1,766 research outputs found
UMSL Bulletin 2023-2024
The 2023-2024 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1088/thumbnail.jp
LIPIcs, Volume 251, ITCS 2023, Complete Volume
LIPIcs, Volume 251, ITCS 2023, Complete Volum
UMSL Bulletin 2022-2023
The 2022-2023 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1087/thumbnail.jp
Game-theoretic statistics and safe anytime-valid inference
Safe anytime-valid inference (SAVI) provides measures of statistical evidence
and certainty -- e-processes for testing and confidence sequences for
estimation -- that remain valid at all stopping times, accommodating continuous
monitoring and analysis of accumulating data and optional stopping or
continuation for any reason. These measures crucially rely on test martingales,
which are nonnegative martingales starting at one. Since a test martingale is
the wealth process of a player in a betting game, SAVI centrally employs
game-theoretic intuition, language and mathematics. We summarize the SAVI goals
and philosophy, and report recent advances in testing composite hypotheses and
estimating functionals in nonparametric settings.Comment: 25 pages. Under review. ArXiv does not compile/space some references
properl
Examining the Impact of Game-Based Learning on Student Engagement and Performance in an Introductory Computer Programming Course at the University of the Southern Caribbean (USC)
At the University of the Southern Caribbean (USC) students often struggle with learning programming. Because of this struggle, they often become disengaged with the programming courses, with some transferring to other degree programmes or withdrawing from the programme. While several strategies have been used to ensure that students can problem- solve, design, and develop coded solutions, it has not been enough to alleviate the issues. Game- based learning (GBL) emerged as a possible strategy that can potentially help students develop these skills while keeping them engaged with the course content. Implementing such a strategy within the department requires evidence that it can be an effective technique for teaching and learning programming. Therefore, the aim of this study is to evaluate the impact of GBL on student engagement and overall performance in an introductory programming course. The research was designed as a deductive exploratory single case study research strategy and method. It approaches the aims and objectives from a pragmatic perspective, and as a result, uses a mixed methodological approach to data collection and analysis. The findings show that while GBL does not alleviate the common negative reactions to learning programming, it does provide a learning environment engaging enough for students to overlook these. This results in students having an enhanced perception of the knowledge and improved performance. In implementing GBL in other programming courses, some features that are potentially the most impactful on students learning are immediate feedback, freedom to fail, user interface, code without limitations, and a visual representation of progress
EXPLORING NOVEL MODES OF ACTIVATION VIA MAIN-GROUP ELEMENTS
A novel cyclopropanation reaction of styrenes is disclosed. Catalytic amounts of tris(pentafluorophenyl)borane were used to decompose aryldiazoacetates to the corresponding Lewis acid activated carbenes. These intermediates behave similarly to their metal-activated congeners and were able to cyclopropanate olefins. Mechanistic investigations revealed that the cyclopropanation likely occurs via a concerted [2+1] cycloaddition reaction. The cyclopropanes are isolated as a single diastereomer in almost all cases in good to excellent yields (41% to 90% yield).Presented also is a novel B(C6F5)3-catalyzed [3+2] cycloaddition of 1,1-donor-acceptor cyclopropanes with allyl silanes for the synthesis of highly-substituted cyclopentanes. Cyclopropane ring-opening is proposed to occur via in situ generation of silylium ions which activate the cyclopropane for ring-opening via coordination to a Lewis basic ester. Preliminary 1D-NOE NMR studies as well as mechanistic experiments indicate retention of cyclopropane stereochemistry (aryl groups cis in the products) and a mixture of diastereomers (1.5:1 d.r.) about the silane-substituted methine is observed. Various electronics on the aryl groups are tolerated (10 examples, 41-74% yield). A novel, catalytic alkylation of cyclopropenium ions is disclosed. Cyclopropenium ions are generated via C–F bond activation of gem-difluorocyclopropenes by B(C6F5)3. Catalytic alkylation is achieved using silyl nucleophiles to liberate silyl fluorides and regenerate the Lewis acid catalyst for a second defluorination. Cyclopropene products are isolated as either the 1,2-double alkylation product or the 1,1-double alkylation product. Regioselectivity can be controlled through the changing the temperature of the reaction, changing the sterics of the nucleophile, or changing the electronics of the cyclopropenium ions. These novel, highly substituted cyclopropenes are readily converted to the corresponding orphaned tert-alkyl cyclopropane via simple Pd/C hydrogenation of the cyclopropene double bond or consecutive hydride reductions.Triarylphosphines bearing groups at the ortho-position were reacted with benzyl bromide and their rates of alkylation were measured via 1H NMR monitoring of the formation of the phosphonium bromide salt. A variety of electronically and sterically different orthosubstituents were evaluated to determine what effects reactivity around P(III) centers. Resultsshowed that a large Bpin group in the ortho- position had a surprisingly fast rate of alkylation (4.7 times faster than triphenylphosphine) with benzyl bromide compared to other large groups in the ortho-position. In comparison, moving the Bpin group to both the meta- and para- positions slowed the rate of alkylation to only 1.3 and 1.5 times faster than triphenylphosphine, respectively. X-Ray crystallographic analysis of a single crystal of the ortho-Bpin phosphonium salt revealed a favorable O–P interaction that may stabilize the transition state during the alkylation, causing the observed rate increase.Doctor of Philosoph
The Role of Entropy and Reconstruction in Multi-View Self-Supervised Learning
The mechanisms behind the success of multi-view self-supervised learning
(MVSSL) are not yet fully understood. Contrastive MVSSL methods have been
studied through the lens of InfoNCE, a lower bound of the Mutual Information
(MI). However, the relation between other MVSSL methods and MI remains unclear.
We consider a different lower bound on the MI consisting of an entropy and a
reconstruction term (ER), and analyze the main MVSSL families through its lens.
Through this ER bound, we show that clustering-based methods such as
DeepCluster and SwAV maximize the MI. We also re-interpret the mechanisms of
distillation-based approaches such as BYOL and DINO, showing that they
explicitly maximize the reconstruction term and implicitly encourage a stable
entropy, and we confirm this empirically. We show that replacing the objectives
of common MVSSL methods with this ER bound achieves competitive performance,
while making them stable when training with smaller batch sizes or smaller
exponential moving average (EMA) coefficients.
Github repo: https://github.com/apple/ml-entropy-reconstruction.Comment: 18 pages: 9 of main text, 2 of references, and 7 of supplementary
material. Appears in the proceedings of ICML 202
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