7,092 research outputs found
Physics as Information Processing
I review some recent advances in foundational research at Pavia QUIT group.
The general idea is that there is only Quantum Theory without quantization
rules, and the whole Physics---including space-time and relativity--is emergent
from the quantum-information processing. And since Quantum Theory itself is
axiomatized solely on informational principles, the whole Physics must be
reformulated in information-theoretical terms: this is the "It from Bit of J.
A. Wheeler. The review is divided into four parts: a) the informational
axiomatization of Quantum Theory; b) how space-time and relativistic covariance
emerge from quantum computation; c) what is the information-theoretical meaning
of inertial mass and of , and how the quantum field emerges; d) an
observational consequence of the new quantum field theory: a mass-dependent
refraction index of vacuum. I will conclude with the research lines that will
follow in the immediate future.Comment: Work presented at the conference "Advances in Quantum Theory" held on
14-17 June 2010 at the Linnaeus University, Vaxjo, Swede
Approximate Inference in Probabilistic Answer Set Programming for Statistical Probabilities
Type 1 statements were introduced by Halpern in 1990 with the goal to represent statistical information about a domain of interest.
These are of the form ''x of the elements share the same property''.
The recently proposed language PASTA (Probabilistic Answer set programming for STAtistical probabilities) extends Probabilistic Logic Programs under the Distribution Semantics and allows the definition of this type of statements.
To perform exact inference, PASTA programs are converted into probabilistic answer set programs under the Credal Semantics.
However, this algorithm is infeasible for scenarios when more than a few random variables are involved.
Here, we propose several algorithms to perform both conditional and unconditional approximate inference in PASTA programs and test them on different benchmarks.
The results show that approximate algorithms scale to hundreds of variables and thus can manage real world domains
MAP Inference in Probabilistic Answer Set Programs
Reasoning with uncertain data is a central task in artificial intelligence.
In some cases, the goal is to find the most likely assignment to a subset of random variables, named query variables, while some other variables are observed.
This task is called Maximum a Posteriori (MAP).
When the set of query variables is the complement of the observed variables, the task goes under the name of Most Probable Explanation (MPE).
In this paper, we introduce the definitions of cautious and brave MAP and MPE tasks in the context of Probabilistic Answer Set Programming under the credal semantics and provide an algorithm to solve them.
Empirical results show that the brave version of both tasks is usually faster to compute.
On the brave MPE task, the adoption of a state-of-the-art ASP solver makes the computation much faster than a naive approach based on the enumeration of all the worlds
Credimus
We believe that economic design and computational complexity---while already
important to each other---should become even more important to each other with
each passing year. But for that to happen, experts in on the one hand such
areas as social choice, economics, and political science and on the other hand
computational complexity will have to better understand each other's
worldviews.
This article, written by two complexity theorists who also work in
computational social choice theory, focuses on one direction of that process by
presenting a brief overview of how most computational complexity theorists view
the world. Although our immediate motivation is to make the lens through which
complexity theorists see the world be better understood by those in the social
sciences, we also feel that even within computer science it is very important
for nontheoreticians to understand how theoreticians think, just as it is
equally important within computer science for theoreticians to understand how
nontheoreticians think
Alternation in Quantum Programming: From Superposition of Data to Superposition of Programs
We extract a novel quantum programming paradigm - superposition of programs -
from the design idea of a popular class of quantum algorithms, namely quantum
walk-based algorithms. The generality of this paradigm is guaranteed by the
universality of quantum walks as a computational model. A new quantum
programming language QGCL is then proposed to support the paradigm of
superposition of programs. This language can be seen as a quantum extension of
Dijkstra's GCL (Guarded Command Language). Surprisingly, alternation in GCL
splits into two different notions in the quantum setting: classical alternation
(of quantum programs) and quantum alternation, with the latter being introduced
in QGCL for the first time. Quantum alternation is the key program construct
for realizing the paradigm of superposition of programs.
The denotational semantics of QGCL are defined by introducing a new
mathematical tool called the guarded composition of operator-valued functions.
Then the weakest precondition semantics of QGCL can straightforwardly derived.
Another very useful program construct in realizing the quantum programming
paradigm of superposition of programs, called quantum choice, can be easily
defined in terms of quantum alternation. The relation between quantum choices
and probabilistic choices is clarified through defining the notion of local
variables. We derive a family of algebraic laws for QGCL programs that can be
used in program verification, transformations and compilation. The expressive
power of QGCL is illustrated by several examples where various variants and
generalizations of quantum walks are conveniently expressed using quantum
alternation and quantum choice. We believe that quantum programming with
quantum alternation and choice will play an important role in further
exploiting the power of quantum computing.Comment: arXiv admin note: substantial text overlap with arXiv:1209.437
A semantics for probabilistic answer set programs with incomplete stochastic knowledge
Some probabilistic answer set programs (PASP) semantics assign probabilities to sets of answer sets and implicitly assume these answer sets to be equiprobable. While this is a common choice in probability theory, it leads to unnatural behaviours with PASPs. We argue that the user should have a level of control over what assumption is used to obtain a probability distribution when the stochastic knowledge is incomplete. To this end, we introduce the Incomplete Knowledge Semantics (IKS) for probabilistic answer set programs. We take inspiration from the field of decision making under ignorance. Given a cost function, represented by a user-defined ordering over answer sets through weak constraints, we use the notion of Ordered Weighted Averaging (OWA) operator to distribute the probability over a set of answer sets accordingly to the user’s level of optimism. The more optimistic (or pessimistic) a user is, the more (or less) probability is assigned to the more optimal answer sets. We present an implementation and showcase the behaviour of this semantics on simple examples. We also highlight the impact that different OWA operators have on weight learning, showing that the equiprobability assumption is not always the best option
Exploring Public Opinions Toward the Use of Generative Artificial Intelligence Chatbot in Higher Education:An Insight from Topic Modelling and Sentiment Analysis
The Generative Artificial Intelligence chatbots (GAI chatbots) have emerged as promising tools in various domains, including higher education, so this study aims to investigate the role of Bard, a newly developed GAI chatbot, in higher education. English tweets were collected from Twitter's free streaming Application Programming Interface (API). The Latent Dirichlet Allocation (LDA) algorithm was applied to extract latent topics from the tweets. User sentiments were extracted using the NRC Affect Intensity Lexicon and SentiStrength tools. This study explored the benefits, challenges, and future implications of integrating GAI chatbots in higher education. The findings shed light on the potential power of such tools, exemplified by Bard, in enhancing the learning process and providing support to students throughout their educational journe
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