25 research outputs found
Speaker Normalization Methods for Vowel Cognition: Comparative Analysis Using Neural Network and Nearest Neighbor Classifiers
Intrinsic and extrinsic speaker normalization methods are systematically compared using a neural network (fuzzy ARTMAP) and L1 and L2 K-Nearest Neighbor (K-NN) categorizers trained and tested on disjoint sets of speakers of the Peterson-Barney vowel database. Intrinsic methods include one nonscaled, four psychophysical scales (bark, bark with endcorrection, mel, ERB), and three log scales, each tested on four combinations of F0 , F1, F2, F3. Extrinsic methods include four speaker adaptation schemes, each combined with the 32 intrinsic methods: centroid subtraction across all frequencies (CS), centroid subtraction for each frequency (CSi), linear scale (LS), and linear transformation (LT). ARTMAP and KNN show similar trends, with K-NN performing better, but requiring about ten times as much memory. The optimal intrinsic normalization method is bark scale, or bark with endcorrection, using the differences between all frequencies (Diff All). The order of performance for the extrinsic methods is LT, CSi, LS, and CS, with fuzzy ARTMAP performing best using bark scale with Diff All; and K-NN choosing psychophysical measures for all except CSi.British Petroleum (89-A-1204); Defense Advanced Research Projects Agency (AFOSR-90-0083, ONR-N00014-92-J-4015); National Science Foundation (IRI-90-00530); Office of Naval Research (N00014-91-J-4100); Air Force Office of Scientific Research (F49620-92-J-0225
BKM superalgebras from counting dyons in N=4 supersymmetric type II compactifications
We study the degeneracy of quarter BPS dyons in N =4 type II
compactifications of string theory. We find that the genus-two Siegel modular
forms generating the degeneracies of the quarter BPS dyons in the type II
theories can be expressed in terms of the genus-two Siegel modular forms
generating the degeneracies of quarter BPS dyons in the CHL theories and the
heterotic string. This helps us in understanding the algebra structure
underlying the degeneracy of the quarter BPS states. The Conway group, Co_1,
plays a role similar to Mathieu group, M_{24}, in the CHL models with eta
quotients appearing in the place of eta products. We construct BKM Lie
superalgebra structures corresponding to Z_N (for N=2,3,4) orbifolds of the
type II string compactified on a six-torus.Comment: 21 page
Common tumour, uncommon presentation: massive lipoma in the retroperitoneum
Retroperitoneal masses are notoriously malignant. Although they are seen commonly in adults, they have been known to occur in children as well. A benign mass in the retroperitoneal location in children is uncommon. Here we describe the presentation and management of a rare benign retroperitoneal mass in a 12-year-old boy.Keywords: abdominal mass, lipoma, paediatric tumours, retroperitoneal mas
BKM Lie superalgebra for the Z_5 orbifolded CHL string
We study the Z_5-orbifolding of the CHL string theory by explicitly
constructing the modular form tilde{Phi}_2 generating the degeneracies of the
1/4-BPS states in the theory. Since the additive seed for the sum form is a
weak Jacobi form in this case, a mismatch is found between the modular forms
generated from the additive lift and the product form derived from threshold
corrections. We also construct the BKM Lie superalgebra, tilde{G}_5,
corresponding to the modular form tilde{Delta}_1 (Z) = tilde{Phi}_2 (Z)^{1/2}
which happens to be a hyperbolic algebra. This is the first occurrence of a
hyperbolic BKM Lie superalgebra. We also study the walls of marginal stability
of this theory in detail, and extend the arithmetic structure found by Cheng
and Dabholkar for the N=1,2,3 orbifoldings to the N=4,5 and 6 models, all of
which have an infinite number of walls in the fundamental domain. We find that
analogous to the Stern-Brocot tree, which generated the intercepts of the walls
on the real line, the intercepts for the N >3 cases are generated by linear
recurrence relations. Using the correspondence between the walls of marginal
stability and the walls of the Weyl chamber of the corresponding BKM Lie
superalgebra, we propose the Cartan matrices for the BKM Lie superalgebras
corresponding to the N=5 and 6 models.Comment: 30 pages, 2 figure
Generalized Kac-Moody Algebras from CHL dyons
We provide evidence for the existence of a family of generalized
Kac-Moody(GKM) superalgebras, G_N, whose Weyl-Kac-Borcherds denominator formula
gives rise to a genus-two modular form at level N, Delta_{k/2}(Z), for
(N,k)=(1,10), (2,6), (3,4), and possibly (5,2). The square of the automorphic
form is the modular transform of the generating function of the degeneracy of
CHL dyons in asymmetric Z_N-orbifolds of the heterotic string compactified on
T^6. The new generalized Kac-Moody superalgebras all arise as different
`automorphic corrections' of the same Lie algebra and are closely related to a
generalized Kac-Moody superalgebra constructed by Gritsenko and Nikulin. The
automorphic forms, Delta_{k/2}(Z), arise as additive lifts of Jacobi forms of
(integral) weight k/2 and index 1/2. We note that the orbifolding acts on the
imaginary simple roots of the unorbifolded GKM superalgebra, G_1 leaving the
real simple roots untouched. We anticipate that these superalgebras will play a
role in understanding the `algebra of BPS states' in CHL compactifications.Comment: LaTeX, 35 pages; v2: improved referencing and discussion; typos
corrected; v3 [substantial revision] 44 pages, modularity of additive lift
proved, product representation of the forms also given; further references
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Exploration of Uncharted Regions of the Protein Universe
Determination of first protein structures, from hundreds of families of unknown function, have shown that divergence, rather than novelty, is the dominant force that shapes the evolution of the protein universe
Speech Communication
Contains table of contents for Part V, table of contents for Section 1, reports on six research projects and a list of publications.C.J. Lebel FellowshipDennis Klatt Memorial FundNational Institutes of Health Grant R01-DC00075National Institutes of Health Grant R01-DC01291National Institutes of Health Grant R01-DC01925National Institutes of Health Grant R01-DC02125National Institutes of Health Grant R01-DC02978National Institutes of Health Grant R01-DC03007National Institutes of Health Grant R29-DC02525National Institutes of Health Grant F32-DC00194National Institutes of Health Grant F32-DC00205National Institutes of Health Grant T32-DC00038National Science Foundation Grant IRI 89-05249National Science Foundation Grant IRI 93-14967National Science Foundation Grant INT 94-2114
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
ARTSTREAM: a neural network model of auditory scene analysis and source segregation
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