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The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision avoidance is considered during the configuration establishment process.

First, six-degrees-of-freedom error kinematic and dynamic models of relative translational and rotational motion between transportation systems are developed. Second, the prescribed transient-state performance bounds of tracking errors are designed. In addition, based on the backstepping, combining the pre-defined performance control method with a robust control method, a pre-defined performance robust controller is designed.

By designing prescribed transient-state performance bounds of tracking errors to guarantee that there is no overshoot, collision-avoidance can be achieved. Combining the pre-defined performance control method with a robust control method, robustness to disturbance is guaranteed.

This paper proposed a pre-defined performance robust control method. Simulation results demonstrate that the proposed controller can achieve a pre-assembly configuration establishment with collision avoidance in the existence of external disturbances.

On-orbit assembly technology is a promising research topic in spaceflight field. For purposes of studying the dynamic performance and reducing weight of an on-orbit assembly satellite structure frame, this paper aims to propose a structural optimization design method based on natural frequency.

The dynamic stability of the satellite under working condition depends on the mechanical properties of the structure matrix. A global structural optimization model is established, with the objective of mass minimization and the constraints of given natural frequencies and given structure requirements. The structural optimization and improvement design method is proposed using sequential quadratic programming calculation.

The optimal result of objective function is effectively obtained, and the best combination of structural geometric parameters is configurated. By analyzing the relationship between the structural variables and optimization parameters, the primary and secondary factors to the mass optimization process of the microsatellite satisfying the dynamic performance requirements are obtained, which improves the effectiveness and accuracy of the system optimization design.

This method can coordinate the relation between satellite vibration stability and weight reduction, which provides an effective way for the optimization design of on-orbit assembly microsatellite. It has reference significance for the similar spacecraft framework structure design.

This paper aims to investigate the impact of ownership concentration of the largest shareholder and foreign ownership on the demand for an external audit for small and medium-sized enterprises (SMEs) in six Latin American countries. In particular, the authors test whether foreign-owned firms (compared with domestic private-owned firms) and domestic firms with minority foreign shareholders are more likely engaged in audit assurance.

The authors applied the logit model to estimate the impact of ownership concentration and owner/shareholder type on audit demand, using a sample of 4,609 SMEs. The probabilities of being audited for firms in these countries are then calculated from the estimation results.

The empirical results suggest an inverse relationship between ownership concentration and audit demand only for Uruguay and Peru. However, foreign-owned firms and domestic private-owned firms with minority foreign ownership have a high probability of being audited for all sample countries.

Policymakers in developing countries may promote foreign investments in domestic private-owned firms to improve their corporate transparency and governance.

This study contributes to the growing literature on the impact of ownership on audit demand by particularly focusing on foreign owners and foreign minority shareholders. The findings indicate that foreign ownership (either majority or minority) contributes to corporate transparency and business environments in emerging countries.