Income distribution dependence of poverty measure: A theoretical analysis

Using a modified deprivation (or poverty) function, in this paper, we theoretically study the changes in poverty with respect to the ‘global’ mean and variance of the income distribution using Indian survey data. We show that when the income obeys a log-normal distribution, a rising mean income generally indicates a reduction in poverty while an increase in the variance of the income distribution increases poverty. This altruistic view for a developing economy, however, is not tenable anymore once the poverty index is found to follow a pareto distribution. Here although a rising mean income indicates a reduction in poverty, due to the presence of an inflexion point in the poverty function, there is a critical value of the variance below which poverty decreases with increasing variance while beyond this value, poverty undergoes a steep increase followed by a decrease with respect to higher variance. Identifying this inflexion point as the poverty line, we show that the pareto poverty function satisfies all three standard axioms of a poverty index [N.C. Kakwani, Econometrica 43 (1980) 437; A.K. Sen, Econometrica 44 (1976) 219] whereas the log-normal distribution falls short of this requisite. Following these results, we make quantitative predictions to correlate a developing with a developed economy.     

Manifestation of the dynamic properties of the solvent in electron transfer reactions

The ability of the multichannel stochastic model to adequately describe the basic features of the kinetics of thermal electron transfer is demonstrated. It is shown that the solution-controlled regime can be realized in the normal Marcus region, whereas it is almost completely suppressed in the inverted region by the reorganization of high-frequency vibrational modes. The continuous transition between the two regions in the neighborhood of the activationless is quantitatively described. It is found that the dynamic properties of the solvent manifest themselves not only in the dependence of the electron transfer rate on the medium relaxation time τ _L , but also in the free energy gap law, shifting the position of the maximum effective rate constant to higher reaction exergonicities. This shift depends on the longitudinal relaxation time of the medium. In slow solvents, the maximum rate constant of electron transfer can exceed 1/τ _L by several orders of magnitude.     

Evolutionary model of the personal income distribution

The aim of this work is to develop a qualitative picture of the personal income distribution. Treating an economy as a self-organized system the key idea of the model is that the income distribution contains competitive and non-competitive contributions. The presented model distinguishes between three main income classes. 1. Capital income from private firms is shown to be the result of an evolutionary competition between products. A direct consequence of this competition is Gibrat’s law suggesting a lognormal income distribution for small private firms. Taking into account an additional preferential attachment mechanism for large private firms the income distribution is supplemented by a power law (Pareto) tail. 2. Due to the division of labor a diversified labor market is seen as a non-competitive market. In this case wage income exhibits an exponential distribution. 3. Also included is income from a social insurance system. It can be approximated by a Gaussian peak. A consequence of this theory is that for short time intervals a fixed ratio of total labor (total capital) to net income exists (Cobb–Douglas relation). A comparison with empirical high resolution income data confirms this pattern of the total income distribution. The theory suggests that competition is the ultimate origin of the uneven income distribution.     

Force between the plates of a plane capacitor in a fluid: a rigorous thermodynamic analysis

Summary A critical analysis of the literature on the deduction of the well-known expression of the attractive force between the plates of a plane-parallel capacitor completely immersed in a linear dielectric fluid is presented. Then, rigorous deductions of this force are proposed. It is shown that, contrary to the statement reported in most references, no pressure difference exists between the fluid within the plates and the external fluid.     

复杂网络系统拓扑连接优化控制方法

为了增加实际网络系统连接增益、减少网络连接成本, 提出了一种基于网络效率和平均连接度的网络拓扑连接优化控制方法, 该方法利用网络效率来表征网络连接收益、用网络平均连接度来表征网络连接成本, 并提出了其计算优化算法, 该算法的时间复杂性为O(Mpn²). 实验分析表明, 可以采取一定的方式对实际复杂网络拓扑连接进行优化控制, 小世界和无标度网络均存在一个最佳的网络平均度值能够使网络连接增益达到最大. 关键词： 复杂网络 拓扑连接 优化控制 连接增益     

Role of Age and Education as the Determinant of Income Inequality in Poland: Decomposition of the Mean Logarithmic Deviation

Measures of inequality can be used to illustrate inequality between and within groups, but the choice of the appropriate measure can have different implications. This study focused on the Mean Logarithmic Deviation, the measure proposed by Theil and based on the techniques of statistical information theory. The MLD was selected because of its attractive properties: fulfillment of the principle of monotonicity and the possibility of additive decomposition. The following study objectives were formulated: (1) to assess the degree of inequality in the population and in the distinguished subgroups, (2) to determine the extent to which education and age influence the level of inequality, and (3) to ascertain what factors contribute to changes in the level of inequality in Poland. The study confirmed an association between the level of education and the average income of the groups distinguished on this basis. The education level of the household head remains an important determinant of household income inequality in Poland, despite the decline in the “educational bonus”. The study also found that differences in the age of the household head had a smaller effect on income inequality than the level of education. However, it can be concluded that the higher share of older people may contribute to an increase in income inequality between groups, as the income from pension in Poland is more homogeneous than the income from work in younger groups. Moreover, the current paper seeks to situate Theil’s approach in the context of scholarly writings since 1967.     

Numerical prediction of heat transfer by natural convection and radiation in an enclosure filled with an isotropic scattering medium

This paper deals with the numerical solution for natural convection and volumetric radiation in an isotropic scattering medium within a heated square cavity using a hybrid thermal lattice Boltzmann method (HTLBM). The multiple relaxation time lattice Boltzmann method (MRT-LBM) has been coupled to the finite difference method (FDM) to solve momentum and energy equations, while the discrete ordinates method (DOM) has been adopted to solve the radiative transfer equation (RTE) using the S8 quadrature. Based on these approaches, the effects of various influencing parameters such as the Rayleigh number (Ra), the wall emissivity (ε_ι), the Planck number (Pl), and the scattering albedo (ω), have been considered. The results presented in terms of isotherms, streamlines and averaged Nusselt number, show that in absence of radiation, the temperature and the flow fields are centro-symmetrics and the cavity core is thermally stratified. However, radiation causes an overall increase in the temperature and velocity gradients along both thermally active walls. The maximum heat transfer rate is obtained when the surfaces of the enclosure walls are regarded as blackbodies. It is also seen that the scattering medium can generate a multicellular flow.     

Cryoelectrochemical reduction of a phenyl sulfide in tetrahydrofuran: mediated reduction gives different products compared to direct reduction

An electrocatalytic reduction of [(3‐{[trans‐4‐(methoxymethoxy)cyclohexyl]oxy}propyl)thio]benzene (RSPh) in the presence of naphthalene as a mediator is investigated, using steady‐state voltammetry at various sized platinum microelectrodes and at low temperature (201 K) in tetrahydrofuran (THF). This mediated process has been found to involve the transfer of one electron, in contrast to the direct electrochemical reduction which involves two electrons. In addition, the mediated reduction proceeds at a potential, some 500 mV less negative than the direct electrochemical reduction. The evidence for the proposed mechanism has been obtained from theoretical simulations, using DIGISIM which shows satisfactory fitting to experimental results and allowed the determination of the rate constant for the homogeneous step. In contrast to direct reduction of RSPh where only one product, trans‐1‐ (methoxymethoxy)‐4‐propoxycyclohexane (RH), has been obtained, the isolation of two products, RH and the dimer, diphenyl disulfide, PhSSPh, following mediated preparative electrolysis of RSPh, in presence of naphthalene shows that this one‐electron process may be carried out at the reduction potential of naphthalene at low temperature and has also validated deductions made from voltammetric results. Copyright © 2007 John Wiley & Sons, Ltd.     

Unseen Coherences Can Be Felt

Forbidden transitions are not observed in the continuous-wave electron paramagnetic resonance (EPR) spectrum nor in the free induction decay because, unlike allowed transitions, their coherences have no observable magnetic moment and are spectroscopically silent. Yet, the paramagnetic relaxation described by Redfield theory can cause coherence transfer between any types of transitions. Coherence transfer between allowed transitions is now known to cause noticeable changes in EPR spectra, but coherence transfer involving forbidden transitions has long been considered to be negligible because those coherences are silent and unseen. However, our simulations of a simple model system indicate that coherence transfer with silent transitions can introduce new features into EPR spectra. The EPR-silent coherence of a forbidden transition can be transferred to an allowed transition by paramagnetic relaxation. A silent coherence can have consequences felt in the EPR spectrum.     

Asymptotics of the partition function of a general Markov random field on an infinite rectangular lattice

We investigate theoretically and numerically the asymptotics of the partition function of a general Markov random field (MRF) on an infinite rectangular lattice. We first propose the general local energy function (LEF)-parameterized MRF. Then we prove that the thermodynamic limit of the free energy of the MRF can be exactly characterized by the Perron root of the fundamental transfer matrix of a particular Markov additive process (MAP). This matrix possesses a special structure and many interesting properties that enable parallel computation of the Perron root and may be beneficial for deriving an analytical form of the free energy. We also develop another transfer matrix for numerical computation of the desired Perron root. Specifically, the former is a site-to-site transfer matrix on a twisted cylindrical lattice, while the latter is the one associated with a row-to-row transition on a vertical strip. Numerical results show that our methods exhibit consistent finite-size scaling behavior even for small values of the lattice width. This study reveals that the fundamental transfer matrix is an alternative direction of research on the analysis of the partition function of general MRFs within the scope of matrix algebra.     

Thermodynamics and topology of disordered systems: Statistics of the random knot diagrams on finite lattices

The statistical properties of random lattice knots, the topology of which is determined by the algebraic topological Jones-Kauffman invariants, was studied by analytical and numerical methods. The Kauffman polynomial invariant of a random knot diagram was represented by a partition function of the Potts model with a random configuration of ferro-and antiferromagnetic bonds, which allowed the probability distribution of the random dense knots on a flat square lattice over topological classes to be studied. A topological class is characterized by the highest power of the Kauffman polynomial invariant and interpreted as the free energy of a q-component Potts spin system for q→∞. It is shown that the highest power of the Kauffman invariant correlates with the minimum energy of the corresponding Potts spin system. The probability of the lattice knot distribution over topological classes was studied by the method of transfer matrices, depending on the type of local junctions and the size of the flat knot diagram. The results obtained are compared to the probability distribution of the minimum energy of a Potts system with random ferro-and antiferromagnetic bonds.     

MHD stagnation point flow towards a stretching sheet

The steady two-dimensional MHD stagnation point flow towards a stretching sheet with variable surface temperature is investigated. The governing system of partial differential equations are transformed into ordinary differential equations, which are then solved numerically using a finite-difference scheme known as the Keller-box method. The effects of the governing parameters on the flow field and heat transfer characteristics are obtained and discussed. It is found that the heat transfer rate at the surface increases with the magnetic parameter when the free stream velocity exceeds the stretching velocity, i.e. ε>1, and the opposite is observed when ε<1.     

Efficient Population Transfer in a Λ-Type Quantum System Coupled to a Gold Nanoparticle Using STIRAP Shortcuts

A theoretical investigation on the population transfer in a Λ-type quantum system near a spherical gold nanoparticle under application of two stimulated Raman adiabatic passage (STIRAP) shortcuts and efficiency comparison with conventional STIRAP. It combines the density matrix approach for system dynamics, with classical electromagnetic calculations used to obtain the modified electric field amplitudes of the applied pulses and the Purcell factor of the quantum system due to the presence of the nanoparticle. The efficiency of population transfer is investigated by varying the distance between the quantum system and the nanoparticle, the free-space decay rate of quantum states, the mutual polarization, and the Rabi frequencies of each STIRAP shortcut pulses. In all cases, at least one of the applied shortcuts is more efficient than conventional STIRAP, while in most cases both perform better. When the pump and Stokes fields of the shortcuts have radial and tangential polarizations with respect to the nanoparticle surface, respectively, high transfer efficiency is obtained for small distances of the quantum system to the nanoparticle, moderate free space decay rates and large Rabi frequencies of the fields, while when the pulse polarizations are interchanged, the transfer becomes highly efficient only at large distances.     

Improving Continuous-Variable Quantum Key Distribution Using the Heralded Noiseless Linear Amplifier with Source in the Middle

We characterize the efficiency of the practical continuous-variable quantum key distribution (CVQKD) while inserting the heralded noiseless linear amplifier (NLA) before detectors to increase the secret key rate and the maximum transmission distance in Gaussian channels. In the heralded NLA-based CVQKD system, the entanglement source is only placed in the middle while the two participants are unnecessary to trust their source. The intensities of source noise are sensitive to the tunable NLA with the parameter g in a suitable range and can be stabilized to the suitable constant values to eliminate the impact of channel noise and defeat the potential attacks. Simulation results show that there is a well balance between the secret key rate and the maximum transmission distance with the tunable NLA.     

Crystallization of sputter deposited amorphous metal thin films

We have studied the crystallization of DC sputter deposited amorphous W-Si alloys under three separate conditions: free standing films, amorphous films deposited on Si substrates, and films with one of four different overlayers. In the case of the free standing films the crystallization temperature versus composition was measured by differential thermal analysis (DTA) for films with Si contents from 5 at% to 38 at%. Films with Si concentrations of 38% to 22% were amorphous as deposited, while those with less Si were crystalline. The crystallization temperature was a strong function of composition with a maximum T_c of 915°C (at a heating rate of 20 K/min) in alloys with 28% Si. Overlayers of W, Cu, Au and Al were investigated. Both the W and Cu overlayers had little effect on the stability of the underlying W-Si, while both the Au and Al reduced the crystallization temperature by at least 100°C. The results reported here reinforce the observation that the choice of overlayer plays a critical role in determining the overall stability of metallization systems that include amorphous layers as diffusion barriers.     

Optical characterization of mechanically tunable microwire based resonators by changing ring radius and wire diameter

Three tunable microring resonators were assembled using 3.5, 2.5, and 2 μm diameter of poly(trimethylene terephthalate) (PTT) wires, respectively. Their free spectral ranges (FSRs) and quality (Q) factors were measured by reducing ring radius of the microrings. For specific wire diameter and operating wavelength, the FSR increases continuously while the Q increases to a maximum value firstly and then decreases with a reduction of the ring radius. For specific ring radius and operating wavelength, the FSR increases a little and the Q decreases with a decrease of the wire diameter.     

Two-Dimensional Transferred Nuclear-Overhauser Effects with Incomplete Averaging of Free- and Bound-Ligand Resonances

Two distinct time scales prevail in the study of conformational exchange in general and specifically in deriving the protein-bound conformations of ligands by two-dimensional transferred-NOE experiments. Fast-exchange compared to the chemical-shift difference leads to a complete averaging of the free and bound resonances of the ligands, while fast exchange compared to the longitudinal relaxation rate 1/T₁ and cross relaxation results in an average of the relaxation matrices in the free and bound states. Slower chemical exchange leads to incomplete averaging of the free and bound resonances, giving rise to a reduction of transferred NOEs compared to fast-exchange conditions, Theoretical analysis and simulation results indicated that, in the absence of information on the chemical-shift time scale, transferred NOEs may be quantitated only to an accuracy with average NOE intensities and transferred NOEs to the free ligands as upper and lower bounds, respectively. Regardless of the exchange conditions, NOE intensities can be approximated by the NOEs transferred to the free ligands when a large excess of the free ligands (α_b < 0.1) is used to amplify the NOE transfers between the bound protons, These results suggest that two-dimensional transferred-NOE experiments (transferred NOESY) can be applied in situations of intermediate and slow exchange as long as the fraction of bound ligands is small and the exchange rates are fast enough to transfer the cross-relaxation pathways in the protein-ligand complex to the easily detected resonances of the free ligands,     

Radiative transfer in a nongray spherical layer: Simplified rectangular model

The problem of radiative transfer in a nongray, absorbing-emitting spherical layer is investigated. The absorption coefficient is assumed to be only a function of frequency, i.e. k_v = α(v)k, and the function α(v) is allowed only two values, zero or unity (simplified rectangular model). The nongray radiative transfer problem is reduced to a gray solution without the use of any approximation (such asthe Plank or Rosseland means) for an isothermal layer and for radiative equilibr     

AWG and EDFA based optical packet switch using feedback shared loop buffer memory

Optical packet switching provides high speed, data rate/format transparency, efficient use of bandwidth and flexibility. The major problem in the implementation of “all-optical” switching is contention which occurs when two or more packets arrive at the same time for the same destination. To resolve the contention, we have proposed an optical packet switch architecture based on WDM loop buffer memory in the feedback configuration. In that architecture, the contending packets are stored in a loop buffer module, and routed in the free time slots. The buffering duration in the recirculating loop is limited by a circulation limit. The analysis was been done to obtain the maximum number of allowed circulations. This paper proposes improved version of that optical packet switch architecture, to increase the number of maximum allowed circulations. The modification is done either by adding an extra erbium doped fiber amplifier (EDFA) in the original switch or by replacing the core space switch with arrayed waveguide grating (AWG). The performance analysis has been done by the simulations.