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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.
191

Možnosti softwaru SinuTrain 4.8 při NC programování pětiosého frézování / SinuTrain 4.8 software tools for NC programming of five-axis milling

Beháň, Jakub January 2021 (has links)
The diploma thesis deals with preparing the production process of the winning prize, which contains a selection in the form of a hyperbolic paraboloid in its upper part. The work is divided into four main chapters. First of all, the introduction part of the diploma thesis presents the possibilities of programming in the Sinumerik control system. Next, the mathematical requirements of the selected surface - hyperbolic paraboloid - are explained. The practical part consists of creating an NC program where all the theoretical knowledge from the introduction is applied. Finally, the diploma thesis ends with an economic evaluation of the selected element.
192

Wearable Electrically Small Resonant Loops for Seamless Motion Capture and Wireless Body Area Networks (WBANs)

Mishra, Vigyanshu January 2021 (has links)
No description available.
193

Phase Synthesis Using Coupled Phase-Locked Loops

Iyer, S.P. Anand 01 January 2008 (has links) (PDF)
Phase Synthesis is a fundamental operation in Smart Antennas and other Phased Array systems based on beamforming. There are increasing commercial applications for Integrated Phased Arrays due to their low cost, size and power and also because the RF and digital signal processing can be performed on the same chip. These low cost beamforming applications have augmented interest in Coupled Phase Locked Loop (CPLL) systems for Phase Synthesis. Previous work on the implementation of Phase Synthesis systems using Coupled PLLs for low cost beamforming had the constraint of a limited phase range of ±90°. The idea behind the thesis is that this phase synthesis range can be increased to ±180° through the use of PLLs employing Phase Frequency Detectors(PFDs), which is a significant improvement over conventional coupled-PLL systems. This work presents the detailed design and measurement results for a phase synthesizer using Coupled PLLs for achieving phase shift in the range of ±180°. Several Coupled PLL architectures are investigated and their advantages and limitations are evaluated in terms of frequency controllability, phase difference synthesis control and phase noise of the systems. A two-PLL system implementation using off the shelf components is presented, which generates a steady-state phase difference in the range ±180° using an adjustable DC control current. This is the proof of concept for doing an IC design for a Coupled Phase Locked Loop system. Commercial applications in the Wireless Medical Telemetry Service (WMTS) band motivate the design of a CPLL system in the 608-614 MHz band. The design methodology is presented which shows the flowchart of the IC design process from the system design specifications to the transistor level design. MATLAB simulations are presented to model the system performance quickly. VerilogA modeling of the CPLL system is performed followed by the IC design of the system and each block is simulated under different process and temperature corners. The transistor level design is then evaluated for its performance in terms of phase difference synthesis and phase noise and compared with the initial MATLAB analysis and improved iteratively. The CPLL system is implemented in IBM 130nm CMOS process and consumes 40mW of power from a 1.2V supply with a phase noise performance of -88 dBc/Hz for 177° phase generation.
194

Testable Clock Distributions for 3d Integrated Circuits

Buttrick, Michael T 01 January 2011 (has links) (PDF)
The 3D integration of dies promises to address the problem of increased die size caused by the slowing of scaling. By partitioning a design among two or more dies and stacking them vertically, the average interconnect length is greatly decreased and thus power is reduced. Also, since smaller dies will have a higher yield, 3D integration will reduce manufacturing costs. However, this increase in yield can only be seen if manufactured dies can be tested before they are stacked. If not, the overall yield for the die stack will be worse than that of the single, larger die. One of the largest issues with prebond die testing is that, to save power, a single die may not have a complete clock distribution network until bonding. This thesis addresses the problem of prebond die testability by ensuring the clock distribution network on a single die will operate with low skew during testing and at a reduced power consumption during operation as compared to a full clock network. The development of a Delay Lock Loop is detailed and used to synchronize disconnected clock networks on a prebond die. This succeeds in providing a test clock network that operates with a skew that is sufficiently close to the target postbond skew. Additionally, a scheme to increase interdie bandwidth by multiplexing Through-Silicon Vias (TSVs) by the system clock is presented. This technique allows for great increase in the number of effective signal TSVs while imposing a negligible area overhead causing no performance degradation.
195

Proving Their Worth : Does Ukrainian battlefield success increase Western military aid commitments?

Elmberg, Arvid January 2023 (has links)
On the 24th of February 2022, interstate war on a scale unseen since World War II returned to Europe, causing devastating suffering and loss of human life. As of writing, Ukraine’s ability to demonstrate battlefield success is frequently cited as key to sustain Western political willpower to send military aid. This study aims to test presumptions of a positive feedback loop between military assistance and its successful implementation with a mixed-method approach. Regression models analyze time-series data tracking a year of 33 countries’ military aid commitments to Ukraine using random effects (RE) to control for unobserved, country-specific and varying mediating variables. Based on German aversiveness to military solutions, a least-likely case debate analysis analyzes three Bundestag debates to uncover lawmakers’ justifications for approving or rejecting military aid proposals. Applying a theory-generating analysis framework, battlefield successes are confirmed as recurring arguments used to enforce pro-aid narratives, but do not necessarily overcome factors constraining military aid commitments. The RE regression finds a statistically significant positive relationship between Ukrainian battlefield success and military aid commitments. This raises immense implications for Ukrainian decisionmakers, who may be compelled to prioritize short-term military gains to secure future Western support.
196

Strategic Improvement: A Systems Approach Using The Balanced Scorecard Methodology To Increase Federally Financed Research At The University Of Central Florida

Walters, Joseph 01 January 2013 (has links)
The University of Central Florida has many successful measures to reflect on as it celebrates its 50th year in 2013. It is the university with the 2nd largest student population in the U. S. and its overall ranking in the U.S. News & World Report has improved 4 years in a row. However, with respect to research, the federally funded research and development for the University of Central Florida (UCF) has remained flat. In addition, when compared to other schools, its portion of those federal research dollars is small. This thesis lays the groundwork for developing a model for improving the federally financed academic research and development. A systems approach using the balanced scorecard methodology was used to develop causal loop relationships between the many factors that influence the federal funding process. Measures are proposed that link back to the objectives and mission of the university. One particular measure found in the literature was refined to improve its integration into this model. The resulting work provides a framework with specific measures that can be incorporated at the university to improve their share of the federally financed research and development. Although developed for UCF this work could be applied to any university that desires to improve their standing in the federal financed academic research and development market.
197

From Abstract to Tangible : An Approach to Learning Loops in Programming

Bengtsson, Thomas January 2023 (has links)
This thesis seeks to advance interaction design practice by exploring the potential of interactive tangible prototypes to enhance university students' understanding of abstract programming structures, such as loops. It addresses prevalent challenges, including the difficulties students encounter when initially learning about loops, and scalability issues inherent in tangible teaching tools within this research area. Two distinct tangible learning methodologies are considered: unplugged programming and tangible computing. The primary contributions of this thesis lie in the creation of innovative tangible learning tools, the emphasis on the scalability of such tools, and the illumination of how physical prototypes can inspire digital software design.
198

Enhancement of Regnase-1 expression with stem loop-targeting antisense oligonucleotides alleviates inflammatory diseases / mRNAステムループ構造標的アンチセンスオリゴ核酸を用いたRegnase-1発現増強による炎症抑制法の開発

Tse, Ka Man Carman 26 September 2022 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第24192号 / 医博第4886号 / 新制||医||1060(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 萩原 正敏, 教授 森信 暁雄, 教授 遊佐 宏介 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
199

Experimental Evaluation of Innovative Thermal Energy Storage Options for a Hypersonic Non-Airbreathing Vehicle's Internal Loads

Arbolino, John Christopher 28 August 2023 (has links)
Managing the thermal loads inside a non-airbreathing hypersonic vehicle is particularly difficult. The heat generated by the power electronics, avionics, etc. must be removed so that the components do not exceed their maximum temperatures. These vehicles cannot dump the waste heat into fuel or ram air because they carry no fuel and do not have provisions for ram air. This means that the thermal energy resulting from the heat generated must be dumped into an onboard heat sink. Existing solutions to this problem have been passive systems based on solid-liquid phase change materials (PCMs), which store thermal energy as they melt. Since space is at a premium, a heat sink must store a lot of energy per unit volume, while keeping components below their maximum temperature. In this project, three heat sink concepts are tested, i.e., one based on PCMs, a second on thermal to chemical (TTC) energy storage, and a third on a hybrid combination of the first two. For the first, three different PCMs are tested and for the second a single endothermic chemical reaction. The hybrid PCM/TTC concept consists of a single PCM which plays the dual role of PCM and reactant in the endothermic chemical reaction of the TTC energy storage. To enhance heat sink performance, the use of thermoelectric generators (TEGs) and a local coolant loop are investigated. The advantage of the former is that they transform waste heat into usable electricity, reducing the amount of thermal energy that needs to be stored by the heat sink. The advantage of the latter is that it results in a more uniform cooling of the heat source and more uniform heating of the heat sink. Prototypes of each of the heat sink concepts and the coolant loop are designed, built, and tested. Experimental results indicate that all the solutions tested in this project outperform widely used paraffin heat sink technologies on an energy per unit volume basis. Our experiments also show that a local coolant loop is indeed advantageous and that current off-the-shelf thermoelectric generators do not generate enough power to offset the power requirements of the coolant loop. Significant improvements in the ZT factor of the thermoelectric materials used by the TEG would be required. / Master of Science / All electronics produce waste heat and have a maximum operating temperature above which they fail due to overheating. Heat sinks absorb the waste heat and prevent overheating. Non-airbreathing hypersonic vehicles do not have natural heat sinks like intake air or liquid fuel which are commonly used as heat sinks in airbreathing vehicles. Heat cannot be transferred to the environment due to the high temperatures caused by the friction of hypersonic air travel. This means that all waste heat must absorbed by an onboard heat sink. Existing heat sinks in non-airbreathing hypersonic vehicles use paraffin based solid-liquid phase change materials (PCMs) which store thermal energy as they melt. Three novel heat sink options are evaluated in this project, hydrated salt PCMs which absorb energy as they melt, a chemical reaction which absorbs heat as it reacts, and a hybrid system which incorporates one of the hydrates salt PCM as a reactant in the chemical reaction. Because space is at a premium, these options are evaluated by the amount of energy they can absorb (kilojoules) per unit volume (in3) while keeping the electronics below their maximum temperature. To enhance heat sink performance, the use of thermoelectric generators (TEGs) and a local coolant loop are investigated. The advantage of the former is that they transform waste heat into usable electricity, reducing the amount of thermal energy that needs to be stored by the heat sink. The advantage of the latter is that it results in a more uniform cooling of the electronics and more uniform heating of the heat sink. Prototypes of each of the heat sink concepts and the coolant loop are designed, built, and tested. Experimental results indicate that all the solutions tested in this project outperform widely used paraffin heat sink technologies on an energy per unit volume basis. Our experiments also show that a local coolant loop is indeed advantageous and that current off-the-shelf thermoelectric generators do not generate enough power to offset the power requirements of the coolant loop. Significant improvements in the state of the art of thermoelectric materials would be required for TEGs to generate enough electricity from our waste heat load to power the local coolant loop.
200

The exoribonuclease XRN2 mediates degradation of the long non-coding telomeric RNA, TERRA

Reiss, Matthew Evan 12 February 2024 (has links)
Telomere dysfunction is a significant source of genomic instability and contributes to the development of cancer. The multi-protein complex shelterin binds telomeric DNA to mitigate telomere dysfunction and ensure overall telomere stability. In addition to shelterin, the telomeric cap includes the telomeric repeat-containing RNA, TERRA, which associates with telomeric proteins and the telomeric DNA itself, often forming RNA:DNA hybrids or R-loops. TERRA is most abundant in cancer cells that utilize the alternative lengthening of telomeres (ALT) pathway, where it has been suggested that TERRA R-loops act as a source of replication stress at telomeric DNA that ultimately contributes to the activation of the ALT mechanism. In an effort to evaluate the effect TERRA may have on the emergence of the ALT phenotype, we sought to identify the enzyme(s) that regulate TERRA degradation in mammalian cells. Here, we leveraged an auxin-inducible degron (AID) system to identify the 5’-3’ exoribonuclease XRN2 as a direct modulator of TERRA stability in mammalian cells. Following XRN2 depletion, we demonstrate a significant increase in TERRA on chromatin in both non-ALT and ALT-positive cell lines. While the stabilization of TERRA on chromatin alone was insufficient to drive replication stress and activation of ALT in telomerase cells, depletion of XRN2 in the ALT-positive context led to a significant increase in R-loops and DNA damage signaling at telomeric DNA. Thus, increased TERRA stability alone is unlikely to activate ALT but may instead exacerbate ALT activity. Taken together, we demonstrate that XRN2 regulates TERRA stability, that defects in TERRA metabolism can alter telomere stability, and dysfunction in both factors drive telomere dysfunction in cells that rely on the ALT pathway. / 2024-08-12T00:00:00Z

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