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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.
311

Feature-based Vehicle Classification in Wide-angle Synthetic Aperture Radar

Dungan, Kerry Edward 03 August 2010 (has links)
No description available.
312

Multiple-Input Single-Output Synthetic Aperture Radar and Space-Time Adaptive Processing

Bryant, Christine Ann 15 September 2010 (has links)
No description available.
313

Sparse Methods for Model Estimation with Applications to Radar Imaging

Austin, Christian David 19 June 2012 (has links)
No description available.
314

Extraction of Linear Features Based on Beamlet Transform

Zhu, Yuan 23 May 2011 (has links)
No description available.
315

Performance Evaluation for Full 3D Projector Calibration Methods in Spatial Augmented Reality

Korostelev, Michael January 2011 (has links)
Spatial Augment Reality (SAR) has presented itself to be an interesting tool for not only interesting ways to visualize information but to develop creative works in performance arts. The main challenge is to determine accurate geometry of a projection space and determine an efficient and effective way to project digital media and information to create an augmented space. In our previous implementation of SAR, we developed a projector-camera calibration approach using infrared markers. However, the projection suffers severe distortion due to the lack of depth information in the projection space. For this research, we propose to develop a RGBD sensor - projector system to replace our current projector-camera SAR system. Proper calibration between the camera or sensor and projector links vision to projection, answering the question of which point in camera space maps to what point in the space of projection. Calibration will resolve the problem of capturing the geometry of the space and allow us to accurately augment the surfaces of volumetric objects and features. In this work three calibration methods are examined for performance and accuracy. Two of these methods are existing adaptations of 2D camera - projector calibrations (calibration using arbitrary planes and ray-plane intersection) with our third proposed novel technique which utilizes point cloud information from the RGBD sensor directly. Through analysis and evaluation using re-projection error, results are presented, identifying the proposed method as practical and robust. / Electrical and Computer Engineering
316

Investigations of polarisation purity and SAR for personal satellite communications antennas using a hybrid computational method

Mangoud, Mohab A., Abd-Alhameed, Raed, Excell, Peter S. January 2001 (has links)
No / The use of the hybrid method of moments/finite difference time domain technique can be effective for solution of electromagnetic problems which are intractable for a single numerical method. Using this method, a study of the effects of human proximity on the polarisation purity of different types of circularly-polarised handset antennas for personal satellite communications was undertaken. Associated with this, assessments of the specific absorption rate in the head were made. The method gave stable results, in accordance with physical expectations; good agreement with the pure method of moments was shown in simplified cases omitting the head
317

Study on isolation improvement between closely-packed patch antenna arrays based on fractal metamaterial electromagnetic bandgap structures

Alibakhshikenari, M., Virdee, B.S., See, C.H., Abd-Alhameed, Raed, Ali, Ammar H., Falcone, F., Limiti, E. 11 October 2018 (has links)
Yes / A decoupling metamaterial (MTM) configuration based on fractal electromagnetic-bandgap (EMBG) structure is shown to significantly enhance isolation between transmitting and receiving antenna elements in a closely-packed patch antenna array. The MTM-EMBG structure is cross-shaped assembly with fractal-shaped slots etched in each arm of the cross. The fractals are composed of four interconnected-`Y-shaped' slots that are separated with an inverted-`T-shaped' slot. The MTM-EMBG structure is placed between the individual patch antennas in a 2 × 2 antenna array. Measured results show the average inter-element isolation improvement in the frequency band of interest is 17, 37 and 17 dB between radiation elements #1 & #2, #1 & #3, and #1 & #4, respectively. With the proposed method there is no need for using metallic-via-holes. The proposed array covers the frequency range of 8-9.25 GHz for X-band applications, which corresponds to a fractional-bandwidth of 14.5%. With the proposed method the edge-to-edge gap between adjacent antenna elements can be reduced to 0.5λ 0 with no degradation in the antenna array's radiation gain pattern. Across the array's operating band, the measured gain varies between 4 and 7 dBi, and the radiation efficiency varies from 74.22 and 88.71%. The proposed method is applicable in the implementation of closely-packed patch antenna arrays used in SAR and MIMO systems. / Partially supported by innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.
318

Biological and Synthetic Studies of Mitochondrial Respiratory Chain Inhibitors / ミトコンドリア呼吸鎖阻害剤に関する生物および合成化学的研究

Tsuji, Atsuhito 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(薬科学) / 甲第24555号 / 薬科博第172号 / 新制||薬科||19(附属図書館) / 京都大学大学院薬学研究科医薬創成情報科学専攻 / (主査)教授 大野 浩章, 教授 小野 正博, 教授 掛谷 秀昭 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM
319

KaSI: a Ka-band and S-band Cross-track Interferometer

Ruiz Carregal, Gerard 24 March 2017 (has links) (PDF)
A dual-frequency system is needed to better understand natural processes that constitute the environment and seasonal cycles of the Earth. A system working at two different wavelengths acquiring data simultaneously will give a valuable dataset since the conditions on the ground will be exactly the same. Hence, elements such as wind, soil moisture or any other changes on the ground will not interfere in the mea- surements. This thesis explains how an S-band radar was built and tested. Moreover, the experiments done with a Ka-band radar used as a scatterometer are explained as well as the data processing and analysis. Finally, the two systems are used to get dual-frequency measurements from an airborne platform. The dual-frequency data is explored, showing the differences in normalized radar cross-section between frequencies and discussing the interferometric measurements.
320

Design and Synthesis of Orally Bioavailable Sphingosine Kinase 2 Selective Inhibitors

Sibley, Christopher David 16 July 2020 (has links)
In humans, mammals, and perhaps all vertebrates, sphingolipids exist as a family of cellular signaling molecules and have been shown to be involved in a wide range of biological processes ranging from proliferation to apoptosis. As such, sphingolipid signaling has garnered the attention of numerous researchers as an attractive candidate for pharmacological manipulation. The synthetic pathway of one prominent sphingolipid, sphingosine 1-phosphate (S1P), has been implicated in a variety of disease states such as cancer, sickle cell disease, multiple sclerosis, and renal fibrosis. Formation of S1P is facilitated from the ATP dependent phosphorylation of sphingosine (Sph) through its generative enzyme's sphingosine kinase 1 and 2 (SphK1 and SphK2). Inhibition of SphK1 and SphK2 results in the manipulation of S1P levels, which has been shown to be therapeutic in various animal models of disease. While there are multiple examples of potent SphK1-selective and dual SphK1/2 inhibitors, SphK2-selective inhibitors are scarce. Herein, we describe the design, synthesis and biological testing of SphK2-selective inhibitors. We first describe the discovery that introducing a trifluoromethyl group onto the internal aryl ring of our inhibitor scaffold led to superior selectivity and potency towards SphK2. We demonstrate that the trifluoromethyl moiety is interacting with a previously unknown side cavity in the substrate binding site of SphK2 that is unique and could be exploited in the design of SphK2-selective inhibitors. The synthesis of 21 derivatives with various substituents spanning off the internal aryl ring was completed, therefore characterizing the preferred size and chemical nature of moieties positioned in that portion of the binding site. This work led to the development of the most potent SphK2-selective inhibitor known at the time. We then describe the transformation of our SphK2-selective inhibitors into an orally bioavailable drug. We explain how the guanidine functionality on our inhibitor scaffold hinders our compounds from being orally bioavailable. Consequently, a library of 24 derivatives with various modifications to the guanidine functionality was synthesized and evaluated for improved orally bioavailability. Highlighted in this work is the development of the most potent SphK2-selective inhibitor currently known 3.14 (SLS1081832), which displays a hSphK2 Ki of 82 nM and 122-fold selectivity for SphK2. Chemical modification and in vivo assessment of 3.14 (SLS1081832) prodrugs was explored. / Doctor of Philosophy / In humans, sphingosine 1-phosphate (S1P) is a signaling molecule that is generated through an ATP dependent reaction of sphingosine (Sph) via sphingosine kinase 1 and 2 (SphK1 and SphK2). Furthermore, S1P has been shown to be implicated in various diseases such as cancer, sickle cell disease, multiple sclerosis, and renal fibrosis. Inhibition of SphK1 and SphK2 has been shown to be therapeutic towards the symptoms of these diseases. Therefore, in order to alleviate these disorders, the concentrations of S1P must be controlled through pharmacological inhibition of SphK1 and SphK2. There are multiple reported examples of potent SphK1-selective and dual SphK1/2 inhibitors; however, SphK2-selective inhibitors are scarce. This work describes the synthesis and biological assessment of 21 compounds for their effectiveness in selectively targeting and inhibiting SphK2. The work led to the discovery of a previously unrecognized side cavity in the binding pocket of SphK2 that enhances inhibitor potency and selectivity towards SphK2. Furthermore, studies characterizing the preferred size and chemical nature of moieties positioned in that portion of the binding site led to the development of the most potent SphK2- selective inhibitor known at the time. Building on this work, we next focused on the transformation of our SphK2-selective inhibitors into a drug that could be administered orally. We describe the synthesis of 24 compounds with various modifications to one portion of our scaffold and their effect on improved orally bioavailability. This work led to the development of the most potent SphK2-selective inhibitor currently known 3.14 (SLS1081832).

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