Ho Lai-yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 53-56). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Peierls Transition --- p.3 / Chapter 2.1 --- The Start of the Idea --- p.3 / Chapter 2.2 --- Peierls Transition in Second Quantization Representation --- p.5 / Chapter 2.3 --- Effect of Peierls Transition on an Antiferromagnetic Chain --- p.6 / Chapter 2.4 --- Evidence of Spin-Peierls Transition --- p.9 / Chapter 2.5 --- Materials with Spin-Peierls Transition --- p.11 / Chapter 3 --- Mean Field Calculations --- p.15 / Chapter 3.1 --- Jordan-Wigner Transformation --- p.15 / Chapter 3.2 --- Diagonalization of the XY Model --- p.17 / Chapter 3.3 --- Hartree-Fock Approximation --- p.19 / Chapter 3.4 --- Quantum Effect of Lattice --- p.21 / Chapter 4 --- Bosonization --- p.25 / Chapter 4.1 --- Continuum Limit --- p.25 / Chapter 4.2 --- Bosonization --- p.28 / Chapter 4.3 --- Relaxation of the Restriction on Lattice Distortion --- p.36 / Chapter 4.4 --- More Discussion on the Phase Hamiltonian --- p.39 / Chapter 4.5 --- Limitation of the Bosonization Technique and the Phase Hamil- tonian Approach --- p.41 / Chapter 5 --- Effect of Doping Impurities on Spin-Peierls Model --- p.43 / Chapter 5.1 --- Experimental Results --- p.43 / Chapter 5.2 --- Analytical Calculations of Doping Effect --- p.44 / Chapter 5.3 --- Criticism on the Calculations --- p.50 / Chapter 6 --- Summary and Conclusions --- p.52 / Bibliography --- p.53 / Chapter A --- Random-Phase Approximation --- p.57

Hoi-Yin Shik. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 92-94). / Text in English; abstracts in English and Chinese. / Hoi-Yin Shik. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Heisenberg Model --- p.1 / Chapter 1.2 --- Exactly Soluble Model --- p.3 / Chapter 1.3 --- This Project --- p.4 / Chapter 2 --- Spin-1 Net Spin Models --- p.6 / Chapter 2.1 --- Solution for the Four Spin Plaquette --- p.8 / Chapter 2.2 --- The Ground State and First Excited State Properties --- p.17 / Chapter 2.2.1 --- Spin Ladder Model --- p.18 / Chapter 2.2.2 --- Double Layer Model --- p.24 / Chapter 2.3 --- Excitation Spectrum for L Goes from One to Infinity --- p.27 / Chapter 2.4 --- General Spin S --- p.28 / Chapter 3 --- Constructing Exactly Soluble Quantum Spin Models --- p.29 / Chapter 3.1 --- Spin-1 Bond Operators --- p.29 / Chapter 3.1.1 --- Net Spin Ladder --- p.30 / Chapter 3.1.2 --- Spin Layer --- p.33 / Chapter 3.2 --- Other Two-dimensional Exactly Soluble Model --- p.35 / Chapter 3.3 --- Three-dimensional Model --- p.38 / Chapter 3.4 --- Spin-1 bond Operators --- p.56 / Chapter 3.5 --- Three-dimensional Spin-1 Model --- p.65 / Chapter 3.5.1 --- Other Exact Soluble Spin-1 Models --- p.68 / Chapter 3.6 --- General Spin-S --- p.68 / Chapter 4 --- Low Lying Excitations for the Net Spin Ladder --- p.72 / Chapter 4.1 --- Solutions of K-Rung Ladder --- p.74 / Chapter 4.1.1 --- K = 1 --- p.74 / Chapter 4.1.2 --- K = 2 --- p.75 / Chapter 4.1.3 --- K = 3 --- p.76 / Chapter 4.1.4 --- K = 4 --- p.78 / Chapter 4.1.5 --- K > 4 --- p.80 / Chapter 4.2 --- The Critical Point --- p.81 / Chapter 5 --- Conclusion --- p.90 / Bibliography --- p.92 / Chapter A --- The matrix represention of different Hamiltonians --- p.95 / Chapter A.1 --- p.95 / Chapter A.2 --- p.97 / Chapter A.3 --- p.99

隨著半導體生產工藝的特徵尺寸日益縮小，工藝變化引起的良率損失亦日益顯著。在現場可編程門陣列平臺，一些優化設計方法根據芯片的特定的工藝變化特徵來優化設計以提高時序良率。然而，目前缺乏一種實際的工藝變化特徵提取方法以支持上述優化設計方法。為了滿足這一需求，在文論文的第一部份，我們提出利用環形振盪器來提取商用現場可編程門陣列芯片的工藝變化特徵。該方法可以提取到邏輯單元級別的時序特徵，并進而推測出互聯電路的時序特徵。為了證明該方法的有效性我們在現場可編程門陣列芯片上任意放置兩個結構完全相同的環形振盪器于不同的位置。我們分別通過直接測量和通過分析特徵提取的數據得到兩振盪器的時序差異。對比結果顯示通過分析特徵提取數據，推算結果和實際測量結果僅平均相差10% 以內。我們在Xilinx 公司的Spartan-3e 芯片上實現了該方法，別且在其他Xilinx 的芯片上同樣適用。 / 在本論文的第二部份，我們提出一種利用現場可編程門陣列架構對稱性的方法來系統化的改變設計道路。通過對一個初始設計電路的旋轉和翻轉，我們可以得到八種時序性能相同的候選設計。在隨機工藝變化的存在下，八種候選設計的任何一個都有同樣的可能性被選為針對某一特定芯片的最優設計。如果大批芯片的單一個體都可以確定最優設計，整體性能將大幅度改善。另外，我們提出交換關鍵路徑上的相鄰邏輯單元來進一步提高時序性能通過對二十個測試電路的仿真實驗，我們發現統計時序性能得到了大幅度改善。相比于其他改善時序性能的方法，該方法從設計時間的角度來看更有效率。 / 雖然工藝變換常被認為一種有害的寄生效應，但是它提供了一些應用前景。物理費克隆方程的提出啟發研究人員把芯片的工藝變化的唯一性轉化為芯片的數字身份。在本論文的第三部份，我們提出利用環形振盪器陣列來測量工藝變化，并通過比較振盪器的相對速度來計算芯片數字身份。然而，芯片身份的穩定性是一個普遍的問題，尤其是在考慮到工作環境(如溫度、這墨)改變的情況下。為了解決這一間包我們提出結合使用可配置的環形振盪器以及重新初始化的方法來提高穩定性。改方法同樣在Xilinx 的Spartan-3e 芯片上實現。實驗結果表明該方法大幅度提高了在工作環境變化下芯片身份的穩定性。 / As semiconductor manufacturing continues towards reduced feature size, yield loss induced by process variation becomes increasingly significant. On the platform of field programmable field array (FPGA), several works proposed to improve timing yield by optimizing design implementation based on chip-specific variation distribution, which are generally defined as variation aware design (VAD) methods. However, there is a lack of practical variation characterization method to facilitate the invented VAD methods. To fulfill this demand, in the first part of this thesis, we proposed to characterize delay variation by measuring the loop delay of ring oscillator (RO) on commercial FPGAs. By comparing the difference of loop delays for ROs with slightly different structures, the logic element (LE) delay can be explicitly characterized. The delays of interconnect circuits can be further derived with existing LE delay information and additional measurements. To evaluate the effectiveness of the proposed variation characterization, two ROs with identical structure are arbitrarily placed at different locations on an FPGA chip. The difference of the loop delays between two ROs can be both directly measured and estimated by characterization results. Taking measurement results as references, the error rate of estimation by characterization results is less than 10% on average. The proposed characterization method is implemented on Xilinx Spartan-3e FPGA chips. Without loss of generality, the proposed method can be also adopted on other Xilinx FPGA devices. / In the second part of this thesis, we proposed to systematically manipulates FPGA post-layout circuits by using FPGA architectural symmetry. Eight timing equivalent “candidate configurations“ can be obtained by rotating and flipping an initial configuration. In presence of random process variation, any of them has equal opportunity to be selected as the optimal implementation for a specific FPGA chip. If each individual from a large number of FPGAs is applied with the optimal among all candidate configurations, the overall timing performance is evidently improved compared to applying a single configuration to those FPGAs. Furthermore, the technique of LE swapping makes faster one of two neighboring LEs occupied by critical paths, which guarantees an incremental timing performance improvement based on any optimized design. Twenty MCNC benchmark circuitsare placed and routed by VPR [12]. Statistical timing performance is obtained by Monte-Carlo simulation with FPGA process variation model. The experimental results demonstrate evident timing yield improvement. Compared to previous VAD works, the proposed method saves the effort of variation characterization and design time. / Although process variation is always stated as a side-effect, it still offers some opportunities for variation-based applications. The invention of physically unclonable function (PUF) enlightens the researchers to translate physical uniqueness to digital identification. In the third part of this thesis, a compact chip identification (ID) circuit on FPGA is presented. An array of ring oscillators is used to measure the process variation. The chip ID is calculated based on their relative speeds. The repeatability of chip ID generation is a common challenge for all kinds of implementations, particularly when variations in operating conditions such as supply voltage and temperature are taken into account. To address this issue, configurable ring oscillators together with an orthogonal (re-)initialization scheme is used to improve reliability. The implementation of the proposed design is tested on nine Xilinx Spartan-3e FPGA chips. The experimental results show that the new method significantly enhances reliability of ID generation and tolerance to environmental changes. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yu, Haile. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 125-137). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.ii / Acknowledgement --- p.vi / Publication List --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction to Process Variation --- p.1 / Chapter 1.2 --- Variation Compensation --- p.3 / Chapter 1.2.1 --- Post-silicon Tuning --- p.3 / Chapter 1.2.2 --- Variation-Aware Design (VAD) --- p.5 / Chapter 1.3 --- Background and Prior Art --- p.6 / Chapter 1.3.1 --- Variation Characterization --- p.6 / Chapter 1.3.2 --- Variation Compensation --- p.8 / Chapter 1.3.3 --- Chip Identification --- p.11 / Chapter 1.4 --- Motivations --- p.17 / Chapter 1.4.1 --- Variation Characterization --- p.17 / Chapter 1.4.2 --- Timing Yield Improvement by Architectural Symmetry --- p.18 / Chapter 1.4.3 --- Chip Identification --- p.18 / Chapter 1.5 --- Key Contributions --- p.19 / Chapter 1.5.1 --- Variation Characterization --- p.19 / Chapter 1.5.2 --- Timing Yield Improvement by Architectural Symmetry --- p.20 / Chapter 1.5.3 --- Chip Identification --- p.20 / Chapter 1.6 --- Thesis Outline --- p.22 / Chapter 2 --- Variation Characterization for FPGA --- p.24 / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Characterization Primitives --- p.27 / Chapter 2.3 --- Methodology --- p.28 / Chapter 2.3.1 --- LE Characterization --- p.30 / Chapter 2.3.2 --- LUT Full Characterization --- p.33 / Chapter 2.3.3 --- Interconnect Characterization --- p.36 / Chapter 2.4 --- Implementation --- p.39 / Chapter 2.5 --- Experimental Results --- p.41 / Chapter 2.5.1 --- Scaling Factor --- p.41 / Chapter 2.5.2 --- Characterization Results --- p.42 / Chapter 2.5.3 --- Verification --- p.47 / Chapter 2.6 --- Conclusion and Discussion --- p.49 / Chapter 2.6.1 --- Discussion --- p.50 / Chapter 3 --- Timing Yield Improvement for FPGA --- p.51 / Chapter 3.1 --- Introduction --- p.52 / Chapter 3.2 --- Variation Model --- p.52 / Chapter 3.2.1 --- Random Variation --- p.53 / Chapter 3.2.2 --- Spatial Correlation --- p.54 / Chapter 3.3 --- Theoretical Analysis --- p.55 / Chapter 3.3.1 --- 1-out-of-N Redundancy Method --- p.55 / Chapter 3.3.2 --- Configuration-Level Redundancy vs. Fine-Grained Adjustment --- p.57 / Chapter 3.3.3 --- Coverage Rate of Fine-Grained Adjustment --- p.61 / Chapter 3.4 --- Architecture --- p.62 / Chapter 3.4.1 --- Modification for Configuration Rotation and Flip --- p.62 / Chapter 3.4.2 --- Modification for Fine-grained Adjustment --- p.65 / Chapter 3.5 --- Flow of Methodology --- p.66 / Chapter 3.6 --- Experimental Results --- p.68 / Chapter 3.7 --- Cost-Efficiency Comparison --- p.74 / Chapter 3.8 --- Conclusions --- p.76 / Chapter 4 --- Chip Identification Circuit for FPGA --- p.78 / Chapter 4.1 --- Introduction --- p.79 / Chapter 4.2 --- Design --- p.80 / Chapter 4.2.1 --- Measurement Circuits --- p.80 / Chapter 4.2.2 --- “Cell“ Composition and One-bit Generation --- p.82 / Chapter 4.3 --- Results --- p.85 / Chapter 4.3.1 --- Distribution of R[subscript i] --- p.86 / Chapter 4.3.2 --- Effect of P,T,N --- p.87 / Chapter 4.3.3 --- Distribution of 1’s and 0’s --- p.88 / Chapter 4.3.4 --- Hamming Distance --- p.89 / Chapter 4.3.5 --- Execution Time --- p.89 / Chapter 4.3.6 --- Variation with Temperature --- p.90 / Chapter 4.4 --- Conclusions --- p.93 / Chapter 5 --- Enhanced Chip Identification Circuit for FPGA --- p.96 / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.2 --- Sources of Instability --- p.97 / Chapter 5.3 --- Implementation --- p.98 / Chapter 5.3.1 --- Overlapped Cell Composition --- p.98 / Chapter 5.3.2 --- Configurable RO --- p.99 / Chapter 5.3.3 --- Configuration Initialization --- p.101 / Chapter 5.3.4 --- Flow of Chip ID Generation --- p.107 / Chapter 5.4 --- Results --- p.109 / Chapter 5.4.1 --- Summary of Hardware Resource Consumption --- p.109 / Chapter 5.4.2 --- Statistical Analysis --- p.109 / Chapter 5.4.3 --- Environmental Influences --- p.117 / Chapter 5.5 --- Conclusion --- p.119 / Chapter 6 --- Conclusion --- p.120 / Chapter 6.1 --- Future Work --- p.122 / Chapter 6.1.1 --- Variation Characterization for FPGA --- p.122 / Chapter 6.1.2 --- Timing Yield Improvement for FPGA --- p.123 / Chapter 6.1.3 --- Chip Identification Circuit for FPGA --- p.124 / Bibliography --- p.137

"Passive scalar concentration and velocity fields of isolated turbulent puffs were examined experimentally using the planar laser Mie scattering and PIV techniques, respectively. Work in WPI laboratories on reacting, fully-modulated jets has indicated significantly reduced flame lengths for compact puffs in comparison with steady and pulsed jets. Of particular interest is the entrainment and mixing of isolated turbulent puffs away from the nozzle. The present experiments were carried out in order to enhance fundamental understanding of the velocity fields associated with isolated, turbulent puffs. Puffs were generated by injecting air through a 5 mm diameter nozzle into a flow chamber with a weak co-flow. The injection time was varied by the use of a fast-response solenoid valve from 20 ms to 161 ms. Puffs with a Reynolds number of 5,000 were examined in the range of 25 - 75 diameters downstream of the nozzle. The results indicate that as the injection volume increases, puffs evolve from a spherical geometry to one with a tail. The distribution of a passive scalar within the examined turbulent puffs is unlike that in turbulent vortex rings. The half-width of radial concentration profile through the puff center decreases as the injection volume increases. On the other hand, the puff length in the axial direction increases with the injection volume. The results from phase-locked PIV measurements indicate that the largest axial mean velocities and the radial velocity fluctuation are within the central portion of the puff and the largest axial velocity fluctuation are typically present above the puff center. The turbulent shear stress profiles within puffs are antisymmetric about the centerline and the maximum magnitude for the smallest injection volume is 2.5 times the steady jet value. The vorticity fields calculated from phase-locked velocity field data indicate the presence of vorticity throughout the puff volume. The ratio of puff volume flow rate to steady jet at the puff center location was largest for the smallest injection volume. The majority of entrainment into the puff occurs below the puff center while the puff cap pushes out into surrounding fluid. In general, the puff characteristics did not reveal an internal structure analogous to that in the turbulent vortex ring."

The thesis designs, constructs, and tests an electrically small dipole antenna probe for the measurement of electric field distributions induced by a transcranial magnetic stimulation (TMS) coil. Its unique features include high spatial resolution, large frequency band from 100 Hz to 300 kHz, efficient feedline isolation via a printed Dyson balun, and accurate mitigation of noise. Prior work in this area is thoroughly reviewed. The proposed probe design is realized in hardware; implementation details and design tradeoffs are described. Test data is presented for the measurement of a CW capacitor electric field, demonstrating the probe’s ability to properly measure conservative electric fields caused by a charge distribution. Test data is also presented for the measurement of a CW solenoidal electric field, demonstrating the probe’s ability to measure non-conservative solenoidal electric fields caused by Faraday’s law of induction. Those are the primary fields for the transcranial magnetic stimulation. Advantages and disadvantages of this probing system versus those of prior works are discussed. Further refinement steps necessary for the development of this probe as a valuable TMS instrument are discussed.

Thesis (M.A.)--Boston University

Orientador: Donato Giorgio Torrieri / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-09-02T05:31:14Z (GMT). No. of bitstreams: 1 Truran_HenriqueDias_M.pdf: 940156 bytes, checksum: 80a833549f8b10145a3af3b38fc79eca (MD5) Previous issue date: 2017 / Resumo: Teoria quântica de campos é uma das mais bem sucedidas teorias da física contemporânea, e suas aplicações no estudo de sistemas acelerados um interessante tópico de pesquisa. De termalização em física de íons pesados à radiação de eletrons em QED de alta intensidade, o estudo de TQC em referenciais acelerados parece mais relevante do que nunca. Nessa dissertação nós apresentamos uma introdução aos princípios da teoria quântica de campos, como podemos estuda-la em referenciais acelerados, e como relacionar a física que um observador acelerado vê com os fenômenos observados no referencial inercial do laboratório / Abstract: Quantum field theory is one of the most successful theories of contemporary physics, and its applications to the study of accelerated systems an interesting topic of research. From thermalization in heavy-ion physics to radiation emission by electrons in high-intensity QED, the study of QFT in accelerated reference frames seems more relevant than ever. In this thesis we present an introduction to the principles quantum field theory, how we can study it in accelerated reference frames, and how to relate the physics seen by an accelerated observer's point of view with the phenomena observed in the inertial frame of the laboratory / Mestrado / Física / Mestre em Física / 132651/2015-7 / CNPQ

Performance of repertoire is a defining curricular aspect in the band area of music education, upon which students will spend significant time. The act of repertoire selection is a potentially complicated one, carrying the norms, values, and beliefs of the overall band area and band directors themselves. A band director’s personal ensemble experience is steeped in aesthetic traditions and canonical notions of repertoire’s quality and its use in band settings, and these notions may be incompatible with highly varied teaching situations. In this study, I examine these issues using Bourdieu’s concepts of habitus and field. The research questions were: is there a tension between the established norms (habitus) regarding the repertoire used in public schools, and practicing band directors’ professional contextual realities? If so, what is the cause of the tension, what do band directors do in response to it, and is the experience or non-experience of tension manifested differently in distinct professional contextual realities? I used a multi-method design to answer the research questions, collecting survey and interview data. Survey participants were randomly sampled from across New York State. The interview participants were purposefully sampled for variation in teaching situations. The data revealed that a tension exists and is manifested in elemental/structural issues and differences in expressed musical/educational goals. Consistent themes were the influence of collegiate ensemble experiences as main drivers of the tension and a resulting expressed reverence for core repertoire, even though it might not be what participants program. These phenomena did not appear to manifest differently across varied contexts. In addressing the tension, participants expand their habitus to include other repertoire that is more suitable or appropriate for their own situations, regardless of normative notions of quality or core repertoire. Music educators may benefit from a reorientation in teacher education programs that acknowledges the potential for this tension and that prepare them to enter their professional contextual realities and evaluate and choose repertoire in a tension-free process. Such a process would be free from a “one size fits all” conceptualization of repertoire’s quality and its role in a band program. Keywords: band, repertoire selection, tension, Bourdieu, habitus, field, hermeneutic phenomenology.

Digitized by Kansas Correctional Industries

Thesis (Ed.M.)--Boston University / It is the purpose of this study, to determine the extent to which the elementary schools of an industrial city in Massachusetts, are utilizing the resources of the community. Although there is much material available as to those community resources that are being utilized and best suited for elementary schools, as well as suggestions and techniques for making the best use of them, little data are available as to a method or plan of determining to what extent the elementary schools are utilizing the resources of their particular community. Through research, it is hoped that a representative list of those community resources that are being utilized by individual teachers or groups of teachers throughout the country can be evolved, and a questionnaire, in the form of a check list, built. In this check list, the community resources will be classified and placed in the following categories: (1) Field trips, (2) Resource Visitors, (3) Interviews with Resource People, (4) Collections and Exhibits, (5) Contacts with Community Agencies, (6) Local Resource Surveys, and (7) Community Service Enterprises.