Is Model Attention Aligned with Human Attention? An Empirical Study on Large Language Models for Code Generation

Large Language Models (LLMs) have been demonstrated effective for code generation. Due to the complexity and opacity of LLMs, little is known about how these models generate code. To deepen our understanding, we investigate whether LLMs attend to the same parts of a natural language description as human programmers during code generation. An analysis of five LLMs on a popular benchmark, HumanEval, revealed a consistent misalignment between LLMs' and programmers' attention. Furthermore, we found that there is no correlation between the code generation accuracy of LLMs and their alignment with human programmers. Through a quantitative experiment and a user study, we confirmed that, among twelve different attention computation methods, attention computed by the perturbation-based method is most aligned with human attention and is constantly favored by human programmers. Our findings highlight the need for human-aligned LLMs for better interpretability and programmer trust.Comment: 13 pages, 8 figures, 7 table

Graduate Teaching Communities of Practice: Fostering a Sense of Belonging and Professional Development for Graduate Students, by Graduate Students

Communities of Practice provide explicit formal recognition for teaching work and serve as a network of pedagogical resources. Communities of Practice create a safe space and a strengthened sense of community. Communities of Practice can be formed anywhere to meet any set of needs but always thrive with members’ agency and institutional support

Exploring How We Teach: Lived Experiences, Lessons, and Research about Graduate Instructors by Graduate Instructors

This book combines the knowledge of 30 graduate student instructors sharing about how they teach and how they’ve learned how to teach

In Situ and Operando Investigation of the Dynamic Morphological and Phase Changes of Selenium-doped Germanium Electrode during (De)Lithiation Processes

To understand the effect of selenium doping on the good cycling performance and rate capability of a Ge0.9Se0.1 electrode, the dynamic morphological and phase changes of the Ge0.9Se0.1 electrode were investigated by synchrotron-based operando transmission X-ray microscopy (TXM) imaging, X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The TXM results show that the Ge0.9Se0.1 particle retains its original shape after a large volume change induced by (de)lithiation and undergoes a more sudden morphological and optical density change than pure Ge. The difference between Ge0.9Se0.1 and Ge is attributed to a super-ionically conductive Li–Se–Ge network formed inside Ge0.9Se0.1 particles, which contributes to fast Li-ion pathways into the particle and nano-structuring of Ge as well as buffering the volume change of Ge. The XRD and XAS results confirm the formation of a Li–Se–Ge network and reveal that the Li–Se–Ge phase forms during the early stages of lithiation and is an inactive phase. The Li–Se–Ge network also can suppress the formation of the crystalline Li15Ge4 phase. These in situ and operando results reveal the effect of the in situ formed, super-ionically conductive, and inactive network on the cycling performance of Li-ion batteries and shed light on the design of high capacity electrode materials

FINCH: A Blueprint for Accessible and Scientifically Valuable Remote Sensing Satellite Missions

Satellite remote sensing missions have grown in popularity over the past fifteen years due to their ability to cover large swaths of land at regular time intervals, making them suitable for monitoring environmental trends such as greenhouse gas emissions and agricultural practices. As environmental monitoring becomes central in global efforts to combat climate change, accessible platforms for contributing to this research are critical. Many remote sensing missions demand high performance of payloads, restricting research and development to organizations with sufficient resources to address these challenges. Atmospheric remote sensing missions, for example, require extremely high spatial and spectral resolutions to generate scientifically useful results. As an undergraduate-led design team, the University of Toronto Aerospace Team’s Space Systems Division has performed an extensive mission selection process to find a feasible and impactful mission focusing on crop residue mapping. This mission profile provides the data needed to improve crop residue retention practices and reduce greenhouse gas emissions from soil, while relaxing performance requirements relative to many active atmospheric sensing missions. This is accompanied by the design of FINCH, a 3U CubeSat with a hyperspectral camera composed of custom and commercial off-the-shelf components. The team’s custom composite payload, the FINCH Eye, strives to advance performance achieved at this form factor by leveraging novel technologies while keeping design feasibility for a student team a priority. Optical and mechanical design decisions and performance are detailed, as well as assembly, integration, and testing considerations. Beyond its design, the FINCH Eye is examined from operational, timeline, and financial perspectives, and a discussion of the supporting firmware, data processing, and attitude control systems is included. Insight is provided into open-source tools that the team has developed to aid in the design process, including a linear error analysis tool for assessing scientific performance, an optical system tradeoff analysis tool, and data processing algorithms. Ultimately, the team presents a comprehensive case study of an accessible and impactful satellite optical payload design process, in hopes of serving as a blueprint for future design teams seeking to contribute to remote sensing research

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

TRANSITION METAL BASED ELECTROCATALYSTS FOR WATER SPLITTING

Electrochemical water splitting is a catalytic process in which water molecule can be catalytically reduced to dihydrogen in cathode and oxidized to oxygen molecule in anode. The electrical energy that is used for water splitting can be renewable when the energy source is sunlight, geothermal heat, tide, etc., and the hydrogen gas can thus be generated sustainably. Nonetheless, the hydrogen produced through electrochemical water splitting is less than 10% of the total amount.The top limitation of its wide applications is the low activity of catalysts in both cathodic reaction (hydrogen evolution reaction, HER) and anodic reaction (oxygen evolution reaction, OER). The dissertation covers heteroatoms doping strategy in activating HER and OER catalysts that I have developed in my PhD study. For instance, N doping has been found to create new facets and active sites of Ni3S2 that are able to improve the hydrogen adsorption. As a result, the overpotential of Ni3S2 can be decreased from 240 mV to 155 mV at 10 mA/cm2, while the TOF of N doped Ni3S2 can be increased as much as 2 times of the pristine Ni3S2. A carbon doping strategy was adopted to activate NiO water-alkali HER catalyst. Combined our experimental and theoreticality study, carbon doping has created under-coordinated Ni sites that are favorable for hydrogen adsorption. Meanwhile, the carbon dopant also serves as the “hot-spot” in water dissociation that contributes to the improved kinetics of HER. The carbon doped NiO showed an ultralow overpotential of 29 mV at 10 mA/cm2, even comparable with the benchmark Pt/C catalysts. On the other hand, Fe-doped β-Ni(OH)2 nanosheets supported on Ni foam were developed for OER and able to achieve a low overpotential of 219 mV at geometric area current density of 10 mA cm-2, and a high electrochemical surface area current density of 6.25 mA cm-2 at the overpotential of 300 mV. This high intrinsic catalytic activity should be due to the strong electron-withdrawing ability of Fe dopant that makes the adjacent Ni active in OER, as well as the unique mixed amorphous/crystalline heterogeneous structure as preferential adsorption sites towards OER intermediates

TRANSITION METAL BASED ELECTROCATALYSTS FOR WATER SPLITTING

Electrochemical water splitting is a catalytic process in which water molecule can be catalytically reduced to dihydrogen in cathode and oxidized to oxygen molecule in anode. The electrical energy that is used for water splitting can be renewable when the energy source is sunlight, geothermal heat, tide, etc., and the hydrogen gas can thus be generated sustainably. Nonetheless, the hydrogen produced through electrochemical water splitting is less than 10% of the total amount.The top limitation of its wide applications is the low activity of catalysts in both cathodic reaction (hydrogen evolution reaction, HER) and anodic reaction (oxygen evolution reaction, OER). The dissertation covers heteroatoms doping strategy in activating HER and OER catalysts that I have developed in my PhD study. For instance, N doping has been found to create new facets and active sites of Ni3S2 that are able to improve the hydrogen adsorption. As a result, the overpotential of Ni3S2 can be decreased from 240 mV to 155 mV at 10 mA/cm2, while the TOF of N doped Ni3S2 can be increased as much as 2 times of the pristine Ni3S2. A carbon doping strategy was adopted to activate NiO water-alkali HER catalyst. Combined our experimental and theoreticality study, carbon doping has created under-coordinated Ni sites that are favorable for hydrogen adsorption. Meanwhile, the carbon dopant also serves as the “hot-spot” in water dissociation that contributes to the improved kinetics of HER. The carbon doped NiO showed an ultralow overpotential of 29 mV at 10 mA/cm2, even comparable with the benchmark Pt/C catalysts. On the other hand, Fe-doped β-Ni(OH)2 nanosheets supported on Ni foam were developed for OER and able to achieve a low overpotential of 219 mV at geometric area current density of 10 mA cm-2, and a high electrochemical surface area current density of 6.25 mA cm-2 at the overpotential of 300 mV. This high intrinsic catalytic activity should be due to the strong electron-withdrawing ability of Fe dopant that makes the adjacent Ni active in OER, as well as the unique mixed amorphous/crystalline heterogeneous structure as preferential adsorption sites towards OER intermediates