Noise in electronic circuits can sometimes cause problems. It is especially problematic in for example high sensitive sensors and high end audio and video equipment. In audio and video equipment the noise will make its way into the sound and picture reducing the overall quality. Sensors that are constructed to sense extremely small changes can only pick up changes larger than the noise floor of the circuit. By lowering the noise, sensors can achieve higher accuracy.  This thesis presents an ultra low noise solution of the biasing circuitry to the bolometer used in one of FLIR Systems high end cameras. The bolometer uses different adjustable direct current voltage sources and is extremely sensitive to noise. The purpose is to improve the picture quality and the thermal measurement resolution. A prototype circuit was constructed and in the end of the thesis a final circuit with successful result will be presented.

The profile of the poloidal velocity in the edge region of tokamak plasmas has been identified as playing a major role in the confinement of particles and energy. It has been suggested that a strongly sheared poloidal flow can reduce particle and energy losses by the stabilization of unstable modes and decorrelation of turbulence the edge region of the plasma. A Gundestrup probe, a Mach probe array, is used to measure both the parallel and perpendicular flow velocities in the Saskatchewan Torus-Modified (STOR-M) tokamak during several discharge conditions. It is observed that during Ohmic discharges there is no velocity shear and the direction of the parallel flow is independent of the direction of the toroidal magnetic field. During H-mode induced by a turbulent heating current pulse, a region of strong velocity shear develops in the plasma edge and an edge transport barrier develops. This results in a short period of improved particle and energy confinement with reduced fluctuation amplitudes. During electrode biasing experiments, a stainless steel biasing electrode is inserted into the plasma up to r = 82 mm and biased to +500 V relative to the vacuum chamber. It is observed that the particle confinement improves during the biasing phase while the energy confinement is degraded. A region of weak shear in the poloidal flow is observed in the plasma scrapeoff layer (SOL). The results from STOR-M are compared with results from data taken in the Czech Academy of Sciences Torus (CASTOR) tokamak during both Ohmic discharges and discharges with electrode biasing.

The profile of the poloidal velocity in the edge region of tokamak plasmas has been identified as playing a major role in the confinement of particles and energy. It has been suggested that a strongly sheared poloidal flow can reduce particle and energy losses by the stabilization of unstable modes and decorrelation of turbulence the edge region of the plasma. A Gundestrup probe, a Mach probe array, is used to measure both the parallel and perpendicular flow velocities in the Saskatchewan Torus-Modified (STOR-M) tokamak during several discharge conditions. It is observed that during Ohmic discharges there is no velocity shear and the direction of the parallel flow is independent of the direction of the toroidal magnetic field. During H-mode induced by a turbulent heating current pulse, a region of strong velocity shear develops in the plasma edge and an edge transport barrier develops. This results in a short period of improved particle and energy confinement with reduced fluctuation amplitudes. During electrode biasing experiments, a stainless steel biasing electrode is inserted into the plasma up to r = 82 mm and biased to +500 V relative to the vacuum chamber. It is observed that the particle confinement improves during the biasing phase while the energy confinement is degraded. A region of weak shear in the poloidal flow is observed in the plasma scrapeoff layer (SOL). The results from STOR-M are compared with results from data taken in the Czech Academy of Sciences Torus (CASTOR) tokamak during both Ohmic discharges and discharges with electrode biasing.

The unique performance offerings of NiTi based shape memory alloys (SMAs), which includes the shape memory effect (SME), pseudoelasticity (PE) and biocompatibility have led to widespread acceptance of these alloys as valuable engineering materials. Over the past several decades the complex metallurgy behind the SME and PE properties has for the most part been uncovered and the design and engineering knowhow has been demonstrated; facilitating successful application of NiTi devices in numerous industries. Specifically, more mature applications in the medical industry including medical devices such as, catheters, guide wires, orthodontic arch wires, maxillofacial reconstruction implants, minimally invasive surgical tools, and arterial and gastrointestinal stents, have become common practice in modern medicine. Recently however, there has been a drive for more demanding functionality of SMAs for example to locally modify properties creating tuneable or gradient SME and PE performance. Unique processing protocols are therefore necessary to meet these demands and allow SMAs to reach their full potential in a wider range of applications. The current thesis successfully details the application of pulsed Nd:YAG laser processing along with post-processing techniques to locally tune both the SME and PE functional properties of monolithic binary NiTi wires and strip, while maintaining confidence in the retained corrosion performance and limited release of biologically harmful Ni ions. This extensive study contains three distinct parts which include: i) application of a laser induced vaporization protocol to locally embed multiple memories in a monolithic wire actuator; ii) uncovering the process, structure, and performance relationship of combined laser, cold working, and heat treatment processes; and iii) comprehensive characterization of surface characteristics and their relationship with corrosion performance and Ni ion release from laser processed material.

The demand to integrate more features has significantly increased the complexity and power consumption of smart portable devices. Therefore extending the battery life-time has become a major challenge and new approaches are required to decrease the power consumed from the source. Traditionally the focus has been on reducing the dynamic power consumption of the digital circuits used in these devices. However as process technologies scale, reducing the dynamic power has become less effective due to the increased impact of the leakage power. Alternatively, a more effective approach to minimize the power consumption is to continuously optimize the ratio of the dynamic and leakage power while delivering the required performance. This works presents a novel power-aware system for dynamic minimum power point tracking of digital loads in portable applications. The system integrates a dc-dc converter power-stage and the supplied digital circuit. The integrated dc-dc converter IC utilizes a mixed-signal current program mode (CPM) controller to regulate the supply voltage of the digital load IC. This embedded converter inherently measures the power consumption of the load in real-time, eliminating the need for additional power sensing circuitry. Based on the information available in the CPM controller, a minimum power point tracking (MiPPT) controller sets the supply and threshold voltages for the digital load to minimize its power consumption while maintaining a target frequency. The 10MHz mixed-signal CPM controlled dc-dc converter and the digital load are fabricated in 0.13µm IBM technology. Experimental results verify that the introduced system results in up to 30% lower power consumption from the battery source.

The demand to integrate more features has significantly increased the complexity and power consumption of smart portable devices. Therefore extending the battery life-time has become a major challenge and new approaches are required to decrease the power consumed from the source. Traditionally the focus has been on reducing the dynamic power consumption of the digital circuits used in these devices. However as process technologies scale, reducing the dynamic power has become less effective due to the increased impact of the leakage power. Alternatively, a more effective approach to minimize the power consumption is to continuously optimize the ratio of the dynamic and leakage power while delivering the required performance. This works presents a novel power-aware system for dynamic minimum power point tracking of digital loads in portable applications. The system integrates a dc-dc converter power-stage and the supplied digital circuit. The integrated dc-dc converter IC utilizes a mixed-signal current program mode (CPM) controller to regulate the supply voltage of the digital load IC. This embedded converter inherently measures the power consumption of the load in real-time, eliminating the need for additional power sensing circuitry. Based on the information available in the CPM controller, a minimum power point tracking (MiPPT) controller sets the supply and threshold voltages for the digital load to minimize its power consumption while maintaining a target frequency. The 10MHz mixed-signal CPM controlled dc-dc converter and the digital load are fabricated in 0.13µm IBM technology. Experimental results verify that the introduced system results in up to 30% lower power consumption from the battery source.

abstract: As wireless communication enters smartphone era, more complicated communication technologies are being used to transmit higher data rate. Power amplifier (PA) has to work in back-off region, while this inevitably reduces battery life for cellphones. Various techniques have been reported to increase PA efficiency, such as envelope elimination and restoration (EER) and envelope tracking (ET). However, state of the art ET supply modulators failed to address high efficiency, high slew rate, and accurate tracking concurrently. In this dissertation, a linear-switch mode hybrid ET supply modulator utilizing adaptive biasing and gain enhanced current mirror operational transconductance amplifier (OTA) with class-AB output stage in parallel with a switching regulator is presented. In comparison to a conventional OTA design with similar quiescent current consumption, proposed approach improves positive and negative slew rate from 50 V/µs to 93.4 V/µs and -87 V/µs to -152.5 V/µs respectively, dc gain from 45 dB to 67 dB while consuming same amount of quiescent current. The proposed hybrid supply modulator achieves 83% peak efficiency, power added efficiency (PAE) of 42.3% at 26.2 dBm for a 10 MHz 7.24 dB peak-to-average power ratio (PAPR) LTE signal and improves PAE by 8% at 6 dB back off from 26.2 dBm power amplifier (PA) output power with respect to fixed supply. With a 10 MHz 7.24 dB PAPR QPSK LTE signal the ET PA system achieves adjacent channel leakage ratio (ACLR) of -37.7 dBc and error vector magnitude (EVM) of 4.5% at 26.2 dBm PA output power, while with a 10 MHz 8.15 dB PAPR 64QAM LTE signal the ET PA system achieves ACLR of -35.6 dBc and EVM of 6% at 26 dBm PA output power without digital pre-distortion (DPD). The proposed supply modulator core circuit occupies 1.1 mm2 die area, and is fabricated in a 0.18 µm CMOS technology. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017

In the Czech Republic, town halls are allowed to issue printed newspapers to inform the residents about local events. The newspapers are funded from municipal budgets and free for the residents, often delivered directly to the mailbox. Apart from being useful source of information, the newspapers may serve also as a platform for election campaign of the incumbent politicians. This fact was the main reason for the amendment of the Press Act in 2013, directing municipalities to issue unbiased news with enough room for all the political stakeholders. The present study uses various secondary data to examine the effects of town hall newspapers on voting decisions during municipal elections held between 1998 and 2014. Econometric analysis finds significant and positive relationship between presence of a newspaper and performance of incumbent politicians. Comparison of election results from 2014 with previous election years suggest that the Press Act amendment has not had substantial impact on this relationship.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18689号 / 工博第3967号 / 新制||工||1611(附属図書館) / 31622 / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 椹木 哲夫, 教授 西脇 眞二, 教授 松原 厚 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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