822 research outputs found
Understanding and Supporting Debugging Workflows in Multiverse Analysis
Multiverse analysis-a paradigm for statistical analysis that considers all
combinations of reasonable analysis choices in parallel-promises to improve
transparency and reproducibility. Although recent tools help analysts specify
multiverse analyses, they remain difficult to use in practice. In this work, we
conduct a formative study with four multiverse researchers, which identifies
debugging as a key barrier. We find debugging is challenging because of the
latency between running analyses and detecting bugs, and the scale of metadata
needed to be processed to diagnose a bug. To address these challenges, we
prototype a command-line interface tool, Multiverse Debugger, which helps
diagnose bugs in the multiverse and propagate fixes. In a second, focused study
(n=13), we use Multiverse Debugger as a probe to develop a model of debugging
workflows and identify challenges, including the difficulty in understanding
the composition of a multiverse. We conclude with design implications for
future multiverse analysis authoring systems
IIFL: Implicit Interactive Fleet Learning from Heterogeneous Human Supervisors
Imitation learning has been applied to a range of robotic tasks, but can
struggle when (1) robots encounter edge cases that are not represented in the
training data (distribution shift) or (2) the human demonstrations are
heterogeneous: taking different paths around an obstacle, for instance
(multimodality). Interactive fleet learning (IFL) mitigates distribution shift
by allowing robots to access remote human teleoperators during task execution
and learn from them over time, but is not equipped to handle multimodality.
Recent work proposes Implicit Behavior Cloning (IBC), which is able to
represent multimodal demonstrations using energy-based models (EBMs). In this
work, we propose addressing both multimodality and distribution shift with
Implicit Interactive Fleet Learning (IIFL), the first extension of implicit
policies to interactive imitation learning (including the single-robot,
single-human setting). IIFL quantifies uncertainty using a novel application of
Jeffreys divergence to EBMs. While IIFL is more computationally expensive than
explicit methods, results suggest that IIFL achieves 4.5x higher return on
human effort in simulation experiments and an 80% higher success rate in a
physical block pushing task over (Explicit) IFL, IBC, and other baselines when
human supervision is heterogeneous
How Do Analysts Understand and Verify AI-Assisted Data Analyses?
Data analysis is challenging as it requires synthesizing domain knowledge,
statistical expertise, and programming skills. Assistants powered by large
language models (LLMs), such as ChatGPT, can assist analysts by translating
natural language instructions into code. However, AI-assistant responses and
analysis code can be misaligned with the analyst's intent or be seemingly
correct but lead to incorrect conclusions Therefore, validating AI assistance
is crucial and challenging. Here, we explore how analysts across a range of
backgrounds and expertise understand and verify the correctness of AI-generated
analyses. We develop a design probe that allows analysts to pursue diverse
verification workflows using natural language explanations, code,
visualizations, inspecting data tables, and performing common data operations.
Through a qualitative user study (n=22) using this probe, we uncover common
patterns of verification workflows influenced by analysts' programming,
analysis, and AI backgrounds. Additionally, we highlight open challenges and
opportunities for improving future AI analysis assistant experiences
StructuralâDeformationâEnergyâModulation Strategy in a Soft Porous Coordination Polymer with an Interpenetrated Framework
German version: https://doi.org/10.1002/ange.202003186To achieve unique molecularârecognition patterns, a rational control of the flexibility of porous coordination polymers (PCPs) is highly sought, but it remains elusive. From a thermodynamic perspective, the competitive relationship between the structural deformation energy (Edef) of soft PCPs and the guest interaction is key for selective a guestâtriggered structuralâtransformation behavior. Therefore, it is vital to investigate and control Edef to regulate this competition for flexibility control. Driven by these theoretical insights, we demonstrate an Edefâmodulation strategy via encoding interâframework hydrogen bonds into a soft PCP with an interpenetrated structure. As a proof of this concept, the enhanced Edef of PCP enables a selective gateâopening behavior toward CHClâ over CHâClâ by changing the adsorptionâenergy landscape of the compounds. This study provides a new direction for the design of functional soft porous materials
Scattering From a Two Dimensional Array of Flux Tubes: A Study of The Validity of Mean Field Theory
Mean Field Theory has been extensively used in the study of systems of anyons
in two spatial dimensions. In this paper we study the physical grounds for the
validity of this approximation by considering the Quantum Mechanical scattering
of a charged particle from a two dimensional array of magnetic flux tubes. The
flux tubes are arranged on a regular lattice which is infinitely long in the
``'' direction but which has a (small) finite number of columns in the
``'' direction. Their physical size is assumed to be infinitesimally small.
We develop a method for computing the scattering angle as well as the
reflection and transmission coefficients to lowest order in the Aharonov--Bohm
interaction. The results of our calculation are compared to the scattering of
the same particle from a region of constant magnetic field whose magnitude is
equal to the mean field of all the flux tubes. For an incident plane wave, the
Mean Field approximation is shown to be valid provided the flux in each tube is
much less than a single flux quantum. This is precisely the regime in which
Mean Field Theory for anyons is expected to be valid. When the flux per tube
becomes of order 1, Mean Field Theory is no longer valid.Comment: 23 pages, University of British Columbia Preprint UBCTP93-01
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