As an active defense technique to change asymmetry in cyberattack-defense confrontation, moving target defense research has become one of the hot spots. In order to gain better understanding of moving target defense, background knowledge and inspiration are expounded at first. Based on it, the concept of moving target defense is analyzed. Secondly, literature analysis method is adopted to explain the design principles and system architecture of moving target defense. In addition, some relevant key techniques are introduced from the aspects of strategy generation, shuffling implementation, and performance evaluation. After that, the applications of moving target defense in different network architectures are illustrated. Finally, existing problems and future trend in this field are elaborated so as to provide a basis for further study.
Background
With the challenges that aging populations pose to healthcare, interventions that facilitate alleviation of age-related morbidities are imperative. A prominent risk factor for developing age-related morbidities is immunosenescence, characterized by increased chronic low-grade inflammation, resulting in T-cell exhaustion and senescence. Contact with nature and associated physical activities have been shown to boost immunity in older adults and may be promoted in the form of Horticultural Therapy (HT). We aimed to examine the effects of HT on immunosenescence.
Methods
We conducted a randomized controlled trial with 59 older adults assigned to either the HT intervention or waitlist control group. Older adults in the HT intervention group underwent HT intervention program over six months. Venous blood was drawn at baseline and at the 3 rd and 6 th month from the commencement of this study. For participants who attended all three blood collection time points (HT: n=22, waitlist: n=24), flow cytometry analysis was performed on whole blood samples to evaluate the kinetics of lymphocyte subsets over the intervention period, revealing the composition of CD4+ and CD8+ subsets expressing exhaustion markers – CD57, CTLA4, and KLRG1. Enzyme-linked immunosorbent assays were employed to measure changes in plasma IL-6 levels.
Results
HT is associated with increased numbers of naïve CD8+ T cells and fewer CTLA4-expressing terminally differentiated effector CD4+ and CD8+ memory T cells re-expressing CD45RA (TEMRA). Furthermore, IL-6 levels were reduced during HT, and the frequencies of naive and TEMRA CD8+ T cells were found to be associated with IL-6 levels.
Conclusion
HT is associated with a reduction in the levels of biomarkers that measure the extent of T-cell exhaustion and inflammaging in older adults. The positive effects of HT on T-cell exhaustionwere associated with the reduction of IL-6 levels.
This paper presents the framework of a powerdispatching automation system (PDAS) based on a virtual private cloud, which extracts advantages of technologies, such as a virtual private cloud, a virtual private network, an https protocol, etc. Unlike existing on-premise or public cloud hosted PDASs that are vulnerable and may be subject to blackouts due to extreme conditions, such as natural disasters or cyberattacks, the proposed framework operates more safely and securely under those conditions, while at the same time meeting the reliability requirements for power systems as well. This paper presents the theory, architectural design, characteristics, and implementation process of the system, as well as its reliability and cyber security measurements. The annual failure time of the proposed system is reduced from 61.2 to about 0.43 min, about 142 times less than those of existing PDASs. This framework has been implemented in the Lipu power system in China since May 2016. Results show that the proposed system is reliable, safe, and cost-effective, with a bright prospect for future applications.
Index Terms-Cyber security, power-dispatching automation system (PDAS), virtual private cloud (VPC), virtual private network (VPN).
I. INTRODUCTIONT HE power-dispatching automation system (PDAS) is the center of a power system. It plays a critical role in monitoring and controlling the electricity production process and is responsible for the overall security and stability of the system. With the expansion of power system scale, the existing PDASs are limited by hardware resources, which are incapable of storing, calculating, and analyzing massive data. On the other hand,
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