5,438 research outputs found
The technology of Incremental Sheet Forming - a brief review of the history
This paper describes the history of Incremental Sheet Forming (ISF) focusing on technological developments. These developments are in general protected by patents, so the paper can also be regarded as an overview of ISF patents in addition to a description of the early history. That history starts with the early work by Mason in 1978 and continues up to the present day. An extensive list of patents including Japanese patents is provided.\ud
\ud
The overall conclusion is that ISF has received the attention of the world, in particular of the automotive industry, and that most proposed or suspected applications focus on the flexibility offered by the process. Only one patent has been found that is explicitly related to the enhancement of formability. Furthermore, most patents refer to TPIF (Two-Point Incremental Forming) as a process.\ud
\ud
Besides simply presenting a historical overview the paper can act as an inspiration for the researcher, and present a rough idea of the patentability of new developments
Enhancing Sensitivity Classification with Semantic Features using Word Embeddings
Government documents must be reviewed to identify any sensitive information
they may contain, before they can be released to the public. However,
traditional paper-based sensitivity review processes are not practical for reviewing
born-digital documents. Therefore, there is a timely need for automatic sensitivity
classification techniques, to assist the digital sensitivity review process.
However, sensitivity is typically a product of the relations between combinations
of terms, such as who said what about whom, therefore, automatic sensitivity
classification is a difficult task. Vector representations of terms, such as word
embeddings, have been shown to be effective at encoding latent term features
that preserve semantic relations between terms, which can also be beneficial to
sensitivity classification. In this work, we present a thorough evaluation of the
effectiveness of semantic word embedding features, along with term and grammatical
features, for sensitivity classification. On a test collection of government
documents containing real sensitivities, we show that extending text classification
with semantic features and additional term n-grams results in significant improvements
in classification effectiveness, correctly classifying 9.99% more sensitive
documents compared to the text classification baseline
Black hole and de Sitter solutions in a covariant renormalizable field theory of gravity
It is shown that Schwarzschild black hole and de Sitter solutions exist as
exact solutions of a recently proposed relativistic covariant formulation of
(power-counting) renormalizable gravity with a fluid. The formulation without a
fluid is also presented here. The stability of the solutions is studied and
their corresponding entropies are computed, by using the covariant Wald method.
The area law is shown to hold both for the Schwarzschild and for the de Sitter
solutions found, confirming that, for the case, one is dealing with a
minimal modification of GR.Comment: 7 paages, latex fil
Evolving rules for document classification
We describe a novel method for using Genetic Programming to create compact classification rules based on combinations of N-Grams (character strings). Genetic programs acquire fitness by producing rules that are effective classifiers in terms of precision and recall when evaluated against a set of training documents. We describe a set of functions and terminals and provide results from a classification task using the Reuters 21578 dataset. We also suggest that because the induced rules are meaningful to a human analyst they may have a number of other uses beyond classification and provide a basis for text mining applications
Applying machine learning to the problem of choosing a heuristic to select the variable ordering for cylindrical algebraic decomposition
Cylindrical algebraic decomposition(CAD) is a key tool in computational
algebraic geometry, particularly for quantifier elimination over real-closed
fields. When using CAD, there is often a choice for the ordering placed on the
variables. This can be important, with some problems infeasible with one
variable ordering but easy with another. Machine learning is the process of
fitting a computer model to a complex function based on properties learned from
measured data. In this paper we use machine learning (specifically a support
vector machine) to select between heuristics for choosing a variable ordering,
outperforming each of the separate heuristics.Comment: 16 page
Role of defects in the electronic properties of amorphous/crystalline Si interface
The mechanism determining the band alignment of the amorphous/crystalline
Si heterostructures is addressed with direct atomistic simulations of the
interface performed using a hierarchical combination of various computational
schemes ranging from classical model-potential molecular dynamics to ab-initio
methods. We found that in coordination defect-free samples the band alignment
is almost vanishing and independent on interface details. In defect-rich
samples, instead, the band alignment is sizeably different with respect to the
defect-free case, but, remarkably, almost independent on the concentration of
defects. We rationalize these findings within the theory of semiconductor
interfaces.Comment: 4 pages in two-column format, 2 postscript figures include
An efficient k.p method for calculation of total energy and electronic density of states
An efficient method for calculating the electronic structure in large systems
with a fully converged BZ sampling is presented. The method is based on a
k.p-like approximation developed in the framework of the density functional
perturbation theory. The reliability and efficiency of the method are
demostrated in test calculations on Ar and Si supercells
Solutions for f(R) gravity coupled with electromagnetic field
In the presence of external, linear / nonlinear electromagnetic fields we
integrate f(R) \sim R+2{\alpha}\surd(R+const.) gravity equations. In contrast
to their Einsteinian cousins the obtained black holes are non-asymptotically
flat with a deficit angle. In proper limits we obtain from our general solution
the global monopole solution in f(R) gravity. The scale symmetry breaking term
adopted as the nonlinear electromagnetic source adjusts the sign of the mass of
the resulting black hole to be physical.Comment: 7 pages no figure, final version for publication in European Physical
Journal
Conserved Quantities in Gravity via Noether Symmetry
This paper is devoted to investigate gravity using Noether symmetry
approach. For this purpose, we consider Friedmann Robertson-Walker (FRW)
universe and spherically symmetric spacetimes. The Noether symmetry generators
are evaluated for some specific choice of models in the presence of
gauge term. Further, we calculate the corresponding conserved quantities in
each case. Moreover, the importance and stability criteria of these models are
discussed.Comment: 14 pages, accepted for publication in Chin. Phys. Let
- …
