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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.
51

Raman Biosensors

Ali, Momenpour January 2017 (has links)
This PhD thesis focuses on improving the limit of detection (LOD) of Raman biosensors by using surface enhanced Raman scattering (SERS) and/or hollow core photonic crystal fibers (HC-PCF), in conjunction with statistical methods. Raman spectroscopy is a multivariate phenomenon that requires statistical analysis to identify the relationship between recorded spectra and the property of interest. The objective of this research is to improve the performance of Raman biosensors using SERS techniques and/or HC-PCF, by applying partial least squares (PLS) regression and principal component analysis (PCA). I began my research using Raman spectroscopy, PLS analysis and two different validation methods to monitor heparin, an important blood anti-coagulant, in serum at clinical levels. I achieved lower LOD of heparin in serum using the Test Set Validation (TSV) method. The PLS analysis allowed me to distinguish between weak Raman signals of heparin in serum and background noise. I then focused on using SERS to further improve the LOD of analytes, and accomplished simultaneous detection of GLU-GABA in serum at clinical levels using the SERS and PLS models. This work demonstrated the applicability of using SERS in conjunction with PLS to measure properties of samples in blood serum. I also used SERS with HC-PCF configuration to detect leukemia cells, one of the most recurrent types of pediatric cancers. This was achieved by applying PLS regression and PCA techniques. Improving LOD was the next objective, and I was able to achieve this by improving the PLS model to decrease errors and remove outliers or unnecessary variables. The results of the final optimized models were evaluated by comparing them with the results of previous models of Heparin and Leukemia cell detection in previous sections. Finally, as a clinical application of Raman biosensors, I applied the enhanced Raman technique to detect polycystic ovary syndrome (PCOS) disease, and to determine the role of chemerin in this disease. I used SERS in conjunction with PCA to differentiate between PCOS and non-PCOS patients. I also confirmed the role of chemerin in PCOS disease, measured the level of chemerin, a chemoattractant protein, in PCOS and non-PCOS patients using PLS, and further improved LOD with the PLS regression model, as proposed in previous section.
52

Locally one dimensional finite difference time domain method with frequency dependent media for three dimensional biomedical applications

Hemmi, Tadashi January 2014 (has links)
The finite difference time domain (FDTD) method is commonly used for numerical simulations of the electromagnetic wave propagation in time domain. The FDTD method is easy to implement and the computational results are highly relevant to the analytical solution, so that the FDTD method is applied to variety application problems. However, the computational efficiency of the FDTD method is constrained by the upper limit of the temporal discretisation. The Courant Friedrich Lewy (CFL) stability condition limits the time step for the computation of the FDTD method, so that if the spatial discretisation of the computation is set to be small in order to obtain high accurate results, the size of the temporal discretisation need to be satisfy the CFL stability condition. The locally one dimensional FDTD (LOD-FDTD) method is unconditionally stable. The time step and the spatial step can be independently chosen for the computation of the LOD-FDTD method. The arithmetic operations of the LOD-FDTD method is fewer than that of the other implicit FDTD method, such as the Crank Nicolson FDTD (CN-FDTD) method and the alternating direction implicit FDTD (ADI-FDTD) method. Although the implementation of the LOD-FDTD method is simpler than that of the ADI-FDTD method,the numerical error in the computational results of the LOD-FDTD method is equivalent to that in the computational results of the ADI-FDTD method. In this thesis, a new three dimensional (3D) frequency dependent (FD) LOD-FDTD method is proposed. The one pole Debye model is incorporated into the 3D-FD-LOD-FDTD method in order to deal with practical applications. The proposed method is implemented in Fortran 90 and parallelised with OpenMP. A simulation model of the human phantom is developed in the 3D-FD-LOD-FDTD method with fine structures and frequency dependent dielectric properties of the human tissues, and numerical simulation of electromagnetic wave propagation inside the human head is shown.
53

Ontological approach for LOD-sensitive BIM-data management

Karlapudi, Janakiram, Valluru, Prathap, Menzel, Karsten 13 December 2021 (has links)
The construction industry is a collaborative environment with the involve-ment of multiple disciplines and activities throughout the Building Lifecycle Stages. The collaboration requires the iterative and coordinated exchange of information for significant improvement of the building design, construction and management. The successful representation of these information re-finements enables the identification of the required level of detail (LOD) for data sharing parameters between the multiple disciplines. Since the last dec-ade, LOD is a promising approach for efficient representation of semantically rich BIM data in different levels. Despite the improvement, there is a lack of efficient implementation in building lifecycle functionalities, because of their fundamental heterogeneity, versatility and adaptability. The proposed approach enables the representation of LOD-sensitive BIM data through the formal definition of ontologies. The paper validates this approach based on the concept of competency questions and their respective SPARQL queries. With the demonstration and validation, the paper provides the conceptual proof for the practical application of the developed approach. The proposed solution can also be easily adaptable and applicable to the present BIM pro-cess since the representation of BIM data in different ontologies (BOT, ifcOWL, etc.) are within reach.:1 Introduction and Background; 2 State-of-art-analysis 2.1 LOD systems 2.2 Information Management 3 Ontology-based LOD representation 3.1 LOD framework 3.2 Exemplary demonstration 4 BIM data management 4.1 LOD sensitive BIM data 4.2 LOD framework to processes 5 Framework validation 6 Conclusion and Future work 7 Acknowledgement 8 References
54

LOD pro GPUEngine / LOD for GPUEngine

Staněk, Jan January 2018 (has links)
The representation of 3D polygonal model on several levels of available detail is a problem inherent in the process of rendering a scene. Highly-detailed models, if placed far from the camera, suffer from spatial aliasing that results from inadequate sampling of their surface, and require disproportionately large amount of time to render. Low-detailed models on the other hand reduce the visual quality of the scene when placed too near to the camera. This report delves in both the theory and the practical techniques used for solving these problems. It describes various published solutions and the principles behind them, and presents a design and an implementation of selected techniques for the GPUEngine library.
55

LOD pro GPUEngine / LOD for GPUEngine

Staněk, Jan January 2018 (has links)
The representation of 3D polygonal model on several levels of available detail is a problem inherent in the process of rendering a scene. Highly-detailed models, if placed far from the camera, suffer from spatial aliasing that results from inadequate sampling of their surface, and require disproportionately large amount of time to render. Low-detailed models on the other hand reduce the visual quality of the scene when placed too near to the camera. This report delves in both the theory and the practical techniques used for solving these problems. It describes various published solutions and the principles behind them, and presents a design and an implementation of selected techniques for the GPUEngine library.
56

Implementace algoritmu Seamless Patches for GPU-Based Terrain Rendering / Seamless Patches for GPU-Based Terrain Rendering Algorithm Implementation

Jozefov, David January 2011 (has links)
This master's thesis deals with terrain rendering using a modern algorithm for adaptive level of detail. It describes two currently most used graphical application interfaces and high-level libraries that use them and summarizes principles and features of several level-of-detail algorithms for terrain rendering. In more detail it then describes the implementation of Seamless patches for GPU-based terrain rendering algorithm.
57

Vizualizace rozsáhlých modelů / Visualization of Large Data Sets

Mokroš, Petr January 2009 (has links)
Work is focused on visualization of large data sets, especially on high resolution terrain models. Thus the goal of this work is to design a library which can divide large models to small regular parts for fast render of whole scene using level of detail techniques. Further goal is theoretical analysis how the library for fast and smooth visualization of large scenes in real time can be used.
58

Implementation of Level of Development for BIM Collaboration in Timber Building Subsystems Design: A Case Study of I-Joist Construction Elements

Gustafsson, Isabell January 2024 (has links)
Due to time, cost, and environmental challenges, wood has become a more common building material even for more complex buildings. Implementing the concept of Level of Development (LOD) on timber structures could provide a tool for BIM collaboration that may save cost and time, and in the early stages mediate wood as an available building material. Studies explain that LOD enables a high level of content and clarity as well as improved control of the design process. As the concept of LOD heavily focuses on general BIM visualisation, existing research at the time of the study lacks descriptions of how to implement LOD for specific projects. The study aims to develop a framework that could provide the industry with a possible implementation concept that could be further developed on other building systems. The goal of the study is to present a framework of a possible LOD implementation on a timber building system with a detailed description focusing on the structural engineer’s role during the design process. From that the questions of how to apply LOD on different project types as well as what data characteristics vary between these project types will be answered. Stated in previous studies, Integrated Project Delivery (IPD)A  is required for a successful design process is gained by utilising Integrated Project Delivery (IPD) and is especiallyalso essential when working with LOD. LOD is defined as five stages: starting with 100, then 200, 300, 350, 400, and finally 500. For each level of a building system, element, or assembly, the vagueness of information decreases and is therefore visualised differently in a BIM model. The study is based on a qualitative analysis of current data and related work about the design process, LOD, and timber buildings. The framework is mainly built upon five theories, the IPD process, the MacLeamy curve, BIM use purposes, data vagueness determination, and data requirement for timber projects. An interview study was conducted where projects using Masonite Beam’s standardised I-joist system were studied and implemented usingg the framework. The resulting framework presents the percentage information vagueness of how mature the information for a given objects is for different data properties and of each LOD level. The analysis leads to the conclusion that if fulfilling three criteria, 1: Following the IPD process, 2: An effort process similar to MacLeamy, and 3: Utilising BIM, the timber system can be implemented on the framework. However, the closer the project meets the criteria the closer the vagueness values will relate to the framework. The project that utilises a highly standardised building system with predefined data presents even lower vagueness values than the framework. Due to varying scales of project complexities, the data properties that showed the most diverse results between the projects were material information, geometric shape, and element dimensions. The findings from the study could be of further use in another research whose authors defined detailed graphical LOD visualisation in a BIM collaborative environment. The concept is strongly dependent on defined vagueness values that the authors of the research did not focus on how to define, which this framework does. Finding theories that support the assumptions made during the analysis development of the framework is continuing work that could strengthen the framework and its reliability. / Med tid -, kostnad- och klimatutmaningar har trä blivit ett mer vanligt byggnadsmaterial även för komplexa byggnader. Implementering av konceptet Level of Devlopment (LOD) på träkonstruktioner kan förse byggnadsindustrin med verktyg för BIM- kollaboration som kan spara på både kostnader och tid, och i tidigt skede framhäva trä som ett möjligt byggnadsmaterial. Studier förklarar att LOD kan bidraförse med en hög klarhetsgrad för olika innehåll, men även förbättra kontrollen under designprocessen. Då LOD-konceptet är starkt fokuserad på generell BIM-visualisering förklarar inte funna studier LOD- implementering för specifika projekt. Studien avser att utveckla ett framework (struktur) som kan förse byggnadsindustrin med ett möjligt implementeringskoncept som vidare kan anpassas till andra byggnadssystem. Målet är att presentera ett framework av en möjlig LOD implementering för ett träbyggandssystem med en detaljerad förklaring utifrån byggnadskonstruktörens roll i designprocess. Från detta kan frågor om hur man kan använda LOD för olika projekttyper samt vilka olika typer av information som varierar mellan dessa projekttyper besvaras. Tidigare studier visar En lyckad designprocess erhålls vi nyttjandet av att Intergrated Project Delivery (IPD) är nödvändigt för att uppnå en lyckad designprocess, särskiltvilket även är essentiellt när man arbetar meddet kommer till LOD. LOD definieras av fem stadier som går: från 100, 200, 300, 350, 400 ochtill 500. För varje nivå minskas osäkerhetsvärdet för en viss information tillhörande ett byggnadssystem, element eller assmembly, och är därmed olika grafiskt visualiserad i en BIM- modell. Studien baseras på en kvalitativ analys av befintliga data and och relaterade studier inom designprocessen, LOD och träbyggnader. Frameworket är huvudsakligen uppbyggt på fem teorier: IPD- processen, MacLeamy- kurvan, användningssyften av BIM, informationsosäkerhetsbestämmelse samt data som behövs för träbyggnadsprojekt. En intervjustudie är utförd där projekt utförda med Masonite Beams standardiserade trä I-balkar av trä studerades och implementerades på frameworket. Det resulterande frameworket presenterar procentuella osäkerhetsvärden som beskriver i vilken grad informationen tillhörande ett objekt går att lita på för olika informationskategorier och för varje LOD- nivå. Analys leder till slutsatsen att om följande tre kriterium uppfylls; 1. Följer IPD- processen, 2. Liknande arbetskurva som MacLeamy, 3. Använder BIM, kan ett träsystem implementeras på frameworket användas för ett träsystem. Det visar sig att desto närmare ett projekt uppfyller kriterierna desto närmare visar sig osäkerhetsvärdena stämma överens med de värden som presenteras för enbart frameworket. Projektet med hög användning av standardiserat byggnadssystem och förbestämdt data påvisar till och med lägre osäkerhetsvärden än vad frameworket gör. På grund av varierade grad av projektkomplexitet visar datakategorierna; materialinformation, geometrisk form och elementdimensioner störst olikheter mellan projekten i resultatet. Resultatet skulle vidare kunna användas till en annan forskningsstudie vars författare definierat detaljerade grafiska LOD visualiseringar i en BIM-kollaborationsmiljö. Konceptet är starkt beroende av givna osäkerhetsvärden som författarna och studien inte fokuserade på att definiera, vilket detta framework gör. Vidare arbete som kan stärka frameworket är att hitta teorier som stödjer de antaganden som gjorts under frameworkets analytiska utvecklande.
59

On incorporating heterogeneity in linkage analysis

Biswas, Swati January 2003 (has links)
No description available.
60

Full-wave modeling and analysis of dispersion-engineered materials and plasmon waveguides

Jung, Kyung Young 11 September 2008 (has links)
No description available.

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