523 research outputs found
Portfolio Allocation for Bayesian Optimization
Bayesian optimization with Gaussian processes has become an increasingly
popular tool in the machine learning community. It is efficient and can be used
when very little is known about the objective function, making it popular in
expensive black-box optimization scenarios. It uses Bayesian methods to sample
the objective efficiently using an acquisition function which incorporates the
model's estimate of the objective and the uncertainty at any given point.
However, there are several different parameterized acquisition functions in the
literature, and it is often unclear which one to use. Instead of using a single
acquisition function, we adopt a portfolio of acquisition functions governed by
an online multi-armed bandit strategy. We propose several portfolio strategies,
the best of which we call GP-Hedge, and show that this method outperforms the
best individual acquisition function. We also provide a theoretical bound on
the algorithm's performance.Comment: This revision contains an updated the performance bound and other
minor text change
How Technology Impacts and Compares to Humans in Socially Consequential Arenas
One of the main promises of technology development is for it to be adopted by
people, organizations, societies, and governments -- incorporated into their
life, work stream, or processes. Often, this is socially beneficial as it
automates mundane tasks, frees up more time for other more important things, or
otherwise improves the lives of those who use the technology. However, these
beneficial results do not apply in every scenario and may not impact everyone
in a system the same way. Sometimes a technology is developed which produces
both benefits and inflicts some harm. These harms may come at a higher cost to
some people than others, raising the question: {\it how are benefits and harms
weighed when deciding if and how a socially consequential technology gets
developed?} The most natural way to answer this question, and in fact how
people first approach it, is to compare the new technology to what used to
exist. As such, in this work, I make comparative analyses between humans and
machines in three scenarios and seek to understand how sentiment about a
technology, performance of that technology, and the impacts of that technology
combine to influence how one decides to answer my main research question.Comment: Doctoral thesis proposal. arXiv admin note: substantial text overlap
with arXiv:2110.08396, arXiv:2108.12508, arXiv:2006.1262
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