Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-07Bitstream added on 2014-06-13T19:28:02Z : No. of bitstreams: 1 tiago_mm_me_ilha.pdf: 962669 bytes, checksum: 4988399c15f758626b264c1adb577b2f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Um dos setores de grande importância na indústria frigorífica é o responsável pelo esquarte- jamento de aves, no qual peças inteiras são separadas em partes menores para comercialização. O processo de esquartejamento pode ser feito de forma automática, através de máquinas de corte, ou por trabalhadores, que cortam as aves utilizando uma serra circular. Por ser um tra- balho manual e envolver uma lâmina de corte, a periculosidade desse tipo de trabalho é alta, de maneira que mesmo com o uso de uma luva de aço inox como equipamento de proteção, costumam ocorrer acidentes que podem variar desde pequenos cortes até amputação de parte da mão do trabalhador atingido. Neste trabalho, é apresentado um método de análise de sinais para evitar que esse tipo de acidente ocorra. Esse sistema baseia-se na análise dos sinais acústicos envolvidos gerados durante esse processo e são utilizados para desligar o motor que impulsiona a serra e acionar um sistema de frenagem em casos quando houver a ocorrência de acidentes. O problema é abordado utilizando inicialmente um filtro digital e, posteriormente, com as técni- cas de análise multirresolução apresentadas pelas wavelets. Além disso, empregou-se também a decomposição de modo empírico, que também realiza uma análise multirresolução dos sinais decompondo os mesmos em funções de modo intrínseco. Visando detectar o maior número possível de toques suaves de luva na serra sem que cortes de ossos de frango fossem confundi- dos com toques de luva, o sistema apresentou um índice de acertos de aproximadamente 70%, havendo a ocorrência de apenas 2% de falsos positivos. Além desse problema, abordou-se o caso de detecção de trinca em ovos, no qual o objetivo era separar ovos trincados de ovos in- teiros utilizando um sistema barato e eficiente... / One of the most important sectors in the meatpacking industry is chicken quartering, where whole pieces are cut into smaller ones. The quartering process can be done by automatic ma- chines or by manually cutting the chickens using a circular saw. The manual technique imposes physical risks for the workers, which wear protective stainless steel gloves. Small injuries or, in the worst case, amputation of part of the hand can occur in the event of an accident. In this work, we propose a methodology to prevent this type of accident, which is based on the anal- ysis of the acoustic signals generated during this process. In the event of an accident, the saw touches the metal glove, the acoustic signals are processed and used to turn off the engine that drives the saw and trigger a braking system. The problem is firstly analyzed using a digital filter and then with multiresolution techniques by wavelet analysis. In addition, the empirical mode decomposition technique is also employed, which also performs multiresolution analysis of sig- nals. These three techniques are implemented and compared. The method presented a 70% of successful detection of light touches of saw/glove and 2% of false positives, when a normal cut operation is detected as a saw/glove touch, in general occurring when cutting specific parts of bone. Besides this problem, the case of eggshell crack detection is studied, where the goal was to separate cracked eggs from intact eggs using an inexpensive and efficient system. A solenoid was used as a source of mechanical excitation and the resulting acoustic signals were acquired and processed. The same signal processing techniques were employed and compared, with small changes in parameters. As a result, it was possible to detect 80% of cracked eggs and 100% of intact eggs. The multiresolution technique... (Complete abstract click electronic access below)

No description available.

Abstract The traditional fault inspection of the motorcar engine cannot detect the noise and sound signal resulted from the abnormalities of some mechanical parts. For instance, the cylinder misfires; the looseness of the fan belt is irregular; the valve clearance is out of order¡K. and so on. When the fault message cannot be delivered by the ECU of the computer, the skilled senior engineers are required at this moment to make the experiential judgments. In the present society, due to the development of information, the computer technology makes progress by leaps and bounds. If we can make use of the monitoring method by the Acoustic signal instrument, build up a set of complete and efficient fault diagnosis system through the computer software and apply speedy and accurate way to assist the repairmen in relocating the causes for such faults, the accuracy of inspection can be greatly enhanced with a huge help in the preventive maintenance work. In that case, the fault conditions of the engine can be validated precisely and effectively, so the overhaul efficiency of the engine can be upgraded to a large extent. In this article, the procedures of sound signal recording will be brought forward by linking the digital camera with such a recording equipment as the high-precision microphone to make records of the fault sounds made when the engine runs. It uses the frequency analyzer to conduct the sampling and combine the computer software to further process and analyze the same. Finally the character parameters will be obtained. By applying the mathematical exercise of ¡§Back-Propagation Neural Network¡¨ to undertake the training and detection of the sounds for the purpose of identifying the kinds of the faults. It replaces the errors caused from the experiential judgments made by the expert senior engineers. In terms of the training and maintenance ability of the newly recruited technical repairmen, their capability for exact and reasonable recognition of the fault types is substantially promoted. Keywords¡GAcoustic Signal¡ABack Propagation Neural Network

Orientador: Ricardo Tokio Higuti / Banca: Francisco Villarreal Alvarado / Banca: Washington Luiz de Barros Melo / Resumo: Um dos setores de grande importância na indústria frigorífica é o responsável pelo esquarte- jamento de aves, no qual peças inteiras são separadas em partes menores para comercialização. O processo de esquartejamento pode ser feito de forma automática, através de máquinas de corte, ou por trabalhadores, que cortam as aves utilizando uma serra circular. Por ser um tra- balho manual e envolver uma lâmina de corte, a periculosidade desse tipo de trabalho é alta, de maneira que mesmo com o uso de uma luva de aço inox como equipamento de proteção, costumam ocorrer acidentes que podem variar desde pequenos cortes até amputação de parte da mão do trabalhador atingido. Neste trabalho, é apresentado um método de análise de sinais para evitar que esse tipo de acidente ocorra. Esse sistema baseia-se na análise dos sinais acústicos envolvidos gerados durante esse processo e são utilizados para desligar o motor que impulsiona a serra e acionar um sistema de frenagem em casos quando houver a ocorrência de acidentes. O problema é abordado utilizando inicialmente um filtro digital e, posteriormente, com as técni- cas de análise multirresolução apresentadas pelas wavelets. Além disso, empregou-se também a decomposição de modo empírico, que também realiza uma análise multirresolução dos sinais decompondo os mesmos em funções de modo intrínseco. Visando detectar o maior número possível de toques suaves de luva na serra sem que cortes de ossos de frango fossem confundi- dos com toques de luva, o sistema apresentou um índice de acertos de aproximadamente 70%, havendo a ocorrência de apenas 2% de falsos positivos. Além desse problema, abordou-se o caso de detecção de trinca em ovos, no qual o objetivo era separar ovos trincados de ovos in- teiros utilizando um sistema barato e eficiente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: One of the most important sectors in the meatpacking industry is chicken quartering, where whole pieces are cut into smaller ones. The quartering process can be done by automatic ma- chines or by manually cutting the chickens using a circular saw. The manual technique imposes physical risks for the workers, which wear protective stainless steel gloves. Small injuries or, in the worst case, amputation of part of the hand can occur in the event of an accident. In this work, we propose a methodology to prevent this type of accident, which is based on the anal- ysis of the acoustic signals generated during this process. In the event of an accident, the saw touches the metal glove, the acoustic signals are processed and used to turn off the engine that drives the saw and trigger a braking system. The problem is firstly analyzed using a digital filter and then with multiresolution techniques by wavelet analysis. In addition, the empirical mode decomposition technique is also employed, which also performs multiresolution analysis of sig- nals. These three techniques are implemented and compared. The method presented a 70% of successful detection of light touches of saw/glove and 2% of false positives, when a normal cut operation is detected as a saw/glove touch, in general occurring when cutting specific parts of bone. Besides this problem, the case of eggshell crack detection is studied, where the goal was to separate cracked eggs from intact eggs using an inexpensive and efficient system. A solenoid was used as a source of mechanical excitation and the resulting acoustic signals were acquired and processed. The same signal processing techniques were employed and compared, with small changes in parameters. As a result, it was possible to detect 80% of cracked eggs and 100% of intact eggs. The multiresolution technique... (Complete abstract click electronic access below) / Mestre

No description available.

Batrachoididae, one of the most well-studied soniferous fishes, are typical examples of fish using intrinsic sonic muscles to excite vibration of swim bladder to emit sound. Most fishes possess a single swim bladder including the Batrachoididae. However, the grunting toadfish (Allenbatrachus grunniens) was found to have two separated swim bladders located in the dorsal part of the abdominal cavity; the size of the swim bladders were quite similar. Sonic muscles were firmly attached to the lateral side of each swim bladder. The aims of this study were to (1) investigate the specialized swimbladder morphology and the acoustic signals of the grunting toadfish (A. grunniens), (2) to falsify the hypothesis that this unique form of swim bladder is a synapomorphic character, and species that possess this character are sister groups. The vocal repertoire in grunting toadfish can generally divided into two types ¡V grunt and boatwhistle. Grunts were harmonic signals with shorter call duration, and could be emitted alone as single grunt (i.e., hand-held grunt) or in series (known as grunt train). Boatwhistles were also hamonic but much longer in call duration and usually appeared in succession. A small portion of signals were found to have acoustic beats, which was previously described in the three-spined toadfish (Batrachomoeus trispinosus), which also possess a pair of swim bladders. Therefore, signals with acoustic beats may be a key character for generating sound by two separated swim bladders. Comparing the morphological measurements of swim bladders indicated that there were no significant differences between swim bladders on different sides. However, comparisons between genders showed that the width, thickness, and weight of sonic muscle in females were significantly higher than males. Less wide sonic muscles with shorter sonic muscle fibers may enables the muscle to contract at a higher velocity in male fishes. However, females were found to have thicker sonic muscle, which indicated that the vocal ability in females may be higher than it was expected. The sonic muscle fibers of females have a larger myofibrillar region compared with males, which have a relatively larger central core. These characters may increase the fatigue-resistance of sonic muscle in males, which can contract at a relatively higher rate for a longer duration. Species with two separated swim bladders were found to be sister group in the molecular phylogenetic tree, implying that this specialized morphological character is synapomorphy.

I characterized dusky dolphin (Lagenorhynchus obscurus) underwater bait-balling behaviors and acoustic signals, and compared data between Argentina and New Zealand (NZ) to investigate the roles of ecology versus social learning. I quantified prey herding and capturing behaviors from video footage, and I analyzed acoustic signals from narrowband recordings. In both locations, I related bait-balling behaviors and acoustic signals to group and prey ball sizes. In NZ, I also related dolphin behaviors to prey ball escape behaviors and acoustic signal parameters to examine proximate functions. Observed herding behaviors typically involved dolphins swimming around or under a prey ball using a side body orientation, while dolphins typically captured fish from the side of a prey ball using a ventral orientation. Coordinated prey-capture behaviors may have made it easier for dolphins to capture fish by trapping fish between dolphins. Signals were categorized as click trains, burst pulses, and combinations due to a bimodal inter-click interval distribution. I observed 3 whistle-like chirp-screams, but no whistles. Sequences of burst pulses also occurred that contained 2-14 burst pulses that aurally and visually appeared closely matched. Similarities between locations suggest that ecological context related to broad behavioral and acoustic parameters, while social learning differences may occur on a finer scale. In NZ, prey balls exhibited horizontal and vertical movements, but the only behavior that preceded escape was “funneling”, the brief formation of a ball shape where the height was at least twice the width. Dolphin behaviors that related to prey balls ascending were type of herding pass, location of prey-capture attempts, and body orientation during attempts. These behavioral parameters may also be used to counter vertical prey escape behaviors. In NZ, all signal categories had a direct or indirect role in capturing prey. Click train-burst pulses were likely used for echolocating on prey, burst pulses and sequences appeared to have communication roles, and the role of click trains was ambiguous. No signal categories appeared to have a herding function, but the sheer number of signals emitted may have caused fish to cluster together more tightly and therefore facilitated capture.

No description available.

In this thesis, localization of the underwater sound sources using matched field processing technique is considered. Localization of the underwater sound sources is one of the most important problems encountered in underwater acoustics and signal processing. Many techniques were developed to localize sources in range, depth and bearing angle. However, most of these techniques do not consider or only slightly takes into account the environmental factors that dramatically effect the propagation of underwater sound. Matched field processing has been developed as a technique that fully considers the environmental factors. Matched field processing has proven to be successful in many applications such as localization of sources in range and depth, the determination of environmental parameters, and the evaluation of model accuracies. In this study, first a comparative analysis of narrowband matched field processors is given. Namely four main processors: Bartlett processor, Minimum Variance Distortionless Response (MVDR) processor, MVDR with neighboring location constraints and MVDR with environmental perturbation constraints are compared in terms of their probability of correct localization under certain environmental conditions. Secondly, a performance assesment for the most common broadband matched field processors is made. The correct localization performances for incoherent broadband matched field processor, Tolstoy/Michalopoulo&#039 / s coherent matched field processor and broadband matched field processor with environmental perturbation constraints is given for certain environmental conditions. Finally, a new weighting approach to combine data for broadband matched field processing is introduced. The fact that information from different frequencies may have different reliability depending on the environmental conditions is considered to develop a weighting scheme. It is shown that a performance gain compared to existing processors can be achieved by using the weighting scheme introduced in this study.

Thesis (M.S.) -- University of Maryland, College Park, 1999. / Thesis research directed by Institute for Systems Research. "M.S. 99-6." Includes bibliographical references (leaves 75-78). Available also online as a PDF file via the World Wide Web.