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University of Macau / Faculty of Science and Technology. / Department of Computer and Information Science

"Ultrasound has developed from 2D into 3D ultrasound in recent years. 3D ultrasound gives enhanced diagnostic capabilities and can make it easier for less trained people to interpret ultrasound images. In general there are two ways of getting a 3D ultrasound image : By using a 2D array scanner (giving 3D images directly) or by using a series of 2D scans and combine these scans to build a 3D volume. The only practical scanning technique that can be used for portable systems is freehand scanning that combines a series of 2D images. 3D images acquired by using a conventional ultrasound transducer and the freehand scanning technique are, however, often misaligned laterally and have unevenly spacing. These errors can be corrected if the position associated with each 2D image is known. Commercially available positioning systems use magnetic or optical tracking, but these systems are very bulky and not portable. We have proposed another way to get the position by tracking on the skin surface. This is done by obtaining digital images of the surface at a very high rate and then cross correlating each image to reveal the change in position. Accumulating these changes will then give the correct location (in two dimensions) relative to a starting point. Correct volume and surface rendering can therefore be achieved when a scan is done. A custom-made housing was made to mount an optical sensor to the ultrasound transducer. The optical sensor was placed in the housing and the hardware circuit from an optical mouse was used to interface to a USB interface. An implementation with an optical fiber was also made since this could fit easily to the transducer handle. In Windows a custom-made mouse driver was used to extract the position information from the sensor. This driver allowed multiple mouse devices in the system and removed the acceleration of the mouse, giving a correct transfer of the position. A DLL (Dynamic Link Library) was used to interface to a 3D ultrasound software called Sonocubic. Using the DLL and a custom modified version of Sonocubic 3D construction software has allowed a correct compensation of the acquired ultrasound images. To validate the accuracy of the optical sensor an optical mouse was placed in an XY-recorder to compare the acquired position with the actual position. The test revealed that the accuracy of the optical sensor is very high. A 55 mm movement of the sensor gave a deviation of 0.56 mm which is well within the expected result. A computer generated phantom was made to see if the compensation algorithm was working. The test revealed that the compensation algorithm and the software is working perfectly. Next a vessel phantom was scanned to see that the compensation algorithm (lateral compensation) was working in real life. The test showed that a correct lateral compensation was made. Finally 3D phantoms were custom made to test the accuracy of the system by estimation of a known volume. The system was able to estimate the volume in a phantom within an accuracy of 6 %. Performance of the system with direct imaging, using the optical sensor and a lens, was compared to an implementation with an optical fiber, two lenses and the optical sensor. The optical fiber was difficult to implement since the image contrast was degraded severely through the optical fiber and the lenses. This made it difficult for the correlation algorithm to function correctly and tracking could therefore not be done on a skin surface. Code for an FPGA was made in VHDL to extract the actual images from the optical sensor and display them directly on a computer screen. This was necessary to see how well the sensor was in focus. This proved to be a really useful tool for adjusting the optical system for maximal contrast. The optical tracking on a skin surface is a good way to assist a user doing a freehand scanning to get images without geometric distortion. Furthermore, it is the only real positioning system for a portable system. One requirement for this system is, however, that the object being scanned is flat and does not curve or vary vertically. For most applications this is not the case, and we are therefore proposing an implementation with microgyros that is able to give angle information as well. This would give the system a total of up to 5 instead of just 2 degrees of freedom. The status of this is currently that it can be easily implemented in the DLL, but it is not implemented in the 3D reconstruction software, Sonocubic."

Orientador: Alex Sandro Campos Maia / Coorientador: Marcos Chiquitelli Neto / Banca: Euclides Braga Malheiros / Banca: Tomas Norton / Banca: William Koury Filho / Banca: Vinicius de França Carvalho Fônseca / Resumo: A fim de utilizar a modelagem tridimensional (3D) para estimar área, volume e massa, bem como avaliar o impacto dos desvios envolvidos nas equações empíricas disponíveis na literatura, em animais, foram utilizados seis ovinos Corriedale tosqueados com massa entre 10 e 105 kg e cinco bovinos Nelore com massa entre 600 a 800 kg. Os animais foram treinados utilizando os princípios de habituação e condicionamento, a fim de reduzir a reatividade dos animais. Para medição da área de superfície, utilizaram-se basicamente três procedimentos: equação empírica (EE) para cada espécie, instrumento manual de medição (IMM) e modelagem 3D do animal por fotogrametria (AR) e escaneamento com sensor kinect (AS_KS). Foi realizada uma análise de covariância, sendo a massa a covariável e uma análise de regressão não linear foi ajustada como uma função potência (alometria). Analisando as médias de área de superfície, para ovinos, em relação aos procedimentos utilizados não houve diferença entre IMM e modelos 3D, bem como entre os modelos 3D, enquanto entre IMM e EE houve diferença significativa. Para os bovinos, observou-se que os procedimentos 3D foram, em média, superiores às estimativas de área de superfície pela EE (a=5%). Quando se plotou os dados de área de superfície, de ovinos, dos métodos testados em função da massa corporal, obteve-se aproximações empíricas distintas daquelas estimadas pela EE em mais de 11% para animais acima de 100kg, enquanto que para os bovinos a diferença média entr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In order to use three-dimensional (3D) modeling to estimate area, volume and mass, as well as to evaluate the impact of the deviations involved in the empirical equations available in the literature, in livestock, six shorn Corriedale sheep were weighed with mass between 10 and 105 kg and five Nelore cattle with mass between 600 and 800 kg. The animals were trained using the principles of habituation and conditioning in order to reduce the reactivity of the animals. For the measurement of the surface area, three procedures were used: empirical equation (EE) for each species, manual measurement instrument (IMM) and 3D animal modeling by photogrammetry (AR) and kinect sensor (AS_KS) scanning. A covariance analysis was performed, with the mass being covariable and a non-linear regression analysis was adjusted as a power function (allometry). Analyzing the surface area averages for sheep, in relation to the procedures used there was no difference between IMM and 3D models, as well as between 3D models, while between IMM and EE there was a significant difference. For cattle, it was observed that the 3D procedures were, on average, higher than the surface area estimates by EE (a=5%). When data were plotted on the surface area of sheep and the methods tested for body mass, empirical approximations were obtained, different from those estimated by EE in more than 11% for animals over 100 kg, while for cattle the difference between 3D and EE models was over 18%. As the adjustments of t... (Complete abstract click electronic access below) / Doutor

De nombreux noyaux atomiques et hypernoyaux se modélisent comme des structures à trois corps. C'est le cas, par exemple, de noyaux à halo, comme 6He, ou de noyaux stables, comme 12C et 9Be. En effet, 6He se caractérise comme un système à trois corps, formé d'un coeur (une particule alpha) et de deux neutrons de valence faiblement liés. Le noyau de 12C peut s'étudier comme un système lié formé de trois particules alphas, tandis que 9Be peut être décrit comme la liaison de deux particules alphas et d'un neutron. Dans les exemples précédents, les particules alphas sont des amas de nucléons. Elles possèdent donc une structure interne dont il faut tenir compte en raison du principe de Pauli. Les modèles les plus réalistes pour décrire les structures à trois corps sont les modèles "microscopiques". Ces modèles prennent en compte explicitement tous les nucléons et respectent exactement le principe d'antisymétrisation de Pauli. Cependant, l'application de ces modèles est fortement limitée en pratique, car ils exigent de trop nombreux et trop longs calculs. Par conséquent, pour simplifier considérablement les calculs et permettre l'étude des structures à trois corps, des modèles moins détaillés, de type "semi-microscopiques", sont également développés. Dans ces modèles, on représente les amas de nucléons comme de simples particules ponctuelles. Dans ce cas, la modélisation consiste à construire les potentiels effectifs entre les amas, puis à les employer dans les modèles à trois corps. Dans ce travail, nous avons développé les modèles "semi-microscopiques à trois corps". Les potentiels effectifs entre amas sont directement déduits des forces entre nucléons (selon la RGM à 2 corps). Ces potentiels sont "non-locaux", et dépendent des énergies des amas qui interagissent. Ils permettent de simuler le principe de Pauli et les échanges de nucléons entre les amas. La dépendance en l'énergie se révèle être un inconvénient dans les modèles à trois corps. Les potentiels effectifs sont par conséquent transformés en de nouveaux potentiels (non-locaux) indépendants de l'énergie, bien adaptés aux modèles à trois corps. Les modèles "semi-microscopiques" sont beaucoup plus simples et plus rapides que les modèles "microscopiques". Ils fournissent les fonctions d'onde des états liés à trois corps des noyaux légers et hypernoyaux. Cela permet d'une part de comprendre les propriétés spectroscopiques nucléaires, et d'autre part, cela ouvre la voie pour de futurs modèles de réactions nucléaires impliquant les structures à trois corps. / Several atomic nuclei and hypernuclei can be modelled as three-body structures: e.g., two-neutron halo nuclei, such as 6He, and other nuclei, such as 12C and 9Be. Indeed 6He can be represented as a three-body system, made up of a core (an alpha particle) and two weakly bound valence neutrons. The 12C nucleus can be studied as a bound system formed by three alpha particles, while the 9Be nucleus can be described as the binding of two alpha particles and one neutron. In these typical examples, the alpha particles are clusters of nucleons. They have an internal structure that must be taken into account because of the Pauli principle. The most realistic models are the "microscopic models". In these models, all the nucleons are taken into account, and the Pauli antisymmetrisation principle is fully respected. However, the application of the "microscopic models" is limited in practice, because they require too many laborious calculations. Therefore, in order to greatly simplify the calculations, "semi-microscopic models" are developed. In those models, the clusters of nucleons are treated as ("structureless") pointlike particles. The models then consist in determining the effective potentials between the clusters, and in using them in three-body models. In the present work, we have developed "semi-microscopic models". The effective potentials between the clusters are directly obtained from the interactions between nucleons (according to the two-cluster RGM). These potentials are "nonlocal", and depend on the energy of the interacting clusters. The non-locality is a direct consequence of the Pauli principle and the exchanges of nucleons between the clusters. The energy-dependence of the potentials turns out to be a drawback in three-body models. Therefore, the effective potentials are transformed into energy-independent potentials, which can be used in three-body models. The "semi-microscopic models" are much simpler and faster than the "microscopic models". They provide the three-body bound-state wave functions (i.e., the spectroscopic properties and the structure) of light nuclei and hypernuclei. Such wave functions are also the basic ingredient that will be used in future reactions models.

Taiwan is a small island and there are more than 90% of the ex/import trade of the country is dominated by the shipping transportation. The shipping transportation is very important to the existence and development of the country. Taiwan and China being an official member of WTO since from the year 2002, the coastal shipping transportation between Taiwan and China is still very busy and even if more frequent than before. The direct navigation between Taiwan and China ports is still strict prohibited by the Taiwan government. All the ships must be direct sailing for the third port such as Hong Kong, Ishigaki Jima, Busan for only port clearance purpose after sailed from China or Taiwan ports, vice versa. The exact effect of the mini three links between China and Taiwan is quite limited, when the major three links will come true is still unclear under the political issue across the Taiwan Strait so far. Taiwan shipping industry is encountering some challenges or obstacles in the current circumstance regarding how to penetrate or break through the existing barriers to be successfully survived in the market or develop their business connection in China those are either coming from Taiwan government or China administration being installed to the Taiwan shipping forwarders. Shipping industry is including the ship owners¡Bshipping agents¡Bfreight forwarders (NVOCC). This study will explore the result of the Taiwan shipping industry can better utilize the company¡¦s core competence to smooth run the business in Taiwan and develop its connection in mainland China. Will use Hansen Group as an individual case by using the company¡¦s strategy of its several different stream business divisions to ¡§think global, act locally¡¨, standing in Taiwan¡Bgo to China and take the world.

Computer vision tasks such as three dimensional (3D) registration, 3D modelling, and 3D object recognition are becoming more and more useful in industry, and have application such as reverse CAD engineering, and robot navigation. Each of these applications use correspondence algorithms as part of their processes. Correspondence algorithms are required to compute accurate mappings between artificial surfaces that represent actual objects or scenes. In industry, inaccurate correspondence is related to factors such as expenses in time and labour, and also safety. Therefore, it is essential to select an appropriate correspondence algorithm for a given surface matching task. However, current research in the area of surface correspondence is hampered by an abundance of applications specific algorithms, and no uniform terminology of consistent model for selecting and/or comparing algorithms. This dissertation presents a correspondence framework for surface matching algorithms. The framework is a conceptual model that is implementable. It is designed to assist in the analysis, comparison, development, and implementation of correspondence algorithms, which are essential tasks when selecting or creating an algorithm for a particular application. The primary contribution of the thesis is the correspondence framework presented as a conceptual model for surface matching algorithms. The model provides a systematic method for analysing, comparing, and developing algorithms. The dissertation demonstrates that by dividing correspondence computation into five stages: region definition, feature extraction, feature representation, local matching, and global matching, the task becomes smaller and more manageable. It also shows that the same stages of different algorithms are directly comparable. Furthermore, novel algorithms can be created by simply connecting compatible stages of different algorithms. Finally, new ideas can be synthesised by creating only the stages to be tested, without developing a while new correspondence algorithm. The secondary contribution that is outlined is the correspondence framework presented as a software design tool for surface matching algorithms. The framework is shown to reduce the complexity of implementing existing algorithms within the framework. This is done by encoding algorithms in a stage-wise procedure, whereby an algorithm is separated into the five stages of the framework. The software design tool is shown to validate the integrity of restructuring existing algorithms within it, and also provide an efficient basis for creating new algorithms. The third contribution that is made is the specification of a quality metric for algorithms comparison. The metric is used to assess the accuracy of the outcomes of a number of correspondence algorithms, which are used to match a wide variety of input surface pairs. The metric is used to demonstrate that each algorithm is application specific, and highlight the types of surfaces that can be matched by each algorithm. Thus, it is shown that algorithms that are implemented within the framework can be selected for particular surface correspondence tasks. The final contribution made is this dissertation is the expansion of the correspondence framework beyond the surface matching domain. The correspondence framework is maintained in its original form, and is used for image matching algorithms. Existing algorithms from three image matching applications are implemented and modified using the framework. It is shown how the framework provides a consistent means and uniform terminology for developing both surface and image matching algorithms. In summary, this thesis presents a correspondence framework for surface matching algorithms. The framework is general, encompassing a comprehensive set of algorithms, and flexible, expanding beyond surface matching to major image matching applications.

Thesis (Ph.D.). / Written for the Dept. of Electrical & Computer Engineering. Title from title page of PDF (viewed 2008/01/12). Includes bibliographical references.

Thesis (D.W.S.)--Institute for Worship Studies, 2007. / Abstract. Includes bibliographical references (leaves 166-171).

Thesis (D.W.S.)--Institute for Worship Studies, 2007. / Abstract. Includes bibliographical references (leaves 166-171).