9,650 research outputs found
Second-order cone programming formulations for a class of problems in structural optimization
This paper provides efficient and easy to
implement formulations for two problems in structural
optimization as second-order cone programming
(SOCP) problems based on the minimum compliance
method and derived using the principle of complementary
energy. In truss optimization both single and
multiple loads (where we optimize the worst-case compliance)
are considered. By using a heuristic which is
based on the SOCP duality we can consider a simple
ground structure and add only the members which
improve the compliance of the structure. It is also
shown that thickness optimization is a problem similar
to truss optimization. Examples are given to illustrate
the method developed in this pape
A knowledge-based geometry repair system for robust parametric CAD models
In modern multi-objective design optimization (MDO) an effective geometry engine is
becoming an essential tool and its performance has a significant impact on the entire MDO
process. Building a parametric geometry requires difficult compromises between the conflicting
goals of robustness and flexibility. This article presents a method of improving the
robustness of parametric geometry models by capturing and modeling engineering knowledge
with a support vector regression surrogate, and deploying it automatically for the
search of a more robust design alternative while trying to maintain the original design
intent. Design engineers are given the opportunity to choose from a range of optimized
designs that balance the ‘health’ of the repaired geometry and the original design intent.
The prototype system is tested on a 2D intake design repair example and shows the potential
to reduce the reliance on human design experts in the conceptual design phase and
improve the stability of the optimization cycle. It also helps speed up the design process
by reducing the time and computational power that could be wasted on flawed geometries
or frequent human intervention
Totems
In modern multi-objective design optimization (MDO) an effective geometry engine is
becoming an essential tool and its performance has a significant impact on the entire MDO
process. Building a parametric geometry requires difficult compromises between the conflicting
goals of robustness and flexibility. This article presents a method of improving the
robustness of parametric geometry models by capturing and modeling engineering knowledge
with a support vector regression surrogate, and deploying it automatically for the
search of a more robust design alternative while trying to maintain the original design
intent. Design engineers are given the opportunity to choose from a range of optimized
designs that balance the ‘health’ of the repaired geometry and the original design intent.
The prototype system is tested on a 2D intake design repair example and shows the potential
to reduce the reliance on human design experts in the conceptual design phase and
improve the stability of the optimization cycle. It also helps speed up the design process
by reducing the time and computational power that could be wasted on flawed geometries
or frequent human intervention
A cascaded approach to normalising gene mentions in biomedical literature
Linking gene and protein names mentioned in the literature to unique identifiers in referent genomic databases is an essential step in accessing and integrating knowledge in the biomedical domain. However, it remains a challenging task due to lexical and terminological variation, and ambiguity of gene name mentions in documents. We present a generic and effective rule-based approach to link gene mentions in the literature to referent genomic databases, where pre-processing of both gene synonyms in the databases and gene mentions in text are first applied. The mapping method employs a cascaded approach, which combines exact, exact-like and token-based approximate matching by using flexible representations of a gene synonym dictionary and gene mentions generated during the pre-processing phase. We also consider multi-gene name mentions and permutation of components in gene names. A systematic evaluation of the suggested methods has identified steps that are beneficial for improving either precision or recall in gene name identification. The results of the experiments on the BioCreAtIvE2 data sets (identification of human gene names) demonstrated that our methods achieved highly encouraging results with F-measure of up to 81.20%
Decoherence suppression by uncollapsing
We show that the qubit decoherence due to zero-temperature energy relaxation
can be almost completely suppressed by using the quantum uncollapsing
procedure. To protect a qubit state, a partial quantum measurement moves it
towards the ground state, where it is kept during the storage period, while the
second partial measurement restores the initial state. This procedure
preferentially selects the cases without energy decay events. Stronger
decoherence suppression requires smaller selection probability; a desired point
in this trade-off can be chosen by varying the measurement strength. The
experiment can be realized in a straightforward way using the superconducting
phase qubit.Comment: 4 page
Introduction
'Introduction' to David Keane and Annapurna Waughray (eds.), Fifty Years of the International Convention on the Elimination of All Forms of Racial Discrimination: A Living Instrument (Manchester University Press, 2017)
This is the very first edited collection on International Convention on the Elimination of All Forms of Racial Discrimination (ICERD), the oldest of the UN international human rights treaties. It draws together a range of commentators including current or former members of the Committee on the Elimination of Racial Discrimination (CERD), along with academic and other experts, to discuss the meaning and relevance of the treaty on its fiftieth anniversary. The contributions examine the shift from a narrow understanding of racial discrimination in the 1960s, premised on countering colonialism and apartheid, to a wider meaning today drawing in a range of groups such as minorities, indigenous peoples, caste groups, and Afro-descendants. In its unique combination of CERD and expert analysis, the collection acts as an essential guide to the international understanding of racial discrimination and the pathway towards its elimination
Weld sequence optimization: the use of surrogate models for solving sequential combinatorial problems
The solution of combinatorial optimization problems usually involves the consideration of many possible design configurations. This often makes such approaches computationally expensive, especially when dealing with complex finite element models. Here a surrogate model is proposed that can be used to reduce substantially the computational expense of sequential combinatorial finite element problems. The model is illustrated by application to a weld path planning problem
Feed intake pattern, behaviour, rumen characteristics and blood metabolites of finishing beef steers offered total mixed rations constituted at feeding or ensiling
peer-reviewedTwo experiments were undertaken. In Experiment 1, behaviour, intake pattern and
blood metabolites, were recorded for steers offered total mixed rations (TMR) based
on grass silage and concentrates, and constituted either at ensiling (E-TMR) or feedout
(F-TMR). Fourteen continental crossbred steers (mean starting weight 505 (s.d.
41.5) kg) were assigned to each of the following eight treatments: grass silage offered
ad libitum (SO), E-TMR diets constituted in approximate dry matter (DM) ratios of
grass:concentrates of 75:25 (EL), 50:50 (EM) and 25:75 (EH), F-TMR diets constituted
in approximate DM ratios of grass silage:concentrates of 75:25 (FL), 50:50 (FM)
and 25:75 (FH), and finally concentrates ad libitum (AL). Total DM intake increased
linearly (P < 0.001) and the time spent eating and ruminating decreased linearly
(P < 0.001) with increasing concentrate proportion. Animals on the F-TMR diets had
higher total DM intakes (P < 0.05) and plasma glucose (P < 0.05) and urea (P < 0.001)
concentrations than animals on the corresponding E-TMR diets. No effect of method
of feed preparation on intake pattern or behaviour was recorded. In Experiment 2,
four ruminally cannulated Holstein-Friesian steers of mean initial live weight 630 (s.d.
23.2) kg were used to evaluate rumen characteristics for four of the above diets (FL,
EL, FH and EH) in a 4 × 4 latin square design. Higher concentrate diets resulted in
lower rumen pH (P < 0.05), higher lactic acid (P < 0.001) and ammonia (P < 0.05)
concentrations and lower acetate:propionate (P < 0.05). F-TMR was associated with
a higher (P < 0.05) rumen volatile fatty acid concentration but no difference in other
rumen fermentation characteristics compared to E-TMR. Concentrate proportion and method of feed preparation had no effect (P > 0.05) on rumen pool sizes but animals
consuming the high concentrate diet had a faster (P < 0.05) rumen passage rate of
NDF than animals on the low concentrate diet.B. Cummins was in receipt of a Teagasc Walsh Fellowship
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