18,731 research outputs found
On the approximation of functions and some applications
Three density theorems for three suitable subspaces of functions, in
the strong topology, are proven. The spaces are , ,
where the absolutely continuous part of the symmetric gradient is in ,
with , and , whose functions are in and the jump set
has finite -measure. This generalises on the one hand the
density result by [Chambolle, 2004-2005] and, on the other hand, extends in
some sense the three approximation theorems in by [De Philippis, Fusco,
Pratelli, 2017] for , , spaces, obtaining also more
regularity for the absolutely continuous part of the approximating functions.
As application, the sharp version of two -convergence results for
energies defined on is derived
The z<=0.1 Surface Brightness Distribution
The surface brightness distribution (SBD) function describes the number
density of galaxies as measured against their central surface brightness.
Because detecting galaxies with low central surface brightnesses is both
time-consuming and complicated, determining the shape of this distribution
function can be difficult. In a recent paper Cross, et al. suggested a
bell-shaped SBD disk-galaxy function which peaks near the canonical Freeman
value of 21.7 and then falls off significantly by 23.5 B mag arcsec-2. This is
in contradiction to previous studies which have typically found flat (slope=0)
SBD functions out to 24 - 25 B mag arcsec^-2 (the survey limits). Here we take
advantage of a recent surface-brightness limited survey by Andreon & Cuillandre
which reaches considerably fainter magnitudes than the Cross, et.al sample (M_B
reaches fainter than -12 for Andreon & Cuillandre while the Cross, et.al sample
is limited to M_B < -16) to re-evaluate both the SBD function as found by their
data and the SBD for a wide variety of galaxy surveys, including the Cross, et
al. data. The result is a SBD function with a flat slope out through the survey
limits of 24.5 B mag arcsec^-2, with high confidence limits.Comment: 5 pages including 5 figures. accepted by A&A
Capturing the industrial requirements of set-based design for CONGA framework
The Configuration Optimisation of Next-Generation Aircraft (CONGA) is a proposed framework in a response industrial need to enhance the aerospace capability in the UK. In order to successfully address this challenge, a need to develop a true multi-disciplinary Set-Based Design (SBD) capability that could deploy new technologies on novel configurations more quickly and with greater confidence was identified. This paper presents the first step towards the development of the SBD capabilities which is to elicit the industrial requirement of the SBD process for the key aerospace industrial partners involved in this CONGA approach
Capturing the Industrial Requirements of Set-Based Design for the CONGA Framework
The Configuration Optimisation of Next-Generation Aircraft (CONGA) is a proposed framework in a response to industrial need to enhance the aerospace capability in the UK. In order to successfully address this challenge, a need to develop a true multi-disciplinary Set-Based Design (SBD) capability that could deploy new technologies on novel configurations more quickly and with greater confidence was identified. This paper presents the first step towards the development of the SBD capabilities which is to elicit the industrial requirement of the SBD process for the key aerospace industrial partners involved in this CONGA approach
Video shot boundary detection: seven years of TRECVid activity
Shot boundary detection (SBD) is the process of automatically detecting the boundaries between shots in video. It is a problem which has attracted much attention since video became available in digital form as it is an essential pre-processing step to almost all video analysis, indexing, summarisation, search, and other content-based operations. Automatic SBD was one of the tracks of activity within the annual TRECVid benchmarking exercise, each year from 2001 to 2007 inclusive. Over those seven years we have seen 57 different research groups from across the world work to determine the best approaches to SBD while using a common dataset and common scoring metrics. In this paper we present an overview of the TRECVid shot boundary detection task, a high-level overview of the most significant of the approaches taken, and a comparison of performances, focussing on one year (2005) as an example
Lupin ingredients in shrimp (Penaeus monodon) diets: influence of lupin species and types of meals
The nutritive value of five isonitrogenous practical diets containing different legume meals, whole or dehulled lupin (Lupinus albus) seed meal (WAD and DAD, respectively), dehulled lupin (L. angustifolius) seed meal (DND), lupin (L. angustifolius) protein concentrate (LPCD), and defatted
soybean meal (SBD), was evaluated in two laboratory experiments (growout and digestibility studies) using juvenile (4.07±0.05 g, mean±SD) shrimp, Penaeus monodon. In the 42-day growout study, shrimp fed SBD or DND had significantly higher (P<0.05) growth rates than those fed LPCD, DAD or WAD. Protein conversion efficiency (PCE) and apparent protein utilization (APU) values of DND were significantly higher than those of LPCD, DAD or WAD. SBD and DND had significantly higher feed intake values and better feed conversion ratios (FCRs) than WAD and
DAD. LPCD had a similar FCR to other diets but lower feed intake than SBD. Shrimp fed WAD had significantly poorer performance in all the above parameters than shrimp fed other diets except for DAD and LPCD. The diets SBD, DND, LPCD, and DAD had significantly higher (P<0.05) apparent
dry matter digestibilities (ADMD) (68.3–71.4%) than WAD (64.4%). All diets had a similar apparent protein digestibility (APD) (87.1–89.1%) with a small, but significant difference being observed for the diets with the highest (DND) and the lowest (WAD) protein digestibility. Pellet water stability was significantly different (P<0.05) among the diets. The most stable pellet was displayed by LPCD, while WAD had the poorest water stability. Dehulling or concentrating lupin seed protein did not improve the nutritive value of lupin diets for juvenile P. monodon. The lupin seed meal of L. angustifolius was better utilized by P. monodon than that of L. albus and the nutritive value of L. angustifolius diet was equal to that of soybean (control) diet. Results of a feeding preference test also indicated that L. angustifolius diet was more attractive for juvenile P.
monodon than L. albus diet
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