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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.
41

Image processing technique to count the number of logs in a timber truck

Shaik, Asif ur Rahman, Yella, Siril, Dougherty, Mark January 2011 (has links)
This paper summarises the results of using image processing technique to get information about the load of timber trucks before their arrival using digital images or geo tagged images. Once the images are captured and sent to sawmill by drivers from forest, we can predict their arrival time using geo tagged coordinates, count the number of (timber) logs piled up in a truck, identify their type and calculate their diameter. With this information we can schedule and prioritise the inflow and unloading of trucks in the light of production schedules and raw material stocks available at the sawmill yard. It is important to keep all the actors in a supply chain integrated coordinated, so that optimal working routines can be reached in the sawmill yard.
42

Informative SNP Selection and Validation

Mohan Babu, Diana 03 August 2007 (has links)
The search for genetic regions associated with complex diseases, such as cancer or Alzheimer's disease, is an important challenge that may lead to better diagnosis and treatment. The existence of millions of DNA variations, primarily single nucleotide polymorphisms (SNPs), may allow the fine dissection of such associations. However, studies seeking disease association are limited by the cost of genotyping SNPs. Therefore, it is essential to find a small subset of informative SNPs (tag SNPs) that may be used as good representatives of the rest of the SNPs. Several informative SNP selection methods have been developed. Our experiments compare favorably to all the prediction and statistical methods by selecting the least number of informative SNPs. We proposed algorithms for faster prediction which yielded acceptable trade off. We validated our results using the k-fold test and its many variations.
43

Synthesis of a fluorous benzodithiol support and its utility in the construction of diverse ring systems

Sharma, Maya 10 September 2008 (has links)
A method for the synthesis of a symmetrical fluorous tagged benzodithiol support has been developed through a seven-step synthetic pathway. The Wittig olefination and catalytic hydrogenation reactions were employed to attach two perfluoroalkyl chains in the o-positions of phthalaldehyde. These fluorous tags were used as soluble supports which facilitated the purification of the crude reaction mixtures using fluorous solid phase extraction (FSPE). A selective and high yielding dibromination reaction was developed to synthesize a fluorous tagged 1,2-dibromo aryl compound. A thorough study was carried out to demonstrate the ease of an aryl-sulfur bond formation with the 1,2-dibromo compound varying palladium catalysts and ligands. A new palladium catalyzed dithiolation reaction is reported to synthesize a surrogated dithiol, which was exploited as a precursor for the synthesis of hitherto inaccessible symmetrical fluorous tagged benzodithiol support. The utility of the benzodithiol was explored by the synthesis of benzodithianes with two aldehydes. The lithiated dithiane generated was further used to form a C-C bond employing the umpolung reaction. The ring-closing metathesis reaction using Grubbs II catalyst was performed to construct 5-membered and 6-membered spiro-ring systems. Several approaches were made to form a C-C bond with lithiated dithianes using various nitrogen containing electrophiles leading to N-heterocycles. / October 2008
44

Flow Imaging Using MRI: Quantification and Analysis

Jiraraksopakun, Yuttapong 2009 May 1900 (has links)
A complex and challenging problem in flow study is to obtain quantitative flow information in opaque systems, for example, blood flow in biological systems and flow channels in chemical reactors. In this regard, MRI is superior to the conventional optical flow imaging or ultrasonic Doppler imaging. However, for high speed flows, complex flow behaviors and turbulences make it difficult to image and analyze the flows. In MR flow imaging, MR tagging technique has demonstrated its ability to simultaneously visualize motion in a sequence of images. Moreover, a quantification method, namely HARmonic Phase (HARP) analysis, can extract a dense velocity field from tagged MR image sequence with minimal manual intervention. In this work, we developed and validated two new MRI methods for quantification of very rapid flows. First, HARP was integrated with a fast MRI imaging method called SEA (Single Echo Acquisition) to image and analyze high velocity flows. Second, an improved HARP method was developed to deal with tag fading and data noise in the raw MRI data. Specifically, a regularization method that incorporates the law of flow dynamics in the HARP analysis was developed. Finally, the methods were validated using results from the computational fluid dynamics (CFD) and the conventional optimal flow imaging based on particle image velocimetry (PIV). The results demonstrated the improvement from the quantification using solely the conventional HARP method.
45

Movement of fishes in a network of streams and implications for persistence

Albanese, Brett, January 2001 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 2001. / Title from PDF title page (viewed on Apr. 2, 2005). Vita. Includes bibliographical references (p. 107-121).
46

Hybrid Tag Recommendation in Collaborative Tagging Systems

Lipczak, Marek 15 March 2012 (has links)
The simplicity and flexibility of tagging allows users to collaboratively create large, loosely structured repositories of Web resources. One of its main drawbacks is the need for manual formulation of tags for each posted resource. This task can be eased by a tag recommendation system, the objective of which is to propose a set of tags for a given resource, user pair. Tag recommendation is an interesting and well-defined practical problem. Its main features are constant interaction with users and availability of large amounts of tagged data. Given the opportunities (e.g., rich user feedback) and limitations (e.g., real-time response) of the tag recommendation setting, we defined six requirements for a practically useful tag recommendation system. We present a conceptual design and system architecture of a hybrid tag recommendation system, which meets all these requirements. The system utilizes the strengths of various tag sources (e.g., resource content and user profiles) and the relations between concepts captured in tag co-occurrence graphs mined from collaborative actions of users. The architecture of the proposed system is based on a text indexing engine, which allows the system to deal with large datasets in real time, while constantly adapting its models to newly added posts. The effectiveness and efficiency of the system was evaluated for six datasets representing a broad range of collaborative tagging systems. The experiments confirmed the high quality of results and practical usability of the system. In a comparative study the system outperformed a state-of-the-art algorithm based on tensor factorization for the most representative datasets applicable to both methods. The experiments on the characteristics of tagging data and the performance of the system allowed us to find answers to important research questions adapted from the general area of recommender systems. We confirmed the importance of infrequently used tags in the recommendation process and proposed solutions to overcome the cold start problem in tag recommendation. We demonstrated that a parameter tuning approach makes a hybrid tag recommendation system adaptable to various datasets. We also revealed the importance of the utilization of a feedback loop in the tag recommendation process.
47

Plastic phenotypic responses of the sea star Pisaster ochraceus to spatial and temporal variation in wave exposure

Hayne, Kurtis Unknown Date
No description available.
48

Synthesis of a fluorous benzodithiol support and its utility in the construction of diverse ring systems

Sharma, Maya 10 September 2008 (has links)
A method for the synthesis of a symmetrical fluorous tagged benzodithiol support has been developed through a seven-step synthetic pathway. The Wittig olefination and catalytic hydrogenation reactions were employed to attach two perfluoroalkyl chains in the o-positions of phthalaldehyde. These fluorous tags were used as soluble supports which facilitated the purification of the crude reaction mixtures using fluorous solid phase extraction (FSPE). A selective and high yielding dibromination reaction was developed to synthesize a fluorous tagged 1,2-dibromo aryl compound. A thorough study was carried out to demonstrate the ease of an aryl-sulfur bond formation with the 1,2-dibromo compound varying palladium catalysts and ligands. A new palladium catalyzed dithiolation reaction is reported to synthesize a surrogated dithiol, which was exploited as a precursor for the synthesis of hitherto inaccessible symmetrical fluorous tagged benzodithiol support. The utility of the benzodithiol was explored by the synthesis of benzodithianes with two aldehydes. The lithiated dithiane generated was further used to form a C-C bond employing the umpolung reaction. The ring-closing metathesis reaction using Grubbs II catalyst was performed to construct 5-membered and 6-membered spiro-ring systems. Several approaches were made to form a C-C bond with lithiated dithianes using various nitrogen containing electrophiles leading to N-heterocycles.
49

Tagging als soziales Bindeglied für Communities

Kammergruber, Walter Christian, Langen, Manfred 13 May 2014 (has links) (PDF)
Social Tagging und soziale Netzwerke sind zentrale Bausteine des Web 2.0 und Enterprise 2.0. In diesem Beitrag werden die sozialen Aspekte von Social Tagging beleuchtet und ein Ansatz aufgeführt, um in Folksonomies Personen mit ähnlichen Interessen zu finden. Ferner wird ein Tagging-Framework beschrieben, das im Use Case Alexandria im Rahmen des BMWi-Projekts Theseus entstanden ist.
50

Synthesis of a fluorous benzodithiol support and its utility in the construction of diverse ring systems

Sharma, Maya 10 September 2008 (has links)
A method for the synthesis of a symmetrical fluorous tagged benzodithiol support has been developed through a seven-step synthetic pathway. The Wittig olefination and catalytic hydrogenation reactions were employed to attach two perfluoroalkyl chains in the o-positions of phthalaldehyde. These fluorous tags were used as soluble supports which facilitated the purification of the crude reaction mixtures using fluorous solid phase extraction (FSPE). A selective and high yielding dibromination reaction was developed to synthesize a fluorous tagged 1,2-dibromo aryl compound. A thorough study was carried out to demonstrate the ease of an aryl-sulfur bond formation with the 1,2-dibromo compound varying palladium catalysts and ligands. A new palladium catalyzed dithiolation reaction is reported to synthesize a surrogated dithiol, which was exploited as a precursor for the synthesis of hitherto inaccessible symmetrical fluorous tagged benzodithiol support. The utility of the benzodithiol was explored by the synthesis of benzodithianes with two aldehydes. The lithiated dithiane generated was further used to form a C-C bond employing the umpolung reaction. The ring-closing metathesis reaction using Grubbs II catalyst was performed to construct 5-membered and 6-membered spiro-ring systems. Several approaches were made to form a C-C bond with lithiated dithianes using various nitrogen containing electrophiles leading to N-heterocycles.

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