Cycles in economic systems with open labor markets

A dynamic macromodel of an economic system with a monopsonic labor market and variable labor resources is considered. The initiation conditions for classical business cycles are investigated for this model. Bifurcation analysis of the model is performed to estimate the effect of the minimum wage on the way such cycles form. The results of theoretical analysis are supplemented with numerical experiments. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 48–72, July–August 2008.     

Homoclinic and Heteroclinic Bifurcations in an Overlapping Generations Model with Credit Market Imperfection

We analyze a nonlinear OLG model with credit market imperfection and endogenous labor supply. When the investors’ protection is perfect, the model reduces to the standard one sector growth model proposed by Reichlin (JET 40:89–102, 1986), while the model reduces to the one studied by Matsuyama (Econometrica 72:853–884, 2004) when the agents’ labor supply is exogenous. Our goal is to highlight that the local analysis of the perfect foresight equilibrium may lead to misleading conclusions because the local analysis neglects the occurrence of different global bifurcation scenarios. In particular, the existence of a heteroclinic connection or the occurrence of a homoclinic bifurcation may be associated with global indeterminacy even when all steady states are locally determinate.     

A taxation model

A new approach to taxation modeling is considered that takes into account the relationship between the costs of fixed capital and direct labor. The well-known Balatskii model in which the emphasis is put on fixed capital is substantially generalized. The problem of optimizing the total tax rate with respect to a Laffer-type criterion is solved. Statistical data for Ukraine over 2000–2003 are used. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 160–164, January–February 2007.     

Optimization Models in Economic Equilibrium

Complete models of an economic system are developed, optimal prices, labor inputs, production volumes, export-import, taxation, and transport inputs are determined from systems of demand-supply balance equations in the labor and produce markets, taking into account the type of production functions and utility functions. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 110–118, September–October 2005.     

Balanced wage rate as a function of the capital endowment and market conjuncture

A balanced wage rate function is determined by the solution of a year balance equation with the coefficients of material consumption, capital amortization, labor use in the manufacturing sphere, and also with the income and payroll tax rates given by a statistics and a state budget. It is shown that the increase in the wage rate with respect to the balanced rate is possible only as a result of “eating up” the capital by the country population and state’s consumers demand. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 158–172, September–October 2008.     

Measuring Unemployment and Inflation as Wages Functions

The functions of unemployment and gross domestic product (GDP) deflator are determined depending on real wage rate for population involved in production, labor utilization rate, money supply, and money velocity. The GDP deflator is equal to the product of the production and money deflators. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 103–117, May–June 2005.     

Numerical analysis on electroosmotic flows in a microchannel with rectangle-waved surface roughness using the Poisson–Nernst–Planck model

The present study has numerically investigated two-dimensional electroosmotic flows in a microchannel with dielectric walls of rectangle-waved surface roughness to understand the roughness effect. For the study, numerical simulations are performed by employing the Nernst–Planck equation for the ionic species and the Poisson equation for the electric potential, together with the traditional Navier–Stokes equation. Results show that the steady electroosmotic flow and ionic-species transport in a microscale channel are well predicted by the Poisson–Nernst–Planck model and depend significantly on the shape of surface roughness such as the amplitude and periodic length of wall wave. It is found that the fluid flows along the surface of waved wall without involving any flow separation because of the very strong normal component of EDL (electric double layer) electric field. The flow rate decreases exponentially with the amplitude of wall wave, whereas it increases linearly with the periodic length. It is mainly due to the fact that the external electric-potential distribution plays a crucial role in driving the electroosmotic flow through a microscale channel with surface roughness. Finally, the present results using the Poisson–Nernst–Planck model are compared with those using the traditional Poisson–Boltzmann model which may be valid in these scales.     

Short term memory in recurrent networks of spiking neurons

We present in this paper a general model of recurrent networks of spiking neurons, composed of several populations, and whose interaction pattern is set with a random draw. We use for simplicity discrete time neuron updating, and the emitted spikes are transmitted through randomly delayed lines. In excitatory-inhibitory networks, we show that inhomogeneous delays may favour synchronization provided that the inhibitory delays distribution is significantly stronger than the excitatory one. In that case, slow waves of synchronous activity appear (this synchronous activity is stronger in inhibitory population). This synchrony allows for a fast ada ptivity of the network to various input stimuli. In networks observing the constraint of short range excitation and long range inhibition, we show that under some parameter settings, this model displays properties of –1– dynamic retention –2– input normalization –3– target tracking. Those properties are of interest for modelling biological topologically organized structures, and for robotic applications taking place in noisy environments where targets vary in size, speed and duration. This revised version was published online in June 2006 with corrections to the Cover Date.     

Liquid–liquid microflows in micro-sieve dispersion devices with dual pore size

Here we present the liquid–liquid microflows and dispersion rules in micro-sieve devices with two different sized pores. The flow pattern, flux distribution and droplet size were investigated to discuss the effect of pore size deviation. Three flow patterns including dripping flow from a single active pore, dripping–dripping flow and dripping–jetting flow from two active pores were identified. A modified active pore model based on a pressure drop balance has been established. The model can predict the transition from a single active pore flow regime to a two active pore flow regime very well. In the latter regime, interactions between the small and large pores can result in dripping–dripping flow at low trans-pore flux and dripping–jetting flow at high trans-pore flux. Controlling the flow pattern in dripping–dripping flow is favorable to decreasing droplet polydispersity.     

Modeling and simulation of residents’ response in nuclear disaster

It is important to model and predict residents’ behaviors in an emergency in order to establish good evacuation schemes during disasters. This research presents modeling and simulation of residents’ behaviors in a nuclear disaster focusing on residents’ decision-making processes: information acquisition, situation assessment, and selecting actions. We selected qualitative causal relations between residents’ behaviors and the attributes of information, human, and situations from 57 reviews of the past 12 disaster cases. We then constructed a conceptual model of residents’ behaviors in a conventional stimulus–organism–response (S–O–R) model of human information processing. We adopted probabilistic reasoning (Bayesian belief network) to simulate the situation assessment of a resident in a nuclear disaster. We carried out a simulation using the announcement log of the JCO criticality accident and confirmed that the model could simulate the tendencies in residents’ behaviors observed in the actual disaster and can reflect various features of the conceptual model.     

Using the effect of information delay in differential pursuit games

An approach to solving linear differential pursuit games is substantiated. It consists in generating the pursuer’s control based on the evader’s previous behavior. The results are illustrated with model soft-meeting problems. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 90–105, March–April 2007.     

Congestion and Fiscal Policy in a Two-Sector Economy with Public Capital: A Quantitative Assessment

This paper analyzes the role of public capital when the services it yields is subject to two forms of congestion, which we characterize as relative and aggregate. We employ a two-sector growth model in which there are conventional profit-maximizing private firms, together with “public firms”, whose objective is to produce a specified quantity of government investment goods – determined by government policy – at minimum cost. We characterize the equilibrium dynamics, and analyze two forms of fiscal disturbances – an increase in public investment, and a decrease in the tax on capital income – by simulating a calibrated economy. We contrast the effects of these two types of congestion on both the existing steady-state equilibrium, as well as for the effectiveness of fiscal policy.     

Model identification and state estimation in grid systems

Depending on the problem statement and available information on the system structure and order, three classes of models are discussed: a linear model of state variables with unknown disturbance, a model in input–output variables, and a neural network model that describes nonlinear objects. To estimate the state and to identify the models, intelligent computations are applied: non-static uncertainty is described using fuzzy sets, and genetic algorithms are used for the structural-parametric identification of input–output models.     

On the air damping of flexible microbeam in free space at the free-molecule regime

Predicting air damping is crucial in the design of high Q microelectromechanical systems. In the past, air damping of rigid microbeam in free space at molecular regime is usually estimated using the free molecular model proposed by Christian (Vacuum 16:175–178, 1966), air damping of flexible microbeam is estimated using the model proposed by Blom (J Vac Sci Technol B 10:19–26, 1992). The relation between the two models is Q _Blom = 3Q _Christian. In this paper, a general proof is presented that shows the Christian’s model is valid for the air damping of flexible microbeam in free space at molecular regime. By comparing with the experimental results available in the literatures (Blom et al. in J Vac Sci Technol B 10:19–26, 1992; Yasumura et al. in J Micromech Syst 9:117–125, 2000), we conclude that the Christian’s model is the best choice in predicting the air damping of flexible microbeam in free space at the molecular regime.     

A Bradley–Terry artificial neural network model for individual ratings in group competitions

A common statistical model for paired comparisons is the Bradley–Terry model. This research re-parameterizes the Bradley–Terry model as a single-layer artificial neural network (ANN) and shows how it can be fitted using the delta rule. The ANN model is appealing because it makes using and extending the Bradley–Terry model accessible to a broader community. It also leads to natural incremental and iterative updating methods. Several extensions are presented that allow the ANN model to learn to predict the outcome of complex, uneven two-team group competitions by rating individuals—no other published model currently does this. An incremental-learning Bradley–Terry ANN yields a probability estimate within less than 5% of the actual value training over 3,379 multi-player online matches of a popular team- and objective-based first-person shooter.     

T–S fuzzy model adopted SLAM algorithm with linear programming based data association for mobile robots

This paper describes a Takagi–Sugeno (T–S) fuzzy model adopted solution to the simultaneous localization and mapping (SLAM) problem with two-sensor data association (TSDA) method. Nonlinear process model and observation model are formulated as pseudolinear models and rewritten with a composite model whose local models are linear according to T–S fuzzy model. Combination of these local state estimates results in global state estimate. This paper introduces an extended TSDA (ETSDA) method for the SLAM problem in mobile robot navigation based on an interior point linear programming (LP) approach. Simulation results are given to demonstrate that the ETSDA method has low computational complexity and it is more accurate than the existing single-scan joint probabilistic data association method. The above system is implemented and simulated with Matlab to claim that the proposed method yet finds a better solution to the SLAM problem than the conventional extended Kalman filter–SLAM algorithm.     

The Performance of German Firms in the Business-Related Service Sectors Revisited: Differential Evolution Markov Chain Estimation of the Multinomial Probit Model

We outline a new estimation method for the multinomial probit model (MNP). The method is a differential evolution Markov chain algorithm that employs a Metropolis-within-Gibbs sampler with data augmentation and the Geweke–Hajivassiliou–Keane (GHK) probability simulator. The method lifts the curse of dimensionality in numerical integration as it neither requires simulation of the whole likelihood function nor the computation of its analytical or numerical derivatives. The method is applied to an unbalanced panel dataset of firms from the German business-related service sector over the period 1994–2000. In spite of its less restricted character, the MNP model is found not to provide more accurate estimates for explaining the performance of these firms than the multinomial logit model.     

Pressure drop of gas–liquid Taylor flow in round micro-capillaries for low to intermediate Reynolds numbers

In this paper, a model is presented that describes the pressure drop of gas–liquid Taylor flow in round capillaries with a channel diameter typically less than 1 mm. The analysis of Bretherton (J Fluid Mech 10:166–188, 1961) for the pressure drop over a single gas bubble for vanishing liquid film thickness is extended to include a non-negligible liquid film thickness using the analysis of Aussillous and Quéré (Phys Fluids 12(10):2367–2371, 2000). This result is combined with the Hagen–Poiseuille equation for liquid flow using a mass balance-based Taylor flow model previously developed by the authors (Warnier et al. in Chem Eng J 135S:S153–S158, 2007). The model presented in this paper includes the effect of the liquid slug length on the pressure drop similar to the model of Kreutzer et al. (AIChE J 51(9):2428–2440, 2005). Additionally, the gas bubble velocity is taken into account, thereby increasing the accuracy of the pressure drop predictions compared to those of the model of Kreutzer et al. Experimental data were obtained for nitrogen–water Taylor flow in a round glass channel with an inner diameter of 250 μm. The capillary number Ca _gl varied between 2.3 × 10⁻³ and 8.8 × 10⁻³ and the Reynolds number Re _gl varied between 41 and 159. The presented model describes the experimental results with an accuracy of ±4% of the measured values.     

Regularized solutions for the discrete forms of the div–curl problem in CFD

In this work different regularization approaches for the solution of the div–curl problems arising from the treatment of the unsteady incompressible Navier–Stokes model are presented. Indeed it is shown how some popular methods for the resolution of the Navier–Stokes problem can be seen as different forms of the same regularization approach. The use of different discretization layouts is illustrated together with the advantages deriving from the employment of this technique. Finally, a strategy for the reduction of the number of the discretized unknowns of the div–curl problem by means of the Singular Value Decomposition is presented. Received: 31 January 2001 / Accepted: 30 September 2001     

Interval Generalization of the Bayesian Model of Collective Decision-Making in Conflict Situations

A constructive interval model of making a collective decision by an independent group of experts is developed. The model is based on a priori information about the frequency of experts' errors in estimating a random state of an object using a finite sample. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 133–144, May–June 2005.