A practical approach for the design of nonuniform lapped transforms

We propose a simple method for the design of lapped transforms with nonuniform frequency resolution and good time localization. The method is a generalization of an approach previously proposed by Princen, where the nonuniform filter bank is obtained by joining uniform cosine-modulated filter banks (CMFBs) using a transition filter. We use several transition filters to obtain a near perfect-reconstruction (PR) nonuniform lapped transform with significantly reduced overall distortion. The main advantage of the proposed method is in reducing the length of the transition filters, which leads to a reduction in processing delay that can be useful for applications such as real-time audio coding

Coding overcomplete representations of audio using the MCLT

We propose a system for audio coding using the modulated complex lapped transform (MCLT). In general, it is difficult to encode signals using overcomplete representations without avoiding a penalty in rate-distortion performance. We show that the penalty can be significantly reduced for MCLT-based representations, without the need for iterative methods of sparsity reduction. We achieve that via a magnitude-phase polar quantization and the use of magnitude and phase prediction. Compared to systems based on quantization of orthogonal representations such as the modulated lapped transform (MLT), the new system allows for reduced warbling artifacts and more precise computation of frequency-domain auditory masking functions

Estudo in vitro da ação do EDTA nas concentrações de 3%, 5%, 10% e 17% sobre a camada residual

The success of microbial disinfection of the endodontic space depends on the endodontic instruments, the ancillary chemicalsselected and the technical skills used in the chemical-mechanical preparation. Upon completion of the instrumentation thedeposition on the dentine surface of an organic and inorganic material extract of amorphous aspect, with an irregular andgranular surface known as residual layer, was observed. Aiming at removal of this layer several chemicals, in differentconcentrations and applied in pre-established time intervals were used alone, conjugated or mixed. The objective of this studywas to analyze, in vitro, through scanning electron microscopy, the effect of EDTA in 3%, 5%, 10% and 17% concentrations onthe removal of the residual layer and cleaning of the dentine tubules through applications ranging from 1 to 3 minutes. Eightunits from an 80-tooth sample were randomly selected to compose the negative control set (GC1) and other 8 units to composethe positive control set (GC2). The remaining 64 composed the 8 experimental sets (GExp.). Analysis of the photomicrographsat magnitude 2000X revealed that the 10 % and 17 % EDTA solutions were the most effective irrespective of the pre-establishedapplication times. It was also observed that the apical third showed a lower degree of cleaning than the cervical and basalthirds.O êxito da desinfecção do espaço endodôntico depende dos instrumentos endodônticos, das substâncias químicas auxiliaresselecionadas e da habilidade técnica no preparo químico mecânico. Concluída a instrumentação, é possível constatar adeposição na superfície dentinária de um extrato de material orgânico e inorgânico de aparência amorfa, superfície irregulare granulosa, denominada camada residual. Com este estudo, buscou-se analisar, in vitro, por meio da Microscopia Eletrônicade Varredura, o efeito do EDTA nas concentrações de 3%, 5%, 10% e 17%, na remoção da camada residual e na desobstruçãodos túbulos dentinários, nos tempos de 1 e 3 minutos. Da amostra constituída de 80 dentes, foram selecionados,randomicamente, 8 unidades para composição do grupo de controle negativo (GC1) e 8 para o grupo de controle positivo(GC2). Os 64 restantes compuseram os 8 grupos experimentais(GExp.). A análise das fotomicrografias com magnitude de2000X revelou que as soluções de EDTA a 10% e 17% foram as mais eficazes e que o terço apical apresentou grau de limpezainferior aos terços cervical e médio

Radio Astronomy

Contains summary of research and reports on nine research projects.National Science Foundation (Grant AST81-21416)National Science Foundation (Grant AST82-14296)National Aeronautics and Space Administration (Grant S-10781-C)National Aeronautics and Space Administration (Grant NAGW-373)National Science Foundation (Grant AST79-19553)M.I.T. Sloan Fund for Basic ResearchNational Oceanic and Atmospheric Administration (Grant 04-8-M01-1)National Aeronautics and Space Administration (Grant NAG5-10)National Aeronautics and Space Administration (Contract NAS5-22929)Defense Advanced Research Projects Agency (Contract MDA 903-82-K-0521)Center for Advanced Television Studie

Radio Astronomy

Contains reports on nine research projects.National Science Foundation (Grant AST 86-17172)National Aeronautics and Space Administration (Contract NAS7-918)Jet Propulsion Laboratory (Contract 958048)U.S. Navy - Office of Naval Research (Contract N00014-84-C-2082)U.S. Navy - Office of Naval Research (Contract N00014-86-C-2114)SM Systems and Research, Inc.National Aeronautics and Space Administration/Goddard Space Flight Center (Grant NAG5-10)Center for Advanced Television StudiesBrazil, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (Grant 300.832-82)National Aeronautics and Space Administration/Goddard Space Flight Center (Grant NAG5-537

Cognitive Information Processing

Contains goals, background, research activities on one research project and reports on three research projects.Center for Advanced Television StudiesAmerican Broadcasting CompanyAmpex CorporationColumbia Broadcasting SystemsHarris CorporationHome Box OfficePublic Broadcasting ServiceNational Broadcasting CompanyRCA CorporationTektronix3M CompanyProvidence Gravure Co. (Grant)International Business Machines, Inc