998 resultados para external


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Corporate governance mandates and listing rules identify internal audit functions (IAF) as a central internal control mechanism. External audits are expected to assess the quality of IAF before placing reliance on its work. We provide evidence on the effect of IAF quality and IAF contribution to external audit on audit fees. Using data from a matched survey of both external and internal audits, we extend prior research which is based mainly on internal audits' assessment and conducted predominantly in highly developed markets. We find a positive relationship between IAF quality and audit fees as well as a reduction in audit fees as a result of external auditors' reliance on IAF. The interaction between IAF quality and IAF contribution to external audit suggests that high quality IAF induces greater external auditor reliance on internal auditors' work and thus result in lower external audit fees.

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Radiation therapy (RT) plays currently significant role in curative treatments of several cancers. External beam RT is carried out mostly by using megavoltage beams of linear accelerators. Tumor eradication and normal tissue complications correlate to dose absorbed in tissues. Normally this dependence is steep and it is crucial that actual dose within patient accurately correspond to the planned dose. All factors in a RT procedure contain uncertainties requiring strict quality assurance. From hospital physicist´s point of a view, technical quality control (QC), dose calculations and methods for verification of correct treatment location are the most important subjects. Most important factor in technical QC is the verification that radiation production of an accelerator, called output, is within narrow acceptable limits. The output measurements are carried out according to a locally chosen dosimetric QC program defining measurement time interval and action levels. Dose calculation algorithms need to be configured for the accelerators by using measured beam data. The uncertainty of such data sets limits for best achievable calculation accuracy. All these dosimetric measurements require good experience, are workful, take up resources needed for treatments and are prone to several random and systematic sources of errors. Appropriate verification of treatment location is more important in intensity modulated radiation therapy (IMRT) than in conventional RT. This is due to steep dose gradients produced within or close to healthy tissues locating only a few millimetres from the targeted volume. The thesis was concentrated in investigation of the quality of dosimetric measurements, the efficacy of dosimetric QC programs, the verification of measured beam data and the effect of positional errors on the dose received by the major salivary glands in head and neck IMRT. A method was developed for the estimation of the effect of the use of different dosimetric QC programs on the overall uncertainty of dose. Data were provided to facilitate the choice of a sufficient QC program. The method takes into account local output stability and reproducibility of the dosimetric QC measurements. A method based on the model fitting of the results of the QC measurements was proposed for the estimation of both of these factors. The reduction of random measurement errors and optimization of QC procedure were also investigated. A method and suggestions were presented for these purposes. The accuracy of beam data was evaluated in Finnish RT centres. Sufficient accuracy level was estimated for the beam data. A method based on the use of reference beam data was developed for the QC of beam data. Dosimetric and geometric accuracy requirements were evaluated for head and neck IMRT when function of the major salivary glands is intended to be spared. These criteria are based on the dose response obtained for the glands. Random measurement errors could be reduced enabling lowering of action levels and prolongation of measurement time interval from 1 month to even 6 months simultaneously maintaining dose accuracy. The combined effect of the proposed methods, suggestions and criteria was found to facilitate the avoidance of maximal dose errors of up to even about 8 %. In addition, their use may make the strictest recommended overall dose accuracy level of 3 % (1SD) achievable.

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Bhatnagar and Rathna (Quar. Journ. Mech. Appl. Maths., 1963,16, 329) investigated the flows of Newtonian, Reiner-Rivlin and Rivlin-Ericksen fluids between two rotating coaxial cones. In case of the last two types of fluids, they predicted the breaking of secondary flow field in any meridian plane. We find that such breaking is avoided by the application of a sufficiently strong azimuthal magnetic field arising from a line current along the axis of the cones.

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In this paper, an attempt is made to study the influence of external light waves on the thermoelectric power under strong magnetic field (TPSM) in ultrathin films (UFs), quantum wires (QWs) and quantum dots (QDs) of optoelectronic materials whose unperturbed dispersion relation of the conduction electrons are defined by three and two band models of Kane together with parabolic energy bands on the basis of newly formulated electron dispersion laws in each case. We have plotted the TPSM as functions of film thickness, electron concentration, light intensity and wavelength for UFs, QWs and ODs of InSb, GaAs, Hg1-xCdxTe and In1-xGaxAsyP1-y respectively. It appears from the figures that for UFs, the TPSM increases with increasing thickness in quantum steps, decreases with increasing electron degeneracy exhibiting entirely different types of oscillations and changes with both light intensity and wavelength and these two latter types of plots are the direct signature of light waves on opto-TPSM. For QWs, the opto-TPSM exhibits rectangular oscillations with increasing thickness and shows enhanced spiky oscillations with electron concentration per unit length. For QDs, the opto-TPSM increases with increasing film thickness exhibiting trapezoidal variations which occurs during quantum jumps and the length and breadth of the trapezoids are totally dependent on energy band constants. Under the condition of non-degeneracy, the results of opto-TPSM gets simplified into the well-known form of classical TPSM equation which the function of three constants only and being invariant of the signature of band structure.

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Krishnan's reciprocity theorem in colloid optics, ρ{variant}u=1+l/ρ{variant}h/1+1/ρ{variant}v is generalised for the case when the scattering medium is subjected to an external orienting field. It is shown theoretically that a general relation of the type IBA=I′AB results in this case, where IBA is the intensity of the component of the scattered light having its electric vector inclined at an angle B to the vertical with the incident light polarised at an angle A to the vertical, the external field direction being parallel to the incident beam. I′AB is the corresponding intensity with the magnetic field parallel of the scattered ray. Experimental verification of the above generalisation is also given.

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This Master's Thesis defines the debt policy of the current European Union Member States towards the developing nations. Since no official policy for debt exists in the EU, it is defined to include debt practices (loans and debt relief in development cooperation) and debt within the EU development policy framework. This study (1) describes how the issue of external debt appears in the development policy framework, (2) compares EU Member States' given loans and debt relief to grants for the developing nations (1960s to the 2000s), and (3) measures the current orientation in ODA of each EU Member State between grant aid and loan aid using the Grant-Loan Index (GLI). Theoretical aspects include reasons for selecting between loans (Bouchet 1987) and grants (Odedokun 2004, O'Brien and Williams 2007), policy context of the EU (Van Reisen 2007) and the meaning of external debt in the set-up between the North and the South. In terms of history, the events and impact of the colonial period (where loans have originated) are overviewed and compared in light of today's policies. Development assistance statistics are derived from the OECD DAC statistics portal and EU development policy framework documents from the EU portal. Methodologically, the structure of this study is from policy analysis (Barrien 1999, Hill 2008, Berndtson 2008), but it has been modified to fit the needs of studying a non-official policy. EU Member States are divided into three groups by Carbone (2007a), the Big-3, Northern and Southern donors, based on common development assistance characteristics. The Grant-Loan Index is used to compare Carbone's model, which measures quality of aid, to the GLI measuring the structure of aid. Results indicate that EU- 15 countries (active in debt practices) differ in terms of timing, stability and equality of debt practices in the long-term (1960s to the 2000s). In terms of current practices, (2000-2008), it is noted that there lies a disparity between the actual practices and the way in which external debt is represented in the development policy framework, although debt practices form a relevant portion of total ODA practices for many EU-15 Member States, the issue itself plays a minor role in development policy documents. Carbone’s group division applies well to the Grant – Loan Index’s results, indicating that countries with similar development policy behaviour have similarities in debt policy behaviour, with one exception: Greece. On the basis of this study, it is concluded that EU development policy framework content in terms of external debt and debt practices are not congruent. The understanding of this disparity between the policy outline and differences in long-term practices is relevant in both, reaching the UN’s Millennium Development Goals, and in the actual process of developing development aid.

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A polymer containing electron-rich aromatic donors (1,5-dialkoxynaphthalene (DAN)) was coerced into a folded state by an external folding agent that contained an electron-deficient aromatic acceptor (pyromellitic diimide (PM)) unit. The donor-containing polymer was designed to carry a tertiary amine moiety in the linking segment, which served as an H-bonding site for reinforcing the interaction with the acceptor containing folding agent that also bore a carboxylic acid group. The H-bonding interaction of the carboxylic acid and the tertiary amine brings the PDI unit between two adjacent DAN units along the polymer backbone to induce charge-transfer (C-T) interactions, and this in turn causes the polymer chain to form a pleated structure. Evidence for the formation of such a pleated structure was obtained from NMR titration studies and also by monitoring the C-T band in their UV-visible spectra. By varying the length of the segment that links the PDI acceptor to the carboxylic acid group, we showed that the most effective folding agent was the one that had a single carbon spacer, as evident from the highest value of the association constant. Control experiments with propionic acid clearly demonstrated the importance of the additional C-T interactions for venerating the folded structures. Further, solution viscosity measurements in the presence of varying amounts of the folding agent revealed a gradual stiffening of the chain in the case of the PDI carrying carboxylic acid, whereas no such affect was seen in the case of simple propionic acid. These observations were supported by D FT calculations of the interactions of a dimeric model of the polymer with the various folding agents; here too the stability of the complex was seen to be highest in the case of the single carbon spacer.

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In this paper, an analytical study considering the effect of uncertainties in the seismic analysis of geosynthetic-reinforced soil (GRS) walls is presented. Using limit equilibrium method and assuming sliding wedge failure mechanism, analysis is conducted to evaluate the external stability of GRS walls when subjected to earthquake loads. Target reliability based approach is used to estimate the probability of failure in three modes of failure, viz., sliding, bearing, and eccentricity failure. The properties of reinforced backfill, retained backfill, foundation soil, and geosynthetic reinforcement are treated as random variables. In addition, the uncertainties associated with horizontal seismic acceleration and surcharge load acting on the wall are considered. The optimum length of reinforcement needed to maintain the stability against three modes of failure by targeting various component and system reliability indices is obtained. Studies have also been made to study the influence of various parameters on the seismic stability in three failure modes. The results are compared with those given by first-order second moment method and Monte Carlo simulation methods. In the illustrative example, external stability of the two walls, Gould and Valencia walls, subjected to Northridge earthquake is reexamined.

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In this paper, an analytical study considering the effect of uncertainties in the seismic analysis of geosynthetic-reinforced soil (GRS) walls is presented. Using limit equilibrium method and assuming sliding wedge failure mechanism, analysis is conducted to evaluate the external stability of GRS walls when subjected to earthquake loads. Target reliability based approach is used to estimate the probability of failure in three modes of failure, viz., sliding, bearing, and eccentricity failure. The properties of reinforced backfill, retained backfill, foundation soil, and geosynthetic reinforcement are treated as random variables. In addition, the uncertainties associated with horizontal seismic acceleration and surcharge load acting on the wall are considered. The optimum length of reinforcement needed to maintain the stability against three modes of failure by targeting various component and system reliability indices is obtained. Studies have also been made to study the influence of various parameters on the seismic stability in three failure modes. The results are compared with those given by first-order second moment method and Monte Carlo simulation methods. In the illustrative example, external stability of the two walls, Gould and Valencia walls, subjected to Northridge earthquake is reexamined.

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In this work, using self-consistent tight-binding calculations. for the first time, we show that a direct to indirect band gap transition is possible in an armchair graphene nanoribbon by the application of an external bias along the width of the ribbon, opening up the possibility of new device applications. With the help of the Dirac equation, we qualitatively explain this band gap transition using the asymmetry in the spatial distribution of the perturbation potential produced inside the nanoribbon by the external bias. This is followed by the verification of the band gap trends with a numerical technique using Magnus expansion of matrix exponentials. Finally, we show that the carrier effective masses possess tunable sharp characters in the vicinity of the band gap transition points.

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An experimental study to ascertain the role of external electron donor in methylene blue sensitized dichromated gelatin (MBDCG) holograms has been carried out. The required volume holographic transmission gratings in MBDCG have been recorded using 633-nm light from a He-Ne laser. Three well-known electron donors, namely, N, N-dimethylformamide (DMF); ethylenediaminetetraacetic acid (EDTA); triethanolamine (TEA), were used in this study. The variation of diffraction efficiency (η) as a function of light exposure (E) and concentration (C) of the electron donor under consideration was chosen as the figure of merit for judging the role of external electron donor in MBDCG holograms. A self-consistent analysis of the experimental results was carried out by recalling the various known facts about the photochemistry and the hologram formation in DSDCG and also DCG. The important findings and conclusions are as follows: (i) Each η vs E graph is a bell-shaped curve and its peak height is influenced in a characteristic manner by the external electron donor used. (ii) High diffraction efficiency/recording speed can be achieved in pure MBDCG holograms. (iii) The diffraction efficiency/recording speed achieved in electron donor sensitized MBDCG holograms did not show any significant improvement at all over that observed in pure MBDCG holograms. (iv) In electron donor sensitized MBDCG holograms, the electron donor used, depending on its type and concentration, appears to promote the process of cross-linking of gelatin molecules in a manner to either retain or deteriorate the refractive-index modulation achieved using pure MBDCG.

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A theoretical analysis of the external heavy atom effect of a halogen atom on the radiative rate constant of phosphorescence is examined as a function of position of a bromine atom or atoms relative to a naphthalene or a benzene chromophore for a series of mono- and dibromo-, naphtho-, and benzonorbornenes. The theoretical results are then compared to experimentaldata and lead to the conclusion that the enhancement of the phosphorescence process takes place through the second-ordermixing of the triplet states of the chromophore with the singlet charge transfer states arising primarily from an electron transferfrom the orbitals of the heavy atom perturber to the unfilled x* orbitals of the chromophore.