Hasil untuk "Revenue. Taxation. Internal revenue"

Michael A. Bekos, Giordano Da Lozzo, Fabrizio Frati et al.

A well-known result by Kant [Algorithmica, 1996] implies that n-vertex outerplane graphs admit embedding-preserving planar straight-line grid drawings where the internal faces are convex polygons in $O(n^2)$ area. In this paper, we present an algorithm to compute such drawings in $O(n^{1.5})$ area. We also consider outerplanar drawings in which the internal faces are required to be strictly-convex polygons. In this setting, we consider outerplanar graphs whose weak dual is a path and give a drawing algorithm that achieves $Θ(nk^2)$ area, where $k$ is the maximum size of an internal facial cycle.

Pengyu Shi, Éric Climent, Dominique Legendre

Direct numerical simulations of a uniform flow past a fixed spherical droplet are performed to determine the parameter range within which the axisymmetric flow becomes unstable. The problem is governed by three dimensionless parameters: the drop-to-fluid dynamic viscosity ratio, $μ^\ast$, and the external and internal Reynolds numbers, $\Rey^e$ and $\Rey^i$, which are defined using the kinematic viscosities of the external and internal fluids, respectively. The present study confirms the existence of a regime at low-to-moderate viscosity ratio where the axisymmetric flow breaks down due to an internal flow instability. In the initial stages of this bifurcation, the external flow remains axisymmetric, while the asymmetry is generated and grows only inside the droplet. As the disturbance propagates outward, the entire flow first transits to a biplanar symmetric flow, characterised by two pairs of counter-rotating streamwise vortices in the wake. A detailed examination of the flow field reveals that the vorticity on the internal side of the droplet interface is driving the flow instability. Specifically, the bifurcation sets in once the maximum internal vorticity exceeds a critical value that decreases with increasing $\Rey^i$. For sufficiently large $\Rey^i$, internal flow bifurcation may occur at viscosity ratios of $μ^\ast = O(10)$, an order of magnitude higher than previously reported values. Finally, we demonstrate that the internal flow bifurcation in the configuration of a fixed droplet in a uniform fluid stream is closely related to the first path instability experienced by a buoyant, deformable droplet of low-to-moderate $μ^\ast$ freely rising in a stagnant liquid.

Nicolas Lanchon, Pierre-Philippe Cortet

Starting from the classical formulation of the weak turbulence theory in a density stratified fluid, we derive a simplified version of the kinetic equation of internal gravity wave turbulence. This equation allows us to uncover scaling laws for the spatial and temporal energy spectra of internal wave turbulence which are consistent with typical scaling exponents observed in the oceans. The keystone of our description is the assumption that the energy transfers are dominated by a class of non-local resonant interactions, known as the ``induced diffusion'' triads, which conserve the ratio between the wave frequency and vertical wave number. Our analysis remarkably shows that the internal wave turbulence cascade is associated to an apparent constant flux of wave action.

Yushu Lin, John Palmore

The current study uses numerical approaches to investigate the effect of droplet deformation and internal circulation on droplet dynamics. Although droplet drag is a classical area of study, there are still theoretical gaps in understanding the motion of large droplets. In applications like spray combustion, droplets of various sizes are generated and move with the flow. Large droplets tend to deform in the flow, and have complex interactions with the flow because of this deformation. To better model spray, the physical understanding of droplets need to be improved. Under spray conditions, droplets are subjected to a high temperature and pressure environment, and the coupling between liquid and gas is enhanced. Therefore, the deformation and internal circulation will affect droplet drag coefficient more significantly than in atmospheric conditions. To study the mechanism on how droplet shape and internal circulation influence droplet dynamics, we will use direct numerical simulation (DNS) to simulate a droplet falling at its terminal velocity in high pressure air. An in-house code developed for interface-capturing DNS of multiphase flows will be employed for the simulation. The drag coefficient is calculated, and the results are consistent with existing literature for slightly deformed droplets. The results show that the drag coefficient is directly related to the droplet deformation and droplet internal circulation. The paper also develops a theory to account the effect of Weber number and liquid/gas properties in droplet deformation.

Robin Ming Chen, Lili Fan, Samuel Walsh et al.

This paper studies the structural implications of constant vorticity for steady three-dimensional internal water waves. It is known that in many physical regimes, water waves beneath vacuum that have constant vorticity are necessarily two dimensional. The situation is more subtle for internal waves that traveling along the interface between two immiscible fluids. When the layers have the same density, there is a large class of explicit steady waves with constant vorticity that are three-dimensional in that the velocity field and pressure depend on one horizontal variable while the interface is an arbitrary function of the other. We prove the following rigidity result: every three-dimensional traveling internal wave with bounded velocity for which the vorticities in the upper and lower layers are nonzero, constant, and parallel must belong to this family. If the densities in each layer are distinct, then in fact the flow is fully two dimensional.

R. Kailasham, Rajarshi Chakrabarti, J. Ravi Prakash

An exact solution of coarse-grained polymer models with fluctuating internal friction and hydrodynamic interactions has not been proposed so far due to a one-to-all coupling between the connector vector velocities that precludes the formulation of the governing stochastic differential equations. A methodology for the removal of this coupling is presented, and the governing stochastic differential equations, obtained by attaching a kinetic interpretation to the Fokker-Planck equation for the system, are integrated numerically using Brownian dynamics simulations. The proposed computational route eliminates the calculation of the divergence of the diffusion tensor which appears in models with internal friction, and is about an order of magnitude faster than the recursion-based algorithm for the decoupling of connector-vector velocities previously developed [J. Rheol., 65, 903 (2021)] for the solution of freely draining models with internal friction. The effects of the interplay of various combinations of finite extensibility, internal friction and hydrodynamic interactions on the steady-shear-viscosity is examined. While finite extensibility leads solely to shear-thinning, both internal friction and hydrodynamic interactions result in shear-thinning followed by shear-thickening. The shear-thickening induced by internal friction effects are more pronounced than that due to hydrodynamic interactions.

Yuan Deng, Jieming Mao, Balasubramanian Sivan et al.

A patient seller aims to sell a good to an impatient buyer (i.e., one who discounts utility over time). The buyer will remain in the market for a period of time $T$, and her private value is drawn from a publicly known distribution. What is the revenue-optimal pricing-curve (sequence of (price, time) pairs) for the seller? Is randomization of help here? Is the revenue-optimal pricing curve computable in polynomial time? We answer these questions in this paper. We give an efficient algorithm for computing the revenue-optimal pricing curve. We show that pricing curves, that post a price at each point of time and let the buyer pick her utility maximizing time to buy, are revenue-optimal among a much broader class of sequential lottery mechanisms. I.e., mechanisms that allow the seller to post a menu of lotteries at each point of time cannot get any higher revenue than pricing curves. We also show that the even broader class of mechanisms that allow the menu of lotteries to be adaptively set, can earn strictly higher revenue than that of pricing curves, and the revenue gap can be as big as the support size of the buyer's value distribution.

Shuchi Chawla, Rojin Rezvan, Yifeng Teng et al.

We study the revenue guarantees and approximability of item pricing. Recent work shows that with $n$ heterogeneous items, item-pricing guarantees an $O(\log n)$ approximation to the optimal revenue achievable by any (buy-many) mechanism, even when buyers have arbitrarily combinatorial valuations. However, finding good item prices is challenging -- it is known that even under unit-demand valuations, it is NP-hard to find item prices that approximate the revenue of the optimal item pricing better than $O(\sqrt{n})$. Our work provides a more fine-grained analysis of the revenue guarantees and computational complexity in terms of the number of item ``categories'' which may be significantly fewer than $n$. We assume the items are partitioned in $k$ categories so that items within a category are totally-ordered and a buyer's value for a bundle depends only on the best item contained from every category. We show that item-pricing guarantees an $O(\log k)$ approximation to the optimal (buy-many) revenue and provide a PTAS for computing the optimal item-pricing when $k$ is constant. We also provide a matching lower bound showing that the problem is (strongly) NP-hard even when $k=1$. Our results naturally extend to the case where items are only partially ordered, in which case the revenue guarantees and computational complexity depend on the width of the partial ordering, i.e. the largest set for which no two items are comparable.

Caroline Heber

This chapter sets out the different forms of differentiation and asks whether qualified majority voting in the field of taxation would be a practical and suitable alternative to differentiated law-making. The first sections show that enhanced cooperation is not the only flexibility mechanism within the European Union. Member States can also establish differentiation through primary EU law, secondary EU law, or by using partial international agreements. Partial international agreements may be a real alternative to enhanced cooperation law-making as they grant Member States the possibility to introduce rules which are only binding between some Member States. However, these sections reveal the clear differences between enhanced cooperation laws and partial international agreements which allow a protection of enhanced cooperation laws within the EU’s legal framework. Based on constitutional legal theory, in particular consociational democracy, the second part of this chapter argues that qualified majority voting should not be pursued in the field of taxation because it may lead to a European Union plagued by internal frustration and conflicts. The people of Europe are too heterogeneous, and unlike many other subject areas, taxation is a vehicle to pursue sensitive national policy objectives. Taxation is not only a revenue raiser, it is also a nuanced tool to steer taxpayers’ behaviour, achieve justice and equal opportunities through redistribution, and address economic needs.

Dailit González Capote, Yusniel Tartabull Contreras, K. Pinto

Christian Heide, Martin Hauck, Takuya Higuchi et al.

The photoelectric effect has a sister process relevant in optoelectronics called internal photoemission. Here an electron is photoemitted from a metal into a semiconductor. While the photoelectric effect takes place within less than 100 attoseconds, the attosecond time scale has so far not been measured for internal photoemission. Based on the new method CHArge transfer time MEasurement via Laser pulse duration-dependent saturation fluEnce determinatiON, CHAMELEON, we show that the atomically thin semi-metal graphene coupled to bulk silicon carbide, forming a Schottky junction, allows charge transfer times as fast as (300 $\pm$ 200) attoseconds. These results are supported by a simple quantum mechanical model simulation. With the obtained cut-off bandwidth of 3.3 PHz for the charge transfer rate, this semimetal-semiconductor interface represents the first functional solid-state interface offering the speed and design space required for future light-wave signal processing.

Marino Gran, James Richard Andrew Gray

When $\mathbb C$ is a semi-abelian category, it is well known that the category $\mathsf{Grpd}(\mathbb C)$ of internal groupoids in $\mathbb C$ is again semi-abelian. The problem of determining whether the same kind of phenomenon occurs when the property of being semi-abelian is replaced by the one of being action representable (in the sense of Borceux, Janelidze and Kelly) turns out to be rather subtle. In the present article we give a sufficient condition for this to be true: in fact we prove that the category $\mathsf{Grpd}(\mathbb C)$ is a semi-abelian action representable algebraically coherent category with normalizers if and only if $\mathbb C$ is a semi-abelian action representable algebraically coherent category with normalizers. This result applies in particular to the categories of internal groupoids in the categories of groups, Lie algebras and cocommutative Hopf algebras, for instance.

B. Irawan, Teguh Budiono

The purpose of this study was to determine how the tax audit can optimize revenues in the tax sector, factors that become an obstacle in carrying out tax audits, and any solution that could be recommended to overcome such obstacles. This study used a qualitative approach, by conducting interviews, observation and document study. The informants in this study are stakeholders who understand the implementation of a tax audit as many as six informants. Tax audits to optimize state income in the taxation sector is influenced by several factors, namely legislation which provides clarity, certainty and simplicity that can reduce the dispute regulations, government policy in implementing regulations, administrative system that provides counseling function, care and supervision as well information systems support, excellent service in the implementation of a tax audit, the level of awareness and understanding of the taxpayer to the tax laws, and functional Examiner and professional integrity. There are several obstacles to the implementation of the tax audit, include unrealistic state revenue target in the taxation sector, tax laws have multiple interpretations, limited external data and unintegrated internal data held, the burden of routine inspections are high, the lack of quantity and quality Functional Tax Audit, and lack of official vehicles and operating funds. Solutions to overcome these obstacles, include preparation of the revenue target should be more realistic, tax laws should be drawn with regard to principles of clarity, certainty and simplicity, optimization of Government Regulation No. 31 of 2012, reducing routine inspection, addition of the quantity and quality Functional Tax Audit, and the provision of vehicles service.

Ernest Ching, Mathieu Bauchy

In the framework of topological constraint theory, network glasses are classified as flexible, stressed--rigid, or isostatic if the number of atomic constraints is smaller, larger, or equal to the number of atomic degrees of freedom. Here, based on molecular dynamics simulations, we show that sodium aluminosilicate glasses exhibit a flexible-to-stressed--rigid transition driven by their composition. This transition manifests itself by a loss of atomic mobility and an onset of internal atomic stress. Importantly, we find that the flexible-to-rigid (i.e., loss of internal flexibility) and unstressed-to-stressed transitions (i.e., onset of internal stress) do not occur at the same composition. This suggests that the isostatic state (i.e., rigid but unstressed) is achieved within a window rather than at a threshold composition.

Bryan Sagredo, Savvas Nesseris, Domenico Sapone

We perform an Internal Robustness analysis (iR) to a compilation of the most recent $fσ_8(z)$ data, using the framework of 1209.1897. The method analyzes combinations of subsets in the data set in a Bayesian model comparison way, potentially finding outliers, subsets of data affected by systematics or new physics. In order to validate our analysis and assess its sensitivity we performed several cross-checks, for example by removing some of the data or by adding artificially contaminated points, while we also generated mock data sets in order to estimate confidence regions of the iR. Applying this methodology, we found no anomalous behavior in the $fσ_8(z)$ data set, thus validating its internal robustness.

Granda Putan, Ruth Elizabeth

Emilia Yustiningrum

Nathan Linial, Sria Louis

An internal partition of a graph is a partitioning of the vertex set into two parts such that for every vertex, at least half of its neighbors are on its side. We prove that for every positive integer $r$, asymptotically almost every $2r$-regular graph has an internal partition.

Olanrewaju Makinde Hassan, A. Sule, J. Abu

Philip J. Havik

IntroductionThe economic and political history of former Portuguese colonies in Africa still needs to be written, above all for the last century of imperial rule.2 This chapter intends to fill a number of lacunae with regard to the economic and financial developments that shaped colonial Angola, Mozambique and Guinea from the late 1800s to the 1950s, with a particular focus on fiscal policies and their impact. The analysis of these developments presented here takes into account not only the ongoing debate on the economic aspects on Portuguese colonial administration, but also takes its cue from studies on British and French colonialism in sub- Saharan Africa for the same period. Over the years, fiscal issues have come to form an essential part of this discussion, given the centrality of taxation for the imperial project. The distinction between indirect and direct taxation is given particular relevance here, given the implications for the question of the exercise of sovereignty over African subjects as tax payers. It raises key issues such as registration, collection and accounting, the important distinction between the gatekeeper state and the sovereign, extractive state, and the nature of citizenship which were to shape the perceptions of the vast majority of African populations that were expected to directly contribute to the colonial project. The question of direct taxation which began to form a major source of colonial revenue in most African colonies between the early 1900s and the 1920s includes a broad gamut of issues, from the question of internal revenue generation, its organization and efficiency, associated with the notion of mise en valeur, to that of the social and political aims of administration, often likened to social engineering, generally summarized by the concept of the civilizing mission. In between, a less visible spectrum of policies and practices associated with colonial governance and the impact of its quest for revenue on African populations and the latter's reactions come into view. The questions raised here intend to go beyond much debated questions such as (compulsory) labor recruitment and crop production, to the no less important fiscal aspects of empire, which have been largely neglected in the Portuguese case. A fresh look at public accounts and colonial economies is warranted, not in the least in view of recent research on taxation in former British, French and Belgian Africa.3In the Portuguese context, the case of Portuguese Guinea (currently Guinea Bissau) has already been studied in some detail for part of the period under consideration,4 as have certain aspects of taxation in Mozambique for the early 1900s,5 while Angola continues to largely remain a neglected region despite its importance for empire.6 A recent attempt to put the relevance of fiscal policy, into perspective for former Portuguese Africa - above all with regard to direct "native" taxation - looked at the changes that occurred in Portuguese West Africa during the 1930s against the background of the global economic crisis.7 The emergence of the Estado Novo regime in Portugal which curbed colonial autonomy and imposed measures to balance colonial budgets while reducing debts to the metropolis, led to increased pressures on administrations and tax payers in order to increase internally generated revenue by all possible means. In addition, the question of colonial administration and fiscal revenue was approached from the angle of empire in order to assert to what extent Portuguese colonial administration Angola, Mozambique and Guinea in the twentieth century merits reassessment.8 The debate on the issue of economic development in Portugal's former African colonies from the 1960s onwards, involved a number of scholars such as Castro,9 Hammond,10 Henriksen,11 Clarence-Smith,12 Alexandre,13 Pedreira,14 Lains15 and Ferreira.16 Although they put the economic relations between Portugal and its colonies on the map, their contributions to the debate tend to bypass or make scant reference to the generation of public revenue through direct taxation on "native" African populations in these regions, which represented a crucial source of colonial income for most of the colonial period during the 1900s. …