Factor proportions and international business cycles

Positive investment comovements across OECD economies as observed in the data are difficult to replicate in open-economy real business cycle models, but also vary substantially in degree for individual country-pairs. This paper shows that a two-country stochastic growth model that distinguishes sectors by factor intensity (capital-intensive vs. labor-intensive) gives rise to an endogenous channel of the international transmission of shocks that first, can substantially ameliorate the “quantity anomalies” that mark large open-economy models, and second, generate a cross-sectional prediction that is strongly supported by the data: investment correlations tend to be stronger for country-pairs that exhibit greater disparity in the factor-intensity of trade. In addition, three new pieces of evidence support the central mechanism: (1) the production composition of capital versus labor-intensive sectors changes over the business cycle; (2) the prices of capital-intensive goods and labor-intensive goods are respectively, procyclical and countercyclical; (3) a positive productivity shock in the U.S. tilts the composition of production towards capital-intensive sectors in other countries

Factor Proportions and International Business Cycles

Positive investment comovements across OECD economies as observed in the data are difficult to replicate in open-economy real business cycle models, but also vary substantially in degree for individual country-pairs. This paper shows that a two-country stochastic growth model that distinguishes sectors by factor intensity (capital-intensive vs. labor-intensive) gives rise to an endogenous channel of the international transmission of shocks that first, can substantially ameliorate the "quantity anomalies" that mark large open-economy models, and second, generate a cross-sectional prediction that is strongly supported by the data: investment correlations tend to be stronger for country-pairs that exhibit greater disparity in the factor-intensity of trade. In addition, three new pieces of evidence support the central mechanism: (1) the production composition of capital versus labor-intensive sectors changes over the business cycle; (2) the prices of capital-intensive goods and labor-intensive goods are respectively, procyclical and countercyclical; (3) a positive productivity shock in the U.S. tilts the composition of production towards capital-intensive sectors in other countries.International business cycles, international comovement, composition effects

Minimum Initial Marking Estimation in Labeled Petri Nets With Unobservable Transitions

In the literature, researchers have been studying the minimum initial marking (MIM) estimation problem in the labeled Petri nets with observable transitions. This paper extends the results to labeled Petri nets with unobservable transitions (with certain special structure) and proposes algorithms for the MIM estimation (MIM-UT). In particular, we assume that the Petri net structure is given and the unobservable transitions in the net are contact-free. Based on the observation of a sequence of labels, our objective is to find the set of MIM(s) that is(are) able to produce this sequence and has(have) the smallest total number of tokens. An algorithm is developed to find the set of MIM(s) with polynomial complexity in the length of the observed label sequence. Two heuristic algorithms are also proposed to reduce the computational complexity. An illustrative example is also provided to demonstrate the proposed algorithms and compare their performance

Numerical Simulation and Experimental Validation of Residual Stresses in Water-Quenched Aluminum Alloy Castings

Aluminum alloy castings are normally water quenched after solution treatment to improve mechanical properties. Rapid water quenching can result in high-residual stress and severe distortion which significantly affect functionality and performance of the products. To optimize product design and durability, one needs to model and predict residual stress and distortion produced in the water-quenched components. In this article, a finite element-based approach was developed to simulate the transient heat transfer and residual stress development during water quenching. In this approach, an iterative zone-based heat transfer algorithm was coupled with material constitutive model called mechanical threshold stress (MTS). With the integrated models, a good agreement was achieved between the numerically predicted and the experimentally measured residual stresses in the aluminum alloy frame-shape casting. The integrated FEA-based heat transfer and residual stress models were also applied to a water-quenched cast aluminum cylinder head with a great success

The Use of a Cell Filter for State Estimation in Closed-Loop NMPC of Low Dimensional Systems

Combining variants of the Kalman filter and moving horizon estimation (MHE) with nonlinear MPC has been studied before. The MHE is appealing due to its ability to impose constraints and demonstrated superiority over extended Kalman filter. However, nonlinear MPC based on MHE requires solutions to two back to back nonlinear programs. In this paper we propose to use the cell filter (CF) to provide state feedback to the MPC regulator. The cell filter is a piecewise constant approximation of the conditional probability density of the states, whose temporal evolution is modeled by an aggregate Markov chain. Since the CF is based on discretized state, input and output spaces, the curse of dimensionality limits its application to low dimensional and constrained systems. In this paper we present simulation examples of closed-loop MPC for a nonlinear reactor and agricultural pest control based on state feedback from both CF and MHE

Error Estimation in the Mean-Field Limit of Kinetic Flocking Models with Local Alignments

In this paper, we present an innovative particle system characterized by moderate interactions, designed to accurately approximate kinetic flocking models that incorporate singular interaction forces and local alignment mechanisms. We establish the existence of weak solutions to the corresponding flocking equations and provide an error estimate for the mean-field limit. This is achieved through the regularization of singular forces and a nonlocal approximation strategy for local alignments. We show that, by selecting the regularization and localization parameters logarithmically with respect to the number of particles, the particle system effectively approximates the mean-field equation