several independent normally distributed random variables xi s the first theorem presents the correlation between the binary response variables signal versus no signal and the component xi the second theorem presents a parallel result for the case that additive internal noise is present thus in psychophysical experiments the relative combination weights may be obtained by correlating the observers responses and the input random variables third three numerical methods which allow the evaluation of the relative magnitude of the decision criterion and the variance of a hypothetical additive internal noise are considered

spectral weighting strategies for sentences measured by a correlational method listeners ability to understand speech in adverse listening conditions is partially due to the redundant nature of speech natural redundancies are often lost or altered when speech is filtered such as done in ai sii experiments it is important to study how listeners recognize speech when the speech signal is unfiltered and the entire broadband spectrum is present a correlational method r a lutfi j acoust soc am 97 1333 1334 1995 v m richards and s zhu j acoust soc am 95 423 424 1994 has been used to determine how listeners use spectral cues to perceive nonsense syllables when the full speech spectrum is present k a doherty and c w turner j acoust soc am 100 3769 3773 1996 c w turner et al j acoust soc am 104 1580 1585 1998 the experiments in this study measured spectral weighting strategies for more naturally occurring speech stimuli specifically sentences using a correlational method for normal hearing listeners results indicate that listeners placed the greatest weight on spectral information within bands 2 and 5 562 1113 and 2807 11 000 hz respectively spectral weighting strategies for sentences were also compared to weighting strategies for nonsense syllables measured in a previous study c w turner et al 1998 spectral weighting strategies for sentences were different from those reported for nonsense syllables

comparison of frequency selectivity and consonant recognition among hearing impaired and masked normal hearing listeners frequency selectivity and consonant recognition were determined for normal hearing and hearing impaired listeners using techniques that facilitate comparisons of performance among listeners whose absolute thresholds vary in magnitude and configuration first for each of six subjects with cochlear hearing loss masked thresholds in notched noise and narrow band noise maskers were obtained and compared to results for three normal hearing listeners whose thresholds were precisely matched to the impaired listeners by masking with spectrally shaped broadband noise second for hearing impaired listeners and their masked normal hearing controls measurements of consonant recognition were obtained at several speech presentation levels selected on the basis of articulation index predictions to assure equal speech spectrum audibility across listeners the results suggest that frequency selectivity is poorer for hearing impaired listeners than for masked normal hearing listeners even when thresholds among subjects are equated but the deviation from normal frequency selectivity is smaller than estimated from comparisons with normal hearing listeners in quiet critical ratios for hearing impaired listeners are equivalent to normal although frequency selectivity is reduced there is no consistent difference in consonant recognition between hearing impaired subjects and masked normal hearing subjects when performance is assessed under conditions that assure equal speech spectrum audibility across subjects

speech recognition for multiple bands implications for the speech intelligibility index the speech intelligibility index sii assumes additivity of the importance of acoustically independent bands of speech to further evaluate this assumption open set speech recognition was measured for words and sentences in quiet and in noise when the speech stimuli were presented to the listener in selected frequency bands the filter passbands were constructed from various combinations of 20 bands having equivalent 0 05 importance in the sii framework this permitted the construction of a variety of equal sii band patterns that were then evaluated by nine different groups of young adults with normal hearing for monosyllabic words a similar dependence on band pattern was observed for sii values of 0 4 0 5 and 0 6 in both quiet and noise conditions specifically band patterns concentrated toward the lower and upper frequency range tended to yield significantly lower scores than those more evenly sampling a broader frequency range for all stimuli and test conditions equal sii values did not yield equal performance because the spectral distortions of speech evaluated here may not commonly occur in everyday listening conditions this finding does not necessarily represent a serious deficit for the application of the sii these findings however challenge the band independence assumption of the theory underlying the sii

use of a correlational method to estimate a listener s weighting function for speech the purpose of this study was to determine if it is feasible to use the correlational method lutfi 1995 richards and zhu 1994 to estimate how listeners use or weight the information contained within various frequency bands of speech three naturally spoken vowel consonant vowel vcv syllables aba aga and ada were presented monaurally to listeners each of the vcv waveforms were filtered into three separate frequency bands i e low mid and high each band was then independently and randomly degraded at various signal to noise s n levels 7 5 3 1 or 1 on each trial listeners were asked to identify the vcv that was presented to them for each trial the s n level of each frequency band the stimulus that was presented and the listener s responses were all recorded and stored in a file from this trial by trial data a point biserial correlation was computed between the listener s response correct or incorrect identification and the degradation within each frequency band the stronger the correlation the greater influence that given frequency band had on the listener s performance on the task from these relations it was shown that it is possible to obtain a listener s weighting function for speech results showed that although most listeners weighted the mid frequency band the greatest several of the listeners used different weighting strategies to perform the task several methodological issues are discussed in regard to improving the future application of the correlational method to speech

relative weights for frequency glide detection using narrowband noise narrowband noise stimuli were used to derive relative weights for detecting frequency glides in a yes no procedure one stimulus set was restricted to the duration of the glide for the second stimulus set there were fringe noise bands preceding and following the glide for both sets the center frequency of the linear glide was either fixed at 1000hz or randomly chosen on each trial from the range of 800 1200hz relative weights as a function of time were derived using a linear model and the linear classification method a ahumada j vis 2 121 131 2002 sensitivity was better for the fixed than random frequency conditions and weight patterns from the random frequency conditions were less reliable than those obtained from the fixed frequency conditions the magnitudes of the relative weights tended to be larger for the second half of the stimulus suggesting that subjects paid more attention to the later than the earlier parts of stimuli in the random frequency conditions the linear model failed to account for subjects performance unless the stimuli were expressed in terms of relative changes in frequency rather than absolute frequency

determination of a new uniform thorax density representative of the living population from 3d external body shape modeling body segment parameters bsp for each body s segment are needed for biomechanical analysis to provide population specific bsp precise estimation of body s segments volume and density are needed widely used uniform densities provided by cadavers studies did not consider the air present in the lungs when determining the thorax density the purpose of this study was to propose a new uniform thorax density representative of the living population from 3d external body shape modeling bi planar x ray radiographies were acquired on 58 participants allowing 3d reconstructions of the spine rib cage and human body shape three methods of computing the thorax mass were compared for 48 subjects 1 the dempster uniform density method currently in use for bsps calculation using dempster density data 2 the personalized method using full description of the thorax based on 3d reconstruction of the rib cage and spine and 3 the improved uniform density method using a uniform thorax density resulting from the personalized method for 10 participants comparison was made between the body mass obtained from a force plate and the body mass computed with each of the three methods the dempster uniform density method presented a mean error of 4 8 in the total body mass compared to the force plate vs 0 2 for the personalized method and 0 4 for the improved uniform density method the adjusted thorax density found from the 3d reconstruction was 0 74g cm 3 for men and 0 73g cm 3 for women instead of the one provided by dempster 0 92g cm 3 leading to a better estimate of the thorax mass and body mass

the simulation of aerial movement ii a mathematical inertia model of the human body a mathematical inertia model which permits the determination of personalized segmental inertia parameter values from anthropometric measurements is described the human body is modelled using 40 geometric solids which are specified by 95 anthropometric measurements a stadium solid is introduced for modelling the torso segments using perimeter and width measurements this procedure is more accurate than the use of elliptical discs of given width and depth and permits a smaller number of such solids to be used inertia parameter values may be obtained for body models of up to 20 segments errors in total body mass estimates from this and other models are discussed with reference to the unknown lung volumes

the intelligibility of speech with holes in the spectrum the intelligibility of speech having either a single hole in various bands or having two holes in disjoint or adjacent bands in the spectrum was assessed with normal hearing listeners in experiment 1 the effect of spectral holes on vowel and consonant recognition was evaluated using speech processed through six frequency bands and synthesized as a sum of sine waves results showed a modest decrease in vowel and consonant recognition performance when a single hole was introduced in the low and high frequency regions of the spectrum respectively when two spectral holes were introduced vowel recognition was sensitive to the location of the holes while consonant recognition remained constant around 70 correct even when the middle and high frequency speech information was missing the data from experiment 1 were used in experiment 2 to derive frequency importance functions based on a least squares approach the shapes of the frequency importance functions were found to be different for consonants and vowels in agreement with the notion that different cues are used by listeners to identify consonants and vowels for vowels there was unequal weighting across the various channels while for consonants the frequency importance function was relatively flat suggesting that all bands contributed equally to consonant identification

on subcategories closed under predecessors and the representation dimension abstract let be an artin algebra a and c be full subcategories of the category of finitely generated modules consisting of indecomposable modules and closed under predecessors and successors respectively in this paper we relate under various hypotheses the representation dimension of to those of the left support algebra of a and the right support algebra of c our results are then applied to the classes of laura algebras ada algebras and nakayama oriented pullbacks

weakly shod algebras abstract we study the class of algebras having a path of nonisomorphisms from an indecomposable injective module to an indecomposable projective module and any such path is bounded by a fixed number we show that such an algebra is an iteration of one point extensions starting at a product of tilted algebras this allows us to describe for instance its auslander reiten quiver

the left and the right parts of a module category abstract in this paper we study for an artin algebra the class l a and r a which is a full subcategory of the category moda of finitely generated a modules and which consists of all indecomposable a modules whose predecessors and successors have projective dimension and injective dimension respectively at most one we consider quotient algebras of a which contain the information on these classes then define and characterize those algebras for which the class is l a is contravariantly finite and r a is covariantly finite respectively