30 research outputs found

    Ownership, Incentives and Monitoring

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    This paper studies the effect of ownership structure on workers' incentives for investing in firm-specific human capital. Particularly, we analyse such incentivers and monitoring under employee ownership and capitalist ownership. In our model, the employee-owned firm is a firm bought by its workers who pay the competitive price. Under certain conditions, we show that the workers' investment and expected income are higher and the monitoring intensity is lower in an employee-owned firm than they are in a capitalist firm. We also show that the incentive effect of employee ownership increases as a worker's reservation wage decreases, as the monitoring cost or as the productivity uncertainty increases. Most of our results are consistent with the available empirical evidenceEmployee ownership, monitoring, incentives, property rights

    A Survey on Passing-through Control of Multi-Robot Systems in Cluttered Environments

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    This survey presents a comprehensive review of various methods and algorithms related to passing-through control of multi-robot systems in cluttered environments. Numerous studies have investigated this area, and we identify several avenues for enhancing existing methods. This survey describes some models of robots and commonly considered control objectives, followed by an in-depth analysis of four types of algorithms that can be employed for passing-through control: leader-follower formation control, multi-robot trajectory planning, control-based methods, and virtual tube planning and control. Furthermore, we conduct a comparative analysis of these techniques and provide some subjective and general evaluations.Comment: 18 pages, 19 figure

    Distributed Control within a Trapezoid Virtual Tube Containing Obstacles for UAV Swarm Subject to Speed Constraints

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    For guiding the UAV swarm to pass through narrow openings, a trapezoid virtual tube is designed in our previous work. In this paper, we generalize its application range to the condition that there exist obstacles inside the trapezoid virtual tube and UAVs have strict speed constraints. First, a distributed vector field controller is proposed for the trapezoid virtual tube with no obstacle inside. The relationship between the trapezoid virtual tube and the speed constraints is also presented. Then, a switching logic for the obstacle avoidance is put forward. The key point is to divide the trapezoid virtual tube containing obstacles into several sub trapezoid virtual tubes with no obstacle inside. Formal analyses and proofs are made to show that all UAVs are able to pass through the trapezoid virtual tube safely. Besides, the effectiveness of the proposed method is validated by numerical simulations and real experiments.Comment: 11 pages, 12 figure

    Distributed Control for a Multi-Agent System to Pass through a Connected Quadrangle Virtual Tube

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    In order to guide the multi-agent system in a cluttered environment, a connected quadrangle virtual tube is designed for all agents to keep moving within it, whose basis is called the single trapezoid virtual tube. There is no obstacle inside the tube, namely the area inside the tube can be seen as a safety zone. Then, a distributed swarm controller is proposed for the single trapezoid virtual tube passing problem. This issue is resolved by a gradient vector field method with no local minima. Formal analyses and proofs are made to show that all agents are able to pass the single trapezoid virtual tube. Finally, a modified controller is put forward for convenience in practical use. For the connected quadrangle virtual tube, a modified switching logic is proposed to avoid the deadlock and prevent agents from moving outside the virtual tube. Finally, the effectiveness of the proposed method is validated by numerical simulations and real experiments.Comment: 12 pages,14 figures. arXiv admin note: substantial text overlap with arXiv:2112.0100

    Characterizing the Usage, Evolution and Impact of Java Annotations in Practice

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    International audienceAnnotations have been formally introduced into Java since Java 5. Since then, annotations have been widely used by the Java community for different purposes, such as compiler guidance and runtime processing. Despite the ever-growing use, there is still limited empirical knowledge about the actual usage of annotations in practice, the changes made to annotations during software evolution, and the potential impact of annotations on code quality. To fill this gap, we perform the first large-scale empirical study about Java annotations on 1,094 notable open-source projects hosted on GitHub. Our study systematically investigates annotation usage, annotation evolution, and annotation impact, and generates 10 novel and important findings. We also present the implications of our findings, which shed light for developers, researchers, tool builders, and language or library designers in order to improve all facets of Java annotation engineering

    Political Resource Curse under Authoritarianism: Evidence from China *

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    Abstract By analyzing a panel constructed on the political turnovers of 4,390 county leaders in China during 1999-2008, we find that the revenue windfalls accrued to these officials from land sales since 1998 have both undermined the effectiveness of the promotion system for government officials and fueled corruption. Instead of rewarding efforts made to boost GDP growth, promotion is now also positively correlated with signaling efforts or specifically increased spending on flamboyant (so-called "image") public projects, with those politically connected to their superiors and those who are beyond the prime age for promotion being the primary beneficiaries. Likewise, the same revenue windfalls have also led to corruption, as gauged from the increases in the government workforce and administrative expenditure but not social welfare spending. Our findings highlight how land revenue windfalls can lead to a political resource curse in a highly politically centralized authoritarian regime

    Corrigendum to: The TianQin project: current progress on science and technology

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    In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article
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