Yan Zhao

Security issue against different attacks is the core topic of cyberphysical systems. In this paper, optimal control theory, reinforcement learning, and neural networks are integrated to provide a brief overview of optimal robust control strategies for a benchmark power system. First, the benchmark power system models with actuator and sensor attacks are considered. Second, we investigate the optimal control issue for the nominal system and review the state-of-the-art RL methods along with the NN implementation. Third, we propose several robust control strategies for different types of cyberphysical attacks via the optimal control design, and stability proofs are derived through Lyapunov theory. Furthermore, the stability analysis with the NN approximation error, which is rarely discussed in the previous works, is studied in this paper. Finally, two different simulation examples demonstrate the effectiveness of our proposed methods.

System security is essential for the operation of the island microgrid. However, the system security is generally threatened due to the presence of physical uncertainties and cyber attacks. In this article, a novel sliding mode load control strategy is proposed for the microgrid to mitigate cyber attacks and physical uncertainties. Firstly, a high-order disturbance observer is designed to estimate the unmeasurable factors in the microgrid. Secondly, a HODO-based sliding mode control strategy is proposed where the estimated value observed by the HODO is applied to the sliding mode surface and control law. It can better guarantee the security of the isolated microgrid. Then, the stability of the HODO-based SMC is demonstrated by Lyapunov stability theory. Finally, simulation results show that the proposed control strategy has excellent control performance.

This study aimed to explore the influence the value modularity and a firm’s innovation performance, directly and indirectly, using knowledge management as mediating variable. Moreover, in this study, we used the resource integration ability as a moderator between the relationship value modularity and firm innovation performance. We collected data from the Chinese state-owned and state-controlled high-tech firms from 2011 to 2018. In this study, we used the gray comprehensive evaluation method to test the degree of value modularity, and hierarchical regression analysis is used to analyze the relationship among variables. The outcomes of this study indicate that value modularity and firm innovation performance has inverted U-shaped and significant association. Similarly, results also confirm that knowledge acquisition and knowledge internalization mediate the relationship between value modularity and firm innovation performance. The finding of this research also confirms that resource integration ability negatively affects the relationship between value modularity and firm innovation performance. This paper enriches the research of the value modularity and gives certain inspiration to knowledge management. At the end of this study, we also suggest some significant practical implications.

Central to scholarly discussions within the field of feminist epistemology is the question of a researcher’s positionality and the subsequent impact on knowledge production. In particular, Donna Haraway’s elaboration of ‘situated knowledge’ has been highly influential. As an epistemological principle, this concept emphasizes the researcher’s embodied location within the research context. Yet the question remains, how does one apply this principle within the concrete practices of knowledge production? In a research project based on Norwegian transnational adoptees’ identity work, the author, being an immigrant, was situated as an ‘outsider within’. How does this positionality influence knowledge production? The concept of ‘outsider within’ comes from standpoint epistemology and has been taken up within black feminist thought to authorize knowledge about dominant society produced from a position of marginality. However as a concrete situatedness, can an ‘outsider within’ position also be used to think about the production of situated knowledge? This article offers an exploration of these questions. The author argues that one way to put feminist situated knowledge to use within an empirical study is through the conceptualization of ‘outsider within’ as a situated interactive space instead of a fixed standpoint.

Background: Optical Doppler tomography combines laser Doppler flowmetry with optical coherence tomography to obtain high-resolution images of blood flow in human skin in situ and in real time. Observations: We present a case in which ODT was used on a patient with a port-wine stain birth-mark to document the change of blood flow in response to laser therapy. It might be possible to use ODT blood flow measurements in situ to assist in assessing the efficacy of laser PWS therapy. If partial restoration of flow occurs immediately or shortly after laser exposure, indicative of reperfusion due to inadequate blood vessel injury, the PWS can be retreated using higher light dosages. Retreatment is continued until the measured Doppler shift is zero due to a permanent reduction in blood flow, indicative of irreversible microthrombus formation in the PWS vessels. Conclusions: We have demonstrated that ODT may be used for noninvasive imaging of blood vessels in PWS skin. Moreover, ODT will potentially allow laser therapy to be optimized on an individual patient basis by providing a fast, semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time.

Spring and Autumn period, the system is an important foundation astronomical calendar period, Zhuangzi thought implies a profound world view, such a pre-scientific sense of the Chuang-tzu's Human Science in the Qin unique. Zhuangzi physical phenomena of the universe and the nature of human life together, the idea of transforming human existence, revealing the primitive way of the ultimate cosmic beauty, infinite beauty, and the whole United States, is an aesthetic view of the universe. China's astronomical calendric system sees its foundation in the Period of Spring and Autumn and Warring States. Deep world outlook is embraced in Zhuangzi's rich thought. Zhuangzi integrates the physical phenomena of the universe with the essence of human life, and reveals the ultimate, unlimited and overall beauty of the original law of the universe, thus fanning an aesthetic world outlook

As an objective tendency in social development, globalization has experienced three different historical forms. They are globalization as communication survival purposes, globalization for capital expansion and globalization in amalgamation of cultures. The thesis point out that globalization does not equally mean capitalization. The capital expansion, however, is only one of the forms of globalization process. In the era of the new globalization, both the developed and the developing countries have to coordinate and make active and positive use of the favorite conditions as well as opportunities for further development. The developed and developing countries must learn to respect each other and open up more channels of communication to understand each other better in an effort to better serve their own interests and create a win-win situation despite of their different cultures and stages of development. This is the only way to bring about harmonious coexistence for peoples of various countries around the world.