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(9,421 - 9,440 of 9,491)
Pages
- Title
- Integral, 1908
- Creator
- Armour Institute of Technology
- Date
- 1908
- Description
-
Volume 10 of Integral, the 1908 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 10 of Integral, the 1908 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1915
- Creator
- Armour Institute of Technology
- Date
- 1915
- Description
-
Volume 3 of The Cycle, the 1915 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 3 of The Cycle, the 1915 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1916
- Creator
- Armour Institute of Technology
- Date
- 1916
- Description
-
Volume 4 of The Cycle, the 1916 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 4 of The Cycle, the 1916 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1919
- Creator
- Armour Institute of Technology
- Date
- 1919
- Description
-
Volume 7 of The Cycle, the 1919 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 7 of The Cycle, the 1919 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1930
- Creator
- Armour Institute of Technology
- Date
- 1930
- Description
-
Volume 18 of The Cycle, the 1930 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 18 of The Cycle, the 1930 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1932
- Creator
- Armour Institute of Technology
- Date
- 1932
- Description
-
Volume 20 of The Cycle, the 1932 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 20 of The Cycle, the 1932 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1935
- Creator
- Armour Institute of Technology
- Date
- 1935
- Description
-
Volume 23 of The Cycle, the 1935 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 23 of The Cycle, the 1935 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1937
- Creator
- Armour Institute of Technology
- Date
- 1937
- Description
-
Volume 25 of The Cycle, the 1937 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 25 of The Cycle, the 1937 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1933
- Creator
- Armour Institute of Technology
- Date
- 1933
- Description
-
Volume 21 of The Cycle, the 1933 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 21 of The Cycle, the 1933 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1931
- Creator
- Armour Institute of Technology
- Date
- 1931
- Description
-
Volume 19 of The Cycle, the 1931 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 19 of The Cycle, the 1931 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1934
- Creator
- Armour Institute of Technology
- Date
- 1934
- Description
-
Volume 22 of The Cycle, the 1934 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 22 of The Cycle, the 1934 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1920
- Creator
- Armour Institute of Technology
- Date
- 1920
- Description
-
Volume 8 of The Cycle, the 1920 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 8 of The Cycle, the 1920 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1924
- Creator
- Armour Institute of Technology
- Date
- 1924
- Description
-
Volume 12 of The Cycle, the 1924 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 12 of The Cycle, the 1924 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- The Cycle, 1938
- Creator
- Armour Institute of Technology
- Date
- 1938
- Description
-
Volume 26 of The Cycle, the 1938 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by...
Show moreVolume 26 of The Cycle, the 1938 yearbook for the Armour Institute of Technology. The Armour Institute of Technology yearbooks was known by three different titles: Integral (1898-1910), Senior Class Book (1911-1912), and The Cycle (1913-1940). A 1902 volume of Integral is not a part of Galvin Library collections; it is uncertain of a yearbook was published that year. Publication of the Armour Institute ceased in 1941, when the Armour Institute of Technology merged with the Lewis Institute to form Illinois Institute of Technology.
Sponsorship: Scanning of the Armour Institute of Technology yearbooks was supported in part by an award from the Illinois State Historical Records Advisory Board, through funding from the National Historical Publications and Records Commission, National Archives and Records Administration.
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- Armour Institute of Technology yearbooks, 1898-1940
- Title
- Quantification of Vascular Permeability in the Retina Using Fluorescein Videoangiography Data as a Biomarker for Early Diabetic Retinopathy
- Creator
- Kayaalp Nalbant, Elif
- Date
- 2023
- Description
-
Diabetic retinopathy, which is the most common reason for blindness in the working-age population, affects over one-third of those who have...
Show moreDiabetic retinopathy, which is the most common reason for blindness in the working-age population, affects over one-third of those who have had diabetes for over ten years. High blood sugar level (hyperglycemia) in the blood damages blood vessels and tight junction at the blood-retinal barrier (BRB). Chronic inflammation leads to changes in vascular health, and over time blood vessels tend to get damaged and exhibit higher “leakage” or permeability. In the late stage of DR, hemorrhages can occur, leading to irreversible damage of neuronal tissue in the retina and vision loss. In the clinic, there are some biomarkers and imaging modalities used to diagnose DR based on some of the more severe products of DR (e.g., hemorrhage), but there is no non-invasive, highly sensitive method to detect diabetic retinopathy before clinical signs occur, when mitigating therapies could be more effective. In this thesis, indicator dilution theory was explored to modeling the temporal dynamics of fluorescein in the retina after intravenous injection, with an aim to quantitatively map subtle changes in retinal blood flow and vascular permeability that could preempt subsequent irreversible damage. Specifically, a simplified version of indicator dilution theory—namely the “adiabatic approximation in tissue homogeneity” (AATH) model—was used to estimate physiological parameters such as the blood flow (F) and the extraction fraction (E: a parameter coupled with vascular permeability) from retinal fluorescein videoangiography data. The AATH fitting protocol was optimized through simulations using a more complex model (the AATH-vascular heterogeneity model, AATH-VH). It was determined that a two-step least square fitting method was more sensitive than a single-step least square fitting of AATH to simulated data to evaluate vascular permeability in early diabetic retinopathy. The optimized data analysis protocol was then evaluated in an initial clinical study comparing healthy control subjects to those with moderate non-proliferative DR. Volumetric blood flow and retinal vascular permeability maps were compared between patient groups with clear increases in extraction fraction observed in the mild NPDR patients compared to control. These promising early data have been the foundation to an ongoing 5 year study tracking 100 Diabetic patients with no DR so see if early changes in vascular permeability can predict which patients are more likely to progress to DR.
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- Title
- Efficient management of uncertain data
- Creator
- Feng, Su
- Date
- 2023
- Description
-
Uncertainty arises naturally in many application domains. It can be caused by an uncertain data source (sensor errors, noise, etc.). Data...
Show moreUncertainty arises naturally in many application domains. It can be caused by an uncertain data source (sensor errors, noise, etc.). Data preprocessing techniques (data curation, data integration, etc.) can also results in uncertainty to the data. Analyzing uncertain data without accounting for its uncertainty can create hard to trace errors, with severe real world implications. Certain answers are a principled method for coping with the uncertainty that arises in many practical data management tasks. Unfortunately, this method is expensive and may exclude useful (if uncertain) answers. Other techniques from incomplete database record and propagate more detailed uncertainty information. However, most of these approaches are either too expensive to be practical, or only focus on a narrow class of queries and only work for a specific representation. In this thesis, we investigate models and query semantics for uncertain data management and present a framework that is general and practically efficient, backed up by fundamental theoretical foundations and with formally proven correctness guarantees. We first propose Uncertainty Annotated Databases (UA-DB), which combine an under- and over-approximation of certain answers to combine the reliability of certain answers with the performance of a classical database system. We then introduce attribute-annotated uncertain databases (AU-DB), which extend the UA-DB model with attribute-level annotations that record bounds on the values of an attribute across all possible worlds. AU-DB extends UA-DBs to encode a compact over-approximation of possible answers which is necessary to support non-monotone queries including aggregation and set difference. With a further extension to AU-DB that supports ranking and windowed aggregation queries using native implementation on modern DBMS, our approaches scale to complex queries and large datasets, and produces accurate results. Furthermore, they significantly outperforms alternative methods for uncertain data management.
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- Title
- High School Mathematics Teachers’ Conceptions of Nature of Mathematics (NOM) and How Prior Learning Environments Affect These Conceptions
- Creator
- Elefteriou, Katherine
- Date
- 2023
- Description
-
Literature shows that the Nature of Mathematics Knowledge (NOMK) dates back to the era of Plato and Aristotle (Dossey, 1992). It suggests that...
Show moreLiterature shows that the Nature of Mathematics Knowledge (NOMK) dates back to the era of Plato and Aristotle (Dossey, 1992). It suggests that mathematics teachers’ beliefs, views, conceptions, and preferences about NOM influence the way in which they teach mathematics. It is important to understand how these conceptions are formed, which may evolve consciously or unconsciously from their experiences. Teachers’ experiences as students of mathematics, their family, school environment, cultural, and social experiences influence their behavior including their decisions, actions, class organization, learning activities, and students’ achievement (Beswick, 2012; Ernest, 2008; Thompson1984). Yet, there is no NCTM standard on NOM (Gfeller, 1999).The purpose of the present study was to assess high school mathematics teachers’ NOMK conceptions, and to explore how these conceptions have been influenced by their personal and educational experiences as students in learning mathematics. Another objective of this study was to explore whether the teachers’ years of mathematics teaching experience, and their level of education have any influence on their NOMK beliefs. The sample consisted of 52 high school mathematics teachers, who were certified to teach secondary mathematics, and who had at least three years of mathematics teaching experience. Two instruments were used to collect the data, 1) the VNOM D instrument to assess the teachers’ beliefs regarding the NOMK aspects, and 2) the demographics instrument to collect information on the teachers’ demographics, and on their experiences as students of mathematics. Interviews were also used to enhance the findings. Results showed that participants had strong beliefs regarding their NOMK, and that their years of experience, and level of education influenced their NOMK beliefs.
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- Title
- Effects of Microstructure Engineering on Laser Powder Bed Fusion Processed Superalloy IN718 through Inoculant Addition
- Creator
- Ho, I-Ting
- Date
- 2023
- Description
-
Additive manufacturing (AM) techniques can now be utilized as innovative tools that provide unlimited design flexibility for the fabrication...
Show moreAdditive manufacturing (AM) techniques can now be utilized as innovative tools that provide unlimited design flexibility for the fabrication of geometrically complex metallic structures. For production of Ni-base superalloy components used in advanced gas turbine engines, laser powder bed fusion (L-PBF), which is one of the AM techniques, is frequently used as it allows good metallurgical bonding of powder feedstock and simultaneously enables development of ultra-efficient power systems for aerospace propulsion, space exploration and power generation. One of the major challenges associated with additively manufactured Ni-base superalloy components is that the extreme temperature gradients encountered during processing negatively impact the underlying microstructure and mechanical properties of the material. Although the macroscopic shape and chemistry of the additively fabricated part may be identical to the conventionally manufactured part, the resulting properties are usually compromised. In an effort to make Ni-base superalloys more amenable for processing via additive manufacturing, varying levels of benign inoculants that promote may heterogeneously grain nucleation were blended into Inconel 718 (IN718) powder feedstock and used for processing via L-PBF to characterize the microstructural evolution. In the first study, 0.2 wt. % of micron-sized CoAl2O4 flakes was found to effectively change the grain morphology during the L-PBF process leading to significant reduction in crystallographic texture and thus resulting elastic anisotropy. Dispersion of nano-oxides resulting from the reduction of CoAl2O4 particles also contributed to improved tensile strength and steady creep strain rate. It should be noted, however, that, the multiple iterations of remelting as the result of deposition of new layers dissolved the Co-rich particles reduced from CoAl2O4 inoculants. Instead of having nucleation events contributed by elemental Co, the oxide agglomerates as a result of Marangoni convection seemed to be the major contribution to facilitating grain refinement by inhibiting the heat transfer in the surroundings. On the other hand, addition CoAl2O4 particles appeared to generally reduce the melt pool width while increase the melt pool depth by inhibiting the degree of heat transfer and Marangoni flow. The changes in melt pool dimension aided in improving the relative density and surface roughness of the bulk samples by generating better metallurgical bonding to the subsequent layers. As the trade-off, however, the changes in melt pool physics also enhanced the tendency for epitaxial growth and hence retarded the columnar-to-equiaxed transition unless oxide agglomerates are present. In addition to CoAl2O4, candidates including Co, TaCr2, TiB2, and CeO2 particles were also considered to be blended with the powder feedstock of IN718. After the L-PBF process, different degree of microstructural evolution was characterized with the addition of Co, TaCr2, TiB2, or CeO2 particles. It was found that the physical presence of inoculants may change the melt pool geometries that accounted for a comparatively more columnar-grained structure with <101> texture in samples containing Co and TaCr2 particles while a relatively equiaxed-grained structure with <001> texture in samples containing TiB2. The comparison between samples containing TiB2 and CeO2 further indicates that the phase transformation induced agglomeration will also reduce the effectiveness of inoculants due to decreasing nuclei density. Findings from this investigation demonstrate the resulting grain structure upon L-PBF can be profoundly impacted by both chemistry and physical properties of the inoculants. These effects may potentially be harnessed to effectively engineer the microstructure and optimize the properties of L-PBF processed Ni-base superalloys.
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- Title
- High-integrity modeling of non-stationary Kalman Filter input error processes and application to aircraft navigation
- Creator
- Gallon, Elisa
- Date
- 2023
- Description
-
Most navigation applications nowadays rely heavily on Global Navigation Satellite Systems (GNSSs) and inertial sensors. Both of these systems...
Show moreMost navigation applications nowadays rely heavily on Global Navigation Satellite Systems (GNSSs) and inertial sensors. Both of these systems are known to be complementary, and as such, their outputs are very often combined in an extended Kalman Filter (KF) to provide a continuous navigation solution, resistant to poor satellite geometry, as well as radio frequency interference. Additionally, recent development in safety critical applications (such as aviation) revealed the performance limitations of current algorithms (Advance Receiver Autonomous Integrity Monitoring - ARAIM) to vertical guidance down to 200 feet above the runway (LPV-200). When nominal constellations are depleted, LPV-200 can only sparsely be achieved. Exploiting satellite motion in ARAIM (for instance using a KF) could help alleviate those limitations, but would require adequate modeling of the errors, including the error's time correlation.Power Spectral Density (PSD) bounding is a methodology that provides high integrity, time correlated error models, but this approach is currently limited to stationary errors (which is rarely the case with real data), and has never been applied to navigation errors. More generally, no high integrity, time correlated error models have ever been derived for navigation errors.As a result, in the first part of this thesis, a methodology for high integrity modeling of time correlated errors is introduced. The PSD bounding methodology is extended to both stationary and non-stationary errors. In the second part of this thesis, these methodologies are applied to the 3 main error sources impacting iono-free GNSS measurements (orbit and clock errors, tropospheric errors and multipath), as well as to inertial errors.The methodology introduced in this dissertation provides high integrity time correlated error models and is applicable to any type of applications where high integrity is required (e.g. Differential GNSS - DGNSS, Aircaft Based Augmentation System - ABAS, Ground Based Augmentation System - GBAS, Space Based Augmentation System - SBAS, etc...). Additionally, the error models derived here are not only limited to high integrity applications, but could also be used in applications were the correlation over time of the errors plays an important role (such as any KF integration).In the last part of this dissertation, we focus on a specific safety critical application: aviation, and in particular ARAIM. The dissertation is concluded with an assessment of the performance improvements provided by recursive ARAIM, using those bounding dynamic error models, with respect to those models, used for baseline snapshot ARAIM. Additionally, a sensitivity analysis is performed on each of the error model parameters to assess which of them impacts the KF performance (i.e. covariance) the most.
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- Title
- A Novel CNFET SRAM-Based Computing-In-Memory Design and Low Power Techniques for AI Accelerator
- Creator
- Kim, Young Bae
- Date
- 2023
- Description
-
Power consumption and data processing speed of integrated circuits (ICs) is an increasing concern in many emerging Artificial Intelligence (AI...
Show morePower consumption and data processing speed of integrated circuits (ICs) is an increasing concern in many emerging Artificial Intelligence (AI) applications, such as autonomous vehicles and Internet of Things (IoT). In addition, according to the 2020 International Technology Road map for Semiconductors (ITRS), the high power consumption trend of AI chips far exceeds the power requirements. As a result, power optimization techniques are highly regarded in nowadays AI chip designs. There are various low-power methodologies from the system level to the layout level, and we are focusing on transistor level and register transfer level (RTL) through this thesis. In this thesis, we propose a novel ultra-low power voltage-based computing-in- memory (CIM) design with a new SRAM bit cell structure for AI Accelerator. The basic working principle of CIM (Computing-in-memory) is to use the existing internal embedded memory array (e.g. SRAM) instead of external memory, and it reduces unnecessary access to external memory by calculating with internal embedded mem- ory. Since the proposed our SRAM bit cell uses a single bitline for CIM calculation with decoupled read and write operations, it supports much higher energy eciency. In addition, to separate read and write operations, the stack structure of the read unit minimizes leakage power consumption. Moreover, the proposed bit cell structure provides better read and write stability due to the isolated read path, write path and greater pull-up ratio. Compared to the state-of-the-art SRAM-CIM, our proposed SRAM-CIM does not require extra transistors for CIM vector-matrix multiplication. We implemented a 16k (128⇥128) bit cell array for the computation of 128x neurons, and used 64x binary inputs (0 or 1) and 64⇥128 binary weights (-1 or +1) values for the binary neural networks (BNNs). Each row of the bit cell array corresponding to a single neuron consists of a total of 128 cells, 64x cells for dot-product and 64x replicas cells for ADC reference. And 64x replicas cells consist of 32x cells for ADC reference and 32x cells for o↵set calibration. We used a row-by-row ADC for the quantized outputs of each neuron, which supports 1-7 bits of output for each neuron. The ADC uses the sweeping method using 32x duplicate bit cells, and the sweep cycle is set to 2N1 +1, where N is the number of output bits. The simulation is performed at room temperature (27C) using 32nm CNFET and 20nm FinFET technology via Synopsys Hspice, and all transistors in bitcells use the minimum size considering the area, power, and speed. The proposed SRAM-CIM has reduced power consumption for vector-matrix multiplication by 99.96% compared to the existing state-of-the-art SRAM-CIM. Moreover, because of the separated reading unit from an internal node of latch, there is no feedback from the read access circuit, which makes it read static noise margin (SNM) free. Furthermore, for the low power AI accelerator design, we propose a new AI accelerator design method that applies low power techniques such as bus specific clock gating (BSCG) and local explicit clock gating (LECG) at the register-transfer- level (RT-level). And evaluates them on the Xilinx ZCU-102 FPGA SoC hardware platform and 45nm technology for ASIC, respectively. It measures dynamic power using a commercial EDA tool, and chooses only a subset of FFs to be gated selectively based on their switching activities. We achieve up to a 53.21% power reduction in the ASIC implementation and saved 32.72% of the dynamic power dissipation in the FPGA implementation. This shows that our RTL low power schemes have a powerful possibility of dynamic power reduction when applied to the FPGA design flow and ASIC design flow for the implementation of the AI system.
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