6,807 research outputs found
The Impact of Physician Intervention and Tobacco Control Policies on Average Daily Cigarette Consumption Among Adult Smokers
Physicians' advice to stop smoking has been found to increase smoking cessation rates in controlled clinical trials. However, these finding may not be applicable under real world conditions. This paper investigates the impact of physicians' advice and tobacco control policies on conditional cigarette demand among adults employing non-experimental data. Because the data is non-experimental, the variable reflect physician advice to stop smoking and cigarette consumption are likely to be endogenous. We implement a three stage least squares regression technique designed to take account the joint determination of physician advice and cigarette smoking. The results from these models imply that smokers that received advice from their physician to quit smoking will decrease their average daily consumption by between 5-6 cigarettes per day as compared to smoker who do not receive advice. This result implies that physicians' advice is effective in curtailing smoking in real world settings. Other policies that were found to decrease average smoking by smokers include: the real price of cigarettes and clean indoor air laws.
A classification of 3+1D bosonic topological orders (I): the case when point-like excitations are all bosons
Topological orders are new phases of matter beyond Landau symmetry breaking.
They correspond to patterns of long-range entanglement. In recent years, it was
shown that in 1+1D bosonic systems there is no nontrivial topological order,
while in 2+1D bosonic systems the topological orders are classified by a pair:
a modular tensor category and a chiral central charge. In this paper, we
propose a partial classification of topological orders for 3+1D bosonic
systems: If all the point-like excitations are bosons, then such topological
orders are classified by unitary pointed fusion 2-categories, which are
one-to-one labeled by a finite group and its group 4-cocycle up to group automorphisms. Furthermore, all such 3+1D
topological orders can be realized by Dijkgraaf-Witten gauge theories.Comment: An important new result "Untwisted sector of dimension reduction is
the Drinfeld center of E" is added in Sec. IIIC; other minor refinements and
improvements; 23 pages, 10 figure
Compressing Deep Convolutional Neural Networks by Stacking Low-dimensional Binary Convolution Filters
Deep Convolutional Neural Networks (CNN) have been successfully applied to
many real-life problems. However, the huge memory cost of deep CNN models poses
a great challenge of deploying them on memory-constrained devices (e.g., mobile
phones). One popular way to reduce the memory cost of deep CNN model is to
train binary CNN where the weights in convolution filters are either 1 or -1
and therefore each weight can be efficiently stored using a single bit.
However, the compression ratio of existing binary CNN models is upper bounded
by around 32. To address this limitation, we propose a novel method to compress
deep CNN model by stacking low-dimensional binary convolution filters. Our
proposed method approximates a standard convolution filter by selecting and
stacking filters from a set of low-dimensional binary convolution filters. This
set of low-dimensional binary convolution filters is shared across all filters
for a given convolution layer. Therefore, our method will achieve much larger
compression ratio than binary CNN models. In order to train our proposed model,
we have theoretically shown that our proposed model is equivalent to select and
stack intermediate feature maps generated by low-dimensional binary filters.
Therefore, our proposed model can be efficiently trained using the
split-transform-merge strategy. We also provide detailed analysis of the memory
and computation cost of our model in model inference. We compared the proposed
method with other five popular model compression techniques on two benchmark
datasets. Our experimental results have demonstrated that our proposed method
achieves much higher compression ratio than existing methods while maintains
comparable accuracy
A theory of 2+1D fermionic topological orders and fermionic/bosonic topological orders with symmetries
We propose that, up to invertible topological orders, 2+1D fermionic
topological orders without symmetry and 2+1D fermionic/bosonic topological
orders with symmetry are classified by non-degenerate unitary braided
fusion categories (UBFC) over a symmetric fusion category (SFC); the SFC
describes a fermionic product state without symmetry or a fermionic/bosonic
product state with symmetry , and the UBFC has a modular extension. We
developed a simplified theory of non-degenerate UBFC over a SFC based on the
fusion coefficients and spins . This allows us to obtain a list
that contains all 2+1D fermionic topological orders (without symmetry). We find
explicit realizations for all the fermionic topological orders in the table.
For example, we find that, up to invertible
fermionic topological orders, there
are only four fermionic topological orders with one non-trivial topological
excitation: (1) the
fractional quantum Hall state, (2) a Fibonacci bosonic topological order
stacking with a fermionic product state, (3) the time-reversal
conjugate of the previous one, (4) a primitive fermionic topological order that
has a chiral central charge , whose only topological excitation has
a non-abelian statistics with a spin and a quantum dimension
. We also proposed a categorical way to classify 2+1D invertible
fermionic topological orders using modular extensions.Comment: 23 pages, 8 table
Do Adolescents with Emotional or Behavioral Problems Respond to Cigarette Prices?
Adolescents with mental health problems have much higher rates of smoking than those without such problems. Although a large body of evidence suggests that higher cigarette prices reduce smoking prevalence and the quantity smoked, little is known about the interaction between mental health or behavioral problems and tobacco consumption in the general population or among adolescents. Using a national representative sample of adolescents from the National Longitudinal Study of Adolescent Health and employing validated psychiatric measures of emotional distress and behavioral problems, we estimate the price elasticity of cigarette demand for adolescents who have behavioral or emotional problems. The results indicate that these adolescents are at least as responsive to cigarette prices as adolescents with no emotional or behavioral problems.
Estimation and model selection in generalized additive partial linear models for correlated data with diverging number of covariates
We propose generalized additive partial linear models for complex data which
allow one to capture nonlinear patterns of some covariates, in the presence of
linear components. The proposed method improves estimation efficiency and
increases statistical power for correlated data through incorporating the
correlation information. A unique feature of the proposed method is its
capability of handling model selection in cases where it is difficult to
specify the likelihood function. We derive the quadratic inference
function-based estimators for the linear coefficients and the nonparametric
functions when the dimension of covariates diverges, and establish asymptotic
normality for the linear coefficient estimators and the rates of convergence
for the nonparametric functions estimators for both finite and high-dimensional
cases. The proposed method and theoretical development are quite challenging
since the numbers of linear covariates and nonlinear components both increase
as the sample size increases. We also propose a doubly penalized procedure for
variable selection which can simultaneously identify nonzero linear and
nonparametric components, and which has an asymptotic oracle property.
Extensive Monte Carlo studies have been conducted and show that the proposed
procedure works effectively even with moderate sample sizes. A pharmacokinetics
study on renal cancer data is illustrated using the proposed method.Comment: Published in at http://dx.doi.org/10.1214/13-AOS1194 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
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