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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Three dimensional object analysis and tracking by digital holography microscopy

Schockaert, Cédric 26 February 2007 (has links)
Digital Holography Microscopy (DHM) is a new 3D measurement technique that exists since Charge Coupled Devices (or CCD cameras) allow to record numerically high resolution images. That opens a new door to the theory of holography discovered in 1949 by Gabor: the door that masked the world of digital hologram processing. A hologram is a usual image but that contains the complex amplitude of the light coded into intensities recorded by the camera. The complex amplitude of the light can be seen as the combination of the energy information (squared amplitude modulus) with the information of the propagation angle of the light (phase of the amplitude) for each point of the image. When the hologram is digital, this dual information associated with a diffractive model of the light propagation permits to numerically investigate back and front planes to the recorded plane of the imaging system. We understand that 3D information can be recorded by a CCD camera and the acquisition rate of this volume information is only limited by the acquisition rate of the unique camera. For each digital hologram, the numerical investigation of front and back regions to the recorded plane is a tool to numerically refocus objects appearing unfocused in the original plane acquired by the CCD.<p>This thesis aims to develop general and robust algorithms that are devoted to automate the analysis process in the 3D space and in time of objects present in a volume studied by a specific imaging system that permits to record holograms. Indeed, the manual processing of a huge amount of holograms is not realistic and has to be automated by software implementing precise algorithms. In this thesis, the imaging system that records holograms is a Mach-Zehnder interferometer working in transmission and studied objects are either of biological nature (crystals, vesicles, cancer cells) or latex particles. We propose and test focus criteria, based on an identical focus metric, for both amplitude and phase objects. These criteria allow the determination of the best focus plane of an object when the numerical investigation is performed. The precision of the best focus plane is lower than the depth of field of the microscope. From this refocus theory, we develop object detection algorithms that build a synthetic image where objects are bright on a dark background. This detection map of objects is the first step to a fully automatic analysis of objects present in one hologram. The combination of the detection algorithm and the focus criteria allow the precise measurement of the 3D position of the objects, and of other relevant characteristics like the object surface in its focus plane, or its convexity or whatever. These extra relevant measures are carried out with a segmentation algorithm adapted to the studied objects of this thesis (opaque objects, and transparent objects in a uniform refractive index environment). The last algorithm investigated in this research work is the data association in time of objects from hologram to hologram in order to extract 3D trajectories by using the predictive Kalman filtering theory. <p>These algorithms are the abstract bricks of two software: DHM Object Detection and Analysis software, and Kalman Tracking software. The first software is designed for both opaque and transparent objects. The term object is not defined by one other characteristic in this work, and as a consequence, the developed algorithms are very general and can be applied on various objects studied in transmission by DHM. The tracking software is adapted to the dynamic applications of the thesis, which are flows of objects. Performance and results are exposed in a specific chapter. <p> / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
332

3D Image Segmentation Implementation on FPGA Using EM/MPM Algorithm

Sun, Yan 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / In this thesis, 3D image segmentation is targeted to a Xilinx Field Programmable Gate Array (FPGA), and verified with extensive simulation. Segmentation is performed using the Expectation-Maximization with Maximization of the Posterior Marginals (EM/MPM) Bayesian algorithm. This algorithm segments the 3D image using neighboring pixels based on a Markov Random Field (MRF) model. This iterative algorithm is designed, synthesized and simulated for the Xilinx FPGA, and greater than 100 times speed improvement over standard desktop computer hardware is achieved. Three new techniques were the key to achieving this speed: Pipelined computational cores, sixteen parallel data paths and a novel memory interface for maximizing the external memory bandwidth. Seven MPM segmentation iterations are matched to the external memory bandwidth required of a single source file read, and a single segmented file write, plus a small amount of latency.
333

Development of a Grond-Based High-Resolution 3D-SAR System for Studying the Microwave Scattering Characteristics of Trees

Penner, Justin Frank 09 December 2011 (has links) (PDF)
This thesis presents the development of a high-resolution ground-based 3D-SAR system and investigates its application to microwave-vegetation studies. The development process of the system is detailed including an enumeration of high-level requirements, discussions on key design issues, and detailed descriptions of the system down to a component level. The system operates on a 5.4 GHz (C-band) signal, provides a synthetic aperture area of 1.7 m x 1.7 m, and offers resolution of 0.75 m x 0.3 m x 0.3 m (range x azimuth x elevation). The system is employed on several trees with varying physical characteristics. The resulting imagery demonstrates successful 3D reconstruction of the trees and some of their internal features. The individual leaves and small branches are not visible due to the system resolution and the size of the wavelength. The foliage's outline and internal density distribution is resolved. Large branches are visible where geometry is favorable. Trunks are always visible due to their size and normal-facing incidence surface and their return has the strongest contribution from their base. The imagery is analyzed for dependencies on radar and tree parameters including: incidence angle, signal frequency, polarization, inclusion size, water content, and species. In the current work, a single frequency (5.4 GHz) and polarization (HH) is used which leaves the door open for future analysis to use other frequencies and polarizations. The improved resolution capabilities of the 3D-SAR system enables more precise backscatter measurements leading to a greater understanding of microwave-vegetation scattering behavior.
334

Fast error detection method for additive manufacturing process monitoring using structured light three dimensional imaging technique

Jack Matthew Girard (17584095) 19 January 2024 (has links)
<p dir="ltr">Monitoring of additive manufacturing (AM) processes allows for saving time and materials by detecting and addressing errors as they occur. When fast and efficient, the monitored AM of each unit can be completed in less time, thus improving overall economics and allowing the user to accept a higher capacity of AM requests with the same number of machines. Based on existing AM process monitoring solutions, it is very challenging for any approach to analyze full-resolution sensor data that yields three-dimensional (3D) topological information for closed-loop real-time applications. It is also challenging for any approach to be simultaneously capable of <i>plug-and-play</i> operation once AM hardware and sensor subsystems are configured. This thesis presents a novel method to speed up error detection in an additive manufacturing (AM) process by minimizing the necessary three-dimensional (3D) reconstruction and comparison. A structured light 3D imaging technique is developed that has native pixel-by-pixel mapping between the captured two-dimensional (2D) absolute phase image and the reconstructed 3D point cloud. This 3D imaging technique allows error detection to be performed in the 2D absolute phase image domain prior to 3D point cloud generation, which drastically reduces complexity and computational time. For each layer of an AM process, an artificial threshold phase image is generated and compared to the measured absolute phase image to identify error regions. Compared to an existing AM error detection method based on 3D reconstruction and point cloud processing, experimental results from a material extrusion (MEX) AM process demonstrate that the proposed method has comparable error detection capabilities. The proposed method also significantly increases the error detection speed, where the relationship between the speed improvement factor and the percentage of erroneous pixels in the captured 2D image follows a power-law relationship. The proposed method was also successfully used to implement closed-loop error correction to demonstrate a potential process monitoring application.</p>
335

Réorganisation spatio-temporelle de l'architecture nucléaire de fibroblastes normaux et cellules de mélanome : effet du peptide (VGVAPG)3 / Spatiotemporel nucleus reorganization of fibroblasts and melanoma cells : effects of elastin peptide (VGVAPG)3

Chatron-Colliet, Aurore 29 September 2011 (has links)
Le mélanome est un cancer agressif dont la progression est facilitée par la dégradation de la matrice extracellulaire, à la fois par les fibroblastes et les cellules tumorales. Cette dégradation génère des peptides d’élastine, notamment responsables de la prolifération des cellules saines et cancéreuses. Le peptide d’élastine (VGVAPG)3 accélère la reprise et le déroulement du cycle cellulaire de fibroblastes normaux et de cellules de mélanomes préalablement synchronisés (expression de pKi-67, détection de la phase S et quantification d’ADN). L’architecture nucléaire associée à la reprise de la synthèse des ARNm concerne les compartiments nucléaires PML-NBs et domaines SC35, partenaires indissociables de la transcription et de l’épissage, qui sont étudiés, après immunomarquages, en microscopie confocale suivie d’une reconstruction 3D. Les compartiment PML-NBs et domaines SC35 se réorganisent en fonction d’une part des phases du cycle cellulaire et d’autre part de l’activité transcriptionnelle, passant d’une séquestration du SC35 dans les PML-NBs à une interpénétration des deux compartiments. L’analyse quantitative de ces compartiments complète les résultats architecturaux en 3D. Le peptide se fixe sur le complexe récepteur de l’élastine, et induit de l’activation de la voie MEK ½ ERK ½. Un antagoniste de cette fixation (lactose) ainsi que l’inhibition de la voie ERK ½ (UO126) conduisent à l’abolition des effets dus au peptide tant pour le cycle cellulaire que pour l’organisation des PML-NBs et domaines SC35, confirmant ainsi l’implication de ces voies. / Melanoma is an aggressive cancer for which invasion is facilitated by degradation of the extracellular matrix, both by normal fibroplasts and tumor cells. This degradation generates elastin peptides, in particular responsible for the proliferation of normal and tumor cells. The elastin peptide (VGVAPG)3. accelerates recovery and progression in cell cycle of normal fibroblasts and melanoma cells previously synchronized (expression of pKi-67, S-phase detection and quantification of DNA). The nuclear architecture associated with the recovery of the synthesis of mRNA on the PML-NBs nuclear compartments and SC35 domains, inseparable partners of transcription and splicing, which are studied after immunostaining by confocal microscopy followed by 3D reconstruction. Compartments PML-NBs and SC35domains are reorganized according of the phases of the cell cycle and also the transcriptional activity, from SC35 sequestration in PML-NBs to an interpenetration of the two compartments. The quantitative analysis of these compartments consolidates the 3D architectural results. The peptide binds to the elastin receptor complex and induceds the activation of the MEK 1/2 ERK 1/2. An antagonist of the fixation (lactose) and inhibition of ERK 1/2 (UO126) lead to the abolition of effects due to the peptide for both the cell cycle and the organized of PML-NBs and SC35 domains, confirming the involvement of these pathways.
336

Evaluation of the dental arch in children with cleft lip and palate by means of 3D digital models / Avaliação dos arcos dentários de criança com fissura labiopalatina por meio de modelos digitais tridimensionais

Jorge, Paula Karine 15 July 2014 (has links)
The aim of this study was to evaluate the dimensional alterations of dental arches of cleft lip and palate children after cheiloplasty at two rehabilitation centers. The sample was composed of 94 digital models and divided in two groups: Group I 23 children, assisted at University of Zurich with presurgical orthopedic intervention (Hotz plate); Group II 24 children, assisted at Hospital for Rehabilitation of Craniofacial Anomalies of the University of São Paulo without presurgical orthopedic intervention. The three dimensional images were used to evaluate before lip repair (stage 1) and approximately 1 year old (stage 2). The obtained measures were: intercanine distance, intertuberosity distance, anterior-posterior arch distance, anterior-posterior cleft length, anterior and posterior cleft width. The comparison between stages 1 and 2 was evaluated in group I, group II and between group I and II. The alterations between groups were verified by Independent t test. If the sample did not present a normal distribution, Wilcoxon and Mann-Whitney tests were used. In Group I, the comparisons between stages 1 and 2 showed that the intertuberosity and anterior-posterior arch distance increased and the intercanine, anterior and posterior cleft distances decreased. In Group II, the comparisons between stages 1 and 2 showed that intertuberosity distance increased and intercanine, anteriorposterior cleft length distances, anterior and posterior cleft widths decreased. The comparison of the dimensional alterations of dental arches between the two rehabilitation centers exhibited differences: in the stage 1, the intercanine distance decreased in Group II; in the stage 2, the anterior cleft width, the intercanine distance and the anterior-posterior cleft length decreased in Group II, suggesting the superposition of maxillary segments; in Group II, there was a greater narrowing of the anterior and posterior cleft widths, suggesting that Hotz plate induced a more evenly and equidistant approximation of maxillary segments in Group I. It is worth emphasizing that more studies should be conduct to reduce the variability in treatment protocols for cleft lip and palate patients, thus assuring the best evidencebased treatment. / O propósito deste estudo foi avaliar as alterações dimensionais dos arcos dentários de crianças com fissura de lábio e palato após a queiloplastia em dois centros de reabilitação. A amostra foi composta por 94 imagens digitais de modelos de gesso, e dividida em dois grupos: Grupo I - 23 crianças, tratas na Universidade de Zurique, com intervenção ortopédica pré-cirúrigica (placa de Holtz); Grupo II - 24 crianças tratadas no Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, sem intervenção ortopédica pré-cirúrgica. As imagens tridimensionais dos modelos de gesso foram avaliados antes da queiloplastia (estágio 1) e com aproximadamente 1 ano de idade (estágio 2). As seguintes dimensões foram obtidas: comprimento anteroposterior da fissura, amplitude anterior da fissura, amplitude posterior da fissura, comprimento anteroposterior do arco, distância intercaninos e distância intertuberosidades. As comparações foram realizadas entre os estágios 1 e 2 e entre os grupos I e II. As diferenças entre os grupos foram verificadas pelo teste t independente, os testes de Wilcoxon e Mann-Whitney foram usados. No Grupo I, entre os estágios 1 e 2, as distâncias intertuberosidade aumentou e as distâncias intercaninos, distância anteroposterior da fissura, amplitude anterior e posterior da fissura diminuíram. A comparação entre as alterações dimensionais dos arcos dentários entre os dois centros de reabilitação apresentaram diferenças: no estágio 1, a distância intercaninos foi menor no Grupo II que no Grupo I; e no estágio 2, a amplitude anterior da fissura, a distância intercaninos e o comprimento anteroposterior da fissura foram menos no Grupo II que no Grupo I, sugerindo sobreposição dos segmentos maxilares. No Grupo II, houve maior estreitamento nas amplitudes anterior e posterior da fissura, sugerindo que a placa de Holtz no Grupo I induziu a aproximação dos segmentos maxilares de forma mais uniforme e equidistante. É importante salientar que mais estudos longitudinais precisam ser conduzidos a fim de reduzir a variabilidade de protocolos de tratamento em pacientes com fissura de lábio e palato, garantindo o melhor tratamento baseado em evidências científicas.
337

Análise em 3D das alterações dimensionais dos arcos dentários de crianças com fissura labiopalatina / 3D analysis of changes in dental arch dimensions in children with cleft lip and palate.

Sakoda, Karine Vaz Laskos 16 July 2014 (has links)
O propósito deste trabalho foi uma avaliação longitudinal das dimensões dos arcos dentários de crianças com fissura labiopalatina após a realização das cirurgias primárias. A amostra foi composta por modelos digitais tridimensionais obtidos a partir de modelos de gesso de 25 indivíduos com fissura transforame incisivo unilateral (Grupo FTIU) e 29 pacientes com fissura pós-forame incisivo (Grupo FP). As dimensões maxilares foram avaliadas aos 3 meses de idade (previamente à queiloplastia), com 1 ano de idade (previamente à palatoplastia) e aos 2 anos de idade. As seguintes dimensões foram obtidas: comprimento anterior do arco maxilar, comprimento total do arco maxilar, distância intercaninos e distância intertuberosidades. Após a queiloplastia, houve redução na distância intercaninos e no comprimento anterior do arco no grupo FTIU. Após a palatoplastia, as dimensões maxilares apresentaram aumento significativo, com exceção da distância intercaninos no grupo FTIU e da distância intertuberosidades em ambos os grupos. Pode-se concluir que, no grupo FTIU, a queiloplastia teve maior influência na porção anterior do arco. A palatoplastia inibiu o crescimento no sentido transversal nas regiões anterior e posterior do arco. No grupo FP, após a palatoplastia houve inibição do crescimento maxilar no sentido transversal, mais pronunciada na região posterior do arco. No momento da palatoplastia e aos 2 anos de idade, as dimensões maxilares do grupo FTIU foram muito semelhantes às dimensões do grupo FP. / The purpose of this study was a longitudinal evaluation of dental arch dimensions in children with cleft lip and palate after primary surgeries. The sample consisted of three-dimensional digital models obtained from plaster casts of 25 subjects with complete unilateral cleft lip and palate (Group UCLP) and 29 patients with cleft palate (Group CP). Maxillary arch dimensions were measured at 3 months (before lip repair), at 1 year (before palate repair) and at 2 years of age. The following dimensions were obtained: anterior maxillary length, total maxillary length, intercanine width and intertuberosity width. Decreased intercanine width and anterior arch length were observed after lip repair in group UCLP. After palatoplasty, maxillary dimensions significantly increased, except for intercanine width in group UCLP and intertuberosity width in both groups. It is concluded that in group UCLP, lip repair had a higher influence on the anterior portion of the arch. Palatoplasty inhibited maxillary growth in transverse direction in anterior and posterior regions. In group CP, the inhibition of transverse maxillary growth after palatoplasty was more pronounced in the posterior region of the arc. At palatoplasty and at 2 years of age, maxillary dimensions were very similar between UCLP and CP groups.
338

The application of visualisation techniques to the process of building performance analysis

Pilgrim, Matthew John January 2003 (has links)
Visualisation, the representation of data in visual form, is at the core of our ability to communicate information. Without clear representation, data would remain in its raw form thus greatly hindering the communication process. This is especially the case when the data source is large, complex and subject to change. One such area is related to the use of computer based simulation tools for thermal analysis. This research investigates the potential of visualisation to improve the ways in which thermal analysis data are presented to building services engineers, with a view to increasing the accuracy and efficiency of its interpretation. The approach taken throughout followed a pattern of research, development, demonstration and evaluation. The research phase included a detailed review of existing visualisation theory and an extensive user requirement survey. The development phase produced three working visualisation software prototypes, each of which was demonstrated or evaluated within the sponsoring company. Whilst the initial emphasis of the research was advanced Three-Dimensional (3D) visualisation, extensive user requirement analysis indicated that comparing multiple datasets in an intuitive manner was more important. In response, the research focused on combining techniques in ways which supported the rapid comparison of multiple files and the data contained within. The final prototype combines techniques for data storage and manipulation with information visualisation techniques and advanced 3D graphics. These elements are tightly integrated within a single application that facilitates the management and interpretation of data from multiple analysis models. Evaluation of the prototype showed high levels of user satisfaction and improvements in the accuracy and efficiency of data interpretation. The techniques demonstrated by the prototype were also understood and liked by the users of thermal analysis tools. Several of the techniques, such as the new Force Directed Difference Diagrams, have potential applications outside of building services engineering. The research has demonstrated it is possible to improve the representation and interpretation of building performance data using visualisation techniques.
339

Avaliação da estabilidade da cirurgia de avanço mandibular através da superposição de modelos tridimensionais / Three-dimensional assessment of mandibular advancement 1 year after surgery

Felipe de Assis Ribeiro Carvalho 12 August 2009 (has links)
Embora a cirurgia de avanço mandibular seja considerada um procedimento altamente estável, existem algumas preocupações clínicas em relação a mudanças nos côndilos e nos segmentos proximais, que podem levar a recidiva sagital e abertura de mordida. A avaliação dos resultados da cirurgia através de ferramentas de geração e superposição de modelos virtuais tridimensionais (3D) permite a identificação e quantificação dos deslocamentos e remodelação óssea que podem ajudar a explicar as interações entre os componentes dentários, esqueléticos e de tecido mole que estão relacionados a resposta ao tratamento. Este estudo observacional prospectivo avaliou, através de tomografia computadorizada de feixe cônico (CBCT), mudanças na posição/remodelação 3D dos ramos mandibulares, côndilos e mento. Assim, exames CBCT de 27 pacientes foram adquiridos antes da cirurgia (T1), imediatamente após a cirurgia(T2), e 1 ano após a cirurgia(T3). Uma técnica automática de superposição na base do crânio foi utilizada para permitir a avaliação das mudanças ocorridas nas regiões anatômicas de interesse (RAI). Os deslocamentos foram visualizados e quantificados em mapas coloridos 3D através da ferramenta de linha de contorno (ISOLINE). Pelo teste t pareado compararam-se as mudanças entre T1-T2 e T2-T3. O coeficiente de correlação de Pearson verificou se os deslocamentos ocorridos nas RAI foram correlacionados entre si e entre os tempos de avaliação. O nível de significância foi determinado em 0,05. O avanço mandibular médio foi de 6,813,2mm em T2 e 6,363,41mm em T3 (p=0,13). Entre T2 e T3, a posição do mento variou positivamente (&#8805;2mm) em 5 pacientes negativamente em 7. 12% dos pacientes sofreram recidivas &#8805;4mm. Para todas as outras RAI avaliadas, apenas a porção inferior dos ramos (lado direito - 2,342,35mm e lado esquerdo 2,972,71mm) sofreram deslocamentos médios >2mm com a cirurgia. No acompanhamento em longo prazo, esse deslocamento lateral da porção inferior dos ramos foi mantido (lado direito - 2,102,15mm, p=0,26; e lado esquerdo -2,762,80, p=0,46), bem como todos os outros deslocamentos observados (p>0,05). As mudanças na posição do mento foram correlacionadas a adaptações pós-cirúrgicas nos bordos posteriores dos ramos (esquerdo r=-0,73 e direito r=-0,68) e côndilos (esquerdo r=-0,53 e direito r=-0,46). Os deslocamentos médios sofridos pelas estruturas do lado esquerdo foram suavemente maiores do que no direito. Correlações dos deslocamentos ocorridos entre T1-T2 e T2-T3 mostraram que: os deslocamentos dos côndilos esquerdos com a cirurgia foram negativamente correlacionados às adaptações pós-cirúrgicas destes (r=-0,51); e que o deslocamento da porção superior do ramo esquerdo com a cirurgia foi correlacionado à adaptação pós-cirúrgica ocorrida nos bordos posteriores (r=0,39) e côndilos do mesmo lado (r=0,39). Pode-se concluir que: (1) os deslocamentos causados pela cirurgia foram de modo geral estáveis no acompanhamento de 1 ano, mas identificou-se uma considerável variação individual; (2) as mudanças pós-cirúrgicas na posição do mento foram correlacionadas a adaptações sofridas pelos côndilos e bordos posteriores dos ramos; e que (3) deslocamentos suavemente maiores causados pela cirurgia nas estruturas do lado esquerdo levaram a maiores adaptações pós-cirúrgicas no segmento proximal deste lado. / Although mandibular advancement surgery is considered a highly stable procedure, some clinical concerns have been raised regarding condylar and proximal segment changes that may lead to sagittal relapse and anterior bite opening. Assessment of surgical treatment outcomes using three-dimensional (3D) virtual models and superimposition tools allow the identification and quantification of bone displacement and remodeling that can help explain the interactions between the dental, skeletal and soft tissue components that underpin the response to treatment. This prospective observational study evaluated changes in the 3D position and remodeling of the mandibular rami, condyles and chin at splint-removal and 1 year after mandibular advancement surgery. For that, pre-surgery(T1), splint-removal(T2), and one year post-surgery(T3) cone-beam computed tomography (CBCT) scans of 27 subjects were used. An automatic technique of cranial base superimposition was used to assess changes in the anatomic regions of interest (ROI). Displacements were visually displayed and quantified in three-dimensional color maps by means of a contour line tool (ISOLINE). A paired t-test was used to compare changes between T1-T2 and T2-T3. Pearson correlation coefficients were used to check if displacements at the ROI were correlated within each other and along the evaluated times . The level of significance was set at 0.05. The mean mandibular advancement was 6.813.2mm at T2 and 6.363.41mm at T3 (p =0.13). Between T2 and T3, the chin position was further forward 2mm or more for 5 subjects and relapsed backwards &#8805;2mm for 7 subjects. 12% of patients showed relapses &#8805;4mm. For all other evaluated ROI, only the inferior rami (right 2.342.35mm and left 2.972.71mm) had mean displacements >2mm with surgery. In the long-term follow-up, those inferior rami lateral displacements were maintained (right 2.102.15mm, p=0.26 and left 2.762.80,p=0.46), as well as all other observed displacements (p>0.05). Post-surgical movement in the position of the chin was significantly correlated to changes in the posterior borders (left r=-0.73 and right r=-0.68) and condyles (left r=-0.53 and right r=-0.46). Mean displacements of the structures at the left side were slightly greater when comparing to the right side. Correlations of T1-T2 with T2-T3 displacements showed that the displacement of the left condyles with surgery were negatively correlated to its post-surgical adaptations (r=-0.51); and that superior portion of the left ramus surgery displacement was correlated to the post-surgical adaptation at the ramus posterior border (r=0.39) and condyle at the same side (r=0.39). It can be concluded that: (1) surgery changes were generally stable in one year follow up, but with a considerable individual variability; (2) post-surgical changes at the chin position are correlated to adaptations at condyles and rami posterior borders; and that (3) slightly greater displacements with surgery at the left side lead to greater post-surgical adaptations in the proximal segment at this side.
340

ICT-enabled collaborative working methodologies in construction

Yeomans, Steven G. January 2005 (has links)
Since the turn of the new millennium the UK construction industry has witnessed the naissance of a new paradigm known as ICT-enabled collaborative working. Advocates of this new approach believe that the adoption of ICTs will lead to better project information exchange, communications, integrated processes and therefore more efficient collaborative working. It is expected that ICT-enabled collaborative working will not only overcome the industry's many inherent problems, such as its adversarial and fragmented nature, but that it will also facilitate benefits for all involved. This supposition is based upon the recognition that its exploitation has proven successful at transforming other industries. The EngD thesis pertains to a four-year study on two methodologies currently applied under the concept of ICT-enabled collaborative working, 'Collaborative Prototyping' (CP) and the use of 'Construction Project Extranets' (CPE). The research project utilised literature reviews, case studies, project observations, active involvement, surveys, interviews and workshops to develop expertise and knowledge within the subject area. It shows that a large disparity exists between the use of a shared 3D model and the use of CPEs to promote collaborative working. Conversely, whilst CPEs have become the de facto ICT-enabled approach to seeking improvements in project efficiency (due to their potential to enhance communications, integration and collaboration) they are not being utilised effectively. This was attributed to the use of inadequate procedures that fail to provide proper consideration of all the necessary issues to ensure successful implementation, application and management of the CPE. As a result, project teams are failing to ascertain the full potential benefits offered by such collaboration tools. The research demonstrates that to overcome this, project teams require the development of an industry best-fit framework that defines proficient procedures. It highlights the main factors for inclusion within a protocol. Furthermore, it provides a simple form to promote greater awareness of the key factors that impinge on the successful application of CPE. The thesis concludes by outlining a number of recommendations for consideration by the industry, along with requirements for future work.

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