1,543 research outputs found
Product Integral Formalism and Non-Abelian Stokes Theorem
We make use of the properties of product integrals to obtain a surface
product integral representation for the Wilson loop operator. The result can be
interpreted as the non-abelian version of Stokes' theorem.Comment: Latex; condensed version of hep-th/9903221, to appear in Jour. Math.
Phy
Analyzing the relationship between social and professional identity characteristics of the audit committee and the steering system on the quality of financial reporting: a legal oriented artificial approach
The purpose of this study was to analyze the impact of the social and professional identity of the members of the audit committee and the characteristics of the governance system on the financial reporting quality. The modified Jones model was used to express the financial reporting quality. Given that part of the data was obtained through a questionnaire and another part by using financial statements. The research period was 2019 and the sample size was 79 companies listed in Tehran Stock Exchange. To test the research hypotheses, the method of decision making artificial intelligence method and MATLAB software were used. The results of the section of the governance system features indicate the effect of the dual role of the CEO and the ratio of institutional owners on the financial reporting quality. It can be stated that corporate governance mechanisms can reduce opportunistic behavior; they can improve the quality of information by reducing the cost of representation. Also, the results of the audit committee's benchmarks indicate the impact of the audit committee's social identity and the number of employees in internal accounting section on the financial reporting quality, which suggests that effective audit committees, as a determining factor in the financial reporting process, increase the credibility of audited financial statements. In this study, for the first time, the impact of audit committee social identity along with other characteristics of governance system on the quality of financial reporting was analyzed by artificial intelligence
Biological treatment of a synthetic dairy wastewater in a sequencing batch biofilm reactor: Statistical modeling using optimization using response surface methodology
In this study, the interactive effects of initial chemical oxygen demand (CODin), biomass concentration and aeration time on the performance of a lab-scale sequencing batch biofilm reactor (SBBR) treating a synthetic dairy wastewater were investigated. The experiments were conducted based on a central composite design (CCD) and analyzed using response surface methodology (RSM). The region of exploration for treatment of the synthetic dairy wastewater was taken as the area enclosed by the influent comical oxygen demand (CODin (1000, 3000 and 5000 mg/l)), biomass concentration (3000, 5000 and 7000 mg VSS/l) and aeration time (2, 8 and 18 h) boundaries. Two dependent parameters were measured or calculated as response. These parameters were total COD removal efficiency and sludge volume index (SVI). The maximum COD removal efficiencies (99.5%) were obtained at CODin, biomass concentration and aeration time of 5000 mg COD/l, 7000 mg VSS/l and 18 h, respectively. The present study provides valuable information about interrelations of quality and process parameters at different values of the operating variables
The impact of age, sex and socioeconomic deprivation on outcomes in a colorectal cancer screening programme
<p>Background: Population-based colorectal cancer screening has been shown to reduce cancer specific mortality and is used across the UK. Despite evidence that older age, male sex and deprivation are associated with an increased incidence of colorectal cancer, uptake of bowel cancer screening varies across demographic groups. The aim of this study was to assess the impact of age, sex and deprivation on outcomes throughout the screening process.</p>
<p>Methods: A prospectively maintained database, encompassing the first screening round of a faecal occult blood test screening programme in a single geographical area, was analysed.</p>
<p>Results: Overall, 395 096 individuals were invited to screening, 204 139 (52%) participated and 6 079 (3%) tested positive. Of the positive tests, 4 625 (76%) attended for colonoscopy and cancer was detected in 396 individuals (9%). Lower uptake of screening was associated with younger age, male sex and deprivation (all p<0.001). Only deprivation was associated with failure to proceed to colonoscopy following a positive test (p<0.001). Despite higher positivity rates in those that were more deprived (p<0.001), the likelihood of detecting cancer in those attending for colonoscopy was lower (8% most deprived vs 10% least deprived, p = 0.003).</p>
<p>Conclusion: Individuals who are deprived are less likely to participate in screening, less likely to undergo colonoscopy and less likely to have cancer identified as a result of a positive test. Therefore, this study suggests that strategies aimed at improving participation of deprived individuals in colorectal cancer screening should be directed at all stages of the screening process and not just uptake of the test.</p>
A new nickel-based co-crystal complex electrocatalyst amplified by NiO dope Pt nanostructure hybrid; a highly sensitive approach for determination of cysteamine in the presence of serotonin.
A highly sensitive electrocatalytic sensor was designed and fabricated by the incorporation of NiO dope Pt nanostructure hybrid (NiO-Pt-H) as conductive mediator, bis (1,10 phenanthroline) (1,10-phenanthroline-5,6-dione) nickel(II) hexafluorophosphate (B,1,10,P,1,10, PDNiPF6), and electrocatalyst into carbon paste electrode (CPE) matrix for the determination of cysteamine. The NiO-Pt-H was synthesized by one-pot synthesis strategy and characterized by XRD, elemental mapping analysis (MAP), and FESEM methods. The characterization data, which confirmed good purity and spherical shape with a diameter of â 30.64 nm for the synthesized NiO-Pt-H. NiO-Pt-H/B,1,10, P,1,10, PDNiPF6/CPE, showed an excellent catalytic activity and was used as a powerful tool for the determination of cysteamine in the presence of serotonin. The NiO-Pt-H/B,1,10, P,1,10, PDNiPF6/CPE was able to solve the overlap problem of the two drug signals and was used for the determination of cysteamine and serotonin in concentration ranges of 0.003-200 ”M and 0.5-260 ”M with detection limits of 0.5 nM and 0.1 ”M, using square wave voltammetric method, respectively. The NiO-Pt-H/B,1,10,P,1,10,PDNiPF6/CPE showed a high-performance ability for the determination of cysteamine and serotonin in the drug and pharmaceutical serum samples with the recovery data of 98.1-103.06%
Special biconformal changes of K\"ahler surface metrics
The term "special biconformal change" refers, basically, to the situation
where a given nontrivial real-holomorphic vector field on a complex manifold is
a gradient relative to two K\"ahler metrics, and, simultaneously, an
eigenvector of one of the metrics treated, with the aid of the other, as an
endomorphism of the tangent bundle. A special biconformal change is called
nontrivial if the two metrics are not each other's constant multiples. For
instance, according to a 1995 result of LeBrun, a nontrivial special
biconformal change exists for the conformally-Einstein K\"ahler metric on the
two-point blow-up of the complex projective plane, recently discovered by Chen,
LeBrun and Weber; the real-holomorphic vector field involved is the gradient of
its scalar curvature. The present paper establishes the existence of nontrivial
special biconformal changes for some canonical metrics on Del Pezzo surfaces,
viz. K\"ahler-Einstein metrics (when a nontrivial holomorphic vector field
exists), non-Einstein K\"ahler-Ricci solitons, and K\"ahler metrics admitting
nonconstant Killing potentials with geodesic gradients.Comment: 16 page
Development of a 3D multispectral scanner
In this paper, a new technique of scanning is proposed. It is based on a stereoscopic set composed of a structured
light projector and a multispectral camera. Such a set can give the 3D information of a point like a scanner but can
add accurate information about the spectral reflectance of this point. This set must be calibrated before using it. It is
done by two steps: the first one is the spectral characterization of the couple illuminant and camera ; the second
allows geometrically calibrating the complete set.
Afterwards, the image acquisition can begin. A first multispectral image of the scene is obtained without projection of
structured light. Then, with a LCD projector, a luminous line scans the scene. For each line, a grey level image is
acquired. The use of the geometrical calibration parameters allows the processing of the three-dimensional coordinates of the lighted points on the scene. Moreover, and it is the main goal of the proposed system, a spectral
reflectance can be associated to the built points. This spectral data comes, on one hand, from the already-done
spectral characterization, and, on the other hand, from the first multispectral image acquired without projection of
structured light. By comparing the results issued from such a system and those from a system composed of a color
camera or a color scanner, we notice that the spectrum associated to the three-dimensional points brings much more
informative data than only three color components: for example, since the spectral reflectance is independent of the
light used during the acquisition, the 3D scene can be easily simulated under any illuminant. This kind of simulations
finds a great interest in several multimedia applications such as 3D objects visualization for virtual museums.Dans cet article, une nouvelle technique de scanning est proposée. Elle est basée sur un systÚme
stĂ©rĂ©oscopique composĂ© dâun projecteur de lumiĂšre structurĂ©e et dâune camĂ©ra multispectrale. Un tel
systĂšme offre la possibilitĂ© de donner lâinformation 3D dâun point comme pour un scanner classique mais
également de fournir une information précise sur le spectre de réflectance de ce point. Avant utilisation, il
est nĂ©cessaire de calibrer lâensemble. Le calibrage se dĂ©roule en deux Ă©tapes : la premiĂšre dâentre elles
consiste Ă caractĂ©riser la rĂ©ponse spectrale de lâensemble illuminant et camĂ©ra, la seconde permet de le
calibrer géométriquement.
A ce stade, lâanalyse de la scĂšne Ă reconstruire consiste, en premier lieu, en lâacquisition dâune unique image
multispectrale de la scĂšne sans projection de motif caractĂ©ristique. Ensuite, Ă lâaide dâun projecteur LCD, une
ligne de lumiÚre est projetée en balayage sur la scÚne. Pour chaque projection de ligne, une image en
niveaux de gris est acquise. Lâutilisation des paramĂštres de calibrage gĂ©omĂ©trique permet de remonter aux
coordonnĂ©es tridimensionnelles des points illuminĂ©s de la scĂšne. De plus, et câest ici que rĂ©side lâapport
principal du systÚme proposé, un spectre de réflectance est associé à chacun des points reconstruits. Cette
information spectrale provient dâune part, de la caractĂ©risation spectrale prĂ©alablement effectuĂ©e et dâautre
part, de la premiĂšre image multispectrale acquise sans projection de lumiĂšre structurĂ©e. Si lâon compare les
rĂ©sultats obtenus avec un tel systĂšme et ceux issus dâun systĂšme composĂ© dâune camĂ©ra couleur ou dâun
scanner couleur, on remarque que le spectre associé aux points tridimensionnels apporte une information
considĂ©rablement plus riche quâun simple triplet de composantes chromatiques : par exemple, lâinformation
spectrale Ă©tant indĂ©pendante de lâilluminant utilisĂ© pendant lâacquisition, la scĂšne 3D reconstruite peut ĂȘtre
aisĂ©ment simulĂ©e sous un illuminant quelconque. Ce genre de simulations trouve son intĂ©rĂȘt dans des
applications multimĂ©dias de type visualisation dâobjets 3D pour des musĂ©es virtuels
ETCE2002/CAE-29015 UNSTEADY HEAT TRANSFER DURING THE RAPID COMPRESSION AND EXPANSION OF AIR
ABSTRACT The instantaneous unsteady heat transfer during rapid compression and expansion of air within a pneumatically driven piston in a cylinder arrangement which offers simple,well-controlled and known boundary conditions was examined. Values of the instantaneous apparent overall heat flux from the cylinder gas to the wall surfaces were calculated using a thermodynamic analysis of the experimentally measured pressure and volume temporal development. Corresponding heat flux values were also calculated through the application of a zero-dimensional model that incorporates the use of the k â Δ turbulence model. Comparison of the results of the model with corresponding experimental data showed fair to good agreement for the wide range of compression ratio values used (8.4~24.3). Also, correlation of the derived data using an effective velocity which is based on the distribution of mean kinetic energy, turbulence energy and piston motion and a characteristic length that is a function of the instantaneous height between the piston top and the cylinder head and bore diameter as the parameters to use when calculating the Reynolds, Prandtl and Nusselt numbers resulted in the following workable relationship: Nu=0.01Re 0.205 Pr 0.033 . Keyword
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